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P Hernigou

Publications and source records attributed to P Hernigou.

At least 19 recordsLinked to original sources
PubMed2006

[Intra- and postoperative fractures of the femur in total knee arthroplasty: risk factors in 32 cases].

PURPOSE OF THE STUDY: We reviewed fractures of the distal femur occurring during or after total knee arthroplasty in order to identify risk factors. MATERIAL AND METHODS: Twelve intraoperative fractures occurred between 1990 and 2000 among 617 total knee arthroplasties performed during this period. The circumstances of these fractures were noted in comparison with other prosthetic implants. Twenty other fractures of the distal femur occurred in 20 patients who had had a total knee arthroplasty during the same time period. Mean patient age at surgery was 72 years (range 69-77). In addition to demographic data, we noted risk factors: bone demineralization related to general condition, rheumatoid arthritis or corticosteroid therapy, trochlear notch prior to the trochlear cut, bone resorption under the femoral implant, repeated knee surgery, abnormal stress on the distal femur due to hip disease, periprosthetic osteolysis without loosening related to polyethylene debris or metallosis, loosening, type of prosthesis, loss of bone stock because of the femoral implant, life of prosthesis. RESULTS: Intraoperative fractures usually occurred in specific circumstances: use of a posterior stabilized prosthesis, probably with insufficient preparation and position of the stabilization element, probably excessive impaction in osteoporotic bone (rheumatoid arthritis), difficult exposure (arthroplasty after prior osteotomy), fracture starting from the separator passing over the posterior aspect of the tibia and reaching the intercondylar notch. Independently of these intercondylar fractures, supracondylar or diaphyseal fractures were essentially observed for revision prostheses using a femoral stem. Postoperative fractures were observed in patients who had prior surgery of the distal femur (revision of femoral osteotomy, fracture of the distal femur, arthrodesis), in patients with significant loss of bone stock (posterior stabilized prosthesis), or poor bone quality (rheumatoid arthritis), and in elderly patients with neurological impairment and frequent falls. The trochlear notch did not appear to be sufficient to be the only cause of fracture but was nevertheless an element frequently associated with other risk factors. DISCUSSION AND CONCLUSION: This study shows that fracture of the distal femur occurs in certain preferential circumstances. Considering these elements, a certain number of preventive measures can be discussed for technical modifications or choice of implants.

Aged↗
PubMed2006

[Treatment of fractures of the distal femur on total knee arthroplasty].

PURPOSE OF THE STUDY: Fractures of the distal femur near a total knee arthroplasty are usually observed in patients aged over 70 years victims of low-energy trauma. The rate of complications is high: in the literature 25-75 %, even when treated by experienced surgeons. The purpose of this study was to detail therapeutic modalities used for the treatment of these fractures with their advantages and disadvantages and to determine the morbidity of complications which do occur. MATERIAL AND METHODS: Twenty distal fracture of the femur were treated between 1990 and 2000 in twenty patients who had a total knee arthroplasty. Mean patient age at surgery was 72 years (range 69-77). The fracture was a short oblique fracture in four, transversal in five, long and spiral in four and comminuted in the others. In four fractures, the preoperative radiographic analysis suggested concomitant loosening. Therapeutic modalities included suspension traction for two, femorotibial external fixation for two. Retrograde nailing was possible in two patients. Fixation with a screw plate or a blade plate was used for nine fractures. The prosthesis was revised systematically if loosening was observed. This was done in three cases with preservation of the tibial piece and in two cases, changing the complete prosthesis, using a long femoral stem in all. RESULTS: Mean follow-up was two to ten years. Immediate weight bearing was possible for four of the five patients for whom only the femoral piece was changed with a long stem. For the others, weight bearing was deferred until fracture healing was obtained after a mean five months (range 4-42). Bone healing required one, or two, revisions in three patients. Three patients died within one year of their fracture of the distal femur. There were no cases of infection or late healing. At last follow-up, the knee and function score regressed after treatment of the fracture. The two scores dropped 20 points compared with the pre-operative score (78 +/- 15 to 56 +/- 19 for the knee score and 72 +/- 16 to 54 +/- 18 for the function score). The knee score fell because of difficulty going up and down stairs and use of crutches. Treatments which stiffened the knee were traction suspension and external fixation. Loss of joint motion was about the same with or without prosthesis revision. The tibiofemoral angle measured before the fractures (postoperative goniometry) then after fracture healing or after changing the femoral prosthesis, showed an alignment of 183 degrees before the fracture and 178 degrees after healing or revision of the femoral piece. Three patients experienced another fracture of the same femur after healing of the initial fracture or after changing the knee prosthesis. DISCUSSION: Fracture of the distal femur on a total knee prosthesis is a serious complications because of the mortality and the difficulty in achieving functional recovery after treatment. Therapeutic difficulties involve the type of skin incision, the position of the screws in relation to the femoral component, the possible need for bone graft, and finally the requirement to change the femoral piece with a centro-medullary stem.

