Porter & Schon: Baxter's The Foot and Ankle in Sport, 2nd ed.

Section 2 - Sport Syndromes

Chapter 10 - Arthritic, metabolic, and vascular disorders

Gregory Rowdon,David Taylor

  

 

Introduction

  

 

Inflammatory/rheumatologic

  

 

Other

  

 

Metabolic disease

  

 

Vascular/lymphatic disorders

Introduction

Foot and ankle problems are common complaints to the physician who cares for athletes. Most of these complaints can be attributed directly to the athlete's training and competition with their sport. However, athletes are not immune from disease. Most of these athletes will present to the sports medicine physician assuming their complaints are related to their participation, and many will try to explain their complaints as being secondary to some aspect of their training. Although the vast number of complaints evaluated by the sports medicine physician is directly attributable to a primary musculoskeletal source, the physician must maintain an appropriate differential diagnosis to include those disease states that also can affect the musculoskeletal system. The foot and ankle are common sites for these disease states to present as they mimic sports injuries.

Many of the individuals who present to a sports medicine clinic are not “highly competitive” athletes but are athletes nonetheless. These individuals are commonly referred to as “recreational athletes” and generally are older. They strive to maximize their abilities in their own chosen activity while attempting to reap the myriad of benefits of a healthy lifestyle. This group of athletes may have concurrent disease states that must be taken into account as they attempt to maintain their healthy, active lifestyle. Diseases such as diabetes, gout, thyroid conditions, osteoporosis, and so forth can present with musculoskeletal complaints. The purpose of this chapter is to review those disease states, which may mimic a primary musculoskeletal problem in both the competitive and recreational athlete. Knowledge of these conditions is essential to the physician caring for athletes.

 

Inflammatory/ Rheumatologic

   Pearl

Suspect inflammatory disease in a joint that has no history of trauma and that is swollen and warmer than expected for the history.

   Pearl

Suspect inflammatory disease if there is a history of multiple joint involvement or other systemic complaints that is, skin, GI, constitutional, and so forth.

Case Study 1: Gout  

A 46-year-old, male runner awakens with a swollen, warm, red right ankle, which is exquisitely painful. He denies injury but did go for his usual 3-mile run 1 day ago. The rest of his history is noncontributory. On physical examination he demonstrates an effusion to the ankle with the joint erythemic and warm. The ankle is diffusely and significantly tender. The rest of the examination is noncontributory. X-rays are normal. Laboratory studies show a normal complete blood count (CBC), ESR, renal function, and uric acid. Joint aspiration demonstrates a mild to moderate inflammatory response and is positive for monosodium urate crystals. The patient was treated with indomethacin and demonstrated a complete response over the next few days.

Case Study 2: Reiter's Syndrome  

A 24-year-old, professional basketball player presents with a left ankle that is painful, swollen, red, and warm. He also notes several toes that are swollen and right heel pain. His past medical history and family history are noncontributory, except that he was treated for a Chlamydia infection 1 month ago. He is on no medications except for Visine for “irritated” eyes. Physical examination demonstrates an erythemic, warm left ankle with mild effusion. Several sausage digits are noted. The right plantar fascia origin is tender. Both conjunctiva are injected. The rest of the examination is noncontributory. X-rays are normal. Laboratory studies are negative, including an inflammatory workup, except that the ESR is elevated and the WBC is at the upper limits of normal. The athlete was treated with nonsteroidal anti-inflammatory drugs (NSAIDs) and physical therapy. The athlete returned to baseline and there were no recurrences.

Still's disease (adult onset)

Still's disease is a seronegative polyarthritis that usually affects young adults. It is characterized in its initial manifestation as a spiking fever and a red/salmon colored rash, usually over the trunk and extremities. The rash is transient and appears at the time of the fever spikes. The inflammatory arthritis is a polyarthritis or oligoarthritis. It commonly affects the proximal interphalangeal (PIP) and metacarpophalangeal (MCP) joints, as well as the wrists, knees, hips, and shoulders. Occasionally, the cervical spine, intertarsal joints, temporomandibular joints (TMJ), and the distal interphalangeal (DIP) joints are affected. It may lead to fusion of the carpal-metacarpal and the intercarpal joints. Laboratory evaluation commonly shows an elevated white blood cell count as well as an elevated erythrocyte sedimentation rate (ESR). Anemia of chronic disease is commonly present. Secondary nonmusculoskeletal findings include lymphadenopathy, hepatosplenomegaly, pericarditis, and carditis. The disease is treated with either high-dose aspirin or other nonsteroidal anti-inflammatory medicines. Often, oral steroids are required to control the disease. Overall, Still's disease has a good prognosis.

