This condition is akin to the presentation of frozen shoulder but affecting the hip.
This 65-year-old female patient presented with a three-month history of insidious onset pain in the groin and hip with no history of trauma.
She reported gradual limitation in the range of motion, particularly with internal rotation, and was symptomatic only on the left side. She experienced no shoulder or neck symptoms and no constitutional symptoms. Inflammatory markers were within normal limits.
Image findings
At MRI, there was striking high signal thickening of the left hip capsule with pericapsular oedema. There is no evidence of trochanteric bursitis, and in fact the hip joint cartilage, joint fluid, synovium and labrum all appear somewhat unremarkable. This appearance is different from synovitis, which typically is associated with prominent joint fluid and is depicted as intermediate signal “frond like” thickening of the inner lining of the joint.
A nuclear medicine Technetium bone scan was also performed that exhibited no abnormality to radionuclide uptake in the shoulder or hip girdle.
Analysis
This is an example of a relatively uncommon and not well understood hip condition termed “adhesive capsulitis of the hip”. This is akin to the presentation of frozen shoulder but affecting the hip.
The differential diagnosis of polymyalgia rheumatica (PMR) would be much less likely as this condition typically presents with bilateral hip symptoms, and on imaging presents with bursitis (mostly trochanteric bursitis; occasionally iliopsoas bursitis or ischiogluteal bursitis) and effusion and synovitis. Inflammatory markers should be elevated. These features were conspicuously absent. Also, presentation of PMR is most commonly with bilateral shoulder involvement which can exhibit abnormal radionuclide uptake of the shoulders. These features were also conspicuously absent.
Management
Management of adhesive capsulitis of the hip aims to reduce inflammation in the acute stages with anti-inflammatory medication, intra-articular steroid injections and targeted physiotherapy. In chronic stages of the disease, treatment is directed towards arresting the progression of fibrotic changes and regaining range of motion through more aggressive physiotherapy.
Following three months of conservative therapy, if the symptoms persist more invasive procedures could be considered, such as manipulation under anaesthesia, hydrodilatation, surgical synovectomy or capsular release.
Dr Sebastian Fung is a musculoskeletal radiologist who undertook an MRI imaging fellowship in Hospital for Special Surgery in New York. He now works in Sydney at St Vincent’s Private Hospital and Mater Hospital.
