To assess the extent of blood loss in prosthetic surgery, considering whether possible variables may influence, either positively or negatively, the extent of such loss. The assessment will be carried out by analysing parameters (haemoglobin - haematocrit) in the immediate preoperative period and then on days 1-3 and 7.

Numerous clinical studies have examined blood loss - both intraoperative and, above all, total blood loss - in shoulder, hip and knee replacement surgery.

Anaesthetic and surgical techniques, relevant medications, the use of pneumatic tourniquets and, more simply, intraoperative positioning, as well as blood-sparing and blood recovery methods, have been the subject of extensive literature. Our study aims to retrospectively evaluate a full year of prosthetic surgery, analysing all the factors involved in the search for a definitive answer regarding the best method for this purpose, if feasible [1,2,3,4,5].

Prior to admission, the patient undergoes a standardised series of tests, which also include a complete blood count, serum iron, transferrin and ferritin levels.

This series of tests concerning haematocrit and haematopoietic function is then repeated on the 1st, 3rd and 7th post-operative days to assess overall blood loss

. Patients of both sexes who have undergone total knee replacement (unilateral or bilateral), unicompartmental and total knee replacement (unilateral or bilateral), and total shoulder replacement.

The above patients operated on between January 2025 and December 2025 at the San Siro Clinic.

3.1 General objective To assess the extent of blood loss in prosthetic surgery, considering whether possible variables may influence, either positively or negatively, the extent of such loss. The primary objective is to evaluate the extent and variability of blood loss in comparison with the literature and in relation to the various intraoperative methods used.

The assessment will be carried out by analysing the parameters (haemoglobin - haematocrit) in the immediate preoperative period and then on days 1-3 and 7.

3.2 Primary objective The primary objective is to assess the extent and variability of blood loss in comparison with the literature and in relation to the various intraoperative techniques used.

The assessment will be carried out by analysing the parameters (haemoglobin - haematocrit) in the immediate preoperative period and then on days 1-3 and 7.

3.3 Secondary objectives

• Long stay: i.e. whether blood loss has, on any occasion, altered the post-operative course and/or delayed orthopaedic discharge

• General and/or local complications: such as the presence of haematomas, or a drop in haemoglobin levels requiring specific treatment and/or transfusions of packed red blood cells or plasma. This may also include difficulties with recovery, including delays in regaining the ability to walk and in overall recovery

• Transfusion of blood or blood products: to be considered a 'relative failure' in preoperative preparation and/or the perioperative course

  4. STUDY DESIGN This is a retrospective, observational, single-centre study involving patients who underwent orthopaedic prosthetic surgery (hip, knee and shoulder) at the IRCCS Istituto Clinico San Siro between January 2025 and December 2025, with clinical data collection. The study will be conducted in accordance with Good Clinical Practice guidelines.

Inclusion criteria:

- Adult patients in ASA Class I-II-III undergoing prosthetic surgery, as a first-time implant

Exclusion criteria:

• Patients who did not receive tranexamic acid prophylaxis (pre-operative and post- operative doses) and are therefore not comparable with the vast majority of cases.
• Reintervention, as bleeding depends on a variable that is not constant, namely the initial implant

Patients of both sexes who have undergone total knee replacement (unilateral or bilateral), unicompartmental and total knee replacement (unilateral or bilateral), and total shoulder replacement.

Dr. Claudio Legnani is an Orthopaedic physician well involv ed in this field, and I want to take part with another expert

March 2026 to March 2028

collecting parameters and analyzing data. Contact Statystical group with me