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Biomedical subjects

D S Hungerford

Publications and source records attributed to D S Hungerford.

At least 73 records · Page 4Linked to original sources
PubMed1997

Intramedullary goniometer can improve alignment in knee arthroplasty surgery.

Fifty total knee arthroplasties were performed using an intraoperative intramedullary goniometer to measure the angle of the distal femoral cut. When deviations of 1 degree or more were found, angled cutting blocks ranging from 1 degree to 5 degrees were used to recut the distal femur. Revised femoral cuts were made it 25 knees (50%). Postoperative evaluation from weight-bearing long-standing anteroposterior radiographs revealed an average distal femoral angle deviation from preoperative planning of 0.64 degree (range, 0 degree-3 degrees). This was statistically significantly different from the value for a comparison group of 50 knees on which arthroplasties were performed without the intraoperative goniometer with an average femoral angle deviation of 1.44 degrees (range, 0 degree-4 degrees) (P < .05). In the control group, there were 7 knees (14%) that deviated by 3 degrees or more versus only 2 knees in the study group. The authors conclude that an intramedullary goniometer is fast, is simple to use, and leads to more accurate preparation of the distal femur in total knee arthroplasty.

Adult↗
PubMed1997

Multiple irrigation, debridement, and retention of components in infected total knee arthroplasty.

The results of 24 infected total knee arthroplasties (22 patients) that were treated by irrigation, debridement, and retention of the prosthetic components were prospectively studied. Strict criteria were used for the selection of this method of treatment. Patients had to be less than 30 days after index arthroplasty (postsurgical group) or had to have less than 30 days of knee symptoms (hematogenous group). In addition, there had to be no radiographic signs of osteitis or evidence of a loose prosthetic component. Patients had one to three irrigation and debridement procedures depending on systemic signs, knee symptoms, or the results of knee aspirations. All of the immediate postsurgical infections (10 knees) and 10 of the 14 (71%) late hematogenously infected knees retained the prosthesis without further evidence of infection at the final follow-up visit at 48 months (range, 24-140 months). This study shows that in selected circumstances, irrigation, debridement, and retention of the components can result in low morbidity with high success rates.

Aged↗
PubMed1997

Effects of grafting on porous metal ingrowth. A canine model.

Twenty-five mongrel dogs were studied using implantation of autograft, fresh-frozen allograft, and beta-tricalcium phosphate around a porous-coated chrome-cobalt plug in the distal femoral metaphysis; interference-fit and overreamed control specimens were also studied. Over the course of this 4-month study, bone ingrowth through the grouting materials into the center plug was noted for autologous, allograft, and ceramic specimens. Quantitatively, in terms of push-out strength and histology, there were no significant differences between grafted groups; significantly higher push-out strengths were attained in each grafted subgroup compared with nongrafted, overreamed control subjects. In the setting of uncemented revision total hip arthroplasty, bone-grafting is frequently required. Because of the limited availability of autogenous bone and the potential liabilities of allograft material, attention has been given to bone substitutes. On the basis of this preliminary study, bone ingrowth into a porous metal substrate has been documented to occur through autograft, allograft, or ceramic grouting agents. Within the limits of this nonloaded experimental model, it appears that these materials are comparable in terms of their osteoconductive capability. Even in the optimal laboratory situation, bone ingrowth does not appear to occur in a canine model across a nongrafted 2-mm gap with regularity over a 16-week period.

Animals↗
PubMed1997

Total knee arthroplasty for corticosteroid associated avascular necrosis of the knee.

Despite their age, patients younger than 50 years who have collapse of their femoral condyles caused by steroid associated avascular necrosis have few options except total knee arthroplasty. There have been no specific reports of the results of total knee replacements for this disease. Between 1980 and 1993, 31 porous coated anatomic total knee replacements were performed in 21 patients younger than 50 years of age with avascular necrosis of the femoral condyles and tibial plateaus. There were 17 women and 4 men, with an average age of 36 years (range, 22-48 years). Seventeen of 21 patients had systemic lupus erythematosus, and all patients had a history of corticosteroid use. Patients underwent a complete clinical and radiographic evaluation at final followup that averaged 8.2 years (range, 2-16 years). Overall, there were 17 good and excellent results (55%). Eleven knees were revised for aseptic loosening (37%), and 3 additional knees (10%) ultimately were revised for deep sepsis. All 6 knees in patients with no diagnosis of systemic lupus erythematosus had excellent clinical results. There were only 11 of 25 successful outcomes (44%) in the patients with systemic lupus erythematosus. There were no differences in results when patients were stratified by degree of steroid use, cemented versus cementless fixation, or activity level.

