Congenital Bowing of the Long Bones (Camptomelic Dwarfism): A Report of Two Cases

JAMES R URBANIAK, M D GEORGE H. DURHAM, II


Congenital bowing of the long bones was described as early as 1846 when Proudfoot reported "a case of compound fractures of the tibia in utero and congenital talipes equinus"8. In 1954, Angle reviewed 37 roentgenographically proven cases of congenital angulation and bowing of the long bones and emphasized the association of a cutaneous dimple overlaying the curvature with the frequent occurrence of other bony anomalies or deformities1.

In 1970, Spranger reported on eight infants and one six-year-old who exhibited similar craniofacial and lower-limb abnormalities9. The craniofacial abnormalities were listed as: flat face, hypertelorism, micrognathia and cleft palate. The lower-limb anomalies included: anterior bowing of the femora and tibiae, bilateral hypoplasia of the fibulae, subcutaneous dimpling over the tibiae, and calcaneovalgus deformities. It was noted that seven of the eight infants died in early infancy. Also, one patient was described as having mild bowing of the ulnae and radii.

Shortly afterwards, Bianchine and her colleagues described a similar case which additionally included low-set, normally structured ears, bilateral Sydney lines across the palms, and thoracolumbar scoliosis. The radiographic description included "large calvarium with small face, narrow clavicles, small scapulae, very narrow ribs (chiefly posteriorly), many flat and narrow vertebrae with swollen, unossified pedicles, delayed ossification centers of the feet, lack of ossification of the distal femoral and proximal tibial epiphyses, absence of normal flaring of the metaphyses of the long bones, tibial and fibular anterior bowing, and proximal shortening of the radii." These authors suggested that this clinical entity be described as camptomelic dwarfism (camptos = bent, melos = limb)4.

Bain and Barrett earlier had reported an extensive autopsy study of a stillborn female with bilateral talipes equinovarus and anterior angulation of the legs above the ankles, with dimpling2. They suggested continued use of the term "congenital bowing of the long bones" in preference to camptomelia for this entity3.

Since December of 1971, two infants have been admitted to the Duke University Medical Center intensive-care nursery following immediate postpartum identification of multiple congenital anomalies consistent with the descriptions of camptomelic dwarfism .

Case Reports

Case 1 (E.C.)-This 2200-gram female infant was born Dec. 29, 1971, as a full-term primigravida product of an uncomplicated pregnancy and delivery. She had micrognathia, a large flat forehead, and laryngotracheomalacia, which contributed to respiratory problems. Orthopaedic examination revealed restricted hip abduction, especially on the right side, and slight anterior bowing of the femora. Bilateral anterior tibial midshaft bowing was evident with subcutaneous dimpling at the apex of the bowing Both tibiae were foreshortened. Bilateral heel-cord contractures were present with definite subcutaneous fibrous bands. Both feet showed talipes equinovarus deformities with an accentuation of metatarsus adductus ( Fig. 1 ). Roentgenograms revealed bilateral dislocated hips, more so on the right limb, anterior bowing of th]e femora and tibiae, fibular hypoplasia and metatarsus adductus ( Fig. 2 Fig. 3 ).

This infant was treated for two weeks in the intensive-care nursery unit because of her respiratory difficulties. Three weeks after birth, long-leg corrective clubfoot plaster casts and an abduction pillow were applied in order to improve the position of her hips. The corrective casts were changed at two- and three-week intervals, and each time an attempt was made to improve the anterior tibial bowing. At nine weeks of age, percutaneous transection of the heel cord was performed with some correction of her equinus deformity. At five months of age she was placed in a Pavlik harness to hold her hips and knees in flexion

At six months of age, she had apparent reduction of her left hip with an essentially full range of motion. The right hip has continued to remain dislocated, but abduction has improved. At the time of this report, the child was 11 months of age with the right hip still dislocated. Prominent anterior tibial bowing and bilateral talipes equinus deformities were present. Her respiratory status has precluded any operative correction of these deformities. Surgery is anticipated during the next year if her respiratory condition improves. She has continued to survive on regular feedings since her discharge from the intensive-care nursery unit and has had excellent parental care.

Case 2 (E.L.)-This infant was born Aug. 2, 1972, as the 2520-gram full-term product of a para 4-2-2* mother who reported an uncomplicated pregnancy and delivery. E.L. was transferred to the Duke University Medical Center intensive-care nursery unit one day after birth She was only 16 in. long at birth with head and chest circumferences of 13)4 in and 11 1/2 in., respectively. She had short arms and legs, a high flat forehead, a high-arched cleft palate, and micrognathia. Abduction of her hips was restricted and both tibiae had anterior bowing with subcutaneous dimples overlaying the angulation She had severe clubfeet with widely separated toes bilaterally Roentgenographic examination revealed hypoplasia of C3, C4, and C5 cervical vertebrae, radii hypoplastic proximally, dislocation of both hips, anterior bowing of the femora and tibiae, and hypoplastic fibulae with bowing This infant also had laryngotracheomalacia and remained in extreme respiratory distress until her death after five respiratory arrests in two days on Aug. 27, 1972, 25 days after her birth. No autopsy was obtained.

