Muscle function after endoprosthetic replacement of the proximal tibia:Different techniques for extensor reconstruction in 17 tumor patients

Abstract

We analyzed in 17 patients the outcome of various surgical techniques for reconstruction of the extension apparatus after resection of the proximal tibia and tumor prosthesis implantation. The mean follow-up period was 5 (1.5-11) years. Knee extension and flexion strength were measured isokinetically by dynamometer and muscle activities of the vastus medialis, the vastus lateralis and the rectus femoris muscles determined by means of EMG. Muscle function of the operated leg was compared to that of the contralateral extremity by using various surgical techniques: fibula transposition, transposition of the gastrocnemius muscle, and combination technique. The results concerning the operated leg were compared within the 3 groups and the activity and strength of both legs were compared to those of a control group of healthy subjects matched for age and weight. The strength of extensor muscles of the healthy leg was greater than that of the control group in flexion position (60 degrees-90 degrees); the hamstring strength values were within the normal range. The strength of extensor muscles of the operated leg differed between groups II and III at 90 degrees in favor of group II (p < 0.01) and at 60 degrees to 20 degrees (p < 0.001) in favor of group III. Expressed in percentage ranges (nonoperated leg set at 100 percent) the flexor muscles averaged 30 percent, the extensor muscles represented on average 12 percent (9-17 percent) in group I, 9 percent (5-18 percent) in group II and 16 percent (6-26 percent) in group III, depending on the knee angle.(ABSTRACT TRUNCATED AT 250 WORDS)

Limb salvage for proximal tibial tumours using a modular prosthesis

“…The major advantage of the use of an allograft is restoration of bone stock and better re-attachment of the Despite using the new techniques for reconstruction of the proximal tibia as suggested by others [8,11] we were not able to reproduce their results. Grimmer et al [8] reported a mean functional score of 79% for pain, function 62%, emotional acceptance 84%, need for support 85%, walking ability 77% and gait 73%.…”

“…Solutions include suturing the tendon to the gastrocnemius flap or, even better, to the transposed fibula if this can be preserved. Petschnig et al [11] studied 17 patients and compared 3 methods of extensor mechanism reconstruction. They found that suture of the patellar tendon either to the gastrocnemius flap or to the transposed fibula were the most successful in obtaining active extension.…”

“…Tumours of the distal femur can usually be removed with successful reconstruction [11,12], but with tumours of the proximal tibia complications are much more frequent.…”

Preservation of the knee joint in limb salvage of osteosarcoma in the proximal tibia

“…Some orthopedic surgeons prefer amputation, as no useful artificial joints exist and it is difficult to use allografts because of postoperative complications. It is possible to use an endoprosthetic replacement for reconstruction of the knee joint after wide resection of the tumour in the proximal tibia [4,9,10,11,14]. Expandable prostheses have also been used successfully for skeletally immature patients with malignant bone tumours in the proximal tibia [5].…”

“…In many patients, the knee joint is reconstructed with a tumor prosthesis or an allograft after wide resection of the upper tibia [4,8,11,14]. Reconstruction of the extensor apparatus of the knee joint is still a problem, and poor soft tissue coverage of the prosthesis or allograft results in impaired wound healing and an increased risk of deep infection [9,10]. If the patient's own knee joint structure can be preserved while allowing a safe surgical margin of excision, better functional results may be obtained for a long period.…”