Bridging the osteoarthritis treatment gap with the KineSpring Knee Implant System: early evidence in 100 patients with 1-year minimum follow-up

• Main Authors: London NJ, Smith J, Miller LE, Block JE
• Format: Article
• Language: English
• Published: Dove Medical Press 2013-09-01
• Series: Orthopedic Research and Reviews
• Online Access: http://www.dovepress.com/bridging-the-osteoarthritis-treatment-gap-with-the-kinespring-knee-imp-a14372

Nicholas J London,1 Jon Smith,2 Larry E Miller,3,4 Jon E Block4 1Department of Orthopaedic Surgery, Harrogate District Foundation Trust, Harrogate, UK; 2The Mid Yorkshire Hospitals NHS Trust, Yorkshire, UK; 3Miller Scientific Consulting, Arden, NC, USA; 4The Jon Block Group, San Francisco, CA, USA Abstract: Almost 4 million Americans are within the knee osteoarthritis (OA) treatment gap, the period from unsuccessful exhaustion of conservative treatment to major surgical intervention. New treatment alternatives for symptomatic knee OA are greatly needed. The purpose of this report was to assess outcomes of a joint-unloading implant (KineSpring&reg; Knee Implant System) in patients with symptomatic medial knee OA. A total of 100 patients enrolled in three clinical trials were treated with the KineSpring System and followed for a minimum of 1 year. All devices were successfully implanted and activated, with no operative complications. Knee pain severity improved 60% (P < 0.001) at 1 year, with 76% of patients reporting a minimum 30% improvement in pain severity. All Western Ontario and McMaster Universities Arthritis Index (WOMAC) subscores significantly improved at 1 year, with a 56% improvement in pain, 57% improvement in function, and a 39% improvement in stiffness (all P < 0.001). The percentage of patients experiencing a minimum 20% improvement in WOMAC subscores was 74% for pain, 83% for function, and 67% for stiffness. During follow-up, six (6%) patients required additional surgery, including four total knee arthroplasties and two high tibial osteotomies. The KineSpring System effectively bridges the treatment gap between failed conservative care and surgical joint-modifying procedures. Keywords: implant, KineSpring, knee, medial, osteoarthritis, unloading