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H E Rubash

Publications and source records attributed to H E Rubash.

70 records · Page 4Linked to original sources
PubMed1992

A long-term study on defect filling and bone ingrowth using a canine fiber metal total hip model.

When performing primary and revision total hip arthroplasty (THA), bone defects are often encountered. At present, grafting osseous defects with autogeneic bone is a common means of treatment. In this study, defects in bone were created in the femora and acetabula of dogs being treated with cementless THA with a fiber metal implant (Group A) or a hydroxyapatite tricalcium phosphate (HA/TCP) sprayed implant (Group B). The following methods of defect filling were compared: (1) leaving defects unfilled, (2) filling with autogeneic bone graft, (3) filling with a 50:50 mixture of autograft and a biphasic ceramic composed of HA/TCP, and (4) filling with a collagen-HA/TCP-bone marrow mixture. Analysis of defect healing and the extent of ingrowth into the overlying fiber metal, at defect sites and sites distant from defects, was made at six, 12, and 24 weeks postimplantation. Defect healing was enhanced at six and 12 weeks in all grafted groups when compared with ungrafted controls. Bone ingrowth into the porous fiber metal overlying the defects was not significantly affected by grafting the defects, compared with the ungrafted defects. The extent of bone ingrowth into the fiber metal acetabular implant at sites away from the defects increased during the entire study. In contrast, the extent of bone ingrowth on the femoral side was maximal at 12 weeks. The HA/TCP coating enhanced ingrowth into the acetabular component at 12 weeks, compared with the uncoated prosthesis, but did not enhance ingrowth on the femoral side. The data from this study demonstrate that defect healing is enhanced with graft materials. However, this does not necessarily result in increased ingrowth into porous surfaces overlying osseous defects. General bone ingrowth and ingrowth at defect sites at 12 weeks postimplantation can be enhanced on the acetabular side with the use of HA/TCP-sprayed implants. However, no positive effect is seen with the use of an HA/TCP-sprayed femoral implant.

Acetabulum↗
PubMed1991

Prospective randomized trial of sequential compression devices vs low-dose warfarin for deep venous thrombosis prophylaxis in total hip arthroplasty.

A prospective randomized trial compared the effectiveness of low-dose warfarin (LDW) to sequential compression devices (SCD) for deep venous thrombosis (DVT) prophylaxis in 95 patients after total hip arthroplasty (THA). Patients were 39 years of age or older, with no history of previous venous disease. Bilateral lower-extremity venography was used for thrombi detection. Venous thrombi occurred in 12 patients (all calf) on LDW (26.6%) and 3 patients with SCDs (one calf, two thigh) (6.0%). The incidence of DVT was significantly higher in the LDW group (P less than .006). In this study of average-risk patients, the use of SCDs significantly outperformed LDW as a prophylactic agent. However, the thrombi that did occur with SCDs were more critical.

Adult↗
PubMed1991

Periprosthetic fractures of the femur after total knee arthroplasty. A literature review and treatment algorithm.

Supracondylar femur fractures after total knee arthroplasty can significantly alter the quality of knee arthroplasties and provide a challenging problem for the treating surgeon. A review of the literature and an approach to the treatment of these periprosthetic fractures is presented. The predisposing factors, mechanisms of injuries, and characteristics of the fractures are identified. A classification system is proposed based on a modified Neer grading system, the degree of comminution, and the location and character of the fracture. A treatment algorithm is developed and based on acceptable alignments of less than 5 mm translations, angulations less than 5 degrees-10 degrees, minimal rotation, less than 1 cm of femoral shortening, and proper tibiofemoral prosthetic joint alignment.

Algorithms↗
PubMed1991

Ingrowth and formation of bone in defects in an uncemented fiber-metal total hip-replacement model in dogs.

