Spontaneous bilateral femoral neck fractures in a young primigravida

Abstract

A 26-year-old woman attended A&E. She was 37 weeks into her fi rst pregnancy, with pain in both groin areas and across her lower abdomen. She gave a history that she had been cleaning her teeth on the morning of her presentation when she heard and felt a loud click from her groin areas and slumped to the ground in pain. She was subsequently unable to weight-bear. She denied sustaining any injury during the fall.Review of her obstetric notes revealed that she had been diagnosed with symphysis pubis dysfunction (pelvic girdle pain, PGP) 4 weeks earlier when she attended the antenatal clinic, and had been using crutches to mobilise due to the extent of the pain she was experiencing. She declined admission to the hospital in the 2 weeks prior to presentation, however she had been largely bed-bound as a result of the pain and discomfort.At the time of booking, she was noted to be fi t and healthy with a BMI of 24.5. She was a non-smoker, was not taking any regular medications, and there was no relevant past medical history.Following discussion with the obstetricians, she was admitted to hospital for obstetric and physiotherapy assessment, Enoxaparin (Clexane) injections and pain relief. Four days later she was assessed for induction and was found to be suitable, with reasonable leg abduction, to achieve vaginal birth. Th ree days later she had an artifi cial rupture of the membranes and later gave birth normally to a healthy boy. She sustained a 2nd degree tear which had to be repaired in theatre under spinal anaesthetic, as abduction of her hips continued to be limited by pain.Post-delivery, her mobility and pain did not improve and therefore an X-ray of her pelvis was performed. Th e X-ray is shown in Figure 1. Th e X-ray revealed subcapital fractures of both femoral necks and she was referred to the orthopaedic team. Further investigation showed her bone biochemistry to be normal. Th e hip fractures were reduced and fi xed with cannulated hip screws 48 h later under a spinal anaesthetic. Postoperatively, there were no complications. Th e postoperative fi lms are shown in Figure 2.Th e rehabilitation regimen included 6 weeks non-weight-bearing, followed by gentle mobilisation and physiotherapy.She was also reviewed by the osteoporosis team who felt that she had sustained bilateral insuffi ciency fractures. No discrete metabolic abnormality was detected except for biochemical thyrotoxicosis, though she remained clinically euthyroid. Her slightly raised alkaline phosphatase was attributed to her recent pregnancy. Vitamin B levels and her parathyroid status were normal.