A. Achilles Tendon Overview [1]

1. Achilles Tendon
   1. Connects calcaneus to gastrocnemius and soleus muscles
   2. Spans two joints
   3. Paratenon in place of synovial sheath
   4. Subjected to many strong forces
   5. Limited blood supply (typical of tendons) which diminishes with age
2. Problems with the Achilles Tendon
   1. Tendonosis
   2. Tendonitis and Peritendonitis
   3. Rupture
   4. Retrocalcaneal Bursitis
3. Tendonosis
   1. Diffuse thickening of tendon
   2. No histologic evidence of inflammation
   3. Common in age >35 years
   4. May present as painless, palpable nodule on Achilles Tendon
   5. Range of motion exercises, evaluation of shoes, may be helpful

B. Achilles Tendonitis and Peritendonitis

1. Occurrence
   1. ~10% of runners - usually cross-country and track and field
   2. Runners repetitively put ~8X runner's weight on tendon
   3. Also occurs with walking, cycling, construction work
   4. Less common with dancers, gymnasts, tennis players
   5. Common when person initially begin (intense) athletic activities
   6. Often related to poor technique
   7. Associated with sarcoidosis, ankylosing spondylitis, psoriatic arthritis
2. Symptoms
   1. Pain
   2. "Knot" palpable in right heal area
   3. Risk for rupture (severe pain)
   4. Peritendonitis - localized tenderness, burning 2-6 cm above tendon insertion
   5. Peritendonitis usually improvs with walking or when heat is applied
3. Diagnosis
   1. Detailed history - training, technique, footwear, previous injury, treatment
   2. Thorough physical examination - patient lying prone, feet hanging off exam table
   3. Active range of motion
   4. Crepitation often present wthin tendon
   5. Consider tears and ruptures during exam
   6. Radiographic evaluation rarely required
4. Treatment
   1. Symptoms often persist for several months, even with treatment
   2. Initial treatment: control inflammation with rest, ice (20 minutes pre- and post- exercise, nonsteroidal antiinflammatory agents (NSAIDs) and/or acetaminophen
   3. Correct biomechanical factors: appropriate shoes, heel lifts, technique evaluation, weight loss, low- to no-impact aerobic exercise
   4. Slow, gentle warm-up before exercise and icing after exercise
   5. Stretching and calf-muscle training associated with more rapid recovery
   6. Local peritendon glucocorticoid injection reduces pain (usually temporarily)
   7. Ultrasound therapy and flexibility training may be added to treatment
   8. Referral for surgery if no improvement after 6 months

C. Achilles Tendon Rupture [1]

1. Break in achilles tendon, often due to sports injury
2. Most common with football, baseball, basketball, softball, tennis, racquetball
3. Most common in men 30-50 years old
4. Spontaneous rupture can occur in elderly
5. Symptoms
   1. Pain may be acute, but only minimal
   2. "Pop" sound
   3. Able to bear weight on affected side, but cannot push off
6. Diagnosis
   1. History focus on sport's injury and specific time of first symptom
   2. Strength on plantar flexion
   3. Inability to raise toe
   4. Abnormal Thompson Test
   5. Ultrasound or magnetic resonance imaging can confirm diagnosis
7. Thompson Test
   1. Patient lies prone on examination table
   2. Calf gently squeezed by physician, watches for plantar flexion in foot
   3. If foot moves, tendon is at least partially intact
   4. No movement indicates rupture (abnormal test)
8. Treatment
   1. Surgery + immobilization or immobilization alone
   2. Surgery usually for younger persons who want to return to sports
   3. Casting preferred in older persons (8-12 weeks)
   4. Initial 1-2 weeks of immobilization should be non-weight bearing

D. Retrocalcaneal Bursitis [1]

1. Occurrence
   1. Most common in age >40 years
   2. Also occurs in athletes as an overuse injury
   3. Associated with ankle injuries, spondyloarthropathy, gout, pseudogout
2. Symptoms and Signs
   1. Pain increasing with activities
   2. Pain posterior to lateral malleolus, near Achilles tendon down to the calcaneous
   3. Pain worse on active, compared with passive, dorsiflexion of the foot
   4. Limp often develops
   5. Swelling and erythema on posterior portion of the heel at tendon insertion
   6. Bursa easily palpated and this causes pain
3. Radiograph
   1. Often shows calcified distal Achilles tendon
   2. Bone spur on superior portion of calcaneus may be seen (Haglund deformity)
4. Treatment
   1. NSAIDs or acetaminophen may be helpful
   2. Heel cup
   3. Alternating ice and heat therapy
   4. Caution with local glucocorticoid injection as may increase risk of tendon rupture
   5. However, glucocorticoid injection is often very effective for pain

