Common deformities, deviations, and injuries of ankle and foot

Common deformities, deviations, and injuries of ankle and foot

1. Common Deformities, Deviations, and Injuries By : Dr. Vicky Kasundra 1 st year MPT (neurological sciences)

2. Bunionette (Tailor’s Bunion) prominence of the lateral aspect of the fifth toe metatarsal head. If associated with hallux valgus , it results in a splayed foot. It is often associated with a pronated foot.

3. Claw Toes Hyperextension of the metatarsophalangeal joints and flexion of the proximal and distal interphalangeal joints. Claw toes usually result from the defective actions of lumbrical and interosseus muscles that cause the toes to become functionless. This condition may be unilateral or bilateral and may be associated with pes cavus , fallen metatarsal arch, spina bifida, or other neurological problems.

4. Hammer Toe extension contracture at the metatarsophalangeal joint and flexion contracture at the proximal interphalangeal joint; the distal interphalangeal joint may be flexed, straight, or hyperextended . The interosseus muscles are unable to hold the proximal phalanx in the neutral position and, therefore, lose their flexion effect. The causes of hammer toe include an imbalance of the synergic muscles, hereditary factors, and mechanical factors, such as poorly fitting shoes or hallux valgus . It is usually seen only in one toe—the second toe.

5. Often, there is a callus or corn over the dorsum of the flexed joint. The condition is often asymptomatic, especially if the hammer toe is flexible or semiflexible . The rigid type of hammer toe is likely to cause the greatest problems.

6. Mallet Toe Flexion deformity of the distal interphalangeal joint It can occur on any of the four lateral toes. Often, a corn or callus is present over the dorsum of the affected joint. The condition is usually asymptomatic. It is commonly seen with ill-fitting or poorly designed footwear.

7. Clubfoot This congenital deformity is relatively common and can take many forms, the most common of which is talipes equinovarus . Its cause is unknown, but there are probably multifactorial genetic causes modified by environmental factors. It sometimes coexists with other congenital deformities, such as spina bifida and cleft palate. The flexible form is easily treated, but the resistant type often requires surgery. On assessment, the ROM is limited and the foot has abnormal form.

8. Crossover Toe Crossover toe is the result of weakening of the lateral collateral ligament of the metatarsophalangeal joint and insufficiency of the plantar plate along with the pull of the extrinsic muscles resulting in medial deviation of the toe. Most commonly in the second or third toe. It is often associated with hallux valgus .

9. Curly Toe A curly toe deformity involves a flexion deformity of both the proximal and distal interphalangeal joints with the metatarsophalangeal joint in neutral or flexion, often combined with rotation. It is the result of contracture of flexor digitorum brevis and longus tendons and is most commonly seen in the fifth toe in children.

10. Equinus Deformity ( Talipes Equinus ) This deformity is characterized by limited dorsiflexion (less than 10°) at the talocrural joint, usually as a result of contracture of the gastrocnemius or soleus muscles or Achilles tendon. It may also be caused by structural bone deformity (primarily in the talus), trauma, or inflammatory disease.

11. Exostosis (Bony Spur) Exostosis is an abnormal bony outgrowth extending from the surface of the bone. It is actually an increase in the bone mass at the site of an irritative lesion in response to overuse, trauma, or excessive pressure. The common areas of occurrence in the foot are on the dorsal aspect of the tarsometatarsal joint, the head of the fifth metatarsal bone, the calcaneus , the insertion of the plantar fascia, and the superior aspect of the navicular bone. Most often these exostoses are the result of poorly fitting footwear that leads to undue pressure on the bone.

12. Forefoot Valgus This structural midtarsal joint deviation involves eversion of the forefoot on the hindfoot when the subtalar joint is in the neutral position. It occurs because the normal valgus tilt (35° to 45°) of the head and neck of the talus to its trochlea has been exceeded. Forefoot Varus This structural midtarsal joint deviation involves inversion of the forefoot on the hindfoot when the subtalar joint is in the neutral position. It occurs because the normal valgus tilt (35° to 45°) of the head and neck of the talus to its trochlea has not been achieved.

