Experience With a Modified Posterior Approach to t h e Hip Joint A Technical Note
J a m e s A. S h a w , M D
Abstract: A modified posterior approach to tile hip joint is described with particular applicability to revision or complex primary hip anhroplasty. The procedure involves oste6tomy of the posterior one-third of the greater trochanter with posterior reflection of a full-thickness flap, consisting of the posterior trochanteric fragment, short external rotators, joint capsule, and posterior portion of the gluteus medius. The approach allows for excellent exposure of the acetabulum and femoral canal, with minimal disruption of the gluteal muscle insertions. The majority of the greater trochantcr is left intact, enhancing femoral component stability. Closure is accomplished by suture of soft tissues and reattachment of the posterior trochanteric fragment with bone screws. An intact soft tissue envelope is thereby restored around the prosthetic components. A limited clinic series has identified no problem referable to this exposure. No loss of reduction or nonunion has been encountered. Key words: hip joint, surgical approaches, trochanteric osteotomy, revision anhroplasty.
Exposure of the hip joint during revision or complex primary total hip arthroplasty may be difficult. An unobstructed view of both the acetabulum and proximal femur are essential, yet, distorted anatomy, dense scar tissue, and obliteration of anatomical planes frequently make dissection difficult, hazardous, and time-consuming. Standard surgical approaches made anterior or p ~ t e r i o r to the femoral neck provide ready access to either the acetabhlum or femur, but not both (2, 9, 12). Combined approaches (11, 12) may improve exposure, but require extensive soft tissue dissection. Release of mus-
cle insertions (7, 13) may weaken gluteal power or compromise hip stability (14). Removal of the greater trochanter facilitates exposure, but reattachment may be frustrating (particularly in revision cases), and failure of fixation, nonunion, limp, and pain are c o m m o n sequellae (1, 3, 5, 6, 8). Moreover, an intact greater trochanter is important for femoral c o m p o n e n t stability. It provides an area for component bone interdigitation, affording rotary stability as well as a potential site for bony ingrowth. Described below is a modified posterior approach to the hip joint, which, in my experience, has proven very useful in revision hip surgery and complex primary cases. This approach, first introduced by Iyer (10), provides an excellent exposure of the acetabulum and femoral shaft, while eliminating m a n y of tile problems associated with other techniques.
From the DMsion of Orthopaedic Surgery, The Milton S. ttershey Medical Center of the Pennsylvania State University Collegeof Medicine, llershey, Pennsylvania. Reprint requests: James A. Shaw, MD, Division of Orthopaedic SurgeD', The Milton S. ttershey M~dical Center, P.O. Box 850, ltershey, PA 17033.
11
12 The Journal of Arthroplasty Vol. 6 No. 1 March 1991
Surgical Technique The patient is positioned o n the operating table in a lateral decubitus position with the involved side up. Bolsters are positioned to securely stabilize the patient, and an axillary roll is placed. After appropriate skin preparation and draping, the hip is approached through a midlateral longitudinal skin incision, curving gently posteriorly at the level of the greater trochanter (Fig. 1). The incision may have to be modified slightly to accommodate previous surgical scars, but I have not encountered difficulty incorporating the distal one-half of a previously existing posterolateral or anterolateral incision. The fascia latae and fascia of the gluteus maximus are split in the direction of the skin incision and re-
tracted. In revision cases the fascia lata may be quite adherent to underlying tissue, and the soft tissue interval overlying the vastus lateralis m a y have to be developed sharply to facilitate retraction and exposure. Partial release of the gluteus maximus insertion may also be helpful. Exposed at this time is the greater trochanter with attached gluteus medius and minimus, proximally; short external rotators, posteriorly; and vastus lateralis, distally (Fig. 2). The greater trochanter is carefully palpated for landmarks, and the posterior one-third osteotomized with an oscillatry saw, as shown in Figure 3.
/
Fig. 1. Line drawing depicting the skin incision used during the described approach to the hip joint. The superficial anatomy is shown, consisting of the gluteus maximus posteriorly; the tensor fascia.latae anteriorly; and the fascia latae, centrally.
