Caffeine intake does not appear to impair tendon-to-bone healing strength in a rat rotator cuff repair model.

Background: Tendon-to-bone (TtB) healing is essential for successful rotator cuff repair (RCR). This study aimed to investigate if caffeine intake impaired TtB healing in a rat RCR model. Methods: Seventy-two rats were randomized into a caffeinated group or a noncaffeinated group. Specimens received one week of oral caffeine solution or normal saline before RCR. All rats then underwent bilateral RCR. Caffeination or saline gavages continued until rats were sacrificed at 2, 4, and 8 weeks postoperatively. Load-to-failure (primary outcomes measure), maximum stress, and stiffness of the TtB interface were measured for one shoulder of each specimen. Six random shoulders from each group underwent histological assessment of TtB healing. Results: Load-to-failure and maximum stress of RCR did not appear to differ between groups at any time point. No difference in RCR stiffness was found between groups at 2 and 4 weeks; however, stiffness in the caffeinated group did appear to lower at 8 weeks (P = .04). Conclusion: Perioperative caffeine intake did not appear to affect load-to-failure strength of RCR in an animal model. Although our secondary outcome measures of maximum stress and stiffness also did not appear to be influenced by perioperative caffeine intake, there did appear to be a trend toward decreased RCR stiffness at 8 weeks postoperatively in specimens that received caffeine.

Resisted adduction sit-up test (RASUT) as a screening tool for pelvic versus hip pathology.

Groin pain is a common symptom in hip and pelvic pathology and differentiating between the two remains a challenge. The purpose of this study was to examine whether a test combining resisted adduction with a sit-up (RASUT) differentiates between pelvic and hip pathology. The RASUT was performed on 160 patients with complaints of hip or groin pain who subsequently had their diagnosis confirmed by magnetic resonance imaging (MRI) or surgery. Patients were categorized as having pelvic pathology (athletic pubalgia or other) or hip pathology (intra-articular or other). Athletic pubalgia was defined as any condition involving the disruption of the pubic aponeurotic plate. Sensitivity, specificity, positive predictive accuracy, negative predictive accuracy and diagnostic odds ratios were computed. Seventy-one patients had pelvic pathology (40 athletic pubalgia), 81 had hip pathology and 8 had both. The RASUT was effective in differentiating pelvic from hip pathology; 50 of 77 patients with a positive RASUT had pelvic pathology versus 29 of 83 patients with a negative test (P < 0.001). RASUT was diagnostic for athletic pubalgia (diagnostic odds ratio 6.08, P < 0.001); 35 of 45 patients with athletic pubalgia had a positive RASUT (78% sensitivity) and 73 of 83 patients with a negative RASUT did not have athletic pubalgia (88% negative predictive accuracy). The RASUT can be used to differentiate pelvic from hip pathology and to identify patients without athletic pubalgia. This is a valuable screening tool in the armamentarium of the sports medicine clinician.

A National Survey of Orthopaedic Residents Identifies Deficiencies in the Understanding of Medical Statistics.

BACKGROUND: Biomedical research is essential for optimizing patient care. Research has suggested inadequacies in nonorthopaedic trainees' understanding of study design and biostatistics. This study assesses orthopaedic residents' knowledge of common biostatistical and study design concepts, as well as their confidence in utilizing the medical literature. METHODS: A validated survey assessing knowledge and the application of study design concepts was administered to residents at 10 U.S. institutions. The survey tested knowledge as well as confidence and attitudes regarding common biostatistics principles. The association of demographic characteristics, work activities, and confidence and attitude ratings with test performance were examined using t tests and analysis of variance. RESULTS: The survey response rate was 64% (178 of 279). The largest group of participants were men (83%, 137 of 165), were between the ages of 26 and 30 years (59%, 105 of 177), and had graduated medical school within the past 4 to 10 years (43%, 76 of 175). Fifty-three percent (93 of 176) had prior biostatistics training, while 44% (77 of 176) had prior epidemiology training. Less than 5% of biostatistics or epidemiology training had taken place after medical school. Forty-seven percent (83 of 176) were unable to determine a study's design. Thirty-eight percent (67 of 178) could not apply the concept of specificity and sensitivity. Eighty-three percent (147 of 178) could not assess the strength of a relationship using odds ratios. Sixty-nine percent (123 of 178) understood the implications of p values. Previous biostatistics training, but not epidemiology or evidence-based medicine training; inclusion of reading research, attending conferences, and data analysis; as well as a self-reported finding of statistics as important for the analysis of one's own research data were significantly associated with better test performance (p < 0.05). CONCLUSIONS: Notable deficits exist in orthopaedic residents' biostatistical knowledge. Greater emphasis is needed to improve biostatistics and research design training. The impact of biostatistics knowledge and/or aptitude on clinical decision-making is an area of suggested research.

Anterior acetabular retractors and the femoral neurovascular bundle in anterior total hip arthroplasty: a cadaveric study.

PURPOSE: The direct anterior approach for primary total hip arthroplasty (THA) has become increasingly popular in recent years. Nerve compression or traction with a retractor is a common cause of nerve injury in this approach. The purpose of this cadaveric study was to evaluate the anatomic relationship of the femoral neurovascular bundle to the anterior acetabular retractor during direct anterior approach THA. METHODS: Eleven fresh-frozen cadavers underwent a standard direct anterior THA, with placement of an anterior acetabular retractor in the usual fashion between the iliopsoas and acetabulum for visualization during acetabular preparation. Careful dissection of the femoral triangle was performed, and the distances from the anterior retractor tip to the femoral nerve, artery, and vein were recorded and analyzed as mean distance ± standard deviation. RESULTS: In all 11 cadavers, the retractor tip was medial to the femoral nerve. The mean distance from retractor tip to femoral artery and vein was 5.9 mm (SD = 5.5, range 0-20) and 12.6 mm (SD 0.7, range 0-35), respectively. CONCLUSIONS: Surgeons should be aware of the proximity of the neurovascular structures in relation to the anterior acetabular retractor in the direct anterior approach, taking care to avoid perforating the iliopsoas muscle during retractor insertion and limit excessive traction to prevent nerve injury.