Total hip and knee arthroplasty: what not to do.
Explore the source record for details and available documents.
Arthroplasty, Replacement, Hip↗
Biomedical subjects
M A Ritter
Publications and source records attributed to M A Ritter.
In vivo selection of sFv from phage display libraries.
The development of phage display technology has facilitated the development of many new and sometimes novel antibody based reagents for scientific research. However, present methods for selection from phage-sFv display libraries are limited to selection against purified antigens or ex vivo cells of known origin and phenotype. Existing methods therefore preclude the isolation of sFv against unknown molecules in their natural environment, where expression is complex and subject to diverse control mechanisms. Since such a complex environment is difficult to mimic in vitro, the development of an in vivo selection procedure would greatly enhance the selection from phage display antibody libraries and lead to the development of reagents against cell surface molecules in their natural environment. This would be particularly advantageous for isolation of sFv against vascular endothelium which can readily change phenotype when cultured and is believed to express molecules in a tissue specific manner and in response to different stimuli. We describe here the development of an in vivo selection procedure in the mouse and demonstrate its potential for the selection of sFv from a phage-sFv library. The target antigen for one sFv is expressed solely on the thymic endothelium, while the second, a 165-170 kDa molecule in present on both thymic endothelium and the perivascular epithelium.
Animals↗
Preliminary report of toxicity following 3D radiation therapy for prostate cancer on 3DOG/RTOG 9406.
PURPOSE: A prospective Phase I dose escalation study was conducted to determine the maximally-tolerated radiation dose in men treated with three-dimensional conformal radiation therapy (3D CRT) for localized prostate cancer. This is a preliminary report of toxicity encountered on the 3DOG/RTOG 9406 study. METHODS AND MATERIALS: Each participating institution was required to implement data exchange with the RTOG 3D quality assurance (QA) center at Washington University in St. Louis. 3D CRT capabilities were strictly defined within the study protocol. Patients were registered according to three stratification groups: Group 1 patients had clinically organ-confined disease (T1,2) with a calculated risk of seminal vesicle invasion of < 15%. Group 2 patients had clinical T1,2 disease with risk of SV invasion > or = 15%. Group 3 (G3) patients had clinical local extension of tumor beyond the prostate capsule (T3). All patients were treated with 3D techniques with minimum doses prescribed to the planning target volume (PTV). The PTV margins were 5-10 mm around the prostate for patients in Group 1 and 5-10 mm around the prostate and SV for Group 2. After 55.8 Gy, the PTV was reduced in Group 2 patients to 5-10 mm around the prostate only. Minimum prescription dose began at 68.4 Gy (level I) and was escalated to 73.8 Gy (level II) and subsequently to 79.2 Gy (level III). This report describes the acute and late toxicity encountered in Group 1 and 2 patients treated to the first two study dose levels. Data from RTOG 7506 and 7706 allowed calculation of the expected probability of observing a > or = grade 3 late effect more than 120 days after the start of treatment. RTOG toxicity scores were used. RESULTS: Between August 23, 1994 and July 2, 1997, 304 Group 1 and 2 cases were registered; 288 cases were analyzable for toxicity. Acute toxicity was low, with 53-54% of Group 1 patients having either no or grade 1 toxicity at dose levels I and II, respectively. Sixty-two percent of Group 2 patients had either none or grade 1 toxicity at either dose level. Few patients (0-3%) experienced a grade 3 acute bowel or bladder toxicity, and there were no grade 4 or 5 toxicities. Late toxicity was very low in all patient groups. The majority (81-85%) had either no or mild grade 1 late toxicity at dose level I and II, respectively. A single late grade 3 bladder toxicity in a Group 2 patient treated to dose level II was recorded. There were no grade 4 or 5 late effects in any patient. Compared to historical RTOG controls (studies 7506, 7706) at dose level I, no grade 3 or greater late effects were observed in Group 1 and Group 2 patients when 9.1 and 4.8 events were expected (p = 0.003 and p = 0.028), respectively. At dose level II, there were no grade 3 or greater toxicities in Group 1 patients and a single grade 3 toxicity in a Group 2 patient when 12.1 and 13.0 were expected (p = 0.0005 and p = 0.0003), respectively. Multivariate analysis demonstrated that the relative risk of developing acute bladder toxicity was 2.13 if the percentage of the bladder receiving > or = 65 Gy was more than 30% (p = 0.013) and 2.01 if patients received neoadjuvant hormonal therapy (p = 0.018). The relative risk of developing late bladder complications also increased as the percentage of the bladder receiving > or = 65 Gy increased (p = 0.026). Unexpectedly, there was a lower risk of late bladder complications as the mean dose to the bladder and prescription dose level increased. This probably reflects improvement in conformal techniques as the study matured. There was a 2.1 relative risk of developing a late bowel complication if the total rectal volume on the planning CT scan exceeded 100 cc (p = 0.019). CONCLUSION: Tolerance to high-dose 3D CRT has been better than expected in this dose escalation trial for Stage T1,2 prostate cancer compared to low-dose RTOG historical experience. With strict quality assurance standards and review, 3D CRT can be safely studied in a co
Adult↗
Source of oncofetal ED-B-containing fibronectin: implications of production by both tumor and endothelial cells.
