Optimized Surgical Strategy for Adult Spinal Deformity: Quantitative Lordosis Correction versus Lordosis Morphology.

BACKGROUND: In surgical correction of adult spinal deformity (ASD), pelvic incidence (PI)-lumbar lordosis (LL) plays a key role to restore normal sagittal alignment. Recently, it has been found that postoperative lordosis morphology act as an important factor in preventing mechanical complications. However, there have been no studies on the effect of postoperative lordosis morphology on the restoration of sagittal alignment. The primary objective of this study was to evaluate the effect of postoperative lordosis morphology on achievement of optimal sagittal alignment. The secondary objective was to find out which radiographic or morphologic parameter affects sagittal alignment in surgical correction of ASD. METHODS: 228 consecutive patients with lumbar degenerative kyphosis who underwent deformity correction and long-segment fixation from T10 to S1 with sacropelvic fixation and follow-up over 2 years were enrolled. Patients were divided according to whether optimal alignment was achieved (balanced group) or not (non-balanced group) at last follow-up. We analyzed the differences of postoperative radiographic parameters and morphologic parameters between two groups. Correlation analysis and stepwise multiple linear regression analysis was performed to predict the effect of PI-LL and morphologic parameters on the sagittal vertical axis (SVA). RESULTS: Of 228 patients, 195 (85.5%) achieved optimal alignment at last follow-up. Two groups significantly differed in postoperative and last follow-up LL (p < 0.001 and p = 0.028, respectively) and postoperative and last follow-up PI-LL (p < 0.001 and p = 0.001, respectively). Morphologic parameters did not significantly differ between the two groups except lower lordosis arc angle (=postoperative sacral slope). In correlation analysis and stepwise multiple linear regression analysis, postoperative PI-LL was the only parameter which had significant association with last follow-up SVA (R2 = 0.134, p < 0.001). Morphologic parameters did not have any association with last follow-up SVA. CONCLUSIONS: When planning spine reconstruction surgery, although considering postoperative lordosis morphology is necessary, it is still very important considering proportional lordosis correction based on individual spinopelvic alignment (PI-LL) to achieve optimal sagittal alignment.

Strategies for prevention of rod fracture in adult spinal deformity: cobalt chrome rod, accessory rod technique, and lateral lumbar interbody fusion.

OBJECTIVE: Restoring the proper sagittal alignment in adult spinal deformity (ASD) can improve radiological and clinical outcomes, but pseudarthrosis including rod fracture (RF) is a common problematic complication. The purpose of this study was to analyze the methods for reducing the incidence of RF in deformity correction of ASD. METHODS: The authors retrospectively selected 178 consecutive patients (mean age 70.8 years) with lumbar degenerative kyphosis (LDK) who underwent deformity correction with a minimum 2-year follow-up. Patients were classified into the non-RF group (n = 131) and the RF group (n = 47). For predicting the crucial factors of RF, patient factors, radiographic parameters, and surgical factors were analyzed. RESULTS: The overall incidence of RF was 26% (47/178 cases), occurring in 42% (42/100 cases) of pedicle subtraction osteotomy (PSO), 7% (5/67 cases) of lateral lumbar interbody fusion (LLIF) with posterior column osteotomy, 18% (23/129 cases) of cobalt chrome rods, 49% (24/49 cases) of titanium alloy rods, 6% (2/36 cases) placed with the accessory rod technique, and 32% (45/142 cases) placed with the 2-rod technique. There were no significant differences in the incidence of RF regarding patient factors between two groups. While both groups showed severe sagittal imbalance before operation, lumbar lordosis (LL) was more kyphotic and pelvic incidence (PI) minus LL (PI-LL) mismatch was greater in the RF group (p < 0.05). Postoperatively, while LL and PI-LL did not show significant differences between the two groups, LL and sagittal vertical axis correction were greater in the RF group (p < 0.05). Nonetheless, at the last follow-up, the two groups did not show significant differences in radiographic parameters except thoracolumbar junctional angles. As for surgical factors, use of the cobalt chrome rod and the accessory rod technique was significantly greater in the non-RF group (p < 0.05). As for the correction method, PSO was associated with more RFs than the other correction methods, including LLIF (p < 0.05). By logistic regression analysis, PSO, preoperative PI-LL mismatch, and the accessory rod technique were crucial factors for RF. CONCLUSIONS: Greater preoperative sagittal spinopelvic malalignment including preoperative PI-LL mismatch was the crucial risk factor for RF in LDK patients 65 years or older. For restoring and maintaining sagittal alignment, use of the cobalt chrome rod, accessory rod technique, or LLIF was shown to be effective for reducing RF in ASD surgery.

Factors Associated with Increased Healing Time in Complete Femoral Fractures After Long-Term Bisphosphonate Therapy.

