Classification and Surgical A p p ro a c h e s t o H i p F r a c t u re s f o r Nonsurgeons Simon C. Mears,
MD, PhD*
KEYWORDS Femoral neck fracture Intertrochanteric hip fracture Surgery Patient activity level Fracture type KEY POINTS Knowledge of hip fractures and surgical repair helps nonsurgeons develop communication with surgeons, leading to improved outcomes for elderly patients. Nondisplaced femoral neck fractures are treated with screw fixation, whereas displaced fractures are treated with hip replacement. Lower activity patients with femoral neck fractures are treated with hemiarthroplasty, whereas high activity patients have better outcomes with total hip replacement. Stable intertrochanteric fractures are treated with a sliding hip screw, whereas unstable fractures are treated with intramedullary hip screws. Subtrochanteric fractures may have typical or atypical patterns (associated with bisphosphonate use), are more difficult to reduce surgically, and are treated with an intramedullary hip screw. The goal of all hip fracture fixation is to allow the patient to bear weight as tolerated after surgery.
INTRODUCTION
The elderly population commonly experiences hip fractures. The care of these fractures before, during, and after the related surgery often involves many different physicians. An appreciation of the types of fractures and the surgical repair may help the nonsurgical physician build rapport with the surgeon, thus promoting better communication, which has been shown to be the crux of multidisciplinary efforts for patient care.1,2 These team efforts have produced better results for the patient and cost savings for the health care system.1,2 The author has no commercial associations or sources of support that might pose a conflict of interest. Department of Orthopaedic Surgery, The Johns Hopkins University/Johns Hopkins Bayview Medical Center, 4940 Eastern Avenue, Baltimore, MD 21224–2780, USA * c/o Elaine P. Henze, BJ, ELS, Medical Editor and Director, Editorial Services, Department of Orthopaedic Surgery, The Johns Hopkins University/Johns Hopkins Bayview Medical Center, 4940 Eastern Avenue, #A665, Baltimore, MD 21224–2780. E-mail address: [email protected] Clin Geriatr Med 30 (2014) 229–241 http://dx.doi.org/10.1016/j.cger.2014.01.004 geriatric.theclinics.com 0749-0690/14/$ – see front matter Ó 2014 Elsevier Inc. All rights reserved.
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In this review, the common types of hip fractures seen in the elderly are described, and the type of procedure used for the surgical repair of each is discussed. ANATOMY AND FRACTURE RISK
Hip fractures typically occur as a result of a fall from standing height in a patient with osteoporosis. The elderly patient often has poor balance because of frailty and poor vision, hearing, and muscle strength. Elderly patients often have osteoporosis, resulting in less bone density. These conditions often overlap, leaving a patient with osteoporosis who is more likely to fall, with a higher risk of fracture. Individual long bones typically respond to loss in bone mass by becoming wider and thinner. The wider tube gives strength but makes the bone brittle and susceptible to fracture. For example, the proximal femur loses bone density and cortical thickness, becoming tube-shaped, with very narrow side walls.3 The hip joint is the articulation of the proximal femur and the acetabulum of the pelvis. The proximal femur is divided into several anatomic zones, which are used to describe fracture type, including the femoral head, the femoral neck, the intertrochanteric area, and the shaft of the femur. The proximal femur is the location of several muscle insertions that are critical to lower extremity function. The hip abductors (the gluteus medius and minimus) insert into the greater trochanter. The main hip flexor (the psoas) inserts into the lesser trochanter. The hip joint is surrounded by a thick ligamentous capsule. The capsule goes from the base of the neck to the pelvis and seals the joint. The femoral head and neck are intracapsular, whereas the trochanters are extracapsular (Fig. 1A). FRACTURE TYPES
There are 3 main types of fractures in the elderly, categorized according to the anatomic position of the fracture line (Fig. 1B): Femoral neck fractures Intertrochanteric fractures Subtrochanteric fractures
Fig. 1. Hip anatomy and fracture types. (A) The hip joint is pictured with the insertions of the gluteus medius and psoas muscles. GT, greater trochanter; LT, lesser trochanter. (B) Regions are shown identifying the areas in which femoral neck (FN), intertrochanteric (IT), and subtrochanteric (ST) fractures occur.
Approaches to Hip Fractures for Nonsurgeons
Each of these locations can have fracture patterns with more or less displacement or more or less fracture fragmentation. By using the fracture location and fracture pattern, and taking into account patient factors such as dementia and mobility status, the best treatment method can be determined. The goal of surgical treatment is to allow the patient to begin immediate full weight bearing and mobilization. Nonoperative treatment is reserved for those at the end of life or who, secondary to severe dementia, do not have pain with their fracture (see the article elsewhere in this issue for further discussion of nonsurgical management). For most others, surgical repair offers reduced pain and return to function, with less morbidity and mortality than nonoperative treatment. Femoral Neck Fractures
Femoral neck fractures are intracapsular and account for approximately 45% of fractures.4,5 Decision making for these fractures is based not only on fracture type but also on the patient’s activity level and frailness. In general, the decision has to be made whether to stabilize the fracture or to replace the hip. Each choice has different modality options. Femoral neck fractures are most commonly classified using the Garden system.6 This system takes into account the location, direction, and displacement of the fracture. Fractures that are more horizontal have more innate stability: the axial load of body weight pushes a horizontal fracture together, whereas it leads to fracture displacement for a vertical pattern. The more vertical and displaced a fracture is, the more unstable is the fracture pattern. Stage I fractures are minimally or nondisplaced, stage II fractures are very horizontal and impacted, and stage III and IV fractures are severely displaced, and the head does not line up with the remainder of the femur. In general, Garden stage I and II fractures are stable and Garden stage III and IV fractures are unstable; this definition is termed the simplified Garden system (Fig. 2).7 The radiographs of Garden stage I and II fractures must be carefully examined to make sure that the femoral head is not tilted or displaced. Angulation of the femoral head, especially with weakening of the posterior cortex, makes the fracture more unstable, and screw fixation often fails.8 An important factor in addition to stability is the
Fig. 2. Anteroposterior radiographs showing stable (A) and unstable (B) femoral neck fractures.
