The knee is a large joint divided into three compartments, which are termed as the inner or medial compartment, the outer or lateral compartment and the frontal or patellofemoral compartment. Whilst the knee can develop wear and tear arthritis in all three compartments in a generalised manner, quite often it will develop arthritis predominantly in one compartment, leading to pain, swelling and change in alignment or deformity.
If the remainder of the knee is in reasonably good condition, pain relief and correction of the deformity can be achieved by making a bony cut (osteotomy) in either the femur – Proximal Fibular Osteotomy (PFO) or High Tibial Osteotomy (HTO) and adjusting the alignment of the femur, tibia and patella. These techniques have existed for many decades.
PFO (Proximal Fibular Osteotomy):
Compared with high tibial osteotomy and total knee arthroplasty, the authors found a simpler surgical procedure, partial fibular osteotomy, could effectively relieve knee pain and also correct the varus deformity for patients with medial compartment knee osteoarthritis (OA).
Patients with medial compartment OA were treated by proximal fibular osteotomy in Immunex hospital. A 2-cm-long section of fibula was resected 6 to 10 cm below the fibular head.
Proximal fibular osteotomy can significantly improve the function of the affected knee joint and also achieve long-term pain relief.
Were the patient are requiring deformity correction -the combination of innovative surgical procedure with PFO gives good and long term results.
HTO (High Tibial Osteotomy):
The commonest pattern of unicompartmental arthritis is wear in the inner or medial aspect of the knee, and if the degree of wear is advanced, the leg may actually be bowed at the knee, with associated medial joint line pain and swelling. If the patient still wishes to perform moderate physical activities for work (tradesman, manual labour) or recreational activities (running, jumping) and has symptomatic unicompartmental arthritis in the medial compartment, they may be suitable for a high tibial osteotomy (HTO).
This involves a 5-6cm vertical skin incision just below the knee at the junction of the anterior (front) and medial calf. The upper tibia is then prepared by making an oblique osteotomy (bony cut) and the gap created between the two cut surfaces gradually increased in increments until the weight bearing axis (a line measured from the centre of the hip to the centre of the ankle) has shifted from the diseased medial compartment to either the middle of the knee or the inner (medial) third of the lateral (disease free) compartment, with the degree of correction depending upon the patients pathology. The size of the osteotomy plate is then chosen based upon whichever gives the optimally corrected weight bearing axis, and it is carefully secured both above (proximally) and below (distally) with titanium locking screws, the gap filled in with bone graft, and the wound closed in layers over a small drain. The drain is removed the following day, and patients usually spend 2* nights in hospital to assist with pain relief.