Complications and outcomes after three-column osteotomy: a 5-year follow-up.

BACKGROUND: Three-column spinal osteotomies (3-CO) are powerful techniques used to correct spinal deformity. These surgeries are associated with an elevated risk of complications. While outcomes have been reported in the literature with 2 years follow-up, longer-term outcomes of three-column osteotomies remain understudied. OBJECTIVES: This study aims to examine patient reported outcomes and complications for three-column osteotomies at 5 years. STUDY DESIGN: Retrospective review of a prospectively collected spinal deformity cases database. PATIENT SAMPLE: All consecutive adult patients at a single spine surgery center treated with either a pedicle subtraction osteotomy (PSO) or vertebral column resection (VCR) for spinal deformity, and with a minimum 5-year follow-up were included. OUTCOME MEASURES: Visual-analog scale (VAS) for back pain score (0 to 10), Oswestry Disability Index (ODI) score (0 to 100), number of complications, revision rate, sagittal balance, lumbar lordosis at preoperative and at 5-year visit. METHODS: Data was extracted from a prospectively collected spinal deformity surgery database continuously updated since 2002 with data from operative reports, patients' medical visit notes and patients' self-reported VAS and ODI questionnaires completed at each office visit. Radiographic measurements were performed on standing full-length spine radiographs taken at pre-op and 5-year visits. Descriptive statistics, comparison of means and proportions among groups, and a logistic regression analysis were conducted using the statistical software package SPSS version 28. Statistical significance was set at p<.05. RESULTS: Of 127 consecutive adult patients with minimum of 5-year follow-up undergoing a 3-CO posterior spinal surgery for spinal deformity were identified and included in the study, 79 (62%) were treated with PSO, and 48 (38%) with VCR. Both PSO and VCR groups demonstrated significant improvements in VAS (PSO pre-op: 6.7, 5-year: 4.6, p<.001; VCR pre-op: 7.1, 5-year: 5.2, p<.001), and ODI (PSO pre-op: 52.9, 5-year: 45.4, p<.001; VCR pre-op: 57.5, 5-year 43.0, p<.001) that were maintained at 5 years. Major and minor complications occurring within 5 years were not statistically different between the PSO and VCR groups (major: 59.5% vs 56.3%, p=.85; minor: 45.6% vs 37.5%, p=.46). The rate of revision surgery within 5 years was 39.4% overall. Of the fifty patients requiring revision, 37.5% were for nonunion, 27.1% instrumentation failure, 14.6% proximal junctional kyphosis (PJK), 12.5% vertebral fracture, 6.3% motor weakness, and 2.1% infection. Improvements in lumbar lordosis were maintained at 5 years in both the PSO (29.9° vs 47.2°, p<.001) and VCR (34.6° vs 48.5°, p<.001) groups while sagittal balance maintained significant improvement in the VCR group (9.5 cm vs 6.3 cm, p=.008) but not the PSO (11.4 cm vs 9.3 cm, p=.065). CONCLUSION: Patients undergoing three-column osteotomies had a major complication rate of 57.5% and a minor complication rate of 42.5% after 5 years. Improvements in lumbar lordosis were maintained at 5-year follow-up, but sagittal balance was only maintained in the VCR group. Despite these radiographic findings, both VCR and PSO groups maintained significant clinical improvements in both VAS and ODI scores at 5-year follow up.

Biomechanical analysis of sagittal correction parameters for surgical instrumentation with pedicle subtraction osteotomy in adult spinal deformity.

