Clinically oriented morphology of pronator quadratus muscle of the forearm: A descriptive cross-sectional study

Background. The aim of this study was to detail the morphology of the pronator quadratus muscle (PQM) and to study its morphometry. The objectives were to perform side-based, sex-based analyses. Methods. A total of 70 upper extremities (35 right and 35 left) from adult embalmed cadavers were included in this study. The quadrilateral-shaped pronator quadratus was pointed at its medio-superior angle, medio-inferior angle, latero-superior angle and latero-inferior angle. These points were used to measure the lateral length, medial length, proximal width and distal width via a digital Vernier caliper (Mitutoyo, Japan). The midpoints of the elbow and wrist joints were considered for measuring the distance of the muscle from these joints. Results. The outline of the muscle in this study was square shaped in 33 (47.1%), rectangular in 9 (12.8%), rhomboid in 8 (11.4%), trapezoidal in 16 (22.8%) and truncated in 4 (5.7%) specimens. PQM had aponeurotic fibers at the ulnar attachment in 47 patients (67.1%), at the radial attachment in 11 patients (15.8%) and from both bones of the forearm in 12 patients (17.1%). The mean lateral and medial lengths of the PQM were 4.64 ± 0.94 cm and 5.66 ± 1 cm, respectively. The mean proximal and distal widths were 4.09 ± 1 cm and 3.74 ± 0.67 cm, respectively. The muscle was located 19.53±24.29 cm away from the elbow and 2.61±7.27 cm from the wrist joint. The mean distance of the AIN from its origin to entry into the PQM was 12.69 ± 1.52 cm. The lateral length of the PQM in males was considerably greater than that in females (p < 0.05). The dimensions compared between the right and left sides were not statistically significant (p > 0.05). Conclusion. This study of our sample population provides in-depth morphometric data on PQM, which can be used to assist in orthopedic and reconstructive surgical procedures such as tendon transfers, flap surgeries and nerve repairs.