Ankylosing spondylitis

Ankylosing spondylitis is an insidious onset seronegative inflammatory condition affecting young individuals, that is, generally younger than 40 years old. It has a uniform sex distribution, but the disease seems to be milder in females. Also, females have more peripheral involvement, rather than spine involvement. Ankylosing spondylitis affects the sacroiliac (SI) joints, followed by the spine and peripheral joints, respectively. There usually is symmetric loss of spine movement. The peripheral joint involvement occurs in 20% to 30% of ankylosing spondylitis patients and has a predilection for the lower extremities. Achilles' tendinitis, plantar fascitis, and costochondritis also are associated with the disease process. It is common to have fatigue, weight loss, low-grade fever, and in more severe cases, uveitis, pulmonary fibrosis, and cardiac abnormalities. Laboratory findings include an elevated ESR. The natural history of ankylosing spondylitis is poorly defined, with some patients experiencing minimal disease and some patients experiencing severe disease. Treatment usually involves physical therapy and anti-inflammatories.

Reiter's syndrome

Reiter's syndrome involves the triad of arthritis, uveitis, and conjunctivitis. It commonly occurs following an episode of either genitourinary or gastrointestinal infection. It has associated features of inflammatory eye lesions, balanitis, oral ulcers, and keratodermatitis. Reiter's syndrome has a male to female occurrence of 5:1. The arthritis experienced in Reiter's syndrome is a reactive arthritis rather than an infectious arthritis. It usually occurs 2 to 6 weeks following the onset of an infectious episode. It is asymmetric and mainly affects knees and ankles. It is usually of acute onset. There may be diffuse swelling of fingers and toes, that is, sausage digits. There is commonly inflammatory change at both the Achilles' tendon insertion and the plantar fascial origin. There also may be associated low-back pain with involvement of the SI joints, making it difficult to distinguish it at times from ankylosing spondylitis. The conjunctivitis in Reiter's syndrome is either unilateral or bilateral. It usually is mild and transient and is a noninfectious source like the arthritis. Common skin lesions in Reiter's syndrome are small, shallow, painless, penile ulcers called balanitis circinata. Another associated skin lesion is keratoderma blenorrhagica, which represents hyperkeratotic skin lesions mainly involving the soles of the feet, but they also can be found on the palms and the scrotum. Radiographic findings may demonstrate erosions or periosteal changes, particularly at the Achilles' tendon insertion or plantar fascial origin. Also, an asymmetric sacroiliitis may be present that is in contrast to the symmetric involvement of ankylosing spondylitis. Reiter's syndrome also is seronegative but usually demonstrates an elevated ESR and elevated white blood count. Treatment for Reiter's syndrome involves anti-inflammatory medications and intra-articular steroid injections as well as physical therapy. Systemic oral steroids have been shown to be of minimal benefit. Topical steroids are used for the skin lesions and for the conjunctivitis. The prognosis for Reiter's syndrome usually falls into one of three courses; the majority of athletes experience recurrent attacks of arthritis, whereas others experience a single, self-limited episode or a continuous, unremitting course.

Psoriatic arthritis

Psoriatic arthritis is the combination of psoriasis and inflammatory arthritis. To make a definitive diagnosis of psoriatic arthritis, skin or nail changes of psoriasis must be present at some point in the course of the disease. The arthritic changes can be present before skin changes develop. The joint pattern in psoriatic arthritis is variable but commonly includes a pauciarticular asymmetric arthritis involving the peripheral joints. It is common to have the spine involved in combination with peripheral joints as well as inflammation of tendon and insertion points of tendons, that is, enthesitis. Digits may become sausage like. There often are associated eye changes, including conjunctivitis, iritis, and episcleritis. Psoriatic arthritis has an equal sex distribution and usually has onset in the 30- to 40-year-old age group. Laboratory results are often normal, but some athletes will present with an elevated ESR and/or a normocytic normochromic anemia. Synovial fluid evaluation typically reveals a mild inflammatory process. Radiographs often reveal DIP erosive disease, sacroiliitis, and enthesopathy and/or periostitis. Treatment of psoriatic arthritis involves the use of anti-inflammatory medications, physical therapy, and intra-articular corticosteroids to treat the inflammatory arthritis. The focus of treatment, however, involves treating the athlete's skin lesions. Oral methotrexate is a common therapeutic choice because it treats both the skin lesions and the arthritis. Overall, psoriatic arthritis has a good prognosis.

