Functional outcomes correlate with sagittal spinal balance in degenerative lumbar spondylolisthesis surgery

Segmental Lordosis Restoration During Lumbar Degenerative Spinal Fusion: Surgical Techniques and Outcomes

The science of spinal alignment has progressed rapidly since Jean Doubousset described the cone of economy in the 1970s. It is now clearly established that global and regional spinal alignment are associated with improved patient-reported outcome and rates of success of lumbar spinal fusion. Evidence has now emerged that segmental level-by-level alignment is also associated with positive patient outcomes. As such, restoring sagittal alignment matched to spinopelvic morphology during degenerative lumbar surgery can optimize surgical outcomes by preventing adjacent segment pathology. This review focuses on the vital importance of spinal alignment in different spinal conditions, provides a guide for measurement of spinopelvic parameters, and outlines literature regarding lumbar restoration in degenerative spinal fusion.

What Radiographic and Spinopelvic Parameters do Spine Surgeons Consider in Decision-Making for Treatment of Degenerative Lumbar Spondylolisthesis?

STUDY DESIGN

Cross-sectional survey.

OBJECTIVE

Surgical treatment of degenerative lumbar spondylolisthesis is remarkably varied due to heterogeneity of clinical-radiological presentations. This study aimed to assess which spinopelvic radiological parameters were considered for decision-making.

METHODS

Survey distributed to International AO Spine members to analyze surgeons' considerations for treatment. Data collected includes demographics, training background, years of experience, and treatment decisions based on various radiographical findings, including segmental and global spinopelvic parameters.

RESULTS

From 479 responses, the most frequently radiological parameter considered was slippage on dynamic X-rays (79.1%), followed by disc height (78.9%), global sagittal balance SVA (71.4%), and PI-LL mismatch (69.7%), while the least important was absolute spondylolisthesis on static lateral radiograph (22.8%). Fellowship-trained surgeons were likelier to use SVA (OR = 1.73, 95% CI = 1.02-2.99, P = 0.049), and disc height (2.13, 1.14-3.98, P < 0.05). There was no difference between orthopedics and neurosurgery in applying SVA and PI-LL mismatch. Surgeons from Asia Pacific emphasizes segmental lordosis (2.39, 1.11-5.15, P = 0.026) as from Latin America (2.55, 1.09-5.95, P = 0.030) and Middle East (4.33, 1.66-11.28, P = 0.003). However, surgeons from Latin America and Middle East also significant consider disc height (2.95, 1.07-8.15, P = 0.037) and (3.03, 1.04-8.83, P = 0.043), respectively. Additionally, the surgeons' age was associated with using angular motion on flexion-extension radiographs, and volume of treated cases yearly with consideration for disc height.

CONCLUSIONS

Treatment of degenerative lumbar spondylolisthesis was influenced by slippage on dynamic radiographs, disc height, global alignment, and PI-LL mismatch. Surgeons' age and Region, fellowship-trained, and volume of treated cases were significantly associated to apply these radiological parameters.

Segmental Sagittal Alignment in Lumbar Spinal Fusion: A Review of Evidence-Based Evaluation of Preoperative Measurement, Surgical Planning, Intraoperative Execution, and Postoperative Evaluation

BACKGROUND AND OBJECTIVES

Maintaining and restoring global and regional sagittal alignment is a well-established priority that improves patient outcomes in patients with adult spinal deformity. However, the benefit of restoring segmental (level-by-level) alignment in lumbar fusion for degenerative conditions is not widely agreed on. The purpose of this review was to summarize intraoperative techniques to achieve segmental fixation and the impact of segmental lordosis on patient-reported and surgical outcomes.

METHODS

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, PubMed, Embase, Cochrane, and Web of Science databases were queried for the literature reporting lumbar alignment for degenerative lumbar spinal pathology. Reports were assessed for data regarding the impact of intraoperative surgical factors on postoperative segmental sagittal alignment and patient-reported outcome measures. Included studies were further categorized into groups related to patient positioning, fusion and fixation, and interbody device (technique, material, angle, and augmentation).

RESULTS

A total of 885 studies were screened, of which 43 met inclusion criteria examining segmental rather than regional or global alignment. Of these, 3 examined patient positioning, 8 examined fusion and fixation, 3 examined case parameters, 26 examined or compared different interbody fusion techniques, 5 examined postoperative patient-reported outcomes, and 3 examined the occurrence of adjacent segment disease. The data support a link between segmental alignment and patient positioning, surgical technique, and adjacent segment disease but have insufficient evidence to support a relationship with patient-reported outcomes, cage subsidence, or pseudoarthrosis.

CONCLUSION

This review explores segmental correction's impact on short-segment lumbar fusion outcomes, finding the extent of correction to depend on patient positioning and choice of interbody cage. Notably, inadequate restoration of lumbar lordosis is associated with adjacent segment degeneration. Nevertheless, conclusive evidence linking segmental alignment to patient-reported outcomes, cage subsidence, or pseudoarthrosis remains limited, underscoring the need for future research.

The Role of L1PA in Patient-reported Outcomes in Patients Undergoing Single-level Lumbar Fusion for Degenerative Spondylolisthesis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine whether the L1 pelvic angle (L1PA) can be used to predict quality of life outcomes for adults one year after L4-L5 fusion to treat degenerative spondylolisthesis.

SUMMARY OF BACKGROUND DATA

L1PA is beneficial in the evaluation of preoperative and postoperative quality of life outcomes in patients undergoing surgery for spinal deformity. No studies have examined its utility in surgical patients with degenerative spinal disease.

