1 Introduction

Historically, for most displaced acetabular fractures, the preferred method of treatment has been open reduction and internal fixation (ORIF) [1–8]. From the pioneering observations of Judet et al [9], an accurate open reduction was believed to provide the highest likelihood of a favorable outcome and the best potential for a secondary reconstructive procedure, if initial treatment culminated in an unfavorable outcome. Although this hypothesis generally has withstood the test of time, it recently has been challenged for a sizable and rapidly growing minority of injuries. On careful examination of the results of Letournel and Judet [10] and Matta [11], even in their highly experienced hands, certain fracture patterns are less likely to have a favorable outcome after open reduction. For example, Letournel and Judet [10] reported excellent to good results for 8 (47%) of 17 posterior column–posterior wall fractures, as opposed to 18 (95%) of 19 transverse patterns. One explanation for the high incidence of fair and poor results for the former injury pattern was the predilection for elderly individuals to sustain this injury pattern. The clinical results of both studies [10, 11] show a progressive deterioration with aging patients. In a series of 424 patients by Mears et al [12] in which 25% were older than 60 years, the unfavorable impact of aging was even more striking. Evaluations of surgically managed posterior wall fractures by Moed et al [13] and Kreder et al [14] identified the potential for recurring unfavorable clinical results in elderly patients secondary to impaction of the acetabulum and femoral head and extensive comminution. Admittedly, Helfet et al [15] reported highly favorable results after open reduction in a selective group of active elderly individuals. Nevertheless, in many elderly patients, the impact of disuse osteoporosis and of other comorbidities that compromise the structural integrity of bone may culminate in a highly comminuted or impacted acetabular fracture after a minor traumatic insult, such as a simple fall ( Fig 2.13-1 ). Previous epidemiological studies [16–18] indicated that an 80-year-old person is ten times more likely to sustain a pelvic or acetabular fracture than a 25-year-old person. For adult women, the risk is twice that of men. With the explosive increase in the numbers of elderly people—a trend that is anticipated to continue well into the present century—the numbers of acetabular fractures in this population are likely to grow steadily [18, 19]. Meanwhile, with the improved safety of automobiles and the recent favorable response to legislation that addresses driving under the influence of alcohol and drugs, the numbers of young adult with acetabular fractures, nominally with normal dense bone, has been decreasing [20, 21]. The impact of these epidemiological factors is likely to progressively increase the numbers of acetabular fractures, which are unlikely to achieve favorable outcomes after open reduction using the currently available techniques.

The problem is further complicated when considering a young adult who sustains violent trauma to the hip. Despite the presence of dense normal bone, the forceful impact may provoke marked acetabular comminution or impaction of both the femoral head and the acetabulum. From the series by Mears and Velyvis [22], other complicating factors that compromised the clinical outcome after an open reduction included a late presentation and morbid obesity.

When the relevant literature pertaining to the management of an elderly patient with an acute acetabular fracture is reviewed, a striking observation is the diverse and conflicting opinions as to the role for acute total hip arthroplasty (THA). This diversity of opinion is particularly notable since the success of these procedures has been documented for more than 25 years. Two heavily contributing factors to this controversy are the different centers where acetabular fractures are managed and the different patient populations. One spectrum of patients is managed in a level 1 trauma center by experienced traumatologists. These patients usually are younger adults, who sustain major traumatic injuries. Open reduction and internal fixation is likely to be the preferred management for most patients. In a level 1 trauma facility, the availability of a surgeon experienced in performing revision arthroplasties and complex primary procedures may be limited or absent. A second group of patients are the elderly, who sustain an acetabular fracture through osteopenic bone from a simple fall. Typically, these patients are managed in a level II trauma center, such as a large regional or a community hospital, as opposed to a level I trauma center. Many elderly patients have numerous medical comorbidities, including dementia. In view of the low-energy dissipation at the fracture site, the fracture usually has only minor or at most modest displacement. Nevertheless, the articular surfaces are vulnerable to extensive impaction and comminution. In a level II center, experienced surgeons may be readily available to perform primary THA. Some patients older than 90 years may be poor surgical candidates because of medical comorbidities, including dementia and limited ability to participate in physical activities. A third group of patients are referred to pelvic and acetabular fracture specialists who may operate in a diverse array of hospital settings. Such a referral practice may cultivate a particular type of patient profile. The most sedentary patients with serious medical comorbidities typically are not referred to these specialists. These different facilities are widely described in the literature. It seems likely that the diverse patient populations treated at these various facilities and the surgeons who treat them contribute heavily to the conflicting reports in the literature as to the role for primary arthroplasty [23–27].

