Return to sports and physical activity after implantable shock absorber surgery for patients with medial knee osteoarthritis

Abstract

Objectives

Symptomatic knee osteoarthritis (OA) is a leading cause of disability. High tibial osteotomy and knee arthroplasty can deliver excellent outcomes, but are complicated by morbidity, times, and activity limitation. This study assesses activities of patients treated with an implantable shock absorber (ISA) that permits immediate weight bearing and unrestricted postoperative range of motion.

Methods

Subjects were prospectively treated with an ISA, 99% of whom had postprocedural physical therapy. Subjects rated their desired activities at baseline through 24 months. Subjects also rated their sports and recreation function and degree to which their knee feels “normal.”

Results

Data were available from 73 of 81 (91%) subjects. At baseline, 1.8% of activities could be performed with minimal or no limitation, while at 24 months, 64.4% could be performed with minimal or no limitation (P < .0001). Improvement was consistent across high impact, strength, and flexibility activities. Sports and recreation function on the Knee Injury and Osteoarthritis Outcome Score scale improved from a mean of 13.8 at baseline to 62.3 at 24 months (P < .0001). Furthermore, 69% of subjects stated that their knee “never” felt normal at baseline, which decreased to 19% at 24 months (P < .0001).

Conclusions

Treatment with ISA removed many activity limitations and made knees feel more normal, likley due to immediate return to full weight-bearing and no activity restriction. ISA represents a proven therapeutic option that provides symptomatic relief as well as return of activity.