Congenital metatarsus varus. A suggestion for a possible mechanism and relation to other foot deformities.

The pathogenesis of metatarsus varus was investigated by a series of dissections of 14 normal feet of stillborn or infants who died during the perinatal period. The deformity could not be produced without the surgical incisions described below. A valgus position of the hindfoot was produced by maximal dorsiflexion of the foot. The deformity of the fore part of the foot could not be produced even by extreme traction on the tibialis anterior tendon even after capsulotomy of the first tarsometatarsal joint. Only extensive capsulotomies in the tarsometatarsal joints distal to the joint of Chopart made it possible to displace the bones into the position analogous to metatarsus varus. It is suggested that metatarsus varus may be a deformity which occurs on a maximally dorsiflexed foot and that the primary mechanism of the forefoot deformity is a subluxation in the fore part of the foot. Secondary contractures of the soft tissues, and adaptive bone changes offer a possible explanation for lack of spontaneous recovery as well as the difficulties encountered in treating late cases.     

The cavovarus foot deformity. Etiology and management

The cavovarus foot is a complex deformity of the forefoot and hindfoot, frequently of neuropathologic etiology. A progressive spinal or peripheral neuromuscular disorder must be excluded by a thorough clinical evaluation. With the failure of nonoperative modalities, surgical options depend on patient age, etiology of the deformity, and the constellation and flexibility of the defects observed. If the hindfoot varus is flexible, correction of the cavus and forefoot pronation through extensive plantar release and metatarsal osteotomies is reliable. The underlying muscle imbalance must be addressed through tendon transfers to prevent further progression. In the young child, a rigid hindfoot varus will often be corrected by a radical plantar-medial release, but the more mature foot may require midtarsal osteotomy and calcaneal osteotomy or triple arthrodesis. The surgery is usually staged to provide correction of deformity and stabilization of the hindfoot prior to tendo Achilles lengthening or tendon transfer. Arthrodesis of a previously well-corrected foot is common due to progression of the neurologic deficit or failure to achieve muscular balance. The claw toe deformity also must be corrected by tendon transfer, osteotomy, and arthrodesis for reasons of both comfort and function.     

Combined split anterior tibial-tendon transfer and intramuscular lengthening of the posterior tibial tendon. Results in patients who have a varus deformity of the foot due to spastic cerebral palsy

Twenty patients who had a varus deformity of the foot secondary to spastic cerebral palsy had twenty-two operations involving combined split anterior tibial-tendon transfer and intramuscular lengthening of the posterior tibial tendon, with and without concomitant lengthening of the Achilles tendon. Preoperatively, all patients had had a dynamic varus deformity of the hindfoot and adduction of the forefoot in both the stance phase and the swing phase of gait. At an average follow-up of 6.2 years (range, 2.3 to 8.8 years), there were fourteen excellent, four good, and four poor clinical results. Two patients who had a fixed varus deformity of the hindfoot and one patient who had a very weak anterior tibial muscle had a poor result. We concluded that the combined procedure is effective for correction of a flexible varus deformity of the foot in patients who have spastic cerebral palsy.     

Surgical correction of the cavus forefoot

A cavus forefoot deformity can exist as a result of muscle imbalance, and, when identified, the patient shouldundergo appropriate neurological evaluation. The deformity can result in increased stresses on the metatarsal heads and push the hindfoot into a varus position. In more advanced cases, it can result in decreased motion of both the subtalar and ankle joints. Physical examination is of great importance in evaluating these patients and includes evaluation of the gait cycle, as well as the position of the heel and toes at rest. Evaluation of the muscle strength available is also important. The Coleman and Chestnut block test can be very helpful in determining hindfoot stiffness and the relationship of the forefoot cavus and the hindfoot varus. Surgical correction of the cavus forefoot often can be accomplished with a Jones procedure, sometimes with a closing wedge osteotomy of the first and possibly second and third metatarsals. This will sometimes be sufficient to allow the hindfoot to come out of varus.     

