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Biomedical subjects

T J Gill

Publications and source records attributed to T J Gill.

At least 19 recordsLinked to original sources
PubMed2001

Arthroscopic reduction and internal fixation of tibial plateau fractures in skiing.

Arthroscopic reduction and internal fixation of tibial plateau fractures can facilitate restoration of articular congruity while permitting rigid fracture stabilization. Twenty-five patients who underwent arthroscpoic reduction and internal fixation of a tibial plateau fracture were reviewed. The average age of the patients was 45. At a mean followup of 24 months, 76% of patients rated their result as excellent and 16% as good. Eighty-four percent returned to full sporting activity. There were no episodes of nonunion, failure of fixation, wound infection, deep venous thrombosis, compartment syndrome, or arthrofibrosis. Preoperative fracture depression averaged 7.7 mm (range, 1-18 mm). Fracture depression at final followup averaged 0.8 mm (range, 0-5 mm). Sixty-four percent of patients had associated intraarticular injury diagnosed and treated at the time of arthroscopy. Arthroscopic reduction and internal fixation provides an accurate assessment of, and allows definitive treatment for, intraarticular injuries associated with tibial plateau fractures. The technique allows less soft tissue stripping than with traditional arthrotomy, better visualization of the articular surface, early return to physical activities, and obviates the need for meniscal detachment and repair.

Adolescent↗
PubMed2001

Surgical dislocation of the adult hip a technique with full access to the femoral head and acetabulum without the risk of avascular necrosis.

Surgical dislocation of the hip is rarely undertaken. The potential danger to the vascularity of the femoral head has been emphasised, but there is little information as to how this danger can be avoided. We describe a technique for operative dislocation of the hip, based on detailed anatomical studies of the blood supply. It combines aspects of approaches which have been reported previously and consists of an anterior dislocation through a posterior approach with a 'trochanteric flip' osteotomy. The external rotator muscles are not divided and the medial femoral circumflex artery is protected by the intact obturator externus. We report our experience using this approach in 213 hips over a period of seven years and include 19 patients who underwent simultaneous intertrochanteric osteotomy. The perfusion of the femoral head was verified intraoperatively and, to date, none has subsequently developed avascular necrosis. There is little morbidity associated with the technique and it allows the treatment of a variety of conditions, which may not respond well to other methods including arthroscopy. Surgical dislocation gives new insight into the pathogenesis of some hip disorders and the possibility of preserving the hip with techniques such as transplantation of cartilage.

Adolescent↗
PubMed2000

The management of severe acetabular bone loss using structural allograft and acetabular reinforcement devices.

The cases of 37 acetabular reconstructions in 35 patients with major structural pelvic bone loss were reviewed. At an average follow-up of 7.1 years, patients rated their results as excellent in 12 cases (32.4%), good in 22 (59.5%), fair in 2 (5.4%), and poor in 1 (2.7%). Thirty-four cases (91.9%) were classified as a clinical success. Thirty-six allografts (97.3%) had radiographic evidence of full incorporation. Of the unrevised hips, 1 (2.7%) was classified as definitely loose, 2 (5.4%) as probably loose, and 4 (10.8%) as possibly loose. One revision of an acetabular component was required because of late sepsis. This is the first reported series on the use of acetabular reinforcement devices with solid bulk allograft covering more than 50% of the socket. The allograft is protected in the early postoperative period, superior migration of the cup is virtually eliminated as a complication, and the incidence of aseptic loosening is greatly diminished.

Acetabulum↗
PubMed1999

Lateral insufficiency fractures of the femur caused by osteopenia and varus angulation: a complication of total hip arthroplasty.

Lateral femoral insufficiency fractures in total hip arthroplasty occur due to osteopenia and varus positioning of the femoral component, the femur itself, or both. The presentation of these fractures can be unclear but usually involves the insidious onset of unexplained thigh or groin pain. The patients are likely to have significant comorbidities as well. Characteristic radiographic findings may be present, depending on when the patient presents. The insufficiency fractures generally occur at the level of the femoral stem tip on the lateral cortex of the femur. If left untreated, pain and loss of function continue. Eventually an insufficiency fracture can progress to a displaced periprosthetic fracture. Nonsurgical treatment is not successful. Recommended treatment involves revision to a long-stem femoral component. The risk of postoperative complications is significant.

Arthroplasty, Replacement, Hip↗
PubMed1999

Acetabular reconstruction in developmental dysplasia of the hip: results of the acetabular reinforcement ring with hook.

