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Biomedical subjects

M A Mont

Publications and source records attributed to M A Mont.

At least 19 recordsLinked to original sources
PubMed2001

Atraumatic osteonecrosis of the patella.

Atraumatic secondary osteonecrosis of the patella is a rare entity and has been reported in only several case reports. The purpose of this study was to define the clinical and radiographic characteristics and outcome of this disease. Osteonecrosis of the patella was found in 25 knees in 19 patients. The mean age was 42 years (range, 21-63 years). Eighteen (95%) patients had greater than 2 g of lifetime corticosteroid exposure, and six (32%) patients had systemic lupus erythematosus. Osteonecrosis was found in the superior pole of the patella in all 23 knees (17 patients) that had magnetic resonance imaging. Osteonecrosis was apparent on plain radiographs in five knees (20%) in four patients, and only one knee (4%) in one patient had collapse of the posterior articulating surface of the patella. One (4%) patient presented with anterior knee pain localized to the patella. At a mean followup of 4 years (range, 2-18 years), none of the patients had an intervention that focused on treating the patellar lesion. Patellar osteonecrosis is characterized by patients with coincident lesions of the distal femur and the proximal tibia and lesions localized to the superior pole of the patella. It is a nonprogressive disease that does not warrant surgical exploration.

Adult↗
PubMed2001

Human immunodeficiency virus testing for elective orthopedic procedures: results in a community-based hospital.

Between January 1, 1989 and July 31, 1995, voluntary preoperative screening tests for human immunodeficiency virus (HIV) infection, using an enzyme-linked immunosorbant assay, were completed on 2,727 patients who underwent elective orthopedic surgical procedures. There were 2,719 (99.7%) negative, 4 (0.15%) positive, and 3 (0.11%) false-positive results; 1 test was indeterminate (0.04%). All 4 positive patients were men with a mean age of 32 years (range: 26-43 years). Although the prevalence of positive tests is low in this setting, voluntary testing alerts the surgeon to higher risk patients, does not sacrifice patient care, and enables the incorporation of more extensive precautionary measures in the operating room to minimize occupational risks to the surgical team.

Adult↗
PubMed2001

Steroid-associated osteonecrosis of the knee: a comprehensive review.

Steroid-associated osteonecrosis of the knee is a disease of young patients (generally younger than 45 years old) who often have underlying immunocompromising disorders. Although many theories have been postulated, the exact pathophysiology of the disorder is still unknown. Precollapse lesions can be treated with core decompression for prolonged symptomatic relief. Later-stage lesions are treated with total knee replacements, which have less than optimal results reported to date.

Diagnosis, Differential↗
PubMed2001

Strut-autografting with and without osteogenic protein-1 : a preliminary study of a canine femoral head defect model.

BACKGROUND: Osteonecrosis of the femoral head frequently leads to collapse of the articular cartilage and to disabling osteoarthritis, which ultimately may necessitate joint arthroplasty. One treatment method that has had moderate success is the so-called trapdoor approach, which involves excavation of diseased (necrotic) bone followed by bone-grafting. Augmentation of this procedure with various growth and differentiation factors may improve the outcome. We developed a canine model that mimics the clinical situation with trapdoor bone-grafting. The objective of this study was to evaluate the effect of the addition of osteogenic protein-1 on healing following the trapdoor procedure with strut-autografting. METHODS: Thirty-four skeletally mature dogs were used in the experiment. After capsulotomy, a trapdoor was created in the anterolateral surface of the femoral head and a 2-cm-diameter subchondral area of bone was removed. In the phase-I experiments, seven dogs had no treatment of the defect (Group I) and nine dogs were treated with strut-grafting (Group II). In phase II, the procedure was modified by collapsing the trapdoor into the created defect intraoperatively in eighteen dogs, which were divided into three equal groups: six untreated defects were left collapsed (Group III), six were treated with bone graft (Group IV), and six were treated with bone graft augmented with osteogenic protein-1 (Group V). RESULTS: Three of the seven femoral heads in Group I (untreated defect) and one of the nine heads in Group II (grafting without collapsing of the trapdoor) had evidence of cartilage collapse. Inspection of sagittal slices and radiographs revealed an unfilled residual defect in all Group-I heads, whereas all Group-II heads were well healed. The mean normalized stiffness value was significantly larger in Group II than it was in Group I. On visual inspection, depression was noted in all of the femoral heads in Group III (untreated defect; trapdoor left collapsed). In both Group IV and Group V (grafting without and with osteogenic protein-1), the trapdoor cartilage appeared to be essentially normal. Groups IV and V had more radiographic healing than did Group III. The defects in Group V (grafting with osteogenic protein-1) healed faster radiographically than did those in Group IV (grafting without osteogenic protein-1). CONCLUSIONS: Moderate-to-excellent healing was seen both radiographically and biomechanically by four months in the groups treated with grafting, with and without osteogenic protein-1, whereas untreated defects did not heal. CLINICAL RELEVANCE: Symptomatic osteonecrosis of the femoral head is a clinical challenge. The animal model in the current study is a useful tool for the evaluation of methods to treat osteonecrosis of the femoral head. Studies investigating additional time-periods between implantation of osteogenic protein-1 and assessment of results as well as different doses of osteogenic protein-1 are warranted.