Enteropathic arthritis

Enteropathic arthritis is arthritis associated with inflammatory gastrointestinal (GI) conditions including ulcerative colitis and Crohn's disease, and infectious GI conditions, including Shigella, Salmonella, Campylobacter, Yersinia, and Whipple's disease. The arthritis, when associated with ulcerative colitis or Crohn's disease, usually is one of a peripheral arthritis with associated sacroiliitis and less often enthesopathies. It often is a transient, oligoarticular, migratory, nondestructive arthritis associated with the bowel disease activity. The knees and ankles are most often involved. Synovial fluid from the affected joints contains mild to severe inflammation. There are a variety of associated cutaneous lesions with the disease, and mucosal, serosal, and ocular lesions may occur. The arthritis with ulcerative colitis and Crohn's disease often resolves with medical or surgical treatment of the intestinal disease.

The arthritis associated with enteropathic infection often comes on a few weeks following the bowel symptoms. The arthritis, in this case, is a reactive arthritis and, again, affects mainly knees and ankles. There also may be axial joint involvement. Enthesopathies, although not common in association with ulcerative colitis and Crohn's disease, are common in association with infectious GI conditions and typically involve the plantar fascia and Achilles' tendon insertions. The arthritis is usually self-limited, resolving weeks to months after the bowel infection. Treatment is symptomatic involving the use of anti-inflammatory medications, physical therapy, and intra-articular corticosteroid injections.

Rheumatoid arthritis

Rheumatoid arthritis is a chronic, systemic inflammatory disease characterized by significant joint involvement. It affects multiple systems extensively, and thus a full detailed description of the disease is beyond the scope of this chapter. It involves symmetric upper extremity, knee, and foot destructive changes, sparing the DIP joints of the hands and feet. It results in progressive joint destruction and deformity. Again, there are multiple extra-articular features, including rheumatoid nodules, arteritis, neuropathies, scleritis, and pericarditis. Lymphadenopathy and splenomegaly are common. The incidence in females is two to three times greater than in males. It may occur at any age and increases in frequency with increasing age. Hand, wrist, knee, and foot are most commonly involved, but any diarthrodial joint can be affected. The elbows, shoulders, sternoclavicular (SC) joints, hips, ankles, and temporomandibular joints (TMJ) are less commonly involved. Spine involvement is limited to the upper cervical spine.

Feet and ankle changes are similar to those seen in the hands. Cocking up of the toes may occur secondary to subluxation of the metatarsal heads. This gives the digits a claw-like appearance. Fibular deviation of the first through fourth toes may occur. Bursal inflammation about the foot/ankle also occurs with the retrocalcaneal bursa being most common. Laboratory evaluation usually shows a normocytic, normochromic or hyperchromic anemia. There often is an elevated ESR and positive rheumatoid factor. Joint fluid evaluation reveals mild inflammation. Treatment involves anti-inflammatory medications, as well as physical therapy. Intra-articular corticosteroid injections are used for symptomatic joints not responsive to initial treatment. Second-line therapy involves disease-modifying antirheumatic drugs (DMARDs) with the trend toward more aggressive/earlier use of these drugs.

Systemic lupus erythematosus (SLE)

SLE is a chronic, multisystem inflammatory disease affecting bone, joints, tendons, skin, kidney, heart, lungs, GI tract, and central nervous system (CNS). Again, a full and detailed description of the disease process is beyond the scope of this text. SLE has a 9:1 female to male ratio. The arthralgias and arthritis are a common presenting complaint. The arthralgia/arthritis often is symmetric. Joint capsule, ligamentous, and tendon involvement can be prominent in the disease, and hand or foot deformities may develop. There often are marked laboratory abnormalities, including a normocytic, normochromic anemia, leukopenia, thrombocytopenia, elevated ESR, and positive antinuclear antibody (ANA) and double-stranded DNA. Treatment is with anti-inflammatories, topical/oral steroids, antimalarials, and immunosuppressive agents.

Gout

The pathogenesis of gouty arthropathy involves tissue deposition of uric acid crystals from a supersaturated extracellular fluid. Gout involves recurrent attacks of severe articular or periarticular inflammation. Late involvement of the disease involves crystal deposition of uric acid within articular, osseous, soft tissue, and cartilaginous structures. These tophi occur late (>10 years) in the disease. There may be renal impairment with or without uric acid urinary calculi. Hyperuricemia may be demonstrated in individuals without gout and uric acid levels may be within the normal range in individuals showing clinical gouty arthropathy. Gout is a disease of middle-aged men and postmenopausal women. It increases in frequency with age.

