Distal humeral fractures (DHHF) are discontinuities that classically occur below the distal insertion of the brachialis muscle and can be extra- or intra-articular [1]. These fractures represent 2% to 6% of all fractures and nearly 30% of source humeral fractures. They occur in young individuals after high-energy trauma and in older individuals (osteoporotic) after a low-energy fall [2]. The goal of their therapeutic management is to achieve consolidation in the correct anatomical position in order to restore optimal joint function.

However, the absence of satisfactory reduction, inadequate management, or insufficient post-treatment follow-up can lead to complications. Among these complications, malunion remains one of the most feared, due to its functional, aesthetic, and sometimes progressive repercussions [3]. Malunion is defined as the healing of a fracture with one or more deformities resulting in functional consequences [4]. A lack of trained personnel, the absence of referral centers, sociocultural beliefs, and economic barriers contribute to exacerbating this situation [5].

Globally, the incidence of malunion remains variable depending on the context and quality of initial care. The literature reports rates ranging from 10% to 57% of supracondylar fractures in children [6].

In sub-Saharan Africa, the risk of malunion is higher, primarily due to limited access to specialized surgery and treatment delays, according to hospital registries [7].

In Chad, little data are available on malunion of the distal humerus. The aim of this study was to determine the profile and management of malunions of the distal extremity in the Orthopedic and Trauma Surgery Department of the National Referral University Hospital of N’Djamena.

This was a monocentric retrospective study spanning 54 months, from January 2020 to July 2024, conducted in the Orthopedic Surgery and Traumatology Department of the National Referral University Hospital of N’Djamena. It included all patients admitted to the department for post-traumatic sequelae of the upper limb. Recruitment was exhaustive.

Inclusion criteria were: all patients treated and followed up in the department for malunion of the distal humerus during the study period; those who consented to the study and whose medical records were complete. Patients treated for a lesion other than malunion and those lost to follow-up were not included in the study.

Data collection was performed using a pre-established questionnaire. Data were collected from patients’ medical records, consultation and hospitalization logs, and surgical and anesthesia reports.

For the variable data collected, patients were either seen in person or contacted by telephone.

The variables studied were:

• Sociodemographic: age, sex, residence, occupation;

• Anatomical and clinical: medical history, affected side, type of initial injury, functional signs, physical signs, circumstances of onset, injury mechanisms, immediate complications;

• Radiological: types of initial fractures, characteristics of malunion, and associated injuries;

• Therapeutic: time to treatment, type of anesthesia, positioning, surgical approach, type of immobilization, immobilization time, length of hospital stay, and postoperative care;

• Outcomes: postoperative complications, and anatomical and functional outcomes.

Patient history and the presence of a wound or scar overlying the bone lesion allowed the initial injuries to be classified as either closed or open fractures. Classification according to Gustilo and Anderson was not possible. Involvement of the joint was determined using standard radiographs and/or CT scans.

Surgery was indicated for significant angular deformity (between 10˚ and 20˚) or complex deformity involving multiple planes, as well as for significant aesthetic concerns. Following osteotomy, fixation with K-wires was preferred for children or for simple lesions in adults, whereas plate fixation was recommended for adults. Arthrolysis was performed in cases of long-standing injuries with extensive adhesions. For minimal deformities (5˚ to 10˚) that were well-tolerated functionally or for lesions with preservation of joint range of motion (Figure 1), a non-surgical approach with monitoring was adopted. Immobilization using an above-elbow splint (brachio-antebrachio-palmar) was employed when K-wire fixation was used. Functional rehabilitation began 48 hours postoperatively following the removal of the drain in cases of plate fixation; in cases of K-wire fixation, it commenced between 21 and 42 days after the removal of the plaster splint.

Figure 1. A 39-year-old patient with a malunion of the distal humerus in varus and recurvatum without major functional impairment, for whom surgical abstention was decided.

The results were assessed using the Mayo Clinic Elbow Performance Score [8]. This score evaluates four parameters: pain (45 points), range of motion (20 points), stability (10 points), and daily function (25 points), for a maximum total of 100 points. The clinical outcomes were graded as excellent (≥90 points), good (75 - 89 points), fair (60 - 74 points), or poor (<60 points).

