您的感受¶
高弓足(cavus foot)的足弓非常高。主要问题是足前部向下倾斜朝向地面。为了使足外侧着地,足跟会向内倾斜。随着时间的推移,足底沿线的厚组织带会收紧,足跟在该倾斜位置变得更加僵硬。
您可能会感到踝关节前部疼痛。由于足前部向下倾斜的角度很大,您的踝关节必须比平时更多地向上弯曲才能使足部放平。当活动空间耗尽时,踝关节前部的骨骼会相互挤压,从而引起疼痛。
您还可能注意到前足掌、大脚趾下方以及足外侧边缘出现坚硬且压痛的皮肤斑块。这些胼胝(老茧)形成是因为您的体重压在小的接触点上,而不是均匀分布。长时间站立或行走可能会使它们更加疼痛。足部内部的小肌肉通常会萎缩,您的脚趾可能会向下卷曲或呈爪形。这种爪形变可能使鞋子摩擦,并使寻找舒适的鞋履变得困难。
许多具有这种足部形态的人感觉不稳。您的踝关节可能会失稳,您可能会在不平整的地面上或走下路缘时崴脚。反复的扭伤、踝关节外侧的酸痛以及足部骨骼的小裂纹,都可能源于体重向足外侧边缘转移的方式。
这些变化通常影响双脚,尽管一侧可能比另一侧更严重。由于这种足部形态常有家族史,且可能与神经或肌肉疾病有关,您的外科医生会询问您的家族史并检查您腿部的神经。如果只有一只脚受影响,可能需要对脊柱进行扫描以查找病因。足部和踝关节的负重X光片可以显示足弓有多高,以及足跟是否仍然灵活。
实际发生了什么¶
将您的足部想象为一个三脚架。健康的足部依靠三个支点站立:足跟、大脚趾后方的跖骨头,以及小脚趾后方的跖骨头。在高弓足中,足部前部下垂过度,尤其是在大脚趾下方。为了使足部外侧接触地面,足跟必须向内倾斜。随后,您的体重沿着三脚架的一条边缘传递,而不是在所有三个支点上均匀分布。
足部前部的下垂通常始于足部内部的小肌肉。当这些肌肉变得薄弱或紧张时,它们无法平衡小腿和腿部更强大的肌肉。足底沿行的紧张组织带将足弓拉得越来越高,并将脚趾的长骨压向地面。在这些肌肉失去平衡的情况下,足跟向内倾斜,脚趾卷曲并呈爪状。
这种足部形态很少单独出现。它通常是潜在神经或肌肉疾病的征兆,最常见的是称为腓骨肌萎缩症(Charcot-Marie-Tooth disease)的疾病,该疾病影响通往肌肉的神经。大约三分之二的高弓足患者伴有此类疾病。大约每十个人中就有一人存在某种程度的这种足部形态,且大多数人没有症状。这种情况很少见于幼儿,但在8至10岁后变得相当常见。
您所感受的一切均源于这种失衡模式。足部前部的下垂迫使踝关节向上弯曲超过其极限,从而导致踝关节前部疼痛。体重压在足部跖骨头和外侧边缘上形成胼胝。倾斜的足跟使踝关节不稳定且容易扭伤。即使是这种足部形态的轻微版本,也可能导致反复扭伤、踝关节外侧肌腱撕裂以及足部骨骼的小骨折。
我们如何处理该问题¶
最简单的治疗旨在放松紧张的组织并强化薄弱的肌肉。拉伸跟腱——即踝关节后方那条强韧的肌腱——是主要手段。物理治疗还着重强化提升足部并使足部外翻的肌肉。对于轻度、灵活且无痛的足部,这套方案可能已足够。更换鞋履和使用鞋垫可以更均匀地分散体重并缓解压力点,尽管它们无法矫正足弓本身。如果您活动量较大,缓冲性好且中性的跑鞋可以减少足底承受的负荷。如果您的脚趾出现爪形畸形,使用简单的支具将脚趾固定得更直,可以在不损伤皮肤的情况下改善行走。对于伴有神经相关足部问题的儿童,这些措施可以推迟手术数年,在随访至生长发育结束的儿童中,约有一半可完全避免手术。在决定进一步处理之前,请给予非手术治疗一个公平的尝试期。
我们不使用皮质类固醇或其他注射治疗此病症,因此不会提供此类治疗。对于常导致这种足部形态的神经病变,肉毒毒素注射是安全且耐受性良好的,但它们无法减缓足弓的变化。连续石膏固定也未见成效,大剂量维生素 C 也不会改变该病症。
当您的足部在上述措施下仍疼痛、僵硬或持续恶化时,手术便进入讨论范围。我们的目标是在可能的情况下保持关节活动。这可能包括松解足底紧张的组织、移位肌腱以重新平衡足部,或截骨并重塑骨骼以降低足弓。如果您的足跟仍具有灵活性,保留关节的手术是我们的首选。当足部僵硬且严重,或关节已磨损时,融合部分关节可能是剩余的选择。我们将详细讨论每种方案的内容,并共同决定适合您足部状况和目标的治疗方案。
预期情况¶
高弓足是一种长期存在的形态,而非短暂的疾病。它不会时好时坏。若不加干预,足弓往往倾向于保持高位或缓慢升高,而足跟则倾向于在其倾斜位置逐渐僵硬。您目前感受到的问题,如前足跖骨头下方的疼痛、踝关节扭伤以及爪形趾,通常会持续存在或逐渐加重,而不会自行缓解。
非手术治疗确实可以改变这一病程。拉伸、强化训练、更换鞋履以及使用矫形鞋垫可以减轻压力并改善足部功能。对于伴有神经相关足部病变的儿童,这些措施可将手术推迟数年,且在随访至生长发育结束的儿童中,约有一半可完全避免手术。若最终需要手术,通常已推迟了约4.5年。话虽如此,这种足部形态通常不会消失。良好管理的目标是使足部尽可能长时间地保持舒适、稳定,并能满足您的功能需求。
当手术是正确选择时,预后取决于足部仍具有的柔韧性以及病变的严重程度。只要可能,首选保关节手术,这类手术适用于大多数柔韧性较好的足部,包括受腓骨肌萎缩症(Charcot-Marie-Tooth disease)影响的足部。这些手术旨在降低足弓,同时保持关节活动度。对于严重僵硬的足部或关节磨损的足部,可能需要融合部分关节,这通常作为最后的选择。大多数接受严重足部畸形矫正手术的患者能够重返工作岗位,并报告术后生活质量有所提高。
了解一些客观的局限性也很重要。手术并不能给您一个正常的足部。矫正旨在更均匀地分散体重、稳定踝关节并使穿鞋更容易。某些手术能很好地改善行走距离、活动能力和鞋履使用,但对疼痛的影响较小。而且,由于潜在的神经或肌肉状况往往持续存在,足部形态可能在数年内再次发生变化,因此持续的随访至关重要。
何时就医¶
