Simple arthrolysis for flexor rigidity of the proximal interphalangeal joint

The authors report 19 cases of simple arthrolysis of the proximal interphalangeal joint for flexion rigidity. Their cases were limited to isolated lesions of the joint without any flexor or extensor tendon involvement. The technique is described, and the importance of postoperative physical therapy is stressed. The results in these cases, in contrast with those in complicated cases of rigidity, are very satisfactory. The etiology is primarily sprains and dislocations of the proximal interphalangeal articulation, immobilized for too long a time in flexion (in the so-called "functional position").     

Free combined thin wrap-around flap with a second toe proximal interphalangeal joint transfer for reconstruction of the thumb

The combined thin wrap-around flap from the big toe and the proximal interphalangeal joint of the second toe is characterized by (1) a single vascularized joint, which is used to preserve the second toe with a free iliac bone graft, (2) a thin wrap-around flap, which allows the pulpal fatty tissue on the remaining bone of the big toe to be retained and accept a skin graft, (3) a wrap-around flap with a partial distal phalangeal bone, and (4) a microplate for firm fixation at the proximal bone union and early joint motion. The advantages of this method are (1) the cosmetic appearance is excellent with use of the thin wrap-around flap; (2) there is joint motion in the reconstructed thumb with strong pinch and vice pinch; (3) the vascularized joint with a microplate allows for early postoperative motion; (4) bone grafting from another donor site is unnecessary; (5) bone growth is possible in children with open epiphyses; and (6) the big and second toes are preserved with minimal donor-site morbidity. This method is indicated for thumb losses at a level distal to the metacarpophalangeal joint or at the level of the proximal phalanx.     

The doorstop procedure. A technique for treating unstable fracture dislocations of the proximal interphalangeal joint

The unstable fracture dislocation of the proximal interphalangeal joint remains a difficult injury to manage despite the availability of a wide variety of treatment options. We describe a simple alternative method of treatment called the doorstop procedure.     

Functional distal interphalangeal joint splinting for trigger finger in laborers: a review and cadaver investigation

This two-part study evaluates the efficacy of functional distal interphalangeal joint (DIP) splinting for the treatment of trigger finger. Thirty-one fingers from 21 meat packing plant workers were treated with DIP splinting. A single corticosteroid injection was offered if triggering was stage 4 or greater. All workers returned to work immediately. Eighty-one percent of the digits were treated successfully (mean follow-up: 1 year). Treatment failure correlated with duration of symptoms and stage of triggering but did not correlate with age, race, sex, disease in multiple digits, or prior treatment. For the second part of the study, the effect of DIP splinting on flexor digitorum profundus (FDP) tendon excursion was studied in 16 fingers from 4 fresh cadavers. Excursion decreased 4.8 mm for the Stax splint and 4.2 mm for the dorsal Alumafoam splint. We conclude that DIP splinting provides a reliable and functional means of treating work-related trigger finger without lost time from work. Our cadaver investigation supports our theory that DIP splinting significantly decreases FDP excursion.     

Studies on the surface and new joint capsule of McKee-Farrar prosthesis implanted for several years (author''s transl)

These studies are intended as a critical contribution to the question, wether the McKee-Farrar (MF) prosthesis, on account of its stronger friction and the consequences of this, as compared to other models, still has its justification or wether these "secundary" manifestations indicate that this prosthesis should be abandoned. Studies on primary and secundary alteration of the surface were carried out on exchanged MF prosthesis with the aid of the grid electron microscope. The signs of wear are clearly visible and can be differenciated from production artefacts. The movement and deposit of abraded particles into the new joint capsule was studied qualitatively and quantitatively with the aid of radioisotopes. All samples showed an increased accumulation of chrome in the tissues as compared to cobalt. There is no indication of significant damage. On the basis of the results of these studies and on account of the favourable personal experience from a surgical and clinical point of view -- particulary with reference to minimal preparation of the acetabulum and ready replacement, the MF prosthesis will continue to hold its place as the standard model for total prosthetic hip joint replacement.     

Long-term results of heart valve replacement with the Edwards Duromedics bileaflet prosthesis: a prospective ten-year clinical follow-up