If a patient is identified as likely to have an unfavorable prognosis after an open reduction, the question remains as to the optimal therapeutic alternative [28]. One possibility is an initial nonoperative course. If symptomatic posttraumatic osteoarthritis ensues, THA may be performed [29]. Although this strategy avoids the potential complications of an open reduction, previously surgeons have reported an unacceptably high failure rate of late arthroplasties that were attributed to the high incidence of an acetabular nonunion or a large defect [4, 30–32]. In the largest reported series of 55 arthroplasties in 53 patients with prior acetabular fracture, Romness and Lewallen [4] documented that both radiographic and symptomatic loosening of cemented cups was five times higher than for a comparable series of patients who underwent THA for degenerative arthritis. Stauffer [31] reported a control series with a mean follow-up of 10 years. In another series by Weber et al [33] that reviewed both cemented and noncemented cups, the results of 22 cementless cups were analyzed after 10 years. None of the cups had been revised or showed radiographic evidence of loosening. A notable shortcoming of the available studies evaluating late THAs after a previous acetabular fracture is that they do not provide comparable patient populations in terms of the reconstructive challenges associated with various procedures. Most studies have diverse populations of patients who underwent non-operative or operative management of the primary acetabular fracture. Some patients had major trauma and others minor trauma injuries. The degree to which patients had large acetabular defects, nonunion, heterotopic bone, and obstructive retained pelvic hardware varied widely in both the patient populations and in the studies. This factor markedly impedes the ability to glean a consistent understanding of the anticipated clinical results after a late THA.

A notable change in the patient population over the past 20 years has been the marked increase in the numbers of patients older than 85 years and potentially beyond 100 years. This phenomenon is more notable in some geographic regions, such as Pittsburgh and Miami, which have more elderly residents than any other regions within the United States. Multiple medical comorbidities, including dementia, limited activity levels, and short-life expectancy, are common characteristics of this population. Although an acetabular fracture may result in symptomatic posttraumatic osteoarthritis, marked deformity with displacement of the acetabulum is uncommon. Delaying THA in this population, therefore, does not complicate the procedure. This fact represents a marked contrast to a situation in which a young adult sustains a highly displaced acetabular fracture and potentially the ipsilateral and/or contralateral hemipelvis from a major traumatic event. In the latter situation, failure to acutely correct the florid pelvic and acetabular deformity culminates in an enormous technical challenge to belatedly reconstruct the pelvis and acetabulum as part of a delayed THA. The available literature concludes that late THA after an initial nonoperative course results in inferior late clinical results following arthroplasty. The published literature does not rigorously distinguish pelvis with considerable acetabular deformity from those with minimal deformity, apart from degenerative arthritic changes within the hip joint. This distinction is critical to appreciate late clinical outcome after nonoperative management for an acute acetabular fracture.

Another possible strategy is a limited open reduction that eliminates large fracture gaps and restores pelvic stability, even though it does not address acetabular comminution and impaction or concomitant damage to the femoral head. This method has the potential for complications without providing a high likelihood for a successful outcome for the acetabulum. A late THA may be required after the acetabulum is united. Indications for this strategy generally are limited.

Results of late THA after acetabular fractures initially managed with open reduction also have been reported [33–36]. The advantage of this strategy is that it corrects the significant deformity of the acetabulum and potentially of the entire pelvic ring. When the acute injury is accompanied by a complex deformity of the acetabulum, corrective surgery significantly simplifies late THA and improves the likelihood for a successful clinical outcome and longevity of the device. Nevertheless, delayed arthroplasty is liable to the presence of impediments, including heterotopic bone, dense scar tissue, interposed hardware, and the potential for occult infection. If the arthroplasty is performed through a posterior approach that primarily was used for open reduction, iatrogenic injury of the sciatic nerve is a concern. The sciatic nerve is likely to be scarified to the posterior column and the underlying posterior column plate. The nerve may sustain a minor subclinical injury as part of the initial injury or during the open reduction. In this way, it becomes susceptible to catastrophic injury with minor manipulation during arthroplasty. Reports of late THAs performed after initial closed or open treatment of an acetabular fracture indicate significantly higher complication rates than THAs done for osteoarthritis.

