Department of Orthopaedic Surgery, Brigham and Women's Hospital, Boston, MA, USA.
Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center, Boston, MA, USA.
Foot Ankle Int. 2020 Nov;41(11):1342-1346. doi: 10.1177/1071100720938668. Epub 2020 Jul 14.
In the setting of apparently isolated distal fibula fractures, the gravity stress view (GSV) is a validated method to determine mortise stability. There is currently no published data evaluating whether dynamic muscle activation can reduce an unstable mortise. If patients with instability can overcome gravity, resultant images could yield false-negative results. The goal of this investigation was to determine if patient effort can influence medial clear space (MCS) measurements in proven unstable bimalleolar-equivalent ankle fractures.
Patients presenting with Weber B fibula fractures were assessed for mortise stability using the GSV. If the GSV demonstrated instability based on MCS widening >4 mm, 3 additional views were performed: GSV with an assistant maintaining the ankle in a neutral position; GSV with the patient actively dorsiflexing to neutral; and GSV with the patient actively dorsiflexing and supinating the foot. Twenty-four consecutive patients met inclusion criteria, with a mean age of 48.7 (range, 22-85) years. Fifteen patients (62.5%) were female and 9 (37.5%) were male. The laterality was evenly divided.
The mean MCS was 5.8 ± 2.0 6.0 ± 2.6, and 6.2 ± 2.7 mm for the manual assist, active dorsiflexion, and active supination radiograph measurement groups, respectively ( = .434). Only 5 of 24 subjects had any measurable decrease in their MCS with active supination, with a maximum change of 1.2 mm. The remainder of the patients had an increase in MCS ranging from 0.1 to 4.0 mm.
There was no significant difference between measurement states indicating that muscle activation is unlikely to yield a false-negative result on GSV. Mortise instability, secondary to deep deltoid injury in the presence of gravity stress, is unlikely to be actively overcome by dynamic stabilizers, supporting the validity and specificity of the GSV.
Level III, prospective study.
在明显孤立的腓骨远端骨折的情况下，重力应力位（GSV）是一种确定距骨稳定性的有效方法。目前尚无发表的数据评估动态肌肉激活是否可以减小不稳定的距骨。如果不稳定的患者能够克服重力，那么结果图像可能会产生假阴性结果。本研究的目的是确定在已证实的不稳定双踝等效踝关节骨折中，患者的努力是否会影响内侧间隙（MCS）测量值。
对出现 Weber B 腓骨骨折的患者进行 GSV 评估，以确定距骨稳定性。如果 GSV 显示 MCS 增宽>4mm 存在不稳定，则进行另外 3 个视图：助手维持踝关节中立位的 GSV；患者主动背屈至中立位的 GSV；患者主动背屈和旋前足部的 GSV。符合纳入标准的 24 例连续患者，平均年龄为 48.7（范围，22-85）岁。15 例（62.5%）为女性，9 例（37.5%）为男性。侧别均匀分布。
手动辅助、主动背屈和主动旋前测量组的平均 MCS 分别为 5.8±2.0mm、6.0±2.6mm 和 6.2±2.7mm（=0.434）。24 例患者中仅有 5 例患者的 MCS 有可测量的减小，最大变化为 1.2mm。其余患者的 MCS 增加范围为 0.1-4.0mm。
各测量状态之间无显著差异，表明肌肉激活不太可能导致 GSV 的假阴性结果。在重力应力的情况下，由于深层三角肌损伤导致的距骨不稳定不太可能被动态稳定器主动克服，这支持了 GSV 的有效性和特异性。
III 级，前瞻性研究。
