PMID- 35315804 OWN - NLM STAT- MEDLINE DCOM- 20220822 LR - 20230902 IS - 1528-1132 (Electronic) IS - 0009-921X (Print) IS - 0009-921X (Linking) VI - 480 IP - 9 DP - 2022 Sep 1 TI - Patellofemoral Arthroplasty Results in Better Time-weighted Patient-reported Outcomes After 6 Years than TKA: A Randomized Controlled Trial. PG - 1707-1718 LID - 10.1097/CORR.0000000000002178 [doi] AB - BACKGROUND: In a previous study, we reported the 2-year outcomes of a parallel-group, equivalence, randomized controlled trial (RCT; blinded for the first year) comparing patellofemoral arthroplasty (PFA) and TKA for isolated patellofemoral osteoarthritis (PF-OA). We found advantages of PFA over TKA for ROM and various aspects of knee-related quality of life (QOL) as assessed by patient-reported outcomes (PROs). Register data show increases in PFA revision rates from 2 to 6 years after surgery at a time when annual TKA revision rates are decreasing, which suggests rapidly deteriorating knee function in patients who have undergone PFA. We intended to examine whether the early advantages of PFA over TKA have deteriorated in our RCT and whether revision rates differ between the implant types in our study after 6 years of follow-up. QUESTIONS/PURPOSES: (1) Does PRO improvement during the first 6 postoperative years differ between patients who have undergone PFA and TKA? (2) Does the PRO improvement at 3, 4, 5, and 6 years differ between patients who have undergone PFA and TKA? (3) Do patients who have undergone PFA have a better ROM after 5 years than patients who have had TKA? (4) Does PFA result in more revisions or reoperations than TKA during the first 6 postoperative years? METHODS: We considered patients who had debilitating symptoms and PF-OA as eligible for this randomized trial. Screening initially identified 204 patients as potentially eligible; 7% (15) were found not to have sufficient symptoms, 21% (43) did not have isolated PF-OA, 21% (43) declined participation, and 1% (3) were not included after the target number of 100 patients had been reached. The included 100 patients were randomized 1:1 to PFA or TKA between 2007 and 2014. Of these, 9% (9 of 100) were lost before the 6-year follow-up; there were 12% (6 of 50) and 0% (0 of 50) deaths (p = 0.02) in the PFA and TKA groups, respectively, but no deaths could be attributed to the knee condition. There were no differences in baseline parameters for patients who had PFA and TKA, such as the proportion of women in each group (78% [39 of 50] versus 76% [38 of 50]; p > 0.99), mean age (64 +/- 9 years versus 65 +/- 9 years; p = 0.81) or BMI (28.0 +/- 4.7 kg/m 2 versus 27.8 +/- 4.1 kg/m 2 ; p = 0.83). Patients were seen for five clinical follow-up visits (the latest at 5 years) and completed 10 sets of questionnaires during the first 6 postoperative years. The primary outcome was SF-36 bodily pain. Other outcomes were reoperations, revisions, ROM, and PROs (SF-36 [eight dimensions, range 0 to 100 best, minimum clinically important difference MCID 6 to 7], Oxford Knee Score [OKS; one dimension, range 0 to 48 best, MCID 5], and Knee Injury and Osteoarthritis Outcome Score [KOOS; five dimensions, range 0 to 100 best, MCID 8 to 10]). Average PRO improvements over the 6 years were determined by calculating the area under the curve and dividing by the observation time, thereby obtaining a time-weighted average over the entire postoperative period. PRO improvements at individual postoperative times were compared for the patients who had PFA and TKA using paired t-tests. Range of movement changes from baseline were compared using paired t-tests. Reoperation and revision rates were compared for the two randomization groups using competing risk analysis. RESULTS: Patients who underwent PFA had a larger improvement in the SF-36 bodily pain score during the first 6 years than those who underwent TKA (35 +/- 19 vs. 23 +/- 17; mean difference 12 [95% CI 4 to 20]; p = 0.004), and the same was true for SF-36 physical functioning (mean difference 11 [95% CI 3 to 18]; p = 0.008), KOOS Symptoms (mean difference 12 [95% CI 5 to 20]; p = 0.002), KOOS Sport/recreation (mean difference 8 [95% CI 0 to 17]; p = 0.048), and OKS (mean difference 5 [95% CI 2 to 8]; p = 0.002). No PRO dimension had an improvement in favor of TKA. At the 6-year time point, only the SF-36 vitality score differed between the groups being in favor of PFA (17 +/- 19 versus 8 +/- 21; mean difference 9 [95% CI 0 to 18]; p = 0.04), whereas other PRO measures did not differ between the groups. At 5 years, ROM had decreased less from baseline for patients who underwent PFA than those who had TKA (-4 degrees +/- 14 degrees versus -11 degrees +/- 13 degrees ; mean difference 7 degrees [95% CI 1 degrees to 13 degrees ]; p = 0.02), but the clinical importance of this is unknown. Revision rates did not differ between patients who had PFA and TKA at 6 years with competing risk estimates of 0.10 (95% CI 0.04 to 0.20) and 0.04 (95% CI 0.01 to 0.12; p = 0.24), respectively, and also reoperation rates were no different at 0.10 (95% CI 0.04 to 0.20) and 0.12 (95% CI 0.05 to 0.23; p = 0.71), respectively. CONCLUSION: Our RCT results show that the 2-year outcomes did not deteriorate during the subsequent 4 years. Patients who underwent PFA had a better QOL throughout the postoperative years based on several of the knee-specific outcome instruments. When evaluated by the 6-year observations alone and without considering earlier observations, we found no consistent difference for any outcome instruments, although SF-36 vitality was better for patients who underwent PFA. These combined findings show that the early advantages of PFA determined the results by 6 years. Our findings cannot explain the rapid deterioration of results implied by the high revision rates observed in implant registers, and it is necessary to question indications for the primary procedure and subsequent revision when PFA is in general use. Our data do not suggest that there is an inherent problem with the PFA implant type as otherwise suggested by registries. The long-term balance of advantages will be determined by the long-term QOL, but based on the first 6 postoperative years and ROM, PFA is still the preferable option for severe isolated PF-OA. A possible high revision rate in the PFA group beyond 6 years may outweigh the early advantage of PFA, but only detailed analyses of long-term studies can confirm this. LEVEL OF EVIDENCE: Level I, therapeutic study. CI - Copyright (c) 2022 by the Association of Bone and Joint Surgeons. FAU - Odgaard, Anders AU - Odgaard A AUID- ORCID: 0000-0002-4841-518 AD - Department of Orthopaedic Surgery and Department of Clinical Medicine, Rigshospitalet - Copenhagen University Hospital, University of Copenhagen, Copenhagen, Denmark. FAU - Kappel, Andreas AU - Kappel A AD - Department of Orthopaedic Surgery, Aalborg University Hospital, Aalborg, Denmark. FAU - Madsen, Frank AU - Madsen F AD - Department of Orthopaedic Surgery, Aarhus University Hospital, Aarhus, Denmark. FAU - Kristensen, Per Wagner AU - Kristensen PW AD - Department of Orthopaedic Surgery, Vejle Hospital, University of Southern Denmark, Vejle, Denmark. FAU - Stephensen, Snorre AU - Stephensen S AD - Department of Orthopaedic Surgery, Copenhagen University Hospital Gentofte, Hellerup, Denmark. FAU - Attarzadeh, Amir Pasha AU - Attarzadeh AP AD - Department of Orthopaedic Surgery, Zealand University Hospital, Koge, Denmark. LA - eng SI - ClinicalTrials.gov/NCT01326156 PT - Journal Article PT - Randomized Controlled Trial DEP - 20220321 PL - United States TA - Clin Orthop Relat Res JT - Clinical orthopaedics and related research JID - 0075674 SB - IM ECI - Clin Orthop Relat Res. 2023 Feb 1;481(2):416-417. PMID: 36516356 EIN - Clin Orthop Relat Res. 2023 Jul 1;481(7):1455-1457. PMID: 37352486 MH - Aged MH - *Arthroplasty, Replacement, Knee MH - Female MH - Humans MH - *Knee Prosthesis MH - Middle Aged MH - *Osteoarthritis, Knee/etiology/surgery MH - Pain/etiology MH - Patient Reported Outcome Measures MH - Quality of Life MH - Reoperation MH - Treatment Outcome PMC - PMC9384928 COIS- All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research (R) editors and board members are on file with the publication and can be viewed on request. EDAT- 2022/03/23 06:00 MHDA- 2022/08/23 06:00 PMCR- 2023/09/01 CRDT- 2022/03/22 12:11 PHST- 2021/08/30 00:00 [received] PHST- 2022/02/24 00:00 [accepted] PHST- 2022/03/23 06:00 [pubmed] PHST- 2022/08/23 06:00 [medline] PHST- 2022/03/22 12:11 [entrez] PHST- 2023/09/01 00:00 [pmc-release] AID - 00003086-202209000-00016 [pii] AID - CORR-D-21-01298 [pii] AID - 10.1097/CORR.0000000000002178 [doi] PST - ppublish SO - Clin Orthop Relat Res. 2022 Sep 1;480(9):1707-1718. doi: 10.1097/CORR.0000000000002178. Epub 2022 Mar 21.