Bennett's fracture: Comparative study between open and closed surgical techniques

Functional and radiological outcomes of Bennett's fractures treated by Iselin's technique: About 29 cases with 6-year (2-14) follow-up

INTRODUCTION

The percutaneous pinning method described by Iselin is one of the techniques used for treating Bennett fractures at the base of the thumb metacarpal. There is little published data on the medium- and long-term outcomes of this treatment, with most studies having a mean follow-up of 4 years. The primary objective of this study was to evaluate the functional and radiological outcomes of percutaneous pinning by Iselin's method with a mean follow-up of 6 years. The secondary objective was to look for evidence of radiographic carpometacarpal (CMC) arthritis.

HYPOTHESES

1) The functional outcomes are good, and the clinical outcomes are comparable to the contralateral side. 2) While radiographic CMC arthritis may be present in the medium term, it will not interfere with work and recreational activities.

METHODS

This was a single-center, multiple-surgeon, retrospective case series. Twenty-nine patients were included who had a mean and median follow-up of 6 years (min 2, max 14). The functional outcomes (satisfaction, pain, subjective strength deficit, DASH), clinical outcomes (tip pinch, key pinch and grip strength compared to contralateral side) and the thumb's mobility (abduction angle, Kapandji score) were determined. Return to work and recreational activities were documented. CMC arthritis was assessed on lateral radiographs of the thumb in neutral position based on the Eaton-Littler classification.

RESULTS

The average patient satisfaction score was 87% (20; 100). The mean pain level was 0.7/10 (0-8) at rest and 2/10 (0-10) during effort. The subjective strength deficit was 12% ± 16. The mean DASH score was 8.8/100 (0-43). The mean tip-pinch strength in the operated thumb was significantly lower than the contralateral side (-9.3% ± 16.5), as was the mean key-pinch (-6.3% ± 16.9). Thumb abduction was significantly reduced relative to the contralateral side (-4.1° ± 5.24) as was the Kapandji score (-0.5 ± 0.81). CMC arthritis was visible on 100% of radiographs (96% were stage 1 or 2).

DISCUSSION

The surgical treatment of Bennett fractures by percutaneous pinning using the Iselin method produces satisfactory functional outcomes in the medium term, although there was a moderate loss of strength and mobility in the thumb.

LEVEL OF EVIDENCE

IV; retrospective, single-center case series.

The Safety of Volar to Dorsal Percutaneous Screw Fixation of Bennett Fracture-Dislocation - A Cadaveric Study

Background: Bennett fractures are traditionally fixed with percutaneous K-wires from dorsal to volar, or with a volar to dorsal screw via a volar open approach. While volar to dorsal screw fixation is biomechanically advantageous, an open approach requires extensive soft tissue dissection, thus increasing morbidity. This study aims to investigate the practicality and safety of Bennett fracture fixation using a percutaneous, volar to dorsal screw, particularly with regard to the median nerve and its motor branch during wire and screw insertion. Methods: Fifteen fresh frozen forearm and hand specimens were obtained from the University of Auckland human cadaver laboratory. A guidewire is placed under image intensifier from volar to dorsal with the thumb held in traction, abduction and pronation. The wire is passed through the skin volarly under image intensifier, then the median nerve is dissected from the carpal tunnel and the motor branch of the median nerve (MBMN) is dissected from its origin to where it supplies the thenar musculature. The distance between the K-wire to the MBMN is measured. Results: In 14 of 15 specimens, the wire was superficial and radial to the carpal tunnel. The mean distance to the origin of the MBMN is 6.2 mm (95% CI 4.1-8.3) with the closest specimen 1 mm away. The mean closest distance the wire gets to any part of the MBMN is 3.7 mm (95% CI 1.6-5.8); in two specimens, the wire was through the MBMN. Conclusions: Wire placement, although done under image intensifier, is subject to significant variation in exiting location. While research has shown the thenar portal in arthroscopic thumb surgery is safe, our guidewire needs to exit further ulnar to capture the Bennett fracture fragment, placing the MBMN at risk. This cadaveric study has demonstrated the proposed technique is unsafe for use.

