Femoral impaction bone grafting with the Exeter stem - the Swedish experience: survivorship analysis of 1305 revisions performed between 1989 and 2002.

We identified 1305 femoral impaction bone grafting revisions using the Exeter stem performed between 1989 and 2002 in 30 hospitals throughout Sweden. There were 1188 patients with a mean age of 71 years (29 to 94) followed up for between five and 18 years. The participating departments reported 70 further revisions in total, of which 57 could also be identified on the Swedish National Arthroplasty Registry. Kaplan-Meier survivorship for all causes of failure was 94.0% (95% confidence interval (CI) 92 to 96) for women and 94.7% (95% CI, 92 to 96) for men at 15 years. Survivorship at 15 years for aseptic loosening was 99.1% (95% CI 98.4 to 99.5), for infection 98.6% (95% CI 97.6 to 99.2), for subsidence 99.0% (95% CI 98.2 to 99.4) and for fracture 98.7% (95% CI 97.9 to 99.2) Statistically significant predictors of failure were the year in which revision was conducted (p < 0.001). The number of previous revisions was slightly above the level of significance (p = 0.056). Age, gender, the length of the stem and previous septic loosening were not predictors of failure (p = 0.213, p = 0.399, p = 0.337, p = 0.687, respectively). The difference in survivorship between high- and low-volume departments was only 3% at ten years. We conclude that impaction bone grafting with the Exeter stem has an excellent long-term survivorship following revision arthroplasty. The technique of impaction grafting appears to be reliable, can be learned rapidly and produces a predictably low incidence of aseptic loosening.

Patient expectation and satisfaction in revision total hip arthroplasty.

Sixty-six consecutive revision total hip arthroplasty patients were asked about their expectations regarding future pain and walking ability. Expectations were high, regardless of background factors: 92% expected to have much less pain, and 82% expected the same walking ability as after the primary arthroplasty or a much improved walking ability. Of the patients, 56% stated a non-surgeon-related origin of expectations, 7% were uncertain, and 37% said expectations derived from the surgeon. At 1 year, Harris hip score had increased from a median 45 to 77 points, but only 69% and 55% said that their expectations had been fulfilled to a very large or rather large extent regarding pain and walking ability. The only predictor of fulfilled expectations was absence of complications (odds ratio, 4.8; 95% confidence interval, 1.1-20.8). Patient satisfaction was only moderate; 63% were very or rather satisfied with a moderate correlation (0.46-0.47) between satisfaction and fulfilled expectations. Patients with a poor preoperative hip condition generally were more satisfied (odds ratio, 5.0; 95% confidence interval, 1.4-17.9), and the most important reason probably was an improved walking ability (r = 0.64). Patient dissatisfaction may originate from unrealistic expectations. At preoperative consultation, it is recommended that the surgeon discuss the revision patient's expectations, especially regarding future walking ability, and inform the patient about the fundamental prognostic differences between revision and primary hip arthroplasty.

Ultrasound for diagnosis of infection in revision total hip arthroplasty.

Eighty consecutive patients (85 hips; 43 women; median age, 74 years [range, 33-90 years]) underwent a revision total hip arthroplasty. Preoperatively and guided by ultrasound, biopsy specimens of the joint pseudocapsule were taken, and joint fluid was aspirated for culture. Capsule morphology was investigated with light microscopy. When septic loosening was defined as 2 intraoperative cultures yielding the same microorganism, the prevalence was 12%. Sensitivity of the capsule biopsy cultures was 67%; specificity, 68%; positive predictive value, 22%; and negative predictive value, 94%. Joint fluid was often sparse and always falsely sterile. One specimen from a hip with septic loosening showed histologic changes (> or =3 foci, each with > or =3 plasma cells/high-power field) consistent with chronic infection. The remaining 8 septic loosenings eluded histologic detection, yielding 11% sensitivity. All aseptic loosenings were classified correctly (specificity 100%). Positive and negative predictive values were 100% and 89%. Ultrasound-guided aspiration and capsule biopsy with cultures and histology does not seem to be sufficiently accurate in the preoperative diagnosis of infected total hip arthroplasty.

