Biomedical subjects

S B Goodman

Publications and source records attributed to S B Goodman.

At least 55 records · Page 3Linked to original sources

PubMed1998

The use of femoral intramedullary nailing as an interim or salvage technique during complicated total hip replacement.

When performing a revision total hip replacement complicated by infection, severe osteolysis, comminuted periprosthetic fracture, and/or extensive bone loss, a single-stage procedure may not be feasible. This study reports four cases of femoral intramedullary nailing as an interim or salvage technique during complicated total hip replacement. This reconstruction provides axial and rotational stability of the femur while maintaining femoral alignment. Furthermore, this reconstruction facilitates early mobilization and rehabilitation of the patient. This interim reconstruction can be converted to a revision total hip replacement at a later time. Alternatively, the stabilized resection arthroplasty may serve as a salvage technique if further reconstruction is not indicated.

Aged↗

PubMed1998

Total hip arthroplasty in juvenile chronic arthritis: a consecutive series.

Twenty-nine total hip arthroplasties in 16 patients with juvenile chronic arthritis were performed by one surgeon and followed prospectively. The 9 female and 7 male patients averaged 21 years of age (range, 14-35). Height and weight averaged 160 cm (63 inches) and 53 kg (118 lb.), respectively. Preoperative planning used small or miniature components to accommodate the small anatomic proportions of the hip. The femoral component was cementless in the majority (20/29), but required cementing in 10 of 29 hips because of poor bone stock. The acetabula were reconstructed with a porous-coated cup with or without screws (27/29) or with a cemented cup (2/29). Follow-up periods averaged 53 months (range, 24-100 months). The average Harris hip score improved from 37 to 78 after surgery (P = .0001). Pain relief was excellent; 15 of 16 patients (27/29 hips) expressed a significant improvement in daily function and lifestyle, despite systemic involvement of their arthritis. The range of motion of the hip improved significantly in all planes (P = .001). Two of the 4 uncemented Muller CDH components (Protek, Bern, Switzerland) with a large offset have migrated into varus; both are pain-free. One cemented femoral component has been revised because of aseptic loosening. The use of a small or miniature, cemented or cementless femoral component and a porous-coated cup appears to provide an excellent method of hip reconstruction for patients with juvenile chronic arthritis and small anatomic proportions; however, a femoral component with too great an offset should be avoided, because this may result in varus migration of the stem.

Adolescent↗

PubMed1998

Estradiol-mediated suppression of apoptosis in the rabbit corpus luteum is associated with a shift in expression of bcl-2 family members favoring cellular survival.

In the rabbit, estradiol is the primary luteotropic hormone. Estradiol withdrawal results in a rapid decline in serum progesterone and eventually in corpus luteum (CL) regression. The objective of this study was to determine whether estradiol modulates luteal cell apoptosis. In the first experiment, rabbits were randomly assigned to one of five experimental groups. An empty capsule (control) or estradiol-filled Silastic capsule was inserted s.c. on Day 0 of pseudopregnancy (day of hCG administration). On Day 11 of pseudopregnancy, some of the group I (control) and group II (estradiol capsule) rabbits were subjected to laparotomy, and one ovary from each rabbit was perfused in vitro to determine progesterone secretion rates. The CL from the contralateral ovary were dissected, snap-frozen, and stored at -70 degrees C until analyzed for internucleosomal DNA cleavage (apoptosis). Estradiol-containing capsules were removed from some of the remaining rabbits on Days 8, 9, and 10 to initiate estradiol deprivation. Rabbits were then subjected to laparotomy 24, 48, or 72 h after capsule removal (groups III, IV, and V, respectively), and ovaries or CL were processed as described above. Deprivation of estradiol for 24 (group III), 48 (group IV), or 72 (group V) h in vivo reduced in vitro progesterone secretion rates by more than 90% as compared to that in ovaries collected from estradiol capsule-intact animals. After in vivo endogenous estradiol suppression, withdrawal of exogenous estradiol resulted in luteal cell apoptosis, which increased in a time-dependent manner. Northern blot analysis revealed an increase in bax mRNA levels and a decrease in bcl-x mRNA levels coincident with luteal cell apoptosis induced by estradiol withdrawal. These data demonstrate that changes in progesterone production caused by estradiol exposure and deprivation are in part related to luteal cell apoptosis, and alterations in the expression of bcl-2 gene family members may be one of the mechanisms by which estradiol exerts its luteotropic effect in the rabbit CL.