如果您发现足弓变高且持续升高,前足掌或足外侧缘反复出现胼胝(老茧),脚趾开始卷曲或呈爪形,或反复发生踝关节扭伤,请咨询您的全科医生(GP)。如果您在行走或上下楼梯时前踝疼痛,踝关节在不平路面上反复不稳,或足部僵硬导致鞋子越来越难穿,请要求专科医生评估。由于这种足部形态通常是神经或肌肉疾病的征兆,请提及任何类似足部形态的家族史、腿部无力或足部感觉丧失。如果您出现突然的无力、麻木或膀胱或肠道控制丧失,请立即前往急诊科,因为这些可能提示需要当日评估的脊髓问题。
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.
Overview¶
- A pes cavus (cavus foot) is characterized by an elevated medial longitudinal arch secondary to forefoot plantar flexion [1].
- A pes cavus (cavus foot) may also result from excessive calcaneal dorsiflexion, though this is less frequent than forefoot plantar flexion [1].
- Two-thirds of patients with a cavus foot have an underlying neurologic disorder [1].
- Charcot-Marie-Tooth disease is the most common underlying neurologic disorder in patients with a cavus foot [1].
- The primary structural problem in cavus foot is forefoot plantar flexion [1].
- The first ray is often more markedly plantarflexed than other rays, resulting in forefoot pronation [1].
- For the lateral half of the foot to contact the ground, the hindfoot must deviate into varus [1].
- First ray plantar flexion may result from a weak tibialis anterior relative to the peroneus longus [1].
- First ray plantar flexion is more commonly caused by intrinsic weakness and contracture than by tibialis anterior weakness [1].
- Over time, the plantar fascia contracts, causing the hindfoot varus deformity to become more rigid [1].
- Patients with cavus foot may report instability, such as ankle sprains [1].
- A neurologic examination and family history are essential for evaluating cavus foot [1].
- Unilateral involvement suggests a focal diagnosis, such as a spinal cord anomaly or nerve injury [1].
- Bilateral involvement and a positive family history are common with Charcot-Marie-Tooth disease [1].
- Asymmetry may be seen in Charcot-Marie-Tooth disease despite bilateral involvement [1].
- Hindfoot flexibility is assessed by placing a 1-inch block under the lateral border of the foot (Coleman block test) [1].
- Weight-bearing radiographs are required for the evaluation of cavus foot [1].
- An increased Meary angle is defined as the long axis of the talus intersecting the long axis of the first metatarsal dorsally on the lateral view of the foot [1].
- The normal value for the Meary angle is 0° to 5° [1].
- An increased calcaneal pitch is defined as the intersection of a line running along the undersurface of the calcaneus and the floor [1].
- A calcaneal pitch greater than 30° indicates a calcaneocavus foot [1].
- MRI of the spine is indicated with unilateral involvement [1].