An osseous defect was created in the acetabulum and femur of twenty dogs, and then a fiber-metal total hip prosthesis was inserted. A comparison was made between the effects of leaving the defects unfilled, filling the defects with an autogenous bone graft, and filling them with a 50:50 mixture of autogenous bone graft and a biphasic ceramic composed of hydroxyapatite and tricalcium phosphate. The characteristics of formation of bone within the sites of the defects and the extent of the ingrowth of bone into the underlying porous surface were analyzed. At six and twelve weeks after implantation, the dogs in the control group (unfilled defects) had the least amount of bone in the sites of the defects. In the dogs that had had an autogenous bone graft and those in which the defects had been filled with a mixture of autogenous bone graft and biphasic ceramic, there were excellent osteoconductive properties in the filling of the sites of the defects with new bone. A comparison was made between the amount of bone that formed in the osseous defects and the amount that formed in the spaces of the porous-surfaced fiber-metal components of the prostheses, directly underlying and adjacent to the defects. At six weeks, the greatest amount of ingrowth of bone into the spaces of the underlying titanium fiber-metal acetabular components was seen in the control group (22 per cent of the porous surface), followed by the group in which the defects had been filled with a mixture of autogenous bone graft and biphasic ceramic (19 per cent). The defects that had been filled only with autogenous bone graft had poor ingrowth of bone into the porous surface (4 per cent) and predominantly fibrous ingrowth. At twelve weeks, these defects again showed the least amount of ingrowth of bone (15 per cent) compared with the defects in the control group (24 per cent) and those that had been filled with a mixture of autogenous bone graft and biphasic ceramic (24 per cent). No statistically significant differences were found in the amount of ingrowth of bone into the defects that had been created in the femur in the three groups of dogs at either six or twelve weeks. However, the trends appeared to correlate with the data for the acetabular defects.

Acetabulum↗
PubMed1990

Acetabular anatomy and the transacetabular fixation of screws in total hip arthroplasty.

An anatomical and radiographic study was undertaken to determine the safest zones in the acetabulum for the transacetabular placement of screws during uncemented acetabular arthroplasty. To avoid injury to intrapelvic structures, which are not visible to the surgeon during placement of the screws, cadavera were studied to define the location of these structures with respect to fixed points of reference within the acetabulum. Four clinically useful acetabular quadrants were delineated. The quadrants are formed by drawing a line from the anterior superior iliac spine through the center of the acetabulum to the posterior fovea, forming acetabular halves. A second line is then drawn perpendicular to the first at the mid-point of the acetabulum, forming four quadrants. The posterior superior and posterior inferior acetabular quadrants contain the best available bone stock and are relatively safe for the transacetabular placement of screws. The anterior superior and anterior inferior quandrants should be avoided whenever possible, because screws placed improperly in these quadrants may endanger the external iliac artery and vein, as well as the obturator nerve, artery, and vein. The acetabular-quadrant system provides the surgeon with a simple intraoperative guide to the safe transacetabular placement of screws during primary and revision acetabular arthroplasty.

Acetabulum↗
PubMed1988

Revision of nonseptic, loose, cemented femoral components using modern cementing techniques.

A series of 43 hips (41 patients) in which a cemented revision arthroplasty was performed for a symptomatic, nonseptic, loose (42) or broken (1) femoral component was reviewed clinically and radiographically. The operation was done using femoral components of contemporary design, a trochanteric osteotomy, a cement gun, and a PMMA femoral plug. The femoral compactor and water pic were used once they became available (36%). The average follow-up period was 74 months (range, 60-111 months). The primary diagnoses included osteoarthritis (52%), CDH (32%), posttraumatic arthritis (6%), AVN (6%), and SCFE (4%). The average age of the patients at the time of the operation that failed was 52.2 years and at revision was 57.4 years. Only one revised cemented femoral component (2% of hips) required rerevision surgery for septic loosening. The average postoperative Harris hip score was 87 points. Four hips (9%) were classified radiographically as definitely loose, one (2%) as probably loose, and one (2%) as possibly loose, but all of these patients had a good or excellent clinical rating. Complications included deep venous thrombosis in 16 patients, trochanteric nonunion in 3 hips, femoral shaft perforations in eight hips, and postoperative dislocations in 6 hips. These techniques appear to represent an improvement over prior techniques.

