Postpartum osteoporosis associated with proximal tibial stress fracture

Abstract

A 33-year-old woman presented with acute nonspecific knee pain, 6 months postpartum. MR imaging, computed tomography and radiography were performed and a proximal tibia plateau insufficiency fracture was detected. Bone densitometry demonstrated mild postpartum osteoporosis. To our knowledge these findings have not been described in this location and in this clinical setting. The etiology of the atraumatic fracture of the tibia is presumed to be due to a low bone mineral density. The bone loss was probably due to pregnancy, lactation and postpartum hormonal changes. There were no other inciting causes and the patient was normocalcemic. We discuss the presence of a postpartum stress fracture in a hitherto undescribed site in a patient who had lactated following an uncomplicated pregnancy and had no other identifiable cause for a stress fracture.

Compression Fracture in Postpartum Osteoporosis

“…[7] A possible mechanism of postpartum osteoporosis involves ligament laxity due to endocrine changes such as parathyroid hormone (PTH)-like peptide, magnesium sulfate management, prolonged bed rest for preterm labor, and stress or fatigue fractures during delivery. [8] The fetus takes 30 g of calcium from the mother, and hypoestrogenemia during breast-feeding leads to bone mineral loss in women. As the gestational age proceeds, total calcium level decreases accordingly.…”

Pelvic Musculoskeletal Disorders Related to Pregnancy

“…Stress fractures related to pregnancy may occur at various other sites, including the spine, coccyx, femoral neck, superior and inferior pubic bones, ischiopubic arch, or pubic body wrist or clavicle (Figures 7 and 8) [9,11].…”

Nonspinal Fragility Fractures

“…Longitudinal fractures of the tibia have been described after renal transplant 48 and healed chronic osteomyelitis. 49 Pregnancy-related osteoporosis has also been described as a cause for insufficiency fracture in the tibial plateau 50 (►Fig. 12).…”