- Joint-sparing procedures are preferred whenever possible for the treatment of cavus foot [1].
- The flexibility of the hindfoot is a key factor in surgical decision making for cavus foot [1].
- Percutaneous plantar fascia release is insufficient to correct a cavus foot [1].
- At minimum, an open release and soft-tissue rebalancing are needed to correct a cavus foot [1].
- Achilles tendon lengthening should not be performed concomitantly with plantar fasciotomy [1].
- An intact Achilles tendon provides the resistance necessary to stretch the contracted plantar tissues and correct the cavus deformity [1].
- In a non-weight-bearing position, the long axes of the tibia and the calcaneus are parallel in a cavus foot [1].
- In a weight-bearing position, a rigid equinus forefoot deformity forces the flexible hindfoot into varus, creating a tripod effect [1].
- For mild, flexible, and painless cavus foot, treatment includes Achilles tendon stretching and an eversion/dorsiflexion strengthening program [1].
- For mild, progressive or symptomatic cavus foot, treatment includes plantar release with or without peroneus longus to brevis transfer [1].
- For varus caused by peroneal weakness, treatment includes adding tibialis anterior and/or posterior tendon transfer to the peroneal muscles [1].
- For moderate rigid medial cavus, treatment includes dorsiflexion osteotomy of either the first metatarsal or cuneiform [1].
- For rigid medial and lateral cavus, treatment includes dorsiflexion osteotomies of the cuboid and cuneiforms [1].
- For rigid hindfoot varus, treatment includes closing/sliding calcaneal osteotomy [1].
- For clawing of the hallux, treatment includes adding an EHL transfer to the first metatarsal (Jones) [1].
- Triple arthrodesis is rarely needed for severe cavus foot and should be avoided whenever possible [1].
Anatomy & Pathophysiology¶
Definition and Structural Components¶
- A pes cavus (cavus foot) is defined by an elevated medial longitudinal arch secondary to forefoot plantar flexion or, less frequently, excessive calcaneal dorsiflexion [1].
- The primary structural problem in cavus foot is forefoot plantar flexion, with the first ray often more markedly plantarflexed, resulting in forefoot pronation [1].
- A cavovarus foot represents a multisegmental deformity characterized by a plantarflexed first ray, elevated medial longitudinal arch, and hindfoot varus [5].
- Approximately 10% of skeletally mature individuals have cavovarus foot alignment, with most being asymptomatic [10].
Neuromuscular Etiology and Prevalence¶
- Two-thirds of patients with a cavus foot have an underlying neurologic disorder, most commonly Charcot-Marie-Tooth (CMT) disease [1].
- CMT disease is the most common neuromuscular cause of cavovarus foot deformity in children [9].
- Cavovarus foot deformities are the most common orthopaedic deformities in all types of CMT disease except type II, in which planovalgus foot deformities are most common [9].
- In a study of more than 2700 patients with CMT, 71% had foot deformities, with pes cavus and hammer toes being the most common [9].
- Patients with bilateral cavovarus feet have a 78% probability of being diagnosed with CMT, which increases to 91% with a family history of CMT [3].
- Cavus foot is rarely found in the absence of an underlying neuromuscular condition [2].
- Cavus foot is rarely found in early childhood but is fairly frequent after 8–10 years of age [2].
- Nonneurologic causes of cavovarus foot include congenital clubfoot, posttraumatic varus malunion, missed compartment syndrome, burn contractures, and idiopathic etiology [10].
Pathogenesis and Muscle Imbalance¶
- The cause of cavus foot is usually muscle imbalance in a growing foot [2].
- First ray plantar flexion may result from a weak tibialis anterior relative to the peroneus longus, but is more commonly caused by intrinsic weakness and contracture [1].
- Neuropathic cavovarus deformity in CMT is caused by a combination of intrinsic and extrinsic weakness, beginning with weakness of intrinsic foot muscles and the anterior tibial muscle, with normal strength of the posterior tibial and peroneus longus muscles [9].
- The triceps surae is weak and may be contracted in CMT-related cavovarus deformity [9].
- The forefoot is pulled into equinus relative to the hindfoot, and the first ray becomes plantarflexed [9].
- Long toe extensors attempt to assist the weak anterior tibial tendon in dorsiflexion but contribute to metatarsal plantarflexion, pronating the forefoot into a valgus position with mild adduction of the metatarsals [9].
- Initially, the forefoot is supple and weightbearing, but as it becomes more rigidly pronated, the hindfoot assumes a varus position [9].
- Weightbearing becomes a "tripod" mechanism, with weight borne on the heel and the first and fifth metatarsal heads [9].
- Neuromuscular imbalance between a nonfunctioning peroneus brevis muscle and its antagonist, the posterior tibialis muscle, pulls the hindfoot into varus [10].
- Forefoot-driven varus occurs when a relatively weak anterior tibialis muscle is overpowered by its antagonist, the peroneus longus muscle, plantarflexing the first ray [10].
