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F J Dorey

Publications and source records attributed to F J Dorey.

At least 37 records · Page 2Linked to original sources
PubMed1999

Etiology and results of tumor endoprosthesis revision surgery in 64 patients.

From December 1980 to December 1995, 278 patients underwent primary custom endoprosthesis replacements for neoplastic disease at the University of California, Los Angeles and have been followed up for a minimum of 2 years or to death. The endoprosthesis reconstruction failed in 64 patients, including 10 additional patients referred for revision of their replacements. Failure was defined as the complete removal of a prosthesis for any reason. The cause of failure were aseptic loosening (44%), fatigue fracture (16%), local recurrence (14%), infection (13%), and failure of the expansion mechanism (6%). Forty-eight of 64 failed endoprostheses were managed by endoprosthesis reconstruction with most being revised using the same type of prosthesis. Nine of these patients with failed replacements experienced a second failure and four went on to require an amputation. Aseptic loosening and mechanical failure accounted for most of the failures and they were revised successfully. Sixty percent of the infected cases were salvaged satisfactorily by endoprosthetic revision, whereas, 89% of the local recurrences resulted in amputation. Based on endoprosthesis survival the 7-year failure rates were 31% and 34% for primary and revision reconstructions, respectively. The functional results for the patients with endoprosthesis revisions either were better, unchanged, or on average only slightly lower than results of patients with a surviving endoprosthesis.

Adult↗
PubMed1998

Evolution and future of surface replacement of the hip.

Surface replacement is a bone-conserving alternative to total hip arthroplasty and is a significant development in the evolution of hip arthroplasty. Surface replacement with polyethylene bearings was largely abandoned, primarily because of component aseptic loosening caused by tissue reaction to high-volumetric polyethylene wear. For patients with osteonecrosis and collapse of the femoral head but with preservation of some acetabular articular cartilage, precision fit, hemisurface replacement of the femoral head only has emerged as the treatment of choice. The survivorship of our series of patients, performed in the 1981-84 era (average age, 32 years), has been 85% at 5 years, 67% at 10 years, and 42% at 16 years. In the absence of polyethylene, there has been no loosening. Revisions were for cartilage wear. The procedure is now much improved with instrumentation for non-trochanteric osteotomy approaches and off-the-shelf components in 1-mm increments. For arthritic hips, a new era of surface replacement has emerged. With metal-on-metal bearings, the volumetric wear has been reduced 20-100 times from those with polyethylene, and there is no penalty for the large ball size. The devices are now conservative on the acetabular as well as femoral side. Hybrid or all-cementless fixation is superior to earlier all-cemented devices. In those patients, the results with up to 4 years have been complication-free, with an absence of pain and a return to high functional levels, including participation in sports. Forty patients have received a Conserve Plus with interference fitting of the acetabular component with sintered beads to obtain fixation. Although the follow-up is short, surface replacement with the large ball size is extremely stable, and dislocation is rare.

Adult↗
PubMed1997

Three-dimensional ultrasound device for rapid determination of bladder volume.

OBJECTIVES: We sought to assess the accuracy, reliability, and clinical utility of the noninvasive determination of bladder volume using an automated, compact three-dimensional (3-D) ultrasound device. METHODS: We prospectively tested 249 adult outpatients for accuracy (n = 182), by comparing scan versus catheter volumes, or reliability (n = 67), by comparing the scan readings of two independent observers. Two models of the bladder scan device were tested (BVI-2500, 1994 and 1995 models). RESULTS: Scan and catheter volumes were correlated (y = 1.02x + 12.6, R2 = 0.90, P < 0.001) across a range of zero to 1015 cc, regardless of which machine model was used. Scan volume underestimated catheter volume by an average of 10 cc in men and 20 cc in women. If a scan-predicted volume of 100 cc or greater were used as a cutpoint for clinical importance, the device exhibited a sensitivity of 97%, a specificity of 91%, and an overall accuracy of 94%. These results were not affected by age, gender, height, weight, diagnosis, uterine presence/prostate size, or user experience. The two observers, one a graduate physician and the other a college student, achieved essentially the same volume determinations (y = 0.96x + 0.13, R2 = 0.90, P < 0.001). CONCLUSIONS: Volume determinations obtained with the bladder scan device are accurate and reliable in adult outpatients. A special technician is not required. These results may be attributable to use of automated planimetry and 3-D volumetry, rather than a fixed geometric formula, to custom measure each bladder shape.

