HIP ISSN 1120-7000

Hip Int 2015; 25 (2): 104-114 DOI: 10.5301/hipint.5000189

REVIEW

Current concepts in management of slipped capital femoral epiphysis Bernd Bittersohl1, Harish S. Hosalkar2, Christoph Zilkens1, Rüdiger Krauspe1 1 2

University of Düsseldorf, Medical Faculty, Department of Orthopedic Surgery, Düsseldorf - Germany Center of Hip Preservation and Children’s Orthopaedics, San Diego, California - USA

ABSTRACT Slipped capital femoral epiphysis (SCFE) is a common hip condition that can be disabling. In this review, we provide an orientation on current trends in the clinical management of SCFE including conventional procedures and specialised surgical developments. Different methods of fixation of the epiphysis, risks of complications, and the rationale of addressing deformity, primarily or secondarily, are presented. Although improved understanding of the anatomy, vascularity and implications of residual deformity have changed management strategies, the best modality of treatment that would restore complete vascularity to the femoral head and prevent any residual deformity, impingement and early osteoarthritis remains elusive. Keywords: Slipped capital femoral epiphysis, Treatment, Avascular necrosis, Residual deformity, Femoroacetabular impingement, Osteoarthritis

Introduction Although described in the 16th century (1), there has been a tremendous increase in our understanding of the management of slipped capital femoral epiphysis (SCFE) over the last few decades that is mainly related to the improved understanding of the anatomy and vascularity of the proximal femur and implications of deformity in the impingement era. Once a SCFE is diagnosed surgical stabilisation is indicated in which the surgical options are determined by the severity of the slip, the presumed duration of the disease and the expertise of the treating surgeon. The current approach in most institutions treating mild to moderate slips involves implementing a reliable method of mechanical stabilisation of the slip using contemporary surgical implants with no attempt at reduction of the slip, which is known as ‘in situ pinning’. Some element of remodelling of the deformed femoral head–neck junction with improvement in range of motion may be expected (2-14). However, many hips fail to achieve a sufficient remodelling resulting in an often significant residual deformity at the anterior femoral head–neck junction with subsequent femoroacetabular impingement (FAI) and chon-

Accepted: July 31, 2014 Published online: October 19, 2014 Corresponding author: Bernd Bittersohl University of Düsseldorf Medical Faculty Department of Orthopedic Surgery Moorenstr. 5 40225 Düsseldorf, Germany [email protected]

drolabral damage at the acetabular rim (15-20). Severe and unstable slips are complex with little consensus on the best treatment method and extensive debate about the timing of surgery. Similarly, the management of mal-united or healed displaced SCFE hips, which is considered a pre-arthritic condition, is equally controversial (21-32). In this review, we present an overview of current knowledge for the treatment of SCFE. Recognising the current lack of evidence-based recommendations for the treatment in SCFE due to various classifications in use, ceiling effects of outcome scores, the high variance between conventional and evolving advanced surgical treatment techniques, which without doubt depend on the individual operating skills and expertise of the treating surgeon, it is difficult to introduce a definitive and universally applicable treatment algorithm. We aim to provide an orientation on current trends in the clinical management of SCFE including conventional procedures as well as unique specialised surgical developments, which are tailored to each patient̕ s necessities and widely applicable to many orthopaedic institutions for routine clinical practice.

Physical examination and imaging Early diagnosis of SCFE is critical for a potential good outcome. A characteristic patient presents with an antalgic gait, an externally rotated limb with possible shortening, nonspecific groin-, thigh- or referred knee pain, and altered abductor function with exercise-triggered weakness of the lower extremity (33). Good quality radiographic imaging is important for documentation and assessment of severity. Standard anterior-posterior (AP) pelvis and frog-leg views of both hips are obtained. In unstable cases the leg should not be manipulated too much and a single view may be all that can be obtained. It is important to keep in mind that a large number of © 2014 Wichtig Publishing

Bittersohl et al

SCFE cases are bilateral (34-45). Early changes can be subtle and may include a generalised osteopenia of the proximal femur and irregularities of the proximal physis (example: widening). Chondrolysis, a rapid loss of articular cartilage with simultaneous progressive irregularity of the subcondral bone, may be present in all forms and stages of SCFE in both untreated and treated hips (46). Magnetic resonance imaging (MRI), computed tomography (CT), hip ultrasound (US) and bone scintigraphy have their role in the evaluation of the disease. Preoperatively, they can aid in diagnosis, assessment of severity, surgical planning and prognostication. Postoperatively, they provide information on near-term and long-term complications such as AVN and FAI. MRI can reveal AVN and chondrolabral damage (47-49) and is capable of identifying periarticular edema and edema-like abnormalities around the physis (50, 51). A CT with three-dimensional (3D) reconstruction provides an accurate estimation of the size, shape and orientation of the SCFE deformity (52). Hence, if the surgical treatment relies on the exact extent and character of the deformity, a preoperative CT may be performed (53). Ultrasound imaging is an effective technique for indirect diagnosis via detection of a hip joint effusion that is commonly seen in acute and unstable cases of SCFE (54, 55) whereas bone scintigraphy is, with a 100% negative predictive value, a valuable means for the diagnosis of AVN (56). Depending on the patient’s history, physical examination and medical imaging, SCFE is classified upon the acuity, stability and the severity of the slip (27). An acute SCFE is characterised by an abrupt epiphyseal displacement through the physis and the presence of symptoms for less than 3 weeks (57). Chronic SCFEs, which account for the large majority of all slips (up to 85%) (41), present with more than 3 weeks of symptoms often having a history of symptom deterioration and remission. Radiologic observations in chronic SCFE include irregularity at the physis and remodelling of the metaphysis (58). The SCFE is classified acute on chronic if acute symptoms such as a sudden exacerbation of pain and inability to walk occurs superimposed on prodromal symptoms, which have been present for more than 3 weeks. Unstable SCFE has been in its first description defined clinically by severe hip pain and the child’s inability to ambulate, with or without crutches and regardless of the duration of the symptoms (28). In contrast, the SCFE is considered stable when the child is able to walk with or without crutches. The severity can be graded upon the magnitude of displacement of the femoral head in which the Southwick angle (angle between a line perpendicular to a line drawn from the anterior to the posterior margin of the physis and the axis of the femoral shaft) calculated on the frog-lateral radiograph measures the posterior angulation of the head with respect to the neck (59). The slip angle is traditionally measured by subtracting the head-shaft angle of the unaffected side from the corresponding angle of the affected side. This allows for the comparison between the symptomatic and asymptomatic side. It may be useful when planning a correction osteotomy because it demonstrates the amount of correction required in the sagittal plane. In bilateral SCFE, an angle of 12° is used as benchmark for comparison. The severity of the slip is then classified mild (0-30°), moderate (30-50°) and severe (>50°) (27). © 2014 Wichtig Publishing

105

Traditionally, prognostication after SCFE treatment was made upon the duration of the patient’s symptoms at the time of presentation for treatment where the studies of Boyer et al and Carney et al revealed that patients presenting acutely within 3 weeks of symptom onset are at an increased risk for the development of AVN of the femoral head (2, 4). However, the SCFE classification introduced by Loder et al in 1993 (28), which is based on physeal stability, has been reported to correlate more accurately with the incidence of AVN of the capital femoral epiphysis (28, 60). Nevertheless, recent studies have questioned the validity of clinically assessed epiphyseal stability in which clinically stable slips were noted to be unstable both during MRI examinations (48) and surgical dislocation (61). Furthermore, the clinical history in SCFE can be uncertain or many times difficult to obtain, making the information about the onset of symptoms unreliable. This is of particular importance if treatment decision and prognostication is based on the duration of clinical symptoms and stability, for example if some reduction is attempted (62). Imaging techniques for example ultrasound and MRI, which target joint effusion, synovitis and bone marrow edema as indirect measures of epiphyseal stability, may potentially be able to improve the assessment of the stability in SCFE although further investigation is warranted (48, 55).

