Stress fracture of the proximal tibia after total knee arthroplasty: a case report.

Stress fracture of the proximal tibia after total knee arthroplasty (TKA) is very rare. We found only 16 cases in a review of the literature. We report the case of a 76-year-old obese woman who sustained a stress fracture of the right proximal tibia without trauma 18 months after TKA. Pain developed in the proximal medial aspect of the tibia during walking. Physical examination showed tenderness of the proximal medial aspect of the tibia and varus deformity of 15 degrees during stress test of the knee. Roentgenography 4 weeks after symptom onset showed an obvious stress fracture line. Treatment with bed rest and above-the-knee plaster cast immobilization for 8 weeks was successful. The causes of this rare complication may include increased level of activity after TKA, generalized osteoporosis, and varus deformity of the knee.