The cardinal (Mackenrodt) ligament is the primary lateral cervical support structure, connecting the cervix to the pelvic sidewall alongside the uterosacral ligaments. Its laxity from vaginal delivery or collagen disorders is the primary cause of uterine prolapse. The ureter runs immediately above the cardinal ligament as it crosses the cardinal ligament ('water under the bridge') — the classic site of ureteral injury during hysterectomy.
| Origin | Lateral cervix and upper vaginal wall |
|---|---|
| Insertion | Pelvic sidewall (tendinous arch of the levator ani) |
| Actions | Primary lateral support of the cervix and upper vagina; resists uterine descent |
|---|
The ureter crosses the cardinal ligament 2 cm lateral to the cervix ('water under the bridge') — inadvertent clamping of the cardinal ligament at hysterectomy is the most common cause of ureteral injury. The cardinal ligament is incorporated in sacrocolpopexy and sacral colpoperineorrhaphy for pelvic floor reconstruction.
Ureter at risk as it crosses under the cardinal ligament during hysterectomy — systematic lateral dissection before clamping prevents ureteral injury.
