Disc-condyle relationship alterations following stabilization splint therapy or arthrocentesis plus hyaluronic acid injection in patients with anterior disc displacement: a retrospective cohort study.

OBJECTIVE: The objective of this study was to quantitatively evaluate the efficacy of stabilization splint (SS) therapy or arthrocentesis plus hyaluronic acid (HA) injection in the treatment of anterior disc displacement (ADD) through magnetic resonance imaging (MRI). METHODS: 99 subjects were collected in this study. 46 subjects received SS treatment (SS group), 53 subjects received arthrocentesis plus HA injection (HA group). Joints with anterior disc displacement with reduction (ADDwR) and anterior disc displacement without reduction (ADDwoR) were compared separately. MRI before the beginning of the treatment and after a set of treatment were used for measurement. Disc-condyle relationship and positions of condyles and discs were determined by disc-condyle angles and X-Y coordinates. RESULTS: The disc-condyle angles decreased significantly in the SS group (P < .0001). Whereas no significant change was found in the HA group. Substantial anteroinferior condyle movement was detected in the SS group, slight anterior movement of condyles was discovered in the HA group. Anterior shift of discs position was observed in HA group and joints with ADDwoR in the SS group. CONCLUSIONS: SS was effective in improving the disc-condyle relationship in ADD subjects, while significant improvement of disc-condyle relationship cannot be achieved through arthrocentesis plus HA injection.