Clinical perception of disease probability associated with Bethesda System diagnoses.

The degree to which clinical perceptions of Papanicolaou smear sensitivity contribute to patient mismanagement is uncertain. A voluntary, anonymous questionnaire was mailed to 350 obstetricians/gynecologists (OGYNs) and 350 other primary care providers (PCPs) located in Pennsylvania or Ohio. The clinicians estimated the probability of no disease, dysplasia, and invasive carcinoma for 1 of 7 Bethesda System diagnoses. Differences in probability estimates between provider types and between the clinicians and medical literature data were measured. The response rate was 22.7%. Compared with published values, clinicians estimated similar disease probabilities for many diagnoses. However, for some diagnoses, the probability estimates differed considerably from published values (e.g., overestimation of dysplasia and invasive carcinoma for benign diagnoses and underestimation of dysplasia for some dysplasia diagnoses), and such errors could contribute to patient mismanagement. OGYNs generally were more accurate in probability estimates than PCPs. Methods to convey more accurately these diagnostic disease probabilities should be examined.

Hydroxyapatite femoral stems for total hip arthroplasty: 10- to 13-year followup.

Three hundred eighty hydroxyapatite-coated titanium alloy stems were implanted in a young and active patient population from 1987 through 1990. Within the population, 274 patients (314 hips) had a minimum 10-year and maximum 13-year followup. The average age of the population was 51 years. Thirty-seven percent of the population was 50 years or younger when operated on (average age, 39 years). Osteoarthritis was seen in 63.7% and avascular necrosis in 16.6% of patients. Fifty-four percent of patients were men. Clinically, these patients had early pain relief and rapid restoration of function. The Harris hip score averaged 92 points, and only 1.6% of patients had mild or moderate activity-related thigh pain. Radiographically, progressive remodeling occurred around the implants, 100% were bone stable, and no patient had endosteal distal osteolysis. Two patients had revision surgery for aseptic loosening: one at 2 years postoperative because of a nonunion of a concomitant subtrochanteric osteotomy and one at 9.5 years postoperative because of polyethylene wear and progressive osteolysis. The mechanical failure rate was 0.5%. The results show excellent lasting fixation of this tapered titanium alloy stem coated proximally with a thin, dense layer of hydroxyapatite. The stem has performed well in a young, active, high-risk population and in the hands of various surgeons.

The Frank Stinchfield Award: Morphologic features of the acetabulum and femur: anteversion angle and implant positioning.

Morphologic features of the hips, in particular those features germane to determination of acetabular and femoral anteversion angles and femoral head offset, were studied in 50 male and 50 female human skeletons with bilateral normal joints. Four distinct configurations were identified relative to the anterior acetabular ridge. The majority (121, 60.5%) were curved; 51 (25.5%) were angular; 19 (9.5%) were irregular; and nine (4.5%) were straight. The acetabular anteversion angle measured 19.9 degrees +/- 6.6 degrees (range, 7 degrees-42 degrees) and was significantly larger in females (21.3 degrees +/- 7.1 degrees) versus males (18.5 degrees +/- 5.8 degrees). The notch acetabular angle, which can be identified easily intraoperatively, was defined as the angle created at the intersection of a line from the sciatic notch along the posterior acetabular ridge and a line from the posterior to the anterior acetabular wall. This angle is almost perpendicular (89.0 degrees +/- 3.5 degrees) and, therefore, may provide an accurate estimate of acetabular anteversion during cup placement. Awareness of the anatomic differences between genders for acetabular anteversion angle, anterolateral bowing of the femur, and neck shaft angle may help reduce the relatively higher incidence of dislocation in females and may lead to different implant designs for male and female patients.

Cytologic features useful for distinguishing small cell from non-small cell carcinoma in bronchial brush and wash specimens.

