Anterior lumbar interbody fusion versus transforaminal lumbar interbody fusion for correction of lumbosacral fractional curves in adult (thoraco)lumbar scoliosis: A systematic review

Background

Anterior lumbar interbody fusion (ALIF) or transforaminal lumbar interbody fusion (TLIF) may be used to correct the lumbosacral fractional curve (LsFC) in de novo adult (thoraco) lumbar scoliosis. Yet, the relative benefits of ALIF and TLIF for LsFC correction remain largely undetermined.

Purpose

To compare the currently available data comparing radiographic correction of the LsFC provided by ALIF and TLIF of LsFC in adult (thoraco)lumbar scoliosis.

Methods

A systematic review was performed on original articles discussing fractional curve correction of lumbosacral spinal deformity (using search criteria: "lumbar" and "fractional curve"). Articles which discussed TLIF or ALIF for LsFC correction were presented and radiographic results for TLIF and ALIF were compared.

Results

Thirty-one articles were returned in the original search criteria, with 7 articles included in the systematic review criteria. All 7 articles presented radiographic results using TLIF for LsFC correction. Three of these articles also discussed results for patients whose LsFC were treated with ALIFs; 2 articles directly compared TLIF and ALIF for LsFC correction. Level III and level IV evidence indicated ALIF as advantageous for reducing the coronal Cobb angle of the LsFC. There were mixed results on relative efficacy of ALIF and TLIF in the LsFC for restoration of adequate global coronal alignment.

Conclusions

Limited level III and IV evidence suggests ALIF as advantageous for reducing the coronal Cobb angle of the LsFC in de novo adult (thoraco) lumbar scoliosis. Relative efficacy of ALIF and TLIF in the LsFC for restoration of global coronal alignment may be dictated by several factors, including directionality and magnitude of preoperative coronal deformity. Given the limited and low-quality evidence, additional research is warranted to determine the ideal interbody support strategies to address the LsFC in adult (thoraco) lumbar scoliosis.

Oblique lateral interbody fusion for lumbosacral fractional curve correction in degenerative lumbar scoliosis

PURPOSE

In combined anterior-posterior adult spinal deformity surgery, the optimal combination of anterior and posterior procedures remains unclear. We aimed to demonstrate the radiological outcomes and relevant factors in oblique lateral interbody fusion (OLIF) for lumbosacral fractional curve (FC) correction combined with open posterior surgery in degenerative lumbar scoliosis (DLS).

METHODS

This study involved 42 consecutive patients with DLS who had a major curve (MC) ≥ 20° and an FC (L4 to S1) ≥ 10°, and underwent a combined anterior-posterior surgery Changes in the MC, FC, coronal balance distance, type of coronal imbalance, coronal/sagittal disc angle at L4-5 and L5-S1, L4 and L5 tilt, and sagittal parameters were examined. The associations between FC correction and demographic, surgical, and radiological factors were analysed.

RESULTS

The FC decreased from 16.9 ± 7.3° preoperatively to 6.6 ± 4.4° at the last follow-up (P < 0.001). The coronal disc angle at L4-5 and L5-S1 were, respectively, 6.8 ± 2.2° and 6.0 ± 4.1° preoperatively and decreased to 2.2 ± 2.1 and 1.2 ± 1.3° at the last follow-up (both P < 0.001). The changes in FC were greater in uppermost instrumented level > T10 (P < 0.001), and associated with the preoperative FC (r = 0.820, P < 0.001), L4 tilt (r = 0.434, P = 0.007), and L5 tilt (r = 0.462, P = 0.003).

CONCLUSION

OLIF at the FC combined with open posterior surgery is an effective combined anterior-posterior correction strategy in DLS.

The Lumbosacral Fractional Curve in Adult Degenerative Scoliosis

Spine surgeons are often faced with a profoundly difficult challenge in surgically treating adult degenerative scoliosis. Deformity correction surgery is complicated by the difficulty in offering extensive surgical corrections to the elderly, complication-prone population it commonly affects. As spine surgeons attempt to offer minimally invasive solutions to this disease process, the need for fusion of the fractional curve at L4, L5, and S1 may be discounted. A treatment strategy to identify, address, and treat the fractional curve with either open or minimally invasive techniques can lead to improved patient outcomes and decrease revision rates in this complicated pathologic process.