Aged↗
PubMed2006

[Radiographic diagnosis of dislocated inverted shoulder prosthesis: two cases of unrecognized dislocation].

Dislocation of inverted shoulder prostheses are rarely described in the literature. Diagnosis is relatively difficult as illustrated by two cases reported here which went unrecognized. The problem is the absence of any clear clinical sign of dislocation and the rather difficult interpretation of the radiographic images. We propose a method for analyzing the radiographic images which can be used to confirm the absence of dislocation on the AP view.

Diagnosis, Differential↗
PubMed2006

[Total hip arthroplasty after failure of per- and subtrochanteric fracture fixation in elderly subjects].

PURPOSE OF THE STUDY: Most pertrochanteric fractures can be successfully fixed with osteosynthesis. Osteosynthesis fails however is a small number of patients who require re-operation for implantation of a total hip prosthesis. This situation occurs in particular when the material has penetrated the acetabulum and in elderly subjects. Although this type of arthroplasty is routine practice, few series have been reported. We present here outcome and complications of total hip arthroplasty after failure of per- and sub-trochanteric fracture fixation. MATERIAL AND METHODS: Between 1990 and 2000, twenty patients aged 79 years on average (range 62-78 years) underwent revision for total hip arthroplasty after failure of osteosynthesis for fracture of the upper femur. A gliding THS had been used for fixation in 18 patients, a plate in one and a Gamma nail in one. Osteosynthesis failure was related to early disassembly in ten patients, pseudarthrosis in eight and malunion in two. Revision was performed via a posterolateral approach in all cases. A standard total hip prosthesis was used in 16 patients, a longer femoral stem was required in four. Femoral components were cemented in 18 patients and non-cemented in two. The cup was a standard cemented cup in 12, retaining and cemented in eight. RESULTS: Mean operative time and blood loss were greater than in first-intention arthroplasties. All patients had lost their independence prior to the revision procedure. Despite their age, all recovered independence after a stay in rehabilitation. Most still required crutches. Use of a retaining cup enabled avoiding dislocation in all cases. For those who did not have a retaining cup, dislocation was the most frequent complication (3/12). The difficulties observed were: 1) elimination of associated infection before surgery; many of these elderly subjects had altered ESR and CRP values for various reasons; 2) abnormal position of the trochanteric mass because of a rotation defect; 3) malunion of the upper femur in the frontal or sagittal planes; 4) more or less easily achieved positioning of the femoral piece on the calcar; 5) difficult intraoperative identification of limb length due to loss of usual landmarks on the lesser and greater trochanter; 6) removal of fracture screws which sometimes required use of a trephine and bridging the last screw hole with a longer centromedullary stem. The most frequent postoperative orthopedic problems were leg length discrepancy (1-2 cm for eight patients), gluteus medius insufficiency, limping and pain at palpation of the trochanteric area. DISCUSSION: Despite the difficult technique and the potential complications which are more important than for first-intention arthroplasties, this series demonstrates that total hip prosthesis is a reliable solution for treating fixation failures of the upper femur.

Age Factors↗
PubMed2006

[Screw fracture after sliding hip screw fixation of an intertrochanteric fracture].