- Atrophy and contracture of the intrinsic musculature of the foot occur because of denervation, leading to collagen replacement of the intrinsic muscles [3].
- These pathologic changes produce elevation of the longitudinal arch because of contracture of the plantar fascia [3].
- Over time, the plantar fascia contracts, and the hindfoot varus deformity becomes more rigid [1].
- Toe deformity results from nonfunctional intrinsic muscles, which normally flex the MTP joints and extend the distal and proximal interphalangeal (IP) joints [3].
- With absent intrinsic function, long toe flexors create flexion deformities of the IP joints, and toes hyperextend through the MTP joints, assuming a dorsally displaced position with metatarsal head prominence [3].
- Loss of intrinsic function, as seen in hereditary motor sensory neuropathy or diabetic neuropathy, predictably leads to claw toes [24].
Clinical Manifestations¶
- Patients may report instability, such as ankle sprains [1].
- One of the most common symptoms of cavus foot is anterior ankle pain, sometimes associated with toe walking [2].
- Anterior ankle pain occurs because the forefoot is severely plantar flexed on the hindfoot, requiring marked ankle dorsiflexion to compensate [2].
- When the cavus becomes too severe, ankle dorsiflexion is blocked, leading to anterior ankle impingement and pain [2].
- The inability to dorsiflex further compromises forefoot clearance, and eventually, only the metatarsals can contact the floor [2].
- This condition can be misinterpreted as ankle plantarflexion contracture, leading to unnecessary heel cord release [2].
- Calluses beneath the metatarsal heads and heel skin are common [2].
- Plantar callosities under the first and fifth metatarsal heads are common, as is plantar intrinsic wasting [5].
- The medial longitudinal arch is elevated when viewed from the side, and the heel is inverted on standing when viewed from behind [5].
- A "peek-a-boo" heel, where the medial heel pad is visible from behind, can signify hindfoot varus [5].
- When standing, the foot has a bean-shaped appearance because of combined hindfoot varus and forefoot adductus [10].
- Clawing of the hallux and lesser toes are often seen in neuromuscular cavovarus foot [10].
- In CMT, increased pressure on the metatarsal heads leads to painful callosities along the lateral border of the foot and beneath the metatarsal heads [3].
- Foot and ankle weakness caused the greatest impact on quality of life in a study of adults with CMT [3].
Radiographic Findings¶
- Weight-bearing radiographs are required for evaluation [1].
- Increased Meary angle is defined as the long axis of the talus intersecting the long axis of the first metatarsal dorsally on the lateral view, with a normal value of 0° to 5° [1].
- In patients with CMT, Meary angle values average 18 degrees [3].
- Increased calcaneal pitch is defined as the intersection of a line running along the undersurface of the calcaneus and the floor, with a pitch greater than 30° indicating a calcaneocavus foot [1].
- On lateral radiographs, the fibula is often located posterior to the posterior border of the distal tibia at the level of the ankle [10].
- The calcaneal pitch angle may be greater than 20° in cavovarus foot [10].
- The talar first metatarsal angle may be apex dorsally angulated because of plantar flexion of the first ray [10].
- On AP radiographs, the metatarsals are often adducted and the forefoot is rotated into supination [10].
- On AP radiographs of the ankle, the talus may tilt into varus as a result of lateral ankle ligament insufficiency [10].
- Varus is seen as parallelism of the talus and calcaneus on the lateral radiograph in CMT patients [3].
- The lack of hindfoot equinus can be documented by measurement of the calcaneal pitch, which usually reveals dorsiflexion of the calcaneus and forefoot equinus with the apex of the deformity in the midfoot [3].
- Hindfoot varus can be assessed using the AP-talocalcaneal angle, and midfoot cavus by the lateral talar–first metatarsal angle [5].
- Foot supination can be quantified by metatarsal overlap [5].
Flexibility Assessment¶
- If lateral foot elevation and first ray plantar flexion succeed in everting the hindfoot, the hindfoot deformity is driven by the plantarflexed first ray (forefoot-driven hindfoot varus) [5].
- If the hindfoot varus corrects with the Coleman block test, the deformity is considered forefoot-driven varus or flexible varus [10].
- If the hindfoot deformity does not correct with passive manipulation or the Coleman block test, the deformity is considered hindfoot-driven varus or fixed varus [10].
- Fixed varus indicates that the Chopart joints are locked in varus and that a hindfoot corrective osteotomy is required [10].
- With time, the varus deformity becomes fixed and does not correct when the block test is performed [3].
- The Coleman block lateral radiograph is a mediolateral weight-bearing view used to evaluate hindfoot flexibility, rotational correction in the ankle, and degree of correction of forefoot supination [3].
- Multiple clinical methods have been described to assess hindfoot flexibility, including the Coleman block test, oblique block test, and prone Price and Mubarak tests [5].
