Comparison of rod fracture rates in long spinal deformity constructs after transforaminal versus anterior lumbar interbody fusions: a single-institution analysis

Abstract

<jats:sec><jats:title>OBJECTIVE</jats:title><jats:p>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.</jats:p></jats:sec><jats:sec><jats:title>METHODS</jats:title><jats:p>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.</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>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 &lt; 0.0001). The reoperation rate for rod fractures was similar between the patient groups (p = 0.40).</jats:p></jats:sec><jats:sec><jats:title>CONCLUSIONS</jats:title><jats:p>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.</jats:p></jats:sec>

Metal failure and nonunion at L5-S1 after long instrumented fusion distal to pelvis for adult spinal deformity: Anterior versus transforaminal interbody fusion

“…In Adogwa's study, they reported that revision surgery was required in 14 (51.9%) out of 27 patients with metal failure in the TLIF cohort and in four (36.3%) of 11 patients with metal failure in the ALIF cohort. 28 Daniels et al 39 found that 38 (9.5%) of 402 patients with radiographically apparent solid fusion suffered a broken rod, suggesting the radiographically apparent fusion mass may not be strong for repetitive mechanical stress in a long-term period. Another study reported rod fracture despite a CT scan showing fusion among spinal tumor patients after total en bloc spondylectomy.…”

The prevalence of proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) in patients undergoing circumferential minimally invasive surgical (cMIS) correction for adult spinal deformity: long-term 2- to 13-year follow-up

“…All these patients went on to have solid L5-S1 fusion on CT scan and have not had a revision. This failure rate again is low compared to published reports of rod failure with open surgery [50][51][52][53][54][55][56][57][58][59][60]. This may be due to two reasons.…”

Revision Surgery for a Rod Fracture with Multirod Constructs Using a Posterior-Only Approach Following Surgery for Adult Spinal Deformity

“…Anterior and transforaminal interbody fusion procedures at the caudal levels of long spinal deformity constructs are associated with low bilateral rod fracture rates and do not differ in the rate of revision surgery between the two groups [15]. Further, the prevalence of rod fractures is not significantly different between anterior and transforaminal groups [15]. Although we performed anterior reconstruction for patients with anterior bone defects using the posterior approach, no failure occurred in most instances.…”

“…These results showed that refracture occurs even after anterior column reconstruction. Anterior and transforaminal interbody fusion procedures at the caudal levels of long spinal deformity constructs are associated with low bilateral rod fracture rates and do not differ in the rate of revision surgery between the two groups [15]. Further, the prevalence of rod fractures is not significantly different between anterior and transforaminal groups [15].…”