Nikola Grzalja

Dr. Nikola Grzalja

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Research Focus & Metrics

Academic Career Length

2Years (2025-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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Journal Article
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NMNikola Matejcic
Nikola Matejcic
NGNikola Grzalja
Nikola Grzalja
KTKarlo Tudor
Karlo Tudor
ALAndrica Lekić
Andrica Lekić
FSFilip Stefanac
Filip Stefanac
Lana RuzicLana Ruzic
Lana Ruzic
Background: Shoulder arthroscopy is a common, minimally invasive surgery, but the resulting postoperative blood loss remains poorly understood. In this study, we quantified the intraoperative and postoperative blood loss, the hemoglobin (Hb) drop, and the effects of irrigation fluid retention, as well as the influence of solutions administered through infusions. Methods: A prospective observational study of 49 patients undergoing arthroscopic rotator cuff tear (RCT) repair was conducted. Their preoperative and postoperative Hb levels were measured, along with the intraoperative and postoperative blood loss. Irrigation fluid retention was analyzed, and multiple regression was used to assess the factors contributing to Hb drops. Results: The intraoperative blood loss amounted to 36.46 ± 20.34 mL, while the total blood loss reached 791.17 ± 280.96 mL, with 94.64% occurring postoperatively. The postoperative Hb drop (2.06 ± 0.74 g/dL) was significantly greater than the intraoperative Hb drop (0.11 ± 0.06 g/dL) (p < 0.001). An older age (p = 0.02) and male sex (p = 0.025) significantly predicted the postoperative Hb drop, while irrigation fluid retention and administration of crystalloids and colloids had no notable effects. Capsulotomy was associated with a small but significant increase in intraoperative blood loss (p < 0.01). Increased intraoperative blood loss correlated with greater irrigation fluid retention (r = 0.41, adjusted R2 = 0.152, p < 0.001). Conclusions: In shoulder arthroscopy, the postoperative blood loss and Hb drop are significantly greater than the intraoperative blood loss and Hb drop, as well as the fluid gain, emphasizing the need for careful monitoring, especially in high-risk patients. Future studies should investigate the potential impacts of low-molecular-weight heparin on postoperative bleeding after shoulder arthroscopy.

13 February 2026 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
VSVeljko Santic
Veljko Santic
NMNikola Matejcic
Nikola Matejcic
VSVeljko Santic
Veljko Santic
NGNikola Grzalja
Nikola Grzalja
Objectives: Medial open-wedge high tibial osteotomy (MOWHTO) is a surgical procedure used to treat medial compartment osteoarthritis of the knee with varus deformity. The aim of this study was to examine whether a larger correction angle in medial open wedge high tibial osteotomy (MOWHTO) leads to greater changes in postoperative patellar height (PH) and posterior tibial slope (PTS). Methods: Data from 83 patients who underwent MOWHTO were retrospectively analyzed. Lower limb alignment was evaluated using the hip–knee–ankle angle (HKAA). The PH was assessed using the Insall–Salvati index (ISI), the Blackburne–Peel index (BPI), the Caton–Deschamps index (CDI), the modified Miura–Kawamura index (MKI), and the plateau–patella angle (PPA). The PTS was determined using the Moore–Harvey method. Results: The median correction of HKAA was 8°. A decrease in PH was observed in the majority of cases across all methods, with the highest frequency of postoperative patella infera detected using the MKI. PTS most frequently increased, with a median increase of 3°. A significant association between the magnitude of HKAA correction and patellar height in the overall cohort was observed only for the MKI, whereas in patients with an HKAA correction ≥ 10°, significant associations were found for both the MKI and CDI. No significant association was found between the magnitude of HKAA correction and changes in posterior tibial slope in the overall cohort, while a significant negative correlation was observed in patients with an HKAA correction ≥ 10°. Conclusions: Assessment using the MKI demonstrated greater sensitivity in detecting postoperative PH decrease, particularly in identifying patella infera. The magnitude of HKAA correction was significantly associated with greater changes in PTS and PH in patients with a coronal plane correction of ≥10°.