Almost any kind of bacteria can be involved in prosthetic joint infections (PJI).

In 2014 we collected data on 3 patients presenting with hip or knee pain and radiological signs of prosthetic joint mobilization without any other clinical or biochemical suspect of infection.

Interestingly, in all cases we isolated bacteria very rarely involved in human infections: Cupriavidus pauculus, Ralstonia paucula and Neisseria flavescens. Both Cupriavidus pauculus and Ralstonia paucula are Gram negative environmental bacteria which can contaminate water (tap, pool and mineral) and have been isolated from a variety of human clinical sources including blood, wounds, sputum, urine, eye, throat and peritoneal fluid, as non pathogenic flora. In such two patients we were able to cure the infection with quinolones (both strains were sensible). Neisseria species are Gram-negative bacteria included among the proteobacteria. Neisseria flavescens is often found in the upper respiratory tract and oropharynx of humans, rarely associated with infectious process (necrotizing pneumonia and empyema). In this last patient we successfully used piperacillin-tazobactam i.v. during hospitalization and shifted to amoxicillin-clavulanate per os at discharge.

In conclusion, any bacteria can induce PJI: in some cases pre-operative blood tests are normal and therefore useless. We need new tests to overcome this diagnostic problem (such as alpha-defensin) and we must check on rare bacteria prolonging incubation to a more extended period of time (as in Propionebacterium acnes or Mycobacterium spp) and/or sending samples to specialized laboratories.

We thank all the medical and nurse staff of Prosthetic Joint Replacement Unit of Orthopaedic Center, Humanitas Research Hospital

Introduction: Angular and torsional deviations of femur are usually combined with Congenital Dislocation of the Hip (CDH) and increase the complications of hip arthroplasty. The aim of this study is to evaluate surgical and reconstructive options for the treatment of CDH.

Material and Methods: In this retrospective study, we evaluated the results and complications of 55 primary cementless total hip arthroplasties, all of whom had Crowe type-IV developmental dysplasia of the hip. The arthroplasty was performed in combination with a subtrochanteric shortening osteotomy and with placement of the acetabular component at the level of the anatomic hip center. The patients were evaluated at a mean of 8,1 years postoperatively.

Results: From 1984, more than 2000 cases of arthroplasty have been performed in dysplastic hip, 565 cases had a previous femoral osteotomy; 128 cases needed correction of femoral side deformity; 64 had a greater trochanteric osteotomy. In 9 cases rotational abnormality and shortening were controlled with plate and distal femur osteotomy. 55 cases were treated by a shortening subtrochanteric osteotomy. Only non-cemented stems were used. 4 failures occurred for the incorrect fixation of the metaphysis. The fixation can be obtained only by prosthetic press-fit, but it is preferable to use metal wires. There was no sciatic injury; indeed shortening osteotomy provides an easy control of deformity and lengthening, with a maximum of 4 cm. One case was reviewed for heterotopic calcification (grade 4). One infection of the soft tissue was medically cured. There were two revisions for polyethylene failure at 8 and 12 years postoperative.

Discussion: The anatomic abnormalities associated with CDH and previous femoral osteotomy increase the complexity of hip arthroplasty. We had best results with the femoral shortening subtrochanteric osteotomy where a rapid consolidation was obtained. Moreover, the functional result was better for the management of the insertion of the muscle tendons in particular the mediogluteus and also for the relatively correct positioning in favour of the reciprocal relationship of the pelvic-trochanter. The detachment of the greater trochanter associated with a metaphyseal proximal shortening, remains an effective technique for the treatment of malformations that are difficult to treat, but there is a high risk of pseudarthrosis of greater trochanter.

Conclusion: Femoral shortening subtrochanteric osteotomy preserves the proximal femoral anatomy, avoids the problems associated with reattachment of the greater trochanter, and facilitating a cementless femoral reconstruction in relatively young patients.

The aim of this study is to evaluate techniques which may reduce intra and Post-Operative (PO) bleeding in hip surgery.