13. Forefoot deformities (right foot). A, Forefoot varus (metatarsal heads raised on medial side). B, Forefoot valgus (metatarsal heads raised on lateral side).

14. Hallux Rigidus Hallux rigidus is a condition in which dorsiflexion or extension of the big toe is limited because of osteoarthritis of the first metatarsophalangeal joint. Hallux rigidus may also be caused by an anatomical abnormality of the foot, an abnormally long first metatarsal bone (index plus type forefoot) pronation of the forefoot, or trauma.

15. There are two types: acute and chronic. The acute, or adolescent, type occurs primarily in young people with long, narrow, pronated feet and occurs more frequently in boys than in girls. Pain and stiffness in the big toe come on quickly; the pain is described as constant, burning, throbbing, or aching. Tenderness may be palpated over the metatarsophalangeal joint, and the toe is initially held stiff because of muscle spasm. The first metatarsal head may be elevated, large, and tender.

16. The second (chronic) type of hallux rigidus is much more common and occurs primarily in adults—again, in men more frequently than in women. It is frequently bilateral and is usually the result of repeated minor trauma resulting in osteoarthritic changes to the metatarsophalangeal joint of the big toe. The toe stiffens gradually, and the pain, once established, persists. The patient complains primarily of pain at the base of the big toe on walking.

17. Hallux Valgus Hallux valgus is a relatively common condition in which there is medial deviation of the head of the first metatarsal bone in relation to the center of the body and lateral deviation of the head in relation to the center of the foot. The cause of hallux valgus is varied. It may result from a hereditary factor and is often familial. Women tend to be affected more than men. Person wears tight or pointed shoes, tight stockings, or high-heeled shoes will be at more risk.

18. A callus develops over the medial side of the head of the metatarsal bone, and the bursa becomes thickened and inflamed; excessive bone ( exostosis ) forms, resulting in a bunion. These three changes callus, thickened bursa, and exostosis make up the bunion, a condition separate from hallux valgus , although it is the result of hallux valgus . In normal persons, the metatarsophalangeal angle (the angle between the longitudinal axis of the metatarsal bone and the proximal phalanx) is 8° to 20°. This angle is increased to varying degrees in hallux valgus .

19. The first type (congruous hallux valgus ) is a simple exaggeration of the normal relation of the metatarsal to the phalanx of the big toe. The deformity does not progress, and the valgus deformity is between 20° and 30°. The opposing joint surfaces are congruent. It requires little treatment, and often the biggest problem is cosmetic.

20. The second type (pathological hallux valgus ) is a potentially progressive deformity, increasing from 20° to 60°. The joint surfaces are no longer congruent, and some may even go to subluxation . This type may occur in deviated (early) and subluxed (later) stages. When looking at the foot, the examiner may find that there is a widening gap between the first and second metatarsal bones (increased intermetatarsal angle) and a lateral deflection of the phalanx at the metatarsophalangeal joint.

21. The joint capsule lengthens on the medial aspect and is contracted on the lateral aspect. The toes rotate on the long axis so that the toenail faces medially because of the pull of the adductor hallucis muscle. Sometimes, the big toe deviates so far that it lies over or under the second toe.

22. Of all hallux valgus cases, 80% are caused by metatarsus primus varus , in which the intermetatarsal or metatarsal angle is increased to more than 15°. Metatarsus primus varus is an abduction deformity of the first metatarsal bone in relation to the tarsal and other metatarsal bones so that the medial border of the forefoot is curved. Normally, this angle is between 0° and 15°.

