Antibiotic-Loaded Hydrogel Does Not Compromise Hip Stem Stability, reports research
Researchers have discovered that an antibiotic-loaded hydrogel did not compromise the primary stability of uncemented hip stems. A biomechanical study recently proved that construct stiffness and stem subsidence in hip implants prepared with or without hydrogel were equivalent under varied load conditions. The study was conducted by Georgios and colleagues which was published in the journal BMJ Surgery.
The primary stability is considered the key determinant of success for uncemented hip implants because it influences long-term fixation. Antibiotic-loaded hydrogels, providing antimicrobial benefits without impacting stability, have been an area of interest and, therefore, required a comprehensive biomechanical assessment.
The primary stability was assessed using an electro-mechanic material test system (#5866, Instron, Norwood, MA, USA) provided with a 10-kN load cell. A quasi-static ramped compression loading protocol was applied at a rate of 0.005 mm/s. Six intermittent load levels from 500 N to 3000 N in steps of 500 N were used for testing.
Twelve artificial femora were set up and instrumented with collarless uncemented standard offset stems (Corail; DePuy Synthes, Zuchwil, Switzerland). These were divided into two groups, one with an application of antibiotic-loaded hydrogel, and one without. Stiffness was calculated by load-displacement curves; stem subsidence was assessed using motion measurement techniques.
Key Findings
Construct Stiffness:
• Control group: 4176±240 N/mm
• Hydrogel group: 4588±448 N/mm
• No significant difference between the groups (p=0.076).
Stem Subsidence:
• There was a marked increase in subsidence at all levels of loading for both groups (p≤0.002).
• No significant difference between the two groups for subsidence (p=0.609).
Load Tolerance:
• Both groups exhibited stable performance at incremental levels of load (500 N to 3000 N).
The study concludes that antibiotic-loaded hydrogel application is associated with non-inferior primary stability in uncemented hip stems. This finding supports its potential use in clinical practice, although further investigations are required to fully establish its safety and efficacy.
Reference:
Orfanos, G., Zderic, I., Gueorguiev, B., Nylund, P., D’Este, M., Varga, P., & Okoro, T. (2024). The impact of adjuvant antibiotic hydrogel application on the primary stability of uncemented hip stems. BMJ Surgery, Interventions, & Health Technologies, 6(1), e000307. https://doi.org/10.1136/bmjsit-2024-00030
