A 64-year-old woman with a spontaneous fused hip sustained a left femoral neck fracture. It was revealed that her left hip joint had a long-standing spontaneous hip fusion due to end-stage osteoarthritis. Additionally, she sustained an ipsilateral femoral intertrochanteric fracture and underwent osteosynthesis using a dynamic hip screw 8 years ago. The one-stage THA was successfully treated with no major complications and good functional recovery was obtained. The hip range of motion improved remarkably at one year after surgery. The Modified Harris Hip Score improved from an estimated 70 points before fracture to 95 points at final follow-up.
The conversion procedure to total hip arthroplasty (THA) for a patient with hip arthrodesis and spontaneous fused hip presented surgical difficulty compared to the common primary THA [
A 64-year-old woman who worked at a laundry and dry-cleaning store was admitted to our hospital due to a fall. She complained of left hip pain and was unable to walk. It was revealed that her left hip joint had a long-standing spontaneous hip fusion due to end-stage osteoarthritis with developmental hip dysplasia (DDH) for more than 30 years. Additionally, she sustained an ipsilateral femoral intertrochanteric fracture 8 years ago and underwent surgery with osteosynthesis using a dynamic hip screw. The physical findings at the initial visit showed spontaneous pain and tenderness around the left hip joint, and she was unable to move her left leg. The left hip joint was fixed at flexion 0° and abduction 0°, and no unusual rotation was detected in the neutral limb position. Plain radiograph of the left hip joint revealed a fused hip and a nondisplacement femoral neck fracture at the tip of the lag screw which was inserted for the intertrochanteric fracture 8 years ago (Figures
The plain radiograph and CT of both hip joints of a 64-year-old woman. Left hip joint showed the femoral neck fracture after postoperative intertrochanteric fracture in the fused hip. Right hip joint shows severe osteoarthritis due to DDH. (a) Anteroposterior view; (b) lateral view; (c) sagittal view of CT image; (d) axial view of CT image.
It was estimated that the ADL of the patient before the fracture was that she could walk without a cane and no support was needed during her daily living; however, she had right hip pain with osteoarthritis.
After discussing treatment options, we selected one-stage THA and to extract the dynamic hip screw. In the preoperative planning, we generally proposed to place the cup at the original hip center; however, in this case, the cup could only be placed at 5 mm higher than the hip center in order to avoid the cup CE angle of less than 0 degrees. Surgery was performed at the lateral decubitus position without navigation under general anesthesia, and the modified Hardinge approach was used to take down hip fusion surgery after extracting the dynamic hip screw. During surgery, atrophy with fatty degeneration in the gluteus medius was observed (Figure
Intraoperative finding. White asterisks
Postoperative plain radiograph. Hybrid THA was performed. (a) Anteroposterior view; (b) whole lower extremities in standing position.
There are a few available reports regarding proximal femoral fractures in arthrodesis or spontaneous fused hip joints [
In the present case, we had several technical advantages on the surgery. First, fortunately, no abnormal contracture was present, and the hip joint had been fused in the neutral limb position. Second, the fracture line in the femoral neck was nearly consistent with the required neck cut line of THA. The femur could be moved a little at the site of the fracture; therefore, we were able to obtain a sufficient surgical field. For that reason, our approach for the surgery did not need trochanteric osteotomy, although Morsi and Richards and Duncan recommend the lateral transtrochanteric approach with trochanteric osteotomy for sufficient visualization of the surgical field [
If severe proximal femoral deformity was present, additional osteotomy in the proximal femur might have been needed. Additionally, if abnormal femoral anteversion was present, version control by modular stem or cemented stem would have been needed to avoid postoperative dislocation. For the acetabulum preparation, fluoroscopy was used for acetabular reaming to confirm the position of the original acetabulum. We could not use navigation in this case; however, CT-based navigation could be safer and more accurate. Postoperative outcomes were satisfactory at final follow-up at one year after surgery. There were no major complications, such as dislocation, deep venous thrombosis, or deep infection encountered during the study period.
The limitations associated with this case report include the fact that the postoperative follow-up period was quite short, and that future observation of progress is necessary. However, to the best of the authors’ knowledge, this is the first report with one-stage THA for a femoral neck fracture after postoperative intertrochanteric fracture in a fused hip.
One-stage THA was successfully treated and good functional recovery was obtained in a patient with a femoral neck fracture after a postoperative intertrochanteric fracture in a spontaneous fused hip.
Informed consent was obtained from the patient in the study, including use of radiographs.
The authors state that there was no conflict of interest.