A systematic review and meta-analysis of the pronator quadratus repair following volar plating of distal radius fractures

Impact of Pronator Quadratus Muscle Tear in Distal Radius Fractures on Patient Outcomes: Analyses of 55 Patients in a Volar Locking Plate Arm of a Randomized Clinical Trial

Background The advantage of pronator quadratus (PQ) repair following internal fixation via the volar approach in distal radius fracture (DRF) surgery remains unconfirmed in the literature. The aim of this study was to compare grip strength, patient-reported outcomes, and functional results between patients with an intact PQ and those with a ruptured PQ before undergoing surgery with a volar locking plate for dorsally displaced unstable extra-articular DRFs. Methods A total of 120 patients aged 55 years and older were included in a randomized controlled trial comparing a volar locking plate with a dorsal nail plate. Of the 60 patients randomized to the volar plate group, the integrity of the PQ muscle was recorded during surgery for 55 patients, who were included in this study. The outcomes measured were the Quick Disabilities of the Arm, Shoulder, and Hand Outcome Measure (QuickDASH) score, the Patient-Rated Wrist Evaluation (PRWE) score, the EQ-5D index, the visual analog scale (VAS) score, grip strength, and range of motion (ROM). Results The median age was 67 years (range 55 to 88), and the one-year follow-up rate was 98%. Patients with an identified intact PQ (28/55) before surgical release had better QuickDASH scores after one year (2.5 vs 8.0, mean difference 5.5, 95% CI: 1.3 to 9.8, p=0.028). Patients in the intact group also had better EQ-5D Index scores after one year (0.94 vs 0.85, mean difference 0.089, 95% CI: 0.004 to 0.174, p=0.031), and demonstrated better grip strength throughout the trial; after one year: 24 kg vs 20 kg (mean difference 3.9; 95% CI: 0.3 to 7.6, p=0.016). After one year, the intact group had regained 96% of their grip strength and the nonintact group had regained 93% of their grip strength compared to the uninjured side. The observed differences may be of questionable clinical importance, as they were lower than those of previously proposed minimal clinically important differences (MCIDs). Conclusions Patients with a DRF and a ruptured PQ prior to surgery exhibited higher QuickDASH scores and lower EQ-5D index scores after one year. The integrity of the PQ should be reported in future studies.

Is pronator quadratus muscle repair required after anterior plate fixation for distal radial fractures? A prospective randomized comparative study

In this prospective, randomized comparative study in patients with distal radial fractures, we aimed to determine whether surgical repair of the superficial head after anterior locking plate fixation of the radius improves clinical or functional outcomes or both, and distal radioulnar joint stability. One hundred patients were randomized to undergo distal radial fixation with or without repair of the superficial head. Twenty-one patients were lost to follow-up, leaving a final sample of 79 patients. No differences were observed between the groups in functional scores or complication after operation. Surgical repair of the superficial head of the pronator quadratus muscle after osteosynthesis with an anterior locking plate for distal radial fractures does not appear to substantially contribute to preserving distal radioulnar joint stability or improving the consolidation process.Level of evidence: II.

Evaluation of the treatment of distal radial volar fracture by different methods sparing the pronator quadratus

OBJECTIVE

The traditional volar approach requires the release of the pronator quadratus (PQ) muscle in the treatment of distal radius fractures. However, intraoperative repair of the PQ muscle often fails due to tissue injury and unstable muscle repair. This study compared the outcomes of different methods of sparing the PQ muscle combined with the volar plate in treating distal radius fractures.

METHODS

A total of 95 patients with distal radius fractures sparing the PQ muscle were enrolled with the brachioradialis (BR) splitting approach (group A, 33 people), the volar plating insertion PQ muscle approach (group B, 35 people) and traditional Henry approach without sparing PQ muscle (group C, 27 people). Postoperative internal fixation, fracture healing and postoperative complications were observed in the three groups. The visual analog scale (VAS) of postoperative wrist pain was compared between three groups. The Dienst joint scale was used to evaluate the wrist function of patients, and imaging indexes were used to evaluate the surgical efficacy.

