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Biomedical subjects

D S Hungerford

Publications and source records attributed to D S Hungerford.

At least 127 records · Page 7Linked to original sources
PubMed1991

Primary total knee arthroplasty in patients with severe varus deformity. A comparative study.

Varus deformity is a common finding in candidates for total knee arthroplasty (TKA), but very little has been written concerning the problems encountered in correcting these deformities at the time of arthroplasty. Compared to patients without deformities, this group of patients require more attention to the technical aspects of the arthroplasty, especially bony alignment and ligament balancing. Specific operative techniques used to correct severe varus deformities at primary TKA were evaluated, and the clinical and roentgenographic results were compared with those of a control group of patients without preoperative angular deformity. Operative findings and clinical results in 27 knees (20 patients) with a minimum preoperative varus deformity of 20 degrees (average follow-up period, 58.7 months; range, 24-102 months) were compared with those of 40 knees (31 patients) with a preoperative angulatory deformity of less than 5 degrees varus or valgus (average follow-up period, 50.0 months; range, 24-90 months), in whom a minimally constrained, posterior-cruciate-ligament-sparing prosthesis was implanted. Operative time was an average of 30 minutes longer in the varus deformity group. The average knee evaluation score in the varus group was 89 points, and for the nondeformity group it was 92 points (p less than 0.02). There were no fair or poor results in the varus deformity group; there was one poor result in the nondeformity group. Postoperative knee are of motion was 98 degrees in the varus deformity group and 107 degrees in the nondeformity group. After arthroplasty, the average angle between the mechanical axis of the femur and the tibia was 3 degrees varus in the varus deformity group and 0 degree varus in the nondeformity group (p less than 0.006). Postoperative functional scores of patients in the varus deformity group approached, but were not equal to, the nondeformity group. Greater variability in results and longer operative times were needed in the varus deformity group. Postoperative alignment of the varus deformity group tended to be in residual varus.

Adult↗
PubMed1991

Primary total knee arthroplasty in patients with fixed valgus deformity.

Ninety-nine knees in 81 patients evaluated from two to ten years and having enough valgus deformity to require specific soft-tissue release were studied. They were also compared to a control group of 40 knees in 31 patients with no angular deformity greater than 5 degrees, who were matched for age and diagnosis. All procedures were performed using a minimally constrained, posterior-cruciate-ligament-sparing prosthesis. Pre- and postoperative axial alignment was measured on weight-bearing long-standing roentgenographs. Analysis included examination for lucent lines in postoperative fluoroscopically positioned roentgenographs and clinical data summarized using the 100-point scoring systems developed by The Knee Society. Knees were classified as having Type I, II, or III valgus deformities: Type I was defined as valgus deformity secondary to bone loss in the lateral compartment and soft-tissue contracture with medial soft tissues intact; Type II was defined as obvious attenuation of the medial capsular ligament complex; and Type III was defined as severe valgus deformity with valgus malpositioning of the proximal tibial joint line after overcorrected proximal tibial osteotomy. Only cases of Type I and Type II were represented in the 99 knees reported. Type I patients were treated with lateral soft-tissue release, and Type II patients were treated with medial capsular ligament tightening (i.e., ligament reconstruction procedures on the medial side). The Knee Society postoperative knee score was 87.6 (+/- 10.6) and mean postoperative functional score was 52.3. Alignment was well corrected and knee scores for the Type I and II groups were almost identical as were the functional scores. The results were grouped as 72% excellent, 18% good, 7% fair, and 2% poor. Notably, the control group was 39 of 40 patients excellent, and only one poor. Ligament stability was satisfactorily established by lateral release in Type I and with the combined medial plication in the Type II patients. The ligament-tightening procedures were on the average 40 minutes longer than those for the Type I or the control groups. The controversial nature of the simultaneous ligament reconstruction method is recognized, but good experience is reported.

Aged↗
PubMed1990

[Role of core decompression as treatment method for ischemic femur head necrosis].