One blinded observer (C.D.S.) retrospectively reviewed 76 previously diagnosed and biopsy-confirmed malignant bronchial brush and wash specimens, 46 non-small cell and 30 small cell carcinomas, obtained from 55 patients. Each case was scored for the presence or absence of 36 standard criteria (architectural, cytoplasmic, and nuclear). Logistic regression analysis was used to determine which criteria were most useful for separating small cell from non-small cell lesions. Although no single criterion displayed 100% sensitivity and specificity for small cell cancer, univariate statistical analysis indicated that 3 individual criteria (nuclear molding, finely granular or "salt and pepper" chromatin, and scant delicate cytoplasm) were more than 90% sensitive and specific in cases of small cell carcinoma. The presence of nuclear molding alone provided the best fit for the logistic regression model. When nuclear molding was present, the odds of a small cell diagnosis increased more than 300-fold. Nuclear molding, finely granular or salt and pepper chromatin, and scant, delicate cytoplasm are the 3 most sensitive and specific cytomorphologic features traditionally used to separate small cell from non-small cell carcinoma. Nuclear molding alone represents the most significant cytomorphologic feature for distinguishing between these malignant lesions.

Effect of clinical history on diagnostic accuracy in the cytologic interpretation of bronchial brush specimens.

There has been little study of the effect of clinical history on pathologic diagnostic accuracy. Five pathologists retrospectively examined 97 bronchial brush specimens with and without clinical historic information. Forty-nine patients had a biopsy-proven malignant lesion, and 48 had a benign lesion. Diagnostic accuracy with and without history for each pathologist was determined with likelihood ratios and receiver operating characteristic curves. The overall diagnostic accuracy with and without history was 0.84 and 0.76, respectively. The average negative predictive value of a benign diagnosis decreased from 89.2% (with history) to 74.0% (without history). Overall, the cytopathologists were more reluctant to make a definitive malignant diagnosis without history compared with history. The average positive predictive value of a malignant diagnosis with and without history was almost identical. The absence of history leads to lower diagnostic accuracy in the cytologic interpretation of bronchial brush specimens partly because pathologists underdiagnose malignant lesions.

Effect of low-friction ion-treated femoral heads on polyethylene wear rates.

Polyethylene wear is a major contributor to osteolysis and subsequent aseptic loosening of prosthetic components in total hip arthroplasty. Use of ion implantation as a surface modification to the metallic bearing component of orthopaedic implants may be an effective means of reducing wear debris at the bearing interface. In July 1991, low friction ion treated femoral heads were introduced. This study evaluates the effect of the low friction ion treated femoral head on polyethylene wear. Fifty-five total hip arthroplasties (53 patients) with low friction ion treated femoral heads followed up a minimum of 3 years were matched with 55 total hip arthroplasties (47 patients) without low friction ion treated femoral heads for the same postoperative period. Socket wear was evaluated radiographically. Case matching and strict inclusion criteria were used to control for known factors influencing polyethylene wear. These criteria included: (1) cases matched for gender and age within 2 years; (2) diagnosis limited to osteoarthritis or avascular necrosis of the femoral head only; (3) femoral head diameter limited to 26 or 28 mm only; (4) hydroxyapatite coated femoral stem of the same design and a metal backed socket of the one of two designs with the same polyethylene insert; and (5) minimum followup of 3 years. The linear wear rate of polyethylene was 0.161 +/- 0.095 mm per year in the group without the low friction ion treated heads and 0.116 +/- 0.101 mm per year in the low friction ion treated group. The volumetric wear rates were 74.5 +/- 44.3 mm3 per year for the group without the low friction ion treated heads and 57.8 +/- 51.1 mm3 per year for the low friction ion treated group. Assuming the sensitivity of these measurements can detect these small differences in wear accurately, these results suggest low friction ion treated prosthetic heads are useful in reducing polyethylene wear at 3-year minimum followup.

Fixation of acetabular cups without cement in total hip arthroplasty. A comparison of three different implant surfaces at a minimum duration of follow-up of five years.

