The Cavovarus Foot in Hereditary Motor and Sensory Neuropathies

Is a Plantarflexed First Ray the Primary Deformity In Children With Cavovarus Feet Secondary to Charcot-Marie-Tooth Disease? A Pedobarographic Analysis

BACKGROUND

Charcot-Marie-Tooth disease (CMT) is a common cause of cavovarus foot deformity in children. This deformity is often quoted as being forefoot driven, with a primary deformity of first ray plantarflexion driving the hindfoot into varus by virtue of the tripod effect of the foot, which was hypothesized by Coleman and is commonly assessed clinically using his eponymous block test. The primary goal of this study was to objectively investigate this hypothesis using dynamic pedobarography.

METHODS

A review of the gait lab archives at a large tertiary referral center was carried out to identify children with CMT who had foot photos and dynamic pedobarographic data. Two orthopaedic surgeons then determined the weight-bearing hindfoot alignment of these children using clinical photography. The order of contact during gait of the first metatarsal relative to the fifth metatarsal was then obtained from the dynamic pedobarographic data.

RESULTS

One hundred eighteen feet from 60 children with CMT met the study inclusion criteria. Sixty-eight varus feet were compared with 50 nonvarus feet. First ray contact occurred before fifth ray contact in only 39.7% of the varus feet compared with 34.0% of the nonvarus feet, which did not meet statistical significance ( P =0.526).

CONCLUSIONS

In this cohort, dynamic pedobarography did not consistently demonstrate the first metatarsal contact occurring before the fifth metatarsal contact in children with varus feet secondary to CMT. While nearly 40% of the feet did make initial contact on the first ray, 60% of the feet landed in varus before the first ray made contact, leading us to believe that the foot is prepositioned in varus. This may be in part due to the progressive muscle imbalance and secondary deformity that has occurred. Surgical management of these children should take this possibility into consideration and focus on rebalancing the forces causing this varus positioning as well as correcting the resultant bony deformity.

Are you sure that ankle is just sprained? A review of common ankle conditions, diagnoses and treatment

PURPOSE OF REVIEW

Acute ankle sprains frequently occur in active children and adolescents but may be the initial clinical presentation of other less common disorders affecting the lower extremities. There are many conditions that may cause one or multiple episodes of ankle injury that are misdiagnosed as an acute ankle sprain. This manuscript highlights diagnoses that should be considered when evaluating and managing a child or adolescent who presents initially and/or repeatedly with an acute ankle sprain.

RECENT FINDINGS

In recent years, various studies have continued to note the prevalence of misdiagnosed ankle sprains, especially amongst the paediatric population. If ankle radiographs demonstrate no abnormalities during an initial clinical examination, often the patient is diagnosed with an acute ankle sprain. However, this can be a misdiagnosis, especially when the patient has had recurrent episodes of ankle injury and ancillary studies are not performed.

SUMMARY

There are many diagnoses that can go unnoticed in the initial evaluation of a paediatric or adolescent ankle sprain. It is important for physicians to be aware of these other conditions to ensure proper treatment plans. This manuscript will analyse five conditions that may be misdiagnosed as an ankle sprain, including juvenile idiopathic arthritis, osteochondritis dissecans of the talus, hereditary sensory motor neuropathy (Charcot-Marie Tooth disease), tarsal coalition and transitional ankle fractures.

Understanding Radiographic Measurements Used in Foot and Ankle Surgery

Given the high volume of patient visits for foot and ankle complaints, developing a systematic approach to evaluation of foot and ankle pathology is important for orthopaedic providers. A thorough evaluation of weight-bearing radiographs is essential to differentiate acute and chronic injury from normal findings to dictate treatment. Radiographic changes and varying degrees of deformity can influence surgical considerations. The purpose of this article was to review and define radiographic measurements relevant to surgical decision making for common foot and ankle pathologies and treatment.

Neurologic Disorders and Cavovarus Deformity

A cavovarus deformity results from muscle imbalances in the foot. There are several etiologies of a cavovarus foot including congenital, neurologic, post-traumatic, and idiopathic. Charcot-Marie-Tooth disease is a common genetic cause of cavovarus foot. History, physical examination, and imaging help determine appropriate treatment. The deformity can be flexible or rigid and can present in children or adults, thus treatment should be individualized to the patient. Non-operative management includes shoe wear modification, physical therapy, and bracing. Operative management consists of soft tissue releases, tendon transfers, osteotomies, arthrodesis, and repair/reconstruction of lateral ankle ligaments and peroneal tendons.