3 DefinitionPes cavus is a high arch that does not flatten with weightbearing. No specific radiographic definition of cavus foot exists. The deformity can be located in the forefoot, midfoot, or hindfoot or in a combination of these sites.
4 What’s the problem?clawing of the toes, posterior hindfoot deformity (described as an increased calcaneal angle), contracture of the plantar fascia, and cock-up deformity of the great toe. This can cause increased weightbearing for the metatarsal heads and associated metatarsalgia and callus.
5 Etiology80% of the time caused from malunion of calcaneal or talar fractures, burns, sequelae of compartment syndrome, residual clubfoot, and neuromuscular disease.20% of cases are idiopathic and nonprogressive .
7 Etiology Cont… Neuromuscular diseases cause muscle imbalance that leads to an elevated arch. These diseases include muscular dystrophy, Charcot-Marie-Tooth (CMT) disease, spinal dysraphism, polyneuritis, intraspinal tumors, poliomyelitis, syringomyelia, Friedreich ataxia, cerebral palsy, and spinal cord tumors. A patient with new onset of a unilateral deformity but without history of trauma must be evaluated for spinal tumor.
8 Etiology Cont… Multiple theories : -Intrinsic muscle imbalance causing the elevated arch.-Extrinsic muscle causes the muscle imbalance.-Combination of the intrinsic and extrinsic musclesis the cause of the imbalance.
9 Etiology Cont… Charcot-Marie-Tooth (CMT) The anterior tibialis muscle and the peroneus muscle develop weakness. Antagonist muscles, posterior tibialis and peroneus longus, pull harder than the other muscles, causing deformity. Specifically, the peroneus longus pulls harder than the weak anterior tibials, causing plantarflexion of the first ray and forefoot valgus. The posterior tibialis pulls harder than the weak peroneus brevis, causing forefoot adduction. Intrinsic muscle develops contractures while the long extensor to the toes, recruited to assist in ankle dorsiflexion, causes cock-up or clawtoe deformity. With the forefoot valgus and the hindfoot varus, increased stress is placed on the lateral ankle ligaments and instability can occur.
10 Etiology Cont… PolioThe deformity is in the hindfoot and caused by the weakness in the gastrocsoleus complex, leading to a marked increase in the calcaneal pitch angle with normal forefoot alignment.
12 Clinical presentation Patients can present with lateral foot pain from increased weightbearing on the lateral foot. Metatarsalgia is a frequent symptom, as is symptomatic intractable plantar keratosis. Ankle instability can be a presenting symptom, especially in patients with hindfoot varus and weak peroneus brevis muscle.Patients with neuromuscular disease complain of weakness and fatigue, the severity of the presenting symptoms is as variable as the symptoms themselves.
14 Work Up - Family history - Neuro exam - X-rays of entire spine - EMG and nerve conduction studies - MRI meylogram
15 EvaluationThorough history and complete examination in an attempt to try to determine the etiology.
16 Imaging StudiesStanding radiography of the feet and ankles is essential. Radiographs should be inspected for degenerative arthritis, positioning of the calcaneus, and forefoot alignment. A calcaneal pitch angle can be measured by drawing a line along the plantar aspect of the calcaneus and the ground. An angle greater than 30° is significant for hindfoot varus. The positioning of the first ray compared to the axis of the talus viewed on the lateral radiograph determines if the first ray is plantar flexed.
17 Imaging Studies Cont…MRI of the spine should be obtained if unilateral progressive cavus is present in a patient without history of trauma.
18 TreatmentThe goal of treatment is to produce a plantigrade foot that allows even distribution of weight.Failure to maintain an asymptomatic plantar grade foot is an indication for surgery. The contraindication to surgery is poor vascularity, and ulcers.
19 Treatment Cont… Medical therapy Ambulate with symptomatic reliefPhysical therapy to stretch tight muscles and strengthen weak muscles.Orthotics with extra-depth shoes to offload bony prominences and prevent rubbing of the toes. lateral wedge sole modification to the shoes can improve function. Bracing for supple deformities or foot drop, and Plastizote linings for sensation deficite.
20 Treatment Cont… Surgical therapy Patient must understand the rationale for treatment and understand that surgical reconstruction does not provide a normal foot. The goal of surgery is to produce a plantigrade foot and pain relief. Also, repeat surgical procedures may be required, especially if the deformity is progressive.
21 Treatment Cont… Surgical therapy No single procedure is appropriate for all patients, and frequently, multiple individual procedures need to be performed.Tendon transfers and osteotomies can provide correction of the deformity without performing an arthrodesis which is used only as a salvage procedure, preserving the joints if possible is the current trend .
22 Treatment of Early Deformity - treatment involves soft-tissue releases and/or tendon transfers.- any proposed osseous procedures must not affect growth of the foot, such as calcaneal and/or metatarsal osteotomies.Planter release:- indicated for patients less than 10 years of age w/ cavus deformity w/ significant plantar flexion of first ray.Plantar medial release:- indicated for rigid hindfoot w/ fixed varus angulation.- involves planter release along w/ medial tarsal structures.- released medial structures include talonavicular joint capsule, superficial deltoid ligament, and possibly the long toe flexors.Tendon transfers:- indicated for patients w/ a supple inversion deformity w/ weak evertors. - a prerequisite for this procedure is a plantagrade foot which is achieved w/ planter release.- consider lateral transfer of tibialis antirior tendon into the mid-tarsal region along the long axis of third ray.
