The patient found it hard to climb stairs--and to complete a particular task when getting dressed. Difficulty with that task provided a useful diagnostic clue.
AN 83-YEAR-OLD WOMAN, with an otherwise noncontributory past medical history, presented with chronic right knee pain. Over the prior 4 years, she had undergone evaluation by an outside physician and received several corticosteroid and hyaluronic acid intra-articular injections, without symptom resolution. She described the pain as a 4/10 at rest and as "severe" when climbing stairs and exercising. The pain was localized to her lower back and right groin and extended to her right knee. She also said that she found it difficult to put on her socks. An outside orthopedic surgeon recommended right total knee arthroplasty, prompting her to seek a second opinion.
Examination of her right knee was unrevealing. However, during the hip examination, there was a pronounced loss of range of motion and concordant pain reproduction with the FABER (combined flexion, abduction, external rotation) and FADIR (combined flexion, adduction, and internal rotation) maneuvers.
The patient's extensive clinical and diagnostic history, combined with benign knee examination and imaging (FIGURE 1), ruled out isolated knee pathology.
* WHAT IS YOUR DIAGNOSIS?
* HOW WOULD YOU TREAT THIS PATIENT?
Dx: Right hip OA with referred knee pain
The patient's history and physical exam prompted us to suspect right hip osteoarthritis (OA) with referred pain to the right knee. This suspicion was confirmed with hip radiographs (figure 2), which revealed significant OA of the right hip, as evidenced by marked joint space narrowing, subchondral sclerosis, and osteophytes. There was also superior migration of the right femoral head relative to the acetabulum. Additionally, there was loss of sphericity of the right femoral head, suggesting avascular necrosis with collapse.
Hip and knee OA are among the most common causes of disability worldwide. Knee and hip pain are estimated to affect up to 27% and 15% of the general population, respectively. (1,2) Referred knee pain secondary to hip pathology, also known as atypical knee pain, has been cited at highly variable rates, ranging from 2% to 27%. (3)
Eighty-six percent of patients with...