Cavovarus Deformity: Why Weight-Bearing Computed Tomography Should Be a First-Line Imaging Modality.

Cavovarus foot is a complex three-dimensional deformity, which includes a wide range of clinical conditions from subtle deformities to disabling feet. In this article, the authors discuss the role of weight-bearing computed tomography, which might enable to avoid double imaging (radiographs + tomography) in patients for which a detailed osteoarticular assessment is required, with the advantage to obtain tomographic images in standing position and a reduction of radiation exposure.

Is Subtle Cavovarus a Problem for Athletes?

Cavovarus or high-arched foot is a common foot deformity that occurs due to the disruption of the foot-driven equilibrium between the first metatarsal, fifth metatarsal, and the heel. This imbalance leads to an increase in the foot's normal plantar concavity. Cavovarus deformity ranges from a mild and flexible malalignment to a fixed, complex, and severe deformation. Subtle cavovarus foot, the mild form of the cavus foot, was first described by Manoli and colleagues.

Nonneurologic Cavovarus Feet in Skeletally Immature Patients: Main Causes and Principles of Treatment.

The foot resembles a tripod. The 3 legs consist of (1) the tip of the heel, (2) the first metatarsal, and (3) the fifth metatarsal. This concept is useful to explain cavus or flat feet. When the tips of the tripod move closer, the arch becomes higher. The leg of the tripod that moves the most will determine the type of cavus feet, which can be hindfoot cavus, forefoot cavus, or first metatarsal cavus. Cavovarus foot denotes the presence of a three-dimensional deformity of the foot, but it is much more a descriptive feature than a diagnosis.

Assessing the coronal plane deformity in Charcot Marie Tooth Cavovarus feet using automated 3D measurements.

BACKGROUND: This study assesses the coronal-plane deformities in cavovarus feet secondary to Charcot-Marie-Tooth disease (CMT) using Weightbearing-CT (WBCT) and semi-automated 3D-segmentation software. METHODS: WBCTs from 30 CMT-cavovarus feet were matched to 30 controls and analysed using semi-automatic 3D-segmentation (Bonelogic, DISIOR). The software used automated cross-section sampling with subsequent straight-line representation of weighted centre points to calculate 3D axes of bones in the hindfoot, midfoot and forefoot. Coronal relationships of these axes were analysed. Supination/pronation of the bones in relation to the ground and within each joint were measured and reported. RESULTS: The most significant deformity in CMT-cavovarus feet occurred at the talonavicular joint (TNJ) with 23 degrees more supination than normal feet (6.4 ± 14.5 versus 29.4 ± 7.0 degrees, p < 0.001). This was countered by relative pronation at the naviculo-cuneiform joints (NCJ) of 7.0 degrees (-36.0 ± 6.6 versus -43.0 ± 5.3 degrees, p < 0.001). Combined hindfoot varus and TNJ supination resulted in an additive supination effect not compensated by NCJ pronation. The cuneiforms in CMT-cavovarus feet were therefore supinated by 19.8 degrees to the ground relative to normal feet (36.0 ± 12.1 versus 16.2 ± 6.8 degrees, p < 0.001). The forefoot-arch and 1st metatarsal-ground angles demonstrated similar supination to the cuneiforms suggesting no further significant rotation occurred distally. CONCLUSION: Our results demonstrate coronal plane deformity occurs at multiple levels in CMT-cavovarus feet. Majority of the supination arises at the TNJ, and this is partially countered by pronation distally, mainly at the NCJ. An understanding of the location of coronal deformities may help when planning surgical correction. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Pes Cavus Deformity: Anatomic, Functional Considerations, and Surgical Implications.

Pes cavus is a complicated, multiplanar deformity that requires a thorough understanding in order to provide the appropriate level of care. The foot and ankle surgeon should perform a comprehensive examination, including a neurologic evaluation, in the workup of this patient population. Understanding the cause of the patient's deformity is a critical step in predicting the disease course as well as the most acceptable form of treatment. The surgical correlation with the patient's pathologic anatomy requires an in-depth clinical evaluation, in addition to the radiographic findings, as the radiographic findings do not necessarily correlate with the patient's discomfort.

Neurologic Conditions Associated with Cavus Foot Deformity.