Management of Bennett's fracture: A systematic review and meta-analysis

Background

First described in 1882, Bennett's fracture is an intra-articular fracture of the first metacarpal associated with a dislocation of the carpometacarpal joint. Usually, open reduction internal fixation is used to manage such fractures. However, closed reduction has shown good outcomes recently. This meta-analysis compares closed reduction to open reduction internal fixation in the management of Bennett's fracture.

Methods

PubMed, Cochrane, and Google Scholar (pages 1-20) were searched until August 2023. The clinical outcomes consisted of post-traumatic arthritis, grip and pinch strengths, range of motion, functional scores, and mean adduction deformity.

Results

Six retrospective studies were included in this meta-analysis. Our results show higher grip and pinch strengths, better extension and flexion of the thumb, and lower mean adduction deformity in the open reduction internal fixation group.

Conclusion

Higher grip and pinch strengths, better extension and flexion of the carpometacarpal joint, and a smaller mean adduction deformity of the thumb in the open reduction internal fixation group. No differences were seen in the remaining outcomes. However, a higher rate of complications is associated with open reduction internal fixation. Nevertheless, more randomized controlled studies are needed to confirm such results.

Level of evidence

III.

Clinical efficacy of closed reduction and percutaneous parallel K-wire interlocking fixation of first metacarpal base fracture

BACKGROUND

This study aimed to explore the clinical efficacy of treating a first metacarpal base fracture by closed reduction and percutaneous parallel K-wire interlocking fixation between the first and second metacarpals.

METHODS

Twenty patients treated by the abovementioned modified technique (modified technique group) and ten patients treated by the traditional percutaneous K-wire fixation technique (traditional technique group) from October 2015 to November 2019 at our institution were retrospectively reviewed. The patients' average age was 38 years (range, 16-61 years). The mean follow-up period was 13 months (range, 10-18 months). At the final follow-up, the functional recovery of the injured hand was assessed and compared between the modified and traditional technique groups. In addition, the functional recovery of the injured hand was compared with that of the uninjured hand within the modified technique group.

RESULTS

All patients recovered well, with no cases of infection or nonunion. Compared with the traditional technique group, the modified technique group had a shorter operative time, lower postoperative visual analogue scale pain score, better effective range of motion score of the first carpometacarpal joint (Kapandji score), and had almost no need for auxiliary plaster fixation, enabling functional exercise to be started earlier. Within the modified technique group, the mean hand grip strength, pinch strength, and Kapandji score on the injured side did not significantly differ to the values on the uninjured side in both the extra-articular and intra-articular fracture subgroups. While the abduction and flexion-extension arcs of the thumb on the injured hand were significantly smaller than those on the uninjured hand in both the extra-articular and intra-articular fracture subgroups, the patients felt clinically well with respect to daily activities and strength.

CONCLUSION

The percutaneous parallel K-wire and interlocking fixation technique is simple, effective, and economical for first metacarpal base fractures.

Bennett's Fracture Repair-Which Method Results in the Best Functional Outcome? A Retrospective Cohort Analysis and Systematic Literature Review of Patient-Reported Functional Outcomes

Surgical fixation of Bennett's fracture of the thumb is critical to prevent functional impairment; however, there is no consensus on the optimal fixation method. We performed an 11-year retrospective cohort analysis and a systematic literature review to determine long-term patient-reported outcomes following Bennett's fracture fixation. Retrospective cohort analysis identified 49 patients treated with Kirschner (K)-wire fixation, 85% returned to unrestricted movement during hand therapy. Forty-seven patients (96%) completed the disabilities of the arm, shoulder, and hand (DASH) questionnaires at a mean of 5.55 years from injury, with a mean score of 7.75. Systematic literature review identified 14 studies with a cumulative 541 patients. Fixation included open or percutaneous methods utilizing K-wires, tension band wiring, lag screws, T-Plates, external fixation, and arthroscopic screw fixation. Functional outcomes reported included DASH, quickDASH (qDASH), and visual analogue scores. Superficial wound infection occurred in 4 to 8% of percutaneous K-wire fixation. Open reduction internal fixation (ORIF) methods were associated with a 4 to 20% rate of reintervention and 5 to 28% rate of persistent paresthesia. Closed reduction with percutaneous K-wire fixation should be the first choice surgical method, given excellent, long-term functional outcomes, and low risk of complications. ORIF should be utilized where closed reduction is not achievable; however, the current evidence does not support one method of ORIF above another.

