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Biomedical subjects

David S Hungerford

Publications and source records attributed to David S Hungerford.

14 recordsLinked to original sources

Glucosamine and chondroitin sulfate are effective in the management of osteoarthritis.

The use of glucosamine and chondroitin sulfate for the symptomatic treatment of osteoarthritis has been a subject of controversy for several reasons. First, the medical community in general took offense at the title of Theodosakis' book, The Arthritis Cure. Second, the medical community is becoming divided into "traditional" and "alternative" camps with deep skepticism between them. Third, the whole nutraceutical industry is essentially unregulated, with manufacturers making outrageous claims on products that have never been tested at all, are often of poor quality, and occasionally lacking in any active ingredient. However, for the nutriceuticals evaluated here, there is abundant in vitro, in vivo, animal clinical, and human clinical evidence of both their efficacy and safety. They deserve a prominent place in the armamentarium of nonsurgical treatment of osteoarthritis.

Animals↗

Procoagulants and osteonecrosis.

OBJECTIVE: To study the relationship between hypofibrinolysis, thrombophilia, and osteonecrosis. We evaluated the frequency of abnormal concentrations of 9 coagulation factors in patients diagnosed with osteonecrosis. METHODS: Blood samples were drawn from 45 patients diagnosed with osteonecrosis. Etiologic associations included systemic lupus erythematosus (n = 9), inflammatory bowel disease (n = 1), corticosteroid therapy (n = 20), or history of heavy alcohol (n = 4) or tobacco (n = 3) use. No associated risk factors were identified in 5 patients; these individuals were labeled "idiopathic." The patient cohort was matched to a similarly studied cohort of 40 healthy individuals without documented osteonecrosis. The following factors were analyzed: plasminogen activator inhibitor (PAI-Fx), stimulated tissue plasminogen activator, lipoprotein (a), resistance to activated protein C, anticardiolipin antibodies (aCL IgG, IgM), protein C, protein S (free), and homocysteine. RESULTS: Thirty-seven of the 45 patients (82.2%) with osteonecrosis were found to have at least one coagulopathy, versus 30% of controls (p < 0.0001). Twenty-one patients (46.7%) were identified with 2 or more abnormal test results versus 2.5% of controls (p < 0.0001). Patients were more likely than controls to have high levels of the hypofibrinolytic plasminogen activator inhibitor activity (42% vs 3%; p < 0.0001), and high anticardiolipin antibody IgG (34% vs 10%; p = 0.008). At least one coagulation factor abnormality was detected in all 5 idiopathic patients; elevated aCL IgG and PAI-Fx were evident in 4 patients. CONCLUSION: This study revealed a high incidence of thrombophilic and hypofibrinolytic coagulation abnormalities in patients with osteonecrosis. These findings have major implications for the diagnosis as well as the treatment of this disease. Since some of these abnormalities may be the result of autosomal dominant disorders, it may be possible to detect individuals at risk for development of this disease.

Adult↗

Total knee arthroplasty in patients </=50 years old.

Thirty patients (30 knees) who underwent total knee arthroplasty at age </=50 were reviewed. These patients were operated on between July 1, 1991, and May 1, 1995, with final follow-up evaluation at a mean of 86 months (range, 60-107 months). At final evaluation, 18 knees (60%) had excellent Knee Society objective scores, 11 knees (37%) had good scores, and 1 knee (3%) had a poor score. There were no statistically significant differences in Knee Society objective scores among the cemented group (mean, 88 points), hybrid group (mean, 88 points), and noncemented group (mean, 90 points). One patient (3%) had a revision because of unexplained pain. In the other knees, there was no radiographic evidence of progressive loosening, lucencies, or change in position or alignment of the prosthesis. Total knee arthroplasty of this design, at least for the time period studied (7-year mean follow-up), has a high rate of success in patients who are </=50 years old.

Adult↗

Osteonecrosis: avoiding total hip arthroplasty.

