Stapes Surgery for Otosclerosis

The goal of stapes surgery is to restore normal transmission of acoustic vibrations to the cochlear fluid when stapes footplate fixation disrupts this process. Improved sound conduction significantly enhances quality of life by restoring auditory perception and enabling effective communication. The origins of stapedectomy trace back to 1892, when Frederick L Jack performed a bilateral procedure on a patient who reportedly retained hearing 10 years postoperatively. In the early 1950s, John J Shea Jr recognized the potential of stapes surgery and introduced the concept of using a prosthesis to replicate stapes function. On May 1, 1956, Dr Shea performed the first successful stapedectomy using a Teflon prosthesis in a patient with otosclerosis. The primary goal when operating on the stapes is to reestablish sound transmission through an ossicular chain stiffened by otosclerosis, a disease process characterized by absorption of compact bone and redeposition of spongiotic bone within the otic capsule. Otosclerosis is the most common cause of acquired conductive hearing loss (CHL) that results in stapes fixation. The condition presents as a progressive, insidious form of CHL. Affected individuals often experience difficulties with having conversations, particularly while chewing, and may perceive speech more clearly in noisy environments than in quiet ones—a phenomenon known as paracusis of Willis. Otoscopic examination may reveal a red blush or discoloration over the promontory of the basal turn of the cochlea in approximately 10% of cases. This finding, when it does not blanch with pneumatic otoscopy, is referred to as the "Schwartze sign." The absence of this sign does not exclude the diagnosis. In some cases, the sign only becomes apparent after elevation of the tympanomeatal flap and direct visualization of the middle ear cleft during surgery. As detailed in the review by Markou and Goudakos, the etiology of otosclerosis remains unknown, though both genetic and environmental factors are believed to contribute. Otosclerosis is classically inherited as an autosomal dominant trait with incomplete penetrance and is associated with 9 chromosomal loci, including and through . The disease primarily affects White individuals, comprising up to 12% of the population, although only 0.3% to 0.4% develop clinical symptoms. A sex-based predisposition has been observed, with a female-to-male ratio of 1.5:1 to 2:1, and pregnancy has been reported to accelerate hearing loss progression, suggesting a hormonal influence. Stapedectomy and stapedotomy address the CHL associated with otosclerosis by reestablishing transmission of acoustic energy through the stapes footplate to the oval window and subsequently to the perilymph in the scala vestibuli. Procedural success is typically assessed by the degree of air-bone gap (ABG) closure on audiometric evaluation. The ABG is calculated as the difference between air and bone conduction thresholds, using a pure-tone average across 0.5, 1, 2, and 4 kHz. Surgical intervention is usually considered when the ABG measures 20 to 30 dB, although patients with smaller gaps may also benefit. The primary goal is to reduce the ABG to 10 dB or less. Multiple studies have compared stapedectomy, which involves the removal of the stapes superstructure and all or most of the footplate, with stapedotomy. This procedure entails removing the superstructure and creating a small fenestra in the footplate to accommodate a prosthesis that transmits vibrations from the incus to the oval window membrane. Results from these studies have found no significant difference between the 2 techniques in achieving closure of the ABG. The most reliable predictors of successful surgical outcomes are the surgeon’s experience and willingness to adopt evolving techniques and technologies in stapes surgery.