A third possibility is an acute THA. At first glance, this option appears to have many formidable technical challenges, including the means to adequately stabilize the cup and eliminate a potentially large acetabular defect. Historically, acute THA was preceded by the unsuccessful attempts by some [37, 38] to use a cup arthroplasty. One study [39] reported equally unsuccessful results for an acute cemented THA. Another study [40] described a successful clinical outcome with a modified technique in which an uncemented multiple-screw cup was used as a hemispherical plate to draw the fracture fragments into a stable and substantially reduced configuration. Subsequently, while examining diverse methods to achieve stability of the accompanying acetabular fracture, one article [41] described the use of cerclage cables. Techniques of impaction grafting with femoral head autograft and supplementary mesh also were evaluated. One study [22] reported the late outcome for 57 patients who underwent acute THA for an acetabular fracture and were followed up for at least 2 years (mean, 8 years). Overall results were favorable, with 45 (79%) of 57 patients achieving an excellent or good Harris Hip Score. The principal source of lower scores was among the 70- and 80-year-old patients who reported good pain relief but required a cane for ambulation before the injury. Although these results will be analyzed in more detail, they have confirmed that, especially for selected elderly patients, the method appears promising. During the past decade, others have confirmed the role for acute THA after selective acetabular fractures [23–27]. Use of an acute THA in highly selective young adults is further complicated by longer-life expectancy and increased likelihood for a premature arthroplastic failure and need for a revision procedure, possibly hampered by extensive lysis of the bone [42]. Certain young adults with an acetabular fracture have a highly self-destructive behavioral pattern that may be associated with alcohol and drug abuse. These patients are poor candidates for acute or late THA.

2 Indications for an acute total THA

As a rule, the indication for an acute THA is irreversible destruction of the acetabulum and/or femoral head that accompanies the fracture so that a symptomatic posttraumatic osteoarthritis or an alternative late symptomatic problem (ie, nonunion, malunion, and avascular necrosis) would be highly likely to occur [28]. Surgical objectives include an attempt to minimize a late symptomatic event, including posttraumatic osteoarthritis, avascular necrosis, nonunion, or malunion. The mechanisms for such destruction include extensive impaction, comminution, or full-thickness abrasive loss of the articular cartilage. In the elderly, profound osteopenia is a major contributing factor. Other considerations include the presence of a nonreconstructible fracture of the femoral head or a concomitant displaced fracture of the femoral neck that is irreducible by closed or open means. The latter situation is associated with a high likelihood for avascular necrosis of the femoral head. A history of severe degenerative or inflammatory arthritis is an occasional factor. The presence of another antecedent problem, such as avascular necrosis of the femoral head, is rarely a consideration. Certain fracture patterns have the greatest predilection for one or more of the traumatically induced problems in an elderly patient.

2.2 Comminuted anterior column fracture

A comminuted anterior column fracture that involves the anterior column, anterior wall, and adjacent quadrilateral surface is another pattern ( Fig 2.13-2 ) [23]. This injury pattern often occurs after a simple fall in an elderly person who lands on his or her side, fracturing the weakest part of the acetabulum [28]. A third pattern is the anterior wall, anterior column-posterior hemitransverse, or both-column fracture ( Fig 2.13-3 ). In a young adult who sustains high-energy injury, two fracture types are associated with the greatest predilection for extensive impaction: (1) a transverse or T-type fracture with impaction of the acetabular roof along the transverse fracture line ( Fig 2.13-4 ) [10]; (2) a posterior fracture dislocation as a transverse-posterior wall or a posterior column–posterior wall fracture ( Fig 2.13-5 ). These injuries are vulnerable to extensive impaction of both the posterior wall and the femoral head.

3 Contraindications to acute THA

Contraindications include any fracture that is suitable for conventional closed treatment or ORIF. Patients, especially young adults, who have tendencies to return to activities or jobs that might cause rapid failure of the arthroplasty or to alcohol and drug abuse, are included in this category. A nearby contaminated wound, septic hip, or potentially septic hip are also contraindications. In certain situations, the contraindication may be temporary when the source of the problem can be eradicated. Other potentially temporary contraindications include hemodynamic instability, an unstable cardiac arrhythmia, electrolyte imbalance, or other unstable comorbidities. These problems usually can be controlled so that ultimately the procedure can be performed. Another contraindication is a history of radiation therapy to the acetabulum. Discussion of a pathological fracture with markedly impaired healing of bone is beyond the scope of this chapter. The potential for intraoperative problems, such as the inability to effectively anchor the cup in the profoundly osteopenic and avascular bone, and for postoperative complications including a deep-wound infection and premature failure of the cup merit special consideration.

Certain injury patterns are characterized by multiple, displaced fractures involving the entire hemipelvis or extensive comminution of the acetabulum ( Fig 2.13-6 , Fig 2.13-7 ). These injuries may require realignment and stabilization of the hemipelvis and may jeopardize stabilization of the acetabular component so that effectively anchoring an acetabular component becomes unrealistic or impossible. This factor is somewhat related to the experience of the surgical team with respect to complex revision THA complicated by a major acetabular defect. Before undertaking acute THA in which the acetabulum is markedly comminuted, the surgical team outlines a suitable, realistic strategy to immobilize the acetabular component and hemipelvis and to possess the necessary technical resources to achieve that goal.

