Preoperative Femoral Bone Texture Features on Radiographs Are Associated with Femoral Stem Subsidence Following Total...

Femoral stem subsidence greater than two mm after total hip arthroplasty has been associated with worse patient outcomes. Identifying poor bone quality preoperatively could help surgeons choose implant designs that minimize subsidence risk. The purpose of this exploratory study was to evaluate whether radiographic bone texture is associated with early femoral stem migration.

A secondary analysis was performed for 63 participants enrolled in a randomized trial comparing collared versus collarless cementless stems implanted by direct anterior or direct lateral approaches. Participants underwent radiostereometric analysis and standardized radiographs preoperatively and at six weeks, one year, and five years postoperatively. Participants were divided into less than or equal to two or greater than two mm subsidence groups from the radiostereometric analysis data. Regions of interest corresponding to the seven Gruen zones were analyzed for radiographic texture features describing bone quality.

At baseline, hips with greater than two mm of early subsidence had lower texture energy (P = 0.0003 to 0.014) and mean intensity (P = 0.0005 to 0.026) across all Gruen zones, reflecting more uniform bone structure. In both groups, texture parameters increased over time (P < 0.0001), consistent with bone remodeling and ingrowth.

These findings demonstrate an association between femoral bone texture on plain radiographs and early subsidence of cementless stems. Because radiographs are routine and widely available, texture analysis may offer an accessible, quantitative method for assessing bone quality to support implant selection and postoperative monitoring.