Zeni Ferras, Cavazos Daniel R, Bouffard José A, Vaidya Rahul
Orthopedics, Allina Health, St. Paul, USA.
Orthopaedic Surgery, Wayne State University School of Medicine, Detroit, USA.
Cureus. 2023 Apr 25;15(4):e38092. doi: 10.7759/cureus.38092. eCollection 2023 Apr.
Introduction In supination external rotation (SER) ankle fractures with an intact medial malleolus, stability hinges upon the competence of the deltoid ligament. The purpose of this study is to define the indications and establish criteria for a positive stress radiograph. Methods This is a prospective study of 27 isolated SER lateral malleolar fractures with a reduced ankle mortise. Pain and swelling were noted about the medial ankle, followed by an ultrasound to evaluate the integrity of the deltoid ligament. Static and stress radiographs were performed on both the fractured and contralateral ankles. Results Fourteen patients were normal on ultrasound examination, eight had partial tears, and five had full-thickness tears. The difference in the level of pain to palpation postero-medially between the complete tear (7 +/- 1) and the partial tear (1.3 +/- 2.4) group was significant (p < .001). The negative predictive values for medial swelling and tenderness were 93% and 100%, respectively. Sensitivity and specificity for medial clear space on stress radiograph (fracture (fx)) > 5.0 mm were both 100% while a 2.5 mm or greater change to the contralateral side yielded a sensitivity of 100% and specificity of 95%. Conclusion The lack of significant medial pain, as well as swelling, implies the absence of a complete ligament tear and eliminates the need for stress examination. Conversely, the presence of medial signs of injury is suggestive, but not pathognomonic for a complete deltoid tear. Medial clear space (MCS) variability prompts to recommend a minimum of 2.5 mm on stress radiographs compared to the contralateral side as indirect evidence for a complete tear of the deltoid ligament.
引言 在伴有完整内踝的旋后外旋（SER）型踝关节骨折中，稳定性取决于三角韧带的完整性。本研究的目的是明确应力位X线片阳性的指征并建立标准。方法 这是一项对27例孤立的SER型外踝骨折且踝关节榫眼已复位患者的前瞻性研究。记录内踝周围的疼痛和肿胀情况，随后进行超声检查以评估三角韧带的完整性。对患侧和对侧踝关节均进行静态和应力位X线片检查。结果 14例患者超声检查正常，8例有部分撕裂，5例有全层撕裂。完全撕裂组（7±1）和部分撕裂组（1.3±2.4）在内踝后内侧触诊疼痛程度上的差异具有统计学意义（p<0.001）。内踝肿胀和压痛的阴性预测值分别为93%和100%。应力位X线片上内侧间隙（骨折（fx））>5.0 mm的敏感性和特异性均为100%，而与对侧相比变化2.5 mm或更大时，敏感性为100%，特异性为95%。结论 内踝无明显疼痛及肿胀提示不存在韧带完全撕裂，无需进行应力检查。相反，内踝损伤体征的存在提示可能存在三角韧带完全撕裂，但并非确诊依据。内侧间隙（MCS）的变异性提示，与对侧相比，应力位X线片上内侧间隙至少2.5 mm可作为三角韧带完全撕裂的间接证据。
