To assess the efficacy of intra-articular steroid injections following arthroscopy and joint lavage in symptomatic OA of the knee.
Seventy-seven patients with OA of the knee were randomized to receive either 120 mg methylprednisolone acetate (MPA) or placebo following arthroscopy. Clinical assessments included severity of pain on movement and at rest, stiffness, the presence of joint effusions, range of movement, WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) score and Lequesne functional assessment. The outcome measures were evaluated at baseline and 2, 4, 8, 12 and 24 weeks. Further arthroscopies and synovial biopsies were performed at the time of clinical response and at relapse.
An intention-to-treat analysis was performed on 71 patients (38 MPA, 33 placebo). Using the OARSI (Osteoarthritis Research Society International) response criteria, 58% of the steroid group vs 33% of the placebo group (adjusted relative risk = 2.38) (P = 0.004) responded at 4 weeks. At other time points, there were no significant differences between the treatment groups. There were no significant differences between the two treatment groups for pain, stiffness or WOMAC or Lequesne assessments at any time point.
The response to intra-articular corticosteroids following joint lavage is short-lived (2-4 weeks), achievement of an OARSI response criterion being the only difference between the two groups.