Total knee arthroplasty in femorotibial instability.

Regarding the reasons for failure of conventional knee arthroplasty a lot of work has be done on loosening and polyethylene wear, often leading to recurrent deformation and osteolysis. But there are only few reports concerning femorotibial instability. This instability is related to failure of the collateral ligaments which can often be found in cases of important frontal deformity both in the varus and valgus knee or in rheumatoid arthritis.

Ambulatory treatment of multidrug-resistant Staphylococcus-infected orthopedic implants with high-dose oral co-trimoxazole (trimethoprim-sulfamethoxazole).

We examined the effectiveness and safety of high-dose oral co-trimoxazole (trimethoprim-sulfamethoxazole) for the treatment of orthopedic implants infected with multidrug-resistant Staphylococcus species. The prospective study was conducted between 1989 and 1997 in a university medical center with ambulatory-care services. Patients eligible for the study consisted of those from whom multidrug-resistant Staphylococcus spp.

Three-dimensional morphology of the proximal femur.

In the field of uncemented hip arthroplasties, secondary biologic fixation of femoral implants depends directly on the quality of the primary stability. Metaphyseal filling and a good fit between the implant and the proximal femur improve initial stabilization and optimize the transmission of forces to the bone. Precise knowledge of the three-dimensional femoral shape is essential to the design and selection of adapted implants.

Psoriasis is a risk factor for hip-prosthesis infection.

Risk factors for hip and knee prosthesis infection have been described, but not psoriasis. Eighty five infected patients from different centers and 202 non infected patients were included in a case-control study. Fifteen of 85 infected patients (17.

Oral treatment of Staphylococcus spp. infected orthopaedic implants with fusidic acid or ofloxacin in combination with rifampicin.

Oral therapy of staphylococcal infection of orthopaedic implants with 900 mg/day rifampicin combined with either 1.5 g/day fusidic acid for 5 days followed by 1 g/day thereafter, or 600 mg/day ofloxacin was compared. Patients with an infected hip were treated for 6 months, with removal of any unstable prosthesis after 5 months' treatment and those with an infected knee prosthesis were treated for 9 months, with removal of the prosthesis after 6 months of treatment.

[Modularity of prostheses].

Modularity allows a large choice of implants, like the use of cementless acetabular cups inducing bone ingrowth. The length and direction of the neck may also be adapted to be new joint. Risks of modularity are: implant dissociation, restriction of joint mobility, and especially augmentation of metal debris as a potential source of polyethylene wear.

[Custom made hip prostheses : principles and design].

The design of a custom made hip prosthesis includes two parts: intramedullary and extramedullary. The design requires X-ray data including a full weight bearing view of the limbs, a frontal pelvis, frontal and sagittal views of the hip. Several CT-Scan cuts are also necessary at every 5 mm of the upper femur and then four cuts are important to design the extramedullary part: at the level of the true acetabulum, above the lesser trochanter to assess the torsion of the upper femur, the knee condylar axis, and the second metatarsal axis in the foot.

Uncemented and custom made hip prostheses in patients younger than 50 years.

One hundred and nine hip arthroplasties using custom cementless stems performed in patients 50 years of age or younger were reviewed after a minimum follow-up of two years. The etiologies included mainly major deformation of the upper femoral metaphysis such as CDH or after osteotomy and some cases of AVN or post-traumatic osteoarthritis. Two stems (1,8%) were revised and the overall clinical and radiographic failure rate was 5,5%.

Cell surface expression of surrogate light chain (psi L) in the absence of mu on human pro-B cell lines and normal pro-B cells.

Surrogate light chains (psi L) encoded by lambda-like (lambda 5) and VpreB genes play a critical role in controlling the early steps of B cell differentiation. We prepared new anti-VpreB monoclonal antibodies (mAb) (3C7/6F6) which preferentially recognize the VpreB epitope at the cell surface of human cell lines that do not express the mu chain. These mAb provide the first characterization of human pro-B cell lines expressing surface psi L.

[Transfusion strategy in programmed hemorrhagic orthopedic surgery].

Objectives: Prospectively assess autologous blood transfusion for programmed orthopedic procedures.

Methods: From January 1 to December 31 1993, 307 patients underwent programmed orthopedic procedures: total hip replacement (n = 191), total knee replacement (n = 83) and osteotomy (n = 33). General (94%) or spinal anesthesia (6%) was used.

Is there a place for patellofemoral arthroplasty?

Indications for patellofemoral arthroplasty were studied based on a 2- to 10-year followup review. Of 183 patellofemoral prostheses implanted between 1980 and 1990, 104 were associated with unicompartmental arthroplasty, and 79 were implanted alone. Thirteen patients were lost to followup.

Why Use a Custom-made Hip Prosthesis? A 10-Year Experience.

Total hip arthroplasty (THA) is now a routine procedure used to relieve pain and restore function. The results of the procedure depend on several factors: implant positioning, bone implant fixation, bone stock, and restoration of a physiological musculo-articular unit. The prosthesis may be cemented or used without cement.

Oral rifampin plus ofloxacin for treatment of Staphylococcus-infected orthopedic implants.

We examined the effectiveness and safety of the combination of rifampin plus ofloxacin given orally for treating prosthetic orthopedic implants infected with staphylococci. The prospective cohort study was conducted in a referral public hospital with ambulatory care services between 1985 and 1991. Consecutive patients from whom Staphylococcus organisms susceptible to the study drugs were isolated from their orthopedic implants and who had no contraindication to the treatment were eligible for the study.

[Biomechanical study of the Oxford knee prosthesis with mobile meniscus].

Polyethylene meniscal bearing of the Oxford knee produce conforming surfaces and are free to move with knee movements. We studied polyethylene wear of 23 meniscal bearings implanted after a mean time of 38 months. The mean penetration rate of the polyethylene was 0.

Polyethylene wear in meniscal knee replacement. A one to nine-year retrieval analysis of the Oxford knee.

We recovered 23 meniscal bearings from 18 failed bicompartmental Oxford knee prostheses. They had been implanted for one to nine years. The minimum thickness of the retrieved bearings was measured and compared with the thickness of 25 unused bearings.

The morphology of the proximal femur. A three-dimensional radiographic analysis.

Biological fixation of cementless femoral implants requires primary stability by optimal fit in the proximal femur. The anatomy of the bone must then be known precisely. We analysed in vitro the accuracy of bone measurements of 32 femurs and compared the dimensions obtained from radiographs and CT scans with the true anatomical dimensions.

[Bilateral genu flessum in a patient with Cooley's disease].

An original case of bilateral knee flexion of sixty degrees is reported in a twenty-four year old mean, with a beta-thalassemia diagnosed at three years old. The defect of straightening is the result of premature epiphysis fusion, only posterior in this case, and affecting preferentially the tibia. That is the reason why the flexion has been corrected by a bilateral tibial soustraction osteotomy, under the tibial tuberosity.