Leg Aches

, Symposium on Common Orthopedic Problems

Leg Aches Hamlet A. Peterson, M.D.*

Discomfort in the lower limbs is not uncommon in children and ranges from a mild ache, sometimes associated with fatigue, to severe pain that may awaken the child from deep sleep. The condition may be acute or chronic. The possible underlying causes are legion (Table 1). All of these conditions, except that designated "growing pains," can usually be properly identified by careful history and physical examination with appropriate laboratory and roentgenographic investigation. Some conditions, such as stress fracture, may require repeat roentgenographic examination before the diagnosis is confirmed. Patients with transient synovitis of the hips also should undergo follow-up roentgenographic examination to rule out incipient Perthes disease. A rational plan of management may usually be instituted, except for growing pains. Because the entity growing pains is so elusive, and because it is commonly understood and all too readily accepted by lay people-and much too frequently diagnosed by physicians-it needs clearer delineation. Definition of Growing Pains What is this malady called growing pains? The term has been in use for approximately 150 years. Its origin has been attributed to Duchamp,7 who published a study on "Maladies de la Croissance" in 1823. The bulk of current knowledge is contained in a series of four investigations. Hawksley'S studies from England in the 1930's succeeded in differentiating growing pains from a manifestation of rheumatismY-13 Naish and Apley (1951) provided some scientific credibility to the entity by their examination of British schoolchildren. 14 Brenning's studies from Sweden in the 1960's are the most extensive and thorough. 3 ,4 0ster of Denmark recently summarized and condensed the literature and added observations of his own. 15-17 The paucity of information on this common malady in the three pediatric orthopedic textbooks in common use today is remarkable. Two 10 ,22 make no mention of the condition, and Tachdjian 24 devotes only one paragraph under the heading "Traumatic Myositis," stating 'Consultant, Section of Pediatric Orthopedics, Mayo Clinic and Mayo Foundation; Assistant Professor of Orthopedic Surgery, Mayo Medical School; Rochester, Minnesota Pediatric Clinics of North America- Vol. 24, No.4, November 1977

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Table 1.

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PETERSON

Pain in the Lower Limbs in Children: An Attempt at Etiologic Classification

1. Trauma Fracture Stress fracture Pathologic fracture Dislocation and subluxation Joint strain, sprain, internal derangement Soft-tissue contusion and hemorrhage Myositis ossificans Traumatic periostitis Traumatic synovitis or hemarthrosis Battered child 2. Infection Osteitis Osteomyelitis Septic arthritis Soft-tissue abscess Cellulitis and ascending lymphadenitis 3. Avascular necrosis of bone Femoral capital epiphysis (Legg-Calve-Perthes disease) Tibial tubercle apophysitis (Osgood-Schlatter's disease) Calcaneal apophysitis (Haglund's disease) Tarsal navicular (Kohler'S disease) Second metatarsal (Freiberg's infraction) Osteochondritis dissecans (hip, knee, ankle) 4. Vascular Hemangioma, lymphangioma Anterior and posterior compartment syndrome Sickle cell intravascular stasis and thrombosis Hemophilia Poor peripheral circulation 5. Congenital Dislocation, subluxation, or dysplasia of hip Tarsal coalition Accessory tarsal ossicle

(Table continues on following page)

that growing pains "seem to be a manifestation of chronic muscle strain and fatigue." No references are listed in his extensive bibliography. These omissions imply that these authors agree with Bennie,2 who states that the longer a physician is in practice and the greater his diagnostic acumen, the less frequently is this diagnosis made. Through the years, growing pains has gradually been defined. It consists of intermittent, often annoying pain or ache, usually localized in the muscles of the legs and thighs. The pain or aching may be associated with a feeling of restlessness. The most common sites of pain are in the front of the thighs, in the calves, and behind the knees. The groin is sometimes affected. The pains are deep and localized in areas outside the region of the joints. Pain in the joints requires detailed investigation to rule out rheumatoid or intra-articular conditions. The pain is typically bilateral, which is an important differentiation from serious causes of pain in the limbs, which are usually unilateral. The pains usually occur late in the day and in the evening,

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T~ble

1.

Pain in the Lower Limbs in Children: An Attempt at Etiologic Classification (Continued)