Clinical Presentation¶
Definition and Etiology¶
- A pes cavus (cavus foot) is characterized by an elevated medial longitudinal arch secondary to forefoot plantar flexion or, less frequently, excessive calcaneal dorsiflexion [1].
- Approximately two-thirds of patients with a cavus foot have an underlying neurologic disorder, most commonly Charcot-Marie-Tooth disease [1].
- Cavus foot is frequently accompanied by hindfoot varus deformity (cavovarus foot) [2].
- Cavus foot is a marker for neuromuscular disease, requiring a thorough search for the underlying cause [2].
- In patients with bilateral cavovarus feet, there is a 78% probability of being diagnosed with Charcot-Marie-Tooth disease [3].
- A family history of Charcot-Marie-Tooth disease increases the probability of diagnosis in patients with bilateral cavovarus feet to 91% [3].
Physical Examination Findings¶
- Anterior ankle pain in cavus foot occurs because the severely plantar flexed forefoot requires marked ankle dorsiflexion to compensate, leading to impingement when dorsiflexion is blocked [2].
- Calluses beneath the metatarsal heads and heel skin are common in cavus foot [2].
- Plantar callosities under the first and fifth metatarsal heads are common clinical findings [5].
- Plantar intrinsic wasting is a common finding on physical examination [5].
- The medial longitudinal arch is elevated when viewed from the side [5].
- The heel is inverted on standing when viewed from behind [5].
- A "peek-a-boo" heel, where the medial heel pad is visible from behind, signifies hindfoot varus [5].
- Clawing of the hallux and lesser toes is often seen in neuromuscular cavovarus foot [10].
- The foot may have a bean-shaped appearance due to combined hindfoot varus and forefoot adductus [10].
- Gait evaluation should look for subtle footdrop, compensatory toe clawing, ankle instability, and peroneal weakness [10].
- Unilateral involvement suggests a focal diagnosis such as spinal cord anomaly or nerve injury [1].
- Bilateral involvement with a positive family history is common with Charcot-Marie-Tooth disease, though asymmetry may be seen [1].
Diagnostic Testing¶
- A neurologic examination and family history are essential for evaluation [1].
- Electromyography and nerve conduction velocity studies are required for careful examination of the peripheral and central nervous systems [9].
- Weight-bearing radiographs are required for radiographic assessment [1].
- An increased Meary angle, where the long axis of the talus intersects the long axis of the first metatarsal dorsally, is a radiographic finding; normal value is 0° to 5° [1].
- In patients with Charcot-Marie-Tooth disease, the Meary angle averages 18 degrees [3].
- Increased calcaneal pitch, defined as the intersection of a line along the undersurface of the calcaneus and the floor, indicates a calcaneocavus foot if greater than 30° [1].
- The Coleman block test assesses hindfoot flexibility by placing a 1-inch block under the lateral border of the foot [1].
- If the hindfoot varus corrects with the Coleman block test, the deformity is considered forefoot-driven or flexible varus [10].
- If the hindfoot deformity does not correct with passive manipulation or the Coleman block test, it is considered hindfoot-driven or fixed varus [10].
- Fixed varus indicates that the Chopart joints are locked in varus and requires a hindfoot corrective osteotomy [10].
- On AP radiographs, metatarsals are often adducted and the forefoot is rotated into supination [10].
- The talus may tilt into varus on AP ankle radiographs as a result of lateral ankle ligament insufficiency [10].
Investigations¶
Clinical Evaluation¶
- A neurologic examination and family history are essential for the evaluation of cavus foot [1].
- Unilateral involvement of cavus foot suggests a focal diagnosis, such as a spinal cord anomaly or nerve injury [1].
- Asymmetry may be seen in patients with Charcot-Marie-Tooth disease despite bilateral involvement [1].
- Cavus foot is frequently accompanied by hindfoot varus deformity, clawing of the toes, and demonstrable weakness of ankle or foot muscles [2].
- Calluses beneath the metatarsal heads and heel skin are common clinical findings in cavus foot [2].
- Anterior ankle pain is one of the most common symptoms of cavus foot, sometimes associated with toe walking [2].
- The inability to dorsiflex the ankle in severe cavus foot can be misinterpreted as an ankle plantarflexion contracture [2].
Physical Examination¶
- Hindfoot flexibility is assessed by placing a 1-inch block under the lateral border of the foot, known as the Coleman block test [1].
- Hindfoot varus in individuals with a cavovarus deformity is considered nonstructural if it can be corrected with the block test [2].
Imaging¶
- MRI of the spine is indicated for patients with unilateral cavus foot involvement [1].
- Diagnosis of cavus foot may require spinal MRI and electromyographic (EMG) studies to search for the underlying neuromuscular cause [2].
- A standard series of weight-bearing radiographs of the foot includes AP, lateral, and oblique views [30].
- The hindfoot alignment view or Saltzman view is commonly obtained to evaluate the axial alignment of the hindfoot in relation to the ankle above [30].