Analysis of Variance↗
PubMed2000

[Potential uses of cytokines and growth factors in treatment of osteonecrosis].

Osteonecrosis of the femoral head remains a devastating disease for young patients. As the normal process of bone formation, bone destruction, and fracture healing becomes more clearly understood, molecular agents--including cytokines, bone morphogenetic proteins, and angiogenic factors--will be identified as potential therapeutic agents for the treatment of osteonecrosis. As the pathology of osteonecrosis and repair of osteonecrotic lesions becomes clear, the potential combination of these molecular factors to influence the outcome of the disease in its repair process should become evident. With the myriad of agents and combinations of agents which may be beneficial in the treatment of osteonecrosis, a reproducible animal model is urgently needed to determine which of these combinations is most effective. Despite the lack of an animal model, progress in the use of cytokines for osteonecrosis treatment in conjunction with traditional treatment methods is possible in human subjects. This is due to the extremely low incidence of adverse reactions when these cytokines are used locally in nanogram to microgram quantities.

Bone Morphogenetic Proteins↗
PubMed2000

[Therapy of osteonecrosis. Basic principles and decision aids].

The treatment of osteonecrosis of the femoral head involves a continuum based on a radiographic spectrum of disease. Core decompression or pharmacological agents can be utilized for the earliest small or medium-sized pre-collapsed lesions. For these types of lesions, osteotomy has been tried by various authors with moderate success. For small or medium lesions that are post-collapse, various bone grafting procedures have been used. This approach should be tempered with a look at the articular cartilage if this is damaged or the lesion is large. Limited femoral resurfacing can be used for hips that do not have acetabular involvement. If there is acetabular involvement, total hip replacement remains the treatment of choice. There are present innovations in total hip arthroplasty that hopefully will lead to increased longevity of these prostheses with newer polyethylenes as well as the use of ceramic and other types of interfaces. Another possible advance for this disease would be the use of metal on metal standard prostheses, as well as metal on metal resurfacing arthroplasties. In terms of a salvage of the femoral head, all of the different procedures--core decompression, osteotomy, bone grafting--can be enhanced by new advances in the development of the utilization of bioactive factors. These range from osteoinductive agents such as cytokines, angiogenic stimulating factors, and bone morphogenetic proteins. In addition, osteoconductive substances may be helpful and can be combined with osteoinductive substances. These bioactive factors are described in detail in another chapter of this issue. With the ushering in of the millennium, there is hope for better results with this disease.

Arthroplasty, Replacement, Hip↗
PubMed2000

Management of osteonecrosis in systemic lupus erythematosus.

Osteonecrosis is commonly found in patients with systemic lupus erythematosus. The effects of this disease are magnified because these patients commonly have, in addition to hip involvement, multiple other joints involved with the disease. Early diagnosis is important for medical and surgical management to try to avoid total joint replacements in this young patient population. There are many joint salvaging procedures that have had moderate success in patients with this disease. In the future, pharmacologic agents and growth and differentiation factors may be effective in the early treatment of this disease and may lead to more successful outcomes with surgical options.

Age of Onset↗
PubMed2000

Infected total knee arthroplasty treated by arthroscopic irrigation and débridement.

Sixteen patients with infected total knee arthroplasties (4 postoperative and 12 late hematogenous) were treated by arthroscopic irrigation and débridement. All patients had < or = 7 days of knee symptoms, and there were no radiographic signs of osteitis or prosthetic loosening. Six of the 16 original total knee arthroplasties (38%) did not need prosthesis removal at a mean follow-up of 64 months (range, 36-151 months). Ten other knees were treated with irrigation, débridement, and hardware removal within 7 weeks of the latest procedure used to try to retain components. Two (13%) of these cases ultimately required an arthrodesis for persistent infection. Although we still believe that this method is preferable to resorting immediately to implant removal for acute infections, arthroscopic débridement was less efficacious for most situations when compared with open treatment. We would use arthroscopic irrigation and débridement only under selected circumstances (medically unstable or anticoagulated patients).

