Quick and safe: why a k-wire-extension-block-fixation of a bony mallet finger is the favoured treatment

INTRODUCTION

Mallet fingers are the most common tendon injuries of the hand. Bony avulsion distal finger extensor tendon ruptures causing a mallet finger require special attention and management. In this monocentral study, we analyzed the clinical and individual outcomes succeeding minimal invasive k-wire extension block treatment of bony mallet fingers.

MATERIALS AND METHODS

In a retrospective study, we sent a self-designed template and a QUICK-DASH score questionnaire to all patients, who were treated because of a bony mallet finger between 2009 and 2022 and fulfilled the inclusion criteria. A total of 244 requests were sent out. 72 (29.5%) patients participated in the study. Forty-five men and twenty-seven women were included.

RESULTS

98.7% (n = 75) of the cases were successfully treated. Patients were highly satisfied with the treatment (median 8.0; SD ± 2.9; range 1.0-10.0). Based on the QUICK-DASH score, all patients showed no difficulties in daily life. The extent of avulsion did not influence the outcome.

CONCLUSION

We conclude that the minimally invasive treatment of a bony mallet finger should be offered to every patient, because it is safe, fast, and reliable. Thus, we propose to perform extension-block pinning independently of the articular area.

Comparison of extension block pinning technique versus pin orthosis-extension block pinning technique for acute mallet fractures: a prospective randomized clinical trial

INTRODUCTION

The extension block pinning technique (EBPT) is a popular surgical treatment for mallet fractures; however, it has several drawbacks. The purpose of this randomized clinical trial was to compare EBPT to the pin orthosis-extension block pinning method (PO-EBPT) in the treatment of mallet fractures involving more than one-third of the joint surface but without primary joint dislocation.

MATERIALS AND METHODS

Sixty-five patients with mallet fractures were randomized into two groups between June 2017 and January 2020: Group I (33 patients) was treated with EBPT and group II (32 patients) was treated with PO-EBPT. Five patients were lost to follow up due to lack of follow-up and death. There were no significant differences in the clinical and demographic characteristics of both groups. Patients were evaluated according to fracture union, extension lag, distal interphalangeal (DIP) joint range of motion, Crawford's criteria, and complication rates. The patients were followed-up post-operatively at 2 weeks, 6 weeks, 3 months, 6 months, 1 year, and annually thereafter.

RESULTS

A total of 60 patients were randomized into two groups: one (30 patients) was treated with EBPT and the second (30 patients) with PO-EBPT. There were no significant differences between the two groups in terms of fracture union and active DIP joint flexion (P = 0.743 and P = 0.059, respectively). The mean extension lag of the DIP joint in the EBPT group was significantly greater than the PO-EBPT group (10° ± 9.47° vs. 4.17° ± 7.2°, P = 0.009). According to the Crawford criteria, the PO-EBPT group showed significantly better outcomes (P = 0.005). The complication rates were similar between groups (P = 0.45).

CONCLUSION

In comparison to the EBPT technique, the group of patients operated with PO-EBPT had superior clinical outcomes and less loss of extension at the DIP joint according to the Crawford's criteria.

Management for Bony Mallet Thumb with a Single Extension Blocking Kirschner Wire

Introduction

Mallet finger injury is defined by disruption of the terminal extensor tendon distal-to-distal interphalangeal (DIP) joint. While in the fingers, it is a relatively common injury, it is a rarely encountered entity when involving the thumb. Various conservative and operative treatment strategies have been reported for the management of mallet thumb with no consensus by clinicians.

Case Report

We present the case of a 27-year-old right hand dominant man with a left bony mallet thumb injury that occurred while playing hurling. Hurling is traditional Irish sport that is one of the fastest field games in the world, involving the use of a wooden Hurley and ball. Clinically, there was loss of active extension at the DIP joint of the non-dominant thumb with radiographs revealing an avulsion fracture involving more than one-third of the articular surface at the base of the distal phalanx. Closed reduction and percutaneous fixation using a single extension block Kirschner wire was performed without a transfixion wire across the DIP joint. Four months postoperatively, the patient had regained that good functional dexterity was able to return to playing hurling.

