Heterotopic Ossification

Key Points While the etiology of heterotopic ossification (HO) is diverse, it most commonly occurs through a process of endochondral ossification after operative procedures about the hip. While HO is typically only a radiographic finding without clinical consequences, clinically meaningful stiffness may result from extensive ectopic bone formation in as many as 10% of patients after total hip arthroplasty (THA). Patients at greatest risk for HO…

Wound Complications After Total Hip Arthroplasty: Prevention and Treatment

Key Points Choice of anticoagulation, body mass index, and high drain output are significant risk factors for persistent wound drainage and subsequent infection. Irrigation and debridement of hip wounds with persistent drainage within 14 days of the index total hip arthroplasty is associated with a higher rate of successful treatment. Negative pressure wound therapy (NPWT) is an option to manage wound drainage in high-risk surgical wounds,…

Neurovascular Injuries : Prevention, Diagnosis, and Treatment

Key Points Neurologic Injuries Know inherent risks and special considerations for each patient in order to predict and avoid complications. Once inherent risks are known, take intraoperative steps to avoid injury to the nervous or vascular structures at risk. Early diagnosis is very important in postoperative nerve palsies. Know the correct physical examination technique to diagnose nerve palsies so that treatment can commence. Once a nerve…

Leg Length Inequality: Prevention/Treatment

Key Points Preoperative assessment of leg length inequality should include a history, physical examination, and radiographic evaluation, including templating. Preoperative education of the patient should include discussion of the patient's perception of leg length discrepancy and a discussion of the possibility of a postoperative leg length discrepancy. Templating to plan leg length equalization involves planning for socket and stem placement, as well as neck resection levels…

Abductor Muscle and Greater Trochanteric Complications

Key Points Early detection of intraoperative and postoperative trochanteric problems is important to optimize chances of successful treatment. Trochanteric claw plates with locking screws and cables have shown promising results in the fixation of trochanteric fractures and nonunions. Trochanteric bursitis after total hip arthroplasty usually responds well to physical therapy and corticosteroid injections as needed. The extended trochanteric osteotomy is most commonly used in revision surgery…

Periprosthetic Fracture: Prevention, Diagnosis, and Treatment

Key Points The diagnosis of periprosthetic fractures is based on the history, physical examination, and radiographic evaluation. Attempts should be made to identify underlying causes of the fracture, if any. Use of a classification system helps the surgeon better understand the problem, construct a treatment algorithm, and maximize the chances of success. It is essential to classify the type of fracture and stability of the prosthesis…

Hip Instability

Key Points Instability is one of the most common indications for revision total hip arthroplasty in the United States. The cost burden for treating dislocation is substantial. Multiple risk factors for instability are known, including patient-specific (female gender, increasing age, lumbar spine disease, underlying diagnosis of avascular necrosis [AVN] or femoral neck fracture) and surgeon-specific factors (surgical approach, component orientation, head size, proper restoration of leg…

Infection

Key Points Periprosthetic infection with a total hip arthroplasty occurs at a rate of approximately 0.5% to 1%; the prevalence will increase substantially as the volume for this procedure grows to meet the projected demand. Prevention relies on optimizing patient selection and other host factors, improving the surgical suite environment, and administering prophylactic antibiotics. The most common infecting organisms are Gram-positive cocci (most notably Staphylococcus species)…

Revision for Metal-on-Metal or Taper Corrosion Failures

Key Points Awareness of metal-on-metal (MOM) failure and taper corrosion has increased and requires special consideration. Regular surveillance of MOM articulations is recommended. Thorough assessment is required to evaluate all common causes of postarthroplasty hip pain. A systematic diagnostic approach should be taken during the workup, including serum and synovial fluid markers of periprosthetic joint infection, metal levels, and advanced imaging when indicated. Traditional laboratory values…

Femoral Revision: Allograft Prosthetic Composites and Proximal Femoral Replacement

Key Points Revision of the femoral component in patients with failed total hip replacement with significant proximal femoral bone loss of more than 5 cm distal to the lesser trochanter may be accomplished by the use of allograft prosthetic composite (APC) or proximal femoral replacement (PFR). The use of proximal allograft aids trochanteric and abductor repairs, resulting in lower rates of abductor impairment, limping, instability, and dislocation…