Aged↗
PubMed2000

Atraumatic osteonecrosis of the adult elbow.

Osteonecrosis is a disease that leads to joint destruction and often involves large joints, such as the hips, knees, and shoulders. Nontraumatic osteonecrosis of the adult elbow, to the best of the authors' knowledge, has not been reported. Nine adult patients with atraumatic osteonecrosis of 11 elbows were identified. The mean age at presentation was 36 years (range, 26-63 years); five patients were women and four were men. Six elbows involved the capitellum, three involved the lateral epicondyles, one involved the trochlea and radial head, and one involved medial and lateral epicondylar disease. All patients were receiving corticosteroid therapy, and no relationship between the duration or the amount of corticosteroid use and the severity of the osteonecrosis was found. Seven patients with radiographic Stage I and Stage II disease responded well to nonoperative treatments consisting of activity modification, analgesics, and a brief period of immobilization. Nonoperative treatment failed in two patients with Stage III disease, and they had core decompressions for pain relief. One patient with late Stage III disease in both elbows underwent bilateral total elbow arthroplasties. In contrast to the pediatric population, osteonecrosis of the adult elbow potentially can lead to end stage arthritis. If the osteonecrosis is diagnosed early, nonoperative treatment may be effective in relieving pain, although the long-term results of these treatments remain unknown.

Adrenal Cortex Hormones↗
PubMed2000

Total hip arthroplasty in patients receiving Workers' Compensation.

Numerous studies have reported on the adverse outcome of patients who sustain job-related injuries. In addition, studies have reported poor outcomes in patients receiving Workers' Compensation who undergo elective surgery. This study sought to determine the influence of Workers' Compensation on the outcome of patients who had undergone primary total hip arthroplasty. Between January 1984 and December 1996, 44 patients (48 hips) were studied. Of these, 17 were men and five were women with a mean age of 45 years (range, 27-76 years) at the time of surgery. These patients were receiving compensation benefits and were matched directly with a group of 22 patients who had 24 arthroplasties and were not receiving compensation. After a mean final followup of 77 months (range, 25-125 months), the compensation group had a mean Harris hip score of 86 points (range, 54-95 points). The matched control group had a mean Harris hip score of 92 points (range, 79-100 points) at a mean final duration of followup of 80 months. Two patients (9%) had undergone revision surgery for aseptic loosening at 28 and 67 months. The percentage of patients with good or excellent results did not differ significantly between the two groups. Based on these findings, the authors think that Workers' Compensation does not negatively influence the outcome of total hip arthroplasty.

Adult↗
PubMed2000

Femoral head osteonecrosis: detection and grading by using a rapid MR imaging protocol.

PURPOSE: To design and evaluate a limited magnetic resonance (MR) imaging examination that can be performed rapidly and potentially inexpensively in patients with clinical suspicion of osteonecrosis. MATERIALS AND METHODS: Both a limited and a full hip MR examination were performed prospectively in 179 hips in 92 patients with clinical suspicion of femoral head osteonecrosis. The presence of osteonecrosis was determined by two radiologists. The percentage of involvement of the femoral head weight-bearing surface was evaluated subsequently for osteonecrosis-positive hips on both sets of images. RESULTS: Both examinations were performed successfully in all cases. Agreement between the limited and full examinations for presence of osteonecrosis was 98.9% (177 of 179 cases; kappa, 0.97). Forty-six (92%) of 50 patients with femoral head osteonecrosis at both examinations were placed in the appropriate quartile of percentage of femoral head weight-bearing surface involvement by both readers (weighted kappa, 0.94). Incidental findings were made at the full examination that could not be made or were difficult to make at the limited examination. CONCLUSION: There was excellent agreement between the full and screening MR examinations for both detection of and determining the extent of osteonecrosis. The time and potential cost reduction achieved with a limited examination may allow introduction of MR imaging earlier in the diagnosis of femoral head osteonecrosis, as well as its more widespread use in patient care.

Adolescent↗
PubMed2000

Atraumatic osteonecrosis of the knee.