Adult↗
PubMed1997

Loosening of massive proximal femoral cemented endoprostheses. Radiographic evidence of loosening mechanism.

A review of the radiographs of 24 patients with massive proximal femoral cemented tumor endoprostheses revealed a repetitive radiographic sequence that culminated in implant loosening. The initial step was osteolysis of the proximal femur at the bone-prosthesis junction (13 of 24 cases, 54%). The osteolysis then progressed into the adjacent periprosthetic bone-cement interface as a radiolucent line (5 of 24 cases, 21%), followed by extension along the stem, culminating in implant loosening (4 of 24 cases, 17%). Two prostheses (8%) have required revision for loosening. The proximal osteolysis was noted prior to the appearance of progressive periprosthetic radiolucent lines in 11 patients and simultaneously in 2 but never followed periprosthetic radiolucent lines (P < .05). These findings are consistent with loosening by debris-induced osteolysis. This loosening sequence, confirming previous observations of cemented component loosening, should encourage efforts to prevent or delay the onset of this sequence.

Adolescent↗
PubMed1997

Short-course indomethacin prevents heterotopic ossification in a high-risk population following total hip arthroplasty.

The efficacy of a 10-day course of indomethacin in preventing heterotopic ossification after total hip arthroplasty was studied in a consecutive series of male patients who were at increased risk for bone formation. Between September 1991 and June 1994, all male patients (123 hips in 109 patients) who underwent total hip, revision, or surface arthroplasty were placed on a 10-day course of indomethacin. Of these, 106 patients (119 hips) successfully completed the 10-day course. There was no significant formation of heterotopic ossification (Brooker grade III or IV). From a group of 45 known heterotopic bone formers following previous total hip arthroplasty, only 2 developed new heterotopic ossification. Overall there were 9 (7.6%) new cases of heterotopic ossification: 7 Brooker grade I (5 primary and 2 revision cases) and 2 Brooker grade II (both primary cases). A 10-day course of indomethacin prevents the more significant grades of heterotopic ossification and is effective at reducing the incidence of heterotopic ossification following total hip arthroplasty. Further, this regimen appears safe and cost effective.

Adult↗
PubMed1997

Risk of underestimation of the bone mineral density of proximal femur.

Decreased bone mineral density (BMD) in the elderly increases the risk of hip fracture. Measurement of proximal femoral BMD can help us predict the risk of hip fracture, especially in the elderly. Since the BMD of proximal femur is usually measured on the unilateral side, we studied the risk of underestimation with measurement of unilateral proximal femur BMD in 266 normal Chinese women. In order to evaluate the effect of age, these subjects were divided into group A (18-59 years, n = 189) and group B (60-88 years, n = 77). BMDs of both proximal femurs were assessed with Norland 2600 dual photon absorptiometry. Using a cutoff T score of -1, the negative predictive value (NPV) in the entire group was 86.9% for femoral neck BMD and 85.7% for trochanter, and 82.2% for Ward's triangle: in group A, the NPV was 88.9% for femoral neck, 88.8% for trochanter, and 97.2% for Ward's triangle, but in group B, the NPV was 60.0% for femoral neck, 71.0% for trochanter, and 24.1% for Ward's triangle. The accuracy in the entire group was 86.1% for femoral neck, 84.2% for trochanter, and 86.3% for Ward's triangle: in group A the accuracy was 84.6% for femoral neck, 84.9% for trochanter, and 92.8% for Ward's triangle, but in group B, the accuracy was 89.6% for femoral neck, 81.7% for trochanter, and 90.0% for Ward's triangle. In general, NPV and accuracy increased at the expense of positive predictive value when the cutoff T score was changed to -2.5. This study suggested that measurement of unilateral proximal femur BMD was sufficient for screening the contralateral hip BMD in group A at a cutoff T score of -1. However, a T score of -2.5 was recommended for group B, and one should be careful in its application to Ward's triangle.

Adult↗
PubMed1997

In vivo rotational stability of the kinematic rotating hinge knee prosthesis.