Improvement of coronal alignment in fractional low lumbar curves with the use of anterior interbody devices

STUDY DESIGN

Retrospective chart review.

OBJECTIVES

To determine if the addition of an anterior lumbar interbody fusion (ALIF) improves the fractional curve in adult spinal deformity correction when compared to posterior surgery alone. ALIF is commonly advocated to improve lordosis and fusion in adult deformity surgery. Improved fractional curve correction may help level the pelvis and minimize proximal malalignment.

METHODS

Patients undergoing thoracolumbar fusion to the pelvis with S2AI screws for deformity were identified and stratified into patients who had an ALIF as part of their deformity correction procedure (ALIF + PSF), and those who had a posterior approach alone. The posterior approach (PSF) includes patients who had a posterolateral fusion with or without a transforaminal lumbar interbody fusion (TLIF). Radiographic parameters measured included pre-op and post-op fractional coronal curve Cobb angle, lumbar lordosis, pelvic tilt, pelvic incidence and sacral slope, major Cobb angle, coronal and sagittal SVA.

RESULTS

There were 31 cases in the ALIF + PSF group and 28 in the PSF group. Baseline demographic characteristics of the two groups were similar. Mean pre-op fractional coronal Cobb (18.3° vs 13.4°, p = 0.027) was larger in the ALIF + PSF group, whereas lumbar lordosis (31.0° vs 33.6°, p = 0.487) and pelvic parameters were similar between the two groups. Post-op lumbar lordosis was similar (48.2° vs 43.0°, p = 0.092). Greater fractional coronal curve correction was achieved in the ALIF + PSF group (67%) compared to the PSF group (36%) with a smaller post-op fractional coronal curve in the ALIF + PSF group (6.1°) compared to the PSF group (8.6°, p = 0.053).

CONCLUSION

There is a greater correction of the fractional curve in the ALIF + PSF group compared with the PSF group. While this may not be the primary indication for ALIF, it is a benefit which may facilitate overall deformity correction and leveling of the pelvis.

Sagittal spinopelvic malalignment in degenerative scoliosis patients: isolated correction of symptomatic levels and clinical decision-making

Background

This study aims to determine if (1) loss of lumbar lordosis (LL), often associated with degenerative scoliosis (DS), is structural or rather largely due to positional factors secondary to spinal stenosis; (2) only addressing the symptomatic levels with a decompression and posterolateral fusion in carefully selected patients will result in improvement of sagittal malalignment; and (3) degree of sagittal plane correction achieved with such a local fusion could be predicted by routine pre-operative imaging.

Methods

A retrospective study design with prospectively collected imaging data of a consecutive series of surgically treated DS patients who underwent decompression and instrumented fusion at only symptomatic levels was performed. Pre- and post-operative plain radiographs and pre-operative magnetic resonance imaging (MRIs) of the spinopelvic region were analyzed. LL, pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS) were assessed in all patients. As a requirement for the surgical strategy, all patients presented with a pre-operative PI-LL mismatch greater than 10^°. Post-operative complications were assessed.

Results

Pre-operative MRIs and lumbar extension radiographs revealed a mean LL of 42^° (range 10-66^°) and 48^° (range 20-74^°), respectively, in 68 patients (mean follow-up 29 months). LL post-operatively was corrected to a mean PI-LL of 10^°. Of patients who achieved PI-LL mismatch within 10^o on their pre-operative extension lateral lumbar radiographs, 62.5% were able to maintain a PI-LL mismatch within 10^° on their initial post-operative films. Only 37.5% were not able to achieve that mismatch on extension radiographs (p = 0.001, OR = 9.58). Similarly, 54.2% were able to achieve a PI-LL < 10^° on initial post-operative radiographs, when pre-operative MRI revealed a PI-LL mismatch within 10^°. In contrast, only 20.5% achieved that goal post-operatively if their mismatch was greater than 10^o on their MRI (p = 0.003, OR = 4.25).

Conclusion

With a decompression and instrumented fusion of only the symptomatic levels in symptomatic DS patients, we were able to achieve a PI-LL mismatch to within 10^°. The loss of LL observed pre-operatively may be largely positional rather than structural. The amount of LL correction observed immediately after surgery can be predicted from pre-operative lumbar extension radiographs and supine sagittal MRI.