An Unusual Aberrant Muscle in Congenital Clubfoot: An Intraoperative Finding

Congenital clubfoot is a common congenital deformity, characterized by equinus of the hindfoot and adduction of the midfoot and forefoot, with varus through the subtalar joint complex. A cavus deformity will also be present. The etiology of this congenital deformity remains elusive. Muscle anomalies are not commonly found in patients with idiopathic clubfoot, and, when present, their significance is not clear. The presence of a flexor digitorum accessorius longus muscle and an accessory soleus muscle found at surgical correction of clubfoot deformity has been previously reported. Our case was a female child, aged 2 years, 3 months, who developed bilateral relapsed congenital clubfoot. She was found to have an unusual aberrant muscle in both legs. This was discovered accidentally during surgical correction of her deformity through posteromedial soft tissue release. This muscle might have contributed to the hindfoot varus and equinus in the clubfoot deformity, because the latter were completely corrected after release of the muscle from its insertion. Awareness of such a new anatomic variant, with the other anatomic variants found in clubfoot deformity, will not only improve our understanding of normal lower limb development, but could also lead to improved genetic counseling and diagnostic and treatment methods of such a common congenital deformity.     

Hindfoot instability in cavovarus deformity: static and dynamic balancing

BACKGROUND: Chronic lateral ankle instability has been associated with varus deformity of the hindfoot, hyperactivity of the peroneus longus muscle, and insufficiency of the lateral ligaments. Many operative procedures have been described to correct this problem, but instability can recur if all contributing components are not treated. The purpose of this study was to offer an approach in the diagnosis and treatment of recurrent lateral ankle instability. METHODS: Eight consecutive patients (nine feet) were treated for recurrent chronic lateral ankle instability. The average age at surgery was 25 (range 8 to 37) years. All patients had prior operative procedures that failed and had persistent pain and functional instability of the ankle joint. After clinical and radiographic examination, lateralizing calcaneal osteotomy to correct the structured varus deformity and peroneus longus to peroneus brevis tendon transfer to add dynamic correction were done in all patients. A Brostr?m ligament reconstruction was added in four feet. All patients were evaluated clinically and radiographically at an average followup of 37 months. Preoperatively and postoperatively patients were evaluated by means of the American Orthopaedic Foot and Ankle Society (AOFAS) Score. RESULTS: All patients were satisfied with the operation. The overall AOFAS-Score improved from 57 points preoperatively to 87 points postoperatively. Hindfoot alignment was restored to a valgus position at final evaluation. CONCLUSIONS: Recurrent chronic lateral ankle instability often is associated with chronic hindfoot malalignment and leads to functional impairment and patient discomfort. Clinical examination should determine the causes of instability. Varus malalignment of the hindfoot, hyperactivity of the peroneus longus muscle, and insufficiency of the lateral ligaments should be assessed and treated in a combined operative procedure to correct structured, static and dynamic components of the instability. The preliminary results of this particular approach are encouraging.     

Neuromuscular issues in cavovarus foot

Differential muscle weakness can cause a cavus foot deformity. Presenting complaints in the hindfoot may include ankle instability, secondary arthritis, or peroneal tendonitis. Presenting complaints in the forefoot may include stress fractures, callus formation over the lateral border of the foot, claw toes, first ray overload, and metatarsalgia. More general presenting complaints can include a drop-foot gait, decreased walking tolerance, and difficulty with shoe or orthotic fitting. To surgically correct the foot shape, soft tissue contractures need to be released, bone deformity corrected, and muscles balanced to optimize their strength and prevent recurrence of the deformity. This article reviews the diagnosis and management of the cavovarus foot secondary to longstanding muscle imbalance.     

Adult cavovarus foot

Cavovarus foot deformity, which often results from an imbalance of muscle forces, is commonly caused by hereditary motor sensory neuropathies. Other causes are cerebral palsy, cerebral injury (stroke), anterior horn cell disease (spinal root injury), talar neck injury, and residual clubfoot. In cavovarus foot deformity, the relatively strong peroneus longus and tibialis posterior muscles cause a hindfoot varus and forefoot valgus (pronated) position. Hindfoot varus causes overload of the lateral border of the foot, resulting in ankle instability, peroneal tendinitis, and stress fracture. Degenerative arthritic changes can develop in overloaded joints. Gait examination allows appropriate planning of tendon transfers to correct stance and swing-phase deficits. Inspection of the forefoot and hindfoot positions determines the need for soft-tissue release and osteotomy. The Coleman block test is invaluable for assessing the cause of hindfoot varus. Prolonged use of orthoses or supportive footwear can result in muscle imbalance, causing increasing deformity and irreversible damage to tendons and joints. Rebalancing tendons is an early priority to prevent unsalvageable deterioration of the foot. Muscle imbalance can be corrected by tendon transfer, corrective osteotomy, and fusion. Fixed bony deformity can be addressed by fusion and osteotomy.     

