Patients with a history of venous thromboembolism (VTE) are considered at very high risk for recurrence after lower limb arthroplasty (LLA). However, the chance of a new VTE episode after LLA has not been yet quantified. The aim of this study was to define the incidence of VTE recurrence following knee and hip arthroplasty.

The case notes for all LLA patients treated at our hospital from 2009 to 2011 were reviewed. There were 5946 primary and revision LLA operations in total; 118 of these interventions were performed in 106 patients with a history of VTE. This group included 69 females and 37 males with a mean age of 69.9. Routine thromboprophylaxis for LLA patients included mechanical (footpumps & TED stockings) plus chemical prophylaxis using Aspirin 150 mg for 6 weeks. Patients with a VTE history had the same mechanical prophylaxis but received warfarin for 3 months.

There were no fatal VTEs within 90 days of surgery. There were 5 episodes (4.2%) of VTE recurrence and specifically 4 PE and one DVT (femoral vein) at 4 months after the operation. Two of the PEs were asymptomatic, diagnosed on CTPA scans being requested for low O2 saturations on routine monitoring. In the group of patients without a VTE history there were 35 VTE episodes (0.6%), indicating a significantly lower rate of VTE (p=0.001) in comparison with the study group.

Patients with a history of VTE had a 4.2% chance of having a further VTE. This is seven times greater than the rate among all other patients despite using more aggressive chemoprophylaxis.

Hip resurfacing preserves proximal femoral bone stock, optimises stress transfer to the proximal femur and offers inherent stability and optimal range of movement. The early results of metal–on-polyethylene resurfacing designs were poor and the resurfacing concept was largely abandoned. Modern metal-on-metal articulations enabled the introduction of a new generation of hip resurfacings with encouraging early results. In 1997 two of the authors developed a hip resurfacing system utilizing a metal-on-metal bearing. Our study reports on the clinical and radiological outcomes of the first 200 hips that were treated with the Durom hip resurfacing at an average follow up of 4.6 years (range 3.5–6).

Between May 2001 and December 2003, 200 consecutive hip resurfacings were performed on 189 patients, using the Durom hybrid metal-on-metal system. The average age of the patients was 50 years (range 22.5 – 72.3) and 119 were male. Patients were seen at 6 weeks and at 3, 6 and 12 months and annually thereafter for clinical and radiological evaluation. Clinical results were evaluated using the Harris Hip Score. A subjective assessment of patient satisfaction was obtained and patient activity was assessed using the UCLA activity score.

No patient was lost to follow up. There were no dislocations and no femoral neck fractures. One femoral component was revised due to aseptic loosening 3.9 years postoperatively. There was one late acute haematogenous infection that was successfully treated elsewhere by debridement and retention of the prosthesis. The mean Harris Hip Score improved significantly from 46.7 preoperatively to 94.4 postoperatively. The mean HHS constituents for pain, function and motion all were significantly improved from the preoperative values of 11.9, 25.7 and 4.2 to 41.8, 43.4 and 4.8 respectively following the resurfacing procedure. The mean UCLA activity score was 7.2 indicating a relatively active patient population and 179 hips were rated as excellent by the patients. No cup was considered radiographically loose. Extensive radiologic changes were observed around the femoral stem in 2.5% of the hips, with migration of the femoral component in one case and stem demarcation in 4 cases. All 5 patients maintained excellent function and had no hip pain. Pelvic osteolysis was observed in 2 cases. Neck remodelling changes were observed in 35 hips (17.5%). Kaplan-Mayer survivorship analysis demonstrated the rate of survival of the resurfacing components to be 99.5% (95% confidence interval 98.5 to 100) with revision for any reason as the endpoint.

Early results with the Durom resurfacing system appear encouraging. Although these should be regarded with caution, modern metal-on-metal hip resurfacing potentially offers the ultimate bone preservation and restoration of function in appropriately selected young patients.

Introduction: Infection is a serious complication of joint arthroplasty. Detection of low-grade prosthetic infection can be difficult, with major implications on the subsequent treatment, cost and patient morbidity. We evaluated the effectiveness of Polymerase Chain Reaction (PCR) in detecting infection in patients undergoing arthroplasty revision surgery.

