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Biomedical subjects

C H Rorabeck

Publications and source records attributed to C H Rorabeck.

At least 91 records · Page 5Linked to original sources

Total hip replacement: the case for noncemented femoral fixation because of age.

Both noncemented fixation and improved cemented fixation of total hip replacements emerged to counteract the clinical and radiographic failures of early cemented procedures. A randomized clinical trial comparing a second-generation cemented with a second-generation noncemented total hip replacement demonstrated that in the medium term both implants allow excellent, disease-specific, global and functional capacity outcome measures. No significant differences existed between the cemented and noncemented implants in terms of these parameters or revision rate. Cost-to-utility analyses of both types of replacements revealed that total hip replacement is one of the most cost-effective medical interventions. Noncemented total hip replacements seem as efficacious as cemented devices in patients younger than 70 years.

Adolescent↗

Clinical comparison of the Miller Galante I and AMK total knee systems.

One hundred patients with primary osteoarthritis of the knee were prospectively randomized to assess the clinical outcome between two contemporary knee designs, namely the Anatomic Modular Knee (AMK, DePuy, Warsaw, IN) and the Miller Galante I (MG I, Zimmer, Warsaw, IN). In addition, patients were stratified by surgeon. While the clinical outcome measured by the Hospital for Special Surgery knee scores was similar for both groups, there was a difference in the number of complications requiring further surgery. Extensor mechanism complications requiring further surgery occurred in four patients (3 MG I and 1 AMK); three patients in the MG I group required a distal realignment procedure for patellar dislocation, while none of the AMK patients had this complication. There was, however, one patellar fracture in the AMK group that required an open reduction. The authors postulate that the major difference contributing to patellofemoral complications relates to the patellofemoral design and patellar tracking, with the more anatomic AMK femoral component having better patellar tracking and stability clinically.

Aged↗

Pain in the thigh following total hip replacement with a porous-coated anatomic prosthesis for osteoarthrosis. A five-year follow-up study.

We performed a study to determine the prevalence, severity, and natural history of pain in the thigh in patients who had a total hip replacement with a porous-coated anatomic prosthesis and to determine if there was an association between the radiographic findings and the pain in the thigh. We previously reported the results in these patients two years after the operation. The present study included ninety-four patients (101 total hip replacements) who had been followed for a minimum of five years--six of the original group of patients had died from unrelated causes, two had had a revision, and one had been lost to follow-up. The patients were assessed prospectively with use of the Harris hip score and a visual-analog scale for pain in the thigh. Two of us, who were blinded to the clinical result, reviewed the radiographs retrospectively for the morphology of the proximal aspect of the femur; distal fit; metaphyseal fill; alignment of the stem; shedding of beads; distal cortical hypertrophy; pedestal formation; cancellous condensations at the distal end of the porous ingrowth surface; and the presence, extent, and location of radiolucent lines around the femoral component. At five years, pain in the thigh was found in association with twenty-seven hips (27 per cent). The pain was new in fourteen thighs (14 per cent), unchanged (from that at the two-year follow-up examination) in eight (8 per cent), increased in four (4 per cent), and decreased in one (1 per cent). Pain in the thigh was most strongly associated with a poor Harris hip score and the presence of loose beads.

Bone Cements↗

A double-blind study of 250 cases comparing cemented with cementless total hip arthroplasty. Cost-effectiveness and its impact on health-related quality of life.

The success of a total hip arthroplasty (THA) is dependent on many more parameters than simply the prosthesis used. This study has demonstrated that a randomized controlled clinical trial of 250 patients comparing two types of hip prostheses (cemented versus cementless) with virtually complete follow-up examination is feasible. It also demonstrates that patients are willing to answer extensive quality-of-life questionnaires that allow complete assessment of the impact of hip arthroplasty on the patient's overall health-related quality of life. This study has also demonstrated that THA is an extremely effective intervention when one assesses its ability to impact on patients health-related quality of life with no difference between cement versus cementless at two years' follow-up examination.

Activities of Daily Living↗

Ingrowth surfaces. Plasma spray coating to titanium alloy hip replacements.

Plasma spray coatings on titanium alloy total hip replacements (THRs) provide a viable alternative to sintered bead or diffusion-bonded fiber metal ingrowth surfaces. The plasma spray process enables the titanium alloy implant to retain 90% of its fatigue strength, as opposed to less than 50% for sintered or diffusion-bonded cementless devices. Laboratory and clinical evidence suggest that plasma spray cementless THRs perform as well, if not better, than other cementless implants. Clinical trials have demonstrated the superiority of a plasma spray cementless THR (Mallory-Head) over a sintered bead cementless THR (PCA) and the equivalent results to a cemented THR. Plasma spray coatings on titanium alloy hip replacements provide a safe, predictable coating for cementless fixation of THRs in the short to medium range of follow-up periods.

