A two-stage retrospective analysis to determine the effect of entry point on higher exit of proximal pins in lateral pinning of supracondylar humerus fracture in children

[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.

Distal Humerus Metaphyseal-Diaphyseal Junctional Fracture of a Four-Year-Old Child Treated With Intramedullary Steinmann Wire Fixation: A Case Report

Distal humeral metaphyseal-diaphyseal fractures are rare and inherently unstable injuries. Non-operative treatments can make it hard to maintain reduction. Open or closed reduction with percutaneous K-wire fixation may be the preferred treatment option for these fracture types. This case report describes successfully managing a rare distal humerus metaphyseal-diaphyseal junctional (MDJ) fracture in a four-year-old child using intramedullary Steinmann wire fixation. A four-year-old male child applied to the emergency service with a swollen elbow. He had a history of trauma 10 days ago. There was a long arm splint on his arm. A displaced distal MDJ fracture of the left humerus was detected on the radiograph. Due to its instability, we preferred surgical management. With a lateral incision, we obtained a successful reduction after manipulation. Subsequently, we achieved the anatomical reduction with three Steinmann pins. We applied two Steinmann pins intramedullary, and the other one crosses from the medial epicondyle and exits the lateral cortex, forming a crossed-pin configuration at the fracture site. We immobilized the extremity for four weeks with a long arm splint. At the end of the fourth week, we removed the Steinmann pins. After removing the wires, we began an active range of motion exercises. The plain X-ray at the two-month follow-up revealed good fracture healing with no residual elbow deformity. The patient could perform a complete elbow range of motion. The case highlights the challenges in treating pediatric distal metaphyseal-diaphyseal humerus fractures, and it demonstrates the effectiveness of this intramedullary Steinmann wire fixation technique in achieving stable fracture reduction and promoting rapid healing in a small child.

Analysis of the location and trajectory of the Kirschner wires in the fixation of extension-type supracondylar fracture of the humerus by 3D computational simulation

BACKGROUND

Closed reduction and percutaneous pinning is still a preference for the treatment of supracondylar humerus fractures in children. However, no reports have shown the pin trajectory and the characteristics of the entry point so far. So we established a computational simulation model of the elbow to observe the trajectory of pinning for supracondylar humerus fractures.

METHODS

We reconstructed an adult elbow computationally and simulated pin placement through lateral and medial pinning. Pin trajectories were traced after placement and after the addition of the skin profile; the relative entry points of the pins were determined. We used the center of the dorsal olecranon inflection as an anatomic reference for the entry points of lateral pinning. Four quadrants were established based on the center of the dorsal olecranon inflection: upper medial quadrant, upper lateral quadrant, lower medial quadrant, and lower lateral quadrant (LLQ).

RESULTS

The maximum angle of pinning through the lateral column was 64° ± 3°. The minimum angles of pinning through the lateral column and middle column were 37° ± 3° and 20° ± 2°, respectively. The range of safe angle pinning through the medial column was between 18° ± 2° and 57° ± 3° to avoid penetration of the olecranon fossa and the cortex of the medial column. The entry points of lateral pinning were within the lateral half of the LLQ, and the lateral one-third of the LLQ contained all entry points of the pins through the lateral column and minor points of the pins through the middle column. The exit points of the medial pinning were within the lateral fringe of the metaphyseal-diaphyseal junction region; entering from the inferior two-thirds of the medial epicondyle could lead to the exit points in the proximal half of the metaphyseal-diaphyseal junction region laterally.

DISCUSSION

For lateral pinning, the entry points would be within the lateral half of the LLQ. For the pins through the lateral column, the entry points should be within the lateral one-third of the LLQ. For medial pinning, entering from the inferior two-thirds of the medial epicondyle would lead to a more proximal exit.

The most stable pinning configurations in transverse supracondylar humerus fracture fixation in children: A novel three-dimensional finite element analysis of a pediatric bone model

PURPOSE

This study aimed at finding out the effect of exit height, trajectory and number of pins on the stability of cross and divergent-lateral pins used in the fixation of extension-type, transverse supracondylar humerus fracture (SHF) in children, based on finite element analysis.

