Partial Knee Replacement

Dr.Vijay Bose

A young 52-year-old mother who had treatment for breast cancer earlier presented with severe right knee pain limiting her daily activities. The pain was confined to the inner aspect of her knee joint. The x-ray examination showed severely damaged cartilage on the medial (inner) compartment alone. The knee has 3 compartments and the other two compartments were pristine. She was treated with conservative methods and intraarticular injections, but this did not work as there was no cartilage remaining in the inner compartment. Once full thickness cartilage loss occurs the only solution is surgical. The routinely done Total Knee Replacement would be an over kill for such a young lady with limited arthritis and hence we performed Partial Knee Replacement (Unicompartmental knee Replacement) which is relatively new in India.

A mini skin incision was used. The eroded bone on the medial (inner) side of the knee is freshened and resurfaced with suitable sized implants recreating the normal anatomy and biomechanics allowing full range of motion without the arthritic pain. The rest of the bones and more importantly the ligaments of the knee were left untouched. (In the total knee replacement surgery the ligaments are removed) The preservation of ligaments gives the partial knee replacement a natural feel (proprioception) that precisely mirrors the other non-operated knee. With mini skin incision the post-operative pain is much less and the post operative rehabilitation recovery was much faster when compared to the routinely done Total Knee Replacement.

Partial Knee Replacement
Partial Knee Replacement

 

Partial Knee Replacement

The incidence of knee arthritis in younger patients is dramatically increasing in India possibly due to the modern lifestyle changes. The non-operative management of such patients is crucial which consists of weight loss, lifestyle modifications, physiotherapy and joint injections. However, for some patients the progressive loss of joint cartilage is relentless resulting in bone on bone situation at which point the only option is surgery. The routinely done Total Knee Replacement can be considered to be too severe an intervention for patients with changes limited to one side of the joint. It goes without saying that bone conservation becomes more critical with decreasing age of the patient. One of the significant features of the partial knee replacement is that a total knee replacement can be done later if required though current studies indicate that revision surgery is unlikely. The only issue with a partial knee replacement is that it is a very technique sensitive and the bearing can dislocate unlike a TKR.

The surgeon experience with this procedure is an important determinant of final outcome.

The patient had complete relief of pain within 3 weeks and was able to do all her household chores and cope with the demands of her job in an insurance company. She does yoga regularly and feels that this surgery has changed her whole personality in a positive way by getting rid of the chronic pain and at the same time preserving the full, normal function of her knee.