Lee Zuckerman, MD Orthopedic Surgeon at the City of Hope, a comprehensive cancer center near Los Angeles discusses Use of Magnetic Growing Intramedullary Nails with Intercalary Allograft Reconstruction after Tumor Resection.
Intention
Reconstruction of tumors after excision has remained difficult. Reconstruction of the intercalary allograft remains an option but is not without complications. Plate fixation, nail fixation, or combined methods have been used in osteosynthesis techniques. In those fixed with intramedullar nails alone, non-union happens more frequently. In 15 osteotomy sites with an 87 percent union average, we previously published on a novel technique of using magnetic growing intramedullary nails to compact across the entire allograft. This procedure also offers the chance to lengthen the bone using the same implant at a later date. The aim of this research is to assess union rates and complications with larger sample size and longer-term follow-up using this technique.
Methodology
A retrospective examination of 12 patients with 27 osteotomy sites was conducted on 7 femurs and 7 humeri. The average age was 45 (9-73) with 24 months of follow-up on average (4-60). Two pleomorphic sarcomas, three osteosarcomas, one metastatic endometrial stromal sarcoma, and six metastatic carcinomas of renal cells were diagnosed. Twenty-four osteotomy sites were primary resections, one site was previously handled with a carbon fiber nail for a persistent non-union, and two sites were for a previously broken intercalary allograft revision. Five patients were treated with neoadjuvant and adjuvant chemotherapy and seven with adjuvant chemotherapy alone. Neoadjuvant radiation was given to one patient. An intercalary allograft with an intramedullary nail rising magnetically was mounted. No autographs were used. The mean length of an allograft was 14 cm (5.5-29). The nails were intraoperatively compressed. Radiographs were evaluated to assess union speeds, union time, and to test for any complications of graft reabsorption or hardware.
Outcomes
After an average of 8 months, twenty-three out of 27 sites showed signs of healing (4-26) (Figure 1). Complications included 1 allograft fracture after a fall, 1 wound dehiscence, 1 native bone intraoperative fracture during surgery in 2 patients, and 1 allograft intraoperative fracture in 1 patient. Hardware complications occurred in 6 patients which included the backing of 4 screws/pegs with one that needed replacement, 1 screw fracture, 1 nail fracture (Figure 2), and 1 patient’s nail cut-out from the humeral head. In order to achieve a union, six patients endured subsequent in-office compression. A total of 3 operations for an acquired limb length difference were successfully performed by two patients (Figure 3). At the final follow-up point, there was no evidence of reabsorption of an allograft, recurrent tumor, or infection.
Symptomatic recurrence and 2 and 4 years of frequent arthroscopic resection are usually without symptoms. The entry into the rear compartment may, in all situations, be confirmed by ultrasound. The neurovascular systems in both situations were able to be visualized and prevented.
Completion
In this sequence compared to 87 percent previously mentioned at 15 osteotomy sites, there was a union rate of 79 percent compared to 27 in this study. The healing of the osteotomy sites was not stopped by the intraoperative host and allograft bone fractures. With the use of a stainless steel variant of this nail, hardware problems are normal and can be changed. No longer-term complications such as allograft reabsorption, infections, or recurrences have occurred.