您正在感受到的症状¶
胫腓联合损伤影响的是位于踝关节上方、将小腿两根骨骼连接在一起的韧带。疼痛通常分布在踝关节周围，而非局限于某一点，且常位于前方和外侧，紧邻外侧踝关节韧带的上方。您也可能在踝关节内侧附近感到压痛。
某些动作会加重疼痛。上坡行走、旋转或扭转，以及用前脚掌站立，通常都会引起疼痛。将脚向外旋转，或向上弯曲脚部朝向胫骨，也可能诱发疼痛。肿胀和瘀青很常见，瘀青可能沿腿部向上延伸，或横跨踝关节内侧。如果踝关节不稳定，负重通常过于疼痛。
一些疼痛发作模式提示该损伤而非单纯扭伤。尽管休息但疼痛持续存在是典型体征。相反，如果扭伤在发作间期完全缓解，则提示外侧踝关节韧带存在其他问题。肿胀和僵硬持续存在、蹬地时力量减弱，以及踝关节可能失稳的感觉，都可能在原始损伤后长期持续，即使标准检查显示正常。
日常任务可能变得困难。爬楼梯或上坡、从椅子上起身，以及单腿站立穿衣都可能引起疼痛。您可能会发现行走时无法正确蹬地，因此会偏向使用另一条腿。
一些早期警示信号很重要。如果您完全无法负重，如果肿胀迅速且严重，或者腿部内侧或上部瘀青范围广泛，则更可能涉及胫腓联合。这些损伤容易漏诊，最初有时会被误认为是简单的扭伤。如果上述任何情况听起来像您的踝关节，值得进行适当评估，而不是等待其自行缓解。
实际发生了什么¶
您的小腿有两根骨头，即胫骨和腓骨，它们并排位于踝关节上方。它们由一束称为胫腓联合的强韧韧带束连接在一起。可以将其想象成一条坚固的带子，在您行走时防止两根骨头向外分离。它还有助于将体重通过腿部向下传导，因此每次站立时它都在发挥实际作用。
当您的足部向小腿方向背屈并同时向外扭转时，就会发生这种损伤。这种扭转力可能将两根骨头撬开并撕裂该韧带束。如果损伤严重，其他结构也可能受损，例如踝关节内侧的韧带或腓骨本身。要使骨头真正分离，必须撕裂多根强韧的韧带以及它们之间坚韧的膜。
当韧带束受损时，踝关节会失去部分稳定性。踝关节下方的小骨头——距骨——在您活动时可能会轻微移位。正是这种移位导致了上述描述中的疼痛、肿胀和打软腿感。撕裂的韧带还可能发生炎症和瘢痕化，从而压迫踝关节前部的组织，使疼痛持续存在。
如果骨头保持分离状态且未得到治疗，关节可能会随时间不均匀磨损，并发展为退行性关节炎。这就是为什么获得正确诊断很重要。有些损伤是稳定的，意味着韧带束虽受拉伤但仍能将骨头保持在原位。这些通常无需手术，通过保护性负重即可恢复。另一些则是不稳定的，意味着骨头可能会漂移分离，这些需要通过手术将其固定在一起以促进愈合。尽早处理这一问题很重要，因为延误超过六个月与日后功能更差有关。
我们如何处理该问题¶
由于此类损伤容易被漏诊，我们有时会在决定治疗方案前使用能清晰显示韧带的扫描技术。
如果您的损伤是稳定的，即韧带束虽受牵拉但仍能维持骨骼位置，则无需手术。我们保护踝关节直至其愈合，并让您逐渐负重。理疗有助于您恢复踝关节的活动度、力量及信心。有些人发现早期使用软敷料即可获得足够的支撑，而另一些人则需要打石膏长达三周。避免负重的时间长短因人而异，我们会为您提供指导。
如果损伤是不稳定的，即骨骼可能发生移位，通常建议进行手术。等待超过六个月会导致预后变差，因此我们旨在尽早处理。手术通过固定两块骨骼来促进韧带愈合。这可以通过螺钉、强韧缝线配合小纽扣，或直接修复撕裂的韧带来实现。我们将与您讨论哪种方案适合您的损伤，并共同商定治疗计划。
术后，理疗有助于加快您的康复。大多数人可在手术后约四个月恢复正常活动，包括体育运动。
预期情况¶
预后取决于您的损伤是稳定型还是不稳定型。稳定型损伤是指韧带束仍能维持骨骼位置，通常无需手术即可恢复。您需要保护踝关节，逐步负重，并通过物理治疗重建力量。采用此方式治疗的患者长期功能良好，且很少有人再次损伤踝关节。
不稳定型损伤需要手术，以在韧带愈合期间固定骨骼。如果手术做得好，即骨骼对位准确且固定牢固，大多数人可恢复正常活动。术后约四个月，大多数人可恢复日常活动，包括运动。尽管影像学检查有时显示关节内存在退行性骨关节炎，但许多患者在数十年后仍保持良好的踝关节功能。在一项长期研究中，所有接受韧带直接修复术的患者都表示，如有需要，他们愿意再次接受该手术。
恢复过程很少是线性的。早期，足部负重是最困难的部分，而恢复踝关节活动需要与物理治疗师进行持续的努力。早期开始负重和活动有助于踝关节在最初几周内更好地工作，但这并不一定意味着能更早返回工作岗位。人们恢复活动的速度因人而异，因此尽量不要与他人比较。
如果未处理不稳定型损伤，问题往往持续存在而非自行缓解。骨骼可能分离，关节可能不均匀磨损，长期不稳定可能导致持续疼痛和踝关节力量减弱。手术延迟超过六个月与后期功能较差有关，因此早期评估至关重要。有时即使经过治疗，韧带也会松弛愈合，而松弛或不稳定的关节与较差的预后相关。
部分损伤还涉及踝关节内部结构的损伤。这种情况发生在多达一半的不稳定型损伤中，约五分之一的病例需要额外治疗。您的外科医生在制定治疗方案时会检查是否存在此类损伤。
何时就医¶
如果您完全无法负重、肿胀迅速且严重，或小腿内侧或上部出现大面积瘀伤，请尽早对踝关节进行评估。这些是早期迹象，表明该损伤可能不仅仅是简单的扭伤。如果休息后疼痛持续、踝关节感觉不稳定或出现“打软腿”现象，或者损伤后肿胀和僵硬长期持续，请寻求专科医生评估。这种损伤容易被漏诊，初期有时会被误诊为普通扭伤。如果延误过久，手术推迟至六个月之后与后期功能更差有关。如果您已被告知是扭伤，但踝关节症状未缓解，值得询问是否已检查过胫腓联合（syndesmosis）。
Evidence & references
