Purpose: To meet the increasing demand for arthroplasty in Canada healthcare providers are investigating efficiency improvements to maximize utilization of limited surgical resources. One target is routine annual arthroplasty follow-up for which there are no established guidelines. A previous study by the authors revealed that 52% of arthroplasty patients could be followed with standardized questionnaires and x-rays resulting in a 30% savings to the healthcare system. In this study we report the patient time, travel and financial burdens for annual follow-up at a tertiary care centre versus a hypothetical model using standardized assessment at community hospitals and a web-enabled PACS.

Method: A consecutive sample survey of elective THA and TKA patients (n=158; 99 females; 94 THA; 64 TKA; mean age=69 years) who were at least twelve months postoperative. Patient’s address, work status, mode of travel and times required for travel, physician consult, x-ray, and clinic wait were recorded. A web-based mapping application was used to determine distances from patients’ homes to the tertiary care centre and nearest community hospital. Financial burden was calculated using Statistics Canada figures for average Canadian wage and private vehicle travel costs.

Results: Sixteen patients were working at the time of the study and 149 travelled in a private vehicle. For the tertiary care centre: round-trip distance was 168 km, total time burden was 194 minutes (travel=129 minutes, clinic wait=54 minutes, time with physician=6 minutes, x-ray=5 minutes), and total financial burden per patient was $58. For the community hospital: round-trip distance was 19 km, total time burden was 39 minutes (travel=14 minutes, clinic wait=20 minutes, x-ray=5 minutes), and total financial burden was $7.

Conclusion: Utilizing community hospital resources for arthroplasty follow-up could reduce patients’ travel by 89%, financial burden by 88%, and time burden by 81%. This approach has the potential to enable the focusing of arthroplasty clinic follow-up resources only on patients reporting problems or with symptomatic x-rays thus freeing up surgeon time for surgeries. There are also the broader societal implications of reducing ‘health miles’ and the resulting carbon dioxide emissions related to health care delivery by leveraging new technologies to move information rather than people.

Purpose: Porous metal technology may have significant impacts on implant fixation and long-term survival due to their high co-efficient of friction and similarity to trabecular bone in morphology and mechanical behaviour. While promising, the in vivo mechanical behaviour and micromotion at the interface has not previously been reported on. We report on the 2-year results of an RCT using radiosterometric analysis (RSA) to asses a porous metal (PM) monoblock tibial component.

Method: Patients undergoing TKA were randomized to receive a either the PM (n=34) or the cemented tibial component (n=33). A standardized protocol was used for intra and post-operative factors. RSA exams were obtained postoperatively within 4 days of surgery and at 6, 12 and 24 months. One patient was excluded due to an intraoperative complication, and four others were lost to follow-up due to poor bead visibility or morbidity. Standard subjective outcome measures were applied.

Results: There were no revisions in either group. The PM group exhibited two distinct migration patterns. One group stabilized immediately with similar migration to the cemented cases (0.38 vs. 0.46 p=0.4). A subset of 6 PM cases demonstrated significantly higher initial migration (mean=2.01mm, p< 0.01) but appeared stable at 2 years. In addition, 3 of the 6 high migration cases manifested independent bead subsidence. This was determined to be due to PM plate deformation. Two cemented cases were considered at risk for early failure due to aseptic loosening because of RSA migration pattern. There were no differences between groups in the subjective health outcome measures.

Conclusion: A subset of PM components demonstrated high early migration followed by stabilization. It appears that some of these PM components deformed under load, most often in the posteromedial corner, perhaps as a result of malalignment or ligament imbalance. The implications of this finding are yet to be determined.