Fracture of an S-ROM stem at the sleeve-stem junction

Abstract

Fracture of a well-ingrown femoral component is a rare and often challenging complication. Modular junctions and sleeve interfaces have been identified as one potential point of weakness with corrosion and fretting being contributing factors to ultimate femoral component fracture. Stem fractures at the sleeve interface were reported occasionally for the proximal ingrowth modular Emperion System (Smith and Nephew, Memphis, TN). However, this failure mechanism has been reported infrequently, often associated with corrosion at the modular junction, for the similarly designed S-ROM system (DePuy Orthopedics Inc., Warsaw, IN). We present the case of a 52-year-old patient, with a body weight of 84 kg (185 lbs) and a body mass index of 30.6 kg/m2, who suffered a fatigue fracture of a 14 × 09 × 130 mm S-ROM stem 42 months after implantation. The present study presents the results of the surface analysis, discusses possible failure mechanisms, provides treatment guidelines, and a review of the literature revealing 15 cases of failure at the level of the stem-sleeve junction. In particular, modifiable risk factors for potential stem failure, including stem diameter, stem offset, and the resulting cantilever bending forces on the proximal sleeve-stem junction, are discussed in detail.

Total hip arthroplasty with transverse subtrochanteric osteotomy and monocortical locking plate for the treatment of Crowe Ⅳ developmental dysplasia of the hip

“…It has also been reported that the combined prosthesis with adjustable anterior inclination (S -ROM prosthesis) can be used to adjust the size of the anterior inclination of the femoral neck by means of osteotomy under the femoral trochanter [32,33]. At the same time, there are also reports that the modular femur component may cause fracture risk at the link of the prosthesis due to fretting, corrosion and other reasons [34,35].…”

Fracture of a Sivash-Range of Motion Femoral Stem at the Diaphyseal Spline

“…In this case report, we discuss one of four reported cases of the fracture of a spline of the S-ROM prosthesis, which was fully discovered during stem extraction. As there are only 18 known reports (including the present study) of fractures of the S-ROM prosthesis at different prosthetic locations, and at different time points postoperatively [ 3 , 4 , 6 - 12 ], it is important to document trends in implant survivorship (Table 1 ).…”

“…At these interfaces between modular components, corrosion, metal ion generation, and fretting may occur [ 14 , 15 ]. This corrosion concentrated in the neck/sleeve region can reduce prosthesis integrity, especially when coupled with small-diameter diaphyseal stems and large neck offsets in obese patients, resulting in “fatigue fracture” due to massive bending forces on the neck-sleeve or sleeve-stem interface [ 6 ]. Approximately 14 cases of S-ROM fractures at the modular neck due to this “fatigue fracture” mechanism exist in the literature [ 6 - 12 ].…”

“…This corrosion concentrated in the neck/sleeve region can reduce prosthesis integrity, especially when coupled with small-diameter diaphyseal stems and large neck offsets in obese patients, resulting in “fatigue fracture” due to massive bending forces on the neck-sleeve or sleeve-stem interface [ 6 ]. Approximately 14 cases of S-ROM fractures at the modular neck due to this “fatigue fracture” mechanism exist in the literature [ 6 - 12 ]. Pearce et al in 2014 and McNabb et al in 2016 described the only three known cases of S-ROM spline fracture, which they attributed to the “fatigue fracture” mechanism as well [ 3 , 4 ].…”

“…Prior studies have demonstrated that removal of an S-ROM prosthesis can be difficult due to cold-welding of the sleeve to the stem, extensive proximal femoral bony fixation (limiting access to the splines), and bony on-growth of the splines themselves [ 6 ]. We elected to extract the patient’s S-ROM prosthesis using a chisel and stacked osteotomes to disengage the bony attachments and an extractor with a mallet to remove the stem, a method discussed in a review by Laffosse in 2016 [ 16 ].…”