Animals↗

PubMed1998

Prediction of postoperative knee flexion in Insall-Burstein II total knee arthroplasty.

Postoperative knee flexion in patients undergoing Insall-Burstein-II total knee arthroplasty at 2 years was evaluated regarding two basic questions: what groups of patients gain or lose the most flexion and what groups of patients have the best or worst postoperative flexion. Thirteen preoperative variables (maximum flexion, flexion arc, tibiofemoral angle, quadriceps strength, extensor lag, Knee Society score, Knee Society patient assessment, gender, age, height, weight, diagnosis, and surgeon) and four postoperative variable (leg length change, tibiofemoral angle, distance from patella to the joint line, and the tibial prosthesis anteroposterior translation on a lateral radiograph) were used in an attempt to explain postoperative flexion. The analysis was performed on 164 consecutive Insall-Burstein-II total knees in which the data were gathered prospectively on a time oriented medical record database. A regression tree analysis was used to identify several groups of patients, characterized by preoperative factor values, who had markedly above average performance on postoperative flexion. The preoperative factors identified include preoperative flexion, flexion arc, tibiofemoral angle, extensor lag, diagnosis, and age. The only postoperative variable of significance was tibiofemoral angle. Among the potential determinants of postoperative flexion that failed to appear predictive were the Knee Society scores and surgeon. Preoperative flexion is known to be a critical determinant of postoperative flexion in total knee replacement. However, in the current study, preoperative flexion accounted for only half of the difference between the best (122 degrees) and the worst (88 degrees) group, as determined with regression tree analysis.

Aged↗

PubMed1998

Cellular profile and cytokine production at prosthetic interfaces. Study of tissues retrieved from revised hip and knee replacements.

The tissues surrounding 65 cemented and 36 cementless total joint replacements undergoing revision were characterised for cell types by immunohistochemistry and for cytokine expression by in situ hybridisation. We identified three distinct groups of revised implants: loose implants with ballooning radiological osteolysis, loose implants without osteolysis, and well-fixed implants. In the cemented series, osteolysis was associated with increased numbers of macrophages (p = 0.0006), T-lymphocyte subgroups (p = 0.03) and IL-1 (p = 0.02) and IL-6 (p = 0.0001) expression, and in the cementless series with increased numbers of T-lymphocyte subgroups (p = 0.005) and increased TNF alpha expression (p = 0.04). For cemented implants, the histological, histochemical and cytokine profiles of the interface correlated with the clinical and radiological grade of loosening and osteolysis. Our findings suggest that there are different biological mechanisms of loosening and osteolysis for cemented and cementless implants. T-lymphocyte modulation of macrophage function may be an important interaction at prosthetic interfaces.

Aged↗

PubMed1998

Induction of matrix metalloproteinase expression in human macrophages by orthopaedic particulate debris in vitro.

We exposed human macrophages isolated from the peripheral blood of healthy donors to metal and bone-cement particles from 0.2 to 10 microm in size. Zymography showed that macrophages exposed to titanium alloy and polymethylmethacrylate (PMMA) particles released a 92- and 72-kDa gelatinase in a dose- and time-dependent manner. Western immunoblotting confirmed that the 92- and 72-kDa gelatinolytic activities corresponded to matrix metalloproteinase-9 and matrix metalloproteinase-2 (MMP-9, MMP-2), respectively. Western immunoblotting also indicated that titanium alloy and PMMA particles increased the release of MMP-1. Northern blotting showed elevated mRNA signal levels for MMP-1, MMP-2, and MMP-9 after exposure to both types of particle. Collagenolytic activity also increased in the macrophage culture medium in response to both types of particle. Our findings support the hypothesis that macrophages release MMPs in proportion to the amount of particulate debris within periprosthetic tissues.

Alloys↗

PubMed1998

Effects of particulate debris on macrophage-dependent fibroblast stimulation in coculture.

