Department of Orthopedic Surgery, Eulji University College of Medicine, 1306, Dunsan-dong, Seo-gu, 35233 Daejeon, Republic of Korea.
Department of Orthopedic Surgery, Eulji University College of Medicine, 1306, Dunsan-dong, Seo-gu, 35233 Daejeon, Republic of Korea.
Orthop Traumatol Surg Res. 2018 Feb;104(1):127-132. doi: 10.1016/j.otsr.2017.08.018. Epub 2017 Oct 9.
Extension-block pinning represents a simple and reliable surgical technique. Although this procedure is commonly performed successfully, some patients develop postoperative extension loss. To date, the relationship between extension-block Kirschner wire (K-wire) insertion angle and postoperative extension loss in mallet finger fracture remains unclear.
We aimed to clarify this relationship and further evaluate how various operative and non-operative factors affect postoperative extension loss after extension-block pinning for mallet finger fracture.
A retrospective study was conducted to investigate a relationship between extension block K-wire insertion angle and postoperative extension loss. The inclusion criteria were: (1) a dorsal intra-articular fracture fragment involving 30% of the base of the distal phalanx with or without volar subluxation of the distal phalanx; and (2) <3 weeks delay from the injury without treatment. Extension-block K-wire insertion angle and fixation angle of the distal interphalangeal (DIP) joint were assessed using lateral radiograph at immediate postoperative time. Postoperative extension loss was assessed by using lateral radiograph at latest follow-up. Extension-block K-wire insertion angle was defined as the acute angle between extension block K-wire and longitudinal axis of middle phalangeal head. DIP joint fixation angle was defined as the acute angle between the distal phalanx and middle phalanx longitudinal axes.
Seventy-five patients were included. The correlation analysis revealed that extension-block K-wire insertion angle had a negative correlation with postoperative extension loss, whereas fracture size and time to operation had a positive correlation (correlation coefficient for extension block K-wire angle: -0.66, facture size: +0.67, time to operation: +0.60). When stratifying patients in terms of negative and positive fixation angle of the DIP joint, the independent t-test showed that mean postoperative extension loss is -3.67° and +4.54° (DIP joint fixation angles of <0° and ≥0°, respectively, P=0.024). When stratifying patients in terms of extension-block K-wire insertion angle (30°, 30°-40°, >40°), ANOVA showed significantly less postoperative extension loss for higher insertion angles (>40°) than for medium insertion angles (30°-40°). Mean postoperative extension loss difference between higher insertion angle (>40°) and medium insertion angle (30°-40°) was 11° (P=0.002).
Using an insertion angle of the extension-block K-wire of 40°-45° and a slightly hyperextended position of the DIP joint may help reducing postoperative extension loss.
Therapeutic level III.
延伸块克氏针固定术是一种简单可靠的手术技术。尽管该手术通常能成功实施，但仍有部分患者术后出现伸展损失。目前，槌状指骨折中延伸块克氏针插入角度与术后伸展损失之间的关系尚不清楚。
我们旨在阐明这种关系，并进一步评估各种手术和非手术因素如何影响槌状指骨折延伸块固定术后的伸展损失。
本研究进行了一项回顾性研究，以探讨延伸块克氏针插入角度与术后伸展损失之间的关系。纳入标准为：（1）背侧关节内骨折碎片累及远节指骨基底的 30%，伴有或不伴有远节指骨掌侧半脱位；（2）受伤后<3 周，未经治疗。术后即刻的侧位 X 线片评估延伸块克氏针插入角度和远节指间关节（DIP）的固定角度。使用侧位 X 线片在末次随访时评估术后伸展损失。延伸块克氏针插入角度定义为延伸块克氏针与中节指骨头部纵轴之间的锐角。DIP 关节固定角度定义为远节指骨与中节指骨纵轴之间的锐角。
共纳入 75 例患者。相关性分析显示，延伸块克氏针插入角度与术后伸展损失呈负相关，而骨折大小和手术时间与术后伸展损失呈正相关（延伸块克氏针角度的相关系数：-0.66，骨折大小：+0.67，手术时间：+0.60）。当根据 DIP 关节的负固定角和正固定角对患者进行分层时，独立 t 检验显示，平均术后伸展损失为-3.67°和+4.54°（DIP 关节固定角分别为<0°和≥0°，P=0.024）。当根据延伸块克氏针插入角度（30°、30°-40°、>40°）对患者进行分层时，方差分析显示，>40°的较高插入角度比 30°-40°的中等插入角度有显著更少的术后伸展损失。较高插入角度（>40°）与中等插入角度（30°-40°）之间的平均术后伸展损失差异为 11°（P=0.002）。
使用延伸块克氏针插入角度为 40°-45°和 DIP 关节的轻微过伸位可能有助于减少术后伸展损失。
治疗学三级。
