Examining the Efficacy of Drain Tip Cultures in Predicting Postoperative Surgical Site Infections in Hip Arthroplasty: A 15-Year Retrospective Study.

Background Postoperative surgical site infections (SSIs) are a significant complication of surgical procedures, leading to increased morbidity, prolonged hospital stays, and substantial healthcare costs; however, the use of drain tip cultures to diagnose SSIs in patients is controversial. The objective of this study was to evaluate the efficacy of drain tip cultures for the prediction of postoperative SSIs in patients recovering from hip arthroplasty. Methodology The data were collected from 1204 patients who underwent hip arthroplasty procedures over 15 years, and statistical analysis was performed to evaluate the diagnostic value of drain tip culture in determining surgical site infection. We also used these data to evaluate whether preexisting conditions such as hypertension or diabetes affected the probability of a patient getting an SSI. Results Drain tip cultures were positive in 12 of 1,112 cases of primary hip arthroplasty, but only one of these 12 patients was ultimately diagnosed with an SSI (sensitivity, 12.5%; specificity, 99.0%; p = 0.0834). Results from postoperative drain tip cultures performed in patients undergoing revision arthroplasty included two false positives and three false negatives; interestingly, no true positives were detected in any of the revision arthroplasty cases we evaluated (sensitivity, 0％; specificity, 97.8％; p = 0.9355). Conclusion Our results indicate that drain tip cultures have no statistically significant predictive value for the diagnosis of postoperative SSIs and thus should not be used as a primary diagnostic or predictive tool for SSIs. We recommend exploring other diagnostic tools for the postoperative diagnosis of SSIs. Standardized guidelines should therefore be established to improve the predictive value of the different methods.

Reoperation for recurrent lumbar disc herniation: a study over a 20-year period in a Japanese population.

BACKGROUND: Many studies have been reported on recurrent lumbar disc herniations covering several pathological conditions. In those studies, reoperation rate of revised disc excisions was calculated by simple division between the number of reoperations and that of the total primary disc excisions. To determine the real reoperation rate, strict definition of pathologies, a large number of patients, a long observation period, and survival function method are necessary. METHODS: Between 1988 and 2007, 5,626 patients with disc excision were enrolled by the spine registration system of the Department of Orthopaedic Surgery, Tohoku University, Japan. Among them, 192 had revised disc surgery, and we obtained data of 186 patients whose clinical features were assessed and reoperation rates analyzed using the Kaplan-Meier method. RESULTS: In total, 205 disc herniations were excised in the revision surgery (including contralateral herniation at the same level and new herniation at a different level), and 101 were real recurrent herniations (recurrence at the same level and side as the primary herniation). The kappa coefficient of the spinal level and side between the primary and revision surgeries was 0.41, indicting moderate correlations. Real recurrent herniations showed shorter intervals between primary and revision surgeries. Male patients with surgery at a younger age carried a higher risk of reoperation. In the revision surgery, transligamentous extrusion was significantly more common than other types of herniation. On Kaplan-Meier analysis, the reoperation rate of overall revised excisions was 0.62% at 1 year, 2.4% at 5 years, 4.4% at 10 years, and 5.9% after 17 years. That of real recurrent herniations was 0.5%, 1.4%, and 2.1%, respectively, and 2.8% after 15.7 years. CONCLUSION: Reoperation rate of real recurrent herniations calculated using survival function method gradually increased year by year, from 0.5% at 1 year after primary surgery to 2.8% at 15.7 years.

Remodeling capacity of malunited odontoid process fractures in kyphotic angulation in infancy: an observation up to maturity in three patients.

STUDY DESIGN: A retrospective case study. OBJECTIVE: To confirm the remodeling potential of the kyphotic malunited odontoid fracture in the pediatric spine. SUMMARY OF BACKGROUND DATA: Nonsurgical reduction and immobilization is the gold standard for the odontoid fracture in infancy. However, the reduction occasionally results in incomplete repositioning of the odontoid process. The cervical spine is subsequently immobilized until fusion in most cases in the hope of achieving remodeling with the growth of the remaining displacement and kyphotic angulation, although there are no precise data on the acceptable limit of the deformity. METHODS: Three patients (age at injury = 1 year 2 months to 3 years) with odontoid process fracture in infancy were treated conservatively and the fractures were observed on plain lateral radiographs until at least the age of 20 years. For evaluation of the angulated odontoid process, we used our original measurement method of the odontoid process tilting angle (OPTA). In addition, the OPTAs were also measured in 127 Japanese adult patients (57 male patients and 70 female patients; average age = 43 years) without a history of odontoid fracture, as normal controls. RESULTS: The OPTA in the normal controls was -21.4° ± 23.3°. The OPTAs ranged from 41° to 62° at the initial evaluation, from 12° to 30° at the time of bony union, and from -4° to -14° at the final follow-up at more than 20 years of age, which were all within one standard deviation of the mean in the normal adult controls. CONCLUSION: Angulated odontoid fractures with the OPTA around 30° at the time of bony union in infants younger than 3 years of age could have the capacity for remodeling to the normal morphology. No surgical reduction might be needed to recommend complete apposition of the odontoid process in the absence of severe or deteriorating neural impairment.