Effect of Using Mobile Bearing on the Incidence of Anterior Knee Pain in Primary Total Knee Arthroplasty Without Patellar Resurfacing: A Randomized Controlled Clinical Trial.

BACKGROUND

Anterior knee pain (AKP) remains a major complication following total knee arthroplasty (TKA). Mobile bearing (MB) is an alternative to fixed bearing (FB), supposing it has theoretical advantages in increasing the range of motion, reducing wear, and reducing anterior knee pain incidence when the patella is not resurfaced.

MATERIALS & METHODS: This research is a double-blinded, randomized controlled clinical trial, conducted between July 2021 and March 2024. It included 76 patients who underwent unilateral primary total knee arthroplasty without patellar resurfacing. Patients were randomized into 2 groups; the first used a MB, and the second used a FB. Patients were followed for 18 months. The 2 groups were compared based on the incidence and severity of anterior knee pain, knee range of motion, Knee Society Score, and patient satisfaction assessment according to the Forgotten Joint Scale (FJS-12).

RESULTS

AKP occurred in 5 patients in the MB group and 6 in the FB group. We did not find a statistically significant difference between the 2 groups (P = 0.744). However, the severity of anterior knee pain according to the Visual Analog Scale (VAS) in the MB group was statistically significantly lower compared with the FB group (p < 0.05). We did not observe any statistically significant differences between the 2 groups in clinical and functional outcomes, or the complications rate.

CONCLUSION

Using a MB does not reduce the incidence of anterior knee pain after primary total knee arthroplasty without patellar resurfacing. However, it could contribute to reducing the severity of this pain if it occurs for other reasons. Therefore, we recommend conducting further studies to determine the causes of anterior knee pain.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.