Flexible Flatfoot

CAMPBELL’S OPRATIVE ORTHOPAEDICS 2013

By: Dr Hamid HejratiResident of Orthopedic Surgery

Iran, Mashhad university of medical science

Definition

Exact incidence in children unknownOne of the most common “deformities”

evaluated by pediatric orthopaedists.“usual in infants, common in children,

and within the normal range in adults” in assessing and documenting the spontaneous development of the longitudinal arch.

The heel excessive eversion during weight bearing

Forefoot usually abducted, midfoot sag with lowering of the longitudinal arch the talar head and navicular tuberosity appear to be in contact with the floor and to participate excessively in weight bearing.

The medial column of the foot appears longer than the lateral column.

Severe flexible flatfoot in an 8-year-old girl. A, Posterior view. Shortening of the Achilles tendon valgus eversion of the heels. The talar heads are prominent. B, Medial view, (left). Weight bearing on the entire arch, particularly on the talonavicular area, is a source of symptoms. C, Medial breakdown of the left shoe.

The entire foot is often described as pronated, although this description is misleading because the forefoot is actually supinated in relation to the hindfoot, a fact that is most appreciated when the hindfoot is corrected operatively or stabilized manually during physical examination.

A standing lateral radiograph allows measurement of the lateral talus–first metatarsal angle, or Meary angle. This angle is normally 0 degrees (a straight line). In a flexible flatfoot an apex-plantarward angle will

be present. The normal range of this angle also varies with age, with spontaneous improvement in plantar sag seen until age 8 years.

The location of the sag—talonavicular or naviculocuneiform joint—can be determined and may suggest the cause of an abnormal measurement (i.e., a tight heel cord producing a plantar flexed talus and talonavicular sag).

The degree of plantar flexion of the talus—the angle formed by the longitudinal axis of the talus and the horizontal—can also be measured (normal, 26.5 ± 5.3 degrees) as can the calcaneal pitch angle, which is formed by the axis of the calcaneus and the horizontal.

Reason to obtain radiographs to rule out causes of the “deformity” other than idiopathy.

The differential diagnosis includes: 1. tarsal coalition, 2. congenital vertical talus (convex pes valgus), 3. persistent talipes calcaneovalgus, 4. an accessory navicular, 5. various arthritic and inflammatory conditions.

Most of these conditions are diagnosed primarily from the history and physical examination findings, and in such situations radiographs should be used to confirm a suspected diagnosis.

radiographs obtained to appease parents—to “prove” that the flexible flatfoot is indeed just that.

In otherwise typical cases it is unnecessary for diagnosis

In the typical flexible flatfoot, the longitudinal arch reconstitutes when the foot is in a non–weight-bearing position.

Inversion of the heels and arch reconstitution during toe standing are requisite examination findings for a diagnosis of flexible flatfoot.

The general neurologic assessment—observation of gait, coordination, and reflexes—will uncover neurologic or myopathic conditions associated with flatfeet in which the foot position may be due to weakness poliomyelitis, peripheral neuropathy, weakness with Achilles tendon contracture Duchenne muscular dystrophy, or spasticity with equinus cerebral palsy.

Particular attention to the Achilles tendon is important because a contracture tends to make hypermobile flatfeet symptomatic.

Should be asked to walk on the heels, which will be difficult. Passive dorsiflexion of the foot, with the heel locked in varus (inverted), will demonstrate contracture. They have had progressive arch pain medially, sometimes with callus development and medial shoe breakdown.

Natural History The arch is usually obscured in an infant’s foot

because of subcutaneous fat, and spontaneous resolution of fat foot can be anticipated as the young child matures and such fat atrophies.

Improvement in the sag of the medial ray of the foot would suggest that ligamentous laxity in a toddler spontaneously resolves as the ligaments become more taut.

Development of the arch is independent of the use of such external orthoses or the wearing of corrective shoes.

Studies shows presence or absence of a longitudinal arch did not correlate with disability and that a flatfoot was compatible with normal function unless an Achilles tendon contracture was present.

More significant is the tendency for children wearing closed-toe or “fashionable” shoes to have arch development inhibited by placing a valgus stress on the first MTP joint.

TreatmentConservative Treatment

No treatment is indicated in an asymptomatic pediatric patient. Education and reassurance are the mainstays.

With the lack of objective studies demonstrating a lasting change in the radiographic anatomy of the foot with the use of corrective devices, there is no medical indication for the treatment of asymptomatic flatfeet.

Exercises to treat flatfoot. A, Manual stretching with the knee extended and the hindfoot inverted. Multiple daily repetitions are prescribed. B, Passive stretching of the triceps surae in an older child. Note that the feet are inverted, the knees are extended, and the heels remain on the floor.

In symptomatic patients medial arch pain, fatigue and cramping at night arch supports and orthoses may be of benefit.

