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Biomedical subjects

R L Barrack

Publications and source records attributed to R L Barrack.

At least 37 records · Page 2Linked to original sources

Patellar resurfacing in total knee arthroplasty. A prospective, randomized, double-blind study with five to seven years of follow-up.

BACKGROUND: Whether to resurface the patella during a primary total knee arthroplasty performed for the treatment of degenerative osteoarthritis remains a controversial issue. Parameters that have been suggested as being useful in guiding this decision include patient height and weight, the presence of anterior knee pain preoperatively, and the grade of chondromalacia encountered intraoperatively. The purpose of this study was to determine whether these parameters were predictive of the clinical result following total knee arthroplasty with or without patellar resurfacing. METHODS: Eighty-six patients (118 knees) undergoing primary total knee arthroplasty for the treatment of osteoarthritis were enrolled in a prospective, randomized, double-blind study. All patients received the same posterior-cruciate-sparing total knee prosthetic components. Patients were randomized to treatment with or without resurfacing of the patella. Evaluations consisted of the determination of a Knee Society clinical score, the completion of a patient satisfaction questionnaire, specific questions relating to patellofemoral symptoms, and radiographs. Sixty-seven patients (ninety-three knees) were followed for a minimum of five years (range, sixty to eighty-four months; average, 70.5 months). RESULTS: With the numbers available, there was no significant difference between the groups treated with and without resurfacing with regard to the overall Knee Society score or the pain and function subscores. Obesity, the degree of patellar chondromalacia, and the presence of preoperative anterior knee pain did not predict postoperative clinical scores or the presence of postoperative anterior knee pain. CONCLUSIONS: The occurrence of anterior knee pain could not be predicted with any clinical or radiographic parameter studied. On the basis of these results, it seems likely that postoperative anterior knee pain is related either to the component design or to the details of the surgical technique, such as component rotation, rather than to whether or not the patella is resurfaced.

Arthroplasty, Replacement, Knee↗

Early failure of modern cemented stems.

In the late 1970s, improved cement technique was introduced in an attempt to address the problem of early cemented stem loosening. Subsequently, numerous centers reported stem survival rates of >95% beyond 10 years. Long-term cemented stem fixation was believed widely to be consistently obtainable in most patients. Despite the widespread clinical success of these early cemented stems, numerous changes were introduced in stem design and cement technique. In more recent years, a surprising number of series of early failures of cemented stems have been reported. Some designs consistently have had a high early failure rate. Others have failed infrequently, but the failures have occurred early and with extensive osteolysis. Numerous causes have been proposed, including poor cement technique, undersized broaches, increased stem offset, decreased stem length, rough surface finish, and circular stem cross-section. Failures often are multifactorial and defy a simple explanation based on a single parameter. Results of cemented stems are more variable than previously appreciated. There are nuances of cemented stem design, cement technique, and patient selection that can lead to early failure and that are not understood completely at present. Given the availability of many cemented designs with proven records of clinical success, new design features should be introduced prudently with extensive premarket testing, limited clinical release, and careful postmarket surveillance.

Arthroplasty, Replacement, Hip↗

Patient satisfaction and outcome after septic versus aseptic revision total knee arthroplasty.

A consecutive series of revision total knee arthroplasties performed at 3 university-affiliated centers by 3 surgeons was prospectively studied. The same implant was used in all cases. The evaluation included a Knee Society clinical score (KSCS); SF-36; satisfaction survey; and radiographs preoperatively, at 6 and 12 months postoperatively, and annually thereafter. Follow-up averaging 36 months (range, 24-60 months) was obtained in 125 of 138 knees (91%). Twenty-eight knees were infected, and 26 of 28 knees were treated successfully with 2-stage exchange with an interval of 4 to 6 weeks using an antibiotic-impregnated spacer block and intravenous antibiotics. The remaining 99 knees were revised for reasons other than infection, including aseptic component loosening, progressive osteolysis, and component instability. Preoperatively, patients with infection had a significantly decreased arc of motion compared with patients without infection (79 degrees vs 92 degrees; P<.05). There was a strong trend for the infected knees to have a lower preoperative KSCS than the noninfected knees, although this trend did not achieve statistical significance (76 vs. 92; P =.11). Postoperatively, patients with infection continued to have a significantly decreased range of motion (89 degrees vs. 99 degrees; P =.05). The postoperative KSCS was markedly lower in the septic versus aseptic revisions (115 vs. 135; P =.02). Patients with infection had a significantly lower function score (44 vs. 57; P =.03). A significantly higher percentage of patients stated that they were unable to return to normal activities of daily living after septic versus aseptic revision total knee arthroplasty (24% vs. 7%; P<.05). Despite the inferior functional result, patients expressed an equal degree of satisfaction with the results of their treatment in septic versus aseptic revision cases.

