[Restoration of knee extension with biceps femoris muscle transfer after resection of the quadriceps femoris muscle].

Objective: Improvement of gait and ability to stand by reconstruction of functional knee extension.

Indications: Loss of function of the quadriceps femoris muscle due to tumour resection or traumatic damage of the muscle with loss of active knee extension.

Contraindications: Inadequate strength of the biceps femoris muscle. Recurrent tumour or ankylosis of the knee joint.

Surgical Technique: The tendon of the biceps femoris is dissected near the knee at the head of the fibula and is mobilized proximally. The underlying common peroneal nerve and the neurovascular supply of the biceps muscle must be spared. Through a ventral approach at the thigh the lateral intermuscular septum is opened and the biceps tendon is pulled through and sutured to the quadriceps tendon and periost of the patella.

Postoperative Management: The knee is immobilized in extension with a cast followed by a knee orthosis for 6 weeks, which is followed by intensive physiotherapy; however, the patient should not be forced to flex the knee extensively. The orthosis can be worn for another 3-4 weeks to stabilize the knee joint, while the muscles are intensively trained.

Results: Reliable reconstruction of functionally useful, active knee extension without an orthosis of a previously unstable knee joint in the sagittal plane, even if full extension is not to be expected.