We have found that the footwear sold in sporting goods stores, especially that running shoes designed for a “hyperpronated” foot have significant heel and arch support built into the shoe itself, thus making prescription of additional orthoses superfluous.

Because running shoes usually support the relaxed portion of the arch or hindfoot, the suggestion to use such footwear may be all that is necessary to resolve the problem.

In more recalcitrant cases UCBL insert can be attempted can acutely change the talonaviculocuneiform axis and improve calcaneal pitch. it has been reported to alleviate symptoms and improve shoe wear in symptomatic patients. Acceptance of this more rigid may be problematic in that the rigid orthosis can be somewhat uncomfortable.

A and B, The University of California Biomechanics Laboratory (UCBL) orthosis used for the treatment of flatfoot.

C, Standing lateral radiograph showing naviculocuneiform sag.

D, Standing lateral radiograph with the UCBL orthosis. The naviculocuneiform sag and calcaneal dorsiflexion (“pitch”) are improved.

A B

C D

TreatmentSurgical Treatment

Indications intractable symptoms unresponsive to shoe or orthotic modifications and who is unable to modify the activities that produce pain. Thus patients with talonavicular calluses and medial arch “strain” whose daily activities are limited by foot pain are the only true candidates for surgical management.

surgical correction of flatfoot must emphasize joint-sparing procedures, usually combining extraarticular osteotomy with soft tissue imbrication.

Arthroereisis. Arthroereisis of the subtalar joint, using a silicone or Silastic implant, has been reported as an alternative to more complex joint reconstruction. The rationale of the procedure is to limit the amount of valgus motion in the subtalar joint by using an interposition peg.

Intraoperative view of a subtalar arthroereisis implant (STA-peg) (arrow), which was removed because of unrelenting subtalar pain. Note the synovitis associated with the device.

Heel Cord Lengthening. An Achilles tendon contracture should always be considered and treated during any surgery for flatfoot. Heel cord lengthening should be part of a comprehensive procedure to reconstruct the longitudinal arch.

Subtalar Fusion. Subtalar fusion as a primary procedure for hypermobile flatfoot should probably be condemned. While there is no question that excessive heel valgus and restoration of the longitudinal arch can be achieved through this procedure, the sacrifice of subtalar motion for this purpose is too great a cost.

Lateral Column Lengthening. Lateral column lengthening by insertion of a bone graft into an osteotomy of the calcaneal neck is currently the most attractive procedure to correct a flatfoot deformity and not sacrifice joint motion.

Dorsal view (A) and lateral view (B) of lateral column lengthening to treat flatfoot. K-wire fixation can be useful to prevent displacement of both the graft and the distal osteotomy fragment.

Post OP short-leg cast immobilization is maintained for 8 to 12 weeks to ensure healing of the osteotomy.

Results of calcaneal lengthening 1. relief of medial arch pain2. resolution of calluses 3. correction of heel valgus4. improvement in the appearance of the arch 5. radiographic restoration of the Meary angle and the

lateral talocalcaneal angle6. maintenance of subtalar motion.

Imbrication of Talonaviculocuneiform Complex. Imbrication of the talonaviculocuneiform complex medially can be performed in combination with calcaneal lengthening.

It is not recommended as a single procedure

Medial imbrication of the talonavicular-cuneiform joints in the surgical treatment of flatfoot.

A, The tibialis posterior is divided (for later imbrication). The osteoperiosteal flap is raised in a proximal-to-distal direction.

B, After reduction of the talonavicular displacement by translating the navicular medially and plantarward, the osteoperiosteal flap is advanced proximally. Internal fixation is recommended.

C, The tibialis posterior is shortened/imbricated after proximal reattachment of the osteoperiosteal flap.

Our technique involves initial detachment and later imbrication of the tibialis posterior tendon and raising of an osteoperiosteal flap of the cuneiform-navicular capsules by sharply dissecting a tongue of the medial capsules from proximal talonavicular to distal and leaving the flap attached at the cuneiform.

The osteoperiosteal flap is advanced proximally and plantarward, and is reattached to the talar neck with heavy suture. The tibialis posterior should be shortened and advanced to restore appropriate tension after “shortening” of the medial column by soft tissue imbrication.

Although excellent results have been reported with this medial reconstruction alone, we continue to use it only in conjunction with a calcaneal osteotomy.

Medial imbrication can also be combined with a sliding calcaneal osteotomy to reestablish the weight-bearing line in the center of the ankle-subtalar coronal plane, merely creates a compensatory varusization for talocalcaneal valgus, the effect of such a shift seems to be helpful in supporting the plantar flexed talus and decreasing overall eversion and midfoot abduction.

Significant improvement in both pain measures and radiographic parameters has been reported in adolescents undergoing this combined correction.

Complications of the combined procedure:1. Nonunion of the calcaneal graft 2. Displacement of the graft requiring revision 3. Displacement of the calcaneocuboid joint, 4. Recurrence of the deformity 5. Pain that develops with time or prolonged weight

bearing.