Flexor pollicis longus tendon rupture by sandwiched underlying volar locking plate and distal radius

Rupture of the Flexor Pollicis Longus Tendon Involved between the Radial Shaft and the Volar Locking Plate

We report the case of a 61-year-old woman with right-sided flexor pollicis longus (FPL) tendon ruptured a month after volar locking plate fixation. Five months after the initial operation, hardware removal and reconstruction of the FPL tendon with the ipsilateral palmaris longus were performed. The proximal stump of the ruptured FPL tendon was found in the space between the distal radius and plate.

Influence of the flexor digitorum superficialis tendon transfer on grip strength

The flexor digitorum superficialis tendon of the ring finger can be transferred to the thumb flexor. We followed ten patients after such a transfer for 5-128 months and measured grip strength and force transmission of the fingers and individual phalanges while the patients gripped 10-cm or 20-cm diameter cylinders. The grip strength of the middle, ring and little fingers was reduced when gripping the 10-cm cylinder, with a significantly larger decrease in the ring finger. With the 20-cm cylinder, grip forces of all fingers were almost identical, with slightly lower force of the ring finger and slightly higher forces in the index and small fingers. We conclude that after transfer of flexor digitorum superficialis tendon from a ring finger, grip strength of the ring finger is reduced. Finger forces are more hampered while gripping objects with smaller circumferences than large ones.

Radiocarpal joint stiffness following surgical treatment for distal radius fractures: the incidence and associated factors

Background

Postoperative radiocarpal joint stiffness (RJS) is common in patients with distal radius fractures (DRFs). The purpose of this study was to record the incidence of RJS and to determine potential risk factors that may be associated with it.

Methods

We retrospectively included a series of patients who suffered from DRFs and underwent volar plate fixation. Patients’ basic data, radiographic data, and postoperative data were collected. The incidence of RJS during follow-up was recorded, and both univariate analyses and multivariate logistic regression were used to determine factors associated with it.

Results

A total of 119 patients were included in this study. After surgical procedures, there were 42 (35.3%) patients with RJS and 77 (64.7%) patients without. The incidence of RJS after surgical treatment is 35.3%. Multivariate analysis showed that intra-articular fracture (OR, 1.43; 95% CI, 1.13–1.81), pre-operative severe swelling (OR, 1.35; 95% CI, 1.05–1.74), post-operative unsatisfied volar tile (OR, 1.38; 95% CI, 1.01–1.89), and improper rehabilitation exercise (OR, 1.72; 95% CI, 1.18–2.51) were correlated with the incidence of RJS during follow-up.

Conclusions

Patients with intra-articular fracture, pre-operative severe swelling, post-operative unsatisfied volar tile, and improper rehabilitation exercise were factors associated with the incidence of wrist stiffness. Preoperative risk notification and postoperative precautions are necessary for relevant patients.

Ultrasound Evaluation of the Protector Role of the Pronator Quadratus Suture in Volar Plating

The main complication of volar locking plates for distal radius fractures is flexor tendon rupture. The flexor pollicis longus (FPL) is the most commonly ruptured. Repair of the pronator quadratus (PQ) is one of the ways to prevent tendon rupture. The main purpose of this series was to evaluate the role of PQ repair after volar plating to prevent flexor tendon rupture using ultrasound (US). This work was a mono-operator prospective series of 20 consecutive patients with volar locking plates for distal radius fracture between September 2014 and May 2015. The PQ was repaired in all patients. A clinical, ultrasound, and perioperative evaluation of the flexor tendon was performed by this same surgeon. There was no flexor tendon rupture or tenosynovitis. There were no type A cases, which are characterized by contact between the plate and the FPL, and mostly type C cases, which are characterized by no contact between the plate and the FPL on US imaging. The suture of the PQ was sustainable over time when we removed the plate. Pronator quadratus repair is one of the ways to prevent flexor tendon rupture after volar plating. The outward-running suture is an effective technique for repairing the PQ. Ultrasound may be helpful during follow-up to detect asymptomatic flexor tendon irritation.

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.

[Basic Evaluation of the Acoustic Lens Narrow Aperture Method Devised for Improving Elevational Resolution of Ultrasonic Probe]

In general probe, the focal length in the elevational direction and resolution are fixed by the acoustic lens, so that sufficient resolution cannot be obtained in the region other than the focal point, except for special ultrasonic probes. Therefore, to improve the elevational resolution in the very shallow region, we devised the "narrow aperture method" for attaching a tape slit to an acoustic lens, and verified the method and its effect. The result of the study, for the slit, use Transpore™ tape overlaid on three layers and set the slit width to 1 mm. In addition, as a result of measurement of the slice thickness of the linear probe PLT-1204B manufactured by Canon Medical Systems, it was possible to reduce the slice thickness to a depth of 9 mm by 1 mm slit. The effectiveness of a 1 mm slit was also confirmed by probes from other companies. Moreover, it was found that the beam profile of 1 mm slit has almost the same shape even if the probe is different. The narrow aperture method of the acoustic lens can improve the elevational resolution in a very shallow region of a general ultrasonic probe.