The in vivo rotary laxity and torsional stiffness of the knee joint were measured in 20 patients with wide intraarticular resection of the distal femoral tumor followed by reconstruction with a custom Kinematic rotating hinge endoprosthesis. The contralateral normal knee served as natural control. Twenty patients underwent 29 measurements, including 9 at the first year, 10 at the second year (4 of these also measured at year 1), and 10 at the third year (3 of these also measured at years 1 and 2; 2 also measured at year 2). The mean followup for the 15 survivors was 134 months (range, 102-156 months). The total rotatory laxity of the hinged knee was significantly greater than that of the contralateral knee. The torsional stiffness in external rotation of the hinged knee was 30.4% less than that of the contralateral knee in the first postoperative year, whereas the torsional stiffness in internal rotation was similar to that of the contralateral knee. Torsional stiffness of the hinged knee in the second year was significantly less than that of the contralateral knee whereas it was within the normal range of stiffness in the third year. The total rotatory laxity and torsional stiffness of the hinged knee in the early postoperative years could not predict the risk of late loosening. In vitro rotational stability of the rotating hinge device with axial load bearing was 6.7 and 8.1 Newton-meters (N-m) at 0 degrees and 20 degrees knee flexion, respectively, under an axial tibial load of 945 Newtons.

Adolescent↗
PubMed1997

Prostate tissue composition and response to finasteride in men with symptomatic benign prostatic hyperplasia.

PURPOSE: We sought to quantify prostate tissue changes induced by finasteride and to identify a predictor of finasteride response in men with symptomatic benign prostatic hyperplasia (BPH) via a randomized, placebo controlled, double-blind clinical trial. MATERIALS AND METHODS: Men with symptomatic BPH (52 to 78 years old) were randomly assigned to 6 months of treatment with finasteride (26) or placebo (15). Outcome measures were clinical (urinary symptom score and flow rate), chemical (serum prostate specific antigen and dihydrotestosterone levels), volumetric (transrectal ultrasound, and magnetic resonance imaging for whole and zonal prostate volumes) and histological (morphometry of prostate sextant biopsies, separated into inner and outer gland segments, to measure the percent epithelium, stroma and glandular lumen). RESULTS: In the finasteride group we found a suggestion of decreasing symptom scores and increasing flow rates (not significant) with significant decreases (p < 0.01) in prostate specific antigen (48%), dihydrotestosterone (74%) and prostate volume (21%). Finasteride treatment induced a 55% decrease in inner gland epithelium (p < 0.01) with little effect on stroma or lumina. We also found a linear correlation between pretreatment inner gland epithelial content and prostate volume decrease induced by the drug (tau = 0.58, p = 0.01). CONCLUSIONS: Finasteride treatment results in a major suppression of prostate epithelium, which is most pronounced in the inner gland. Moreover, a finasteride induced prostate volume decrease was predictable by quantification of epithelial tissues of the inner gland. These data lend additional support to the emerging concept of transition zone primacy in symptomatic BPH.

Aged↗
PubMed1997

Influence of health status and the timing of surgery on mortality in hip fracture patients.

The purpose of the study was to determine the relationship of preoperative health status and time to surgery to mortality and late functional outcome in hip fracture patients. The records of 168 consecutive patients who had operations for 171 intertrochanteric or femoral neck fractures were reviewed retrospectively. Preoperative health status was assessed by the American Society of Anesthetists (ASA) classification. Postoperative outcome was determined by mortality and ambulatory status. The follow-up period for survivors averaged 33 months. The overall mortality was 14% at 1 year, which rose to 26% at 2 years, and 33% at 3 years. The 3-year mortality was significantly less for ASA I and II patients (23%) than for ASA III, IV, and V patients (39%). There was also a significant difference in mortality between patients having surgery within 24 hours of admission (20%) and those having surgery beyond 24 hours of admission (50%). Even when only the healthy subgroup of ASA I and II patients were considered, the relative risk of death was 4.5 times greater if surgery occurred after 24 hours from admission. These data support the concept that hip fracture patients are not a homogeneous group with respect to mortality and that the ASA classification is a good predictor of mortality. Patients who had surgery within 24 hours of admission had a significantly lower mortality rate than did patients having surgery beyond 24 hours of admission, regardless of their preoperative ASA classification.

Adult↗
PubMed1996

Bone mineral density in Chinese elderly women with hip fracture.

