Department of Orthopedic Surgery, University of California.
Pediatric Orthopedics and Scoliosis Center, Rady Children's Hospital, San Diego, CA.
J Pediatr Orthop. 2020 Oct;40(9):474-480. doi: 10.1097/BPO.0000000000001601.
Screw fixation is the most commonly employed fixation strategy for displaced medial epicondyle fractures, but in younger patients with minimal ossification, the fracture fragment may not accommodate a screw. In these situations, Kirschner-wires (K-wire) or suture anchors may be utilized as alternatives. The purposes of this study were to examine the biomechanical properties of medial epicondyle fractures fixed with a screw, K-wires, or suture anchors, to evaluate clinical outcomes and complications of patients 10 years of age or younger treated with these approaches, and to perform a cost-analysis.
Biomechanical assessment: Immature pig forelimbs underwent an osteotomy through the medial epicondyle apophysis, simulating a fracture. These were then fixed with a screw, K-wires or suture anchors. Cyclic elongation (mm), displacement (mm), load to failure (N), and stiffness (N/mm) were assessed. Clinical assessment: a retrospective review was performed of patients 10 years of age or younger with a medial epicondyle fracture fixed with these strategies. Radiographic outcomes, postoperative data and complications were compared. These data were used to perform a cost-analysis of each treatment approach.
Biomechanically, screws were stronger (P=0.047) and stiffer (P=0.01) than the other constructs. Clinically, 51 patients met inclusion criteria (screw=27, wires=11, anchor=13). Patients treated with K-wires were younger (P<0.05) and patients treated with screw fixation had a shorter casting duration (P=0.008). Irrespective of treatment strategy, all fractures healed (100%) and only 1 patient in the screw group lost reduction. Clinical outcomes and complications were similar between groups, but the suture anchor group was less likely to require a second surgery for implant removal (P<0.05). This lower reoperation rate led to a cost-saving of 10%.
Biomechanically, all 3 approaches provided initial fixation exceeding the forces observed across the elbow joint with routine motion. The screw construct was the strongest and stiffest. Clinically, all 3 strategies were acceptable, with screw fixation offering a shorter casting duration, but greater implant removal need with higher associated costs.
螺丝钉固定是治疗内侧髁突骨折最常用的固定方法，但在骨化程度较低的年轻患者中，骨折块可能无法容纳螺丝钉。在这些情况下，克氏针或缝线锚钉可作为替代方法。本研究的目的是研究使用螺丝钉、克氏针或缝线锚钉固定内侧髁突骨折的生物力学特性，评估 10 岁及以下患者接受这些治疗方法的临床结果和并发症，并进行成本分析。
生物力学评估：不成熟的猪前肢通过内侧髁突骨骺切开术进行切开，模拟骨折。然后用螺丝钉、克氏针或缝线锚钉固定。评估循环伸长（mm）、位移（mm）、断裂负荷（N）和刚度（N/mm）。临床评估：对 10 岁及以下接受这些策略固定内侧髁突骨折的患者进行回顾性研究。比较影像学结果、术后数据和并发症。使用这些数据对每种治疗方法进行成本分析。
生物力学上，螺丝钉的强度（P=0.047）和刚度（P=0.01）均优于其他结构。临床上，51 例患者符合纳入标准（螺丝钉组 27 例，克氏针组 11 例，锚钉组 13 例）。克氏针组患者年龄更小（P<0.05），螺丝钉固定组的石膏固定时间更短（P=0.008）。无论治疗策略如何，所有骨折均愈合（100%），仅在螺丝钉组有 1 例患者丢失复位。各组的临床结果和并发症相似，但锚钉组需要再次手术取出植入物的可能性较小（P<0.05）。这种较低的再手术率导致 10%的成本节约。
生物力学上，所有 3 种方法提供的初始固定均超过了肘部常规运动所产生的力。螺丝钉结构最强和最硬。临床上，所有 3 种方法均可行，螺丝钉固定的石膏固定时间更短，但需要更多的植入物取出，相关费用更高。