The interactions between the different cell types in periprosthetic tissue are still unclear. We used a non-contact coculture model to investigate the effects of polymethylmethacrylate (PMMA) particles and human macrophage-derived soluble mediators on fibroblast activation. Macrophages were either exposed or not exposed to phagocytosable PMMA particles, but fibroblasts were not. Increasing numbers of macrophages were tested in cocultures in which the fibroblast cell number was held constant and cultures of macrophages alone were used for comparison of cytokine release. We used the release of interleukin-1 beta (IL-1beta), interleukin 6 (IL-6), tumour necrosis factor alpha (TNF-alpha), lysosomal enzyme and metalloproteinase activity to assess the cultivation of macrophages and fibroblasts. In cocultures, IL-6 release was increased 100-fold for both unchallenged and particle-challenged cultures when compared with macrophage cultures alone. Furthermore, particle-challenged cocultures had threefold higher IL-6 levels than unchallenged cocultures. Release of TNF-alpha was similar in cocultures and in macrophage cultures. IL-1beta release in cocultures was independent of the macrophage-fibroblast ratio. Lysosomal enzyme activity and metalloproteinase activity were increased in cocultures. Our data show that macrophages and fibroblasts in coculture significantly increase the release of IL-6 and to a less degree other inflammatory mediators; particle exposure accentuates this effect. This suggests that macrophage accumulation in fibrous tissue may lead to elevated IL-6 levels that are much higher than those caused by particle activation of macrophages alone. This macrophage-fibroblast interaction represents a novel concept for the initiation and maintenance of the inflammatory process in periprosthetic membranes.

Coculture Techniques↗

PubMed1998

Preoperative duplex ultrasonography evaluation for deep vein thrombosis in hip and knee arthroplasty patients.

We performed preoperative and postoperative duplex ultrasonography examinations on both lower extremities in 128 patients undergoing 146 hip and knee reconstructive procedures. The results of the examinations were reviewed by an independent radiologist who specializes in these studies. Three of the 128 patients (146 procedures; 2.1%) had evidence of a deep venous thrombosis or other venous abnormality before surgery. Three additional patients developed a deep venous thrombosis after surgery, despite mechanical and pharmacologic prophylaxis. We have discontinued performing preoperative duplex ultrasonography prior to primary, uncomplicated total joint replacement of the lower extremities. We continue to perform duplex ultrasonography before surgery in patients at high risk, with a history of deep venous thrombosis or phlebitic syndrome, and in those who have previously had major surgery on the lower extremities.

Adolescent↗

PubMed1998

Norian SRS cement augmentation in hip fracture treatment. Laboratory and initial clinical results.

Bone quality, initial fracture displacement, severity of fracture comminution, accuracy of fracture reduction, and the placement of the internal fixation device are important factors that affect fixation stability. New high strength cements that are susceptible to remodeling and replacement for fracture fixation may lead to improved clinical outcome in the treatment of hip fractures. Norian SRS is an injectable, fast setting cement that cures in vivo to form an osteoconductive carbonated apatite of high compressive strength (55 MPa) with chemical and physical characteristics similar to the mineral phase of bone. It can be used as a space filling internal fixation device to facilitate the geometric reconstruction, load transfer, and healing of bone with defects and/or fractures in regions of cancellous bone. Furthermore, this cement can improve the mechanical holding strength of conventional fixation devices. Use of this material potentially could improve fracture stability, retain anatomy during fracture healing and improve hip function, thus achieving better clinical outcomes. In vivo animal studies have shown the material's biocompatibility, and cadaveric studies have shown the biomechanical advantage of its use in hip fractures. Initial clinical experience (in 52 femoral neck fractures and 39 intertrochanteric fractures) showed the potential clinical use of this innovative cement in the treatment of hip fractures.

Aged↗

PubMed1998

In vitro, in vivo, and tissue retrieval studies on particulate debris.

The biologic effects of wear debris are an important factor limiting the longevity of total joint replacements. In vivo, in vitro, and tissue retrieval studies have underlined a central role for the macrophage in the etiology of loosening and periprosthetic osteolysis. Wear particles from the materials used for total joint replacement activate macrophages to secrete proinflammatory factors. Complex interactions between macrophages and other cells stimulate bone resorption and suppress bone formation at the prosthetic interface. To improve the long term outcome of joint replacements, future research must find innovative approaches to minimize the production and biologic effects of wear debris.