Although no cases have been reported to date, fracture of a sliding hip screw on a screw-plate fixation is a real entity since material watch registries have revealed two non-published cases. We report an illustrative case. A 67-year-old man was hospitalized for a right intertrochanteric fracture. The patient was treated with a sliding hip screw plate fixation (short cannon, 105 mm screw). On the eighth postoperative day, fracture impaction was present with complete loss of impaction reserve associated with secondary discrete divergence in the cannon-screw alignment. Weight-bearing was postponed until the 45th postoperative day. At three months, bone healing had not been achieved. A clear image was also visible at the plate end of the cannon. The patient complained of persistent pain but there were no signs of infection. At the fifth month, the patient fell from the standing position and standard x-rays visualized the nonunion of the intertrochanteric fracture plus a infratrochanteric diaphyseal fracture line in addition to a fracture of the sliding hip screw. The plate screws were intact. The patient underwent revision osteosynthesis with a Medoff plate. Fracture of a sliding hip screw is a rare event. In the present case, the mechanism involved an insufficient impaction reserve and use of a short cannon. Treatment requires extraction of the distal fragment of the screw and a new cemented osteosynthesis.

Aged↗
PubMed2005

[Osteolysis in revision total knee arthroplasty: a comparative study of osteolysis with and without metallosis].

PURPOSE OF THE STUDY: Metallic debris from metallosis can compensate for the radiolucency resulting from bony destruction and compromise preoperative diagnosis of osteolysis. We compared the radiological findings in two groups of patients: those with pure osteolysis resulting from polyethylene debris and those with osteolysis associated with metallosis. MATERIAL AND METHODS: This study compared ten total knee arthroplasties free of metallosis at revision (pathology examination revealed only polyethylene debris) with ten total knee arthroplasties with pathologically confirmed metallosis of the synovium and periprosthetic bony tissue. Revisions were performed for loosening or a femoropatellar problem. At revision, the localization and the degree of tibial and/or femoral osteolysis were noted. Preoperative x-rays were analyzed to search for femoral, tibial or patellar osteolysis and were compared with operative findings. On the AP and lateral views, ten osteolysis zones were defined for each knee (four tibia, five femur, and one patella). RESULTS: Ten knees had osteolysis associated with polyethylene debris alone. Tibial osteolysis was found intraoperatively in 16 of the 40 theoretically possible localizations and was recognized on the preoperative x-rays in all 16. Femoral osteolysis was found intraoperatively in 18 of the 50 theoretically possible localizations was only recognized in 6 of the 18. For the ten knees with metallosis, tibial osteolysis was found intraoperatively in 22 of the theoretically possible localizations and was recognized on preoperative x-rays in 10 of the 22. Femoral osteolysis was found intraoperatively in 32 of the 50 theoretically possible localizations but was only recognized preoperatively in 5 of the 32. Comparisons between the two groups showed that femoral osteolysis was significantly more difficult to identify preoperatively than tibial osteolysis irrespective of the type of osteolysis (with or without metallosis). Furthermore, in patients with metallosis, it was significantly more difficult to recognize osteolysis preoperatively in both the tibial and femoral localizations. DISCUSSION: Metallosis can mask the diagnosis of femoral osteolysis and makes it very difficult to recognize tibial osteolysis. Arguments in favor of osteolysis (abnormal skin pigmentation, radio-opaque effusion, abnormal color and density of the joint fluid) are discussed. When the diagnosis of metallosis is established preoperatively, the chances of finding osteolysis intraoperatively are much higher than suggested by the preoperative x-rays.

Arthroplasty, Replacement, Knee↗
PubMed2004

[Total hip arthroplasty for the treatment of septic hip arthritis in adults with sickle-cell disease].

