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Biomedical subjects

A E Gross

Publications and source records attributed to A E Gross.

At least 19 recordsLinked to original sources
PubMed2000

Revision total hip arthroplasty with the use of structural acetabular allograft and reconstruction ring: a case series with a 10-year average follow-up.

From 1980 through 1993, 20 consecutive massive structural acetabular allografts and reconstruction rings were performed in 19 patients. In all cases, the magnitude of the acetabular bone deficiency was such that the allograft supported >50% of the cup. The allograft was necessary to restore normal anatomy, bone stock, and leg length. Of the 19 patients who met the inclusion criteria, 7 subjects died of unrelated causes, and 3 subjects failed and underwent resection arthroplasty, 1 (8%) for graft resorption and 2 (15%) for recurrent dislocation. The remaining 9 patients (10 allografts) had a minimum follow-up of 5 years and average follow-up of 10.5 years. The cohort was analyzed using radiographic and outcome data collection questionnaires (AAOS/HKOD, WOMAC, SF-36). The study supports the use of massive structural allografts and reconstruction rings and achieves satisfactory results in 77% (10 of 13) of the patients. We believe these results reveal an impressive outcome for what used to be thought of as a salvage operation.

Acetabulum↗
PubMed2000

Minor column structural acetabular allografts in revision hip arthroplasty.

A minor column (shelf) allograft is used for uncontained defects that involve less than 50% of the acetabulum. The prospectively collected records and radiographs of 47 patients (51 hips) who had undergone minor column structural acetabular allograft reconstruction during revision hip arthroplasty were reviewed. The purpose was to identify the long-term results (minimum 5 years) and factors that may influence longevity of the allograft and predispose the patient to subsequent acetabular component failure. The mean duration of followup was 119 months (range, 68-195 months). There was one perioperative death and six patients were lost to followup. Eleven patients (22%) required additional surgery. Three acetabular cups could not be revised successfully, despite multiple attempts, and the patients were treated with Girdlestone excisions. Eight patients underwent successful revision surgery with only three requiring a repeat structural allograft. Survival time for the acetabular cup as determined by Kaplan-Meier analysis was 153 months (95% confidence interval; range, 136-169 months). Cup failure was associated with more operative procedures performed before revision surgery (mean, 3.2 procedures), and failure to restore the vertical center of hip rotation to within 12 to 14 mm of the predicted value. The acetabular abduction angle was not a predictor for failure. The current study shows that good results can be achieved with structural acetabular allograft reconstruction with mid-term to long-term implant survival (cup aseptic survival, 80.4% and allograft re-construction survival, 94.1%), especially if there is restoration of near normal hip biomechanics.

Acetabulum↗
PubMed2000

Complications of total hip arthroplasty: MR imaging-initial experience.

PURPOSE: To investigate the use of standard magnetic resonance (MR) imaging sequences with simple parameter modifications for the detection and characterization of total hip arthroplasty (THA) complications. MATERIALS AND METHODS: An initial phantom study was performed with cobalt-chrome and titanium prostheses to establish the imaging parameters for a subsequent clinical study. In the clinical study, coronal and transverse MR imaging of 14 THA prostheses was performed before and after intravenous contrast material administration in 12 patients who were being considered for revision arthroplasty. The images were reviewed for evidence of juxtaarticular or periprosthetic abnormalities, patterns of contrast enhancement, and quality of periprosthetic tissue depiction. RESULTS: Phantom study results showed improved periprosthetic tissue depiction with use of thin sections, increased frequency-encoding gradient strength, and fast spin-echo sequences. The clinical study results demonstrated periprosthetic abnormalities in 11 cases: mechanical loosening in two cases (including one case with an associated periprosthetic fracture); granulomatosis, eight; and infection, one. In 100% of cases, tissue depiction around the femoral component was judged to be of "diagnostic quality." Tissue depiction around the acetabular component was of diagnostic quality in five (36%) cases. In all seven surgically confirmed cases, a correct diagnosis was made preoperatively with MR imaging. CONCLUSION: By using simple modifications to standard MR imaging sequences, diagnostic-quality MR imaging of THA complications can be performed, particularly around the femoral prosthetic stem.

Acetabulum↗
PubMed1999

The use of structural allografts for treating periprosthetic fractures about the hip and knee.

When a periprosthetic fracture about the knee or hip is associated with segmental bone loss and a loose implant, a structural allograft may be indicated. The implant is cemented into the allograft but not into the host. The host graft junction is stabilized by the long stem of the implant and a step-cut osteotomy. The junction can be further reinforced by cortical strut allograft and residual host bone with soft tissues still attached to enhance union. Once the host bone unites to the allograft, the reconstruction is stabilized.

Aged↗
PubMed1999

Economic evaluations in the hip arthroplasty literature: lessons to be learned.

