Evaluation of the Failed Total Hip Arthroplasty: History and Physical Examination

CASE STUDY

A 45-year-old man presented with bilateral hip pain (greater on the right side than the left) that had been worsening over the past 5 years. The pain was located in the groin and was exacerbated by walking. His hip motion had deteriorated over time. Radiographs demonstrated severe osteoarthritis, and total hip arthroplasty (THA) was recommended ( Fig. 38.1 ).

FIGURE 38.1, A 45-year-old man who presented with a 5-year history of worsening right hip pain was treated with cementless primary total hip arthroplasty using a short, tapered stem and a ceramic on highly cross-linked polyethylene bearing.

THA was performed by a less-invasive direct lateral approach without complication. At regular postoperative assessments during the first 6 months, he complained of low-grade right hip pain, but he was able to return to work.

He presented 2.5 years after surgery with continued and mildly worsening right hip pain that he said had never resolved ( Fig. 38.2 ). Radiographs were obtained, and lucency was observed in Gruen zones 1 and 7. We assumed that ingrowth of the femoral stem had failed and that it had become loose. Laboratory studies, including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), were ordered to rule out infection. Because the ESR and CRP levels were mildly elevated, aspiration was ordered. It yielded minimal fluid and a culture that was positive for Staphylococcus epidermidis . Repeat aspiration was performed, and a white blood cell count of 57,500 cells/µL was obtained with 93% polymorphonuclear leukocytes (PMNs). The culture result was again positive for S. epidermidis . The patient was treated for infection in stages with radical débridement, placement of an antibiotic-laden polymethylmethacrylate articulating spacer, and a 6-week course of intravenous antibiotics followed by reimplantation.

FIGURE 38.2, Three years later, the same patient as in Figure 38.1 returned with persistent right hip pain. Radiographs obtained 3 years after the total hip arthroplasty demonstrate signs of loosening compared with the initial postoperative radiographs.

Algorithm

The algorithm in this chapter summarizes the steps that are followed when assessing the patient who presents with a painful hip after undergoing total hip arthroplasty (THA).

CRP , C-reactive protein; ESR , erythrocyte sedimentation rate; MARS , metal artifact reduction sequence; MRI , magnetic resonance imaging; ORIF , open reduction and internal fixation; WBC , white blood cell.

Chapter Preview

Total hip arthroplasty (THA) is increasingly common and very successful, but a small percentage of patients continues to have hip pain postoperatively.
A detailed history and physical examination are necessary to accurately diagnose the source of the failed THA.
The differential diagnosis is broad, and an algorithmic approach must consider intrinsic and extrinsic causes of pain.
Even in the presence of obvious mechanical failure or instability, infection must be ruled out, because the treatment is fundamentally different from that for an aseptic revision.
Metal-on-metal bearings are associated with unique complications, but because data to guide the workup are sparse, skillful and attentive communication with the patient is required.

Introduction

Total hip arthroplasty (THA) is one of the most common orthopedic procedures. An estimated 280,000 procedures are performed annually at a cost of $12 billion in the United States. The number is projected to increase to approximately 572,000 procedures performed annually by the year 2030. Analyses have demonstrated that THA is one of the most cost-effective interventions in health care.

Follow-up assessments have demonstrated high clinical success rates, defined by patient satisfaction, reduction in pain, and improvement in function. Despite these successes, approximately 25% of patients report some level of pain at the 6-month follow-up. Britton and colleagues reported that the pain tended to improve slightly from 6 months to 2 years postoperatively but began to gradually deteriorate after 4 years. They also reported that pain correlated with patient opinion and was predictive of revision.

The estimated probability of THA revision at 5 years is 4.1%, with revisions accounting for approximately 18% of the THA procedures performed annually in the United States. This revision burden is expected to grow over the next 2 decades. Revision THA results in increased institutional costs, longer lengths of hospital stay, longer operative times, and increased risks for patients with less predictable clinical benefits. These are most commonly performed because of instability, mechanical loosening, and infection. The need for hip arthroplasty surgeons to systematically and accurately evaluate the patient with a painful, potentially failed THA will become increasingly important as patient volume grows in the setting of diminishing resources.

Indication and Contraindications

A medical history, physical examination, and radiographic evaluation are indicated each time a THA patient is seen during follow-up, especially if there is a complaint of pain postoperatively. Laboratory testing usually is indicated.

Equipment

The medical history and physical examination require minimal equipment. A goniometer is helpful to accurately quantify motion of the hip and knee. Graduated blocks may be required to accurately assess a limb length discrepancy (LLD) in the standing patient. A reflex hammer may assist in a thorough neurologic examination that includes assessing deep tendon reflexes. Access is needed to plain radiography viewing equipment, such as a picture archiving and communication system (PACS) or a light box.

Laboratory evaluation is necessary in most cases. It is facilitated by convenient access to a laboratory with a full range of services, including synovial fluid analysis and ESR and CRP determinations. Testing of serum levels of metal ions, including chromium and cobalt, use specific protocols that, for example, require collection of blood samples in certified metal-free vacutainers. Compliance with published protocols should be verified before basing clinical decisions on reported levels.

Evaluation Techniques

When a patient presents with a painful THA, a thorough investigation must follow to ensure that important information is not overlooked. An algorithmic approach is recommended. The algorithm may be completed in a single office visit, but return appointments and follow-up testing often are required. Communication with the patient regarding imaging and laboratory testing results cannot be overemphasized, because pain after THA may be a tremendous source of anxiety for patients. Application of this algorithm requires an understanding of the broad differential diagnosis of pain after THA ( Table 38.1 ).

Table 38.1

Differential Diagnosis of the Painful Total Hip Replacement

Intrinsic causes	Infection Mechanical loosening Tip of stem pain (modulus mismatch) Stress fracture Periprosthetic fracture Nonunion Osteolysis Occult instability Inflammatory bursitis (trochanteric) Inflammatory tendonitis (iliopsoas)
Extrinsic causes	Lumbar spine disease Stenosis Disc herniation Spondylolysis or spondylolisthesis Peripheral vascular disease Nerve injury or irritation (sciatic, femoral, meralgia paresthetica) Causalgia or complex regional pain syndrome Metabolic disease (Paget’s disease, osteomalacia) Malignancy or metastases Hernia (femoral, inguinal, obturator)

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