6. Developmental Transient synovitis of hip and knee Slipped capital femoral epiphysis Limb deformities such as flatfoot, ankle valgus, genu valgum Infantile cortical hyperostosis (Caffey's disease) Hypervitaminosis A Baker's cyst 7. Tumors A. Benign Osteoid osteoma Unicameral cyst Fibrous dysplasia Aneurysmal bone cyst Giant cell tumor Osteochondroma B. Malignant Osteogenic sarcoma Ewing's sarcoma Soft-tissue sarcoma Leukemia Neuroblastoma 8. Collagen diseases Rheumatoid arthritis Rheumatic fever Dermatomyositis Scleroderma 9. Growing pains

although they may have their onset at night and awaken the child from sleep. When the child awakens in the morning, the pain has disappeared. The pains typically occur in children and young people, but they may commence in early infancy and disappear once the child reaches maturity. In older children, the pain may resemble what adults more accurately describe as cramps in the legs, creeping sensations, or restless legs. 3 • 16 However, Ekbom makes sharp distinctions between growing pains and restless legs. 8 • 9 Growing pains may be accentuated by much running during the day. Pain from fatigue may occur with or without violent physical activity in children. Its character resembles the condition designated growing pains, but in contrast to growing pains, the pain of fatigue disappears after rest. Growing pains are not associated with limping or limited mobility. The case history does not indicate local trauma or infection. The pain is not associated with local tenderness, erythema, or swelling. There is a lack of objective findings. Results of physical examination, laboratory studies, and roentgenograms are normal. The pathogenesis remains unknown. 3 • 6. 9.16.17

Incidence The reported incidence of growing pains varies widely with different investigators. Only four studies appear to be scientifically significant (Table 2). These differences in incidence are probably related

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Table 2.

Incidence of Growing Pains PER CENT WITH GROWING PAINS

NO. IN AUTHOR

Hawksley 12 1938 Naish and Apley14 1951 Brenning3 1960 Brenning" 1960 0ster16 1972

SAMPLE

505

AGE (YR)

SAMPLE TYPE

Total sample

4 to 14

Hospital patients

33.6

721 257

6 to 7

419

10 to 11

2,178

6 to 19

Boys

Girls

Schoolchildren

4.2

4.0

4.7

Schoolchildren

13.6

9.1

18.4

Schoolchildren (questionnaire) Schoolchildren

19.8

19.9

19.7

15.5

12.5

18.4

more to the criteria used for case selection and the thoroughness of investigation than to nationality or to etiologic factors. For example, Hawksley12 used hospitalized patients-a positive selection factor producing a high incidence-whereas Naish and Apley14 included only those schoolchildren who had noted nonjoint pain of 3 months' duration and of sufficient severity to cause interruption of normal activities, thereby obtaining a low incidence. Slightly higher (but not statistically significant) incidences have been noted in females as compared with males.3. 11. 14. 16-18

Age at Occurrence Brenning3 found that growing pains may start in infancy, that they generally commence before the age of 5 years, and that the discomfort is most pronounced between the ages of 3 and 5 years. Others examining schoolchildren above age 5 have noted the pain to be most prominent between 8 and 12 years. 14. 18. 21, 25 The period of childhood from 3 to 12 years is not the period of most rapid growth, which leads many authors to disregard growth per se as the underlying cause. 3, 9,14,16,17 The pain typically ceases with maturity, although Ekbom9 has documented one case in which the pains continued into adulthood. Pathogenesis The following conditions have been implicated either as causing or at least as being closely related to growing pains: rapid growth 3,7 (growing fever), puberty,7.19 myalgia from the fatigue of overexertion,3, 12, 14,23 rheumatism or rheumatic conditions,3, 20, 25 convalescence or recovery from infectious disease (particularly scarlatina),12,14 fibrositis,6 strained or relaxed sacroiliac joints,5 postural and orthopedic defects,3, 4, 12, 13 vague ill health,12,13 weather,2:l damp housing,12 psychoneurotic rheumatism (neurosis), 1 psychologic factors,12-14 emotional strain,12, 14, 17 unhappiness,12,13 inadequate sleep,13 social status,3 constitutional status,16 inheritance,3 nationality, 11, 13 race,1l,13 and complex-

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ionY; 13 None of these has been substantiated as an etiologic agent in growing pains. It is improbable that such a gradual process as growth could cause pains of such intermittent character. The concept of inefficient elimination of accumulated tissue waste products:!' 24 needs more scientific investigation.

Treatment Over the past 50 years, much has been learned about leg aches in children. A great deal has been learned about what growing pains are not, but very little is known about what they are. In the present state of knowledge, treatment cannot be rational. Because of this, supportive measures that do no harm, such as heat, massage, and salicylic acid, seem reasonable. Even those who consider vitamin C in rather large doses to be the best treatment for growing pains acknowledge that hypovitaminosis C is not involved in its etiology. If repeated history, examination, laboratory studies (particularly hemoglobin, white blood cell count and differential, and erythrocyte sedimentation rate), and roentgenograms fail to uncover a specific entity, and leg aches persist despite these supportive measures, referral to a pediatric orthopedist should be considered. Terminology Several authors have suggested that the term growing pains be discarded, noting that the pains probably have nothing to do with growth. 3 • 14,20 Also, it is not the pain that is "growing" but the child. In addition, this diagnosis can be a dangerous pretext to parents and doctors for doing nothing if the examining physician rests content with it and thereby possibly overlooks serious disease. Other descriptions have been proposed that are consonant with what was regarded at the time as the cause of the disease. However, views have changed so often, and have had such confusing and negative consequences for treatment, that some skepticism has arisen with regard to the usefulness of the new descriptions. For example, a general term such as "pain in the limbs" is too meaningless and so comprehensive that one hesitates to employ it when faced with these pains, which are so characteristic to the expert although' so difficult to define. Proponents note that' the name growing pains has the advantage of not implicating any particular disease and also lays emphasis on childhood as the period when these complaints are most common. 15 , 23 The pains occur in growing children and not after growth is complete. It is, therefore, still the current term in the French, English, German, Italian, and Scandinavian languages. 15 Summary In the investigation of children with leg aches, it is essential to identify those with demonstrable underlying organic disease. Growing pains is a poorly named, nebulous entity that can be diagnosed only by exclusion. The greatest diagnostic error is to make a diagnosis of growing pains while overlooking some serious underlying condition.