BACKGROUND: High complication rate has been documented in spinal instrumentation with pedicle subtraction osteotomy. The objective was to analyze the biomechanics of spinal instrumentation with pedicle subtraction osteotomy as functions of three instrumentation parameters. METHODS: Patient-specific biomechanical computer models of 3 adult patients who were instrumented with pedicle subtraction osteotomy were used to simulate the actual instrumentations and alternative instrumentations derived by varying instrumentation parameters: pedicle subtraction osteotomy wedge angle and rod contouring angle, location of the osteotomy, and number of rods (2 vs. 4). FINDINGS: A change of the sagittal correction by +7.5° (-7.5°) resulted in a change in the screw axial forces and rods bending loads around the osteotomy by +38% (-19%) and +28% (-11%), respectively. The bending moments in the rods were 31% lower at the osteotomy site when it was located at one level above, and 20% higher when it was located at a level below. Additional rods allowed the rod bending and screw axial loads to be reduced by 24% and 22%, respectively. INTERPRETATION: The amount of sagittal correction was positively correlated with loads sustained by the screws and rods. Rods were subjected to higher bending loads at the pedicle subtraction osteotomy site when it was done at a lower level. A 4-rod construct is an effective way to reduce the risk of rod breakage by reducing the loads sustained by the rods.

Adult spine deformity surgery in elderly patients: are outcomes worse in patients 75 years and older?

STUDY DESIGN: Retrospective study of a prospectively collected database at one center. OBJECTIVES: Assess the outcomes and complications of adult spinal deformity (ASD) surgery in patients that are 75 years and older compared with patients of 65-75 years of age. With increasing amounts of ASD surgery being performed on elderly patients, it is important to assess how age plays a factor in corrective reconstruction surgery. METHODS: Inclusion criteria for the study were all patients ≥ 65 years of age that underwent thoracolumbar deformity correction involving ≥ four levels at a single institution by two surgeons. Patients were divided based on age into 65-74.9 or ≥ 75 groups. Radiographic parameters were measured preoperatively, postoperatively, and at 2 years. The Numeric Rating Scale (NRS) and Oswestry Disability Index (ODI) were collected preoperatively, at 1 year, and 2 years. Comorbidities included were based around the Charlson Comorbidity Index (CCI) and compared to the incidence of complications and need for further surgery. RESULTS: Both age groups had improvements in their radiographic parameters postoperatively which was maintained at 2 years. Comparing the different age groups with similar comorbidity burden in regard to complications and need for additional surgery yielded no statistically significant difference between groups. Both groups had comparable decreases in NRS and increases in ODI at 2 years. CONCLUSIONS: Analysis of our study population indicates that there is no difference between the outcomes and complications of deformity surgery in patients 75 years and older when compared to a younger elderly population. It also does not appear that a ≥ 3 comorbidity burden has a significant impact on the complications or need for additional surgery in our elderly spinal deformity surgery population. LEVEL OF EVIDENCE: Level IV.

Preservation of Spine Motion in the Surgical Treatment of Adolescent Idiopathic Scoliosis Using an Innovative Apical Fusion Technique: A 2-Year Follow-Up Pilot Study.

BACKGROUND: This trial reports the 2-year and immediate postremoval clinical outcomes of a novel posterior apical short-segment (PASS) correction technique allowing for correction and stabilization of adolescent idiopathic scoliosis (AIS) with limited fusion. METHODS: Twenty-one consecutive female AIS patients were treated at 4 institutions with this novel technique. Arthrodesis was limited to the short apical curve after correction with translational and derotational forces applied to upper and lower instrumented levels. Instrumentation spanned fused and unfused segments with motion and flexibility of unfused segments maintained. The long concave rods were removed at maturity. Radiographic data collected included preoperative and postoperative data for up to 2 years as well as after long rod removal. RESULTS: All 21 patients are beyond 2 years postsurgery. Average age at surgery was 14.2 years (11-17 years). A mean of 10.5 ± 1 levels per patient were stabilized and 5.0 ± 0.5 levels (48%) were fused. Cobb angle improved from 56.1° ± 8.0° to 20.8° ± 7.8° (62.2% improvement) at 1 year and 20.9° ± 8.4°, (62.0% improvement) at 2 years postsurgery. In levels instrumented but not fused, motion was 26° ± 6° preoperatively compared to 10° ± 4° at 1 year postsurgery, demonstrating 38% maintenance of mobility in nonfused segments. There was no report of implant-related complications. CONCLUSIONS: PASS correction technique corrected the deformity profile in AIS patients with a lower implant density while sparing 52% of the instrumented levels from fusion through the 2-year follow-up.

