Sonographic probe induced tenderness for lateral epicondylitis: an accurate technique to confirm the location of the lesion.

The purpose of this study is to evaluate the hypothesis that ultrasonographic probe-induced tenderness is a useful adjunct to the simple sonography in confirming the location of the pathology within the extensor carpi radialis brevis tendon in patients with lateral epicondylitis of the elbow. We conducted a case controlled study by evaluating 27 consecutive patients in the age group of 37-59 years (median 44) who had typical symptoms of lateral epicondylitis and a visual analogue score of more than 4 and evaluating a same number of asymptomatic healthy volunteers in the age group of 37-59 years (median 43) by means of ultrasound examination of the lateral elbow in a period of 5 months from 2007 to 2008. When we identified sonographic anechoic or hypoechoic lesions within the common extensor tendon we compressed it with the ultrasound probe to elicit tenderness so as to confirm the site of lesion within the affected tendon. We observed that the abnormal lesion detected by ultrasonography corresponded to the point of maximal tenderness when compressed by the probe in all the symptomatic patients. We therefore conclude that as it is essential to accurately detect the lesion within the extensor carpi radialis brevis for the purpose of diagnosis and treatment of lateral epicondylitis of elbow the technique of inducing tenderness at site of abnormal shadow on ultrasound within the extensor carpi radialis brevis tendon improves the accuracy of identifying the site of lesion, prevents the misinterpretation of anisotropy as pathological lesion and also can be useful to maximize the efficacy of interventions aimed in treating the lateral epicondylitis.

Biomechanical evaluation of anterior cruciate ligament femoral fixation techniques.

BACKGROUND: A number of different femoral anterior cruciate ligament fixation techniques are currently in use. Slippage of the graft caused by excessive early loading or aggressive rehabilitation may negate benefits of surgery and result in a knee with undesirable laxity. HYPOTHESIS: Anterior cruciate ligament femoral graft slippage varies by fixation technique and amount of cyclic loading. STUDY DESIGN: Controlled laboratory study. METHODS: Graft slippage in 5 different soft tissue anterior cruciate ligament femoral fixation techniques (Bio-TransFix cross-pin technique, Stratis ST cross-pin technique, Bilok ST transverse femoral screw, Delta tapered bio-interference screw, and single-loop TensionLok) was compared by cyclic loading of double-bundle grafts in porcine femurs. Graft slippage was measured using a differential variable reluctance transducer. RESULTS: The Bio-TransFix had significantly less (P = .002) total graft slippage (1.14 +/- 0.43 mm) compared to the Delta (3.74 +/- 3.25 mm), Bilok ST (3.92 +/- 2.28 mm), and TensionLok (5.09 +/- 1.12 mm) but not the Stratis ST (1.92 +/- 1.55 mm). All techniques showed the greatest amount of dynamic excursion (P < .001), slippage (P < .001), and percentage of total slippage (mean 68%, P < .001) during the first 100 cycles of loading. The TensionLok had the greatest amount of dynamic excursion during the first 100 cycles (4.15 +/- 1.00 mm) followed by the Bilok ST (3.37 +/- 2.07 mm), Delta (1.76 +/- 0.93 mm), and Stratis ST (1.75 +/- 0.96 mm); the Bio-TransFix demonstrated the least (1.26 +/- 0.48 mm). There was no statistical difference in failure load between repair techniques (P = .103). CONCLUSION: Graft slippage was statistically different between anterior cruciate ligament femoral fixation techniques for static and dynamic loading. All techniques exhibited the greatest amount of slippage during the first 100 cycles of loading. The differential variable reluctance transducer permitted evaluation of dynamic graft-construct-bone displacement during experimental loading, simulating the loading experienced during early rehabilitation. CLINICAL RELEVANCE: The optimal method of graft fixation for anterior cruciate ligament reconstruction remains unknown. In the current study, cross-pin constructs appeared to be superior to certain other available fixation systems.

