Early outcomes of an anatomic trochlear-cutting patellofemoral arthroplasty: patient selection is key

Abstract

Purpose The purpose of this study was to report outcomes of a recent anatomic trochlear‐cutting patellofemoral arthroplasty (PFA) system at > 3 years. The hypothesis was that its functional scores and revision rates would be at least equivalent to those reported for other ‘trochlear‐cutting’ implants in the literature. Methods Twenty‐eight consecutive patients that had received PFA using the same anatomic trochlear‐cutting implant (KneeTech PFJ, Corin‐Tornier, Montbonnot, France) with a dome‐shaped patellar button and had systematic lateral facetectomy without lateral release were enrolled. Radiographic parameters collected pre‐operatively included: trochlear dysplasia type and patellar height, TT–TG, patellar tilt and shape. Clinical scores collected pre‐operatively and at > 3 years included: Oxford Knee Score (OKS) and Knee Society Score (KSS). Results The initial cohort comprised 23 women (82%) and five men (18%), aged 63.3 ± 14.7 years, of which 23 had trochlear dysplasia (82%). One patient (4%) could not be reached, and three (11%) were revised to TKA due to arthritic progression, aged 77, 80 and 83 years at index operation, only one of which had trochlear dysplasia (type A). At final follow‐up, none of the remaining 24 patients had complications; their OKS was 35.0 ± 10.3 and KSS symptoms and function were 19.8 ± 5.0 and 71.7 ± 13.6. Conclusion The anatomic trochlear‐cutting PFA granted satisfactory scores and prevented mechanical complications, but the high incidence of early revisions, all due to spread of arthritis hence to improper patient selection. PFA should be restricted to patients with trochlear dysplasia, in whom arthritis was triggered by patellar instability and maltracking rather than degenerative or age‐related diseases. Study design Retrospective case series, Level IV.

Intraarticular injection of microfragmented adipose tissue plus arthroscopy in isolated primary patellofemoral osteoarthritis is clinically effective and not affected by age, BMI, or stage of osteoarthritis

“…Early (stage 1–2 according to Iwano classification) isolated primary PFOA results are often refractory to the conservative treatment (physiotherapy, intraarticular viscosupplementation, and/or PRP), whereas nonreplacement surgery (arthroscopic debridement with or without lateral release, chondroplasty, lateral facetectomy) results are often ineffective in patients with moderate (stage 3) isolated primary PFOA. Certainly, in all those patients, arthroplasty surgery [patellofemoral arthroplasty (PFA) or total knee arthroplasty (TKA)] appears premature and is reserved for patients with severe (stage 4) PFOA [ 8 , 9 , 33 ]. The 23 patients of this study presented early (70%) or moderate (30%) PFOA, whereas none of the patients presented a stage 4 (bone-on-bone) patellofemoral degeneration.…”

Patellofemoral arthroplasty: expert opinion

“…The second and third generation PFA are reported to have satisfactory patient reported and functional outcomes and reduction in mechanical complications [ 2 , 4 , 11 , 28 ].…”

Treatment of Unicompartmental Cartilage Defects of the Knee with Unicompartmental Knee Arthroplasty, Patellofemoral Partial Knee Arthroplasty or Focal Resurfacing

“…A recent study showed similar patient-reported outcomes after second-generation PFJR and TKA if patients were selected appropriately [ 74 ]. Dejour et al [ 75 ] postulated that early revision surgeries due to OA progression only occurred when patients were selected improperly. They also showed that PFJR should be restricted to patients that developed patellofemoral OA due to instability or maltracking of the patella and that it should not be used in patients with degenerative patellofemoral OA.…”