Pes cavus

Pes cavus

1. DR PRATIK DHABALIA CAVUS FOOT

2. DEFINITION In its simplest form, a cavus foot is one with an abnormally high arch . This high arch usually accompanies a spectrum of deformities, including hyperextension of the toes at the metatarsophalangeal joints and hyperflexion at the interphalangeal joints , pronation and adduction of the forefoot ( forefoot valgus ), a “bony” dorsum of the midfoot with wrinkled skin folds on the medial plantar aspect, lengthened lateral border of the foot and shortened medial border, calluses beneath the metatarsal heads , varied stiffness of the subtalar joint , fixed or flexible varus deformity of the heel, and tightness of the Achilles tendon with or without an equinus contracture.

3. Mild cavus deformity and clawing of toes in patient Shortening of medial column of foot.

4. Marked forefoot equinus and resulting dorsal prominence of tarsus in patient w Calluses beneath metatarsal heads are most common symptom prompting orthopaedic consultation.

5. ETIOLOGY NEUROMUSCULAR CAUSES The most common neuromuscular diseases causing pes cavus in skeletally mature feet are Charcot-Marie-Tooth disease and poliomyelitis. Patients with spinal dysraphism . cerebral palsy. primary cerebellar disease. arthrogryposis . severe clubfeet may develop cavus deformity, but these conditions usually are recognized and treated before skeletal maturity.

6. Traumatic cavus deformity can be caused by deep posterior compartment syndrome after fracture of the tibia or fibula or by malunion of midfoot fractures or fracture dislocations. In patients with neuromuscular diseases and patients with idiopathic deformities, the underlying pathologic mechanism of the cavus deformity is believed to be an imbalance of the extrinsic-intrinsic muscles.

7. The principle that the hindfoot deformity follows forefoot equinus is supported by the observations of Paulos et al.: the rigid plantarflexed first ray forces the heel into varus , and eventually the deformity becomes fixed.

8. The Coleman and Chestnut block test is an excellent method of determining the hindfoot -forefoot relationship in pes cavus and determining whether the hindfoot component is flexible. Other than the cause and possibly the age of the patient, the flexibility of any or all of the anatomic components of a cavus foot is the most important factor for determining persistence of symptoms and appropriate treatment

9. CLINICAL FEATURES High arch. Hyperextension at metatarsophalyngeal joint. Hyperflexion of interphalyngeal joint. Pronation and adduction of fore foot. Lengthened lateral border and relatively shorter medial border. Talus body prominence in mid foot with prominent medial planter crease. A patient with progressive muscular and sensory deficits with or without fixed deformity is s/o Charcot-Marie-Tooth disease, it is more common in males (2 : 1), but more severe in females. It may cause profound sensory deficits that eventually require amputation.

10. HOW TO DIFFERENTIATE A patient presenting with spasticity, even of the mildest degree, or with a preulcerative or ulcerative lesion of the plantar surface of the foot must be offered nonoperative treatment with shoe or ankle-foot orthoses . Surgery in the presence of decreased plantar sensation is fraught with complications that are most difficult to overcome. The postpoliomyelitis cavus foot has anterior and posterior (or forefoot and hindfoot ) components to the deformity, in contrast to patients with Charcot-Marie-Tooth disease, who usually have no fixed hindfoot calcaneal deformity. Because of intact sensation and the nonprogressive nature of the deformities, patients with postpoliomyelitis cavus feet have a better, or at least more predictable, prognosis than patients with Charcot-Marie-Tooth disease, with or without treatment.

11. Posttraumatic cavovarus results from injury to the extrinsic foot musculature, creating an imbalance with the intrinsic musculature. Affecting the deep posterior leg compartment, compartment syndrome and subsequent Volkmann contracture can lead to a cavus foot with claw toe deformities. Soft-tissue injuries from crush mechanisms or severe burns can lead to muscle imbalance that results in cavus deformity