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REFERENCES 1. 2. 3. 4. 5.

Abels, H.: Wachstumschmerzen. Wein. Med. Wochenschr., 86:736,1936. Bennie, P. B.: Growing pains. Arch. Paediat., 11 :337,1894. Brenning, R.: "Growing pains." Acta Soc. Med. Upsal., 65:185,1960. Brenning, R.: "Viixtvark" och plattfiitter. Sven. Lakartidn., 57:3646, 1960. Brown, L. T.: Growing pains: A possible mechanical explanation. Boston Med. Surg. J., 162:424, 1910. 6. Calabro, J. J., Holgerson, W. B., and Repice, M. M.: Growing pains: Fact or fiction? Postgrad. Med., 59:66, 1976. 7. Duchamp, M.: Maladies de la croissance 1823. In Levrault, F. G. (ed.): Memoires de Medicine Practique. Paris, Jean-Frederic Lobstein, 1832. 8. Ekbom, K. A.: Restless legs. In Vinken, P. J., and Bruyn, G. W. (eds.): Handbook of Clinical Neurology, Vol. 8, part 2. Amsterdam, North-Holland Publishing Company, 1970, p. 311. 9. Ekbom, K.-A.: Growing pains and restless legs. Acta Paediat. Scand., 64:264, 1975. 10. Ferguson, A. B., Jr.: Orthopedic Surgery in Infancy and Childhood. Edition 2. Baltimore, Williams and Wilkins Co., 1963. 11. Hawksley, J. C.: Race, rheumatism and growing pains. Arch. Dis. Child., 6:303,1931. 12. Hawksley, J. C.: The incidence and significance of "growing pains" in children and adolescents. J. R. Inst. Public Health, 1 :798, 1938. 13. Hawksley, J. C.: The nature of growing pains and their relation to rheumatism in children and adolescents. Brit. Med. J., 1 :155, 1939. 14. Naish, J. M., and Apley, J.: 'Growing pains': A clinical study of non-arthritic limb pains in children. Arch. Dis. Child., 26:134,1951. 15.0ster, J: Growing pain: A symptom and its significance; a review. Dan. Med. Bull., 19:72, 1972. 16.0ster, J.: Recurrent abdominal pain, headache, and limb pains in children and adolescents. Pediatrics, 50:429, 1972. 17. 0ster, J., and Nielsen, A.: Growing pains: a clinical investigation of a school population. Acta Paediat. Scand., 61 :329, 1972. 18. Pollack, L. J.: Multiple neuritis. The neuralgias. Herpes zoster (shingles). Growing pains. Spasms. Polymyositis. Progressive myositis ossificans. Ischemic muscular paralysis and muscle contracture. Tumors of the nerves. In Abt, I. A. (ed.): Pediatrics, Vol. 7. Philadelphia, W. B. Saunders Co., 1925, p. 495. 19. Quinton, J. F. P.: Growing pains. Practitioner, 168:533, 1952. 20. Seham, M., and Hilbert, E. H.: Muscular rheumatism in childhood. Am. J Dis. Child., 46:826, 1933. 21. Shapiro, M. J.: Differential diagnosis of nonrheumatic "growing pains" and subacute rheumatic fever. J Pediat., 14:315, 1939. 22. Sharrard,W. J W.: Paediatric Orthopaedics and Fractures. Oxford, Blackwell Scientific Publications, 1971. 23. Sheldon, W. P. H.: On aches and pains in the limbs-so called growing pains. In Sheldon, W. P. H. (ed.): Diseases ofInfancy and Childhood. Fifth edition. London, J. & A. Churchill, 1946. 24. Tachdjian, M. 0.: Pediatric Orthopaedics. Philadelphia, W. B. Saunders Co., 1972. 25. Williams, M. F.: Rheumatic conditions in school children: An investigation into growing pains and nodules (grains). Lancet, 1 :720, 1928. Department of Orthopedic Surgery Mayo Clinic and Mayo Foundation 200 First Street S.W. Rochester, Minnesota 55901