An acute, gouty, arthritic flare most commonly involves the great toe metatarsophalangeal (MTP) joint but also commonly involves the ankle. It usually involves a single joint with an acute onset, often during the evening hours. The joint often appears warm, red, and swollen and usually is exquisitely tender. The flare may subside spontaneously 3 to 10 days following onset without treatment. Individuals often are symptom free following an acute attack, but over time, if untreated, the attacks may increase in frequency, increase in the number of joints affected, and increase in duration of symptoms when flared. The flares may be triggered by trauma, alcohol, drugs, stress, or medical illness. Tophi when present occur most commonly in the synovial tissue, subchondral bone, olecranon bursa, patellar and Achilles' tendons, subcutaneous tissue on the extensor surface of the forearms, and overlying joints. Radiographic findings in gout usually are negative. Often they are obtained to rule out other joint processes, such as a septic joint, or to evaluate for the presence of chondrocalcinosis. More chronic cases can show periarticular erosions and frank degenerative changes, especially in the great toe MTP joint. The gold standard for diagnosis is monosodium uric crystals demonstrated in joint fluid. The white blood cell count from a symptomatic joint usually reveals moderate inflammation. Treatment in the acute setting may involve colchicine, anti-inflammatory medications, steroids, or intramuscular adrenocorticotrophic hormone (ACTH). Treatment in the chronic setting may also involve the use of colchicine as well as allopurinol or probenecid.

Pseudogout

Pseudogout involves acute, gout-like, inflammatory attacks that occur secondary to calcium pyrophosphate dihydrate crystal deposition within joints. The incidence of clinically symptomatic pseudogout is one half that of true gout. Calcium pyrophosphate dihydrate crystal deposition may occur as an incidental finding in a symptom-free joint with radiographic evaluation. The term “chondrocalcinosis” is used to describe this x-ray appearance. The male to female ratio of pseudogout is 1.4:1 and is in marked contrast to the distribution in gout. The pseudogout flare usually involves one or more joints lasting for several days. It usually is abrupt in onset but self-limited. Findings may be as severe as in true gout, but typically the attacks of pseudogout are less painful. The knee is the most commonly affected joint, but all joints are susceptible, including the first MTP joint. The flare may be triggered by trauma, surgery, stress, or medical illness. Individuals usually are symptom free between flares. Treatment is with anti-inflammatory medications and intra-articular steroid injections.

 

Other

Lyme disease

Lyme disease is a multisystem illness caused by the tick-borne spirochete Borrelia burgdorferi. The disease is characterized by a rash at the bite site (erythema chronicum migrans), constitutional symptoms, neurologic abnormalities, cardiac involvement, musculoskeletal complaints, and a reactive arthritis. Early in the disease course, there often is migratory pain without specific inflammation to the joints. Tendon, bursal, and muscular inflammation is common. The reactive arthritis usually occurs in intermittent attacks. It can be monoarticular to oligoarticular and has a preference for large joints, especially the knees. It can last for months, with chronic flares over several years. The treatment for Lyme disease early in its course is tetracycline, penicillin, or erythromycin. Late in the course of the disease, intravenous penicillin usually is the treatment of choice.

Sarcoidosis

Sarcoidosis is a multisystem illness characterized by noncaseating epithelioid granulomas in affected tissues. It has a tendency to affect young adults of either sex. It most often begins as bilateral hilar lymphadenopathy, pulmonary infiltrates, and skin and eye lesions. However, there may be bone lesions, localized muscular granulomas, and acute inflammatory arthritis. The arthritis is the most common rheumatologic manifestation and can be the initial complaint. The arthritis most commonly affects the ankles and knees. The most severe attacks usually occur during active disease. These flares usually last for 2 to 3 weeks. Chronic arthritic changes are much less common. The prognosis in sarcoidosis is favorable. Treatment usually is anti-inflammatory medication or a short course of oral corticosteroids.

 

Metabolic Disease

Metabolic diseases are an uncommon cause of concern in the athletic foot and ankle. The most common metabolic disease that may present with foot and ankle issues is diabetes mellitus. The neuropathy and microvasculopathy in the extremities, especially the foot and ankle, can result in a wide range of sequelae. Metabolic bone disease is another common metabolic disease that uncommonly affects an athlete's foot and ankle. In cases of recurrent stress fractures, metabolic bone disease such as osteoporosis may be the underlying cause. Medications and/or supplements can cause metabolic bone disease or can cause other conditions that are risk factors for metabolic bone disease. Examples include steroid use (or abuse), which causes drug-induced osteopenia, or vitamin B12 deficiency, which can cause a neuropathy that may present with diabetes-like complications.