The cavus foot deformity is an often less understood deformity within the spectrum of foot and ankle conditions. The hallmark concern is the possibility of an underlying neurologic or neuromuscular disorder. Although a proportion of these deformities are idiopathic, a significant majority do correlate with an underlying disorder. The appropriate evaluation of this deformity, in coordination within the multidisciplinary scope of health care, allows for a timely diagnosis and understanding of the patient's condition. We provide an abbreviated survey of possible underlying etiologies for the patient with the cavus foot deformity as a reference to the foot and ankle surgeon.

The Role of Peroneal Tendinopathy and the Cavovarus Foot and Ankle.

Peroneal tendon pathology is often an overlooked and underdiagnosed condition. It is often confused with chronic ankle instability. It is important when surgically managed to assess the condition of the tendons, muscle viability and strength, and associated cavovarus deformity. Complex reconstruction may be needed, including 2-stage procedures with a silicone rod and tendon transfer.

Managing the Complex Cavus Foot Deformity.

This article describes approaches to and the management of complex cavus foot deformities. Correction of rigid multiplanar deformities can be very challenging, given the presence of skeletal deformities in multiple planes and combined with a varying degree of muscle imbalance. The complexity of these cases always requires a case-by-case approach. Some of the cases presented here occur in patients who have previously undergone surgical management for their deformity, several of which are complicated by additional deformities. With a firm understanding and application of the principles of deformity correction, however, one may reliably offer satisfactory results.

The Cole Midfoot Osteotomy: Clinical and Radiographic Retrospective Review of Five Patients (Six Feet) with Different Etiologies.

BACKGROUND: Cole osteotomy is performed in patients having a cavus deformity with the apex of the deformity in the midfoot. Correction of the deformity at this midfoot level improves foot and ankle stability by creating a plantigrade foot. We retrospectively reviewed the clinical and radiographic results of six feet (five patients) that underwent Cole midfoot osteotomy (2011-2015). METHODS: The patients had different etiologies (spastic cerebral palsy, burn sequelae, spina bifida, and Charcot-Marie-Tooth disease). Dorsal and slightly laterally based transverse wedge osteotomy through the navicular bone medially and the cuboid bone laterally was performed. Patients were under routine clinical follow-up. We evaluated clinical and radiographic results. RESULTS: Mean clinical follow-up was 15.7 months (range, 6-36 months). The mean preoperative and postoperative talo-first metatarsal angles on lateral radiographs were 29.9° and 8.7°, respectively (P < .05) and on anteroposterior radiographs were 30.3° and 8.6° (P < .05). The mean preoperative talocalcaneal angle on anteroposterior radiographs increased from 19.2° to 29.8° postoperatively (P < .05). The mean postoperative calcaneal pitch angle change was 10.8° on the lateral radiograph (P < .05). At final follow-up, all five patients were independently active, had plantigrade feet, and were able to wear conventional shoes. The mean American Orthopaedic Foot and Ankle Society questionnaire score was 38.8 preoperatively and 79.5 postoperatively (P < .05). Only one patient did not have full bony union. Achilles tightness was seen in one patient. CONCLUSIONS: Cole midfoot osteotomy is a laboring procedure to correct adult pes cavus deformity with the apex in midfoot, although having some complication risks.

Clinical Examination and Radiographic Assessment of the Cavus Foot.

The purpose of the clinical examination is to detect subtle cavus or cavovarus deformity, assess the severity and type of deformity, differentiate between idiopathic versus secondary etiologies of cavus foot deformity, and evaluate for other associated abnormalities. The clinical examination should begin with a gait analysis. The neurologic examination reveals peripheral neuropathy or central nervous system etiology for the foot deformity. On plain radiographs, forefoot-driven deformity can be assessed using the Meary angle, and hindfoot-driven deformity can be measured by the calcaneal pitch. Computed tomography and MRI scans can assess for tarsal coalitions and soft tissue pathologies, respectively.

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.

Updates in Pediatric Cavovarus Deformity.

The treatment goal for pediatric cavovarus deformities is to neutralize plantar pressure distribution, reduce hindfoot varus deformity, and avoid or postpone ankle, midfoot, and hindfoot arthritis. If nonoperative treatment is not sufficient, surgical realignment must be discussed. Promising improvements in decision making and operative techniques have been published. To avoid disappointment owing to recurrence or failures of operative procedures, selection of the appropriate and preferably single operative procedure remains the most crucial factor for success. This article focuses on current treatment options depending on the localization of the anatomic pathology. Outcomes of nonoperative and operative treatments are presented.

