Correlation of radiographic, clinical, and patient assessment of shoulder balance following fusion versus nonfusion of the proximal thoracic curve in adolescent idiopathic scoliosis.

STUDY DESIGN: Retrospective clinical, radiographic, and patient outcome review of surgically treated adolescent idiopathic scoliosis. OBJECTIVES: To correlate radiographic and clinical features of shoulder balance and the proximal thoracic curve with patient satisfaction outcomes at a minimum 2-year follow-up. SUMMARY OF BACKGROUND DATA: Traditionally, radiographic features of a structural proximal thoracic curve have been T1 tilt, proximal thoracic Cobb angle, and proximal thoracic side-bending Cobb; however, these do not always correlate with clinical shoulder balance. METHODS: A total of 112 patients (single surgeon) with adolescent idiopathic scoliosis and a proximal thoracic curve >or=20 degrees (average 32 degrees, range 20-78 degrees) were evaluated in terms of shoulder balance and curve flexibility/correction. Four groups were analyzed: Group 1, posterior spinal fusion to T2 (proximal thoracic curve included, n = 24); Group 2, posterior spinal fusion to T3 (proximal thoracic curve partially included, n = 23); Group 3, posterior spinal fusion to T4 or T5 (proximal thoracic curve not included, n = 21); and Group 4, anterior spinal fusion to T4 or below (proximal thoracic not included, n = 44). Proximal thoracic, main thoracic, and thoracolumbar-lumbar upright coronal, side-bending, and sagittal Cobb measurements were assessed before surgery, 1 week after surgery, and at a minimum 2-year postoperative follow-up (average 3.8 years, range 2.0-7.6 years). In addition to T1 tilt, clavicle angle (intersection of a horizontal line and the tangential line connecting the highest two points of each clavicle), coracoid height difference, trapezius length (horizontal distance of the T2 pedicle to second rib-clavicle intersection), first rib-clavicle height difference (vertical distance of first rib apex to superior clavicle), and proximal thoracic, main thoracic, and thoracolumbar-lumbar apical vertical translation were determined. Shoulder asymmetry as measured by the radiographic soft tissue shadow was graded as balanced (<1 cm), slight (1-2 cm), moderate (2-3 cm), or significant (>3 cm). A postoperative patient questionnaire addressed shoulder balance and overall appearance at most recent follow-up. RESULTS: The four groups were found to be statistically equivalent in terms of preoperative proximal thoracic curve (P = 0.4146), proximal thoracic side-bending Cobb (P = 0.2199), main thoracic curve (P = 0.6999), and main thoracic side-bending curves (P = 0.7307). Radiographic: Preoperative proximal thoracic measurements correlating with postoperative shoulder balance (P < 0.05) included the clavicle angle (three of four groups with a trend toward statistical significance in the fourth group, P = 0.07) and coracoid height (two of four groups). No other measurement, including T1 tilt and proximal thoracic side-bending Cobb, correlated in more than one group. Proximal thoracic curve correction was greatest in Group 1 (posterior spinal fusion to T2; average 12 degrees) and Group 4 (anterior spinal fusion to T4 or below; average 12 degrees). Clinical: Shoulder balance improved in all four groups (range 0.38-1.00 grades). There was no difference in shoulder balance between groups (P = 0.2723). Patient assessment: All four groups also reported improvement in self-perceived shoulder balance (63% up to one grade, 37% over two-grade improvement), whereas no patient reported worsening of shoulder balance. There was no significant difference in patient outcomes between the four groups (P = 0.3654). CONCLUSION: The clavicle angle, not T1 tilt, upright proximal thoracic, or side-bending proximal thoracic Cobb, provided the best preoperative radiographic prediction of postoperative shoulder balance. In each of the four groups, postoperative shoulder balance and clinical appearance also improved and correlated with patient postoperative assessments.

Prospective radiographic and clinical outcomes and complications of single solid rod instrumented anterior spinal fusion in adolescent idiopathic scoliosis.