Diabetes mellitus

Diabetes mellitus is a common disorder. Younger athletes are more likely to be type I, but many type II diabetics are involved with athletics, especially on a recreational or fitness level. The most important factor is achieving optimal control of the athlete's diabetes. Tighter control usually equates with fewer complications. In the setting of the foot and ankle, the most important complication is peripheral neuropathy, which usually occurs in a long standing diabetic. Peripheral neuropathy leads to the possibility of skin breakdown and subsequent ulceration and infection. In an athlete's foot and ankle, skin integrity can be a concern, regardless of diabetes. Callus formation, blisters, abrasion, and fungal infections are very common in athletes. In the setting of diabetes, these conditions can lead to ulceration and bacterial infection and potentially may develop a serious complication faster than in a nondiabetic athlete.

Skin ulceration is a significant concern for all diabetic athletes. Cellulitis can develop quickly. Even worse is the possibility of osteomyelitis. Left untreated, these complications could be career altering or even career ending. Most plantar wounds or ulcers in a diabetic are polymicrobial. Superficial skin infections on the dorsum of the foot or around the ankle may be less likely to be polymicrobial, but if empiric treatment is warranted, standard regimens to cover typical pathogens for diabetic ulcerations should be used. Proper wound care is essential, and weight-bearing activities may have to be restricted temporarily. One special note is that deep foot ulcers with signs of cellulitis may be infected with Pseudomonas because athletic shoes may harbor these bacteria. Lastly, deep ulcers need debridement and/or other investigation to search for osteomyelitis, although this would be unusual in the athlete.

Diagnosis and testing of diabetes is beyond the scope of this chapter, but it is important to note that monofilament tactile and vascular examinations are essential for the evaluation and monitoring of diabetic neuropathy. Routine diabetic care is essential for tight control of glucose levels and prevention of complications. It also is important to note that sports participation should be encouraged in the diabetic population because physical activity can have beneficial effects on the disease as a whole. Simply keep in mind that more attention must be paid to lower-extremity skin care in the athlete. In individuals with foot alignment prone to callus formation, such as a cavus foot, professional callus shaving may be warranted. Orthotics may be useful in spreading out load-bearing surface of the foot and may help to alleviate pressure spots before they can ulcerate.

Diabetics have other complications that can affect the athlete's performance and general health, but one that can have specific foot and ankle relevance is the fact that diabetics have a higher incidence of osteoporosis and may have an increased rate of stress fractures. The key is focusing on the foot and ankle but remembering to see the athlete as a whole person.

Metabolic bone disease

Metabolic bone disease encompasses any disorder that changes the mineralization of the normal skeleton. Osteoporosis is the most common metabolic bone disease that could affect the foot or ankle. This is a concern primarily in the mature or elderly athlete.

Osteoporosis and osteopenia are common disorders, especially in postmenopausal women. However, they do not usually affect the foot and ankle. The most common sites of fracture in osteoporosis are the spine, wrist, ribs, pelvis, hip, and humerus. Osteoporosis is a concern in mature or elderly athletes because weaker bones may lead to an increased fracture rate or recurrent fractures. Osteoporosis and osteopenia are abnormalities of the bony matrix, where bone is less dense but of normal architecture. Other metabolic bone diseases may not have normal bony architecture, such as osteomalacia.

Bone densitometry (dual energy x-ray absorptiometry [DEXA] scan) is the test of choice for diagnosis of osteoporosis. Standard radiographs are unreliable. DEXA scanning will differentiate osteoporosis from osteopenia. A DEXA score of 2.5 standard deviations below the mean is diagnostic of osteoporosis. Scores of 1.0 to 2.5 are diagnostic of osteopenia.

Treatment of osteoporosis is beyond the scope of this chapter, but a brief summary follows. The best treatment is prevention. Calcium intake should be at least 1000mg/day in an adult, and vitamin D is needed to aid in the absorption of the calcium. Weight-bearing resistance exercise also is important in building and maintaining strong bones. Once osteoporosis has been diagnosed, several treatment options exist. Calcium and vitamin D need to be taken, but they will not adequately increase bone density. At this time bisphosphonates (e.g., alendronate and risedronate) are a first-line treatment for increasing bone density. Estrogen increases bone density in postmenopausal osteoporosis but has other significant tissue effects that need to be taken into account before use. Selective estrogen-receptor modulators (raloxifene and tamoxifen) can prevent bone density loss and decrease fractures. Calcitonin can directly inhibit osteoclasts and prevent further bone loss. Parathyroid hormone actually can stimulate osteoblastic activity if the concentration is not too high. Follow-up DEXA scanning is important to monitor therapy.

