导针引导下踝关节外翻畸形矫形：内固定取出的挑战

Guided Growth for Ankle Valgus Deformity: The Challenges of Hardware Removal.

机构信息

Motion Analysis Laboratory, Department of Pediatric Orthopedic Surgery, Shriners Hospitals for Children.

Shriners Hospitals for Children.

出版信息

J Pediatr Orthop. 2020 Oct;40(9):e883-e888. doi: 10.1097/BPO.0000000000001583.

DOI:10.1097/BPO.0000000000001583

PMID:32398628

Abstract

BACKGROUND

Ankle valgus deformity is associated with conditions such as clubfoot, cerebral palsy, and myelodysplasia. Guided growth strategies using a transphyseal screw provide effective correction of ankle valgus deformity. When correction occurs before skeletal maturity, screw removal is required to prevent overcorrection in the coronal plane. In this study, we reviewed the outcomes of guided growth procedures for correction of ankle valgus and related difficulty with hardware extraction.

METHODS

A retrospective review of patients with ankle valgus managed with transphyseal screw placement was performed. Clinical and radiographic data, including the lateral distal tibial angle (LDTA), type of screw placed, and time to correction was recorded. At hardware removal, we reviewed elements associated with difficult extraction defined as requiring the use of specialized screw removal/extraction sets or inability to remove the entirety of the screw.

RESULTS

One hundred nineteen patients (189 extremities) with a mean age of 11.7 years at time of screw placement met study inclusion criteria. Following correction of the valgus deformity, hardware removal occurred at an average of 18.4 months after placement of the screw. Preoperatively, the mean LDTA for the entire cohort was 81.3 degrees, and was corrected to a mean LDTA of 91.1 degrees. Complicated hardware removal occurred in 69 (37%) extremities. These 69 extremities had hardware in place an average of 1.8 years compared with an average of 1.4 years in extremities without difficult extraction (P<0.01). Six (9%) screws were unable to be removed in their entirety. Rebound valgus deformity occurred in 5 extremities (3%).

CONCLUSIONS

Extraction of transphyseal screws in the correction of ankle valgus can be problematic. Specialized instrumentation was required in approximately one third of cases. Longevity of screw placement may be a factor that affects the ease of extraction. Additional exposure, access to specialized instrumentation, and additional operative time may be required for extraction.

LEVEL OF EVIDENCE

Level IV-case series.

摘要

背景

踝关节外翻畸形与马蹄足、脑瘫和脊髓发育不良等疾病有关。使用经骺板螺钉的引导生长策略可有效矫正踝关节外翻畸形。当在骨骼成熟前进行矫正时，需要移除螺钉以防止冠状面过度矫正。在这项研究中，我们回顾了经骺板螺钉固定治疗踝关节外翻畸形及相关内固定取出困难的治疗效果。

方法

对接受经骺板螺钉固定治疗的踝关节外翻患者进行回顾性研究。记录临床和影像学数据，包括外侧远端胫骨角（LDTA）、置入螺钉的类型和矫正时间。在取出内固定时，我们分析了与困难取出相关的因素，定义为需要使用特殊的螺钉取出/取出套件或无法完全取出螺钉。

结果

符合研究纳入标准的患者共有 119 例（189 侧），平均年龄为 11.7 岁。在矫正外翻畸形后，平均在置入螺钉后 18.4 个月取出内固定。整个队列的术前平均 LDTA 为 81.3°，矫正至平均 91.1°。复杂的内固定取出发生在 69 侧（37%）。这 69 侧的内固定在位时间平均为 1.8 年，而无困难取出的 120 侧的内固定在位时间平均为 1.4 年（P<0.01）。6 枚（9%）螺钉无法完全取出。5 例（3%）出现反弹性外翻畸形。