© 2020Introduction: The origin and content of prolonged wound drainage (PWD) after arthroplasty remain uncertain. In this study, we performed the biochemical, biological and advanced proteomic analysis of the drainage fluid collected from PWD patients following hip hemiarthroplasty (HA). Methods: Data of 28 patients who developed PWD after HA were prospectively analyzed. After examining the biochemical content of the drainage fluid collected on postoperative day 6, to find out if the drainage fluid was transudate or exudate, it was compared with the patient's serum values according to the Light criteria. Subsequently, biological and proteomic analyzes of both drainage fluid and serum were performed. The similarities and differences in terms of protein concentrations, protein identities were examined. In the drainage fluid, we analyzed lymph-specific proteins. Results: 16 patients with PWD were male (61.1%), 12 were female (38.9%), and the mean age of all patients was 79.64 ± 8.44 (65-95). Biochemical test results of the drainage fluid / serum were as follows: Total protein: 2.1 / 5.2 g/dl, albumin: 1.3 / 3.1 g/dl, lactate dehydrogenase (LDH): 121/324 U/l, cholesterol: 28/160 mg/dl, triglyceride: 37/122 mg/dl, sodium (Na): 140/ 140mg/dl, potassium (K): 4.1/ 4.1 mg/dl. pH of the drainage fluid was 7.6. According to these biochemical values, drainage fluid was classified as transudate. As a result of protein identification, fibrinogen beta chain, keratin type 1, creatine kinase M-type protein were detected in drainage fluid. Subsequent western analysis revealed that, gliseraldehyde-3-phosphate dehydrogenase (GAPDH) and beta actin antibody were detected in the drainage fluid but not in serum. Conclusion: Despite the similarity in serum and transudative PWD fluid in terms of biochemical content, we found that when we carried out further proteomic analysis, PWD contains lymph-specific proteins. Unlike PWD, these proteins were not determined in serum. PWD fluid can be also called as lymphorrhea. PWD fluid with abundant proteins may also provide an appropriate environment for the growth of microorganisms.