Department of Neurosurgery, Leiden Nerve Center, Leiden University Medical Center, Leiden, the Netherlands.
Department of Orthopedic Surgery, Leiden Nerve Center, Leiden University Medical Center, Leiden, the Netherlands.
J Bone Joint Surg Am. 2022 Nov 16;104(22):2008-2015. doi: 10.2106/JBJS.22.00373. Epub 2022 Sep 9.
A typical feature in infants with severe C5-C6 brachial plexus birth injury (BPBI) requiring nerve repair is the formation of shoulder internal rotation contracture (IRC). The underlying pathophysiological mechanism is unknown, and the sequelae can be difficult to treat. The severity of the IRC differs among children. C5-C6 lesions are heterogeneous at the root level. Our null hypothesis was that the type of root-level lesion (axonotmesis or neurotmesis versus avulsion) was not associated with the extent of IRC formation over time in children with upper-trunk BPBI.
We performed a retrospective analysis of all patients with upper-trunk BPBI who underwent primary surgery of the C5 and/or C6 spinal nerves between 1990 and 2020 and had follow-up of at least 2 years. The primary outcome was passive shoulder external rotation (ER) in adduction at 1, 3, 5, 7, and 15 years of age. The secondary outcome was whether additional shoulder surgery was performed. The relationship between the nature of the C5-C6 lesion and IRC formation was analyzed using linear mixed models. The Kaplan-Meier method was used to estimate the cumulative risk of secondary shoulder procedures.
In total, 322 patients were analyzed; mean follow-up was 7.2 ± 4.6 years. The C5-C6 root lesion type was significantly related to the passive range of ER (overall test in linear mixed model, p = 0.007). Children with avulsion of C5 and C6 (n = 21) had, on average, 18° (95% confidence interval [CI], 6.3° to 30°) less IRC formation than those with neurotmesis of C5 and C6 (n = 175) and 17° (2.9° to 31°) less than those with neurotmesis of C5 and avulsion of C6 (n = 34). IRC formation did not differ between the neurotmesis C5-C6 and neurotmesis C5-avulsion C6 groups. Secondary shoulder procedures were performed in 77 patients (10-year risk, 28% [95%CI, 23% to 34%]).
Shoulder IRC formation in infants with BPBI with surgically treated C5-C6 lesions occurs to a lesser degree if the C5 root is avulsed than when C5 is neurotmetic. This finding provides insight into the possible causative pathoanatomy and may ultimately lead to strategies to mitigate IRC.
Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.
患有严重 C5-C6 臂丛神经出生损伤（BPBI）需要神经修复的婴儿的典型特征是形成肩内旋挛缩（IRC）。其潜在的病理生理机制尚不清楚，且后遗症可能难以治疗。IRC 在儿童之间的严重程度存在差异。根水平的 C5-C6 病变存在异质性。我们的零假设是，上肢 BPBI 儿童中，C5-C6 神经根损伤类型（轴突断裂或神经断裂与撕脱）与 IRC 形成的程度无关。
我们对 1990 年至 2020 年间接受 C5 和/或 C6 脊神经根初次手术且随访至少 2 年的所有上干 BPBI 患者进行了回顾性分析。主要结局是 1、3、5、7 和 15 岁时的被动肩关节外展（ER）。次要结局是是否进行了额外的肩部手术。采用线性混合模型分析 C5-C6 病变性质与 IRC 形成之间的关系。采用 Kaplan-Meier 法估计二次肩部手术的累积风险。
共分析了 322 例患者，平均随访 7.2±4.6 年。C5-C6 神经根病变类型与被动 ER 范围显著相关（线性混合模型整体检验，p=0.007）。C5 和 C6 撕脱的儿童平均 IRC 形成减少 18°（95%置信区间 [CI]，6.3°至 30°），C5 和 C6 神经断裂的儿童减少 17°（2.9°至 31°），C5 神经断裂和 C6 撕脱的儿童减少 17°（2.9°至 31°）。C5-C6 神经断裂与 C5-C6 神经断裂和 C6 撕脱的儿童 IRC 形成无差异。77 例患者行二次肩部手术（10 年风险 28%[95%CI，23%至 34%]）。
与 C5 神经断裂相比，如果 C5 神经根撕脱，婴儿患有手术治疗的 C5-C6 病变的 BPBI 后肩 IRC 形成程度较轻。这一发现为可能的病因病理提供了深入了解，并可能最终导致减轻 IRC 的策略。
预后 III 级。请参阅作者说明以获取完整的证据水平描述。