STUDY DESIGN: Prospective clinical cases series. OBJECTIVES: To prospectively evaluate outcomes and critically review radiographic results and complications associated with single solid rod anterior spinal fusions in adolescent idiopathic scoliosis with 2-year minimum follow-up (range, 2-6 years). METHODS: Ninety consecutive patients at a single institution with thoracic (n = 43) or thoracolumbar/lumbar (n = 47) adolescent idiopathic scoliosis were treated by one of two surgeons with a similar anterior surgical technique using rib autograft, intradiscal structural (Harms) cages placed below T12, and anterior single solid rod convex compressive instrumentation. The patients were evaluated prospectively with the Scoliosis Research Society outcome instrument and upright radiographs before surgery and minimum 2-year follow-up. RESULTS (RADIOGRAPHIC): The average coronal correction of thoracic curves was from 55 degrees to 29 degrees (47%). The average correction of thoracolumbar/lumbar curves was from 50 degrees to 15 degrees (70%). In the sagittal plane, kyphosis was improved in thoracic fusions from 23 degrees to 30 degrees (T5-T12) and lordosis maintained in thoracolumbar/lumbar fusions at -58 degrees (T12-sacrum). Five patients (5.5%) developed a pseudarthrosis, four with implant failure. Three of five required a posterior fusion for a reoperation rate of 3.3%. The fourth and fifth patients were asymptomatic and appeared fused at the 2-year follow-up, with minimal loss of correction. Common risk factors for pseudarthrosis were smoking (4 of 5), weight >70 kg (4 of 5), and for thoracic pseudarthrosis, hyperkyphosis >40 degrees T5-T12 (2 of 3). RESULTS (CLINICAL OUTCOME): Scoliosis Research Society domain average scores were improved for function, pain, and self-image (P < 0.01). With the Scoliosis Research Society satisfaction domain, 88% responded that they were satisfied with their results and 89% would undergo the same treatment again. Four of five patients with pseudarthrosis did not have statistically significant lower final Scoliosis Research Society scores than those with solid fusions (93 vs. 97, P = 0.18). CONCLUSION: Anterior instrumented fusions for adolescent idiopathic scoliosis using a single solid rod had good radiographic and clinical outcomes. Consideration should be given to alternate techniques in larger adolescents (>70 kg) with thoracic hyperkyphosis (>40 degrees ), and smoking should be avoided. Poor radiographic outcomes did not correlate with final Scoliosis Research Society scores.

Spontaneous proximal thoracic curve correction after isolated fusion of the main thoracic curve in adolescent idiopathic scoliosis.

STUDY DESIGN: Retrospective clinical, radiographic, and patient outcome review of surgically treated adolescent idiopathic scoliosis. OBJECTIVES: To evaluate the spontaneous correction of the noninstrumented proximal thoracic (PT) curve after isolated correction of the main thoracic (MT) curve by either an anterior (ASF) or posterior (PSF) instrumentation and fusion. SUMMARY OF BACKGROUND DATA: There are no studies comparing the structural PT curve response after anterior versus posterior instrumented fusion of the MT curve in adolescent idiopathic scoliosis. METHODS: Eighty-five patients (single surgeon) with adolescent idiopathic scoliosis underwent operative instrumentation and fusion of their MT curve. All patients had a PT curve > or =20 degrees (average 29 degrees, range 20-49 degrees; average residual side-bending 18 degrees, range 3-42 degrees ) and were evaluated for preoperative PT curve flexibility and postoperative curve correction after PSF with the PT curve not instrumented (n = 44) and ASF with the PT curve not instrumented (n = 41). Minimum follow-up was 2 years (average, 3.6 years). Preoperative, 1 week postoperative, and latest follow-up (minimum 2-year) full-length radiographs were evaluated for the PT, MT, and thoracolumbar-lumbar coronal, side-bending, and sagittal Cobb measurements, as well as T1 tilt, clavicle angle, radiographic shoulder height, and the PT, MT, and thoracolumbar-lumbar apical vertical translation. A patient outcome questionnaire was also completed to correlate patient satisfaction with respect to their shoulder balance and overall appearance. RESULTS: The two groups were found to be statistically equivalent (P = 0.66) in terms of preoperative PT curve, MT curve, and MT side-bending curves, with the PT side benders slightly more flexible for the ASF (43%) versus the PSF group (31%) (P = 0.02). RADIOGRAPHIC: The spontaneous improvement in the PT curve was significant (P < 0.0001) in both groups. Additionally, this correction was maintained over time. However, the spontaneous PT curve correction was significantly greater after an ASF versus PSF correction of the MT curve on both the immediate postoperative (P =0.017) and minimum 2-year (P = 0.0024) evaluations, whereas the MT curve correction was the same in both groups (P = 0.45). There was no difference in the postoperative sagittal change in the PT curve (P = 0.12) between the two groups, and there was no difference in radiographic shoulder height (P = 0.5883). PATIENT OUTCOME: Both groups reported improvement in shoulder balance and clinical appearance, but there was no statistical difference between the two groups (P = 0.24). Additionally, no patients reported deterioration in either parameter. CONCLUSIONS: Spontaneous proximal thoracic curve correction consistently occurs after instrumented correction of the main thoracic curve. Furthermore, this spontaneous correction is as good as or slightly better after an ASF versus PSF of the MT curve. The preoperative side bender radiographs (PT curve flexibility) positively correlate with the postoperative spontaneous PT curve correction.

Maintaining lumbar lordosis with anterior single solid-rod instrumentation in thoracolumbar and lumbar adolescent idiopathic scoliosis.