ED-B fibronectin (FN) is a FN isoform derived from alternative splicing of the primary transcript of a single gene. Its expression on tumor stroma and neoformed tumor vasculature and its absence, with few exceptions, in normal adult tissues imply a prognostic and diagnostic value for ED-B FN. We investigated the location and source of ED-B FN because this will be of importance both in understanding its role in tumor development and in designing strategies to target this molecule. We have confirmed that ED-B FN is expressed in the majority of breast and colorectal carcinoma tissue samples, with strong immunohistochemical staining around the tumor cells and in the tumor stroma. No staining of tumor neovasculature was seen. ED-B FN is produced by a range of tumor and endothelial (both primary and transformed) cell lines, as detected by reverse transcription-PCR, but is not expressed at the plasma membrane. Strong expression of human ED-B FN is seen in tumor xenografts. These data indicate that neoplastic cells can act as the source of ED-B FN in tumors. The lack of cell surface expression on tumor cell lines has clear implications for the design of therapeutic strategies which target this molecule.
Adult↗
The effect of intraoperative intravenous fixed-dose heparin during total joint arthroplasty on the incidence of fatal pulmonary emboli.
All patients who underwent primary total knee arthroplasty (TKA), revision TKA, primary total hip arthroplasty (THA), and revision THA between January 1, 1990, and December 31, 1996, were retrospectively reviewed to determine the incidence of fatal pulmonary emboli. All TKA patients received 1,000 U of intravenous heparin sodium before the tourniquet was inflated and an additional 500 U of intravenous heparin sodium before the inflation of the second tourniquet during bilateral TKA. All THA patients received 1,000 U of intravenous heparin sodium at the time of the skin incision and 500 U of intravenous heparin sodium before preparation of the femoral canal. The overall incidence of fatal pulmonary emboli was extremely low (TKA, 0.096%; THA, 0.16%). With this regimen of intravenous intraoperative heparin, postoperative aspirin, thromboembolic disease hose, and early ambulation, there is no risk of postoperative bleeding, it is inexpensive, and there is no concern on how long to keep the patients on this regimen postoperatively. We recommend this regimen for the prevention of fatal pulmonary emboli after total joint arthroplasty.
Aged↗
Determining the necessity for routine pathologic examinations in uncomplicated total hip and total knee arthroplasties.
Total hip and total knee arthroplasties (n = 951) were retrospectively reviewed to determine the cost-effectiveness of routine pathologic examination of surgical specimens in primary total hip and total knee replacements. Discrepancies between the postoperative diagnosis and the final pathologic diagnoses were recorded. Of the 951 cases reviewed, 27 (2.8%) noted conflicting postoperative and pathologic diagnosis. In all cases, the discrepancy was between a postoperative diagnosis of osteoarthritis and pathologic diagnosis of avascular necrosis. No new cases of neoplasia or inflammatory arthropathy were noted based on the pathologic interpretation. Sixteen of these discrepancies (5.1%) and were noted in total hip arthroplasties, and 11 (1.7%) were noted in total knee arthroplasties. In no case was postoperative medical or surgical treatment altered. Based on this review, strong consideration should be given to the elimination of routine pathologic evaluation of surgical specimens during primary joint arthroplasty, leaving this pathologic evaluation optional, at the discretion of the orthopaedic surgeon, rather than mandatory.
