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D K Collis

Publications and source records attributed to D K Collis.

16 recordsLinked to original sources
PubMed1999

Comparison of enoxaparin and warfarin for the prevention of venous thromboembolic disease after total hip arthroplasty. Evaluation during hospitalization and three months after discharge.

BACKGROUND: Venous thromboembolic disease in the form of deep venous thrombosis and pulmonary embolism is a major risk after a total hip arthroplasty. Enoxaparin, a low-molecular-weight heparin, has been shown to reduce the prevalence of deep venous thrombosis after total hip arthroplasty. Warfarin, an orally administered anticoagulant, has been used historically to reduce the risk of deep venous thrombosis after total hip arthroplasty. METHODS: We compared enoxaparin and adjusted-dose warfarin with respect to their safety and their efficacy in the prevention of clinically important venous thromboembolic disease, defined as distal or proximal deep venous thrombosis or pulmonary embolism, or both, during hospitalization after total hip arthroplasty. We also evaluated the prevalence of complications and mortality from venous thromboembolic disease within three months after discharge. RESULTS: Three thousand and eleven patients at 156 centers were randomly assigned to prophylactic treatment with injection of enoxaparin or oral administration of adjusted-dose warfarin during hospitalization. During the study, fifty-five (3.6 percent) of the 1516 patients who were managed with enoxaparin and fifty-six (3.7 percent) of the 1495 patients who were managed with warfarin had venous thromboembolic disease. Twenty-one patients (0.7 percent), which included four (0.3 percent) of those managed with enoxaparin and seventeen (1.1 percent) of those managed with warfarin (p = 0.0083), had venous thromboembolic disease during hospitalization. After discharge from the hospital, venous thromboembolic disease developed in ninety patients (3.0 percent): fifty-one (3.4 percent) of those managed with enoxaparin and thirty-nine (2.6 percent) of those managed with warfarin. One patient who had been managed with enoxaparin died because of a pulmonary embolism, which was confirmed at autopsy. Three additional patients (one who had been managed with enoxaparin and two who had been managed with warfarin) died, and the deaths were attributed to venous thromboembolic disease; however, no autopsies were performed. Twenty-six patients (0.9 percent) (eighteen managed with enoxaparin and eight managed with warfarin) had clinically important bleeding. CONCLUSIONS: Inpatient programs providing treatment with either enoxaparin (thirty milligrams every twelve hours) or adjusted-dose warfarin for a mean of 7.3 days afforded protection against venous thromboembolic disease, with overall rates of morbidity and mortality of 3.7 and 0.6 percent, respectively, and a very low rate of major bleeding complications (0.9 percent) for three months after total hip arthroplasty. During hospitalization, the patients managed with enoxaparin had a lower rate of venous thromboembolic disease than those managed with adjusted-dose warfarin (p = 0.0083). This benefit was lost after the medication was discontinued, with no difference in the prevalences of venous thromboembolic disease between the two groups at three months after discharge from the hospital.

Adolescent↗
PubMed1998

Loosening rates and bone lysis with rough finished and polished stems.

In the senior author's 27-year experience in cementing femoral components, stems with smooth and rough surfaces were implanted. Prospective data have been kept on all patients allowing extensive long term followup. The polished Charnley stem was implanted in 168 hips from 1971 to 1975. To date, only four (2.4%) stems have required revision for aseptic loosening and four others for fracture. None showed significant bone lysis. The experience with the T-28 and TR-28 allows comparison of stems of similar geometry, but with different surface finishes. From 1972 to 1977, 209 polished T-28 stems were inserted and to date 18 (14 for fracture and four for loosening, 1.9%) have required revision. None had associated bone lysis. From 1977 to 1982, 227 second generation TR-28 matte surface finish stems (Ra 30) were implanted. Five required revision, three (2.2%) with major bone lysis. Radiographic review revealed minimal lysis in four (1.9%) polished T-28 stems and in 11 (4.9%) TR-28 stems, three of which showed major bone destruction. From 1980 to 1993, 1061 Iowa stems were implanted. In 1986 proximal precoat was added, which required additional roughening of the surface. In 1995 a 1.5% early loosening rate was reported with significant bone lysis, complicating revision. By 1998 34 (3.2%) stems have required revision, all associated with significant bone loss. Revision of one of 12 original Iowa (Ra 30) and 12 of 22 (Ra 80) grit blasted stems was needed before 5 years postoperatively. These early failures prompted the author to return to a polished stem with a geometry almost identical to the Charnley stem.

Adult↗
PubMed1997

The value of maintaining outcomes in an individual practice for 25 years.