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anatomic position of the blood supply to the femoral head. The medial femoral circumflex artery runs along the posterior side of the femoral neck.9 Displaced fractures can interrupt the blood supply, which can lead to death of the bone in the femoral head. This condition is termed osteonecrosis, and it leads to collapse of the femoral head and arthritis, with a subsequent need for hip replacement. The decision-making process for determining the best surgical procedure uses both the fracture type and the patient’s activity level to choose between internal fixation and arthroplasty. Internal fixation is usually performed for stable fracture patterns in the following manner under fluoroscopic guidance. The fracture is aligned by placing traction on the leg and checking biplanar fluoroscopic views. A small incision is made, and 3 guide wires are placed across the fracture. When these guide wires are correctly positioned, cannulated screws are placed across the fracture into the femoral head (Fig. 3A) over the top of the guide wires. Washers can increase the compressive force developed by the screws. Arthroplasty (or joint replacement) should be the workhorse for displaced femoral neck fractures. It is reliable and leads to fewer subsequent procedures than does internal fixation, as has been shown by several long-term randomized studies.10–14 However, within the general category of arthroplasty, there are still several decisions to be made: the arthroplasty may be partial or total and may be attached to the bone using different methods. With a partial hip replacement (hemiarthroplasty), the femoral head is removed, and a metal replacement is inserted into the femur with or without bone cement. This replacement has a metal ball that articulates against the native acetabular cartilage (Fig. 3B). Current replacements have a modular head that attaches to the stem to allow for adjustment of length during surgery, which permits the surgeon to gain the correct muscle tension and leg length. Hemiarthroplasty may involve a unipolar device (1 solid head ball) or a bipolar device, in which a secondary cap is placed over a smaller head ball on the trunnion. No overall differences have been noted between these types of devices.15 Hemiarthroplasty is a successful procedure but may lead to wear of the articular cartilage or subsequent pain. With a total hip replacement, the acetabular cartilage is removed with a reamer and a metal acetabular component is impacted into the acetabulum. Inside the metal acetabular component, a liner is placed, which is usually made of highly crosslinked polyethylene (Fig. 3C). Recent studies have found that in active and younger patients, total hip arthroplasty results in less pain and better outcomes than hemiarthroplasty.16,17 However, total hip arthroplasty has a higher risk of dislocation than partial replacement because the latter uses a larger head.18 Initially, replacement was performed in patients whose hip fractures had been repaired but whose uncemented devices were working poorly. A widely used historical device was called the Austin Moore replacement. These implants had no ingrowth surfaces and were wedged into the femur with little or no fixation. Overall, results were poor.19 Current uncemented femoral implants come in many sizes, are shaped to wedge into the proximal femur, and are coated with surfaces to allow permanent bone ingrowth. For cemented implants, the device is smooth, and after it is inserted, the femur is filled with polymethylmethacrylate cement, which acts as a grout, filling in all the spaces between the bone and the implant. Results with both types of implants are excellent.20 However, uncemented stems must be wedged into the bone and present a slightly higher risk of fractures during or after insertion.21–24 Recent studies have shown that there is a lower risk of periprosthetic fractures with the use of cemented stems in elderly patients.21–24
Approaches to Hip Fractures for Nonsurgeons
Fig. 3. Anteroposterior radiographs showing treatment options for a femoral neck fracture. (A) Cannulated screws. (B) Hemiarthroplasty. (C) Total hip arthroplasty.
The hip replacement may be implanted using different surgical approaches. Commonly used approaches include the posterolateral, the anterolateral, and the anterior approaches. There is no overall consensus as to the best approach for hip replacement. Each approach has a different risk and benefit profile. The posterolateral approach has a slightly higher rate of dislocation, whereas the anterolateral approach results in a slightly higher rate of limp, because of damage to the hip abductor muscles.25–27 More recently, the anterior approaches have become more popular. The most important factor in determining approach is the experience of the surgeon. Patients with a very high dislocation risk (ie, those with contracture or neurologic disorders) may have lower dislocation rates with anterior or anterolateral approaches (Table 1).
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Table 1 Advantages and disadvantages of the 3 surgical approaches to arthroplasty Approach
Advantage
Disadvantage
Posterolateral
No abductor damage (low limp) Extensile
Higher dislocation risk
Anterolateral
Low dislocation risk
Possible abductor damage (higher limp)
Anterior
Low dislocation risk Low limp risk
More difficult Requires fluoroscopy
The decision-making process when selecting an arthroplasty involves consideration of:
Surgical approach Cemented versus uncemented femoral component Hemiarthroplasty versus total hip arthroplasty If hemiarthroplasty, unipolar versus bipolar
Overall results for patients with displaced fractures have been shown to be better with arthroplasty than with internal fixation, primarily because the former is associated with fewer reoperations (approximately a 40% chance of requiring reoperation13). Common reasons for failure are nonunion or osteonecrosis with delayed need for hip arthroplasty. Because older patients do not tolerate repeat surgery well, arthroplasty is believed to be a better option for most geriatric patients with femoral neck fracture. This finding leads to 1 common algorithm for surgery: stable or nondisplaced fractures are treated with internal fixation, whereas displaced fractures are treated with arthroplasty, that is, hemiarthroplasty for most patients and total arthroplasty for those who are very active and functional (Fig. 4).28 Intertrochanteric Fractures
Intertrochanteric fractures are extracapsular and account for approximately 45% of fractures.4,5 These fractures have been classified using several different systems based on the position of the fracture and the amount of fracture fragmentation (comminution). The most common system used is the AO Foundation (AO)/Orthopaedic
Fig. 4. Algorithm for the treatment of femoral neck fractures.
Approaches to Hip Fractures for Nonsurgeons
Trauma Association (OTA) system.29 This system uses both comminution and fracture position. Overall, fractures can be divided into those that are more stable and those that are less stable. This type of classification then can drive treatment algorithms. In general, fractures with an intact lateral wall and calcar are stable (AO/OTA 31-A1.1, A1.2, A1.3, and A2.1), whereas fractures with more comminution and an unstable lateral wall are unstable (AO/OTA 31-A2.2, A2.3, A3.1, A3.2, and A3.3) (Fig. 5). Fracture Stability Stable Intact lateral buttress Few pieces (no comminution) Unstable Lateral buttress is fractured Many pieces (comminution) Reverse oblique pattern Subtrochanteric fractures Two main surgical procedures are used for these fractures. One is called the sliding hip screw (SHS) with side plate. With this procedure, the fracture is reduced under fluoroscopy with traction, and then a guide wire is inserted across the fracture into the center of the femoral head. The screw is placed over the guide wire, and the plate is attached to the side of the femur. The screw is thus able to slide within the barrel of the plate, which permits fracture compression, aiding in fracture fixation (Fig. 6A). This device has been widely adopted and is successful.30 The SHS is successful for fractures that have a solid buttress against which the femoral headpiece can slide. However, some fracture patterns lack this stability. One particularly unstable pattern is called the reverse oblique pattern. In this pattern, the plate does not provide a stop point for sliding, and failure rates are higher.31 In this case, all of the pressure of walking is placed on the interface of the plate with the bone, which fails with time (Fig. 6B). Sometimes, fracture stability can be difficult to determine or can change intraoperatively. It is important that the lateral wall is intact for the SHS to work well.32,33 The other type of device used for intertrochanteric fractures is the intramedullary hip screw (IMHS). With this device, the fixation on the shaft side of the fracture is placed within the bone. First, the fracture is reduced, and then, an intramedullary nail is placed
Fig. 5. Anteroposterior radiographs showing stable (A) and unstable (B) intertrochanteric fractures.
