Is diaphyseal fixation of short neck-retaining stem prostheses related to the size of the implant?. Issue 2 (March 2021)

• Record Type: Journal Article
• Authors: Pons-Cabrafiga, Miquel; Arias de la Torre, Jorge; Berlanga-de-Mingo, Daniel; Lobo-Escolar, Luis
• Is Part Of: Hip international. Volume 31:Issue 2(2021)
• Page Start: 196
• Page End: 200
• Publication Date: 2021-03
• Subjects: Bone remodelling -- hip prosthesis -- short stem -- size; Hip joint -- Pathophysiology -- Periodicals; Hip joint -- Diseases -- Periodicals; Hip joint -- Surgery -- Periodicals; 617.581005
• DOI: 10.1177/1120700020932937
• Languages: English
• ISSNs: 1120-7000

Abstract

Introduction: Short-stem hip prostheses present variable proximal femoral bone radiological findings. The aims of this study were to analyse, in our patients with implanted collum femoris-preserving (CFP) stems, cancellous bone remodelling, cortical distal hypertrophy and pedestal formation, and the relationship between those radiological changes that suggest distal fixation with the size of the stem. Methods: From October 2001 to December 2012 a total of 199 consecutive primary total hip arthroplasties in 180 patients were performed at our department using the CFP stem and followed up for a minimum of 5 years until December 2017. Results: Stress shielding was present in 74% of oversized stems cases, but in normal or undersized stems, stress shielding was present in 8.5%. Cortical hyperthrophy was observed in 49% of the oversized stems and in 6% of the normal or undersized ones. Finally, non-statistically significant differences ( p = 0.089) in pedestal formation were found, present in 16.3% of the oversized stems and in 6% of normal or undersized ones. Conclusions: Oversized stems cause more stress shielding and distal cortical hypertrophy in the distal part of the stem, which indicates distal fixation in bigger sizes of stem.