Nontraumatic ischemic necrosis of the femoral head remains a source of much controversy. The etiology is also controversial. Possibilities are: hypertrophy of intraosseous structures (lipocytes, hematopoietic elements), creating intraosseous hypertension; alcohol and steroids as toxic agents; circulating fat globules embolizing the microcirculation of the metaphysis. The disease appears most frequently in young adults, but no satisfactory nonoperative treatment modalities have been reported as yet. In 1971, Ficat and Arlet published their results on core decompression performed in 100 patients, with a follow-up of from 1 to 5 years. The results for those with stage I disease (n = 40) were good or excellent in 88% of the patients. The results for those with stage II disease (n = 16) were good or excellent in 69%. Based on current experience, the treatment is to be recommended for patients with pre-collapse stages 0, I and IIA of ischemic necrosis of the femoral head. For stage III disease, the procedure may reduce pain at night and at rest and can be considered in patients wishing to avoid total hip arthroplasty for a period of time.

Adult↗
PubMed1990

Total knee arthroplasty fixation. Comparison of the early results of paired cemented versus uncemented porous coated anatomic knee prostheses.

The results of 18 matched pairs of Porous Coated Anatomic knee prostheses were studied to compare the early clinical and functional performance of cemented versus uncemented fixation with an average five-year follow-up period for both. The knee score improved from a preoperative average of 35 points to a postoperative average of 90 points in the cemented group, and from 38 points to 93 points in the uncemented group. In particular, the individual pain scores and the range-of-motion values were well matched at the three-, six-, and 12-month follow-up visits and showed a steady improvement. Subjectively, all patients were pleased with the results of surgery; one-third preferred the cemented side, one-third preferred the uncemented side, and one-third found no difference in the performance of either knee. The clinical and functional performance of knee prostheses in patients who had one cemented knee and one uncemented knee were comparable and possibly unrelated to the type of fixation method.

Bone Cements↗
PubMed1990

Approaches to senior care #9. Results of total knee arthroplasty in patients 80 years and older.

Experience with total knee arthroplasty in the extremely elderly population, which has not been previously reported, is reviewed. Sixty-two total knee prostheses were implanted in 43 patients aged 80 to 95 years (average, 82 years). Ninety percent of the patients had a preoperative diagnosis of osteoarthritis. The results were compared with those obtained in a younger reference group (average age, 62 years) receiving 60 total knee prostheses.

Aged↗
PubMed1989

Patellofemoral instability in total knee arthroplasty.

Patellofemoral instability following total knee arthroplasty remains one of the major complications requiring operative intervention. In spite of recent advances in technique and instrumentation, the rate of this complication remains disturbingly high. A comprehensive analysis of cause reveals malalignment of any of the components to be potentially responsible, particularly valgus or internal rotation malalignment of either femoral or tibial component, as well as lateral displacement of the patellar component. Underresection of the patella or oversizing the femoral component may also contribute to excessive lateral retinacular tightness. When confronted with patellofemoral instability, the surgeon must first look for and correct the cause. Component malalignment requires component revision. Extensor mechanism imbalance requires either proximal or distal realignment. Lateral release alone invites recurrence of the problem.

Arthroplasty↗
PubMed1989

Intertrochanteric osteotomy for avascular necrosis of the femoral head.

Of 24 intertrochanteric osteotomies for avascular necrosis of the femoral head, 22 were followed up for an average of 63 months. Sixteen of the 22 cases had good or excellent results, including 5 of the 6 cases with Stage II disease and 11 of the 16 with Stage III changes. Success seemed to be inversely related to the size of the lesion. There were six major orthopaedic complications, but despite these we feel that the operation has a definite role in the treatment of the young active patient.

Adult↗
PubMed1989

Core decompression of the distal femur for avascular necrosis of the knee.

From 1974 to 1981, we performed 28 core decompressions of the distal femur for pathologically confirmed avascular necrosis. At a mean follow-up of 54 months (range 20 to 140 months) and using the Ficat stages, all seven cases in stage I and stage II had good results. Of 21 cases in stage III, 11 cases had good results, four had poor results, and six needed total knee replacement. There were no significant orthopaedic complications. The procedure is worthwhile and will be more accurate with new methods of imaging.

Adult↗
PubMed1989

Primary and revision total hip replacement without cement and with associated femoral osteotomy.

Nine porous-coated total hip prostheses were implanted without cement in nine patients who had a major proximal femoral deformity. Six patients had revision and three, primary total hip replacement. In all nine patients, as well placed corrective osteotomy was needed to successfully perform the arthroplasty. The average time until union of the proximal femoral osteotomy was fifteen weeks for the patients who had a primary arthroplasty and twenty-seven weeks for the patients who had a revision arthroplasty. The average Harris hip-rating score was 94 points for the patients who had a primary arthroplasty and 84 points (range, 60 to 93 points) for those who had a revision arthroplasty. The length of follow-up averaged forty-seven months.

