INDICATIONS

Approaching the hip joint from a posterior direction was originally described by the German surgeon Bernard Von Langenbeck. Von Langenbeck's approach was later modified by the Swiss surgeon Theodor Kocher, who used it mainly for the treatment of septic arthritis from Mycobacterium tuberculosis. The posterior approach, as we know it today, was described by Austin T. Moore as the “low posterior approach” or “southern exposure,” because it was more inferior than the traditional posterolateral approach at that time (1). Historically, this approach was utilized by Moore and others for hip arthroplasty, arthrodesis, and osteotomies for congenital hip dislocations (1). The approach has been further modified for arthroplasty into what is commonly referred to as the “mini-posterior” approach that utilizes shorter skin and fascial incisions (6 to 10 cm) by eliminating the proximaland distal-most aspects of the standard posterior incision (2,3).

Currently, the posterior approach is most commonly used for primary (Fig. 3-1) and revision total hip arthroplasty, as well as hip hemiarthroplasty for fracture. A major advantage of this approach is that it is extensile. The standard approach, as used for arthroplasty, can be extended proximally into the Kocher-Langenbeck approach for fixation of the posterior wall of the acetabulum or the posterior column of the pelvis. It can be also extended distally to expose the femur to perform trochanteric osteotomies or to fix periprosthetic femur fractures. Although primary and revision hip arthroplasty may be performed through multiple different approaches, there are some scenarios in which a posterior approach may be preferred, that is, total hip replacement in cases requiring trochanteric osteotomy for exposure (the stiff or ankylosed hip) or for congenital hip dislocation requiring femoral shortening, revisions in which fixation of the posterior column is required or revisions of well-fixed femoral components requiring extended trochanteric osteotomy for removal.

Perhaps, the most important advantage of the posterior approach is that the abductor musculature is preserved (1). This results in a lesser incidence of postoperative limp in comparison to the anterolateral or direct lateral approaches (4,5). Further, the posterior approach can be performed without the need for special equipment, such as a fracture table or fluoroscopy, which makes it more cost-effective than some direct anterior approaches. Lastly, the posterior approach affords limited risk to damaging the lateral femoral cutaneous nerve, which occurs often during the direct anterior approach (6).

 

CONTRAINDICATIONS

Use of the posterior approach is controversial in joint-preserving procedures requiring an arthrotomy, such as drainage of a septic hip, removal of a loose body, or fixation of a femoral head fracture due to concerns for disruption of the blood supply to the femoral head. The primary blood supply to the adult

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femoral head courses posteriorly from branches of the medial femoral circumflex artery (7); therefore, a posterior capsulotomy could disrupt this and risk the development of osteonecrosis. In cases of arthroplasty, the posterior approach may be avoided by some surgeons in favor of other approaches in patients in whom

 

the risk of dislocation is high, such as those with cognitive impairment, neuromuscular disorders, or those

who are wheelchair-bound. However, this is only a relative contraindication, and hip arthroplasty can be successfully performed via the posterior approach in these clinical scenarios.

 

FIGURE 3-1 These are the preoperative (A,B) and 1-year postoperative (C,D) radiographs of a 42-year-old male with hip osteoarthritis who underwent primary cementless total hip arthroplasty through a posterolateral approach (Videos 3-1 through 3-6).

 

 

 

 

TECHNIQUE

Positioning

After the anesthesia of choice is established, the patient is placed in the lateral decubitus position with the operative side up. There are many different devices for lateral positioning, including peg boards, bean bags, and anterior and posterior pads. We use a peg board, placing pegs anteriorly on the pubis symphysis and posteriorly on the sacrum to stabilize the pelvis. We aim to have the posterior surface of the sacrum perpendicular to the floor and to minimize any cephalad or caudal tilt of the pelvis. An axillary roll is placed just inferior to the axilla.