23 Treatment of Rigid Deformity - fixed bony deformity is better managed by a combination of calcaneal and metatarsal osteotomies and may require the use of AFO's.Calcaneal osteotomy:- for correction of hindfoot varus deformity & mid-tarsal osteotomy for correction of midfoot cavus and varus deformity.- calcaneal osteotomy does not impede growth since it is not made thru cartilage growth surface.- posterior displacement calcaneal osteotomy is effective in correcting calcaneocavus deformity of the type II neuropathy.- in young patients w/ milder deformity, translate the distal and posterior calcaneal fragment laterally w/o removal of an osseous wedge.- lateral slide osteotomy is cut slightly obliquely, passing from superior position on lateral surface to a more inferior position on the medial surface.- distal fragment can be translated laterally as much as 1/3 of its transverse diameter, thus allowing for conversion of wt-bearing from a varus to a slight valgus position.- w/ severe deformity consider: triplearthodesis.
25 Treatment Cont… Surgical therapy Plantar fascia release:Is usually combined with tendon transfer, osteotomy, or both. This is frequently the first step in improving the deformity. Stripping the fascia off the calcaneus and complete resection of the plantar fascia.
26 Treatment Cont… Surgical therapy Great toe Jones procedure:Performed for cock-up deformity of the great toe with associated weakness of the anterior tibialis muscle. extensor hallucis longus (EHL) has been recruited to assist in ankle dorsiflexion, which causes hyperextension at the MTP joint and hyperflexion at the interphalangeal (IP) joint. This procedure transfers the EHL to the neck of the first metatarsal with arthrodesis of the IP joint to improve the dorsiflexion of the ankle and remove the deforming force at the MTP joint.
27 Treatment Cont… Surgical therapy Extensor shift procedure:Transfer of the EHL and the extensor digitorum longus (EDL) to the first, third, and fifth metatarsals. The technique includes completion of the Jones procedure with incisions in the second and fourth web space. The tendons are harvested. The second and third tendons are transferred through a drill hole on the third metatarsal, and the fourth and fifth tendons are transferred to the fifth metatarsal.
28 Treatment Cont… Surgical therapy Girdlestone-Taylor transfer:This procedure is used for flexible clawtoe deformities. The deforming force of the flexor digitorum longus tendon is transferred to the extensors.
29 Treatment Cont… Surgical therapy Base of the first metatarsal osteotomy:In patients with a fixed plantar-flexed first ray, a base of the metatarsal closing wedge osteotomy corrects the deformity, which is especially observed in CMT disease. This procedure is usually combined with a plantar fascia release in a mild deformity or a Jones procedure.
30 Treatment Cont… Surgical therapy Midfoot osteotomy:Tarsal osteotomy has been described for deformities through the midfoot. however, these osteotomies require cutting through multiple joints.
31 Treatment Cont… Surgical therapy Peroneus longus to peroneus brevis tenodesis:In patients with CMT disease that have a weak peroneus brevis (PB) and a preserved peroneus longus (PL), a tenodesis can be performed to help stabilize the ankle. This is frequently combined with a calcaneal osteotomy.
32 Treatment Cont… Surgical therapy Calcaneal osteotomy:Patients with hindfoot involvement usually require a calcaneal osteotomy to correct the deformity. The osteotomy can include a closing wedge, a vertical displacement, or a combination (triplanar osteotomy). This procedure is usually combined with a plantar fascia release and frequently a tendon transfer.
33 Treatment Cont… Surgical therapy Beak triple arthrodesis:The Siffert beak triple arthrodesis corrects the deformity through wedge resection and a triple arthrodesis. This is used for a rigid fixed deformity in adults. The technique involves mortising the navicular into the head. The technique involves mortising the navicular into the head of the talus and depressing the navicular, cuboid, and cuneiforms to improve the forefoot cavus deformity.
34 ComplicationsThe complications of these procedures include nonunion, malunion, infection, undercorrection, overcorrection, recurrence of the deformity, progression of the deformity, nerve injury, and continued pain.For progressive disorders, deformities can recur; patients need to be educated about this prior to the initial surgery.
36 MoKazem.comهذه المحاضرة هي من سلسلة محاضرات تم إعدادها و تقديمها من قبل الأطباء المقيمين في شعبة الجراحة العظمية في مشفى دمشق, تحت إشراف د. بشار ميرعلي.الموقع غير مسؤول عن الأخطاء الواردة في هذه المحاضرة.This lecture is one of a series of lectures were prepared and presented by residents in the department of orthopedics in Damascus hospital, under the supervision of Dr. Bashar Mirali.This site is not responsible of any mistake may exist in this lecture.Dr. Muayad Kadhimد. مؤيد كاظم