The Role of Dynamic Ultrasound in the Immediate Conservative Treatment of Volar Plate Injuries of the PIP Joint: A Series of 78 Patients.

INTRODUCTION: The management of volar plate avulsion fractures in the context of a stable joint and a bony fragment of less than 30% has traditionally been conservative. This study was performed to assess volar plate healing with high-resolution ultrasound in order to provide early full mobilization.
MATERIAL AND METHODS: Between January 2012 and December 2013, 78 patients with volar plate injuries of the proximal interphalangeal (PIP) joints (42 distortions and 36 dislocations) were treated conservatively in our department for volar plate avulsion fracture associated with stable joint and bony fragment inferior to 30% of the intra-articular surface assessed both by radiography and ultrasound. Conservative treatment included extension stop splinting for the first 2 weeks and Coban bandage until 6 weeks postinjury. However, it may be possible to modify the duration of extension stop splinting based on clinical and ultrasound findings (with no additional X-ray) performed every 2 weeks for the first 3 months and then at 4 months postinjury. Only patients with residual contracture at the 4-month assessment had prolonged follow-up in order to ensure adequate dynamic splint therapy.
RESULTS: The amount of soft tissue oedema and the mobility of the volar plate were factors used to determine return to full mobilization. Mean extension-stop-splint wear was 16 ± 2 days. During the first 2 follow-up assessments, 4 patients were excluded from the study because of the instability of the PIP joint. One patient required refixation of a large fragment of 30%, 2 patients required superficial flexor tendon (FDS) tenodesis of the unstable volar plate in hyperextension and 1 other patient required arthrodesis of the PIP joint. In 51 patients, the postoperative follow-up was free of complications at 4 months. In 18 patients, flexion contracture of 20° (range 11°-40°) and oedema during follow-up required dynamic extension splints for 3 to 5 months. After this time, 5 patients had a residual contracture of 10° to 15°.
CONCLUSION: Avulsion fractures of the volar plate at the PIP joint are common. In general, they have a good outcome using the conservative treatment with extension block splints. Flexion contracture is a common complication and may be reduced by immediate splints in full extension at night and Coban bandage during the day. High-resolution sonography is a convenient tool to evaluate palmar plate stability, to assess reduction of oedema, and thus to guide safe return to full range of movement.