The torso is stabilized with an anterior peg at the distal sternum and a posterior peg at the same level. It is important to ensure that the torso and pelvis are stabilized in a neutral position, or even slightly tilted posteriorly, as the pelvis tends to fall forward once the hip is dislocated and the leg is held in an adducted position. Any excessive anterior or posterior tilt of the pelvis in the lateral position makes it more difficult to place the acetabular component in an appropriately anteverted position. Once the positioning is deemed acceptable, all bony prominences are padded. Padding is placed between the pegs and the patient, especially the proximal pegs. Padding or a gel pad is also placed beneath the nonoperative leg to protect the peroneal nerve. The nonoperative hip is flexed to approximately 45 degrees. While the exact amount of flexion is not critical, it is important to be consistent as hip flexion tends to flex the pelvis, which can influence the final acetabular

 

component position. The dependent arm is placed in full extension on a well-padded arm board. The ulnar nerve must be

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well-padded at the elbow. Two pillows are then placed between the dependent arm and the upper arm, which is then taped in place. Alternatively, a padded Mayo stand can be used as a rest for the upper arm.

 

Draping

A nonsterile U-drape is used to isolate the surgical limb from the remainder of the body and define the surgical field. It is important that around the hip itself, this drape is placed as widely as possible, in order to allow the exposure to be extensile posteriorly, if necessary. The limb is sterilely prepped with ChloraPrep (3M, St. Paul, MN). In most cases, the foot is not prepped, as the leg is being held up by a candy cane leg holder. A sterile half sheet is used to cover the patient's torso. An impervious sterile U-drape is placed on top of the previously placed nonsterile U-drape. A sterile stockinette is used to cover the leg to a level just above the knee. The leg is then wrapped with 6-inch Coban (3M, St. Paul, MN), a self-adherent wrap. A hip drape is placed. All exposed skin is then covered with Ioban (3M, St. Paul, MN), an iodine-impregnated adhesive skin barrier.

 

Surgical Technique

With the hip flexed to approximately 45 degrees, a curvilinear incision, centered at the tip of the greater trochanter, is made on the lateral aspect of the hip. The distal aspect of the incision is in line with the femoral shaft. The proximal aspect curves posteriorly from the tip of the greater trochanter toward the posterior superior iliac spine (PSIS). The length of the incision is highly dependent on the exposure needed for adequate visualization. It may vary due to the patient's body habitus. In our hands, it is generally 15 cm or less in length (Video 3-1).

The skin and subcutaneous tissue are incised sharply down to the level of the fascia lata. A Cobb elevator is used to elevate the overlying adipose tissue from the fascia. The adipose tissue is peeled back just enough to facilitate the fascial incision. Excessive stripping of the adipose tissue may yield poor cosmetic results due to dimpling from fat necrosis. The fascia lata and gluteal fascia are then incised sharply in line with the incision. A plane between the gluteus maximus and the underlying abductors is developed bluntly. The gluteus maximus is manually split, and when resistance is encountered, dissection is paused to identify crossing blood vessels for cauterization. The sciatic nerve is identified. A Charnley retractor is placed beneath the gluteus maximus. The posterior aspect of the gluteus medius is identified and retracted gently anteriorly. Great care is taken to avoid rigorous retraction of the gluteus medius, as this may contribute to the formation of heterotopic ossification postoperatively. The piriformis tendon is identified, released from the trochanteric ridge, and tagged with a suture. The short external rotators (superior gemellus, obturator internus, and inferior gemellus) and quadratus femoris are then identified and elevated from the posterior aspect of the trochanter subperiosteally, using electrocautery. Some surgeons prefer to leave the quadratus femoris muscle intact. A plane is further developed between these muscles and the underlying posterior hip capsule using electrocautery. Further dissection around the inferior femoral neck is performed bluntly with a sponge. The inferior border of the gluteus minimus is identified and retracted gently with a Hibbs retractor. We avoid retracting this with a Cobra retractor, as this is usually unnecessary and may place the muscle under undue tension.