Readers are increasingly encountering articles dealing with health economic evaluations that compare various surgical strategies, leaving orthopaedists with the challenge of determining which program is cost-efficient and truly pertains to their setting. This study carries out a systematic review of the literature to appraise the quality, quantity, and type of economic evaluation as it pertains to the hip arthroplasty literature. To identify all relevant articles, we conducted a comprehensive computerized bibliographic search of Medline from 1966 to 1996. This search produced 1,611 abstracts that were screened. Studies that were incorporated met the following inclusion criteria: i) formal economic analysis, ii) an intervention specific to hip arthroplasty, and iii) the perspective of the study was evident (ie, patient, provider, society). These studies were appraised with regards to methodologic soundness based on 8 established economic principles. Only 68 articles from the 138 retrieved met the study criteria. Only 2 of the 68 articles met all 8 criteria of a comprehensive economic evaluation. The hip arthroplasty literature is deficient in methodologically sound economic evaluations. Several guidelines are introduced to aid orthopaedists in appraising the various economic studies, and recommendations are made to improve the quality of these studies in the orthopaedic literature. We suggest that the generation of such information should rank high on the priority list of the orthopaedic profession, granting agencies, and governments.

Arthroplasty, Replacement, Hip↗
PubMed1999

Revision arthroplasty of the acetabulum with restoration of bone stock.

Bone defects on the acetabular side are defined as contained (cavitary) and uncontained (segmental). Contained (cavitary) defects can be treated by morselized allograft bone with an uncemented cup if contact can be made with 50% host bone. If contact cannot be made with 50% host bone, the author prefers to use a ring and a cemented cup. Defining success as a stable implant, no additional surgery, and improvement in hip score of at least 20 points, the success rate was 90% in 51 hips in 51 patients at an average followup of 7 years. Segmental defects involving between 30% and 50% of the acetabulum are treated by minor column allografts (shelf graft), and a cemented or an uncemented cup. In 29 hips in 28 patients with an average followup of 7 years the success rate was 86%. Segmental defects involving more than 50% of the acetabulum are treated by major column allografts. These grafts are fixed by cancellous screws and protected by a reconstruction ring that extends from ilium to ischium. In 33 hips in 32 patients with an average followup of 7 years, the success rate was 76%.

Acetabulum↗
PubMed1999

Evaluation of the allograft-prosthesis composite technique for proximal femoral reconstruction after resection of a primary bone tumour.

OBJECTIVE: To evaluate clinical and functional outcomes resulting from the allograft-composite technique used for proximal femoral osteoarticular reconstruction in patients who had limb salvage surgery for primary bone tumours. DESIGN: A retrospective review of a prospectively gathered database to provide a descriptive study. SETTING: A tertiary care musculoskeletal oncology unit in a university hospital. PATIENTS AND INTERVENTIONS: Patients treated between 1987 and 1993 were eligible for inclusion in this study if they met the following criteria: they were treated surgically for a primary malignant bone tumour; and a proximal femoral allograft-implant composite technique was used for the reconstruction. MAIN OUTCOME MEASURES: Major postoperative complications with emphasis on mechanical complications in the reconstructive composite implant. Functional outcome in a subset of patients using the 1987 and 1994 versions of the Musculoskeletal Tumor Society instrument, the Short-Form-36 and the Toronto Extremity Salvage Score. RESULTS: There were 5 mechanical and 2 infectious complications requiring surgical intervention. Functional scores were generally low. CONCLUSIONS: Our results suggest that the perceived benefits of the composite technique may accrue only to a few patients, partly owing to the risk of mechanical complications. Although these can be reduced by avoiding the use of cement in the host femur, the generally poor functional outcomes suggest that this technique needs to be studied further in this group of patients and compared with other reconstructive techniques, particularly the prosthetic implant.

Adult↗
PubMed1998

Proximal femoral allografts for reconstruction of bone stock in revision arthroplasty of the hip.

Full circumferential bone loss of the proximal femur can be managed by segmental allografts. The use of these grafts is indicated for uncontained defects longer than five cm in length. The femoral implant is cemented into the allograft but not into the host. The allograft host junction is stabilized by a step cut or oblique osteotomy and autografted with residual host femur. The results at five and nine years support this kind of reconstruction as a good alternative for this difficult problem.

Arthroplasty, Replacement, Hip↗
PubMed1998

The treatment of isolated articular cartilage lesions in the young individual.

The treatment of isolated articular cartilage defects is an evolving field in orthopaedic surgery today. We have summarized the basic science and clinical date on the treatment of isolated articular cartilage defects. Further long-term controlled studies are required in order to compare definitively the efficacy of treatments in this difficult clinical area. In future studies, inclusion/exclusion criteria must be detailed, and classification systems need to be standardized Comparative analysis can then be performed to assess the efficacy of various techniques.

Adolescent↗