Unloading the osteoarthritic knee with a novel implant system

Area of Science:

• Orthopedics
• Biomechanics
• Biomedical Engineering

Background:

• Medial knee osteoarthritis (OA) is a prevalent condition often caused by abnormal joint loading.
• Current treatments like insoles, braces, and high tibial osteotomy have limitations in reducing medial knee joint loads effectively.

Purpose of the Study:

• To evaluate the efficacy of the KineSpring System implant in reducing knee joint loads in patients with medial knee OA.
• To assess the implant's impact on medial and lateral femorotibial contact pressures during simulated gait.

Main Methods:

• Six cadaver knees with Outerbridge Grade I-II medial OA were utilized.
• A kinematic test system simulated gait, and thin film sensors measured femorotibial contact pressures.
• Knees were tested both with and without the KineSpring System implant.

Main Results:

• The KineSpring System implant resulted in significant reductions in medial compartment knee loads (134 ± 53 N, P = .002) during the stance phase of gait.
• Significant decreases in total joint loads (91 ± 40 N, P = .002) were observed.
• These load reductions were achieved without substantial alterations in lateral compartment knee loads.

Conclusions:

• The KineSpring System implant effectively reduces medial and total intra-articular knee loads.
• The observed load reductions are comparable to clinically effective unloading systems.
• The KineSpring System presents a potential viable treatment option for medial knee osteoarthritis.