Variations in Laxity After Total Knee Arthroplasty Do Not Affect Prosthesis-generated Noise.

BACKGROUND

Prosthesis-generated noise following total knee arthroplasty (TKA) may affect patient satisfaction and function. The advent of robotic-assisted TKA (RA-TKA) allows for objective knee laxity measurements. The purpose of this study was to compare knee laxity measurements in RATKA patients with and without reported noise generation.

MATERIALS AND

METHODS

This was a single-institution, retrospective study of 133 patients who underwent primary unilateral RA-TKA from 2018 to 2021. Patients completed a survey consisting of four Likert scale questions related to prosthesis noise, the Forgotten Joint Score (FJS), and the Knee Injury and Osteoarthritis Outcome Score-Joint Replacement (KOOS, JR). Intraoperative laxity measures were obtained from the robotic system and compared between patients who did and did not report noise generation.

RESULTS

Of the patients, 57.9% did not report noise and 42.1% did report noise. There were no significant differences in medial extension laxity (1.7 mm vs 1.8 mm; P = .454), lateral extension laxity (1.9 mm vs 2.0 mm; P = .567), medial flexion laxity (2.2 mm vs 2.0 mm; P = .419), and lateral flexion laxity (2.7 mm vs 2.9 mm; P = .307). Compared to patients who reported noise, those who did not had significantly higher satisfaction (94.8% vs 37.5%; P < .001), postoperative KOOS, JR scores (79.2% vs 69.7%; P = .005), and FJSs (60.3 vs 44.2; P = .002). Patients who felt noise also had higher satisfaction (90.0% vs 41.5%, P < .001).

CONCLUSION

While prosthesis-generated noise symptoms affect satisfaction following TKA, variability in knee laxities does not seem to significantly affect whether a patient will experience noise following TKA.