Biomechanical performance of rotator cuff repairs with humeral rotation: a new rotator cuff repair failure model.

BACKGROUND: Traditional biomechanical evaluations of rotator cuff repair techniques employ cyclic loading of the supraspinatus tendon in an isolated medial direction. PURPOSE: This study was conducted to evaluate 2 different rotator cuff repair techniques that are currently the subject of debate with cyclic loading and with internal and external humeral rotation to better simulate postoperative rehabilitation. STUDY DESIGN: Controlled laboratory study. METHODS: Nine fresh-frozen paired human cadaver shoulders (18 shoulders) were studied. A single-row repair with 2 suture anchors was compared with a double-row repair with 4 suture anchors. The shoulders were tested in a custom device to position the shoulder in neutral, 45 degrees of internal rotation, and 45 degrees of external rotation. Cyclic loading of the supraspinatus tendon was performed with an MTS material testing machine. Gap formation was measured and analyzed for each rotational position using the MTS device. RESULTS: For the single-row repair, average gap formation per 100 cycles in the positions of neutral, internal, and external humeral rotation was 1.47 +/- 0.63, 3.11 +/- 1.55, and 2.24 +/- 0.94 mm, respectively. For the double-row repair, average gap formation per 100 cycles in the positions of neutral, internal, and external humeral rotation was 1.25 +/- 0.54, 2.29 +/- 1.10, and 1.57 +/- 0.48 mm, respectively. For gapping averaged over all positions, the double-row repair had significantly less gapping than the single-row repair (P = .0109); gapping was greatest for internal rotation, followed by external rotation, and least for neutral (P < .0001). CONCLUSION: The testing method of including a rotational component in biomechanical rotator cuff repair testing is a more realistic model of the loading conditions experienced by a repaired rotator cuff as the patient participates in postoperative rehabilitation. Double-row repair has better fixation strength than single-row repairs when exposed to cyclic loading and changes in humeral rotation position. CLINICAL RELEVANCE: Humeral rotation affects rotator cuff fixation and should be considered in postoperative rehabilitation.

Training resources in arthroscopic rotator cuff repair.

BACKGROUND: All-arthroscopic rotator cuff repair is becoming more commonly performed with recent improvements in implants, instrumentation, and techniques. This study evaluated the influence of different training resources for surgeons performing this procedure. METHODS: A twenty-eight-item survey was created to evaluate the methods by which orthopaedic surgeons are trained in the skill of all-arthroscopic rotator cuff repair. We selected 2455 surgeons from the American Academy of Orthopaedic Surgeons web site who indicated that they performed shoulder surgery, arthroscopic surgery, and/or sports medicine as part of their practice. Using a 5-point Likert scale, the respondents rated the relative importance of different training resources, including the completion of a sports medicine or shoulder surgery fellowship, attendance at instructional courses, and practice on shoulder models, in contributing to their ability to perform arthroscopic rotator cuff repair. RESULTS: Of the 2455 surveys sent, 1076 were returned (a response rate of 43.8%). Significantly more surgeons indicated that they performed arthroscopic repairs for a 2-cm tear compared with a 5-cm tear (p < 0.001). A younger age, higher volume of shoulder arthroscopies, and higher volume of rotator cuff repairs were all associated with significantly higher rates of preference for all-arthroscopic repairs compared with other types of repairs (p < 0.001). Compared with surgeons who received training in shoulder surgery during residency only, surgeons who had completed either shoulder or sports medicine fellowships were more likely to perform all-arthroscopic repairs. When ranking the relative importance of resources in the training for all-arthroscopic repair, the overall Likert scale scores were highest for a sports medicine fellowship (3.49), hands-on instructional courses (3.33), and practice in an arthroscopy laboratory on cadaver specimens (3.22). Likert scores were lowest for residency training (2.02), practice on artificial shoulder models (2.13), and Internet resources (2.25). CONCLUSION: The information from this survey may be used to direct the continually evolving training of surgeons in arthroscopic rotator cuff repairs.