The Vascular Basis of the Pronator Quadratus Muscle Flap and Its Use in Clinical Cases

Background Pronator quadratus (PQ) is a deeply situated muscle in the forearm which may occasionally be utilized for soft-tissue reconstruction. The purpose of this anatomical and clinical study was to confirm vascular supply of PQ muscle (PQM) in order to optimize its transfer and confirm its utility in clinical situations. Methods In Part A of the anatomical study, fresh human cadavers (n = 7) were prepared with an intra-arterial injection of lead oxide and gelatin solution, and PQM and neurovascular pedicle were dissected (n = 14). In the anatomical study Part B, isolated limbs of embalmed human cadavers (n = 12) were injected with India ink-gelatin mixture and PQ were dissected.Results PQ is a type II muscle flap, with one major pedicle, the anterior interosseous (AI) vessels and two minor pedicles from the radial and ulnar vessels. The mean dimensions of the muscle were 5.5 × 5.0 × 1.0 cm3, mean pedicle length was 9.6 cm, and the mean diameter of the artery and the vein was 2.3 mm and 2.8 mm, respectively. The dorsal cutaneous perforating branch (DPB) of the artery supplied the skin over the dorsal forearm and wrist. This branch also anastomosed with the 1, 2 intercompartmental supraretinacular artery (ICSRA). Conclusion This study confirms the potential utility and vascular basis of the PQM flap and its associated cutaneous paddle.In the clinical part, two patients with nonhealing wounds exposing the median nerve and flexor tendons in the distal forearm were treated using the PQM flap with good results.

Do We Need to Suture the Pronator Quadratus Muscle When We do Open Reduction and Internal Fixation for Fracture of the Distal Radius

Background: For fracture of the distal radius, open reduction and internal fixation are often used for treatment. In the process of open reduction and internal fixation, it is often necessary to open the pronator quadratus muscle to achieve sufficient exposure. So it's important to know if it's necessary to suture the pronator quadratus muscle. Purpose: To see if suturing the pronator quadratus during the treatment of fracture of the distal radius would improve limb function. Methods: 126 patients were selected for our study. These patients had open reduction and internal fixation.During the procedure, the pronator quadratus is cut open to allow the plate to be placed.Before the surgery was completed, the pronator quadratus muscles of these patients were stitched together. After the fracture healed, the patients underwent surgery to remove the internal fixation. These patients received wrist function scores prior to removal of internal fixation.The healing of the pronator quadratus was investigated during surgery. These patients were grouped according to the healing of the pronator quadratus. Functional scores were compared between the two groups Results: 23 patients were considered to have muscle healing during surgery. However, in these patients, the PQ muscles were obviously atrophic, with scar hyperplasia and fibrosis.The muscle fibers were loose and thin, and the number was reduced. At the same time, the remaining muscle fibers have different degrees of adhesion with radial carpal flexor muscles, steel plates and interosseous membrane. According to the intraoperative situation,23 patients were included in group A and 103 patients were included in group B. There were no statistically significant differences in age and fracture type between group A and group B.At the same time, there were no statistically significant differences in isokinetic forearm pronation strength and clinical outcomes including grip strength, wrist ROM, and PRWE scores between the two groups.Conclusions: this study demonstrates that whether the PQ muscle healing or not does not affect the outcomes of volar plating for distal radius fractures in terms of isokinetic forearm rotation strength, grip strength, wrist ROM, and PRWE scores.

No effect on functional outcome after repair of pronator quadratus in volar plating of distal radial fractures: a randomized clinical trial

Aims The aim of this study was to investigate the difference in functional outcome after repair and non-repair of the pronator quadratus muscle in patients undergoing surgical treatment for a distal radial fracture with volar plating. Patients and Methods A total of 72 patients with a distal radial fracture were included in this randomized clinical trial. They were allocated to have the pronator quadratus muscle repaired or not, after volar locked plating of a distal radial fracture. The patients, the assessor, the primary investigator, and the statistician were blinded to the allocation. Randomization was irreversibly performed using a web application that guaranteed a secure and tamper-free assignment. The primary outcome measure was the Patient Rated Wrist Evaluation (PRWE) after 12 months. Secondary outcomes included the Disabilities of the Arm, Shoulder and Hand (DASH) score, pronation strength, grip strength, the range of pronation and supination, complications, and the operating time. Results Of the 72 patients, 63 (87.5%) completed follow-up for the primary outcome measure: 31 (86.1%) from the non-repair group and 32 (88.9%) from the repair group. At the 12-month follow-up, the mean difference in PRWE of 5.47 (95% confidence interval (CI) -4.02 to 14.96) between the repair (mean 18.38 (95% CI 10.34 to 26.41)) and non-repair group (mean 12.90 (95% CI 7.55 to 18.25)) was not statistically significant (p = 0.253). There was a statistically significant difference between pronation strength, favouring non-repair. We found no difference in the other secondary outcomes. Conclusion We found that repairing pronator quadratus made no difference to the clinical outcome, 12 months after volar plating of a distal radial fracture. We conclude that there is no functional advantage in repairing this muscle under these circumstances and advise against it. Cite this article: Bone Joint J 2019;101-B:1498–1505