Purpose: Instability is a major cause of revision total hip arthroplasty (rTHA). It was the third leading cause (5%) after aseptic loosening (75.7%), and infection (7.2%) in the Swedish registry for 2000. The rate of dislocation is however variable depending on the reported series. We conducted a statistical analysis of nearly 3000 files of rTHA to study factors favouring failure.

Material and methods: AVIO, a watch association for orthopaedic implants, was created in 1994 to evaluate factors favouring failure of THA in France, and to furnish statistical data on prosthesis revision. About one hundred orthopaedic surgeons throughout France completed an information card for each revision for a five year period (September 1994 to September 1999). A total of 2926 card were analysed. Patient data (gender, side, number of revisions, age at implantation, age at removal, reason for THA, reason for revision, duration of THA) were cross analysed. The statistical analysis was conducted with chi-square tests and non-parametric tests. Significant results were compared with data in the literature. We present here the results concerning dislocation as the reason for revision.

Results: The rTHA for dislocation accounted for 9.2% of the revisions. Dislocation was the primary reason for revision in patients with repeated revisions and was also the main reason for revision in patients aged over 70 years (20.6%). In this group of older patients, 72.8% of the prostheses were implanted for degenerative disease.

Discussion: The original finding in this study, not clearly reported in the literature, is that dislocation is the primary cause of revision after 70 years, coming before aseptic acetabular loosening. Although mentioned by Charnley in 1979, very few studies (Newington in 1990, Edelund in 1992) have studied the relationship between dislocation and age.

Conclusion: Patient-related factors play an important role in the stability of THA. After 70 years, dislocation becomes the primary reason for revision and should be taken into consideration in our ageing population. This study has led us to modify our therapeutic strategy in patients aged over 70 years.

Purpose: Classification of the lower extremity of the radius does not have prognostic value. We propose a severity score based on the initial radiographic presentation. We tested five radiographic criteria to determine their correlation with the final outcome (function, radiographic aspect, subjective assessment).

Material and methods: The study series included 86 patients (91 wrist fractures) hospitalised between January 1998 and March 2000. The initial radiological severity score (IRSS) was noted on a scale of 20 points (five items): comminution (extent, aspect, localisation), cancellous impaction (metaphyseal, epiphyseal, both), ulnar fractures (localisation), severe fracture deviation, carpal and ligamentary injury. Each item was scored 0 to 4. Higher IRSS indicated a more severe fracture. Initial radiograms with or without traction were analysed carefully. Intra- and inter-observer reliability was proven. To evaluate the prognostic significance of the IRSS, the final outcome was scored using four items: motion (palmar and dorsal flexion, radial and ulnar inclination, pronosupination), final radiogram (frontal and sagittal tilt, index of deviation), subjective outcome (very good, good, fair, poor), osteoarthritis (one or two facets involved). The outcome score was noted on a 20 point scale (higher score indicating poorer outcome).

Results: We found a statistically significant relationship between the IRSS and the final outcome score.

Discussion: Precise analysis demonstrated other significant correlations with the IRSS: skin opening and occupational accident were generally related with poor initial scores. There was no statistically significant relationship with age, gender, high or low-energy trauma, associated upper limb damage, multiple injury, osteoporosis or reflex dystrophy. The final outcome was statistically and logically related with age, osteoporosis, open fractures, but also with reflex dystrophy and degree of secondary displacement.

Conclusion: This study validated the prognostic severity score of fractures of the lower extremity of the radius. The IRSS can be determined solely from the initial radiograms with or without traction. This score should be useful to modulate aggressive treatment as a function of the patient’s age and functional demands.

Purpose: The purpose of this study was to analyse the epidemiology, management, and cure rate in 49 infected shoulder prostheses.

Material and methods: This retrospective multicentric study included 2396 shoulder prostheses with at least two years follow-up (mean 34 months): 2146 first intention prostheses and 250 revision prostheses. Results were analysed as a function of: — time to development of infection: 12 acute (less than 2 months after surgery), 6 subacute (2 to 12 months after surgery), and 29 chronic (more than one year after surgery); — cause leading to the first intention implantation; — therapeutic management of the infection.

Results: Two patients died and five were lost to follow-up. The results were thus evaluated in 42 patients. The rate of infection in this series was 1.8% for first intention prostheses and 4% for revision prostheses. Fracture, joint degeneration with massive rotator cuff tears and radiation-related necrosis were factors of high risk of infection (25% for radiation-related necrosis). Thirty patients achieved cure (71%). Three patients had a doubtful cure and nine patients remained infected (29%). The Constant score moved from 20 points before revision to 38 points. Active elevation was below the horizontal (74°). Eighty percent of the acute infections were cured but one-third of the cases required a new revision. Single-procedure replacements provided better functional results and better cure rates. There was a strong correlation between early surgical intervention, adapted antibiotic treatment, and rate of cure.

Discussion: The overall rate of infection in this series is comparable with data in the literature. The rate of certain cure of infection was disappointing (71%). For acute infections, the patients underwent surgery too late and treatment was too aggressive. If there is a doubt about possible infection, revision should be performed as early as possible to allow cure and preserved function. For chronic infections, time to diagnosis and management was too long. This led to anthroplastic resection in one-third of the patients. The choice of the antibiotics and duration of treatment, associated with rigorous surgical technique, should allow switching from arthroplastic to resection prosthetic replacement using one or two surgical times which, for these infected shoulder prostheses, appears to offer the best compromise between cure and function.

The management and outcome of treatment in 42 patients (49 shoulders) with an infected shoulder prosthesis was reviewed in a retrospective multicentre study of 2343 prostheses. The factors which were analysed included the primary diagnosis, the delay between the diagnosis of infection and treatment and the type of treatment. Treatment was considered to be successful in 30 patients (71%). Previous surgery and radiotherapy were identified as risk factors for the development of infection. All patients with an infected prosthesis had pain and limitation of movement and 88% showed radiological loosening. In 50% of the shoulders, the antibiotics chosen and the length of treatment were considered not to be optimal. The mean follow-up was 34 months. Antibiotics or debridement alone were ineffective. In acute infection, immediate revision with excision of all infected tissue and exchange of the prosthesis with appropriate antibiotic therapy gave the best results. Multidisciplinary collaboration is recommended.