 

A trapezoidal capsulotomy is performed, and the capsule is tagged with two sutures at its proximal and distal points. Then, using these tagging sutures, the capsule is reduced to the intertrochanteric ridge, and the point where the edge of capsule meets the trochanter is marked with electrocautery, as an indicator of the patient's native offset and limb length (Fig. 3-2). It is important to note that the limb must be in a similar position when these measurements are carried out after the reconstruction. Further,

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fixed pins in the pelvis and greater trochanter can also be used to optimize limb length and offset. We prefer to use a jig on the inferior poles of the patellae as an additional reference point for limb length.

 

 

 

FIGURE 3-2 This photograph shows the posterior capsular flap referenced to two fixed points on the greater trochanter for assistance with reconstruction of limb length and offset.

 

The hip is then dislocated from the acetabulum, using a flexion, adduction, internal rotation maneuver. The leg is held with the hip in approximately 45 degrees of flexion, 90 degrees of internal rotation, and maximum adduction. Any remaining soft tissue on the femoral neck is removed, and the lesser trochanter is exposed. The retinacular vessels are cauterized where they exit the posterior femoral neck. The femoral neck osteotomy is made with a reciprocating saw, according to the preoperative plan. The leg is then allowed to rest in neutral rotation, and the acetabulum is exposed. We keep the knee flexed at 90 degrees at all times to reduce tension on the sciatic nerve.

Exposure of the acetabulum is achieved with a cobra retractor placed anteriorly (4 or 8 o'clock for the left or right hip, respectively). A second cobra retractor is placed in a posterior-inferior position (8 or 4 o'clock for the left or right hip, respectively). A self-retaining cerebellar retractor is placed superiorly, which holds the trochanter anteriorly and the capsular flap posteriorly (Video 3-2). The labrum is removed, and the acetabular rim is exposed superiorly. The pulvinar is also removed to expose the floor of the acetabulum. The acetabulum is reamed, and the acetabular component is implanted. The transverse acetabular ligament and the native anterior and posterior acetabular walls are referenced for optimization of anteversion (8). Proper inclination is achieved with the use of an external alignment guide as well as ensuring that the inferior edge of the component rests inside of the transverse acetabular ligament.

In revision surgery, the piriformis/short external rotators/quadratus muscles are usually taken down as a single layer with the pseudocapsule off the trochanteric ridge. An anterior capsulotomy or capsulectomy may be needed. Mobilization of the femur can be optimized by using electrocautery to release the anterior capsule off the proximal femur anteriorly. Release of the iliopsoas tendon from the lesser trochanter and a gluteus maximus tenotomy can assist with femoral mobilization anteriorly. In cases where a femoral implant is retained, we use meniscal scissors and/or a Cobb elevator to create a pocket over the anterior wall and anterior column. A sharp Hohmann retractor is then placed carefully over the anterior wall, and the trunnion is then retracted anteriorly into the pocket adjacent to the anterior wall and column.

After implantation of the acetabular component, a single screw and trial liner, attention is then turned to the proximal femur. Once all of the retractors are removed, the surgical assistant again holds the leg with the hip flexed, adducted, and internally rotated as described previously. It is important that the leg remains perpendicular

to the floor with the knee flexed to 90 degrees to allow a constant reference for femoral version. A proximal femoral elevator is used on the anterior aspect of the femoral neck to elevate it from the wound. A Cobb elevator is used to protect the gluteus medius as the instruments used to prepare the femur are passed into and out of the femoral neck (Video 3-3).

After achieving appropriate stability, an intraoperative radiograph can confirm socket position, stem fit, offset, and limb length. The femoral broach is removed, and the socket is reexposed. The trial liner is removed, and additional screws are inserted as needed. The final liner is placed. The proximal femur is then reexposed, and the implant is placed (Video 3-4). A series of head trials are performed (Video 3-5). The capsular flap is referenced to the marks made on the proximal femur for optimization of limb length and offset. The jig is used to re-reference the relative locations of the inferior poles of the patellae as an additional data point for limb length. General soft tissue tension is assessed as well. The final head is placed on a clean and dry Morse taper. The hip is reduced. Great care is taken to avoid scratching the femoral head on the rim of the socket.

