The use of patient-reported outcome measures to guide referral for hip and knee arthroplasty

Abstract

Aims To calculate how the likelihood of obtaining measurable benefit from hip or knee arthroplasty varies with preoperative patient-reported scores. Methods Existing UK data from 222,933 knee and 209,760 hip arthroplasty patients were used to model an individual’s probability of gaining meaningful improvement after surgery based on their preoperative Oxford Knee or Hip Score (OKS/OHS). A clinically meaningful improvement after arthroplasty was defined as ≥ 8 point improvement in OHS, and ≥ 7 in OKS. Results The upper preoperative score threshold, above which patients are unlikely to achieve any meaningful improvement from surgery, is 41 for knees and 40 for hips. At lower scores, the probability of improvement increased towards a maximum of 88% (knee) and 95% for (hips). Conclusion By our definition of meaningful improvement, patients with preoperative scores above 41 (OKS) and 40 (OHS) should not be routinely referred to secondary care for possible arthroplasty. Using lower thresholds would incrementally increase the probability of meaningful benefit for those referred but will exclude some patients with potential to benefit. The findings are useful to support the complex shared decision-making process in primary care for referral to secondary care; and in secondary care for experienced clinicians counselling patients considering knee or hip arthroplasty, but should not be used in isolation. Cite this article: Bone Joint J 2020;102-B(7):941–949.

Microfragmented Adipose Tissue Injection (MFAT) May Be a Solution to the Rationing of Total Knee Replacement: A Prospective, Gender-Bias Mitigated, Reproducible Analysis at Two Years

“…We set the upper threshold for analysis at OKS of >39. This has been shown to be the upper limit of preoperative score where patients can still have a clinically meaningful benefit from knee arthroplasty [ 8 ].…”

“…We set the third threshold on the OKS ≤ 27 points where patients have a ≥70% chance of improvement with a knee replacement [ 8 ]. In this analysis, we can assess the likely benefit of an intra-articular injection of MFAT for patients who are very likely to have an improvement following a TKR [ 10 ].…”

“…Although evidence behind this approach is still weak, it is likely to continue and become refined to address many of the criticisms against it [ 7 ]. A recent study has validated a model to link an individual's preoperative Oxford score to their probability of a meaningful improvement after arthroplasty and determined the effect of setting different and varying preoperative scores as thresholds for referral into secondary care [ 8 , 9 ]. By setting a threshold of 31 points on the OKS, they estimated that patients with a ≥70% chance of improvement would be identified.…”

“…By setting a threshold of 31 points on the OKS, they estimated that patients with a ≥70% chance of improvement would be identified. Thresholds of 25 and 36 points would identify patients with 80% and 50% chance of meaningful improvement, respectively [ 8 ]. However, by restricting access to knee replacement surgery to those with an OKS of <27 some 10% would be denied the procedure [ 10 ].…”

Patient-reported outcome measures used in patients undergoing total knee arthroplasty

“…PROMs have advantages over objective measurements because they: 1) largely eliminate clinicians’ biases and measure health status accurately from the patients’ perspective; 6 2) enable better detection of what patients account for, and help to address possibly modifiable factors; 7 3) aid the possibility of follow-up of patients regardless of their direct attendance; and 4) facilitate decision-making for surgical procedures. 8 , 9 …”