Operative Treatment Options for Patellofemoral Arthritis: An Expert Recommendation of the AGA Patellofemoral Committee

Abstract

Background: The operative therapy of patellofemoral arthritis requires an individual approach depending on the underlying injury. However, the literature lacks recommendations for its course of action. Purpose: To generate an expert recommendation of therapy for different patellofemoral abnormalities in patients suffering from isolated patellofemoral arthritis. Study Design: Consensus statement. Methods: To generate recommendations, the AGA Patellofemoral Committee performed a consensus process using the Delphi method based on the available literature on isolated patellofemoral arthritis. Results: In most statements and recommendations, a high percentage of consensus could be found. However, also in the expert group of the AGA Patellofemoral Committee, some controversies on the treatment of patellofemoral arthritis exist. Conclusion: The operative therapy of isolated patellofemoral arthritis is a challenging topic that leads to controversial discussions, even in an expert group. With this consensus statement of the AGA Patellofemoral Committee, recommendations on different operative treatment options were able to be generated, which should be considered in clinical practice.

Modern Patellofemoral Arthroplasty

“…Contraindications to PFA include inflammatory arthropathy, uncorrected patella instability or malalignment, uncorrected tibiofemoral or mechanical malalignment (valgus >8° and varus >5°), and infection and loss of knee range of motion (fixed flexion contracture or flexion <110°) 30,31,34,38-42 . A recent consensus statement from the AGA Patellofemoral Committee on the operative treatment options for patellofemoral OA (PFOA) agreed that PFA should be performed in the case of advanced PFJ degenerative change with minimal degenerative change in the tibiofemoral compartments and failed nonoperative therapy for a minimum of 3 to 6 months 35 .…”

“…The anatomy of the knee is variable between individuals and intimately affects PFA outcome. Preoperative planning is recommended and should assess patella height, tibial tubercle to trochlear groove (TT-TG) distance, genu varum or valgum, and both femoral and tibial rotation 35 . Isolated PFOA is associated with higher rates of trochlear internal rotation and dysplasia 47 .…”

“…The AGA Patellofemoral Committee concluded that surgeons should use an onlay prosthesis for severe trochlear dysplasia and address mild femoral rotational malalignment, aim to achieve 3° of external rotation between the posterior condylar axis and anterior aspect of the prosthesis, and that the femoral prosthesis should be placed on the lateral aspect of the femur while avoiding overhang. Regarding the patella itself, they recommend a symmetric patella button placed on the medial aspect of the patella and a partial lateral facetectomy if the button does not cover the entirety of the patella 35 .…”

“…Table II outlines the relevant factors that, according to the literature, affect the outcome of PFA and potential ways to improve modifiable risk factors for a poor outcome. The classic indication for PFA is degenerative or posttraumatic arthritis confined to the patellofemoral joint causing severe pain and functional impairment that is not manageable by conservative measures 30-36 . Several authors have emphasized the importance of patient selection with the best patient outcomes being reported in a refined patient group 31,37 .…”

“…Worse outcomes were seen with malalignment or an increased Q angle 33 . The AGA Patellofemoral Committee suggests that the surgeon consider concomitant procedures if the patella is not central or a severe lateral patella tilt is noted after implantation of the PFA 35 . The importance of improving patellofemoral mechanics and tracking cannot be emphasized enough as the underlying pathologic changes are often secondary to anatomic abnormalities within the PFJ, which must be corrected as well as resurfacing the articular surfaces.…”