Avascular necrosis in slipped capital femoral epiphysis Avascular necrosis of the femoral head is a challenging and often an unavoidable complication in SCFE. The risk of AVN is increased in unstable slips and in hips with a substantial separation of the epiphysis from the metaphysis (21, 28, 63, 64). In spite of differences in methodology and study population, reported rates of AVN ranges between 6 and 58% in treated unstable and nearly 0% in treated stable SCFE patients (25, 60, 65, 66). Further factors related to the prevalence of AVN include the delay from presentation to surgery (67), severity of the slip (4, 64, 65, 68), younger age and short duration of prodromal symptoms (66), increased intra-capsular pressure (69), and the surgical technique (26, 64, 70, 71). The aetiology of AVN is likely multifactorial in origin including varieties of causes for an interruption of the blood supply to the femoral head such as an increased intracapsular pressure leading to a decreased blood flow to the femoral head and overstretching, tearing or kinking (compression) of the posterior retinacular blood vessels at the time of injury, during epiphyseal reduction at the level of a metaphyseal spur (as the result of new bone formation) or at the moment of (improper) fixation-implant placement (21, 24, 28, 46, 60, 63, 64, 72-74). Efforts to decrease the occurrence of AVN should address all these factors. A detailed knowledge of the vascular anatomy of the femoral neck and head is a prerequisite for the treatment of SCFE in order to preserve the hip anatomy without further disturbing the blood supply of the femoral head. In acute and severe SCFE, early reduction may minimise the adverse effects of a mechanical blockage and kinking on the femoral neck vasculature (24, 25, 73-76). The open ‘‘partial reduction’’ approach has been proposed by Parsch et al where the epiphysis is gently, finger-controlled reduced only to the position where it was located prior to the acute

106

component of the slip minimising the tendency to stretch the posterior vessels over the posterior callus at the epimetaphyseal level (77). Notably, in Parsch et al’s approach, surgery was done as an emergency procedure if possible within 24 hours after the onset of acute symptoms. Ziebart et al have reported their observations in 35 surgically confirmed disconnected (unstable) epiphyses where in six hips perfusion could be documented only after epiphyseal reduction that may be interpreted as reperfusion after kinking and/or stretching of the retinacular blood vessels (75). The observations of an increased risk for AVN (AVN rate 58%) in connection with the reduction of unstable SCFE made by Tokmakova et al somehow contradict this approach of early reduction (64). Furthermore, surgery within the “safe” 24-hour interval may not always be possible in a tertiary center and thus, such information should therefore be carefully considered. Increased intra-capsular pressure from intra-articular haematoma and/or effusion formation, which could lead to a tamponade effect compromising the femoral head blood circulation, may be successfully treated by the evacuation of the haematoma/effusion (69). If manipulation is intended, an arthrotomy should be performed to decompress the joint in particular in the presence of an intra-articular haematoma (24, 76). The fixation devices should be directed to the centre of the epiphysis in order to circumvent vital femoral head vessels at the posterior-superior and anterior-inferior quadrant (78). This has been emphasised by Brodetti et al who noted that placing a nail or a screw in the posterior-superior quadrant of the femoral head is associated with a high risk of impairment of the lateral epiphyseal vessels (79). Forceful over-reduction of an acute slip or the attempted reduction of a chronic slip into an anatomic alignment conveys excessive tension on the posterolateral vessels and thus, can cause a direct arterial injury (42, 64, 68, 80). However, even “gentle” and incomplete closed reduction can compromise the epiphyseal perfusion. A relatively new strategy in the treatment of SCFE is the modified Dunn procedure which encompasses open reduction with subcapital correction osteotomy after surgical hip dislocation (81). Besides its ability to prevent FAI, in terms of AVN, this technique has the potential to further decrease the risk of vascular injury by allowing direct preservation of the femoral head blood supply. Outcomes with this technique are variable (67, 70, 81-89), which may be related to differences in patient population, study methodology, interval between injury and surgery and technical experience with this demanding technique which has a steep learning curve.

Fixation of the epiphysis: techniques, benefits and drawbacks The goal of surgical stabilisation of the epiphysis using fixation is to prevent further slippage until eventual closure of the growth plate. Several methods have been described where the surgical procedure involving the placement of one screw (alternatively 3 to 4 Kirschner wires) across the growth plate through a small incision is technically simple, considered minimally invasive, and continues to be widely used. Several reports establish long-term results of such fixation with low morbidity, low incidence of slip progression, and a

Management of slipped capital femoral epiphysis

low incidence of complications (2, 4, 10, 13, 27, 42, 44, 72, 78, 90-98). The ideal screw position is perpendicular to the growth plate along the central axis with the screw threads within the center of the epiphysis thus ensuring maximum fixation and high safety with regard to the prevention of inadvertent joint penetration (23, 78, 90, 97, 99-103). As anticipated, incorrect screw positioning has been associated with increased complications including accidental joint penetration, slip progression, chondrolysis, delays in physeal fusion if originally intended, AVN, sub-trochanteric fracture or windshield-wiper loosening of the screw (46, 79, 97, 99, 104-109). In some instances when a 2-screw fixation is required or being considered, the first should be placed in the central position. The second is then placed in the inferior-lateral quadrant. Because the screws and drill holes constitute stress risers that weaken the bone one should seek to keep the starting point at the level of the lesser trochanter or above since placing it below the level of the lesser trochanter increases the risk of a peri-implant fracture (110). Notably, with increasing severity of the slip, the entry point of the screw may have to be placed further anterior in order to properly enter the epiphysis whereby a resultant prominent screw may produce an iatrogenic FAI (105). Repeated attempts of guidewire placement create unfilled holes in the proximal femoral cortex that increases the risk of a postoperative fracture (111). Intraoperative fluoroscopic imaging in two planes through a full arc of motion (flexion/ extension, internal rotation/external rotation) is performed to guide the placement of the fixation device (102). One has to be careful with simple bi-planar fluoroscopic imaging without additional multi-planar assessment as some images may give a false security of correct implant placement due to the superposition of the spherical shaped femoral head (103). Many surgeons follow the school of thought that the principle of epiphyseal stabilisation is to allow physeal fusion to occur (112-114) while others are concerned that the premature closure of the capital femoral physis would compromise the desirable remodelling of the femoral head and neck after in situ fixation (115, 116). Furthermore, particularly in younger subjects, premature closure of the growth plate may induce growth disorders of the proximal femur including coxa vara, coxa breva, and overgrowth of the greater trochanter that may cause hip joint mechanic alterations, functional impairment and secondary OA (95, 117, 118). When rationalising and evaluating the reported epiphyseal fixation concepts in the treatment of SCFE, it appears that the implementation of smooth Kirschner wires has a low risk of compromising the femoral head remodelling or injuring the growth plate (95, 116). In addition, in their standard construct of three to four fan-like placed 2 mm Kirschner wires (Fig. 1) they seem to provide similar biomechanical stability when compared to contemporary short threaded screws (119, 120) although some studies outline the increased risk of complication that is related to the repeated attempts of the pin placement (11, 12, 100, 103). The growth-triggered secondary slippage is another issue that must be taken into consideration if Kirschner wire fixation is planned (12, 114, 120). Hackenbroch reported their results on the dynamic screw fixation using a long cannulated  screw  with a short threaded component (121). This compressive fixation construct © 2014 Wichtig Publishing

Bittersohl et al

107

risk of the additional surgery (29, 30, 32, 36, 43, 98). Notably, in a long-term study reported by Hägglund et al, 25% of the patients who did not undergo prophylactic pinning developed OA of the hip before the age of 50 in those hips revealing a secondary slip while no OA was seen in any hip which was stabilised prophylactically (35).

Residual deformity and femoroacetabular impingement

Fig. 1 - Construct of 3 fan-like placed 2 mm Kirschner wires that provides similar biomechanical stability when compared to contemporary short threaded screws.

achieved a reliable stabilisation but, in contrast to the comments outlined above, no evident growth disorder of the proximal femur was noted in any case. The results of this study are similar to others which utilised a sliding screw construct with the proximal threading placed entirely within the epiphysis to ensure stabilisation, growth, and remodelling of the slipped epiphysis (115, 118, 122). Based on the implant type used, several studies report difficulties during implant removal in which, despite several advantages such as an excellent biocompatibility and the prospect of postoperative MRI assessment (123, 124), cannulated titanium screws reveal a high rate of implant removal failure (125-127). Bone covering of the screw head can equally complicate implant removal. Therefore, several authors recommend using fully threaded (no cutting back mechanism) stainless steel screws and to perform the removal as soon as the physis is closed (125-131).

