Efficacy of denervation for osteoarthritis in the proximal interphalangeal joint (DOP): protocol of a randomized controlled trial.

Background: Osteoarthritis (OA) contributes increasingly to disability worldwide. There is ample high-quality research on the treatment of knee and hip OA, whereas research on surgical and non-surgical treatment in hand OA is sparse. Limited evidence suggests that education and exercise may improve pain, function, stiffness, and grip strength in hand OA. The established surgical options in hand OA have disadvantages. Prostheses preserve motion but have a high complication rate, whereas fusions decrease function due to limited movement. There is an unmet need for high-quality research on treatment options for hand OA and a need for the development of effective and safe movement-sparing therapies. This study aims to compare the effects of a motion-preserving surgical treatment (denervation of the proximal interphalangeal (PIP) joint) with a patient education and exercise program on patient-reported outcomes and objective function in painful PIP OA.

Methods: In this parallel-group, two-armed, randomized, controlled superiority trial (RCT), 90 participants are assigned to surgical PIP joint denervation or education and exercise. Pain on load 1 year after intervention is the primary outcome measure. Secondary outcome measures include pain at rest, Patient-Rated Wrist and Hand Evaluation (PRWHE), HQ8 score, EQ5D-5L, objective physical function, complications, two-point discrimination, Mini Sollerman, consumption of analgesics, and the need for further surgery. Assessments are performed at baseline, 3 and 6 months, and 1 year after intervention.

Discussion: There are no previous RCTs comparing surgical and non-surgical treatment in PIP OA. If patient education plus exercise or PIP denervation improve function, these treatments could be implemented as first-line treatment options in PIP OA. However, if denervation does not achieve better results than non-surgical treatment, it is not justified to use in PIP OA.

Trial Registration: Prospectively registered in ClinicalTrials.gov (NCT05980793) on 8 August 2023. URL https://classic.

Clinicaltrials: gov/ct2/show/NCT05980793 .