BACKGROUND: The purposes of this study were to define the clinical, demographic, and radiographic patterns of atraumatic osteonecrosis of the distal part of the femur and the proximal part of the tibia at presentation and to report the outcome of treatment of this condition. METHODS: Two hundred and forty-eight knees in 136 patients who were younger than the age of fifty-five years were treated at our institution between July 1, 1974, and September 15, 1998, for atraumatic osteonecrosis of the distal part of the femur or the proximal part of the tibia, or both. Demographic and radiographic features were characterized. The results of nonoperative treatment, core decompression, arthroscopic debridement, and total knee arthroplasty were evaluated. RESULTS: There were 106 female patients and thirty male patients, and their mean age was thirty-six years (range, fifteen to fifty-four years) at the time of diagnosis. One hundred and one patients (74 percent) had involvement of other large joints, with eighteen (13 percent) presenting initially with knee symptoms. One hundred and one patients (74 percent) had a disease that affected the immune system; sixty-seven of them had systemic lupus erythematosus. One hundred and twenty-three patients (90 percent) had a history of corticosteroid use. Technetium-99m bone-scanning missed lesions in sixteen (29 percent) of fifty-six knees. Eight (20 percent) of forty-one initially symptomatic knees treated nonoperatively had a successful clinical outcome (a Knee Society score of at least 80 points and no additional surgery) at a mean of eight years. The knees that remained severely symptomatic for three months were treated with either core decompression (ninety-one knees) or total knee arthroplasty (seven knees). Seventy-two (79 percent) of the ninety-one knees treated with core decompression had a good or excellent clinical outcome at a mean of seven years. Efforts to avoid total knee arthroplasty with repeat core decompression or arthroscopic debridement led to a successful outcome in fifteen (60 percent) of twenty-five knees. Thirty-four (71 percent) of forty-eight knees treated with total knee arthroplasty had a successful clinical outcome at a mean of nine years. CONCLUSIONS: Atraumatic osteonecrosis of the knee predominantly affects women, and in our study it was associated with corticosteroid use in 90 percent of the patients. Evaluation should include standard radiographic and magnetic resonance imaging of all symptomatic joints. Prognosis was negatively related to large juxta-articular lesions. Nonoperative treatment should be reserved for asymptomatic knees only. Core decompression was successful (a Knee Society score of at least 80 points and no additional surgery) in 79 percent of the knees in which the disease was in an early stage. Total knee arthroplasty was successful in only 71 percent of the knees.

Adolescent↗
PubMed2000

Evaluation of preoperative cultures before second-stage reimplantation of a total knee prosthesis complicated by infection. A comparison-group study.

BACKGROUND: Two-stage reimplantation has proven to be highly successful in the treatment of patients with infection at the site of a total knee arthroplasty. However, up to 20 percent of patients have a recurrence of infection following this treatment. The purpose of our study was to determine whether aspiration of the affected joint and culture of the specimen, performed before reimplantation and after discontinuation of antibiotic therapy, would help to identify patients who might have a recurrent infection. METHODS: We prospectively followed sixty-nine patients who were treated for a culture-proven deep infection at the site of a total knee arthroplasty. Group I consisted of thirty-five patients who were treated with removal of the prosthetic components and irrigation and debridement of the joint, followed by six weeks of antibiotic therapy and reimplantation of a prosthesis. Group II was composed of thirty-four patients who were treated with removal of the components and irrigation and debridement of the joint, six weeks of antibiotic therapy, and then repeat culture four weeks after the antibiotic course had ended. If the culture was negative, the patient was managed with a second-stage reimplantation of a prosthesis. If the culture was positive, the protocol was repeated, beginning with irrigation and debridement. The two groups were similar with regard to male-to-female ratio, age, preoperative Knee Society scores, time since primary surgery, types of infectious organisms, duration of symptoms, duration of follow-up, and number of previous revisions. All of the patients were evaluated clinically with use of the objective scoring system of the Knee Society and were followed with serial radiographs. Success was defined as no infection and a functional prosthesis, with a Knee Society score of at least 75 points at the last (thirty-six-month-minimum) follow-up evaluation. RESULTS: Of the thirty-five patients in Group I, five (14 percent) had recurrence of infection. One of the patients was managed with a successful second-stage revision, three were managed with arthrodesis of the knee, and one continued with chronic antibiotic suppressive treatment. Of the thirty-four patients in Group II, three (9 percent) had a positive culture after the course of antibiotics. The protocol was repeated for all three, and they subsequently had a successful second revision. One other patient (3 percent) in Group II, who had a negative culture, had a recurrent infection and was eventually managed with arthrodesis of the knee. CONCLUSIONS: Prerevision cultures, grown after discontinuation of antibiotic treatment and before reimplantation of the components, helped to identify the patients with infection at the site of a total knee arthroplasty in whom the infection might recur. The performance of aspiration and cultures resulted in a substantial improvement in the clinical outcome.