Fig. 2. Line drawing depicting the deep anatomy exposed after division of the fascia latae and retraction of the gluteus maximus and tensor fascia latae. Exposed is the greater trochanter with attached gluteus medius and minimus, proximally; short extemal rotators, posteriorly; and vastus lateralis, distally. The line of osteotomy of the greater trochanter and splinting incision through the gluteus medius is shown.
Modified Posterior Approach to the Hip Joint
9 Shaw
13
\ '
t
J
Fig. 3. (A) Model depicting the described trochanteric osteotomy extending from the tip of the trochanter to the lateral trochanteric ridge with an oblique posterior extension directed toward the calcar. (B) Same model illustrating the completed trochanteric osteotomy with representative exposure of the femoral component and resulting broad osteotomy surfaces for reattachment.
The trochanteric osteotomy is made with two cuts. The first is a vertical cut extending from the tip of the trochanter to the level of the lateral trochanteric ridge. The second portion is made at an obtuse angle with respect to the vertical cut and is directed slightly proximally in a compound miter fashion toward the calcar or medial flange of the femoral prosthesis. This allows for broad reattachment surfaces and, at the same time, minimally compromises the strength of the remaining trochanter (Fig. 3B). Soft tissues should be divide'~ along the line of the osteotomy prior to making the bony cuts so that they can be surgically repaired at completion of the procedure. The gluteus medius and superior capsule are split proximally in line with the vertical portion of the osteotomy, using a Bovie cutting system or scalpal {Fig. 2). Care must be taken not to extend the incision too far proximally for fear of damaging the superior gluteal artery and nerve, which lie in the internal between the gluteus medius and minimus.
A measure of 4 cm proximal to the superior edge of the acetabulum represents a safe interval according to Foster (4). A flap is thus created, consisting of the posterior one-third of the greater trochanter, posterior capsule, short external rotators, and posterior portion of the gluteus medius (Fig. 4). The entire flap is developed posteriorly off the proximal femur, with progressive internal rotation of the femur to the level of the lesser trochanter. Occasionally the psoas muscle insertion must be released from the lesser trochanter, but this can be done in continuity with the developed flap with minimal loss of function. Similarly (and simultaneously) the flap is developed off the acetabulum superiorly and posteriorly. At this time the femoral component (or femoral head) can be dislocated into the wound with internal rotation of the femur, and removed. With the posterior one-third of the greater trochanter reflected posteriorly, exposure to the femoral neck and shaft,
14
The Journal of Arthroplasty Vol. 6 No. 1 March 1991
Fig. 4. Line drawing depicting posterior reflection of the posterior trochanteric fragment with attached short external rotators, posterior capsule, and posterior portion of the gluteus medius. The insert depicts reattachment of the osteotomized fragment with bone screws.
for extraction of any remaining cement mantle and subsequent reaming of the medullary canal, is excellent. If the acetabular component is to be revised, further anterior exposure will generally be needed. This can be done in a safe fashion by progressively elevating the anterior capsule off the acetabular rim from the inside out until the required exposure is realized. Altematively, a routine anterior capsulotomy can be performed by developing the interval 9 between the capsule and the glutus minimus superiorly, and the capsule and rectus femoris and iliopsoas anteriorly. This is done in identical fashion to a standard posterior approach, but with the advantage of starting the dissection superiorly on the acetabulum, rather than posteriorly. The soft tissue interval between capsule and overlying muscle is more readily visualized, minimizing blind dissection. A complete capsulectomy has not been needed in my experience. Revision of the acetabular component is done in routine fashion. Great care should be taken throughout the pro.cedure to avoid breaking off the remaining anterior two-thirds of the greater trochanter, since this would disrupt the gluteal insertion and defeat the whole purpose of this exposure. To this end, saw cuts should be carefully made and not overlapped at their intersection. Retraction on the greater trochanter should be avoided and .great care taken during broaching of the proximal femur.
