Effectiveness of Ultrasound-guided versus Landmark-based Glucocorticoid Injection in the Treatment of First Carpometacarpal Joint Osteoarthritis.

Background: Osteoarthritis is a debilitating degenerative disease more pronounced in elderly affecting many joints. The first carpometacarpal joint (CMC1) is commonly affected. Pain is the major complaint, which can impact patient's daily activities. Intra-articular glucocorticoid injection can be considered if conservative measures fail and ultrasound guided injection might be superior to the traditional anatomic landmark-guided technique. Objective: The aim of this study is to evaluate the effectiveness of ultrasound-guided versus landmark-based approach to intra-articular CMC1 injection using the Australian Canadian osteoarthritis hand index (AUSCAN). Methods: Adult patients diagnosed with symptomatic CMC1 osteoarthritis who failed conservative measures were enrolled. In this prospective observational cohort study, utilizing a convenience sample, intra-articular corticosteroid injection was administered either by ultrasound-guided technique or landmark-based approach. Pain, stiffness and function in 10-points scale at baseline, 6 and 12 weeks were collected and analyzed using descriptive analysis. Results: There were 33 patients enrolled. Mean age was 63 years, with females making up the majority of participants (n = 28, 84.8%). Mean duration of CMC1 pain was 10 months (SD=2.5) up to the point of receiving the injection. Ultrasound guided injection was performed in 60.6% (n=20), while 39.4% (n=13) had the landmark approach. Both groups achieved a statistically and clinically significant level of change in AUSCAN score at week 6 (P≤ 0.05) but with a recurrence of symptoms at week 12 (P ≤ 0.05). At both intervals the AUSCAN scores were better than baseline (P ≤ 0.05). There was no difference between the two groups regarding baseline pain VAS score (mean ultrasound group= 6.6 vs landmark group= 7.5; P = 0.18). No significant differences were identified between two groups in terms of changes from baseline to 6, 12 and between 6 to 12 weeks in pain, stiffness and hand function (P > 0.05). Conclusion: No difference was found between the ultrasound-guided and landmark-based approaches for CMC1 injection on pain score, stiffness, or function.