23. A, Bunions apparent on both feet. B, Schematic line drawing of a bunion

24. A, An example of congruous hallux valgus . B, Pathological hallux valgus with bilateral bunions and overlapped toes.

25. Pes Cavus (“Hollow Foot” or Rigid Foot) A pes cavus may be caused by a congenital problem; a neurological problem, such as spina bifida, poliomyelitis, or Charcot- Marie-Tooth disease; talipes equinovarus ; or muscle imbalance. There may also be a genetic factor, because it tends to run in families. The longitudinal arches are accentuated and the metatarsal heads are lower in relation to the hindfoot so that there is a dropping of the forefoot on the hindfoot at the tarsometatarsal joints. The soft tissues of the sole of the foot are abnormally short, which gives the foot a shortened appearance.

26. If the deformity persists, the bones eventually alter their shape, perpetuating the deformity. The heel is normal, at least initially. Claw toes are often associated with the condition because of the dropping of the forefoot combined with the pull of the extensor tendons. The examiner often finds painful callosities beneath the metatarsal heads that are caused by the loss of the metatarsal arch and tenderness along the deformed toes. There is pain in the tarsal region after time because of osteoarthritic changes in these joints.

27. The longitudinal arches are high on both the medial and lateral aspects so that a lateral longitudinal arch occurs in some severe cases, and the forefoot is thickened and splayed. The metatarsal heads are prominent on the sole of the foot, and the toes do not touch the ground, even on active or passive movement. This type of deformity leads to a rigid foot with little ability to absorb shock and adapt to stress. People with this deformity have difficulty doing repetitive stress activity (e.g., long-distance running, ballet) and require a cushioning shoe. In severe cases, the cavus foot is often associated with neurological disorders.

28. Pes Planus (Flatfoot or Mobile Foot) Flatfoot may be congenital, or it may result from trauma, muscle weakness, ligament laxity, dropping of the talar head, paralysis, or a pronated foot. For example, a traumatic flatfoot may follow fracture of the calcaneus . It may also be caused by a postural deformity, such as medial rotation of the hips or medial tibial torsion. It is a relatively common foot deformity that often causes little or no problem.

29. Therefore, the examiner should not necessarily assume that a flat, mobile foot needs to be treated. Because the foot is mobile, patients with flatfoot function well without treatment and often need only a control shoe to avoid problems in prolonged stress situations. It must be remembered that all infants have flatfeet up to approximately 2 years of age. This appearance in part results from the fat pad in the longitudinal arch and in part from the incomplete formation of the arches. With pes planus , the medial longitudinal arch is reduced so that on standing its borders are close to or in contact with the ground.

30. This results from the hindfoot dropping in relation to the forefoot. If the condition persists into adulthood, it may become a permanent structural deformity, leading to a defect or alteration of the tarsal bones and the talonavicular joints. There are two types of flatfoot deformities. The first type (rigid or congenital flatfoot) is relatively rare. The calcaneus is found in a valgus position, whereas the midtarsal region is in pronation . The talus faces medially and downward, and the navicular is displaced dorsally and laterally on the talus. There are accompanying softtissue contractures and bony changes.

31. The second type is acquired or flexible flatfoot . In this case, the deformity is similar to the rigid flatfoot, but the foot is mobile; and there are few, if any, softtissue contractures and bony changes. It is usually caused by hereditary factors and is sometimes called a hypermobile flatfoot. Flexible flatfoot may result from tibial or femoral torsion, coxa vara , a defect in the subtalar joint, or injury to the posterior tibial tendon. If the arch appears when the patient stands on tiptoes, the patient may have a mobile flatfoot. This type of flatfoot seldom needs treatment.

32. Hindfoot Valgus ( Subtalar or Rearfoot Valgus ) This structural deformity involves eversion of the calcaneus when the subtalar joint is in the neutral position. The hindfoot is mobile, which may lead to excessive pronation and limited supination . It may result from genu valgum (knock knees) and may contribute to the appearance of a pes planus foot with the medial longitudinal arch appearing flattened. It is often associated with tibia valgus and has been associated with posterior tibial tendon insufficiency.