In order to examine the status of osteoporosis of the patients with hip fracture, we assessed the bone mineral density (BMD) of the contralateral hip of 81 elderly females with hip fracture and compared those with 77 normal Chinese women. The age of fracture subjects was 73.5 +/- 6.6 years (mean +/- SD), and 69.2 +/- 6.9 years for the controls. All of these fractures were caused by minor trauma, such as falls from a standing position or slipping to the ground. The Norland 2600 dual-photon absorptiometer (DPA) was used to evaluate the BMD in the femoral neck, trochanter, and Ward's triangle areas. The BMD for the fracture subjects was significantly lower than those of the controls. By linear regression, the probability of fracture increased exponentially with age and low BMD. The mean BMD for femoral neck of the fracture subjects versus controls was 0.556 versus 0.624 g/cm2; for trochanter: 0.505 versus 0.566 g/cm2; for Ward's triangle: 0.432 versus 0.485 g/cm2. Both negative predictive value (NPV) and positive predictive value (PPV) were acceptable at the prevalence of hip fracture of 5% or 20% and at a cutoff point of 0.65 g/cm2. These data revealed that the degree of relative osteoporosis in the patients with hip fractures was more severe than that of controls.

Absorptiometry, Photon↗
PubMed1996

The contribution of frictional torque to loosening at the cement-bone interface in Tharies hip replacements.

We evaluated the results in a series of 170 osteoarthrotic hips (156 patients) at a median of 10.0 years (range, 3.0 to 16.4 years) after a Tharies resurfacing arthroplasty performed with cement. Our purpose was to assess the role of frictional torque in loosening at the cement-bone interface. The hips were divided into three groups on the basis of the diameter of the bearing surface: small (thirty-six, thirty-nine, or forty-three millimeters), medium (forty-seven millimeters), and large (fifty-one or fifty-four millimeters). Comparisons were made with Kaplan-Meier survivorship analysis, with stepwise discriminant analysis of risk factors for aseptic loosening. Revision for aseptic loosening was the end point for survivorship analysis. Despite higher frictional torques due to the increased diameter of the bearing surface and the increased average load, the larger prostheses survived significantly longer than the smaller ones (p=0.002). Stepwise covariate discriminant analysis indicated that the size of the bearing surface was the only factor identified that significantly affected survival. In six patients who had had a bilateral surface replacement with a component of a different size in each hip, the smaller prosthesis always failed first (p=0.001), at an average of seventy-seven months; the larger prosthesis failed at an average of 113 months. Nine patients had had a bilateral replacement with components of the same size, and there was no significant difference in the durations of survival of the two prostheses. Analysis of radiographs and retrieved specimens indicated that, regardless of the size of the component, the mechanism of loosening on both the acetabular and the femoral side of this so-called double-cup replacement was progressive resorption of bone induced by polyethylene wear particles that compromised the fixation of the components. More time was required for the process to disrupt++ the larger fixation area of the larger components. These data indicate that frictional torque was not the primary factor in the loosening of these prostheses with a large bearing surface and that higher friction and frictional torques can be tolerated if the generation of wear debris is sufficiently limited. These findings may be important as alternatives to polyethylene bearing surfaces are investigated.

Acetabulum↗
PubMed1996

Serum prostate specific antigen levels after transurethral resection of prostate: a longitudinal characterization in men with benign prostatic hyperplasia.

PURPOSE: We studied the long-term effects of adenomectomy on serum levels of prostate specific antigen (PSA) in men with benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: A consecutive series of 82 men undergoing adenomectomy for BPH between 1990 and 1992 was studied. PSA levels were determined before and serially after operation for as long as 5 years. RESULTS: Mean PSA decreased from 4.6 ng/ml. preoperatively to 0.7 ng./ml. 6 months postoperatively. These low levels were maintained throughout the 5-year observation period. The PSA decrease correlated with grams of tissue removed (r = 0.54, p < 0.001) and averaged 0.11 ng./ml./gm. Postoperatively mean PSA velocity was 0.01 ng./ml. per year, that is essentially flat, and it was not influenced by patient age, race, type of operation, grams of tissue removed, baseline PSA, PSA density of T1a lesions (7). One to 5 years after adenomectomy 6 of the 82 men had invasive prostatic carcinoma, and PSA levels and velocities remained low. CONCLUSIONS: These data support the concept of transition zone primacy in determining serum PSA. Furthermore, they suggest a possible need for a modified reference range when using PSA to screen for prostatic carcinoma in the estimated 3 million men alive in the United States who previously underwent adenomectomy for BPH.

