Temperatures and chemical potentials at kinetic freeze-out in relativistic heavy ion collisions from coarse grained transport simulations

Using the UrQMD/coarse graining approach we explore the kinetic freeze-out stage in central Au + Au collisions at various energies. These studies allow us to obtain detailed information on the thermodynamic properties (e.g. temperature and chemical potential) of the system during the kinetic decoupling stage. We explore five relevant collision energies in detail, ranging from sNN=2.4GeV 8, after UKA or HTO procedures. Methods A retrospective review of patients with a pre-arthritis UCLA score > 8 operated between January 2014 and September 2017 has identified 91 patients with open-wedge HTO and 117 patients with UKA. A matching process based on age (+/- 3 years) and gender allowed to include 50 patients in each group for comparative analysis. Patient reported outcomes included Knee Osteoarthritis Outcomes Score (KOOS), UCLA Score, Knee Society Score (KSS) and time to return to sport or previous professional activities at 3, 6, 12 and 24 months following surgery. Results Mean time to return to sport activities or previous professional activities were significantly lower for the HTO group than for UKA group [respectively, 4.9 +/- 2.2 months for HTO group vs 5.8 +/- 6.2 months for UKA group (p = 0.006) and 3 +/- 3 months for HTO group vs 4 +/- 3 months for UKA group (p = 0.006)]. At 24-month follow-up, UCLA score, KOOS Sports Sub-score and KSS activity score were significantly higher for HTO group than for UKA group (Delta: 2 CI 95% (1.3-2.5 points) p < 0.0001, (Delta: 10.9 CI 95% (2.9-18.9 points) p = 0.04 and Delta: 7.8 CI 95% (2.4-13.4 points) p = 0.006, respectively) and 31 patients (62%) were practicing impact sport in the HTO group versus 14 (28%) in the UKA group (odd-ratio 4.2 CI 95% (1.8-9.7) p < 0.0001). Conclusion HTO offers statistically significant quicker return to sport activities and previous professional activities with a higher rate of patients able to practice impact activity (62% for HTO vs 28% for UKA) and better sports related functional scores at two years after surgery compared to UKA.