Total knee replacement following repeated cycles of intra-articular sodium hyaluronate (500-730 Kda) in failed conservative treatment of knee osteoarthritis: a 54-month follow-up.

BACKGROUND: Treatment with repeated cycles of Intra-Articular Sodium Hyaluronate (IA-HA), from previous study, can improve symptoms and delay surgical interventions in knee osteoarthritis patients who failed conservative treatment within minimum 2-years follow-up. This is a continued study to follow-up responded patients in the mentioned study whether continuing treatment with IA-HA could prolong time to surgery until the end of follow-up.

OBJECTIVE: To evaluate the incidence of total knee replacement (TKR) in patients receiving repeated cycles of IA-HA during a 54-month follow-up period.

MATERIAL AND METHOD: This was a prospective cohort study with 54-month follow-up period. All patients received at least a single course of 3-weekly injections of IA-HA (500-730 Kilodalton, Hyalgan). Patients who well responded to the treatment were recommended to repeat the administration of a 3-weekly injections every 6-12 months based on their symptoms. The incidence of TKR and time was recorded. Time to event analysis using Kaplan-Meier survival analysis was performed.

RESULTS: 183 patients were recruited during March 2001 and March 2004 and followed-up until October 2008. Patients were classified into three groups according to Ahlback radiological grading system. 46 patients were in group 1 (Ahlback grade I-II), 70 patients were in group 2 (Ahlback grade III-IV) and 67 patients were in group 3 (Ahlback grade V). The incidence of TKR was 28.4% with a mean time to TKR of 15.4 months (0.7-51.7 months). For the rest of patients who had no TKR during study period (80.4%, 64.3% and 73.1% for group 1, 2, and 3 respectively), their mean follow-up time was 45.6 months (19.0-53.1 months). Mean survival time was 42.1 months (95% CI = 39.4-44.9 months).

CONCLUSION: The repeated cycles of intra-articular sodium hyaluronate treatment in delay time to TKR in patients with knee osteoarthritis which failed conservative treatment was found efficacious during a 54-month follow-up period.