Heterotopic ossification of the long head of the triceps after reverse total shoulder arthroplasty.

BACKGROUND: Heterotopic ossification (HO) around shoulder arthroplasty is a frequent finding with unclear clinical relevance. This study evaluated the incidence, relevance, and predisposing factors of HO in the long head of the triceps tendon after reverse shoulder arthroplasty. METHODS: Retrospective chart review was conducted to identify patients who had a reverse shoulder arthroplasty performed between 2008 and 2012. Patient demographics, implant types, and diagnoses were noted. Three fellowship-trained shoulder/elbow surgeons independently evaluated postoperative Grashey radiographs using a novel classification system. RESULTS: Within a 164-patient cohort, the overall HO rate in the long head of the triceps tendon was 61.6%; 23.2% of osteophytes were considered impinging, 14.6% had notching, 14.0% were free-floating, and 3.0% appeared ankylosed. Although not statistically significant, revision surgery had a higher rate of HO (68.3%) compared with primary surgery (59.4%). There was no difference in HO rates between diagnoses or implant types. Male and female HO rates were 74.0% and 56.1%, respectively (P = .0304). Between patients with and without HO, forward elevation was 121° compared with 133° (P = .0087) and external rotation was 19° compared with 25° (P = .0266); however, HO size did not significantly affect motion. CONCLUSIONS: Using our novel classification scheme, HO was a common finding in this series. Men had a higher rate of HO formation, and HO formation was associated with worse postoperative motion. Further study is needed to fully characterize the clinical implications of HO involving the long head of the triceps tendon and to explore potential preventive measures.

Comparison of Asymmetric Reaming versus a Posteriorly Augmented Component for Posterior Glenoid Wear and Retroversion: A Radiographic Study.

BACKGROUND: Managing posterior glenoid wear and retroversion remains a challenge in shoulder arthroplasty. Correcting glenoid version through asymmetric reaming (AR) with placement of a standard glenoid component and the use of posteriorly augmented glenoid (PAG) components are two methods used to address this problem. Our objective is to report the radiographic outcomes of patients with posterior glenoid wear and/or retroversion treated with either approach. METHODS: Patients with posterior glenoid wear and a minimum of 15 degrees of retroversion, treated with AR and standard glenoid component or with a PAG component (3 mm, 5 mm, or 7 mm posterior augmentation), were consecutively identified through retrospective chart review. Pre-operative axillary views were evaluated for version, humeral head subluxation in relation to scapular axis and to mid-glenoid face. Post-operative axillary views were reviewed to measure corrected inversion and humeral head subluxation. RESULTS: There were 48 patients in the AR group and 49 patients in the PAG group. Version improved 6.8 degrees in the AR group. In the PAG group, version improved 8.8 degrees with 3 mm augment, 13.4 degrees with 5 mm augment, and 12.8 with 7 mm augments. There were significantly more central peg perforations in the 5 mm PAG group compared to other groups. The humeral head was re-centered within 6.1% of normal in all groups except 7 mm augments. CONCLUSION: This study demonstrates that AR and PAGs have the ability to re-center the humeral head when utilized in patients with retroversion and posterior wear. Use of a PAG component may allow for greater correction of glenoid retroversion, however, there is an increased risk for central peg perforation with the specific implant utilized in this study. Long-term follow-up is ongoing and needed to understand the clinical implications of these findings.

Development of injectable thermogelling chitosan-inorganic phosphate solutions for biomedical applications.

Thermosetting polymers are attractive candidates for biomedical applications as noninvasive therapeutic delivery vehicles. In the present study, the feasibility of developing a neutral physiological temperature setting injectable formulation based on chitosan and an inorganic phosphate salt have been demonstrated. The in situ gelling system was developed by adding different concentrations of ammonium hydrogen phosphate (AHP) to chitosan solution. The resulting solutions have pH in the range of approximately 7-7.2. The gelling time of the chitosan-AHP solution was determined by incubating the solutions at 37 degrees C. Depending on the concentrations of AHP added, the gelling time varied from 5 min to 30 h at 37 degrees C. Addition of various diluents to chitosan-AHP solution did not significantly change the gelling time of the solutions. The gels were found to be cytocompatible as evidenced from in vitro cytocompatibility evaluation using MC3T3-E1 mouse osteoblast like cells. The feasibility of using the gels as a stem cell carrier vehicle as well as a macromolecular delivery vehicle has been demonstrated.

Reverse Shoulder Arthroplasty and Latissimus Dorsi Tendon Transfer.