Gait electromyographic evaluation of the long-toe flexors in children with spastic cerebral palsy

In a prospective study of the phasic activity of the long-toe flexors of patients with spastic cerebral palsy, the electrical activity of the long-toe flexors in 37 children with varus or valgus hindfoot deformity was measured by wire electrode dynamic electromyography. Although gross abnormalities in the phasic timing of the flexor hallucis longus and flexor digitorum longus were observed, these muscles could not be implicated in the etiology of hindfoot deformity. In planning gait analysis protocols for children with cerebral palsy and hindfoot deformity, electromyography of the long-toe flexors is not necessary unless toe curling is clinically evident.     

Flexor-Digitorum-Longus-Transfer und medialisierende Kalkaneusosteotomie zur Therapie der zweitgradigen erworbenen Plattfußdeformität

Acquired flatfoot deformity is characterized by flatening of the longitudinal arch of the foot and a varus alignement of the hindfoot due to insufficiency of the postero-medial soft tissue structures and is divided in four different stages. Stage II represents a flexible flatfoot deformity without active hindfoot inversion due to insufficiency of the Tendon of the posterior tibial muscle. Symptoms include pain at the medial hindfoot and difficulites associated with walking on uneven surfaces. Clinically, there occurs hindfoot varus and excessive forefoot abduction (‚too many toes sign’). Imaging studies include weight bearing a/p and lateral xrays as well as MRI scans in order to visualize tendon degeneration. Conservative treatment options include longitudinal arch support and physical therapy respectively. In case of failure of conservative treatment surgical options include flexor digitorum longus transfer and medial displacement calcaneal osteotomy. This procedure reveals good functional results with the restoration of single heel rise.     

Split tibialis posterior tendon transfer for correction of spastic equinovarus hindfoot deformity

Equinovarus hindfoot deformity is one of the most common deformities in children with spastic paralysis ; it is usually secondary to cerebral palsy. Split tibialis posterior tendon transfer is performed to balance the flexible spastic varus foot and is preferable to tibialis posterior lengthening, as the muscle does not loose its power and therefore the possibility of a valgus or calcaneovalgus deformity is diminished. We retrospectively evaluated 33 consecutive ambulant patients (38 feet) with flexible spastic varus hindfoot deformity. Twenty-eight presented unilateral and five bilateral involvement. The mean age at operation was 10.8 yrs (range 6-17) and the mean follow-up was 10; yrs (4-14). There were 20 hemiplegic feet, 11 diplegic and 7 quadriplegic. Eighteen feet also presented an equinus position of the hindfoot, requiring Achilles tendon lengthening. The surgical technique applied was similar to the one described by Green et al, with four skin incisions, two on either side of the foot and ankle. The evaluation of the results was carried out using Kling and Kaufer's clinical criteria. Results were graded excellent or good for 34 out of 38 feet (89.5%). Twenty feet were graded excellent, indicating that the children managed to walk with a plantigrade foot without fixed or postural deformity and did not have callosities. Fourteen feet were graded good in children who walked with less than 50,varus, valgus or equinus of the hindfoot and had no callosities. Four were graded poor, with recurrent equinovarus deformity. The feet with poor results presented a residual varus deformity due to intraoperative technical errors.     