Most cases of osteoporosis are idiopathic, age-related, or postmenopausal. There are many secondary causes that are not as common but need to be kept in mind. Please see Table 10-1 for a list of these secondary causes. The majority of patients with osteoporosis will be older recreational athletes, but bone loss can occur in a younger athlete. The classic scenario in a younger patient would be a college-age, female runner with recurrent stress fractures and an eating disorder and who is anovulatory. This is the classic female athletic triad (see Chapter 24 ). The results of the female athletic triad syndrome include metabolic bone disease and can lead to an increased rate of stress fractures. Any patient with recurrent stress fractures or problems healing existing fractures must be evaluated for possible metabolic bone disease. Clinical judgment is needed to determine when to test an athlete for metabolic bone disease in the setting of recurrent stress fractures. There are no established guidelines for the number or frequency of fractures that necessitate further investigation. In our opinion there is no specific number of fractures needed to prompt workup for metabolic bone disease, but if there is enough clinical evidence to suggest metabolic bone disease, a work-up is warranted (i.e., two to three stress fractures within a 2-year period).

Table 10-1   -- Secondary Causes of Osteoporosis

Nutritional

Inadequate calcium intake

Malabsorption

Bulimia or anorexia nervosa

Exogenous Substances

Glucocorticoids

Some chemotherapeutic agents

Excessive alcohol

Some anticonvulsants

Cyclosporine

Tacrolimus

Thyroxine

Bone Marrow Disease

Leukemia

Lymphoma

Myeloma

Metastatic carcinoma

Bone cysts

Rheumatologic/Connective Tissue Disease

Rheumatoid arthritis

Marfan's syndrome

Ehlers-Danlos syndrome

Osteogenesis imperfecta

Endocrine Disease

Diabetes mellitus

Hyperparathyroidism

Hyperthyroidism

Cushing's syndrome

Vitamin D deficiency (rickets/osteomalacia)

Hypogonadism

Growth hormone deficiency

Functional

Prolonged immobilization or disuse

Miscellaneous

Postsurgical

Subtotal gastrectomy

Celiac disease

Renal

Renal tubular acidosis

Hypercalciuria

 

 

Workup for metabolic bone disease is directed toward the suspected cause. For example, in a mature fitness athlete with recurrent stress fractures the cause is most likely to be a result of idiopathic or primary osteoporosis, and initial workup would start with a DEXA scan. A significantly different approach would be the case for a teenage girl with recurrent stress fractures and would include a more detailed dietary and menstrual history, as well as laboratory workup.

Medications/supplements/deficiency states

Several medications, supplements, or deficiencies can result in disease-like states that can result in foot and ankle issues in an athlete. Most cases concern medications or supplements that result in metabolic bone disease. Table 10-1 has several examples of medications that can cause osteoporosis. Also, deficiencies can result in metabolic bone disease. The obvious is calcium deficiency, but other states can lead to osteoporosis as well. Examples include growth hormone deficiency, thyroid hormone deficiency, and hypogonadism. Please see Table 10-1 for more examples. In some cases, excess states can lead to metabolic bone disease. Hyperparathyroidism and Cushing's disease would be examples. In addition, medications, supplements, or deficiency states can lead to other conditions that can affect the foot and ankle. Vitamin B12 or folate deficiency can lead to a peripheral neuropathy, which in turn could lead to some of the same concerns that a diabetic athlete may have. The bottom line is to search for clues to the underlying cause and, if possible, correct the disorder, discontinue the medicine or replete the deficiency.

Case Study 3: Female Athlete Triad  

A 19-year-old, female, college freshman, cross country/track athlete presents with a 2-week history of gradually worsening left foot pain. The pain initially was present at the start of her runs and became worse as she tried to run through the pain. Now the pain is present with activities of daily living (ADLs). Over the last 24 hours, her pain has worsened significantly. She has noted some mild swelling in the area of her dorsal midfoot/forefoot. About 1 month ago she added some runs outside of her usual training runs/practices. She has concern for a possible stress fracture as she has a history of prior stress fractures (three fractures during her senior and junior years of high school). The rest of her history of present illness is noncontributory. She is on no medications but admits to the use of over-the-counter (OTC) diet pills. She has a history of “spotty” periods and has not had a period since she was a sophomore in high school. The rest of her past medical history is noncontributory. Physical examination demonstrates a height of 5 feet 6 inches and a weight of 105lb (BMI = 17), minimal erosions of the enamel of the teeth and fine hair on the arms but is otherwise noncontributory. X-rays show a completed fourth metatarsal stress fracture. Laboratory studies including CBC, electrolytes, thyroid, and hormonal status tests are noncontributory. DEXA testing shows bone mineral density 2.5 standard deviations below the mean of young adults. A multiteam approach was used to treat the athlete and involved the team internist, a dietician, and a sports psychologist. Treatment included a walking boot for the stress fracture with activity modification, increased caloric intake and calcium supplementation to 1500mg per day, hormonal supplementation, counseling, and involvement of the athlete's family for emotional support.