E. Plantar Fasciitis [2]

1. Most common cause of pain in inferior heal
   1. ~12% of foot pain syndromes
   2. Typically presents in persons age 40-60 years
   3. Earlier age presentation in runners
2. Etiology
   1. Overuse injuries involving microtears of fasia at origin
   2. Increased risk in obese persons
   3. Common in runners, especially during intense training
   4. Bone spur, calcific tendinitis should be ruled out with radiography
   5. Increased risk with cavus deformity (high arch) and pes planus (flat foot)
   6. Common presenting symptom in juvenile arthritis and spondyloarthropathy
3. Symptoms and Signs
   1. Heel pain, usually sharp and piercing while standing, especially on awakening
   2. In patients with inflamatory disease, pain is worse at beginning of day, better later
   3. Usually better with initial use, but during day pain may return with overuse
   4. Palpation of heel elicits pain, especially along medial aspects of inferior heel
   5. Examine patient's footware - often loose heals, inadequate arch support
   6. Bilateral in ~30% of cases
   7. Disease is self-limited, ~80% resolving within 12 months
4. Imaging
   1. Limited role in usual clinically oriented diagnosis
   2. Plain radiograph most useful to rule out calcaneal (stress) fracture
   3. Bone scans can also distinguish plantar fasciitis from calcaneal stress fracture
   4. Plantar fasciitis shows early blood flow and blood pooling in bone scan
   5. Ultrasonography or magnetic resonance imaging (MRI) show thickened plantar fascia
5. Differential Diagnosis
   1. Plantar fascial rupture - abrupt onset of tearing pain; inability to bear weight
   2. Enthesopathies - usually with spondyloarthropathy, unilateral or bilateral
   3. Calcaneal Fracture - evaluate with radiograph
   4. Calcaneal Apophysitis (Sever's Disease) - overuse injury to open epiphysis of the posterior calcaenous, most common in adolescents
   5. Bone bruise - generalized pain over inferior heal after weight bearing exercise, trauma
   6. Infection or malignancy - pain often worse at night
   7. Paget's disease - bowing of tibia, bone pain elsewhere, elevated alkaline phosphatase
   8. Bursitis - retrocalcaneal welling and erythema of posterior heel
   9. Atrophy of heel fat pad - usually elderly, pain or tenderness in central heel, worse with use
   10. Tarsal Tunnel Syndrome - posterior tibial nerve entrapment (see below)
   11. Other nerve entrapments (see below)
6. Treatment
   1. Heel pads or heel cups
   2. High dose NSAIDs - mildly effective
   3. Local glucocorticoid injection often highly effective - medial approach
   4. Usually combine 1mL 1% lidocaine with 1mL (25mg) depot-prednisolone
   5. Correction of underlying abnormal foot pathology with splints, prosthetics
   6. Taping plantar surface of foot has shown variable results
   7. Strengthening gastrocnemius
   8. Posterior splinting (particularly at night)
   9. Surgical Correction - usually after >6 months of failed therapy
   10. Ultrsound-guided extracorporeal shock wave therapy is not effective [5]
   11. Disease is usually self-limited and controlled data for efficacy of therapy is poor

F. Tarsal Tunnel Syndrome

1. Entrapment neuroapthy of posterior tibial nerve at the ankle (medial malleolus)
2. Usually occurs due to compression of posterior tibial nerve
3. Symptoms
   1. Follow path of posterior tibial nerve, may also radiate up calf
   2. Aching, burning, tingling
   3. Numbness of plantar surface
   4. Aggrevated by prolonged weight bearing, walking on hard surfaces
   5. May occur in association with plantar fasciitis
4. Underlying conditions similar to carpal tunnel
   1. Hypothyroidism
   2. Inflammatory arthritis
   3. Amyloid
   4. Pregnancy
5. Signs are variable, sometimes positive Tinel's Sign by tapping on plantar foot surface
6. Diagnosis by nerve conduction study or MRI
7. Differential Diagnosis
   1. See above for plantar fasciitis
   2. Compression of medial calcaneal branch of posterior tibial nerve leads to burning pain in medial and plantar areas
   3. Compression of nerve to abductor digiti quinti - burning pain in heel pad
   4. S1 Radiculopathy - pain radiating down leg to heel, absent or reduced ankle reflex, weakness of dorsiflexion of the big toe
   5. Neuropathic pain - diffuse foot pain, often at night
8. Local injection or anti-inflammatory drugs are sometimes helpful
9. Surgical decompression may be required in severe cases