Animals↗

PubMed1997

The role of insulin-like growth factor-I (IGF-I) and estradiol in rabbit corpus luteum progesterone production.

To determine whether insulin-like growth factor-I (IGF-I) plays a role in rabbit corpus luteum (CL) physiology the authors examined: IGF-I expression, the effect of IGF-I on progesterone (P) production in vitro, and the interaction of IGF-I with estradiol, the primary luteotropin in the rabbit. Northern blot analysis revealed that IGF-I mRNA is present in the rabbit CL throughout pseudopregnanacy. An intact ovarian in vitro perfusion model and dispersed luteal cell culture were used to determine effects of IGF-I on P production and interactions with estradiol. IGF-I significantly stimulated P production compared to control medium by the isolated, intact perfused rabbit ovary and by dispersed, cultured luteal cells. Estradiol alone did not stimulate P production in vitro. Estradiol did augment IGF-I stimulated P production in the intact perfused ovary and in luteal cell culture. These findings support a role for IGF-I in rabbit CL P production.

Animals↗

PubMed1997

Loosening and osteolysis of cemented joint arthroplasties. A biologic spectrum.

The purpose of this study was to characterize the cell types (using immunohistochemistry) and cytokine expression (using in situ hybridization) of tissues surrounding well fixed and loose cemented prostheses undergoing revision. Clinical and radiographic data were gathered prospectively for a series of cemented total joint replacements undergoing revision. Three groups were identified: (1) loose implants with osteolysis (10 specimens), (2) loose implants without osteolysis (11 specimens), and (3) well fixed implants (7 specimens). At surgery, a specimen was harvested from the bone cement interface. Immunohistochemical staining was performed using monoclonal antibodies to identify macrophages and lymphocyte subgroups. Human antisense probes were selected to identify the mRNA for specific cytokines using in situ hybridization. The percentage of positively staining cells was determined for each antibody or probe using a grid counting technique. Tissues from loose cemented prostheses with osteolysis contained significantly greater numbers of macrophages and T lymphocytes compared with tissues from loose and well fixed cemented prostheses without osteolysis. The number of interleukin-1 and interleukin-6 positive cells was highest in specimens with osteolysis and lowest in specimens from well fixed prostheses. These cytokines modulate the growth and differentiation of cells in the immune system and the monocyte and macrophage system and mediate the remodeling of bone and mesenchymal tissues. Specific cell populations and cytokine profiles appear to be involved in periprosthetic osteolysis; this information may be useful in planning strategies for prevention and treatment.

Aged↗

PubMed1997

Stability of open-book pelvic fractures using a new biomechanical model of single-limb stance.

OBJECTIVE: A new biomechanical model of single-limb stance was developed to test the stability of intact, injured, and internally fixed pelves. DESIGN: Single-limb stance was simulated by applying muscle forces and body mass loading to cadaver pelves. We created a rotationally unstable "open-book" pelvic injury in nine embalmed pelves by dividing the ligaments of the pubic symphysis, pelvic floor, and anterior and interosseus sacroiliac joint. All pelves were devoid of gross structural abnormalities. INTERVENTION: Two methods of internal fixation of the pubis symphysis were compared: (a) a curved six-hole 3.5-millimeter reconstruction plate across the superior pubic symphysis, and (b) the same six-hole 3.5-millimeter reconstruction plate plus a perpendicularly oriented four-hole 3.5-millimeter reconstruction plate placed across the anterior symphysis. MAIN OUTCOME MEASUREMENTS: We measured vertical shear displacement at the public symphysis and horizontal displacement at the anterior sacroiliac joint. The results for the injured and fixed specimens were compared with each other and with the results for the intact specimens. RESULTS: The injured unfixed specimens showed marked instability that was prevented by both methods of fixation of the pubic symphysis. No significant differences could be demonstrated between single and double plating of the disrupted pubic symphysis when using this single-limb stance model. CONCLUSION: This model of single-limb stance suggests that a single symphyseal plate across the pubic symphysis can stabilize the open-book injury under short-term quasi-static loads.