Conclusion

A single K-wire technique may be beneficial with theoretical reduction of chance of iatrogenic nail bed, bone fragment rotation, chondral damage, and bone injury. To the best of our knowledge, no previous reports of its application to bony mallet thumb have been described.

The non-operative management of bony mallet injuries

Over a 4-year period, 218 mallet fractures in 211 adult patients were treated using a custom-made thermoplastic splint. Clinical results were collected prospectively, including the visual analogue score for pain, the range of motion and extensor lag, and the Patient Evaluation Measure (PEM). The joints were congruent in 168 and subluxed in 50. There were no differences in range of movement, extensor lag or PEM associated with articular subluxation or the size of the articular fragment. Pre-existing joint degeneration did not influence outcome. Non-surgical treatment demonstrates predictably good outcomes regardless of fragment size or subluxation in most patients and should be considered when discussing treatment for patients with bony mallet fractures.Level of evidence: III.

Functional outcomes and complications of hook plate for bony mallet finger: a retrospective case series study

Background

The treatment of mallet fracture using hook plate fixation was first introduced in 2007 and has subsequently shown excellent outcomes. Common complications, such as nail deformity and screw loosening, have also been reported. Very few studies have focused on these common complications or their prevention. In this study, we present the clinical outcomes and complications of our case series and describe the pitfalls and detailed solution of surgical tips to avoid common complications related to this procedure.

Methods

The retrospective case series of 16 patients with mallet fractures who underwent open reduction and hook plate fixation in our hospital from 2015 to 2020 were retrospectively reviewed. Data on extension lag, range-of-motion (ROM) of the distal interphalangeal joint (DIP) joint, the Disabilities of the Arm, Shoulder, and Hand (DASH) score, and surgical complications were collected and analysed. The clinical outcome was graded according to the Crawford mallet finger criteria.

Results

Sixteen patients were included in our analysis. The median DIP extension lag was 0° (range, 0° to 30°) and the median active DIP flexion angle was 60° (range, 40° to 90°). The median DASH score was 0 (range, 0–11.3). Fourteen patients with good and excellent results were satisfied with this treatment. The Complication rate in our patient series was 18%. Common complications reported in articles included wound necrosis, extension lag, nail deformity, and plate loosening.

Conclusions

Despite the fact that the treatment of mallet fracture with hook plate fixation has satisfactory functional outcomes, pitfalls, including iatrogenic nail germinal matrix injury, unnecessary soft tissue dissection, and insufficient screw purchase, were still reported. To avoid complications, we suggest modifications of the skin incision, soft tissue dissection, and screw position.

Clinical outcomes after mini-hook plate fixation for small avulsion fractures around the interphalangeal or metacarpophalangeal joints of the hand

BACKGROUND

Mini-hook plate has been described for the treatment of various small avulsion fragments in the hand. This retrospective study aimed to evaluate clinical outcomes after mini-hook plate fixation in patients with an avulsion fracture around the interphalangeal or metacarpophalangeal joints of the hand.

METHODS

Nineteen patients with avulsion fractures around the interphalangeal or metacarpophalangeal joints of the hand were included in this study. Seven patients had a mallet fracture, and 12 patients had other phalangeal avulsion fractures including central slip, collateral ligament, volar plate, and flexor avulsion fractures. The osseous union and functional outcomes, including finger joint motion, joint stability, pinching strength, and the disabilities of the arm, shoulder, and hand score, were evaluated.

RESULTS

The mean duration of follow-up was 33.8 months. All patients in mallet and other phalangeal avulsion fractures achieved osseous union between the avulsion fragment and phalangeal bone, and there was no joint subluxation. There were no significant differences in the disabilities of the arm, shoulder, and hand scores. However, the patients with mallet fracture have lower mean percentage values of the total active range of motion and pinching strength than other phalangeal avulsion fractures. We abandoned this procedure in mallet fractures because the early results after mini-hook plate fixation in mallet fractures appeared unfavorable.

CONCLUSION

These results suggest that the mini-hook plate fixation can provide sufficient stability and good clinical outcomes in those with phalangeal avulsion fractures. However, the outcomes for mallet fractures were not as good as those for other phalangeal avulsion fractures.

