Assessment of Pronator Quadratus Repair Integrity Using Dynamic Ultrasonography Following Volar Plate Fixation for Distal Radius Fractures

Pronator quadratus preserving versus pronator quadratus dissecting approaches in volar plate fixation of distal radius fractures: a systematic review of comparative studies

PURPOSE

To compare pronator quadratus preserving (PQ-P) approaches with PQ dissecting (PQ-D) approaches in volar plate fixation of distal radius fractures (DRFs).

METHODS

Three databases were searched on March 10th, 2024. The authors adhered to the PRISMA and R-AMSTAR guidelines and Cochrane Handbook for Systematic Reviews. Data on demographics, fracture classifications, patient reported outcome measures (PROMs), range of motion, radiographic parameters, and complications were extracted.

RESULTS

Thirteen studies with a total of 1007 fractures were included. Two of three studies reported lower DASH scores in the PQ-P group between 6 weeks and 3 months postoperative, however no studies reported lower scores in the PQ-P group after 3 months. Three of three studies reported significantly lower VAS scores at 6 weeks postoperative, however no studies reported significant differences after 6 months. Only one of six studies reported significantly greater flexion, extension, and pronation in the PQ-P group. One of four studies reported greater radial deviation in the PQ-P group, while there were no differences in supination or ulnar deviation. One of ten and one of six studies reported greater volar tilt and ulnar variance or radial length, respectively, in the PQ-P group.

CONCLUSION

There is not sufficient evidence supporting the utility of PQ-P approaches over conventional PQ-D approaches for volar plate fixation of DRFs, especially at long-term follow-ups (3+ months). There may be short term benefits with PQ-P approaches, specifically with regards to PROMs in the short-term (< 6 weeks), however there is limited high-quality evidence supporting these findings.

LEVEL OF EVIDENCE

Level III.

Pronator Quadratus Repair Does Not Affect Reoperation Rates Following Volar Locking Plate Fixation of Distal Radius Fractures

BACKGROUND

The purpose of this study was to evaluate the impact of pronator quadratus (PQ) repair on reoperation rates after distal radius open reduction internal fixation (ORIF) using a volar locking plate.

METHODS

A retrospective study of all patients undergoing distal radius ORIF with a volar locking plate between January 2012 and December 2016 at 2 urban, academic level I trauma centers was performed. Patient demographics, fracture and procedure characteristics, surgeon subspecialty, PQ repair, and reoperations were recorded. Descriptive statistics were used to determine whether patient-related or injury-related characteristics were associated with PQ repair. Bivariate and multivariable regression analyses were used to assess the effect of PQ repair on subsequent reoperations.

RESULTS

In total, 509 patients were included, including 31 patients with bilateral injuries. The average follow-up time was 3.7 ± 2.8 years. Patients undergoing PQ repair were younger (57 ± 17 years vs 61 ± 17 years) and were more likely to have a lower Soong grade (53% vs 44% with Soong grade 0) than patients without PQ repair. Pronator quadratus repair was not found to have a significant impact on hardware removal, reoperations for flexor tendon pathology, or overall reoperations.

CONCLUSIONS

Pronator quadratus repair was more commonly performed in younger patients and in patients with a lower Soong grade. Hand-subspecialized surgeons are more likely to pursue PQ repair than trauma-subspecialized surgeons. This study did not detect statistically significant differences in hardware removal, flexor tendon pathology, or overall reoperations between groups.

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.