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Fig. 6. Anteroposterior radiographs showing treatment options and biomechanics for intertrochanteric fractures. (A) SHS in a stable fracture. The arrow shows the vector of force during standing. With the lateral cortex intact, the fracture can stably impact as the screw slides within the barrel of the plate. (B) SHS in an unstable fracture. In this reverse oblique pattern, the plate cannot resist the sliding force in the direction of the arrow, and the device fails before fracture healing. (C) IMHS in an unstable fracture. The fracture impacts along the path indicated by the arrow, and the nail itself acts as a limitation to the sliding of the screw.
within the femur. It is typically inserted by making a hole in the greater trochanter. After the nail is placed in the bone, the hip screw is then placed through a hole in the nail. In general, more unstable fractures are probably best treated with an intramedullary device. The nail of the device acts as a stop point for the sliding of the screw (Fig. 6C). Controversy exists as to which fracture should be treated with which device.30 Overall, the SHS has been successful and is less expensive than the IMHS. Despite these findings, the rate of usage of the IMHS has steadily increased over the past 10 years.34
Approaches to Hip Fractures for Nonsurgeons
Some of this increase is the result of changes in design features of the IMHS. Initial designs had a propensity toward fracture at the distal end of the device.35,36 This problem has largely been solved. Some surgeons use the IMHS for all intertrochanteric fractures, which permits less inventory in the operating room. It also protects the surgeon if the fracture pattern has been misjudged. Sometimes, it is possible to miss fracture lines that make the fracture more unstable than was initially appreciated.37 The rates of success for the SHS and IMHS have been shown to be related to the positioning of the hip screw within the femoral head.38 The screw needs good purchase within the bone of the femoral head. If it does not gain purchase, the screw migrates and cuts out into the acetabulum. Then, the construct must be revised to a total hip replacement, which is a complex procedure. The screw should be centrally and deeply placed in the femoral head. A useful marker for this location is called the tipapex distance. The distance between the end of the screw and the tip of the femoral head is measured on anteroposterior and lateral views of the hip. These measurements are added. A long measurement gives poorer fixation. For example, if the distance is greater than 24 mm, the rate of failure of the fracture to heal is significantly higher.39 In another study, in which surgeons consciously measured this distance and made sure it was less than 24 mm, outcomes were significantly better.40 The tip-apex distance is also believed to be important for the IMHS.41 Other treatments are rarely used for intertrochanteric fractures. Arthroplasty can be considered, but it is technically difficult. Although a femoral neck fracture leads to an easy hip replacement, the location of the intertrochanteric fracture is further down the femur and involves the greater and lesser trochanters, which means that there is less bone in which to insert the femoral component and may mean that a revision style implant must be used. The trochanter may also have to be repaired and anchored to the remainder of the femur. Overall, these factors make arthroplasty for intertrochanteric fractures more difficult than when it is used for a femoral neck fracture. However, there are times when arthroplasty may be the best solution for an intertrochanteric fracture. One such situation is the presence of preexisting arthritis in the hip joint. The replacement then repairs the fracture and solves the problem of the arthritic joint rather than staging a repair and subsequently replacing the hip. Subtrochanteric Fractures
Subtrochanteric fractures are the least common type, accounting for approximately 10% of fractures,5,42 and are located below the lesser trochanter, in the top part of the femoral shaft. These fractures can be difficult to treat, because the psoas muscle pulls on the lesser trochanter, which flexes the proximal piece of bone. Reduction can be difficult, and these fractures may need to be further surgically exposed to reduce the fracture fragments. They are treated with IMHS. Fractures may be classified as typical or atypical. Typical fractures result from falls. Atypical fractures have now become widely recognized and are associated with bisphosphonate use.43 They begin as a stress fracture, usually on the lateral wall of the femur in the subtrochanteric or midshaft region. The bone thickens as a result of poor turnover. A stress fracture develops and is seen as a black line in the thickened area of femur (Fig. 7). The stress fracture is susceptible to full fracture with minimal force. If a stress fracture is seen and is painful, careful consideration should be given to prophylactic treatment with an IMHS to prevent full fracture.44 Nonoperative treatment often leads to complete fracture. In general, treatment with IMHS is successful, although healing may take longer.45
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Fig. 7. Anteroposterior radiograph showing an atypical subtrochanteric fracture. The arrow points to the area of bone hypertrophy on the lateral cortex.
SUMMARY
Some appreciation for the types of hip fracture and treatment mechanisms is useful to the nonsurgeon. Surgeons treat fractures by the type of fracture and patient. Femoral neck fractures are treated with internal fixation or arthroplasty, depending on the stability of the fracture. Unstable fractures are best treated with arthroplasty; if the patient is very active, treatment should be a total hip replacement. Intertrochanteric fractures are treated with SHS or IMHS, depending on the stability of the fracture. Unstable intertrochanteric fractures and all subtrochanteric fractures should be treated with IMHS. REFERENCES
1. Friedman SM, Mendelson DA, Kates SL, et al. Geriatric co-management of proximal femur fractures: total quality management and protocol-driven care result in better outcomes for a frail patient population. J Am Geriatr Soc 2008;56(7): 1349–56. 2. Kates SL, Mendelson DA, Friedman SM. Co-managed care for fragility hip fractures (Rochester model). Osteoporos Int 2010;21(Suppl 4):S621–5. 3. Dorr LD, Faugere MC, Mackel AM, et al. Structural and cellular assessment of bone quality of proximal femur. Bone 1993;14(3):231–42. 4. Lofman O, Berglund K, Larsson L, et al. Changes in hip fracture epidemiology: redistribution between ages, genders and fracture types. Osteoporos Int 2002; 13(1):18–25.
Approaches to Hip Fractures for Nonsurgeons
5. Zuckerman JD. Hip fracture. N Engl J Med 1996;334(23):1519–25. 6. Garden RS. Low-angle fixation in fractures of the femoral neck. J Bone Joint Surg Br 1961;43(4):647–63. 7. Van Embden D, Rhemrev SJ, Genelin F, et al. The reliability of a simplified Garden classification for intracapsular hip fractures. Orthop Traumatol Surg Res 2012; 98(4):405–8. 8. Clement ND, Green K, Murray N, et al. Undisplaced intracapsular hip fractures in the elderly: predicting fixation failure and mortality. A prospective study of 162 patients. J Orthop Sci 2013;18(4):578–85. 9. Gautier E, Ganz K, Krugel N, et al. Anatomy of the medial femoral circumflex artery and its surgical implications. J Bone Joint Surg Br 2000;82(5):679–83. 10. Avery PP, Baker RP, Walton MJ, et al. Total hip replacement and hemiarthroplasty in mobile, independent patients with a displaced intracapsular fracture of the femoral neck: a seven- to ten-year follow-up report of a prospective randomised controlled trial. J Bone Joint Surg Br 2011;93(8):1045–8. 11. Blomfeldt R, Tornkvist H, Ponzer S, et al. Comparison of internal fixation with total hip replacement for displaced femoral neck fractures. Randomized, controlled trial performed at four years. J Bone Joint Surg Am 2005;87(8):1680–8. 12. Chammout GK, Mukka SS, Carlsson T, et al. Total hip replacement versus open reduction and internal fixation of displaced femoral neck fractures: a randomized long-term follow-up study. J Bone Joint Surg Am 2012;94(21):1921–8. 13. Leonardsson O, Sernbo I, Carlsson A, et al. Long-term follow-up of replacement compared with internal fixation for displaced femoral neck fractures: results at ten years in a randomised study of 450 patients. J Bone Joint Surg Br 2010;92(3): 406–12. 14. Rogmark C, Johnell O. Primary arthroplasty is better than internal fixation of displaced femoral neck fractures: a meta-analysis of 14 randomized studies with 2,289 patients. Acta Orthop 2006;77(3):359–67. 15. Ong BC, Maurer SG, Aharonoff GB, et al. Unipolar versus bipolar hemiarthroplasty: functional outcome after femoral neck fracture at a minimum of thirty-six months of follow-up. J Orthop Trauma 2002;16(5):317–22. 16. Blomfeldt R, Tornkvist H, Eriksson K, et al. A randomised controlled trial comparing bipolar hemiarthroplasty with total hip replacement for displaced intracapsular fractures of the femoral neck in elderly patients. J Bone Joint Surg Br 2007;89(2):160–5. 17. Hedbeck CJ, Enocson A, Lapidus G, et al. Comparison of bipolar hemiarthroplasty with total hip arthroplasty for displaced femoral neck fractures: a concise four-year follow-up of a randomized trial. J Bone Joint Surg Am 2011;93(5): 445–50. 18. Poignard A, Bouhou M, Pidet O, et al. High dislocation cumulative risk in THA versus hemiarthroplasty for fractures. Clin Orthop Relat Res 2011;469(11): 3148–53. 19. Emery RJH, Broughton NS, Desai K, et al. Bipolar hemiarthroplasty for subcapital fracture of the femoral neck. A prospective randomised trial of cemented Thompson and uncemented Moore stems. J Bone Joint Surg Br 1991;73(2):322–4. 20. Parker MJ, Gurusamy K. Arthroplasties (with and without bone cement) for proximal femoral fractures in adults. Cochrane Database Syst Rev 2006;(3):CD001706. 21. Gjertsen JE, Lie SA, Vinje T, et al. More re-operations after uncemented than cemented hemiarthroplasty used in the treatment of displaced fractures of the femoral neck: an observational study of 11,116 hemiarthroplasties from a national register. J Bone Joint Surg Br 2012;94(8):1113–9.
