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.

Introduction and Aims: Establishing pathogenic mechanisms that are important for OA progression would support development of therapies to delay arthoplasty and extend the life of the joint. The aim of this study was to define a human model system for comparing minimal and advanced OA cartilage at the tissue, cellular, and molecular level.

Method: Cartilage was isolated from femoral condyles of patients undergoing knee arthroplasty, with advanced OA cartilage obtained from areas within 1cm of overt lesions, and minimal OA cartilage taken from areas with no obvious surface defects. Representative histological sections were scored for disease severity based on four categories: fibrillation, chondrocyte cloning, matrix depletion and cellularity using Bioquant Nova v5.00.8 software. The proteoglycan and hydroxyproline content of the cartilage was determined by biochemical analysis. Following RNA isolation and reverse transcription, the cDNA was analysed for relative gene expression using real-time PCR. Gene expression patterns were compared on a patient-matched basis.

Results: Histological analysis showed that the advanced OA cartilage differed from the minimal cartilage with regard to cloning (p< 0.001), fibrillation (p< 0.001), and proteoglycan depletion (p< 0.001). There was no difference in overall cellularity. The advanced OA cartilage had significantly less proteoglycan content than the minimal tissue, with no difference found in hydroxyproline content. The following changes were observed in the relative expression level of specific genes: 1) the steady state level of osteopontin mRNA showed an overall 3.5-fold increase in advanced OA cartilage compared to minimal (p< 0.01); 2) The mRNA coding for aggre-can was down-regulated in advanced disease tissue to less than 50% the level found in minimal tissue in nine out of 11 patients; 3) the expression of mRNA coding for link protein was also significantly decreased in advanced OA cartilage compared to minimal in nine out of 11 patients; and 4) the mRNA level coding for collagen II did not show an obvious pattern of expression in the minimal versus advanced cartilage. The expression of mRNA coding for MMPs was variable with regard to disease state with the majority of patients showing decreased MMP3, MMP9, and MMP13 mRNA expression in advanced OA tissue compared to minimal.

Conclusions: This study clearly demonstrates that patient-matched minimal and advanced OA cartilage show significant differences in cell and matrix characteristics. In addition, differential patterns of gene expression are observed in this model that may relate to the pathogenic mechanism operating during progression of OA.

Introduction: The anatomy and biomechanics of the thoracic spine is different from the cervical and lumbar spine particularly due to the ribs and sternum which contribute to stability and controlling motion. The role of the sternum and costosternal articulation in the biomechanics of thoracic fracture or deformity correction has not been well studied. The effects of releasing each of these structures, whether alone or in combination, is potentially relevant in the surgical correction of thoracic deformities such as severe kyphosis. The purpose of this study was to investigate the relative effects of releasing the intervertebral disc, the costosternal joint, the sternum, and the facet joints on sagittal thoracic motion and the consequences of altering the sequence of the releases.

Methods: Eighteen human torsos were tested in three experiments (A, B, and C) to determine the effect on sagittal motion due to three different sequences of three surgical releases. In Experiment A the release sequence was back to front: Total facetectomy, then radical discectomy, then sternal osteotomy plus costosternal release. In experiment B the release sequence was front to back: Sternal osteotomy plus costosternal release, then radical discectomy, then total facetectomy. In Experiment C, it was disc first: Radical discectomy, then sternal osteotomy plus costosternal release, then total facetectomy. The different sequences allowed separate analysis of each component and the synergistic patterns. In each of the three experiments, the torso was flexed then extended each time by an applied force (25 N) before and after each release. The extent of both angular flex-ion and angular extension were compared to the intact condition, and after each release.

Results: Radical discectomy provided the greatest increase (P< 0.05) in range of motion (ROM) as compared to the other two single releases, no matter what the sequence. For paired release combination, the radical discectomy and sternal osteotomy plus costosternal release (as in Experiments B and C) provided a significant (P< 0.05) increase in sagittal ROM compared to the combination of radical discectomy and total facetectomy (Experiment A). In Experiment A, if sternal osteotomy and costosternal release (the final release) had not been carried out, then 42% of the sagittal motion would have been lost compared to the 27% related to the total facetectomy (Experiment B). All of the releases allowed more extension than flexion; the only exception was facetectomy when carried out first as in Experiment A.

Conclusions: To increase sagittal thoracic range of motion radical discectomy provided the greatest increase in both extension and total ROM as compared to total facetectomy or sternal osteotomy plus costosternal release, no matter what the sequence. For two releases, the combination of radical discectomy and sternal osteotomy plus costosternal release provided the greatest increase in both extension and total ROM. Total facetectomy was the least useful release. These data have relevance for surgical strategies to correct severe thoracic sagittal plane deformity. The sequence of combined release has important clinical implications.