Management of primary anterior shoulder dislocations using immobilization.

UNLABELLED: Reference/Citation : Paterson WH, Throckmorton TW, Koester M, Azar FM, Kuhn JE. Position and duration of immobilization after primary anterior shoulder dislocation: a systemic review and meta-analysis of the literature. J Bone Joint Surg Am. 2010;92(18):2924-2933. CLINICAL QUESTION: Does an optimum duration and position of immobilization after primary anterior shoulder dislocation exist for reducing recurrence rates? DATA SOURCES: MEDLINE/PubMed, EMBASE, and Cochrane databases were searched up to December 2009 without limitations. The search terms for all databases used were shoulder AND dislocation and shoulder AND immobilization. STUDY SELECTION: Criteria used to include articles were (1) English language, (2) prospective level I or level II studies (according to Journal of Bone & Joint Surgery guidelines), (3) nonoperative management of initial anterior shoulder dislocation, (4) minimum follow-up of 1 year, and (5) rate of recurrent dislocation as a reported outcome. DATA EXTRACTION: A standardized evaluation method was used to extract data to allow assessment of methods issues and statistical analysis to determine sources of bias. The primary outcome was the recurrence rate after nonoperative management of anterior shoulder dislocation. Additional data extracted and used in subanalyses included duration and position of immobilization and age at the time of initial dislocation. Data were analyzed to determine associations among groups using 2-tailed Fisher exact tests. For pooled categorical data, relative risk of recurrent dislocation, 95% confidence intervals, and heterogeneity using the I(2) statistic and χ(2) tests were calculated for individual studies. The Mantel-Haenszel method was used to combine studies and estimate overall relative risk of recurrent dislocation and 95% confidence intervals. The statistical difference between duration of immobilization and position was determined using z tests for overall effect. Pooled results were presented as forest plots. MAIN RESULTS: In the initial search of the databases, the authors identified 2083 articles. A total of 9 studies met all of the criteria and were included in this review. In most of the studies, age was a risk factor for recurrence. Patients less than 30 years of age were more likely to sustain a recurrent dislocation than patients more than 30 years of age. In 5 studies (n = 1215), researchers found no difference in recurrence of shoulder dislocation when immobilized in internal rotation (IR) for less than 1 week (41%, 40 of 97) compared with more than 3 weeks (37%, 34 of 93) in patients less than 30 years of age (P = .52). Authors of 3 studies (n = 289) compared the effect of immobilization in IR versus external rotation (ER), and whereas they found no statistical difference, a trend appeared toward reduced recurrence rates in ER but not IR (P = .07). The rate of recurrent dislocation was 40% (25 of 63) in patients treated with IR sling immobilization and 25% (22 of 88) in patients immobilized in ER. CONCLUSIONS: Overall, the investigators found that younger age (<30 years) was a predictor of recurrent dislocations, immobilization for more than 1 week did not improve recurrence rates, and an apparent trend existed toward decreased recurrence rates with ER rather than IR. According to the review and meta-analysis by Paterson et al, the level of evidence for recommendations regarding optimal duration and position of immobilization to reduce the risk of recurrent dislocation was therapeutic level II. This level of evidence was appropriate because the review included only prospective studies of level I or II and a minimum follow-up of 1 year.

ACL reconstruction: do outcomes differ by sex? A systematic review.

BACKGROUND: Anterior cruciate ligament (ACL) reconstruction is frequently performed to restore knee stability and function following ACL injury. Female sex is known to predispose to ACL injury; however, it remains unclear whether female sex predisposes to poor outcomes following ACL reconstruction. We hypothesized that male and female patients exhibit no differences in (1) graft failure risk, (2) contralateral ACL injury risk, (3) knee laxity, and (4) patient-reported outcome scores following ACL reconstruction. METHODS: A systematic review of the literature was performed to identify studies in which results of ACL reconstruction were reported by sex at a minimum of two years. Study findings were reviewed, and meta-analysis was performed when data were sufficiently homogenous. RESULTS: Thirteen studies were identified from the literature review. Meta-analysis revealed no difference in graft failure risk (eight studies), contralateral ACL rupture risk (three studies), or postoperative knee laxity on physical examination (six studies). There was no evidence of a clinically important difference in patient-reported outcomes according to sex. CONCLUSIONS: Results of ACL reconstruction were similar in male and female patients. More high-quality studies are needed to further evaluate these findings.

