(P 525) ALL INTERNAL DISTRACTION OSTEOGENESIS AFTER TUMOR RESECTION

Objective: Multiple options for reconstructing bony defects and correcting limb-length discrepancies after tumor resection are available. The use of all internal distraction osteogenesis can be used to reconstruct the defect and correct limb-length discrepancies (LLD’s) using the patient’s own bone. This study evaluates the outcomes of multiple techniques for all-internal distraction osteogenesis using magnetic lengthening nails.

Methods: A retrospective review of twenty cases of all internal distraction osteogenesis were reviewed. The following data was collected from all patients: age at the time of initial surgery, time to follow-up, location of the surgery, length of distraction osteogenesis performed, number of surgeries performed and complications.

Results: A total of 12 males and 8 females underwent all-internal distraction osteogenesis on 16 femurs, 3 tibiae and 1 humerus. The average age was 32.0 years (range 9-70), the average defect was 10.3 cm (range 3-23) and the average follow-up was 29.9 months (range 3-85). Six patients passed away due to their cancer by final follow-up. Four patients were treated with lengthening alone for LLD after hemipelvectomy, after an acute shortening or joint replacement. Four patients underwent lengthening after intercalary or osteoarticular allograft reconstruction, five patients underwent plate-assisted bone segment transport (PABST), five patients were treated with a bone transport nail (BTN) and two patients underwent extramedullary distraction osteogenesis.
The patients undergoing lengthening for a LLD alone required an average of 1.5 surgeries (range 1-2) and had no complications. The patients undergoing lengthening after allograft reconstruction, only required 1 surgery each with no complications. The PABST patients required an average of 2.6 surgeries (range 1-5). One patient sustained a superficial wound infection requiring surgical debridement. The patients who were treated with a BTN required an average of 4.4 surgeries (range 2-8). Three patients had hardware failure requiring revision surgery, two patients had locking screws back out, one patient had a retained broken intercalary screw that occurred during removal of the nail, and two patients had a non-union. One patient required a revision surgery due to early consolidation of the regenerate and one patient formed poor regenerate requiring grafting. Two of the patients had residual limb-length discrepancies at latest follow-up. For the two cases of extramedullary nailing, each patient required a total of 5.5 surgeries (range 3-8). One patient required 2 revision surgeries due to 2 separate occurrences of hardware failure, and one patient required a revision surgery due to hardware failure.

Conclusion: All-internal distraction osteogenesis after tumor resection provides an option for reconstruction of both intercalary defects and treatment of LLD. Simple lengthening after hemipelvectomy, joint replacement and allograft reconstruction required the least number of procedures and had no complications. When reconstructing an intercalary defect with distraction osteogenesis with or without subsequent lengthening required multiple procedures. The PABST technique had the least number of complications followed by the use of an extramedullary nail and BTN. Although each option provided for limb-salvage with distraction osteogenesis, further research is needed to determine if there is an optimal technique for treatment of these complicated reconstructions.