Non-parametric tests were used to analyze the results. Comparisons of radiological parameters, joint ranges of motion, and the Mayo Clinic functional score before and after treatment (paired samples) were performed using the Wilcoxon signed-rank test. Fisher’s exact test was applied to the cross-tabulation of qualitative variables with low expected frequencies. The 95% confidence interval (CI) was calculated using the Wilson method. The threshold for statistical significance was set at p < 0.05.

The analysis was performed using SPSS version 25.0, and the statistical test used was the chi-square (chi-square) test with a significance level of 5%. The results are presented in tables, figures, and text. They are expressed as percentages and absolute values.

All ethical considerations were respected.

During the study, we collected 1705 cases of fractures, including 166 humeral fractures, representing a hospital frequency of 1.6%. Among the humeral fractures, 32 cases of malunion of the distal humerus were noted, yielding a frequency of 19.28% (95% CI: [14% - 25.95%]). Figure 2 shows the flowchart.

Figure 2. Flowchart.

The mean age of the patients at the time of fracture was 13.4 ± 8.6 years (range: 5 - 41). It was 14.5 ± 8.8 years (range: 6- 42).

The population consisted of 75% (n = 21) men and 25% (n = 7) women (male-to-female ratio of 3). Patients from rural areas represented 57.1% (n = 16) and 42.9% from urban areas (n = 12). The patients were right-sided in 89.3% (n = 25). The injury was located on the left in 20 (71.4%) patients and on the right in 8 (28.6%) others.

The etiology of the initial injuries was as follows: recreational accident (n = 14; 50%), domestic accident (n = 7; 25%), road traffic accident (n = 6; 21.4%), and fight (n = 1; 3.6%).

The mean time to admission was 11.8 ± 4.3 months (range: 3 - 26).

The fractures were closed in 96.4% (n = 27) of patients and open in 3.6% (n = 1). The location of the deformities was extra-articular (n = 23; 82.1%), intra-articular (n = 2; 7.1%), or mixed (n = 3; 10.3%). Mixed median nerve involvement was noted in one patient (3.6%).

The type of initial treatment performed was traditional (n = 17; 60.7%), inpatient (n = 7; 25%), or both traditional and inpatient (n = 4; 14.3%). Inpatient treatment was orthopedic (n = 6; 21.4%) or surgical (n = 1; 3.6%).

The types of deformities observed at admission are shown in Table 1. The treatment indications are shown in Table 2.

Table 1. Type of intake deformation.

Table 2. Therapeutic indications.

All patients received postoperative functional rehabilitation. The postoperative outcome was assessed with a mean follow-up of 32.6 ± 8.8 months (range 12 - 8).

Table 3 shows the range of motion for the elbow and for pronation-supination before and after treatment. The comparative values of radiological parameters before and after treatment are presented in Table 4. The Mayo Clinic scores at admission and after surgical treatment are listed in Table 5.

Table 3. Joint range of motion before and after treatment.

Table 4. Comparative evolution of radiological parameters before and after treatment.

(NV = Normal Values).

Table 5. Mayo Clinic functional score before and after surgery.

The frequency of malunions of the distal humerus in resource-limited countries, particularly in sub-Saharan Africa, is often related to the socioeconomic context, notably the preference for traditional treatment over conventional medicine [9][10].

We collected 28 cases of malunions of the distal humerus over 54 months. The hospital incidence of humeral malunions was 16.86% compared to fractures of this region. This finding is similar to data from other African authors [11][12]. Furthermore, Othman et al. [12] found a rate of 12%. Socioeconomic factors such as the use of traditional healers and the scarcity of specialized surgical centers in our context could explain this difference. Overall, this injury remains infrequent in the hospital population (overall hospital incidence was 1.6%).

Our results show a bimodal age distribution, with a large proportion of children (13.4 ± 8.6 years, with a range from 5 to 41 years). However, the presence of adult subjects indicates that malunion of the distal humerus is a multifactorial complication with a bimodal distribution. A Western series also reported a lower mean age in children (5.23 ± 2.45 years) [13].

In this series, the patients’ geographic origin was predominantly rural (57.1%), consistent with data from other African authors. This result is in line with that of other authors who have reported a higher figure [14]. This trend highlights the key role of sociodemographic factors in the management of fractures in Africa. Furthermore, rural populations are more susceptible to treatment delays due to limited access to specialized care. Systematic recourse to traditional therapists as a first resort was noted in the majority of cases. These factors contribute to the long consultation delays observed and significantly worsen the functional prognosis.