Biomechanical comparison of the docking technique with and without humeral bioabsorbable interference screw fixation.

BACKGROUND: Surgical reconstruction of the ulnar collateral ligament has evolved since Frank Jobe's original description. The "docking technique" is a popular modification that allows for securing the graft within a single humeral tunnel. More recently, interference screw fixation has been introduced as a means of improving the ultimate strength, stiffness, and kinematics of these constructs. PURPOSE: This study was conducted to compare the biomechanical performance of the docking technique with and without interference screw fixation in the humerus. STUDY DESIGN: Controlled laboratory study. METHODS: Nine matched pairs of human cadaveric elbows (age 49.9 +/- 8.0 years) were reconstructed with a tendon graft using the docking technique (group 1) or the docking technique with the addition of a 4.75-mm bioabsorbable humeral interference screw (group 2). Before the reconstruction, joint laxity was measured on each specimen with the ulnar collateral ligament intact and then after transection of the ligament. Laxity measurements were repeated after the reconstruction. Failure testing was then performed at 70 degrees of elbow flexion. The specimens were preloaded with a 1-N.m moment and then loaded to failure at a displacement rate of 14 mm/s to approximate 50% strain per second. RESULTS: Within group 1, the elbow laxity of the reconstructed state was significantly greater than the intact state at all tested flexion angles (P < .021). Within group 2, no statistically significant difference existed in elbow laxity between the intact state and the reconstructed state. When comparing laxities between groups, group 1 tended to be more lax at all tested flexion angles but was only significantly greater at 105 degrees of flexion. The most common mode of failure for both groups involved the sutures pulling out of the tendon. No significant difference was found for ultimate moment of failure between the 2 groups. However, the moment associated with 3 mm of gap formation for group 2 (12.8 +/- 4.2 N x m) was statistically greater than that of group 1 (7.5 +/- 1.2 N x m) (P = .001). The stiffness of group 2 (14.7 +/- 6.4 N/mm) was significantly greater than group 1 (9.9 +/- 3.1 N/mm) (P = .044). CONCLUSION: The biomechanical performance of the docking technique with and without a humeral interference screw is similar. CLINICAL RELEVANCE: The stiffness of the construct, along with the difference in moment that allows a 3-mm gap formation, suggests that the addition of a humeral interference screw is potentially beneficial. Further research in a healing model will help clarify this benefit.

Duration of anesthesia and venous thromboembolism after hip and knee arthroplasty.

OBJECTIVE: To determine whether longer duration of anesthesia predisposes patients undergoing orthopedic surgery to venous thromboembolism (VTE). PATIENTS AND METHODS: We conducted a secondary analysis of a retrospective case-control study that examined risk factors for postoperative VTE in postmenopausal women. We matched women aged 50 years and older with radiographically confirmed postoperative VTE (cases) by age, surgeon, year of surgery, and surgical joint (knee vs hip) with women without postoperative VTE (controls). Duration of anesthesia, operative variables, demographic data, comorbid illnesses, and laboratory data were determined by medical record review. RESULTS: Eighty-eight cases were matched with 181 controls. Duration of anesthesia of 3.5 hours or longer (corresponding to the upper tertile of patients) was strongly associated with postoperative VTE compared with a shorter duration of anesthesia (odds ratio, 3.58; 95% confidence Interval, 2.11-6.16; P < .001). This relationship was maintained after controlling for multiple covariates with propensity score methods, Including type of arthroplasty, route of anesthesia, type of antithrombotic prophylaxis, and surgical approach. In multivariate analysis, the Important predictors of VTE included anesthesia duration of 3.5 hours or longer, type of antithrombotic prophylaxis, revision (vs primary) arthroplasty, and allogeneic blood transfusion. CONCLUSION: We found a marked association between the duration of anesthesia and postoperative VTE in patients undergoing Joint arthroplasty. Although it is possible that unmeasured intraoperative variables account for this relationship, we suggest that duration of anesthesia may be an important risk factor for postoperative VTE after orthopedic surgery.