Adult↗
PubMed1997

Core decompression for osteonecrosis of the femoral head in systemic lupus erythematosus.

A cross sectional study was performed to try to identify various demographic and radiologic risk factors for disease progression in 50 patients (79 hips) with corticosteroid associated osteonecrosis of the femoral head who had a core decompression. Thirty-one of the hips were in 18 patients who had systemic lupus erythematosus and were compared with the remaining group of 48 hips in 32 patients who were taking corticosteroids for other reasons. All patients in the study had been taking greater than 30 mg of prednisone for at least 2 weeks at least 6 months before the onset of osteonecrosis. Patients underwent a core decompression and were then observed for an average of 12 years (range, 4-18 years). Overall, 42 of the 79 hips (53%) had satisfactory outcomes. Of the 31 hips in patients with systemic lupus erythematosus, 21 (68%) were converted to a total hip replacement. In the patients without systemic lupus erythematosus taking corticosteroids, 16 of 48 hips (33%) progressed to arthroplasty. A subset of 25 hips from each group (systemic lupus erythematosus and without systemic lupus erythematosus) were matched for age, gender, prednisone dose, Ficat and Arlet Stage, and length of followup. The matched group without systemic lupus erythematosus had 44% survival (11 of 25 hips), which was not statistically different when compared with the 36% survival (9 of 25 hips) found in the systemic lupus erythematosus group. The major risk factors for disease progression were late stage of disease (Stage III) at presentation and radiographic extent of the lesion (>200 degrees), regardless of diagnosis. None of the factors that have been found to be associated with osteonecrosis in patients with systemic lupus erythematosus could be associated with disease progression. Because cause seems to be less significant than the onset and extent of the disease, the clinician should make the diagnosis of osteonecrosis as promptly as possible so that treatment can be started at the earliest possible time, when it will be most efficacious.

Adolescent↗
PubMed1997

Core decompression for avascular necrosis of the distal femur: long term followup.

Seventy-nine knees (45 patients) with a diagnosis of avascular necrosis of the distal femur treated between 1978 and 1989 were evaluated. All patients had a corticosteroid association (had been treated with >30 mg of prednisone for >2 weeks predating by at least 6 months the onset of avascular necrosis). Thirty-two knees were managed with protected weightbearing and rest. Core decompression was performed at a minimum of 3 months after the onset of symptoms in another 47 knees. The knees treated with protected weightbearing had an average asymptomatic period of only 11 months and all but 6 (18%) proceeded to total knee replacement within 6 years. Core decompression yielded good or excellent results in 73% of the knees at an average followup of 11 years (range, 4-16 years). Of the 13 knees with failed core decompression, 7 were asymptomatic for greater than 5 years. A subset of 26 knees from each group was matched for age, gender, diagnosis, Ficat and Arlet Stage, and length of followup. The matched noncore group had 23% survival as compared with 74% survival in the core group. This long term followup suggests that core decompression may slow the rate of symptomatic progression of avascular necrosis of the knee. In addition, core decompression may extend the symptom free interval in certain patients and may delay the need for more extensive procedures such as total knee arthroplasty.

Adult↗
PubMed1997

Risk factors for osteonecrosis in systemic lupus erythematosus.

OBJECTIVE: To study clinical and laboratory factors in patients with systemic lupus erythematosus (SLE) to identify subgroups at extraordinary risk for developing osteonecrosis. METHODS: 31 of 103 (30%) patients with SLE had developed osteonecrosis. Patients were studied to identify clinical characteristics that differentiated patients with and without osteonecrosis. Subjects were studied to determine whether and to what degree factors leading to thrombophilia (anticardiolipin antibodies, aCL) or hypofibrinolysis [lipoprotein(a)] are associated with osteonecrosis. RESULTS: Clinically, the patients with osteonecrosis had significant increases in Cushingoid body habitus, thrombophlebitis, vasculitis, cigarette smoking, and preeclampsia. Highest prednisone dose was positively associated with osteonecrosis. Although IgG aCL were also found to be associated with osteonecrosis, particularly in the white patients with SLE, lipoprotein(a) levels were not increased in either the white or black patients. CONCLUSION: Maximal prednisone doses, changes in body habitus in response to corticosteroid therapy, IgG aCL levels, and clinical evidence of venous thrombosis and vasculitis were associated with osteonecrosis in patients with SLE.

