Presentation
89yo previously active, living independently with family support, presents with a painful right knee for an opinion and management.
12 month history of right knee pain, mainly medial in location. No injury. Also distal thigh pain. Underwent right knee arthroscopy 6 months previously (Nov 2015) for treatment of a meniscal tear (degenerative). No sustained improvement post scope. No history of knee swelling or locking. Some giving way episodes right leg. Patient reports a progressive deterioration in pain, requiring regular oral analgesics. Using a walking frame to ambulate last 3 months, becoming more difficult to maintain independence.
Examination
Antalgic gait. Short right leg 1.5 cm. Right knee – well healed scope scars, no effusion, flexed posture whilst lying supine but no fixed contracture (able to be fully extended passively), good ROM, mild patellar crepitus, no local tenderness. Right hip – 35 degree flexion contracture, markedly reduced ROM (flexion 75 degrees) with bony crepitus. Hip movement reproduces knee and thigh pain.
Investigations
Xray right knee 2015 – essentially normal.
MRI scan right knee Oct 2015 – degenerative medial meniscus tear. Mild patellofemoral arthritis. Good preservation of medial and lateral articular cartilage.
Xray right hip ordered May 2016 – degenerative arthritis with complete joint space loss and femoral head flattening.
Diagnosis
Advanced Osteoarthritis of the right hip.
Recommendation
Consideration of total hip replacement surgery. Has serendipitously tried reasonable conservative treatment measures for hip arthritis with activity reduction, analgesia and gait aids to assist with ambulation.
Case Comment
Older patients with hip arthritis can present with predominantly knee pain. The presence of thigh pain in addition to knee pain is a clue to the diagnosis. A considered examination should point to the hip as the pain source. This situation can also occur in children – slipped upper femoral epiphysis classically presents with knee pain.
It is uncommon to recommend hip replacement in a patient of this age. However deterioration has been quite acute and the patient is otherwise medically well but very significantly incapacitated. Ability to manage at home alone even with support is threatened. Hip replacement is the only treatment option that would have a high likelihood of major pain and quality of life improvement.
Meniscal tears are almost universal at this age on MRI scan. Degenerative tears with mainly a horizontal or cleavage component are not unstable as a general rule and most unlikely to cause pain and mechanical symptoms. Surgery for these tears is often unrewarding.
