Resumen: Objectives: The aim of this study is to analyse the efficacy of using a combined infiltration between a popliteal artery and knee cap (IPACK) anaesthetic block and a selective saphenous nerve block compared to local infiltration with anaesthetic in knee replacement surgery. Methods: A retrospective observational study was conducted. A total of 312 patients who underwent primary total knee arthroplasty in our hospital between January 2019 and December 2022 were reviewed. Local intra-articular anaesthesia was used in 207 patients and combined nerve block in 105 patients (IPACK group). The mean age in the LIA group was 72.9 years and 70.4 years in the IPACK group. There were 44% men in the LIA group and 53.3% in the IPACK group. The primary outcome was the presence of poorly controlled pain requiring rescue opioid analgesia in the postoperative period. Secondary outcomes included pain scores, range of motion and length of hospital stay. Results: There were no significant differences in the age or gender distribution of patients between the two groups. One patient treated with anaesthetic blocks required rescue analgesia with opioids, while in the LIA group this occurred in 28.5% of cases. There were statistically significant higher VAS scores in the LIA group (p < 0.001). Range of motion was slightly greater in the block group (4.6°, p < 0.05). There were significant differences in hospital stay (2.4 days in the blocks group and 2.8 days in the LIA group (p < 0.05). Conclusions: In our series, patients treated with anaesthetic blocks showed better results with similar postoperative pain control. However, further studies are needed. Idioma: Inglés DOI: 10.3390/jcm13195706 Año: 2024 Publicado en: Journal of Clinical Medicine 13, 19 (2024), 5706 [10 PP.] ISSN: 2077-0383 Tipo y forma: Article (Published version) Área (Departamento): Área Estadís. Investig. Opera. (Dpto. Métodos Estadísticos) Área (Departamento): Área Traumatología y Ortopedia (Dpto. Cirugía) Área (Departamento): Área Cirugía (Dpto. Cirugía)