Decision making in orthopaedic surgery is facilitated by outcome data, not only from the literature, but also from one's own practice. Between 1971 and 1996, 2602 primary and 587 revision total hip replacements were performed. All had prospective collection of data, which altered surgical practice. A posterior approach in 147 primary total hip replacements resulted in 10 dislocations (6.8%) leading to the use of the anterolateral approach in 1788 subsequent hips with only eight dislocations (0.45%). The initial 298 hips were done in a standard operating room with restricted access and were covered with perioperative antibiotics. No infections occurred permitting ongoing use of inexpensive infection prevention. From 1971 to 1975, 168 classic polished Charnley stems were implanted with only seven stems requiring revision to date. In contrast, use of the matte finished Müller prosthesis in the early 1970s in 58 hips has resulted in nine revised stems. From 1980 to 1990, 789 second generation design matte finished Iowa stems were implanted. Prospective data collected disclosed that a small number (1.5%) of early loosenings occurred and all were associated with extensive bone lysis which made revision difficult. Only polished stems are now cemented by the author. The author firmly believes that his practice patterns have been promptly and appropriately altered by the availability of a prospectively collected hip data file.

Arthroplasty, Replacement, Hip↗
PubMed1995

Early loosening of the femoral component at the cement-prosthesis interface after total hip replacement.

Between 1980 and 1990, 1941 total hip replacements were performed with use of the Iowa femoral component fixed with cement. Twenty-seven of these patients (twenty-nine hips) had early loosening of the femoral component two to ten years (average, five years) after the operation. The average age of these patients at the time of the operation was fifty-nine years (range, forty-one to seventy-seven years). The acetabular cup had been inserted without cement in seventeen hips, and the cup had been inserted with cement in twelve. The femoral stems had a matte finish; twenty had been precoated with polymethylmethacrylate and nine had not been precoated. The pattern of loosening of the femoral stem was unique: in each hip, the loosening was initially reflected by debonding (a superolateral lucency between the cement and the prosthesis in zone 1 of Gruen et al.), and this was followed by progressive loosening at the cement-prosthesis interface with maintenance of the bone-cement interface. In twenty hips, the debonding was followed by extensive osteolysis. Twenty patients (twenty-one hips) had a revision, and one was considering a revision at the time of writing. The average time from the onset of the symptoms to the revision for the nineteen hips for which this information was available was nine months. We believe that both the geometry (a cylindrical shape distal to the proximal cobra shape) and the surface finish of the Iowa femoral component were responsible for the pattern of progressive loosening.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Revision total hip replacement with cement.

This article outlines the author's perspectives on the use of cement in revision total hip replacement. The results reported in the literature are briefly described and a follow-up of the author's personal results using cement the second time on the femoral side will be outlined. Specifically, 110 revisions were performed between 1974 and 1989 and only four of those have required revision for aseptic loosening. Three have been noted to be radiologically loose without sufficient symptoms to warrant revision. Specific cement techniques and prosthetic choices are described. Several clinical examples using cement will illustrate its versatility for treating significant femoral anatomical deficiencies.

Aged↗
PubMed1993

Classification of femoral abnormalities in total hip arthroplasty.

Bony abnormalities of the femur can significantly complicate total hip arthroplasty both for the primary and revision operations. No standard nomenclature exists for the description of these femoral abnormalities. A classification system is presented to standardize nomenclature, assist in preoperative planning, and to assist in the reporting of these defects.

Bone Malalignment↗
PubMed1992

Separation of the polyethylene liner from acetabular cup metal backing. A report of three cases.

In three young patients with cementless Porous Coated Anatomic (PCA) total hip prostheses implanted two to four years previously, the polyethylene liner separated from metal backing. These cups were of the original PCA design, manufactured and packaged as single assembled components, rather than the more recent two-piece components packaged with interchangeable liners separate from the metal backing. Each case of separation was associated with the failure of the thin outer polyethylene rim and central polyethylene peg on the back of the liner that secures it to the metal backing. Cup liners should be securely attached to the metal backing. The possibility of polyethylene failure is considerable when cementless metal-backed acetabular cups are used in active young patients.

Acetabulum↗
PubMed1988

Long-term results of an individual surgeon.

In conclusion, my 17-year experience with total hip arthroplasty leads me to believe that hip replacements can be done in a standard operating room if adequate preoperative precautions are taken, traffic in the operating room is strictly controlled, and prophylactic antibiotics are given (infection rate 0.28 per cent). Cemented resurface arthroplasty was not a successful enough operation to warrant its continued use (revision rate 44 per cent). The revision rate for all hips operated on 10 or more years ago was 7.0 per cent. In patients younger than fifty years of age, a revision rate of 19.6 per cent was observed after 10 years. Excessive body weight and heavy physical activity levels were frequently noted among the failures. Total hip arthroplasty should be done cautiously in patients under 50 and very rarely in patients under 30. Thirteen of the 25 revisions required in the early series were due to stem fracture, a complication rarely seen now with improved stem design and superalloy metallurgy. Despite radiologic identification of prosthesis loosening, revision THR may not be necessary for many years, if at all. Uncemented arthroplasty, particularly the acetabular component, seems to hold promise for the future; however, the experience to date is too limited to make any definite conclusions.

