Introduction

It is not unusual to hear orthopaedic surgeons comment that restorative procedures such as autologous chondrocyte implantation or osteochondral allografts are expensive. However, what should matter is not the cost of the procedure, but its cost-effectiveness.

Cost-effectiveness analysis includes all costs and all benefits, over an appropriate duration, which can be as long as a lifetime. Costs should consider not just the cost of the procedure, but also the costs of alternative treatments, if ACI or OCA was not available, in order to produce the net costs. Depending on age and symptoms, the alternative may be a less effective intervention, with less durability and so return of symptoms. The cost and timing of knee arthroplasty should also be considered. In economics, a cost postponed is a cost reduced, because of discounting. So an intervention that postponed TKA may result in cost-saving to offset the initial procedure cost.

The benefits should be summarised as quality adjusted life years (QALYs), taking account of relief of symptoms and return to usual activities, such as sport or occupation, and hence quality of life, ideally using a generic measure such as EQ5D, to allow comparison with other uses of scarce health care funds.

Cost-effectiveness is reported as the cost per QALY. Thresholds vary amongst countries. In the UK the starting threshold used by the National Institute for Clinical Excellence (NICE) is £20,000 per QALY, but treatments with higher costs per QALY are funded. A key criterion is strength of evidence of clinical effectiveness.

Content

Examples

Autologous chondrocyte implantation in the knee.

In the UK, ACI has been approved by NICE subject to certain restrictions, based on the cost per QALY (which means that some unapproved uses might be approved if the price of the cells was reduced). Approval required several appraisals, and took many years because of the need for long-term data, and for trials – the earliest evidence came from case series. This presentation will include an account of the NICE ACI saga.

Osteochondral allografts in the knee

ESSKA commissioned us to do a health technology report on the use of allografts in the knee. The report has been published on the ESSKA website with short versions in the June 2019 issue of the journal KSSTA. We concluded that osteochondral allografting in the knee was highly cost-effective, but that conclusion was based on case series and historical natural history studies.

We concluded that meniscal allograft implantation was probably cost-effective but the available evidence was insufficient to be sure, being mainly from uncontrolled case series and one pilot RCT.

Evidence needs in knee interventions – some key points;

Case series do not usually provide sufficient evidence for cost-effectiveness analysis. We need data on outcomes for the best alternative care so we need more trials, of sufficient duration

We need to identify short-term (e.g. 2-4 years) outcomes that are reliable guides to long-term (20 year) outcomes

It is not enough to say that treatment A is better than treatment B – we need to know how much better A is (the “effect size”)

There are tried and tested outcome measure such as KOOS but for economic analysis we need generic “utility” measures such as EQ5D, in order to provide results in the common currency of cost per QALY. Decisions for funders of care involve assessing costs and benefits of investing in the whole spectrum of possible care. So orthopaedics has to compete with, e.g., new cancer drugs.

There are several new forms of ACI coming, including one-stage versions – we need proper trials set up as soon as data on proof of concept are available.

We need a longer-term trial of meniscal allograft implantation against optimised conservative care.

We need trials of OCA versus ACI

Most of the existing studies come from centres of excellence. Will their results be replicated in routine care?

It would be good to have some multi-centre and indeed multinational trials

Conclusion. Some orthopaedic interventions that might be perceived as expensive, are cost-effective.

References

Mistry H, Connock M, Pink J, Shyangdan D, Clar C, Royle P, Court R, Biant LC, Metcalfe A, Waugh N. Autologous chondrocyte implantation in the knee: systematic review and economic evaluation. Health Technology Assessment 2017/21/ number 6

Waugh N, Mistry H, Metcalfe A, Colquitt J, Loveman E, Royle P, Smith NA. . Allografts in reconstruction of the posterior cruciate ligament: a health economics perspective. Knee Surg Sports Traumatol Arthrosc. 2019/27/1810-16. doi: 10.1007/s00167-019-05477-4.

Waugh N, Mistry H, Metcalfe A, Loveman E, Colquitt J, Royle P, Smith NA, Spalding T. Meniscal allograft transplantation after meniscectomy: clinical effectiveness and cost-effectiveness. Knee Surg Sports Traumatol Arthrosc 2019/27/1825-46 doi.org/10.1007/s00167-019-05504-4

Waugh N, Mistry H. A brief introduction to health economics. Knee Surg Sports Traumatol Arthrosc. 2019/27/1704-1707. doi: 10.1007/s00167-019-05372-y.

Mistry H, Metcalfe A, Colquitt J, Loveman E, Smith NA, Royle P, Waugh N. Autograft or allograft for reconstruction of anterior cruciate ligament: a health economics perspective. Knee Surg Sports Traumatol Arthrosc. 2019/27/1782-90. doi: 10.1007/s00167-019-05436-z.

Mistry H, Metcalfe A, Smith N, Loveman E, Colquitt J, Royle P, Waugh N. The cost-effectiveness of osteochondral allograft transplantation in the knee. Knee Surg Sports Traumatol Arthrosc. 2019/27/1739-53. doi: 10.1007/s00167-019-05392-8.

Acknowledgments

Our review of the use of allografts in knee reconstructions was funded by the European Society of Sport Traumatology, Knee Surgery and Arthroscopy.