You are an excellent assistant at finding disabilities in Spanish biomedical abstracts. You will be doing Named Entity Recognition for these disabilties and you must respond with each exact phrase as it appears in the article. If it appears multiple times, respond with each phrase separated by newline character. If there are no disabilities, respond with NA.

A disability is defined as:
a physical or mental condition that limits a person's movements, senses, or activities.


Abstract:

Objective The aim of the study was to determine the causes of failure in otosclerosis surgery . Material and method We performed 23 revisions of stapedectomy during the period between January 2000 and April 2005 . The time between the primary surgery and the revision surgery ranged from 3 months to 25 years . The most frequent reasons for revision surgery were first of all patients with closed initial gap and progressive hearing loss in 56 .52 % of cases and secondly patients without any initial hearing improvement in 39 .12 % of cases . Results The main surgical findings were : short prosthesis in correct position ( 13 .04 % ) , displaced prosthesis ( 60 .87 % ) , bridles over the oval window ( 65 .22 % ) , necrosis of the long process of the incus ( 26 .2 % ) , and obliterative footplate ( 26 .09 % ) . As for the audiometric results , we got a complete closure of gap in 60 .8 % of patients ( n=14 ) , partial closure of gap in 13 .2 % ( n=3 ) , persistence of the initial gap in 21 .7% ( n=5 ) , and cophosis in 4 .3 % ( n=1 ) . Conclusions The migration of the prosthesis is the main cause of failure after stapedectomy . Good closure of the gap was achieved in two thirds of the patients .
progressive hearing loss
cophosis