We have designed a prospective study to evaluate the usefulness of prolonged incubation of cultures from sonicated orthopaedic implants. During the study period 124 implants from 113 patients were processed (22 osteosynthetic implants, 46 hip prostheses, 54 knee prostheses, and two shoulder prostheses). Of these, 70 patients had clinical infection; 32 had received antibiotics at least seven days before removal of the implant. A total of 54 patients had sonicated samples that produced positive cultures (including four patients without infection). All of them were positive in the first seven days of incubation. No differences were found regarding previous antibiotic treatment when analysing colony counts or days of incubation in the case of a positive result. In our experience, extending incubation of the samples to 14 days does not add more positive results for sonicated orthopaedic implants (hip and knee prosthesis and osteosynthesis implants) compared with a conventional seven-day incubation period.

Cite this article: Bone Joint J 2013;95-B:1001–6.

Between July 2000 and December 2002, 263 consecutive patients across 5 surgical centers underwent to a revision surgery of a failed acetabular component in which TM acetabular components were used.

There were 150 women and 113 men with a mean age of 69.5 years.

The indication for acetabular revision was aseptic loosening in 186 cases (70.7%)

Clinical evaluations were performed using the Harris hip score, the WOMAC and UCLA activity scale.

Implant and screw position, polyethylene wear, radiolucent lines, gaps, and osteolysis were assessed. Preoperatively, acetabular bone deficiency was categorized using the classification of Paprosky et al.

Statistical analysis was performed using nonparametric correlations. Standard life table was constructed, and the survival rate was calculated by means of Kaplan-Meier method.

The overall mean follow-up was 73.6 months (range, 60–84 months), and no patient was lost to follow-up.

The preoperative HHS rating improved from a mean of 43.6 ± 11.4 before revision, to a mean of 82.1 ± 10.7.

None of the patients was re-revised for loosening. The cumulative prosthesis survival was 99.2% at 5 years.

There was no correlation found between the various degrees of acetabular bony defect and the magnitude of clinical results (independent of pre-revision Paprosky grade). The use of component augments allowed us to minimize the volume of morsellized allograft used for defect repair.

TM acetabular component demonstrates promising midterm results similar to those reported by other authors.

Advanced MRI cartilage imaging such as T₁-rho (T1ρ) for the diagnosis of early cartilage degradation prior to morpholgic radiological changes may provide prognostic information in the management of joint disease. This study aimed first to determine the normal T1ρ profile of cartilage within the hip, and secondly to identify any differences in T1ρ profile between the normal and symptomatic femoroacetabular impingement (FAI) hip. Ten patients with cam-type FAI (seven male and three female, mean age 35.9 years (28 to 48)) and ten control patients (four male and six female, mean age 30.6 years (22 to 35)) underwent 1.5T T1ρ MRI of a single hip. Mean T1ρ relaxation times for full thickness and each of the three equal cartilage thickness layers were calculated and compared between the groups. The mean T1ρ relaxation times for full cartilage thickness of control and FAI hips were similar (37.17 ms (sd 9.95) and 36.71 ms (sd 6.72), respectively). The control group demonstrated a T1ρ value trend, increasing from deep to superficial cartilage layers, with the middle third having significantly greater T1ρ relaxation values than the deepest third (p = 0.008). The FAI group demonstrated loss of this trend. The deepest third in the FAI group demonstrated greater T1ρ relaxation values than controls (p = 0.028).

These results suggest that 1.5T T1ρ MRI can detect acetabular hyaline cartilage changes in patients with FAI.

Introduction and purpose: Different bearing surfaces have been used to prevent osteolysis, such as alumina-alumina. We present here an analysis of the results of a prospective multi-center study of complications related to the use of alumina-alumina bearings.

Materials and methods: In 4 hospitals 319 cups with hydroxyapatite stems and alumina-alumina bearing surfaces were implanted with a mean follow-up of 5.6 years (range: 3–8). The mean age of the patients was 52.7 (range: 14–70). Alumina wear was calculated by means of a special program.

Results: Revision was performed of 5 cups and 2 stems. In one hip with a horizontal acetabular angle (35°) and a thin alumina liner (size 50/32), an acetabular liner fracture occurred 36 months after surgery. The probability of not undergoing revision due to any cause was 96.9% (CI 95%:94.7–99.1%). None of the patients reported any type of noise. All the non-revised cases showed good results both on clinical and X-ray exam at the end of the follow-up. The difference between the center of the head of the femur and the center of the head of the cup at 6 weeks after surgery was −2.45+0.53 mm, with no further changes seen during the follow-up.

Conclusions: These data suggest that the prosthetic alumina-alumina bearing surface has excellent results over 5 years and that alumina fractures are infrequent. No changes were seen in terms of the penetration of the femoral head in any case. Longer follow-ups are necessary to determine if the reduction of wear translates into less osteolysis and loosening.

Introduction. Alternative bearing surfaces to polyethylene have been introduced to avoid the appearance of osteolysis in THR. The aim of this study has been to perform prospective analysis of the data from a multi-center clinical trial for assessing the incidence of early alumina-specific-complications.

Material and Methods. We analysed 310 Cerafit cups associated with a Multicone-HA stem using alumina-on-alumina bearings implanted in four institutions from 1999 to 2003, with a mean follow-up of 4.7 years. Patients’ mean age was 52.8+13.4 years. Linear femoral head penetration was analysed using a software package.

