A T-capsulotomy provides increased hip joint visualization compared with an extended interportal capsulotomy.

The purpose of this study was to compare the cross-sectional area (CSA) of joint visualization between extended interportal and T-capsulotomies. Twenty fresh-frozen cadaveric hips were dissected to their capsuloligamentous complexes and fixed in a custom apparatus in neutral hip position. Ten hips underwent sequential interportal capsulotomies at lengths of 2, 4, 6, and 8 cm. Ten hips underwent sequential T-capsulotomies starting from a 4 cm interportal capsulotomy, creating a 2 cm T-capsulotomy (Half-T), and finally a 4 cm T-capsulotomy (Full-T). Following each sequential capsule change in both groups, a high-resolution digital photograph was taken to measure the visualized intra-articular cross-sectional area (CSA). Independent t-test was used to compare CSA interportal and T-capsulotomy groups. Analysis demonstrated a statistically significant increase in CSA visualization with each sequential increase in interportal capsulotomy length up to 6 cm (2cm: 0.6 ± 0.2 cm2; 4cm: 2.1 ± 0.5 cm2 (p<0.001); 6cm: 3.6 ± 1.0 cm2 (p=0.001)), and no difference at 8cm (4.2 ± 1.2 cm2 (p=0.20)). For the T-capsulotomy group the average CSA visualization significantly increased from 3.2 ± 0.9 cm2 for the Half-T to 7.1 ± 1.0 cm2 for the Full-T (p<0.001). The Half-T CSA visualization was not statistically different from the 6 cm capsulotomy (p=0.4) and the 8cm capsulotomy (p=0.05). The Full-T had significantly superior CSA visualization area as compared to the 6 cm and 8 cm interportal capsulotomies (p<0.001 for both). In conclusion, T-capsulotomy resulted in improved cross-sectional area of joint visualization compared to an extended (8cm) interportal capsulotomy in a cadaveric model. Surgeons must weigh the benefits of greater visualization from T-capsulotomy that may help to avoid residual FAI while ensuring to completely repair the capsulotomy to avoid iatrogenic instability.

Biomechanical Analysis of Latarjet Screw Fixation: Comparison of Screw Types and Fixation Methods.

PURPOSE: To compare the initial fixation stability, failure strength, and mode of failure of 5 different screw types and fixation methods commonly used for the classic Latarjet procedure. METHODS: Thirty-five fresh-frozen cadaveric shoulder specimens were allocated into 5 groups. A 25% anteroinferior glenoid defect was created, and a classic Latarjet coracoid transfer procedure was performed. All grafts were fixed with 2 screws, differing by screw type and/or fixation method. The groups included partially threaded solid 4.0-mm cancellous screws with bicortical fixation, partially threaded solid 4.0-mm cancellous screws with unicortical fixation, fully threaded solid 3.5-mm cortical screws with bicortical fixation, partially threaded cannulated 4.0-mm cancellous screws with bicortical fixation, and partially threaded cannulated 4.0-mm captured screws with bicortical fixation. All screws were stainless steel. Outcomes included cyclic creep and secant stiffness during cyclic loading, as well as load and work to failure during the failure test. Intergroup comparisons were made by a 1-way analysis of variance. RESULTS: There were no significant differences among different screw types or fixation methods in cyclic creep or secant stiffness after cyclic loading or in load to failure or work to failure during the failure test. Post-failure radiographs showed evidence of screw bending in only 1 specimen that underwent the Latarjet procedure with partially threaded solid cancellous screws with bicortical fixation. The mode of failure for all specimens analyzed was screw cutout. CONCLUSIONS: In this biomechanical study, screw type and fixation method did not significantly influence biomechanical performance in a classic Latarjet procedure. When performing this procedure, surgeons may continue to select the screw type and method of fixation (unicortical or bicortical) based on preference; however, further studies are required to determine the optimal method of treatment. CLINICAL RELEVANCE: Surgeons may choose the screw type and fixation method based on preference when performing the Latarjet procedure.

Optimal axon counts for brachial plexus nerve transfers to restore elbow flexion.

BACKGROUND: Nerve transfer surgery has revolutionized the management of traumatic brachial plexus injures. However, the optimal size ratio of donor to recipient nerve has yet to be elucidated. The authors investigated the axon count ratios of ulnar and median fascicular transfers to restore elbow flexion. The authors hypothesized that donor nerve axon counts would be correlated with historical success of various nerve transfers used to restore elbow flexion. METHODS: Ten cadaveric specimens were used for a histomorphologic analysis of fascicular nerve transfers. Review of previously published axon counts and clinical results following transfer to the musculocutaneous nerve to restore elbow flexion was performed for the following donor nerves: medial pectoral, spinal accessory, intercostal, thoracodorsal, ulnar, and median fascicular. RESULTS: The average number of fascicles identified was 7.9 in the ulnar nerve and 8.0 in the median nerve. The mean fascicular axon count was 1318 for the ulnar nerve and 1860 for the median nerve. Mean recipient nerve axon count was 1826 for the musculocutaneous biceps branch and 1840 for the brachialis branch. A significant correlation between axon count and clinical results of transfers to restore elbow flexion was observed. Donor-to-recipient nerve axon count ratios below 0.7:1 were associated with a decreased likelihood of a successful outcome. CONCLUSIONS: In nerve transfers to restore elbow flexion, an appropriate size match between donor and recipient nerves appears to be a factor affecting clinical success. These data support a donor-to-recipient axon count ratio greater than 0.7:1 as the goal for brachial plexus nerve transfers to restore elbow flexion.

Patient-reported outcome measures for the knee.

In the past 20 years, there has been considerable growth in the number of knee instruments and rating scales designed to measure outcomes from the perspective of the patient. Only a few of these instruments have been evaluated for reliability, validity, and responsiveness. The purpose of this systematic review was to examine the psychometric evidence of patient-reported outcome measures for the knee and identify the best scores for specific knee conditions. A literature search was performed to retrieve references relating to the development and evaluation of knee-specific instruments. Twenty-four unique instruments were identified, and most have satisfactory evidence for internal (alpha > or = 0.82) and test-retest reliability (intraclass correlation coefficient > or = 0.80). Face/content validity was typically assessed during the item selection process, and construct validity was evaluated through strict hypothesis testing or correlations with other clinical measures. For many instruments, effect sizes and standardized response means measuring responsiveness were large (> or = 0.80) within disease-specific populations. Based on the psychometric data, recommendations include the Cincinnati Knee Rating System, Knee Injury and Osteoarthritis Outcome Score (KOOS), and Lysholm Knee Score for anterior cruciate ligament (ACL) injuries, the Kujala Anterior Knee Pain Scale for anterior knee pain, the International Knee Documentation Committee (IKDC) Subjective Knee Form, KOOS, and Lysholm Knee Score for focal chondral defects, the Western Ontario Meniscal Evaluation Tool (WOMET) for meniscal injuries, and the KOOS for osteoarthritis (OA). Although the IKDC can be used as a general knee measure, no instrument is currently universally applicable across the spectrum of knee disorders and patient groups. Clinicians and researchers looking to use a patient-based score for measurement of outcomes must consider the specific patient population in which it has been evaluated. Using a diagnostic algorithm that measures the anatomic parts of the knee as separate constructs may solve this dilemma, allowing for measurement of treatment outcomes across patient groups and selection of the optimal clinical intervention.