Cementation↗
PubMed1986

Periprosthetic femoral fractures following total knee arthroplasty.

Supracondylar and distal femoral fractures involving total knee arthroplasties present a relatively new and challenging problem. The alignment of the total knee components prior to and subsequent to the fracture, as well as the patients' range of motion, symptoms, and level of function following their treatment, were investigated in 14 cases. Ten of the patients had nonoperative treatment. Four had had an operative procedure. Osteoporosis, notching of the femur, and revision arthroplasty were identified as predisposing factors with femoral fractures. The results of treatment depended primarily on reduction of varus deformity and/or posterior displacement of the femoral component. Nonoperative treatment was most successful in this regard.

Aged↗
PubMed1985

Fractures of the acetabulum.

A critical analysis of the results reveals the following major factors in determining the outcome of an individual acetabular disruption: The damage to the acetabular articular surface, which is reflected by the pattern of fracture and its degree of comminution, impaction, and osteoporosis, and associated damage of the femoral head The adequacy of the reduction, which is reflected by intraoperative inspection and postoperative radiographs The associated complications of the fracture and treatment (e.g., avascular necrosis, sciatic palsy, and heterotopic ossification) We recommend principles of treatment of acetabular fractures comparable to those employed for most other displaced intraarticular fractures, namely an anatomic reduction, stable internal fixation, and early motion, to realize reproducibly optimal results. The principal contraindications to open reduction are osteoporosis and generalized comminution to a degree that precludes a reasonable likelihood for the surgical team to achieve a stable anatomic reduction. We have provided guidelines for the surgical approach, techniques of reduction, and methods of fixation, and an analysis of results, which provide the basis for the successful treatment of these difficult intraarticular injuries.

Acetabulum↗
PubMed1984

Experimental arthritis induced by intraarticular injection of allogenic cartilaginous particles into rabbit knees.

Human synovial fluid often contains small cartilaginous "wear particles." Previous in vitro experiments have indicated the potential involvement of these particles in the pathophysiology of arthritis. To determine whether this potential is realized under the conditions existing within joints, standard suspensions of lapine articular cartilage were injected intraarticularly into the knee joints of rabbits. Thrice-weekly injections of 1 mg allogenic cartilage produced an inflammatory arthritis, accompanied by a marked cellular effusion, in all rabbits within 5 months. The synovium became hyperplastic, discolored, and infiltrated with mononuclear inflammatory cells. Embedded particles of the injected material were seen in histologic preparations of these synovia. Organ cultures of such synovia produced 4 to 5 times more collagenase, plasminogen activator, "Pz-peptidase," neutral and acid azocaseinase, and beta-glucuronidase than did cultures of synovia from control knees injected with saline. Furthermore, the articular cartilage of knees injected with cartilaginous particles showed elevated intrinsic collagenolytic activity. Histologic examination of the articular cartilage revealed an attendant loss of metachromasy, resulting in friability, pitting, and discoloring of the cartilage. Preliminary immunoassays failed to demonstrate a systemic immune response to the injected material.

Animals↗
PubMed1984

Stability of acetabular fractures after internal fixation. A cadaveric study.

The rigidity of a transverse acetabular fracture in a laboratory cadaveric model immobilized by internal fixation was studied. On the application of a longitudinal load imposed on the fifth lumbar vertebra, four modes of displacement of the acetabular fracture were monitored by the use of variable impedance transducers. The rigidity of various combinations of lag screws and plates was assessed. The fracture deformations documented were generally quite small at any observation point with any of the fixation methods, and in most cases they were recoverable on load release. Anterior column lag screw fixation combined with plate fixation of the posterior column provided a degree of stability indistinguishable from that of other methods, and allowed the minimal exposure and devascularization of the pelvis. The 3.5 mm reconstruction plate, which is readily contoured to the intricate peri-acetabular bony structure, showed no significant difference in rigidity compared to the other apparently more rigid plates under study.