RESULTS

A total of 95 patients with distal radius fractures were followed up for more than one year after surgery. All fractures obtained good union, with no vascular injury, nerve injury or wound infection. Outcomes at three days, one month and three months all showed no significant differences in postoperative imaging indexes among three groups and no significant differences in various indexes among three groups during the same period. The mean operative time in group C was significantly lower than that in groups A and B. There was significant difference in the mean operation time between group A and group B. The amount of mean operative blood loss or mean bone union time in groups A and B was significantly lower than those in group C. No significant difference was shown in mean operative blood loss or mean bone union time between group A and group B. No significant differences in limb function scores, VAS scores and the mean range of motion existed among three groups at the 12-month postoperative follow-up. However, outcomes assessed one week, one month and three months after surgery demonstrated significant differences in the VAS scores and the mean range of motion among three groups, and the group B had lower VAS score and greater the mean range of motion. According to Dienst score, the excellent rate in groups A, B and C was 91.0% (30/33), 94.2% (33/35) and 85.2% (23/27), respectively, at 12 months after surgery. Tendon irritation occurred in 2 cases and joint stiffness in 1 case in group A. In group B, there were 2 cases traumatic arthritis and 2 cases delayed carpal tunnel syndrome and 1 case tendon irritation. In group C, tendon irritation and delayed carpal tunnel syndrome occurred, respectively, in 3 cases.

CONCLUSION

Our results demonstrated that these two different surgical approaches were effective ways to reserve PQ and had good clinical outcomes. The volar plating insertion PQ muscle approach could reduce early postoperative pain, promote early activity and return to normal life, while the BR splitting approach was more advantageous in intraoperative fracture exposure and could shorten the operative time. However, some defects also existed. At 12 months of follow-up, no significant advantage was seen in sparing the PQ muscle. Therefore, surgeons should be aware of their individual characteristics and choose patients carefully.

Factors influencing functioning after volar locking plate fixation of distal radius fractures: a scoping review of 148 studies

BACKGROUND AND PURPOSE

A better understanding of factors that influence functioning may improve the identification of patients with distal radius fractures (DRFs) who need hand therapy. The purpose of this scoping review was to provide a comprehensive overview of factors that have been evaluated for their influence on hand functioning following volar plate fixation of DRFs.

MATERIAL AND METHODS

6 databases were searched from 2005 to 2021 for publications regarding surgical treatment for a DRF with a volar locking plate. Included studies evaluated demographic, perioperative, and postoperative factors within the 6 weeks post-surgery for their influence on functioning at least 3 months post-surgery. Functioning was assessed with patient-reported outcome measures. The factors were categorized into themes and mapped to the International Classification of Functioning, Disability and Health (ICF).

RESULTS

148 studies were included. 708 factors were categorized into 39 themes (e.g. pain) and mapped to the ICF components. The themes were primarily mapped to "body functions and structures" (n = 26) and rarely to "activities and participation" (n = 5). Fracture type (n = 40), age (n = 38), and sex (n = 22) were the most frequently evaluated factors.

CONCLUSION

This scoping review identified an extensive number of factors evaluated within 6 weeks after surgery for their influence on functioning at least 3 months after volar plate fixation of a DRF and the existing research has primarily evaluated factors related to "body functions and structures," with limited focus on factors related to "activities and participation."

Does pronator quadratus repair affect functional outcome following volar plate fixation of distal radius fractures? A systematic review and meta-analysis

Introduction

The study aimed to evaluate the efficacy of pronator quadratus (PQ) repair versus no repair following volar plate fixation of distal radius fractures.

Methods

A comprehensive search was performed in PubMed, CNKI, EMBASE, Web of Science, Ovid, and Cochrane Library databases. All randomized controlled trials comparing PQ repair with no repair in distal radius fractures before January 2023 were included. Two investigators independently screened eligible articles, assessed the study quality, and extracted data from included studies. Continuous variables used standardized mean difference and 95% confidence interval as efficacy statistics. The meta-analysis was performed using the Revman 5.4 software.

Results

A total of 430 patients in 7 RCT studies were included in this meta-analysis, of which 218 underwent PQ repair, while 212 patients underwent no repair. The results of the meta-analysis displayed statistically significant differences in grip strength (short-term), pronation angle (short-term), and pronation strength (short- and long-term) between the two groups. No significant difference in other outcomes was found between the two treatment arms.

Discussion

The repair of PQ may further increase grip strength and pronation function in the short-term and enhance long-term pronator muscle strength compared to no repair. However, due to the small number of articles included in the study, the above conclusions need to be verified by a larger sample and multi-center clinical study.

