Faculty Bibliography

Total hip arthroplasty (THA) is considered one of the mosteffective treatments for hip arthritis, but the decision toperform simultaneous bilateral THA versus staged bilateralTHA remains a source of controversy based primarily on theanalysis of the risks and benefits of each approach. Manysurgeons are reluctant to consider simultaneous total hiparthroplasty even though the procedure is associated witha shorter total hospitalization, shorter recovery and rehabilitationtime, and decreased cost. However, in this review,we find that despite higher blood loss in the simultaneousgroup, there are no significant differences in terms of cardiopulmonarycomplications, thromboembolic events, stroke,surgical site infection, and rate of allogeneic transfusionbetween simultaneous and staged procedures. In addition,careful patient selection (ASA 1 and 2) can further minimizethe risks of simultaneous bilateral total hip arthroplasty andincrease the likelihood of consistent successful outcomes.

BACKGROUND: Traditional total shoulder arthroplasty (TSA) involves releasing the subscapularis tendon for exposure. This can potentially lead to subscapularis insufficiency, compromised function, and dissatisfaction. A novel TSA technique preserves the subscapularis tendon by performing the procedure entirely through the rotator interval, allowing accelerated rehabilitation. However, early reports on this approach have noted malpositioning of the humeral component and residual osteophytes. In a randomized trial, we examined the incidence of humeral head malpositioning, incorrect sizing, and residual osteophytes on postoperative radiographs after subscapularis-sparing TSA compared with the traditional approach. METHODS: Patients were prospectively randomized to undergo TSA performed through the traditional or subscapularis-sparing approach. The operating surgeon was blinded to the randomization until the day of surgery. Anatomic reconstruction measurements included humeral head height, humeral head centering, humeral head medial offset, humeral head diameter (HHD), and head-neck angle. Two independent reviewers analyzed the postoperative radiographs to determine anatomic restoration of the humeral head and the presence of residual osteophytes. RESULTS: We randomized 96 patients to undergo either the standard approach (n = 50) or the subscapularis-sparing approach (n = 46). There were no significant differences in humeral head height, humeral head centering, humeral head medial offset, HHD, head-neck angle, and anatomic reconstruction index between the 2 groups. However, significantly more postoperative osteophytes (P = .0001) were noted in the subscapularis-sparing TSA group. Although the overall mean was not statistically different, further analysis of HHD showed that more patients in the subscapularis-sparing TSA group were outliers (mismatch >4 mm) than in the traditional TSA group. CONCLUSIONS: Although anatomic restoration of the shoulder can be accomplished using subscapularis-sparing TSA, retained osteophytes and significant mismatch of the HHD raise concerns regarding long-term outcomes.

BACKGROUND: Total shoulder arthroplasty (TSA) may be associated with substantial blood loss, and some patients require perioperative blood transfusion. Possible blood transfusion methods include predonated autologous blood transfusion, perioperative autologous blood transfusion, and allogeneic blood transfusion (ALBT). The purposes of the present study were to assess the incidence and recent trends over time of blood transfusion in TSA and analyze patient and hospital characteristics that affect the risk of ALBT. METHODS: This study used national hospital discharge data from the National Inpatient Sample between 2000 and 2009. The data were used to generate the overall blood transfusion rate, and linear regression was used to assess trends in transfusion patterns over time. Logistic regression analysis was performed to analyze which patient and hospital characteristics independently influence the likelihood that a given patient undergoes ALBT. RESULTS: The overall blood transfusion rate (ie, the proportion of patients who received at least 1 transfusion of any kind) was 6.7%. This rate increased over time, from 4.9% in 2000 to 7.1% in 2009 (P < .001). Risk factors associated with ALBT included age, gender, race, insurance status, hospital region, and hospital annual caseload. CONCLUSIONS: The increase in overall blood transfusion rate in TSA found in the present study may be related to factors specific to TSA, such as the introduction of reverse total shoulder arthroplasty during the study period. A variety of patient and hospital characteristics contribute to the risk of undergoing ALBT.

This study analyzes the muscle moment arms of three different reverse shoulder design philosophies using a previously published method. Digital bone models of the shoulder were imported into a 3D modeling software and markers placed for the origin and insertion of relevant muscles. The anatomic model was used as a baseline for moment arm calculations. Subsequently, three different reverse shoulder designs were virtually implanted and moment arms were analyzed in abduction and external rotation. The results indicate that the lateral offset between the joint center and the axis of the humerus specific to one reverse shoulder design increased the external rotation moment arms of the posterior deltoid relative to the other reverse shoulder designs. The other muscles analyzed demonstrated differences in the moment arms, but none of the differences reached statistical significance. This study demonstrated how the combination of variables making up different reverse shoulder designs can affect the moment arms of the muscles in different and statistically significant ways. The role of humeral offset in reverse shoulder design has not been previously reported and could have an impact on external rotation and stability achieved post-operatively. (c) 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:605-613, 2015.

BACKGROUND: The purpose of this study was to evaluate the effect of sling immobilization on driving performance with use of a driving simulator. METHODS: This is a prospective trial with a cohort of 21 healthy volunteers comparing their driving ability with and without sling immobilization on their dominant (driving) extremity. Multiple variables, including number of collisions, off-road excursions, and centerline crossings, were measured with a validated driving simulator. Trials were separated by 2 weeks to control for "adaptations" to the simulator. Statistical significance was found in collisions between sling and no-sling tests. RESULTS: The total number of collisions for trial 1 (no sling) was 36 (mean, 1.7 +/- 1.2) compared with 73 (3.7 +/- 1.6) (P < .01) for trial 2 (sling immobilization). Approximately 70% of participants with upper extremity immobilization were involved in >/=3 collisions; approximately 70% of no-sling participants were involved in