Biomechanical effect of pedicle screw distribution in AIS instrumentation using a segmental translation technique: computer modeling and simulation.

BACKGROUND: Efforts to select the appropriate number of implants in adolescent idiopathic scoliosis (AIS) instrumentation are hampered by a lack of biomechanical studies. The objective was to biomechanically evaluate screw density at different regions in the curve for AIS correction to test the hypothesis that alternative screw patterns do not compromise anticipated correction in AIS when using a segmental translation technique. METHODS: Instrumentation simulations were computationally performed for 10 AIS cases. We simulated simultaneous concave and convex segmental translation for a reference screw pattern (bilateral polyaxial pedicle screws with dorsal height adjustability at every level fused) and four alternative patterns; screws were dropped respectively on convex or concave side at alternate levels or at the periapical levels (21 to 25% fewer screws). Predicted deformity correction and screw forces were compared. RESULTS: Final simulated Cobb angle differences with the alternative screw patterns varied between 1° to 5° (39 simulations) and 8° (1 simulation) compared to the reference maximal density screw pattern. Thoracic kyphosis and apical vertebral rotation were within 2° of the reference screw pattern. Screw forces were 76 ± 43 N, 96 ± 58 N, 90 ± 54 N, 82 ± 33 N, and 79 ± 42 N, respectively, for the reference screw pattern and screw dropouts at convex alternate levels, concave alternate levels, convex periapical levels, and concave periapical levels. Bone-screw forces for the alternative patterns were higher than the reference pattern (p < 0.0003). There was no statistical bone-screw force difference between convex and concave alternate dropouts and between convex and concave periapical dropouts (p > 0.28). Alternate dropout screw forces were higher than periapical dropouts (p < 0.05). CONCLUSIONS: Using a simultaneous segmental translation technique, deformity correction can be achieved with 23% fewer screws than maximal density screw pattern, but resulted in 25% higher bone-screw forces. Screw dropouts could be either on the convex side or on the concave side at alternate levels or at periapical levels. Periapical screw dropouts may more likely result in lower bone-screw force increase than alternate level screw dropouts.

Associations Between Body Mass and Revision Surgical Outcomes in Adult Scoliosis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To determine whether an association exists between high body mass index (BMI>25 kg/m) and surgical outcomes in revision adult scoliosis patients. SUMMARY OF BACKGROUND DATA: Obesity is thought to be associated with increased surgical complications and inferior clinical outcomes in adults. There are no studies analyzing the effect of obesity on surgical outcomes in revision patients for adult scoliosis. METHODS: Forty-five consecutive revision adult scoliosis patients (35 women and 10 men; mean age, 62.7±9.3 y) with a minimum follow-up of 2 years were included in this study. Patients were divided into 2 groups according to BMI: overweight (BMI≥25 kg/m, n=27) and nonoverweight (<25 kg/m, n=18). Radiographic measures, Oswestry Disability Index (ODI), Visual Analog Scale (VAS), as well as comorbidities and complications were reviewed and compared at preoperative and 2-year follow-up. RESULTS: No significant differences in surgical methods, complication rates, or radiographic measures were found between the 2 groups except for the greater preoperative and final follow-up thoracic kyphosis in the overweight group (P<0.05). A higher comorbidity rate of circulatory disorders (33.3% vs. 0%, P=0.018) and diabetes (25.9% vs. 0%, P=0.053) was observed in the overweight group, as well as a higher preoperative VAS score (7.1±1.7 vs. 5.2±2.9, P=0.031). At 2-year follow-up, VAS and ODI improvements for both groups showed significant and similar improvement from preoperative (P<0.01). CONCLUSIONS: Overweight revision adult scoliosis patients had higher thoracic kyphosis and more significant preoperative pain compared with normal-weight individuals. Overweight patients also had significantly higher rates of medical comorbidities. However, BMI did not affect the functional outcome of surgical correction or perioperative complication rates. Overweight patients benefited from surgery just as much as nonoverweight patients at 2-year follow-up.