Methods: Ninety-one consecutive patients (92 joints) undergoing revision THA or TKA were assessed prospectively. Preoperative assessment included clinical examination, blood tests and plain radiographs. At revision, tissue samples were sent for microbiology and histology. Cultures, using blood culture bottles, and PCR were performed on the synovial fluid. Diagnosis of infection relied on the surgeon’s opinion encompassing the clinical presentation, the results of various investigations and the intraoperative findings. Infected arthroplasties underwent a 2-stage revision. Post-operatively patients were followed up at regular intervals for a minimum of 2 years.

Results: Twelve (13%) joints were infected. Histology was positive for infection in 11 cases, tissue cultures were positive in 12 and PCR was positive in 32 cases. Intraoperative tissue cultures had sensitivity 0.75, specificity 0.96, positive predictive value 0.75 and negative predictive value 0.96; histology had sensitivity 0.92, specificity 1, positive predictive value 1 and negative predictive value 0.99 and PCR had a sensitivity 0.92, specificity 0.74, positive predictive value 0.34 and negative predictive value 0.98. At 2 years no patient showed evidence of infection.

Discussion: PCR is a sensitive method of diagnosing prosthetic infection but has poor specificity. False positive results may be due to contamination in theatre or in the laboratory. Positive results in apparently non-infected cases could be due to the detection of low virulence organisms, a small number of bacteria or a strong host immune response. Bacterial fragments and non-culturable forms of bacteria may also be responsible.

Conclusion: PCR was not helpful as a screening test for prosthetic infection. Cultures and histology combined with the surgeon’s clinical judgment remain the gold standard.

Aims: The evaluation of the results becoming from the use of demineralized bone matrix (DBM) in the bone defects. Methods: In the present study the above substance was implanted during the period 2000-2002 (28 months) to 24 patients, 11 males and 13 females average age 39,1 for the males and 60 for the females. As a cause was referred in 12 patients the fall, in 3 patients the car crash, in 5 patients the following the removal of osteosynthesis materials, in 2 patients the bone cysts, in 1 patient fracture of ankle joint following fusion and in 1 patient a pseudarthrosis. The implantation of DBM concerned 8 hips, 4 femurs, 6 knees, 1 humerus, 1 forearm, 1 ankle, 2 metacarpal and 1 phalanx. All the fractures as well the fusion were treated through internal fixation. There was a regular post op follow-up and concerned the clinical and x-ray examination per month until the total incorporation of the graft (12 weeks). Results: In all patients the total incorporation of the DBM was accomplished in a brief period of time, depended on the place of implantation without having local or systemic side effects. We have to remark the early signs of bone shadow around the 3rd week, as well the incorporation of the matrix around the 12th week in the x-ray findings. Conclusions: The use of DBM in bone defects could play an important role to the filling of bone defrects due to fractures or benign cysts as a result of its incorporation and without inducing local or systematic side effects.

Aim: The purpose of this study is to determine the outcome in patients with acetabular fractures treated either conservatively or surgically

Method: From 1990–2000, we treated 152 patients with 158 acetabular fractures. 63 patients were treated nonoperatively and 95 operatively. According to Tile classification there were 70 type A, 52 type B, 36 type C fractures. Mean follow up was 90 months (23–151 months). Indications for surgery were fracture displacement of more than 2mm, hip joint instability, intrarticular fragments and ipsilateral femoral fracture. Surgical approaches used included the kocher-Langenbeck and the triradiate approach. Follow up consisted of radiological examination and functional assessment using Merle d’ Aubigne score.

Results: 53 conservatively treated patients followed up. 39 (73.6%) had excellent and good results and 14 (26.4%) fair and poor results due to excessive fracture comminution, severe osteoporosis, or they were too sick to be operated on.

83 operatively treated patients with 85 fractures were followed-up. Anatomic reduction was achieved in 57 fractures, satisfactory in 18 and poor in 10 fractures.

Functional outcome was excellent or good in 60 (72.3%) patients and fair and poor in 23 (27,7%).The complications were 3 wound infections, 4 cases of femoral head osteonecrosis, 3 cases of secondary loss of reduction and 5 cases of significant ectopic ossification.

