November 03, 2020
2 min read
Patellofemoral OA did not affect preoperative outcome measures in medial, lateral OA
Preoperative knee-specific and generic patient-reported outcome measures were not affected by the presence of patellofemoral osteoarthritis among patients with medial or lateral OA, according to results from the Virtual EFORT Congress.
Using preoperative anterior-posterior and lateral/sunrise radiographs with Kellgren-Lawrence grade 3 or 4 and joint space width of less than 2.5 mm, Veronique Vestergaard, MD, PhD, and colleagues categorized 384 patients who underwent total knee arthroplasty for compartmental OA into a medial OA group, medial with patellofemoral OA group, lateral OA group, lateral with patellofemoral OA group, medial and lateral OA (bi-compartmental) group, or medial and lateral with patellofemoral OA (tri-compartmental) group.
“The KOOS, [EuroQol-5D] EQ-5D weighted and the EQ-5D VAS were collected [preoperatively] and 1 and 3 years postoperatively,” Vestergaard said in her presentation. “Multivariable regression models were used to adjust for potential confounders.”
Vestergaard noted patellofemoral OA had no effect on preoperative KOOS and EQ-5D scores. Patients with bi- and tri-compartmental OA had less pain preoperatively, higher daily function both preoperatively and 1 year postoperatively, and higher sports activity at 1 year postoperatively vs. patients with medial OA with or without patellofemoral OA, according to Vestergaard. She added patients with lateral OA with or without patellofemoral OA had more symptoms, more pain, lower daily function, lower quality of life and lower general health at 3 years postoperatively compared with patients with medial OA with or without patellofemoral OA.
“Patients with less common osteoarthritis patterns thus demonstrate surgical challenges,” Vestergaard said. “Further development of indications for and correct timing for TKA in different patient subgroups is warranted.”
Perspective
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Vestergaard and colleagues, in their international multicenter prospective study, analyzed 384 patients undergoing total knee arthroplasty (TKA) between 2011 and 2014. One of the questions raised in this study is whether patellofemoral osteoarthritis (PFOA) affect preoperative knee injury and osteoarthritis (OA) outcome scores in TKA. In other words, does PFOA influences outcomes as much as medial and lateral compartmental osteoarthritis do? They conclude that PFOA does not seem to affect preoperative Knee Injury and Osteoarthritis Outcome Score (KOOS) in patients with medial and/or lateral OA, challenging the importance of PFOA in TKA.
In total, 292 of 384 patients underwent patella resurfacing. That is, 76% of patients underwent patella resurfacing, while only 17.4% of patients had PFOA. This percentage of patellar resurfacing is in line with the 2019 patellar resurfacing figures (72.7% in 2019) published in the Australian Orthopaedic Association National Joint Replacement Registry (Annual Report 2020). Therefore, we are possibly over-indicating the patella resurfacing in TKA surgery. This is in accordance with the study by Hamilton and colleagues in 2017 that has demonstrated that anterior knee pain and evidence of PFOA should not be considered contraindications to mobile-bearing unicompartmental knee arthroplasty.
In my eyes, in the patellofemoral joint, patellofemoral congruence and smooth kinematics are much more important than normal articular cartilage. Patellofemoral resurfacing techniques including patellofemoral arthroplasty are indicated only in very selected cases. All of this agrees with the trends in TKA in some countries such as Sweden. According to the Swedish Knee Arthroplasty register (Annual Report 2020), the proportion of resurfacing of the patella has been reduced below 2.7% in 2019. But, what is really relevant from the clinical point of view is that a resurfacing technique is not a substitute for patellofemoral maltracking correction.
Vicente Sanchis-Alfonso, MD, PhD
Consultant orthopaedic surgeon
Hospital Arnau de Vilanova
Valencia, Spain
Disclosures: Sanchis-Alfonso reports no relevant financial disclosures.
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Source:
Vestergaard V, et al. Paper 1010. Presented at: Virtual EFORT Congress; Oct. 28-30, 2020.
Disclosures:
Vestergaard reports no relevant financial disclosures.
