With clearly defined indications, high tibial osteotomy offers a good outcome, provided the correction is performed as accurately and as early as possible. Ideally, in a varus osteoarthritis knee, there should be an over correction of the leg’s axis by a minimum of 2 degrees but not greater than 4 degrees.

The Balansys high tibial osteotomy instrumentation provides the surgeon with the means to determine the extent of the correction intraoperatively, with reference to clearly identifiable skeletal points. This intraoperative determination improves the accuracy of the osteotomy over conventional methods based on x-ray planning. The instrumentation controls the fulcrum of the wedge to be removed during the procedure as well as controlling the width of the residual bone bridge. The precise nature of the saw cuts offer the best conditions for fast, reliable consolidation.

For stabilization an 8 or 9 hole pre-contoured semi-tubular AO plate is used.

The cost of the plate is RM 72.80 (US$19.15). No external immobilization is done. The patient is mobilized non-weight bearing with crutches on the 1st postoperative day and discharged from hospital on the 2nd post-operative day.

From 1.6.1998 to 30.6.1998 we performed 20 consecutive cases of high tibial osteotomy using the Balansys system. The average follow up is 24 months. The indication for operation was painful varus knee with or without medial unicompartmental osteoarthritis.

The results were analysed and showed early union with excellent knee flexion and good cosmesis.

The only complication that was encountered was transient lateral popliteal nerve palsy. This complication can be avoided if attention is paid to the lateral popliteal nerve when the fibular head is osteotomised.