Intra-articular hip viscosupplementation with synthetic hyaluronic acid for osteoarthritis: efficacy, safety and relation to pre-injection radiographs

The aim of this study was to determine the efficacy and safety of viscosupplementation with synthetic hyaluronic acid to the hip joint and to determine if there was any relation to pre-injection radiographic changes of osteoarthritis (OA). Three Suplasyn injections were performed each to 15 hips with OA. Standing antero-posterior radiographs of the pelvis were performed prior to injection and scored according to Kelgren and Lawrence grades along with recordings of the minimum joint space width. Harris Hip Scores (HHS) which contain a component for pain, function, activities, absence of deformity and range of motion were recorded pre-injection and at 3 and 6 months. We established that at 3 months the HHS is significantly higher (P < 0.05). At 6 months, four hips had been excluded as they has went on to total hip arthroplasty (these hips showed a lower HHS at 3 months). For the remaining hips the HHS was highly significantly increased (P < 0.001). No side effects or complications were observed. Analysis of the pre-injection radiographs showed a trend towards a bigger increase in HHS with less radiographic OA changes. Viscosupplementation performed under fluoroscopic guidance is an effective and safe method of treating hip OA and appears to be more efficacious in those with less radiographic changes of OA.