Evaluation of the relationship of tibiofemoral kinematics before and after total knee replacement in an in vitro model of cranial cruciate deficiency in the dog.

OBJECTIVE: To investigate the relationship between tibiofemoral kinematics before and after total knee replacement (TKR) in vitro. ANIMALS: Eight canine hemipelves. METHODS: A modified Oxford Knee Rig was used to place cadaveric limbs through a range of passive motion allowing the kinematics of the stifle to be evaluated. Four measurements were performed: a control stage, followed by a cranial cruciate transection stage, then following TKR with the musculature intact stage, and finally TKR with removal of limb musculature stage. Joint angles and translations of the femur relative to the tibia, including flexion-extension versus adduction-abduction, flexion-extension versus internal-external rotation, as well as flexion-extension versus each translation (cranial-caudal and lateral-medial) were calculated. RESULTS: Significant differences were identified in kinematic data from limbs following TKR implantation as compared to the unaltered stifle. The TKR resulted in significant decreases in external rotation of the stifle during flexion-extension compared to the limb prior to any intervention, as well as increasing the abduction. The TKR significantly increased the caudal translation of the femur relative to the tibia compared to the unaltered limb. When compared with the cranial cruciate ligament-transection stage, TKR significantly decreased the ratio of the external rotation to flexion. DISCUSSION: All three test periods showed significant differences from the unaltered stifle. The TKR did not completely restore the normal kinematics of the stifle.

Quality Varies Across Health Insurance Marketplace Pricing Regions.

BACKGROUND: Although consumers purchasing health plans in the new Health Insurance Marketplace will be provided information on the cost and quality of participating health plans, it is unclear whether the state-wide plan quality averages that will be reported will accurately represent quality at the pricing region level where care will be received. OBJECTIVES: To evaluate whether currently reported state-wide health plan quality scores accurately represent quality within pricing regions established for the Health Insurance Marketplace. RESEARCH DESIGN: Observational, historical cohort study using health plan administrative and pharmacy data. SUBJECTS: A total of 5.2 million members enrolled in the preferred provider organization health plans of 1 large commercial California insurer in 2012. MEASURES: State-wide and pricing region performance on each of the 17 Healthcare Effectiveness Data and Information Set (HEDIS) measures. RESULTS: Across the 17 measures assessed in each of the 19 pricing regions, scores were statistically different (P<0.05) than the overall plan rate for 176 (54%). Variations in scores across regions were observed for each measure ranging from 6.4-percentage points for engagement in treatment for people with dependence of alcohol or other drugs to 47.2-percentage points for appropriate testing for pharyngitis among children. CONCLUSIONS: Quality scores in California vary greatly across geographic regions. Statewide averages may misrepresent the quality of care that consumers are likely to receive within a geographic area making difficult assessments about the value of the health care.