PURPOSE OF THE STUDY: Septic hip arthritis is a recognized complication of sickle-cell disease. The incidence is difficult to assess but is significant since certain authors estimate that 11% of children with sickle-cell disease develop orthopedic complications. We report our experience with hip joint infection in adults with sickle-cell disease. MATERIAL AND METHODS: We diagnosed ten cases of hip joint infection in seven adults with sickle-cell disease. The characteristic feature of the septic arthritis was the development of a septic focus in a zone of osteonecrosis of the femoral head. Diagnosis was difficult due to the presence of prior hip disease and also the circumstances of development: other infectious foci, septicemia, distant osteomyelitis. The diagnosis was confirmed by joint puncture and isolation of the causal germ. Despite adapted antibiotics and immobilization with traction-suspension, hip joint destruction could not be prevented and all patients became bedridden. Surgery was therefore undertaken to remove the head and neck and institute local antibiotic treatment. A total hip prosthesis was implanted in all patients. RESULTS: At 2 to 12 years follow-up, all seven patients had nearly normal hip function (all 10 hips). Recurrent infection nevertheless developed in 2 hips, demonstrating the limitations of this technique.

Adult↗
PubMed2004

Fate of very small asymptomatic stage-I osteonecrotic lesions of the hip.

BACKGROUND: The prognosis for a patient with osteonecrosis of the hip is generally considered to be worse if a large volume of the femoral head is involved, the patient is symptomatic, and the stage of the lesion is advanced. In 1990, we began a prospective study to detect collapse in asymptomatic hips with a very small stage-I osteonecrotic lesion in the femoral head. We hypothesized that such patients would have a favorable prognosis. These hips were followed for a minimum of ten years after the diagnosis. METHODS: A small asymptomatic stage-I osteonecrotic lesion (not seen on plain radiographs) was diagnosed with magnetic resonance imaging in forty patients (forty hips) contralateral to a hip with symptomatic osteonecrosis. The criterion for inclusion in the study was a lesion with a volume of <5 cm(3) involving <10% of the volume of the femoral head. Plain radiographs were made annually in six different projections for all patients. At the most recent follow-up evaluation (average, eleven years), patients with a symptomatic hip but without evidence of collapse on plain radiographs underwent a computerized tomography scan. RESULTS: Thirty-five (88%) of the forty hips became symptomatic, and twenty-nine (73%) demonstrated collapse. The mean interval between the diagnosis and the first symptoms was eighty months. Symptoms always preceded collapse by at least six months. The mean interval between the diagnosis and the collapse was ninety-two months (range, seventy-two to 140 months). The diagnosis of collapse could be made on only one or two of the six radiographic views obtained for each patient at each evaluation. The diagnosis of collapse for two patients was made only on a computerized tomography scan at the most recent follow-up evaluation. At the time of final follow-up, the twenty-nine hips with collapse had symptoms of intractable pain and required surgery. CONCLUSIONS: This study confirms that the diagnosis of collapse is difficult in hips with a very small stage-I osteonecrotic lesion. Multiple radiographic views and computerized tomography scans may be required to demonstrate small areas of collapse. Clinical and radiographic signs of progression of the disease in asymptomatic hips with a very small asymptomatic lesion progress more slowly than do those signs in hips with a large symptomatic stage-II lesion. Because hips with a small area of osteonecrosis do collapse in a large percentage of patients, such patients should be followed carefully over a long period of time. LEVEL OF EVIDENCE: Prognostic study, Level I-1 (prospective study). See Instructions to Authors for a complete description of levels of evidence.

Adult↗
PubMed2003

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. Our aim was to compare the two ceramics. There was an increased linear rate of penetration of the femoral heads into the liner between years five and 12 for the zirconia and the stainless-steel groups. This was severe in the zirconia group (0.4 mm/year compared with 0.13 mm/year for the stainless-steel group). During the same 12-year period there was, however, no significant change in the rate of wear in the alumina group (0.07 mm/year). The mean wear at the most recent follow-up was 1360 mm3 for the 28 mm zirconia group, 683 mm3 for the 28 mm stainless-steel group, 755 mm3 for the 32 mm alumina group and 1314 mm3 for the 32 mm stainless-steel group. The monoclinic content rose on the surface of three zirconia heads which were retrieved at revision. This change was associated with an increase in the surface roughness. A change in the roundness with an increase in the sphericity deviation was also observed both in the articular and non-articular parts of the femoral heads. The increase in rate of wear in the zirconia group was only evident after eight years and may be linked to a long-term biodegradation of zirconia in vivo, associated with the altered roughness and roundness which was observed on the retrieved heads.