 

Vascular/ Lymphatic Disorders

Arterial disease

Arterial disease represents decreased blood flow to the lower extremity. The most common cause is occlusive disease secondary to atherosclerosis and associated embolic phenomenon. It is uncommon in young healthy athletes unless there is a genetic predisposition or severe risk factors. It is most common in middle-aged to older-aged recreational athletes, especially those who have concurrent disease, that is, diabetes or elevated triglycerides or cholesterol. It presents as claudication of the lower extremities, which is defined as exercise-related pain. Evaluation at rest, unless late in the disease, may be entirely normal, although decreased lower-extremity pulses may be present. The disease usually is progressive, causing increased pain at lesser workloads. Evaluation may include arteriography, and definitive treatment may require vascular surgery.

Claudication in a young athlete may be caused by popliteal artery entrapment (see Chapter 20 ). Its cause is either an entrapment of the popliteal artery in the popliteal fossa secondary to an anatomic variation of the popliteal artery and surrounding myofascial structures or a functional entrapment compressing the artery by the exercising muscles and surrounding bone. It has an 85% male preponderance and usually occurs in the second or third decade. It is bilateral in 25% of cases. The athlete usually complains of cramping to the calf and foot with associated numbness or paresthesias. In 10% of patients, there are acute or chronic ischemic changes of the lower extremity, including skin and temperature changes as well as rest pain and possible tissue necrosis. Physical examination usually is normal, but the diagnosis may be suspected if pulses diminish in the affected extremity with maximal ankle dorsiflexion or with active plantarflexion with the knee fully extended. However, these examination findings also are found in normal individuals who have no lower-extremity complaints. Evaluation usually includes noninvasive vascular studies, including lower-extremity Doppler, preexercise and postexercise ankle/brachial blood pressure indices, continuous wave Doppler ultrasound with provocative maneuvers, mentioned previously, and a duplex ultrasound that combines anatomic evaluation with quantitative and qualitative analysis of arterial blood flow. The gold standard for evaluation, however, is arteriography. Treatment involves surgical release of the entrapped artery. Although few long-term studies exist regarding the prognosis of popliteal artery entrapment syndrome, studies suggest that the prognosis is most favorable if no arterial damage has occurred at the time of diagnosis and treatment.

Raynaud's phenomenon is manifested by pallor and cyanosis of the digits in response to some type of stressor, usually exposure to the cold but also possibly secondary to an emotional distress. It can present at any age but is most common in women between the ages of 20 and 40 years. It has an unknown etiology. Patients usually have no findings at the time of physical examination. Occasionally, some bluish discoloration of the tips of the digits may be present between attacks. A typical attack causes the digits to become pale and cyanotic with a sharp demarcation of these findings with the skin more proximally. Raynaud's may be associated with other diseases such as scleroderma, and when this occurs it is referred to as Raynaud's phenomenon. When just the Raynaud's findings are present without concurrent other disease, then it is called Raynaud's disease.

The prognosis for Raynaud's patients generally is good. For athletes who are exposed to cold weather conditions, protective clothing is usually sufficient. More severe cases may require a pharmacologic treatment, which may include calcium channel blockers, alpha-adrenergic blockers, or vasodilators.

Another condition that may affect the foot during cold weather outdoor activities is chilblain or pernio. Chilblain is an inflammatory disorder of the skin induced by cold temperature. It often affects women in the second or third decade of life. The etiology of chilblain is unknown. It presents as bluish red edematous areas of the skin overlying the lower extremities. Patients may complain of itching/burning to the areas of skin change. Repeated exposure may cause the lesions to become chronic and ulcerative. The lesions generally resolve with avoidance of the cold. Often, however, there will be a permanent area of hyperpigmentation at the prior site of the lesions.

Venous disease

Thrombophlebitis is uncommon in a young, healthy athlete. It may occur from direct trauma from a contact sport, especially in association with postgame travel in an away team returning to the home location or following limited activity after a significant injury or elective surgery. A previous history of thrombophlebitis may predispose an individual to a second episode. Three factors as part of Virchow's triad may lead to the formation of a thrombosis, and these include venous stasis, injury to the venous wall, and a hypercoagulable state. Any unexplained swelling associated with lower-extremity erythema and increased temperature should raise the suspicion of a venous thrombus.

