Persistent median artery in the carpal tunnel: anatomy, embryology, clinical significance, and review of the literature

The median artery usually regresses after the eighth week of intrauterine life, but in some cases it persists into adulthood. The persistent median artery (PMA) passes through the carpal tunnel of the wrist, accompanying the median nerve. During anatomical dissection in our department, we found two unilateral cases of PMA originating from the ulnar artery. In both cases the PMA passed through the carpal tunnel, reached the palm, and anastomosed with the ulnar artery, forming a medio-ulnar type of superficial palmar arch. In addition, in both cases we observed a high division of the median nerve before entering the carpal tunnel. Such an artery may result in several complications such as carpal tunnel syndrome, pronator syndrome, or compression of the anterior interosseous nerve. Therefore, the presence of a PMA should be taken into consideration in clinical practice. This study presents two cases of PMA along with an embryological explanation, analysis of its clinical significance, and a review of the literature. The review of the literature includes cases observed during surgical procedures or anatomical dissections. Cases observed by means of imaging techniques were not included in the study

Suture anchors, properties versus material and design: A biomechanical study in ovine model

The aim of our work was to compare the performance of suture anchors with various material and design that could be used in shoulder surgery. Three metallic and three bioabsorbable anchors mounted with stainless steel wire were tested. Their load to failure and mode of failure was determined in ex vivo ovine glenoids using Materials Testing Machine and attached load cell. Tensile load was applied at a rate of 60 mm/min, while load and displacement were recorded at a sampling rate of 100 Hz. Load to failure and failure mode was recorded. The mean load to failure for screw-type metallic anchors was Arthrex Fastak 678.3 N and Smith+Nephew Ti 3.5 499.7 N. Mitek GII (cylindrical with arcs) had a load to failure of 86.8 N. All bioabsorbable anchors exhibited lower load to failure comparing to screw-type metallic ones (P = 0.007), which was not statistically different between each other (P = 0.056): Arthrex BioFastak: 179.5 N; Mitek Panalok: 136.0 N; Smith+Nephew Bioraptor: 258.8 N. Metallic or bioabsorbable anchors had 30% eyelet failure (5/15 and 4/13, respectively). Our results suggest that metallic anchors have a better load to failure than bioabsorbable ones. Often the suture anchors' weak point is their eyelet and needs further design improvement. © 2010 Springer-Verlag

Correlation between the four types of acromion and the existence of enthesophytes: A study on 423 dried scapulas and review of the literature

The purpose of this study was to correlate the four types of acromial shape with the existence of enthesophytes, which together comprise two important parameters for subacromial impingement syndrome and rotator cuff tears. In addition, a review of the literature was carried out. Four hundred twenty-three dried scapulas Were studied at the Department of Anatomy in the University of Cologne, Germany. Four types of acromion were found: the three classical ones as described by Bigliani et al. ([1986] Orthop Trans 10:216) and a fourth one, where the middle third of the undersurface of acromion was convex (Gagey et al. [1993] Surg Radiol Anat 15:63-70). The correlation between the four types of acromion and the presence of enthesophytes at its anterior undersurface was also recorded. The distribution of acromial types was as follows: type I, flat, 51 (12.1%); type II, curved, 239 (56.5%); type III, hooked, 122 (28.8%); and type IV, convex, 11 (2.6%). Enthesophytes were found in 1 of type I (2%), in 19 of type II (7.9%), in 46 of type III (37.7%), and in 0 (0%) of type IV acromions. Overall, 66 (15.6%) out of 423 scapulas had enthesophytes. In all cases, they were localized at the site of the coracoacromial ligament insertion on the acromion. Enthesophytes were significantly (P < 0.05) more common in type III acromions and this combination is particularly associated with subacromial impingement syndrome and rotator cuff tears. In type I and in type IV acromions, the incidence of enthesophytes is very small and, according to other studies, with these two acromial types rotator cuff tears are also rare