- MRI can be useful in the diagnosis of metatarsalgia, such as distinguishing among a neuroma, cyst, bursa, or synovitis [14].
- MRI is a fundamental tool in the workup of a patient with a soft-tissue or bone tumor in the foot [35].
- MRI is a valuable imaging modality in the evaluation of patients with suspected bone or soft-tissue infection [35].
- MRI has a high false-positive rate in the diagnosis of osteomyelitis, particularly with concurrent Charcot arthropathy [33, 34].
- Labeled WBC scan or dual-image technetium/indium (Tc/In) scan is more sensitive and specific for osteomyelitis than isolated Tc scan [33, 34].
- Normal MRI marrow signal confidently excludes osteomyelitis [35].
Treatment¶
Non-Operative¶
- Conservative treatment of cavus foot includes accommodation by shoe modifications or inserts [2].
- Shoe modifications and inserts do not actually correct the condition [2].
- Initial management includes an orthotic that recesses the first ray and elevates the entire lateral foot, reserved for deformities with flexible hindfoot varus [5].
- For mild, flexible, and painless cavus foot, treatment consists of Achilles tendon stretching and an eversion/dorsiflexion strengthening program [1].
- Nonoperative treatment of the cavovarus foot, including the use of serial casting and botulinum toxin, has generally been unsuccessful [9].
- A randomized trial found that 8 weeks of botulinum toxin to prevent pes cavus progression was safe and well tolerated but did not affect the progression of the deformity [9].
- Medical treatment with high-dose ascorbic acid has been found to be ineffective in altering the natural history of Charcot-Marie-Tooth disease [9].
Operative¶
- Joint-sparing procedures are preferred whenever possible for cavus foot [1].
- A key to surgical decision making for cavus foot is the flexibility of the hindfoot [1].
- For mild, progressive or symptomatic cavus foot, treatment is plantar release with or without peroneus longus to brevis transfer [1].
- For varus caused by peroneal weakness, tibialis anterior and/or posterior tendon transfer to the peroneal muscles is indicated [1].
- For moderate rigid medial cavus, treatment is dorsiflexion osteotomy of either the first metatarsal or cuneiform [1].
- For rigid medial and lateral cavus, treatment is dorsiflexion osteotomies of the cuboid and cuneiforms [1].
- For rigid hindfoot varus, treatment is a closing/sliding calcaneal osteotomy [1].
- For clawing of the hallux, an EHL transfer to the first metatarsal (Jones) is added [1].
- If the patient is symptomatic, the treatment of choice is plantar release with first metatarsal osteotomy and possible tendon transfers [2].
- Severe deformity requires surgical correction by tendon transfers to restore muscle balance, midfoot wedge osteotomy to correct bony deformity, or triple arthrodesis [2].
- When done early in the disease in young patients, soft tissue surgery consisting of plantar fascia release or extensive plantar release, including capsulotomies with tendon transfer, may be sufficient to postpone or avoid triple arthrodesis [3].
- Surgical correction of the cavovarus foot in patients with CMT can be divided into deformity correction and rebalancing of deforming muscle forces [3].
- For a plantarflexed first metatarsal with mild cavovarus and a fully flexible hindfoot, treatment involves soft-tissue procedures and possible first metatarsal osteotomy [9].
- For increased plantarflexion of the first metatarsal, increased supination, and a stiffer hindfoot, treatment involves first metatarsal osteotomy, midfoot/hindfoot osteotomies, and possible triple arthrodesis [9].
- For rigid cavovarus deformity, treatment is triple arthrodesis [9].
- Surgical procedures for CMT foot deformities are classified as soft tissue for flexible deformities, osteotomy for stiffer flexible or rigid deformities, and joint stabilizing for completely rigid deformities [9].
- Early, aggressive treatment when the hindfoot is flexible and early soft-tissue releases can delay the need for triple arthrodesis [9].
- In equinocavovarus deformity, if the hindfoot is correctable into valgus, isolated soft-tissue surgeries can be used to correct the deformity [50].
- A split transfer of the tibialis anterior tendon to the lateral cuneiform can maintain active dorsiflexion while reorienting the force vector out of varus [50].
- If the tibialis anterior tendon is weak, a split tibialis posterior tendon transfer to the peroneus brevis should be used [50].
- If the hindfoot is not correctable into valgus, tendon transfer should be coupled with a calcaneal lateral closing wedge osteotomy or a slide osteotomy [50].
- Cavus can be addressed with a plantar fascia release through either a plantar or a medial incision [50].
- If both cavus and equinus are present, their correction should be staged because the surgeon cannot control the contributions of each procedure if done concurrently [50].
- When deformities are too severe to correct through reconstruction, or when reconstruction fails, triple arthrodesis is an option [50].
- The addition of a lateral column lengthening to the triple arthrodesis has been described to address severe deformity [50].
- Lateral column lengthening added to triple arthrodesis results in a stiff foot that is at higher risk for skin breakdown [50].