Conclusion: The outcome of these difficult fractures depends on restoration of hip joint congruity and stability and correlates closely to radiographic result.

Introduction: Infection constitutes a serious complication of joint arthroplasty, with an incidence of 1–2% after primary arthroplasty and even higher after revision procedures. Detection of low-grade infection in a prosthetic joint can often be very difficult, with huge implications on the subsequent treatment, cost and patient morbidity. Revision of an unrecognised infected arthroplasty may lead to less satisfactory results in a high proportion of cases. We utilized Polymerase Chain Reaction, a molecular biology technique to detect bacterial DNA from the synovial fluid of patients undergoing revision surgery, in comparison with conventional infection detection techniques.

Methods: We prospectively assessed 81 patients undergoing revision arthroplasty (67 hips and 14 knees). Each patient was pre-operatively assessed clinically and radiologically. ESR and CRP results were noted. During revision, synovial fluid and tissue cultures were obtained and antibiotics were given only after the specimens were taken. Standard microbiology and histology study were done on tissue samples. In addition Polymerase Chain Reaction study was performed on the synovial fluid. In this method, DNA is extracted from the bacterial cell; it is polymerised and finally visualized by gel electrophoresis. Post-operatively patients were followed up at regular intervals. Diagnosis of infection included correlation between clinical, radiological and laboratory investigations along with intra-operative findings, tissue culture and histology results and a period of postoperative follow up of 12 to 36 months.

Results: Eleven (13.58%) of the 81 cases that had revision arthroplasty were clinically infected. Polymerase chain reaction was positive in 30 cases, tissue cultures were positive in 8 cases and histology was positive in 10 cases for infection. PCR showed sensitivity and specificity of 0.92 and 0.72 respectively. Tissue culture showed sensitivity and specificity of 0.72 and 0.81 respectively. Histology showed sensitivity and specificity of 0.9 and 1 respectively.

Discussion: Twenty out of 30 PCR positive cases did not show any clinical evidence of infection. It is unclear whether this represents contamination during surgery or in the PCR lab. Alternatively this may represent true positive PCR results in cases with low bacterial count or bacteria growing within a biofilm that can be detected only by ultrasonication of the implant and immunofluorescence methods. PCR could also be detecting non-culturable forms of bacteria or bacterial fragments.

Conclusion: PCR has high sensitivity and low specificity for detection of bacterial DNA. The combination of tissue cultures and histology can still provide a reliable diagnosis of infection.

Background: Revision hip arthroplasty in the presence of extensive proximal femoral bone loss constitutes a major challenge. Several reconstruction alternatives have been introduced to deal with the problem of severe proximal bone loss. One of the techniques widely used is bridging the bone defect with the use of a distally fixing implant. The Link- MP reconstruction prosthesis is such a diaphyseal-fixing stem and we report on the early experience with its use.

Methods: The prosthesis has a modular design that allows restoration of hip biomechanics, femoral anteversion and leg length. It is made of a Titanium alloy with a micro-porous surface. The distal part (the stem) has a conical shape that allows cementless anchoring in the femoral diaphysis and it also has 8 or 10 longitudinal grooves, which provide rotational stability.

We report on the early results of its use, mean follow-up 30 months, (range, 9–54 months). Between 1997 and 2001, 32 hip revisions using the Link MP reconstruction prosthesis were performed in 31 patients. There were 13 females and 18 males with a mean age of 65 years (range 35 – 82). The indication for the revision operation was aseptic loosening in twenty-one cases, septic loosening in six and periprosthetic fracture in five cases. Cancellous bone allografts were used in 25 patients. Patients with proven infection were treated by a two-stage procedure.

Results: The mean Merle d’ Aubigne score increased from 6.8 preoperatively to 14.1 postoperatively and there was radiographic evidence of bone regeneration in the proximal femur in 80% of the patients. There were two intraoperative femoral fractures, which didn’t necessitate more than an extension of the partial weight bearing period and healed without complications. No stem was re-revised.

Conclusions: The early results with the use of the Link MP reconstruction prosthesis are encouraging, as shown by the improved patient functional status, the low incidence of complications and the observed proximal femoral bone regeneration.