Management of extensor mechanism complications in total knee arthroplasty.
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Biomechanical Phenomena↗
Biomedical subjects
D S Hungerford
Publications and source records attributed to D S Hungerford.
Knee challenges: what would you do?
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Adult↗
Total knee arthroplasty after failed high tibial osteotomy.
Total knee arthroplasty performed after failed high tibial osteotomy is an important subgroup encompassing close to 10% of replacements performed and may be difficult in 20% to 40% of these patients. The problems in this group can be different from those encountered with primary of revision total knee arthroplasty. The authors present a review of the literature on this subject including assessments of variables affecting outcome. Preoperative clinical and radiographic factors to be considered are discussed and surgical technical factors are delineated.
Humans↗
Total knee arthroplasty after failed high tibial osteotomy. A comparison with a matched group.
The results of 73 total knee arthroplasties in 67 patients after a high tibial osteotomy (HTO) were carefully reviewed at an average follow-up period of 73 months (range, 24-132 months). An extensive clinical as well as radiographic review was performed in an attempt to evaluate parameters that might portend more favorable or worse outcomes. Additional comparisons were made with two groups of 73 primary TKAs matched according to age, gender, diagnosis, prosthetic fixation, and length of follow-up period. The two comparison groups differed in that one (Group A) was additionally matched to deformity before TKA with a second comparison group (B) matched to pre-HTO deformity. On the basis of a 100-point knee rating scale, 36% of the study group patients had either a fair or poor result or required additional surgery. This was significantly greater than either comparison group (p < 0.01). Factors that prognosticated a worse outcome in the HTO patients (p < 0.01) included (1) workmen's compensation patient, (2) history of reflex sympathetic dystrophy after HTO, (3) early onset (less than one year) or no period of relief of pain after HTO, (4) multiple surgeries before HTO, and (5) an occupation as a laborer.
Adult↗
Polymethylmethacrylate particles enhance DNA and protein synthesis of human fibroblasts in vitro.
Aseptic loosening of polymethylmethacrylate (PMMA) fixed prosthesis is characterized by formation of a radiolucent fibrous membrane, accumulation of inflammatory cells and osteolysis. Since this membrane is produced by fibroblasts, it is likely that these connective tissue cells play a critical role in the loosening process. Whether fibroblasts form the radiolucent membrane in response to stimulation by PMMA has not yet been established, nor is it known whether fibroblasts play a role in attracting inflammatory cells to the bone-cement interface by secreting chemical mediators. To address this question, we analyzed the in vitro response of normal human fibroblasts to PMMA. Cells were plated with 10(5)/mL Dulbecco minimal essential medium and were incubated 4 h later with PMMA particles, polystyrene (PS) particles, or medium alone. Proliferative capacity monitored by incorporation of 3H-thymidine was significantly increased following a 48 h exposure to PMMA. Protein synthesis determined by incorporation of 14C-leucine and 14C-proline was also increased. In contrast, levels of secreted prostaglandin (PG) E2 assayed immunoenzymatically was not altered by PMMA. Fibroblasts exposed to control PS did not change their proliferative or protein synthetic activity. Fibroblasts internalized PMMA and PS particles without detectable ultrastructural damage. PMMA enhancement of fibroblast proliferative capacity and protein synthetic ability observed in our in vitro assay system suggests similar effects on fibroblasts in vivo.
Cells, Cultured↗
Avascular necrosis of the humeral head treated by core decompression. A retrospective review.
Thirty shoulders, in 20 patients, which had undergone core decompression for symptomatic avascular necrosis of the humeral head were reviewed 2 to 14 years later (average 5.6). Twenty-two showed good or excellent clinical results; the other eight shoulders had required arthroplasty. All 14 shoulders with stage I or II radiological changes (Ficat and Arlet 1980) at operation had good or excellent results. We advocate early core decompression for symptomatic avascular necrosis of the humeral head.
Adult↗
Total hip replacement without cement for non-inflammatory osteoarthrosis in patients who are less than forty-five years old.
Forty-two patients (forty-four hips) who, at an age of less than forty-five years, had a total hip replacement without cement for the treatment of non-inflammatory osteoarthrosis, were followed for three to seven years (average, four and one-half years). At the latest follow-up evaluation, thirty-seven hips (84 per cent) had an excellent Harris rating; three (7 per cent), good; one (2 per cent), fair; and three (7 per cent), poor. The mean Harris hip score was 92 points, compared with 43 points before the operation. Two hips (5 per cent) had a revision due to complications. In another hip, there was a progressive radiolucent line around the femoral component, increased shedding of beads, and a low score for fixation and stability, according to the criteria of Engh et al. We concluded that total hip arthroplasty without cement, at least for the time-period studied, has a high rate of success for the management of patients less than forty-five years old who have non-inflammatory osteoarthrosis of the hip.