Comparative analysis of clinical outcomes and complications in patients with degenerative scoliosis undergoing primary versus revision surgery.

STUDY DESIGN: Retrospective cohort analysis of prospectively collected data. OBJECTIVE: To compare clinical outcomes and postoperative complications in patients with lumbar degenerative scoliosis who underwent primary (P) versus revision (R) surgery. SUMMARY OF BACKGROUND DATA: Revision surgery for spinal deformity is technically challenging and may be associated with greater risks of complications and inferior clinical outcomes. There is a paucity of data in the literature comparing primary versus revision surgery in patients with degenerative scoliosis with respect to their clinical outcomes and complications. METHODS: An analysis of 84 consecutive patients with degenerative scoliosis who underwent primary versus revision surgery between 2002 and 2010 with a minimum 2-year follow-up was performed. RESULTS: There were 53 patients in the primary group and 31 in the revision group. The average number of previously operated levels in the revision group was 3.5 ± 2.6. Mean age at surgery, sex, and body mass index were similar between the 2 groups, as well as comorbidities and postoperative complication rates (P > 0.05). Although a greater preoperative coronal imbalance was noticed in the revision group (P: 2.5 cm vs. R: 4.8 cm, P = 0.022), the final radiographical measures were comparable between the 2 groups. At 2-year follow-up, Oswestry Disability Index and visual analogue scale scores improved significantly in both groups compared with preoperatively (P < 0.001). The improvement in scores of Oswestry Disability Index and visual analogue scale preoperatively to final follow-up was similar between the 2 groups (P > 0.05). CONCLUSION: Revision patients achieved the same radiographical and clinical outcomes as primary patients. The complication rates were similar between primary and revision patients. Revision patients benefit from surgery just as much as primary patients at 2-year follow-up.

Does obesity affect surgical outcomes in degenerative scoliosis?

STUDY DESIGN: Retrospective cohort analysis of prospectively collected data. OBJECTIVE: To determine whether an association exists between body mass and surgical outcomes in patients with degenerative scoliosis after long instrumented spinal arthrodesis (≥ 4 discs). SUMMARY OF BACKGROUND DATA: Obesity is thought to be associated with increased surgical complications and inferior clinical outcomes in adults. There are no studies analyzing the effect of obesity on surgical outcomes in patients with degenerative scoliosis after long instrumented spinal arthrodesis. METHODS: Eighty-four consecutive patients with degenerative scoliosis (69 females and 15 males; mean age, 68.6 ± 8.0 yr) with a minimum follow-up of 2 years were included in this study. Patients were divided into 3 groups according to body mass index (BMI): obese (BMI ≥ 30 kg/m², n = 19), overweight (BMI = 25-29.9 kg/m², n = 35), and normal weight (BMI < 25 kg/m², n = 30). Radiographical measures, Oswestry Disability Index, visual analogue scale score, as well as comorbidities and complications were reviewed and analyzed for all patients preoperatively and at 1- and 2-year follow-ups. RESULTS: Compared with the normal weight group, no significant differences in surgical methods, comorbidities, complication rates, curve correction, or radiographical measures were found in the obese and overweight groups, except for a greater preoperative lumbar lordosis in the overweight group (-40.3° ± 13.8° vs. -26.0° ± 18.9°, P < 0.05). At 2-year follow-up, Oswestry Disability Index and visual analogue scalescores improved significantly in all groups compared with preoperatively (P < 0.01). The changes of Oswestry Disability Index and visual analogue scalescores from preoperatively to final follow-up were similar in the 3 groups (P > 0.05). CONCLUSION: Obesity did not affect the amount of deformity correction and did not increase comorbidities and postoperative complication rates. Overweight patients had a greater lumbar lordosis before surgery than normal weight patients. Obese and overweight patients benefited from surgery just as much as normal weight patients at 2-year follow-up.

