Objective: To explore the mechanism, surgical method, and effectiveness of proximal phalangeal bone avulsion fracture caused by A2 circular trochlea injury of the flexor digitorum tendon.
Methods: A retrospective analysis was conducted on the clinical data of 4 patients with proximal phalangeal bone avulsion fracture caused by A2 circular trochlea injury of flexor digitorum tendon admitted between May 2018 and September 2022. The patients were all male, the age ranged from 26 to 52 years, with an average of 33 years. The injured fingers included 1 case of middle finger and 3 cases of ring finger. The causes of injury were rock climbing of 2 cases and carrying heavy objects of 2 cases. Preoperative anteroposterior and lateral X-ray films and CT examination of the fingers showed a lateral avulsion fracture of the proximal phalanx, with a fracture block length of 15-22 mm and a width of 3-5 mm. The total active range of motion (TAM) of the injured finger before operation was (148.75±10.11)°. The grip strength of the middle and ring fingers was (15.50±2.88) kg, which was significantly lower than that of the healthy side (50.50±7.93) kg ( t=-8.280, P<0.001). The time from injury to operation was 2-7 days, with an average of 3.5 days. One Kirschner wire with a diameter of 1.0 mm was used for direct fixation through the fracture block, while two Kirschner wires with a diameter of 1.0 mm were used for compression fixation against the fracture block. The fracture healing was observed, and the TAM of the injured finger and the grip strength of the middle and ring fingers were measured. The finger function was evaluated according to the upper limb functional assessment trial standards of the Chinese Medical Association Hand Surgery Society.
Results: The incisions all healed by first intention after operation. All patients were followed up 6-28 months, with an average of 19 months. X-ray films showed that all avulsion fractures of proximal phalanx reached bony union, and the healing time ranged from 4 to 8 weeks, with an average of 4.6 weeks. At last follow-up, the grip strength of the middle and ring fingers was (50.50±7.76) kg, which significantly improved when compared with preoperative one ( t=-8.440, P<0.001). The TAM of the injured finger reached (265.50±2.08)°, and there was a significant difference when compared with preoperative one ( t=-21.235, P<0.001). According to the upper limb functional assessment trial standards of the Chinese Medical Association Hand Surgery Society, the finger function was all evaluated as excellent in 4 cases.
Conclusion: Using Kirschner wire fixation through bone blocks and external compression fixation of bone blocks for treating proximal phalangeal bone avulsion fracture caused by A2 circular trochlear injury of the flexor digitorum tendon can achieve good effectiveness.
目的: 探讨屈指肌腱A2环形滑车损伤致近节指骨撕脱骨折受伤机制、手术方法及临床疗效。.
方法: 回顾分析2018年5月—2022年9月收治的4例屈指肌腱A2环形滑车损伤致近节指骨撕脱骨折患者临床资料。患者均为男性；年龄26～52岁，平均33岁。损伤指别：中指1例，环指3例。致伤原因：攀岩运动伤2例，搬运重物伤2例。术前手指正侧位X线片及CT检查示近节指骨侧方撕脱骨折，骨折块长15～22 mm，宽3～5 mm。伤指术前总主动活动度（TAM）为（148.75±10.11）°；中、环指握力为（15.50±2.88）kg，较健侧（50.50±7.93）kg明显下降，差异有统计学意义（ t=−8.280， P<0.001）。受伤至手术时间2～7 d，平均3.5 d。采用1枚直径1.0 mm克氏针经骨折块直接固定，2枚直径1.0 mm克氏针对骨折块进行扣压固定。随访观察骨折愈合情况，并测量伤指TAM及中、环指握力；采用中华医学会手外科学会上肢部分功能评定试用标准评价手指功能。.
结果: 术后切口均Ⅰ期愈合。4例患者均获随访，随访时间6～28个月，平均19个月。X线片示近节指骨撕脱骨折均达骨性愈合，愈合时间4～8周，平均4.6周。末次随访时，中、环指握力为（50.50±7.76）kg，较术前显著改善，差异有统计学意义（ t=−8.440， P<0.001）。伤指TAM达（265.50±2.08）°，与术前比较差异有统计学意义（ t=−21.235， P<0.001）。参照中华医学会手外科学会上肢部分功能评定试用标准评定手指功能，4例均获优。.
结论: 采用克氏针经骨折块固定及骨折块外扣压固定治疗屈指肌腱A2环形滑车损伤致手指近节撕脱骨折，可取得较好临床效果。.
Keywords: A2 circular trochlea; Phalangeal fracture; injury mechanism; internal fixation.