Aged↗

The results of retaining a well-fixed patellar component in revision total knee arthroplasty.

The results of revision total knee arthroplasty (TKA) in which a well-fixed patellar component was left in place (retained) were compared with those in which the patellar component was revised to a cemented all-polyethylene component. The patella was retained in 34 cases, 12 of which were metal-backed, and was revised in 39 cases. Data collected on all patients included a Knee Society clinical and radiographic score, SF36, a patellofemoral questionnaire, and a satisfaction survey. There were no differences in clinical score, responses to specific patellofemoral questions, or patient satisfaction between the 2 groups. Retaining a well-fixed patellar component at the time of revision TKA appears to be a viable option with equivalent short-term results to those obtained when the patellar component is revised.

Adult↗

Patients' perception of pain after total hip arthroplasty.

A study was undertaken to determine the frequency with which patients had pain that they attributed to their hip after total hip arthroplasty. Pain drawings were used to allow patients to localize the area of their symptoms, and the degree of pain was quantified with visual analog scales. Complete clinical and radiographic data were collected on all patients so that the occurrence of pain could be correlated with a number of parameters previously reported to affect the incidence of pain, including age, sex, activity level, length of follow-up, stem size, bone type (Dorr index), and type of stem fixation (proximally coated, fully coated, or cemented). Results indicated that type of stem fixation was the only parameter statistically correlated with a higher incidence of thigh pain. Patients with proximally coated stems were more than twice as likely to complain of pain than patients with fully coated or cemented hips (P < .01). Although the incidence of thigh pain was significantly higher with proximally coated stems, the severity was not, averaging 3.0 to 3.5 out of 10 on visual analog scale in all 3 groups. The results indicate that patients perceived pain as originating in the hip in a high percentage of cases, particularly when proximally coated stems were used.

Adult↗

The use of a modular rotating hinge component in salvage revision total knee arthroplasty.

Revision total knee arthroplasty (TKA) using a second-generation modular rotating hinge design was performed on 16 knees in 15 patients over a 5-year period. Follow-up of 2 to 6 years (mean, 51 months) was obtained in 14 knees in 13 patients. Indications for revision were aseptic loosening of a hinged prosthesis (8 knees), loosening and bone loss associated with chronic extensor mechanism disruption (2 knees), component instability with chronic medial collateral ligament disruption (3 knees), and comminuted distal femur fracture (1 knee). Clinical and radiographic results were reviewed and compared with 87 patients who underwent revision TKA using a standard condylar revision design during the same period. Early results showed comparable postoperative knee scores and range of motion between the 2 groups despite the use of the rotating hinge component in more complex revision cases. No patient has exhibited radiographic evidence of definite component loosening. Alignment of 5 degrees to 10 degrees of valgus in the frontal plane and within 2 degrees of neutral in the sagittal plane was achieved consistently. Short-term clinical and radiographic results are encouraging and suggest that a second-generation modular rotating hinge component can be used successfully in selected salvage revision cases.

Adult↗

Proximal tibia--extensor mechanism composite allograft for revision TKA with chronic patellar tendon rupture.

Rupture of the patellar tendon following TKA is fortunately an uncommon complication with an incidence of 0.2-4% (Abril et al. 1995). Numerous options have been reported for treating this complication, including primary suture into a bone trough (Abril et al. 1995), autogenous tendon transfer (Cadambi and Engh 1992), and use of an artificial ligament (Fujikawa et al. 1994). Allograft patellar tendon has also been utilized either retaining the host patella and using a bone-tendon-bone graft or excising the host patella and using a quadriceps tendon-patella-patellar tendon-tibial tubercle graft (Emerson et al. 1990, Emerson et al. 1994, Zanotti et al. 1995, Booth et al. 1999). All of these techniques require structural integrity of the proximal tibia in the area of the tibial tubercle in order to attach the repair or graft to restore continuity of the extensor mechanism. When there is massive osteolysis and bone loss involving the proximal tibia, the situation becomes more complex and the previously described techniques are not advisable. In such cases, function can be obtained with a composite allograft of proximal tibia-patellar tendon-patella-quadriceps tendon. We describe a technique for dealing with this difficult clinical situation.

Arthroplasty, Replacement, Knee↗

The Otto Aufranc Award. Strut allograft healing to the femur with recombinant human osteogenic protein-1.