Aged↗
Windswept deformity in bilateral total knee arthroplasty.
Windswept deformity, when an individual has 1 knee in extreme varus alignment and the other in severe valgus alignment, is an unusual occurrence in patients presenting for bilateral total knee arthroplasty. This condition was evaluated in 22 patients to examine possible differences between knees in the same individual. Differences between the varus and valgus knees included alignment (P = .0001), as expected, and the position of the lateral joint line (P = .0161) preoperatively. No significant differences were observed between these 2 knee categories in any other comparison preoperatively or postoperatively. Total knee arthroplasty in patients with windswept deformity can be expected to be successful in both knees when attention is given to proper alignment and soft tissue balancing intraoperatively.
Aged↗
Long-term survival of the T-28 versus the TR-28 cemented total hip arthroplasties.
Between 1974 and 1980, 550 total hip arthroplasties (THAs) (479 patients) were performed using T-28 and TR-28 cemented prostheses (TR-28 is shot-blast chrome and T-28 is polished stainless steel). There were 379 cemented THAs in 321 patients in the T-28 group and 171 cemented THAs in 158 patients in the TR-28 group. Average follow-up of the patients still alive at the end of the study was 20.96 years in the T-28 group and 17.54 years in the TR-28 group. When considering failure as revision of the hip for aseptic acetabular loosening, there were 36 (9.5%) failures in the T-28 group and 12 (7%) failures in the TR-28 group. This difference was statistically significant (P = .0132). When considering failure as radiographic acetabular loosening with or without radiographic femoral loosening, there were 52 failed acetabula (13.7%) in the T-28 group and 18 failed acetabula (10.5%) in the TR-28 group. These differences were not statistically significant. When considering failure as revision for aseptic femoral loosening with or without acetabular component loosening, there were 42 failures (11.1%) in the T-28 group and 22 failures (12.8%) in the TR-28 group. This difference was not statistically significant. When considering failure as radiographic femoral loosening with or without acetabular component loosening, there were 42 failures (11.1%) in the T-28 group and 27 failures (15.8%) in the TR-28 group. This difference was statistically significant for log-rank test (P = .0318) and Wilcoxon's test (P = .0083). Surface finish may be an important contributor to the survival of cemented femoral stems.
Adult↗
Total knee arthroplasty after high tibial osteotomy.
Between 1980 and 1995, 95 consecutive total knee replacements were performed at an average of 10 years 4 months after high tibial osteotomy. The average age of the 82 patients was 66 years, with a preoperative diagnosis of osteoarthritis in 94 knees. One patient died 6 months after surgery. The followup of the remaining 81 patients (94 knees) averaged 8.6 years (range, 2-17 years). Knee Society knee score at final followup improved to an average of 87.6 points from a preoperative average of 38.1 points. No pain was present in 86.2% of knees, and 12.8% of knees had only mild or occasional pain. Tibial radiolucencies were identified in 12 (12.8%) knees at final followup, and in only four knees were radiolucent lines found about the lateral zones. Only one tibial component required revision 3 years after surgery. Although no preoperative factor was identified that predisposed to an inferior knee score, function score, or pain score, the severity of the preoperative flexion contracture and the number of previous surgeries did relate to diminished postoperative motion. However, an increased number of patellar radiolucencies were seen in the knees in which the lateral joint line was raised (referenced from the fibular head) a greater degree. The clinical results of total knee replacement after high tibial osteotomy appeared similar to those of primary total knee replacement. The previous high tibial osteotomy had no adverse effect on the eventual results of a cemented posterior cruciate retaining total knee replacement.
Adult↗
Is the preoperative radiograph useful in predicting the outcome of a total hip replacement?
The preoperative radiographs of 1015 patients undergoing 1163 total hip replacements for osteoarthritis were evaluated to determine if a relationship exists between the extent of osteoarthritis and the clinical results of a total hip replacement. Preoperative radiographs were graded with respect to the degree of cartilage space loss, direction of cartilage space loss (femoral head migration), and severity of osteophyte formation. Followup averaged 32.1 months (range, 6-93 months). Greater degrees of cartilage space loss correlated with lower hip scores preoperatively but were unrelated to preoperative pain. These patients had statistically less pain at 6 months and 1 year. Patients with superior cartilage space loss before surgery also had statistically less pain at 6 months. However, at 3 years and beyond, pain was independent of degree of preoperative cartilage space loss, osteophyte formation, or femoral head migration. In addition, hip scores at any followup were independent of the degree of osteoarthritis observed on the preoperative radiograph. These findings provide statistical support to the concept that greater degrees of joint space loss correlate with better relief of pain and less severe joint space loss correlates with less relief of pain within the first year after total hip replacement. At 3 years and beyond, hip and pain scores were independent of the degree of preoperative osteoarthritis.