Adult↗

Posteromedial tibial polyethylene failure in total knee replacements.

This report details 16 cases of focal posteromedial tibial polyethylene wear and failure after total knee arthroplasty. This wear phenomenon was associated with an external rotatory subluxation of the tibial component relative to the femoral component. Failure occurred in ten Miller Galante 1, three Porous Coated Anatomic, two Kinematic, and one Press-Fit Condylar knee designs at a mean time of 45 months from their implantation. With this type of failure, there did not seem to be a relationship with metal type, fixation, polyethylene manufacturing method, or polyethylene thickness. A relatively flat design of the tibial articular surface was common to all of these components. In certain patients this articular design may allow excessive component translation, which leads to polyethylene deformity, wear, and subluxation. Some methods for preventing this failure mode are reported here.

Aged↗

The efficacy of tourniquet release in blood conservation after total knee arthroplasty.

One hundred consecutive primary total knee arthroplasties performed by a single surgeon were prospectively randomized into two groups to study the effect of tourniquet release for hemostasis on postoperative blood loss and transfusion requirements. The two groups were comparable. Variables such as antiinflammatory drug use; anesthetic; soft-tissue release; and component fixation were analyzed. There was no significant difference between the groups in terms of perioperative blood loss, decrease in hemoglobin or hematocrit level, transfusion need, or incidence of wound or thromboembolic complications. Tourniquet release for hemostasis is not an effective means of limiting postoperative blood loss or reducing transfusion need after primary total knee arthroplasty.

Adult↗

Total knee arthroplasty in the octogenarian.

Fifty consecutive Miller-Galante (Zimmer, Warsaw, IN) and Kinematic II (Howmedica, Rutherford, NJ) total knee arthroplasties for osteoarthritis in patients 80 years of age and over were compared to 50 arthroplasties in patients aged 65-69 years, with a minimum 2-year follow-up period. Each patient was assessed clinically using the Hospital for Special Surgery knee rating scores and radiographically by an independent observer. Average age of the study group participants was 83 years and of the comparison group, 68 years. Apart from age, the two groups were similar with respect to sex, bilaterality, prosthetic type, and preoperative Hospital for Special Surgery scores. No significant differences were noted for pain, functional level, strength, stability, or range of motion throughout the 2-year follow-up period. More octogenarian patients were found to have a preoperative deformity, and these deformities were larger, on average, than in the retiree group, suggesting a more advanced disease pathophysiology. A larger number of elderly patients required continued use of walking aids. An analysis of the cost-effectiveness data, collected for both groups, showed that although the in-hospital costs and length of stay were the same ($17,160 Can), the cost per patient after discharge was slightly greater ($2,00 Can) in the octogenarian. This prospective clinical study of total knee arthroplasties for osteoarthritis has shown that it is a reliable and cost-effective procedure for the octogenarian.

Age Factors↗

The Miller-Galante knee prosthesis for the treatment of osteoarthrosis. A comparison of the results of partial fixation with cement and fixation without any cement.

In a prospective, non-randomized study of 344 patients who had 392 primary total knee replacements with a Miller-Galante I prosthesis for the treatment of osteoarthrosis, the results of partial fixation with cement (insertion of the tibial and patellar components with cement and of the femoral component without cement) were compared with those of fixation without any cement. Of the 392 knees, 183 (163 patients) had fixation without cement (Group I) and 209 (181 patients), with and without cement (Group II). The average duration of follow-up was three years (range, two to five years). Nine patients died during the follow-up period, but no others were lost to follow-up. Analysis of the knee scores, range of motion of the knee, radiographs, and rates of complications revealed no differences between the outcomes in the two groups during the follow-up period. The rate of complications due to problems related to the extensor mechanism was high in both groups: a reoperation was performed in fifteen (8 per cent) of the knees that had had fixation without cement and in nineteen (9 per cent) of those that had had both types of fixation. Thirteen patients had additional operative treatment for recurrent patellar dislocations; twelve patients, for abnormal wear of the polyethylene of the patellar component: two patients, for avulsion of the patellar ligament from the tibia; and two patients, for unexplained pain in the knee. In addition, there were eight patellar fractures (two of which led to a reoperation) and three deep infections (all of which led to a reoperation).

Adult↗

Isometric hip abductor strength following total hip replacement and its relationship to functional assessments.