- Reconstruction is preferred over triple arthrodesis when possible [50].
- Several different osteotomies of the midfoot have been proposed for surgical reconstruction of a cavus foot, all involving removing a dorsally based V-shaped wedge of bone from the midfoot at or just proximal to the apex of the cavus deformity [41].
- Plantar soft tissue release is generally performed either before or in addition to an osteotomy of the midfoot [41].
- Cole described a dorsal closing wedge osteotomy of the midfoot with the proximal cut made through the navicular and cuboid bones [41].
- Jahss proposed a tarsometatarsal dorsal wedge resection osteotomy for the correction of cavus deformity [41].
- The amount of forefoot equinus that can be corrected with the Jahss osteotomy should not exceed 20 to 25 degrees [41].
- Jahss recommended triple arthrodesis for feet with severe deformities because greater correction with the Jahss osteotomy led to the development of a rocker deformity in the sole of the foot and persistent symptoms [41].
- If a callus is present on the sole of the foot preoperatively, the osteotomy must be performed proximal to the callus for successful redistribution of pressure across the foot [41].
- Japas described a V-shaped osteotomy made dorsally with the apex at the navicular and limbs extending distally to just proximal to the cuboid–fifth metatarsal joint laterally and proximal to the medial cuneiform–first metatarsal joint medially [41].
- The Japas osteotomy does not include resection of a wedge, so the foot is not shortened further by bony resection, yet the joints are all left mobile in the midfoot and hindfoot [41].
- The Japas osteotomy cannot correct severe cavus because a wedge is not resected [41].
- The Japas osteotomy cannot correct rigid hindfoot varus [41].
- Wilcox and Weiner modified the Japas osteotomy by making a dome osteotomy with bone resection through the base of the fifth metatarsal, the cuboid, and the three cuneiforms [41].
- At long-term follow-up of 139 feet, 76% of patients had satisfactory results with the Wilcox and Weiner modified Japas osteotomy [41].
- Satisfactory results with the Wilcox and Weiner modified Japas osteotomy were only obtained in 67% of children younger than 8 years old [41].
- Wicart and Serings performed plantar-based opening wedge osteotomies of the cuneiforms combined with plantar release and a calcaneal osteotomy, with satisfactory results in 64% of 36 feet [41].
- Triple arthrodesis was ultimately necessary in 33% of patients treated with plantar-based opening wedge osteotomies of the cuneiforms combined with plantar release and a calcaneal osteotomy [41].
- Correction of severe pes cavovarus or calcaneocavus has been achieved by osteotomy and gradual distraction and correction with external fixation such as the Ilizarov device [41].
- The bone correction attained with Ilizarov reconstruction is insufficient for long-term satisfactory outcomes in cavus deformity [41].
- Soft tissue balancing procedures or arthrodesis must be performed after Ilizarov reconstruction to decrease the likelihood of recurrence [41].
- Arthrodesis should be avoided in patients with myelomeningocele as insensate feet are susceptible to skin breakdown and ulceration [45].
Complications¶
Post-traumatic Deformity¶
- Pes cavus deformity is a reported adverse outcome following tarsal navicular fractures [51].
- Coulibaly et al. reported an incidence of 26% of pes cavus deformities after navicular fracture care [51].
Neuromuscular Sequelae¶
- In Charcot-Marie-Tooth disease, denervation leads to atrophy and contracture of the intrinsic musculature of the foot [3].
- Collagen replacement of the intrinsic muscles of the foot occurs due to denervation in Charcot-Marie-Tooth disease [3].
- Contracture of the plantar fascia in Charcot-Marie-Tooth disease increases pressure on the metatarsal heads [3].
- Increased pressure on the metatarsal heads leads to painful callosities along the lateral border of the foot and beneath the metatarsal heads in Charcot-Marie-Tooth disease [3].
- Absent intrinsic muscle function in Charcot-Marie-Tooth disease results in flexion deformities of the interphalangeal joints of the toes [3].
- Toes in Charcot-Marie-Tooth disease hyperextend through the metatarsophalangeal joints, assuming a dorsally displaced position with metatarsal head prominence on the plantar aspect of the foot [3].
- Foot and ankle weakness caused the greatest impact on quality of life in a study of adults with Charcot-Marie-Tooth disease [3].
Surgical Complications and Risks¶
- Unnecessary heel cord release may be performed if anterior ankle impingement in cavus foot is misinterpreted as an ankle plantarflexion contracture [2].
- Achilles tendon lengthening performed concomitantly with plantar fasciotomy is contraindicated because an intact Achilles tendon provides the resistance necessary to stretch contracted plantar tissues and correct the cavus deformity [1].
Recovery¶
- Dynamic pedobarography has shown that operative treatment of cavovarus foot deformity does not normalize pressure distribution even when the foot deformity is corrected [3].
