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Biomedical subjects

S D Stulberg

Publications and source records attributed to S D Stulberg.

At least 37 records · Page 2Linked to original sources
PubMed1994

The hemostatic effects of desmopressin on patients who had total joint arthroplasty. A double-blind randomized trial.

The effects of desmopressin on postoperative bleeding and postoperative transfusion requirements were studied in ninety-two hemostatically normal patients who had had an elective primary total hip or total knee arthroplasty. The patients were randomized into either a placebo or a desmopressin group in a double-blind prospective clinical trial. During closure of the wound, desmopressin (0.03 microgram per kilogram of body mass) or the placebo was infused into a peripheral vein over a twenty-minute period. Compared with the placebo, desmopressin did not significantly decrease blood loss or transfusion requirements, and it did not affect the postoperative platelet or fibrinogen levels or the bleeding time. The results were no different even when the treatment and control groups were matched according to surgeon, use of cement for the femoral and knee components, preoperative use of non-steroidal anti-inflammatory agents, or performance of a lateral release for total knee arthroplasty. We concluded that desmopressin does not reduce blood loss or transfusion requirements after total joint arthroplasty.

Aged↗
PubMed1994

Safety of 1-stage bilateral total knee arthroplasty.

Bilateral total knee replacements during a single operation with intramedullary femoral guide rods have been associated with the possible development of a fat embolism syndrome. To assess the safety of this procedure, in which the femoral canal was decompressed by the use of an overdrilled entrance hole and fluted guide rod, 17 unilateral and 18 bilateral consecutive total knee patients were evaluated. There were no differences between the groups on the basis of changes in chest radiographs, percentage of estimated pulmonary shunting, mental status changes, or fat and bone marrow elements drawn from a central venous catheter in the right atrium. Although no patient had free fat in the blood, bone marrow elements were found in 3 bilateral and 2 unilateral cases. No patient had clinical manifestations of a fat emboli syndrome. With appropriate femoral canal decompression, bilateral 1-stage total knee replacement appears to be a safe procedure.

Adult↗
PubMed1994

Polyethylene wear in unicompartmental knee arthroplasty.

From 1983 to 1989, 147 unicompartmental knee arthroplasties (UKA) were performed. Eighteen knees (13%) have required revision: there were 11 (37%) Porous Coated Anatomic (PCA), three (8%) Microloc, and four (17%) Fibermesh UKAs. Retrieved implants were examined to determine the pattern and extent of polyethylene wear. Wear was severe in each series and was characterized by delamination, pitting, peripheral cracking, deformation, and abrasion. Polyethylene failure appeared to result from large localized stresses resulting from lack of conformity of the articular geometries of the prostheses. Progressive subluxation of the implants occurred that produced very high localized contact stresses at the periphery of the tibial component where the polyethylene was thinnest. The progression of osteoarthritis in these knees, particularly the attenuation of the anterior cruciate ligament, increased the tendency of these incongruous implants to subluxate. Although changes in the design and manufacturing of unicompartmental knee arthroplasties may increase the resistance of these implants to polyethylene wear, the progression of osteoarthritis at an unpredictable rate is likely to be associated with persistent polyethylene wear in this type of arthroplasty.

Aged↗
PubMed1994

Progressive subluxation and polyethylene wear in total knee replacements with flat articular surfaces.

