Mechanical Alignment in Knee Replacement Homogenizes Postoperative Coronal Hip-Knee-Ankle Angle in Varus Knees: A Navigation-Based Study.

After knee replacement, postoperative lower limb alignment is influenced by the geometry of the prosthesis position and surrounding soft tissue that contributes to the hip-knee-ankle (HKA) angle. The purpose of this study is to determine the dynamic coronal HKA angle after mechanical alignment in total knee replacement using computer navigation. We conducted a pre-post design study of 71 patients with varus osteoarthritic knees on which total knee arthroplasty was performed. The HKA was measured before and at the end of the surgical procedure with the patient in the supine position using a navigation system at 30, 60, and 90 degrees of knee flexion. Postoperative implant position and flexion and extension gaps were assessed. HKA was clustered in three preoperative dynamic patterns (PDPs; Varus-Neutral, Varus-Valgus, and Varus-Varus). There were statistically significant differences in the dynamic coronal HKA between the preoperative and postoperative statuses after mechanically aligned knee replacement (with p < 0.0001) Before the surgical procedure, statistically significant differences were found between patterns at any angle of flexion confirming a well-differentiated preoperative dynamic behavior between the three groups. Postoperatively, 98.6% (71 out of 72) of the knees were within ± 3 degrees of the HKA at full extension. Fifty-eight knees (80.6%) were assessed to a "within-range" postoperative dynamic alignment at any grade of flexion considered. There are differences between the preoperative and postoperative status of the dynamic coronal HKA angle after mechanically aligned knee replacement. We proposed that an excellent dynamic HKA alignment is achieved not only at full extension within the range of 0 ± 3 degrees but also when this alignment is maintained at 30, 60, and 90 degrees.

[Maternal and fetal morbidity related to delayed antenatal work incapacity]. / Morbilidad materno fetal relacionada con el aplazamiento de la incapacidad laboral prenatal.

OBJECTIVE: To determine if there is higher maternal fetal morbidity associated to delayed antenatal work incapacity. PATIENTS AND METHOD: A case-control study was carried out, including 220 pregnant workers. They were divided into 110 women who delayed their antenatal work incapacity (cases) and 110 women who took it on time (controls). Sociodemographic and clinical data, which included maternal fetal morbidity, were registered. Results were analyzed by percentage values and arithmetic mean. Differences between groups were evaluated with Student's t test, chi square test, or exact test of Fisher. An alpha value was set at 0.05. RESULTS: There were 48 (43.6%) women who had antenatal complications in the group of cases and 27 (24.5%) in the controls, p= 0.004. The most common complication in the cases was preterm labor (29.1%), and in the controls was threatening of spontaneous abortion (55.5%). Other significant variables were: higher maternal age in the cases group (32.2 vs 22.5 years, p < 0.001), and lower number of antenatal visits (8.2 vs 9.5, p < 0.001). CONCLUSIONS: We conclude that there is higher maternal morbidity in women who delayed their antenatal work incapacity. It is recommended to give this incapacity according to present normative.