 

Once the final components are placed, the closure begins with the posterior capsular repair (Video 3-6). The leg is placed on a sterilely-padded Mayo stand in neutral abduction and rotation. The posterior capsule is retagged with two #5 Ethibond sutures (Ethicon, Somerville, NJ), and the original tagging sutures are removed. Two drill holes are then made in the inferior aspect of the posterior trochanter, and these sutures are passed through these holes with a suture passer (Fig. 3-3). The

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sutures are then tied together on the bone bridge between these two holes. Next, the piriformis tendon is tagged with a #5 Ethibond suture (Ethicon, Somerville, NJ), and these sutures are passed through the distal aspect of the gluteus medius tendon and tied together. A deep drain that exits through a separate fascial incision is placed (surgeon preference). The fascia lata is closed with two running #1 PDS sutures (Ethicon, Somerville, NJ). The subcutaneous layer is closed with two running #2-0 PDS sutures (Ethicon, Somerville, NJ) in two layers. The skin is reapproximated with two running #3-0 Monocryl sutures (Ethicon, Somerville, NJ).

 

 

 

FIGURE 3-3 This photograph shows the posterior capsular flap repaired through drill holes to the posterior aspect of the greater trochanter.

 

POSTOPERATIVE MANAGEMENT

Following standard total hip arthroplasty, patients begin to mobilize with physical therapy on the first postoperative day and continue daily physical therapy until discharged. While weight bearing is determined by the surgeon on a case-by-case basis, the vast majority of patients are allowed to bear weight as tolerated. We recommend posterior dislocation precautions for 6 weeks. In the revision setting, weight-bearing status is modified on a case-by-case basis. All of our revision patients use an abduction brace for 6 weeks, though the utility of this is controversial (9).

 

 

COMPLICATIONS

The complication most commonly associated with hip arthroplasty through the posterior approach is dislocation. Historically, the dislocation has been reported in up to 7.2% of primary total hip arthroplasties (4,10,11,12,13,14). However, with posterior capsular repair, that rate has been reduced to 2% or less (4,12,14,15,16,17). The addition of posterior soft tissue repair has made the dislocation rate in total hip arthroplasty done from the posterior approach more comparable to those in hips done from other approaches—1% to 3% for the anterolateral and transtrochanteric approaches and less than 1% for the direct lateral approach (4,12,18). Other technical improvements in total hip arthroplasty, namely modularity, improved metallurgy allowing for extended offset stems, and increased femoral head size, have also contributed to a decrease in the dislocation rate in total hip replacement from the posterior approach (18).

Revision hip arthroplasty through the posterior approach has had relatively high rates of instability— up to 25% in some studies (13,19). However, this has been associated with many factors, including revision type (i.e., head/liner exchange), number of previous surgeries, abductor function, and femoral head size (13,20,21,22,23). Posterior soft tissue repair has also been shown to help decrease instability following revision total hip arthroplasty (24).

 

CLINICAL OUTCOMES

Recently, there have been negative perceptions of the posterior (and mini-posterior) approach, especially with the popularization of the direct anterior approach. Some comparative studies have demonstrated advantages for the direct anterior approach in immediate postoperative functional recovery (25,26).

However, no studies have shown worse clinical outcomes, beyond the immediate postoperative period (6 weeks), following the posterior approach compared to others. Some studies have shown similar Harris and Oxford hip scores in comparison to the anterolateral and direct lateral approaches at both short-term (3 months) and mid-term (5-year) follow-up (27,28). Several studies have demonstrated better clinical outcomes after the posterior approach, compared to the anterolateral approach, including better Harris Hip and Western Ontario and McMaster Osteoarthritis Index (WOMAC) scores, better patient satisfaction, and less incidence of Trendelenburg gait at 1 to 3 years after surgery (5,29). Another study of over 42,000 patients in the Swedish Hip Arthroplasty Register demonstrated better patient-reported outcomes following total hip arthroplasty via the posterior approach compared to the direct lateral approach, including higher patient satisfaction and lower pain scores at 1- and 6-year follow-up (30).