Aged↗

PubMed1997

Design of the femoral component for cementless hip replacement: the surgeon's perspective.

Few guidelines are currently available to the surgeon when choosing a specific femoral component for cementless total hip replacement (THR). A survey of the members of the American Association for Hip and Knee Surgeons (AAHKS) was conducted to gain insight into the importance of implant material, stress shielding, and micromotion in the selection of cementless femoral components. A comprehensive survey was distributed to 300 orthopedic surgeons selected from the members of the AAHKS; 169 of the 300 surgeons completed the detailed questionnaire. The results of the survey were analyzed using the SPSS software package to obtain general trends in opinion, and a stepwise regression analysis was used to correlate responses with training and clinical experience. Interestingly, there was little consensus among surgeons with respect to the relative importance of implant material, stress shielding, and micromotion in the selection of prostheses for cementless THR. In general, bone loss secondary to stress shielding was the least important issue, and axial and rotational micromotion were considered progressively more significant problems. Cementless titanium alloy stems were perceived as offering no significant advantage over cobalt chrome alloy stems. Moreover, there was no consensus as to whether a collar was advantageous. Prosthesis stability, restoration of motion, and a proven clinical record were more important to surgeons than were ease of implantation and removal, cost, and availability.

Bone Cements↗

PubMed1996

Effect of size, concentration, surface area, and volume of polymethylmethacrylate particles on human macrophages in vitro.

This study investigated effects of different sizes, concentrations, volumes, and surface areas of polymethylmethacrylate (PMMA) particles on human macrophages. Adherent peripheral blood monocytes isolated from five healthy individuals were exposed for 48 h to phagocytosable (0.325 micron and 5.5 microns) and nonphagocytosable (200 microns) spherical particles. Each particle size was tested over a range of concentrations (10(4)-10(11) particles per milliliter [0.325 micron], 10(2)-10(7) particles per milliliter [5.5 microns], 10(1)-10(4) particles per milliliter [200 microns]) to provide overlap in number, volume, and surface area. Primary human monocyte/macrophages were cultured in macrophage serum-free medium and 5% fetal calf serum. Macrophage viability was assessed by 3H-thymidine uptake and activation was quantified by release of interleukin-1 beta, interleukin-6, tumor necrosis factor-alpha, prostaglandin E2 (PGE2), and the lysosomal enzyme hexosaminidase. Medium alone served as a negative control; lipopolysaccharide (10 micrograms/mL) was also tested. PMMA particles were not toxic to human macrophages at any concentration tested. The smallest phagocytosable particles (0.325 micron) stimulated the release of interleukin-1 beta, interleukin-6, prostaglandin E2, and hexosaminidase at concentrations of 10(10)-10(11) particles/mL. The release of cytokines, PGE2, and hexosaminidase depended on the size, concentration, surface area, and volume of the phagocytosable particles. This study demonstrates that PMMA particle load Mi.e., the concentration of phagocytosable particles per tissue volume, characterized by size, surface area, and volume, rather than simply particle number-determines the degree of macrophage activation.

Cell Survival↗

PubMed1996

Heterogeneity in cellular and cytokine profiles from multiple samples of tissue surrounding revised hip prostheses.

