Epidemiology and treatment of phalangeal fractures: conservative treatment is the predominant therapeutic concept

Purpose Despite the high number of patients with phalangeal fractures, evidence-based recommendations for the treatment of specific phalangeal fractures could not be concluded from the literature. The purpose of the present study was to assess current epidemiological data, classification of the fracture type, and mode of treatment. Methods This study presents a retrospective review of 261 patients with 283 phalangeal fractures ≥ 18 years of age who were treated in our level I trauma centre between 2017 and 2018. The data were obtained by the analysis of the institution’s database, and radiological examinations. Results The average age of the patients was 40.4 years (range 18–98). The ratio of male to female patients was 2.7:1. The two most typical injury mechanisms were crush injuries (33%) and falls (23%). Most phalangeal fractures occurred in the distal phalanx (P3 43%). The 4th ray (D4 29%) was most frequently affected. The P3 tuft fractures, and the middle phalanx (P2) base fractures each accounted for 25% of fracture types. A total of 74% of fractures were treated conservatively, and 26% required surgery, with Kirschner wire(s) (37%) as the preferred surgical treatment. The decision for surgical treatment correlated with the degree of angular and/or rotational deformity, intraarticular step, and sub-/luxation of specific phalangeal fractures, but not with age and gender. Conclusions Our findings demonstrated the popularity of conservative treatment of phalangeal fractures, while surgery was only required in properly selected cases. The correct definition of precise fracture pattern in addition to topography is essential to facilitate treatment decision-making.


Introduction
Phalangeal fractures are common injuries and can be complicated by deformity without sufficient treatment and stiffness due to inadequate immobilisation or overtreatment [1][2][3]. Despite the high number of patients, evidence-based recommendations for the treatment of specific phalangeal fractures could not be concluded from the literature and randomised controlled trials are prevented from being performed due to the wide range of variation in fracture patterns and the associated variables that are thought to affect treatment and outcome [4]. In this context, it is also evident that there is a lack of a comprehensive and generally accepted classification [5][6][7][8]. This study was performed to evaluate current epidemiological data, classification of the fracture type, and mode of treatment.

Patients and methods
Institutional review board approval (GN239/16) was obtained prior to initiating this retrospective study. The study included all patients ≥ 18 years of age with phalangeal fractures who were treated in our level I trauma centre over a 2-year period (2017)(2018)). An electronic ICD-10 search was conducted and 261 patients were identified. The data were collected by the analysis of the institution's database, and radiological examinations. Information 1 3 obtained included age, gender, injury mechanism, injured side, phalanx, ray, fracture type, and mode of treatment. Injury mechanism was divided into the following categories: crush injury, jam injury (axial loading to the tip of the finger), distorsion, hyperextension, fall from standing or seating height, violent assault, bicycle accident, motor vehicle accident, and other/unclear. All patients underwent standard of care imaging that included radiographs in two planes. Computed tomography (CT) imaging was used in 6% (17/283) of fractures, of which 53% (9/17) were intraarticular, and 47% (8/17) extraarticular. The phalangeal fractures were classified according to the topography using preoperative radiological imaging (Table 1) [3,9]. Stable and reducible fractures, which do not displace in a cast in the first 5-14 days after reduction, were treated nonoperatively. The indication for surgical fixation included angular and/or rotational deformity, intraarticular impression and/or step > 2 mm, and sub-/luxation. All operative patients were treated by surgeons specialised in orthopaedic trauma care. Statistical evaluation was performed using Chi-square test. Values of p < 0.05 were considered statistically significant.  Table 2).

Discussion
Age and gender are both important factors for defining the risk of sustaining phalangeal fractures [10]. Young males and elderly females are known to be most susceptible for this injury [2,10,11]. Males remain at a relatively greater risk for phalangeal fractures than females up until the age of 60 likely resulting from increased behavioural risk factors such as participation in higher risk sport and occupational activities until the age of retirement [10,12]. Females begin to show a greater risk after the age of 65 due to a longer life expectancy with exponential increase in the incidence of falls and osteoporosis [13,14]. The age and gender distribution of the present study was congruent with those published demonstrating predominantly adult male patients and a larger female proportion in the elderly population.
The two most typical injury mechanisms are direct blow and accidental fall, with a variable distribution in the different age groups [4,15]. De Jonge et al. showed that falls are responsible for most of phalangeal fractures in patients over 70 years, in contrast to another study, in which the majority of the fractures were caused by a direct, or crush injury, even in the retired population [1,15]. Our data demonstrated that adult patients sustained predominantly crush injury whereas falls occurring primarily in elderly patients consistent with the study of de Jonge et al. [1].
The ratio of right and left hands of phalangeal fractures has been reported to be 1:1 in previous studies which is similar to the present study population [14,16]. Hence, right-hand dominance does not result in higher incidence of phalangeal fractures of the right hand [14,17].
The D5, as border ray, has been shown to be most frequently affected [4,15]. However, we noticed that our ray profile differed, in which the D4 was most commonly injured confirming the theory that the incidence of phalangeal fractures is proportional to the length of the digit [18]. Congruently, most phalangeal fractures occurred in the P3 reflecting the kind of injury mechanism (crush injury) in our study population.
Few data are available in the literature regarding fracture type of phalangeal fractures [15]. Stanton et al. found that the P3 tuft and base were common sites of injury, in which intraarticular fractures were rare [15]. Our study revealed a different distribution of fracture types which were also classified according to the topography (Table 1) [3,9]. The two most frequent fracture types were P3 tuft and P2 base fractures. The most vulnerable parts of the P1 and P2 were their bases accounting for 73% of fractures. Subdividing the base, the most common fracture type of the P1 was the base fracture compared to volar avulsion in the P2. Intraarticular fractures represented a large proportion of all fractures, which could be explained, in part, by the different injury mechanism.
The majority of phalangeal fractures can be treated without an operation [2,15,19]. Our data were consistent with the conservative trend, but the percentage of fractures treated surgically was higher compared to the current literature. This could be due to the higher number of intraarticular fractures in our trauma centre, which accounted for 34% of fractures requiring surgery.
Age has been shown to be the most important variable in determining whether operative or nonoperative management is appropriate, with advanced age more predictive of nonoperative management [20]. Contrarily, in the present study, elderly patients were just as likely to get surgical treatment as adult patients due to a variety of reasons. First, the high percentage of intraarticular fractures (34%). Second, it was also due to a personal request of the elderly patients who are now more active than ever and often prefer surgical treatments that do not hamper their activities.
Kirschner wires and screw-plate fixation generally predominate in the various modes of surgical treatment [4,15,21]. Similarly, in our study, Kirschner wire(s) were required in most cases, while the proportion of locking plates was lower. The further fixation methods included suture anchor, dynamic distraction external fixator, screw(s), and mini external fixator in that order reflecting the kind of fracture pattern with a high number of intraarticular fractures in our study population. Some limitations must be considered for the present study. First, the study design was retrospective. Second, our data provided no information on outcomes. Even though this study contributes to currently available epidemiological data, the definite answer regarding appropriate algorithm for phalangeal fractures requires prospective long-term outcome studies.

Conclusion
In conclusion, our results validated the trend of conservative treatment for the vast majority of phalangeal fractures. Surgery, however, was required in properly selected cases depending on the degree of angular and/or rotational deformity, intraarticular impression and/or step, and sub-/ luxation, with the use of Kirschner wire(s) as preferred surgical treatment. The correct definition of precise fracture pattern in addition to topography is essential to facilitate clinical treatment decision-making.