Adult↗
PubMed1984

Cemented total hip replacement in patients who are less than fifty years old.

Forty-five cemented total hip replacements in thirty-eight patients who were less than fifty years old were followed with physical examinations and radiographs for five to eleven years (average, 7.3 years) after surgery. The average age of the patients at the time of surgery was 40.7 years. The average Iowa hip rating at follow-up was 91.9 points (range, 58 to 100 points). No surgical deaths, infections, or dislocations were encountered. All of the patients had been repeatedly advised to avoid running, jumping, heavy labor, and lifting more than forty pounds (eighteen kilograms). Revision of a prosthetic component was necessary in four hips (8.9 per cent); all of the revisions were successful. Radiolucent lines were seen about the acetabular components of thirty-one hips but in only three (6.6 per cent) were these judged to be progressive bone-cement demarcation lines. Only one of those three hips was symptomatic. Three hips (6.6 per cent) also had subsidence of the femoral component into the femoral canal, but only one hip was symptomatic. Resorption of the medial aspect of the proximal end of the femur was seen in five hips, the maximum resorption being three to five millimeters. I have concluded that cemented total hip arthroplasty can give acceptable results in patients who are thirty to fifty years old, and that the result can be reasonably long-lasting if the patients are willing to avoid strenuous activity.

Adult↗
PubMed1982

Long-term radiographic follow-up of total hip replacements.

This report relates the long-term clinical result with the serial radiologic findings of 350 consecutive total hip replacements done by the author. Thirteen femoral components and one acetabular component have been revised, and 12 of the 14 components had shown radiologic changes in the surrounding cement prior to the need for revision. Available roentgenograms at 6 weeks, 1 year, 5 years, and 8 to 10 years after surgery made radiologic assessment possible in 129 hips. Heterotopic bone formation, calcar resorption and distal cortical hypertrophy all appeared to be primarily radiologic findings with little effect on clinical results. A variety of changes seen in the cement or bone-cement interface were noted on the femoral component side of 13.6% of the hips. None of these patients had any symptoms or functional limitations. These radiologic femoral cement mantle changes showed a high correlation with apparently inadequate initial cementing techniques and were usually already seen on the 1- and 5-year postoperative roentgenogram. Only one acetabular cup was identified as radiologically loose and one as migrated. Radiolucent lines at the bone-cement interface on the acetabular side showed vascillating increases and decreases on the serial roentgenograms. Since the lucent lines on the acetabular component side improved as often as they increased in size, these lucencies did not seem to be of similar predictive value as those on the femoral side. Of the hips followed 8 to 10 years only 2 circumferential and 10 lucencies greater than 2 mm could be found. I could not correlate these with inadequate cup position or inadequate cement mantle on the initial radiograph. The 29 patients in this series who were under 50 years of age did not have a revision rate or radiologic change different from the group as a whole.

Adult↗
PubMed1977

Femoral stem failure in total hip replacement.

Reported here are four fractured femoral components from a consecutive series of 200 total hip reconstructions. All four had been placed in patients who weighed ninety-one kilograms or more and who were more than 1.8 meters tall. In each patient, roentgenograms made prior to the time of failure of the prosthesis revealed roentgenographic lucency, which was interpreted as cement failure. Metallurgical examination revealed fatigue failure and some abnormality in each prosthetic stem. Review of all 200 total hip replacements suggested that there was failure to position the prosthesis in strong valgus in there four hips and in thirty others. In the four failures, the contributing influences of large size of patients, inadequate valgus positioning of the prosthesis, inadequate support by cement, and metallurgical inadequacies of the prosthesis used are discussed.

Aged↗
PubMed1976

Total hip replacement without deep infection in a standard operating room.

In a consecutive series of 298 total hip-joint replacements performed by a single surgeon using a standard operating room, early deep infection was eliminated by simple inexpensive methods of controlling contamination in the operating room. Settling-plate monitoring revealed an average of 4.8 colonies of bacterial growth per hour of exposure. All patients received prophylactic antibiotics. One patient had a superficial wound infection which was controlled with antibiotic therapy. No deep infections were encountered in the 252 hips followed for two to five years after operation. We conclude that total hip arthroplasty can be performed in the standard operating room without undue risk of infection by consistently employing strict measures of operating-room discipline to limit contamination.

Air Microbiology↗