Minimally Invasive Pronator Quadratus Sparing Approach versus Extended Flexor Carpi Radialis Approach with Pronator Quadratus Repair for Volar Plating in Distal Radial Fractures

Background  Several volar plating techniques exist to treat distal radial fractures. Question  We investigated minimally invasive plate osteosynthesis (MIPO) with pronator quadratus (PQ) sparing versus conventional flexor carpi radialis approach for volar plating with PQ repair after distal radial fractures during the first postoperative year. Patients and Methods  Prospective data of two consecutive cohorts were compared: 62 patients in MIPO group with an average age of 61.2 years and 66 patients in PQ repair group with an average age of 61.4 years completed the entire follow-up period. Results  Range of motion was not significantly different, except flexion-extension that was significantly higher in the MIPO group. Quick Disabilities of the Arm, Shoulder and Hand was significantly lower in the MIPO group. Pain visual analogue scale was only significantly lower at 6 weeks. Grip strength measurements and patient satisfaction were not significantly different. Conclusions  MIPO volar plating with PQ sparing is a surgical technique that can be chosen according to surgeon's preference and expertise, resulting in a better flexion-extension mobility and function score according to our study. Level of evidence  This is a Level 3 study.

The Pronator Quadratus Muscle After Volar Plating: Ultrasound Evaluation of Anatomical Changes Correlated to Patient-Reported Clinical Outcome

Background: Repair of the pronator quadratus (PQ) muscle with sutures has been reported durable after volar plating of distal radius fractures (DRF). It is unclear how the muscle reacts if not repaired and if a retracted muscle correlates to worse functional outcome or complications. In this study, we use ultrasound to investigate the anatomy of the PQ muscle after volar plating with PQ repair or nonrepair and correlate the ultrasound findings with patient-reported outcome. Methods: Participants were recruited from a clinical trial where they were randomly allocated to repair or nonrepair of the PQ muscle after volar plating of DRF. The participants and radiologist were blinded to group allocation. Ultrasound imaging of both fractured and contralateral wrists was performed 3 months after surgery. Ultrasound measurements included the difference in length of PQ muscle between the injured and uninjured side, retraction of PQ muscle, and tendon complications. The length and number of retractions were correlated to complications and Patient-Rated Wrist Evaluation (PRWE). Results: The mean difference of the difference in length measurements was 4.4 mm in the nonrepair group and 2.7 mm in the repair group with a mean difference between groups of 1.7 mm. This was statically significant; however, there were no clinical or statistical differences in complication rate or PRWE between the two groups. Conclusion: The PQ length was significantly shorter and the number of retractions significantly larger without repair of the PQ muscle; however, neither length nor retraction correlated significantly with complication rate or PRWE.

Pronator quadratus repair after volar plate fixation in distal radial fractures: evaluation of the clinical and functional outcome and of the protective role on the flexor tendons-a randomized controlled study

The objective was to evaluate pronator quadratus (PQ) repair following volar plating of distal radial fractures on clinical and functional outcome, as well as flexor tendon friction, during the first 12 months in ideally positioned plates (Soong 0). Confounding factors like variation in plate positioning, anatomical consolidation of the fracture and associated lesions were excluded. Eighty patients were included with distal radius fractures treated by volar locking plate in Soong grade 0 position, who were randomized to group PQ repair and group no repair. Sixty-five patients completed the 1-year follow-up: group PQ repair (n = 35) and group no repair (n = 30). Primary outcomes included range of motion, grip strength, pain level and QuickDASH. Secondary outcomes included distance between flexor pollicis longus (FPL) and volar rim and the largest distance between FPL and plate (soft tissue thickness occupied by PQ), assessed by ultrasonography. Mobility, grip strength and QuickDASH revealed no significant differences, except extension was significantly higher only in first 3 months and radial deviation was significantly higher only at 6 weeks after PQ repair. Pain level was significantly lower after PQ repair only in the first 3 months. Distance between FPL and volar rim and the largest distance between FPL and plate were significantly higher after PQ repair. No friction contact between FPL and volar rim was measured in both groups at all measurement moments. Consequently, protective flexor tendon effect of PQ repair could consequently not be concluded. In conclusion, clinical and functional short term benefits, except improved wrist extension and reduced pain in the first 3 months, were not proven in this study. In Soong grade 0, PQ repair is probably not necessary to prevent flexor tendon pathology. In Soong grade 1 or 2, this is still to be investigated. LEVEL OF EVIDENCE: 2.

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