Does modularity affect clinical success? A comparison with a minimum 10-year followup

Area of Science:

• Orthopedic surgery
• Biomedical engineering
• Knee replacement research

Background:

• Metal-backed monoblock Insall-Burstein I and modular Insall-Burstein II Posterior Stabilized Knee Prostheses are commonly used.
• Long-term clinical and radiographic outcomes are crucial for evaluating prosthetic performance.

Purpose of the Study:

• To compare the clinical and radiographic results of Insall-Burstein I and Insall-Burstein II posterior stabilized knee prostheses.
• To assess the long-term efficacy and safety of these two knee implant designs.

Main Methods:

• A comparative study of patients undergoing knee replacement with Insall-Burstein I or Insall-Burstein II prostheses.
• Minimum follow-up period of 10 years.
• Evaluation of clinical outcomes using Hospital for Special Surgery (HSS) knee scores and Knee Society Scores (KSS).
• Radiographic assessment for radiolucent lines, loosening, polyethylene wear, and osteolysis.

Main Results:

• Comparable clinical results between Insall-Burstein I and II prostheses, with similar average HSS scores (85 vs. 84).
• No statistically significant difference in Knee Society Knee and Functional Scores.
• Higher incidence of minor radiolucent lines in Insall-Burstein II (29%) compared to Insall-Burstein I (11%), with no clinical significance.
• No clinical or radiographic evidence of tibial component loosening for either design.
• Zero revisions for polyethylene wear or osteolysis in both patient cohorts.

Conclusions:

• Both Insall-Burstein I and II posterior stabilized knee prostheses demonstrate comparable long-term clinical efficacy and survivorship.
• Radiographic findings, including minor radiolucencies, do not appear to impact clinical outcomes negatively.
• These prosthetic designs show excellent durability with no significant issues related to loosening, wear, or osteolysis at the 10-year minimum follow-up.