Adolescent↗
PubMed1997

Total knee arthroplasty infections associated with dental procedures.

Total knee arthroplasties are at risk for hematogenous seeding secondary to procedures that create a transient bacteremia. To define the risk of infection associated with dental surgery, a retrospective review of the records of 3490 patients treated with total knee arthroplasty by the authors between 1982 and 1993 was performed. Sixty-two total knee arthroplasties with late infections (greater than 6 months after their procedure) were identified, and of these, seven infections were associated strongly with a dental procedure temporally and bacteriologically. These seven cases represented 11% of the identified infections or 0.2% of the total knee arthroplasty procedures performed during this period. In addition, among 12 patients referred for infected total knee arthroplasties from outside institutions, two infections were associated with a dental procedure. Five of the nine (56%) patients had systemic risk factors that predisposed them to infection, including diabetes and rheumatoid arthritis. All dental procedures were extensive in nature (average, 115 minutes; range, 75-205 minutes). Eight of the patients received no antibiotic prophylaxis. One patient had only one preoperative dose. Infections associated with dental procedures may be more common than previously suspected. Eight of these patients had no prophylactic antibiotics, and one had inadequate coverage. The authors think that patients with a total knee arthroplasty who have systemic disease that compromises host defense mechanisms against infections and who undergo extensive dental procedures should receive prophylactic antibiotics. A first generation cephalosporin, given 1 hour preoperatively and 8 hours postoperatively would provide the best prophylaxis against the organisms identified in this study.

Aged↗
PubMed1997

Proximally coated ingrowth prostheses. A review.

Proximally coated femoral components for cementless total hip replacement were conceived in the early 1980s in response to the proximal stress shielding that was seen with extensively coated devices. The main purpose of this study was to analyze whether these prostheses remain viable options based on the results of presently used devices, while detailing the problems encountered with first generation devices. The evolution of these designs and how they were modified in response to early problems, was reviewed. Initial iterations were less successful because they were sometimes not stable, had problems with thigh pain, and progressive osteolysis. However, second generation devices with greater than 5 years clinical experience seem promising and have shown very low aseptic loosening rates (1%-3%), and less thigh pain (under 5% in most studies). The reader still must await longer term studies to know whether progressive osteolysis will be a problem. These encouraging midterm results can be attributed to improved geometry, instruments, and technique which ensure initial implant stability. Proximal coating must be circumferential, to seal the diaphysis from were debris. After incorporating design changes in response to the significant failures of early devices, the concept of proximal coating for cementless femoral stems seem viable, as long as the twin requirements of circumferential coating and rigid initial stability are realized.

Arthroplasty, Replacement, Hip↗
PubMed1997

A second-generation cementless hip prosthesis: improved results over the first-generation prosthesis.

Forty-two patients who had a Porous Coated Anatomic (PCA) "E" series, second-generation, cementless hip arthroplasty (Howmedica, Rutherford, NJ) were compared with 42 patients who had a first-generation PCA prosthesis. Patients were directly matched for age, sex, diagnosis, weight, Charnley functional status, and duration of follow-up. All of the operations were done by the same two surgeons, who used the same operative approach and the same postoperative rehabilitation plan. All of the patients were followed up for at least 5 years (range, 60 to 76 months). In the "E" series group, there were 41 of 42 (98%) good and excellent clinical results with a mean Harris hip score of 94 points (range, 46 to 100 points); the first-generation group had 34 of 42 (81%) good and excellent clinical results and a mean Harris score of 81 points (range, 42 to 100 points) (P = 0.001). There was one acetabular component revision in the "E" series group (2%), which can be compared with eight revisions (19%) in the first-generation group (P = 0.012). The incidence of femoral radiolucencies was 19% (eight hips) for the "E" series group compared with 50% (21 hips) in the first-generation group (P = 0.009). The radiolucencies in the "E" series group were small, nonprogressive, and confined typically to zone I. We believe that the improvements in design of the "E" series component may account for these differences.

Adult↗
PubMed1996

Cementless total knee arthroplasty in obese patients. A comparison with a matched control group.