After insertion of the prosthetic components, the wound is closed by reapproximating the posterior soft tissue and bony flap to the greater trochanter. I have generally used one or two cancellous screws (with washers) placed from posterior to anterior and angled slightly distally (Figs. 5, 6). Maximal purchase is best achieved with the screws placed quite superficially (laterally) in the greater trochanter. In obese patients, angled drills and screw drivers are helpful. Alternatively, mersilene tape or wire can be used if screw purchase proves inadequate or insertion difficult. The posterior bony fragment may have to be hollowed out slightly to allow for anatomical fit over the revision femoral stem. If the femur and greater trochanter have been significantly lateralized with the insertion of new components, some difficulty may be encountered in reapproximating the posterior fragment back to the greater trochanter in anatomical fashion. Sequential thinning and/or release of the posterior capsule (much like a lateral release in the knee), without division of the short external rotators, has been universally successful in my experience. Attention
5 ?
,
\ N
.........
i
9
...............
J
Fig. 5. Model illustrating reattachment of the posterior trochanteric fragment with bone screws.
Modified Posterior Approach to the Hip Joint
9 Shaw
15
and superolateral acetabular bone stock loss, and three with posttraumatic arthritis following open reduction-internal fixation of acetabular fractures. Eight additional patients with a minimum of 6 months of follow-up study have been handled using this approach. There h a v e been no complications related to this exposure. Specifically, there has been no loss of trochanteric fragment reduction, no obvious nonunion~ no clinically apparent loss ofgluteal muscle function, no femoral or sciatic nerve palsies, no trochanteric fractures, and no prosthetic hip dislocations.
Case 1
Fig. 6. Clinical example showing a reapproximated posterior trochanteric fragment and attached soft tissue flap with two lag screws. The posterior gluteus medius interval and underlying joint capsule have been closed with suture. Closure has restored an intact soft tissue envelope around the prosthetic hip joint.
should, of course, be paid to neck length and femoral component offset in preoperative planning. The superior capsule is then closed with heavy suture, as are the gluteal interval and fascia over the greater trochanter. Superficial layers are closed over drains in routine fashion.
Clinical Correlation The modified posterior approach to the hip joint described in this manuscript has been used in the author's practice on 13 patients with 12 or more months of follow-up study. Eight cases were revisions of loOse cemented hip prostheses. Five cases were primary anhroplasties--,-one being a CDH patient, another a patient with a dysplastic acetabulum
The first patient is a 66-year-old man who presented 6 years after cemented right total hip arthroplasty with progressive pain and disability referable to the prosthetic hip joint. Radiographic evaluation revealed obvious loosening of the cemented femoral component with interval subsidence (Fig. 7A). The acetabular component appeared to be stable without interval change. An anterolateral approach had been used for the original surgery. Revision of the femoral component was undertaken using the modified posterior approach described above. A long-stemmed revision component was used. Allograft bone was utilized to fill defects in the trochanteric region and femoral shaft. A radiograph taken 12 months after operation is shown in Figure 7B. At 18 postoperative months, the patient notes minimal limp and no pain.
Case 2 The second patient is a 27-year-ol d man who was involved in an industrial accident, sustaining bilateral acetabular fractures with central protrusion of both femoral heads, tie underwent open reduction and internal fixation of both acetabuli with near anatomical restoration of bony anatomy. Posttraumatic arthritis became disabling in the right hip approximately 2 years after injury (Fig. 8A). He underwent primary total hip arthroplasty using the modified posterior approach (Fig. 8B). Dense scar tissue was present on both sides of hip joint due to the es exposure needed to internally fix both columns and the posterior wall. The modified posterior approach allowed excellent visualization of the acetabulum with sufficient exposure to remove obstructing hardware. At 12 postoperative
16
The Journal of Arthroplasty Vol. 6 No. 1 March 1991
j
Fig. 7. (A) Preoperative radiograph showing a loose femoral component, as evidenced by component subsidence and a lucent cement-prosthesis interval. The large cement mass within the greater trochanter may have created problems with trochanteric attachment and union if a conventional trochanteric osteotomy had been performed. (B) Radiograph taken 12 months after operation showing a revision femoral component in place. The posterior trochanteric osteotomy has been secured with one bone screw and soft tissue suture. There is no loss of reduction or failure of fixation. Allograft bone appears to be incorporating in the trochanteric region. months, the patient shows an excellent clinical resuit.
