Search

Acetabular bone loss continues to be a challenging clinical problem faced by the revision total hip arthroplasty surgeons. The presence of a chronic pelvic discontinuity further complicates this clinical entity. Several surgical techniques have been described for the management of severe acetabular bone loss with an associated chronic pelvic discontinuity, with increasing enthusiasm for noncemented reconstruction. The focus is on noncemented reconstruction of Paprosky type IIIB acetabular defects with a chronic pelvic discontinuity.

Acetabular bone loss, and specifically when it is associated with a chronic pelvic discontinuity, presents a difficult clinical challenge at the time of revision total hip arthroplasty. Most centers have advocated the use of noncemented constructs in an effort to achieve biologic fixation. The authors prefer noncemented fixation with use of the acetabular distraction technique in conjunction with modular porous metal augments for the treatment of severe acetabular bone loss and an associated chronic pelvic discontinuity.

Acetabular bone loss is commonly encountered in patients who undergo revision total hip arthroplasty. Severe bony defects may be associated with chronic pelvic discontinuity, which makes acetabular reconstruction considerably more difficult. Surgeons must understand the current treatment options for patients with severe acetabular bone loss and chronic pelvic discontinuity. Surgeons also should understand how to perform acetabular distraction with the use of a porous acetabular shell and porous, modular metal augments.

Revision total hip arthroplasty in patients with acetabular bone loss is a challenge and should only be performed by experienced surgeons. Correct classification of the acetabular bone loss pattern allows for the formulation and execution of a detailed treatment plan. However, reclassification of the bone loss pattern is essential if additional bone loss is discovered intraoperatively so that the patient is appropriately treated. Modular, uncemented, porous metal augments and a jumbo acetabular cup should be used to treat patients with severe acetabular bone loss (Paprosky type IIIA and type IIIB acetabular defects).

Total knee arthroplasty (TKA) has become an increasingly common treatment option for patients who have debilitating knee arthritis. TKA is a relatively safe and efficient procedure that results in promising outcomes and has a positive effect on a patient's quality of life. More TKAs are being performed annually because the procedure substantially reduces pain and improves functionality; however, as the number of TKAs continues to rise, there is concern for potential complications that may result in prosthetic joint failure. Primary TKA failure may result in revision procedures that have high costs and an increased risk for additional complications. Infection is the second most common cause of primary TKA failure and the single most common cause of revision TKA failure. Surgeons who have a better understanding of the epidemiology, risk factors, and diagnostic modalities associated with periprosthetic knee infection will be able to implement preventive measures and treat patients in whom such a complication occurs.

Two-stage revision total knee arthroplasty (TKA) is the standard of care for patients who require a revision procedure for the mangement of a late or chronic periprosthetic knee infection. A careful examination of two-stage revision TKA is warranted as the number of patients who require revision TKA in the United States continues to rise. Surgeons should understand the intricacies involved in two-stage revision TKA, including the indications, procedural variations, and current deliberations on two-stage revision TKA in the literature. Surgeons also should understand the alternative treatments for periprosthetic knee infections.

Single-stage revision total knee arthroplasty has become an increasingly common treatment option for patients with failed knee prostheses. Periprosthetic knee infection is the leading and most devastating cause of revision total knee arthroplasty. Although periprosthetic knee infection has been extensively studied in the orthopaedic literature, the role of single-stage revision total knee arthroplasty for the treatment of periprosthetic knee infection warrants further research. As healthcare reform shifts from a volume-based to a value-based system, it is imperative that orthopaedic surgeons understand the procedural indications, risks, and benefits of single-stage revision total knee arthroplasty.

Osteolysis in the periacetabular region is a common long-term complication of total hip arthroplasty that can lead to bone loss, implant loosening, and protrusio. Several systems have been developed for classifying osteolysis and guiding treatment. Options such as bone grafting or augmentation, with exchange of the bearing surface and, in some cases, revision of the acetabular component, can be used for treatment. Most cavitary and protrusio defects can be treated with a cementless revision cup using screw fixation and grafting with morcellized bone. However, structural augmentation, custom components, or cage reconstruction may occasionally be necessary for managing larger defects with severe loss of acetabular bone stock.

Acetabular osteolysis can be difficult to diagnose because patients often have no clinical symptoms even when there is substantial bone loss. Ideally, early detection would lead to early interventions. Imaging continues to be the frontline modality for the early detection of acetabular osteolysis. Although plain radiography is the current imaging modality most commonly used in routine follow-up examinations, its low sensitivity limits its usefulness. CT and MRI have proven to be better imaging modalities for the early detection of osteolysis; however, their use is limited by cost, radiation exposure, and time. Biomarkers hold promise for the early detection of osteolysis; however, their efficacy requires more rigorous research for validation. Early diagnosis and treatment of osteolysis may lead to better outcomes for patients.

Acetabular reconstruction in revision total hip arthroplasty can be complicated by acetabular bone loss. In patients with severe acetabular bone deficiency with segmental bone defects or pelvic discontinuity, obtaining a stable, well-fixed acetabular component can be challenging. Although porous-coated, uncemented hemispheric cups can be used in most acetabular revisions, as the severity of acetabular deficiency increases, more complex alternatives are needed. Antiprotrusio cages have traditionally been used in the presence of acetabular columnar deficits, but higher failure rates and complications necessitated the development of alternative treatments. More recently, porous-coated acetabular augments have become an attractive alternative to structural allograft and oblong components when segmental bone loss is present. In the setting of severe bone loss or pelvic discontinuity, multiple reconstructive options are available. Depending on individual patient characteristics, plating of the pelvic discontinuity along with structural allografts, custom components, and modular or standard reconstructive cages can be used to obtain a stable acetabular component.

As the incidence of primary and revision hip arthroplasty increases, the need for a comprehensive approach to acetabular revision cannot be overstated. In the presence of osteolysis, there is a substantial population of patients with a well-fixed acetabular shell. It will be helpful to orthopaedic surgeons to review the classification of acetabular defects, techniques for exposing an acetabular component when the femoral component will be retained, methods of facilitating access to osteolytic lesions, the principles of bone grafting, options for liner fixation, and when removal of a well-fixed shell is necessary.

The management of bone loss encountered during acetabular revision remains challenging. In order to obtain a successful surgical result, preoperative planning is required to estimate the severity and location of bone defects. Most acetabular revisions can be treated with the use of a cementless hemispherical component. However, a successful surgical reconstruction requires component stability. Depending on the degree of bone loss, the surgical reconstruction may require the use of cancellous or structural bone graft, acetabular augmentation, an acetabular cage, a custom implant, or an acetabular transplant.

Periprosthetic fractures of the acetabulum that occur in association with a total hip arthroplasty are unusual injuries that present several challenges to successful management. As the number of total hip arthroplasties performed each year increases along with the number of patients with severe bone loss who require revision surgery, periprosthetic fractures of the acetabulum are becoming more prevalent. However, there is little information available to guide the orthopaedic surgeon in the management of these injuries. A comprehensive classification of these injuries is presented that is useful for guiding the management of these complex problems.