Relationship Between Intracapsular Fracture Patterns and Arthroscopic Findings

Abstract

To observe the superior joint compartment (SJC) using ultrathin arthroscopy in intracapsular condylar fracture (ICF) of the temporomandibular joint, describe the changes, and evaluate the relations among fracture pattern, arthroscopic findings, and clinical outcome. Twenty patients with 27 ICFs were the subject group. Thirteen patients had unilateral ICFs and 7 had bilateral ICF. The fracture patterns were classified into 9 categories, and all patients had arthroscopic examination of the traumatized joint at the time of definitive treatment. At 4months after treatment of the injury, all patients had a secondary arthroscopy ofthe ICF joint. In all patients, range of motion (ROM) was measured as the interincisal distance (millimeters) at the first visit to 12months after the first treatment, and the data were statistically evaluated. Intra-articular hyperemia, hypervascularity, and temporal bone damage were found, and 4 patients had disc perforations at the first examination. At the second arthroscopy 4months later, normal healing occurred in 11 joints, all of which had minimally displaced fractures. Fifteen joints showed complete filling of the SJC, all of which had a displaced minor fragment from the fossa. Comparison of the effect of the presence versus absence of SJC fibrosis on ROM showed marked differences from 1 to 12months. The effect of early versus delayed definitive treatment showed marked differences at 4 and 12months. The intra-articular condition at 4months after ICF as observed arthroscopically was related to the minor fragment position. If the minor fragment is nondisplaced, then it will heal to a normal state; however, if the minor fragment is displaced from the fossa, then the SJC shows disc damage and fibrosis. This could lead to fibrous ankylosis.