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22. Leonardsson O, Karrholm J, Akesson K, et al. Higher risk of reoperation for bipolar and uncemented hemiarthroplasty. 23,509 procedures after femoral neck fractures from the Swedish Hip Arthroplasty Register, 2005–2010. Acta Orthop 2012; 83(5):459–66. 23. Taylor F, Wright M, Zhu M. Hemiarthroplasty of the hip with and without cement: a randomized clinical trial. J Bone Joint Surg Am 2012;94(7):577–83. 24. Viberg B, Overgaard S, Lauritsen J, et al. Lower reoperation rate for cemented hemiarthroplasty than for uncemented hemiarthroplasty and internal fixation following femoral neck fracture: 12- to 19-year follow-up of patients aged 75 years or more. Acta Orthop 2013;84(3):254–9. 25. Hailer NP, Weiss RJ, Stark A, et al. The risk of revision due to dislocation after total hip arthroplasty depends on surgical approach, femoral head size, sex, and primary diagnosis. An analysis of 78,098 operations in the Swedish Hip Arthroplasty Register. Acta Orthop 2012;83(5):442–8. 26. Jolles BM, Bogoch ER. Posterior versus lateral surgical approach for total hip arthroplasty in adults with osteoarthritis. Cochrane Database Syst Rev 2006;(3):CD003828. 27. Mulliken BD, Rorabeck CH, Bourne RB, et al. A modified direct lateral approach in total hip arthroplasty: a comprehensive review. J Arthroplasty 1998;13(7): 737–47. 28. Callaghan JJ, Liu SS, Haidukewych GJ. Subcapital fractures: a changing paradigm. J Bone Joint Surg Br 2012;94(11 Suppl A):19–21. 29. Marsh JL, Slongo TF, Agel J, et al. Fracture and dislocation classification compendium–2007: Orthopaedic Trauma Association classification, database and outcomes committee. J Orthop Trauma 2007;21(Suppl 10):S1–133. 30. Parker MJ, Handoll HHG. Gamma and other cephalocondylic intramedullary nails versus extramedullary implants for extracapsular hip fractures in adults (review). Cochrane Database Syst Rev 2010;(9):CD000093. 31. Haidukewych GJ, Israel TA, Berry DJ. Reverse obliquity fractures of the intertrochanteric region of the femur. J Bone Joint Surg Am 2001;83(5):643–50. 32. De Bruijn K, den Hartog D, Tuinebreijer W, et al. Reliability of predictors for screw cutout in intertrochanteric hip fractures. J Bone Joint Surg Am 2012;94(14): 1266–72. 33. Hsu CE, Shih CM, Wang CC, et al. Lateral femoral wall thickness: a reliable predictor of post-operative lateral wall fracture in intertrochanteric fractures. Bone Joint J 2013;95(8):1134–8. 34. Anglen JO, Weinstein JN. Nail or plate fixation of intertrochanteric hip fractures: changing pattern of practice. A review of the American Board of Orthopaedic Surgery Database. J Bone Joint Surg Am 2008;90(4):700–7. 35. Norris R, Bhattacharjee D, Parker MJ. Occurrence of secondary fracture around intramedullary nails used for trochanteric hip fractures: a systematic review of 13,568 patients. Injury 2012;43(6):706–11. 36. Osnes EK, Lofthus CM, Falch JA, et al. More postoperative femoral fractures with the Gamma nail than the sliding screw plate in the treatment of trochanteric fractures. Acta Orthop Scand 2001;72(3):252–6. 37. Palm H, Jacobsen S, Sonne-Holm S, et al. Integrity of the lateral femoral wall in intertrochanteric hip fractures: an important predictor of a reoperation. J Bone Joint Surg Am 2007;89(3):470–5. 38. Rubio-Avila J, Madden K, Simunovic N, et al. Tip to apex distance in femoral intertrochanteric fractures: a systematic review. J Orthop Sci 2013;18(4): 592–8.
Approaches to Hip Fractures for Nonsurgeons
39. Baumgaertner MR, Curtin SL, Lindskog DM, et al. The value of the tip-apex distance in predicting failure of fixation of peritrochanteric fractures of the hip. J Bone Joint Surg Am 1995;77(7):1058–64. 40. Baumgaertner MR, Solberg BD. Awareness of tip-apex distance reduces failure of fixation of trochanteric fractures of the hip. J Bone Joint Surg Br 1997;79(6): 969–71. 41. Kuzyk PR, Zdero R, Shah S, et al. Femoral head lag screw position for cephalomedullary nails: a biomechanical analysis. J Orthop Trauma 2012;26(7):414–21. 42. Napoli N, Schwartz AV, Palermo L, et al. Risk factors for subtrochanteric and diaphyseal fractures: the study of osteoporotic fractures. J Clin Endocrinol Metab 2013;98(2):659–67. 43. Shane E, Burr D, Ebeling PR, et al. Atypical subtrochanteric and diaphyseal femoral fractures: report of a task force of the American Society for Bone and Mineral Research. J Bone Miner Res 2010;25(11):2267–94. 44. Banffy MB, Vrahas MS, Ready JE, et al. Nonoperative versus prophylactic treatment of bisphosphonate-associated femoral stress fractures. Clin Orthop Relat Res 2011;469(7):2028–34. 45. Egol KA, Park JH, Rosenberg ZS, et al. Healing delayed but generally reliable after bisphosphonate-associated complete femur fractures treated with IM nails. Clin Orthop Relat Res 2013. [Epub ahead of print].
