Comparative analysis of functional outcomes between cruciate-retaining and posterior-stabilized knee prostheses in...

Obesity is a well-recognized risk factor for knee osteoarthritis and contributes to the increasing demand for total knee arthroplasty (TKA). Excess body weight alters gait mechanics, increases joint loading, and accelerates degeneration, potentially compromising outcomes. Although cruciate-retaining (CR) and posterior-stabilized (PS) prostheses are widely used, their comparative outcomes in obese patients remain controversial. This study aimed to compare outcomes of CR versus PS prostheses in obese patients undergoing primary TKA.

A retrospective cohort study included 79 knees from 56 obese female patients (BMI > 30 kg/m²) who underwent cemented primary TKA between 2011 and 2017. All procedures were performed by a single surgeon using the Vanguard® Knee System. Patients were grouped according to implant design. Clinical outcomes were assessed using the visual analogue scale (VAS), Lysholm knee score, and Knee Society score (KSS). Radiological evaluation followed the Knee Society roentgenographic system.

The mean follow-up was 41.3 ± 20.8 months. Both groups showed significant postoperative improvement in all clinical scores (p < 0.01). The PS group achieved greater postoperative range of motion (ROM) (p = 0.035) and higher KSS-knee scores (p = 0.022). No significant differences were observed in VAS, Lysholm, or KSS-function scores. Radiolucent lines were noted in 8.9% of knees without migration or loosening. Prosthesis survival was 100% in both groups.

Both CR and PS implants yield satisfactory outcomes in obese patients undergoing TKA. PS designs may provide superior range of motion and functional recovery. Further prospective studies are needed to confirm these findings.