Alignment and technique in total ankle arthroplasty

Total ankle arthroplasty has emerged as a promising alternative to ankle arthrodesis, especially in cases where multiple hindfoot joints are arthritic. Proper alignment of the limb must be restored to be most successful over the long term. Misalignment above the ankle typically involves a malunion of a previous tibia fracture and can be treated by corrective osteotomy. Deformity in the joint itself can arise from congenital malformation or from bony erosion, usually as a late result of joint trauma. Mild amounts of bone loss can be corrected through bone cuts during ankle replacement, but more severe deformity may require distal tibial osteotomy. Misalignment below the ankle (in the foot) is probably the most common deformity. Secondary procedures in the foot and leg, including muscle balancing, osteotomies, or fusions are often a part of the surgical plan and are performed either before or simultaneously with ankle replacement. The goal is to restore an ankle with neutral static and dynamic balance during stance and gait. Achieving that goal will give the best chance for pain free ankle motion over the long term.     

SPECT‐CT compared with conventional imaging modalities for the assessment of the varus and valgus malaligned hindfoot

The combined single‐photon emission computed tomography and conventional computed tomography (SPECT/CT) technique has increased the sensitivity and specificity of bone scans. We examined the value of using SPECT/CT for the assessment of coronal plane hindfoot deformities. Twenty‐seven patients with varus (11 patients) or valgus (16 patients) malalignment of the hindfoot were assessed using radiography, conventional CT, bone scintigraphy, and SPECT/CT. The amount of deformity, stage of osteoarthritis, and level of activation on bone scans and SPECT/CT were measured. Activation was assessed in 12 regions of interest. The stage of osteoarthritis seen on plain radiographs correlated significantly with the level of activation detected on bone scans (p < 0.05). No correlation was observed between the amount of deformation and activity, and between bone scan activation and signs of osteoarthritis on CT scans. The varus malaligned ankles showed higher radioisotope uptake in the medial areas, while the valgus malaligned ankles showed increased uptake in the lateral areas (p < 0.05). SPECT/CT may be a valuable tool for the assessment and staging of osteoarthritis. Our findings underline the adverse effects of coronal plane deformity of the hindfoot. In addition, results from this study provide useful information for future basic research on coronal plane deformity of the hindfoot and for determining appropriate surgical approaches. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1461–1466, 2009     

Cavus foot deformity in children

A cavus deformity of the foot is easily recognizable, but appropriate neurologic assessment can help to determine the etiology. Cavovarus, the most frequent type of cavus foot, presents with an elevated medial longitudinal arch, first ray plantarflexion, and, if rigid, a fixed heel varus. Common causes include progressive motor sensory conditions, typically Charcot-Marie-Tooth disease, and nonprogressive conditions such as cerebral palsy and poliomyelitis. A calcaneocavus foot may be seen in poliomyelitis, spinal dysraphism, and peripheral neuropathy. Initially, the cavus deformity is flexible, but if left untreated, it becomes a fixed bony deformity. Physical examination should include the cavovarus block test, which assesses flexibility of the hindfoot deformity and can direct surgical treatment. Standing radiographs of the feet and spine, magnetic resonance imaging, and electrodiagnostic studies may be useful. Management goals are to obtain a plantigrade, mobile, pain-free, stable, motor-balanced foot. Surgical options include soft-tissue and plantar fascia releases for a flexible deformity, osteotomy for a fixed deformity, and tendon transfers to restore muscle balance. Triple arthrodesis has poor long-term results in patients with progressive deformity and sensory impairment.     

Accessory soleus muscle in clubfoot deformity: a report in four feet

The commonest presentation of accessory soleus muscle is a swelling at the posteromedial aspect of the ankle in adolescents or young adults. Accessory soleus is rarely encountered in children undergoing surgical release for congenital clubfoot, and only a few isolated reports are available in the literature. The purpose of this study is to heighten awareness about the role of accessory soleus muscle in clubfoot deformity. Four cases of accessory soleus muscle in patients undergoing surgical release for clubfoot deformity are reported here in which, a distinct anomalous muscle deep to the tendoachilles was identified. Hindfoot varus and equinus persisted in each of these cases despite an adequate posteromedial soft tissue release, which could be corrected only on tenotomizing the tendon of the accessory soleus muscle at its insertion. An awareness about the accessory soleus muscle is important, particularly when non-operative methods of clubfoot management with tendoachilles tenotomy or limited surgery are employed. Failure to recognize this muscle if present in patients with congenital clubfoot may lead to persistent hindfoot deformity. A high index of suspicion should be maintained in cases in which hindfoot deformity persists despite an otherwise adequate soft tissue correction.     

