The Relationship of Volar Plate Position and Flexor Tendon Rupture: Should We Question the Validity of the Soong Classification?

Complications of operatively treated distal radial fractures

Distal radial fractures represent the most common fractures of the upper extremity. Operative treatment is performed for approximately one-third of distal radial fractures in the adult population. Complications following operative treatment of distal radial fractures vary depending on the treatment modality and can be stratified into preoperative and postoperative complications. Complications can occur in the near, intermediate and long term. The most common complications seen are tendon irritation and rupture, chronic regional pain syndrome (CRPS), carpal tunnel syndrome, ulnar or radial neuropathy, compartment syndrome, malunion, inadequate fixation or loss of fixation, symptomatic hardware, post-traumatic arthritis, stiffness and infection. Careful planning, treatment and patient selection can help to mitigate these complications.Level of evidence: V.

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.

Higher Soong grade predicts flexor tendon issues after volar plating of distal radius fractures - a retrospective cohort study

BACKGROUND AND PURPOSE

Soong classification is used to estimate volar locking plate prominence and evaluate the risk for flexor tendon ruptures after surgical treatment of distal radius fractures (DRFs). However, the scientific community has questioned the Soong classification due to lacking evidence. Therefore, this study aimed to evaluate the accuracy of Soong grading as a predictor for flexor tendon issues and plate removal.

PATIENTS AND METHODS

We performed a retrospective single-center review of adult distal radius fracture patients treated with a volar locking plate between 2009 and 2019. In total, 2779 patients were included in the study. The primary outcome was a flexor tendon issue (flexor tendon rupture, tendinitis, or flexor irritation), whereas plate removal was a secondary outcome. Using Soong grade 0 as a reference, we used univariable and multivariable logistic regression to calculate odds ratios (OR) with 95% confidence intervals (CI) for flexor tendon issues and plate removal.

RESULTS

In total, 756 (27%) patients were graded as Soong 0, 1679 (60%) Soong 1, and 344 (12%) Soong 2, respectively. There were 32 (1.2%) patients with flexor tendon issues, of which 4 were flexor tendon ruptures, 8 tendinitises, and 20 flexor irritations. The adjusted OR for flexor tendon issues was 4.4 (CI 1.1-39.7) for Soong grade 1 and 9.7 (CI 2.2-91.1) for Soong grade 2. The plate was removed from 167 (6.0%) patients. Soong grade 1 had a univariable OR of 1.8 (CI 1.2-2.8) for plate removal, and Soong grade 2 had an OR of 3.5. (CI 2.1-5.8), respectively.

CONCLUSION

Flexor tendon ruptures are rare complications after the volar plating of DRFs. A higher Soong grade is a risk factor for flexor tendon issues and plate removal.

TRIAL REGISTRATION

The trial was retrospectively registered.

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.

The Interobserver Reliability of Grading of Distal Radius Volar Plate Prominence

PURPOSE

The 3-category rating of volar plate prominence in relation to the most volar edge of the distal radius (the watershed line) on lateral radiographs was reliable among a small group of surgeons and associated with the probability of flexor tendon irritation and potential rupture. Classifications are often less reliable when tested among a large group of practicing surgeons in different environments.

METHODS

In this survey-based experiment, an international group of 115 fracture and upper extremity surgeons viewed 1 of 4 sets of 24 lateral radiographs (96 unique lateral radiographs) of patients with distal radius fractures who underwent volar plating in the practice of a single surgeon using 2 types of plates. Surgeons were asked to rate the following metrics: (1) the grade of plate prominence according to Soong, (2) whether the plate was more prominent than the watershed line, (3) whether the plate was separate from the bone distally, and (4) whether there is more than 5° of dorsal angulation of the distal radius articular surface.

RESULTS

The interobserver agreement of the classification was "fair" (κ = 0.32; 95% confidence interval [CI] = 0.27-0.36), and grading was more reliable among surgeons who do not supervise trainees. Volar prominence was less reliable (κ = 0.034; 95% CI = 0.013-0.055) than plate separation from bone (κ = 0.50; 95% CI = 0.42-0.59) and more than 5° of dorsal angulation (κ = 0.42; 95% CI = 0.35-0.48).

