Biomechanical basis of the tibial recurvation osteotomy

Abstract

Tibial recurvation osteotomy which was introduced by Lok, et al more than ten years ago has been applied to over 140 patients with a high rate of success. Results depend on the preoperative functional status of the different muscles of the hip and the lower extremity. The operation is primarily performed on poliomyelitis patients with loss of quadriceps function where there are no other muscles of substantial mass for surgical transfer and knee arthrodesis is not desirable. In principle it is aimed at modifying the knee joint angle so that the knee is locked at an angle of recurvation early during stance. This allows the patient to walk without the aid of his hand to stabilise the knee or without the support of a prosthetic device. Knee stabilisation is thus accomplished with minimal muscle power that is with whatever muscle function exists (Fig. 1 & 2). The technique and the complications that may arise were reported previously. The size of the recurvation angle appropriate for each patient is different and depends on available muscle strength; particularly of the gluteus maximus and the triceps muscles. Determination of the recurvation angle has until now been based on experience. In what follow is we attempt to establish objective criteria for determining the recurvation angle appropriate for each patient by following a biomechanical approach.