PSEUDO-OSTEOMALACIA Report of a Case

DAVID SAVAGE, M.B., F.R.C.S., M.R.C.O.G. Charing Cross Hospital, London

BY

OSTEOMALACIA is a rarity in this country and, while obstetric textbooks frequently contain radiographs of a tri-radiate pelvis, the condition is seldom seen. We are indebted to Maxwell (Maxwell, 1923, 1930, 1947; Maxwell and Miles, 1925) who described in detail the condition as it occurred in China.

Since Lambert in 1700 (Ribbmont-Dessaignes and Lepage, 1894) reported the first case in Europe, sporadic cases have occurred especially in the Rhine Valley, Switzerland and Hungary, and in times of famine when calcium and vitamin D intake are reduced. Dalyell and Chick (1921) reported hunger osteomalacia in Vienna following the Great War and in this country Bulmer (1935) traced 12 cases and further cases have been reported by O’Donovan (1939), Kenny (1941) and MacLennan (1944).

Osteomalacia must be distinguished from pseudo-osteomalacia in which the characteristic pelvic deformity is produced in hyperpara- thyroidism, idiopathic steatorrhoea, renal osteo- dystrophy, senile and thyrotoxic osteoporosis and fracture of the pelvis. Baird (1955) illustrates a case of osteitis fibrosa cystica causing a pelvic deformity similar to osteomalacia.

Both Bulmer (1935) and Maxwell (1947) stress the difficulty in diagnosis of sporadic cases of osteomalacia in this country and its differentiation from pseudo-osteomalacia.

CASE REPORT Mrs. D.C., aged 23 years, was first seen at the 1 lth week

of her first pregnancy. She had never travelled abroad and was a Londoner, except for the war years 1939 to 1942 when she lived in Surrey. As a baby she was breast fed for three months and easy to rear. Though of small stature, she sat up and walked at the usual age and played games normally at school. Her teeth erupted at the expected times and were healthy. No illnesses of note occurred in childhood and there was no history of rickets or renal or

gastro-intestinal disease; tetany and muscular cramps had not occurred. Her family were economically secure and food was plentiful. At 16 years of age transient pain occurred in her left hip; it lasted for a week and was attributed to “rheumatism”; it was not severe and did not limit her physical activity. At no time was there pain in her pelvis or legs.

On examination this patient weighed 108 pounds and was 5 feet 2 inches tall. Her urine contained no albumen and her haemoglobin was 88 per cent. Her teeth were healthy, her limbs straight, and there was no chest deformity or other evidence of childhood rickets. There was no thyroid enlargement or evidence of thyrotoxicosis. The pubic symphysis projected forward as a beak and the ischio-pubic rami were parallel, markedly reducing the pelvic outlet, and making Vaginal examination difficult.

Radiological pelvimetry at the 35th week of pregnancy showed a tri-radiate pelvic brim with approximation of the acetabulae (Fig. 1). The sacrum was well hollowed with forward displacement of its second segment (Fig. 2) and the pelvic outlet was extremely small with inturning of the ischial tuberosities (Fig. 3). The pelvic measurements were as follows : conjugate, 4 . 3 inches ; transverse brim, 3.3 inches; available transverse brim, 1 *2 inches; A.P. mid-cavity, 5 .O inches; ischial bi-spinous, 1.9 inches; A.P. outlet, 5.3 inches; inter-tuberous, 2.0 inches; subpubic angle, 30 degrees. Radiological examination of both pelvic and limb bones showed good differentiation between cortex and medulla with normal bone density and there was no suggestion of any active bone disease.

An elective Caesarean section at term was planned. Throughout the pregnancy this patient remained well ; vitamin supplements were prescribed and taken and no pain or discomfort was experienced in the pelvis or legs. At the 38th week she was admitted in strong labour having felt no foetal movements for the preceding two days. There was no evidence of pre-eclamptic toxaemia, the foetal heart was inaudible and the foetal head was not engaged. Lower segment Caesarean section was performed, since craniotomy was considered a hazardous procedure in such a grossly contracted pelvis, and a macerated stillborn female infant weighing 4 pounds 5 ounces was delivered, followed by an infarcted placenta weighing 11 ounces.

No cause was found for the intra-uterine death and the infant showed no evidence of foetal rickets. The sub- sequent puerperium was uneventful.

Four months later the patient became pregnant for the 2 PI. 923 623

924 JOURNAL OF OBSTETRICS AND GYNAECOLOGY

the patient and her mother) was unenlightening. Her “osteomalacic” pelvis is either due to a congenital abnormality or has resulted from an undiagnosed childhood steatorrhoea preventing the absorption of vitamins and calcium. The deformity is so extreme, and so localized, that a local rather than a general cause is likely and the former theory is favoured.

second time. At the 38th week of an uneventful preg- nancy, elective lower segment Caesarean section was performed and a healthy male infant weighing 5 pounds 2 ounces was delivered. The baby thrived and the puerperium was uneventful.

Biochemical estimates of the mother’s serum calcium and phosphorus and phosphatase were within normal limits, i.e., serum calcium 10.2 mg. per 100 ml. (normal 9-11); serum phosphorus 3 . 1 mg. per 100 ml. (normal 2.5-3.5); and serum alkaline phosphatase 1 I units (normal 4-14).

Family History Mrs. D.C., was the fifth of 6 siblings. Her mother was

delivered of her first and sixth children, both weighing 9 pounds, by obstetric forceps. Her second pregnancy ended in a stillborn breech delivery and her remaining pregnancies were normal. Radiological pelvimetry was performed on the mother of Mrs. D.C. and revealed a large gynaecoid pelvis.

DISCUSSION The clinical features of osteomalacia are too

well known to require amplification, its onset being heralded by pain in the lumbar region and thighs. This aching pain is intermittent but characteristic and to the Chinese patient the disease goes under the name of “Yao T’ui T’eng” or “back and thigh pain” (Maxwell and Miles, 1925). The case reported here had fleeting pains in the left hip at the age of 16 years, and, though osteomalacia may occur at puberty, it is difficult to believe that such a gross degree of pelvic deformity was accompanied by such trivial symptoms.

The cause of the pelvic deformity in this case must remain obscure, for no active bone disease was in progress whilst this patient was under observation and her history (obtained from both

SUMMARY A case of pseudo-osteomalacia is described

of unknown aetiology.

ACKNOWLEDGMENTS My thanks are due to Dr. C. MacLean for

the radiographs and to the Charing Cross Hospital Photographic Department for their reproduction. Dr. Swale’s co-operation was appreciated with the biochemical estimations.

REFERENCES Baird, D. (1955): in Holland, E., and Bourne, A. (ed.):

British obstetric and gynaecological practice. Obstetrics. Heinemann, London. p. 683.

Bulmer, E. (1935): Lancet, 1, 740. Dalyell, E. J., and Chick, H. (1921): Lancet, 2, 842. Kenny, M. (1941): Proc. R. SOC. Med., 34, 801. MacLennan, H. R. (1944): J. Obstet. Gynaec. Brit. Emp.,

Maxwell, J. P. (1923): Chin. med. J., 37, 625. Maxwell, J. P. (1930): Proc. R . SOC. Med., 23, 639. Maxwell, J. P. (1947): Proc. R . SOC. Med., 40, 738. Maxwell, J . P., and Miles, L. M. (1925): 1. Obstet.

O’Donovan, E. (1939): Brit. med. J. , 2, 1139. Ribemont-Dessaignes, A., and Lepage, G. (1894): Pricis

51, 127.

Gynaec. Brit. Emp., 32, 433.

d’obstdirique. Paris. p. 931.

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