Ultrasonographic movement of the flexor pollicis longus tendon before and after removal of a volar plate for the distal radius fracture

Analysis of risk factors associated with flexor pollicis longus injury after volar plating of distal radius fractures

Objective

This study was performed to analyze the risk factors associated with flexor pollicis longus (FPL) attrition or rupture after volar plating of distal radius fractures.

Methods

Three hundred thirty-eight patients with distal radius fractures were included in this retrospective study. Univariate analysis and multivariate logistic regression analysis were performed to predict risk factors.

Results

Univariate analysis showed that sex, volar tilt, the Soong grade, the plate-to-critical line distance (PCLD), the plate-to-volar rim distance (PVRD), and the time of plate removal were significantly associated with FPL attrition or rupture. Multivariate logistic regression analysis demonstrated that decreased volar tilt, Soong grade 2, PCLD of >2 mm, PVRD of <3 mm, and plate removal at ≥1 year were the risk factors significantly associated with FPL attrition or rupture.

Conclusions

Reduced volar tilt, Soong grade 2, PCLD of >2 mm, and PVRD of <3 mm appear to be risk factors that are significantly associated with FPL attrition or rupture. The findings of this study also suggest that the risk of tendon rupture is lower if a Soong grade 2 plate is removed, the PCLD is >2 mm, the PVRD is <3 mm, or reduced volar tilt is achieved earlier (at <1 year).

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

BACKGROUND

Purpose was to correlate flexor pollicis longus tendon (FPL) attrition using Ultrasonography with plate position on radiographs following volar locked compression plate fixation (LCP) in patients who have undergone pronator quadratus (PQ) repair for distal radius fractures.

METHODS

Status of flexor pollicis longus tendon was analyzed by ultrasonography in patients who underwent volar locked compression plating with pronator quadratus repair at a minimum of one year follow up. Soong's criteria was used to assess the plate position and then correlated the ultrasonography findings of flexor pollicis longus.

RESULTS

There were 33 patients included in our study, of which 15 belonged to Soong's grade zero, 10 were grade one and eight were grade two. Flexor pollicis longus attrition was noted in all cases with grade two plating.

CONCLUSION

Pronator quadratus repair may not prevent attritional changes in higher grades of Soong's, hence follow up may be required in these patients to identify attritional changes and early implant removal to prevent complications.

Clinical and ultrasonographical follow-up after standard removal of distal radius volar plates positioned distal to the watershed line

Marginal fracture types of the distal radius may require volar plate positioning distal to the watershed line. Subsequently, plate prominence with direct friction with the flexor tendons occurs which is associated with flexor tendon pathology. Standard plate removal can be proposed. This cohort study examined clinical outcome, patient satisfaction and ultrasonographical assessment of the relation of the flexor pollicis longus (FPL) and the volar rim after standard plate removal. Twenty patients with volar plate prominence after osteosynthesis for distal radius fractures were included. Plate removal was performed at least 4 months after initial surgery. The mean age was 60 years (range 39-84). The average delay from hardware removal to assessment was 2.9 years (range 1.0-5.0 years). Mean flexion, extension and radial deviation were significantly decreased (p < 0.05) compared to the contralateral side, while ulnar deviation, pro- and supination and grip strength were not. Mean QuickDASH score was 21.5. 85% of patients described their result as good to excellent. 80% would undergo the intervention again. During ultrasonography, distance from FPL to volar rim remained significantly decreased compared to the uninjured side in neutral and flexed position (p < 0.05) despite plate removal. The largest distance between the FPL and the volar cortical bone, which is mainly occupied by the pronator quadratus, did not differ. In this study, the range of motion and FPL distance to the distal radius normalized only partially compared to the uninjured wrist after standard plate removal.

Positioning of a Volar Locking Plate with a Central Flexor Pollicis Longus Tendon Notch in Distal Radius Fractures

Background  Volar locking plates with a central notch were designed to reduce the risk of flexor pollicis longus (FPL) tendon irritation after volar plating for distal radius fractures. Objective  The purpose of this study was to evaluate the course of the FPL tendon after FPL-plate osteosynthesis to identify a plate position that avoids an impingement with the FPL tendon. Patients and Methods  Nineteen patients treated with volar plating using an FPL plate for a distal radius fracture were evaluated. Transverse ultrasound images were used to assess whether the profile of the FPL tendon lied within the plate notch. The position of the FPL tendon on transverse ultrasound images was transferred onto postoperative dorsovolar X-ray images to define an FPL tendon corridor for a plate position not interfering with the FPL tendon. Results  The FPL tendon was aligned inside the plate notch completely in three cases, partially in 11 cases, and missed the notch in five cases. An FPL corridor was defined at the level of the watershed line with all FPL tendons being completely (74%) or partially (26%) aligned inside that corridor. There was a moderate correlation between the plate notch being positioned inside this corridor and the FPL tendon being positioned inside the plate notch ( r  = 0.49; p  = 0.033). Conclusion  It seems advantageous to place the plate notch within a corridor parallel to the radial shaft between the ulnar edge of the scaphoid tubercle and the scapholunate interval for the FPL tendon protection. Level of Evidence  This is Level IV study.

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.

Anatomical-positional relationship between the bone structure of the distal radius and flexor pollicis longus tendon using ultrasonography

PURPOSE

In this study, using an ultrasonography, we investigated the positional relationship between the volar bone cortex of distal radius and flexor pollicis longus (FPL) tendon in the distal radius of healthy subjects.

METHODS

The subjects were 32 healthy volunteers (56 wrists) (Age 32.9 ± 8.5, 16 males and 16 females). Their wrists were imaged by an ultrasonography. The distances between the watershed line (WS) and FPL (A), between the distal margin of pronator quadratus (DMPQ) and FPL (B), between the FPL and volar radial bone cortex at the maximum muscle belly of the PQ muscle right below the sliding region of the FPL tendon (C), and between the WS and DMPQ (D) were measured.

RESULTS

All these parameters showed a normal distribution. When the correlation among the parameters was investigated, a correlation with an index of the physique, BMI, was noted in A (P < 0.01), B (P < 0.01), and C (P < 0.01), but no correlation was noted only in D (P = 0.59).

CONCLUSIONS

Our results were suggested that when distal radius fracture is treated with a distal plate placement, the appropriate placement can be achieved by applying about 3 mm additional dissection of soft tissue on the volar bone cortex distal to the DMPQ.