12. RADIOGRAPHIC FINDING A standing lateral view allows assessment of ankle joint position, calcaneal pitch, and midfoot and forefoot position, especially the degree of plantarflexion of the first ray.This information is invaluable in preoperative planning. The standing lateral radiograph also allows estimation of the contribution of the hindfoot (talus and calcaneus ), midfoot ( navicular and cuboid -cuneiform), and forefoot ( Lisfranc ) to the cavus deformity. The extension deformity of the phalanges on the metatarsal heads during weight bearing helps determine the severity of the fixed deformity

13. A line is drawn from planter most surface of calcaneum to the inferior border of distal articular surface. Normal 17-32 degree Usually normal in CMT with forefoot equinus , increased in idiopathic cases and in poliomyelitis

14. Standing anteroposterior views with the hindfoot in as neutral a position as possible help corroborate any metatarsus adductus component suspected clinically The talocalcaneal angle (Kite angle) is determined on this view. The closer the talocalcaneal angle approaches zero, the more parallel the talus is in relation to the calcaneus , indicating hindfoot varus . Other radiographic findings that may be helpful include (1) degenerative changes (2) rotation of the talus in the ankle mortise (3) dystrophic ossification in soft tissue suggesting tendon or ligament injury on the oblique view

15. The  talocalcaneal angle , also known as the  kite angle , refers to the angle between lines drawn down the axis of the  talus  and  calcaneus  measured on a  weightbearing DP foot radiograph . The  mid- talar line  should pass through (or just medial to) the base of the 1 st  metatarsal and the  mid- calcaneal line  should pass through the base of the 4 th  metatarsal. The talocalcaneal angle should measure between 25 and 40 degrees. 

16. TREATMENT CLAW TOES In patients with traumatic pes cavus , only the claw toe deformities and possibly tight plantar fascia may require surgical treatment, leaving the bony midfoot deformity to appropriate shoe and orthotic management. For fixed contractures at the metatarsophalangeal and interphalangeal joints, the following are recommended: 1. Lengthening of the extensor hallucis longus and extensor digitorum longus . 2. Tenotomy of the extensor digitorum brevis and the extensor hallucis brevis . 3. Dorsal capsulotomy of the metatarsophalangeal joints. 4. Resection of the head and neck of the proximal phalanges. 5. Release of the plantar fascia, if indicated.

17. 6. Arthrodesis of the interphalangeal joint of the hallux or plantar plate release and sectioning of the collateral ligaments at the interphalangeal joint of the hallux with temporary Kirschner wire fixation

18. 1.PLANTAR FASCIA RELEASE Make a longitudinal incision along the medial side of the calcaneus and carry it distally to a point 4 cm anterior to the medial tubercle Separate the superficial and deep surfaces of the plantar fascia from the muscle and fat and free it throughout its breadth. Incise the fascia transversely close to where it blends into the plantar surface of the calcaneus . Place a periosteal elevator or retractor on the deep surface of the fascia as it is released. If the plantar fascia still feels tight, incise the medial band again through a separate incision 2 cm proximal to the first metatarsal head. Protect the flexor hallucis longus while releasing the medial band of the plantar fascia down to, but not through, the flexor hallucis brevis , and dorsiflex the first metatarsal by pushing up on the metatarsal head. Secure hemostasis and close the wound with nonabsorbable sutures in adult patients.

19. Correction of clawing of great and second toe

20. Surgical technique for clawing of great and second toes. A- Incision. B- Extensor hallucis longus is lengthened in coronal or sagittal plane, and extensor hallucis brevis is tenotomized . C- Dorsal capsulotomy and collateral ligament release. D- Approach to interphalangeal joint through separate dorsal incision. E-Corrected position on lateral view; arthrodesis of interphalangeal joint of great toe with longitudinal wire down to base of proximal phalanx. F, Correction of second toe by excision of head and neck of proximal phalanx, dorsal capsulotomy at metatarsophalangeal joint, lengthening of extensor digitorum longus , and tenotomy of extensor digitorum brevis . G, Correction at metatarsophalangeal and proximal interphalangeal joints.

21. 2.TENDON SUSPENSION OF THE FIRST METATARSAL AND INTERPHALANGEAL JOINT ARTHRODESIS The Jones procedure, which is basically a tendon suspension of the first metatarsal combined with arthrodesis of the interphalangeal joint, has proved valuable over many decades. Instead of Z-lengthening of the extensor hallucis longus , the proximal end is placed through a hole in the first metatarsal neck.