METHODS

Patients undergoing L4-L5 posterolateral decompression and fusion or transforaminal lumbar interbody fusion for degenerative lumbar spondylolisthesis were grouped by preoperative and postoperative L1PA, and further stratified by cut offs of >7.2° and <7.2° based on previous literature. We also stratified patients by presence of an ideal calculated L1PA, defined as (0.5×Pelvic incidence) -21 +/-5°, as proposed by prior literature. Preoperative, one-year postoperative and Δ (postoperative minus preoperative) patient-reported outcome measures (PROMs) and radiographic measurements were collected.

RESULTS

Twenty-four patients were identified with preoperative L1PAs <7.2° and 132 with L1PAs >7.2°. Eighteen patients were identified with postoperative L1PAs <7.2° and 138 with L1PAs>7.2°. Sixty-five and fifty-seven patients were identified as having ideal calculated preoperative and postoperative L1PAs, respectively. When using absolute cutoffs, L1PA correlated with pelvic tilt, pelvic incidence, and pelvic incidence-lumbar lordosis mismatch (PI-LL). When using calculated L1PAs, L1PA correlated with lumbar lordosis, PI-LL, pelvic tilt and sacral slope. With respect to PROMs, no statistically significant differences existed between cohorts both preoperatively and at one-year postoperatively on either univariate and multivariate analyses.

CONCLUSION

L1PA may be a helpful radiographic consideration that translates to clinically relevant outcomes in spinal deformity. However, it does not appear as predictive of patient outcomes after single-level fusion for patients with L4-L5 degenerative spondylolisthesis. Further studies are warranted to investigate the role of L1PA in degenerative spine patients.

Radiographic and surgery-related predictive factors for increased segmental lumbar lordosis following lumbar fusion surgery in patients with degenerative lumbar spondylolisthesis

OBJECTIVE

This study aimed to evaluate preoperative (pre-op) radiographic characteristics and specific surgical interventions in patients with degenerative lumbar spondylolisthesis (DLS) who underwent lumbar fusion surgery (LFS), with a focus on analyzing predictors of postoperative restoration of segmental lumbar lordosis (SLL).

METHODS

A retrospective review at a single center identified consecutive single-level DLS patients who underwent LFS between 2016 and 2022. Radiographic measures included disc angle (DA), SLL, lumbar lordosis (LL), anterior/posterior disc height (ADH/PDH), spondylolisthesis percentage (SP), intervertebral disc degeneration, and paraspinal muscle quality. Surgery-related measures included cage position, screw insertion depth, spondylolisthesis reduction rate, and disc height restoration rate. A change in SLL ≥ 4° indicated increased segmental lumbar lordosis (ISLL), and unincreased segmental lumbar lordosis (UISLL) < 4°. Propensity score matching was employed for a 1:1 match between ISLL and UISLL patients based on age, gender, body mass index, smoking status, and osteoporosis condition.

RESULTS

A total of 192 patients with an average follow-up of 20.9 months were enrolled. Compared to UISLL patients, ISLL patients had significantly lower pre-op DA (6.78° vs. 11.84°), SLL (10.73° vs. 18.24°), LL (42.59° vs. 45.75°), and ADH (10.09 mm vs. 12.21 mm) (all, P < 0.05). ISLL patients were predisposed to more severe intervertebral disc degeneration (P = 0.047) and higher SP (21.30% vs. 19.39%, P = 0.019). The cage was positioned more anteriorly in ISLL patients (67.00% vs. 60.08%, P = 0.000), with more extensive reduction of spondylolisthesis (- 73.70% vs. - 56.16%, P = 0.000) and higher restoration of ADH (33.34% vs. 8.11%, P = 0.000). Multivariate regression showed that lower pre-op SLL (OR 0.750, P = 0.000), more anterior cage position (OR 1.269, P = 0.000), and a greater spondylolisthesis reduction rate (OR 0.965, P = 0.000) significantly impacted SLL restoration.

CONCLUSIONS

Pre-op SLL, cage position, and spondylolisthesis reduction rate were identified as significant predictors of SLL restoration after LFS for DLS. Surgeons are advised to meticulously select patients based on pre-op SLL and strive to position the cage more anteriorly while minimizing spondylolisthesis to maximize SLL restoration.

Evaluation of lumbar paraspinal muscles degeneration and fatty infiltration in dynamic sagittal imbalance based on magnetic resonance imaging

PURPOSE

To explore degeneration and fatty infiltration (FI) of lumbar paraspinal muscles in patients with dynamic sagittal imbalance (DSI) and the relationship between lumbar paraspinal muscles degeneration, fatty infiltration and severity of the disease.

METHODS

We recruited 41 DSI patients and selected 22 lumbar spinal stenosis (LSS) patients without osphyalgia as controls. All patients received magnetic resonance imaging (MRI) scan and DSI patients also received pre-walk and post-walk X-rays. DSI patients were divided into 2 subgroups according to their symptom improvement after conservative treatment. We calculated rmCSA and FI of the lumbar paraspinal muscles. The rmCSA and FI between DSI and control and between DSI subgroups were compared by t test. The regression analysis was used to explore the risk factors influencing disease severity. Receiver operating characteristic (ROC) curves and area under curves (AUCs) were used to evaluate the severity of the disease.

RESULTS

In comparison of rmCSA and FI between DSI and control, there are significant differences of most muscles. In comparison of rmCSA between two subgroups, there are significant differences of most muscles, while in comparison of FI, only muscles in L4 segment have significant different. In logistic regression analysis, total rmCSA and total FI are risk factors influencing disease severity. ROC curves shows that total rmCSA and total FI both achieve an AUC greater than 0.7.

CONCLUSION

Compared with control, DSI patients have degeneration and fatty infiltration of the lumbar paraspinal muscles. The degeneration and fatty infiltration are risk factors influencing disease severity. The total rmCSA and total FI can be used as an indicator to determine whether a patient has severe DSI.