Discussion The modified posterior'approach, described above, has several distinct advantages. First and foremost, it allows for excellent exposure of both the acetabulum and f e m u r without dissection through scarred anterior or posterior soft tissue planes or forceful retraction on adherent tissues. The potential for d a m age to the sciatic or femoral nerves or femoral vessels is thereby lessened. The plane of dissection is fundamentally within the borders of the acetabulum and is therefore inherently "safe".
Second, muscle insertions are minimally disturbed, with obvious advantages to postoperative function. Third, the majority of the greater trochanter is left attached to the femoral shaft, enhancing femoral c o m p o n e n t stability while eliminating concerns over trochanteric fixation. Finally, the closure restores hip stability. The short external rotator insertions are undisturbed. An intact and essentially u n compromised envelope of tissue remains around the prosthetic hip joint. The seal is almost hermetic. I have not encountered any problems with failure of fixation or n o n u n i o n of the posterior trochanteric fragment, a s evidenced by loss of reduction on AP or lateral radiographs, in m y limited series. Since only a small portion of the gluteus medius pulls on the detached portion of the greater trochanter and a strong and effective soft tissue closure can be accom-
Modified Posterior Approach to the Hip Joint
9 Shaw
17
Fig. 8. (A) Preoperative radiograph showing internal fixation of a right acetabulum fracture (similar internal fixation was also done on the left acetabulum) and advanced arthritic changes in the right hip. (B) Radiograph taken 6 months after operation showing a stable trochanteric osteotomy secured with two bone screws.
plished through reapproximation of its split tendenous insertion (even in the face of suboptimal bony fixation), I suspect the functional disability would be minimal even if a nonunion were to occur. This is in contradistinction to the marked gluteal lerch that results with failure of fixation and proximal migration of the entire greater trochanter. In summary, the modified posterior approach provides a safe and effective method of exposing the hip joint with minimal compromise of muscle insertions and a stable means of closure. It represents a tiseful addition to the armamentarium of the hip surgeon.
References Amstutz tIC, Maki S: Complication of trochanteric osteotomy in total hip replacement. J Bone Joint Surg 60A:214, 1978
2. Calandrnccio RA: Arthroplasty of the hip. p. 1213. In: Campbell's Operative Orthopaedics 7th ed. Crenshaw, A. H. (ed) C.V. Mosby Company, St. Louis, 1987 3. Clark RP, Shea WD, Bierbaum BE: Trochanteric os-, teotomy: analysis of pattern of wire fixation failure and complications. Clin Orthop 141i102, 1979 4. Foster DE, Hunter JR: The direct lateral approach to the hip for arthroplasty: advantages and complications. Orthopaedics 10:274, 1987 5. Glover MG, Convery FR: Migration of fractured greater trochanteric osteotomy wire with resultant sciatica: a report of two cases. Orthopaedics 12:743, 1989 6". Gottschalk FA, Morein G, Weber F: Effect of the position of the greater trochanter on the rate of union after trochanteric osteotomy for total hip arthroplasty. J Arthroplasty 3:235, 1988 7. Hardinge K: The direct lateral approach to the hip. J Bone Joint Surg 64B:17, 1982 8. Harris Wtt: Advances in surgical technique for total hip replacement: without and with osteotomy of the greater trochanter. Clin Orthop 146:188, 1980
18
The Journal of Arthroplasty Vol. 6 No. 1 March 1991
9. Hoppenfeld S, deBoer P: Surgical exposures in orthopaedics: the Anatomic Approach. J.B. Lippincott, Philadelphia, 1984 10. Iyer KM: A new posterior approach to the hip joint. Injury 13:76, 1981 11. Krackow KA, Steinman H, Cohn BT, Jones LC: Clinical experience with a triradiate exposure of the hip for difficult total hip arthroplasty. J Arthroplasty 3:267, 1988
12. Lusskin R, Goldman A, Absatz M: Combined anferior and posterior approach to the hip joint in reconstructive and complex arthroplasty. J Arthroplasty 3:313, 1988 13. McFarland B, Osborn G: Approach to the hip: a suggested improvement on Kocher's method. J Bone Joint Surg 36B:364, 1959 14. Woo RYG, Morrey BF: Dislocations after total hip arthroplasty. J Bone Joint Surg 64A: 1295, 1982
J a m e s A. S h a w , M D
Abstract: A modified posterior approach to tile hip joint is described with particular applicability to revision or complex primary hip anhroplasty. The procedure involves oste6tomy of the posterior one-third of the greater trochanter with posterior reflection of a full-thickness flap, consisting of the posterior trochanteric fragment, short external rotators, joint capsule, and posterior portion of the gluteus medius. The approach allows for excellent exposure of the acetabulum and femoral canal, with minimal disruption of the gluteal muscle insertions. The majority of the greater trochantcr is left intact, enhancing femoral component stability. Closure is accomplished by suture of soft tissues and reattachment of the posterior trochanteric fragment with bone screws. An intact soft tissue envelope is thereby restored around the prosthetic components. A limited clinic series has identified no problem referable to this exposure. No loss of reduction or nonunion has been encountered. Key words: hip joint, surgical approaches, trochanteric osteotomy, revision anhroplasty.
