Longitudinally Extensive Transverse Myelitis and Bilateral Pellegrini-Stieda Syndrome Coexisting in a Young Woman With Systemic Lupus Erythematosus: Report of a Rare Case.

Systemic lupus erythematosus is a complex autoimmune disease, with longitudinally extensive transverse myelitis representing a rare yet severe neuropsychiatric manifestation that can be its inaugural presentation. While Pellegrini-Stieda disease, characterized by ossification of the medial collateral ligament of the knee, is typically a post-traumatic condition, its occurrence in the context of neurological injury is extremely uncommon. We report a rare case of a 31-year-old woman with systemic lupus erythematosus presenting with longitudinally extensive transverse myelitis and paraplegia. This neurological manifestation was later complicated by bilateral Pellegrini-Stieda disease, an unusual musculoskeletal manifestation likely triggered by neurogenic mechanisms related to prolonged immobilization. Her symptoms improved with Extracorporeal Shockwave Therapy, a case that underscores the importance of recognizing atypical joint complications like Pellegrini-Stieda disease in immobilized Systemic lupus erythematosus patients, advocating for early multidisciplinary intervention. This rare association highlights the need for early rehabilitation strategies to prevent such complications.