Early loosening of the stemmed McMinn cup.

The stemmed McMinn cup was used in 26 acetabular reconstructions (median age, 59 [range, 33-85 years]; 21 women) at 5 orthopaedic centers in Sweden between 1995 and 1998. Of the patients, 24 (92%) had severe bone defects (Gustilo-Pasternak grade 3 and 4). At a clinical and radiographic follow-up of median 3 years (range, 1-5 years), 4 (17%) cups were rerevised at 1 (2 cups), 2, and 3 years owing to symptomatic aseptic loosening. Another 8 cups (40%) were radiographically definitely loose and 1 (5%) was probably so. With an overall mechanical failure rate (rerevised plus definitely loose devices) of 43.8% at a minimum 3-year follow-up, the stemmed McMinn cup does not seem to be a reliable solution in acetabular reconstruction.

Revision total hip arthroplasty using third-generation cementing technique.

A total of 83 consecutive first-revision total hip arthroplasties were performed in 83 patients using pressurized vacuum-mixed cement, a third-generation cementing technique. At a median follow-up of 3.6 years (range, 1.5-6.3 years), the overall failure rates (radiographic loosening, re-revision, or both) were 39% for the femoral components and 30% for the acetabular components. With definite radiographic loosening as an endpoint, the cement-bone interface achieved was the only significant factor to predict stem durability, with an adjusted odds ratio of 1.8 (95% confidence interval, 1.1-3.0). On the acetabular side, bone stock was the only significant factor, with an adjusted odds ratio of 5.3 (95% confidence interval, 4.0-27.7). In this retrospective cohort study, femoral cement pressurization per se did not appear to improve the results over those of other studies using second-generation techniques.

Backscattering cross section of a rigid biconic reflector.

Plane wave incidence on a rigid biconic target is considered. A biconic reflector consists of two cones truncated by planes perpendicular to their axes and joined at their smaller flat faces. The cone angles are allowed to be variable, provided their sum is equal to 90 degrees. The backscattering cross section is expressed in terms of a surface integral of the geometrical acoustics field, which results from incident singly and doubly reflected rays. A saddle-point calculation gives a first-order high-frequency approximation in which the backscattering cross section is proportional to the incident wave number and a function of the angle of incidence, cone angles, and inner and outer radii of the truncated cones. This expression is algebraically complex but easy to implement numerically. Results are presented that exercise the parameters of the problem. An interesting result of the solution is that for fixed outer radii there is a nonzero optimum inner radius for backscattering strength. For broadside incidence on 45 degrees cones with equal outer radii, this optimum value is approximately equal to 11% of the outer radius.

Metabolism of (-) deprenyl to amphetamine and methamphetamine may be responsible for deprenyl's therapeutic benefit: a biochemical assessment.

The urinary excretion of some important phenylethylamines, catecholamines, their metabolites, amphetamine, and methamphetamine were measured in parkinsonian patients on Sinemet (L-dopa plus carbidopa, a peripheral dopadecarboxylase inhibitor) and depressed patients after chronic (-) deprenyl treatment. Deprenyl was efficiently metabolized to amphetamine and methamphetamine. It increased the excretion of phenylethylamine and of m- and p-tyramine, and reduced the output of norepinephrine metabolites, but failed to alter the excretion of dopamine-deaminated metabolites. These changes were attributed more to amphetamine and methamphetamine than to inhibition of monoamine oxidase type B. Sinemet treatment alone increased the excretion of dopamine, 3-methoxytyramine, and their respective deaminated metabolites, 3, 4-dihydroxyphenylacetic acid and homovanillic acid. It is concluded that conversion of deprenyl to amphetamine and methamphetamine may contribute to some of the therapeutic benefits of deprenyl.

Prolactin secretion in Parkinson disease.