Role of prophylactic pinning The risk of bilateral hip involvement ranges from 14 to 63% (34, 36, 38-41, 43-45). In children diagnosed at a very young age, this risk increases to 80% and in those with endocrinopathy, it may be as high as 100% (35, 37). Therefore, the prophylactic pinning of the contra-lateral hip must be considered in patients with pain on the contra-lateral side, young age at diagnosis, high risk of insufficient follow-up and endocrine disorders (39, 43). Otherwise it is necessary to perform close follow-up visits and radiographic imaging of the contralateral (often asymptomatic) hip for early detection (“observation hip”) (34, 36, 37, 41). In the above circumstances, and considering the risks related to FAI from minor slips (20, 132138), many advocate the immediate prophylactic fixation of the contra-lateral hip explaining and accepting the potential © 2014 Wichtig Publishing

Based upon the anticipated bone remodelling at the epiphyseal-metaphyseal interface, minimal complications and relatively successful clinical results, management with in situ pinning with no attempt at slip-reduction is widely accepted in the treatment of mild and moderate slips (2-7, 9-11, 16, 42, 72, 78, 97, 101, 102). Nevertheless, many hips fail to remodel, resulting in various grades and forms of FAI that predisposes the hip to early OA (18, 20, 85, 139-143). Furthermore, it is still uncertain what secondary changes occur in the acetabulum during the course of remodelling (remodelling at the cost of labrum and cartilage damage?) leading to speculation that timely correction of the mechanical deformity should be performed before progressive cartilage damage occurs (83, 136, 144). In cases with moderate and severe SCFE treated with in situ pinning, many are left with substantial residual deformity of the proximal femur that leads to alterations in gait, significant limitation of hip motion, and chronic pain. As early as 1997, after having studied the femora of 2665 adult human skeletons, Goodman et al noted that a post-slip morphology was associated with hip OA (141). In 1999, Rab described an anterior FAI with a limited range of hip motion related to the prominent anterior metaphyseal bone after the displacement of the metaphysis in the anterior-superior direction in relation to the femoral head (20). Based upon a 3D volume/surface computer model, two types of impingement were classified: impaction and inclusion impingement. The impaction-type impingement (typically occurring in severe slips) is characterised by a mechanical abutment of the proximal femur at the acetabular rim causing restriction of hip joint motion. The inclusion-type impingement is rather expected in mild or moderate slips and refers to a prominent region at the anterior metaphysis that is small enough to enter the joint during flexion producing sheer stress and various degrees of chondrolabral damage in the articulating acetabular regions. Therefore, the severity of the proximal femoral deformity, the range of motion in the hip joint and the degree of joint damage are not linearly correlated in which mild slips can cause substantial intra-articular damage. Of note, because of bone remodelling, an original impaction-type FAI may eventually merge into a late inclusion-type impingement (20). Rab’s theory was substantiated by numerous studies (15-19, 75, 81, 83, 133, 135-139, 141, 142, 145) and parallels our own clinical experience. There are several potential treatment options including arthroscopic osteochondroplasty, arthroscopically assisted mini-open osteochondroplasty via an anterolateral open approach, surgical dislocation osteochondroplasty and proximal femoral osteotomy, which aim at restoring the normal femoral head–neck offset in order to prevent or correct FAI to potentially preclude the development of progressive OA (143, 146, 147). As early as 1957, Heyman et al reported the

108

restoration of good motion and function, correction of deformity, and relief from pain by means of in situ pinning and the simultaneous removal of the anterior ‘‘bump’’ in patients with a severe SCFE (146). Leunig et al reported their results in three patients with mild (slip angles between 15° and 30°) and stable slips and signs of impingement that they treated with in situ pinning and concomitant arthroscopic head-neck osteochondroplasty (136). After a follow-up period of 2 years, each patient was pain-free and each patient had returned to unrestricted activities. Although this represents an attractive supplemental treatment with the possibility of addressing mild deformity and potentially preventing considerable chondrolabral damage in future, the results of this preliminary study need to be interpreted with caution. In particular, one has to be careful if this approach can really reduce subsequent FAI and articular damage, which may also result from continuing growth disturbance at the physeal plate (133). It also remains to be seen whether these procedures should be performed concomitantly (in the train of thought that the chondrolabral damage progresses unless the impacting lesion is eradicated demanding to intervene before patients become symptomatic and irreversible articular injury has followed) (148, 149) or if they can/should be performed in a staged fashion considering that further remodelling and/or growth disturbance may occur. In all circumstances, a prolonged follow-up and monitoring for FAI into adulthood is strongly recommended. This also applies for the limited open anterior femoral head-neck osteoplasty as a supplemental procedure to in situ pinning, an approach that is advocated by some surgeons typically in slip angles of up to 30° or as an supplemental approach in cases were the metaphyseal osseous bone and chondrolabral lesions cannot be sufficiently addressed by means of arthroscopy (136). In severe SCFE, osteochondroplasty on its own either arthroscopically, by means of a mini-open approach or after surgical hip dislocation, may not be sufficient to restore a normal head–neck offset or, on the other hand, it bears the risk of an iatrogenic femoral neck fracture if too much bone is removed. Although the removal of the impinging bone alone to increase hip range of motion seems elegant, as noted by Abraham et al a femoral head–neck osteochondroplasty does not realign the thick, high-quality central articular cartilage of the femoral head into the center of the acetabulum potentially leading to sub-optimal outcomes (139). Proximal femoral osteotomies either performed at the physis (80, 150, 151), at the base of the femoral neck (152, 153) or at the intertrochanteric/subtrochanteric level (59, 154) may correct severe deformities at the time of initial treatment, thereby probably preventing or delaying the onset of hip OA. Subcapital osteotomies as described by Dunn and Angel (80) and later Fish (150) allow for a great deal of correction. However, although some studies revealed a good outcome (150, 151, 155-157), they have been challenged by high complication rates, specifically AVN (reported rate highly variable ranging from approximately 10 to 100 %) (83) and chondrolysis whereby treatment options are hip fusion or hip arthroplasty. The high risk of AVN is related to the close proximity of the osteotomy to the posterior superior retinaculum with limited visualisation and protection of the vital posterior-superior retinacular arteries through this approach.

Management of slipped capital femoral epiphysis

The modified Dunn technique – in simple terms a combination of the Dunn osteotomy (80) with the open surgical hip dislocation approach (158) - was established by Ganz and colleagues for the treatment of moderate or severe SCFE (83). It entails a trochanteric osteotomy, a Z-shaped capsular incision, surgical hip dislocation, the creation of an extended posterior-superior retinacular flap with subperiosteal exposure of the femur and shortening of the femoral neck to minimise tension to the retinaculum and retinacular arteries, the removal of the epiphyseal plate to promote bony union and revascularisation of the epiphysis, the excision of the posterior and medial callus if present, controlled open reduction of the epiphysis, the internal fixation of the slip with screws and/or pins (Fig. 2), and screw fixation of the greater trochanter osteotomy. Although the procedure has been described for the treatment of stable and unstable SCFEs, as pointed out by the authors (83) this approach may be, in some respects, an ideal technique for the treatment of moderate to severe unstable SCFE because it has the capability of restoring the mechanical alignment of the hip and the femoral head-neck contour both on site of the deformity and at the time of the diagnosis in a one stage procedure thus normalising hip range of motion, minimising the need for a second surgery and potentially minimising secondary chondrolabral damage and early OA. Additionally, it allows full visualisation of the proximal femur and acetabulum to debride or repair any preexisting chondrolabral tear and to reduce and stabilise the slip ensuring sufficient reduction and restoration of the femoral head neck offset while preserving the blood supply of the femoral head and neck (70, 71, 81, 82). Disadvantageous is the fact that the modified Dunn approach is considerably more invasive and technically complex with a significant learning curve. Furthermore, long-term outcomes are, yet, not available. However, in contrast to the initial techniques for anatomic restoration, which resulted in high rates of AVN and poor outcome results in many studies (83), the short-term results are generally good provided that this procedure is performed by orthopaedic surgeons and their teams who are sufficiently trained in this operation (70, 71, 81-87). Nevertheless, some studies (67, 88, 89) illustrated drawbacks and potential pitfalls of this technique (relatively high rate of AVN, epiphyseal implant breakage, implant joint penetration associated with AVN, revision surgical dislocation and osteochondroplasty for residual deformity related to AVN), which may be complications as part of the surgical intervention or an inevitable consequence of the initial injury and the time until surgery is being performed. A surgical hip dislocation with a subcapital correction osteotomy through the remodeled head-neck junction (to re-establish a sufficient anteversion and neckshaft angle) combined with a re-contouring osteochondroplasty and/ or chondrolabral repair if needed may be used to correct the deformity of the proximal femur in patients with closed growth plates and a mal-united SCFE (145, 159). In addition, depending on the height of the greater trochanter relative to the repositioned femoral head, a greater trochanteric distalisation may aid in reducing abductor strength deficiency with exercise-induced fatigue, lateral-based pain and, potentially, the risk of future OA (160). © 2014 Wichtig Publishing

Bittersohl et al

109 Fig. 2 - Severe and unstable SCFE of the right hip treated with the modified Dunn procedure and prophylactic pinning of the contra-lateral hip using 3 Kirschner wires. After gentle reduction of the right capital epiphysis onto the metaphysis, definitive fixation of the capital epiphysis was achieved by two 3 mm fully threaded wires inserted through the fovea and exciting the lateral cortex below the greater trochanter. Care must be taken that the wires disappear into the fovea before the head is repositioned into the acetabulum. The greater trochanter was refixed with 2 screws.

