Objective      To investigate the geometric parameter changes in anatomy abnormalities of cardinal ligaments (CL) and uterosacral ligaments (USL) in uterine prolapse

and to evaluate different types of pelvic floor reconstruction for uterine prolapse treatment by MRI-based three-dimensional (3D) reconstruction.       Methods      Twenty patients with diagnosed uterine prolapse from October 2010 to October 2011 and 20 healthy volunteers were assigned as a patient group and a control group

respectively. The 3D reconstruction models of CL

USL and pelvic organs were constructed from the MRI data of the two groups of subjects by 3D reconstruction software. The origin

end point

length

volume and curvature of CL and USL

the angle of USL and the angle between the same side of CL and USL were compared between the two groups.       Results      The length of USL in the patient group was shorter than that in the control group (P0.05). The angle of USL in the patient group was larger than that in the control group (P0.05). There was no significant difference in the measurement parameters of CL between the two groups (P0.05). In the patient group

the USL origins were 2 cases (10%) on sacrum

16 cases (80%) on coccygeus/sacrospinous complex

and 2 cases (10%) on ischial spine

and its endpoints attached to cervix in 8 cases (40%)

to vagina in 2 cases (10%)

and to both cervix and vagina in 10 cases (50%). The CL originated from greater sciatic foramen at the same side of pelvic sidewall

and its endpoints attached to cervix in 8 cases (40%)

to vagina in 4 cases (20%)

and to both cervix and vagina in 8 cases (40%). In the control group

the USL origins were 6 cases (30%) on sacrum

13 cases (65%) on coccygeus/sacrospinous complex

and 1 case (5%) on ischial spine

and its endpoints attached to cervix in 6 cases (30%)

to vagina in 2 cases (10%)

and to both cervix and vagina in 12 cases (60%). The CL originated from greater sciatic foramen at the same side of pelvic sidewall

and its endpoints attached to cervix in 8 cases (40%)

to vagina in 2 cases (10%)

and to both cervix and vagina in 10 cases (50%).       Conclusion      The MRI 3D reconstruction model can clearly demonstrate the geometrical and anatomical relationships between pelvic organs and the ligaments of CL and USL. The angle and the length of USL are the main parameters associated with uterine prolapse

but not the parameters of CL. The reconstruction of USL is the key point of different types of pelvic floor reconstruction for uterine prolapse treatment.