Précis: A recently developed Classification of adult scoliosis was utilised to study surgical treatment in 339 patients. At 12 month follow up after surgery for thoracolumbar/lumbar scoliosis greatest improvement in outcome scores were noted in the following patients: lost lumbar lordosis, treatment with osteotomies, fusion to the sacrum for marked sagittal imbalance. Complication rates were greatest for: fusion to the sacrum, sagittal imbalance greater than 4cm.

Introduction: A recently proposed radiographic Classification of adult scoliosis offers a useful system with high clinical impact and reliability. Continued work is required to apply this system in the development of treatment guidelines. The purpose of this study was to anal surgical treatment outcomes, and complications, by Classification subtype at 12 months post-operative follow up.

Material and Method: This study included 339 patients: Type IV (thoracolumbar major) and Type V (lumbar major) adult scoliosis (Spinal Deformity Study Group). All patients had complete full-length spine radiographs and outcomes questionnaires (SRS, ODI and SF-12). An analysis of classification subtypes (modifiers) included outcome scores by surgical treatment. The latter included approach (anterior, posterior, both), use of osteotomies, and extension to the sacrum (or not).

Results: Lordosis modifier was strongly correlated with baseline disability and post-operative improvement. Type C (loss of lordosis) patients had the lowest baseline outcome but also greatest improvement with surgery (p< 0.05). Subluxation modifier had impact on preoperative but not on postoperative outcomes measures. Marked sagittal balance had the worst outcomes of all groups if fusion fell short of the sacrum. Patients with osteotomies saw greater improvement than those without (p< 0.05). Anterior, posterior or combined procedures showed no significant difference in outcomes. Peri- and post-operative complications did not vary by lordosis modifier, subluxation modifier but were elevated for fusion to the sacrum (p< 0.05).

Conclusion: At 12 month follow up for surgical treatment of adult thoracolumbar/lumbar scoliosis greatest improvement in outcome scores were noted in the following patients: lost lumbar lordosis, treatment with osteotomies, fusion to the sacrum for marked sagittal imbalance. Complication rates were greatest for: fusion to the sacrum, sagittal imbalance greater than 4cm. Further longitudinal follow up will permit validation of optimal treatment by Classification type of adult spinal deformity and refine patient and surgeon expectations of operative care.

Précis: A multi-centre prospective effort focused on analysis of a previously reported Classification of adult scoliosis. 809 thoracolumbar/lumbar deformities were studied. Radiographic analysis (deformity apex, lumbar lordosis, intervertebral subluxation), outcomes measures (ODI, SRS instruments) and surgical rates were examined. The Classification into Types, based on deformity apex location, and addition of modifiers (lordosis, subluxation) established clinically significant groups (disability, pain). In addition to high clinical impact, the Classification was also able to predict surgical rates.

Introduction: A recently proposed radiographic classification of adult scoliosis offers a reliable method of categorizing patients. Continued work on this classification is expected to develop treatment guidelines. This investigation anald treatment patterns of a large patient population of thoracolumbar and lumbar adult scoliosis, emphasizing surgical rates and approaches by classification subtypes.

Methods: This investigation anald 809 Type IV (thoracolumbar major) and Type V (lumbar major) curves from the Spinal Deformity Study Group database. Enrolled patients had complete SRS, ODI and SF-12 outcomes questionnaires and free standing full-length spine radiographs. Analysis compared non-operative versus surgical treatment (no imposed protocol) with surgical treatment assessed by approach (anterior, posterior, both), +/− osteotomies.

Results: Of 809 patients, 348 were treated surgically (43%) and classified as lordosis type A (n=422), B (n=313), C (n=74). Surgical rates were greater for B vs. A (51% vs. 37%, p< 0.05)), trend for A vs. C (46%). Subluxation modifier scores: 0 (n=360), + (n=159), ++ (n=290). Surgical rates were greater for ++ vs. 0 (52% vs. 36 %, p< 0.05), trend vs. + (42 %). Greater sagittal imbalance was more likely to receive surgical treatment. Loss of lumbar lordosis (modifier B, C) was associated with increased osteotomy rates and posterior or circumferential treatment versus anterior only procedures (most common in modifier A). Greater subluxation (modifier ++) was associated with more circumferential surgery. Greater sagittal imbalance was associated with higher rate of posterior only surgery.

Discussion: In this analysis, greater lordosis or subluxation modifier score was associated with higher surgical rates. Loss of lordosis and greater subluxation grade was associated with higher rates of circumferential surgery than lordotic spines or those without significant subluxation. This information suggests the ability of this classification system to predict treatment. Longitudinal follow up will permit validation of optimal treatment by classification of adult spinal deformity.