Moving distally from the level of deformity, the extracapsular base of the neck osteotomy as described by Barmada in 1964 and popularised by Kramer et al in 1976 (153, 161) is a wedge osteotomy that provides correction of the varus and retroversion components in SCFE while preserving the anatomy of the proximal femur. Although, only a moderate degree of deformity correction (approximately 35-55°) can be achieved by this procedure (42), this technique is safer than a subcapital cuneiform osteotomy through the callus of the slipped epiphysis because the osteotomy is distal to the vascular supply of the posterior retinaculum (94). Good to excellent outcome with a low rate of AVN in the long term were reported after this type of osteotomy (152, 153). Peritrochanteric redirectional osteotomies such as the widely used Southwick (59) or Imhäuser (162) technique, which are predominantly performed secondarily in residual deformity after closure of the growth plate after in situ pinning has been completed for stabilisation (163, 164), provide improvement in function for patients with moderate to severe (residual) deformity as they move the impinging zone of the metaphysis away from the acetabular rim and realign the weight-bearing articular surface of the femoral head within the acetabular dome (59, 139, 149, 165, 166). These techniques are associated with a low incidence of AVN and chondrolysis (149, 167, 168). Nevertheless, the multi-planar correction required can be difficult to achieve. Furthermore, they do not provide an anatomic realignment meaning that metaphyseal deformities are not directly addressed by any extracapsular proximal femur osteotomy regardless of whether © 2014 Wichtig Publishing

they are performed basicervical intertrochanteric or subtrochanteric. Instead, to correct flexion, varus and external rotation they create an additional (reverse) deformity distally that alters normal hip biomechanics (167) and potentially complicates a THA later in life (169). Peritrochanteric redirectional osteotomies may also be performed with or without head–neck recontouring (170) while the timing of performing the osteotomy relative to the SCFE stabilisation remains controversial. Performing the realigning osteotomy immediately (154) or at an early phase may be beneficial if chondrolabral damage because of FAI plays a role. Alternatively and typically the osteotomy is performed at closure of the growth plate or with decay in range of motion (163, 164, 171).

Conclusion SCFE is a challenging hip disorder where the aim of management is to stabilise the epiphysis whilst avoiding complications of AVN of the femoral head, chondrolysis and FAI. Numerous management strategies have been reported and all come with their specific advantages and disadvantages. In this regard, the choice of surgical management should be made upon the acuity, the severity of displacement and hip morphology, the individual expectations of recovery and, not to be underestimated, the surgeons’ experience and level of comfort with any of these methods and techniques. In general, good clinical results have been achieved with the relatively low-risk procedure in situ pinning using various screw designs and fixation techniques - with sufficient remodelling

Management of slipped capital femoral epiphysis

110

of the head–neck junction after SCFE in many cases. However, a remarkable number of patients will develop residual cam deformities that can lead to FAI, chondrolabral damage and premature hip OA in young adulthood. For that reason, when in-situ pinning has been performed, we recommend a prolonged patient follow-up to skeletal maturity and beyond. In selected cases, a secondary corrective osteotomy or osteochondroplasty (either arthroscopically or open) as a two-stage approach may be indicated. Surgical dislocation of the hip combined with a modified Dunn procedure, which has the advantage of achieving both stabilisation and deformity correction in one stage potentially preventing pathologic abutment and chondrolabral damage, has been reported to be effective and safe in the treatment of moderate and severe unstable SCFE. Nevertheless, given the relatively small incidence of unstable SCFE and the significant risk of major complications including AVN, orthopaedic surgeons should be sufficiently trained and remain prudent if they adopt this technically demanding and novel technique. Furthermore, preoperative counseling should include a thorough discussion of these risks and encourage realistic expectations. Prophylactic pinning of the contralateral hip needs to be considered in the management of SCFE taking age, skeletal maturity, endocrine status, patient compliance and the ability to regularly follow-up into account. High-quality prospective multi-center studies with homogenous preoperative patient classification and sufficient follow-up including sensitive functional and imaging scoring systems are needed to verify what approach works best in the treatment of SCFE in various settings. Finally, AVN of the femoral head has multiple potential origins and may not be completely unavoidable. Consequently, the reported rates of osteonecrosis and their cause shall be conveyed to the patient and parents preoperatively and postoperatively.

7.

Disclosure

18.

Financial support: None. Conflict of interest: None.

References 1. 2. 3. 4. 5.

6.

Howorth B. Slipping of the capital femoral epiphysis. History. Clin Orthop Relat Res. 1966;48(48):11-32. Boyer DW, Mickelson MR, Ponseti IV. Slipped capital femoral epiphysis. Long-term follow-up study of one hundred and twenty-one patients. J Bone Joint Surg Am. 1981;63(1):85-95. Carney BT, Weinstein SL. Natural history of untreated chronic slipped capital femoral epiphysis. Clin Orthop Relat Res. 1996;(322):43-47. Carney BT, Weinstein SL, Noble J. Long-term follow-up of slipped capital femoral epiphysis. J Bone Joint Surg Am. 1991; 73(5):667-674. Dawes B, Jaremko JL, Balakumar J. Radiographic assessment of bone remodelling in slipped upper femoral epiphyses using Klein’s line and the α angle of femoral-acetabular impingement: a retrospective review. J Pediatr Orthop. 2011;31(2): 153-158. DeLullo JA, Thomas E, Cooney TE, McConnell SJ, Sanders JO. Femoral remodeling may influence patient outcomes in slipped capital femoral epiphysis. Clin Orthop Relat Res. 2007; 457(457):163-170.

8.

9. 10. 11.

12.

13. 14. 15. 16.

17.

19.

20. 21. 22.

23. 24.

25.

Dobbs MB, Weinstein SL. Natural history and long-term outcomes of slipped capital femoral epiphysis. Instr Course Lect. 2001;50:571-575. Hansson G, Billing L, Högstedt B, Jerre R, Wallin J. Long-term results after nailing in situ of slipped upper femoral epiphysis. A 30-year follow-up of 59 hips. J Bone Joint Surg Br. 1998; 80(1):70-77. Jones JR, Paterson DC, Hillier TM, Foster BK. Remodelling after pinning for slipped capital femoral epiphysis. J Bone Joint Surg Br. 1990;72(4):568-573. O’Brien ET, Fahey JJ. Remodeling of the femoral neck after in situ pinning for slipped capital femoral epiphysis. J Bone Joint Surg Am. 1977;59(1):62-68. Ordeberg G, Hansson LI, Sandström S. Slipped capital femoral epiphysis in southern Sweden. Long-term result with no treatment or symptomatic primary treatment. Clin Orthop Relat Res. 1984;(191):95-104. Stambough JL, Davidson RS, Ellis RD, Gregg JR. Slipped capital femoral epiphysis: an analysis of 80 patients as to pin placement and number. J Pediatr Orthop. 1986;6(3):265273. Wilson PD, Jacobs B, Schecter L. Slipped Capital Femoral Epiphysis: An End-Result Study. J Bone Joint Surg Am. 1965;47: 1128-1145. Wong-Chung J, Strong ML. Physeal remodeling after internal fixation of slipped capital femoral epiphyses. J Pediatr Orthop. 1991;11(1):2-5. Akiyama M, Nakashima Y, Kitano T, et al. Remodelling of femoral head-neck junction in slipped capital femoral epiphysis: a multicentre study. Int Orthop. 2013;37(12):2331-2336. Bellemans J, Fabry G, Molenaers G, Lammens J, Moens P. Slipped capital femoral epiphysis: a long-term follow-up, with special emphasis on the capacities for remodeling. J Pediatr Orthop B. 1996;5(3):151-157. Dodds MK, McCormack D, Mulhall KJ. Femoroacetabular impingement after slipped capital femoral epiphysis: does slip severity predict clinical symptoms? J Pediatr Orthop. 2009; 29(6):535-539. Larson AN, Sierra RJ, Yu EM, Trousdale RT, Stans AA. Outcomes of slipped capital femoral epiphysis treated with in situ pinning. J Pediatr Orthop. 2012;32(2):125-130. Mamisch TC, Kim YJ, Richolt JA, Millis MB, Kordelle J. Femoral morphology due to impingement influences the range of motion in slipped capital femoral epiphysis. Clin Orthop Relat Res. 2009;467(3):692-698. Rab GT. The geometry of slipped capital femoral epiphysis: implications for movement, impingement, and corrective osteotomy. J Pediatr Orthop. 1999;19(4):419-424. Aronsson DD, Loder RT. Treatment of the unstable (acute) slipped capital femoral epiphysis. Clin Orthop Relat Res. 1996;(322):99-110. de Sanctis N, Di Gennaro G, Pempinello C, Corte SD, Carannante G. Is gentle manipulative reduction and percutaneous fixation with a single screw the best management of acute and acute-on-chronic slipped capital femoral epiphysis? A report of 70 patients. J Pediatr Orthop B. 1996;5(2):90-95. Goodman WW, Johnson JT, Robertson WW Jr. Single screw fixation for acute and acute-on-chronic slipped capital femoral epiphysis. Clin Orthop Relat Res. 1996;(322):86-90. Gordon JE, Abrahams MS, Dobbs MB, Luhmann SJ, Schoenecker PL. Early reduction, arthrotomy, and cannulated screw fixation in unstable slipped capital femoral epiphysis treatment. J Pediatr Orthop. 2002;22(3):352-358. Kalogrianitis S, Tan CK, Kemp GJ, Bass A, Bruce C. Does unstable slipped capital femoral epiphysis require urgent stabilization? J Pediat Orthop B. 2007;16(1):6-9. © 2014 Wichtig Publishing