Adult↗
Technical considerations of cemented acetabular components: a 30-year evaluation.
The effect of porosity reduction cementing techniques with respect to radiolucent lines in Zone 1 and failure in acetabular components was studied in 2,237 consecutive cemented acetabular components done between 1970 and 1998. The minimum followup was 2 years. Radiolucencies in Zone 1 on initial radiographs obtained postoperatively were tabulated for five groups of patients based on cementing techniques. The percentage of loose or revised cups was calculated for six groups based on type of prosthesis used. The lowest percentage of Zone 1 radiolucencies was in a group in which bowl mixing was used. The lowest failure rate was in the group that received Charnley prostheses in which simple first generation cement techniques were used. Porosity reduction techniques did not reduce the incidence of Zone 1 radiolucencies. For the acetabular side of a total hip replacement, the biology of the bone and the techniques of cement insertion that include a dry cancellous bone bed, perforation and removal of peripheral sclerotic areas, pressurization of the entire cement mantle in the socket at one time, and complete burying of the acetabular component within the boundary of the bony acetabulum are the essential factors, not porosity reduction in the cement.
Acetabulum↗
Total knee arthroplasty after high tibial osteotomy. A comparison study in patients who had bilateral total knee replacement.
BACKGROUND: The outcome of total knee replacement after high tibial osteotomy remains uncertain. We hypothesized that the results of total knee replacement with or without a previous high tibial osteotomy are similar. METHODS: The results of a consecutive series of thirty-nine bilateral total knee arthroplasties performed with cement at an average of 8.7 years after unilateral high tibial osteotomy were reviewed. There were twenty-seven men and twelve women. Preoperatively, the knee scores according to the system of the Knee Society were similar for all of the knees; however, valgus alignment and patella infera were more common in the knees with a previous high tibial osteotomy. Bilateral total knee replacement was staged in seven patients and was simultaneous in thirty-two patients. The results of the total knee arthroplasties were retrospectively reviewed with respect to the knee and function scores according to the system of the Knee Society, the radiographic findings, and the complications. RESULTS: Intraoperatively, no notable differences were identified in the number of medial, lateral, or lateral patellar releases required. However, less lateral tibial bone was resected in the group with a previous high tibial osteotomy (average, 3.3 millimeters) than in the group without a high tibial osteotomy (average, 7.5 millimeters). The average duration of follow-up was 7.5 years (range, three to sixteen years) in the group with a previous high tibial osteotomy and 6.8 years (range, two to ten years) in the group without a high tibial osteotomy. At the time of the final follow-up, the knee and function scores were similar for the two groups (89.0 and 81.0 points, respectively, for the group with a previous high tibial osteotomy, and 89.6 and 83.9 points, respectively, for the group without a high tibial osteotomy). Although more knees were free of pain in the group without a previous high tibial osteotomy (thirty-six) than in the group with a previous osteotomy (thirty-three), this difference was not found to be significant with the numbers available (p = 0.4810). Knee alignment and stability, femoral and tibial component alignment, and range of motion also were similar in both groups postoperatively. One allpolyethylene tibial component was revised in the high tibial osteotomy group. Two knees in each group required manipulation. There were no deep infections. CONCLUSIONS: While patients with a previous high tibial osteotomy may have important differences preoperatively, including valgus alignment, patella infera, and decreased bone stock in the proximal part of the tibia, the present study suggests that the clinical and radiographic results of primary total knee arthroplasty in knees with and without a previous high tibial osteotomy are not substantially different. In our relatively small group of patients, the previous high tibial osteotomy had no adverse effect on the outcome of the subsequent total knee replacement.
Aged↗
Bilateral simultaneous TKR: doing what's best for the patient.
Explore the source record for details and available documents.
