A study depicted that in knee osteoarthritis patients with chronic pain, chemical neurolysis of genicular nerves with phenol offers remarkable improvement in pain and function for at least six months, with only minor and short-term adverse effects.

An open-label prospective cohort trial was conducted to determine the efficacy and safety of ultrasound‐guided chemical neurolysis for genicular nerves using phenol to manage patients suffering from chronic pain due to knee osteoarthritis.

The study cohort included 43 knee osteoarthritis individuals having pain intensity score (Numeric Rating Scale, NRS) ≥4, and pain duration of more than six months. Utilizing 1.5 ml of 0.25% bupivacaine, ultrasound‐guided diagnostic blocks of genicular nerves (inferomedial, superomedial, and superolateral) at each site were carried out.

Subjects who noted greater than 50% decline in NRS went on to undergo chemical neurolysis, utilizing 1.5 ml 7% glycerated phenol in each genicular nerve. The NRS and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were examined prior to the intervention and at two weeks, one, two, three, and six months after the intervention.

Improvement in knee pain intensity by NRS during the six months follow-up after chemical neurolysis with phenol was the primary endpoints and the adverse events incidence and WOMAC scores were the secondary endpoints.

At all the time points, an improvement in NRS and WOMAC scores were witnessed.  The mean pain intensity improved from 7.2 at baseline to 4.2 at six‐month follow-up. The composite WOMAC score improved from 48.7 at baseline to 20.7 at the six‐month follow up, as shown in the following table:

The noxious events did not persist beyond one month as shown in the following table:

Thus, chemical ablation of the genicular nerve with phenol appears to yield satisfactory outcomes in individuals suffering from knee osteoarthritis.