Bittersohl et al 26. Loder RT. Unstable slipped capital femoral epiphysis. J Pediatr Orthop. 2001;21(5):694-699. 27. Loder RT, Aronsson DD, Dobbs MB, Weinstein SL. Slipped capital femoral epiphysis. Instr Course Lect. 2001;50:555-570. 28. Loder RT, Richards BS, Shapiro PS, Reznick LR, Aronson DD. Acute slipped capital femoral epiphysis: the importance of physeal stability. J Bone Joint Surg Am. 1993;75(8):1134-1140. 29. Mooney JF III, Sanders JO, Browne RH, et al. Management of unstable/acute slipped capital femoral epiphysis: results of a survey of the POSNA membership. J Pediatr Orthop. 2005; 25(2):162-166. 30. Sonnega RJ, van der Sluijs JA, Wainwright AM, Roposch A, Hefti F. Management of slipped capital femoral epiphysis: results of a survey of the members of the European Paediatric Orthopaedic Society. J Child Orthop. 2011;5(6):433-438. 31. Uglow MG, Clarke NM. The management of slipped capital femoral epiphysis. J Bone Joint Surg Br. 2004;86(5):631-635. 32. Witbreuk M, Besselaar P, Eastwood D. Current practice in the management of acute/unstable slipped capital femoral epiphyses in the United Kingdom and the Netherlands: results of a survey of the membership of the British Society of Children̕ s Orthopaedic Surgery and the Werkgroep Kinder Orthopaedie. J Pediatr Orthop B. 2007;16(2):79-83. 33. Gholve PA, Cameron DB, Millis MB. Slipped capital femoral epiphysis update. Curr Opin Pediatr. 2009;21(1):39-45. 34. Castro FP Jr, Bennett JT, Doulens K. Epidemiological perspective on prophylactic pinning in patients with unilateral slip­ ped capital femoral epiphysis. J Pediatr Orthop. 2000;20(6): 745-748. 35. Hagglund G. The contralateral hip in slipped capital femoral epiphysis. J Pediatr Orthop B. 1996;5(3):158-161. 36. Hägglund G, Hansson LI, Ordeberg G, Sandström S. Bilaterality in slipped upper femoral epiphysis. J Bone Joint Surg Br. 1988;70(2):179-181. 37. Jerre R, Billing L, Hansson G, Karlsson J, Wallin J. Bilaterality in slipped capital femoral epiphysis: importance of a reliable radiographic method. J Pediatr Orthop B. 1996;5(2):80-84. 38. Jerre R, Billing L, Hansson G, Wallin J. The contralateral hip in patients primarily treated for unilateral slipped upper femoral epiphysis. Long-term follow-up of 61 hips. J Bone Joint Surg Br. 1994;76(4):563-567. 39. Kocher MS, Bishop JA, Hresko MT, Millis MB, Kim YJ, Kasser JR. Prophylactic pinning of the contralateral hip after unilateral slipped capital femoral epiphysis. J Bone Joint Surg Am. 2004;86-A(12):2658-2665. 40. Lehmann TG, Engesæter IO, Laborie LB, Rosendahl K, Lie SA, Engesæter LB. In situ fixation of slipped capital femoral epiphysis with Steinmann pins. Acta Orthop. 2011;82(3):333-338. 41. Loder RT, Aronson DD, Greenfield ML. The epidemiology of bilateral slipped capital femoral epiphysis. A study of children in Michigan. J Bone Joint Surg Am. 1993;75(8):1141-1147. 42. Loder RT, Aronsson DD, Weinstein SL, Breur GJ, Ganz R, Leunig M. Slipped capital femoral epiphysis. Instr Course Lect. 2008;57:473-498. 43. Schultz WR, Weinstein JN, Weinstein SL, Smith BG. Prophylactic pinning of the contralateral hip in slipped capital femoral epiphysis : evaluation of long-term outcome for the contralateral hip with use of decision analysis. J Bone Joint Surg Am. 2002;84(8):1305-1314. 44. Wensaas A, Svenningsen S, Terjesen T. Long-term outcome of slipped capital femoral epiphysis: a 38-year follow-up of 66 patients. J Child Orthop. 2011;5(2):75-82. 45. Yildirim Y, Bautista S, Davidson RS. Chondrolysis, osteonecrosis, and slip severity in patients with subsequent contralateral slipped capital femoral epiphysis. J Bone Joint Surg Am. 2008;90(3):485-492. © 2014 Wichtig Publishing

111 46. Lubicky JP. Chondrolysis and avascular necrosis: complications of slipped capital femoral epiphysis. J Pediatr Orthop B. 1996;5(3):162-167. 47. Staatz G, Honnef D, Kochs A, et al. Evaluation of femoral head vascularization in slipped capital femoral epiphysis before and after cannulated screw fixation with use of contrast-enhanced MRI: initial results. Eur Radiol. 2007;17(1):163-168. 48. Tins B, Cassar-Pullicino V, McCall I. The role of pre-treatment MRI in established cases of slipped capital femoral epiphysis. Eur J Radiol. 2009;70(3):570-578. 49. Zilkens C, Miese F, Bittersohl B, et al. Delayed gadoliniumenhanced magnetic resonance imaging of cartilage (dGEMRIC), after slipped capital femoral epiphysis. Eur J Radiol. 2011;79(3):400-406. 50. Lalaji A, Umans H, Schneider R, Mintz D, Liebling MS, Haramati N. MRI features of confirmed “pre-slip” capital femoral epiphysis: a report of two cases. Skeletal Radiol. 2002;31(6):362-365. 51. Umans H, Liebling MS, Moy L, Haramati N, Macy NJ, Pritzker HA. Slipped capital femoral epiphysis: a physeal lesion diagnosed by MRI, with radiographic and CT correlation. Skeletal Radiol. 1998;27(3):139-144. 52. Engelhardt P, Roesler H. [Radiometry of epiphyseolysis capitis femoris. A comparison of conventional roentgen study with axial computerized tomography]. [Article in German]. Z Orthop Ihre Grenzgeb. 1987;125(2):177-182. 53. Monazzam S, Dwek JR, Hosalkar HS. Multiplanar CT assessment of femoral head displacement in slipped capital femoral epiphysis. Pediatr Radiol. 2013;43(12):1599-1605. 54. Castriota-Scanderbeg A, Orsi E. Slipped capital femoral epi­ physis: ultrasonographic findings. Skeletal Radiol. 1993;22(3): 191-193. 55. Kallio PE, Paterson DC, Foster BK, Lequesne GW. Classification in slipped capital femoral epiphysis. Sonographic assessment of stability and remodeling. Clin Orthop Relat Res. 1993;(294):196-203. 56. Fragniere B, Chotel F, Vargas Barreto B, Berard J. The value of early postoperative bone scan in slipped capital femoral epiphysis. J Pediatr Orthop B. 2001;10(1):51-55. 57. Fahey JJ, O’Brien ET. Acute Slipped Capital Femoral Epiphysis: Review of the Literature and Report of Ten Cases. J Bone Joint Surg Am. 1965;47:1105-1127. 58. Boles CA, el-Khoury GY. Slipped capital femoral epiphysis. Radiographics. 1997;17(4):809-823. 59. Southwick WO. Osteotomy through the lesser trochanter for slipped capital femoral epiphysis. J Bone Joint Surg Am. 1967;49(5):807-835. 60. Kennedy JG, Hresko MT, Kasser JR, et al. Osteonecrosis of the femoral head associated with slipped capital femoral epiphysis. J Pediatr Orthop. 2001;21(2):189-193. 61. Ziebarth K, Domayer S, Slongo T, Kim YJ, Ganz R. Clinical stability of slipped capital femoral epiphysis does not correlate with intraoperative stability. Clin Orthop Relat Res. 2012;470(8): 2274-2279. 62. Loder RT. Controversies in slipped capital femoral epiphysis. Orthop Clin North Am. 2006;37(2):211-221, vii. 63. Ballard J, Cosgrove AP. Anterior physeal separation. A sign indicating a high risk for avascular necrosis after slipped capital femoral epiphysis. J Bone Joint Surg Br. 2002;84(8):1176-1179. 64. Tokmakova KP, Stanton RP, Mason DE. Factors influencing the development of osteonecrosis in patients treated for slipped capital femoral epiphysis. J Bone Joint Surg Am. 2003;85-A(5): 798-801. 65. Palocaren T, Holmes L, Rogers K, Kumar SJ. Outcome of in situ pinning in patients with unstable slipped capital femoral epiphysis: assessment of risk factors associated with avascular necrosis. J Pediatr Orthop. 2010;30(1):31-36.

