Summary Statement

This study assesses the service provision of viscosupplementation within an NHS (British National Health System) hospital. The results of this study show long term efficacy of the treatment, when provided by a dedicated, orthopaedic unit.

Aim: To see if there are any differences in pain relief and complications with intraarticular Knee injection of avian and synthetic Hyaluronic acid products.

Methodology: After following the inclusion and exclusion criteria, 115 patients [130 Knees] were randomly allocated two groups, receiving either synthetic or natural Hyaluronic acid injections. Patients were explained about the study and consent was sought. They were given Western Ontario and McMaster University [WOMAC] questionnaires to be filled before, 48 hours, 6 weeks and 3 months after the injections. They were examined at 3 and 6 months post injections.

Results: 110 of these patients promptly responded. Avian product was injected in 66 Knees and synthetic product in 58 Knees.

In the avian injection group of 66 Knees, 57 had pain relief at 3 months.

In the synthetic injection group of 58 Knees, 48 had pain relief at 3 months

No complications were noted in either of the groups.

Using Chi square test and with 95% confidence interval, synthetic injection has no significant difference with avian injections in pain relief at 3 months [p=0.724].

Conclusion: Synthetic injections are equally safe and effective and economical than natural ones. So, using synthetic products gives pain relief to the patients and will also decrease the financial burden on the organisation.

Purpose of the study: To see if there are any differences in pain relief and complications with intraarticular Knee injection of synthetic and avian Hyaluronic acid products.

Summary: After following the inclusion and exclusion criteria, 130 patients were randomly allocated two groups, receiving either synthetic or avian Hyaluronic acid injections. Patients were explained about the study and consent was sought. They were given Western Ontario and McMaster University [WOMAC] questionnaires to be filled before, 48 hours, 6 weeks and 3 months after the injections. They were examined at 6 weeks, 3 and 6 months post injections.

124 of these patients promptly responded. 68 patients had natural product and 56 patients had synthetic product.

In the natural injection group of 68 patients, 57 had pain relief at 3 months and 20 of these continued to have relief at 6 months.

In the synthetic injection group of 56 patients, 48 had pain relief at 3 months and 28 of these continued to have relief at 6 months.

No complications were noted in either of the groups.

Difference of WOMAC scores were done at 6weeks and 3 months for each group. The p value of this difference of scores was 0.12 at 6 weeks and 0.92 at 3 months showing no significant difference. The 95% confidence intervals [avian vs synthetic] at 6weeks were −0.8 to 7.2 and at 3 months were −3.8 to 4.2. The p value of clinical examination at 6 months was 0.043 showing significance.

Conclusion: Synthetic injections are significantly more effective, economical and equally safe as avian injections.

This study was designed to identify the radiological changes of the knee that correlated with an unfavorable outcome when treated with an intra-articular knee viscoelastic supplementation. A prospective cohort of 60 patients receiving a standard course of intra-articular knee viscoelastic supplementation with a commercial uncrosslinked hyaluronic acid derivative of an intermediate molecular weight were studied.

Follow-up was for 12 weeks post treatment with clinical improvement measured using the Western Ontario and McMasters Universities Osteoarthritis Index. Radiographs of the relevant knee were viewed and graded for the severity of joint space, osteophyte, tibial spine, sclerosis, cyst formation, alignment and general severity by an observer blinded to the outcome of the treatment.

There were no appreciable differences noted in the age, sex, length of follow up, prior treatment, the severity of symptoms before treatment and number of intra-articular injections given per course in each radiographic category identified. There was a significant amount of improvement in patients with a minor loss of medial and lateral joint space in all outcome measures. Minimal changes in tibial spine and global appearance also indicated a positive outcome in stiffness, pain and overall improvement. Thus, patients with moderate to severe osteoarthritic changes in joint space on radiographic examination would not significantly benefit from intra-articular knee viscoelastic supplementation. In addition, we feel that changes in the tibial spine and global appearance are not reviewed consistently enough to be included as part of our recommendation. As such, we conclude that only patients with a minimal to mild loss in joint space on radiological examination should form part of the target group who are likely to benefit from intra-articular knee viscoelastic supplementation.