Evaluation of the Failed Total Hip Arthroplasty

History

Pain is the most common presentation of a patient with a failed THA. Characterizing the temporal onset, duration, severity, location, and quality of the pain and/or functional impairment is essential in determining whether the symptoms are due to intrinsic hip pathology or extrinsic causes ( Table 88.1 ). Additionally, information concerning potential signs and symptoms of hip instability and infection should be obtained, along with a past medical and surgical history and review of systems, patient-reported joint-specific and general health measures, and an assessment of patient expectations.

If the patient's preoperative pain complaints remain unresolved postoperatively in the absence of a pain-free interval, the original diagnosis prior to surgery should be questioned. If the pain differs and is worse postoperatively without a meaningful pain-free interval, a high index of suspicion should be present for a postoperative complication. Examples include infection, hematoma, component instability or loosening, impingement, or intraoperative fracture. The delayed onset of pain around a previously well-functioning implant suggests that the inciting problem may be the implant itself, as can be seen in osteolysis, implant loosening, wear-related instability, adverse local tissue reactions (ALTRs) to metal debris, and chronic infection.

Determining the anatomic location of the symptoms aids in narrowing the differential diagnosis. Commonly cited locations of pain include the lateral aspect of the hip and/or thigh, buttock pain, groin pain, and thigh pain. Pain localized over the lateral aspect of the hip/thigh suggests a source originating in the lateral aspect of the femur or the overlying soft tissues. Examples of bony sources of lateral pain include osteolysis and pathologic or stress fractures, whereas soft tissue causes can include muscle strain, trochanteric bursitis, and suture/wire irritation. Although buttock pain can be an indication of acetabular loosening or other pelvic-sided complications, it is also typical of vascular or neurogenic claudication. These diagnoses should be considered in addition to any implant-related causes. This is especially important in the setting of bilateral symptoms or when the pain is associated with radiation distal to the knee. Groin pain commonly originates from the region of the hip articulation and may indicate intraarticular issues, such as bearing wear, acetabular loosening, and osteolysis. However, it may also be related to extraarticular hip-related causes, such as iliopsoas tendinitis and/or impingement, or insufficiency fracture of the pubic rami. Although less common, nonorthopedic extraarticular causes—such as hernias and gynecologic/genitourinary problems—may also present as groin pain. Thigh pain typically suggests an issue at or around the femoral stem. Examples include stem micromotion, excessive stress transfer in the setting of a large rigid implant, component loosening, and fracture. Another source of thigh pain is the lateral femoral cutaneous nerve, typically presenting with burning neuropathic symptoms. These can be due to injury at the time of anterior approach to the hip or from causes unrelated to the hip surgery, as in meralgia paresthetica.

It is important to note circumstances that aggravate and alleviate symptoms. Night pain or persistent pain at rest is suggestive of a nonmechanical cause, such as infection, malignancy, or an ALTR. Pain that is severe with initiating movements—such as getting out of a chair or taking first steps, but improves once active—is known as start-up pain and is associated with component loosening. Symptoms that are positional or reproduced with specific movements tend to suggest particular underlying causes. For example, groin pain reproduced with active hip flexion, especially against resistance, suggests iliopsoas tendinitis, whereas lateral hip pain reproduced with active hip extension and circumduction suggests a snapping iliotibial band. Any history of a traumatic event, such as a sudden slip or fall, preceding the onset of painful symptoms raises the suspicion of traumatic loosening or fracture. Patients with a history of contralateral hip, knee, or spine pathology may experience increasing pain in those joints postoperatively as a result of an increase in their activity levels.

Any patient-reported concerns about instability or “giving out” of their hip merit further questioning. Frank dislocations of the hip are rarely subtle events. Most patients will have sought emergency department treatment for them, and often the dislocation will have been radiographically documented. In the setting of acute or previous dislocation, information surrounding the episode(s)—including temporal relationship to the arthroplasty surgery, inciting movement/cause, and any history of previous dislocations—is crucial in helping elucidate the cause of instability. Patients may also describe a recurrent sensation of popping or clicking with or without previous history of dislocation, suggesting abnormal motion at an implant interface. This can be as a result of polyethylene bearing wear but can also be due to several other intraarticular causes—such as impingement, modular junction failure, implant subsidence, and soft tissue compromise secondary to metal debris. It is important to also consider extraarticular causes of instability. Patients with external or internal snapping hips frequently present with a chief complaint of hip instability or subluxation, mistaking the soft tissue snapping for their hip shifting in its socket.

