What’s New in Adult Reconstructive Knee Surgery

Abstract

The COVID-19 pandemic has inflicted challenges that have affected every facet of our personal and professional lives1,2. During this time, the orthopaedic community has demonstrated resilience, persistence, and innovation in providing care to our patients3. We are called to redouble our efforts as knee arthroplasty surgeons to continue to provide safe and efficient value-driven care. Osteoarthritis of the Knee: Nonsurgical Management As the incidence of knee osteoarthritis (OA) increases4, patient wait times continue to increase for arthroplasty. For 12% of these patients in 1 recent study, their health (as measured by the EuroQol 5-Dimension [EQ-5D]) was actually “worse than death.”5 However, in a separate report, patients receiving physical therapy in the setting of knee OA, involving exercise and manual therapy, received benefit at 1 year (90% attained the minimally clinical important difference [MCID] in the Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] score)6. If patients with obesity and diabetes7 begin intensive lifestyle changes before experiencing knee pain, some can prevent the need for total knee arthroplasty (TKA): 29% in 1 recent report8. Considerable debate continues to exist regarding the effectiveness of platelet-rich plasma, stem cell, and hyaluronic acid injections9,10. Operative Management: Non-Arthroplasty Options High Tibial Osteotomy With the availability of reliable arthroplasty options for unicompartmental OA, the decision for high tibial osteotomy (HTO) continues to be under increased scrutiny. A meta-analysis found a rate of conversion to TKA of 13% at a mean of 71 months11. In a prospective comparative study, at 2 years, the rate of return to sport was 94.1% in a unicompartmental knee arthroplasty (UKA) group compared with 74.0% in the HTO group (p = 0.031)12. Conversion from UKA or HTO to TKA leads to longer operative time and an increased utilization rate of revision implants than with primary TKA (96.1 versus 90.0 minutes [p = 0.01]; and 8.5% versus 0.8% [p = 0.005], respectively)13. Risk and Health Policy To ensure fiscal soundness in orthopaedic practice, a complete understanding of cost variation will assist in appropriate risk adjustment for reimbursement in alternative payment models, which is critically important for orthopaedic practice in the U.S. Currently, the only risk adjustment provided for primary TKA has been the 469 DRG (Diagnosis-Related Group) code. Ryan et al. found that 17 comorbidities are predictive of increased cost for the TKA episode, but only 4 of them are predictive of MS (Medicare Severity)-DRG classification14. For the initial in-hospital costs during TKA, another recent study found that characteristics of the surgical episode (implants, operating room time, etc.) accounted for 35.3% of cost variation. Patient characteristics were markedly associated with discharge disposition15. In addition, an age of ≥72 years and increasing modified frailty index (mFI) score were associated with increased cost16. Furthermore, as the U.S. Centers for Medicare & Medicaid Services (CMS) has removed TKA from the Inpatient Only (IPO) list, a much larger number of those patients are now classified as “outpatient.” CMS has excluded outpatients from the CMS bundled-payment programs. This has led to confusion among surgeons and health-care systems. Without any change in quality, many programs have seen increased mean costs in their bundled-payment program, leading to financial loss17. This requires further intervention and guidelines by CMS to head off the negative implications of removing TKA from the IPO list. UKA Outcomes and Design As modern UKA implant designs mature, better long-term data emerge. The pooled 5 and 10-year survivorship of medial UKA in a meta-analysis of 26 studies was 95.3% and 91.3%, respectively18. Additionally, the presence of patellofemoral OA did not appear to affect the outcome of fixed-bearing UKA19. In a retrospective study of 308 media