Is the Induced-membrane Technique Successful for Limb Reconstruction After Resecting Large Bone Tumors in Children?

Abstract

Background: Resection of primary malignant tumors often creates large bony defects. In children, this creates reconstructive challenges, and many options have been described for limb salvage in this setting. Studies have supported the use of an induced-membrane technique after placement of a cement spacer to aid in restoration of bone anatomy.

Questions/purposes: We asked: (1) What complications are associated with the induced-membrane technique? (2) How often is bone healing achieved after resection greater than 15 cm using this technique? (3) What is the functional outcome of patients treated with this technique?

Methods: We performed a retrospective evaluation of eight patients with a mean age of 13.3 years (range, 11-17 years) treated for a malignant bone tumor between 2002 and 2012 at our centers. The primary malignant tumors involved the proximal humerus, femur, and tibia. All patients were treated using the induced-membrane technique after a resection with mean bone loss of 18 cm (range, 16-23 cm). The general indication for using the induced-membrane technique during this time was a large diaphyseal defect after resection of the tumor. In addition to using cancellous graft as with the original technique, in the current patients an autogenous nonvascularized fibula was used to enhance stability. The patients were assessed at the last followup using the Musculoskeletal Tumor Society (MSTS) scoring system. Mean followup was 47.1 months (range, 24-120 months), and none of the patients were lost to followup before 2 years.

Results: A total of four unplanned reoperations were performed in these eight patients. A fracture of the reconstruction occurred in three patients and all were treated successfully, two with surgery and one with immobilization. Bone fusion was obtained in all patients within 4 to 8 months (mean, 5.6 months) after the reconstruction. The mean healing index was 0.31 month/cm of reconstruction (range, 0.23-0.5 month/cm). At last followup, the mean MSTS score was 74% (range, 67%-80%).

Conclusions: Our findings suggest that the modified induced-membrane technique is a reasonable alternative to other limb reconstruction techniques for bone tumors in children and has the advantage of not requiring a bone bank or an expensive metal prosthesis. Although more patients will be needed to substantiate our findings, it has become a standard part of our arsenal in the treatment of large bone defects after resection of pediatric primitive bone tumors.

Level of evidence: Level IV, therapeutic study.

Fig. 1A–G

(A) The AP radiographic view shows an Ewing sarcoma of the proximal left humerus (Patient 2). (B) The MR image shows extension in the surrounding tissues. (C) After large tumor resection, a cement spacer was inserted and stabilized with a nail. (D) During the second stage of the procedure, the membrane was opened carefully before removing the cement. (E) The postoperative AP view of the second stage shows the nonvascularized fibula and the cancellous iliac graft inside the membrane. (F) The AP radiographic view from the 7-year followup after plate removal shows a solid glenohumeral arthrodesis. (G) The patient had no additional complications. He had an MSTS score of 80%.

Fig. 2A–E

(A) An AP radiographic view shows a right distal femur osteosarcoma (Patient 7). (B) The distal femur resection with epiphyseal preservation can be seen on this radiograph. The red line represents the measurement of the bony resection, which in this case was 16.11 cm. (C) A postoperative lateral radiographic view shows the cement spacer in the bed of the resection stabilized with a locking plate.) (D) AP and (E) lateral radiographic views obtained 2 years after the second stage surgery show the reconstructed femur with the locking plate on the medial side and the nonvascularized fibula on the lateral side of the reconstruction. Knee flexion was 90°.

Fig. 3

An AP radiographic view shows spontaneous reconstruction of the fibula on the donor site with intramedullary nailing to stabilize the extremities.

Fig. 4A–G

(A) An AP radiographic view shows a proximal tibial osteosarcoma (Patient 3). (B) The MR image shows epiphyseal integrity. (C) An AP radiographic view shows the proximal tibia resection with epiphyseal preservation, stabilized with a locking plate. A cement spacer was placed inside the bed of the resection. Collateral ligaments were reinserted on the epiphysis and patellar ligament on the induced membrane. (D) An AP radiographic view shows the reconstruction 8 months after the second stage surgery. (E) The fracture (in white circle) is seen on this radiograph. The plate was broken at the fracture site. (F) AP and (G) lateral radiographic views were obtained 6 months after cancellous grafting at the fracture site. The plate was changed. Knee flexion was 120° with active full extension at the last followup.

Fig. 5A–B

(A) An AP radiographic view obtained 2 months after the second-stage surgery shows a fracture of the fibula (Patient 6). (B) This AP radiographic view shows spontaneous healing with use of a simple thermoplastic thoracobrachial orthosis for 6 weeks.