Pushpasekaran Narendran, Rathipelli Srinivas Karthik, Koshy George Mathew, Khaleel Veliyaveettil Muhamed
Department of Orthopaedics, Medical Trust Hospital, Cochin, Kerala, India.
J Orthop Case Rep. 2019;9(4):6-9. doi: 10.13107/jocr.2019.v09.i04.1454.
An isolated second metacarpal dislocation is one of the least reported injuries of the hand. This particular injury assumes clinical significance as they occur subsequent to high energy direct trauma and are usually missed with associated carpal and metacarpal bone fractures. We describe this unique case of an isolated metacarpal-trapezoidal disruption with clinical presentation as the pseudo-pointing index finger and also describe a novel radiological sign to ascertain the rotational deformity of metacarpals on plain radiographs.
A 32-year male information technology employee experienced a road traffic accident and developed pain, localized swelling over dorsum of the left hand. He exhibited an inability to form a complete fist with the index finger lagging behind, giving a pointing index finger like appearance. Plain radiographs showed isolated disruption of second metacarpal-trapezoid articulation. The computed tomography (CT) scans were used to confirm the absence of associated carpal injuries. The patient was managed successfully by closed reduction and Kirschner wiring. All the deformities resolved and regained normal hand functions in the follow-up period of 13 months with no recurrent episodes or evidence of arthritis.
Although a rare presentation, astute clinical examination and systematic radiological evaluation are the key to diagnose second through fourth carpometacarpal disruptions. The asymmetrical appearance of the metacarpal head tuberosities on anteroposterior radiographs is a strong indicator for rotational deformity of hands. These injuries must be evaluated with CT scans due to the increased potential for associated carpal injuries and poor prognosis when missed. More than often, an open reduction may be required to obtain stable concentric reduction.
孤立性第二掌骨脱位是手部报道最少的损伤之一。这种特殊损伤具有临床意义，因为它发生在高能直接创伤之后，并且通常会与腕骨和掌骨骨折同时出现而被漏诊。我们描述了这例孤立性掌骨 - 大多角骨脱位的独特病例，其临床表现为类似指向的食指，并描述了一种新的放射学征象，以在普通 X 光片上确定掌骨的旋转畸形。
一名 32 岁的男性信息技术员工遭遇道路交通事故，左手背出现疼痛和局部肿胀。他无法完全握拳，食指落后，呈现出类似指向的食指外观。普通 X 光片显示第二掌骨 - 大多角骨关节孤立性脱位。计算机断层扫描（CT）用于确认无相关腕骨损伤。患者通过闭合复位和克氏针内固定成功治疗。在 13 个月的随访期内，所有畸形均得到纠正，手部功能恢复正常，无复发或关节炎迹象。
尽管这种表现罕见，但敏锐的临床检查和系统的放射学评估是诊断第二至第四腕掌关节脱位的关键。前后位 X 光片上掌骨头结节的不对称外观是手部旋转畸形的有力指标。由于存在相关腕骨损伤的可能性增加且漏诊时预后较差，这些损伤必须进行 CT 扫描评估。通常，可能需要切开复位以获得稳定的同心复位。