Femoral Revision: Uncemented Tapered Fluted Modular Implants

Key Points The success of revision surgery of the hip can be divided into 3 parts: the prosthesis design, the surgical technique, and the patient. Surgical technique is probably the most important factor. The surgeon should understand the concept of press-fit fixation. For successful implantation and fixation of the stem, the importance of primary stability and secondary stability and their relevance to uncemented tapered, fluted, modular…

Femoral Revision: Uncemented Implants With Bioactive Coatings

Key Points Planning: Careful preoperative templating Instruments: Specific and complete instrumentation Implants: System of fully hydroxyapatite-coated stems Fixation: As proximal as possible Anchoring: As distal as necessary Introduction The choice of cementless versus cemented implants for mild and moderate bone stock loss is still a topic of controversy. Cementless femoral revision surgery for cases of severe deficiency has increasingly gained acceptance over the past decade because…

Femoral Revision: Uncemented Extensively Porous-Coated Implants

Key Points Managing femoral bone loss in revision total hip arthroplasty is challenging, requiring meticulous clinical evaluation and preoperative planning. The ideal revision femoral stem is easy to insert, can be used to treat most revision situations, and has reproducible clinical results. Extensively porous-coated stems can be used to treat most femoral defects. Preoperative planning and surgical technique are essential for success with extensively porous-coated stems.…

Femoral Revision: Impaction Bone Grafting

Key Points Impaction bone grafting provides restoration of bone stock loss. It is indicated for any age, but particularly in younger patients. The surgeon must adequately bypass and protect lytic defects or areas of weakness within the proximal femur with the use of longer stems, strut grafts, or plates, minimizing the risk of periprosthetic fracture. The procedure should be performed mainly in specialist centers, where a…

Cemented Femoral Revision in Total Hip Arthroplasty: A View in the 21st Century

Key Points Cement-bone interface strength is reduced in revisions owing to loss of cancellous bone and less cement interdigitation with bone. The historical rate of cemented femoral component failure was high when cemented revisions were used in all cases owing to mechanical failure of the cement-bone interface. Cemented femoral revision now is used mostly in first-time revisions of older, low-demand patients in whom good cancellous bone…

Femoral Revision: Classification of Bone Defects and Treatment Options

Key Points Failure of a primary total hip arthroplasty (THA) typically occurs with varying degrees of femoral bone loss. Classifying femoral bone defects is a critical part of the preoperative planning required for a successful revision THA. Paprosky, the American Academy of Orthopaedic Surgeons, Endo-Klink, Mallory, Saleh et al., Engh and Glassman, Gustillo and Pasternak, and Chandler and Penenberg have all published classification systems that differ in…

Acetabular Revision With Metal Cup Augments or Cage Construct

Key Points Several key steps are required to maximize the chance of a successful reconstruction and durable long-term fixation: Obtain excellent acetabular exposure and visualization. Minimize bone damage during prior implant removal. Cancellous bone grafting of contained bone defects. Maximize implant contact on host bone. Gain rigid initial fixation of the implant to allow subsequent bone ingrowth (with adjunctive fixation or support as needed). Major bone…

Acetabular Revision With Custom Implants

Key Points A thorough preoperative radiographic examination, including thin-slice computed tomography, is necessary to evaluate osseous defects and help identify a pelvic discontinuity. Extensive planning is necessary in the design of custom triflanged acetabular components (CTACs), which is a dynamic process often requiring multiple iterations. Obtaining an adequate buttress between the implant and remaining ilium is vital to reducing shear stresses on the flange screws. Failure…

Acetabular Revision: Impaction Bone Grafting

Key Points Acetabular impaction grafting allows restoration of bone stock and normal hip biomechanics. Acetabular impaction grafting is particularly successful as a technique for the reconstruction of cavitary defects. It is a technically exacting procedure; attention to surgical detail is required for successful results. The creation of a stable, contained acetabular defect is essential to its success. Secure fixation of mesh using appropriately placed screws is…

Acetabular Revision: Uncemented Hemispheric Components

Key Points A cementless hemispheric acetabular component has become the preferred system to employ for most acetabular revisions. Radiographic evidence of polyethylene wear with significant osteolysis warrants acetabular revision even in the absence of clinical or functional symptoms. The most critical feature of preoperative planning is careful evaluation of anteroposterior (AP) and lateral radiographs. A computed tomography (CT) scan with 3-dimensional (3D) reconstructions can be extremely…