Evaluating the Symptomatic Hip Replacement
Because surgery is not the best option for all patients complaining of problems after total hip arthroplasty (THA), a thorough workup is necessary to determine the cause of symptoms and identify which patients who would benefit from a revision procedure.
As Aaron Rosenberg, MD, of Rush Medical College, Chicago, Illinois, shared with attendees at ICJR’s Philadelphia Revision Course, the workup includes a hip history, physical examination, x-rays, and other tests as needed.
Patients may present with a broad spectrum of complaints, including:
- Leg length discrepancy
The first step in the workup is to discover where the patient’s problem originates:
- Articular, affecting the hip joint
- Peri-articular, affecting tissues surrounding the hip joint
- Extra-articular, referred from elsewhere but experienced as if it were in the hip joint
Taking a hip history involves asking about:
- Symptoms that occurred before the THA procedure
- Pre-operative and current expectations
- Any problem-free interval
- Pain (if pain is a symptom), including character, location, radiation, aggravations, relief
- Ambulation distance before symptoms occur
The physical exam includes evaluation of:
- Gait, including stance phase, stride length, pelvic rotation, trunk shift, foot position
- Stance, including pelvic obliquity, Trendelenburg sign, lumbar spine motion, presence of scoliosis
- Active and passive range of motion
- Active and passive straight leg raise and any accompanying pain
- Pain on resisted motion
- Tenderness in the groin or trochanter
- Presence of a hernia
- Leg lengths
Neurovascular and muscular exams (adductors and abductors) should be done as well.
Extra-articular problems can be identified fairly easily. These are rarely issues involving weight-bearing or hip motion. In most cases, the lumbar spine is involved. For example, scoliosis is a common cause of symptoms in THA patients, who may think the pain is coming from the replaced hip instead of the spine.
Referred abdominal and pelvic pain can also be experienced as hip pain. Dr. Rosenberg offered a short list of causes:
- Intra-pelvic inflammation
Findings that suggest articular complications should be confirmed using x-rays, which can reveal a loose component, impingement, or metal-on-metal issues. Dr. Rosenberg recommends the following views:
- AP pelvis
- AP hip
- Lateral hip (frog, shoot-through)
- Acetabular oblique (if there is suspicion of an acetabular problem)
Comparing current x-rays with previous x-rays provides especially useful information, as they can reveal changes in the hip and implant over time.
A positive history and physical exam but negative x-rays suggest peri-articular problems such as neuropathy, vascular issues, and contractures. Peri-articular causes should be confirmed using MRI or a bone scan. However, although bone scans are very sensitive, they are not very specific in this situation. Dr. Rosenberg tends to use bone scans when:
- The x-rays are unremarkable.
- There is no other pain source.
- A patient is not going to have surgery and he wants a baseline scan to compare again future scans
A negative scan, Dr. Rosenberg said, is a good indication that the articulation is not the problem.
Dr. Rosenberg’s presentation can be found here.