G. Hallux Valgus [3]

1. Components
   1. Deviation of large toe lateral to midline
   2. Deviation of first metatarsal medially
2. Very common condition occurs to some degree in ~33% of adults wearing shoes
3. Bunion (adventitious bursa) often develops on head of first MTP - pain, swelling
4. More common in women
5. Risks: pointed, tight shoes, genetic predisposition, osteoarthritis, inflammatory arthritis
6. Treatment [3]
   1. Larger (wider) shoes
   2. Bunion pad
   3. Orthoses (insoles) - short term symptomatic relief by resolving abnormal function
   4. Surgical correction: >200,000 operations per year
   5. Distal metatarsal (chevron) osteotomy is usual operation for mild to moderate

H. Hammer Toe

1. PIP joint fixed flexion with toe pointing downwards
2. Second toe most commonly involved
3. If MTP is also hyperextended, then deformity is called cock-up toes
4. Congenital or secondary to trauma or inflammatory arthritis (RA, SLE)
5. Often quite painful, difficulty getting into shoes
6. Surgical correction may be required

I. Morton's Neuroma

1. Entrapment neorpathy of an interdigital nerve in the foot
2. Usually occurs in middle-aged women between the third and fourth toes
3. Paresthesia and burning usually present in 4th toe
4. Treatment includes a metatarsal bar or local glucocorticoid injection
5. Surgical Correction is often needed

J. Metatarsalgia

1. Pain arising from metatarsal heads, often with calluses over the painful areas
2. Multiple causes leading to maldistribution of weight on the forefoot
3. Orthotic devices with elevation of transverse arch of the foot are useful

K. Corns [4]

1. Circumscribed hyperkeratotic with conical core of keratin (defined margins)
2. Causes pain and inflammation
3. Central core distinguishes corn from callus
4. Two Types: Hard and Soft Corns
5. Hard Corn (heloma durum)
   1. Most common type, dry, horny mass with hard central core
   2. Usually on dorsolateral aspect of fifth toe
   3. Also common on dorsum of interphalangeal joints of lesser toes
6. Soft Corn (heloma molle)
   1. Results from absorption of extreme amount of moister from perspiration
   2. Characteristic macerated appearance
   3. Extremely painful
   4. Develops between any of the toes, usually between 4th and 5th toes
7. Corns often caused by hammertoe deformity
8. Treament
   1. Depends on extent of hammertoe deformity
   2. Reducible deformities may respond to crest pad placed in sulcus of digits 2-4
   3. Crest pad is made from two-inch cotton role
   4. Place crest pad on plantar aspect of foot under interphalangeal joints of lesser toes
   5. Crest pad leads to straightening of hammertoe deformity when foot is load-bearing
   6. Nonreducible hammertoes often require surgical correction

L. Calluses

1. Broad-based or diffuse hyperkeratotic lesion
2. Undefined margins with relatively even thickness
3. Usually under metatarsal head at site of friction, irritation, pressure
4. Pathogenesis
   1. Abnormal mechanical stress on skin
   2. Leads to accumulation of several layers of "horny" layer of epithelium
   3. Bony prominences or hammertoe deformities common
   4. Tight or irregularly fitting shoes
   5. High activity levels - very common in athletes
5. Two Types: Diffuse-shearing and discrete-nucleated
6. Discrete-Nucleated Callus
   1. Painfull lesion on plantar surface often called plantar corn
   2. Has a central keratin plug
   3. May be confused with plantar wart which is more painful on lateral compression
7. Sharp Debridement
   1. Helps differentiate between warts and
   2. Warts tend to bleed on sharp debridement
   3. Small black or brown dots visible after removal of hyperkeratotic tissue also suggests warts (thrombosed blood vessels)
8. Treatment
   1. Alleviation of mechanical stress is key
   2. Sharp debridement to reduce amount of hyperkeratotic tissue
   3. Chisel blade or number 15 scalpal blade can be used to remove keratin plug
   4. Nonpainful lesions may be removed by patients using a pumice stone after soaking in warm water
   5. Salicylic acid containing agents are avoided as they can damage normal tissues
   6. Therapeutic padding can alleviate symptoms as well
   7. Low healed shoes with soft upper portion and roomy toebox recommended
   8. Surgery may be required to correct underlying abnormalities

References

1. Mazzone MF and McCue. T. 2002. Am Fam Phys. 65(9):1805
2. Buchbinder R. 2004. NEJM. 350(21):2159
3. Torkki M, Malmivaara A, Seitsalo S, et al. 2001. JAMA. 285(19):2474
4. Freeman DB. 2002. Am Fam Phys. 65(11):2277
5. Buchbinder R, Ptasznik R, Gordon J, et al. 2002. JAMA. 288(11):1364