4 Preoperative assessment

The force of the provocative blow provides insight into the strength of the bone or the potential presence of osteoporosis. A major trauma insult is consistent with a motor vehicle injury or a fall from a height. In contrast, a moderate or minor event that results in acetabular fracture, such as a fall from standing position, is highly suspicious for the presence of osteoporosis [19]. Other contributing factors for osteoporosis, such as the long-term use of oral corticosteroids, a history of degenerative or inflammatory arthritis of the hip, or a history of osteonecrosis are evaluated. A displaced insufficiency fracture of the acetabulum is another contributing factor in the elderly population [28].

Other relevant features of the history include an evaluation for drug and alcohol abuse, the nature of vocational activities or hobbies that may provide a high likelihood for falls, major injuries, heavy lifting, or other abuse of the hip. In the elderly, the presence of posturing of the hip, marked weakness of the hip abductor muscles, or comorbidity that causes recurrent falls merits consideration as a contraindication to acute THA.

Radiographic evaluation of the hip and pelvis includes the standard AP, iliac, and obturator oblique views, along with a computed tomographic (CT) scan [10, 43]. The images are assessed for impaction, which are optimally visualized in sagittal and coronal reconstructions ( Fig 2.13-1 , Fig 2.13-5 ). On standard CT transaxial images, a large area of impaction of the femoral head or the dome may not be visualized. In a person with osteoporosis who sustains a fracture after a simple fall, despite minimal radiographic evidence of impaction, an extraordinarily large area of impaction or of abrasive damage may be seen at the time of the surgical procedure. A 3-D CT is especially useful to identify the rotational elements of a complex acetabular deformity ( Fig 2.13-2 ). Images that show dissociation of the femoral head from the acetabulum may permit the recognition of occult impaction of the femoral head ( Fig 2.13-5 ) [43].

In patients with complicating features that may lead to a decision to perform acute THA, consent for the acute arthroplasty is obtained. In patients with a potentially reconstructible hip but with osteopenic bone, consent for open reduction and/or THA is obtained, so that the decision for the appropriate procedure can be made intraoperatively after the hip joint has been inspected.

5 Surgical strategies for acute THA with stabilization of the acetabulum

Multiple factors heavily influence the planning aspects for acute THA combined with ORIF of the acetabulum. Perhaps the most important factor for surgical planning is the experience of the surgical team. When the team includes a surgeon who is experienced in acute THA combined with ORIF, an integrated procedure can be designed, whereby a single surgical approach suitable for the arthroplasty is selected. The fixation may rest heavily on the use of a multiple-holed cup and potentially specialized fixation techniques, such as the use of cerclage cables. This strategy is most efficient with respect to operation time and use of a limited surgical approach. Examples of fracture patterns in which this strategy is beneficial include selective both-column and T-type injuries, and complex anterior injuries involving the quadrilateral surface. Many trauma teams might use two incisions for such an injury pattern. For the experienced surgeon, all these injuries could be addressed with an anterolateral approach.

A more common scenario is a trauma team that has limited capabilities in performing arthroplasty but includes a surgeon experienced in THA for the relevant part of the procedure. The procedure typically is performed sequentially with the initial ORIF performed by the trauma team and the THA performed secondarily by the arthroplastic surgeon. For the open reduction, the trauma team generally uses a Kocher-Langenbeck posterior approach, possibly accompanied by an ilioinguinal or alternative anterior approach for selective fractures. The arthroplastic surgeon has to use the posterior exposure and undertake the insertion of a cup in a manner that is consistent with the presence of the acetabular fixation.

An additional factor is whether the arthroplasty is a certainty or a possibility. If the arthroplasty is a certainty, then a surgical approach most suitable for that particular procedure may be selected. In many instances, an anterolateral approach may be the most efficient exposure for the arthroplasty, potentially combined with cerclage cable fixation. If the surgical plan includes a possible arthroplasty along with the open reduction, then the surgical approach is designed to favor the open reduction.

If arthroplasty is planned, the role for an associated ilioinguinal or alternative anterior approach should be minimized. The anterior approach is unsuitable for the arthroplasty. A liability of the anterior approach is the potential to insert screws through the pelvic brim that subsequently are an obstruction with respect to the insertion of the cup. In that situation, removal of the obstructive screw is cumbersome. As the most practical technique, the screw is cut within the acetabular exposure so that the obstructive segment of the screw can be removed.