A Randomised Double Blind Controlled Trial of Injection of Local Anaesthetic and Corticosteroid Under Ultrasound Control in the Greater Trochanteric Pain Syndrome.

The greater trochanteric pain syndrome (GTPS) is a frequent soft tissue syndrome which is often not recognised by medical practitioners. Currently, there is no validated definition of this syndrome and it is classically defined as pain and tenderness in the region of the greater trochanter that may radiate down to the postero-lateral aspect of the thigh and may mimic nerve root compression. The prevalence of GTPS amongst adult patients referred to a spine clinic for chronic low back pain (LBP) has been reported to be 20-35%. In addition to pain, GTPS induces functional disability which at times may profoundly interfere with patients' daily activities. The diagnosis of GTPS is suspected in a patient complaining of lateral hip pain. The reproduction of typical pain on palpation of the posterior part of the greater trochanter is the only well recognised clinical sign, although other clinical signs have been described. As is frequently the case with these type of syndromes, the physiopathology of GTPS is probably a mixture of several musculoskeletal problems, among which trochanteric bursitis and gluteus medius (GMe) tendinosis are the most frequently cited. MRI studies have demonstrated GMe tendinosis or tears in patients with GTPS and MRI is used as the gold standard for the diagnosis of GTPS in many studies. Musculoskeletal ultrasound (US) is of increasing interest among rheumatologists. It readily demonstrates soft tissue lesions, fluid collections, allows dynamic examination and the undertaking of ultrasound guided procedures. GMe and gluteus minus (GMi) tendinopathy or tears as well as bursitis can be clearly demonstrated by ultrasound and US may guide steroid injection for the treatment of GMe tendinopathy. However, to date no study has compared the utility of MRI compared to US. There are very few well-performed studies regarding the treatment of GTPS. Although poorly studied, analgesics and non steroidal anti-inflammatory drugs (NSAIDs) are often used as first line therapy. The duration of therapy required with these oral agents is unknown and there are significant potential side-effects from these treatments. The vast majority of patients referred to secondary or tertiary centres have failed these oral therapies. Some authors advocate physiotherapy (massage or stretching) but once again, there is no strong evidence to support this approach. Thus, most patients are treated with an injection of a combination of steroids and local anaesthetic. However, there is no convincing evidence in the literature that this practice is effective. The use of musculoskeletal ultrasound (US) has been shown to improve the accuracy of corticosteroid injections for many joints and extra-articular structures such as bursa and tendon sheaths. Although small observational studies have suggested that local corticosteroid injection may be effective in the short term, no prospective controlled study has been carried out to establish the efficacy of this common intervention.