Exposure of the hip joint during revision or complex primary total hip arthroplasty may be difficult. An unobstructed view of both the acetabulum and proximal femur are essential, yet, distorted anatomy, dense scar tissue, and obliteration of anatomical planes frequently make dissection difficult, hazardous, and time-consuming. Standard surgical approaches made anterior or p ~ t e r i o r to the femoral neck provide ready access to either the acetabhlum or femur, but not both (2, 9, 12). Combined approaches (11, 12) may improve exposure, but require extensive soft tissue dissection. Release of mus-
cle insertions (7, 13) may weaken gluteal power or compromise hip stability (14). Removal of the greater trochanter facilitates exposure, but reattachment may be frustrating (particularly in revision cases), and failure of fixation, nonunion, limp, and pain are c o m m o n sequellae (1, 3, 5, 6, 8). Moreover, an intact greater trochanter is important for femoral c o m p o n e n t stability. It provides an area for component bone interdigitation, affording rotary stability as well as a potential site for bony ingrowth. Described below is a modified posterior approach to the hip joint, which, in my experience, has proven very useful in revision hip surgery and complex primary cases. This approach, first introduced by Iyer (10), provides an excellent exposure of the acetabulum and femoral shaft, while eliminating m a n y of tile problems associated with other techniques.
From the DMsion of Orthopaedic Surgery, The Milton S. ttershey Medical Center of the Pennsylvania State University Collegeof Medicine, llershey, Pennsylvania. Reprint requests: James A. Shaw, MD, Division of Orthopaedic SurgeD', The Milton S. ttershey M~dical Center, P.O. Box 850, ltershey, PA 17033.
11
12 The Journal of Arthroplasty Vol. 6 No. 1 March 1991
Surgical Technique The patient is positioned o n the operating table in a lateral decubitus position with the involved side up. Bolsters are positioned to securely stabilize the patient, and an axillary roll is placed. After appropriate skin preparation and draping, the hip is approached through a midlateral longitudinal skin incision, curving gently posteriorly at the level of the greater trochanter (Fig. 1). The incision may have to be modified slightly to accommodate previous surgical scars, but I have not encountered difficulty incorporating the distal one-half of a previously existing posterolateral or anterolateral incision. The fascia latae and fascia of the gluteus maximus are split in the direction of the skin incision and re-
tracted. In revision cases the fascia lata may be quite adherent to underlying tissue, and the soft tissue interval overlying the vastus lateralis m a y have to be developed sharply to facilitate retraction and exposure. Partial release of the gluteus maximus insertion may also be helpful. Exposed at this time is the greater trochanter with attached gluteus medius and minimus, proximally; short external rotators, posteriorly; and vastus lateralis, distally (Fig. 2). The greater trochanter is carefully palpated for landmarks, and the posterior one-third osteotomized with an oscillatry saw, as shown in Figure 3.
/
Fig. 1. Line drawing depicting the skin incision used during the described approach to the hip joint. The superficial anatomy is shown, consisting of the gluteus maximus posteriorly; the tensor fascia.latae anteriorly; and the fascia latae, centrally.
