[Fracture of the ceramic head in total hip prosthesis. Apropos of 2 cases].

Fracture of the ceramic head of a replacement arthroplasty of the hip has been encountered in 2 patients. After studying the literature the causation of such fractures has been assessed. Defects in manufacture of the prosthesis, damage during its handling and incorrect use may be responsible, with the tapered neck being the principal instrument of failure.

[Results of total knee prostheses with or without preservation of the posterior cruciate ligament].

Purpose Of The Study: This study was undertaken to assess the functional repercussion of retention or sacrifice of the posterior cruciate ligament in total knee replacement.

Material: Two homogeneous randomised series of 24 cases were matched. They concerned primary total knee arthroplasty for osteoarthritis using the same prosthetic design.

[Osteoid osteoma of the sigmoid notch of the ulna].

We report one case of osteoid-osteoma (0.0.) developed in the radio-ulnar proximal joint in a young male adult.

[Digastric trochanterotomy in reoperated total hip prostheses. Apropos of 53 cases].

A new technic of trochanteric osteotomy preserving the attachment of the vastus-lateralis is described: this procedure leads to mobilize the greater trochanter which becomes interposed between the gluteus-medius upward and the vastus-lateralis downward. A true digastric muscle is therefore realized where functional integrity is preserved. The biomechanical and vascular advantages of this surgical approach are used in revisions of total hip arthroplasties in which a large exposure is often required.

[The use of Müller acetabular rings in revision surgery of total hip prosthesis. Apropos of 141 cases with a minimal 5-year follow-up].

211 acetabular reinforcement rings of Müller have been implanted when revising total hip arthroplasties, 141 were followed up for more than 5 years. In 52 per cent of cases, an acetabular reconstruction using bone grafts was associated: in 51 cases, a bank allograft was used, one third of the grafts had only a role of filling. Theses rings remained remarkably stable and there were only 2 lacks of fixation: 1.