112 66. Sankar WN, McPartland TG, Millis MB, Kim YJ. The unstable slipped capital femoral epiphysis: risk factors for osteonecrosis. J Pediatr Orthop. 2010;30(6):544-548. 67. Alves C, Steele M, Narayanan U, Howard A, Alman B, Wright JG. Open reduction and internal fixation of unstable slipped capital femoral epiphysis by means of surgical dislocation does not decrease the rate of avascular necrosis: a preliminary study. J Child Orthop. 2012;6(4):277-283. 68. Rattey T, Piehl F, Wright JG. Acute slipped capital femoral epiphysis. Review of outcomes and rates of avascular necrosis. J Bone Joint Surg Am. 1996;78(3):398-402. 69. Herrera-Soto JA, Duffy MF, Birnbaum MA, Vander Have KL. Increased intracapsular pressures after unstable slipped capital femoral epiphysis. J Pediatr Orthop. 2008;28(7):723-728. 70. Adolfsen SE, Sucato DJ. Surgical technique: open reduction and internal fixation for unstable slipped capital femoral epiphysis. Oper Tech Orthop. 2009;19(1):6-12. 71. Leunig M, Slongo T, Ganz R. Subcapital realignment in slipped capital femoral epiphysis: surgical hip dislocation and trimming of the stable trochanter to protect the perfusion of the epiphysis. Instr Course Lect. 2008;57:499-507. 72. Aronsson DD, Loder RT, Breur GJ, Weinstein SL. Slipped capital femoral epiphysis: current concepts. J Am Acad Orthop Surg. 2006;14(12):666-679. 73. Maeda S, Kita A, Funayama K, Kokubun S. Vascular supply to slipped capital femoral epiphysis. J Pediatr Orthop. 2001; 21(5):664-667. 74. Peterson MD, Weiner DS, Green NE, Terry CL. Acute slipped capital femoral epiphysis: the value and safety of urgent manipulative reduction. J Pediatr Orthop. 1997;17(5):648-654. 75. Ziebarth K, Leunig M, Slongo T, Kim YJ, Ganz R. Slipped capital femoral epiphysis: relevant pathophysiological findings with open surgery. Clin Orthop Relat Res. 2013;471(7):2156-2162. 76. Phillips SA, Griffiths WE, Clarke NM. The timing of reduction and stabilisation of the acute, unstable, slipped upper femoral epiphysis. J Bone Joint Surg Br. 2001;83(7):1046-1049. 77. Parsch K, Weller S, Parsch D. Open reduction and smooth Kirschner wire fixation for unstable slipped capital femoral epiphysis. J Pediatr Orthop. 2009;29(1):1-8. 78. Aronson DD, Carlson WE. Slipped capital femoral epiphysis. A prospective study of fixation with a single screw. J Bone Joint Surg Am. 1992;74(6):810-819. 79. Brodetti A. The blood supply of the femoral neck and head in relation to the damaging effects of nails and screws. J Bone Joint Surg Br. 1960;42(4):794-801. 80. Dunn DM, Angel JC. Replacement of the femoral head by open operation in severe adolescent slipping of the upper femoral epiphysis. J Bone Joint Surg Br. 1978;60(3):394-403. 81. Leunig M, Slongo T, Kleinschmidt M, Ganz R. Subcapital correction osteotomy in slipped capital femoral epiphysis by means of surgical hip dislocation. Oper Orthop Traumatol. 2007;19(4): 389-410. 82. Rebello G, Spencer S, Millis MB, Kim YJ. Surgical dislocation in the management of pediatric and adolescent hip deformity. Clin Orthop Relat Res. 2009;467(3):724-731. 83. Ziebarth K, Zilkens C, Spencer S, Leunig M, Ganz R, Kim YJ. Capital realignment for moderate and severe SCFE using a modified Dunn procedure. Clin Orthop Relat Res. 2009;467(3): 704-716. 84. Massè A, Aprato A, Grappiolo G, Turchetto L, Campacci A, Ganz R. Surgical hip dislocation for anatomic reorientation of slipped capital femoral epiphysis: preliminary results. Hip Int. 2012;22(2):137-144. 85. Slongo T, Kakaty D, Krause F, Ziebarth K. Treatment of slipped capital femoral epiphysis with a modified Dunn procedure. J Bone Joint Surg Am. 2010;92(18):2898-2908.

Management of slipped capital femoral epiphysis 86. Huber H, Dora C, Ramseier LE, Buck F, Dierauer S. Adolescent slipped capital femoral epiphysis treated by a modified Dunn osteotomy with surgical hip dislocation. J Bone Joint Surg Br. 2011;93(6):833-838. 87. Madan SS, Cooper AP, Davies AG, Fernandes JA. The treatment of severe slipped capital femoral epiphysis via the Ganz surgical dislocation and anatomical reduction: a prospective study. Bone Joint J. 2013;95(3):424-429. 88. Souder CD, Bomar JD, Wenger DR. The role of capital realignment versus in situ stabilization for the treatment of slipped capital femoral epiphysis. J Pediatr Orthop. 2014;1. 89. Sankar WN, Vanderhave KL, Matheney T, Herrera-Soto JA, Karlen JW. The modified Dunn procedure for unstable slipped capital femoral epiphysis: a multicenter perspective. J Bone Joint Surg Am. 2013;95(7):585-591. 90. Aronson DD, Peterson DA, Miller DV. Slipped capital femoral epiphysis. The case for internal fixation in situ. Clin Orthop Relat Res. 1992;(281):115-122. 91. Carlioz H, Vogt JC, Barba L, Doursounian L. Treatment of slipped upper femoral epiphysis: 80 cases operated on over 10 years (1968-1978). J Pediatr Orthop. 1984;4(2):153161. 92. Hansson LI, Hägglund G, Ordeberg G. Slipped capital femoral epiphysis in southern Sweden 1910-1982. Acta Orthop Scand Suppl. 1987;226(s226):1-67. 93. Koval KJ, Lehman WB, Rose D, Koval RP, Grant A, Strongwater A. Treatment of slipped capital femoral epiphysis with a cannulated-screw technique. J Bone Joint Surg Am. 1989;71(9): 1370-1377. 94. Loder RT, Dietz FR. What is the best evidence for the treatment of slipped capital femoral epiphysis? J Pediatr Orthop. 2012;32(Suppl 2):S158-S165. 95. Morscher E, Staubli A, Meyer S, Imhoff A. [5.) 10-year results after epiphyseolysis capitis femoris. a) 10-year results with nails and screws in epiphyseolysis capitis femoris]. Orthopade. 1979;8(1):60-64. 96. Strong M, Lejman T, Michno P, Sulko J. Fixation of slipped capital femoral epiphyses with unthreaded 2-mm wires. J Pediatr Orthop. 1996;16(1):53-55. 97. Ward WT, Stefko J, Wood KB, Stanitski CL. Fixation with a single screw for slipped capital femoral epiphysis. J Bone Joint Surg Am. 1992;74(6):799-809. 98. Seller K, Raab P, Wild A, Krauspe R. Risk-benefit analysis of prophylactic pinning in slipped capital femoral epiphysis. J Pediatr Orthop B. 2001;10(3):192-196. 99. Carney BT, Birnbaum P, Minter C. Slip progression after in situ single screw fixation for stable slipped capital femoral epiphysis. J Pediatr Orthop. 2003;23(5):584-589. 100. Lehman WB, Menche D, Grant A, Norman A, Pugh J. The problem of evaluating in situ pinning of slipped capital femoral epiphysis: an experimental model and a review of 63 consecutive cases. J Pediatr Orthop. 1984;4(3):297-303. 101. Morrissy RT. Principles of in situ fixation in chronic slipped capital femoral epiphysis. Instr Course Lect. 1989;38:257-262. 102. Morrissy RT. Slipped capital femoral epiphysis technique of percutaneous in situ fixation. J Pediatr Orthop. 1990;10(3): 347-350 103. Walters R, Simon SR. Joint destruction: a sequel of unrecognized pin penetration in patients with slipped capital femoral epiphyses. In: The hip: proceedings of the eighth open scientific meeting of the Hip Society. St. Louis: CV Mosby 1980; 145-164. 104. Canale ST, Azar F, Young J, Beaty JH, Warner WC, Whitmer G. Subtrochanteric fracture after fixation of slipped capital femoral epiphysis: a complication of unused drill holes. J Pediatr Orthop. 1994;14(5):623-626. © 2014 Wichtig Publishing