Mallet Fractures with Long Fragment Had Poor Outcomes on Extension Block Pinning

Background: Although extension block pinning for mallet fracture is popular, it occasionally results in poor outcome. We reviewed previous cases to elucidate the factors associated with poor outcome. Methods: From 2012 to 2017, 50 mallet fingers in 50 patients were consecutively repaired by extension block pinning using modified Ishiguro method. Inserted Kirschner-wires (K-wires) were removed at 6 weeks, followed by night splinting in extension. For outcome evaluation, distal interphalangeal (DIP) joint motion was measured and classified as either good or poor. Poor outcome was defined as either > 10° of extension lag or < 40° of active flexion or the presence of DIP joint pain. Associations between outcome and age, affected finger, interval to operation, fragment size (in terms of joint surface and dorsal cortex ratios), and fixation angle were evaluated. Results: 33 fingers (66%) had good outcome and 17 (34%) had poor outcome. Mean age was significantly greater in the poor (50.6 years) than in the good (40.1 years) outcome group (p < 0.05). The dorsal cortex ratio was also significantly larger in the poor than in the good outcome group (p = 0.006), but there was no significant difference between two groups in joint surface ratio. Affected finger, interval to surgery, and fixation angle also did not significantly differ between groups. Conclusions: Fracture fragments with a long dorsal cortex and older age associated with poor outcome following extension block pinning for mallet finger. The dorsal cortex ratio should be evaluated pre-operatively to determine the appropriate treatment method.

Mallet finger - A modified technique using the finger nail as a fixation point for the temporary immobilization of the distal interphalangeal joint - A biomechanical study

BACKGROUND

The aim of the current biomechanical study was to investigate a newly developed surgical technique for mallet fingers. The new method is based on the Ishiguro method which requires a K-wire through the distal interphalangeal joint for temporary fixation. The new technique avoids the joint trans fixation using a specially designed finger nail holder. This method was compared to the established Ishiguro's technique.

METHODS

For biomechanical testing, 32 paired, fresh-frozen human fingers (Digit II-V) of 4 donors (ages 60 to 71 years) were used. The paired fingers were assigned to either the new method or Ishiguro's technique. The biomechanical testing consisted of a cyclic cantilever bending (2000 cycles, 1-7N) followed by a load to failure test. The groups were evaluated for plastic deformation, stiffness, change in stiffness during cyclic loading, subluxation and failure load by analysing force-deflect data and fluoroscopic images.

FINDINGS

The nail fixation group showed significantly higher failure loads and stiffness than the trans fixation group. The values of plastic deformation were significantly lower in the nail fixation group. No differences were found in the change of stiffness. No subluxation was found in both groups.

INTERPRETATION

In the current biomechanical study, nail fixation performed at least as good as Ishiguro's trans fixation technique. The results and ease of implementation indicate that the newly developed nail fixation technique might be a useful treatment method in daily clinical practice without the need of temporary joint trans-fixation avoiding possible associated problems. To establish this method, clinical trials will be necessary.

Patient satisfaction after hook plate treatment of bony avulsion fracture of the distal phalanges

BACKGROUND

Bony avulsion fractures of the distal phalanges can result in mallet finger deformity if not treated appropriately. Therefore, only minimally displaced fractures can be treated conservatively with a good outcome, as dislocation occurs very often. Several surgical treatment options have been developed during the past decades. Data concerning the recently developed hook plate are promising. So far, no data concerning the subjective satisfaction with this method have been published. Therefore, we have analyzed the outcome after hook plate implantation using a self-assessment score, which focuses also on subjective parameters and satisfaction.

METHODS

Standardized questionnaires (self-assessment scores and SF-36 questionnaire) were sent to each patient treated with a hook plate due to fracture of the distal phalanx, type Doyle IVb and IVc. Clinical data were evaluated according to the medical record. Scores given per question range from 0 to 10, 10 is the worst and 0 the best outcome.

RESULTS

From 69 patients treated, 38 (58%) were enrolled. The whole collective (n = 38) reached a score of 39.7 ± 28.7 points, while men had slightly better results. Men (n = 24) achieved 37.3 ± 27.9 points, women (n = 14) 43.9 ± 30.7 points. Women had significantly better results when analyzed later than 12 months after surgery (52.1 ± 27.9 vs. 29.1 ± 32.8), whereas no changes could be detected in the male group (37.1 ± 29.9 vs. 37.4 ± 27.6). Overall, men were slightly more satisfied than women. Most satisfaction was found regarding pain and fine motor skills (0-0.46 points). Esthetic aspect and nail deformities (3.65 points average) led to the highest dissatisfaction. No differences in the SF 36 score could be detected.