This study examined the clinical results and technical challenges associated with acetabular reconstruction in developmental dysplasia of the hip using the acetabular reinforcement ring with hook. We reviewed 33 consecutive reconstructions performed by a single surgeon. At an average follow-up of 6.7 years, the mean Merle-d'Aubigne score had increased from 7 to 16. Two revisions were performed for aseptic loosening. Of the unrevised hips, 1 was classified as definitely loose and 1 as possibly loose. These results compare favorably with others in the literature. The acetabular reinforcement ring may prevent graft resorption and cup migration, major causes of socket failure in reconstruction of the deficient acetabulum.

Acetabulum↗
PubMed1999

Mechanisms of action of major-histocompatibility-complex-linked genes affecting reproduction.

PROBLEM: To provide insight into the mechanisms of action of the major-histocompatibility-complex (MHC)-linked genes affecting reproduction. METHOD OF STUDY: The data were obtained using a variety of cellular and molecular techniques in experimental animals and from population genetic studies in humans. RESULTS: In the mouse, the preimplantation embryonic development (Ped) locus, whose functional gene is Q9, regulates fast and slow cleavage of the early embryo. There is also evidence for a growth and reproduction complex (Grc)-like region from serologic, molecular, and cytogenetic studies. In the human, the human leukocyte antigen (HLA)-G gene has been associated with an increased rate of embryonic cleavage in those embryos that express the HLA-G antigen. Sharing of HLA antigens in couples has been associated with recurrent spontaneous abortions, gestational trophoblastic tumors, and unexplained infertility. Detailed mapping studies showed that the genes responsible are not the HLA genes themselves, but genes closely linked to the HLA-DR-DQ-B genes. The HLA region genes can interact epistatically with the C3 allele of transferrin to increase the incidence of fetal loss. In the rat, the Grc region, which is closely linked to the MHC, has been associated with embryonic loss, growth defects, and susceptibility to chemical carcinogens. The Grc can interact epistatically with the tail anomaly lethal (Tal) gene or the hood restriction (Hre) gene to enhance these effects. CONCLUSIONS: There are two basic mechanisms for the effects of MHC-linked genes on reproduction and development: individual gene effects (Ped [Q9], HLA-G) and extended genetic effects (MHC-linked genes in the rat [Grc] and in the human). The nature of these genetic effects, particularly the MHC-linked effects, can also provide some insight into the different theories of human origins: These effects are most consistent with the monogenic theory.

Animals↗
PubMed1999

Biological effects of genes in the Grc and EC region of the rat major histocompatibility complex.

PROBLEM: To study the mechanism of action of major histocompatibility complex (MHC)-linked genes affecting reproduction, growth, and susceptibility to chemical carcinogens. METHOD OF STUDY: Tumors derived from rat embryonic fibroblasts were transfected with cosmids from the Grc and its linked regions, the unrelated A region, and a nonMHC region, or with genes from the Grc, Grc-linked, and nonMHC regions, to determine whether they could suppress tumor growth as determined by in vitro (soft agar) and in vivo assays. RESULTS: Tumor fibroblasts transfected with cosmids from the Grc or from the EC region decreased tumor growth in both the in vitro and in vivo assays. Transfection with individual genes from the Grc had no effect on tumor growth in either assay. CONCLUSIONS: The effects of the Grc on reproduction, growth, and tumorigenesis are mediated by extended genetic effects, i.e., by the conformation of the DNA in this region. Similar effects were seen following transfection with cosmids from the Grc-linked EC region, and this finding strengthens the hypothesis that the conformation of the DNA in this general region is critical for its function. A similar effect has been described for the locus control region (LCR) in the beta-globin gene family in the human.

Animals↗
PubMed1999

Cytogenetic localization of the growth and reproduction complex (Grc) in the rat and in the mouse and its position in relation to RT1.EC and other loci in the rat MHC.

The segment of rat chromosome 20 (RNO20p12) that contains the classical loci of the major histocompatibility complex (MHC; RT1.A-RT1.E) also contains genes affecting growth, reproduction and susceptibility to chemical carcinogens (the Grc) and multiple genes encoding class I MHC antigens (the EC region). The relative positions of the MHC, Grc, and EC region have not been demonstrated explicitly, although they have been postulated from genetic mapping studies. The present study was undertaken to map these regions cytogenetically by several different approaches using cosmids specific for the Rps 18, Hspa1 and Bat1 genes. The order was shown to be: centromere-Rps 18-Hspa1-Bat1-EC-Grc.

Animals↗
PubMed1998

HLA and mate choice.

Explore the source record for details and available documents.