STUDY DESIGN: A prospective radiographic evaluation of 20 consecutive patients with primary lumbar or thoracolumbar adolescent idiopathic scoliosis who were treated with anterior convex compressive single solid-rod spinal instrumentation and structural titanium mesh (Harms) cages. OBJECTIVES: To evaluate a lordosis-preserving anterior single solid-rod instrumented fusion technique for these specific adolescent idiopathic curves. SUMMARY OF BACKGROUND DATA: Maintaining instrumented segmental lumbar lordosis after anterior fusion and instrumentation for thoracolumbar and lumbar curves has been difficult. Twenty consecutive patients who underwent anterior single solid-rod fusion, aged 18 or younger with a primary thoracolumbar or lumbar curve, were observed for preservation of lordosis for a minimum of 2 years. METHODS: All patients underwent an identical anterior surgical technique, involving discectomies and anulectomies of all convex discs, structural titanium mesh (Harms) cages placed in the anterior half of all disc spaces below T12, morselized rib autograft packed in all disc spaces to be fused and inside the cages, and anterior single solid-rod (5.0-mm or 5.5-mm diameter) convex compressive spinal instrumentation with appropriate lordotic rod contour and rod rotation as necessary. The anterior rod was placed just posterior to the cages to optimize lordotic contouring of the spine during compression. None of the patients was braced after surgery. The lowest instrumented vertebrae (LIV) were L2 (n = 3), L3 (n = 15), and L4 (n = 2), typically the lower end vertebra of the Cobb measurement. RESULTS: Measurements for the primary coronal Cobb before surgery, 1 week after surgery, and 2 years after surgery were 48 degrees, 11 degrees, and 12 degrees; for C7 plumb line deviation from the midline: 3.6 cm, 1.9 cm, and 1.2 cm; for lowest instrumented vertebra translation: 31 mm, 15 mm, and 15 mm; and for LIV tilt: 29 degrees, 6 degrees and 6 degrees, respectively. Sagittal measurements before surgery, 1 week after surgery, and 2 years after surgery were: T12-L2: -1 degree, -6 degrees, and -6 degrees; T12-LIV: -8 degrees, -13 degrees, -9 degrees; T12-S1: -61 degrees, -56 degrees, -60 degrees; and entire instrumented levels: -6 degrees, -9 degrees, and -6 degrees, respectively. Coronal plane correction improved: 75% in the primary Cobb, 66% in the plumb line, 50% in LIV translation, and 80% in LIV tilt. Sagittal plane alignment improved in T12-L2 lordosis (P < 0.01) with preservation of physiologic lordosis in the instrumented levels, T12-LIV, and T12-sacrum. There were no instrumentation failures, pseudarthroses, or reoperations. CONCLUSIONS: Coronal plane correction with preservation of thoracolumbar and lumbar lordosis 2 years after anterior convex compressive spinal instrumentation was accomplished using a lordotically contoured single solid rod with structural cages placed anteriorly in the disc spaces of patients with primary thoracolumbar or lumbar adolescent idiopathic scoliosis.

Complications and predictive factors for the successful treatment of flatback deformity (fixed sagittal imbalance).

STUDY DESIGN: This is an analysis of consecutive cases of flatback deformity (fixed sagittal imbalance), treated by one of two surgeons at a university hospital. OBJECTIVE: To define factors that contribute to results with treatment of flatback syndrome, classify types of sagittal deformities, and discuss complications. SUMMARY OF BACKGROUND DATA: There are few reports that detail the results and complications of current instrumentation and osteotomy techniques for correction of fixed sagittal deformities. METHODS: Twenty-eight patients treated with osteotomies for sagittal imbalance were eligible for 2-year minimum follow-up (average, 3.6 years). Patients were classified (segmental imbalance, Type 1; or global imbalance, Type 2) and evaluated by upright radiographs, chart review, and a questionnaire. RESULTS: Twenty-eight (100%) patients returned the questionnaire, and 28 had current radiographs. Five treatment groups were evaluated based on osteotomy type (anterior, posterior [Smith-Petersen], both, or pedicle subtraction) and use of anterior structural grafting. All patients were treated with modern bilateral hook-rod-screw constructs. Mean correction at the osteotomy levels was 25 degrees for Type 1 deformities and 30 degrees for Type 2 (P < 0.05). Sagittal correction averaged 6.6 cm in Type 2 deformities (P < 0.05). Questionnaire analysis showed a significant and persistent reduction in subjective pain level. There were seven patients with 11 total complications and no neurologic deficits. Associations among patients who were not satisfied with their results (n = 4) included insufficient sagittal correction (P = 0.045), pseudarthrosis (P = 0.045), coronal imbalance, and four or more medical comorbidities (P = 0.03). CONCLUSIONS: Satisfaction with the results of treatment may be reduced in patients with four or more major co-existent medical problems, insufficient sagittal correction, and resultant pseudarthrosis.