Aged↗
PubMed2000

Atraumatic osteonecrosis of the humeral head.

OBJECTIVE: To define the epidemiology, clinical and radiographic presentation, treatment, and prognosis of atraumatic osteonecrosis of the humeral head. METHODS: Of the 1,056 patients managed for osteonecrosis of any joint between July 1, 1974, and December 1, 1996, 127 shoulders in 73 patients were treated for atraumatic osteonecrosis of the proximal humerus. Clinical and radiographic characterization of this patient cohort was performed. RESULTS: At presentation, there were 47 women and 26 men with a mean age of 41 years (range 20-60). Numerous associated factors were noted: alcohol use (38%), moderate smoking (30%), asthma (8%), and nephrosis (3%). A corticosteroid association was noted in 60 patients (82%) and 42 of the patients (58%) had an immunocompromising disease. The severity of humeral head osteonecrosis did not correlate with dose or duration of corticosteroid therapy. According to the modified Ficat and Arlet radiographic staging system, there were 20 shoulders with Stage I disease, 55 shoulders with stage II disease, and 52 shoulders with Stage ITI or IV disease. Seventy-four of the shoulders treated with core decompression (78%) had good to excellent clinical outcomes at a mean followup of 6 years (range 2-21). Fourteen of the 16 patients (88%) treated with hemiarthroplasty or total shoulder arthroplasty were clinically successful at a mean followup 4 years (range 2-11). CONCLUSION: We observed a low incidence of humeral head involvement in the osteonecrosis patient cohort (7% of all osteonecrosis patients), and a high incidence of corticosteroid use (82%). hip involvement (81%), and bilateral disease (74%). Osteonecrosis of the humeral head should be suspected in patients presenting with shoulder pain and a history of osteonecrosis in other joints. Hip screening for osteonecrosis is advocated in patients with shoulder involvement. Early detection of shoulder osteonecrosis may permit a more conservative, joint-sparing approach as an alternative to surgical management.

Adult↗
PubMed1999

Clinical experience with a proximally porous-coated second-generation cementless total hip prosthesis: minimum 5-year follow-up.

This study reports the minimum 5-year follow-up of our experience with the Porous-Coated Anatomic E (PCA-E) series femoral stem and the modular acetabular cup. A total of 115 consecutive total hip replacements using PCA-E series (Howmedica, Rutherford, NJ) were performed in 108 patients. Six patients whose hips were performing well clinically died before 5-year follow-up and were excluded from the final evaluation. The remaining 109 hips (102 patients) were assessed at a mean follow-up of 72 months (range, 60-84 months). The hip diagnoses were osteoarthritis in 73, osteonecrosis in 31, rheumatoid arthritis in 2, and hip dysplasia in 3. The mean age was 56 years (range, 24-83 years). Three hips were revised: 1 because of late hematogenous infection, 1 because of aseptic loosening of the femoral component, and 1 because of postoperative loosening of an acetabular component. The Harris hip scores improved from a mean of 50 points (range, 20-66 points) preoperatively to a mean of 92 points (range, 64-100 points) at final follow-up. The score differed in each Charnley functional class, with a mean of 93 points (range, 72-100 points) in 57 hips of class A (no other joint involvement); 90 points (range, 58-100 points) in 26 hips of class B (opposite hip involvement); and 85 points (range, 37-100 points) in 26 hips of class C (multiple joint involvement or severe systemic disease). Out of 106 hips that had a full radiographic evaluation performed, 103 femoral components revealed stable bony ingrowth, 2 revealed stable fibrous ingrowth, and 1 showed migration with progressive loosening. This patient with radiographic loosening has minimal symptoms and has not required or been offered further surgery (Harris hip score of 86 points). The low aseptic loosening rate (2%) at minimum 5-year follow-up compares favorably with any cemented or cementless series. The osteolysis that was seen was focal and localized. The short follow-up does not allow determination of progression. There were no cases of distal osteolysis. We attribute the improved results from reported first-generation experience to multiple factors, including increased number of sizes (9 vs 6), increased proportional metaphyseal size, improved polyethylene manufacture (ram extruded vs machined), improved acetabular locking mechanism, and change to 26-mm from 32-mm femoral heads.

Adult↗