Hip Arthroplasty Alone for Treatment of Selected Acetabular Fractures in Older Patients

Fig. 8.1

97-year-old female with a displaced anterior column, posterior hemitransverse fracture (top panel). Reconstruction was accomplished by fixation of her posterior column with a contoured 3.5 mm reconstruction ring and a reconstruction cage, with a cemented polyethylene cup, and cemented stem (lower panel)

Primary arthroplasty can be easily performed in most cases of isolated anterior wall fractures. Posterior wall fractures may also be treated with THA alone when the fracture fragments are small and peripheral, so that the posterior wall fragments can essentially be ignored. Thus, in cases of posterior wall fracture, the size and location of the fracture fragment(s) tend to have more impact on the necessity of fracture fixation to achieve a stable acetabular component than in anterior wall fractures, which essentially have no impact on the ability to achieve primary stability of the acetabular cup. Low, small fragments in the posterior wall are less likely to influence cup stability. However, fragments more proximal in the posterior wall or involving some degree of the weight-bearing dome become challenging to achieve acetabular component stability without additional fracture fixation.

However, for some fractures, revision acetabular components and techniques may be considered. For example, in fractures involving the anterior column, a technique by Enocson et al. has been described using a Burch-Schneider reconstruction ring into which an acetabular component is cemented without any other fracture fixation [1]. This technique can also be used in the anterior column – posterior hemitransverse fracture pattern. The authors do not advocate this technique in associated both-column patterns where there is no acetabular subchondral bone in continuity with the intact ilium. A similar technique using a specific implant where the polyethylene can be snap-fit into place is described by Malhotra et al. [2] These authors again excluded associated both-column fractures preoperatively, but otherwise included a mix of elemental and associated fractures in their series of 15 patients.

A cup-cage technique as described by Chana-Rodriguez et al. has also been employed [3]. This small series reported on six displaced geriatric fractures treated with a tantalum ingrowth cup over which an anti-protrusio cage was fixated. In their series, there were three elemental fractures as described by Letournel [4] and three associated patterns; however, there were no reported cases of associated both-column fractures. All of these cases were performed by employing a posterior approach.

Finally, in some cases with unrepairable posterior wall fractures, the patient’s femoral head can be used as a primary structural graft, as may be done using allograft bone in the revision setting (Fig. 8.2). These grafts can be shaped to fit into the remaining bone defect after debridement of the fracture fragments and fixed to the pelvis with multiple lag screws (Figs. 8.2, 8.3, 8.4, and 8.5). Once fixed, they can be reamed with the remaining acetabulum and serve to restore the rim of the acetabulum.

../images/395168_1_En_8_Chapter/395168_1_En_8_Fig2a_HTML.jpg — Fig. 8.2

(a) 68-year-old male with a posterior left hip fracture – dislocation. (b) Axial CT showing severe impaction and involvement of the posterior wall. (c) Multiple posterior wall fragments. (d) Postoperative anteroposterior pelvis and Judet views showing uncemented total hip replacement with a structural allograft from the femoral head used to reconstruct the irreparable posterior wall

../images/395168_1_En_8_Chapter/395168_1_En_8_Fig2b_HTML.jpg — Fig. 8.2

(a) 68-year-old male with a posterior left hip fracture – dislocation. (b) Axial CT showing severe impaction and involvement of the posterior wall. (c) Multiple posterior wall fragments. (d) Postoperative anteroposterior pelvis and Judet views showing uncemented total hip replacement with a structural allograft from the femoral head used to reconstruct the irreparable posterior wall

../images/395168_1_En_8_Chapter/395168_1_En_8_Fig3_HTML.jpg — Fig. 8.3

Patient is positioned laterally, with the pelvis stabilized using a total hip positioner and with free motion of the hip. The leg is draped free. An image intensifier is available to use as needed

../images/395168_1_En_8_Chapter/395168_1_En_8_Fig4_HTML.jpg — Fig. 8.4

A curved incision is made centered over the greater trochanter, exposing the iliotibial tract (top panel). The IT band is incised along the axis of the femoral shaft distally and extended into the gluteus maximus proximally (lower panel)

../images/395168_1_En_8_Chapter/395168_1_En_8_Fig5_HTML.jpg — Fig. 8.5

The curved end of a Homan retractor is used to retract the gluteus medius anteriorly, and a scissors is placed beneath the conjoined tendons of the obturator internus and gemelli (top panel). The short rotators and piriformis are released and retracted with sutures, exposing the posterior capsule and posterior wall fragments (lower panel)

Surgical Technique: Posterior Approach

In fractures involving the posterior wall only, THA alone without fracture fixation is feasible in those cases where the posterior wall fragment is too small to maintain fixation. For a posterior approach, the patient is given either spinal or general anesthesia. A Foley catheter is usually placed, and the patient is then positioned laterally with the operative hip accessible (Fig. 8.3). The entire lower extremity is then prepped with the leg free. It is important that anterior hip positioners are placed proximally enough to allow ninety degrees of hip flexion during the procedure. After preoperative intravenous antibiotics are given, a longitudinal or slightly curved incision is made over the lateral aspect of the hip. Dissection is carried down to the iliotibial band which is then split longitudinally (Fig. 8.4). Trochanteric bursal tissue is removed as needed for visualization. A retractor is placed under the hip abductors. The piriformis, triceps coxae, and quadratus femoris are identified and released from their insertions on the posterior surface of the proximal femur (Fig. 8.5). The piriformis tendon and triceps tendon are typically tagged with suture. At this point, fractures of the posterior wall can usually be palpated. The posterior capsule is then identified and a capsulotomy is performed. Superior and inferior capsular flaps are tagged for repair at the end of the procedure. Based on preoperative templating for the determination of level, a femoral neck osteotomy is made with an oscillating saw. The femoral head and neck is then removed, and the acetabular fracture can be more easily identified. In cases where fixation of acetabular fragments is not necessary, reaming can then begin. After reaming, a trial acetabular component can then be impacted into place. If the trial component is stable, it is reasonable to proceed with implantation of the final acetabular component as there should be reasonable stability of a press-fit cup. The cup is further secured with multiple screws. Once primary cup stability is assured, the small posterior wall fragment(s) can be excised.

