The aim of this study is to evaluate which patients, if any, can be eligible for a rapid discharge from Hip Surgery Department at 24 hours after primary total hip arthroplasty.

Methods In this retrospective clinical trial were included all patients undergone to primary total hip arthroplasty in our Hip Surgery Department from January to June 2004. Exclusion criteria were preoperative anaemia (Hb< 12g/dL), coagulation disease, hip fracture, previous hip surgery and not-weight bearing indication after operation. All patients received an uncemented total hip arthroplasty with posterior surgical approach in regional anaesthesia. All patients had the same post-operative (PO) management including analgesia, prevention of DVT, immediate muscle exercises and physiotherapy for walking on crutches starting on the second PO day. The clinical history, vital parameters, haemoglobin (Hb) value before surgery and for 5 days PO, adverse events like luxation and transfusion were registered. For the statistical evaluation were used the paired “t-test” with a level of significance set at 95%. Differences and p values of < 0.05 were considered significant.

Results 234 patients (mean age 65y; range 21–91y) were admitted to the study. 128 women and 106 men. For the blood loss evaluation, the presence of no homogeneous preoperative Hb lead us to analyse the decrease rate of preoperative Hb (DRPH). The mean DRPH was: 22,47% at 1dayPO; 25,09% at 2 daysPO; 22,83% at 3 daysPO; 26,76% at 5 daysPO. For the safety evaluation were considered the incidence of transfusions (limit was set at Hb< 8g/dL) that were related to the preoperative Hb and the age. The transfusion incidence for each preoperative Hb (PrHb) value was: 14% (7/49) for 12< PrHb< 13; 11% (6/53) for 13< PrHb< 14; 11% (5/43) for 14< PrHb< 15; 7% (2/26) for 15< PrHb< 16g/dL. For age under 70y and PrHb> 14g/dL there were the lowest transfusion incidence: 3% (2/41). No adverse events were able to prevent patients from going to Rehabilitation Unit. All patients were able to do their own physiotherapical programme. Pain during physiotherapy was low (mean value of VAS = 3,47).

Discussion During the last decade the improvement of anaesthesiologic and surgical technique with minimally invasive soft tissue approach (small incision and little muscular sacrifice) lead to a significant reduction in adverse events after primary total hip arthroplasty. So the relative safety of this surgery justifies the growing importance of intensive rehabilitation and fast recovery. This study shows the safety of a rapid discharge from the Hip Surgery Department. The main adverse event after 24 hours PO is the necessity of blood transfusions, but the incidence rate of only 3%, like in patients with preoperative Hb> 14g/dL and age below 70 years, is not a problem for the physicians of the Rehabilitation Unit.

Conclusion This study confirms the possibility to perform a safe One Day Hip Surgery by an accurate selection of the patient.