[Clinical pathway for total knee arthroplasty. I: Pathway conception and effect on functional quality of results]

[Experience in establishing a certified endoprosthesis center]

BACKGROUND

It is well known that morbidity rates of arthroplasties are inversely related to procedure volume. In the department of orthopaedics at a German medical school, a performance of certification of high-volume center for total hip and knee arthroplasties, called the EndoCert(®) Initiative, was started. This project was initiated by the German society of orthopaedic surgery (DGOOC) to secure the quality of total knee and hip arthroplasties.

OBJECTIVES

The aim of this study is to evaluate effects of certification, pathwaycontrolled therapy and quality indicators on outcome in arthroplasty three years after implentation.

MATERIALS AND METHODS

Arthroplasties performed in this certified center for total hip and knee arthroplasties were evaluated. Outcome was evaluated after the implementation of quality indicators and clinical pathways.

RESULTS

After establishment of certification in the center for total hip and knee arthroplasties morbidity rates decreased as quality increased.

CONCLUSION

The implementation of pathway-controlled therapy and quality indicators in a high-volume center for total joint arthroplasties shows better clinical results. Capital investment and efforts are legitimated.

Cost effectiveness of total knee arthroplasty from a health care providers' perspective before and after introduction of an interdisciplinary clinical pathway--is investment always improvement?

Background

Total knee arthroplasty (TKA) is an effective, but also cost-intensive health care intervention for end stage osteoarthritis. This investigation was designed to evaluate the cost-effectiveness of TKA before versus after introduction of an interdisciplinary clinical pathway from a University Orthopedic Surgery Department's cost perspective as an interdisciplinary full service health care provider.

Methods

A prospective trial recruited two sequential cohorts of 132 and 128 consecutive patients, who were interviewed by means of the WOMAC questionnaire. Direct process costs from the health care providers' perspective were estimated according to the German DRG calculation framework. The health economic evaluation was based on margiual cost-effectveness ratios (MCERs); an individual marginal cost effectiveness relation ≤ 100 € per % WOMAC index increase was considered as primary endpoint of the confirmatory cohort comparison. The interdisciplinary clinical pathway under consideration primarily consisted of a voluntary preoperative personal briefing of patients concerning postoperatively expectable progess in health status and optimum use of walking aids after surgery. All patients were supplied with written information on these topics, attendance of the personal briefing also included preoperative training for postoperative mobilisation by the Department's physiotherapeutic staff.

Results

An individual marginal cost effectiveness relation ≤ 100 €/% WOMAC index increase was found in 38% of the patients in the pre pathway implementation cohort versus in 30% of the post pathway implementation cohort (Fisher p = 0.278). Both cohorts showed substantial improvement in WOMAC scores (39 versus 35% in median), whereas the cohort did not differ significantly in the median WOMAC score before surgery (41% for the pre pathway cohort versus 44% for the post pathway cohort). Despite a locally significant decrease in costs (4303 versus 4194 € in median), the individual cost/benefit relation became worse after introduction of the pathway: for the first cohort the MCER was estimated 108 € per gained % WOMAC index increase (86 - 150 €/%) versus 118 €/% WOMAC gain (93 - 173 €/%) in the second cohort after pathway implementation. In summary, the proposed critical pathway for TKA could be shown to be significantly cost efficient, but not cost effective concerning functional outcome, when the above individual marginal cost effectiveness criterion was concentrated on.

Conclusions

The introduction of an interdisciplinary clinical pathway does not necessarily improve patient related outcomes. On the contrary, cost effectiveness from the health care providers' perspective may even turn out remarkably reduced in the setting considered here (functional outcome assessment after treatment by a full service health care provider).