Lo, Sheng-Fu L

Abstract BACKGROUND Total en bloc sacrectomy provides the best long-term local control for large primary bony sacral tumors, but often requires lumbosacral nerve root sacrifice leading to loss of ambulation and/or bowel, bladder, and/or sexual dysfunction. Nerve-sparing techniques may be an option for some patients that avoid these outcomes and accordingly improve postoperative quality of life. OBJECTIVE To describe the technique for a posterior-only en bloc hemisacrectomy with maximal nerve root preservation and to summarize the available literature. METHODS A 38-yr-old woman with a 7.7 × 5.4 × 4.5 cm biopsy-proven grade 2 chondrosarcoma involving the left L5-S2 posterior elements underwent a posterior-only left hemisacrectomy tri-rod L3-pelvis fusion. A systematic review of the English literature was also conducted to identify other descriptions of high sacrectomy with distal sacral nerve root preservation. RESULTS Computer-aided navigation facilitated an extracapsular resection that allowed preservation of the left-sided L5 and S3-Co roots. Negative margins were achieved and postoperatively the patient retained ambulation and good bowel/bladder function. Imaging at 9-mo follow-up showed no evidence of recurrence. The systematic review identified 4 prior publications describing 6 total patients who underwent nerve-sparing sacral resection. Enneking-appropriate resection was only obtained in 1 case though. CONCLUSION Here we describe a technique for distal sacral nerve root preservation during en bloc hemisacrectomy for a primary sacral tumor. Few prior descriptions exist, and the present technique may help to reduce the neurological morbidity of sacral tumor surgery.

Study Design International survey. Objectives To assess variability in the treatment practices for spinal metastases as a function of practice setting, surgical specialty, and fellowship training among an international group of spine surgeons. Methods An anonymous internet-based survey was disseminated to the AO Spine membership. The questionnaire contained items on practice settings, fellowship training, indications used for spinal metastasis surgery, surgical strategies, multidisciplinary team use, and postoperative follow-up priorities and practice. Results 341 gave complete responses to the survey with 76.3% identifying spinal oncology as a practice focus and 95.6% treating spinal metastases. 80% use the Spinal Instability Neoplastic Score (SINS) to guide instrumentation decision-making and 60.7% recruit multidisciplinary teams for some or all cases. Priorities for postoperative follow-up are adjuvant radiotherapy (80.9%) and systemic therapy (74.8%). Most schedule first follow-up within 6 weeks of surgery (62.2%). Significant response heterogeneity was seen when stratifying by practice in an academic or university-affiliated center, practice in a cancer center, completion of a spine oncology fellowship, and self-identification as a tumor specialist. Respondents belonging to any of these categories were more likely to utilize SINS ( P < .01-.02), recruit assistance from plastic surgeons (all P < .01), and incorporate radiation oncologists in postoperative care ( P < .01-.03). Conclusions The largest variability in practice strategies is based upon practice setting, spine tumor specialization, and completion of a spine oncology fellowship. These respondents were more likely to use evidenced-based practices. However, the response variability indicates the need for consensus building, particularly for postoperative spine metastasis care pathways and multidisciplinary team use.

Background: Local, intrawound use of antibiotic powder, such as vancomycin and tobramycin, in spinal fusion surgery has become an increasingly common prophylactic measure in an attempt to reduce rates of postsurgical infection. However, the effects of localized antibiotic delivery on fusion remain unclear. The objective of this study was to examine the in vivo effects of intraoperative local delivery of 2 antibiotics commonly used in bone-grafting surgery on spinal fusion outcomes in a rat model. Methods: Single-level (L4-L5), bilateral posterolateral intertransverse process lumbar fusion surgery was performed on 60 female Lewis rats (6 to 8 weeks of age) using syngeneic iliac crest allograft mixed with clinical bone-graft substitute and varying concentrations of antibiotics (n = 12 each): (1) control without any antibiotics, (2) low-dose vancomycin (14.3 mg/kg), (3) high-dose vancomycin (71.5 mg/kg), (4) low-dose tobramycin (28.6 mg/kg), and (5) high-dose tobramycin (143 mg/kg). Eight weeks postoperatively, fusion was evaluated via micro-computed tomography (µCT), manual palpation, and histological analysis, with blinding to treatment group. In the µCT analysis, fusion-mass volumes were measured for each rat. Each spine specimen (L4-L5) was rated (manual palpation score) on a scale of 2 to 0 (2 = fused, 1 = partially fused, and 0 = non-fused). Results: The mean fusion-mass volume on µCT (mm 3 ) was as follows: control, 29.3 ± 6.2; low-dose vancomycin, 26.3 ± 8.9; high-dose vancomycin, 18.8 ± 7.9; low-dose tobramycin, 32.7 ± 9.0; and high-dose tobramycin, 43.8 ± 11.9 (control versus high-dose vancomycin, p < 0.05; and control versus high-dose tobramycin, p < 0.05). The mean manual palpation score for each group was as follows: control, 1.46 ± 0.58; low-dose vancomycin, 0.86 ± 0.87; high-dose vancomycin, 0.68 ± 0.62; low-dose tobramycin, 1.25 ± 0.71; and high-dose tobramycin, 1.32 ± 0.72 (control versus high-dose vancomycin, p < 0.05). The histological analyses demonstrated a similar trend with regard to spinal fusion volume. Conclusions: Intraoperative local application of vancomycin, particularly at a supraphysiological dosage, may have detrimental effects on fusion-mass formation. No inhibitory effect of tobramycin on fusion-mass formation was observed. Clinical Relevance: When spine surgeons decide to use intraoperative intrawound antibiotics in spinal fusion surgery, they should weigh the reduction in surgical site infection against a possible inhibitory effect on fusion.