A rare cause of severe dyspareunia: post‐osteomalacic contracted pelvic outlet

Abstract

Osteomalacia is rare in current urban life and societies that have normal diets. Vitamin D helps to maintain the adequate plasma calcium levels. It increases the absorption of the calcium in the intestine, decreases the renal loss of calcium and stimulates the resorption of bones (1,2). In this case, the patient was presented with pelvic deformity, which is rarely seen as a result of osteomalacia. A 28-year-old woman, who had one normal delivery and one cesarean section before was admitted to the Obstetrics and Gynecology Clinics with a history of having difficulty and pain with sexual contact for the previous year. Vaginal examination was tried at the normal lithotomic position, but after an unsuccessful try, the examination was repeated ultrasonographically under anesthesia and considered a bony obstruction tightening the vagina bilaterally. A pelvic X-ray showed that the patient had an obstruction at the pelvic outlet. A three-dimensional CT scan reported multiple pseudo-fractures on the bilateral ischion arms and related deformities, plus protrusion acetabuli and pelvic deformity caused by osteomalacia (Fig. 1). The biochemical analysis confirmed the diagnosis with high serum alkaline phosphates and low sodium and calcium levels. Preoperative three-dimensional CT images of pelvic outlet are seen as highly restricted with decreased bone density and pseudo-fracture apparent. Under general anesthesia, a lithotomical position vaginal examination was performed. The ischion arms were reached by performing an oblique incision from the lateral margin of labia major. The bilateral ischion arms seem to have been quite softened. Approximately 8 cm of bilateral ischion arms were resected and a vaginal examination was repeated intraoperatively and established relaxed vagina. After 3 months, this appearance was confirmed with three-dimensional CT scan (Fig. 2). The patient was given vitamin D about 1 year for osteomalacia. After 1 year, she became pregnant via the normal coital way. The patient was admitted to our clinics with the complaint of absence of fetal movement at sixth month of gestation. An ultrasonographical examination showed two baby deaths. After the cesarean section, the patient had an uneventful recovery period. Three-dimensional CT images of widened pelvic outlet after bilateral ischion arms excision. Osteomalacia, related to the deficiency of vitamin D, depends on many factors. The major causes are: deficiency of production in the skin, failure in intake, increased catabolism, increased requirements, or increased loss of calcium. In our patient, the main factor was established as frequent periods of pregnancy accompanied with failure in intake. In the literature, such kinds of deformities were mostly found in India. During pregnancy the rate of osteomalacia is very high: 1–10% in China and 1–3% in India (3). The main cause in India is, especially, the poor dietary intake of calcium and vitamin D deficiency, high dietary intake of phytic acid, and inadequate exposure to sunlight in the crowded urban life. Phytic acid prevents the absorption of calcium from intestinal lumen by forming an amorphous calcium precipitate. In our patient Chovestek's and Trousseau's signs were negative, but high serum alkaline phosphates, low sodium and calcium levels, hypochromic anemia and pseudo-fractures (Milkman) and looser zones seen on X-rays and CT scan verified the diagnosis of osteomalacia (4,5). In the literature, only a few reports about pelvic outlet obstruction related to osteomalacia were established but only one case that was treated with surgical resection was found. As the other cases could allow sexual intercourse, the deliveries were performed with cesarean section. Pelvic deformities of the osteomalacic type are considered rare medical curiosities, and elective cesarean section is usually indicated. There is emphasis on the fact that vaginal delivery is not granted from a pelvic point of view for multiparous women who have delivered normally in the past. That is why every woman coming in for birth should be evaluated thoroughly from a pelvic point of view without taking into consideration whether they were previously pregnant or not.