Revision spinal fusion in patients older than 75: is it worth the risks?

STUDY DESIGN: Retrospective clinical study of a prospective database. OBJECTIVE: This study aims to determine whether revision spinal fusion surgery is worthwhile in patients older than 75 from a risk-benefit perspective. SUMMARY OF BACKGROUND DATA: The benefits of spinal fusion in patients older than 65 is well documented. However, the clinical benefit to patients older than 75 of revision surgery, which often yields worse outcomes with higher complication rates, is uncertain. METHODS: Ninety-nine consecutive patients older than 75 with minimum 2-year follow-up underwent spinal fusion as either a primary (n = 58) or revision (n = 41) operation. Diagnoses were spondylolisthesis (n = 43), scoliosis (n = 28), kyphosis (n = 5), and other degenerative spinal disorders (n = 26). Outcomes were obtained prospectively by visual analogue scale (VAS) and Oswestry Disability Index (ODI) at preoperative, 1-year, 2-year, and latest follow-up. RESULTS: Revision patients had significantly worse scores compared with primary patients at all time intervals, for both VAS (preoperative: 6.4 vs. 5.8, 1 yr: 3.6 vs. 2.4, 2 yr: 4.7 vs. 2.5) and ODI (preoperative: 52.2 vs. 44.1, 1 yr: 37.3 vs. 25.6, 2 yr: 47.0 vs. 25.0). Both groups improved significantly at 1 year postoperatively. At 2 years, the results of revision surgery deteriorated (ΔVAS: -1.7, ΔODI: -5.2), whereas the benefits of primary procedures were maintained (ΔVAS: -3.3, ΔODI: -19.1). Complications were generally greater in the revision group and included revision surgery (8[19.5%] vs. 7[12.1%]), nonunion (2[4.9%] vs. 3[5.2%]), adjacent level fracture (4[9.8%] vs. 6[10.3%]), infection (6[14.7%] vs. 2[3.4%]), foot drop (0[0.0%] vs. 4[6.9%]), imbalance (4[9.8%] vs. 1[1.7%]), pulmonary failure (1[2.4%] vs. 1[1.7%]), and death (0[0.0%] vs. 1[1.7%]). CONCLUSION: Despite having worse initial ODI and VAS scores, revision patients older than 75 initially benefit as much as patients older than 75 undergoing primary operations. However, at 2 years, revision patients do not have a sustained benefit despite a higher complication rate. LEVEL OF EVIDENCE: 4.

Transforaminal lumbar interbody fusion with rhBMP-2 in spinal deformity, spondylolisthesis, and degenerative disease--part 1: Large series diagnosis related outcomes and complications with 2- to 9-year follow-up.

STUDY DESIGN: Retrospective review of prospectively collected data. OBJECTIVE: To evaluate long-term clinical outcomes and complications of the transforaminal lumbar interbody fusion (TLIF) procedure from a large consecutive series, without industry funding. Clinical outcomes and complications are analyzed by diagnosis and primary versus revision surgery to assess whether TLIF with bone morphogenic protein (BMP) is appropriate for common use in deformity, spondylolisthesis, and degenerative disease. SUMMARY OF BACKGROUND DATA: A common method for achieving spinal arthrodesis includes TLIF with a cage and off-label interbody BMP-2, supported by posterior arthrodesis and a pedicle screw construct. There are no large studies analyzing outcomes and complications after TLIF in different diagnoses, for primary and revision surgery, leading some to question the widespread use of TLIF. METHODS: A total of 509 consecutive adults underwent open posterior instrumented fusion, augmented with TLIF at 872 discs using a cage and rhBMP-2, with minimum 2-year follow-up. Cohort diagnoses included 179 degenerative, 207 spondylolisthesis, and 123 deformity patients. Patient age averaged 61 years, 207 had undergone prior decompression or fusion surgery. All patients underwent posterior instrumented fusion and pedicle screw instrumentation at average 3.6 levels (range, 1-16); all patients had TLIF 1.7 levels (range, 1-4 levels) with BMP and autograft, stabilized with an interbody cage. RESULTS: At average 59 months follow-up, 12 patients developed pseudoarthrosis, 8 at TLIF levels (8/872 discs, 0.92%) most commonly at L5-S1 (6/8). Significant clinical improvement was noted in patients with deformity, spondylolisthesis, and degenerative disease undergoing primary and revision surgery. Overall, visual analogue scale preoperative score was 6.6, at 1 year 3.8, at 2 years 3.5 (P < 0.001) and the preoperative ODI was 50.9, at 1 year 36.1, and at 2 years 35.0 (P < 0 0.001). Pain medication requirements also declined. CONCLUSION: The efficacy of TLIF with BMP is supported in this large series with long-term follow-up, independent of industry. Reliable fusion and improved outcomes can be expected in adults undergoing TLIF for deformity, spondylolisthesis, and degenerative disease. Most complications occurred in patients with deformity. LEVEL OF EVIDENCE: 3.

