Are Short Stems Associated With Higher Fracture Rates and Early Revision Rates in Primary Total Hip Arthroplasty? A...

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Clinical Epidemiology

Background:

• The utilization of "short" uncemented femoral hip stems has increased during total hip arthroplasty (THA).
• Concerns exist regarding the safety and efficacy of these shorter implants compared to traditional standard-length stems.
• Evaluating outcomes such as periprosthetic fractures and revision rates is crucial for patient safety and implant selection.

Purpose of the Study:

• To determine if short femoral stems are noninferior to standard-length stems in total hip arthroplasty.
• To assess the rates of 90-day periprosthetic fractures and 1-year revision for short femoral stems.
• To compare the outcomes of different classifications of short femoral stems against standard-length stems.

Main Methods:

• A retrospective analysis of statewide data from the MARCQI implant registry (2012-2017) involving 64,084 total hip arthroplasties.
• Classification of short stems using the Khanuja Classification System (Types 2A, 3, and 4) and comparison with standard-length Type 5 stems.
• Application of inverse probability of treatment weighting (IPTW) to mitigate confounding variables and chi-square tests for statistical analysis.

Main Results:

• Noninferiority for 90-day fracture rates was established for all short stem types (OR < 1.5, P < 0.05).
• Noninferiority for 1-year revision rates was demonstrated for Type 3 and Type 4 short stems (P < 0.05).
• Overall 1-year revision and 90-day fracture rates were 1.3% and 1.1%, respectively, across all stem types.

Conclusions:

• The increased adoption of short femoral stems in Michigan THA procedures did not correlate with elevated 1-year revision or 90-day fracture rates.
• Short femoral stems, particularly Types 3 and 4, demonstrate comparable safety and efficacy to standard-length stems.
• These findings support the use of short femoral stems as a viable alternative in total hip arthroplasty.