Bittersohl et al 105. Goodwin RC, Mahar AT, Oswald TS, Wenger DR. Screw head impingement after in situ fixation in moderate and severe slipped capital femoral epiphysis. J Pediatr Orthop. 2007;27(3): 319-325. 106. Greenough CG, Bromage JD, Jackson AM. Pinning of the slipped upper femoral epiphysis—a trouble-free procedure? J Pediatr Orthop. 1985;5(6):657-660. 107. Maletis GB, Bassett GS. Windshield-wiper loosening: a complication of in situ screw fixation of slipped capital femoral epiphysis. J Pediatr Orthop. 1993;13(5):607-609. 108. Riley PM, Weiner DS, Gillespie R, Weiner SD. Hazards of internal fixation in the treatment of slipped capital femoral epiphysis. J Bone Joint Surg Am. 1990;72(10):1500-1509. 109. Sanders JO, Smith WJ, Stanley EA, Bueche MJ, Karol LA, Chambers HG. Progressive slippage after pinning for slipped capital femoral epiphysis. J Pediatr Orthop. 2002;22(2):239-243. 110. Skaggs DL, Flynn JM. Staying out of trouble in pediatric orthopaedics. Philadelphia, PA: Lippincott Williams & Wilkins, 2006. 111. Canale ST. Problems and complications of slipped capital femoral epiphysis. Instr Course Lect. 1989;38:281-290. 112. Aronsson DD, Karol LA. Stable Slipped Capital Femoral Epiphysis: Evaluation and Management. J Am Acad Orthop Surg. 1996;4(4):173-181. 113. Carey RP, Moran PL, Cole WG. The place of threaded pin fixation in the treatment of slipped upper femoral epiphysis. Clin Orthop Relat Res. 1987;(224):45-51. 114. Laplaza FJ, Burke SW. Epiphyseal growth after pinning of slipped capital femoral epiphysis. J Pediatr Orthop. 1995;15(3): 357-361. 115. Sailhan F, Courvoisier A, Brunet O, Chotel F, Berard J. Continued growth of the hip after fixation of slipped capital femoral epiphysis using a single cannulated screw with a proximal threading. J Child Orthop. 2011;5(2):83-88. 116. Seller K, Wild A, Westhoff B, Raab P, Krauspe R. Clinical outcome after transfixation of the epiphysis with Kirschner wires in unstable slipped capital femoral epiphysis. Int Orthop. 2006;30(5):342-347. 117. Chen CE, Ko JY, Wang CJ. Premature closure of the physeal plate after treatment of a slipped capital femoral epiphysis. Chang Gung Med J. 2002;25(12):811-818. 118. Segal LS, Davidson RS, Robertson WW Jr, Drummond DS. Growth disturbances of the proximal femur after pinning of juvenile slipped capital femoral epiphysis. J Pediatr Orthop. 1991;11(5):631-637. 119. Druschel C, Sawicki O, Cip J, Schmölz W, Funk JF, Placzek R. Biomechanical analysis of screw fixation vs. K-wire fixation of a slipped capital femoral epiphysis model. Biomed Tech (Berl). 2012;57(3):157-162. 120. Reize P, Rudert M. Kirschner wire transfixation of the femoral head in slipped capital femoral epiphysis in children. Oper Orthop Traumatol. 2007;19(4):345-357. 121. Hackenbroch MH, Kumm DA, Rütt J. [Dyamic screw fixation for slipped capital femoral epiphysis. Treatment results]. Orthopade. 2002;31(9):871-879. 122. Guzzanti V, Falciglia F, Stanitski CL. Slipped capital femoral epiphysis in skeletally immature patients. J Bone Joint Surg Br. 2004;86(5):731-736. 123. Albrektsson T, Brånemark PI, Hansson HA, Lindström J. Osseointegrated titanium implants. Requirements for ensuring a long-lasting, direct bone-to-implant anchorage in man. Acta Orthop Scand. 1981;52(2):155-170. 124. Linder L, Lundskog J. Incorporation of stainless steel, titanium and Vitallium in bone. Injury. 1975;6(4):277-285. 125. Ilchmann T, Parsch K. Complications at screw removal in slipped capital femoral epiphysis treated by cannulated titanium screws. Arch Orthop Trauma Surg. 2006;126(6):359-363. © 2014 Wichtig Publishing

113 126. Maus U, Ihme N, Niedhart C, et al. [Comparison of the treatment of slipped capital femoral epiphysis with K-wires and cannulated titanium screws]. Z Orthop Unfall. 2008;146(2): 251-255. 127. Vresilovic EJ, Spindler KP, Robertson WW Jr, Davidson RS, Drummond DS. Failures of pin removal after in situ pinning of slipped capital femoral epiphyses: a comparison of different pin types. J Pediatr Orthop. 1990;10(6):764-768. 128. Dragoni M, Heiner AD, Costa S, Gabrielli A, Weinstein SL. Biomechanical study of 16-mm threaded, 32-mm threaded, and fully threaded SCFE screw fixation. J Pediatr Orthop. 2012;32(1):70-74. 129. Miyanji F, Mahar A, Oka R, Pring M, Wenger D. Biomechanical comparison of fully and partially threaded screws for fixation of slipped capital femoral epiphysis. J Pediatr Orthop. 2008;28(1):49-52. 130. Pretell-Mazzini J, Rodriguez-Vega V, Muñoz-Ledesma J, et al. Complications and associated risk factors at screw removal in slipped capital femoral epiphysis treated by cannulated stainless steel screws. J Child Orthop. 2012;6(4):285-289. 131. Warner JG, Bramley D, Kay PR. Failure of screw removal after fixation of slipped capital femoral epiphysis: the need for a specific screw design. J Bone Joint Surg Br. 1994;76(5):844845. 132. Fraitzl CR, Käfer W, Nelitz M, Reichel H. Radiological evidence of femoroacetabular impingement in mild slipped capital femoral epiphysis: a mean follow-up of 14.4 years after pinning in situ. J Bone Joint Surg Br. 2007;89(12):1592-1596. 133. Fraitzl CR, Nelitz M, Cakir B, Käfer W, Reichel H. Transfixation in slipped capital femoral epiphysis: long-term evidence for femoro-acetabular impingement. Z Orthop Unfall. 2009;147(3):334340. 134. Futami T, Kasahara Y, Suzuki S, Seto Y, Ushikubo S. Arthroscopy for slipped capital femoral epiphysis. J Pediatr Orthop. 1992;12(5):592-597. 135. Lee CB, Matheney T, Yen YM. Case reports: acetabular damage after mild slipped capital femoral epiphysis. Clin Orthop Relat Res. 2013;471(7):2163-2172. 136. Leunig M, Horowitz K, Manner H, Ganz R. In situ pinning with arthroscopic osteoplasty for mild SCFE: A preliminary technical report. Clin Orthop Relat Res. 2010;468(12):3160-3167. 137. Sink EL, Zaltz I, Heare T, Dayton M. Acetabular cartilage and labral damage observed during surgical hip dislocation for stable slipped capital femoral epiphysis. J Pediatr Orthop. 2010; 30(1):26-30. 138. Zilkens C, Bittersohl B, Jäger M, et al. Significance of clinical and radiographic findings in young adults after slipped capital femoral epiphysis. Int Orthop. 2011;35(9):1295-1301. 139. Abraham E, Gonzalez MH, Pratap S, Amirouche F, Atluri P, Simon P. Clinical implications of anatomical wear characteristics in slipped capital femoral epiphysis and primary osteoarthritis. J Pediatr Orthop. 2007;27(7):788-795. 140. Ganz R, Leunig M, Leunig-Ganz K, Harris WH. The etiology of osteoarthritis of the hip: an integrated mechanical concept. Clin Orthop Relat Res. 2008;466(2):264-272. 141. Goodman DA, Feighan JE, Smith AD, Latimer B, Buly RL, Cooperman DR. Subclinical slipped capital femoral epiphysis. Relationship to osteoarthrosis of the hip. J Bone Joint Surg Am. 1997;79(10):1489-1497. 142. Leunig M, Casillas MM, Hamlet M, et al. Slipped capital femoral epiphysis: early mechanical damage to the acetabular cartilage by a prominent femoral metaphysis. Acta Orthop Scand. 2000;71(4):370-375. 143. Millis MB, Novais EN. In situ fixation for slipped capital femoral epiphysis: perspectives in 2011. J Bone Joint Surg Am. 2011;93(Suppl 2):46-51.

