Posterior slope of the tibial implant and the outcome of unicompartmental knee arthroplasty.

Background: Laboratory studies have suggested that the sagittal displacements permitted by a knee replacement are influenced by the posterior slope of the tibial implant. The effect of the posterior slope of the tibial implant on the outcome of unicompartmental arthroplasty is not well known. The purpose of the present study was to assess the effect of the posterior slope on the long-term outcome of unicompartmental arthroplasty in knees with intact and deficient anterior cruciate ligaments.

Zirconia and alumina ceramics in comparison with stainless-steel heads. Polyethylene wear after a minimum ten-year follow-up.

Although alumina has been used in orthopaedic surgery since the 1970s, the long-term clinical results of zirconia have not been well documented in vivo. We studied hips with these two different ceramics during the same period and with a minimum follow-up of ten years. Because the size of the alumina and zirconia heads was different, hips with 32 mm alumina heads and those with 28 mm zirconia heads were compared with control hips with stainless-steel heads of the same size.

The natural history of symptomatic osteonecrosis in adults with sickle-cell disease.

Background: Adult patients with sickle-cell disease are at risk for the development of osteonecrosis of the hip. However, there is little information in the literature about the rate of progression of osteonecrosis once symptoms begin. The purpose of this study was to evaluate the natural history of the symptomatic hip in adult patients with osteonecrosis and sickle-cell disease.

Treatment of osteonecrosis with autologous bone marrow grafting.

Core decompression with bone graft is used frequently in the treatment of osteonecrosis of the femoral head. Many different techniques have been described. In the current series, grafting was done with autologous bone marrow obtained from the iliac crest of patients operated on for osteonecrosis of the hip.

Intercondylar notch width and the risk for anterior cruciate ligament rupture in the osteoarthritic knee: evaluation by plain radiography and CT scan.

We measured the intercondylar notch morphometrically from radiographs and CT scans of 30 osteoarthritic knees. Our purpose was to assess the accuracy of the standing posteroanterior 30 degrees flexion view in determining whether there is a critical notch width that might predict a higher risk for rupture of the anterior cruciate ligament due to osteophytes. A correlation was found between measurements made on radiographs and CT scans and the appearance of the anterior cruciate ligament at operation.

Determining humeral retroversion with computed tomography.

Background: The purpose of this study was to develop and standardize a technique in which computed tomography images are used to determine the humeral torsion angle with landmarks that can be used during surgery.

Methods: One hundred and twenty cadaveric humeri were studied. The retroversion of these anatomical specimens was measured on a computed tomography scan and compared with the direct measurements of the specimens.

Patellar impingement following unicompartmental arthroplasty.

Background: Patellofemoral complications (osteoarthritis and impingement) have been rarely reported after unicompartmental arthroplasty, and their long-term consequences are not known. The purpose of the present study was to analyze these complications following unicondylar arthroplasty.

Methods: We evaluated the results of ninety-nine unicompartmental arthroplasties that had been performed in eighty patients with osteoarthritis of the knee.

Unrecognized shoulder joint penetration during fixation of proximal fractures of the humerus.

In osteosynthesis of proximal humerus fractures, the screws frequently penetrate the joint. Using orthogonal frontal and lateral radiographs, we found unrecognized pin penetration in 8 of 30 patients during fixation of unstable neck fractures of the humerus.

[Leg length changes after upper tibial osteotomy: analysis of different preoperative planning methods].

Purpose Of The Study: The amount of change in the length of the lower limb resulting from upper tibial osteotomy depends on the type of osteotomy performed, the preoperative length of the limb, the degree of preoperative deformity and the amount of correction obtained. Wedge resection, for example, removes bone tissue and can lead to shortening. Inversely, a lengthening effect may result from correction of deformity.

Open wedge tibial osteotomy: combined coronal and sagittal correction.

A theoretical mathematical study of coronal and sagittal correction during upper tibial osteotomy is proposed. The amount of opening to be made in the coronal and sagittal planes is quantified with the help of tables. The precision of the correction is not limited by the method itself but rather by the clinical and radiological determination of the pre-operative deformity as well as the precision of the surgical technique.

Routine use of adjusted low-dose oral anticoagulants during the first three postoperative months after hip fracture in patients without comorbidity factors.

Objective: This study reports the efficacy of adjusted low-dose oral anticoagulants in the prevention of fatal pulmonary embolism after hip fracture.

Study Design: Consecutive clinical study.

Patients: Five hundred patients with hip fracture received oral anticoagulants as exclusive treatment.

Volumetric analysis of osteonecrosis of the femur. Anatomical correlation using MRI.

We tested the accuracy of MRI for the precise quantification of the volume of osteonecrosis in 30 hips (stage III). The values were compared with direct anatomical measurements of the femoral heads obtained after total hip replacement. When the area of osteonecrosis was determined visually, and manually outlined on each slice, the accuracy of the measurement of volume was satisfactory, and the mean absolute deviation between MRI and anatomical measurements was similar to that between two MRI data sets.