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KEYWORDS Femoral neck fracture Intertrochanteric hip fracture Surgery Patient activity level Fracture type KEY POINTS Knowledge of hip fractures and surgical repair helps nonsurgeons develop communication with surgeons, leading to improved outcomes for elderly patients. Nondisplaced femoral neck fractures are treated with screw fixation, whereas displaced fractures are treated with hip replacement. Lower activity patients with femoral neck fractures are treated with hemiarthroplasty, whereas high activity patients have better outcomes with total hip replacement. Stable intertrochanteric fractures are treated with a sliding hip screw, whereas unstable fractures are treated with intramedullary hip screws. Subtrochanteric fractures may have typical or atypical patterns (associated with bisphosphonate use), are more difficult to reduce surgically, and are treated with an intramedullary hip screw. The goal of all hip fracture fixation is to allow the patient to bear weight as tolerated after surgery.
INTRODUCTION
The elderly population commonly experiences hip fractures. The care of these fractures before, during, and after the related surgery often involves many different physicians. An appreciation of the types of fractures and the surgical repair may help the nonsurgical physician build rapport with the surgeon, thus promoting better communication, which has been shown to be the crux of multidisciplinary efforts for patient care.1,2 These team efforts have produced better results for the patient and cost savings for the health care system.1,2 The author has no commercial associations or sources of support that might pose a conflict of interest. Department of Orthopaedic Surgery, The Johns Hopkins University/Johns Hopkins Bayview Medical Center, 4940 Eastern Avenue, Baltimore, MD 21224–2780, USA * c/o Elaine P. Henze, BJ, ELS, Medical Editor and Director, Editorial Services, Department of Orthopaedic Surgery, The Johns Hopkins University/Johns Hopkins Bayview Medical Center, 4940 Eastern Avenue, #A665, Baltimore, MD 21224–2780. E-mail address: [email protected] Clin Geriatr Med 30 (2014) 229–241 http://dx.doi.org/10.1016/j.cger.2014.01.004 geriatric.theclinics.com 0749-0690/14/$ – see front matter Ó 2014 Elsevier Inc. All rights reserved.
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In this review, the common types of hip fractures seen in the elderly are described, and the type of procedure used for the surgical repair of each is discussed. ANATOMY AND FRACTURE RISK
Hip fractures typically occur as a result of a fall from standing height in a patient with osteoporosis. The elderly patient often has poor balance because of frailty and poor vision, hearing, and muscle strength. Elderly patients often have osteoporosis, resulting in less bone density. These conditions often overlap, leaving a patient with osteoporosis who is more likely to fall, with a higher risk of fracture. Individual long bones typically respond to loss in bone mass by becoming wider and thinner. The wider tube gives strength but makes the bone brittle and susceptible to fracture. For example, the proximal femur loses bone density and cortical thickness, becoming tube-shaped, with very narrow side walls.3 The hip joint is the articulation of the proximal femur and the acetabulum of the pelvis. The proximal femur is divided into several anatomic zones, which are used to describe fracture type, including the femoral head, the femoral neck, the intertrochanteric area, and the shaft of the femur. The proximal femur is the location of several muscle insertions that are critical to lower extremity function. The hip abductors (the gluteus medius and minimus) insert into the greater trochanter. The main hip flexor (the psoas) inserts into the lesser trochanter. The hip joint is surrounded by a thick ligamentous capsule. The capsule goes from the base of the neck to the pelvis and seals the joint. The femoral head and neck are intracapsular, whereas the trochanters are extracapsular (Fig. 1A). FRACTURE TYPES
There are 3 main types of fractures in the elderly, categorized according to the anatomic position of the fracture line (Fig. 1B): Femoral neck fractures Intertrochanteric fractures Subtrochanteric fractures
Fig. 1. Hip anatomy and fracture types. (A) The hip joint is pictured with the insertions of the gluteus medius and psoas muscles. GT, greater trochanter; LT, lesser trochanter. (B) Regions are shown identifying the areas in which femoral neck (FN), intertrochanteric (IT), and subtrochanteric (ST) fractures occur.
Approaches to Hip Fractures for Nonsurgeons
Each of these locations can have fracture patterns with more or less displacement or more or less fracture fragmentation. By using the fracture location and fracture pattern, and taking into account patient factors such as dementia and mobility status, the best treatment method can be determined. The goal of surgical treatment is to allow the patient to begin immediate full weight bearing and mobilization. Nonoperative treatment is reserved for those at the end of life or who, secondary to severe dementia, do not have pain with their fracture (see the article elsewhere in this issue for further discussion of nonsurgical management). For most others, surgical repair offers reduced pain and return to function, with less morbidity and mortality than nonoperative treatment. Femoral Neck Fractures
Femoral neck fractures are intracapsular and account for approximately 45% of fractures.4,5 Decision making for these fractures is based not only on fracture type but also on the patient’s activity level and frailness. In general, the decision has to be made whether to stabilize the fracture or to replace the hip. Each choice has different modality options. Femoral neck fractures are most commonly classified using the Garden system.6 This system takes into account the location, direction, and displacement of the fracture. Fractures that are more horizontal have more innate stability: the axial load of body weight pushes a horizontal fracture together, whereas it leads to fracture displacement for a vertical pattern. The more vertical and displaced a fracture is, the more unstable is the fracture pattern. Stage I fractures are minimally or nondisplaced, stage II fractures are very horizontal and impacted, and stage III and IV fractures are severely displaced, and the head does not line up with the remainder of the femur. In general, Garden stage I and II fractures are stable and Garden stage III and IV fractures are unstable; this definition is termed the simplified Garden system (Fig. 2).7 The radiographs of Garden stage I and II fractures must be carefully examined to make sure that the femoral head is not tilted or displaced. Angulation of the femoral head, especially with weakening of the posterior cortex, makes the fracture more unstable, and screw fixation often fails.8 An important factor in addition to stability is the
Fig. 2. Anteroposterior radiographs showing stable (A) and unstable (B) femoral neck fractures.