Acetabulum↗
PubMed1984

External and internal fixation of the pelvic ring.

From the basis of this experience an algorithm for the stabilization of virtually all types of pelvic ring disruption is provided which appears to outline suitable options in stabilization for virtually all types of pelvic ring fracture including those with acetabular disruption. Surgical complications have been sufficiently uncommon so that more widespread use of this protocol would appear to be justifiable. Nevertheless, the surgical techniques of internal fixation are formidable operations that should be undertaken only by those surgeons who possess appropriate training and experience.

Biomechanical Phenomena↗
PubMed1983

External fixation of the pelvis.

During the past decade the useful classification and principles of management of the fractured pelvis have progressed rapidly. For the acute management the principal consideration is the control of severe intrapelvic hemorrhage. A protocol has been developed that combines the early application of external fixation with a closed reduction of the pelvic fracture. A marked decrease in the anticipated amount of intrapelvic hemorrhage has been documented. The coupled double anterior frame and its biomechanical equivalent, the newly developed triangular system, are easily applied to the pelvic ring and provide adequate stability for the treatment of the patient with a stable or unstable pelvic ring fracture. Thus the complex earlier design has been replaced by a simpler system. The triangular frame provides adequate stability so that the patient can undertake independent bed-to-chair transfers and early resumption of a weight-bearing gait. Late pulmonary, gastrointestinal, and urologic complications with prolonged bed rest and cast immobilization therefore have greatly diminished. In the present series in which external fixation has been applied to unstable pelvic ring fractures with a single posterior disruption, late loss of reduction, nonunion, and malunion almost have been entirely avoided. In addition, a simple triangular frame provides access to the abdominal wall and offers minimal postoperative interference with nursing care of the patient. Once the general condition of the patient has stabilized, supplementary techniques of open reduction and internal fixation may be applied to appropriate complex fracture patterns. These methods are fully reviewed elsewhere. Thus early rigid stabilization of the patient who sustains a pelvic ring fracture facilitates diminution of fracture pain, early mobilization of the patient, discharge, improved morale, and ultimately, decreased fracture morbidity and mortality.

Adult↗
PubMedDate not supplied

Predicting discharge outcome after elective hip and knee arthroplasty.

The objective of this prospective study was to determine if differences exist between individuals who require an inpatient rehabilitation program after elective hip and knee arthroplasty from those patients who can be discharged directly home. Multiple variables consisting of baseline demographics, social status, insurance status, medical history, pain level, quantitative strength, range of motion, and functional ability were examined. The primary outcome measure was the discharge destination from the orthopedic service and consisted of either a discharge to home or a discharge to an inpatient rehabilitation unit. Of the 162 patients followed, 65 (40%) were discharged to an inpatient rehabilitation unit, whereas 97 were discharged to home. The patients discharged to inpatient rehabilitation tended to live alone, were significantly older (mean difference = 6.3 yr), and had increased comorbid conditions (p < 0.001 for all variables). Patients discharged to a rehabilitation unit reported significantly greater pain levels than those discharged to home (P < 0.001). The attainment of a supervision level of function demonstrated greater differences between groups than the attainment of independent function for all functional measures. A logistic regression model was developed that predicted 76% of the discharges to rehabilitation by the third physical therapy session postsurgery. In conclusion, predictive markers do exist that differentiate individuals who require further inpatient therapy services after joint replacement surgery.

Aged↗
PubMedDate not supplied

The efficacy of postoperative autotransfusion in total joint arthroplasty.

Although postoperative blood salvage is used routinely in orthopaedic surgical procedures, little data exists to evaluate this practice. The purpose of this study was to evaluate the effectiveness of the Solcotrans autotransfusion system following elective total joint arthroplasty. This study compared two groups of patients: 59 patients who used the Solcotrans Orthopaedic Drainage/Reinfusion System and 56 patients who used a standard drainage system. Based on the results of the study, the researchers questioned the clinical efficacy and cost-effectiveness of a postoperative wound drainage/reinfusion system in patients after elective total joint arthroplasty.

Adult↗