Arthroplasty, Replacement, Knee↗
The human thymic microenvironment: new approaches to functional analysis.
Although immunohistological techniques have revealed molecular niches within the human thymic microenvironment, functional analysis is limited by the assay systems available. However, our recent studies using antibody phage display have revealed a high degree of molecular conservation between the microenvironmental molecules of different species. We have therefore isolated single-chain antibodies specific for evolutionarily conserved epitopes, shared by human and mouse, and used these in murine thymic functional assays. The detection of such shared human/rodent molecules makes it possible to functionally 'walk' from mouse to man, providing us with an experimental approach to functional analysis of the human thymus.
Animals↗
The natural history of a posteriorly dislocated total hip replacement.
A retrospective review was conducted to delineate the natural history of the posteriorly dislocated total hip replacement. A total of 1,036 consecutive total hip replacements were performed between 1989 and 1992. Forty (3.9%) were known to have dislocated posteriorly. Twenty-four of these dislocations occurred after primary replacements, and 16 occurred after revision. Eighty-five percent of the dislocations occurred within 2 months and were reduced closed. No statistical differences were noted between these 2 groups with respect to height, weight, sex, age, and femoral and acetabular anteversion. Nonunion of the greater trochanter, modular femoral neck length, and operative approach appeared to affect hip stability. Twenty-three of the 40 dislocated hips (57.5%) redislocated. Sixteen of the 40 hips (40%) required reoperation for recurrent dislocation. Thirteen of the 16 revisions (81.3%) were successful. A dislocated total hip replacement that has been rendered stable does not preclude one from having a successful total hip replacement, and it does not appear to affect survivorship at intermediate follow-up.
Aged↗
A comparison of collared and collarless femoral components in primary cemented total hip arthroplasty: a randomized clinical trial.
Between July 1986 and November 1989, 437 consecutive primary cemented total hip arthroplasties were performed using a straight-stemmed titanium alloy femoral component. Collared and collarless versions of this identical stem were randomly chosen by computer allowing a comparison between 213 collared stems (198 patients) and 224 collarless stems (209 patients). Diagnosis, sex, weight, and average age (72.8 years, collared; 72.0 years, collarless) were similar. Follow-up averaged 76 months (collared) and 72 months (collarless) with 49 patients followed for at least 10 years. Calcar-collar contact was noted in 205 hips (96%) on the initial postoperative radiograph. Early complications, including dislocations (5% each group), were similar. Late complications included 3 deep infections (2 collared, 1 collarless) and 2 postoperative femur fractures (1 each). Hip scores at the most recent follow-up averaged 91.2 and 90.1 in the collared and collarless groups. No or slight pain was noted in 93% of collared and 91.5% of collarless hips. Although no radiographic differences were noted in distal cortical hypertrophy, stem subsidence, and osteolysis, collarless hips lost significantly more medial femoral neck cortical bone (average 0.90 mm vs 0.63 mm). A higher incidence of radiolucent lines in femoral zone VI (20.7% vs 9.4%) was also noted in collarless hips.
Aged↗
Comparison of the midvastus muscle-splitting approach with the median parapatellar approach in total knee arthroplasty.
A total of 100 patients having bilateral total knee replacements simultaneously were randomized prospectively--one knee having a vastus muscle-splitting approach and the other knee having a median parapatellar approach-to evaluate differences in lateral release, postoperative rehabilitation, ease of approach, and complications in total knee replacement surgery. There were 25 lateral releases on the muscle-splitting side and 26 on the median parapatellar side (P = .871). There were no differences in range of motion on day 2 or discharge, straight-leg raise, terminal knee extension, extensor lag, lateral release, or rehabilitation. There were 2 postoperative hematomas and 1 manipulation, all on the muscle-splitting side. All complications occurred from the muscle-splitting side. The muscle-splitting approach cannot be recommended as being superior to the median parapatellar approach.
Adult↗
Indomethacin-induced postoperative psychosis.
Indomethacin is used commonly for the prevention of postoperatively heterotopic ossification. There have been 3 reports in the pharmacologic literature of indomethacin-induced psychosis. We describe a case of indomethacin-induced psychosis in a patient in whom indomethacin was used for the prevention of postoperative heterotopic ossification after bilateral uncemented total hip replacements.
Arthroplasty, Replacement, Hip↗