CONCLUSIONS

The hook plate is not only a convenient method but it also results in high patient satisfaction. Nail deformities are challenging; however, with increasing experience of the surgeon they decrease. SF 36 score is not an appropriate testing tool for this problem.

The Outcomes of Extension Block Pinning and Nonsurgical Management for Mallet Fracture

PURPOSE

We aimed to compare the clinical and radiographic results of patients with a mallet fracture involving more than one-third of the articular surface, but without a high degree of distal interphalangeal (DIP) joint subluxation, treated with extension block pinning or nonsurgical management.

METHODS

Forty-nine patients with a mallet fracture involving more than one-third of the articular surface were reviewed. Twenty-six cases were treated using extension block pinning (surgery group) and 23 were treated nonsurgically (nonsurgical group). At the final follow-up, extension lag and flexion of the DIP joint of the affected digit were measured. Distal interphalangeal joint pain was rated using a visual analog scale and the overall clinical outcomes were graded using Crawford's criteria. Complications, including nail deformity and dorsal prominence, were also assessed. The rate of DIP joint subluxation and fracture fragment size were radiographically evaluated.

RESULTS

Mean extension lag and flexion of the DIP joint and mean visual analog pain scores were not significantly different in the 2 groups. Outcomes, as assessed using Crawford's criteria, were excellent in 5, good in 12, fair in 6, and poor in 3 in the surgery group, and excellent in 2, good in 11, fair in 8, and poor in 2 in the nonsurgical group. Moreover, the frequency of nail deformity or dorsal prominence was similar in the 2 groups. The rate of DIP subluxation and mean fracture fragment size were similar between the 2 groups. All the fractures had united by 3 months after injury in both groups.

CONCLUSIONS

The clinical outcomes do not significantly differ between extension block pinning and nonsurgical management for mallet fractures involving more than one-third of the articular surface, but without high degree subluxation of the DIP joint.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Factors associated with subluxation in mallet fracture

Radiographs and medical record of all adult patients with a mallet fracture in three hospitals between 2004 and 2014 were reviewed. International Classification of Diseases, Ninth Revision (ICD-9) codes and text search in radiographic reports were used to identify all acute patients with potential mallet fractures in our institutional database. Manually checking, 392 true mallet fractures were identified among them, 78 had subluxation at the time of diagnosis and 19 had subluxation at a later time point during treatment. Fragment size, fragment displacement, and interval between injury and treatment were associated with initial and late subluxation. Subluxation was not observed when the fracture size was less than 39% of the total articular surface. For each 1% increase in total articular surface involvement in fractures with more than 39% involvement, the risk of subluxation increased by 4% and for each 1% of displacement, the risk of subluxation increased by 4%.

LEVEL OF EVIDENCE

IV.

Extension block technique for mallet fractures: a comparison of one and two dorsal pins

The aim of this study was to compare the clinical and radiological outcomes of one or two dorsal pins for extension blocking of mallet fractures. We treated 36 mallet fractures with the extension block technique. A single pin was used in 19 fractures (Group 1) and two pins in 17 fractures (Group 2). The mean age was 33.6 years and the mean follow-up time was 12.2 months. All patients were assessed by the Crawford outcome score. Extensor lag and other complications were noted. All fractures united with a mean time of 6.0 weeks (4-9) in Group 1, and 6.1 weeks (4-7) in Group 2. We obtained 74% and 71% excellent and good outcome scores in Group 1 and in Group 2, respectively. The final extension lag was 6° in Group 1, and 7° in Group 2. No difference was found between the two groups in terms of clinical outcomes, radiological values and complications.Level 3 non-randomized controlled study.