22. 3.Proximal First Metatarsal Osteotomy and Plantar Fasciotomy . This combined procedure is applicable in hereditary motor sensory neuropathy, after trauma and peripheral nerve injury, although today it is probably used more often in Charcot-Marie-Tooth disease to correct a predominantly forefoot (first ray) driven cavus deformity.

23. In Charcot-Marie-Tooth disease, the correction of the forefoot equinus should proceed in an orderly fashion

24. 4.COMBINED PROXIMAL FIRST METATARSAL OSTEOTOMY, PLANTAR FASCIOTOMY, AND TRANSFER OF THE ANTERIOR TIBIAL TENDON In treatment for cavus deformity secondary to Charcot-Marie-Tooth, also included transfer of the anterior tibial tendon to the lateral cuneiform if grade 4 or 5 strength was present. Later in the study, this transfer was done for a tenodesis to negate any residual deforming force that the anterior tibial muscle may have on the varus component of the cavovarus deformity.

25. 5.PLANTAR FASCIOTOMIES AND CLOSING WEDGE OSTEOTOMY DOUBLE PLANTAR FASCIOTOMIES (IF REQUIRED— MOST OFTEN IN ADULTS AND AFTER TRAUMA) BY GOULD TECH. CLOSING WEDGE GREENSTICK DORSAL PROXIMAL METATARSAL OSTEOTOMIES

26. 5.EXTENSOR TENDON TRANSFER (HIBBS) ■ Make a curved incision 7.5 to 10 cm long on the dorsum of the foot lateral to the midline and expose the common extensor tendons ■ Divide the tendons as far distally as feasible, draw their proximal ends through a tunnel in the third cuneiform, and fix them with a nonabsorbable suture ■ As an alternative, use a plantar button and felt with a Bunnell pull-out stitch. ■ Close the wounds and apply a plaster boot cast with the foot in the corrected position

27. TARSOMETATARSAL TRUNCATEDWEDGE ARTHRODESIS Another procedure for forefoot equinus advocated by Jahss is arthrodesis of all tarsometatarsal joints Indications : 1. Equinus deformity of the forefoot with persistent painful metatarsalgia and associated plantar keratoses , unrelieved by conservative management. Such patients usually have more than 10 degrees of equinus angulation . 2. Pes cavus with normal muscle balance and without advanced metatarsal fat pad atrophy

28. 3. Equinovarus or equinoadductovarus deformity of the forefoot with the heel in neutral or almost neutral position. This group includes the residual clubfoot deformities and compartment syndromes. If the lesion is caused by neuromuscular disease, such as poliomyelitis, the foot should be stable. 4. Normal vascular status and normal skin coverage. 5. The procedure preferably is done at an early stage. If the associated hammertoes are still flexible, the toes straighten as the dorsal wedge is closed and do not require separate surgery.

29. Contraindications : 1. When skin coverage of the forefoot is poor from previous surgery, or vascularity of the skin is questionable, no surgery should be performed. 2. Surgery should not be done before skeletal maturity.

30. MIDFOOT CAVUS Cavus deformity can occur at the midtarsal joints ( talonavicular-calcaneocuboid ) or naviculocuneiform joints, but is most common at the former. Depending on the rigidity of the deformity, plantar fascia release combined with calcaneal or metatarsal osteotomy may correct the deformity sufficiently to achieve a plantigrade foot. For mild-to-moderate fixed cavus deformity at the midfoot , the following osteotomies have been described. Any of these midfoot osteotomies may produce a short, wide, unattractive foot, depending on how much bone is removed.

31. 1.ANTERIOR TARSAL WEDGE OSTEOTOMY

32. 2.V-OSTEOTOMY OF THE TARSUS The disadvantage of the anterior tarsal wedge osteotomy is the foot is shortened, widened, and thickened. Japas described a technique to produce a more normal-appearing foot. It consists of a V- osteotomy in which the apex of the V is proximal and at the highest point of the cavus , usually within the navicular . One limb of the V extends laterally and the other medially through the first cuneiform to the medial border. No bone is excised; instead, the proximal border of the distal fragment of the osteotomy is depressed plantarward while the metatarsal heads are elevated, correcting the deformity and lengthening the plantar surface of the foot. The technique is recommended for moderate deformity in children 6 years old or older. Deformities of the hindfoot or midtarsal joint are not corrected by this osteotomy and may require later correction by triple arthrodesis or the Dwyer osteotomy .

