Pathological Rupture of the Quadriceps Tendon in a Patient With Osteogenesis Imperfecta With Leg-length Discrepancy: A Case Report.

Quadriceps tendon rupture is typically caused by severe trauma, such as a fall, leading to substantial restriction of knee joint movements. However, pathological ruptures (one third of all quadriceps ruptures) can occur spontaneously or caused by minor trauma. Pathological ruptures are usually caused by chronic systemic diseases, such as systemic lupus erythematosus, chronic renal failure, and rheumatoid arthritis, and rarely by osteogenesis imperfecta (OI), a genetic disorder that affects the musculoskeletal system. Defective type 1 collagen formation in OI leads to bone fragility, ligamentous laxity, tendon rupture, and short stature. Here, we report the case of a 55-year-old man diagnosed with OI who experienced a pathological rupture of the right quadriceps tendon. The patient also had a leg-length discrepancy in the left leg due to the malunion of several femoral fractures. The rupture was repaired using the Krackow suture technique. The patient regained preinjury range of motion within 3 months postoperatively and could walk without pain.