The heaviest 45 patients (50 knees) who underwent cementless total knee arthroplasty were compared with a matched control group of 45 total knee arthroplasty patients (50 knees) with respect to clinical and radiographic data. Surgery was performed over a 10-year period (1980-1989) and follow-up evaluation averaged 7 years (range, 2-11 years). The control group consisted of nonobese patients matched to the obese group with respect to age, sex, diagnosis, preoperative deformity, and length of follow-up evaluation. Clinical evaluation was made using the Knee Society rating scale as well as an analysis of multiple other clinical parameters. Radiographically, each patient was evaluated with long-standing anteroposterior views, lateral and patellar views, and spot fluoroscopic views of the involved knee. This evaluation included an analysis of lucencies, bead shedding, and prosthetic alignment. The final average clinical score in the obese group was 88 points with four revisions, and that for the control group was 91 points with two revisions. There were no significant differences in the combined percentage of good and excellent results between the two groups. On the basis of the results of this study, it is believed that weight as a factor by itself should not compromise the early (7-year average follow-up period) results of total knee arthroplasty.

Adult↗
PubMed1996

Partial denervation for persistent neuroma pain around the knee.

The authors present the results of denervation procedures treatment for 70 patients with persistent knee pain after total knee replacement, trauma, or osteotomy. In patients with total knee arthroplasty, aseptic loosening, sepsis, ligamentous instability, malalignment, and polyethylene wear had to be systematically ruled out as the source of pain. In patients with nontotal knee arthroplasty, arthrosis, synovitis, ligamentous instability, and meniscal derangement had been excluded as a source of pain. All candidates for the procedure had a successful selective nerve block. Sixty of the 70 (86%) patients were satisfied with the denervation procedure as judged by direct questioning and a reduction in their preoperative pain visual analog score of 5 or more points. The average Knee Society score improved from a preoperative mean of 51 points (range, 40-62 points) to a followup mean of 82 points (range, 15-100 points). Forty-nine of 70 (70%) patients had final Knee Society objective scores greater than 80. There was no difference in patient satisfaction whether the followup period was less than 2 years or more than 2 years. Selective knee denervation is indicated in the management of intractable knee pain after exhaustion of traditional approaches to any structural or infectious etiologies and after successful selective nerve block.

Adult↗
PubMed1996

Exploration of radiographically normal total knee replacements for unexplained pain.

Twenty-seven patients underwent exploration of their total knee replacements because of severe debilitating pain of an unknown cause. The group was further subdivided into (1) patients who had painful knees with range of motion greater than 80 degrees and (2) patients who had painful knees with decreased range of motion (< 80 degrees arc). At final followup, there were 11 excellent and good results (41%) with 16 fair or poor results (59%). For the 15 patients with decreased range of motion, 9 of 15 knees (60%) had good or excellent results. Range of motion arc improved from a preoperative 43 degrees average to a 81 degrees average. For the pain only group, there were only 2 excellent or good results (17%). Poor results were encountered in 6 of 7 patients (86%) in whom a cementless prosthesis was converted to a cemented prosthesis. If a problem was identified at surgery, only 3 of 12 knees (25%) had successful outcomes.

Adult↗
PubMed1996

Osteonecrosis of the talus: treatment by hindfoot fusion.

The results were reviewed for 11 ankles (10 patients) that had been treated with various hindfoot arthrodeses because of symptomatic osteonecrosis of the talus. Follow-up averaged 6.5 years (range, 2-15 years). A functional assessment using a modified Mazur grading system was performed both before surgery and at final follow-up. Data were also collected on the duration of the procedure, intraoperative findings, and the patient's assessment of postoperative cosmesis (excellent, good, fair, or poor). Radiographs were analyzed to determine the interval from the procedure until bony union. Nine of the 11 arthrodeses (82%) fused with the primary procedure and achieved excellent Mazur ratings (mean, 86 points; range, 81-90 points). The average interval until radiographic fusion was 7 months (range, 4-13 months). All eight patients (nine fusions) with successful fusions graded their cosmetic outcomes as excellent or good. The average length of the procedure was 148 minutes (range, 130-300 minutes), compared with an average of 92 minutes (range, 62-151 minutes) for ankle arthrodeses performed by the same surgeons in rheumatoid or osteoarthritic ankles (P < 0.001) and 102 minutes (range, 75-164 minutes) from a report in the literature. Two of the procedures were complicated by nonunions secondary to infections. In one patient, after treatment by debridement and intravenous antibiotics, reinfection and chronic osteomyelitis developed with a subsequent below-knee amputation. The other patient was treated successfully with debridement, antibiotics, and subsequent revision arthrodesis, which fused solidly at 9 months with an excellent result. We conclude that hindfoot arthrodeses for osteonecrosis can be technically demanding, but, despite having a long time to bony union, they can have an excellent clinical outcome.

Adult↗