Open wedge tibial osteotomy with acrylic bone cement as bone substitute.

We studied the results of 245 valgus producing high tibial osteotomies performed with the use of an opening wedge technique and rigid internal fixation followed by early passive and active motion of the knee. Previous studies have used iliac bone grafts or hemicollastasis held by an external fixator for opening the osteotomy. In our series the opening was obtained by a block of cement interposed in the postero-medial part of the osteotomy.

Inactivation of HIV by application of heat and radiation: implication in bone banking with irradiated allograft bone.

We developed methods for inactivating the human immunodeficiency virus by heat and ionizing radiation and tested the effects of these treatments on the mechanical strength of bone. Simultaneous use of heat and radiation caused a considerably greater inactivation of HIV than the additive effects of the two separate treatments, but also caused a significant reduction in the maximum load sustained by the bone specimens tested with an Instrom machine. Application of the same doses but given in the sequential fashion of radiation followed by heat also caused marked inactivation of HIV and had less effect on the mechanical strength of the bone.

Bilateral hip osteonecrosis: influence of hip size on outcome.

Objective: To measure the volume of osteonecrosis in 30 patients with disease in both hips (one side with collapse and the other without at Ficat stage I).

Method: The volume of the osteonecrosis was measured by magnetic resonance imaging.

Results: The progression to collapse was influenced by the size of the lesion in each patient.

[Hand on composite prosthesis after resection of peri-acetabular sarcoma].

Purpose Of The Study: To improve function after pelvic resection involving theacetabulum we have used an anatomic composite implant built with screws and cement.

Material And Method: Since 1990, 27 patients with peri-acetabular bone sarcoma have been treated by extensive resection followed by "hand on innominate prosthesis with constrained total hip prosthesis. The hand on innominate prosthesis was made of a titanium cup, a set of long titanium screws and 2 or 3 packs of gentamycin loaded ciment.

Proximal entry for intramedullary nailing of the tibia. The risk of unrecognised articular damage.

The risk of articular penetration during tibial nailing is well known, but the incidence of unrecognised damage to joint cartilage has not been described. We have identified this complication in the treatment of tibial fractures, described the anatomical structures at risk and examined the most appropriate site of entry for tibial nailing in relation to the shape of the bone, the design of the nail and the surgical approach. We studied the relationship between the intra-articular structures of the knee and the entry point used for nailing in 54 tibiae from cadavers.

Interleukin-6 in the blood of patients with total hip arthroplasty without loosening.

Patients with total hip arthroplasty were screened for the presence of proinflammatory cytokines in the systemic circulation. Only increased levels of interleukin-6 were detected in patients having had total hip arthroplasty more than 10 years ago. These increased levels of interleukin-6 were associated with a decrease in bone mineral density associated with polyethylene wear and with radiologic osteolysis in some patients.

Do voids in a femoral cement mantle affect the outcome?

A total of 156 ceramic versus ultra-high-molecular-weight polyethylene hip prostheses were followed for a minimum of 10 years to compare the outcome of the femoral component in 2 groups: those with and those without radiologically detectable voids in the cement mantle. No significant difference was observed. In this series, voids with a 5-mm diameter had no effect on loosening of the femoral component over a 10-year period.

Decrease in the mesenchymal stem-cell pool in the proximal femur in corticosteroid-induced osteonecrosis.

We have evaluated bone-marrow activity in the proximal femur of patients with corticosteroid-induced osteonecrosis and compared it with that of patients with osteonecrosis related to sickle-cell disease and with a control group without osteonecrosis. Bone marrow was obtained by puncture of the femoral head outside the area of necrosis and in the intertrochanteric region. The activity of stromal cells was assessed by culturing fibroblast colony-forming units (FCFUs).

[Influence of irradiation on the risk of HIV virus transmission by bone allograft].

Purpose: The purpose of this study was to determine, when assuming the worst case scenario of bone contamination, the sterility assurance level in bone transplantation treated by irradiation and after donor screening.

Material And Methods: The virus: We employed the HIV-1, LAV-1 as our reference strain, which has always been cultured on normal human cells (and has therefore never been in contact with cell lines). To test viral virulence, we used a very sensitive cell line: MT2 cell line, a T lymphoblastoid cell line which is HTLV-I positive and is sensitive to HIV-1/LAV-1 infection.

[Evaluation of the risk of mediastinal or retroperitoneal injuries caused by dorso-lumbar pedicle screws].

Purpose Of The Study: Within an anatomical and a clinical study, the authors employed computerized tomographic scans to evaluate the risks of anterior surrounding tissues injuries during screw insertion.

Material And Methods: CT scans of 20 patients suffering from cardiac disease were reviewed retrospectively. Scans through the thoracic and lumbar spine were obtained using 6 mm slice thickness.