Porous tantalum is a highly osteoinductive biomaterial, initially introduced in orthopedics in 1997, with a subsequent rapid evolution of orthopedic applications. The use of porous tantalum for the acetabular component in primary total hip arthroplasty (THA) has demonstrated excellent short-term and mid-term results. However, long term data are scarce. The purpose of this prospective study is to report the long-term clinical and radiological outcome following use of an uncemented porous tantalum acetabular component in primary THA with a minimum follow-up of 17.5 years, in a previously studied cohort of patients.

We prospectively followed 128 consecutive primary THAs in 140 patients, between November 1997 and June 1999. A press-fit porous tantalum monoblock acetabular component was used in all cases. The presence of initial gaps in the polar region, as sign of incomplete seating of the monoblock cup, was assessed on the immediate postoperative radiographs. All patients were followed clinically and radiographically at 6, 12, and 24 weeks and 12 months and then at 2, 5, 8, 10, and 19 years, for a mean of 18.1 years (range 17.5 – 19 years). Periacetabular dome gap filling, acetabular cup migration and polyethylene wear were assessed by the EBRA digital measurement system, until 2 years postoperatively.

Mean age of patients at the time of operation was 60.4 years old (range 24 – 72). Harris hip score, Oxford Hip Score and range of motion (ROM) were dramatically improved in all cases (p < 0.001). In the initial postoperative radiographs, periacetabular dome gaps were observed in the 15% of cases, and were progressively filled within 6 months. In 2 years postoperatively, the mean component migration, as shown in EBRA study, was 0.67 mm. At last follow-up, all cups were radiographically stable with no evidence of migration, gross polyethylene wear, progressive radiolucencies, osteolytic lesions or acetabular fractures. The survivorship with re-operation for any reason as end point was 92.8%, whereas the survivorship for aseptic loosening as an end point was 100%. Upon visual inspection, two removed acetabular components due to recurrent dislocation and infection, respectively, showed extensive bone osseointegration.

In our primary THA series, the porous tantalum monoblock cup demonstrated excellent clinical and radiographic outcomes with no failures because of aseptic loosening at a mean follow-up of 18.1 years. Porous tantalum acetabular components showed excellent initial stability, produced less wear debris and revealed a great potential for bone ingrowth. Due to its unique osteoinductive properties and elliptical shape, porous tantalum monoblock cups have demonstrated superior short and long-term survivorship compared to other press fit prostheses in the market.

Periprosthetic knee infection is a serious complication of total knee replacement, connected to the formation of microbial biofilm on the surface of the implant. The most common bacteria causing periprosthetic infections are: Staphylococcus aureus, coagulase negative staphylococci and Gram negative bacteria. The purpose of this study is to present a rare case of periprosthetic knee infection caused by Ralstonia pickettii, which ultimately resulted in knee arthrodesis.

A 70 years old patient was referred to our clinic because of persistent pain, swelling and fistula in his left knee, 18 months after total knee arthroplasty. The patient had received oral ciprofloxacin and rifampicin during the last three months. The cultures of the fistula and knee aspiration were negative. A 2-stages revision of the total knee arthroplasty was decided. The patient underwent surgical removal of the prosthesis, cement and suspicious tissues and a spacer was placed. Samples from periprosthetic tissues were sent for conventional culture and all metal components were sonicated.

Intraoperative periprosthetic tissue cultures were negative. The culture of the sonicated fluid was positive for Ralstonia pickettii, a finding which was confirmed by the method of 16s rDNA. Ralstonia pickettii is a gram negative bacterium, capable of forming biofilm on metal surfaces. Postoperatively, the patient received intravenous antibiotic therapy with ciprofloxacin and cefepime, for 6 weeks, according to the results of the antibiogram. Due to fistula relapse after two surgical debridements, large bone defects and degeneration of the patellar tendon, knee arthodesis was performed.

In literature, there is only one reference of periprosthetic knee infection because of Ralstonia pickettii. Although quite rare, the periprosthetic knee infection caused by Ralstonia pickettii can be extremely durable with disastrous results for the knee joint.

In spite of its incidence decreasing to 1% nowadays, prosthesis-related infections remain a research, diagnostic, therapeutic and cost-related problem. Early diagnosis, selection of an appropriate surgical strategy, accurate identification of the responsible microorganisms and construction of an appropriate antibiotic regimen are essential elements of any management strategy. Our study aim was firstly to compare the diagnostic accuracy of conventional periprosthetic tissue culture and culture of fluid derived from vortexing and bath sonication of the explanted hardware and secondly to investigate the role of possible metabolic factors affecting the sensitivity of the sonication method.

We investigated 70 patients undergoing revision hip or knee arthroplasty because of loosening of the prostheses, at our institution, between October 2011 and November 2013. Patients’ medical history and demographic characteristics were recorded. We compared the culture of samples obtained by sonication of explanted hip and knee prostheses with conventional culture of periprosthetic tissue for the microbiological diagnosis of prosthetic-joint infection.

Infectious Diseases Society of America (IDSA) Guidelines were used for the definition of prosthetic-joint infection. Thirty-two patients had septic loosening and 38 aseptic loosening (48 hip prostheses and 22 knee prostheses). The sensitivity of sonication fluid culture was 81.25% and the sensitivity of conventional tissue cultures was 56.25% (p-value = 0.043). The sensitivity of the sonication method was statistically higher in obese, diabetic patients, with age above 60, in uncemented arthroplasties and in arthroplasties because of primary osteoarthritis (p-values < 0.05).

The sonication method represents a reliable test for the diagnosis of prosthetic – joint infections with a greater sensitivity than the conventional periprosthetic tissue cultures, especially in obese, diabetic patients, with age above 60, in uncemented arthroplasties and in arthroplasties because of primary osteoarthritis.

Introduction

Early identification and conservative management of paediatric Monteggia fractures has been shown to correlate with good results. Nevertheless, several authors advocate more aggressive management with open reduction and internal fixation (ORIF) for unstable fractures. We herein present the experience of a tertiary paediatric hospital in the management of Monteggia fractures.

Introduction

Lateral humeral condyle fractures account for 17% of the distal humeral condyle fractures. They affect children between 5 and 10 years of age. Recent reports advocate closed reduction and internal fixation for the less displaced fractures.

Introduction

The incidence of spondylolysis is estimated about 5–6% in the general population and accounts for one of the most frequent cause of backpain in the adolescent. The purpose of this study is to present our results from the management of these patients.