Transforaminal lumbar interbody fusion with rhBMP-2 in spinal deformity, spondylolisthesis, and degenerative disease--part 2: BMP dosage-related complications and long-term outcomes in 509 patients.

STUDY DESIGN: Retrospective review of prospectively collected data. OBJECTIVE: Without industry funding, the study evaluated short- and long-term complications related to off-label bone morphogenetic protein (BMP) used with transforaminal lumbar interbody fusion (TLIF) from a large consecutive series. Complications and results were analyzed by BMP dose, fusion length, and primary versus revision surgery. Based on the results, surgical technique and BMP dose recommendations were proposed. SUMMARY OF BACKGROUND DATA: Off-label use of BMP in TLIF, although common, has only been studied in small series and case reports using various techniques, cage types, and doses of BMP. Several of these studies have reported minimal complications. Others report problems related to BMP, which has led to questions regarding current widespread use of TLIF with BMP. METHOD: TLIF with rhBMP-2 was performed at 872 discs in 509 consecutive adults who underwent open posterior instrumented fusion and had minimum 2-year follow-up; diagnoses included degenerative disease (179), spondylolisthesis (207), deformity (123). Patient age averaged 61 years: 12% were smokers and 41% had revision surgery. TLIF was performed at 1.7 levels: single level: 229, 2 levels: 201, 3 levels: 74, 4 levels: 5. Local autograft was used for backfill around and behind each rectangular cage. Varying doses of interbody BMP were used at an average 7.3 mg per disc (range: 2-12 mg per disc). RESULTS: At 5 years average follow-up, 8 patients developed pseudoarthrosis at levels of TLIF (8 of 872 discs, 0.92%). Seroma (0.4%) and ectopic bone growth (0.6%) were too infrequent to be associated with a particular BMP dose. Deep infection was 2.6% overall (1.7% of the degenerative group). Symptomatic osteolysis or cage subsidence did not occur. Significant long-term improvement was noted in clinical and functional outcomes compared with preoperation. CONCLUSION: Five-year follow-up after TLIF with BMP, independent of industry, confirms effective arthrodesis in short and long fusions, both primary and revision. Most complications occurred in deformity patients. BMP-related complications (seroma, ectopic bone) were rare. LEVEL OF EVIDENCE: 3.

Characteristics of immediate and fatigue strength of a dual-threaded pedicle screw in cadaveric spines.