 

 

SUMMARY

Despite the recent increased enthusiasm for the direct anterior approach, the posterior approach continues to be a highly utilitarian approach for primary and revision hip arthroplasty that is extensile, when necessary, and preserves the abductor musculature. Additionally, it affords excellent clinical outcomes in comparison to other approaches. As such, we anticipate that it will remain a popular approach for hip surgeons worldwide.

 

 

 

 

REFERENCES

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13. Callaghan JJ, Heithoff BE, Goetz DD, et al.: Prevention of dislocation after hip arthroplasty: lessons from long-term follow-up. Clin Orthop Relat Res 393: 157-162, 2001.

     

     

14. White RE Jr, Forness TJ, Allman JK, et al.: Effect of posterior capsular repair on early dislocation in primary total hip replacement. Clin Orthop Relat Res 383: 163-167, 2001.

     

     

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17. Weeden SH, Paprosky WG, Bowling JW: The early dislocation rate in primary total hip arthroplasty following the posterior approach with posterior soft-tissue repair. J Arthroplasty 18(6): 706-713, 2003.

     

     

18. Berry DJ, von Knoch M, Schleck CD: Effect of femoral head diameter and operative approach on risk of dislocation after primary total hip arthroplasty. J Bone Joint Surg Am 87(11): 2456-2463, 2005.

     

     

19. Alberton GM, High WA, Morrey BF: Dislocation after revision total hip arthroplasty: an analysis of risk factors and treatment options. J Bone Joint Surg Am 84: 1788-1792, 2002.

     

     

20. Wetters NG, Murray TG, Moric M, et al.: Risk factors of dislocation after revision total hip arthroplasty.

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21. Kosashvili Y, Backstein D, Safir O, et al.: Dislocation and infection after revision total hip arthroplasty: comparison between the first and multiply revised total hip arthroplasty. J Arthroplasty 26(8): 1170-1175, 2011.

     

     

22. Garbuz DS, Masri BA, Duncan CP, et al.: The Frank Stinchfield Award: dislocation in revision THA: do large heads (36 and 40 mm) result in reduced dislocation rates in a randomized clinical trial? Clin Orthop Relat Res 470(2): 351-356, 2012.

     

     

23. Boucher HR, Lynch C, Young AM, et al.: Dislocation after polyethylene liner exchange in total hip arthroplasty. J Arthroplasty 18(5): 654-657, 2003.

     

     

24. Suh KT, Roh HL, Moon KP, et al.: Posterior approach with posterior soft tissue repair in revision total hip arthroplasty. J Arthroplasty 23(8): 1197-1203, 2008.

     

     

25. Rodriguez JA, Deshmukh AJ, Rathod PA, et al.: Does the direct anterior approach in THA offer faster rehabilitation and comparable safety to the posterior approach? Clin Orthop Relat Res 472(2): 455-463, 2014.

     

     

26. Nakata K, Nishikawa M, Yamamoto K, et al.: A clinical comparative study of the direct anterior with mini-posterior approach: two consecutive series. J Arthroplasty 24(5): 698-704, 2009.

     

     

27. Palan J, Beard DJ, Murray DW, et al.: Which approach for total hip arthroplasty: anterolateral or posterior? Clin Orthop Relat Res 467(2): 473-477, 2009.

     

     

28. Witzleb WC, Stephan L, Krummenauer F, et al.: Short-term outcome after posterior versus lateral surgical approach for total hip arthroplasty—a randomized clinical trial. Eur J Med Res 14(6): 256-263, 2009.

     

     

29. Smith AJ, Wylde V, Berstock JR, et al.: Surgical approach and patient-reported outcomes after total hip replacement. Hip Int 22(4): 355-361, 2012.

     

     

30. Lindgren JV, Wretenberg P, Kärrholm J, et al.: Patient-reported outcome is influenced by surgical approach in total hip replacement: a study of the Swedish Hip Arthroplasty Register including 42,233 patients. Bone Joint J 96-B: 590-596, 2014.