Uterine artery embolization combined with intra-arterial MTX infusion: its application in treatment of cervical pregnancy.

OBJECTIVE: To investigate the efficacy and safety of uterine artery chemoembolization (UAE) combined with intra-arterial MTX infusion for the treatment of cervical pregnancy. METHODS: Retrospective chart review for 26 cervical pregnancy patients treated at Renji hospital between January 2000 and December 2012. 14 patients received UAE combined with intra-arterial MTX infusion (UAE group) and 12 patients received single intramuscular MTX injection combined with subsequent uterine curettage (non-UAE group). RESULTS: All 14 patients in the UAE group were treated successfully and 1 patient in the non-UAE group had 1200 ml vaginal bleeding during uterine curettage and was then treated with emergency UAE. The mean estimated blood loss during uterine curettage in the UAE group was much less than in non-UAE Group. A quicker regression of serum ß-hCG level and normal menses resumed and a shorter hospital stay were observed in the UAE group than in the non-UAE group. CONCLUSIONS: Uterine artery chemoembolization combined with intra-arterial MTX infusion is an efficient conservative treatment for cervical pregnancy.

Relative contributions of plantar fascia and ligaments on the arch static stability: a finite element study.

The plantar fascia (PF) and major ligaments play important roles in keeping the static foot arch structure. Their functions and relative contributions to the arch stability have not been well studied. A three-dimensional finite element foot model was created based on the reconstruction of magnetic resonance images. During balanced standing, four cases after individual releases of the PF, spring ligament (SL), and long and short plantar ligaments (LPL and SPL) were simulated, to compare their biomechanical consequences with the normal predictions under the intact structure. Although the predictions showed the arch did not collapse obviously after each structure sectioning, the internal mechanical behaviors changed considerably. The PF release resulted in the maximal increases of approximately 91%, 65% and 47% in the tensions of the LPF, SPL and SL, produced the largest changes in all bone rotations, and brought an obvious shift of high stress from the medial metatarsals to the lateral metatarsals. The SL release mainly enhanced bone rotation angles and weakened the joint stability of the arch structure. The LPL and the SPL performed the roles of mutual compensation as either one was released. The influence of the LPL on the load distribution among metatarsals was greater than for the SPL and the SL.

A three-dimensional parameterized and visually kinematic simulation module for the theoretical range of motion of total hip arthroplasty.

BACKGROUND: Proper option and optimal alignment of implants are major factors in obtaining the desired range of motion of total hip arthroplasty. It would be very useful if a tool is available to assist clinicians to preoperatively determine proper implants and their optimal intraoperative alignment for individual patient. METHODS: Based on the secondary development function of ADAMS/VIEW, a three-dimensional parameterized module was developed to simulate six motions of implants for total hip arthroplasty. Total eight parameters (stem abduction, acetabular size, head size, general head-neck ratio, stem-neck angle, acetabular anteversion, acetabular inclination and femoral antetorsion) were included and three definitions of acetabular orientations (operative, radiographic and anatomical) were available. Any initial position of implants and simulation precision could be defined on the demand. FINDINGS: After entering these eight parameters, a special model of total hip arthroplasty would be constructed. Single or combined motion until the prosthetic impingement could be simulated visually and the corresponding maximal rotation angle would be quantified. INTERPRETATION: Clinical factors, such as patients with severe deformity of hip joint or a large range of motion demand, should be considered during total hip arthroplasty. This module can provide references for clinicians on proper option and intraoperative implantation of components, and be suitable for postoperative evaluation. Furthermore, it is a tool to investigate the "safe-zones" of total hip arthroplasty and also can be employed for the design of new implant system.

The contour of cementless femoral stem has minor effect on initial periprosthetic von Mises stress distribution. A 3-dimensional finite element analysis.

OBJECTIVE: To evaluate periprosthetic von Mises stress distribution with cementless femoral stems of various contours. METHODS: The study was carried out at the Department of Orthopaedics, Shanghai 6th Hospital, Shanghai, China between May 2008 and February 2009. Finite element models of proximal femoral replacement with 4 cementless stems (Alloclassic, Ribbed Anatomic, VerSys, and Securi-fit) of various contours were set up. Under the loading conditions of walking and stair climbing, 3-dimensional periprosthetic von Mises stresses were calculated, and the stress distribution patterns were compared. RESULTS: Periprosthetic stresses were increased in level 1, 2, and 3 under the 2 loading conditions, and more considerably in level 2 and 3. The stresses were higher on the medial side in all cases. No remarkable difference was found in the patterns between the 4 stems. CONCLUSION: The contour design of femoral stem has minor effect on initial periprosthetic von Mises stress distribution.