Correlation of Flexor Pollicis Longus Tendon Status by Ultrasonography with Plate Position on Radiographs Following Volar Plate Fixation of Distal Radius Fractures with Pronator Quadratus Repair

The use of ultrasound to predict flexor tendinopathy after anterior locking plating of the distal radius

This study compares ultrasound to clinical and radiographic measurements for assessing tendon pathology associated with distal radial anterior locking plates. A total of 46 patients undergoing removal of a distal radial plate had a preoperative clinical examination, radiographs and ultrasound evaluation to detect evidence of tendon irritation. Gross changes to the tendon were assessed during plate removal. In total, 32 patients demonstrated clinical abnormality. Soong 2 position was noted in 13 patients. Ultrasound revealed tenosynovitis in nine patients, tendon fibrillation or thickening in four patients and a single case of partial discontinuity. Intraoperative assessment revealed tenosynovitis in 28 patients and tendon fibre discontinuity in eight patients. Ultrasound findings were not predictive of intraoperative tenosynovitis and discontinuity. A relationship was noted between higher Soong grade, especially grade 2, and intraoperative presence of tenosynovitis, as well as Soong grade and amount of soft-tissue coverage. This study negates our hypothesis that ultrasound is useful for identifying tendinopathy after distal radial anterior plate fixation.Level of evidence: II.

Ultrasonographic evaluation of contact configuration between flexor pollicis longus tendon and the volar prominence of volar plate in patients with distal radius fracture

INTRODUCTION

We classified the contact configuration between the volar prominence of volar locking plate (VLP) and flexor pollicis longus (FPL) tendon using ultrasound (US) into indentation contact and smooth contact, and investigated whether the contact configuration is associated with the flexor tendon attrition.

MATERIALS AND METHODS

Ninety-four patients who underwent VLP removal were included in this study. We assessed pain using visual analogue scale, grip strength, and Disabilities of the Arm, Shoulder and Hand score for clinical evaluations, radial inclination, palmar tilt, ulnar variance, and Soong classification for radiological evaluations, and contact configuration using US at 1 year after VLP fixation. After these evaluations, we removed the VLP with observation for the presence of fibrillation or wear of FPL tendon substance. Subsequently, we classified the patients into either of FPL attrition and FPL intact group.

RESULTS

Twenty-eight patients had indentation contact configuration and 66 patients had smooth contact configuration. The kappa value for inter-observer reliability for the contact configuration was 0.78. Twelve patients were included in the FPL attrition group and 82 in the FPL intact group. There was no significant difference in clinical outcomes and Soong classification between the groups. However, palmar tilt of the flexor tendon attrition group was significantly lower than that of the flexor tendon intact group and the FPL attrition group showed significantly higher indentation contact configuration rate than the FPL intact group. FPL tendon attrition was diagnosed using the contact configuration on US with a sensitivity of 100% and specificity of 80%.

CONCLUSION

This study demonstrated that FPL tendon attrition was significantly associated with indentation contact on US with high sensitivity. Therefore, we recommend selective implant removal in patients with indentation contact configuration.

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.

Diagnostic ultrasound of tendon injuries in the setting of distal radius fractures

OBJECTIVE

Describe tendon injuries and their structural causes seen on ultrasound in wrists with distal radius fractures and estimate the accuracy of ultrasound and its impact on clinical management.

MATERIALS AND METHODS

Ultrasounds of 226 wrists (221 patients) with distal radius fractures were retrospectively reviewed. Ultrasound findings of tendon injuries and their structural causes were correlated with surgery and clinical outcome. Accuracy and inter- and intra-observer reproducibilities were calculated.

RESULTS

Twenty-five wrists were treated non-operatively while 201 underwent surgery. Ultrasound demonstrated hardware contact with flexor pollicis longus (FPL) in 76 wrists, extensor pollicis longus (EPL) in 21, and other tendons in 94. Ultrasound identified tendon ruptures in 23 wrists (13 EPL/8 FPL/2 extensor indicis proprius (EIP)), most of which were surgically confirmed. Among 12 wrists with confirmed EPL ruptures, distal radius fracture had been treated with volar plating in 6 and non-operatively in 6, and ultrasound showed osseous irregularity at the rupture site in 8. All FPL ruptures occurred in wrists with volar plating. Ultrasound findings were concordant with subsequent clinical management in most. In 2, ultrasound findings led to the decision to remove hardware despite lack of symptoms. Ultrasound had sensitivity/specificity/accuracy of 88/99/98% for identifying a specific tendon as ruptured and 88/87/88% for tendon abnormalities in general. Inter- and intra-observer reproducibilities were excellent (kappa = 0.85 ~ 1.0).

CONCLUSION

Certain wrist tendons, particularly EPL and FPL, are vulnerable after distal radius fractures. Ultrasound is accurate and useful for detecting tendon injury and sources of tendon irritation and can guide clinical management.