Osteonecrosis of the femoral head afflicts approximately 20,000 new patients per year, at an average age of 38. Of the patients seen in our institution, 25% are <25 years old. Without treatment, most of these patients can be expected to need a total hip arthroplasty. Joint-preserving procedures have a significant failure rate, and some have significant morbidity. It is desirable to avoid or delay total hip arthroplasty because most patients with osteonecrosis outlive the current state-of-the-art prostheses. Four issues need to be weighed to arrive at a reasonable algorithm for the preservative treatment of osteonecrosis: i) patient risk factors, ii) morbidity of the proposed procedure, iii) size of the lesion, and iv) stage of the lesion. All of the issues must be considered to make sense out of a complex clinical situation.

Arthroplasty, Replacement, Hip↗

Is coding of diagnoses, comorbidities, and complications in total knee arthroplasty accurate?

Coding of diagnoses, comorbidities, and complications is important for health care delivery, not only for appropriate hospital and physician reimbursement, but also for a correct assessment of complication rates. The purpose of this study was to determine the agreement of coding of diagnoses, comorbidities, and complications for total knee arthroplasty between 2 groups of coders. Between January 1, 1997, and November 18, 1997, 100 consecutive primary total knee arthroplasties were done by 2 orthopaedic surgeons. Diagnoses, comorbidities, and complications were coded by professional hospital coders according to the Healthcare Finance Administration guidelines, then recoded by a second team with orthopaedic experience. Although the hospital coders matched diagnoses with the orthopaedic team 96.5% of the time, they determined a complication rate of 1.4 per patient and a comorbidity rate of 2.9 per patient, whereas the orthopaedic team coded for 0.7 complications per patient and 3.7 comorbidities. Based on these results, there should be interaction and communication between hospital coders and health care professionals to check that coding is accurate and reproducible.

Adult↗

Outcome and management of infected wounds after total hip arthroplasty.

Infected wounds after total hip arthroplasty can be limb threatening. Management strategies are designed to eradicate infection, to obtain stable wound coverage, and to preserve the prosthesis. However, there is no general consensus for optimal management. The authors reviewed their 7-year combined orthopaedic and plastic surgical experience to provide a protocol for management. Ten patients (six women and four men) with a mean age of 60 years (range, 41-82 years) were studied. Primary hip diagnoses included arthritis (n = 8) and avascular necrosis (n = 2). Wound analysis included the size, depth, and infection as well as exposure of bone, joint capsule, and prosthetic components. Follow-up ranged from 1 to 6 years (mean, 3.9). Primary plastic surgical operations included a pedicle muscle flap (n = 4), debridement and local wound care (n = 3), and delayed wound closure (n = 3). Salvage of the total hip arthroplasty was achieved in 6 of 10 patients. Complete wound healing was achieved in 9 of 10 patients. The authors conclude that salvage of the infected hip prosthesis is accomplished best via early recognition, irrigation, debridement, and plastic surgery consultation. Management strategies include muscle flap coverage for complex wounds associated with exposure of prosthetic components, bone, or hardware; debridement with delayed closure or skin graft for large superficial wounds without deep structure involvement; and local wound care for small superficial wounds, poor surgical candidates with clean wounds, and when surgical options are not possible.

Adult↗

Varus and valgus flexion laxity of total knee alignment methods in loaded cadaveric knees.

Both total knee alignment methods, the anatomic and classic, seek to achieve stability in flexion and extension. However, posterior femoral condyle referencing (anatomic alignment) combined with perpendicular tibial resection (classic alignment) results in a 3 degree relative internal rotation of the femoral component with lateral joint opening. The current cadaver study investigated the influence of total knee alignment methods and femoral component malrotation (3 degrees and 6 degrees internal and external malrotation) on femorotibial laxity. Varus and valgus excursion tests were done at 0 degrees, 30 degrees, 60 degrees, and 90 degrees knee flexion under vertical loading conditions of 150 N. None of the alignments produced increased laxity in extension. The largest laxity was found on the varus test at 60 degrees flexion with the femoral component at 6 degrees internal rotation. A 3 degree internal rotation of the femoral component showed increased varus laxity only for the combined alignment method. This finding shows that the femoral component position of the combined alignment method is a 3 degree relative internal malrotation and that an additional internal malrotation may compromise varus stability. Posterior femoral condyle referencing did not provide proper femoral component rotation. A ligament tensor may be helpful in determining femoral component rotation after soft tissue release in extension is performed.

