Research Article: Paravertebral muscle degeneration-guided selective fusion strategy for degenerative lumbar scoliosis: a novel approach to minimize surgical invasiveness while optimizing clinical outcomes
Abstract:
Proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) remain unresolved complications in degenerative lumbar scoliosis (DLS) surgery. This study evaluated a PVM degeneration-guided selective fusion strategy in which fusion levels were determined according to pre-operative paravertebral muscle (PVM) degeneration patterns.
This retrospective cohort study included 22 patients with DLS treated between January 2022 and December 2024 (mean follow-up 28.4 ± 3.8 months, range 24–36 months). Fusion-degeneration concordance was defined as exact alignment between fusion boundaries and the contiguous block of significantly degenerated PVM segments (Goutallier grade ?3). PJK was defined as a proximal junctional angle ?10° and at least 10° greater than the pre-operative measurement. PJF was defined as PJK associated with vertebral fracture, instrumentation failure, subluxation, or requiring revision surgery. The radiographic correction maintenance rate was calculated as [(immediate post-operative correction amount – final follow-up correction loss) / immediate post-operative correction amount] × 100%. The primary outcome was the incidence of PJK/PJF at final follow-up. Secondary outcomes included radiographic correction maintenance and patient-reported outcomes. Longitudinal radiographic changes were analyzed using repeated-measures ANOVA. Multivariable linear regression was performed to identify factors associated with ODI improvement rate.
No cases of PJK or PJF were observed. Mean fusion length was 4.3 ± 1.1 segments, with fusion-degeneration concordance achieved in 19/22 patients (86.4%). Coronal and sagittal alignment improved significantly post-operatively and were maintained at final follow-up (all P < 0.001). Correction loss at final follow-up was 1.0 ± 1.2°, corresponding to a maintenance rate of 88.2 ± 7.3%. In multivariable analysis, a greater number of degenerated PVM segments was negatively associated with ODI improvement rate ( B = ?0.11, 95% CI ?0.18 to ?0.04, P = 0.003), whereas fusion-degeneration concordance was positively associated with ODI improvement ( B = 0.38, 95% CI 0.12 to 0.63, P = 0.006).
Selective fusion guided by PVM degeneration patterns represents a paradigm shift from geometry-based to biology-guided surgical planning for DLS. This strategy achieves excellent clinical and radiographic outcomes with reduced fusion extent, surgical trauma, and junctional complications. The approach warrants validation through prospective multicenter trials.
Introduction:
Proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) remain unresolved complications in degenerative lumbar scoliosis (DLS) surgery. This study evaluated a PVM degeneration-guided selective fusion strategy in which fusion levels were determined according to pre-operative paravertebral muscle (PVM) degeneration patterns.
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