Methods: In this prospective study, from 9/2005 to 6/2006, we evaluated Blood Loss (BL) after primary total hip arthroplasty. Exclusion criteria were anti-coagulant drugs not discontinued 10 days before surgery and patients whose condition precluded weight bearing PO. We included total hip arthroplasty with posterior surgical approach, spinal anaesthesia, hypotensive surgery and peri-operative blood salvage (Ortho PAS, Euroset). When appropriate, the Mini-Invasive Approach (MIA) was used. In a different sub-set of patients, including some of the minimally invasive patients, a new bipolar Radio-Frequency sealer (TissueLink) was used. The PO program had pain control, LMWH for prevention of DVT, exercise from the day of surgery and walking on crutches from the next day. We analysed: blood loss after surgery and for 3 days; haemoglobin values (g/dL) before surgery and for 5 days PO; thigh circumference pre-op and at 5 days and adverse events such as transfusions and luxation. For the statistical evaluation the paired “t-test” was used, with a level of significance set at 95%. Differences and p values of < 0.05 were considered significant.

Results: 324 patients (mean age 68; range 23 to 89; 179 F & 145 M) were admitted to the study. Mean BL was 305ml intraoperative, 501ml at 6 hours PO, 304ml at 1day PO, 132ml at 2 days PO and trace at 3 days. Rather than simple unit measures, we analyzed the Percent Change in Hb from preoperative levels (%CHb). The patients had a mean %CHb of 23,09% at 1day PO, 26,67% at 2 days PO, 28,13% at 3 days and 29,07% at 5 days. Transfusion rates (TR; trigger set at Hb< 8g/dL) were related to the preoperative Hb and age. Overall TR was 15% (51/324), the prevalence of homologous transfusion was 7% (24/324). The TR for each Hb value: 21% (15/69) for Hb=12–13, 20% (20/98) for Hb=13–14, 17% (15/88) for Hb=14–15 and 5% (1/29) for Hb=15–16. The mean value of pain during rehabilitation was 3,11(VAS). MIA (53/324) was associated with reduced BL (mean %CHb at 1st day PO 19.12; TR 9%), but with high variability. The use of bipolar sealer (58/324) was associated with a significant reduction in overall BL (mean %CHb at 1st day PO 15.83; TR 5%) as well as a reduction of thigh swelling (37%) and of mean rehabilitation pain (30%; VAS=2.15).

Discussion: Reduced blood loss, reduced post-operative pain and a faster functional resumption are obtained with both the minimally invasive approach and the TissueLink sealer approach. In addition, MIA provides muscle preservation and the use of the TissueLink sealer provides reduced post-operative swelling.

Conclusion: This study shows that both the minimally invasive surgical approach and the use of an irrigated RF bipolar sealer can lead to reduced blood loss and faster functional resumption following hip surgery.

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.

Xenografts of bovine bone were used successfully for years with a minimum acceptable rate of side effects in total hip revision arthroplasty for filling large bone defects. The great majority of them was withdrawn from the market when any biological product of bovine origin was considered as a potential carrier of prions infection. However, current EEC regulations permit their surgical therapeutic use if obtained from cattle under 6 months of age, which are supposed to be not at risk of prion transmission. Lubboc, a purified trabecular bone matrix containing only type-1 collagen and hydroxyapatite, fulfils this requirement. From 2001 to 2003 we used this product in fragments (chips) to fill bone defects of the acetabulum before screwing the acetabular rings in 37 patients. No massive grafts were implanted. Minimum follow-up was 12 months, maximum 27 months. Four subjects were lost to follow-up. The fate of the grafts was evaluated for evidence of union, remodelling, resorption, migration of the rings or fracture of the newly formed bone. No significant adverse events were registered. If the risk of transmitting infectious agents is excluded or minimised according to the present legislation, it seems unjustified to remove xenografts from the options available to orthopaedic surgeons, considering the problems of bone stock deficiency and reconstruction in hip arthroplasty revision surgery.