Arthroplasty, Replacement, Knee↗

The fate of revised uncemented acetabular components in patients with rheumatoid arthritis.

The results of patients with rheumatoid arthritis who had revision hip arthroplasty have been studied infrequently. The purpose of this study was to review the authors' clinical and radiographic experiences and outcomes with revision hip arthroplasty. Revision total hip arthroplasties were done on 28 patients (30 hips). All hips had morselized bone grafting and four hips had bulk allografts for segmental defects. The mean age of the patients at the time of surgery was 50 years (range, 20-74 years). Patients were followed up for 4 to 15 years (mean, 7 years). At the latest followup, 14 hips (13 patients) of the 30 hips (47%) had good and excellent Harris hip score ratings. Mechanical failures included six hips (five patients) that had revision arthroplasty and two hips (two patients) that had resection arthroplasty. Six other hips (five patients) had poor Harris hip score ratings. The Kaplan-Meier survivorship curve for failure of the acetabular component revealed an 89% chance of survivorship curve for failure of the acetabular component revealed an 89% chance of survival at 60 months and a 44% chance of survival at 108 months. Based on the results of this study, revision hip arthroplasty for acetabular loosening with a cementless acetabular prosthesis has a low rate of success in patients with rheumatoid arthritis.

Adult↗

Coding of diagnoses, comorbidities, and complications of total hip arthroplasty.

International Classification of Diseases coding of patient charts is used by hospitals to allow for billing of patients. Coding information also is used for assessing physician effectiveness. The purpose of the current study was to examine hospital coding for patients having total hip arthroplasty. One hundred consecutive primary total hip replacements were done at one medical center by two orthopaedic surgeons. Patient charts were coded by hospital coders according to the Health Care Finance Administration guidelines. Subsequently, an orthopaedist-based team did a secondary review of these charts and the two sets of codes were compared. The diagnostic codes were similar between the two groups for 87% (174 of 200 codes) of the cases. Comorbidities generally were undercoded by the hospital coders who reported 2.9 comorbidities per patient, whereas the secondary review reported 3.7 comorbidities per patient. The hospital coders found a complication rate of 1.2 per patient, whereas the secondary review revealed a rate of 0.4 per patient. Based on the results of the current study, the authors conclude that it is important to ensure three issues regarding the standard of coding and quality control: (1) the qualifications of the coders; (2) an interaction between coders and healthcare professionals to check that coding is accurate and reproducible; and (3) communication among various health professionals (including the primary surgeon) and coders to determine what actually are appropriate diagnoses, comorbidities, and complications.

Arthroplasty, Replacement, Hip↗

Total knee arthroplasty for osteonecrosis.

BACKGROUND: A patient with collapse of a femoral condyle caused by osteonecrosis has few treatment options other than total knee arthroplasty. The purpose of this study was to report the clinical and radiographic outcome of total knee arthroplasty for osteonecrosis. METHODS: Between 1987 and 1996, thirty-two total knee arthroplasties were performed with cement in thirty patients with osteonecrosis of the femoral condyle and/or tibial plateau. The study group included twenty-forty women and five men with a mean age of fifty-four years (range, thirty-one to seventy-seven years) at the time of the arthroplasty. Twenty-two patients had atraumatic osteonecrosis associated with corticosteroid use, and eight had spontaneous osteonecrosis. All patients had a complete clinical and radiographic evaluation at a mean of 108 months (range, forty-eight to 144 months) postoperatively. RESULTS: Overall, thirty-one (97%) of the thirty-two knees had a successful clinical outcome. The mean Knee Society score improved from 54 points preoperatively to 95 points at the time of the latest follow-up. No evidence of progressive radiolucency was found around any prosthetic component. CONCLUSIONS: Previous studies have demonstrated less-than-optimal results following total knee arthroplasty in patients with osteonecrosis. The excellent results found in the present study may have been secondary to the use of cemented implants in all cases and ancillary stems when appropriate.