One hundred eighty-six Microloc tricompartmental, cruciate-sparing, primary total knee replacements in 136 patients were performed between 1983 and 1987. Femoral components were made of cobalt-chrome-molybdenum alloy. The tibial component baseplates were made of titanium-aluminum-vanadium alloy. The baseplates were made with three small porous-coated pegs for fixation with or without cement, or with a central stem for fixation with cement. The polyethylene was affixed to the baseplate by a mechanical locking mechanism that was nonmodular. The articular surfaces of both components were flat mediolaterally and anteroposteriorly. The patellar components were dome shaped and metal backed with titanium-aluminum alloy. Seventy-three percent of the femoral components, 26% of the tibial components, and 48% of the patellar components were inserted without bone cement. The average time to maximum follow-up examination was 6.1 years (range, four to nine years). Of implants that had not been revised, 84.4% had good or excellent results (using the Hospital for Special Surgery scoring system) at final follow-up examination. The average range of motion of functioning implants at final follow-up examination was 108 degrees. Revisions for failure only of the metal-backed patellar component were performed in 22 knees (11.8%). Forty knees (21.5%) required revision for failure of the femoral-tibial articulation. Reasons for failure in this group included: polyethylene wear (57.5%); loosening (15.0%); tibial tray fracture (10.0%); sepsis (12.5%); and dislocation or ligament laxity (5.0%). An additional 15 functioning knees (8.1%) have radiographic evidence of progressive femoral-tibial subluxation. Future failure of these devices is considered likely. Polyethylene wear requiring revision was not statistically associated with patient age, gender, preoperative diagnosis, height, weight, or component size. Polyethylene failure leading to revision was related to the radiographic appearance of femoral-tibial component subluxation. This subluxation was most likely to occur after five years of component implantation. The development of progressive femoral-tibial subluxation was statistically associated with postoperative extremity malalignment, excessive varus positioning of the tibial component, bone grafting of the tibial plateau, the use of the small-pegged tibial component, and the use of this component without cement. Polyethylene wear associated with progressive femoral-tibial subluxation occurred at the periphery of the tibial plateau and along the raised portion of the tibial spine. The metal baseplate at the edge of the plateau was frequently exposed and worn. Bone lysis associated with the presence of polyethylene, metal, and cement debris was frequently observed.

Adult↗
PubMed1993

A randomized, controlled trial of arthroscopic surgery versus closed-needle joint lavage for patients with osteoarthritis of the knee.

OBJECTIVE: To compare arthroscopic surgery and closed-needle joint lavage for patients with non-end-stage osteoarthritis (OA) of the knee under controlled, experimental conditions. METHODS: Thirty-two subjects who met specific clinical, radiologic, medical, and rehabilitation criteria were randomized to receive arthroscopic surgery (n = 18) or joint lavage (n = 14). Outcome measures evaluated at baseline and at 3 and 12 months of followup included 3 standard clinical parameters, self-reported pain and functional status (by the Arthritis Impact Measurement Scales), 50-foot walk time, 2 global scales, and direct and indirect medical costs. RESULTS: At 3 months of followup, there were no significant between-group differences in pain, self-reported and observed functional status, and patient and "blinded" physician global assessments. The arthroscopic procedure cost $3,840 more than did closed-needle joint lavage. After 1 year, there were no between-group differences in medication costs, utilization of medical services, or indirect costs related to employment or use of household help. After 1 year, 44% of subjects who underwent arthroscopy reported improvement and 58% of subjects who underwent joint lavage improved. Patients with tears of the anterior two-thirds of the medial meniscus or any lateral meniscus tear had a higher probability of improvement (by "blinded" physician assessment) after arthroscopic surgery (0.63) than did patients with other intraarticular pathology (0.20). CONCLUSION: The search for and removal of soft tissue abnormalities via arthroscopic surgery does not appear justified for all patients with non-end-stage OA of the knee who fail to respond to conservative therapy, but it may be beneficial for certain subgroups.

Aged↗
PubMed1993

Failure of the porous-coated anatomic prosthesis in total knee arthroplasty due to severe polyethylene wear.

Four hundred and eighty-seven total knee arthroplasties were performed by a single surgeon with use of a porous-coated anatomic prosthesis between 1982 and 1989. There were thirty-two clinical failures (7 per cent) due to severe wear of the surfaces of the tibial and patellar polyethylene components. Thirty patients had a revision. The average time to failure of the implant was four and one-half years. The initial clinical symptoms of failure by wear consisted of a painless effusion with a decreased range of motion. Subsequent pain was considered as the criterion for failure necessitating operative intervention. Increased weight and decreased age of the patient and a thinner tibial component were significant predictors of an increased risk of failure (p < 0.01). Examination of retrieved tibial components revealed extensive delamination caused by fracture of the polyethylene at a depth of about one millimeter below the surface. Cracks that had propagated in from the medial and lateral peripheries of the tibial component toward the center of the condyles were also a common finding. It appears that the design of the implant as well as clinical factors (the age and weight of the patient) contributed to the mechanical failure of the polyethylene of these implants.

