What is knee arthritis?

Arthritis of the knee arises in any one of the three regions of the knee joint. If you suffer from knee arthritis, you’ll find it difficult to walk, climb stairs and jog. Anti-inflammatories, physiotherapy and corticosteroid injections provide temporary pain relief.  On the other hand, partial knee replacement surgery is a permanent solution for pain and restores joint mobility.

What is partial knee replacement surgery?

Partial knee replacement is surgery to replace a single compartment of the knee instead of total knee replacement where all three compartments are replaced. For knee arthritis in a single section of the knee, only damaged cartilage is removed, and ligaments supporting the knee joint are preserved. The prosthesis replaces the diseased part of the knee and preserves other knee compartments.

The most commonly done partial replacement is where the medial compartment is replaced. This procedure is referred to as ‘Unicondylar knee replacement'. This type of surgery is only suitable for a minority of patients. The lateral compartment can also be replaced, but the results of such operation are less predictable, and in such instances, Dr Mokete prefers to replace the entire joint.

Arthritis may be isolated to the patellofemoral joint. This isolated arthritis is sometimes the case in those patients who have had childhood knee cap disorders and may have undergone surgery in their adolescence. Patellofemoral joint replacement involves resection of the diseased part of the joint and replacement with a metal alloy part and Polyethylene on the knee cap. Hospital stays, rehabilitation and return to normal function is often shorter following partial knee replacement surgery.

Partial knee replacement surgery is appropriate in only a minority of patients – arthritis should be limited to the compartments being replaced to ensure the success of the operation. Also, there are other considerations, including the stability of the knee and age of the patient. In general, recovery from partial knee surgery is quicker than following total knee replacement and return to normal activities of daily life is also faster.

Day of Surgery

Surgery involves careful repositioning of support structures that comprise the knee joint. Bone tissue and cartilage are then removed from the tibia and femur's surfaces. A type of special surgical cement fixes the prosthetic parts in place. Surrounding tissues and structures are restored to their anatomic position.

There are two prostheses: standard Unicondylar fixed-bearing prosthesis and mobile-bearing Unicondylar, made of metal and plastic components. The prosthesis used depends on the extent of damage and the current state of the anterior cruciate ligament (ACL).

After Surgery

After partial knee replacement, you stay overnight in the hospital for two nights. The complication risk profile from this type of procedure is lower than that of total knee replacement. Your new replacement knee also feels more natural, and you can resume daily activities sooner than you think.