Warfarin prophylaxis and venous thromboembolism in the first 5 days following hip and knee arthroplasty.

Many orthopaedic surgeons use warfarin to prevent venous thromboembolism (VTE) following hip or knee arthroplasty. Since warfarin's antithrombotic effects are delayed, we hypothesized that early VTE (occurring within 5 days post-operatively) would be more common in arthroplasty patients receiving warfarin monotherapy compared to those receiving enoxaparin. We performed a secondary analysis of a case-control study examining risk factors for post-operative thrombosis in postmenopausal women. We defined cases as patients who were diagnosed with thrombosis within 5 days of surgery. Controls without thrombosis were matched with cases by age, surgeon, year of surgery and surgical joint. 84 women with early post-operative thrombosis (cases) were matched with 206 controls. 18 cases (21.4%) had been prescribed warfarin mono-therapy, compared with 7 controls (3.4%). 58 (69.1%) cases and 195 (94.7%) controls had been prescribed subcutaneous enoxaparin 30 mg twice daily, starting 12-24 hours after surgery. The odds ratio for any early thrombosis in patients receiving warfarin as opposed to enoxaparin 30 mg twice daily was 8.6 (p<0.0001). For proximal thrombosis, the odds ratio was 11.3 (p<0.0001). Multivariate analysis did not alter these findings. Warfarin's delayed antithrombotic effects may not provide adequate VTE prophylaxis in the immediate post-operative setting. We suggest caution in employing warfarin monotherapy following joint arthroplasty.

Postmenopausal hormone replacement and venous thromboembolism following hip and knee arthroplasty.

Hormone replacement therapy has been associated with venous thromboembolism. Controversy exists regarding the appropriate management of hormone replacement in the perioperative setting and in other situations--such as acute illness--predisposing to acute venous thromboembolism. We performed a case-control study to determine whether perioperative hormone replacement is associated with venous thromboembolism following hip and knee arthroplasty. 108 patients with postoperative venous thrombosis were matched by age, date and type of surgery, and surgeon with 210 controls without thrombosis. Perioperative hormone replacement use was no more prevalent in patients with postoperative thrombosis than those without. Eighteen (16.7%) women with post-operative thrombosis had taken perioperative hormone replacement compared to 49 (23.3%) of controls: odds ratio = 0.66; (95% CI 0.35-1.18; p=0.17). After multivariate analysis, the adjusted odds ratios were similar. Variables predicting post-operative thrombosis included: prior venous thromboembolism (OR = 2.3; p = 0.02), rheumatologic disease (OR = 2.2; p = 0.03), and absence of pharmacologic antithrombotic prophylaxis (OR = 13.4; p = 0.005). Cases and controls were otherwise similar. Users of hormone replacement were similar to non-users except that they were less likely to have coronary disease (OR 0.34; p = 0.03) or prior thrombosis (OR = 0.28; p = 0.04), and were younger (median age 67 versus 74 years; p <0.0001). We found no association between perioperative hormone replacement and post-operative thrombosis in patients undergoing major orthopaedic surgery. Routine discontinuation of these medications preoperatively--and possibly in other situations predisposing to thrombosis, such as acute medical illness--may be unnecessary in patients receiving appropriate pharmacologic antithrombotic prophylaxis.