Young age and wedge stem design are risk factors for periprosthetic fracture after arthroplasty due to hip fracture

Background It has been suggested that a hip fracture as a primary diagnosis for arthroplasty is a risk factor for periprosthetic fracture.

Patients and methods We compared 16 patients with late periprosthetic fracture of the femur to 48 controls. The primary diagnosis for all patients was hip fracture. The date of operation for hip fracture was used to select the control group of patients, all of whom were operated at the same time and in the same hospital district. No other selection criteria were used. Complications at the time of index operation, type of prosthesis, age, sex, BMI, patient’s diseases, medication, and surgeon’s experience were compared using conditional logistic regression.

Results We found that low age at the time of the hip fracture operation increased the risk of periprosthetic fracture (OR = 4.9, CI = 1.2-20). The polished wedge type of prosthesis was associated with a higher risk of periprosthetic fracture than were other designs (OR = 11, CI = 1.2-97).

Interpretation These findings of risk factors for peri-prosthetic fracture are new and should be confirmed by further studies using larger numbers of patients.