Redefining Clinical Success Following Adult Spine Deformity Surgery Using a Multifactorial Composite Metric.

STUDY

DESIGN

Retrospective multicenter registry.

OBJECTIVE

To establish a multidimensional definition of surgical success in ASD surgery and evaluate achievement rates across diverse patient subgroups.

SUMMARY OF BACKGROUND DATA: Adult spinal deformity (ASD) encompasses diverse deformity types, disability levels, and treatment options. Optimal surgery aims in part to improve function, reduce radicular pain, and minimize revisions. Despite some studies considering combined outcomes, comprehensive multifactorial evaluation remains limited.

MATERIALS AND

METHODS

Success was assessed across disability (2 yr ODI ≤20 or ∆ODI >14), radicular pain (NRS leg ≤3 or ∆NRS leg >3), and reoperation (no mechanical/neurologic revision). Patients were categorized by preoperative high disability (ODI >40) and/or high pain (NRS leg >5). Individual and composite success rates were compared across preoperative deficits and deformity types. Satisfaction and treatment repetition willingness were analyzed by success achievement.

RESULTS

Of 1504 patients, 1084 (71.9%) completed two-year follow-up (median age: 64 yr, 75.4% female, 50.7% prior surgery). Median preoperative scores: ODI 44, NRS back 8, NRS leg 5. Preoperatively, 40.7% had combined high disability and pain, 21.6% high disability only, 13.5% high pain only, and 20.2% neither. At two years, success rates were 60.9% for disability, 64.8% for leg pain, 81.2% for revision avoidance, and 40.5% composite. Composite success was highest without preoperative deficits (59.4%), intermediate with isolated deficits (38.0% high disability, 43.8% high pain), and lowest with combined deficits (32.2%). Severe coronal deformities achieved the highest composite success (51.7%) versus 32.0% to 41.3% for other types. Composite success strongly correlated with satisfaction (87.2%) and willingness to repeat treatment (94.4%).

CONCLUSIONS

Success in ASD surgery should reflect both improvement and final outcomes. Composite success measures provide a more comprehensive surgical assessment than single metrics. By identifying patient characteristics associated with higher success rates, this framework informs evidence-based patient selection, enables realistic preoperative counseling, and guides outcome-driven surgical planning.