Hindfoot Injuries: How to Avoid Posttraumatic Varus Deformity?

Posttraumatic hindfoot varus may result from nonoperative treatment or inadequate reduction and fixation of talar and calcaneal fractures. Adequate visualization of the talar neck via bilateral approaches is essential in avoiding malreduction. In cases of medial comminution of the talar neck, lag screws must be avoided and the use of single or double plates should be considered. A Schanz screw introduced into the calcaneal tuberosity is instrumental in realigning shortening, varus, or valgus deformity of the heel. Special attention should be paid to addressing impaction of the medial facet of both the talus and calcaneus to avoid hindfoot varus.

A Review of Extensor Hallucis Longus Variants Featuring a Novel Extensor Primi Internodii Hallucis Muscle Merging With Extensor Hallucis Brevis.

The extensor hallucis longus (EHL) muscle/tendon complex has been used in a variety of tendon transfer and tenodesis surgeries to correct iatrogenic hallux varus deformity, equinovarus foot deformity, clawed hallux associated with a cavus foot, and dynamic hyperextension of the hallux and, even, to prevent pedal imbalance after transmetatarsal amputation. Although it is usually considered a unipennate muscle inserting into the dorsum of the base of the distal phalanx of the hallux, a vast majority of EHL muscles possess ≥1 accessory tendinous slips that insert into other neighboring bones, muscles, or tendons, which can complicate these surgeries. The present report reviewed the reported data on EHL variants and describe a new variant, in which the tendons of the extensor primi internodii hallucis muscle of Wood and extensor hallucis brevis muscle merged together proximal to the tarsometatarsal (Lisfranc) joint, a site of rupture for extensor tendons of the foot. The reported variant might have contributed to the development of the clawed hallux seen in our patient and could complicate its operative management by mimicking the normal extensor digitorum longus tendon. Knowledge of the EHL variants and the particular muscular pattern described in the present review could improve the diagnosis and tendon transfer and tenodesis operative planning and outcomes.

[Triple arthrodesis for correction of cavovarus deformity]. / Die Triplearthrodese als Baustein für die Korrektur der Pes-cavovarus-Deformität.

OBJECTIVE: The aim is to correct the underlying cavovarus deformity and to achieve a pain-free and stable hindfoot. INDICATIONS: Rigid neurologic, posttraumatic, congenital, and idiopathic cavovarus deformities. CONTRAINDICATIONS: General surgical or anesthesiological risks, infections, critical soft tissue conditions, neurovascular impairment of the lower extremity, noncompliance, patients with severely reduced bone quality, insulin-dependent diabetes mellitus, smoking. SURGICAL TECHNIQUE: The talonavicular and subtalar joints are exposed using a single medial approach. Joint cartilage is carefully debrided. Hindfoot reposition with complete correction of cavovarus deformity in all three planes. Joints are stabilized using cannulated screws, followed by wound closure. POSTOPERATIVE MANAGEMENT: A soft wound dressing is used. Thromboprophylaxis is recommended. Patient mobilization starts on postoperative day 1 using a stabilizing walking boot or cast for 6 weeks with 15 kg partial weight bearing. Clinical and radiographic follow-up 6 weeks postoperatively to assess osseous consolidation at the arthrodesis site. Following clinical and radiographic follow-up at 6 weeks, full weight bearing is gradually initiated. RESULTS: Between January 2012 and July 2014, triple arthrodesis was performed in 11 patients with a mean age of 62 ± 14 years due to cavovarus deformity. The mean follow-up was 34 ± 8 months (range 24-48 months). In all patients, the cavovarus deformity was substantially corrected. Significant pain relief from 7.1 ± 2.2 (range 5-10) to 1.8 ± 1.5 (range 0-4) on the visual analogue scale was observed.

Is non-operative management of childhood neurologic cavovarus foot effective?