../images/395168_1_En_8_Chapter/395168_1_En_8_Fig6_HTML.jpg — Fig. 8.6

The important bony features for acetabular component stability are the subchondral bone attached to anterior inferior iliac spine (AIIS) and the subchondral bone attached to the ischium (both represented with red arrows). The bony contours of the posterior wall and the anterior wall adjacent to the iliopectineal eminence are less important for component stability (yellow arrows). (Property of Theodore Manson and the R Adams Cowley Shock Trauma Center. Used with Permission)

../images/395168_1_En_8_Chapter/395168_1_En_8_Fig7_HTML.jpg — Fig. 8.7

This elderly patient sustained a posterior wall fracture dislocation in a motor vehicle collision. (Property of Theodore Manson and the R Adams Cowley Shock Trauma Center. Used with Permission)

../images/395168_1_En_8_Chapter/395168_1_En_8_Fig8_HTML.jpg — Fig. 8.8

The CT scan image shows that the subchondral bone in the superior acetabulum attached to the anterior inferior iliac spine as seen in this image is intact. (Property of Theodore Manson and the R Adams Cowley Shock Trauma Center. Used with Permission)

One of the original techniques described for acute hip arthroplasty for acetabular fractures employed cerclage cables to fixate the fractured acetabulum [5]. In the series by Mears and Velyvis, all patients were positioned laterally, and three different approaches were used based on fracture morphology: posterior, anterolateral, or extended lateral [6]. Displaced column fractures or supratectal transverse fractures are reduced and fixated with screws. Juxtatectal or infratectal fracture lines or anterior column fractures with quadrilateral surface displacement are stabilized using two 2.0 braided cables in a cerclage fashion to stabilize the quadrilateral surface. These are typically passed from a drill hole made in the anterior inferior iliac spine and passed through the lesser sciatic notch. The acetabulum is then reamed, and a press-fit cup is selected that is larger than the largest reamer that was used. The cup is then impacted into place for an interference fit and secured with multiple screws.

Other means of acetabular component placement without fracture fixation have been described. Enocson et al. described a technique for acetabular component fixation using a Burch-Schneider reconstruction ring [1]. In their case series of 15 patients, two of these surgeries were performed through a posterior approach, while the other thirteen were carried out using a modified Hardinge approach. No fracture reduction was performed. The acetabular cartilage was removed. The cartilage on the femoral head was also removed, and the morselized femoral head was used as autograft and packed into fracture lines in the acetabulum. The Burch-Schneider reconstruction ring was then fixated to the intact ilium with screws. Into the Burch-Schneider ring, an all-poly acetabular component was then able to be cemented into place.

In the cup-cage technique described by Chana-Rodriguez, the posterior approach was always utilized [3]. Despite no use of plates to fixate the fractures, displaced column fractures and supratectal transverse fractures were reduced with clamps and fixated with screws. The acetabular cartilage was then removed, and morselized femoral head autograft was packed into the fracture lines. A porous ingrowth press-fit cup was then impacted into place and secured with screws through the cup. Next, an anti-protrusio cage was secured to the intact ilium and the ischium, and screws were passed additionally through the cage and cup. With the anti-protrusio cage in place, a polyethylene acetabular liner was then able to be cemented into place, with the cement engaging both the anti-protrusio cage and the trabecular metal press-fit cup.

Despite the methods, when a posterior approach is used, a capsular repair is recommended to add stability. Debridement of nonviable muscle is usually performed to decrease the risk of postoperative heterotopic ossification. Posterior hip precautions limiting hip flexion, adduction, and internal rotation are generally employed.

Postoperative Care

There is little uniformity in postoperative care after acute total hip arthroplasty for acetabular fracture. Most authors will advocate mobilization on postoperative day zero or one. Like other hip arthroplasty procedures, twenty-four hours of postoperative intravenous antibiotics are given for perioperative infection prophylaxis. Depending on the approach for surgery and any predicted instability, hip precautions are employed. Drains are placed depending on the surgeon’s bias.

There is also no consensus in the reported series regarding weight-bearing after THA for acute acetabular fracture. Mears and Velyvis reported on 57 patients that were mobilized almost immediately after surgery, but were restricted to touchdown weight-bearing for 6 weeks postoperatively [6]. The same postoperative weight-bearing protocol was employed by Enocson in a series of fifteen patients [1]. In the series by Malhotra, patients were mobilized within 48 hours of surgery and then allowed partial weight-bearing at three weeks and full weight-bearing at six weeks postoperatively [2]. In the series by Chana-Rodriguez, full weight-bearing was allowed when the surgical drain was removed, which ranged from 2–10 days [3].

Similarly, postoperative prophylaxis for venous thromboembolism varies in reported series. Mears et al. reported using warfarin or low molecular weight heparin for 3 weeks postoperatively [6]. Chana-Rodriguez et al. reported use of LMWH for 4 weeks in their series of six patients [3]. Enocson et al. treated patient for 10–14 days with prophylactic LMWH [1].

Prophylaxis for heterotopic ossification also varies in the literature. In the series of 15 patients reported by Malhotra, prophylaxis using oral indomethacin for two weeks postoperatively was employed [2]. Other series [3, 6] did not use prophylaxis for heterotopic bone formation.