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.

To determine the gross structural alterations of the nailed bone (femur or tibia) after the removal of an intramedullary nail (IMN).

Eighteen patients (14 femoral and 4 tibia nail) underwent an IMN removal from their femur or tibia. Every patient had a spiral computed tomography scan and a plain X-ray study, immediately after the nail removal and also at their latest follow-up (24–30 months). The 4 patients with a tibia nail were additionally examined using a peripheral quantitative computed tomography study at their latest follow-up. All patients were asymptomatic.

An intramedullary shell of compact bone was demonstrated around the nail track. This new bone was apparent on plain radiographs in all of the patients. Peripheral quantitative computed tomography study revealed that the density of the bony ring was similar to that of subcortical bone. The histologic examination of the intra-medullary shell of one of our patients suggested that the bony ring was made of cortical bone.

Intramedullary nailing may enhance new cortical bone formation within the bone marrow cavity. This “cortical bone” still exists more than 2 years after implant removal. Nail insertion also causes thickening of the normal cortex at the sites of nail–cortex contact where loads are transferred from the nail to the cortex. This new finding could probably lead the research of intramedullary nailing biomechanics toward new directions as to understand the body’s reaction to IMNs.

This study concerns an epidemiological analysis of foot and ankle injuries during the Athens Olympic Games 2004.

An epidemiological survey was used to analyse injuries in all sport tournaments over the period of the Games. During the Athens Olympic Games 2004 in the period from August 1st to September 1st, 624 patients presented to the Foot and Ankle Department for treatment. The mean age of athletes was 24 years (range 21 to 32). Among the patients there were more males, 358 (58%) than females, 266 (42%).

In 525 (84.1%) patients there was only a soft tissue injury and in 99 (15.9%) patients there was bone involvement. Regarding specific diagnoses, tendinitis was the most common reason for a visit, followed by ankle sprains, nail infections/injuries, lesser toes sprains, and stress fractures. Sixty-nine (11%) required emergency transfer to the hospital.

Our experience from the Athens Olympic Games will inform the development of public health surveillance systems for future Olympic Games, as well as other similar mass events.

Objective: we present the long-term behavior of polyethylene’s insert in acetabular implants ARC2F.

Materials and Methods: from 1989 to 1995, 668 THA’s were implanted. Mean patients age was 54 years (28–75). The preoperative diagnosis included: primary OA 501 cases, post-traumatic arthritis 24, hip dysplasia 112, AVN 31. In all cases Omnifit femoral stem with proximal HA coating and ARC2F acetabular component were used. 165 patients (182 arthroplasties) were lost to follow-up. The average time of observation was 15 years (13–18.5).

Results: all THA’s performed well without signs of wear at 10 years. No implant was revised during the first decade because of mechanical loosening. Since then, during the 13th – 14th year, a significant number of patients appeared with symptoms of polyethylene’s massive destruction and significant osteolysis at the femoral and acetabular side of the arthroplasty. We recalled all patients that could be found. Totally, 178 from 486 THA’s had similar radiographic signs of wear. Only 33 of all these had initial wrong orientation of the cup.

Conclusion: despite the excellent early and middle-term results, ARC2F shows rapid and massive wear of the insert after 12 years, probably because of degeneration and loss of polyethylene’s structural integrity due to the method of sterilization. We suggest to recall and inspect all the patients which have this kind of implant more than 12 years.

Between November 1997 and December 2000 we performed 27 total hip replacements in 22 patients with high congenital dislocation of the hip using porous tantalum monoblock acetabular components implanted in the true acetabular bed. Clinical and radiological evaluation was performed at regular intervals for a mean of 10.2 years (8.5 to 12). The mean Harris Hip Score improved from 48.3 (15 to 65) pre-operatively to 89.5 (56 to 100) at the final follow-up. The mean Oxford Hip Score was 49.5 (35 to 59) pre-operatively and decreased to 21.2 (12 to 48) at one year and 15.2 (10 to 28) at final follow-up. Migration of the acetabular component was assessed with the EBRA software system. There was a mean migration of 0.68 mm (0.49 to 0.8) in the first year and a mean 0.89 mm (0.6 to 0.98) in the second year, after excluding one initial excessive migration. No revision was necessary for any reason, no acetabular component became loose, and no radiolucent lines were observed at the final follow-up.

The porous tantalum monoblock acetabular component is an implant offering adequate initial stability in conjunction with a modulus of elasticity and porosity close to that of cancellous bone. It favours bone ingrowth, leading to good mid-term results.