Discussion

The respiratory difficulty present in the two infants seen at Duke University Medical Center would appear to be the primary cause of death in patients described as camptomelic dwarfs. The first patient has survived in spite of her laryngotracheomalacia. The orthopaedic management of the complex lower-limb anomalies has been perplexing because her respiratory status will not permit the use of general anesthesia for the performance of surgical procedures. Her tight heel cords have been improved by percutaneous tenotomies and serial casting. Her dislocated hips, especially on the right, and her clubfeet have been improved with Pavlik harness and serial clubfoot casting. Her bowed tibiae have remained unchanged despite long-leg casting. It is anticipated that in the next year she will be able to tolerate general anesthesia for a proposed open reduction of the dislocated right hip, osteotomies of the tibia and corrective clubfoot surgery.

Etiology. Bain's 1959 report on infants with congenital bowing of the long bones described the pathological findings as "generalized cartilaginous dysplasia." Necropsy findings included an abnormal, cartilaginous axial skeleton and abnormal ossification in the angulated long bones. The defect was located in the primary centers of ossification and was felt to be intrinsic in nature. Deficiencies in both the vascular and cellular elements of the perichondrium were suggested as the basic disorders producing angulation of the long bones2. Spranger9 recently suggested that this syndrome may be occurring with increasing frequency and speculated on the role of possible exogenous causes for the increased incidence. Blessinger stated that similar problems had been observed in the offspring of mothers who had ingested antifolic acid compounds (methotrexate and aminopterin) 5 .

Earlier, Gardner described a phenotypic female infant with XY chromosome genotype with cleft palate, retrognathia, kyphoscoliosis, external rotation of the hips and bilateral pes equinovarus deformities. This child was the full-term 2436-gram product of a mother who had taken multiple norethindrone-mestranol contraceptive pills (as many as six at a time) following conception, in an attempt at abortion 6 . Gardner recommended thorough documentation of possible teratogens taken prior to delivery of such children and also karyotype analysis of all phenotypic females. He pointed out that as many as 0.5 to 3 percent of all women on oral contraceptives continue to take them either by accident or otherwise during pregnancies 7 . To our knowledge, neither of the mothers of our two reported cases received any medications during their pregnancies aside from the usually prenatal nutritional supplements.

Genetics have been implicated as a possible etiological factor in this unfortunate entity. Stüve and Wiedemann report two female siblings who displayed some characteristics of camptomelic dwarfism and died two weeks after birth from respiratory distress. One had dolichocephaly, micrognathia and thoraco-scoliosis; the other had dolicoplagiocephaly, slight hypertelorism, low-set ears, low-set right mandible, bowing of the lower ribs and subcutaneous dimples on the lateral aspect of the tibiae. They reported a maternal male cousin who had died two days after birth with multiple limb malformations 10

Summary

Two cases of camptomelic dwarfism or congenital bowing of the long bones have been presented. The findings frequently include a large, flat forehead, hypertelorism, micrognathia, laryngotracheomalacia, respiratory difficulties, dislocated hips, anterior bowing of the femora and tibiae with associated subcutaneous dimpling, foot deformities and other skeletal anomalies. Both infants exhibited severe respiratory distress from birth. One has survived and the management of her limb deformities has been discussed. The etiology of this rare but possibly increasing entity remains obscure.

Division of Orthopaedic Surgery Duke University Medical Center Durham, North Carolina

References:
1. Angle, C. R., Congenital bowing and angulation of long bones Pediat, 13:257-268, March 1954.
2. Bain, A. D., and A. S. Barrett, Congenital bowing of the long bones: Report of a case. Arch Dis. Child., 34:516-524, December 1959.
3 Bain, A. D., and A. S. Barrett, Congenital bowing of the long bones, Letters to the Editor. The Lancet, 1:1244, June 12, 1971.
4. Bianchine, J. W., H. M. Risemberg, S. S. Kanderian, and H. E. Harrison, Camptomelic dwarfism, Letters to the Editor. The Lancet, 1:1017-1018, May 15, 1971.
5. Blessinger, G. M., Syndrome of multiple osseous deformities, Letters to the Editor The Lancet, 2:982, Nov. 7, 1970.
6. Gardner, L. I., S R. Assemany, and R. L. Neu, 46 XY female: Anti-androgenic effect of oral contraceptive? Letters to the Editor. The Lancet, 2:667-668, Sept. 26, 1970.
7. Gardner, L. I., S. R. Assemany, and R. L. Neu, Syndrome of multiple osseous defects with pretibial dimples, Letters to the Editor. The Lancet, 2:98, July 10, 1971.
8. Proudfoot, L., Case of compound fracture of the tibia in utero and congenital talipes talus. N.Y.J. Med. and the Collateral Sciences, 7:199, 1846.
9. Spranger, J , L. O. Langer, and P. Maroteaux, Increasing frequency of a syndrome of multiple osseous defects? Letters to the Editor. The Lancet, 2:716, Oct. 3, 1970.
10. Stiive, A., and H R. Wiedemann, Congenital bowing of the long bones in two sisters, Letters to the Editor. The Lancet, 2:495, Aug. 28, 1971
Descriptors: congenital, bowing, long bones, camptomelic dwarfism, genetics.