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anatomic position of the blood supply to the femoral head. The medial femoral circumflex artery runs along the posterior side of the femoral neck.9 Displaced fractures can interrupt the blood supply, which can lead to death of the bone in the femoral head. This condition is termed osteonecrosis, and it leads to collapse of the femoral head and arthritis, with a subsequent need for hip replacement. The decision-making process for determining the best surgical procedure uses both the fracture type and the patient’s activity level to choose between internal fixation and arthroplasty. Internal fixation is usually performed for stable fracture patterns in the following manner under fluoroscopic guidance. The fracture is aligned by placing traction on the leg and checking biplanar fluoroscopic views. A small incision is made, and 3 guide wires are placed across the fracture. When these guide wires are correctly positioned, cannulated screws are placed across the fracture into the femoral head (Fig. 3A) over the top of the guide wires. Washers can increase the compressive force developed by the screws. Arthroplasty (or joint replacement) should be the workhorse for displaced femoral neck fractures. It is reliable and leads to fewer subsequent procedures than does internal fixation, as has been shown by several long-term randomized studies.10–14 However, within the general category of arthroplasty, there are still several decisions to be made: the arthroplasty may be partial or total and may be attached to the bone using different methods. With a partial hip replacement (hemiarthroplasty), the femoral head is removed, and a metal replacement is inserted into the femur with or without bone cement. This replacement has a metal ball that articulates against the native acetabular cartilage (Fig. 3B). Current replacements have a modular head that attaches to the stem to allow for adjustment of length during surgery, which permits the surgeon to gain the correct muscle tension and leg length. Hemiarthroplasty may involve a unipolar device (1 solid head ball) or a bipolar device, in which a secondary cap is placed over a smaller head ball on the trunnion. No overall differences have been noted between these types of devices.15 Hemiarthroplasty is a successful procedure but may lead to wear of the articular cartilage or subsequent pain. With a total hip replacement, the acetabular cartilage is removed with a reamer and a metal acetabular component is impacted into the acetabulum. Inside the metal acetabular component, a liner is placed, which is usually made of highly crosslinked polyethylene (Fig. 3C). Recent studies have found that in active and younger patients, total hip arthroplasty results in less pain and better outcomes than hemiarthroplasty.16,17 However, total hip arthroplasty has a higher risk of dislocation than partial replacement because the latter uses a larger head.18 Initially, replacement was performed in patients whose hip fractures had been repaired but whose uncemented devices were working poorly. A widely used historical device was called the Austin Moore replacement. These implants had no ingrowth surfaces and were wedged into the femur with little or no fixation. Overall, results were poor.19 Current uncemented femoral implants come in many sizes, are shaped to wedge into the proximal femur, and are coated with surfaces to allow permanent bone ingrowth. For cemented implants, the device is smooth, and after it is inserted, the femur is filled with polymethylmethacrylate cement, which acts as a grout, filling in all the spaces between the bone and the implant. Results with both types of implants are excellent.20 However, uncemented stems must be wedged into the bone and present a slightly higher risk of fractures during or after insertion.21–24 Recent studies have shown that there is a lower risk of periprosthetic fractures with the use of cemented stems in elderly patients.21–24
Approaches to Hip Fractures for Nonsurgeons
Fig. 3. Anteroposterior radiographs showing treatment options for a femoral neck fracture. (A) Cannulated screws. (B) Hemiarthroplasty. (C) Total hip arthroplasty.
The hip replacement may be implanted using different surgical approaches. Commonly used approaches include the posterolateral, the anterolateral, and the anterior approaches. There is no overall consensus as to the best approach for hip replacement. Each approach has a different risk and benefit profile. The posterolateral approach has a slightly higher rate of dislocation, whereas the anterolateral approach results in a slightly higher rate of limp, because of damage to the hip abductor muscles.25–27 More recently, the anterior approaches have become more popular. The most important factor in determining approach is the experience of the surgeon. Patients with a very high dislocation risk (ie, those with contracture or neurologic disorders) may have lower dislocation rates with anterior or anterolateral approaches (Table 1).
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Table 1 Advantages and disadvantages of the 3 surgical approaches to arthroplasty Approach
Advantage
Disadvantage
Posterolateral
No abductor damage (low limp) Extensile
Higher dislocation risk
Anterolateral
Low dislocation risk
Possible abductor damage (higher limp)
Anterior
Low dislocation risk Low limp risk
More difficult Requires fluoroscopy
The decision-making process when selecting an arthroplasty involves consideration of:
Surgical approach Cemented versus uncemented femoral component Hemiarthroplasty versus total hip arthroplasty If hemiarthroplasty, unipolar versus bipolar
Overall results for patients with displaced fractures have been shown to be better with arthroplasty than with internal fixation, primarily because the former is associated with fewer reoperations (approximately a 40% chance of requiring reoperation13). Common reasons for failure are nonunion or osteonecrosis with delayed need for hip arthroplasty. Because older patients do not tolerate repeat surgery well, arthroplasty is believed to be a better option for most geriatric patients with femoral neck fracture. This finding leads to 1 common algorithm for surgery: stable or nondisplaced fractures are treated with internal fixation, whereas displaced fractures are treated with arthroplasty, that is, hemiarthroplasty for most patients and total arthroplasty for those who are very active and functional (Fig. 4).28 Intertrochanteric Fractures
Intertrochanteric fractures are extracapsular and account for approximately 45% of fractures.4,5 These fractures have been classified using several different systems based on the position of the fracture and the amount of fracture fragmentation (comminution). The most common system used is the AO Foundation (AO)/Orthopaedic
Fig. 4. Algorithm for the treatment of femoral neck fractures.
Approaches to Hip Fractures for Nonsurgeons
Trauma Association (OTA) system.29 This system uses both comminution and fracture position. Overall, fractures can be divided into those that are more stable and those that are less stable. This type of classification then can drive treatment algorithms. In general, fractures with an intact lateral wall and calcar are stable (AO/OTA 31-A1.1, A1.2, A1.3, and A2.1), whereas fractures with more comminution and an unstable lateral wall are unstable (AO/OTA 31-A2.2, A2.3, A3.1, A3.2, and A3.3) (Fig. 5). Fracture Stability Stable Intact lateral buttress Few pieces (no comminution) Unstable Lateral buttress is fractured Many pieces (comminution) Reverse oblique pattern Subtrochanteric fractures Two main surgical procedures are used for these fractures. One is called the sliding hip screw (SHS) with side plate. With this procedure, the fracture is reduced under fluoroscopy with traction, and then a guide wire is inserted across the fracture into the center of the femoral head. The screw is placed over the guide wire, and the plate is attached to the side of the femur. The screw is thus able to slide within the barrel of the plate, which permits fracture compression, aiding in fracture fixation (Fig. 6A). This device has been widely adopted and is successful.30 The SHS is successful for fractures that have a solid buttress against which the femoral headpiece can slide. However, some fracture patterns lack this stability. One particularly unstable pattern is called the reverse oblique pattern. In this pattern, the plate does not provide a stop point for sliding, and failure rates are higher.31 In this case, all of the pressure of walking is placed on the interface of the plate with the bone, which fails with time (Fig. 6B). Sometimes, fracture stability can be difficult to determine or can change intraoperatively. It is important that the lateral wall is intact for the SHS to work well.32,33 The other type of device used for intertrochanteric fractures is the intramedullary hip screw (IMHS). With this device, the fixation on the shaft side of the fracture is placed within the bone. First, the fracture is reduced, and then, an intramedullary nail is placed
Fig. 5. Anteroposterior radiographs showing stable (A) and unstable (B) intertrochanteric fractures.