In a systematic review, we critically examined and synthesized the results of individual studies on reverse shoulder arthroplasty (RSA) with latissimus dorsi tendon transfer. Two electronic databases were searched. For each included study, 2 reviewers evaluated the quality of its methods and retrieved data. In cases in which outcomes data were similar between studies, data were pooled using frequency-weighted (FW) mean values to generate summary outcomes. Seven studies met the inclusion and exclusion criteria, and 133 patient cases were reviewed. FW mean age was 69.5 years. Patients were followed up an FW mean of 39.9 months. FW mean Constant score improved from 28.7 before surgery to 64.4 afterward (P = .0001). External rotation improved from an FW mean of -4° to 25° (P < .0001). The overall complication rate was 22.8%. RSA combined with latissimus dorsi tendon transfer can improve function and external rotation in patients with cuff tear arthropathy and teres minor dysfunction. Its overall complication rate appears to be similar to that of RSA alone, though the rate of neuropraxia may be increased.

Metal Allergy as a Cause of Implant Failure in Shoulder Arthroplasty.

Metal allergy is an uncommon and poorly understood cause of failure of orthopedic implants. To the authors' knowledge, there have been no reports of the management of shoulder arthroplasty patients with metal allergy. The authors present their experience with the diagnosis and management of patients with metal allergy. Patients with metal allergy undergoing shoulder arthroplasty were identified through retrospective chart review from January 1, 2012, to January 31, 2015. Case characteristics collected included patient risk factors (age, sex, prior cutaneous reactions to metal), metal allergy factors (type of metal allergy, method of diagnosis), and surgery factors (implant type, primary/revision, type of shoulder arthroplasty). Outcomes measured included American Shoulder and Elbow Surgeons score, Penn Shoulder Score, and Single Assessment Numeric Evaluation score. Eleven patients were identified with metal allergy. Five were diagnosed prior to the index arthroplasty, and 6 were diagnosed after shoulder replacement. The diagnosis was made through skin patch testing, memory lymphocyte immunostimulation assay, or clinical history. Patients identified after implantation presented with progressive pain and stiffness, but none had cutaneous manifestations. Patients with metal allergy had better results undergoing primary shoulder arthroplasty than undergoing revision. Metal allergy is rare but may be a clinically significant cause of unsatisfactory shoulder arthroplasty. Given the superior results of primary shoulder arthroplasty compared with revision, screening for metal allergy by clinical history is recommended. [Orthopedics. 2017; 40(5):e844-e848.].

Quantitative Anatomical Differences in the Shoulder.

This study explored the radiographic and anatomical differences in normal shoulders between men and women, as well as factors such as race, height, weight, and age. A total of 205 patients with documented normal anatomical radiographs comprised the study population. Five fellowship-trained orthopedic surgeon reviewers measured head diameter, humeral head size, head to tuberosity distance, greater tuberosity width, neck-shaft angle, surface-arc angle, glenoid neck length, and distance from the lateral acromion process to the greater tuberosity on anteroposterior radiographs with the shoulder in external rotation. After the reviewers identified and marked defined anatomical landmarks, a comprehensive automated calculator was used to compute all parameters. Between men and women, head diameter (P<.001), humeral head size (P<.001), greater tuberosity width (P<.001), distance from the lateral acromion process to the greater tuberosity (P<.001), and glenoid neck length (P<.001) were significantly different, whereas race was not significantly different for any anatomical parameter. Using Spearman's rho, there was a strong correlation between head diameter/humeral head height and height (rs=0.77/rs=0.68), weight (rs =0.62), and greater tuberosity width (rs=0.66/rs= 0.61); there also was a strong negative correlation between head to tuberosity distance and neck-shaft angle (rs=-0.80). This study demonstrated precisely defined proximal humeral anatomical relationships and sizes using an advanced standardized imaging software program. With these data, orthopedic surgeons and implant designers can better understand the anatomy and glenohumeral relationships to re-create when performing total shoulder arthroplasty. [Orthopedics. 2017; 40(3):155-160.].

Effectiveness of a microvascular surgery training curriculum for orthopaedic surgery residents.