Aged↗
PubMed2003

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. METHODS: Ninety-two symptomatic hips in sixty-four consecutive adult patients with sickle-cell disease were initially evaluated between 1980 and 1987. Sixty symptomatic hips had radiographic evidence of osteonecrosis at the initial evaluation: forty-three were classified as stage II; two, as stage III; and fifteen, as stage IV, according to the system of Steinberg et al. The other thirty-two hips had lesions (stage I) that were evident only on magnetic resonance imaging. All patients were evaluated after a mean duration of follow-up of seventeen years. RESULTS: Of the seventy-five hips without collapse of the femoral head at the initial evaluation, sixty-five demonstrated collapse within five years after the diagnosis. The average time between the diagnosis and collapse was forty-two months for stage-I hips and thirty months for stage-II hips. At the most recent follow-up examination, ninety hips had had collapse of the femoral head and eighty-eight of the ninety-two hips had had surgery because of intractable pain. CONCLUSIONS: Symptomatic osteonecrosis of the hip in sickle-cell disease has a high likelihood of leading to femoral head collapse, necessitating surgical intervention. When osteonecrosis develops, the deterioration is rapid and, in most patients, operative intervention is necessary because of intractable pain. LEVEL OF EVIDENCE: Prognostic study, Level II-1 (retrospective study). See Instructions to Authors for a complete description of levels of evidence.

Adolescent↗
PubMed2002

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. The medial compartment was replaced in seventy-four knees and the lateral compartment, in twenty-five. All ninety-nine knees were evaluated with regard to patellar impingement and osteoarthritic changes on skyline radiographs after an average duration of follow-up of fourteen years (range, ten to twenty years). In addition, the seventy-seven knees (fifty-eight patients) that had not been revised were evaluated with use of the clinical scoring system of the Knee Society and specific questions regarding patellofemoral symptoms after an average duration of follow-up of fifteen years (range, ten to twenty years). The relationship between patellar complications (osteoarthritis and impingement) and the position of the femoral component was evaluated with use of lateral radiographs of the knee. RESULTS: At the time of the most recent follow-up, twenty-nine knees had osteoarthritic changes in the portion of the patellofemoral joint opposite the compartment with the implant and twenty-eight knees had impingement of the femoral component on the patella. The knees that had impingement did not have osteoarthritic changes. Pain while ascending or descending stairs and pain on rising from a chair were noted more frequently in knees with patellar complications (impingement and osteoarthritis) (p = 0.02), and these symptoms affected the stair-climbing functional score. These symptoms were more severe in knees with patellar impingement than in knees with degenerative changes. One revision was performed because of patellar impingement. Patellar impingement was more frequent after lateral arthroplasty than after medial arthroplasty (p = 0.02) and was associated with placement of the femoral component too far anteriorly (p = 0.001). CONCLUSION: After unicompartmental arthroplasty, the patellofemoral joint was affected by degenerative changes and patellar impingement. These complications appeared to have been mutually exclusive and affected the functional outcome of the arthroplasty. Patellar impingement affected the knee more severely with regard to both symptoms and the need for revision.

Adult↗
PubMed2002

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. The retroversion of the humerus was measured by determining the orientation of the proximal articular surface of the humerus with respect to the transepicondylar line of the distal part of the humerus and the forearm axis. To evaluate this method of measuring retroversion, the protocol was tested in patients before and after shoulder arthroplasty. RESULTS: The degree of reproducibility of the measurements made on the computed tomography scan was evaluated by determining the interclass correlation coefficient. The interclass correlation coefficient was considered good (between 0.85 and 0.90) for the measurements of the normal humeri when the orientation of the articular surface measured in the distal part of the humeral head, the epicondylar axis, and the ulnar axis were used as references. There was a significant difference (p < 0.01) between the mean angular orientation of the proximal articular surface with respect to the epicondylar axis (17.6 degrees ) and the mean angular orientation of the proximal articular surface with respect to a line perpendicular to the forearm axis (28.8 degrees ). Despite a wide variation in the humeral torsion angle among the specimens from the different cadavera, the angle varied little between the two normal humeri of the same individual (mean side-to-side difference, 2.1 degrees ). CONCLUSION: This study demonstrated that retroversion of the proximal part of the humerus can be reliably measured with computed tomography. CLINICAL RELEVANCE: Determining retroversion with computed tomography is more accurate than palpating the epicondylar axis or using the forearm as a goniometer during surgery. Computed tomography is useful for measuring the amount of rotation of humeri with a malunited fracture or severe arthritic deformity.

