✓ Surgical treatment of intraforaminal disc herniations at the L5–S1 level is technically demanding. The 2 most commonly used procedures involve either a medial or lateral ipsilateral approach and often require a partial or even complete facet resection, which may in turn result in vertebral instability and/or back pain, as well as, in some cases, a fusion or stabilization procedure. In this report, the authors present a new minimally invasive technique for the treatment of L5–S1 intraforaminal disc herniations. Using this technique, which involves tubular retractors and an operative microscope to approach the neural foramen from the contralateral side, the authors could easily visualize and remove the herniated disc material and perform a thorough microdiscectomy with minimal resection of osseous and ligamentous structures. To illustrate this new minimally invasive technique for the treatment of intraforaminal disc herniations at L5–S1, they describe the cases of 2 patients who underwent the procedure and in whom successful results were achieved.
Jin S. Yeom, Kyeong Hwan Kim, Soon Woo Hong, Kun-Woo Park, Bong-Soon Chang, Choon-Ki Lee and Jacob M. Buchowski
Panya Luksanapruksa, Jacob M. Buchowski, Neill M. Wright, Frank H. Valone III, Colleen Peters and David B. Bumpass
The incidence of suboccipital spinal metastases is rare but has increased given cancer patients' longer life expectancies. Operative treatment in this region is often challenging because of limited fixation points due to tumor lysis, as well as adjacent neural and vascular anatomy. Few studies have reported on this population of cancer patients. The purpose of this study was to evaluate clinical outcomes and complications of patients with suboccipital spinal metastases who had undergone posterior occipitocervical fixation.
A single-institution database was reviewed to identify patients with suboccipital metastases who had undergone posterior-only instrumented fusion between 1999 and 2014. Clinical presentation, perioperative complications, and postoperative results were analyzed. Pain was assessed using the visual analog scale. Survival analysis was performed using a Kaplan-Meier curve. The revised Tokuhashi and the Tomita scoring systems were used for prognosis prediction.
Fifteen patients were identified, 10 men and 5 women with mean age of 64.8 ± 11.8 years (range 48–80 years). Severe neck pain without neurological deficit was the most common presentation. Primary tumors included lung, breast, bladder, myeloma, melanoma, and renal cell cancers. All tumors occurred in the axis vertebra. Preoperative Tokuhashi and Tomita scores ranged from 5 to 13 and 3 to 7, respectively. All patients had undergone occipitocervical fusion of a mean of 4.6 levels (range 2–7 levels). Median survival was 10.3 months. In all cases, neck pain markedly improved and patients were able to resume activities of daily living. The average postoperative pain score was significantly improved as compared with the average preoperative score (1.90 ± 2.56 and 5.50 ± 2.99, respectively, p = 0.01). Three patients experienced postoperative medical complications including urinary tract infection, deep vein thrombosis, myocardial infarction, and cardiac arrhythmia. In the follow-up period, no wound infections or reoperations occurred and no patients experienced spinal cord deficits from tumor recurrence.
Posterior-only occipitocervical stabilization was highly effective at relieving patients' neck pain. No instrumentation failures were noted, and no neurological complications or tumor progression causing spinal cord deficits was noted in the follow-up period.
Owoicho Adogwa, Jacob M. Buchowski, Lawrence G. Lenke, Maksim A. Shlykov, Mostafa El Dafrawy, Thamrong Lertudomphonwanit, Mitchel R. Obey, Jonathan Koscso, Munish C. Gupta and Keith H. Bridwell
Pseudarthrosis is a common complication of long-segment fusions after surgery for correction of adult spinal deformity (ASD). Interbody fusions are frequently used at the caudal levels of long-segment spinal deformity constructs as adjuncts for anterior column support. There is a paucity of literature comparing rod fracture rates (proxy for pseudarthrosis) in patients undergoing transforaminal lumbar interbody fusion (TLIF) versus anterior lumbar interbody fusion (ALIF) at the caudal levels of the long spinal deformity construct. In this study the authors sought to compare rod fracture rates in patients undergoing surgery for correction of ASD with TLIF versus ALIF at the caudal levels of long spinal deformity constructs.
We reviewed clinical records of patients who underwent surgery for correction of ASD between 2008 and 2014 at a single institution. Data including demographics, comorbidities, and indications for surgery, as well as postoperative variables, were collected for each patient. All patients had a minimum 2-year follow-up. Patients were dichotomized into two groups for comparison on the basis of undergoing a TLIF versus an ALIF procedure at the caudal levels of long spinal deformity constructs. The primary outcome of interest was the rate of rod fractures.
A total of 198 patients (TLIF 133 patients; ALIF 65 patients) underwent a long-segment fusion to the sacrum with iliac fixation. The mean ± standard deviation follow-up period was 62.23 ± 29.26 months. Baseline demographic variables were similar in both patient groups. There were no significant differences between groups in the severity of the baseline sagittal plane deformity (i.e., baseline lumbar-pelvic parameters) or the final deformity correction achieved. Mean total recombinant human bone morphogenetic protein 2 (rhBMP-2) dose for L1–sacrum fusion was significantly higher in the ALIF (100 mg) than in the TLIF (62 mg) group. The overall rod failure rate (cases with rod fracture/total cases) within this case series was 19.19% (38/198); 10.60% (21/198) were unilateral rod fractures and 8.58% (17/198) were bilateral rod fractures. At last clinical follow-up, there were no statistically significant differences in bilateral rod fracture rates between the group of patients who had a TLIF procedure and the group who had an ALIF procedure at the caudal levels of the long spinal deformity constructs (TLIF 10.52% vs ALIF 4.61%, p = 0.11). However, the incidence rate (cases per patient follow-up years) for bilateral rod fractures was significantly higher in the TLIF than in the ALIF cohort (TLIF 2.20% vs ALIF 0.70%, p < 0.0001). The reoperation rate for rod fractures was similar between the patient groups (p = 0.40).
Although both ALIF and TLIF procedures at the caudal levels of long spinal deformity constructs achieved similar and satisfactory deformity correction, ALIFs were associated with a lower rod fracture incidence rate. There were no differences between groups in the prevalence of rod fracture or revision surgery, however, and both groups had low bilateral rod fracture prevalence and incidence rates. One technique is not clearly superior to the other.