Adult↗
PubMed1995

Surgical indications for Ewing's sarcoma of the pelvis.

BACKGROUND: Despite advances in adjuvant therapy, Ewing's sarcoma of the pelvis remains an anatomic site with a poor prognosis. This study evaluate the role of surgery in the management of patients with pelvic Ewing's sarcoma who also received conventional radiation therapy and chemotherapy. METHODS: From May 1978 to February 1994, 19 patients with Stage IIB Ewing's sarcoma of the pelvis were treated at the UCLA Medical Center (Los Angeles, CA). There were eight lesions of the ilium, two of the sacrum, and nine involving two adjoining regions of pelvis. All patients received conventional medical management. The 19 patients were divided into two groups according to treatment modality. A group of 12 patients (Group A) had surgical resection, and their results were compared with those of another group of 7 patients (Group B) who did not have surgery. RESULTS: The 5-year cumulative survival (Kaplan-Meier method) was 39% for all patients, 51% for Group A, and 18% for Group B. The 3-year cumulative survival was 59% for all patients, 72% for Group A, and 36% for Group B. Although the survival rate of Group A seemed better than that of Group B, the difference was not statistically significant (P = 0.093, log rank method). This study also suggested that, regardless of treatment modality, the outcome of patients with lesions involving two adjoining pelvic bones was poorer than that of those with a single lesion. In Group A, the 3-year cumulative survival rate for patients with single bone lesions (n = 8) was 86% and for patients with lesions involving two adjoining pelvic bones (n = 4) was 50% (P = 0.045, log rank method). Furthermore, the statistical analysis of the combined data of the single pelvic bone lesions in UCLA and that of Mayo Clinic series (n = 16 for surgery group and n = 15 for nonsurgery group) confirmed the better results for the surgical patients, which was consistent with the results from the Mayo Clinic with an even greater significance (P < 0.002). CONCLUSION: This study demonstrates that surgery plus chemotherapy and radiation therapy is helpful for treating patients with pelvic Ewing's sarcoma so long as the tumor is limited to a single pelvic bone.

Adolescent↗
PubMed1995

High grade soft tissue sarcoma of the flexor fossae. Size rather than compartmental status determine prognosis.

BACKGROUND: High grade soft tissue sarcoma arising in the popliteal space, axilla, and antecubital fossae (flexor fossae tumors) have by convention been classified as extracompartmental tumors by the accepted staging and grading criteria of the Musculoskeletal Tumor Society (MSTS). Advances in neoadjuvant chemotherapy and radiation therapy have made surgical resection more feasible. The hypothesis to be tested is that compartmental status may not be of prognostic significance if the tumor is adjusted for size, histologic grade, and distant metastasis after undergoing adjuvant chemotherapy and radiation. METHODS: From June 1976 to December 1992, 22 patients with high grade soft tissue sarcomas of the flexor fossae (Group A) were treated at UCLA Medical Center. The histologic subtypes were liposarcoma (five), synovial cell sarcoma (eight), malignant fibrous histiocytoma (four), leiomyosarcoma (two), angiosarcoma (two), and rhabdomyosarcoma (one). The popliteal fossa was the location in 11, the axilla in 10, and the antecubital fossa in 1. Wide resection was attempted in all patients after preoperative chemotherapy and radiation therapy. Amputation was performed in 5 patients because of repeated or extensive recurrent tumor. A group of 77 patients (Group B) with high grade soft tissue sarcoma located within an extremity compartment were chosen to test the hypothesis that survival of patients with tumors in the flexor fossae is equal to that of patients with intracompartmental tumors of similar size and grade if both are given adjuvant therapy. This group was chosen so that histologic subtype, size, sex, and location would be similar in the two groups. The authors selected thigh and calf tumors for comparison with popliteal fossa tumors and periscapular, deltoid, and arm tumors for comparison with axilla and antecubital fossae tumors. All of these patients had similar treatment and follow-up protocols. The median follow-up of survivors in Group A was 104 months and for patients in Group B was 79 months. RESULTS: The 5-year cumulative survival rate (Kaplan-Meier method) of patients in Group A was 76%, and 67% for those in Group B. The difference was not significant. Three patients in Group A (14%) and 17 (22%) in Group B had local tumor recurrence. Eight patients in Group A (36%) and 27 (35%) in Group B had lung metastases. Age, sex, histologic subtype, and surgical margins did not affect survival outcomes, lung metastasis, and local recurrence. However, patients with larger tumors (maximum dimension > or = 8 cm or cross-sectional area > or = 40 cm2) had significantly poorer survival, more metastases, and local recurrences. CONCLUSION: Flexor fossae sarcomas do not have a poorer prognosis than extremity intracompartmental tumors when adjusted for size, distant metastasis, and histologic grade when they are treated with adjuvant radiation therapy, chemotherapy, and surgery.