33. Hindfoot Varus ( Subtalar or Rearfoot Varus ) This structural deviation involves inversion of the calcaneus when the subtalar joint is in the neutral position. The hindfoot is mildly rigid with calcaneal eversion ; therefore, pronation is limited. It may contribute to the appearance of a pes cavus foot, making the medial longitudinal arch appear accentuated. It may be the result of tibia varus ( genu varum ). This deviation can contribute to conditions, such as retrocalcaneal exostosis (pump bumps), shin splints, plantar fasciitis, hamstring strains, and knee and ankle pathology.

34. Metatarsus Adductus (Hooked Forefoot) This deformity is the most common foot deviation in children. It may be seen at birth but often is not noticed until the child begins to stand. The foot appears to be adducted and supinated (kidney shaped with medial deviation), and the hindfoot may or may not be in valgus . It may be associated with hip dysplasia. 85% to 90% of cases resolve spontaneously.

35. Morton’s (Atavistic or Grecian) Foot With a Morton’s foot, the second toe is longer than the first. The length difference may be due to different lengths of the metatarsals. Increased stress is put on this longer toe, and the big toe tends to be hypomobile . There is often hypertrophy of the second metatarsal bone because more stress is put through the second toe. People with this deformity often have difficulty putting on tight-fitting footwear (e.g., skates, ski boots) or dancing (e.g., en pointe in ballet).

36. Morton’s Metatarsalgia (Interdigital Neuroma) Morton’s metatarsalgia (Morton’s neuroma ) refers to the formation of an interdigital neuroma as a result of injury to one of the digital nerves. Usually, it is the digital nerve between the third and fourth toes, so the examiner must take care to differentially diagnose the condition from a stress fracture of one of the metatarsals in the same area (march fracture). (A stress fracture will be more painful when the bone is palpated and a bone scan would be positive.) point out that if a Morton’s neuroma is suspected, pressure palpation should be applied on the plantar aspect avoiding counter pressure on the dorsal aspect.

37. Dorsal palpation pain is more likely to be associated with a stress fracture, metatarsophalangeal synovitis , or dorsal neuralgia. While walking or running, the patient is suddenly seized with an agonizing pain on the outer border of the forefoot. The pain is often intermittent, like a cramp, shooting up the side and to the tip of the affected toe or the adjacent two toes. Squeezing the metatarsal bones together elicits pain because of the pressure on the digital nerve. On palpation, pain is more likely to be between the bones rather than on the bone. The condition tends to occur more frequently in women than in men.

38. Plantar Flexed First Ray This structural deformity occurs when the first ray (big toe) lies lower than the other four metatarsal bones so that the forefoot is everted when the metatarsal bones are aligned. If present congenitally, it is indicative of a cavus foot. In its acquired form, it occurs as compensation for tibia varum ( genu varum ) with limited calcaneal eversion .

39. Polydactyly This developmental anomaly is characterized by the presence of an extra digit or toe. It may be seen in isolation or with other anomalies, such as polydactyly of the hands and syndactyly (webbing) of the toes or hands. The primary concern with this anomaly is cosmesis .

40. Rocker-Bottom Foot In the rocker-bottom foot deformity, the forefoot is dorsiflexed on the hindfoot . This results in a “broken midfoot ,” so that the medial and longitudinal arches are absent and the foot appears to be bent the wrong way (i.e., convex to the floor instead of the normal concave).

41. Splay Foot This deformity, which is broadening of the forefoot, is often caused by weakness of the intrinsic muscles and associated weakness of the intermetatarsal ligament and dropping of the anterior metatarsal arch.

42. Turf Toe Turf toe is a hyperextension injury (sprain) combined with compressive loading to the metatarsophalangeal joint of the hallux . It can cause a significant functional disability, especially in sports, where the hallux is put under high loads. It is often related to the use of flexible footwear and artificial turf.

43. Thank you