Adult↗
The rationale for cementless total hip replacement.
Current cementing techniques of distal plugging, pulsatile water cleaning of the canal, and retrograde filling with PMMA in a low-viscous state prepared using porosity reduction techniques and then pressurized have been shown to give excellent results at 10 or more years after operation. However, physical and aging characteristics of PMMA do not guarantee that those results will hold up in the 20- to 30-year time frame. Fifteen-year experience with bony ingrowth systems indicate the development of a durable interface without PMMA, although the interface does appear more vulnerable to attack by the biologic reaction to HMWPE debris. Bone remodeling appears more favorable around proximally fixed bone ingrowth prostheses than around distally fixed prostheses. Softening of the physical characteristics of the stem tip may reduce the incidence of thigh pain. Patients with high activity potential and a life expectancy of greater than 25 years should be strongly considered for a proximally fixed bone ingrowth or ongrowth prosthesis.
Adult↗
A common problem with cementless femoral components.
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Bone Cements↗
Minimum 4-year follow-up of the PCA total knee arthroplasty in rheumatoid patients.
One hundred twenty-one consecutive nonrandomized primary total knee arthroplasties in 94 patients were performed between 1980 and 1984 using the Porous-Coated Anatomic prosthesis in patients with a diagnosis of severe rheumatoid arthritis. Of the 94 patients, 81 patients were able to be followed for more than 4 years, with the remaining 13 dying from unrelated causes prior to the 48-month follow-up. Of those arthroplasties with 48-month follow-up, 55 were uncemented and 26 were cemented. An 81% good to excellent result was seen for the cemented group and a 91% good to excellent result for the uncemented group. The postoperative arc of motion for the cemented group was 94 degrees, with the postoperative arc of motion in the uncemented group being 102 degrees. In evaluation of component interfaces, there were almost no lucencies seen among the femoral group, with no component failures in either group. Thirty-six percent of the uncemented group developed nonprogressive radiolucent lines along the tibial tray; 97% of these radiolucencies were less than 1 mm. Complications in the cemented group included a revision of one patellar and one tibial component for component loosening. In the uncemented group, complications included one case of deep sepsis following an intra-articular injection, loosening of two patellar components requiring revision, and loosening of two tibial components requiring revision.
Adult↗
Evaluation of marrow perfusion in the femoral head by dynamic magnetic resonance imaging. Effect of venous occlusion in a dog model.
RATIONALE AND OBJECTIVES: There is a continuing need for a greater sensitivity of magnetic resonance imaging (MRI) in the diagnosis of avascular necrosis (AVN). Previously, it was demonstrated that a dynamic MRI method, with gadolinium-DTPA (Gd-DTPA) enhancement, can detect acute changes not seen on spin-echo images after arterial occlusion in a dog model. Because venous congestion appears to be a more directly relevant hemodynamic abnormality in a majority of clinical AVN cases, the authors extended the dynamic MRI technique to study changes in venous occlusion. METHODS: Dynamic MRI of the proximal femur was performed in five adult dogs before and after unilateral ligation of common iliac and lateral circumflex veins. Sixteen sequential gradient-recalled pulse sequence (GRASS) images (time resolution = 45 mseconds, echo time = 9 mseconds, flip angle = 65 degrees) were obtained immediately after a bolus intravenous injection of 0.2 mmol/kg of Gd-DTPA. Simultaneous measurements of regional blood flow were made using the radioactive microsphere method. RESULTS: After venous ligation, there was a 25% to 45% decrease in the degree of enhancement compared with preligation values on the ligated side. The decrease in cumulative enhancement (integrated over the entire time course) was statistically significant. The occlusion technique was verified by confirming a statistically significant decrease in blood flow determined by the microsphere method. CONCLUSIONS: Dynamic Gd-DTPA-enhanced fast MRI technique can detect acute changes in bone marrow perfusion due to venous occlusion. This technique may have applications in the early detection of nontraumatic AVN.
Animals↗
Hoop-stress fractures of the proximal femur during hip arthroplasty. Management and results in 19 cases.
Retrospective review of 730 consecutive primary uncemented and cemented total hip arthroplasties revealed 19 intra-operative hoop-stress fractures of the femoral neck. These were incomplete, linear, and minimally displaced. Management was by cerclage wiring (12), bone graft and cerclage (two), further impaction (two), and the use of cement (three), with no change from our standard postoperative management and rehabilitation. Eighteen patients had excellent or good results with an average Harris hip score of 93. Radiographically, all but one patient had Engh stability-fixation scores consistent with stable bone ingrowth. We conclude that hoop-stress fractures of the proximal femur, properly managed, do not detract from the results of total hip arthroplasty.
Baltimore↗
The initial stability of uncemented acetabular components.