Aged↗
PubMed1993

The natural history of unicompartmental arthroplasty. An eight-year follow-up study with survivorship analysis.

From 1983 to 1987, 82 unicondylar arthroplasties were performed for primary unicompartmental osteoarthrosis. Seven knees had lateral compartment arthroplasties and 75 had medial unicompartmental knee arthroplasties (UKA). At a minimum follow-up period of four years, eight patients had been revised, one patient was scheduled for revision, and one patient had died with a failed UKA, for a total failure rate of 12%. Reasons for failure were progression of tricompartmental arthritis in two patients (2.4%), polyethylene wear in two (2.3%), component failure in two (2.3%), component loosening in three (3.5%), and technical error in one (1.6%). Furthermore, 14 (17%) patients showed roentgenographic evidence of impending failure and an additional 12 (15%) patients showed a gradual decline in Hospital for Special Surgery knee scores. Unicondylar knee arthroplasty does not appear to provide as reliable pain relief as total knee arthroplasty. Progression to tricompartmental arthritis, polyethylene wear, and component loosening were seen to limit the usefulness of this arthroplasty. Unlike total knee arthroplasty, factors affecting the success or failure of UKA cannot be predictably controlled by the surgeon.

Aged↗
PubMed1992

A new surgical technique for tibial tubercle transfer in total knee arthroplasty.

Several methods are described for extensor mechanism realignment in total knee arthroplasty, including lateral release, medial reefing, V-Y quadricepsplasty, and tibial tubercle transfer. Each has its indications, merits, and pitfalls. The advantages of tibial tubercle transfer include precise realignment of the quadriceps mechanism, the ability to properly locate the patella proximally or distally, and maintenance of quadriceps power. The authors present a new technique for tibial tubercle transfer in total knee arthroplasty. Important points include (1) full-thickness medial and lateral soft tissue flaps that are anchored to bone and cover the transferred tubercle at the end of the procedure; (2) osteotomy of a long (10-cm) strip of tubercle and tibial crest; (3) placement of the osteotomized segment in a prepared, inset cancellous bone bed; and (4) fixation of the graft with multiple staples that hold the graft in place without being inserted through the graft. The method described will allow surgeons to perform tibial tubercle transfer reproducibly while avoiding the frequently cited complications of nonunion, loss of fixation, and wound slough.

Aged↗
PubMed1992

Wear of polyethylene in total joint replacements. Observations from retrieved PCA knee implants.

Observations of wear damage were performed on 12 retrieved porous coated anatomic (PCA) tibial components, all of which were removed because of excessive polyethylene wear. Density measurements of the remaining polyethylene were obtained as a function of depth from the surface of the components. Comparison to previous results from similar studies of total condylar type knee components and total hip acetabular components revealed distinct differences between the types and severity of damage, emphasizing the influence of design factors on the corresponding wear damage. These results confirm previous conclusions that nonconforming articulating surfaces on thin polyethylene components will be at higher risk of damage than more conforming surfaces on thicker components. It also appears that the high cyclic loads to which polyethylene implants are subjected in vivo are most responsible for the degradation in properties of the material near the articulating surface, although the heat pressing of the articulating surface of the PCA components may contribute to the problem.

Aged↗
PubMed1991

Failure to awaken after general anaesthesia secondary to paradoxical venous embolus.

A patient is presented who failed to regain consciousness after an apparently uneventful nine-hour revision of a total hip replacement. There were no clinically important haemodynamic changes during the operation, and oxygen saturation, capnography and acid base balance were normal throughout. Postop CT of the head showed a large left MCA infarct with midline shift. At autopsy, the patient was found to have a previously unsuspected patent foramen ovale, and a venous embolus in the left internal carotid artery, which probably had originated from the periprostatic venous plexus with a large infarct in the distribution of the left anterior and middle cerebral arteries. The authors conclude that massive paradoxical venous emboli can occur during surgery with minimal haemodynamic changes.

Anesthesia, General↗