Aged↗
PubMed2002

[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. The purpose of this article was to present an analysis of the differences between different types of osteotomies and compare their effect on leg length. METHODS: Change in length of the lower limb was studied with a mathematical analysis in opening wedge osteotomy, closing wedge osteotomy, and dome osteotomy. Leg length was calculated for several preoperative deformity angles of the entire limb (hip-knee-ankle angle) and several values of planned correction. RESULTS: The theoretical mathematical model demonstrated that the greatest changes in leg length are obtained with opening wedge osteotomy, followed by dome, then closing wedge osteotomy. Tables were established showing calculated change in leg length. Tracings on radiographs or CT scans used to measure these changes are explained. Methods applicable in case of flexion contracture of the knee are presented. DISCUSSION AND CONCLUSION: Once the initial question regarding length changes is posed, many of the points become evident on image tracings. This work points out how quickly tables can be used to recognize significant differences in leg length changes produced by different osteotomies.

Anthropometry↗
PubMed2001

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. This series confirms that the opening wedge osteotomy allows good accuracy for the correction. Ninety-three percent of the knees had a correction adjusted between 180 and 187 degrees for the hip-knee-ankle angle. Survivorship analysis showed an expected rate of survival, with conversion to a total knee on the end point, of 94% at 5 years, 85% at 10 years and 68% at 15 years. Conversion to a total knee arthroplasty was accomplished without difficulty in the patients who had this procedure done. We recommend opening wedge tibial osteotomy with acrylic cement bone cement as bone substitute, rigid internal fixation, and early motion for patients who undergo high tibial osteotomy.

Adult↗
PubMed2001

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. These patients were considered preoperatively not to have an increased risk for the development of postoperative pulmonary embolism; they had no poorly controlled systemic illness and were followed-up for at least three months. The average age was seventy-four years (range, 65-80). Anticoagulant therapy was begun on the evening of the operation and continued for three months. The dose was adjusted to keep the prothrombin time between seventeen and twenty seconds. Neither phlebography, sonography, nor lung scan was done routinely. RESULTS: Among the 500 patients, 476 continued to take low-dose oral anticoagulant for three months after the operation. Eight pulmonary embolisms were observed, but none was fatal. Only one patient developed a postoperative hematoma requiring surgical reoperation. CONCLUSIONS: In the absence of poorly controlled systemic illness, low-dose oral anticoagulants can be used after hip fracture.

Administration, Oral↗
PubMed2001

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. For ten of the hips which were measured by MRI, both before and after collapse, the volume did not appear to change significantly. Our findings suggest that the volume of osteonecrosis can be determined with accuracy by MRI, both before and after collapse.

Femur Head↗
PubMed2000

Influence of Irradiation on the Risk of Transmission of HIV in Bone Grafts Obtained from Appropriately Screened Donors and Followed by Radiation Sterilization.

We studied the effects of radiation (electrons of 6.2 MeV) at different temperatures with respect to the inactivation of the human immunodeficiency virus to determine the radiosensitivity of the virus. Using a mathematical model describing the dependence on radiation dose of the proportion of sterile items in a population of bone allografts contaminated by HIV, and subjected to irradiation, we have commented on and explained the calculation of the sterility assurance level in bone transplantation according to different doses of irradiation at different temperatures. Simultaneous application of heat and radiation increases inactivation of HIV. Given the relative imprecision of viral sensitivity curves and the impossibility of knowing the number of viral particles in a patient at a given moment of the disease, irradiation does not authorize bone transplantation without screening. However, irradiation can be considered as a serious adjuvent to decrease the risk of contamination after screening.

Journal Article↗