The osseo-integration of an uncemented acetabular component depends on its initial stability. This is usually provided by under-reaming of the acetabulum. We have assessed the fixation of 52 mm porous-coated hemispherical prostheses inserted into cadaveric acetabula under-reamed by 1, 2, 3 and 4 mm. We tested the torsional stability of fixation, after preloading with 686 N in compression, by measuring the torque required to produce 1 degree and 2 degrees of rotation. Under-reaming by 2 mm and 3 mm gave significantly better fixation than 1 mm (p less than 0.01, p less than 0.02). Insertion after under-reaming of 4 mm caused some fractures. To obtain maximum interference fit and optimal implant stability, we recommend the use of an implant 2 mm or 3 mm larger than the last reamer.
Acetabulum↗
The management of fixed flexion contractures during total knee arthroplasty.
Fifty-one knees in 40 patients with joint surface degeneration accompanied by fixed flexion contractures (FFC) greater than 20 degrees were treated with total knee arthroplasty using a minimally constrained posterior cruciate ligament retaining prosthesis. Special techniques were employed in an attempt to achieve maximal correction at the time of surgery. The residual FFC measured 3.1 degrees at the completion of the arthroplasty, 10.1 degrees at three months, and 7 degrees at two years. At 55 months postoperatively, the FFC for the osteoarthrotic group had improved from 25.5 degrees to 3.6 degrees, whereas the rheumatoid group improved from 28.7 degrees to 8.6 degrees. The average knee score for the osteoarthrotic group was 89 compared with 81 for the rheumatoid group. Knees that were left with greater residual FFC at the completion of the arthroplasty were found to have greater residual FFC at the latest review.
Adult↗
Long-term (twelve to eighteen-year) follow-up of cemented total hip replacements in patients who were less than fifty years old. A follow-up note.
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Cementation↗
Bone marrow perfusion evaluated with gadolinium-enhanced dynamic fast MR imaging in a dog model.
The authors studied, in a dog model, the feasibility of using gadolinium-enhanced dynamic magnetic resonance (MR) imaging to noninvasively monitor bone marrow perfusion of the proximal femur. With a gradient-recalled acquisition, sequential images of 10 hips in five healthy dogs were obtained for 14 minutes after an intravenous bolus injection of 0.2 mmol of gadopentetate dimeglumine per kilogram. The study was repeated after unilateral arterial embolization of major femoral vessels. Radiolabeled microspheres were injected before and after vessel occlusion. After unilateral embolization, statistically significant differences in enhancement were observed between embolized and control sides (eg, 31% vs 83% average peak enhancement in the femoral neck). There was a high correlation (r = .81 [average]) between the MR data and the microsphere blood flow measurements. The postembolization data indicate that contrast-enhanced fast MR imaging may allow early detection of abnormal bone marrow flow. This technique may be valuable in evaluating patients at risk for avascular necrosis of the femoral head, especially in posttraumatic cases.
Animals↗
The effect of extraarticular varus and valgus deformity on total knee arthroplasty.
Because of trauma, metabolic bone disease, congenital deformity, or prior osteotomy, an extraarticular deformity may be present in patients requiring total knee arthroplasty. If the extraarticular deformity is not corrected extraarticularly, it must be corrected by compensatory distal femoral or proximal tibial wedge resection to produce overall limb alignment. Because such a wedge resection between the proximal and distal attachments of the collateral ligaments will produce asymmetrical ligament length, complex instabilities may result. This article, through overlay templates and trigonometric analysis, evaluates all the issues confronting the surgeon deciding whether to pursue intraarticular or extraarticular correction. The conclusions are as follows: (1) the closer a deformity is to the knee, the greater its importance, (2) femoral deformities are more difficult to correct intraarticularly than tibial deformities because femoral compensatory wedge resection produces instability only in extension, and (3) intraarticular correction of varus deformities produces lateral instability that is usually better tolerated than medial instability, and some extraarticular deformities are best treated by extraarticular correct, independent, or total knee arthroplasty.
Aged↗
The clinical and roentgenographic results of cementless porous-coated patellar fixation.
From May 1980 to July 1988, 522 porous-coated, metal-backed patellar components were implanted without cement in conjunction with the Porous Coated Anatomic (PCA) knee system during primary total knee arthroplasty (TKA). Four different designs were evaluated clinically and roentgenographically. Fixation failure at the bone-prosthesis interface was the most common cause of failure. The addition of a third peg to the metal backing led to a dramatic decrease in the rate of revision for loosening (from 6.1% to 0.6%). Two patellar implants, one two-pegged and one three-pegged (central dome), were revised because of polyethylene wear. The low incidence of polyethylene wear is attributed to careful attention to technique and the high degree of congruency at the femoral articulation. Porous-coated metal-backing offers a viable means of patellar fixation during primary TKA. Design modifications have led to enhanced fixation and improvements in short-term clinical and roentgenographic results.
Adult↗