The Thumb Test: A Simple Physical Examination Maneuver for the Diagnosis of Symptomatic Posterior Shoulder Instability.

Posterior shoulder instability is becoming increasingly recognized in young active patient populations. Diagnosing posterior instability can be challenging because patients commonly present with a complaint of pain without a history of a dislocation or subluxation event. Additionally, a posterior labral tear is not always clearly visualized on advanced imaging studies. As such, physical examination is critical to the diagnosis. We report a simple physical examination maneuver for the diagnosis of symptomatic posterior shoulder instability. The thumb test attempts to replicate a posterior bone block procedure, helping to re-establish stability and relieve pain. The examiner places his or her thumb over the posterior glenohumeral joint line while the patient actively forward elevates the affected arm overhead. Improvement in pain and stability with this maneuver is diagnostic for symptomatic posterior shoulder instability. This test augments current physical examination maneuvers to assist with correctly diagnosing posterior shoulder instability.

Revision Open Subpectoral Biceps Tenodesis With Allograft Tendon Reconstruction for Symptomatic Failed Biceps Tenodesis.

Biceps tenodesis and tenotomy are both effective surgical procedures for management of shoulder pain and dysfunction secondary to SLAP tears, biceps tendinitis, rotator interval pulley lesions, and failed SLAP repairs. These procedures are generally safe with low complication rates. However, failure of a proximal biceps tenodesis or tenotomy can rarely lead to symptomatic Popeye deformity with pain and cramping with repetitive forearm supination and elbow flexion. Surgical revision is indicated in young active patients to restore the length tension relationship of the biceps brachii to improve supination and flexion strength, as well as to provide symptomatic relief and improved endurance. Failed biceps tenodesis can be a challenging surgical scenario, as oftentimes there is limited available proximal biceps tendon tissue, especially in the setting of prior subpectoral biceps tenodesis. We report a technique of revision open subpectoral biceps tenodesis with allograft tendon augmentation for the management of symptomatic Popeye deformity in young active patients with little to no remaining proximal biceps tendon.

Successful Closed Reduction of Distal Radius Volar Locking Plate Plastic Deformation with Associated Fracture: A Case Report.

CASE: Distal radius fractures are among the most common orthopaedic injuries. The volar locking plate is now the most utilized internal fixation method for these fractures. There are few reports of mechanical failure of volar locking plates within the literature. In this case report, we describe successful closed reduction of traumatic volar locking plate plastic deformation with associated fracture. In addition, we discuss existing literature regarding plastic deformation of distal radius plates. CONCLUSION: Traumatic, plastic deformation of distal radius volar locking plates with associated fracture may be managed nonoperatively with closed reduction.

The Relationship between Estrogen and Nitric Oxide in the Prevention of Cardiac and Vascular Anomalies in the Developing Zebrafish (Danio Rerio).

It has been known that both estrogen (E2) and nitric oxide (NO) are critical for proper cardiovascular system (CVS) function. It has also been demonstrated that E2 acts as an upstream effector in the nitric oxide (NO) pathway. Results from this study indicate that the use of a nitric oxide synthase (NOS) inhibitor (NOSI) which targets specifically neuronal NOS (nNOS or NOS1), proadifen hydrochloride, caused a significant depression of fish heart rates (HR) accompanied by increased arrhythmic behavior. However, none of these phenotypes were evident with either the inhibition of endothelial NOS (eNOS) or inducible NOS (iNOS) isoforms. These cardiac arrhythmias could also be mimicked by inhibition of E2 synthesis with the aromatase inhibitor (AI), 4-OH-A, in a manner similar to that of nNOSI. In both scenarios, by using an NO donor (DETA-NO) in either NO + nNOSI or E2 + AI co-treatments, fish could be significantly rescued from decreased HR and increased arrhythmias. However, the addition of an NOS inhibitor (L-NAME) to the E2 + AI co-treatment fish prevented the rescue of low heart rates and arrhythmias, which strongly implicates the NO pathway as a downstream E2 targeted molecule for the maintenance of healthy cardiomyocyte contractile conditions in the developing zebrafish. Cardiac arrhythmias could be mimicked by the S-nitrosylation pathway inhibitor DTT (1,4-dithiothreitol) but not by ODQ (1H-[1-3]oxadiazolo[4,3-a]quinoxalin-1-one), the inhibitor of the NO receptor molecule sGC in the cGMP-dependent pathway. In both the nNOSI and AI-induced arrhythmic conditions, 100% of the fish expressed the phenotype, but could be rapidly rescued with maximum survival by a washout with dantrolene, a ryanodine Ca2+ channel receptor blocker, compared to the time it took for rescue using a control salt solution. In addition, of the three NOS isoforms, eNOS was the one most implicated in the maintenance of an intact developing fish vascular system. In conclusion, results from this study have shown that nNOS is the prominent isoform that is responsible, in part, for maintaining normal heart rates and prevention of arrhythmias in the developing zebrafish heart failure model. These phenomena are related to the upstream stimulatory regulation by E2. On the other hand, eNOS has a minimal effect and iNOS has little to no influence on this phenomenon. Data also suggests that nNOS acts on the zebrafish cardiomyocytes through the S-nitrosylation pathway to influence the SR ryanidine Ca2+ channels in the excitation-coupling phenomena. In contrast, eNOS is the prominent isoform that influences blood vessel development in this model.