33. COMBINED CAVUS (CALCANEOCAVUS DEFORMITY) 1. OSTEOTOMY OF THE CALCANEUS (DWYER’S)

34. 2. CRESCENTIC CALCANEAL OSTEOTOMY Samilson recommended crescentic calcaneal osteotomy for ambulatory patients with symptomatic calcaneocavus feet. On a lateral radiograph, the calcaneus must be relatively vertical, and the apex of the cavus must be posterior to the midtarsus . The operation does not correct midtarsal or forefoot cavus but does correct hindfoot cavus ( calcaneocavus ).

35. CALCANEOCAVOVARUS AND CAVOVARUS DEFORMITY Seen in patients with Charcot-Marie-Tooth disease, but occasionally this deformity occurs after poliomyelitis or malunion of displaced fractures of the talus subtalar arthrodesis (removing more bone laterally) combined with lateral closing wedge (7 to 10 mm) osteotomy of the anterior aspect of the calcaneus 1 cm proximal to the calcaneocuboid joint (reverse Evans osteotomy ) may correct the deformities, while allowing some degree of midtarsal motion. If the talonavicular or calcaneocuboid joints show arthritic changes, triple arthrodesis is indicated. The wedges of bone must be planned carefully to correct the multiplane deformity. In neuromuscular cavovarus or calcaneocavovarus deformities, one of the following methods is recommended.

36. 1. TRIPLANAR OSTEOTOMY AND LATERAL LIGAMENT RECONSTRUCTION For unstable ankle joints without significant degenerative changes associated with calcaneocavovarus deformity, Saxby and Myerson recommended performing a lateral ligament reconstruction at the time of calcaneal triplanar osteotomy . If degenerative changes are noted: triple arthrodesis with lateral ligament reconstruction. Saxby and Myerson emphasized that in hereditary sensorimotor neuropathy (Charcot-Marie-Tooth disease), the peroneus brevis is not functioning and tendon can be used to help stabilize the ankle joint that tilts into varus .

37. 2. Z-SHAPED CALCANEAL OSTEOTOMY Knupp et al. described a procedure using a step-cut (scarf) osteotomy that allows correction of the heel in frontal and transverse planes. Indications: 1.rigid varus hindfoot combined with forefoot valgus and an excessively plantarflexed first ray. Osteotomy of the calcaneus is necessary if the varus deformity is caused by metatarsus primus flexus without a rigid hindfoot deformity. Likewise, additional tendon transfers may be required in an excessively pronated forefoot. Degenerative disease and coalitions are contraindications to this procedure. A neurologic assessment should be done, especially if Charcot-Marie-Tooth disease is suspected.

38. 3.PERONEUS BREVIS TENODESIS When the ankle joint is unstable in varus from chronic weakness of the peroneal tendons, Myerson recommended a tenodesis using the peroneus brevis tendon because it has no active function. Realignment of the hindfoot with an osteotomy or arthrodesis may correct the tibiotalar tilt by shifting the weight-bearing axis of the leg laterally. In patients with hindfoot varus and ankle instability not associated with any neuromuscular imbalance, the peroneus brevis tendon is split and reconstruction is performed (Chrisman and Snook). If the talar tilt is fixed and rigid and articular pain is present, a pantalar arthrodesis should be performed.

39. CALCANEOCAVOVARUS AND CAVOVARUS DEFORMITY ASSOCIATED WITH ARTHRITIC CHANGES OF THE SUBTALAR AND MIDTARSAL JOINTS 1.TRIPLE ARTHRODESIS Siffert , Forster, and Nachamie triple arthrodesis

40. DUNN TECHNIQUE An alternative method is . Occasionally, the deformity is so severe that the entire navicular is removed :Dunn technique

41. LAMBRINUDI TRIPLE ARTHRODESIS

42. THANK YOU