Adult↗
PubMed1989

The predictive value of hemodynamic studies in preclinical ischemic necrosis of bone.

This study evaluated the predictive value of bone marrow pressures and intraosseous venography in joints at risk for developing ischemic necrosis of bone. Forty-two patients with ischemic necrosis of bone had hemodynamic studies performed on their contralateral, asymptomatic joint. A followup evaluation of symptoms and radiographs was obtained to establish the prevalence of clinical ischemic necrosis in the index joints. Thirty-six of 48 joints had increased bone marrow pressure and of these, 15 (42%) developed histologically or radiographically confirmed ischemic necrosis of bone. In none of the 12 bones with normal bone marrow pressure did ischemic necrosis of bone occur (p = 0.005). Venography was also significantly predictive for ischemic necrosis of bone, both alone and in conjunction with bone marrow pressure. Our study reaffirms the risk of developing bilateral ischemic necrosis of bone (31% at a mean followup of 47 months) once the diagnosis has been made on one side. Bone pressure measurements are of predictive value in establishing those joints which require close clinical followup so that detection of disease may be in the precollapse stage of ischemic necrosis of bone.

Adult↗
PubMed1989

Osteotomy of the tibial tubercle during total knee replacement. A report of twenty-six cases.

The cases of twenty-four patients who had twenty-six osteotomies of the tibial tubercle in conjunction with total knee replacement were analyzed with regard to complications and technical considerations. The patients were followed for a minimum of two years (average, three years and six months). Major complications related to the surgical technique occurred in 23 per cent of the knees and complications not related to the technique, in an additional 8 per cent. Rheumatoid arthritis and a history of at least one previous operation about the knee were predisposing factors for these complications.

Adult↗
PubMed1989

Revision of septic total knee arthroplasty.

Nine patients with septic total knee arthroplasties (TKA) were treated between 1980 and 1984; six were gram-positive infections and three were gram-negative. Initial treatment included the maintenance of all solidly fixed components. Patients with loose components were treated with removal of all prosthetic material and subsequent reimplantation after a six-week course of antibiotics. At follow-up examination six of nine patients had satisfactory results. One patient maintained his original femoral and tibial components and one patient required a knee fusion to treat his recurrent gram-negative infection. Overall, complications were associated with chronic infection, gram-negative infection, and abnormalities of the extensor mechanism.

Arthritis, Infectious↗
PubMed1988

Experimental determination of forces transmitted through the patello-femoral joint.

Tensions in the quadriceps tendon and infrapatellar ligament were measured as a function of flexion angle in eight cadaver knees using a load cell of a materials tester to determine the quadriceps force and a spring balance to quantify the patellar tendon force. The ratio between the tensions in the quadriceps tendon and the patellar tendon (FQ/FP) ranged from 1.55 at 70 degrees of flexion to 0.86 at 10 degrees of flexion. The patello-femoral joint reaction (PFJR) force for extension against resistance was maximal at 60 degrees. No change in the quadriceps force required to extend the knee occurred with changes of the Q-angle of +/- 5 degrees. This study demonstrates that FQ does not equal FP as several authors have reported (Bandi, 1972; Barry, 1979; Ficat and Hungerford, 1977; Hungerford and Barry, 1979; Reilly and Martens, 1972; Smidt, 1973). Furthermore, the difference in FQ and FP influences both the magnitude and direction of PFJR. Studies that assess the influence of surgical procedures which alter the patello-femoral joint or the extensor mechanism must take these differences into account.

Biomechanical Phenomena↗
PubMed1988

Revision total knee arthroplasty for aseptic failure.

Twenty-four patients with 28 failed total knee arthroplasties replaced with porous-coated anatomic (PCA) primary or revision components were studied over a two- to four-year period. Overall, there were 68% good and excellent results and three failures. When evaluated according to mode of failure, 83% of the patients who had a definable mechanical problem achieved good or excellent results. Patients who had revision operations for incapacitating pain or in whom no clearly definable problem could be ascertained before operation were not significantly improved. Complications that led to poor results were deep sepsis, wound necrosis, and extensor mechanism abnormalities.

Aged↗