Despite the rehabilitative emphasis on hip abductor strength following total hip replacement (THR), it is unclear how muscular strength is related to function. The purposes of this study were to examine changes in hip abductor strength during the first 6 months following THR and to determine the relationship between hip abductor strength and functional performances. Forty-three patients (mean age 64 +/- 7 years) completed strength assessments before surgery and at 1, 6, 12, and 24 weeks after surgery, and functional assessments before surgery and at 12 and 24 weeks after surgery. Both hip abductor strength and functional performance were significantly improved at each assessment (p < 0.01). The correlation between isometric hip abductor torques and the distance walked in 6 minutes was modestly high (r = 0.48-0.51; p < 0.01). This study provides baseline data for isometric hip abductor strength that can be used comparatively to assess patient progress and to help set clinical goals. Although strength is related to function, isometric measurements of strength should not be relied upon as the sole predictors of function in patients who have undergone THR.

Bone Cements↗

Total hip arthroplasty in rheumatoid arthritis: comparison of cemented and uncemented implants.

In a group of patients who underwent total hip arthroplasty because of rheumatoid arthritis, the outcome in 42 hips was assessed. There were 17 cemented and 25 uncemented prostheses. The average follow-up was 5 years for cemented prostheses and 3 years for uncemented prostheses. The average Harris hip scores were similar in the two groups (84 and 86 respectively). Radiologically, the incidence of migration of femoral and acetabular components was similar in the two groups. Component migration was not affected by component fixation. Uncemented implants may have a role in hip arthroplasty in patients with rheumatoid arthritis.

Adult↗

Thigh pain in cementless total hip arthroplasty. A comparison of two systems at 2 years' follow-up.

Cementless total hip arthroplasties using 110 porous-coated anatomic (PCA) and 105 consecutive Mallory-Head (MH) prostheses were reviewed using prospectively gathered clinical data and a detailed radiographic analysis. In an earlier experience with the PCA, 13% of patients experienced thigh pain at 1 year and 23% at 2 years. Positive radiographic correlates with thigh pain included subsidence, distal cortical hypertrophy, a tight diaphyseal fit, and stem tip sclerosis. In the current MH study group, the incidence of thigh pain was 7% at 1 year and 3% at 2 years. No radiographic findings correlated positively with thigh pain. The results of this short-term clinical comparison suggest that a long, straight, tapered design offered better initial stability than its anatomic counterpart as reflected in the much lower incidence of thigh pain. These results may translate into improved osseous integration and long-term success.

Adult↗

Management of recurrent dislocation of the patella following total knee arthroplasty.

Fifteen knees with patellar dislocation after total knee arthroplasty had realignment of the extensor mechanism using a modification of the Trillat procedure. The onset of dislocation occurred on average 4.7 months from the time of surgery. After total knee arthroplasty the patients had an average range of motion of 109 degrees. All patients had medialization of the tibial tubercle and lateral release. No patient had a recurrent dislocation after a minimum 2-year follow-up period. The average knee score was 82 and the average flexion arc was 112 degrees. All but one of the osteotomies healed uneventfully.

Aged↗

Thigh pain after cementless hip arthroplasty. Annoyance or ill omen.

A retrospective review of 148 consecutive porous-coated hip arthroplasties (PCA) showed an incidence of thigh pain of 13% one year after surgery, and 22% at two years. Positive correlations were made with femoral stem subsidence (greater than 2 mm) and with distal periosteal and endosteal bone formation. No positive correlations were made with parameters of bone quality or component fit. Resolution of pain occurred in one-third and an anti-inflammatory agent produced partial relief in two-thirds of the patients. We conclude that thigh pain is secondary to stem instability with distal stress transfer in the absence of stable proximal fixation.

Age Factors↗

Total hip arthroplasty in patients with avascular necrosis of the hip. Follow-up observations on cementless and cemented operations.

Thirty-one patients with avascular necrosis of the hip were treated by 34 total hip arthroplasties (THAs). All patients were observed prospectively with a minimum two-year follow-up evaluation (average, 46 months; range, 24-84 months). Twenty had cemented arthroplasties using contemporary cementing techniques. This included insertion of a medullary plug, cleansing of the canal with a medullary brush, pulsatile lavage irrigation, and insertion of the cement with a cement gun. In 14 hips, a cementless prosthesis was used. Patients were rated using a modified Harris hip score. Sequential postoperative roentgenograms were analyzed in each patient. The overall Harris hip score ratings were 88 in the cemented and 84 in the noncemented groups. Mechanical failure with loosening of the femoral component occurred in one patient who developed deep sepsis. Significant thigh pain occurred in four patients in the noncemented group. Previous studies in the literature have generally reported unfavorable results in patients with avascular necrosis of the hip treated with THA. Using cementless and cemented fixation with contemporary cementing techniques, improved results can be expected. A high incidence of thigh pain (29%) in the cementless group remains a problem.

Adult↗