The main concern in detecting a venous thrombus is to determine whether the lesion occurs within the superficial venous system or the deep venous system. Superficial lesions are treated symptomatically and may present as tender, erythemic, palpable cords within the subcutaneous tissue. However, because of the potential serious complications of a deep venous thrombus, definitive study should be obtained to rule out any deep system involvement if there is any question regarding the presentation. Testing involves noninvasive, lower-extremity Doppler examination that provides an approximate 90% accuracy. If deep venous thrombosis is discovered, treatment involves rest and initiation of anticoagulation therapy. Anticoagulation therapy usually is instituted for 3 to 6 months for the first episode and may require chronic anticoagulation therapy for repeated episodes. Anticoagulation reduces the likelihood of further formation of the thrombus and lessens the potential complications of embolic phenomenon. Measures aimed at correcting any underlying risk factors such as minimizing immobilization and treating any cause for the hypercoagulable state, also are recommended.

Varicose veins are prominent, abnormally distended, tortuous, superficial veins of the lower extremities that occur in approximately 20% of adults. The cause is usually one of defective valves within the veins or congenitally absent valves. They are more common in females and often are associated with a family history of varicosities. Any condition that decreases venous outflow from the lower extremities, that is, pregnancy, also may cause varicosities.

Normal venous return from the lower extremities usually is accomplished by contraction of the lower-extremity musculature to pump the blood back up the venous gradient. Intact/competent venous valves prevent back flow. When the valves are incompetent or absent, pooling blood distends the veins, leading to further obstruction that causes worsened flow from the lower extremities. An exercising athlete with varicose veins further worsens this condition because of increased arterial flow into the exercising lower extremities. Usually this worsening of the venous return during exercise has little effect on exercise tolerance. Some athletes, however, may complain of a nonspecific heavy sensation to the extremities with exercise. This vague, exercise-related discomfort is known as “venous claudication.”

If venous congestion of the superficial system progresses it may lead to involvement of the deep venous return. This may then result in chronic edema, venous dermatitis, and/or stasis ulcers. Treatment is initially symptomatic using elevation and support stockings. Surgical vein stripping also may be an option for persistent problems, which do not respond to a more conservative approach. Proper skin care to treat the chronic dermatitis and any ulcers that may develop also is necessary.

Lymphatic disease

Other sources of edema of the lower extremities, but usually not associated with pain, are abnormalities of the lymphatic system. Lymph vessels serve to transport lymph fluid back to the venous system through the thoracic duct at the left jugular vein. At lymph node junctions along the lymph system, immunologic and filtering is done to the lymph fluid. Lymphatic channels, which normally follow the venous tree, are susceptible to many of the same forces that affect the venous system and include trauma, mechanical obstruction, and surgical removal of lymph nodes as well as venous hypertension.

Primary lymph edema is a disease of the lymph systems with an unknown cause. It is most common in females and often is unilateral. It usually has onset before the age of 40. The diagnosis may be confirmed with either lymphogram or contrast lymphangiography. Treatment is symptomatic and aimed at reducing the lower-extremity edema with elevation, support stockings and, occasionally, diuretics. Chronic lymphedema may cause recurrent skin infections, which in turn lead to an overload of the lymph system, causing further edema. Rarely, surgical intervention may be necessary.

Case Study 4: Popliteal Artery Entrapment  

A 17-year-old, high school senior CC runner presents with a several-month history of exercise-related left calf and foot pain. The pain is described as cramp-like in quality and has become progressively worse with time. The pain has become more intense and has onset earlier in his runs. There are no associated paresthesias, increased tension to the calf musculature, or loss of foot or ankle control during the runs. The pain will resolve after several minutes of rest but with return to running after resolution the pain will return almost immediately. There are no symptoms noted on the right or symptoms outside of activity. Past medical history and family history are noncontributory. Physical examination is noncontributory except that with the knee in full extension and forced dorsiflexion or active plantarflexion the dorsalis pedis and posterior tibialis pulses diminish. X-rays are negative. Superficial and deep posterior chronic exertional compartment testing is negative. Arteriography demonstrates entrapment of the artery at the knee. The athlete is treated surgically with release of the artery and makes a gradual return to running.

In summary, inflammatory metabolic, vascular diseases are common in the general population but uncommon causes of foot and ankle concerns in athletes. However, being attuned to the possibility of these disease processes complicating an athlete's ability to perform his or her chosen sport can allow the physician to address these issues and enhance the athlete's performance or enjoyment of sport.