Compartmental knee arthroplasty

Compartmental arthritis forms a significant disease subgroup in patients presenting with osteoarthritis of the knee. Medial compartment disease is the more common sub-group and is most amenable to treatment by compartmental arthroplasty (Fig. 7). The first step is to obtain an accurate diagnosis of the disease process and evaluate the integrity of the anterior cruciate ligament. After clinical, radiographic, and perhaps arthroscopic assessment the final decision to proceed will inevitably depend upon personal judgement made at the time of arthrotomy. This judgement appears to improve with experience and it is essential that the surgeon has sufficient such experience and regularly practices compartmental arthroplasty. The decision on selection of the design of the prosthesis to be used is critical. This should be based on published 10 -year survivorship studies revealing success rates of at least 85-90%. The technically more demanding prostheses can produce superlative long-term results in some centres. The less demanding prostheses can produce good long-term results for less experienced surgeons. Most studies report lower complication rates, more rapid recovery, and better quality long-term results than alternative treatments. Set against this is the recognition that failure due to disease progression can occur, but there is no convincing evidence that the well tried and tested prostheses have a greater overall failure rate than a total knee replacement. Reports of revisions show that this is seldom technically demanding and the results of revision are probably little different from those of revising a primary knee replacement. The resurgent interest in compartmental arthroplasty has followed successful reports from those few centres that have persisted with this form of treatment. Successful results require a detailed knowledge of the indications, technique, and management of the procedure, but the technique adds several extra dimensions to the management of established knee arthritis.