Abstract
Statement of Purpose
The UK and Australian clinical experience of an implantable load absorber was reviewed for knee OA patients who have exhausted conservative care, but are not ideal candidates for HTO or arthroplasty due to age, activity level, obesity, or disinclination.
Methods and Results
The load absorber was implanted in 58 patients, with the longest duration exceeding two years. Patients included younger OA sufferers (31-68 years), and had a mean BMI > 30kg/m2. Early surgical experience and adverse events with the device were recorded and clinical outcomes using validated patient reported outcomes tools were collected at baseline, post-op, 2 and 6 weeks, and 3, 6, 12 and 24 month timepoints.
All patients were successfully implanted with a mean surgical time of 76.4 minutes (range 54-153). After a mean hospital stay of 1.7 days (range 1-3), patients resumed full weight bearing within 1-2 weeks and achieved normal range of motion by 6 weeks. Mean WOMAC pain (0-100 scale) improved from 42.4 to 16.1 (p<0.001); mean WOMAC function (0-100 scale) improved from 42.0 to 14.7 (p<0.001). Most patients reported “no or mild” pain (85%) or “no or mild” functional impairment (90%) at last follow-up (9.5 ± 3.5 months). Patients reported high satisfaction with the implant. Initial UK results mirror the positive Australian experience: reduced pain, improved function, and high satisfaction.
Complications arising in the early surgical experience were effectively resolved through revised surgical technique and minor design modifications.
Conclusions
The initial UK experience with the load absorber is consistent with the positive Australian experience. The load absorber preserves natural knee anatomy and kinematics whilst providing durable pain relief and resumption of high activity levels. This device, with these early encouraging results, can fill a major void in the treatment options for young and active OA patients.