CONCLUSIONS

Among a large number of international practicing surgeons, the classification of volar plate prominence in 3 categories was fair.

CLINICAL RELEVANCE

The diagnosis of plate prominence might develop toward criteria with moderate reliability, such as separation of the plate from the bone and residual angulation of the distal radius.

Evaluation of the Coronal Malposition of the Volar Locking Plate in the Treatment of Distal Radius Fractures

Background and objectives: Literature does not show any studies regarding plate placement problems in the coronal plane of patients with volar plating due to distal radius fracture diagnosis. We aimed to investigate the functional and laboratory results of the coronal malposition of the volar locking plate in patients with distal radius fracture treated with internal fixation.

Methods: In this retrospective study, we included patients who had volar plate fixation, were aged between 18 and 80, had no pathological fracture, had a minimum of six months of follow-up, and had the same rehabilitation protocol. We consider the angle subtended on the coronal axis between the distal radius long axis and the distal radius locking plate as coronal malposition. We named the coronal malposition angle the "AYE Angle." Patients with an AYE angle of over 1 degree were evaluated under group 1. Patients with an AYE angle of 0-1 degrees were evaluated under group 2. Radiological parameters were taken from AP-Lateral X-ray views. Superficial University System of Georgia (USG) examinations were applied to detect tendon problems. The DASH and QUICK-DASH scoring systems were used for clinical evaluation. Grip strength was measured with a dynamometer in all patients. All results were compared between the two groups.

Results: Thirteen patients were female and 27 patients were male. Nineteen patients who had coronal malposition were added to group 1, while 21 patients who had no coronal malposition were added to group 2. Fifteen patients had normal USG results in group 2, while 18 patients had edema around the flexor pollicis longus (FPL) tendon as a result of USG in group 1. Statistically, a significant difference was detected between the two groups in terms of the amount of tenosynovitis around FPL (p=0.01).

A statistically significant relationship was found between USG grading and malposition grading. The study revealed that a higher rate of USG grade 2 was found in patients with malposition grade 2 (90.9%), while a higher rate of USG grade 1 (50%) was observed in patients with malposition grade 1 (p=0.01).

A statistically significant difference was not found between Soong grading and USG in terms of the level of tenosynovitis around the FPL tendon. The amount of tenosynovitis detected around the FPL tendon was 62.5% for Soong and grade 0 level, 60.7% for grade 1 level, and 50% for grade 2 level. There was no statistically significant difference between the two groups in the DASH and QUICK-DASH scoring systems (p=0.96). There was no statistically significant difference between the two groups in the grip strength (p=0.52).

Conclusion: Coronal plate position in the treatment of the distal radius fracture is important to avoid potential flexor tendon problems. The volar plate position should be adjusted properly both in the coronal and sagittal axes.

Outcomes of Flexor Pollicis Longus Reconstruction for Volar Plate Related Ruptures

Aim A rare complication following volar plate fixation of a distal radius fracture is flexor pollicis longus (FPL) rupture. This study aims primarily to analyze the radiographic features and secondly to report the patient-reported outcomes of FPL reconstruction after volar plate fixation.

Methods Ten patients were retrospectively identified and contacted for follow-up. Seven patients participated in the study and completed the numeric rating scale (NRS) for pain, patient-reported outcome measurement information system—upper extremity (PROMIS-UE), and quick disability of arm, shoulder, and hand (QuickDASH) questionnaires at a median of 3.4 years following FPL reconstruction. Soong grade was determined on preoperative radiographs.

Results Six patients were classified as Soong grade 1 and two patients had a screw or wire protruding volarly. The median time to tendon rupture was 21.6 months. At final follow-up, the median NRS pain score was 0 (range: 0–7); the median PROMIS-UE score was 47.1 (range: 25.9–61); and the median QuickDASH-score was 12.5 (range: 4.5–75).

Conclusions The outcome of FPL reconstruction after volar plate fixation is highly variable. All ruptures in our cohort occurred in patients with plate positioning classified as Soong grade 1 and occurred at up to 3 years following distal radius fixation.