Fig. 2. Line drawing depicting the deep anatomy exposed after division of the fascia latae and retraction of the gluteus maximus and tensor fascia latae. Exposed is the greater trochanter with attached gluteus medius and minimus, proximally; short extemal rotators, posteriorly; and vastus lateralis, distally. The line of osteotomy of the greater trochanter and splinting incision through the gluteus medius is shown.
Modified Posterior Approach to the Hip Joint
9 Shaw
13
\ '
t
J
Fig. 3. (A) Model depicting the described trochanteric osteotomy extending from the tip of the trochanter to the lateral trochanteric ridge with an oblique posterior extension directed toward the calcar. (B) Same model illustrating the completed trochanteric osteotomy with representative exposure of the femoral component and resulting broad osteotomy surfaces for reattachment.
The trochanteric osteotomy is made with two cuts. The first is a vertical cut extending from the tip of the trochanter to the level of the lateral trochanteric ridge. The second portion is made at an obtuse angle with respect to the vertical cut and is directed slightly proximally in a compound miter fashion toward the calcar or medial flange of the femoral prosthesis. This allows for broad reattachment surfaces and, at the same time, minimally compromises the strength of the remaining trochanter (Fig. 3B). Soft tissues should be divide'~ along the line of the osteotomy prior to making the bony cuts so that they can be surgically repaired at completion of the procedure. The gluteus medius and superior capsule are split proximally in line with the vertical portion of the osteotomy, using a Bovie cutting system or scalpal {Fig. 2). Care must be taken not to extend the incision too far proximally for fear of damaging the superior gluteal artery and nerve, which lie in the internal between the gluteus medius and minimus.
A measure of 4 cm proximal to the superior edge of the acetabulum represents a safe interval according to Foster (4). A flap is thus created, consisting of the posterior one-third of the greater trochanter, posterior capsule, short external rotators, and posterior portion of the gluteus medius (Fig. 4). The entire flap is developed posteriorly off the proximal femur, with progressive internal rotation of the femur to the level of the lesser trochanter. Occasionally the psoas muscle insertion must be released from the lesser trochanter, but this can be done in continuity with the developed flap with minimal loss of function. Similarly (and simultaneously) the flap is developed off the acetabulum superiorly and posteriorly. At this time the femoral component (or femoral head) can be dislocated into the wound with internal rotation of the femur, and removed. With the posterior one-third of the greater trochanter reflected posteriorly, exposure to the femoral neck and shaft,
14
The Journal of Arthroplasty Vol. 6 No. 1 March 1991
Fig. 4. Line drawing depicting posterior reflection of the posterior trochanteric fragment with attached short external rotators, posterior capsule, and posterior portion of the gluteus medius. The insert depicts reattachment of the osteotomized fragment with bone screws.
for extraction of any remaining cement mantle and subsequent reaming of the medullary canal, is excellent. If the acetabular component is to be revised, further anterior exposure will generally be needed. This can be done in a safe fashion by progressively elevating the anterior capsule off the acetabular rim from the inside out until the required exposure is realized. Altematively, a routine anterior capsulotomy can be performed by developing the interval 9 between the capsule and the glutus minimus superiorly, and the capsule and rectus femoris and iliopsoas anteriorly. This is done in identical fashion to a standard posterior approach, but with the advantage of starting the dissection superiorly on the acetabulum, rather than posteriorly. The soft tissue interval between capsule and overlying muscle is more readily visualized, minimizing blind dissection. A complete capsulectomy has not been needed in my experience. Revision of the acetabular component is done in routine fashion. Great care should be taken throughout the pro.cedure to avoid breaking off the remaining anterior two-thirds of the greater trochanter, since this would disrupt the gluteal insertion and defeat the whole purpose of this exposure. To this end, saw cuts should be carefully made and not overlapped at their intersection. Retraction on the greater trochanter should be avoided and .great care taken during broaching of the proximal femur.
