RESUMO
Objective:To investigate the early- and mid-term clinical, functional and radiographic outcomes of patellofemoral arthroplasty (PFA).Methods:A retrospective analysis was conducted in 64 patients (80 knees) who suffered from severe patellofemoral osteoarthritis (PFOA) and underwent PFA from January 2013 to December 2020. These patients were aged 60.50±8.82 (range from 27 to 82) years, including 9 males (12 knees) and 55 females (68 knees). All enrolled individuals presented typical PFOA. Unilateral PFA was performed in 48 cases, bilateral PFA in 16 cases, including one-stage PFA in 9 cases and two-stage PFA in 7 cases. The visual analogue scale (VAS), Hospital for Special Surgery (HSS) knee score and Oxford knee score (OKS) of patients with more than 5 years' follow-up were assessed to evaluate the clinical effects of PFA at the time before surgery, 1 year and 5 years after surgery. In addition, the patellar tilt angle (PTA) and hip-knee-ankle (HKA) angle were measured and analyzed to evaluate the improvement of patellar tracking and progression of tibiofemoral osteoarthritis, based on axial X-ray imaging (skyline view) of knee and the full length standing X-ray imaging of the lower limbs at before surgery and 5 years after surgery. Meanwhile, the complications of all patients that related to the operation were recorded.Results:A total of 64 patients were followed up for 4.31±1.79 (range, 1.5 to 8.2) years. Twenty-five patients (32 knees) who followed up more than 5 years were analyzed. The VAS, HSS and OKS improved from 5.91±0.82, 68.06±6.03 and 21.22±3.46 preoperatively to 0.88±1.01, 90.09±3.30 and 39.06±3.37 at 1 year after surgery, and to 0.41±0.76, 94.53±2.99 and 42.13±3.17 at 5 years after surgery, respectively ( F=89.38, 81.47, 56.73, P<0.001). Additionally, comparing to the preoperative radiological data, the patellar tract was improved with the PTA decreased from 8.21°±3.14° preoperatively to 3.58°±4.48°at 5 years after surgery ( t=4.96, P<0.001). The HKA angle changed from 179.01°±1.43° preoperatively to 178.77°±1.67° at 5 years follow up ( t=1.71, P=0.096). There was no case of prosthesis loosening or wear and no case of obvious progression of tibiofemoral osteoarthritis that needed revision in all patients. Conclusion:Satisfied early- and mid-term clinical outcomes could be achieved by PFA in treating severe PFOA patients. PFA could relieve pain and improve function of knee joint.