BACKGROUND: The purpose of this study was to analyze factors that affect healing time after operative treatment of complete femoral fractures associated with long-term use of bisphosphonates. In particular, we sought to determine surgically controllable factors related to fracture-healing time. METHODS: Ninety-nine consecutive patients (109 fractures) who had been surgically treated for a complete atypical femoral fracture were enrolled. All patients had a documented history of bisphosphonate therapy at the time of presentation, with an average duration of 7.4 ± 3.5 years (range, 3 to 20 years). Baseline demographic data, characteristics of the fracture and surgery, and radiographic findings including femoral neck-shaft angle, coronal and sagittal bowing of the femur, and thickness of the femoral cortex were examined. Univariate and multivariate logistic regression analyses were performed to identify predictive factors associated with delayed union or nonunion. RESULTS: Of the 109 fractures, 76 (69.7%) showed osseous union within 6 months after the index surgery and were assigned to the successful healing group. The remaining 33 fractures (30.3%), which showed delayed union or nonunion, were assigned to the problematic healing group. There were differences in body mass index (BMI), bisphosphonate therapy duration, and the rate of prodromal symptoms between the 2 groups. Supra-isthmic fracture location, femoral bowing of ≥10° in the coronal plane, and a lateral/medial cortical thickness ratio of ≥1.4 were predictive of problematic healing but were uncontrollable factors. Iatrogenic cortical breakage around the fracture site as well as a ratio of ≥0.2 between the remaining gap and the cortical thickness on the anterior and lateral sides of the fracture site were controllable predictive factors associated with problematic healing. CONCLUSIONS: Intramedullary nailing without cortical breakage around the fracture site and decreasing the anterior and lateral fracture gaps (avoidance of distraction) as much as possible are recommended to reduce healing time in complete femoral fractures associated with long-term use of bisphosphonates. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Triangular Fixation Technique for Bicolumn Restoration in Treatment of Distal Humerus Intercondylar Fracture.

BACKGROUND: Distal humerus intercondylar fractures are intra-articular and comminuted fractures involving soft tissue injury. As distal humerus is triangle-shaped, parallel plating coupled with articular fixation would be suitable for bicolumn restoration in treatment of distal humerus intercondylar fracture. METHODS: This study included 38 patients (15 males and 23 females) who underwent olecranon osteotomy, open reduction and internal fixation with the triangle-shaped cannulated screw and parallel locking plates (triangular fixation technique). Functional results were assessed with the visual analog scale (VAS) scores, Mayo elbow performance (MEP) scores and Disabilities of the Arm, Shoulder and Hand (DASH) questionnaires. Anteroposterior and lateral elbow radiographs were assessed for reduction, alignment, fracture union, posttraumatic arthrosis, and heterotopic ossification, and computed tomography (CT) scans were used to obtain more accurate measurements of articular discrepancy. RESULTS: All fractures healed primarily with no loss of reduction. The mean VAS, MEP, and DASH scores of the affected elbow were not significantly different from those of the unaffected elbow (p = 0.140, p = 0.090, and p = 0.262, respectively). The mean degree of flexion was significantly lower in the affected elbow than in the unaffected elbow, but was still considered as functional (p = 0.001, > 100° in 33 of 38 patients). Two cases of articular step-offs (> 2 mm) were seen on follow-up CT scans, but not significantly higher in the affected elbow than in the unaffected elbow (p = 0.657). Binary logistic regression analysis revealed that only Association for Osteosynthesis (AO) type C3 fractures correlated with good/excellent functional outcome (p = 0.012). Complications occurred in 12 of the 38 patients, and the overall reoperation rate for complications was 10.5% (4 of 38 patients). CONCLUSIONS: Triangular fixation technique for bicolumn restoration was an effective and reliable method in treatment of distal humerus intercondylar fracture. This technique maintained articular congruency and restored both medial and lateral columns, resulting in good elbow function.

Factors that Influence Reduction Loss in Proximal Humerus Fracture Surgery.

OBJECTIVES: This study was performed to identify the risk factors for reduction loss after locking plate fixation of proximal humerus fractures. DESIGN: Retrospective study. SETTING: University trauma center. PATIENTS AND INTERVENTION: We retrospectively evaluated 252 patients who had been surgically treated for proximal humeral fractures with locking plates between January 2004 and December 2011. MAIN OUTCOME MEASUREMENTS: Charts and standardized x-rays (true anteroposterior and axillary lateral views) were used to evaluate the Neer and AO OTA fracture types, initial neck-shaft angle (NSA, varus displacement), medial comminution, postoperative NSA (reduction adequacy), medial support restoration, healing progress, reduction loss, and implant-related problems immediately after surgery and at 2 weeks, 1 month, 3 months, 6 months, 9 months, and at least 1 year after surgery. Reduction loss was defined as (1) ≥10 of angulation in any direction, (2) ≥5 mm of height loss of the humeral head from the plate, and (3) fixation failure. RESULTS: Reduction loss occurred in 6.7% (17 of 252) of cases; revision surgeries were performed in all cases. Univariable logistic regression analysis revealed that older age (P = 0.023), osteoporosis (P = 0.001), varus displacement (P = 0.001), medial comminution (P = 0.001), reduction adequacy (P = 0.036), and insufficient medial support (P = 0.001) had significant correlations with reduction loss. CONCLUSIONS: Multivariable regression analysis revealed that osteoporosis (less than -2.5 bone mineral density, P = 0.015), displaced varus fracture (less than 110° of NSA, P = 0.025), medial comminution (more than 1 fragment, P = 0.018), and insufficient medial support (no cortical or screw support, P = 0.001) were independent risk factors for reduction loss in the proximal humerus fractures surgery. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.