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Fig. 6. Anteroposterior radiographs showing treatment options and biomechanics for intertrochanteric fractures. (A) SHS in a stable fracture. The arrow shows the vector of force during standing. With the lateral cortex intact, the fracture can stably impact as the screw slides within the barrel of the plate. (B) SHS in an unstable fracture. In this reverse oblique pattern, the plate cannot resist the sliding force in the direction of the arrow, and the device fails before fracture healing. (C) IMHS in an unstable fracture. The fracture impacts along the path indicated by the arrow, and the nail itself acts as a limitation to the sliding of the screw.
within the femur. It is typically inserted by making a hole in the greater trochanter. After the nail is placed in the bone, the hip screw is then placed through a hole in the nail. In general, more unstable fractures are probably best treated with an intramedullary device. The nail of the device acts as a stop point for the sliding of the screw (Fig. 6C). Controversy exists as to which fracture should be treated with which device.30 Overall, the SHS has been successful and is less expensive than the IMHS. Despite these findings, the rate of usage of the IMHS has steadily increased over the past 10 years.34
Approaches to Hip Fractures for Nonsurgeons
Some of this increase is the result of changes in design features of the IMHS. Initial designs had a propensity toward fracture at the distal end of the device.35,36 This problem has largely been solved. Some surgeons use the IMHS for all intertrochanteric fractures, which permits less inventory in the operating room. It also protects the surgeon if the fracture pattern has been misjudged. Sometimes, it is possible to miss fracture lines that make the fracture more unstable than was initially appreciated.37 The rates of success for the SHS and IMHS have been shown to be related to the positioning of the hip screw within the femoral head.38 The screw needs good purchase within the bone of the femoral head. If it does not gain purchase, the screw migrates and cuts out into the acetabulum. Then, the construct must be revised to a total hip replacement, which is a complex procedure. The screw should be centrally and deeply placed in the femoral head. A useful marker for this location is called the tipapex distance. The distance between the end of the screw and the tip of the femoral head is measured on anteroposterior and lateral views of the hip. These measurements are added. A long measurement gives poorer fixation. For example, if the distance is greater than 24 mm, the rate of failure of the fracture to heal is significantly higher.39 In another study, in which surgeons consciously measured this distance and made sure it was less than 24 mm, outcomes were significantly better.40 The tip-apex distance is also believed to be important for the IMHS.41 Other treatments are rarely used for intertrochanteric fractures. Arthroplasty can be considered, but it is technically difficult. Although a femoral neck fracture leads to an easy hip replacement, the location of the intertrochanteric fracture is further down the femur and involves the greater and lesser trochanters, which means that there is less bone in which to insert the femoral component and may mean that a revision style implant must be used. The trochanter may also have to be repaired and anchored to the remainder of the femur. Overall, these factors make arthroplasty for intertrochanteric fractures more difficult than when it is used for a femoral neck fracture. However, there are times when arthroplasty may be the best solution for an intertrochanteric fracture. One such situation is the presence of preexisting arthritis in the hip joint. The replacement then repairs the fracture and solves the problem of the arthritic joint rather than staging a repair and subsequently replacing the hip. Subtrochanteric Fractures
Subtrochanteric fractures are the least common type, accounting for approximately 10% of fractures,5,42 and are located below the lesser trochanter, in the top part of the femoral shaft. These fractures can be difficult to treat, because the psoas muscle pulls on the lesser trochanter, which flexes the proximal piece of bone. Reduction can be difficult, and these fractures may need to be further surgically exposed to reduce the fracture fragments. They are treated with IMHS. Fractures may be classified as typical or atypical. Typical fractures result from falls. Atypical fractures have now become widely recognized and are associated with bisphosphonate use.43 They begin as a stress fracture, usually on the lateral wall of the femur in the subtrochanteric or midshaft region. The bone thickens as a result of poor turnover. A stress fracture develops and is seen as a black line in the thickened area of femur (Fig. 7). The stress fracture is susceptible to full fracture with minimal force. If a stress fracture is seen and is painful, careful consideration should be given to prophylactic treatment with an IMHS to prevent full fracture.44 Nonoperative treatment often leads to complete fracture. In general, treatment with IMHS is successful, although healing may take longer.45
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Fig. 7. Anteroposterior radiograph showing an atypical subtrochanteric fracture. The arrow points to the area of bone hypertrophy on the lateral cortex.
SUMMARY
Some appreciation for the types of hip fracture and treatment mechanisms is useful to the nonsurgeon. Surgeons treat fractures by the type of fracture and patient. Femoral neck fractures are treated with internal fixation or arthroplasty, depending on the stability of the fracture. Unstable fractures are best treated with arthroplasty; if the patient is very active, treatment should be a total hip replacement. Intertrochanteric fractures are treated with SHS or IMHS, depending on the stability of the fracture. Unstable intertrochanteric fractures and all subtrochanteric fractures should be treated with IMHS. REFERENCES
1. Friedman SM, Mendelson DA, Kates SL, et al. Geriatric co-management of proximal femur fractures: total quality management and protocol-driven care result in better outcomes for a frail patient population. J Am Geriatr Soc 2008;56(7): 1349–56. 2. Kates SL, Mendelson DA, Friedman SM. Co-managed care for fragility hip fractures (Rochester model). Osteoporos Int 2010;21(Suppl 4):S621–5. 3. Dorr LD, Faugere MC, Mackel AM, et al. Structural and cellular assessment of bone quality of proximal femur. Bone 1993;14(3):231–42. 4. Lofman O, Berglund K, Larsson L, et al. Changes in hip fracture epidemiology: redistribution between ages, genders and fracture types. Osteoporos Int 2002; 13(1):18–25.
Approaches to Hip Fractures for Nonsurgeons
5. Zuckerman JD. Hip fracture. N Engl J Med 1996;334(23):1519–25. 6. Garden RS. Low-angle fixation in fractures of the femoral neck. J Bone Joint Surg Br 1961;43(4):647–63. 7. Van Embden D, Rhemrev SJ, Genelin F, et al. The reliability of a simplified Garden classification for intracapsular hip fractures. Orthop Traumatol Surg Res 2012; 98(4):405–8. 8. Clement ND, Green K, Murray N, et al. Undisplaced intracapsular hip fractures in the elderly: predicting fixation failure and mortality. A prospective study of 162 patients. J Orthop Sci 2013;18(4):578–85. 9. Gautier E, Ganz K, Krugel N, et al. Anatomy of the medial femoral circumflex artery and its surgical implications. J Bone Joint Surg Br 2000;82(5):679–83. 10. Avery PP, Baker RP, Walton MJ, et al. Total hip replacement and hemiarthroplasty in mobile, independent patients with a displaced intracapsular fracture of the femoral neck: a seven- to ten-year follow-up report of a prospective randomised controlled trial. J Bone Joint Surg Br 2011;93(8):1045–8. 11. Blomfeldt R, Tornkvist H, Ponzer S, et al. Comparison of internal fixation with total hip replacement for displaced femoral neck fractures. Randomized, controlled trial performed at four years. J Bone Joint Surg Am 2005;87(8):1680–8. 12. Chammout GK, Mukka SS, Carlsson T, et al. Total hip replacement versus open reduction and internal fixation of displaced femoral neck fractures: a randomized long-term follow-up study. J Bone Joint Surg Am 2012;94(21):1921–8. 13. Leonardsson O, Sernbo I, Carlsson A, et al. Long-term follow-up of replacement compared with internal fixation for displaced femoral neck fractures: results at ten years in a randomised study of 450 patients. J Bone Joint Surg Br 2010;92(3): 406–12. 14. Rogmark C, Johnell O. Primary arthroplasty is better than internal fixation of displaced femoral neck fractures: a meta-analysis of 14 randomized studies with 2,289 patients. Acta Orthop 2006;77(3):359–67. 15. Ong BC, Maurer SG, Aharonoff GB, et al. Unipolar versus bipolar hemiarthroplasty: functional outcome after femoral neck fracture at a minimum of thirty-six months of follow-up. J Orthop Trauma 2002;16(5):317–22. 16. Blomfeldt R, Tornkvist H, Eriksson K, et al. A randomised controlled trial comparing bipolar hemiarthroplasty with total hip replacement for displaced intracapsular fractures of the femoral neck in elderly patients. J Bone Joint Surg Br 2007;89(2):160–5. 17. Hedbeck CJ, Enocson A, Lapidus G, et al. Comparison of bipolar hemiarthroplasty with total hip arthroplasty for displaced femoral neck fractures: a concise four-year follow-up of a randomized trial. J Bone Joint Surg Am 2011;93(5): 445–50. 18. Poignard A, Bouhou M, Pidet O, et al. High dislocation cumulative risk in THA versus hemiarthroplasty for fractures. Clin Orthop Relat Res 2011;469(11): 3148–53. 19. Emery RJH, Broughton NS, Desai K, et al. Bipolar hemiarthroplasty for subcapital fracture of the femoral neck. A prospective randomised trial of cemented Thompson and uncemented Moore stems. J Bone Joint Surg Br 1991;73(2):322–4. 20. Parker MJ, Gurusamy K. Arthroplasties (with and without bone cement) for proximal femoral fractures in adults. Cochrane Database Syst Rev 2006;(3):CD001706. 21. Gjertsen JE, Lie SA, Vinje T, et al. More re-operations after uncemented than cemented hemiarthroplasty used in the treatment of displaced fractures of the femoral neck: an observational study of 11,116 hemiarthroplasties from a national register. J Bone Joint Surg Br 2012;94(8):1113–9.