BACKGROUND CONTEXT: Novel dual-threaded screws are configured with overlapping (doubled) threads only in the proximal shaft to improve proximal cortical fixation. PURPOSE: Tests were run to determine whether dual-threaded pedicle screws improve pullout resistance and increase fatigue endurance compared with standard pedicle screws. STUDY DESIGN/SETTING: In vitro strength and fatigue tests were performed in human cadaveric vertebrae and in polyurethane foam test blocks. PATIENT SAMPLE: Seventeen cadaveric lumbar vertebrae (14 pedicles) and 40 test sites in foam blocks were tested. OUTCOME MEASURES: Measures for comparison between standard and dual-threaded screws were bone mineral density (BMD), screw insertion torque, ultimate pullout force, peak load at cyclic failure, and pedicular side of first cyclic failure. METHODS: For each vertebral sample, dual-threaded screws were inserted in one pedicle and single-threaded screws were inserted in the opposite pedicle while recording insertion torque. In seven vertebrae, axial pullout tests were performed. In 10 vertebrae, orthogonal loads were cycled at increasing peak values until toggle exceeded threshold for failure. Insertion torque and pullout force were also recorded for screws placed in foam blocks representing healthy or osteoporotic bone porosity. RESULTS: In bone, screw insertion torque was 183% greater with dual-threaded than with standard screws (p<.001). Standard screws pulled out at 93% of the force required to pull out dual-threaded screws (p=.42). Of 10 screws, five reached toggle failure first on the standard screw side, two screws failed first on the dual-threaded side, and three screws failed on both sides during the same round of cycling. In the high-porosity foam, screw insertion torque was 60% greater with the dual-threaded screw than with the standard screw (p=.005), but 14% less with the low-porosity foam (p=.07). Pullout force was 19% less with the dual-threaded screw than with the standard screw in the high-porosity foam (p=.115), but 6% greater with the dual-threaded screw in the low-porosity foam (p=.156). CONCLUSIONS: Although dual-threaded screws required higher insertion torque than standard screws in bone and low density foam, dual-threaded and standard pedicle screws exhibited equivalent axial pullout and cyclic fatigue endurance. Unlike single-threaded screws, the mechanical performance of dual-threaded screws in bone was relatively independent of BMD. In foam, the mechanical performance of both types of screws was highly dependent on porosity.

Transforaminal lumbar interbody fusion versus anterior lumbar interbody fusion as an adjunct to posterior instrumented correction of degenerative lumbar scoliosis: three year clinical and radiographic outcomes.

STUDY DESIGN: Prospective, nonrandomized consecutive single surgeon series. OBJECTIVE: To compare the clinical and radiographic outcomes in degenerative lumbar scoliosis (DLS) patients treated with posterior instrumented correction and fusion with additional anterior lumbar interbody fusion (ALIF) versus transforaminal lumbar interbody fusion (TLIF) to help define whether anterior surgery should be routinely required in treating DLS. SUMMARY OF BACKGROUND DATA: The benefits of interbody support in promoting postoperative stability and arthrodesis are well established. Whether the interbody fusion is better performed from an anterior or posterior approach has not been studied for patients undergoing surgical correction for DLS. METHODS: Forty consecutive patients with DLS, stenosis, and olisthesis underwent posterior instrumented reduction/arthrodesis at average 7 levels (range: 4-9 levels). Additional ALIF was performed in 20 patients, TLIF in the other 20. Follow-up averaged 38 months (24-68 months). Oswestry Disability Index (ODI), visual analog pain scores (VAS) were evaluated preoperative, 1 and 2 years postoperative. Radiograph measurements included the scoliosis, T12 to S1 lordosis, coronal and sagittal balance, and pelvic incidence. CT evaluation of the fusion integrity was performed after 1 year. RESULTS: The ALIF group complications included 4 nonunions, 5 adjacent level fractures, 5 adjacent degeneration, 3 infections, and 1 footdrop. Revision surgery was performed in 8 of 20. Medical complications included 2 nonfatal pulmonary embolus, 1 ileus requiring colostomy, and 1 stroke. TLIF group complications included 3 adjacent segment degeneration, 2 adjacent fractures, 2 nonunions, and 1 infection and transient footdrop. Two of 20 required revision surgery. VAS and ODI improvements for both groups showed significant improvement from preoperative (P < 0.0019) but were not different. Deformity correction was also similar (70%) between ALIF and TLIF groups. CONCLUSION: With current deformity correction techniques, both ALIF and TLIF are effective in DLS surgery. Anterior surgery is not routinely required to treat all cases of DLS.