After insertion of the prosthetic components, the wound is closed by reapproximating the posterior soft tissue and bony flap to the greater trochanter. I have generally used one or two cancellous screws (with washers) placed from posterior to anterior and angled slightly distally (Figs. 5, 6). Maximal purchase is best achieved with the screws placed quite superficially (laterally) in the greater trochanter. In obese patients, angled drills and screw drivers are helpful. Alternatively, mersilene tape or wire can be used if screw purchase proves inadequate or insertion difficult. The posterior bony fragment may have to be hollowed out slightly to allow for anatomical fit over the revision femoral stem. If the femur and greater trochanter have been significantly lateralized with the insertion of new components, some difficulty may be encountered in reapproximating the posterior fragment back to the greater trochanter in anatomical fashion. Sequential thinning and/or release of the posterior capsule (much like a lateral release in the knee), without division of the short external rotators, has been universally successful in my experience. Attention
5 ?
,
\ N
.........
i
9
...............
J
Fig. 5. Model illustrating reattachment of the posterior trochanteric fragment with bone screws.
Modified Posterior Approach to the Hip Joint
9 Shaw
15
and superolateral acetabular bone stock loss, and three with posttraumatic arthritis following open reduction-internal fixation of acetabular fractures. Eight additional patients with a minimum of 6 months of follow-up study have been handled using this approach. There h a v e been no complications related to this exposure. Specifically, there has been no loss of trochanteric fragment reduction, no obvious nonunion~ no clinically apparent loss ofgluteal muscle function, no femoral or sciatic nerve palsies, no trochanteric fractures, and no prosthetic hip dislocations.
Case 1
Fig. 6. Clinical example showing a reapproximated posterior trochanteric fragment and attached soft tissue flap with two lag screws. The posterior gluteus medius interval and underlying joint capsule have been closed with suture. Closure has restored an intact soft tissue envelope around the prosthetic hip joint.
should, of course, be paid to neck length and femoral component offset in preoperative planning. The superior capsule is then closed with heavy suture, as are the gluteal interval and fascia over the greater trochanter. Superficial layers are closed over drains in routine fashion.
Clinical Correlation The modified posterior approach to the hip joint described in this manuscript has been used in the author's practice on 13 patients with 12 or more months of follow-up study. Eight cases were revisions of loOse cemented hip prostheses. Five cases were primary anhroplasties--,-one being a CDH patient, another a patient with a dysplastic acetabulum
The first patient is a 66-year-old man who presented 6 years after cemented right total hip arthroplasty with progressive pain and disability referable to the prosthetic hip joint. Radiographic evaluation revealed obvious loosening of the cemented femoral component with interval subsidence (Fig. 7A). The acetabular component appeared to be stable without interval change. An anterolateral approach had been used for the original surgery. Revision of the femoral component was undertaken using the modified posterior approach described above. A long-stemmed revision component was used. Allograft bone was utilized to fill defects in the trochanteric region and femoral shaft. A radiograph taken 12 months after operation is shown in Figure 7B. At 18 postoperative months, the patient notes minimal limp and no pain.
Case 2 The second patient is a 27-year-ol d man who was involved in an industrial accident, sustaining bilateral acetabular fractures with central protrusion of both femoral heads, tie underwent open reduction and internal fixation of both acetabuli with near anatomical restoration of bony anatomy. Posttraumatic arthritis became disabling in the right hip approximately 2 years after injury (Fig. 8A). He underwent primary total hip arthroplasty using the modified posterior approach (Fig. 8B). Dense scar tissue was present on both sides of hip joint due to the es exposure needed to internally fix both columns and the posterior wall. The modified posterior approach allowed excellent visualization of the acetabulum with sufficient exposure to remove obstructing hardware. At 12 postoperative
16
The Journal of Arthroplasty Vol. 6 No. 1 March 1991
j
Fig. 7. (A) Preoperative radiograph showing a loose femoral component, as evidenced by component subsidence and a lucent cement-prosthesis interval. The large cement mass within the greater trochanter may have created problems with trochanteric attachment and union if a conventional trochanteric osteotomy had been performed. (B) Radiograph taken 12 months after operation showing a revision femoral component in place. The posterior trochanteric osteotomy has been secured with one bone screw and soft tissue suture. There is no loss of reduction or failure of fixation. Allograft bone appears to be incorporating in the trochanteric region. months, the patient shows an excellent clinical resuit.
