Experiences and results with a cementless femoral stem design: SL-PLUS MIA

Abstract

Aim: To evaluate the outcomes of the SL-PLUS^® MIA cementless femoral stem (Smith & Nephew Orthopedics AG, Switzerland) application using the modified lateral approach.

Method: Demographic and clinical data, in addition to the operational outcomes of 42 patients who underwent total hip arthroplasty (THA) and partial hip arthroplasty (PHA) using the MIA cementless femoral stem with the modified lateral approach, between November 2015 and June 2017, were collected. Harris Hip Scores were calculated preoperatively and at 6 weeks, and 3 and 6 months, and 1 and 3 years postoperatively (a total of 6 times) in the THA group and at 6 weeks, and 3 and 6 months, and 1 and 3 years postoperatively (a total of 5 times) in the PHA group.

Results: Data from 24 THA patients with a diagnosis of primary or secondary coxarthrosis and 18 PHA patients with a diagnosis of isolated collum femoris fracture were collected. The average patient (26 females, 16 males, mean age 68.1 ± 13.1 years) follow-up period was 46.7 ± 1.4 months. There were no intraoperative or postoperative trochanteric fractures. No patients displayed the trendelenburg sign. The Harris Hip Scores of all of the patients increased postoperatively, proportional to the duration of follow-up.

Conclusions: In hip arthroplasties performed using the modified lateral approach, femoral preparation with a MIA femoral stem, which has a proximal lateral slope, reduced the tension in the trochanteric region. This was believed to lower the risk of trochanteric fractures. Additionally, this type of femoral component may help to avoid the trendelenburg sign postoperatively by protecting more gluteal muscle during the femoral preparation stage due to its proximal design.