Better restoration of joint line obliquity in tibia first restricted kinematic alignment versus mechanical alignment TKA.

INTRODUCTION: In total knee arthroplasty (TKA), suboptimal restoration of joint line obliquity (JLO) and joint line height (JLH) may lead to diminished implant longevity, increased risk of complications, and reduced patient reported outcomes. The primary objective of this study is to determine whether restricted kinematic alignment (rKA) leads to improved restoration of JLO and JLH compared to mechanical alignment (MA) in TKA. MATERIALS AND METHODS: This retrospective study assessed patients who underwent single implant design TKA for primary osteoarthritis, either MA with manual instrumentation or rKA assisted with imageless navigation robotic arm TKA. Pre- and post-operative long standing AP X-ray imaging were used to measure JLO formed between the proximal tibial joint line and the floor. JLH was measured as the distance from the femoral articular surface to the adductor tubercle. RESULTS: Overall, 200 patients (100 patients in each group) were included. Demographics between the two groups including age, sex, ASA, laterality, and BMI did not significantly differ. Distribution of KL osteoarthritis classification was similar between the groups. For the MA group, pre- to post-operative JLO significantly changed (2.94° vs. 2.31°, p = 0.004). No significant changes were found between pre- and post-operative JLH (40.6 mm vs. 40.6 mm, p = 0.89). For the rKA group, no significant changes were found between pre- and post-operative JLO (2.43° vs. 2.30°, p = 0.57). Additionally, no significant changes were found between pre- and post-operative JLH (41.2 mm vs. 42.4 mm, p = 0.17). Pre- to post-operative JLO alteration was five times higher in the MA group compared to the rKA group, although this comparison between groups did not reach statistical significance (p = 0.09). CONCLUSION: rKA-TKA results in high restoration accuracy of JLO and JLH, and demonstrates less pre- and post-operative JLO alteration compared to MA-TKA. With risen interest in joint line restoration accuracy with kinematic alignment, these findings suggest potential advantages compared to MA. Future investigation is needed to correlate between joint line restoration accuracy achieved by rKA and enhanced implant longevity, reduced risk of post-operative complications, and heightened patient satisfaction.

Chronic Warfarin Anticoagulation in Hip Fracture Patients Delays Surgery and Is Associated With Increased Risk of Postoperative Complications: A Multicenter Propensity-Score-Matched Analysis.

OBJECTIVE: To evaluate the effect of warfarin on blood transfusion and postoperative complications in a low-energy hip fracture population compared with a non-anticoagulated comparison group. DESIGN: Multicenter Retrospective Cohort. SETTING: Three Urban Level I Academic Trauma Centers. PATIENTS: Acute, low-energy, native hip fractures in patients 55 years of age or older on chronic warfarin anticoagulation, propensity score matched 1:2 to non-anticoagulated hip fracture patients meeting all other inclusion criteria. MAIN OUTCOME MEASUREMENTS: Transfusion and postoperative complication rates. RESULTS: Two hundred ten anticoagulated hip fracture patients were matched to 420 nonanticoagulated patients. A higher proportion of patients required blood transfusion in the warfarin cohort (52.4% vs. 43.3%, P < 0.001), attributable mostly to the subgroup of patients undergoing arthroplasty. Warfarin patients had higher incidence of overall 90-day complications (47% vs. 38%, P = 0.039) and readmissions (31.4% vs. 8.9%, P < 0.001). Day of surgery international normalized ratio (INR) did not influence transfusions or complications among warfarin patients. Warfarin patients undergoing surgery within 24 hours had no difference in transfusions and had fewer complications compared with those undergoing surgery after 24 hours. On multivariable logistic regression analysis, warfarin use and day of surgery INR were not predictors of transfusion or complications. CONCLUSIONS: Patients on warfarin experienced longer time to surgery and higher incidence of overall transfusion and postoperative complications within 90 days of surgery. However, warfarin use and day of surgery INR was not independently associated with transfusions or complications. The reason for poorer outcomes in warfarin patients remains a topic of further investigation. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Delayed Surgery Does Not Reduce Transfusion Rates in Low-Energy Hip Fractures on Direct Oral Anticoagulants.

OBJECTIVES: To compare transfusion rates in patients on direct oral anticoagulants (DOACs) with nonanticoagulated patients undergoing hip fracture surgery and, secondarily, to determine whether time to surgery or complications differ between these groups. DESIGN: Multicenter retrospective cohort. SETTING: Three tertiary care, academic, Level I trauma centers. PATIENTS: Acute, operatively treated, low-energy hip fracture patients 55 years of age and older were included. Anticoagulated patients were matched in a 1:2 ratio to "control" nonanticoagulated hip fracture patients using propensity score matching. MAIN OUTCOME MEASUREMENTS: The primary outcome was incidence of perioperative transfusion. The secondary outcomes included time to surgery, length of stay, and 90-day complications, readmissions, reoperations, and mortality. RESULTS: One hundred thirty-two patients with hip fracture admitted on DOACs were identified (107 factor Xa inhibitors, 25 dabigatran) and were matched to 262 "control" nonanticoagulated patients. There was no difference in overall transfusion rates between anticoagulation and control groups (43.2%; n = 57 DOAC vs. 39.7%; n = 104 control; P = 0.517). The median time from admission to surgery was 41.7 hours in the DOAC group and 26.0 hours in the control group (P < 0.001). There were no differences in 90-day complication, readmission, reoperation, or mortality rates between DOAC and control groups. Comparing DOAC patients undergoing surgery within 24 hours and after 24 hours, there were no differences in transfusion rates (P = 0.558) or overall complication rates (P = 0.179). CONCLUSIONS: This study supports growing evidence that DOAC use should not be a determining factor in delaying surgery for patients with hip fracture who are otherwise medically optimized. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.