Allograft struts are used to reinforce the deficient proximal femur in hip arthroplasty or for fixation of a periprosthetic fracture. Although the use of strut grafts wired or cabled to the proximal femur generally has been successful, the time for healing is slow. The purpose of the current study was to determine whether cortical strut graft healing to the femur could be enhanced by the addition of recombinant human osteogenic protein-1. Fourteen adult dogs underwent bilateral onlay allograft strut procedures to the midfemur using stainless steel cables. In each animal one femur received 500 mg of osteogenic protein-1 device (2.5 mg recombinant human osteogenic protein-1/g Type I collagen) interposed between the graft and host bone. The results showed that the healing of cortical strut grafts to the femur was enhanced dramatically by the addition of the osteogenic protein-1 device. The sites treated with osteogenic protein-1 had significantly greater radiographic, histologic, and microradiographic scores at all times. Rapid formation of new bone and graft incorporation was observed in sites treated with the osteogenic protein-1 device. Strut healing with the osteogenic protein-1 device at 4 weeks postoperative was superior to the healing in control sites at 8 weeks. Improving and accelerating the course of cortical strut graft healing should provide a substantial clinical benefit in lowering the risk of graft nonunion and fracture and shorten the time of protected weightbearing and functional disability.

Animals↗

The effect of weight-bearing on the radiographic measurement of the position of the femoral head after total hip arthroplasty.

BACKGROUND: In most radiographic studies of polyethylene wear, investigators have used routine annual radiographs made with the patient in the supine position in order to measure penetration by the femoral head into the polyethylene liner. However, researchers have begun to question the effect of weight-bearing on the position of the head within the acetabular cup and, consequently, the effect of weight-bearing on measurements of penetration by the head. The purpose of the current study was to determine the effect of weight-bearing on the two-dimensional radiographic position of the femoral head within the acetabular cup. METHODS: Thirty-seven patients (forty-seven hips) who had had a total hip arthroplasty had radiographs made at one of two separate institutions. A set of anteroposterior radiographs was made for each patient: one radiograph was made with the patient supine and one was made with the patient upright bearing full weight on the replaced hip. At one of the institutions, a third anteroposterior radiograph was made with the patient in the same upright position but not bearing weight on the replaced hip. All measurements of the two-dimensional position of the head were performed by a single observer with use of a previously published computerized measurement system. RESULTS: Data from both institutions revealed that measurements of the position of the head on radiographs made with the patient supine were strongly and significantly correlated with measurements of the position of the head on radiographs made with the patient bearing weight (r2>0.93, p<0.001 for both regressions). Examination of the differences between the measurements revealed no bias for one set of measurements to consistently underestimate or overestimate the values derived with use of the other method. Moreover, we found a nearly perfect relationship between the measurements of the position of the head on radiographs made with the patient standing and bearing weight and those on radiographs made with the patient standing but not bearing weight (r2 = 0.97, p<0.001, slope = 0.99, intercept = 0.02 millimeter). CONCLUSIONS: On the basis of these findings, there is no evidence that radiographs must be made with the patient bearing weight in order to accurately measure the position of the femoral head within the polyethylene liner.

Arthroplasty, Replacement, Hip↗

Core decompression and conservative treatment for avascular necrosis of the femoral head: a meta-analysis.

Core decompression for avascular necrosis (AVN) of the femoral head continues to be a controversial procedure. Meta-analysis techniques were employed to identify 22 studies with a single surgical core decompression technique. A similar procedure identified eight studies that treated patients conservatively. The success rates for core decompression were 84%, 63%, and 29% for Steinberg stages I, II, and III, respectively. Conservatively treated patients with stage 0, I, III, and III AVN demonstrated success rates of 86%, 61%, 59%, and 25%, respectively. Chi-square analysis showed the success rate of core decompression to be statistically higher than conservative treatment for stage I hips only. Large multicenter prospective double-blinded studies with patients randomized to either core decompression or conservative treatment, then stratified by stage, cause, and bilaterality, are needed to determine the best treatment for early-stage AVN.

Adult↗

Lateral extra-articular knee reconstruction: long-term patient outcome and satisfaction.