BACKGROUND: The safe and effective acquisition of microvascular surgical skills is a challenge for any residency program. Variable clinical exposure to microsurgery, premiums on operating room efficiency, and a steep learning curve make these skills difficult to acquire through clinical experience alone. The purpose of this study was to determine the effectiveness of a training curriculum on the development of microvascular surgical skills in our orthopaedic residents. METHODS: A microvascular training curriculum was completed during each third-year resident's rotation on the hand and upper-extremity service. The training cycle began with learning the basics of microvascular surgery on nonliving models and progressed to performing end-to-end arterial anastomoses on a live rat femoral artery in the second session. Outcome evaluations consisted of the Global Rating Scale score, achievement of patency, and time to completion. T test analyses of Global Rating Scale scores, achievement of patency, and time to completion were conducted to determine significance (p < 0.05). RESULTS: All residents significantly improved (p < 0.005) on Global Rating Scale scores from a mean score (and standard deviation) of 15 ± 4 points for the initial score to 20 ± 3 points for the post-test score. Of the twelve residents, patency was achieved by eleven at the final evaluation, compared with six before training. Time to completion of the anastomosis also significantly improved (p < 0.005), from a mean of 37:17 ± 8:41 minutes for the initial time to 24:46 ± 5:32 minutes for the final time. CONCLUSIONS: In an effort to improve the microvascular surgical skills of orthopaedic residents at our institution, a microvascular training curriculum was developed and was implemented. This curriculum was effective at improving resident microvascular surgical skills at the completion of an eight-week course.

Traditional threshold for retropharyngeal soft-tissue swelling is poorly sensitive for the detection of cervical spine injury on computed tomography in adult trauma patients.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To examine the diagnostic value of prevertebral soft-tissue swelling in the setting of cervical spine trauma. SUMMARY OF BACKGROUND DATA: In adult patients with trauma, an increase in the thickness of the retropharyngeal soft tissues is commonly used as a potential indicator of occult injury, but no studies have examined this parameter using computed tomography (CT) as a screening modality. METHODS: A total of 541 patients with trauma with injuries at any level of the spine underwent CT. Patients with cervical injury were divided into those requiring noninvasive (observation or cervical collar, n = 142) management, and those requiring invasive (surgery or halo, n = 61) treatment. A control group of patients with isolated thoracic or lumbar injuries was used for comparison (n = 542). Retropharyngeal soft tissues were measured at the cranial and caudal endplates of all cervical levels on sagittal and axial CT. Sensitivity and specificity were calculated for +1, +2, and +3 standard deviations from mean values. RESULTS: Sensitivity for detection of injury was found to be universally poor for all measurement groups. This ranged from 14.4% to 21.2% at +1 SD to 5.3% to 8.7% at +2 SD. Positive and negative predictive values for injury were also universally poor, ranging from 38% to 75%. Soft-tissue swelling as a sentinel sign of cervical spine injury demonstrates consistently high specificity and low sensitivity, precisely the opposite of what would be desired in a screening test. This study shows at best a sensitivity of 21.6% when using this parameter for the detection of these injuries in adult patients with trauma. CONCLUSION: On the basis of the results of this study, we recommend against the routine use of measurement of the prevertebral soft tissues on CT as a screening tool for cervical spine injury in adult patients with trauma. LEVEL OF EVIDENCE: 3.

Late reconstruction of median nerve palsy.

The median nerve provides sensory innervation to the radial aspect of the hand, including the palm, thumb, index, long, and half of the ring fingers. It provides motor innervation to most of the volar forearm musculature and, importantly, to m ost of thenar musculature. The main goal of median nerve reconstructive procedures is to restore thumb opposition. There are a variety of transfers that can achieve this goal but tendon transfers must recreate thumb opposition, which involves 3 basics movements: thumb abduction, flexion, and pronation. Many tendon transfers exist and the choice of tendon transfer should be tailored to the patient's needs.

Sagittal plane knee joint moments following anterior cruciate ligament injury and reconstruction: a systematic review.

BACKGROUND: Gait adaptations in persons with anterior cruciate ligament (ACL) injuries have been debated. Many studies examine high speed, 3-dimensional video gait analysis to compare knee joint torques during simulated activities of daily living. METHODS: We performed a systematic review of the literature for published clinical papers that reported sagittal plane knee joint kinetics in ACL deficient or reconstructed individuals. We calculated weighted effect sizes (Cohen's d) to evaluate the magnitude of differences between the injured limb and the contralateral limb and healthy, uninjured limbs in control subjects. FINDINGS: Ten published papers reported kinetic data in ACL deficient subjects while walking for comparisons to the contralateral side (weighted average d=-0.83, range: -3.21, 1.07), and to healthy control knees (weighted average d=-1.0, range: -3.36, 0.17); four papers reported data during jogging compared to the contralateral side (weighted average d=-0.94, range: -4.15, 0.17), and to controls (weighted average d=-1.42, range: -3.83,-0.2). Four papers reported data for ACL-reconstructed patients compared to healthy controls during walking (weighted average d=-0.94, range: -0.4, -1.77) and jogging (weighted average d=-1.18). INTERPRETATION: Effect sizes comparing knee joint moments in injured vs. healthy control subjects appear to be slightly higher while jogging than walking, and higher in ACL-deficient patients compared to reconstructions. However, magnitudes are all large. Few studies report stair climbing. Consequently, it is difficult to make inferences with confidence during these tasks.