In the planned study the investigators want to evaluate the relation between postoperative complications and minor/ major morbidities, mortality and Mean Platelet Volume (MPV) and Neutrophil/ lymphocyte (N/L) ratio.

• In this study the investigators aim to determine the relation between the MPV and N/L ratio and the incidence of postoperative adverse events and complications in patients undergoing knee arthroplasty.
• In this study only the laboratory tests that are routinely used for the operative patients are going to be used and no extra tests will be performed. The study will begin after the postoperative blood samples are collected for routine laboratory measurements. The patients will be allocated to 4 groups according to the type of anesthesia and VAS scores. Preoperative and postoperative peripheral blood total whole blood MPV and N/L ratio and 1st 6th 12th ve 24th hours VAS scores and complications, morbidities and mortality will be recorded. The patients will receive analgesics according to the routine practice in the ward and the doses of analgesics given will be recorded at 1st 6th 12th ve 24the hours wil be recorded.
• Statistical analysis: the numerical variables will be analyzed tested with Kolmogorov-Smirnov test for normality. For the parametric variables that are normally distributed t-test will be used for the comparison between groups. For the parametric variables that are not normally distributed Mann Whitney-U test will be used. All the categorical variables will be evaluated with q- square tests. A p value < 0.05 will be determined as statistically significant.

Inclusion Criteria:

• knee arthroplasty patients with general or spinal anesthesia.

Exclusion Criteria:

• patients not giving consent
• reoperations
• patients having inflammatory disease
• infection in the knee
• sepsis
• bleeding disorders
• hematologic diseases,
• using steroids.
• trauma
• fracture patients,
• bilateral knee prothesis
• combined surgery procedures
• patients needing perioperative transfusions
• uncooperative patients.

All consecutive patients undergoing knee arthroplasty in 3 years period with general or spinal anesthesia.