Review of Acute Traumatic Closed Mallet Finger Injuries in Adults

In adults, mallet finger is a traumatic zone I lesion of the extensor tendon with either tendon rupture or bony avulsion at the base of the distal phalanx. High-energy mechanisms of injury generally occur in young men, whereas lower energy mechanisms are observed in elderly women. The mechanism of injury is an axial load applied to a straight digit tip, which is then followed by passive extreme distal interphalangeal joint (DIPJ) hyperextension or hyperflexion. Mallet finger is diagnosed clinically, but an X-ray should always be performed. Tubiana's classification takes into account the size of the bony articular fragment and DIPJ subluxation. We propose to stage subluxated fractures as stage III if the subluxation is reducible with a splint and as stage IV if not. Left untreated, mallet finger becomes chronic and leads to a swan-neck deformity and DIPJ osteoarthritis. The goal of treatment is to restore active DIPJ extension. The results of a six- to eight-week conservative course of treatment with a DIPJ splint in slight hyperextension for tendon lesions or straight for bony avulsions depends on patient compliance. Surgical treatments vary in terms of the approach, the reduction technique, and the means of fixation. The risks involved are stiffness, septic arthritis, and osteoarthritis. Given the lack of consensus regarding indications for treatment, we propose to treat all cases of mallet finger with a dorsal glued splint except for stage IV mallet finger, which we treat with extra-articular pinning.

The risk factors associated with subluxation of the distal interphalangeal joint in mallet fracture

Surgical fixation is recommended when a mallet fracture involves more than one-third of the articular surface of the distal phalanx. This recommendation originates from the idea that involvement of more than one-third of the base of the distal phalanx causes subluxation of the distal interphalangeal (DIP) joint. Eighty-six fingers of 85 patients with a mallet fracture involving more than one-third of the articular surface of the distal phalanx were enrolled in this study. Patients were allocated on the basis of subluxation of the DIP joint into a group with no subluxation or a group with subluxation. These two groups were compared with respect to age, sex, fracture size, fracture displacement, time to finger immobilizer application, and initial extensor lag of the DIP joint. Backward stepwise multiple logistic regression analysis was performed to identify the risk factors of DIP joint subluxation, and receiver operating curve analysis was used to calculate the optimal cut-off point for the risk factors. Half of our patients with a mallet fracture involving > one-third of the articular surface of the distal phalanx showed subluxation of the DIP joint. A significant intergroup difference was found for fracture size and time to application of a finger immobilizer, but no significant difference was observed for other parameters. The risk factors of DIP joint subluxation were fracture size and time to application of finger immobilizer. The optimal cut-off values for the development of DIP joint subluxation were 48% for the fracture size and 12.5 days for time to finger immobilizer application.

The Meniscus Arrow® as a fixation device for the treatment of mallet fractures: results of 50 cases

BACKGROUND

The treatment of mallet fractures is a controversial and challenging problem. Generally, mallet fractures are treated conservatively except those involving more than one third of the base of the distal phalanx. Many different surgical fixation techniques have been published. This paper describes a new fixation procedure using ultimate bioresorbable meniscal fixation nails (Meniscus Arrows®).

METHODS

Mallet fractures in 50 digits of 49 patients were fixed with this nail in an outpatient surgical procedure, mostly under local (Oberst-block) anaesthesia. The average operation time was 21 min.

RESULTS

According to the Crawford criteria, patient outcome was graded as excellent in 48 %, good in 22 %, and fair in 28 %. In one patient, the outcome was graded as poor, but the fracture was in a pre-existent arthritic joint. All fractures were consolidated without recurrent dislocation. Complications included one wound infection, which was successfully treated with antibiotics and without further consequences. No nail deformities occurred. Two times, the nail spontaneously and gradually dislocated during intensive use of the hand after, respectively, 3 and 6 months and could easily be removed under local anaesthesia without any functional sequelae.

CONCLUSION

The bioresorbable meniscal nail fixation technique provides a fast and successful surgical treatment for mallet fractures with a minimum of adverse events.

Transtendinous wiring of mallet finger fractures presenting late

PURPOSE

To determine if transtendinous wiring was an effective late treatment for bony mallet injuries.

METHODS

Between 2005 and 2011, 19 consecutive patients (13 men, 6 women) with a mean age of 29 years (range, 13-52 y) were treated late for mallet finger fractures. The mean interval from injury to initial operation was 57 days (range, 28-141 d).

RESULTS

Fifteen of 18 mallet fractures demonstrated evidence of radiographic healing after an average of 6 weeks (range, 5-10 wk). One patient developed ankylosis, and 3 patients failed to achieve bone union at the final follow-up. The mean motion of the distal interphalangeal joint was 73° (range, 35°-95°), and the mean extension lag was 7° (range, 0°-25°).

