Arthroscopic anatomy of the middle glenohumeral ligament. A series of 300 cases.

PURPOSE: The anatomy of the middle glenohumeral ligament (MGHL) is seldomly described during arthroscopy. The aim of this study was to determine the arthroscopic variants concerning the anatomy of the MGHL. METHODS: A prospective, observational, single-center study was conducted between June 2016 and June 2017. All patients undergoing a first-time arthroscopy of the shoulder and with no history of prior surgery or trauma of the same shoulder were consecutively enrolled. The variations of the MGHLs shape and of its glenoid and distal insertions were documented during surgery. RESULTS: A total 300 patients were included. Surgeries included rotator cuff sutures, tenotomy/tenodesis of the long head of the biceps tendon (LHBT) and subacromial decompression in respectively 31%, 32.7% and 35.5% of cases. The MGHL was absent in 12% of cases, presented a flat structure in 72% of cases, a cord-like shape in 14% and a Buford complex was observed in 1%. Its glenoid insertion was located on the labrum between the superior (SGHL) and inferior (IGHL) in 43% of cases, presented a combined insertion with the LHBT in 7%, with the SGHL in 29% and with both the SGHL and LHBT in 9%. The distal insertion was located in 67% of cases on the subscapularis tendon (SCCT) or the capsule covering it, and on the humeral bone in 21%. CONCLUSION: This study confirms and details the anatomic variants of the MGHL, notably describing the lesser-known variants of its distal insertion, yet arises the question of the exact nature and function of this so-called ligament.

Event-by-event fluctuations of the Kaon-to-Pion ratio in central Pb+Pb collisions at 158 GeV per nucleon.

We present the first measurement of fluctuations from event to event in the production of strange particles in collisions of heavy nuclei. The ratio of charged kaons to charged pions is determined for individual central Pb+Pb collisions. After accounting for the fluctuations due to detector resolution and finite number statistics we derive an upper limit on genuine nonstatistical fluctuations, which could be related to a first- or second-order QCD phase transition. Such fluctuations are shown to be very small.