Carl J. Basamania

An anatomic study of the effects on the suprascapular nerve due to retraction of the supraspinatus muscle after a rotator cuff tear

The purpose of this anatomic study was to assess the risk to the suprascapular nerve by measuring the tension on the nerve and the angle between the nerve and its motor branch at the scapular notch with medial supraspinatus tendon retraction. Twelve shoulders in six cadavers were dissected to evaluate the branching point of the first motor branch of the suprascapular nerve, the change in angle between the nerve and its first motor branch at the scapular notch with retraction of the supraspinatus tendon, and the resulting tension on the nerve. The first motor branch originated at the notch in 9 cadavers, just proximal in 1, and just distal in 2. With the supraspinatus muscle in its anatomic position, the suprascapular nerve and its first motor branch angle measured 142.6 degrees at the scapular notch. After retraction of the supraspinatus, the angle markedly decreased to 98.7 degrees and 34.6 degrees with 1 cm and 5 cm of medial retraction, respectively. The motor branch was taut in all specimens at 2 to 3 cm of retraction. Medial retraction of the supraspinatus tendon drastically changes the course of the suprascapular nerve through the scapular notch, creating increased tension on the nerve. The degree of rotator cuff muscle atrophy frequently observed after a massive tear may be explained by increased tension on the nerve due to muscle retraction.

Incidence of Major Tendon Ruptures and Anterior Cruciate Ligament Tears in US Army Soldiers

Background Although a rare event, the prevalence of major tendon rupture has increased in recent decades. Identification of risk factors is important for prevention purposes. Hypothesis Race is a risk factor for major tendon ruptures. Study Design Cohort study (prevalence); Level of evidence, 2. Methods All patients admitted for surgical management of a rupture of a major tendon at Womack Army Medical Center, Fort Bragg, North Carolina, in 1995 and 1996 were identified and evaluated for risk factors. Results The authors identified 52 major tendon ruptures 29 Achilles, 12 patellar, 7 pectoralis major, and 4 quadriceps tendon ruptures. All patients were active-duty soldiers, and 1 was a female soldier. Forty-one tendon ruptures occurred among black soldiers, 8 occurred among white soldiers, and 3 occurred among Latino soldiers. The population at risk included 93 224 exposures during the 2-year period, of which 67.1% were white, 24.5% were black, and 8.4% were self-classified as other race. The rate ratio for tendon rupture, adjusted for gender and age, was 13.3 (95% confidence interval, 6.2-28.5) between blacks and whites and 2.9 (95% confidence interval, 0.8-10.9) between Latinos and whites. Conclusion The rate of major tendon rupture was 13 times greater for black men in this study population when compared with whites. Interventions among those at a higher risk for injury should be considered.

Relationship of the axillary nerve to the proximal screws of a flexible humeral nail system: an anatomic study.

Objective To investigate the risk of axillary nerve injury during placement of the proximal interlock and tension screws of the Synthes Titanium Flexible Humeral Nail System (Synthes, Paoli, PA). Design Cadaver study. Main Outcome Measure Anatomic relationships. Methods A titanium flexible humeral nail was inserted in an antegrade manner in 10 fresh-frozen cadaver shoulders. Proximal interlock and tension screws were inserted. The axillary nerve was carefully exposed, and the distance from the center of the nerve to each screw was measured. Results In 8 of 10 specimens, the nerve traversed the interval between the proximal interlock screw and the tension screw. The average distance from the axillary nerve to the closer of the two proximal screws was 2.6 mm. The proximal interlock screw transected the axillary nerve in one specimen. Conclusions There is significant risk to the axillary nerve when inserting the proximal interlock screw and the tension screw of this flexible humeral nail system. We recommend blunt dissection through the deltoid, direct visualization of the lateral humeral cortex, and use of a soft tissue protection sleeve when predrilling and placing these screws.

Thoracic Outlet Syndrome in a Competitive Baseball Player Secondary to the Anomalous Insertion of an Atrophic Pectoralis Minor Muscle A Case Report

Thoracic outlet syndrome secondary to axillary artery compression by the pectoralis minor muscle in overhead throwing athletes is well described. Lord and Stone first described this entity and called it pectoralis minor syndrome in the 1950s, whereas others have included it in the description of hyperabduction syndrome. Typically, hyperabduction causes the pectoralis minor tendon near its insertion on the coracoid tip to displace the axillary vessels. Most descriptions to date have focused on the development of aneurysms, thrombosis, and showering of emboli in repetitive throwing athletes with this condition. However, several authors have described the temporary diminution of vascular flow through the axillary artery as a result of impingement of a hypertrophied pectoralis minor muscle on the compressible axillary artery with the shoulder in a hyperabducted and externally rotated position during overhead throwing. These patients often display a constellation of symptoms related to transient ischemia. Overhead throwers complain of a “dead arm syndrome” with early fatigue and forearm claudication. The classic treatment for axillary artery impingement by a hypertrophied pectoralis minor is tendon release from the coracoid. Although anomalous insertions of the pectoralis minor have been reported in the literature, this finding has not been correlated with the clinical presentation of thoracic outlet syndrome. We report on the diagnosis and treatment of a nonhypertrophic pectoralis minor muscle with an anomalous insertion and related dense fascial band that resulted in hyperabduction syndrome in a competitive baseball player.

Pectoralis Major Tendon Ruptures: Diagnosis and Treatment

Pectoralis major tendon ruptures have been uncommon injuries in the past. More recently there seems to be an increase in the reported occurrence. Most physicians have little experience with the surgical treatment of this injury. The purpose of this article is to outline a diagnosis and treatment plan for pectoralis major tears. Specific physical examination and radiographic findings to help diagnose this injury will be discussed. A detailed preoperative plan and surgical technique will be outlined. Postoperative care, rehabilitation, and possible complications are also presented.

Pullout Forces of Sutures in Muscle Lacerations

The purpose of this study was to determine if complex suture techniques had higher pullout forces from muscle tissue than conventional stitching. Using transected cadaver muscle bellies, we performed repairs with various suture techniques and measured pullout forces. Epimyseal repair with conventional stitches (Kessler, figure eight, horizontal mattress) was inferior to complex stitches (modified Mason-Allen, perimeter). The combined complex stitches (perimeter and Mason-Allen) were strongest. Conventional stitches failed longitudinally through the muscle, whereas complex stitches failed transversely across the muscle. The complex combination of perimeter and Mason-Allen stitches had superior pullout resistance compared to conventional stitches.