Bennett Fracture

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.

Optimal Immobilization After Fixation of Bennett's Fracture: A Cadaveric Study

OBJECTIVE

Treating high-level athletes involves a balance between early and safe return to play. Various types of protective immobilization have been recommended after operatively treated Bennett's fracture. The purpose of this study was to investigate if hand-based immobilization offers protection equivalent to forearm-based immobilization.

MATERIALS AND METHODS

A cadaveric model of Bennett's fracture was created in 8 fresh-frozen, cadaveric forearms. Osteosynthesis was performed using a single headless compression screw. Three matched pairs were casted in either hand-based or forearm length, thumb spica casts, while 2 specimens remained un-casted as controls. Specimens were mounted on a custom testing apparatus. Weights were added in 6.8-kg increments until fixation failed and the fracture displaced. Fluoroscopy was performed after each trial. We used the Kruskal-Wallis non-parametric test to compare the groups. We considered P<.05 statistically significant.

RESULTS

Failure of fixation occurred at 6.8 kg in the control specimens. Fixation failed in hand-based and forearm length casts at a mean of 18.1±5.1 kg. We did not find a statistically significant difference between median values of load at failure in kilograms across control specimens and 2 immobilization categories (P=.114). All specimens in the hand-based group sustained additional wrist injuries, while no additional injuries were noted in the forearm length group.

CONCLUSION

Our study results showed that hand-based immobilization provides equivalent protection against fixation failure for operatively treated Bennett's fractures but may predispose athletes to increased risk of wrist injury compared with traditional, forearm-based casting. [Orthopedics. 2024;47(3):157-160.].

The Current Concept and Evidence-Based Practice in the Base of the First Metacarpal Bone Fracture

Repetitive instances of sudden injuries to the first metacarpal bone can affect thumb movement. These injuries typically occur after vertical impact to the thumb. The treatment for these injuries should focus on restoring the structure and biomechanics of the trapeziometacarpal joint, with surgery being recommended for optimal results. Bennett's fracture involves the bifurcation of the bone into two distinct fragments, characterized by a smaller fragment and a larger counterpart. Rolando fracture is associated with a fracture of the base of the first metacarpal bone, typically divided into three parts. An extra-articular fracture involves the metacarpal bone of the thumb. Conservative treatment outcomes have been found to be unsatisfactory when the fracture is displaced. Therefore, surgery methods such as minimally invasive surgery, open reduction, and arthroscopic surgery have been proven to be effective. Surgical techniques for bone procedures include pin fixation, direct screw fixation, indirect screw fixation, and mini-plate fixation. Additionally, the prognosis of this condition depends on the ability to restore joint mobility during rehabilitation.

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.

Intra-Articular Osteotomy for Symptomatic Bennett Fracture Malunion

Bennett's fractures are the most common fractures around the trapeziometacarpal joint but require specialized radiographs to be correctly diagnosed. If a fracture is missed at initial presentation, it may heal with an intra-articular gap, leading to joint incongruency and a painful trapeziometacarpal joint. We present a new technique to correct the intra-articular gap and restore joint congruency in the event of a symptomatic Bennett malunion with a gap of at least 2 mm. The joint is exposed through an anterolateral approach, and the malunion is marked with K-wires under fluoroscopic control. A closing wedge osteotomy with excision of the malunion site is then performed to restore joint congruency. The osteotomy is fixed with 3 interfragmentary screws, and the joint is immobilized for 2 weeks before passive mobilization is initiated. Hardware can be removed between 3 and 6 months postoperatively after consolidation of the osteotomy. We recommend this technique in active patients without trapeziometacarpal osteoarthritis who present with a painful Bennett malunion. Restoration of the joint congruency reduces pain and may prevent the development of posttraumatic osteoarthritis.

Arthroscopic Management of Bennett Fracture

Bennett fracture is the most common fracture of the thumb. Choosing the appropriate approach to fracture fixation requires a thorough knowledge of the anatomy surrounding the first carpometacarpal joint, which is necessary to prevent injury to local sensory nerves and tendons. Although no study has shown superior outcomes compared with open reduction internal fixation and fluoroscopically guided closed reduction and percutaneous pinning, arthroscopic-assisted fixation allows for debridement of the carpometacarpal joint, direct visualization of the articular surface during reduction, and has minimal morbidity and associated complications.