Revision surgery for instrumentation failure after total en bloc spondylectomy: a retrospective case series

Abstract

Background: There have been several reports of instrumentation failure after three-column resections such as total en bloc spondylectomy (TES) for spinal tumors; however, clinical outcomes of revision surgery for instrumentation failure after TES are seldom reported. Therefore, this study assessed the clinical outcomes of revision surgery for instrumentation failure after TES. Methods: This study employed a retrospective case series in a single center and included 61 patients with spinal tumors who underwent TES between 2010 and 2015 and were followed up for > 2 years. Instrumentation failure rate, back pain, neurological deterioration, ambulatory status, operation time, blood loss, complications, bone fusion after revision surgery, and re-instrumentation failure were assessed. Data were collected on back pain, neurological deterioration, ambulatory status, and management for patients with instrumentation failure, and we documented radiological bone fusion and re-instrumentation failure in cases followed up for > 2 years after revision surgery. Results: Of the 61 patients, 26 (42.6%) experienced instrumentation failure at an average of 32 (range, 11-92) months after TES. Of these, 23 underwent revision surgery. The average operation time and intraoperative blood loss were 204 min and 97 ml, respectively. Including the six patients who were unable to walk after instrumentation failure, all patients were able to walk after revision surgery. Perioperative complications of reoperation were surgical site infection (n = 2) and delayed wound healing (n = 1). At the final follow-up, bone fusion was observed in all patients. No re-instrumentation failure was recorded. Conclusion: Bone fusion was achieved by revision surgery using the posterior approach alone.

Mechanical Failure After Total En Bloc Spondylectomy and Salvage Surgery

“…Nonetheless, several recent reports have presented results on mechanical failure after TES, such as screw loosening, screw back-out, cage breakage, screw fracture, and rod fracture; these studies identified rod fracture as the most common type of failure, and it often led to reoperation [ 8 , 11 , 12 , 22 , 23 ]. Shinmura et al [ 8 ] showed that instrumentation failure occurred in 43% of patients at a mean interval of 32 months (range, 11–92 months). Li et al [ 11 ] also showed that mechanical failure occurred in 27% (9 of 30) of patients at a mean interval of 32 months (range, 13–64 months).…”

“…The causes of rod fracture varied, and radiotherapy and surgery at the lumbar spine were common causes [ 8 , 11 - 13 , 18 , 22 , 23 ]. Although wide resection is the goal of TES, preoperative or postoperative radiotherapy and/or chemotherapy may be necessary for better oncologic outcomes.…”

“…As the present case showed, mechanical failure occurred after reoperation with a single rod on each side, and it was salvaged with a multiple-rod system. To prevent mechanical failure, solid bony union was important, but it was not very successful after TES and radiotherapy [ 8 , 11 - 13 , 19 , 20 ]. In addition, mechanical failure could occur despite solid bony fusion [ 21 ].…”

“…The concept of en bloc resection of spinal tumors is similar to that of marginal or wide resection for musculoskeletal tumors [ 1 - 3 ]. Weinstein, Boriani, and Biagini (the WBB system) and Tomita et al suggested staging systems for the proper application of TES, which is a rewarding but challenging surgical technique with a local tumor control rate of more than 80%–90% for both primary and metastatic tumors [ 3 - 8 ]. When it is indicated, the 3 spinal columns are totally resected, and reconstruction of the vertebra and the durability of constructs are of paramount importance [ 1 - 3 ].…”

“…However, mechanical failure is a concerning issue for long-term survivors, especially for patients who have undergone radiotherapy and/or chemotherapy [ 3 , 11 , 12 ]. For long-term survivors, mechanical failure was reported in 27%–43% of patients [ 8 , 11 , 13 ].…”