Subchondral Insufficiency Fracture of the Femoral Head in a Pregnant Woman with Pre-existing Anorexia Nervosa

Abstract

Subchondral insufficiency fracture (SIF) is a fragility fracture secondary to osteoporosis that leads to collapse of the femoral head with no evidence of osteonecrosis. SIF of the femoral head has been reported in adults of varying ages and both sexes, but it has never been reported to occur in pregnant women. Herein, we describe a 40-year-old primiparous patient with pre-existing anorexia nervosa who developed SIF of the femoral head in the third trimester. At 29 weeks of gestation, the patient complained of sudden pain on walking in both hips. Despite the bed rest, her hip pain increased; consequently, cesarean section was performed at 36 weeks. After delivery, plain radiographs showed that the left femoral head was collapsed. Dual-energy X-ray absorptiometry indicated that the patient was osteoporotic. The magnetic resonance imaging (MRI) of her hips showed the findings that were compatible with SIF. Her left hip pain worsened during follow-up, and a radiograph showed progressive collapse of the left femoral head. The patient then underwent left bipolar hip arthroplasty 18 months after delivery, and she was diagnosed with SIF histopathologically. This is the first report of SIF in a pregnant woman that may reflect pregnancy-associated osteoporosis. SIF in pregnancy might be overlooked or misdiagnosed because the MRI findings have several overlaps with those of other hip disorders. Precise diagnosis of SIF in pregnancy may contribute to a better outcome by avoiding early arthroplasty in young women and appropriate evaluation of the osteopenic status of the patient.

Pregnancy outcomes in women with active anorexia nervosa: a systematic review

“…Based on the level of evidence, anaemia [ 23 – 25 ], caesarean section [ 7 , 26 , 27 ] and concurrent recreational substance use [ 28 , 29 ] were the most commonly reported by the studies included. In comparison to women without a history of AN, the odds ratios (OR) were 2.1 (95%CI 1.3–3.2) [ 23 ] and 2.39 (95%CI 1.20–4.76) [ 24 ] for anaemia.…”

“…Based on the level of evidence, preterm birth [ 23 , 24 , 26 – 28 , 34 , 40 , 41 ], SGA birth [ 23 , 24 , 28 , 30 , 38 – 40 ], and low birth weight [ 24 , 25 , 27 – 29 , 39 ] were the most reported by the studies included. Three of the case reports that mentioned preterm birth were twin pregnancies [ 27 , 34 , 41 ]. Only one infant of a case report with twin pregnancy had low birth weight [ 27 ].…”

“…Three of the case reports that mentioned preterm birth were twin pregnancies [ 27 , 34 , 41 ]. Only one infant of a case report with twin pregnancy had low birth weight [ 27 ].…”

Unilateral Atraumatic Femoral Neck Fracture in the Peripartum Period: Case Report and Literature Review

“…The majority of cases specifically described fracture of the femoral neck and as such, the severity was amenable to grading per the Gardner classification [ 19 ]. However, in some cases this approach was not applicable as the fracture involved either a subchondral head fracture or complete femoral head collapse [ 12 ]. The average age of the patients was 31.6 years (range 20-40).…”

“…BME was found to affect both hips - despite being prescribed antiresorptive therapy (alendronate and vitamin D) after delivery, the patient still presented with unilateral atraumatic femoral neck fracture 15 days after delivery. In another patient, where the likely catalyst of TOH was anorexia nervosa (BMI 15.4 kg/m2), the symptoms of the patient were exacerbated during five weeks of bed rest [ 12 ]. These two cases highlight a stern outlook regarding the utility of early diagnosis, as even avoidance of load bearing with antiresorptive therapy failed to prevent the advancement of TOH to a pathological fracture.…”