We evaluated 377 patients (428 hips) who had been managed, by a total of fourteen surgeons at twelve clinical sites in the United States and Europe, with a porous-coated press-fit acetabular cup, a hydroxyapatite-coated threaded screw-in cup, or one of two similar designs of hydroxyapatite-coated press-fit cups between April 1987 and November 1992. The same type of hydroxyapatite-coated femoral stem was inserted without cement in all patients. After a minimum duration of follow-up of five years (mean, 7.9 years; range, 5.3 to 9.1 years), one (1 per cent) of the 131 hydroxyapatite-coated threaded cups, two (2 per cent) of the 109 porous-coated press-fit cups, and twenty-one (11 per cent) of the 188 hydroxyapatite-coated press-fit cups had been revised because of aseptic loosening. A common radiographic sign of impending failure of the hydroxyapatite-coated press-fit cups was radiolucency at the interface between the implant and the subchondral bone beneath it. This radiolucency usually was seen initially more than two years after implantation. Radiographic evaluation of the 383 acetabular implants that were in situ at the time of the most recent follow-up showed that 123 (99 per cent) of the 124 hydroxyapatite-coated threaded cups, 101 (98 per cent) of the 103 porous-coated cups, and 139 (89 per cent) of the 156 hydroxyapatite-coated press-fit cups were stable with osseous ingrowth (as indicated by the absence of radiolucency at the interface and the absence of migration within the acetabulum). The probability of revision due to aseptic loosening was significantly greater for the hydroxyapatite-coated press-fit cups than it was for the hydroxyapatite-coated threaded cups or the porous-coated press-fit cups (p < 0.001 for both comparisons). Within the group of patients who had a hydroxyapatite-coated press-fit cup, the probability of revision due to aseptic loosening was significantly greater in association with a young age (p = 0.003), female gender (p = 0.02), the use of a femoral head with a diameter of thirty-two millimeters (p = 0.018), and the use of a thin polyethylene liner (p < 0.001). We found that the hydroxyapatite-coated threaded cups and the porous-coated press-fit cups continued to perform well more than five years after the operation. The hydroxyapatite-coated press-fit cups that were revised probably failed because the fixation interface beneath the cup could not sustain the tensile stresses that were imposed between the cup and the bone by the activity of the patient. Our data suggest that, in the specific biomechanical environment of the acetabulum, physical interlocking between the cup and the supporting bone beneath it may be a prerequisite for long-term stability.

Hydroxyapatite in total hip arthroplasty. Clinical results and critical issues.

Surgeons who perform arthroplasties have posed some critical questions about hydroxyapatite. Does hydroxyapatite coating enhance bone ingrowth or ongrowth? Will hydroxyapatite lead to increased polyethylene wear or an increased incidence of osteolysis? Will the hydroxyapatite coating disappear, and if so, what will be left to maintain implant fixation? A multicenter study of 316 hips (282 patients) with a proximally hydroxyapatite coated stem and either a hydroxyapatite or porous coated cup were followed up 8.1 years (range, 5.6-9.9 years). The average patient age was 50 years (range, 16-81 years), and 61% of the patients were male. One (0.3%) stem, three (2.7%) porous coated cups, and 25 (11.9%) hydroxyapatite coated cups were revised for aseptic loosening. Disappointing results on the acetabular side indicate that substrate design is critical. There were no cases of intramedullary femoral osteolysis, and the incidence of acetabular and proximal femoral osteolysis- and polyethylene wear was no greater than that seen with other cementless or cemented components. Based on these clinical results and a critical review of the literature, it is concluded that hydroxyapatite coated hip components do enhance ingrowth or ongrowth with no increased incidence of osteolysis for as many as 10 years. Concern about the disappearance of the hydroxyapatite coating with time seems moot in light of the above clinical findings.

Hydroxyapatite coated implants. Total hip arthroplasty in the young patient and patients with avascular necrosis.

Two high risk groups for total hip arthroplasty, 136 patients (155 hips) younger than 50 years of age (average age, 38 years) and 44 patients (53 hips) with the diagnosis of avascular necrosis, have a minimum followup of 5 years and a mean followup of 6.8 years. The average Harris Hip Score at last followup totaled 93 and 90, respectively, and thigh pain was reported in 1.3% and 3.8%, respectively. All patients in both groups received the same hydroxyapatite coated femoral stem and the mechanical failure was 0%. No stem was revised for aseptic loosening, 100% of stems were bony stable by radiographic criteria, new bone formation was progressive about the femoral stem, and 0% endosteal lysis was found. The acetabular components had a mechanical failure rate of 10% and 7.5%, respectively, without osteolysis, and an additional 7% and 7.5% failure as a direct result of progressive osteolysis. The results with the porous press fit and hydroxyapatite threaded sockets were far superior to that of the smooth hydroxyapatite press fit sockets and socket failure was associated with thin polyethylene liners and the use of 32-mm head diameters. These findings show a high success rate with a nonporous hydroxyapatite coated titanium femoral stem. However, hydroxyapatite on a smooth acetabular component yielded less predictable results indicating that for long term fixation of the acetabulum an interlock of bone is preferred.

