Hearing Outcomes and Complications of Cochlear Implantation in Patients With Cochlear Ossification: A Systematic Review and Meta-analysis

Background: Cochlear implantation, the primary treatment for severe to profound hearing loss, relies critically on proper electrode array design and insertion. Objectives: This systematic review and meta-analysis examined the complications and hearing outcomes of cochlear implantation in ossified cochleae, compared with non-ossified cases, and explored management strategies to enhance surgical success and patient outcomes. Methods: A comprehensive literature search was conducted using the PubMed, Scopus, Web of Science, and Cochrane Library databases, following the PRISMA guidelines. We used the following broad search strategy: Ossified OR ossification and cochlear AND implantation or implant. Two independent investigators screened titles, abstracts, and full texts and extracted data. A total of 20 studies and 971 patients were included. Results: Post implantation and intraoperative complications had pooled incidence rates of 13.48% and 7.2%, respectively. Complete electrode insertion was successful in 82.2% of cases, while partial insertion occurred in 22.6%. Hearing performance outcomes [Speech Perception Categories (SPCs), Categories of Audiological Performance Scores (CAPS), Speech reception threshold (SRT), and Speech Intelligibility Rating (SIR)] were significantly better for patients without ossification (SMD=0.35, P =0.005), although word and sentence scores showed no significant differences. Conclusions: Despite adaptations such as modified drilling and electrode arrays, hearing outcomes were inferior compared with non-ossified cochleae in addition to the risk of complications associated with the procedure. These findings underscore the need for continued research to improve outcomes in this patient population and have important implications for surgical planning and patient counseling.