Adolescent↗
PubMed1995

Surgical approach and nerve palsy in total hip arthroplasty.

A prospective study of the relation between nerve palsy and the surgical approach used for total hip arthroplasty was performed on 1,000 consecutive patients. A postoperative neuropathy was diagnosed in eight patients for an overall prevalence of 0.8%. The overall prevalence of nerve palsy with the posterior approach was 0.6% and 1.0% with the lateral transtrochanteric approach. In both primary and revision surgeries, there were no statistical differences between the two approaches. Our data suggest that it is the anatomic variations and complexity of the reconstruction that are associated with nerve injury and not the surgical approach per se. The increased prevalence of nerve palsy seen in revision surgeries (1.4%) regardless of the approach supports this position.

Female↗
PubMed1995

Long-term durability of cemented primary total hip arthroplasty.

The results of all primary cemented total hip arthroplasties that were performed at UCLA Medical Center between 1974 and 1982 and had at least 1 year of follow-up evaluation were reviewed. Five hundred ninety-seven hips were implanted in 513 patients receiving a T28 (81%), a TR28 (16%), or a Charnley (3%) prosthesis (all from Zimmer, Warsaw, IN). The overall 15-year survival of the implants was 82%, although age at surgery was a strong predictor of implant failure (P < .001). The 15-year aseptic revision estimate was 37% in those patients younger than 50 at implantation, 17% in those patients aged 50 to 60 at implant surgery, and 4% in patients older than 60 at surgery. After adjustment for patient age, primary etiology was not significantly related to implant failure. Sepsis necessitated revision in 2.6% of the patients by 10 years. Lucencies throughout all three acetabular zones were noted in 45% of patients with long-term follow-up evaluation; however, this "radiographic loosening" was not a good indicator of impending clinical failure. (Only 49% of these components required revision in the ensuing 10 years following evidence of radiographic loosening.) The results for the younger patients are markedly inferior to those for older patients. Excellent results obtained with earlier prosthetic designs and cementing techniques make cemented hip arthroplasty a strong contender for the method of choice in the older patient.

Age Factors↗
PubMed1995

Prostatic aperture resulting from visual laser ablation: classification system based on follow-up endoscopy.

To study the evolving prostatic aperture created by visual laser ablation (VLAP), we performed 38 video-endoscopies in 24 men with prostatism at various intervals 2 weeks to 1 year after treatment. Complete healing was generally observed within 3 to 4 months, never before 6 weeks; and in some patients, tissue sloughing was still apparent beyond 6 months. By review of the cystoscopic findings and video hard copies, three independent observers classified the healed prostatic apertures with great uniformity into one of four categories: (I) minimal change (lateral lobes still meet in midline throughout gland length) (N = 3); (II) minor aperture (opening less than 50% of cystoscopic field over less than 50% of gland length) (N = 5); (III) major aperture (opening more than 50% of cystoscopic field over more than 50% of gland length) (N = 11); and (IV) full ablation (nearly complete replacement of lobar configuration with a general concavity) (N = 5). Clinical outcomes (symptom scores, uroflow rates) matched with follow-up cystoscopic categories but not with any other readily identifiable measures. The four-category system proved to be simple, reproducible, and clinically relevant. If a standardized tissue aperture is the ultimate aim of new methods to ablate the prostate, the proposed system for classifying the aperture could have a considerable future application.

Aged↗