Asymptomatic Flexor Tendon Damages after Volar Locking Plate Fixation of Distal Radius Fractures

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.

Changes in Distance Between the Flexor Pollicis Longus Tendon and Volar Locking Plate: An Ultrasonographic Study

PURPOSE

Flexor pollicis longus rupture is a major complication after volar locking plate fixation of distal radius fractures. Although the distance between the flexor pollicis longus tendon and the plate (plate-tendon distance) measured by ultrasonography is used to predict tendon rupture risk, the timing of the ultrasonography can affect the measurements. Therefore, this study aimed to analyze the chronological change of the plate-tendon distance between the tendon and plate.

METHODS

A total of 166 wrists underwent the plate-tendon distance measurement twice or more times within 15 months after surgery. Longitudinal ultrasonography scans with the wrist in a neutral position and the thumb flexed were used to measure the plate-tendon distance. The plate-tendon distances at 0-5 months, 5-10 months, and 10-15 months after surgery were compared. A multiple linear regression analysis was performed to evaluate the influence of the interval between surgery and examination, Soong grade, and plate type on the plate-tendon distance.

RESULTS

The plate-tendon distance decreased as the interval between surgery and examination increased. The plate-tendon distance was an average of 2.0 ± 1.1 mm, 1.4 ± 0.9 mm, and 1.2 ± 0.9 mm at 0-5 months, 5-10 months, and 10-15 months after surgery, respectively. Significant differences were observed between 0-5 months and 5-10 months and between 5-10 months and 10-15 months after surgery. A multiple linear regression showed that significant predictors of the plate-tendon distance were the intervals between surgery and examination and Soong grade.

CONCLUSIONS

The plate-tendon distance decreased as the time since surgery increased. When ultrasonography is used for the assessment of tendon rupture risk, it should be considered that the plate-tendon distance decreases as the interval between the surgery and examination increases.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognosis IV.

Flexor tendon rupture after volar plating of distal radius fracture: A systematic review of the literature

Flexor tendon rupture after volar plate fixation of distal radius fracture (DRF) is rare. There is no consensus as to how to prevent them. The aim of our study was to identify the pathological mechanisms, and to establish the clinical and epidemiological profile of patients suffering from this complication. We carried out a systematic review using the PubMed, Scopus and Cochrane databases. Studies were included if they described complete or partial flexor tendon rupture following volar plate fixation of DRF. Forty-six 46 were included, for a total of 145 patients were reported: 138 from the literature, and 7 from our personal experience. Etiology was usually mechanical, by impingement with either the plate or protruding screws. Plate impingement was due to positioning beyond the watershed line, consolidation with posterior tilt, plate thickness, or low palmar cortical angle. Mean patient age was 62.4 years (range, 23-89 years). Median postoperative interval was 8 months (range, 3-120 months). Flexor pollicis longus was the most frequently injured tendon. The plate should be positioned proximally to the watershed line if possible, to ensure good initial reduction. Hardware should be removed 4 months after surgery if the plate is causing impingement according to the Soong criteria or if signs of tenosynovitis appear.

Shear Wave Elastography (SWE) Evaluation of Asymptomatic Flexor Pollicis Longus Tendon Condition After Volar Plate Fixation for Distal Radius Fracture

Objective

This study aimed to evaluate asymptomatic flexor pollicis longus (FPL) tendon condition after volar plate fixation for distal radius fracture using shear wave elastography (SWE).

Methods

We evaluated 36 distal radius fractures with shear wave elastography to evaluate the FPL tendon after volar plate fixation. Ultrasonography was used to measure the FPL distance to the volar plate in the involved wrists, and the thickness of the FPL tendon in the involved wrists was measured on SWE sonograms taken 12 months postoperatively. Measurements of the involved wrists were compared with those of the intact wrists. The radiographic parameters and Soong grade were collected to analyze the correlation between these indicators and the value of the Young’s modulus and asymptomatic tendon injury.

Results

The mean values of the Young’s modulus for involved wrist were lower than for intact wrist tendons. The values of the Young’s modulus were correlated with the FPL distance, radial inclination, and Soong grade. FPL tendons of involved wrists exhibited in the majority a yellow (intermediate) SWE signal, compared to intact wrist tendons, which exhibited a red (hard) signal in the vast majority, and there were significant differences between the involved and intact wrist.

Conclusion

FPL tendon may develop asymptomatically changes after volar locking plate fixation of distal radius fractures, which can be detected by SWE effectively. FPL distance, radial accretion, and Soong grade may be the main causes of asymptomatic FPL tendon erosion.

