Age and Prosthetic Design as Risk Factors for Secondary Patella Resurfacing.

Background: Selectively resurfacing the patella based on a patient's risk of secondary patella resurfacing (SPR) may be the optimal strategy for primary total knee arthroplasty (TKA). However, exactly which factors increase the risk of SPR is unknown. Utilizing New Zealand Joint Registry data, we investigated the following: (1) What patient and surgical factors are more prevalent among TKA patients who received SPR compared to those who did not? and (2) What is the difference in Oxford Knee Scores (OKS) between those who receive SPR and those who do not?

Methods: Prevalence of various patient and surgical factors was compared between 197 non-resurfaced TKAs that proceeded to SPR and 31,399 that did not.

Usually, Selectively, or Rarely Resurfacing the Patella During Primary Total Knee Arthroplasty: Determining the Best Strategy.

Background: Surgeons may "usually" resurface the patella during total knee arthroplasty (TKA), "rarely" resurface, or "selectively" resurface on the basis of certain criteria. It is unknown which of these 3 strategies yields superior outcomes. Utilizing New Zealand Joint Registry data, we investigated (1) what proportion of surgeons employs each of the 3 patellar resurfacing strategies, (2) which strategy is associated with the lowest overall revision rate, and (3) which strategy is associated with the highest 6-month and 5-year Oxford Knee Score (OKS).

Validation of a body-worn accelerometer to measure activity patterns in octogenarians.

Objective: To determine the validity of a triaxial body-worn accelerometer for detection of gait and postures in people aged >80 years.

Design: Participants performed a range of activities (sitting, lying, walking, standing) in both a controlled and a home setting while wearing the accelerometer. Activities in the controlled setting were performed in a scripted sequence.