Regarding the types of lesions observed in this study, varus deformity was the most common (Figure 3(A), Figure 3(B) & Figure 4(A), Figure 4(B)) at 67.9%, with 46.5% of these involving an angle greater than 10˚. This high rate directly reflects the unstable nature of these lesions, but also, and perhaps more importantly, the often imperfect traditional treatment methods, which include immobilization techniques that do not adhere to basic biomechanical principles [9]. Varus deformities have been the most studied forms in the literature [6][15]. These deformities cause significant discomfort, particularly during walking, as they are poorly aligned with the pelvic morphology. Joint stiffness, on the other hand, results from prolonged immobilization of the elbow or joint fractures.

Figure 3. Standard anteroposterior and lateral radiographs of a malunion of the distal humerus in an adult; note the varus deformity on the anteroposterior image and the recurvatum deformity on the lateral image.

Figure 4. (A) (B) Standard anteroposterior and lateral radiographs of a malunion of the distal humerus in an 11-year-old child (note the varus deformity on the anteroposterior image and the recurvatum deformity on the lateral image); (C) (D) Radiographic images taken after osteoclasty and osteosynthesis using Kirschner wires in a cross configuration.

From a therapeutic standpoint, osteotomy combined with pin fixation (Figure 4(C), Figure 4(D)) and splint immobilization was the most frequently used technique (64.3%), primarily in children. Osteotomy followed by plate stabilization was often the preferred technique in adults. Other authors have reported distal osteotomy combined with pins and a splint as the technique of choice for correcting deformities in children and, under certain conditions, in adults [15][16].

In this study, mean elbow flexion increased from 97.7˚ preoperatively to 136.8˚ postoperatively, and mean extension improved from 17.7˚ (flexum) to 1.9˚. Pronation-supination stiffness was also significantly improved. This good recovery of joint mobility has been similarly observed in other studies, with recovered angular values ranging from 10˚ to 15˚ [17]-[20]. These results reflect a satisfactory recovery of the range of motion after surgical correction. The small differences noted between studies can be explained by the methods of postoperative functional rehabilitation, as well as the patients’ profiles and ages.

The patients’ functional outcomes were assessed using the Mayo Clinic score [8]. The mean score increased from 69.5% to 88.1%, with 92.8% of results being good or excellent. This rate is close to that reported by studies that mentioned 90% and 80% of excellent and good results, respectively, after treatment [18][21]. These results are consistent with systematic functional rehabilitation and a predominantly pediatric study population with good potential for joint recovery and tissue remodeling.

Statistical analysis comparing different variables before and after treatment showed a highly significant change (p < 0.05) in all the clinical and radiological parameters studied. This demonstrates the importance of surgical and postoperative management, as practiced in our center.

Furthermore, the interpretation of these results must take into account the limitations associated with the study’s retrospective nature, small sample size, and lack of a control group. A subsequent prospective study involving a larger number of patients is necessary to further investigate these lesions.

Malunion of the distal humerus remains a serious complication of fractures in this region. Its frequency is relatively low in our setting, likely due to underreporting. It affects people of all ages, with a marked predominance in children and those from rural areas. Recreational accidents are the primary cause of injury. Delayed initial treatment, incomplete reduction, and the use of traditional home-based techniques are the main contributors to functional sequelae. Treatment is primarily surgical and relies on corrective osteotomy.

Patient consent was obtained for the publication of this article. The ethical principles of the Declaration of Helsinki regarding medical research involving human subjects were adhered to, and approval was obtained from the National Referral University Hospital.

Conceptualization, Daniel Mossalbaye Adendjingue, Magloire Dingam-Nodje and Valentin Andjeffa; methodology, Daniel Mossalbaye Adendjingue; software Daniel Mossalbaye Adendjingue; validation, Rimtebaye Kimassoum, Valentin Andjeffa, and Daniel Mossalbaye Adendjingue ; formal analysis, Allamine Hassan Adoum; investigation, Adoumbaye Djimtolnan, Service Minguemadji; resources, Daniel Mossalbaye Adendjingue; data curation, Magloire Dingamnodje Magloire Dingamnodje; writing—original draft preparation, Daniel Mossalbaye Adendjingue; writing—review and editing, Daniel Mossalbaye Adendjingue; visualization, Allamine Hassan Adoum; supervision, Rimtebaye Kimassoum ; project administration, Valentin Andjeffa; funding acquisition, Adoumbaye Djimtolnan. All authors have read and agreed to the published version of the manuscript.