This is the clinical evidence summary written for health professionals. It is technical, and it lists the research this page was built from. You do not need to read it to understand your treatment or to make a decision about it.
Anatomy & Pathophysiology¶
Ligamentous Anatomy¶
- The ankle syndesmosis is composed of the anterior-inferior tibiofibular ligament, the posteroinferior tibiofibular ligament, and the interosseous membrane [2].
- A separate anterior-inferior tibiofibular ligament fascicle, known as the Bassett ligament, may be present and contribute to syndesmotic impingement [2].
- Approximately 20% of the syndesmotic ligament is intra-articular [2].
- The interosseous membrane is important in weight transmission through the fibula [3].
Pathomechanics¶
- Syndesmotic injuries result from a combination of dorsiflexion and external rotation forces [1].
- Syndesmotic rupture can occur as a result of a torsional movement of the talus that forces the tibia and fibula apart [3].
- Syndesmotic rupture can occur as a result of a severe abduction force [3].
- Severe syndesmotic injuries are associated with deltoid ligament disruption and fibula fracture [1].
- Syndesmotic instability results in lateral and rotatory displacement of the talus [1].
Radiographic Anatomy & Measurements¶
- Normal tibiofibular clear space is less than 6 mm on either the AP or mortise ankle view [1].
- Normal tibiofibular overlap is greater than 6 mm on the AP view and greater than 1 mm on the mortise view [1].
- A tibiofibular clear space of greater than 5 mm on the AP view has been suggested to correlate with syndesmotic rupture [3].
- A tibiofibular overlap of less than 5 mm on the AP view or less than 1 mm on the mortise view has been suggested to correlate with syndesmotic rupture [3].
- The mean tibiofibular clear space in the normal population is 3.8 mm in females and 4.6 mm in males [3].
- Some normal individuals have a shallow incisura resulting in no radiographic tibiofibular overlap [3].
- CT studies show wide variation in the shape of the syndesmosis, including deep concave incisurae and limited curves [3].
Pathophysiological Consequences¶
- Injury to the ankle syndesmosis can result in persistent pain and dysfunction secondary to syndesmotic impingement [2].
- Syndesmotic impingement most often involves the anterior tibiofibular ligament, with resulting synovitis and scarring [2].
- Untreated syndesmotic diastasis may result in persisting instability, pain, and progressive osteoarthritis [3].