Incidence of Flexor Pollicis Longus Complications Following Volar Locking Plate Fixation of Distal Radius Fractures

Background: Distal radius fractures are among the most common orthopedic injuries presenting to emergency departments. The complications of distal radius open reduction and internal fixation (ORIF) range from paresthesia to tendon ruptures. The Soong grading system was designed to evaluate volar plate position to predict postoperative flexor pollicis longus (FPL) ruptures. This study evaluates post-distal radius volar fixation FPL ruptures and other postoperative complication rates relative to Soong grade, surgical training, and plate design. Methods: A retrospective chart review was conducted to assess recorded complications after distal radius ORIF. Soong grade was determined on postoperative radiographs. Other demographic features, along with the surgeon fellowship training and plate design, were noted. Analysis was performed via t test, χ² test, rank sum test, and Fisher exact test. Results: A total of 522 patients met inclusion criteria. Flexor tenosynovitis was the most commonly recorded complication (21% of total complications). No FPL ruptures were recorded. Soong grades between patients with and without complications were not significantly different. Soong grades between patients with flexor tenosynovitis and other complications were not significantly different. Flexor tenosynovitis had higher odds of occurring compared with other complications when the surgeon was hand-trained or when the plate type was designed by Acumed. These higher odds were not maintained under multivariate regression analysis. Conclusion: Lack of FPL ruptures in this large series may reflect improved plate technology and increased awareness. The association between flexor tenosynovitis and hand fellowship-trained surgeons may be associated with more complex cases being referred to specialists.

The Effect of Plate Design on the Flexor Pollicis Longus Tendon After Volar Locked Plating of Distal Radial Fractures

BACKGROUND

Injury to and rupture of the flexor pollicis longus (FPL) tendon are known complications after volar locking plate fixation for distal radial fractures. Recent investigations have demonstrated that plate positioning contributes to the risk of tendon rupture; however, the impact of plate design has yet to be established. The purpose of this study was to compare FPL tendon-to-plate distance, FPL tendon-plate contact, and sonographic changes in the FPL tendon for 2 volar locking plate designs (ADAPTIVE compared with FPL) using ultrasound examination.

METHODS

We identified patients who underwent distal radial fracture fixation by 2 fellowship-trained hand surgeons with either standard (ADAPTIVE) or FPL plates. Patients were matched by age, sex, and Soong grade. Enrolled patients returned for a research-related office visit for a clinical examination and bilateral wrist ultrasound. We measured plate-tendon distance, plate-tendon contact, sonographic changes in the FPL tendon, and postoperative radiographic parameters in the operatively treated wrist and the uninjured wrist.

RESULTS

Forty patients with Soong grade-1 or 2 plate prominence underwent bilateral wrist ultrasound examination; all of the patients had distal radial fracture fixation, 20 with the standard volar locking plate and 20 with the FPL volar locking plate. Similar proportions of patients with the FPL plate (65%) and those with the standard plate (79%) had plate-tendon contact (p = 0.48); however, the FPL volar locking plate group had significantly less of the FPL tendon in contact with the volar plate than the standard volar locking plate group at wrist extension at both 0° (p < 0.001) and 45° (p < 0.001). There was no difference (p = 0.5) in the proportion of patients with sonographic changes in the FPL tendon between the FPL volar locking plate group (25%) and the standard volar locking plate group (21%). The postoperative volar tilt was significantly lower in patients with FPL plate-tendon contact (p = 0.01) and correlated moderately with the percentage of FPL tendon-plate contact at 0° (r = -0.51; p < 0.001) and 45° (r = -0.53; p < 0.001). There were no cases of tendon rupture in the cohort.

CONCLUSIONS

We found that the FPL volar locking plate and increased volar tilt significantly reduced the plate-tendon contact area compared with the standard volar locking plate. In our asymptomatic cohort, we were unable to find a difference in sonographic changes in the FPL tendon. Further studies are needed to determine the clinical importance of decreased tendon-plate contact area seen in modified volar locking plate designs.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of Levels of Evidence.

Usefulness of CT-based measurement of volar prominence for evaluation of risk of flexor tendon injury following fixation of a distal radius fracture

BACKGROUND

Although some radiographic evaluations of the risk of flexor tendon injury following fixation of a distal radius fracture are useful, these radiographic measurements are limited because of their inability to obtain three-dimensional measurements. We hypothesized that CT-based measurements would be more sensitive indicators for risk estimation than radiography.

METHODS

We retrospectively evaluated the relationship between plate positioning and the incidence of flexor tendon symptoms based on postoperative radiographic and CT-based measurements in 99 hands that were followed up for more than 12 months. We also compared the reproducibility, diagnostic accuracy, and ability to detect the plate-bone gap between radiographic and CT-based measurements. We also assessed the correlation between the volar prominence and plate-bone gap using CT. Multivariable analysis using stepwise logistic regression was performed to identify factors independently associated with tendon rupture or irritation.

RESULTS

In single variable analysis, we found that the volar tilt was significantly smaller and the radiographic plate-to-critical line distance (PCL), CT-PCL, and CT-gap were significantly greater in the group with tendon irritation or rupture. Multivariable logistic regression analysis indicated that the CT-based measurement of the volar prominence is a significantly positive independent predictor of tendon rupture or irritation.

CONCLUSION

CT-based measurement of the volar prominence may be one of the best radiographic predictors of the risk of flexor tendon injury following fixation of a distal radius fracture regardless of the plate type and distal prominence and the extent of rotation. This measurement may assist surgeons when deciding on the need for removal of hardware to decrease the long-term risk of flexor tendon rupture.