From wheelchair to walking: first reported case in Saudi Arabia of transformative orthopedic surgery in a patient with spondyloepimetaphyseal dysplasia with joint laxity type 3 due to EXOC6B mutation-a case report.

backgroundSpondyloepimetaphyseal dysplasia with joint laxity type 3 (SEMD-JL3) is a rare autosomal-recessive skeletal disorder caused by pathogenic variants in the EXOC6B gene. It is characterized by abnormal bone and joint development, resulting in generalized joint laxity, recurrent dislocations, and short stature from early childhood. CASE PRESENTATION: We report the case of a 16-year-old Saudi girl with severe bilateral hip and knee involvement since early childhood. She was non-ambulatory and wheelchair-dependent prior to intervention. Following whole-genome sequencing, a pathogenic EXOC6B variant was identified, confirming the diagnosis of SEMD-JL3. A staged surgical plan was implemented, consisting of bilateral total hip arthroplasties (THA) followed by bilateral total knee arthroplasties (TKA). Postoperatively, the patient demonstrated marked pain reduction and improved mobility, ultimately regaining the ability to ambulate with support.

conclusionThis case represents the first documented report of SEMD-JL3 managed surgically in Saudi Arabia and highlights how individualized, staged orthopedic interventions can significantly improve function and quality of life in patients with rare skeletal dysplasias.