- Patients with radiographic evidence of syndesmosis widening demonstrated a poorer overall outcome at 5 years in a study of ankle fracture outcomes [3].
Clinical Presentation¶
History and Physical Examination¶
- Acute syndesmotic injuries are typically associated with a twisting mechanism [1].
- Patients with syndesmotic instability usually cannot bear weight [1].
- Physical examination findings include tenderness near the syndesmosis and the deltoid ligament [1].
- Pain is elicited by external rotation of the ankle [1].
- A positive squeeze test is defined as pain at the syndesmosis when compressing the tibia and fibula at midcalf [1].
- Swelling and ecchymosis are present in acute syndesmotic injuries [1].
- Patients with syndesmotic impingement exhibit localized tenderness along the anterior syndesmosis [2].
- Dorsiflexion and external rotation of the ankle increase symptoms in patients with syndesmotic impingement [2].
- Tenderness during the squeeze test may be present in patients with syndesmotic impingement [2].
Imaging¶
- The AP view of plain radiography shows decreased tibiofibular overlap in syndesmotic injury [1].
- The mortise view of plain radiography shows increased tibiofibular clear space in syndesmotic injury [1].
- Tibial radiographs should be obtained to rule out a proximal fibula fracture (Maisonneuve fracture) [1].
- In subtle cases, the diagnosis is confirmed by weight-bearing radiographs and stress radiographs in eversion and external rotation, with comparison to the opposite side [1].
- CT may help evaluate the syndesmotic space, especially in chronic cases [1].
- MRI may show subtle syndesmotic ligament injury [1].
Investigations¶
Clinical Evaluation¶
- Tenderness near the syndesmosis and deltoid ligament is a clinical sign of syndesmotic injury [1].
- Pain with external rotation is a clinical sign of syndesmotic injury [1].
Plain Radiography¶
- A tibiofibular clear space greater than 5 mm on the AP view has been suggested to correlate with syndesmotic rupture [3].
- A tibiofibular overlap less than 5 mm on the AP view has been suggested to correlate with syndesmotic rupture [3].
- A tibiofibular overlap less than 1 mm on the mortise view has been suggested to correlate with syndesmotic rupture [3].
- The tibiofibular clear space is the most reliable parameter among plain radiographic measurements for syndesmotic rupture [3].
- Cadaveric models have shown that no predictable increase in measurements on plain radiography can be found on sectioning of the syndesmotic ligaments [3].
- An increase in the tibiofibular clear space in comparison to the contralateral ankle may be more accurate than absolute values [3].
Advanced Imaging¶
- Axial imaging has been shown to demonstrate disruptions not evident on plain radiographs [3].
- CT studies have shown wide variation in the shape of the syndesmosis, including a deep concave incisura in some and a limited curve in others [3].
- MRI provides a more accurate assessment of syndesmotic injury than plain radiography [3].
- MRI assessment of syndesmotic injury correlates well with direct arthroscopic assessment [3].
- MR arthrography may add further accuracy to the assessment of syndesmotic injury [3].
- The integrity of syndesmotic ligaments is rarely visualized on MRI and is surmised from radiographic diastasis [3].
Treatment¶
- Anatomic ligament repairs are a described surgical technique for syndesmotic injuries [4].
- An evidence-based approach to the treatment of acute traumatic syndesmosis (high ankle) sprains has been outlined [4].
- Syndesmotic fixation and management is a current practice among orthopedic surgeons for ankle fractures [4].
- Deltoid ligament repair is an alternative to syndesmotic fixation in bimalleolar equivalent ankle fractures [4].
- Repair of acute superficial deltoid complex avulsion is performed during ankle fracture fixation in National Football League players [4].
- Magnetic resonance imaging has been compared to physical examination for the diagnosis of syndesmotic injury after lateral ankle sprain [4].
References¶
[1] Aaos Comprehensive Orthopaedic Review 3. Acute and Chronic Injuries of the Ankle > IV. Syndesmotic Instability.
[2] Aaos Comprehensive Orthopaedic Review 3. Arthroscopy of the Ankle > IV. Syndesmotic Impingement.
[3] Rockwood And Green S Fractures In Adults. 59: Patellar Fractures and Dislocations and Extensor Mechanism Injuries > Syndesmotic Injuries.
[4] Campbell S Operative Orthopaedics 4 Volume Set. REPAIR OF ACUTE RUPTURE OF LATERAL LIGAMENTS > ACUTE ANKLE LIGAMENT INJURIES, CHRONIC ANKLE INSTABILITY.