Preoperative planning and surgical technique: how do I balance my ankle?

Ligament balancing during total ankle arthroplasty is an important step in optimizing the mechanical balance of the ankle joint. Soft-tissue contractures that result from varus or valgus coronal plane deformity can pose a difficult problem, and the surgeon should have a standard procedure for managing such situations in the operating room. Balance may be assessed intraoperatively with the use of spacer blocks, laminar spreaders, and tensioning devices as well as by placement of trial components. Techniques used to balance the varus or valgus ankle during primary total ankle arthroplasty include osteophyte resection, soft-tissue release, and bone resection. Mediolateral ligament balancing is crucial for long-term success and patient satisfaction.     

Principles of reorientation in triple arthrodesis

Triple arthrodesis can be used for a three-dimensional correction of all types of hindfoot deformities. Prerequisites are a functional integrity of the ankle joint and an adequate bone stock. The procedure blocks the cardanic mechanism of the hindfoot and therefore reduces the shock-absorbing and mobile-adaptive functions of the foot. This results in increased stresses with the risk of long-term degenerative changes. In addition to triple arthrodesis, procedures to the forefoot are often necessary. Especially in neurogenic deformities, muscle lengthening and balancing procedures may be needed. In the evaluation of the results, different etiologies (e.g. posttraumatic, degenerative, neurogenic, congenital) and different deformities (varus, valgus, cavovarus, equinus) should not be mixed up. The results in congenital and neurogenic deformities in the literature are inferior to those of degenerative and posttraumatic origin. A standardization of indications, techniques, and evaluation criteria is still needed in order to exactly estimate the value of this procedure for different pathologies.     

Prinzipien der reorientierenden Tripelarthrodese

Triple arthrodesis can be used for a three-dimensional correction of all types of hindfoot deformities. Prerequisites are a functional integrity of the ankle joint and an adequate bone stock. The procedure blocks the cardanic mechanism of the hindfoot and therefore reduces the shock-absorbing and mobile-adaptive functions of the foot. This results in increased stresses with the risk of long-term degenerative changes. In addition to triple arthrodesis, procedures to the forefoot are often necessary. Especially in neurogenic deformities, muscle lengthening and balancing procedures may be needed. In the evaluation of the results, different etiologies (e.g. posttraumatic, degenerative, neurogenic, congenital) and different deformities (varus, valgus, cavovarus, equinus) should not be mixed up. The results in congenital and neurogenic deformities in the literature are inferior to those of degenerative and posttraumatic origin. A standardization of indications, techniques, and evaluation criteria is still needed in order to exactly estimate the value of this procedure for different pathologies.     

Sprunggelenkprothese bei Varusarthrose

Coronal plane deformity has been found to be one of the main risk factors for poor clinical results, higher complication rates and failure of total ankle replacements. Initially, many authors considered a malalignment of more than 10° to be a contraindication for total ankle replacement, however, several publications later underlined the usefulness of the distinction of different etiologies of hindfoot malalignment. This subsequently led to suggestions for additional procedures in order to avoid early implant failure.The aim of the present article is to illustrate the different causes of varus malaligned arthritic ankles and to present procedures to balance these ankles at the time of replacement.     

Limb salvage after subtotal supramalleolar amputation by initial shortening followed by tibial lengthening

BACKGROUND: We present a patient with a subtotal traumatic supramalleolar amputation of the leg, which was initially treated by a vascular reconstruction with deliberate bone and soft-tissue shortening. METHODS: To correct the ensuing complex deformity, which consisted of a varus hindfoot, leg length discrepancy and equinus, a staged reconstruction was planned. Initially, the hindfoot varus, in presence of a stiff ankle, was corrected by a supramalleolar osteotomy, followed by a Wagner distraction and finally a correction of the equinus. RESULTS: After a relatively long period of normal functioning, she regained painful minimal ankle function, which necessitated ankle fusion and correction of a pronation deformity. At the most recent follow-up 13 years after the injury, the patient is fully functional and has near normal leg length. CONCLUSION: Although a mangled lower extremity is often a candidate for primary amputation allowing early rehabilitation, in certain cases a good result can be obtained by a creative strategy.