Hard-on-hard bearing surface have been accepted as a valuable alternative for young and active patients needing a hip replacement because these combinations are resistant to wear. Initial development of alumina-on-alumina bearings faced complications such as fractures, and socket loosening. But, with the increasing number of prostheses implanted, noise occurrence appeared as a new complication. The primary aim of the present survey was to quantify the prevalence of having noise in a population receiving alumina-on-alumina hip arthroplasty.

Two hundred and eighty-four ceramic-on-ceramic hips were performed in 238 patients (126 males and 112 females) from January 2003 to December 2004. The average age at the index operation was 52.4 ± 13.4 years (range, 13 to 74 years). We used the same type of prosthesis for all patients manufactured in all cases by Ceraver-Osteal^®. Clearance between femoral and insert was between 20 and 50 microns in order to achieve minimal wear. The survey was conducted by an independent surgeon who did not participated in patients care during the last 6 months of 2007. He interviewed the patients by phone with a standardized questionnaire (appendix) that aimed to assess if noise was present and the characteristics of this noise if present. No suggestion was done on how they could describe the noise and they felt free to use the word that they considered to be the most adapted. Satisfaction was evaluated asking if the patient was very satisfied, satisfied or dissatisfied with its prosthesis.

When the noise was present, the X-ray was independently evaluated to assess if sign of component fracture was present.

Four patients (six hips) died of unrelated cause during the follow-up. Three patients (three hips) lived outside France and could not be followed (1.3%). Nine patients (ten hips) could not be traced and are considered lost to follow-up (3.8%). Two hundred and twenty-two patients with 265 hips were therefore surveyed. Among these 265 hips, 28 experienced noise generation (10.6%). It was defined as a snap for 6 patients, as a cracking sound by 6, as rustling by 6 patients, as a squeaking by 7 patients (2.6%), a tinkling by 2 patients, one patient was unable to define the sound she felt. No factor related to the patient influenced the occurrence of noise. Twelve patients were dissatisfied with the result of the hip prosthesis, 5 of them experienced noise (41.7%); 210 were satisfied or very satisfied 23 of them experienced noise (11%); this difference was significant (p=0.002). No patients required revision for noise.

The origins of noise occurrence are unknown but several hypotheses can be suggested.

Squeaking may be due to absence of sufficient lubrication. Other types of noise can be due to microseparation, occult dislocation, impingement between the femoral neck and the acetabular rim but demonstration remain an issue.

Purpose of the study: Complex fracture-dislocation of the elbow, and subsequent surgical treatment, is often the source of a stiff joint. The purpose of this study was to assess the efficacy of a therapeutic protocol combining systematic insertion of a dynamic external fixator allowing early mobilization of the elbow with restitution of the radial height and the coronoid process.

Material and methods: This consecutive series of ten patient, six men and four women, mean age 49 years, age range 27–67 years, underwent surgery from 2002 to 2004. Three patients presented a posterior Monteggia fracture (two type IIA, one type IId associated with comminutive fracture of the trochlea), four patients presented a dislocation associated with a Masson 4 fracture of the radial head and two presented inveterated dislocations diagnosed three weeks after the traumatic event. In all, seven patients presented a fracture of the radial head and six a fracture of the coronoid process. For all patients, the operation consisted in stabilization with a dynamic external fixator of the elbow associated or not with restoration of the radial height with a radial head prosthesis (n=4) and reconstitution of the coronoid process (n=6). The lateral ligaments had to be reinserted in four elbows. The comminutive fracture of the rochlea was treated with an iliac crest graft.

Results: One patient died early. One patient presented pin tract infection and four developed heterotopic ossifications. At mean follow-up of twelve months, outcome was excellent in our patients, good in four, fair in one (Mayo clinic classification). All patients had a stable elbow. The mean range of motion was 89° flexion-extension and 145° pronationsupination.

Conclusion: In this series, systematic use of external fixation for complex fracture-dislocation of the elbow joint yielded satisfactory results when the element stabilizing the joint were appropriately restored and when rehabilitation was undertaken early.

Purpose: It is widely agreed that fusion of a spinal segment modifies the mechanical behaviour of sub-jacent vertebrae. The mean centre of rotation (MCR) is defined to study changes in the mechanical behaviour at junctions. This parameter describes the relative movement of an object moving from one position to another. The purpose of this study was to describe changes in the position of the MCR after posterolateral lumbar spine fusion and to determine factors influencing these changes.

Material and methods: Fifty-one patients with posterolateral fusion with or without instrumentation of the lumbar spine limited to one or two levels were reviewed. Preoperative and last follow-up stress x-rays of the lumber spine were studied. The following parameters were determined with Spinview, a devoted software, at the level of fusion, at the three suprajacent levels, and when appropriate, at subjacent levels: disc height, intervetebral angular mobility, position of the MCR. Pre and postoperative positions of the MCR were compared with the Wilcoxon test for paired variables. Univariate and multivariate analyses were performed to search for factors influencing changes in the position of the MCR. Variables studied were: age, follow-up, extent of the fusion and its anatomic position, instrumentation, preoperative mobility of the zone to be fused, and quality of the arthrodesis at last follow-up.

Results: There were no significant changes in the position of the MCR of the first suprajacent level. Two variables exhibited significant correlation with these changes: pre and postoperative angular mobility of the future zone of fusion, and use of instrumentation. Instrumentation significantly increased variability in the position of the MCR. Postoperative mobility of the zone of fusion minimised this variability.

Discussion: Studying variations in the position of the MCR appears to reflect well changes in the mechanical behaviour of levels adjacent to the spinal fusion. Use of appropriate software should be helpful for routine applications. In our series, changes in the position of the MCR correlated well with significant increase in angular and anteroposterior mobility and also with decreased disc height at the first suprajacent level. These observations explain early degradation of junction zones observed after arthrodesis.