INTRODUCTION: Neurologic pes cavus is a progressive deformity that is difficult to treat during growth. The present study reports results of non-operative management, based on the pathophysiology of the deformity, by untwisting nocturnal splint, preceded in some cases by untwisting walking cast. The objective was to assess efficacy and impact on indications for surgery. METHOD: Twenty-three children (35 feet) were included. All had neurologic cavovarus foot, which was progressive in 24 feet (69%) (Charcot-Marie-Tooth disease). Mean age at initiation of treatment was 8.8 years. In 13 feet (38%), treatment began with a untwisting walking cast and in 22 (62%) began directly with the splint. RESULTS: Mean follow-up was 4.5 years. Fifteen feet showed very good and 8 good clinical results (65%); 9 children (12 feet) had moderate or poor results, requiring renewed treatment in 11 feet at a mean 4.5 years after initiation of non-operative treatment. Thirteen patients (56.5%, 21 feet) had reached end of growth by last follow-up; 10 of these feet (48%) had good or very good results without surgery. No triple arthrodeses were required. Factors weighing against good outcome comprised young age at treatment initiation and poor compliance with the splint. Primary deformity severity did not affect outcome. CONCLUSION: The present study demonstrated efficacy for non-operative treatment of childhood neurologic cavovarus foot. Surgery was either avoided (in half of the cases followed up to end of growth) or delayed by a mean 4.5 years, allowing a single procedure before end of growth. We recommend initiating non-operative treatment of childhood cavovarus foot, associating untwisting walking cast and untwisting nocturnal splint, as soon as clinical progression is detected and/or Méary angle on lateral X-ray with block reaches 15°. LEVEL OF EVIDENCE: IV.

Pé cavo: revisão da literatura / Cavus foot: review

OBJETIVO: Realizar uma revisão sobre o pé cavo, sua fisiopatologia, avaliação clínica, diagnósticos diferenciais com ênfase na doença de Charcot-Marie-Tooth e tratamento. MÉTODO: Revisão não sistemática de artigos abordando a fisiopatologia do pé cavo, avaliação clínica, diagnósticos diferenciais e tratamento. RESULTADOS E DISCUSSÃO: Foram utilizados 33 artigos de língua inglesa e 02 artigos em português para a confecção desta revisão. CONCLUSÃO: O pé cavo é geralmente secundário a doenças neurológicas, em especial a doença de Charcot-Marie-Tooth e raramente é originado por doenças não neurológicas. O diagnóstico etiológico do pé cavo permite um melhor tratamento, cirúrgico ou não, com adequada orientação ao paciente quanto ao prognóstico e eficácia da terapia.

OBJECTIVE: We realize a review about cavus foot, discussing pathophysiology, clinical evaluation, differential diagnosis with emphasis on Charcot-Marie-Tooth Disease and treatment. METHOD: We perform a non-systematic review of articles about cavus foot pathophysiology, physical examination, etiology and treatment. RESULTS AND DISCUSSION: We used 33 articles in english and 02 articles in portuguese for this review. CONCLUSION: The cavus foot is mostly a consequence of neurological etiologies, in particular Charcot-Marie-Tooth disease and rarely is caused by non-neurological diseases. The correct diagnosis allows better treatment, conservative or surgical, with appropriate guidance to patients in terms of prognosis and therapy effectiveness.

The biomechanical effect of acupuncture for poststroke cavovarus foot: study protocol for a randomized controlled pilot trial.

BACKGROUND: Poststroke cavovarus foot greatly affects patients' activities of daily life and raises the risks of falls and consequent fractures. Acupuncture appears to be safe and effective in promoting motor functions and enhancing the activities of daily life among patients with poststroke cavovarus foot. The current study aims to study the biomechanical effect of acupuncture for poststroke cavovarus foot with objective outcome measurements. METHODS/DESIGN: This is an assessor and analyst-blinded, randomized, controlled pilot study. A total of 60 eligible patients with poststroke cavovarus foot will be allocated by a 1:1 ratio into an acupuncture treatment group and a control group. Patients in the control group will receive conventional rehabilitation therapies, whereas a combination of acupuncture and conventional rehabilitation therapies will be applied in the acupuncture group. The primary outcome measures are three objective biomechanical parameters from the RSSCAN gait system: varus angle, dynamic plantar pressure distribution, and static plantar contact area. Scores of the Berg Balance Scale, the Fugl-Meyer Assessment, and the Stroke-Specific Quality of Life Scale, as well as other biomechanical parameters such as the step length and width, step time phase, and weight shifting phase will be selected as secondary outcome measurements. All assessments will be conducted at baseline, 4 weeks after the treatment course, and after a follow-up period of 3 months. DISCUSSION: Results of the current study will provide detailed interpretations of the biomechanical effect of acupuncture for stroke rehabilitation and foundations for future larger clinical studies. TRIAL REGISTRATION: Chinese Clinical Trial Registry: ChiCTR-IPC-15006889 (8 August 2015).