METHODS

Distal humerus model consisting of the ossific nucleus of the capitellum (ONC) and distal cartilage of a 6-year-old boy was developed via three-dimensional finite modeling. Various cross and divergent-lateral pinning models with either two or three pins were simulated on an extension-type, transverse SHF and tested in six loading directions.

RESULTS

Two-cross pins and 2-divergent-lateral pins were more stable against torsional and translation forces respectively, while 3-cross pins were the most stable against all forces. The cross pins exiting at the upper border of the distal metaphyseal-diaphyseal junction (MDJ) had the best stiffness among the 2-cross pins, while the lateral pins with a middle third ONC distal pin provided the best stiffness among the 2-lateral pins. A third olecranon fossa pin greatly enhanced stability of the 2-lateral pins.

CONCLUSION

For typical transverse fractures, 2-cross pins are found to be superior to 2-divergent lateral pins only against torsional forces. Pins exiting at the upper border of the MDJ provides the best mechanical stability with 2-cross pins. Two-divergent-lateral pins with a distal pin going through the middle third of the ONC provides the best mechanical stability against translation forces for these transverse fractures. Three-cross pins however offer the best mechanical stability against both translation and torsional forces. This study offers important clues in the preoperative evaluation and management of extension-type supracondylar fractures in children.

Closed Reduction and Percutaneous Pinning in the Treatment of Humeral Distal Metaphyseal-Diaphyseal Junction Fractures in Children: A Technique Note and Preliminary Results

Objective: The metaphyseal-diaphyseal junction (MDJ) fracture is an uncommon but problematic type of fracture occurring at the distal humerus in children. Closed reduction and fixation are challenging and may not be possible with the conventional reduction maneuver utilized in supracondylar fractures. The purpose of this study was to evaluate a novel closed reduction and percutaneous pinning (CRPP) technique for the treatment of these fractures. Methods: We retrospectively evaluated 14 children (8 boys and 6 girls) who underwent closed reduction and percutaneous fixation for the treatment of MDJ fractures. Six children who underwent treatment with a novel CRPP technique were enrolled as Group A. Eight children underwent the conventional reduction maneuver utilized in supracondylar fracture and were enrolled as Group B. Clinical and radiographic outcomes in the two groups were then compared. Results: In Group A, all six MDJ fractures were treated successfully with the novel CRPP technique without the need for open procedures or re-operation. No complications such as pin-site infection or iatrogenic nerve injury were found in this group. In group B, five of the eight fractures were treated successfully with the conventional CRPP technique; three fractures needed open reduction, and one of them had further surgery because of the loss of fixation. Children with successful CRPP in each group were included to compare the efficacy of the novel CRPP technique. The average duration of the surgery in Group A was significantly shorter than that in Group B (p < 0.001). At last follow-up, both groups obtained satisfactory clinical and radiographic outcomes. Conclusion: MDJ fractures can be reduced successfully and fixed stably via a novel CRPP technique, and laborious and frustrating attempts at closed reduction and further open reduction can be avoided.

Supracondylar Humerus Fractures: Classification Based Treatment Algorithms

Supracondylar humerus fractures are the most common fractures around the elbow in children between 4 and 10 years of age. The treatment of supracondylar humerus fractures can vary from conservative treatment to operative treatment depending on the fracture type. All around the world, the most commonly used classification system is the Wilkins-modified Gartland classification of supracondylar humerus fractures. Currently, the decision to operate or conserve the fracture is taken on basis of this classification system. Non-operative treatment for type I fractures and operative treatment for type III fractures have been well-established in literature. The management of type II supracondylar humerus fracture creates confusion in the minds of numerous orthopaedic surgeons around the world. We have tried addressing this using a classification-based treatment algorithm. Other classification systems like the AO classification, Lagrange and Rigault classification and Bahk classification with special reference to special fracture patterns that require attention and pre-op planning have also been mentioned. It is important to understand that operative management of each supracondylar humerus fracture is unique as regards fixation method and it is important to consider the fracture pattern before internal fixation.