Previous studies have attempted to define the biologic properties of the bone-implant interface using a single specimen harvested from the periprosthetic tissues. The purpose of this study was to examine the heterogeneity in cellular and cytokine profiles of multiple samples taken from the tissues surrounding revised hip prostheses. Clinical and radiographic data for nine patients undergoing surgical revision was gathered prospectively. Three tissue samples were taken systematically from the acetabular and/or femoral bed. Morphologic characteristics of the tissues were assessed using hematoxylin and eosin-stained sections. Immunohistochemical staining was performed using monoclonal antibodies to identify macrophages (EMB11 and CD68); activated macrophages (Leu M3); total T lymphocytes (Leu 4 and T11); T-helper lymphocytes (Leu 3A and CD4); cytotoxic/suppressor T lymphocytes (Leu 2A and CD3); and fibroblasts (5B5). In situ hybridization was used to identify the mRNA for specific proteins: interleukin (IL)1 alpha and -beta, IL-2, IL-6, transforming growth factor beta, tumor necrosis factor alpha (TNF alpha), platelet-derived growth factor alpha (PDGF alpha), and interferon gamma. A quantitative assessment was performed for each section by calculating the percentage of positively staining cells using a light microscope and grid-counting technique. A random effect analysis of variance was calculated to determine both the variance between samples within each patient and the variance between different patients. Standard deviations contributed by sampling variance and patient variance were calculated and an F test was applied. Tissue samples taken from different regions of the bone-prosthesis interface showed marked heterogeneity in cellular and cytokine profiles. Critical F values indicating a statistically significant degree of variance between different tissue samples were exceeded for macrophages, cytotoxic/suppressor T lymphocytes, and T-helper lymphocytes. The cytokine profile was significantly different for IL-2, PDGF alpha, and TNF alpha. This tissue heterogeneity may be due to different mechanical and biologic environments along the bone-prosthesis interface. Thus, caution must be exercised in defining the biologic properties of the tissue surrounding revised prostheses according to a single biopsy.

Adult↗

PubMed1996

Histomorphological reaction of bone to different concentrations of phagocytosable particles of high-density polyethylene and Ti-6Al-4V alloy in vivo.

Wear debris has been implicated in the pathogenesis of loosening and osteolysis of total joint replacements by stimulating a foreign body and chronic inflammatory reaction capable of bone resorption. Whether increasing concentrations of wear particles have an adverse biological effect on bone has not been elucidated. We performed a histomorphological and semi-quantitative morphometric analysis of the reaction of bone to different concentrations of phagocytosable particles of high-density polyethylene (HDPE) and titanium 6-aluminium 4-vanadium alloy (Ti-6Al-4V) implanted in the rabbit tibia. The Ti-6Al-4V particles had a diameter of 4.0 +/- 4.4 microns (mean +/- SD); the HDPE particles averaged 4.7 +/- 2.1 microns. Suspensions of 10(6)-10(9) particles per ml were mixed in saline, sterilized, and introduced through a drill hole into the proximal tibia of 30 mature female rabbits. Controls included drilled, but non-implantable limbs. The animals were killed at 16 weeks and histological sections were made of the implant area. Histomorphological assessment was carried out using an interactive image analysis system. The parameters assessed included the presence of histiocytes, foreign body giant cells and inflammatory cells, the location and number of particles, the presence of haematopoeitic elements, fat or necrosis of the marrow, whether healing of the cortical window had taken place, and whether there was evidence of formation or resorption of bone by the periosteum, cortex and marrow. A semi-quantitative rating system was employed. Phagocytosable particles of Ti-6Al-4V and HDPE, in concentrations of 10(6)-10(9) particles per ml, evoked a histiocytic reaction without extensive fibrosis, necrosis or granuloma formation. This reaction occurred without disturbing the normal repair processes of bone formation and resorption to the surgical insult. A clear dose-response effect on the histological parameters assessed in this study was not noted. Using the present model, by 16 weeks, a similar "one time' particle load could be accommodated. The ongoing generation of particulate debris over a more extended period of time might be necessary before the remodelling processes of bone would be disturbed.

Alloys↗

PubMed1996

Benign response to particles of diamond and SiC: bone chamber studies of new joint replacement coating materials in rabbits.

Wear particles from total joint replacements are thought to accelerate prosthetic loosening. Diamond coating may improve the smoothness and wear characteristics of the femoral head component of total hip replacements, and thus increase their longevity. The brittleness of a thin diamond coat may be overcome by using an SiC-whisker diamond composite. This study describes the reactions of regenerating bone tissue to phagocytosable particles of diamond and SiC, using implanted bone harvest chambers in rabbits. The particles were dispersed in hyaluronan and introduced into a canal transversing the implant. The tissue that entered the canal during the following 3 weeks was then harvested. In previous studies using this model, particles of high density polyethylene, bone cement and chromium-cobalt all caused an inflammatory reaction and a marked decrease in the amount of ingrown bone. In the present study, neither the diamond nor the SiC particles caused any decrease in bone formation. It appears that particles of diamond and SiC are comparatively harmless.

Animals↗