Intra-articular Synject in the Management of Knee OA in Nigeria

Method: 20 patients with clinical and radiological evidence of knee OA had intra-articular injection of 2mls 0.9% hyaluronic acid (in a pre-packed syringe) under aseptic condition. The knee pain was scored using the visual analogue scale (VAS) prior to and one week after injection. The plain radiographs of the affected knees at first presentation to the hospital were scored using the radiographic atlas by Spector and Cooper (Figure 2).

Results: There were 18 female and 2 male patients in this study. The mean VAS was 7.5 prior to the injection but this reduced to an average of 3 one week after the injection. There was further decline in the VAS to 2.5 on completion of the once-weekly Synject injection in 10 patients. However, many patients declined further injections because of the remarkable relief of pain and opted to report for review when they experience noticeable knee pain. Of the 10 patients followed up for 12 weeks, there was a gradual decline in the pain score over time. Over 90% of the knee radiographs had severe OA changes when they were scored using the radiographic atlas by Spector and Cooper.

Conclusion: The initial result of pain reduction following intra-articular injection of 0.9% hyaluronic acid (Synject) in knee OA in Nigerian patients is encouraging and the long-term effect of a 3-course once weekly injection has been embarked upon. This is in spite of the late presentation of these patients consequent on self-medication and easy access to analgesics and anti-inflammatory drugs without prescription. The patients in this pilot study will be followed-up to ascertain the long-term effect of this medication.