The incidence of open distal humerus fractures is not high, but the fractures are difficult to treat, and the prognoses are very poor [30]. The fractures are difficult to treat because most of these injuries are caused by high-energy trauma, and the fractures are severely comminuted. In addition, compared with other joints, the elbow is special. It is a subcutaneous joint with thin soft tissue coverage and a complicated bone structure. If elbow injuries are not managed properly, patients will develop joint stiffness and other major complications. Even if good soft tissue treatment, anatomical reduction, and early rehabilitation have been achieved after surgery, postoperative upper limb dysfunction and related complications may still occur [31-33].
Chaudhary et al. [10] reported 8 cases of open intra-articular distal humerus fractures that were treated with open reduction and external fixation. The patients were followed up for an average of 11.4 months, they had an average ROM of 20°-120°, and 6 patients’ functional outcomes were excellent. Kömürcü et al. [34] reported 20 cases of open distal humerus fractures caused by gunshot wounds. The average follow-up duration was 34.3 months. There were 19 cases that were managed with external fixators. Regarding to MEPS, 8 cases had excellent final results, 7 cases had good results, and 4 cases had poor results. McKee et al. [5] reviewed 26 patients with open distal humerus fractures who were followed up for an average of 51 months. All the patients were treated with internal fixation after emergency debridement. The final average ROM was 97° (55°~140°), and the MEPS was 79 (52 to 100). The complications included 1 case of deep infection and 2 cases of superficial infection. The patient with deep infection had Gustilo type III fractures. Kloen et al.[16] reported 16 cases of open intra-articular distal humeral fractures with temporary joint-spanning external fixation before internal fixation. The patients were followed up for an average of 35.2 months. All fractures united at an average of 5.2 months after internal fixation. No complications specifically related to the external fixation occurred. The DASH outcome score averaged 15.1, and 10 of 16 had an excellent/good outcome score. Min et al. [14] reported 14 patients with AO/OTA type C open distal humeral fractures and 14 closed fractures. For the open group, external fixation or ORIF were performed according to the injury after debridement treatment. For the closed group, ORIF was performed within 5 days after injury. The average follow-up time was 98.9 (52-160) weeks. The flexion-extension ROM was 108±28.5° in the closed group and 82.5±32.2° in the open group; the MEPS was 84.6±19.3 in the closed group and 67.9±22.4 in the open group. These differences between groups were statistically significant (P<0.05).
These studies show that open distal humerus fractures can be treated with open reduction and internal or external fixation, and their prognoses are worse than those of closed fractures. However, previous studies have not considered the Gustilo subtypes. For Gustilo I, II and III fractures, the treatment methods and prognoses are significantly different. At present, the mainstream view is that Gustilo I and II fractures can be fixed in one surgery after debridement [4, 18-20, 35], and whether type III distal humerus fractures can be fixed in one surgery with debridement is still controversial. [36-39] Type III distal humerus fractures are mostly caused by high-energy trauma. The fractures are comminuted and accompanied by soft tissue defects, often requiring damage control surgery and multiple secondary soft tissue reconstruction treatments [40], with external fixation as the primary surgery and open reduction and internal fixation (ORIF) or external fixation as the definitive treatment [15, 16, 18]. Both treatments lead to a prolonged time of immobilization, which will result in functional loss of the involved elbow. In McKee's study, severe complications such as deep infections occurred only in Gustilo III patients, and the author did not discuss type I/II patients separately [5]. Therefore, although this study showed that ORIF can be used to treat open distal humeral fractures, for patients with Gustilo type I and II fractures, whether ORIF can provide the same clinical effect and is safe and effective is inconclusive.
In summary, the clinical prognosis and risk of complications of Types I/II and III are significantly different, and previous clinical studies did not classify patients by Gustilo classes. Therefore, this study classified patients according to Gustilo classes and compared the treatment outcomes and prognoses of Gustilo I/II open fractures and closed fractures.
A total of 64 cases of type C distal humerus fractures were collected, and 25 cases were open fractures. There were no statistically differences in the hospitalization time, operation time, intraoperative blood loss, treatment cost, ROM, MEPS or DASH score between the open group and the closed group. In terms of complications, there were no statistically significant differences in the rates for ulnar nerve injuries, elbow stiffness, nonunion or local irritation in the region of internal fixation.
Based on this result, for both AO/OTA type C Gustilo I/II open distal humerus fractures and closed distal humerus fractures, ORIF can be performed with the same approach after thorough debridement. Emergency ORIF can lead to early rehabilitation, so we recommend this procedure if possible in order to prevent elbow stiffness.
The advantage of this study is that it is the first to compare the efficacy of ORIF for AO/OTA Type C Gustilo I/II open distal humeral fractures and closed distal humeral fractures. However, this study also has some limitations: (1) this study is a retrospective rather than a prospective study, and the method of grouping can bias the results; (2) the Gustilo classification criteria is relatively broad and is determined by the surgeon's judgment intraoperatively; (3) the sample size is larger than those in previous studies, but as open distal humeral fractures are still rare, the sample size is limited, which may have impact the results and statistical power; (4) there were differences between the open group and the closed group in the BMI, which may have impact the results. Therefore, additional large-scale studies are needed.
In summary, AO/OTA type C Gustilo I and II open distal humerus fractures treated with ORIF can exhibit satisfactory clinical results similar to those of closed distal humerus fractures in short terms. There were no significant differences in functional outcomes or complications between the open and closed groups. Moreover, the mean hospitalization time, operation time, intraoperative blood loss and treatment cost did not differ between groups. These results prove that the current treatment for this type of open fracture is reasonable.