[Application of external fixator combined with Kirschner wire fixation for oblique and comminuted distal humeral metaphyseal-diaphyseal junction fractures in children].

Objective: To analyze the effectiveness of external fixator combined with Kirschner wire (EF-KW) fixation in the treatment of oblique and comminuted distal humeral metaphyseal-diaphyseal junction (DHMDJ) fractures in children. Methods: A clinical data of 22 children with DHMDJ fractures who met the selection criteria between April 2021 and December 2023 was retrospectively analyzed. All patients were treated with EF-KW fixation. There were 14 boys and 8 girls with an average age of 6.8 years (range, 1.5-12.0 years). The time from injury to operation was 14-38 hours (mean, 24.2 hours). There were 18 cases of comminuted fractures and 4 cases of oblique fractures; and 1 case of median nerve injury and 1 case of radial nerve injury before operation. The occurrence of postoperative complications was recorded. At last follow-up, the function of the affected elbow joint was evaluated according to the Mayo elbow joint function score, and the Baumann's angle (BA) and humero-capitellar angle (HCA) of the affected and healthy sides were recorded and compared. Results: All fractures were successfully treated with closed reduction and no complications such as nerve injury occurred. Superficial infection occurred in 4 cases after operation and healed after symptomatic treatment. The incisions of other patients healed by first intention. All patients were followed up 9-24 months (mean, 13.8 months). At last follow-up, according to the Mayo elbow joint function score, the elbow joint function was rated as excellent in 15 cases, good in 6 cases, and fair in 1 case, with an excellent and good rate of 95.5%. The neurologic injury before operation recovered gradually. X-ray films reexamination showed that all fractures healed, and the healing time of fractures ranged from 29 to 61 days, with an average of 35.6 days. At last follow-up, there was no significant difference in BA and HCA between the healthy side and the affected side ( P>0.05). During follow-up, 1 case developed mild cubitus varus, while the other patients had no serious complications. Conclusion: EF-KW fixation for oblique and comminuted DHMDJ fractures in children has the advantages of less trauma, simple operation, easy reduction, good stability after reduction, low incidence of serious complications, and good elbow functional recovery.

[Research progress in the treatment of distal humeral metaphyseal-diaphyseal junction fracture in children].

Objective: To summarize the research progress in the treatment of distal humeral metaphyseal-diaphyseal junction (DHMDJ) fractures in children and to provide reference for clinical practice. Methods: The characteristics and treatment methods of transverse and comminuted DHMDJ fractures in children were summarized and analyzed by referring to relevant literature at home and abroad. Results: DHMDJ fractures in children are not uncommon clinically, with high fracture line position, multi-directional instability, difficult closed reduction in treatment, and easy to cause complications such as coronal and sagittal deformity of the elbow. The Kirschner wire technique was effective for DHMDJ fractures with the fracture line at the middle and low levels, but was prone to iatrogenic ulnar nerve injury. Elastic stable intramedullary nail is suitable for higher-position transverse DHMDJ fractures. However, this technique requires a second operation to remove the internal fixator, and may cause iatrogenic epiphysis plate injury in children. External fixator is a new way to treat DHMDJ fractures, and it can show satisfactory results for transverse and comminuted DHMDJ fractures. However, at present, there are few relevant studies, and most of them focus on biomechanical studies, and the efficacy lacks high-quality clinical research support. Conclusion: The ultimate goal of DHMDJ fracture treatment in children is to restore the anatomical alignment of the fracture and prevent the loss of reduction. The choice of internal fixator depends on the location of the fracture line and the shape of the fracture to provide personalized treatment.

[Effectiveness comparison of ultrasound-guided closed reduction and Kirschner wire fixation for different unstable humeral lateralcondylar fractures of children].

Objective: To compare the effectiveness of ultrasound-guided closed reduction and Kirschner wire fixation for different unstable humeral lateralcondylar fractures of children. Methods: The clinical data of 94 children with unstable humeral lateralcondylar fractures admitted to three medical centers between January 2021 and October 2022 were retrospectively analyzed. The children were divided into three groups according to the Song classification and whether the elbow joint was dislocated or not, including 42 cases of Song 4 type (group A), 38 cases of Song 5 type (group B), and 14 cases of elbow joint dislocation (group C). There was no significant difference in gender, age, side, cause of injury, and time from injury to operation among the three groups ( P>0.05). All children were treated with ultrasound-guided closed reduction and Kirschner wire fixation. The operation time and complications of the three groups were recorded and compared, and the failure of closed reduction was evaluated by ultrasound. X-ray examination was performed at last follow-up to measure the Baumann angle, condylar angle, carrying angle, and lateral osteophyte of the affected side; the extension, flexion, pronation, and supination range of motion of the affected elbow joint were measured; the function of the elbow joint was evaluated by Mayo score. Results: The operation time in group A was significantly longer than that in groups B and C ( P<0.05). There were 7, 2, and 5 cases of closed reduction failure in groups A, B, and C, respectively, and there was no significant difference in the incidence of the closed reduction failure ( P>0.05). All patients were followed up 6-28 months, with an average of 15.7 months. There was no significant difference in the follow-up time among the three groups ( P>0.05). Complications: in group A, there were 2 cases of delayed union, 4 cases of needle tract infection, 1 case of trochlear necrosis, and 39 cases of lateral osteophyte; in group B, there was 1 case of malunion, 5 cases of needle tract infection, 1 case of redisplacement, and 26 cases of lateral osteophyte; in group C, there were 2 cases of needle tract infection and 10 cases of lateral osteophyte. There was no significant difference in the incidence of complications among the three groups ( P>0.05). No cubitus varus or cubitus valgus deformity was found in all patients. At last follow-up, except that the condylar angle in group A was significantly greater than that in groups B and C ( P<0.05), there was no significant difference in other imaging indicators, elbow range of motion, or Mayo score between groups ( P>0.05). Conclusion: The Song type 4 of humeral lateralcondylar fracture treated with ultrasound-guided closed reduction and Kirschner wire fixation has a longer operation time, more postoperative complications, and is more prone to lateral osteophyte.