CONCLUSIONS

Transtendinous wiring was an effective late treatment for mallet fractures, demonstrating satisfactory fixation, allowing early mobilization, and showing good functional results while avoiding salvage operations.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

A prospective randomized controlled trial comparing night splinting with no splinting after treatment of mallet finger

BACKGROUND

The effectiveness of night splinting after treatment of mallet finger is unknown. We tested the hypothesis that there is no difference in extensor lag between patients with mallet finger that wear a night splint for an additional month after 6 to 8 weeks of continuous splinting and patients that do not wear a night splint.

METHODS

Fifty-one patients were enrolled in this randomized controlled trial. At enrollment, range of motion was measured for the injured and contralateral uninjured finger. The follow-up was conducted approximately 4 weeks later in person (41 patients) or by phone (10 patients). Analysis was by intention to treat.

RESULTS

There were no significant differences in final extensor lag between patients that did and did not receive a night splint. Among the 41 patients with a final in-person evaluation, the final average extensor lag was 14°, and 34 % (14 of 41 patients) had a lag of 20° or greater. Final extensor lag correlated significantly with age, enrollment distal interphalangeal joint (DIP) flexion and extensor lag, and final DIP flexion, with the latter two accounting for 28 % of the variation in final lag in the final multivariable model (p < 0.001). There were no differences in disability (p = 0.67) or treatment satisfaction (p = 0.48) between patients that did and did not use night splints.

CONCLUSIONS

Supplemental night splinting does not improve the outcome of mallet finger in terms of extensor lag, disability, or satisfaction with treatment. Patients with worse initial extensor lags should expect worse final lags; residual lags of 20° or greater are commonplace.

Closed Extension-Block Pinning for Management of Mallet Fracture - A Case Report Based Description

INTRODUCTION

Close reduction by extension-block K-wire fixation for acute mallet fracture is based on two sound orthopedic principles - stable arc splinting and early protected motion. Distal interphalangeal joint splinting is still the technique commonly used for mallet fractures with significant morbidity and only moderate functional outcome.

CASE REPORT

We have demonstrated here Ishiguro's technique in a partially treated 2 weeks old mallet fracture with the flexion deformity at distal interphalangeal (DIP) joint after proper preoperative assessment. Peroperatively, proper anatomical localization of mallet fragment was done under fluoroscopy. Reduction of the avulsion fracture was done by extension block K-wire and intra-articular K-wire was inserted subsequently to hold the reduction in place and DIP joint in extension. Later on K-wires were removed at the end of 6 weeks follow up. Patient was subjected to the physiotherapy during the course of the treatment. Excellent functional outcome was noted at the end of three months.

CONCLUSION

Closed Extension block pinning can give acceptable functional outcome even in delayed mallet finger injuries. Full range of movement at the affected joint is an important pre-requisite for the same.

Is the use of biodegradable devices in the operative treatment of avulsion fractures of fingers, the so-called mallet finger advantageous? A feasibility study with meniscus arrows

Purpose:

Treatment of Mallet fingers or fractures remains a controversial topic. No evident preference can be distilled from the reports of the clinical results obtained by conservative treatment with splints and internal fixation. If operative treatment is indicated, several techniques can be used. However, each technique has disadvantages like the risk of comminution of the fragment, the risk of infection and necrosis, a demanding operative technique and-or the necessity of removing the metallic devices. This can be avoided by the use of biodegradable devices. The purpose of this feasibility study was to evaluate the outcome of internal fixation of a Mallet fracture with a biodegradable device, the Meniscus Arrow^®.

Methods:

We treated nine consecutive patients with a Mallet fracture by fixation of the fragment with a biodegradable Meniscus Arrow^®, at this moment the smallest device available, with an average operation time of 14 minutes.

Results:

Postoperatively, no complications were found. All patients were satisfied by the results after surgery, with a restored range of motion in the distal interphalangeal joint as previously and good alignment with full consolidation of all fractures at radiological evaluation.

Conclusions:

The operative treatment of bony mallet fingers with the Meniscus Arrow^® is a fast procedure without complications in our prospective series of nine patients and without the need of a second operation to remove the implant.