- Undercorrection is the leading cause of poor outcomes in patients who undergo cavovarus reconstruction [10].
- Nonsurgical treatment for cavovarus deformity includes utilization of laterally posted custom orthotic inserts with the posting extended to the midfoot to simulate a Coleman block test [10].
- Nonsurgical treatment for cavovarus deformity includes physical therapy to optimize peroneal muscle strength and function [10].
- A custom ankle-foot orthosis (AFO) can be considered for more severe cavovarus deformities involving the hindfoot or ankle [10].
- Initial management of cavovarus foot includes an orthotic that recesses the first ray and elevates the entire lateral foot, reserved for deformities with flexible hindfoot varus [5].
- For mild, flexible, and painless cavus foot deformity, treatment consists of Achilles tendon stretching and an eversion/dorsiflexion strengthening program [1].
- For mild, progressive or symptomatic cavus foot deformity, treatment consists of plantar release with or without peroneus longus to brevis transfer [1].
- For cavus foot deformity with varus caused by peroneal weakness, treatment involves adding tibialis anterior and/or posterior tendon transfer to the peroneal muscles [1].
- For moderate rigid medial cavus deformity, treatment consists of dorsiflexion osteotomy of either the first metatarsal or cuneiform [1].
- For rigid medial and lateral cavus deformity, treatment consists of dorsiflexion osteotomies of the cuboid and cuneiforms [1].
- For rigid hindfoot varus deformity, treatment consists of a closing/sliding calcaneal osteotomy [1].
- For clawing of the hallux in cavus foot deformity, treatment involves adding an extensor hallucis longus (EHL) transfer to the first metatarsal (Jones procedure) [1].
- Triple arthrodesis is rarely needed for severe cavus foot deformity and should be avoided whenever possible [1].
- Arthrodesis should be reserved for salvage procedures or in combination with tendon transfers in patients with severe deformity in whom joint-sparing surgery would fail or has failed [10].
- Achilles tendon lengthening should not be performed concomitantly with plantar fasciotomy for cavus foot correction [1].
References¶
[1] Aaos Comprehensive Orthopaedic Review 3. Pediatric Foot Conditions > Pes Cavus.
[2] A Lange Medical Book Current Diagnosis Treatment In Orthopedics Fifth Edition. 10Pediatric Orthopedic Surgery > 4. Cavus Foot.
[3] Tachdjian S Pediatric Orthopaedics From The Texas Scottish Rite Hospital For Children E Book. Iliopsoas Muscle Transfer for Lateral Stability of the Hip > Orthopaedic Manifestations and Surgical Treatment > Foot.
[5] Orthopaedic Knowledge Update 13 Ebook Without Multimedia. Pediatric Lower Extremity and Foot Disorders > Cavovarus Foot.
[9] Campbell S Operative Orthopaedics 4 Volume Set. DIFFERENTIATION OF MUSCLE DISEASE FROM NERVE DISEASE > CHARCOT-MARIE-TOOTH DISEASE (PERONEAL MUSCULAR ATROPHY) > CAVOVARUS FOOT DEFORMITY.
[10] Orthopaedic Knowledge Update 13 Ebook Without Multimedia. Foot and Ankle Reconstruction > Cavovarus Foot.
[14] A Lange Medical Book Current Diagnosis Treatment In Orthopedics Fifth Edition. 8Foot and Ankle Surgery > METATARSALGIA.
[24] Miller S Review Of Orthopaedics. 2. Hindfoot and midfoot > 3. Forefoot.
[30] Orthopaedic Knowledge Update 13 Ebook Without Multimedia. Foot and Ankle Anatomy and Biomechanics > Imaging > Plain Radiographs.
[33] Miller S Review Of Orthopaedics. SECTION 16 PATELLAR TRACKING IN TOTAL KNEE ARTHROPLASTY > CLINICAL PROBLEMS > 3. Diabetic foot infections.
[34] Miller S Review Of Orthopaedics. CLINICAL PROBLEMS > 3. Diabetic foot infections.
[35] Campbell S Operative Orthopaedics 4 Volume Set. OTHER DISORDERS OF FOOT AND ANKLE.
[41] Tachdjian S Pediatric Orthopaedics From The Texas Scottish Rite Hospital For Children E Book. Plate 15.3 Kramer/Barmada Osteotomy of the Base of the Femoral Neck for Slipped Capital Femoral Epiphysis > Midfoot Osteotomies..
[45] Orthopaedic Knowledge Update 13 Ebook Without Multimedia. Neuromuscular Disorders in Children > Myelomeningocele > Foot and Ankle Deformity.
[50] Orthopaedic Knowledge Update. Cerebral Palsy > Lower Extremity Surgery in Ambulatory Children > Foot and Ankle.
[51] Rockwood And Green S Fractures In Adults. 67: Fractures and Dislocations of the Midfoot and Forefoot > Management of Adverse Outcomes and Unexpected Complications Related to Tarsal Navicular Fractures.