Abortion, Spontaneous↗
PubMed1998

The Bürch-Schneider anti-protrusio cage in revision total hip arthroplasty: indications, principles and long-term results.

Patients who had a revision total hip arthroplasty using the Bürch-Schneider anti-protrusio cage (APC) by a single surgeon have been reviewed after a minimum of five years. There were 63 operations in 58 patients with an average age of 63 years (41 to 83) at the time of revision. At an average follow-up of 8.5 years (5 to 18), 15 patients (25.9%) rated their results as excellent, 38 (65.5%) as good, and five (8.6%) as fair. Five further revisions of the acetabular prosthesis were required, three due to aseptic loosening, one for recurrent dislocation and one due to sepsis. Of the remainder, one was definitely loose, two probably loose, and 12 possibly so. Impressive augmentation of bone stock can be achieved with the anti-protrusio cage, while enabling the hip to be centred in its anatomical position.

Adult↗
PubMed1998

Total hip arthroplasty with use of an acetabular reinforcement ring in patients who have congenital dysplasia of the hip. Results at five to fifteen years.

The purpose of our study was to examine the clinical and technical problems associated with reconstruction of the hip in patients who had congenital dysplasia and to offer recommendations for their solution. We reviewed the records on 123 consecutive total hip arthroplasties that had been performed by one of us (M. E. M.), between 1981 and 1986, for the treatment of coxarthrosis due to congenital dysplasia of the hip. A minimum of five years of follow-up was required for inclusion in the study. The study group consisted of seventy patients who had had a total of eighty-seven reconstructions. According to the classification of Crowe et al., eleven hips had type-IV acetabular dysplasia; sixty-five, type-II; and eleven, type-II. Acetabular reconstruction was performed with use of the Müller acetabular roof-reinforcement ring and a polyethylene cup, which was inserted with cement. Autologous graft from the femoral head was used in forty-two hips. Femoral reconstruction was performed with use of the Müller straight-stem component for congenital dysplasia of the hip in eighty hips and with use of a standard Müller straight-stem component in seven hips. At an average of 9.4 years (range, five to fifteen years) postoperatively, the result was described as excellent for sixty hips (69 per cent), as good for twenty-three (26 per cent), as fair for two (2 per cent), and as poor for two. Nine (10 per cent) of the hips had been revised. One revision had been performed because of aseptic loosening of the acetabular component; one, because of aseptic loosening of the femoral component; one, because of aseptic loosening of both components; and six, because of infection. Of the unrevised hips, three had had superior migration of the acetabular component of less than five millimeters, and mild protrusion had developed in one. Two hips had a continuous radiolucent line around the acetabular construct. Two hips had had subsidence of the femoral stem of less than three millimeters; one had a complete, non-progressive radiolucent line at the bone-cement interface; and four had a radiolucent line at the proximal part of the bone-cement interface. Six hips had evidence of endosteal osteolysis. Six hips had grade-III or IV heterotopic ossification according to the system of Brooker et al. These results compare favorably with others in the literature. We recommend restoration of the anatomical hip center with the use of an acetabular roof-reinforcement ring and a polyethylene cup inserted with cement for the reconstruction of a deficient acetabulum. The acetabular reinforcement ring prevents resorption of bone graft and migration of the cup, which are major causes of failure of the cup in patients who have had a reconstruction of a deficient acetabulum. Bone graft should be used medially and superiorly as needed to augment bone stock notably. Cement should not be used to fill acetabular defects as we believe that it contributes to aseptic loosening.

Arthroplasty, Replacement, Hip↗
PubMed1998

Assessment of neuroforaminal decompression in degenerative spinal stenosis.

Surgical decompression of spinal stenosis is a balance between adequate removal of bone and soft tissue for an effective decompression of neural structures and a sufficient retention of bone to maintain mechanical stability of the spine. To develop an objective, reproducible technique for the assessment of neuroforaminal decompression in the adult lumbar spine, facet sparing laminectomies were performed from L1-S1 on the lumbar spines of 59 human cadavers. A series of semirigid probes in 0.5-mm increments were passed into each successive intervertebral foramen bilaterally, beginning at L2-L3. The minimum space available for the nerve root within the foramen of the lumbar spine is 3.5 mm at L2-L3, 3.9 mm at L3-L4, 4.3 mm at L4-L5 and 5.1 mm at L5-S1, as determined by three independent observers. There were no significant differences in interobserver or intraobserver measurements. There were no complications related to passage of the probes. This study provides a method for the intraoperative determination of the adequacy of neuroforaminal decompression.

Adult↗