Outcomes of the Management of Distal Radius Fractures in the Last 5 Years: A Meta-analysis of Randomized Controlled Trials

Objective  Over the last decades, volar locking plates (VLPs) have been the mainstay treatment for distal radius fractures (DRFs). With the growing body of evidence, we systematically reviewed studies on recent VLP modifications. Methods  A systematic search was performed in the PubMed/MEDLINE database for studies published in English in the past five years. The inclusion criteria were randomized controlled trials (RCTs) on the operative treatment of DRFs. We excluded ongoing trials and studies not directly addressing DRF. The primary outcomes assessed were subjective (such as the scores on the Disabilities of the Arm, Shoulder and Hand [DASH] questionnaire, the Patient-rated Wrist Evaluation [PRWE], the European Quality of Life-5 Dimensions [EQ-5D], the 36-item Short Form Health Survey [SF-36], and the Visual Analog Scale [VAS]) and objective clinical outcomes (the complication rate). Results  We identified 29 articles published from 2016 to 2020 with high quality of evidence, except for one, which had evidence of moderate quality. In total, 3,079 DRFs were analyzed in the present study. All studies except one had a greater proportion of female participants, and only in 1 study the mean age of the sample was < 40 years old. There were no significant differences between the VLP and external fixation (EF) in terms of the scores on the DASH ( p  = 0.18) and PRWE ( p  = 0.77). The VLP alone without pronator quadratus (PQ) repair yielded significantly better outcomes. Conclusion  In unstable fractures, the VLP and EF yielded comparable long-term results. There is no clear benefit of adding PQ repair to current the VLP surgical technique. Level of Evidence  Level I.

Role of Pronator Quadratus Repair in Volar Locking Plate Treatment of Distal Radius Fractures

Distal radius fractures are the most common type of upper extremity fractures, and their incidence is increasing. There has been a rise in the surgical treatment of distal radius fractures, primarily with volar locking plate fixation. Although this procedure is commonly done among orthopaedic surgeons, the role of pronator quadratus repair after fixation remains controversial. The pronator quadratus serves as a secondary forearm pronator and a dynamic stabilizer of the distal radioulnar joint. Aside from a functional role, repair of the pronator quadratus has been proposed to serve as a biologic barrier between the volar locking plate and the flexor tendons to minimize tendon irritation. In this narrative review, we discuss the current treatment trends, the surgical approach for volar locking plate treatment of distal radius fractures, and the anatomy and function of the pronator quadratus. We discuss the case for and against the repair of the pronator quadratus, both for function and prevention of flexor tendon irritation and rupture. The preponderance of high-level evidence demonstrates no benefit to pronator quadratus repair for pain relief or function. The current evidence does not conclusively support or refute pronator quadratus repair as a biologic barrier from the flexor tendons.

The intra-muscular course and distribution of the anterior interosseous nerve within pronator quadratus: An anatomical study

BACKGROUND

The anterior interosseous nerve (AIN) is a terminal motor branch of the median nerve innervating the following three muscles from proximal to distal: Flexor pollicis longus (FPL), the radial half of flexor digitorum profundus (FDP), and the pronator quadratus (PQ). The aim of this study was to define the course of the AIN within the PQ to aid surgeons performing distal radial procedures.

METHODS

Ten embalmed cadaveric forearms were dissected to identify the path of the AIN within PQ. An en-bloc excision of the PQ with its supplying AIN and vasculature was performed to identify a safe zone where PQ can be elevated without damaging AIN. A scoping literature search was performed to identify other studies reporting the path of AIN through PQ.

RESULTS

The mean distance from the radial border of the radius perpendicular to the point at which the AIN enters the PQ was 22.3 mm (range 21-24 mm). The mean distance from the distal wrist crease to the AIN entering PQ was 74.3 mm (range 59-84 mm). The mean number of nerve branches to PQ was 5.2 (range 3-8). In all specimens, the AIN was found to lie on the radial side of the anterior interosseous artery (AIA).

CONCLUSIONS

The AIN courses on the deep surface of the PQ in a longitudinal proximal to distal direction. A 'safe zone' was identified within 20 mm of the radial border of the distal radius, which may be utilised by surgeons in a muscle-splitting approach to the distal radius.

Volar plating: functional recovery of the pronator quadratus

Purpose

The pronator quadratus (PQ) is reflected in the surgical approach to the distal radius. This study explores the functional strength of PQ, 12 months after volar plating without repair of PQ.

Methods

A total of 135 patients were identified from our prospectively collected database. All volunteers had grip strength and pronation power tested in the treated and contralateral forearms at 45, 90 and 135 degrees of elbow flexion using a custom-built torque measuring device and hydraulic hand dynamometer to evaluate forearm pronation.

Results

Twenty-seven participants were included in the study. No significant difference was identified in mean peak pronation torque between the volar plated and non-treated forearms. Pronation strength was identified as being independent of angle of elbow flexion. Grip strength was correlated with forearm pronation showing no significant difference between groups.

Conclusions

Our results suggest adequate long-term (15–32 months) functional recovery of the pronator quadratus after volar plating.

Level of Evidence

III.