Closed mallet thumb injury: a review of the literature and case study of the use of magnetic resonance imaging in deciding treatment

Etiology of Traumatic Causes of Extensor Pollicis Longus Tendon Rupture: A Systematic Review

Introduction

The extensor pollicis longus (EPL) is a muscle that follows a complex anatomical course in the hand to allow for thumb extension. Almost all manual activities require the use of the EPL; therefore, when ruptured it can be very disabling for patients. The etiologies behind traumatic EPL rupture were mostly attributed to distal radius fracture in the literature. However, EPL rupture remains uncommon, and other traumatic etiologies exist. Therefore, this systematic review aimed to provide a holistic view of the traumatic etiologies behind the EPL rupture and fill the global lack of knowledge regarding this rare injury.

Materials and Methods

We searched among Cochrane Central Register of Controlled Trials (CENTRAL) Embase, Medline, and Cochrane Database of systematic review register databases via Ovid, with no restriction on the date, including studies containing data about the etiology of traumatic causes of EPL tendon rupture with available full text, and excluding non-English and animal studies.

Results

A total of 37 articles with 371 cases constituted the basis of this review. We classified the etiology of the EPL rupture into three groups according to the affected anatomical structure that caused the EPL rupture (fracture-related, soft tissue-related, and mallet thumb).

Conclusion

Distal radius fractures remain the most common cause of EPL rupture; however, other causes, such as lacerations, blunt trauma, and direct cuts to the EPL tendon, should be considered.

The Role of High Frequency Ultrasonography in Diagnosis of Acute Closed Mallet Finger Injury

To evaluate the role of high frequency ultrasonography in diagnosis of acute closed mallet finger injury. 36 patients diagnosed with mallet finger were included in this study. All patients underwent ultrasonography, magnetic resonance imaging(MRI) and X-ray examinations. A new kind of classification of acute mallet finger injury based on ultrasonography findings was described. The difference in terms of extensor tendon injury and bony fragment identification ability among the three types of examinations were described respectively. Either an injury of extensor digital tendon or an avulsion fracture of distal phalangeal base was identified clearly on ultrasonography. Among the 36 cases, avulsion fracture of the distal phalangeal base was found without extensor tendon rupture in Type A, complete rupture of the extensor tendon was found without avulsion fracture in Type B, and contusion of the extensor tendon was found in Type C. Compared with X-ray, ultrasonography and MRI could show the extensor tendon injury clearly. While compared with MRI, ultrasonography and X-ray was more sensitive in showing bony fragment. High frequency ultrasonography could be an accurate, reliable, and non-invasive diagnostic imaging method in diagnosis of acute close mallet finger injury.

Closed mallet thumb injury treated surgically: a case report

In this report a case of closed mallet thumb injury is described, which was diagnosed clinically and indication for surgical treatment was confirmed with ultrasound examination. The EPL-tendon was successfully reconstructed with an excellent result. We propose a mandatory ultrasound examination of all closed mallet thumb injuries.

Mallet Fractures of the Thumb Compared With Mallet Fractures of the Fingers

BACKGROUND

The purpose of this study was to look for differences in mechanism, radiographic findings, and treatment between mallet fractures of the thumb and mallet fractures of the index through small fingers.

METHODS

This retrospective study included 24 mallet fractures of the thumb and 392 mallet fractures of other digits. We compared demographics, injury factors (side, dominant hand, time between injury and first visit, and injury mechanism), subluxation, fragment size, treatment, and time from injury to final evaluation between the 2 groups.

RESULTS

Mallet fractures of the thumb presented for treatment sooner after injury (2.9 vs 13 days on average), had less fragment displacement (27% vs 33%), and less articular involvement (39% vs 46% on average). None of the mallet fractures of the thumb had radiographic evidence of subluxation, whereas 25% of mallet fractures of other fingers had initial or later subluxation.

CONCLUSIONS

Mallet fractures of the thumb are not likely to subluxate.

Crescentic Osteotomy for Revision Hallux Interphalangeal Joint Arthrodesis

Treatment for rigid mallet toe deformity of the hallux has commonly consisted of arthrodesis of this interphalangeal joint. However, such procedure is not without complications resulting in operative revision. We report on a case of considerable deformity of the distal phalanx of the hallux following hallux interphalangeal joint arthrodesis that underwent revision using a unique crescentic osteotomy technique.

LEVELS OF EVIDENCE

Level V: Case report/Technique.

Closed mallet thumb injury: Our experience of 10 patients treated with surgery and a systematic review

OBJECTIVE

This retrospective study reports 10 patients with closed mallet thumb injury treated with surgery and compares the clinical outcomes achieved with those of previously described patients who were treated with either conservative therapy or surgery.

METHODS

We report the outcomes of a series of 10 patients who received surgical treatment at our institutions. Due to the rarity of closed mallet thumb, a systematic review was conducted, and the results of a literature search were compared with our case series to strengthen our conclusions. The previously described patients were categorized into two groups: the surgically treated group (16 patients) and the conservatively treated group (10 patients). The following patient and injury characteristics were documented: age, gender, injured side, time from injury to treatment, mechanism of injury, extension lag at first visit, postoperative range of motion (ROM) of the interphalangeal joint, immobilization period, and follow-up period.

RESULTS

Statistical analyses showed no significant differences in the clinical results, except for shorter immobilization periods between our series and the previously described patients involving conservative treatment (4.9 ± 0.9 vs. 9.5 ± 2.3 weeks, respectively; P = 0.0053).

CONCLUSIONS

This study suggests that surgery may result in more rapid recovery.

Peak load resistance of the JuggerKnot™ soft anchor technique compared with other common fixation techniques for large mallet finger fractures

INTRODUCTION

To identify the strongest peak load resistance among four mallet finger fracture fixation methods (Kirschner wire, pull-out wire, tension-band wiring and the JuggerKnot™ (Biomet) soft anchor fixation).

METHODS

Fixation techniques were assigned among 24 specimens from six cadaveric human hands in a randomized block fashion. Peak load resistance was tested at 30°, 45° and 60° of flexion of the distal interphalangeal joint.

RESULTS

The mean peak load of tension-band wiring was 67.8 N at 60° of flexion which was most superior. The JuggerKnot™ fixation had mean peak loads of 13.35 N (30°), 22.51 N (45°) and 32.96 N (60°). No complications of implant failure or fragmentation of the dorsal fragment was noted.

CONCLUSIONS

Tension-band wiring was the strongest fixation method but was most prominent on the skin surface as seen in three specimens. The JuggerKnot™ soft anchor fixation had similar peak load resistance as k-wire fixation and pull-out wiring.

Bony mallet thumb

Unlike mallet finger, mallet thumb is rare. We treated a case of mallet thumb with avulsion fracture using extension block Kirchner wire technique, and achieved excellent results.