Modularity When Using a Tapered Stem in Revision THA
Modularity When Using a Tapered Stem in Revision THA
After obtaining approval from our institution's review board, we retrospectively reviewed the clinical records of 58 patients who underwent revision total hip arthroplasty performed by three surgeons using a distally tapered, splined, grit-blasted, ongrowth femoral stem. The cohort included 24 women and 34 men, with a mean age of 72 yr (range 47 to 91). Patients were followed for a mean 12 mo postoperatively (range, 1–59 mo).
Femoral defects were classified according to the system described by Della Valle and Paprosky as type IIIA in 36 patients, IIIB in 17, and IV in five (Figures 1 and 2). Implants were modular in 15 (ZMR, Zimmer, Warsaw IN) and nonmodular in 43 (Wagner SL revision, Sulzer Orthopedics Ltd. Winterthur, Switzerland). Indications for surgery included aseptic loosening (32), resolved periprosthetic infection (24), and periprosthetic fracture (2). All but five patients (91.4%) underwent extended trochanteric osteotomy for femoral exposure. All two-stage procedures performed for infection used an articulating implant (Prostalac, Depuy, Warsaw, IN) designed to maintain a normal hip center. Revision of both the femoral and acetabular components was performed in 27 of 43 (62.8%) nonmodular implants, and 12 of 15 (80%) modular implants; the remainder underwent isolated femoral component revision.
(Enlarge Image)
Figure 1.
(A) Anteroposterior radiograph of a cementless right hip arthroplasty in a 67-year-old man. The patient presented with chronic drainage 4 yr after total hip arthroplasty. (B) Postoperative anteroposterior radiograph of the hip after staged resection arthroplasty using a high-dose antibiotic spacer. (C) Immediate postoperative anteroposterior radiograph taken after reimplantation using a nonmodular tapered femoral stem. (D) Anteroposterior radiograph taken 2 yr after revision.
(Enlarge Image)
Figure 2.
(A) A 56-year-old female with aseptic loosening of a left total hip arthroplasty. At the time of revision, a Paprosky type IV femoral defect was encountered. (B) Anteroposterior radiograph taken 1 yr after revision using a nonmodular tapered femoral stem.
Preoperative and postoperative leg-length discrepancies were determined using radiographic landmarks, specifically the distance from the lesser trochanter (or comparable bony landmark in cases of severe bone-loss) to the hip center; the values were then compared to determine the mean change in leg-length discrepancy. Implant subsidence was determined by comparing the femoral component position on the immediate postoperative radiograph to the most recent radiograph.
Materials and Methods
After obtaining approval from our institution's review board, we retrospectively reviewed the clinical records of 58 patients who underwent revision total hip arthroplasty performed by three surgeons using a distally tapered, splined, grit-blasted, ongrowth femoral stem. The cohort included 24 women and 34 men, with a mean age of 72 yr (range 47 to 91). Patients were followed for a mean 12 mo postoperatively (range, 1–59 mo).
Femoral defects were classified according to the system described by Della Valle and Paprosky as type IIIA in 36 patients, IIIB in 17, and IV in five (Figures 1 and 2). Implants were modular in 15 (ZMR, Zimmer, Warsaw IN) and nonmodular in 43 (Wagner SL revision, Sulzer Orthopedics Ltd. Winterthur, Switzerland). Indications for surgery included aseptic loosening (32), resolved periprosthetic infection (24), and periprosthetic fracture (2). All but five patients (91.4%) underwent extended trochanteric osteotomy for femoral exposure. All two-stage procedures performed for infection used an articulating implant (Prostalac, Depuy, Warsaw, IN) designed to maintain a normal hip center. Revision of both the femoral and acetabular components was performed in 27 of 43 (62.8%) nonmodular implants, and 12 of 15 (80%) modular implants; the remainder underwent isolated femoral component revision.
(Enlarge Image)
Figure 1.
(A) Anteroposterior radiograph of a cementless right hip arthroplasty in a 67-year-old man. The patient presented with chronic drainage 4 yr after total hip arthroplasty. (B) Postoperative anteroposterior radiograph of the hip after staged resection arthroplasty using a high-dose antibiotic spacer. (C) Immediate postoperative anteroposterior radiograph taken after reimplantation using a nonmodular tapered femoral stem. (D) Anteroposterior radiograph taken 2 yr after revision.
(Enlarge Image)
Figure 2.
(A) A 56-year-old female with aseptic loosening of a left total hip arthroplasty. At the time of revision, a Paprosky type IV femoral defect was encountered. (B) Anteroposterior radiograph taken 1 yr after revision using a nonmodular tapered femoral stem.
Preoperative and postoperative leg-length discrepancies were determined using radiographic landmarks, specifically the distance from the lesser trochanter (or comparable bony landmark in cases of severe bone-loss) to the hip center; the values were then compared to determine the mean change in leg-length discrepancy. Implant subsidence was determined by comparing the femoral component position on the immediate postoperative radiograph to the most recent radiograph.