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22. Leonardsson O, Karrholm J, Akesson K, et al. Higher risk of reoperation for bipolar and uncemented hemiarthroplasty. 23,509 procedures after femoral neck fractures from the Swedish Hip Arthroplasty Register, 2005–2010. Acta Orthop 2012; 83(5):459–66. 23. Taylor F, Wright M, Zhu M. Hemiarthroplasty of the hip with and without cement: a randomized clinical trial. J Bone Joint Surg Am 2012;94(7):577–83. 24. Viberg B, Overgaard S, Lauritsen J, et al. Lower reoperation rate for cemented hemiarthroplasty than for uncemented hemiarthroplasty and internal fixation following femoral neck fracture: 12- to 19-year follow-up of patients aged 75 years or more. Acta Orthop 2013;84(3):254–9. 25. Hailer NP, Weiss RJ, Stark A, et al. The risk of revision due to dislocation after total hip arthroplasty depends on surgical approach, femoral head size, sex, and primary diagnosis. An analysis of 78,098 operations in the Swedish Hip Arthroplasty Register. Acta Orthop 2012;83(5):442–8. 26. Jolles BM, Bogoch ER. Posterior versus lateral surgical approach for total hip arthroplasty in adults with osteoarthritis. Cochrane Database Syst Rev 2006;(3):CD003828. 27. Mulliken BD, Rorabeck CH, Bourne RB, et al. A modified direct lateral approach in total hip arthroplasty: a comprehensive review. J Arthroplasty 1998;13(7): 737–47. 28. Callaghan JJ, Liu SS, Haidukewych GJ. Subcapital fractures: a changing paradigm. J Bone Joint Surg Br 2012;94(11 Suppl A):19–21. 29. Marsh JL, Slongo TF, Agel J, et al. Fracture and dislocation classification compendium–2007: Orthopaedic Trauma Association classification, database and outcomes committee. J Orthop Trauma 2007;21(Suppl 10):S1–133. 30. Parker MJ, Handoll HHG. Gamma and other cephalocondylic intramedullary nails versus extramedullary implants for extracapsular hip fractures in adults (review). Cochrane Database Syst Rev 2010;(9):CD000093. 31. Haidukewych GJ, Israel TA, Berry DJ. Reverse obliquity fractures of the intertrochanteric region of the femur. J Bone Joint Surg Am 2001;83(5):643–50. 32. De Bruijn K, den Hartog D, Tuinebreijer W, et al. Reliability of predictors for screw cutout in intertrochanteric hip fractures. J Bone Joint Surg Am 2012;94(14): 1266–72. 33. Hsu CE, Shih CM, Wang CC, et al. Lateral femoral wall thickness: a reliable predictor of post-operative lateral wall fracture in intertrochanteric fractures. Bone Joint J 2013;95(8):1134–8. 34. Anglen JO, Weinstein JN. Nail or plate fixation of intertrochanteric hip fractures: changing pattern of practice. A review of the American Board of Orthopaedic Surgery Database. J Bone Joint Surg Am 2008;90(4):700–7. 35. Norris R, Bhattacharjee D, Parker MJ. Occurrence of secondary fracture around intramedullary nails used for trochanteric hip fractures: a systematic review of 13,568 patients. Injury 2012;43(6):706–11. 36. Osnes EK, Lofthus CM, Falch JA, et al. More postoperative femoral fractures with the Gamma nail than the sliding screw plate in the treatment of trochanteric fractures. Acta Orthop Scand 2001;72(3):252–6. 37. Palm H, Jacobsen S, Sonne-Holm S, et al. Integrity of the lateral femoral wall in intertrochanteric hip fractures: an important predictor of a reoperation. J Bone Joint Surg Am 2007;89(3):470–5. 38. Rubio-Avila J, Madden K, Simunovic N, et al. Tip to apex distance in femoral intertrochanteric fractures: a systematic review. J Orthop Sci 2013;18(4): 592–8.
Approaches to Hip Fractures for Nonsurgeons
39. Baumgaertner MR, Curtin SL, Lindskog DM, et al. The value of the tip-apex distance in predicting failure of fixation of peritrochanteric fractures of the hip. J Bone Joint Surg Am 1995;77(7):1058–64. 40. Baumgaertner MR, Solberg BD. Awareness of tip-apex distance reduces failure of fixation of trochanteric fractures of the hip. J Bone Joint Surg Br 1997;79(6): 969–71. 41. Kuzyk PR, Zdero R, Shah S, et al. Femoral head lag screw position for cephalomedullary nails: a biomechanical analysis. J Orthop Trauma 2012;26(7):414–21. 42. Napoli N, Schwartz AV, Palermo L, et al. Risk factors for subtrochanteric and diaphyseal fractures: the study of osteoporotic fractures. J Clin Endocrinol Metab 2013;98(2):659–67. 43. Shane E, Burr D, Ebeling PR, et al. Atypical subtrochanteric and diaphyseal femoral fractures: report of a task force of the American Society for Bone and Mineral Research. J Bone Miner Res 2010;25(11):2267–94. 44. Banffy MB, Vrahas MS, Ready JE, et al. Nonoperative versus prophylactic treatment of bisphosphonate-associated femoral stress fractures. Clin Orthop Relat Res 2011;469(7):2028–34. 45. Egol KA, Park JH, Rosenberg ZS, et al. Healing delayed but generally reliable after bisphosphonate-associated complete femur fractures treated with IM nails. Clin Orthop Relat Res 2013. [Epub ahead of print].
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