Accuracy of fluoroscopic examination in the treatment of Bennett's fracture

Background

Restoration of joint congruity is an important factor for the prevention of subsequent arthritis in patients with Bennett’s fracture. Surgical treatment of Bennett’s fracture is thus generally recommended for displaced intra-articular fractures to the proximal aspect of the thumb metacarpal. Fluoroscopic examination is used to evaluate the adequacy of closed reduction after pinning of Bennett’s fracture. The purpose of this study was to determine the accuracy of fluoroscopy to determine the reduction of Bennett’s fractures.

Methods

A model was created, to mimic a Bennett’s fracture utilizing ten fresh-frozen cadaveric hands. An oblique cut was made in the proximal aspect of the thumb metacarpal using an oscillating saw. The small oblique fragment involved 1/4–1/3 of the joint surface was then shifted in position creating a step-off or gap at the fracture site. An anatomical reduction model, gap models (1 mm, 2 mm, 3 mm), and step-off models (1 mm, 2 mm, 3 mm) were created using percutaneous fixation with two 1.0 mm Kirschner wires for each cadaveric hand. Fluoroscopic assessment then took place and was reviewed by 2 attending hand surgeons blinded to the actual position. Their estimated fluoroscopic position was then compared to the actual displacement.

Results

The step-off and gap on fluoroscopic examination showed a significant difference compared to the step-off and gap from direct visualization. The frequency of underestimation for the 3 mm displacement models from the fluoroscopic examination was 60%. The frequency for overestimated was 9% for the models in which displacement was within 2 mm (0, 1, 2 mm).

Conclusions

The assessment of articular gap and step-off using PA (postero-anterior), AP (antero-posterior), and lateral view of fluoroscopic examination is not accurate as compared to the examination by direct visualization. Surgeons need to be aware that PA, AP and lateral view of fluoroscopic examination alone may not be sufficient to judge the final position of a reduced Bennett’s fracture. Other methods such as live fluoroscopy in multiple different planes, 3-dimensional fluoroscopy or arthroscopic examination should be considered.

Surgeon level of expertise reported in Journal of Hand Surgery (American Volume) and (European Volume) publications

The purpose of the study was to evaluate the trend in documentation of surgeon level of expertise among the Journal of Hand Surgery (American Volume) and the Journal of Hand Surgery (European Volume) publications. A review of Journal of Hand Surgery (American Volume) and Journal of Hand Surgery (European Volume) databases for level of expertise between January 2015 and October 2019 was performed. Of 1042 articles identified, all 115 (20%) reporting level of expertise were published in Journal of Hand Surgery (European Volume). Since 2015, there has been an increase in reported level of expertise in Journal of Hand Surgery (European Volume) (2015: 8 (7%); 2016: 15 (13%); 2017: 22 (19%); 2018: 28 (24%); 2019: 42 (37%)). In the same period, no publications have reported level of expertise in Journal of Hand Surgery (American Volume). Documenting level of expertise may provide readers with additional information for incorporation of novel techniques into their practices. It may identify procedures that require a baseline level of expertise for effective performance. Further evaluation of level of expertise criteria may improve the reliability of the numeric scale, while widespread adoption of this scale will allow future outcome analysis by level of expertise.

Safe approach for fixation of first metacarpal fractures: an anatomical study

This anatomical study defines a safe zone for percutaneous or minimally invasive fixation of first metacarpal fractures in order to avoid injury of the superficial branch of the radial nerve and the dorsal branch of the radial artery. The courses of the nerve and artery branches were marked in 20 embalmed cadaver specimens. With computer-assisted surgical anatomy mapping, a large diversity in the anatomical patterns for the nerve and a consistent pattern for the artery were found. Based on these findings, we conclude that transfixation of the first and the second metacarpals with K-wires placed in the distal 75% of both the first and second metacarpals is the safest way to avoid damages to the nerve and artery branches during fracture fixation.