Adult↗

Total knee arthroplasty for patellofemoral arthritis.

BACKGROUND: Multiple treatment methods have been advocated for patellofemoral arthritis. The purpose of the present study was to report on our experience with the use of total joint replacement for the treatment of primarily severe patellofemoral arthritis of the knee in patients more than fifty-five years of age. METHODS: Between January 1980 and December 1994, thirty knee replacements were performed in twenty-seven patients for the treatment of arthritis that primarily involved the patellofemoral joint. The Ahlbück radiographic evaluation scale was used to grade the severity of arthritis; the mean score was 4.83 points (range, 4 to 5 points) for the patellofemoral compartment and 0.6 point (range, 0 to 1 point) for both the medial and lateral compartments. The patients included eighteen women and nine men who had a mean age of seventy-three years (range, fifty-nine to eighty-eight years). None of the patients had had any prior procedures on the knee, but all had been treated for a minimum of six months with nonoperative measures. The mean preoperative Knee Society score was 50 points (range, 20 to 64 points). RESULTS: At a mean duration of follow-up of eighty-one months (range, forty-eight to 133 months), there were twenty-eight excellent, one good, and one poor result. The mean Knee Society objective score was 93 points (range, 67 to 100 points). The poor result was in a patient who sustained a rupture of the patellar tendon postoperatively as the result of a fall, which necessitated a tendon reconstruction. CONCLUSION: Total knee arthroplasty was found to be a viable treatment option in patients more than fifty-five years of age with primarily severe patellofemoral disease.

Aged↗

Tennis after total knee arthroplasty.

In this study, patients who played tennis after undergoing a total knee arthroplasty were analyzed in terms of their functional abilities and degree of satisfaction. The patients were recruited by means of a questionnaire that was sent to players from lists supplied by the United States Tennis Association. The study group consisted of 28 men and 5 women (46 total knee replacements) with a mean age of 64 years. Only 21% (7 of 33) of the patients' surgeons approved of their patients undertaking tennis activity, with 45% (15 of 33) recommending only doubles tennis. At both 1 year and a mean of 7 years after arthroplasty, players were playing both singles and doubles tennis approximately three times per week (range, one to seven). All tennis players polled were satisfied with their knee arthroplasties and their ability to resume playing tennis. Because the study patients played at a high level, future studies are needed to determine the effect of tennis on the general population, which does not play at such a uniformly high level. The long-term (15 to 20 years) effect of tennis activity on the clinical and radiologic outcome of total knee arthroplasty also needs to be determined.

Adult↗

Enhancement of osteoblast proliferative capacity by growth factor-like molecules in bear serum.

The use of animal serum in cell culture is vital for providing the nutrient factors required to promote proliferation and function. Fetal calf serum has become the preferred choice because of its abundance, reasonable cost, and ability to sustain human cells in vitro. Although a wide variety of serum sources have been tested and used, little is known about the ability of serum obtained from the American black bear (Ursus americanus) to support human cell growth in culture. The American black bear, an animal comparable in size to humans, is unique in that it hibernates for mo at a time but does not experience extensive bone loss normally associated with extended immobility. The aim of this study was to analyze the effect of bear serum on human osteoblast cultures. We discovered that three of the eight bear serum samples induced significantly higher proliferation rates in osteoblasts than did fetal calf serum over a 24-h period. Osteoblasts incubated in bear serum displayed higher messenger ribonucleic acid levels for phenotype markers osteocalcin and type I collagen than did those incubated in fetal calf serum. The mitogenic activity of the bear serum was reduced when heated at 56 degrees C for 30 min before use in culture. The molecular weight of the mitogenic factors was found to be primarily greater than 50 kDa. The present work demonstrates the capability of serum from American black bears to support human osteoblast proliferation in vitro.

Animals↗