UNASSIGNED: Retrospective analysis of 9 patients with intertrochanteric fractures treated between July 2014 and June 2023 was conducted, in which off target occurred during the insertion of the distal interlocking screw by jig-guided targeting device in short cephalomedullary nailling (<24 cm). There were 1 male and 8 females, with an average age of 82.7 years (range, 73-94 years). There were 3 cases of type A1, 5 cases of type A2, and 1 case of type A3 according to 2018-AO/Orthopaedic Trauma Association (AO/OTA) fracture classification. As for the misaligned distal interlocking screw, six parameters were collected and analyzed, including the time of finding, the position, the type of passing through the cortical bone, the special circumstances during operation (such as the need to remove the intramedullary nail for reaming the diaphysis, hammering, etc.), the treatment, and the patient follow-up results.
UNASSIGNED: In the 9 patients, the off target of the distal interlocking screw was found in 7 cases during operation and in 2 cases after operation; the locking screw was located behind the nail in 7 cases and in front of the nail in 2 cases; the off target locking screw was passing tangentially in transcortical patern in 6 cases and in bicortical pattern through the medullary cavity in 3 cases. Three cases were attributed to the mismatch between the nail and the femur, two of which were attributed to the narrow femoral medullary cavity, one of which was attributed to the large anterolateral femoral bowing, and the other 6 cases were attributed to technical errors such as the loosening of the jig-guided targeting device, the tension of the fascia lata, and the blunt of the drill. In the 7 cases found during operation, the misaligned interlocking screw was removed first and the screw hole was left vacant, then in 2 cases, the interlocking screw was not used further; in 1 case, the distal dynamic hole was successfully inserted with a dynamic guide frame, and in 4 cases, the interlocking screw was successfully put after 2-3 attempts, leaving a large hole in the lateral cortex. No special treatment was performed in 2 cases found after operation. One patient was out of bed early after operation, 7 patients were in bed for 1 month, and 1 patient deteriorated to A3 type after operation and was in bed for 3 months. All the 9 patients were followed up 6-12 months, with an average of 8 months. Fracture healing was achieved in 8 patients. One patient with vacant interlocking screw had a secondary spiral fracture of the femoral shaft 3 months later, and was refixed with a long cephalomedullary nail and circlage wiring.
UNASSIGNED: Distal interlocking screw off target is rare, but when it occurs, it leaves a large cortical hole in the osteoporotic femoral shaft, reducing bone strength; the use of precision instruments and attention to technical details can reduce this adverse phenomenon.
UNASSIGNED: 分析短型头髓钉经体外框架导向器安装远侧交锁螺钉失准的原因、处理方法,并提出预防失准的技术要点。.
UNASSIGNED: 2014年7月—2023年6月,9例股骨转子间骨折患者术中采用短型头髓钉(<24 cm)经体外框架导向器安装远侧交锁螺钉时发生螺钉失准。其中男1例,女8例;年龄73~94岁,平均82.7岁。2018-国际内固定研究协会/美国骨创伤协会(AO/OTA)骨折分型:A1型3例,A2型5例,A3型1例。分析失准发现时间、失准方位、失准螺钉穿过皮质骨的类型、术中特别情况(如需拔除髓内钉重新进行骨干扩髓、榔头敲击等)以及对失准情况的处理及随访结果。.
UNASSIGNED: 9例患者中,远侧交锁螺钉失准为术中发现7例,术后发现2例;失准的远侧交锁螺钉位于髓内钉后方7例,前方2例;6例为不经过髓腔的皮质切线位贯穿,3例为经过髓腔的双皮质穿透。失准原因:3例归因于髓内钉与股骨不匹配,其中2例属于股骨髓腔过于狭小,1例股骨前外侧弓太大;另6例归因于操作失误,如导向架松动、阔筋膜张力、钻头迟钝等。术中发现的7例均先取出失准的交锁螺钉并空置该螺钉孔,其中2例不再打入交锁螺钉;1例换用动态导向架成功打入远侧的动态孔,4例在尝试2~3次后交锁成功,在外侧皮质遗留较大孔洞。术后发现的2例未做特殊处理。术后1例患者早期下床活动,7例卧床1个月,1例术后恶化为A3型,卧床3个月。9例患者均获随访,随访时间6~12个月,平均8个月。8例患者骨折愈合;1例交锁螺钉空置者术后3个月站立时发生经皮质孔洞的股骨干螺旋形骨折,再次手术换用长型头髓钉并捆扎固定。.
UNASSIGNED: 远侧交锁螺钉失准情况比较少见,一旦发生将在骨质疏松的股骨干上遗留一较大皮质孔洞,降低骨强度;使用精密器械并注意操作细节可以减少此现象的发生。.