Hydroxyapatite-coated total hip femoral components in patients less than fifty years old. Clinical and radiographic results after five to eight years of follow-up.

One hundred and thirty-three patients (152 hips) who were an average of thirty-nine years old (range, sixteen to forty-nine years old) received a proximally hydroxyapatite-coated femoral prosthesis as part of a total hip arthroplasty and were followed for a minimum of five years (average, 6.4 years; range, five to 8.3 years) or until revision. The average Harris hip score was 47 points (range, 22 to 77 points) preoperatively and 93 points (range, 49 to 100 points) at the time of the latest clinical evaluation. Two patients who had a well fixed femoral implant had activity-limiting pain in the thigh at the time of the most recent examination. Radiographic changes consistent with bone-remodeling (cortical hypertrophy and bone condensation) typically were seen around the mid-part of the shaft of the prosthesis. Forty-eight (32 per cent) of the 148 hips that were included in the radiographic analysis demonstrated a small amount of erosive scalloping in either zone 1 or zone 7 of Gruen et al., and intramedullary osteolysis was suspected in only one hip. All stems were radiographically osseointegrated according to a modification of the criteria described by Engh et al. Four stems were revised, but none of the revisions were performed because of mechanical failure (two stems were revised in conjunction with a revision of the cup because of pain; one, because of an infection; and one, after a traumatic femoral fracture that occurred six years postoperatively). Thus, the rates of aseptic and mechanical failure were both 0 per cent. The combined rate of failure, which included the two stems that were revised because of pain and the two stems that were associated with pain that limited activity, was 2.6 per cent (four of 152 stems). The over-all clinical results associated with hydroxyapatite-coated femoral components were excellent in this group of young patients after intermediate-term follow-up. A review of serial radiographs showed mechanically stable implants with osseous ingrowth, evidence of stress transmission at the middle part of the stem, and minimum endosteal osteolysis.

Establishing a nurse-managed wellness clinic in a predominantly older African American inner-city high rise: an advanced practice nursing project.

With funding from a U.S. Department of Housing and Urban Development contract awarded to a private university, advanced practice nurse faculty established a nurse-managed wellness clinic in an apartment building populated by predominantly African American older people. Ethnographic methods were used to ensure culturally competent care. The clinic provided nursing, pharmacy, and health sciences faculty and students with community-focused clinical experiences as interdisciplinary team members.

The advanced practice nurse role in implementing and evaluating two nurse-managed wellness clinics: lessons learned about structure, process, and outcomes.

By the year 2000, the baby boom generation will be reaching its sixth decade and 34 million U.S. citizens will be over the age of 65. One strategy for promoting healthy aging is having older persons participate in health promotion programs. Nurse-managed wellness clinics (NMWCs) staffed by advanced practice nurses (APNs) offer an option for health promotion among older individuals. This article describes the APN role in implementing and evaluating two NMWCs for older people living in urban, high-rise apartment buildings subsidized by the U.S. Department of Housing and Urban Development. Lessons learned about structure, process, and outcomes in a community-based wellness center are identified and discussed.

Remodeling of bone around hydroxyapatite-coated femoral stems.