Fifty-two patients who had an extraarticular reconstruction for anterior cruciate ligament (ACL) insufficiency were interviewed at an average of 11.4 years after their reconstruction. During the follow-up period, 4 patients (8%) had intra-articular reconstructions for persistent instability or re-injury, and another 4 (8%) had arthroscopic surgery for meniscal lesions. The mean Lysholm score at follow-up was 76.9. Of the 52 patients, 5 had had subsequent surgery during the follow-up period. In the remaining 47 patients, the results were excellent in 14 (29%), good in 10 (23%), fair in 7 (15%), and poor in 16 (33%). Patients operated on acutely (<6 weeks after injury) had a mean score of 82, whereas patients operated on more than 6 weeks after injury had a mean score of 75. Adding those patients who required subsequent reconstructions for persistent instability (4 knees) and those who obtained fair and poor results yielded an alarming rate of unsatisfactory results (52%). On the basis of these findings, we believe the lateral extraarticular reconstruction is not an acceptable form of treatment for the functionally unstable knee.

Adolescent↗

Patient compliance and satisfaction with mechanical devices for preventing deep venous thrombosis after joint replacement.

A consecutive series of patients having total joint arthroplasty at a single university hospital were sequentially treated with two mechanical devices for prevention of deep venous thrombosis (DVT). The first 104 patients (group 1) wore thigh-high sequential compression device (SCD). The next 120 patients (group 2) wore a foot pump. Daily documentation of hourly compliance with each respective device was recorded until discharge. A patient satisfaction questionnaire was also obtained. Patient understanding about the devices' function aided compliance (73% compliance in group 1, and 77% in group 2). The satisfaction questionnaire revealed significantly greater satisfaction in group 2 (73%) versus group 1 (55%). Of a subgroup of 35 patients who had used both devices, 24 preferred the foot pump, 7 the SCD, and 4 had no preference. This study showed a higher degree of compliance and satisfaction for foot pumps as prophylaxis against DVT.

Adult↗

Cost analysis of revision total hip arthroplasty. A 5-year followup study.

A stratified, unselected sample of 30 patients who underwent revision total hip arthroplasty between 1990 and 1992 for whom complete clinical and financial data were available was studied. Clinical data included age, gender, diagnosis, length of stay, operative time and blood loss. Financial data included cost of implants, bone graft and accessories, hospital charge, and surgeon reimbursement. Results were compared with the results of an analogous group of 50 patients who underwent revision total hip arthroplasty at the same institution between 1995 and 1997. Cases were classified as simple (involving revision of only acetabular liner and/or femoral head), routine (revision of acetabular and/or femoral components), or complex (major structural graft, antiprotrusio cage, impacted grafting). For patients undergoing routine revision total hip arthroplasty, a dramatic decline of 52% occurred in length of stay during the 5-year span (10.7 days to 5.1 days). The average operative time also declined significantly (238 minutes to 199 minutes) as did the average implant cost ($4349 to $2827). Despite this, the average hospital charge increased 16% ($29,666 to $34,328). There was a significant and dramatic 35% decline in surgeon reimbursement ($3240 to $2178). There was no significant difference in surgeon reimbursement between simple, routine, and complex total hip arthroplasty. Patients who underwent complex procedures had a significantly greater length of stay (7.3 versus 5.1 days) and operative time (297 versus 199 minutes). The hospital charge was dramatically higher for patients undergoing complex procedures ($51,290 versus $34,328) but the surgeon reimbursement was lower on average, although not statistically significant ($1926 versus $2178). There was a significant increase in the number and complexity of revision total hip arthroplasties between the two periods. Significant decreases were achieved in length of stay, operating room time, and implant cost. Benefits from these changes were accrued to the hospital but not the surgeon because hospital costs decreased significantly whereas surgeon reimbursements declined dramatically.

Arthroplasty, Replacement, Hip↗

An analysis of sports knee evaluation instruments.

This study examined four commonly used sports knee evaluation instruments to establish normative data. A total of 91 volunteers who had not sought treatment for knee pain or any other knee complaint at any time in the past underwent a detailed medical history and examination of both of their knees. Three numerical systems (Feagin and Blake Knee Score, Lysholm Knee Score, and the Hospital for Special Surgery Knee Disability Assessment) and one nonnumerical system (the International Knee Documentation Committee Quick Knee Profile) were evaluated. A significant difference in the proportion of knees with excellent/normal ratings was seen among the four evaluation systems (P<.0001): Hospital for Special Surgery Knee Disability Assessment, 99.5%; Feagin and Blake Knee Score, 84.6%; Lysholm Knee Score, 84.1%; and the International Knee Documentation Committee Quick Knee Profile, 50.5%. Results showed that three objective component scores for the International Knee Documentation Quick Knee Profile were significantly lower than all other component scores (P<.05). These components included: overall ligament examination, Lachman, and total AP translation. These data may be useful as a baseline by which investigators studying patients following knee reconstructive procedures have a basis for comparison of their results.

Adolescent↗