Discussion The modified posterior'approach, described above, has several distinct advantages. First and foremost, it allows for excellent exposure of both the acetabulum and f e m u r without dissection through scarred anterior or posterior soft tissue planes or forceful retraction on adherent tissues. The potential for d a m age to the sciatic or femoral nerves or femoral vessels is thereby lessened. The plane of dissection is fundamentally within the borders of the acetabulum and is therefore inherently "safe".
Second, muscle insertions are minimally disturbed, with obvious advantages to postoperative function. Third, the majority of the greater trochanter is left attached to the femoral shaft, enhancing femoral c o m p o n e n t stability while eliminating concerns over trochanteric fixation. Finally, the closure restores hip stability. The short external rotator insertions are undisturbed. An intact and essentially u n compromised envelope of tissue remains around the prosthetic hip joint. The seal is almost hermetic. I have not encountered any problems with failure of fixation or n o n u n i o n of the posterior trochanteric fragment, a s evidenced by loss of reduction on AP or lateral radiographs, in m y limited series. Since only a small portion of the gluteus medius pulls on the detached portion of the greater trochanter and a strong and effective soft tissue closure can be accom-
Modified Posterior Approach to the Hip Joint
9 Shaw
17
Fig. 8. (A) Preoperative radiograph showing internal fixation of a right acetabulum fracture (similar internal fixation was also done on the left acetabulum) and advanced arthritic changes in the right hip. (B) Radiograph taken 6 months after operation showing a stable trochanteric osteotomy secured with two bone screws.
plished through reapproximation of its split tendenous insertion (even in the face of suboptimal bony fixation), I suspect the functional disability would be minimal even if a nonunion were to occur. This is in contradistinction to the marked gluteal lerch that results with failure of fixation and proximal migration of the entire greater trochanter. In summary, the modified posterior approach provides a safe and effective method of exposing the hip joint with minimal compromise of muscle insertions and a stable means of closure. It represents a tiseful addition to the armamentarium of the hip surgeon.
References Amstutz tIC, Maki S: Complication of trochanteric osteotomy in total hip replacement. J Bone Joint Surg 60A:214, 1978
2. Calandrnccio RA: Arthroplasty of the hip. p. 1213. In: Campbell's Operative Orthopaedics 7th ed. Crenshaw, A. H. (ed) C.V. Mosby Company, St. Louis, 1987 3. Clark RP, Shea WD, Bierbaum BE: Trochanteric os-, teotomy: analysis of pattern of wire fixation failure and complications. Clin Orthop 141i102, 1979 4. Foster DE, Hunter JR: The direct lateral approach to the hip for arthroplasty: advantages and complications. Orthopaedics 10:274, 1987 5. Glover MG, Convery FR: Migration of fractured greater trochanteric osteotomy wire with resultant sciatica: a report of two cases. Orthopaedics 12:743, 1989 6". Gottschalk FA, Morein G, Weber F: Effect of the position of the greater trochanter on the rate of union after trochanteric osteotomy for total hip arthroplasty. J Arthroplasty 3:235, 1988 7. Hardinge K: The direct lateral approach to the hip. J Bone Joint Surg 64B:17, 1982 8. Harris Wtt: Advances in surgical technique for total hip replacement: without and with osteotomy of the greater trochanter. Clin Orthop 146:188, 1980
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9. Hoppenfeld S, deBoer P: Surgical exposures in orthopaedics: the Anatomic Approach. J.B. Lippincott, Philadelphia, 1984 10. Iyer KM: A new posterior approach to the hip joint. Injury 13:76, 1981 11. Krackow KA, Steinman H, Cohn BT, Jones LC: Clinical experience with a triradiate exposure of the hip for difficult total hip arthroplasty. J Arthroplasty 3:267, 1988
12. Lusskin R, Goldman A, Absatz M: Combined anferior and posterior approach to the hip joint in reconstructive and complex arthroplasty. J Arthroplasty 3:313, 1988 13. McFarland B, Osborn G: Approach to the hip: a suggested improvement on Kocher's method. J Bone Joint Surg 36B:364, 1959 14. Woo RYG, Morrey BF: Dislocations after total hip arthroplasty. J Bone Joint Surg 64A: 1295, 1982
