BACKGROUND
Knee osteoarthritis (KOA) may contribute to physical frailty through chronic pain, reduced gait speed, and decreased activity. Cooled radiofrequency ablation (CRFA) is a minimally invasive treatment for chronic KOA pain, but longitudinal changes in pain, rehabilitation experience, and frailty after CRFA are not fully described.
CASE REPORT
A 74-year-old woman with right KOA (Kellgren-Lawrence grade II) had experienced pain while walking for 5 years despite pharmacotherapy and intra-articular hyaluronic acid injections. Before CRFA, walking pain was 3.6 cm (visual analog scale score), gait speed was 0.92 m/s, and she was physically prefrail according to the revised Japanese version of the Cardiovascular Health Study criteria. CRFA was performed on the right superolateral, superomedial, and inferomedial genicular nerves; lifestyle guidance was initiated before treatment. At 1 month, walking pain decreased to 0.0 cm, gait speed improved to 1.11 m/s, and frailty status changed to robust. At 3 months, pain recurred after sitting in the seiza position, and reduced grip strength led to reclassification as physically prefrail. Seven 40-minute supervised outpatient rehabilitation sessions were provided once every 2 weeks from 3 to 6 months; they included multicomponent exercise, home exercise instruction, and reinforced lifestyle guidance. At 6 months, pain and grip strength improved. Robust status was restored and maintained at 12 months.
CONCLUSIONS
This case suggests that frailty status can change with pain relief, pain recurrence, and staged rehabilitation after CRFA. It generates the hypotheses that frailty monitoring may be a relevant longitudinal outcome after CRFA and that rehabilitation after pain relief may support sustained functional recovery in selected patients.

Keywords: Frailty; Knee; Rehabilitation