European Database of Explanted UHMWPE Liners from Total Joint Replacements: Correlations among Polymer Modifications, Structure, Oxidation, Mechanical Properties and Lifetime In Vivo.

This contribution lays the foundation for the European database of explanted UHMWPE liners from total joint replacements. Three EU countries (Czech Republic, Italy and Spain) have joined their datasets containing anonymized patient data (such as age and BMI), manufacturer data (such as information on UHMWPE crosslinking, thermal treatment and sterilization), orthopedic evaluation (such as total duration of the implant in vivo and reasons for its revision) and material characterization (such as oxidative degradation and micromechanical properties). The joined database contains more than 500 entries, exhibiting gradual growth, and it is beginning to show interesting trends, which are discussed in our contribution, including (i) strong correlations between UHMWPE oxidative degradation, degree of crystallinity and microhardness; (ii) statistically significant differences between UHMWPE liners with different types of sterilization; (iii) realistic correlations between the extent of oxidative degradation and the observed reasons for total joint replacement failures. Our final objective and task for the future is to continuously expand the database, involving researchers from other European countries, in order to create a robust tool that will contribute to the better understanding of structure-properties-performance relationships in the field of arthroplasty implants.

Extensive osteolysis caused by polyethylene particle migration in an anatomical hydroxyapatite-coated hip prosthesis: 10 years' follow-up.

We report our 10-year follow-up results of 630 consecutive Anatomique Benoist Giraud I hip prostheses implanted between June 1990 and December 1995. At this time, 520 were satisfactory and 25 had been revised. Although the majority of patients remained asymptomatic at the end of follow-up, the real survivorship of the implant was less than 91% (33 patients who were in the waiting list for revision due to osteolysis at that time were revised by December 2007). On the other hand, radiographic outcomes were of concern: around 90% of patients showed progressive stress shielding and large granulomatous lesions in the proximal femur, and more than 82% of patients exhibited polyethylene wear in excess of 1 mm (mean=1.69 mm).

Long-term remodeling in proximal femur around a hydroxyapatite-coated anatomic stem: ten years densitometric follow-up.

Bone remodeling after a hip arthroplasty has been quantified with dual energy x-ray absorptiometry, usually for short-term follow-up. We used this technique to determine the long-term remodeling produced by a hydroxyapatite-coated, anatomic stem. Eighty patients with unilateral hip osteoarthritis were included in the study. The contralateral, healthy hip was taken as control. Bilateral dual energy x-ray absorptiometry scans were done before the surgery, at 15 days, and 1 and 10 years postoperatively. There was a decrease of bone mineral density in zones 1 and 7, which ranged from 12.2% to 27.3% at the end of the first year. There were no changes in zones 1 to 6 from the 1st to the 10th year, but there was a late decrease, up to 42.9%, in zone 7. The changes of bone mineral density promoted by this stem occurred in the first postoperative year. Late loss was seen only in area 7.

Changes in periprosthetic bone remodelling after redesigning an anatomic cementless stem.

The aim of this prospective cohort study was to determine the densitometric relevance of minor design modifications of a cementless stem designed to improve proximal load transfer. We used a prospective cohort study with densitometric analysis over a five-year period of two groups of patients with primary osteoarthritis. The first group, 56 hips, received the first version of the ABG stem (ABG-I); the second group, 54 hips, had the ABG-II stem. The results obtained with the ABG-I stem showed a decrease of bone density in proximal areas that ranged from 13% to 37%. However, the new design had a decrease of the same areas that ranged from 9% to 23%. These differences were noted at the end of the first post-operative year and remained stable, except in zone 7, where they were progressive. There is little evidence that the modified stem reduces femoral bone density loss.

Minifragment plating for fractures of the distal radius.

Twelve patients with fracture of the distal radius were treated by open reduction and internal fixation with titanium minifragment plates. There were 8 women and 3 men, with a mean age of 42 years. The mean follow-up was 18 months. According to the score of Gartland and Werley, 11 patients had an excellent result and one patient had a good result. All patients reported no pain in their activities of daily living and were satisfied with the result. All workers returned to work. One patient developed reflex sympathetic dystrophy which resolved with treatment. No patients needed plate removal because of irritation of the tendons. The results obtained with this technique appear promising, although more cases are needed to achieve a definitive conclusion.

Aggressive digital papillary adenocarcinoma of the hand: an unsuspected malignant tumour of the sweat glands.

We report a case of a man with a tumour of the palm that grew slowly for five years, being repeatedly diagnosed as a synovial cyst. Histopathological diagnosis showed an aggressive digital papillary adenocarcinoma. Thirty-eight months postoperatively there was neither recurrence nor signs of metastases.

Management of types III and IV acetabular deficiencies with the longitudinal oblong revision cup.

Thirty-five longitudinal oblong revision (LOR) cups were used to reconstruct 29 type III and 6 type IV acetabular defects. Intraoperatively, we considered that cup contact was complete when we achieved a continuous contact between the cup periphery and the acetabular rim. When there were areas with a lack of contact, we considered that the contact was partial or incomplete. All patients were followed up for 4 to 8 years (mean = 6.3 years). At the latest follow-up, 30 cups were stable (85.8%) and 5 had migrated (14.2%). We found a significant relation between incomplete cup contact with the acetabular rim and subsequent failure (P = .042). The abduction angle was significantly increased in the group of unstable cups (P = .032) because of the migration of the acetabular component that became more vertical. Pain, limp, use of walking aids, functional level, and limb-length discrepancy significantly improved postoperatively (P < .0001). The Harris hip score improved from a mean preoperative score of 37 points to that of 79 points (P < .01). This implant showed satisfactory stability at early to midterm follow-up.

Carpal tunnel syndrome due to heterotopic ossification.

We report a rare case of carpal tunnel syndrome due to heterotopic ossification in the carpal tunnel in a 34-year-old woman without antecedents of neurological injury, musculoskeletal trauma, or metabolic disorder. To our knowledge, this is the first reported case. Incomplete excision of heterotopic ossification resulted in partial relief of symptoms.

Seven to 10 years followup of an anatomic hip prosthesis: an international study.

Hypothetically, hydroxyapatite-coated anatomic-shaped femoral stems and hemispheric acetabular cups should improve biologic fixation of the implant and strength transmission to the bone, improving unsatisfactory results of the first cementless hip prosthesis focused on the stress-shielding phenomenon at the femur and failure of the threaded acetabular cups. A consecutive series of 312 patients who had primary Anatomique Benoist Giraud hip prostheses unilaterally implanted were followed up. We analyzed the clinical and radiographic results and report the outcomes 7-10 years after implantation. Two hundred thirty-two patients were assessed at 7-10 years. The survival rate for the implant was 96.8%; 77.2% of patients had no pain, 72.4% maintained total mobility, and 62.9% were able to walk without restrictions. However, radiologic assessment shows that problems improved but did not disappear. More than 55% of femurs had signs of proximal stress-shielding develop. More important, substantial polyethylene wear was observed in at least 62% of the acetabular inserts at 7-10 years followup.