Total hip arthroplasty in Belgium: the contribution of a social health insurer to the debate.

This study describes current clinical practice and outcomes of Total Hip Arthroplasty in Belgian hospitals. Orthopaedic registries concentrate on implant related analyses and sometimes on patient reported outcomes. Our aim was to describe the extent and to generate hypotheses about the determinants of the variability of health care practices and of prosthesis survival in Belgium. Only unilateral elective primary Total Hip Arthroplasties were included. Length of stay, costs, transfusion rates and other care activities were analysed over 2008 and 2009 together. Prosthesis survival was studied using Kaplan-Meier and Cox regression hazard ratio computations over the period 2000-2009. 36798 elective Total Hip Arthroplasties have been included in a study of all members of the Belgian Christian Sickness Fund. The non-standardised ten year Total Hip Arthroplasty survival rate is 93% (Kaplan-Meier). Quality has progressed notably compared with 10 years earlier. Important variations still persist though between hospitals, for all studied indicators.

Anti-CD40 plus interleukin-4-activated human naive B cell lines express unmutated immunoglobulin genes with intraclonal heavy chain isotype variability.

Combination of anti-CD40 antibody and interleukin-4 (IL-4) induces B cell clonal expansion reminiscent of the T-dependent proliferation following antigenic challenge in vivo. We have analyzed the usage of CH genes and the presence or absence of somatic mutations within the progeny of a single human naive B cell activated with anti-CD40 + IL-4. To address this issue, single-cell cultures of naive (sIgD+) tonsillar B lymphocytes expressing the VH1-restricted G8 idiotype were set up. After culture and RNA extraction, VH1+ Ig mRNA were reverse-transcribed, amplified by polymerase chain reaction and sequenced. A single sIgD+ B cell could generate clones expressing mu, gamma 1, gamma 3, or epsilon, illustrating that the progeny of a single cell can express different isotypes in response to the same stimulus in vitro. The rate of somatic mutations affecting the immunoglobulin variable heavy chain gene was indistinguishable from the background of errors introduced by Taq polymerase.

Locking graft in the treatment of tibial pseudarthrosis.

Despite modern treatments of tibial fractures, we still have nonunions. In case of failure we used a method of treatment which has become less popular over the last decades. A rectangular inlay graft is harvested from the anteromedial tibial surface. The graft, measuring about 12 to 15 cm long, is placed over the nonunion with 2/3 of its length on one side and the remaining third on the other side. The graft is turned 180 degrees and fixed with four lag screws in the original donor site. Postoperatively, we place a nonweight-bearing cast for 3 months. The results are quite satisfactory for both nonunions and difficult multi-operated nonunions.

Internal fixation of tibial plateau fractures using the AO instrumentation.

Between January 1970 and December 1985, 76 patients (76 fractures) underwent internal fixation for tibial-plateau fractures as recommended by the AO-group (14). Fifty patients were available for follow-up. The long term results of this retrospective study are reported. Subjective results were satisfying. Forty-four percent of the patients were painfree and only 8% had severe postoperative pain, which was clearly related to osteoarthritis. Eight-eight percent of patients had no instability at follow-up. Clinical and radiographic results were evaluated for mobility, laxity and osteoarthritis. Thirty-five patients had a loss of flexion averaging 16.6 degrees. In 12 patients the average decrease in extension amounted to 7.5 degrees. Valgus increase averaged 9.7 degrees in 17 patients, and the average varus increase was 7.5 degrees in 4 patients. Seventy-four percent of patients showed no laxity at follow-up. The finding of osteoarthritis on X-ray was well correlated with the postoperative incongruence of the articular surface. It was also found to develop earlier in patients who underwent (partial) meniscectomy. Some general considerations about tibial condyles fractures are presented, and the technique used by the authors is discussed at length. The indications for internal fixation are also evaluated. The importance of adequate reduction, stable internal fixation and vigorous postoperative rehabilitation is stressed.

[Long-term results of the Krogius-Roux operation]. / Les résultats à longue échéance de l'opération Krogius-Roux.

The authors have reviewed patients treated with the operation of Krogius-Roux with a long follow-up, especially on the indication of recurrent dislocation of the patella. Thirty-nine patients out of 76 operations have been evaluated.

A reinvestigation of the Geman-Miller respiratory oscillator model.

The model of Geman-Miller of the respiratory oscillator is reinvestigated for its interpretation of the parameters: W and T. It was found that the interpretation of Geman-Miller, that the parameters T and W represent the chemosensitive feedback, is incorrect. The extension to the model made by Engeman and Swanson is not necessary to produce afterdischarge. It is demonstrated that the afterdischarge can be predicted in the original Geman-Miller model from the Jacobian Matrix.