Periprosthetic infection must always be included in the differential diagnosis for a painful or poorly functioning prosthetic joint, and pertinent questions should be included when obtaining the patient history. The goal is not only to determine whether a periprosthetic infection is the likely cause of symptoms but also to attempt to clarify its chronicity and source. One common approach is to stratify infections by whether they are acute (3 weeks or less since onset) or chronic and whether the infection arose by direct invasion (e.g., seeding during surgery or via wound compromise) or hematogenous spread. Patients should be asked about any systemic or constitutional symptoms that might suggest infection, such as fever, chills, sweating, and malaise. Similarly, clinicians should look for the presence of any local signs of infection, such as persistent or purulent wound drainage, or presence of a red, swollen wound. Although such signs and symptoms often accompany acute postoperative infections, chronic, low-grade, indolent periprosthetic infections rarely present with such classic signs and symptoms of infection. Consequently, it is also important to ask about any prior or remote history of joint infection, persistent or purulent drainage, and prolonged antibiotic use for incisional problems that might suggest recurrence of a previous or suppressed infection. There may be a history of previous infection from another source that preceded the hip symptoms. In the case of acute hematogenous infection of a previously well-functioning joint, patients usually can recall a previous dental procedure, respiratory infection, genitourinary procedure or infection, or open skin lesion before the onset of symptoms. However, medications such as antibiotics or steroids can mask these symptoms. Immunocompromised patients, intravenous (IV) drug users, and patients who require frequent urinary catheterizations are at higher risk.

In attempting to assess the impact that the problematic THA is having on daily activities, it can be helpful to quantify the patient's functional status and degree of disability using standardized questionnaires. Ideally, these instruments should be short, validated, and assess meaningful outcomes from the patient's perspective. It is useful to obtain information using both a disease-specific instrument and a general health questionnaire, which together can provide insight into the relative contribution of the hip symptoms to overall physical and mental health. Examples of these instruments can be found in Table 88.2 . If age-adjusted values for the general population are available, these can also be helpful to place the patient's level of disability and function into context relative to the general population. By comparing scores over time, these instruments can be useful in assessing the success of any future treatment. Consider also obtaining a third patient-reported outcome measure that assesses psychological factors, such as depression, anxiety, catastrophizing, or resilience. This can provide valuable information concerning the effect of any hip symptoms on the patient's psychological well-being and ability to cope with them. For patients whose hip was never satisfactory or problem free following the initial surgery, consider exploring what their expectations were for the procedure and how these may differ from their current state. Although less common in hip arthroplasty as compared with knee replacement, in some cases the dissatisfaction may be the result of unmet expectations and not an underlying organic cause.

The patient's medical and surgical history, medications, and a review of systems should be obtained. Most often, THA is performed on members of the elderly population who may have comorbidities that predispose them to certain postoperative complications and/or extrinsic causes of hip pain. Just a few examples would include history of spinal or vascular disease, diabetes, or inflammatory arthritis. The presence of constitutional symptoms should not be overlooked, thereby avoiding the danger of missing an underlying infection or malignant process. Atypical femoral fractures associated with bisphosphonate therapy have been reported following THA ; they should be considered in any patient with a painful THA and a history of prolonged antiresorptive therapy.

Elements of this history may factor into future treatment decision making, especially if revision surgery is being considered. For example, any history of venous ulcers or vascular insufficiency may warrant a vascular surgery consultation. A positive cardiac history will require preoperative risk assessment and medical optimization. Patients who have received previous radiation treatment to the pelvis may have different surgical options because traditional porous-coated implants may not be suitable for use in this setting. Finally, all previous hip operations should be documented. An attempt should be made to obtain all operative records from the previous operations, especially the most recent one, along with the implant labels. These will provide insight into any technical challenges that may have arisen. They also describe the type and size of implant that was used, providing valuable diagnostic information in addition to being invaluable in preoperative planning and assessment of compatibility and the need for specific extraction instruments if revision surgery is contemplated. The presence of metal-on-metal articulations, modular junctions, or recalled implants should increase suspicion for component failure. However, surgeons should also remain sensitive to the fact that patients who know that they have a high-risk implant may experience heightened anxiety and worry that a mild ache or strain represents impending catastrophic implant failure. Although the subject of allergy to orthopedic implants is controversial, consider asking about any known metal allergies as well as skin reactions to contact with costume jewelry or specific metals.