Midterm Outcomes and Predictors of Clinical Success with the KineSpring Knee Implant System

Abstract

The purpose of this study was to (1) evaluate joint pain and function in knee osteoarthritis (OA) patients treated with a joint-sparing, extracapsular implant and (2) identify patient characteristics that influenced clinical outcomes. This study included 99 patients with symptomatic medial knee OA refractory to conservative care who were treated with the KineSpring Knee Implant System and followed for a mean of 17 months (range, 1.5 to 48 months). All devices were successfully implanted and activated with no intraoperative complications. Statistically significant mean improvements of 56%, 50%, and 38% were observed for Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain, Function, and Stiffness scales, respectively (all P < 0.001). Regardless of gender, age group, body mass index classification, or disease severity, all WOMAC domain scores significantly improved during the postoperative follow-up period. WOMAC clinical success rates were 77.8% for Pain, 77.8% for Function, and 68.7% for Stiffness. Neither gender, age group, body mass index classification, nor disease severity predicted clinical success in any WOMAC domain. In conclusion, the KineSpring System yields clinically meaningful improvements in joint pain and function in patients with medial knee OA. Additionally, unlike joint-altering procedures such as knee arthroplasty or high tibial osteotomy, patient characteristics had little association with postoperative clinical outcomes.

Post-traumatic knee osteoarthritis in the young patient: therapeutic dilemmas and emerging technologies

“…A recent study of 99 patients with 17 months mean follow-up reported excellent safety and effectiveness outcomes 78. All devices were successfully implanted and activated with no intraoperative complications.…”

“…The initial clinical experience with this implant is promising 78. A recent study of 99 patients with 17 months mean follow-up reported excellent safety and effectiveness outcomes 78.…”

Minimally Invasive Load-Sharing Implant for Medial Compartment Knee Osteoarthritis

“…2 Additional studies are underway to further characterize the safety and efficacy of this novel implant for treatment of medial knee OA.…”

Early knee osteoarthritis management should first address mechanical joint overload

“…Extra-capsular (non-articular) medial compartment knee load absorber implants fixed to the medial distal femoral cortex and the medial proximal tibial cortex to achieve offloading of the medial compartment are under evaluation 31 , 32 . A recent series of patients with Kellgren-Lawrence grade I or II knee OA treated with this joint unloading implant and followed for at least 1 year reported a 70% decrease in WOMAC Pain, a 68% decrease in WOMAC Function, and a 59% decrease in WOMAC Stiffness scores 33 , 34 . The premise of these implants is that the device is surgically implanted via a minimally invasive incision, the joint remains fully intact, the procedure is reversible, and the medial knee compartment is unloaded sufficiently to reduce pain and improve joint function.…”