Results. There were 4 revisions: 2 revisions due to dislocations resulting poor surgical technique (1 cup and 1 stem) and 2 revisions after a trauma (1cup and 1 stem). There was 1 alumina liner fracture 36 months after implant in a hip with a horizontal acetabular angle (35°) and a thin alumina liner (size 50/32). The other cases showed good clinical and radiographic results at the end of follow-up. The radiographic difference between the femoral head and cup centres at 6 weeks postsurgery was 2.48+0.60 mm, without changes in the course of the follow-up. The mean linear femoral head penetration was unreliable (0.00186+0.0032 mm/year) because it was below the mean error for the measurement system.

Conclusions. These data demonstrate that Cerafit Alumina-on-Alumina prostheses show excellent results after 5 years. Liner fractures are uncommon. Despite the blurred alumina images, the digitized method, although not totally accurate and used only for a general estimate, allows us to measure the approximate distance between the centre of the cup and the centre of the femoral head. Changes in linear femoral head penetration were not seen in any hip. Continued follow-up should determine if reduction in wear among the alumina-on alumina bearings results in less osteolysis.

Introduction. Tantalum is a pure metallic element and is attractive for use in orthopaedic implants because it is one of the most biocompatible metals available for implant fabrication. The potential advantages for the use of porous tantalum in total hip arthroplasty include: 1) excellent bone and tissue ingrowth observed histologically; 2) direct polyethylene intrusion into the metal substrate. This allows the elimination of any potential backside wear in the monoblock cup; 3) The two-piece design consist of a tantalum shell with screw holes for fixation into the dome of the ilium and posterior column. A polyethylene liner is cemented into the tantalum shell to eliminates backside motion. In addition, acetabular augments of porous tantalum have been developed for use in restoration of major bone deficiencies.

Prospective study on a case serie of 113 THA’s performed by two surgeons in a single institution.

Material & Methods. From 2000 to December 2003, 113 hips have undergone arthroplasty using porous tantalum implants consisting of 54 primary hip arthroplasties and 59 revision THA’s. The patients where evaluated clinical and radiographically every 3 month during the first year, and after yearly. Mean patient age was 64,2 years, (range 44–87); with 59% males and 41% females.

Results. No patients died or lost to follow-up. No further surgeries of the involved hip. No radiographic signs of loosening of the acetabular component according to the criteria of Hodgkinson et al. No problems specifically from the use of acetabular augments or extra screws has been noted. Of the revision series, a total of 16 cases have received acetabular augments.

Complications included 1 superficial infection, 2 dislocations. No vasculo-nervous complication; and in 2 cases technical difficulties to achieve good fixation due to ethiology of the THA (desarthrodesis).

The average Harris hip score improved from 48 to 89 following primary surgery.

Discussion and Conclusions Tantalum acetabular components for primary and revision hip surgery have performed well for up to 3 years, and have excellent stability.

The two-piece acetabular shell and augments permits the reconstruction of every acetabular bone defect.

Aims: Hydroxyapatite HA-coated hip replacements were introduced in the late 1980ñs when the intermediate term results of porous-coated hip replacements were not proving to be satisfactory with a high rate of thigh pain even well þxed implants. The aim of our retrospective study was to review the results of group of patients who underwent HA-coated cup between 1992 and 2001, and evaluate the clinical and radiological outcome of the HA-coated cup over a 7 to 10 year period. Methods: In a multicenter study between 1992 and 2001 were used 2899 Bihapro cups (Biomet-Merck). This is a press-þt model with a porous surface coated with hydroxyl-apatite and three peripheral þns to improve primary þxation and also dome holes to allow the use of bone screws. In 993 (34.2%) cases a posterior approach was performed, lateral approach in 1419 (49%) and the anterior approach in 487 (16.8%) cases. All patients were mobilised on the second post-operative day once drains had been removed. They were encouraged to use crutches while walking for the þrst 6 weeks. Results: 35 patients (1.2%) showed dislocation. 47% of the seires had some degree of periarticular ossiþcation one year after surgery; the approach used did not show signiþ-cative differences. The survival study was done using Kaplan-Meierñs score. The end point for failure in this study was the need to perform aseptic revision surgery; being the survival at 9 years of 99.49% (CI 95%: 99.08 Ð 99.90).Conclusions: The acetabular shells with plasma spray porous coating in combination with HA results stable at mid term. The supplementary þxation of the three peripheral þns avoids micromotion optimizing lon-term þxation.

Introduction and Objectives: The increase in hip replacement surgery in recent years as a consequence of the aging population and a greater demand placed on joints by our current lifestyle has caused an increase in related complications. The rate of intraoperative periprosthetic fractures is between 0.8 and 2.3%, and postoperative fracture rates reach 0.1% in some studies. This type of fracture is usually complex, and treatment is almost always quite difficult.

Materials and Methods: This study concentrates on peri-prosthetic hip fracture as a postoperative complication examining cases treated during the last 5 years. We have included cases of cemented and cementless partial and total arthroplasty. In this study, we did not include intra-operative fractures (secondary to surgical manipulation, as a result of reaming, cementing, or impaction of prosthetic components) because an irregular clinical history was associated with such cases, only reflecting those which required some type of synthesis, particularly cer-clage. The Johanson scale and the AAOS classification were used to classify fractures.

Results: Of 30 periprosthetic fractures recorded during the study period, 11 patients (36.7%) were males and 63.3% were female. Of fractures of the femoral diaphysis, more than half were Johanson Type II. Only one case involved the acetabulum. Nearly 17% required revision of some prosthetic component, and about one-third could be resolved orthopaedically. Of cases treated surgically, most complications were related to the surgical wound.

Discussion and Conclusions: The type of treatment used depends on various factors, such as type of fracture and fracture line, patient age, prosthetic loosening, etc. Individualised treatment is therefore the standard. We have observed no abnormalities in bone healing. Although this type of fracture is fortunately rare, we consider good preoperative planning and a thorough postoperative follow-up to be very important for the correct resolution of this difficult problem.