STAPES SURGERY IN OSTEOGENESIS IMPERFECTA PATIENTS

Osteogenesis imperfecta (OI), or the Van der Hoeve-de Kleyn syndrome, is a heterogeneous group of connective tissue disorders. The key featu res in this disease are bone fragility with a tendency to spontaneous fractures and deformations. The classical triad of symptoms involves a conductive and/or sensorineural hearing impairment together with a te ndency to spontaneous bone fractures and blue sclerae. Between January 1988 and December 1994, ear surgery was performed on eight ears of si x OI patients who presented with mixed hearing loss preoperatively. Pa thological changes observed in the middle ear were atrophy and/or frac tures of the stapedial crura in combination with thickening and fixati on of the stapes footplate. Partial stapedectomy was performed in seve n cases and a neo-window was created in the promontory of one patient when an overhanging facial canal obscured visualization of the oval wi ndow niche. Pre- and postoperative bone conduction thresholds did not differ in any of the patients. Postoperatively, mean values of the air -bone gap in the main speech frequency range were below 10 dB. Functio nal results following stapes surgery in patients with otosclerosis dur ing the same time interval (n = 857) did not differ significantly. The se data indicate that stapes surgery in OI patients can be performed w ith the same functional predictability as in otosclerosis patients, ev en though the underlying etiology is considerably different.