We studied the dopaminergic control of lactotroph cells in the anterior pituitary of parkinsonian patients and age-matched normal subjects. The resting levels of prolactin and the TRH-induced rise in prolactin were normal in Parkinson disease. Levodopa elicited a normal suppression of prolactin concentrations in parkinsonian subjects; the major abnormality to emerge was attenuation of the response to thyrotropin-releasing hormone (TRH) in the parkinsonian patients following administration of Sinemet (levodopa plus carbidopa) or bromocriptine. These findings imply pathology of extrastriatal dopamine systems in Parkinson disease. Since the addition of carbidopa enhanced the suppression of prolactin induced by levodopa, exogenous levodopa probably acts predominantly through the formation of dopamine in the hypothalamus, but inside the blood-brain barrier, rather than as a direct effect of circulating dopamine on the anterior pituitary or areas of the hypothalamus outside the blood-brain barrier.

Erythromelalgia-like eruption in parkinsonian patients treated with bromocriptine.

In a previous report about the chronic use of bromocriptine in Parkinson disease, a distinctive cutaneous eruption was noted and termed "erythromelalgia." This eruption has occurred in 9 of 110 patients on chronic bromocriptine therapy; histopathologic examination in 3 patients showed a prominent perivascular lymphocytic infiltration and perivascular edema of the dermis, without frank vasculitis. This is a reversible unwanted effect of bromocriptine therapy.

Absorption of levodopa after rectal administration.

Absorption of levodopa was studied after administration by mouth and rectum. Given by mouth, levodopa benefited all 12 patients studied, and levodopa blood levels rose significantly (p less than 0.01). When it was given rectally, there was no rise in levodopa concentration in the blood and no clinical benefit. Rectally administered levodopa is therefore of no value in the management of postoperative parkinsonian patients who cannot take oral medication.

Deprenyl in Parkinson disease.

(-)Deprenyl, a specific monoamine oxidase subtype B inhibitor (MAOI-B), has been reported to be a safe and valuable adjunct to conventional treatment of parkinsonism. A double-blind, clinical comparison of (-)deprenyl with placebo was undertaken in 11 parkinsonian patients; the efficacy of 10 mg daily was studied over 4 weeks. In four cases the clinical score for parkinsonian deficits improved during deprenyl therapy, and in five it deteriorated; there was no change in one patient. Two subjects failed to complete the study. (-)Deprenyl induced euphoria and insomnia. It was concluded that any advantages deriving from the use of (-)deprenyl in parkinsonism are limited, and probably dominated by its elevation of mood. Biochemical analysis failed to reveal any significant increase in platelet or plasma catecholamine concentrations during deprenyl therapy. There was, however, a significant decrease in plasma epinephrine (p < 0.05) and platelet MAO activity (p < 0.005).

Effect of an opiate antagonist on movement disorders.

Animal experiments suggest that opiate peptides might play a role in extrapyramidal function. This hypothesis was tested by administering the opiate antagonist, naltrexone, in doses sufficient to antagonize exogenous opiates, to patients with parkinsonism and Huntington's disease. No improvement in the clinical features of either disorder was noted.

Muscle fiber-type disproportion. Report of a family with symptomatic and asymptomatic members.

Two members of a family have slowly progressing proximal muscle weakness starting from ages 2 and 6 years. Muscle biopsy specimens from these patients, as well as two other asymptomatic members of the same family, demonstrate predominance of type I fibers (without fiber-type grouping) and minimally enlarged type II fibers. In all four cases there was an increase in serum creatine phosphokinase levels, but electromyographic studies were normal. To our knowledge, this family represents a previously undescribed syndrome of type I muscle fiber predominance without a history of "floppy" babies and includes asymptomatic members with similar pathologic changes.

Ergot derivatives for Parkinsonism.

The response of Parkinsonism to three ergot derivatives which modify dopaminergic transmission was studied. CF 25-397 behaved more as an antagonist than an agonist. Lergotrile was an agonist with therapeutic properties marred by prominent hepatotoxicity. Bromocriptine is an effective anti-Parkinsonian agent, particularly useful in patients with prominent dyskinesia or "on-off" reactions to levodopa; in most patients optimal results have been obtained by combining from 40 to 90 mg of bromocriptine daily with approximately 60% of the previous maximal dose of levodopa. Unfortunately, only some 50% of patients tolerate long-term bromocriptine therapy, but all adverse reactions have been dose dependent and reversible.