Two hundred and twenty-four total hip arthroplasties were performed in 201 patients with use of a femoral component with hydroxyapatite coating of the proximal portion of the stem. The mean duration of follow-up was seventy-one months (range, fifty-eight to eighty-seven months). Of the 224 arthroplasties, 208 (93 per cent; 190 patients) yielded a good or excellent clinical result. Four patients (2 per cent) reported mild-to-moderate activity-related pain in the thigh, and two (1 per cent) had aseptic loosening. The radiographic findings of progressive new-bone formation (cancellous condensation and cortical hypertrophy) throughout the zones adjacent to the middle and distal portions of the stem were evidence of early, extensive proximal fixation of the implant, with distal stress transfer through the implant, which is stiffer than the surrounding bone. Remodeling of the femur began early, was predictable, and progressed throughout the follow-up period. Cortical hypertrophy about the middle and distal portions of the stem occurred predominantly in the mediolateral plane (in 105 hips [47 per cent], compared with thirteen hips [6 per cent] in the anteroposterior plane), and it was more common in patients who had had poorer bone quality preoperatively. Intramedullary osteolysis was present in one femur (0.4 per cent) at five years; the osteolytic area was less than five millimeters in its greatest dimension and had not progressed at the time of the six-year follow-up evaluation. This low rate of osteolysis suggests that a circumferential coating of hydroxyapatite may effectively minimize migration of wear debris along the femoral stem. The progressive remodeling of the femur about the middle and distal portions of the stem, as evidenced by cancellous condensation and cortical hypertrophy, has not, to our knowledge, been described previously to this magnitude in association with proximally coated (porous or hydroxyapatite-coated) femoral implants.

Acetabular reconstruction in revision total hip arthroplasty.

Acetabular revision surgery is always associated with some degree of bone loss. Where an intact peripheral rim is present it can be used to achieve ingrowth and cementless prosthetic fixation. Where major segmental defects are present and prosthetic stability is not possible in host bone, structural allografts may be necessary to satisfy the principles of acetabular reconstruction. Using quality bone, proper fixation, and buttressing of structural allografts against host bone, a high degree of success can be expected. The majority of acetabular revisions can be reconstructed with large hemispherical sockets and adjuvant screw fixation and the use of bulk allografts should be reserved for those reconstructions where no good alternative exists.

Antihistamines reduce blood-retinal barrier permeability in type I (insulin-dependent) diabetic patients with nonproliferative retinopathy. A pilot study.

PURPOSE: To determine if histamine receptor stimulation mediates increased blood-retinal barrier (BRB) permeability in patients with diabetic retinopathy, as it does in experimental diabetes. METHODS: Fourteen patients with type I (insulin-dependent) diabetes and mild nonproliferative diabetic retinopathy were treated with combined astemizole, 20 mg, and ranitidine, 600 mg, or an identical placebo for 6 months in a double-masked fashion. Blood-retinal barrier permeability was measured by vitreous fluorometry at baseline and at 3 and 6 months. RESULTS: Permeability was significantly reduced in the group treated with antihistamines (P < 0.05) compared with the placebo group. There were no concomitant significant changes in systemic arterial blood pressure or HbA1c values. CONCLUSION: These pilot data suggest that histamine receptors influence permeability of the BRB in human diabetes. Further studies of the effects of antihistamines on diabetic retinopathy are warranted.

Recruitment and screening experience for a clinical trial involving tear concentrations of a new drug.

The process of recruitment and screening of volunteers for clinical research studies has not been thoroughly evaluated in the ophthalmic literature. The data for the current report were derived from a double-masked randomized clinical trial designed to evaluate and compare the effective tear level concentrations of three topical ophthalmic medications. Subjects were recruited from the general population and were healthy volunteers on no medications. Tear volume was measured by the Schirmer test with anesthesia; acceptable results were in the range of 10-25 mm/5 min. Study enrollment was limited to 32 subjects per week, with a total sample size goal of 320. The study population, 18-45 years of age, consisted primarily of white male college students. Nine hundred fifty-seven volunteers were recruited. Of the 498 of these subjects that reported for screening (52%), 459 (48%) were actually screened, and 320 (33%) were enrolled. The overall prevalence of an abnormal Schirmer test (< 10 or > 25 mm/5 min in either eye) in the screened population was 22%. The frequency of decreased tear production (13%) was slightly greater than that of increased tear production (9%). An abnormal Schirmer test was the primary reason for ineligibility. The completion rate for those enrolled was 96%. This type of information is valuable when designing a clinical trial, especially with regard to budgetary, time table, and sample size estimations.