Radiographic Assessment of Bone Quality Using 4 Radiographic Indexes: Canal Diaphysis Ratio Is Superior.

BACKGROUND: Osteoporosis increases the risk of periprosthetic fracture and loosening in hip arthroplasty. Many methods have been proposed to assess bone quality in X-rays, including both qualitative such as the Dorr classification and quantitative such as the Calcar-Canal Ratio (CCR) and Cortical-Thickness index/Canal-Bone ratio (CTI/CBR). The Canal-Diaphysis ratio (CDR) has been described as a predictor for hip fragility fractures; however, its relationship with bone mineral density (BMD) has not been described. The purpose of this study was to evaluate the correlation of the Dorr classification, CCR, CTI/CBR, and CDR with BMD of the proximal femur in patients without hip fracture. METHODS: Forty-seven patients over 45 years of age who had less than 6 months between radiographs and dual-energy X-ray absorptiometry were evaluated. Measurements of CCR, CBR, CDR, and Dorr classification were performed in all radiographs by 2 independent observers. RESULTS: The CDR had a high correlation (r = 0.74, P=<0.01) with BMD, whereas the CTI/CBR had a moderate correlation (r = 0.49, P=<0.01), and the CCR had no correlation with BMD (r = 0.06, P = .96). When evaluating the receiver operating characteristic curve, CDR showed the best performance (area under curve [AUC] = 0.75) followed by CBR (AUC = 0.73) and CCR (AUC = 0.61). The optimal cutoff value for the CDR was 0.49, with 100% sensitivity and 58% specificity. The inter- and intra-observer variability was good for all methods. No differences were found between Dorr classification of patients who had or did not have osteoporosis. CONCLUSION: Of all the analyzed methods, the CDR was found to have the best correlation with BMD. This study proposes the use of CDR as a tool for assessing bone quality when deciding the implant fixation method in hip arthroplasty.

An independent interobserver reliability and intraobserver reproducibility evaluation of the new AOSpine Thoracolumbar Spine Injury Classification System.

STUDY DESIGN: Agreement study. OBJECTIVE: To perform an independent interobserver and intraobserver agreement evaluation of the new AOSpine Thoracolumbar Spine Injury Classification System. SUMMARY OF BACKGROUND DATA: The new AOSpine Thoracolumbar Spine Injury Classification System was recently published. It showed substantial reliability and reproducibility among the surgeons who developed it; however, an independent evaluation has not been performed. METHODS: Anteroposterior and lateral radiographs, and computed tomographic scans of 70 patients with acute traumatic thoracolumbar injuries were selected and classified using the morphological grading of the new AOSpine Thoracolumbar Spine Injury Classification System by 6 evaluators (3 spine surgeons and 3 orthopedic surgery residents). After a 6-week interval, the 70 cases were presented in a random sequence to the same evaluators for repeat evaluation. The Kappa coefficient (κ) was used to determine the interobserver and intraobserver agreement. RESULTS: The interobserver reliability was substantial when considering the fracture type (A, B, or C), with a κ= 0.62 (0.57-0.66). The interobserver agreement when considering the subtypes was moderate; κ= 0.55 (0.52-0.57). The intraobserver reproducibility was also substantial, with 85.95% full intraobserver reproducibility considering the fracture type, with κ= 0.77 (0.72-0.83), and was also substantial when considering subtypes with 75.71% full agreement and κ= 0.71 (0.67-0.76). No significant differences were observed between spine surgeons and orthopedic residents in the overall interobserver reliability and intraobserver reproducibility, or in the inter- and intraobserver agreement of specific A, B, or C types of injuries. CONCLUSION: This classification allows adequate agreement among different observers and by the same observer on separate occasions. Future prospective studies should evaluate whether this classification improves clinical decision making.

An assessment of the Surgical Apgar Score in spine surgery.

BACKGROUND CONTEXT: The Surgical Apgar Score (SAS), a simple metric based on intraoperative heart rate, blood pressure, and blood loss, was developed in general and vascular surgery to predict 30-day major postoperative complications and mortality. No validation of SAS has been performed in spine surgery. PURPOSE: To perform a prospective assessment of SAS in spine surgery. STUDY DESIGN: Prospective study. PATIENT SAMPLE: Two hundred sixty-eight consecutive patients undergoing major and intermediate spinal surgeries in an 18-month period. OUTCOME MEASURES: Occurrence of major complications or death within 30 days of surgery. METHODS: Intraoperative parameters were registered, and SAS was calculated immediately after surgery. Outcome data were collected during a 30-day follow-up. The relationship between SAS and the outcomes was analyzed calculating relative risks (RRs) and likelihood ratios (LRs) for different scoring groups. A univariate logistic regression analysis was also performed. The discriminatory accuracy of SAS was evaluated calculating a C-statistic. RESULTS: Eighteen patients had ≥1 complications (6.72%). Patients with SAS 9-10 exhibited a 1.64% complication rate (RR=1; LR=0.23), which monotonically augmented as the score decreased: (SAS 7-8=2.75%; RR=1.68; LR=0.39), (SAS 5-6=13.33%; RR=8.13; LR=2.14), (SAS≤4=17.39%; RR=10.61; LR=2.92). The regression analysis odds ratio was 0.66 (95% confidence interval, 0.54-0.82), p<.01. The C-statistic was 0.77 (95% confidence interval, 0.66-0.88). CONCLUSIONS: Surgical Apgar Score allows risk stratification and has a good discriminatory power in patients undergoing spine surgery.