Variations and morphometrics of palmaris longus in fetuses: a meta-analysis of cadaveric studies

Anatomical variations of the superficial palmar arch in human fetuses

The superficial palmar arch is an important anatomical structure that contributes to the arterial supply of the palmar side of the hand in the upper extremity. However, there is limited information on the embryological morphological structure of the superficial palmar arch in the literature. We studied the types of the superficial palmar arch and determined their variations by dissecting 80 upper extremities of 40 formalin-fixed human fetuses (19 males, 21 females) 18-37 weeks of age. The types and variations of the superficial palmar arch were examined, and the median artery was imaged. The superficial palmar arch type was complete in 58 hands (72.5%) and incomplete in 22 hands (27.5%). The complete group consisted of type A (47.5%), type B (16.25%), type C (3.75%), type D (1.25%), and type E (3.75%). On the other hand, the incomplete group consisted of type F (15%), type G (8.75%), type H (2.5%), and type I (1.25%). A median artery that originated from the ulnar artery and passed through the carpal tunnel during its course was detected in two hands (2.5%). Knowledge of the superficial palmar arch variations will contribute to hand microsurgery particularly in vascular graft and free flap application interventions for arterial bleeding in the palmar region.

Prevalence, variants, and morphometrics of Palmaris Longus tendon: a magnetic resonance imaging study

PURPOSE

The palmaris longus (PL) tendon present a high degree of variations; the commonest is its absence which could reach more than 40% in some populations. The PL tendon is highly relevant in hand reconstructive surgery; however, MRI variations of PL tendon have been exceptionally reported. To this, this study investigated PL tendon variations using MRI in a Lebanese population.

METHODS

This is a retrospective study of distal forearm MRI examinations to evaluate the presence, anatomical variations and morphometric of PL tendon. The outcomes were set as overall frequency, gender-based and side-base frequencies, correlations between prevalence and gender/side, morphological variants, thickness, and width of PL tendon.

RESULTS

The sample comprised 335 patients including a total of 339 MRI scans. The PL was present in 221 wrists (65.2%), and bilaterally in only one (25%) out of the 4 bilateral cases. All PL were located using the Axial T1 views. Univariate and multivariate analyses showed no correlation with side, gender, or Tesla power. The only morphological variation was a reversed PL in 2 cases (0.6%). The mean width was 4.24 ± 1.2 mm. The mean thickness was 2.75 ± 0.6 mm.

CONCLUSION

As far as we know, this is the first study to report the total array of variations of PL tendon using MRI, and its prevalence in a Lebanese population. The mean width of PL tendon calculated with high quality MR imaging was found to be similar to that reported by cadaveric studies.