Supplementary file 1_Case Report: Arthroscopic synovectomy and loose body removal for charcot knee in an adolescent with congenital insensitivity to pain with anhidrosis.pdf

Charcot neuroarthropathy (CN) of the knee in adolescents with congenital insensitivity to pain with anhidrosis (CIPA) is exceptionally rare and presents unique diagnostic and therapeutic challenges. We present the case of a 13-year-old girl with genetically confirmed CIPA and a two-year history of recurrent knee swelling, effusion, and functional limitation. Imaging revealed intra-articular loose bodies and osteochondral defects in the left knee. The patient was treated with arthroscopic synovectomy and removal of a large loose body via standard anteromedial, anterolateral, and posteromedial portals. Intraoperative findings included extensive synovial proliferation and a 3 × 4 cm mobile loose body. Postoperatively, the patient followed a function-based rehabilitation protocol. At 30 days, she ambulated without assistive devices. At 1-year and 17-month follow-up, she demonstrated sustained clinical improvement with increased Lysholm score (from 50 to 82) and enhanced range of motion (from 10°–110° to 0°–140°). Magnetic resonance imaging (MRI) confirmed joint stability and absence of recurrent loose bodies. This case illustrates that arthroscopic management may offer a joint-preserving option in carefully selected adolescents with CIPA-associated Charcot knee and persistent mechanical symptoms. The approach may function as a temporizing measure to delay more invasive reconstructions. Adherence to protective joint education and close follow-up are essential in this population. This report highlights the clinical presentation, technical considerations, and mid-term outcomes of arthroscopic intervention in a rare neuropathic knee condition.