114 144. Hosalkar HS, Pandya NK, Bomar JD, Wenger DR. Hip impingement in slipped capital femoral epiphysis: a changing perspective. J Child Orthop. 2012;6(3):161-172. 145. Anderson LA, Gililland JM, Pelt CE, Peters CL. Subcapital correction osteotomy for malunited slipped capital femoral epiphysis. J Pediatr Orthop. 2013;33(4):345-352. 146. Heyman CH, Herndon CH, Strong JM. Slipped femoral epiphysis with severe displacement; a conservative operative treatment. J Bone Joint Surg Am. 1957;39-A(2):293-303, passim. 147. Lavigne M, Parvizi J, Beck M, Siebenrock KA, Ganz R, Leunig M. Anterior femoroacetabular impingement: part I. Techniques of joint preserving surgery. Clin Orthop Relat Res. 2004;418:61-66. 148. Schai PA, Exner GU, Hansch O. Prevention of secondary coxarthrosis in slipped capital femoral epiphysis: a long-term followup study after corrective intertrochanteric osteotomy. J Pediatr Orthop B. 1996;5(3):135-143. 149. Witbreuk MM, Bolkenbaas M, Mullender MG, Sierevelt IN, Besselaar PP. The results of downgrading moderate and severe slipped capital femoral epiphysis by an early Imhauser femur osteotomy. J Child Orthop. 2009;3(5):405-410. 150. Fish JB. Cuneiform osteotomy of the femoral neck in the treatment of slipped capital femoral epiphysis. J Bone Joint Surg Am. 1984;66(8):1153-1168. 151. Fish JB. Cuneiform osteotomy of the femoral neck in the treatment of slipped capital femoral epiphysis. A follow-up note. J Bone Joint Surg Am. 1994;76(1):46-59. 152. Abraham E, Garst J, Barmada R. Treatment of moderate to severe slipped capital femoral epiphysis with extracapsular baseof-neck osteotomy. J Pediatr Orthop. 1993;13(3):294-302. 153. Kramer WG, Craig WA, Noel S. Compensating osteotomy at the base of the femoral neck for slipped capital femoral epiphysis. J Bone Joint Surg Am. 1976;58(6):796-800. 154. Kartenbender K, Cordier W, Katthagen BD. Long-term follow-up study after corrective Imhäuser osteotomy for severe slipped capital femoral epiphysis. J Pediatr Orthop. 2000;20(6):749-756. 155. Biring GS, Hashemi-Nejad A, Catterall A. Outcomes of subcapital cuneiform osteotomy for the treatment of severe slipped capital femoral epiphysis after skeletal maturity. J Bone Joint Surg Br. 2006;88(10):1379-1384. 156. DeRosa GP, Mullins RC, Kling TF Jr. Cuneiform osteotomy of the femoral neck in severe slipped capital femoral epiphysis. Clin Orthop Relat Res. 1996;(322):48-60. 157. Velasco R, Schai PA, Exner GU. Slipped capital femoral epiphysis: a long-term follow-up study after open reduction of the femoral head combined with subcapital wedge resection. J Pediatr Orthop B. 1998;7(1):43-52. 158. Ganz R, Gill TJ, Gautier E, Ganz K, Krügel N, Berlemann U. Surgical dislocation of the adult hip a technique with full access to the femoral head and acetabulum without the risk of avascular necrosis. J Bone Joint Surg Br. 2001;83(8):1119-1124.

Management of slipped capital femoral epiphysis 159. Spencer S, Millis MB, Kim YJ. Early results of treatment of hip impingement syndrome in slipped capital femoral epiphysis and pistol grip deformity of the femoral head-neck junction using the surgical dislocation technique. J Pediatr Orthop. 2006;26(3):281-285. 160. Bardakos NV, Villar RN. Predictors of progression of osteoarthritis in femoroacetabular impingement: a radiological study with a minimum of ten years follow-up. J Bone Joint Surg Br. 2009;91(2):162-169. 161. Barmada R, Bruch RF, Gimbel JS, Ray RD. Base of the neck extracapsular osteotomy for correction of deformity in slipped capital femoral epiphysis. Clin Orthop Relat Res. 1978;(132): 98-101. 162. Imhäuser G. [Late results of Imhäuser’s osteotomy for slipped capital femoral epiphysis (author’s transl)]. [Article in German]. Z Orthop Ihre Grenzgeb. 1977;115(5):716-725. 163. Diab M, Daluvoy S, Snyder BD, Kasser JR. Osteotomy does not improve early outcome after slipped capital femoral epiphysis. J Pediatr Orthop Part B. 2006;15(2):87-92. 164. Kallitzas J, Braunsfurth A. [Should osteotomy after Imhäuser be performed immediately or only following setting and healing of epiphysiolysis of the head of the femur? (author’s transl)]. [Article in German]. Z Orthop Ihre Grenzgeb. 1977;115(6): 848-850. 165. Imhäuser G. [Pathogenesis and therapy of hip dislocation in youth]. [Article in German]. Z Orthop Ihre Grenzgeb. 1956; 88(1):3-41. 166. Parsch K, Zehender H, Buhl T, Weller S. Intertrochanteric corrective osteotomy for moderate and severe chronic slip­ ped capital femoral epiphysis. J Pediatr Orthop B. 1999;8(3): 223-230. 167. Fujak A, Müller K, Legal W, Legal H, Forst R, Forst J. [Long-term results of Imhäuser osteotomy for chronic slipped femoral head epiphysiolysis]. Orthopade. 2012;41(6):452-458. 168. Maussen JP, Rozing PM, Obermann WR. Intertrochanteric corrective osteotomy in slipped capital femoral epiphysis. A longterm follow-up study of 26 patients. Clin Orthop Relat Res. 1990;(259):100-110. 169. Shinar AA, Harris WH. Cemented total hip arthroplasty following previous femoral osteotomy: an average 16-year follow-up study. J Arthroplasty. 1998;13(3):243-253. 170. Whiteside LA, Schoenecker PL. Combined valgus derotation osteotomy and cervical osteoplasty for severely slipped capital femoral epiphysis: mechanical analysis and report preliminary results using compression screw fixation and early weight bearing. Clin Orthop Relat Res. 1978;(132):88-97. 171. Tjoumakaris FP, Wallach DM, Davidson RS. Subtrochanteric osteotomy effectively treats femoroacetabular impingement after slipped capital femoral epiphysis. Clin Orthop Relat Res. 2007;464(464):230-237.

© 2014 Wichtig Publishing

Copyright of Hip International is the property of Wichtig Publishing srl and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.