Revision of the Sheehan total knee arthroplasty

The use of the Sheehan knee prosthesis extended from 1971 to 2002. It incorporated a semi-constrained hinge with intra-medullary stems cemented into the femur and tibia. While some authors have reported excellent short-term results, others have reported revision rates of up to 31% at 5–10 years. The aim of this study was to review the senior authors experience in revising these arthroplasties. We review 54 Sheehan total knee replacements and discuss the difficulties encountered during first and subsequent revisions and the often-complex reconstruction techniques used to overcome these.

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Résumé Lutilisation de la prothèse de genou de type Sheehan sest étendue de 1971 à 2002. Elle comportait une charnière semi-contrainte avec des tiges intra-médullaires cimentées dans le fémur et le tibia. Tandis que dexcellents résultats à court terme ont été rapportés par quelques auteurs, un taux de révision jusquà 31% à 5–10 ans a été rapporté par dautres. Le but de cette étude était examiner lexpérience de lauteur senior dans la révision des prothèses de Sheehan. Nous avons examiné 54 prothèses et discutons les difficultés rencontrées pendant larthroplastie initiale et les révisions ultérieures ainsi que les techniques souvent complexes de reconstruction utilisées pour les mener à bien.

     

Positive apical surgical margins after radical retropubic prostatectomy, truth or artefact?

OBJECTIVE: The significance of a positive apical surgical margin following radical retropubic prostatectomy has been the subject of controversy. We examined the hypothesis that a positive apical margin alone is not associated with an increased probability of biochemical relapse. MATERIAL AND METHODS: A total of 162 men underwent radical prostatectomy for clinically organ-confined disease between May 1990 and December 1998. The mean follow-up period was 55 months (minimum 24 months). The mean patient age was 60.8 years. Clinical staging was 67.9% T1 and 32.1% T2. The mean preoperative prostate-specific antigen level was 11.5 ng/ml, and the mean Gleason score was 5.8. RESULTS: Overall, 5/64 patients (7.8%) with negative surgical margins and 42/98 (42.9%) with at least one positive surgical margin had biochemical recurrence (p < 0.001). Seven of 25 patients (28%) with a solitary positive apical margin relapsed. A solitary apical positive margin was associated with a statistically significant higher risk of recurrence versus controls (p < 0.05). CONCLUSION: All patients with a positive surgical margin, including those with a solitary apical margin alone, are at significantly increased risk of biochemical failure.     

Lung heme oxygenase-1 is elevated in acute respiratory distress syndrome

OBJECTIVE: We aimed to quantify concentrations of inducible heme oxygenase (HO)-1 in the lungs of patients with acute respiratory distress syndrome (ARDS) and to investigate its role as a source of ferrous iron and as a signaling agent for iron regulation. Control of such processes by heme oxygenase has implications for the onset, progression, and resolution of ARDS. DESIGN: Retrospective analysis of archived samples. SETTING: Adult intensive care unit of a postgraduate teaching hospital. PATIENTS: Patients admitted to the adult intensive care unit who fulfilled the American-European Consensus Conference criteria for ARDS. INTERVENTIONS: Biochemical and immunohistochemical studies using bronchoalveolar lavage fluid or lung tissue were performed in patients with established ARDS and in those undergoing lung resection (controls). MEASUREMENTS AND MAIN RESULTS: Concentrations of heme oxygenase protein were significantly elevated in lung tissue (193.7 +/- 13.27 vs. 81.0 +/- 16.0%, p < .01) and in bronchoalveolar lavage fluid (2.4 x 10(5) vs. 1.4 x 10(5) densitometric units, p = .047) taken from patients with ARDS compared with controls. Concentrations of heme oxygenase protein in bronchoalveolar lavage fluid from patients with ARDS correlated positively and significantly with changes in the concentrations of ferritin (r = .697, p = .02) and the iron saturation of transferrin (r = .8, p = .014) but correlated negatively and significantly with concentrations of bleomycin-detectable (redox-active) iron (r = -.73, p = .031). Significantly elevated (p < .05) concentrations of heme oxygenase staining in cell types expressing this protein were detected in patients with ARDS, compared with concentrations in the same cells taken from controls undergoing lung resection. CONCLUSIONS: Heme oxygenase protein is elevated in the lungs of patients with ARDS and may contribute to the changes in iron mobilization, signaling, and regulation seen in this condition.     

Should patients with a pre-operative prostatespecific antigen greater than 15ng/ml be offered radical prostatectomy?

Background Patients with prostate cancer with a pre-operative prostate-specific antigen (PSA) τ;15ng/ml who undergo radical retropubic prostatectomy (RRP) generally do not have a good outcome, yet may have organ-confined cancer and should be offered the option of surgery. Aim To assess the outcome of patients who underwent RRP with a pre-operative PSA ≥ 15ng/ml. Methods Thirty-four patients, mean pre-operative PSA: 25.46ng/ml (15.03–76.6) and mean Gleason score: 6.4 (5–9) were assessed. Results Two groups were identified. Group I: 41% (14/34) have no biochemical recurrence to mean follow up of 58 months (30–106). Mean PSA: 18.8ng/ml (15.03–25.84). Mean Gleason score: 6.1 (5–7). Clinical stage: T1c in 80%. No patient had seminal vesicle or lymph node involvement. Group II: 59% (20/34) have biochemical recurrence or died (3) from their disease to mean follow up of 66 months (36–98). Mean PSA: 28.9ng/ml (15.28–76.6). Mean Gleason score: 6.7 (5–9). Clinical stage: T1c in 25%. Eleven patients had seminal vesicle (8) involvement or positive lymph nodes (3) or both (2). Conclusion RRP seems feasible in patients whose pre-operative PSA is between 15 and 25ng/ml with stage T1c, Gleason score ≤ 7 and negative lymph node frozen section.     

Photostimulator allowing independent control of rods and the three cone types

This report describes a second-generation photostimulator with four primary lights that allows independent control of the stimulation of the four receptor types in the human eye. The new design uses LEDs (with light levels controlled by eight drivers that include voltage-to-frequency converters that provide 1-micros pulses at frequencies up to 250 kHz), with four center channels being combined by use of a fiber optic assembly, and likewise for four surround channels. Four fiber optic bundles are merged into a single bundle whose output is fed into a spatial homogenizer terminated by a diffuser. An interference filter is sandwiched between each LED and the fiber optic bundle. Two camera lenses collimate light from the diffusers, one for center and one for surround. The center-surround field configuration is formed by a photometric cube with a mirrored ellipse on the hypotenuse. A field lens places images of the diffusers in the plane of an artificial pupil. The fields are highly uniform. Following alignment and calibration, the center and surround fields are indistinguishable. An observer calibration procedure, designed to compensate for prereceptoral filtering, is shown by calculation to correct also for normal observer receptoral spectral sensitivity variation. With the instrument calibrated for the individual observer, a peripherally fixated 200-ms 40% contrast rod center field pulse, highly conspicuous under dark adaptation, is invisible following light adaptation.