OBJECTIVE: The Edwards Duromedics valve (Baxter Healthcare Corp., Edwards Division, Santa Ana, Calif.) was designed with a self-irrigating hinge mechanism to reduce thromboembolic complications. After good initial clinical results, distribution was suspended in 1988 after reports of valve fracture after 20,000 valves had been implanted. The manufacturer conducted extensive studies to improve the Edwards Duromedics and reintroduced a modified version, which is available as Edwards Tekna. The purpose of the study was the evaluation of long-term results of the original Edwards Duromedics that might be important for the current version, the Edwards Tekna valve. METHODS: A prospective clinical 10-year follow-up was performed of 508 patients who underwent valve replacement with the Edwards Duromedics valve in the aortic (n = 268), mitral (n = 183), and aortic and mitral (n = 56) position. RESULTS: The perioperative mortality rate was 6.9%; follow-up was 98% complete, comprising 3648 patient-years for a mean follow-up of 86 months (range: 33 to 144 months). The actuarial freedom from complications at the 10-year follow-up and the incidence rate (percent per patient-year) were as follows: late mortality rate, 69.2% +/- 2.4% (3.5% per patient-year); thromboembolism, 90.7% +/- 1.6% (0.96% per patient-year); anticoagulation-related hemorrhage, 87.7% +/- 1.7% (1.34% per patient-year); prosthetic valve endocarditis, 96.7% +/- 0.09% (0.38% per patient-year); valve-related mortality rate, 89.3% +/- 1.6% (1.21% per patient-year); valve failure, 86.2% +/- 1.85% (1.54% per patient-year); and valve-related morbidity and mortality rate, 71.1% +/- 2.3% (3.2% per patient-year). Three leaflet escapes were observed (one lethal, two successful reoperations; 99.1% +/- 0.05% freedom, 0.08% per patient-year). All patients functionally improved (86% in New York Heart Association classes I and II), and incidence of anemia was insignificant. CONCLUSIONS: These results confirm that the Edwards Duromedics valve shows excellent performance concerning thromboembolism, hemolysis, and functional improvement and will serve as a reference for the last version, the Edwards Tekna valve, where comparable long-term data are currently not available.     

Statistics of total knee replacement: partial and total knee replacement, design St. Georg: a review of a 4-year observation

Since 1969, we have used 2 different types of knee prostheses to reconstruct arthritic knees. The surface replacement prosthesis (sledge) is indicated where ligamentous stability is present and angular deformity is not severe. In addition, the sledge prosthesis may be implanted with good results in selected acute comminuted tibial plateau fractures. The total hinged prosthesis of metal design is recommended in knees which are severely deformed, and unstable, and therefore not suitable for the sledge prosthesis. Marked relief of pain was the most significant result in our patients. Residual knee pain was most frequently due to patello-femoral pain and, when severe, this was satisfactorily controlled by performing a patellectomy. Motion was usually maintained at the preoperative range or improved, mainly by reducing or eliminating the knee flexion contracture. In a high percentage, the unicompartmental sledge prosthesis has given excellent results. However, we tend to insert a bi-compartmental sledge prosthesis because experience has shown that even slight damage of the articular surfaces of the opposite side is likely to further deteriorate rapidly. Although a significant number of complications occurred, these have been minimized by further conservative and operative treatment. We anticipate a further reduction in complications based on our initial experience, and prosthetic revisions.     

Further evidence for the validity of assessment center dimensions: A meta-analysis of the incremental criterion-related validity of dimension ratings.

This study investigates the incremental variance in job performance explained by assessment center (AC) dimensions over and above personality and cognitive ability. The authors extend previous research by using meta-analysis to examine the relationships between AC dimensions, personality, cognitive ability, and job performance. The results indicate that the 7 summary AC dimensions postulated by W. Arthur, Jr., E. A. Day, T. L. McNelly, & P. S. Edens (2003) are distinguishable from popular individual difference constructs and explain a sizeable proportion of variance in job performance beyond cognitive ability and personality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Speaking clearly for the hard of hearing IV: Further studies of the role of speaking rate

The contribution of reduced speaking rate to the intelligibility of "clear" speech (Picheny, Durlach, & Braida, 1985) was evaluated by adjusting the durations of speech segments (a) via nonuniform signal time-scaling, (b) by deleting and inserting pauses, and (c) by eliciting materials from a professional speaker at a wide range of speaking rates. Key words in clearly spoken nonsense sentences were substantially more intelligible than those spoken conversationally (15 points) when presented in quiet for listeners with sensorineural impairments and when presented in a noise background to listeners with normal hearing. Repeated presentation of conversational materials also improved scores (6 points). However, degradations introduced by segment-by-segment time-scaling rendered this time-scaling technique problematic as a means of converting speaking styles. Scores for key words excised from these materials and presented in isolation generally exhibited the same trends as in sentence contexts. Manipulation of pause structure reduced scores both when additional pauses were introduced into conversational sentences and when pauses were deleted from clear sentences. Key-word scores for materials produced by a professional talker were inversely correlated with speaking rate, but conversational rate scores did not approach those of clear speech for other talkers. In all experiments, listeners with normal hearing exposed to flat-spectrum background noise performed similarly to listeners with hearing loss.     

Anisotropic plastic potentials for polycrystals and application to the design of optimum blank shapes in sheet forming

Recently, some potentials were proposed to analytically describe the plastic behavior of orthotropic metals. These potentials, when expressed in six-dimensional stress space, were called yield functions or, when expressed in six-dimensional strain-rate space, were called strain-rate potentials. It was shown that these phenomenological potentials provide good approximations of the plastic potentials calculated with polycrystal models. They can be used for any type of loading condition, and they can account for orthotropic anisotropy. In a parallel effort, called ideal forming theory, a forming design theory that optimizes processes and initial blank shapes in sheet forming was developed. This ideal forming theory was implemented in a finite element modeling code in order to design the blank shape directly from the final part shape. The main input to this model includes the final part geometry and the constitutive behavior of the material. In the present article, the constitutive equations describing the plastic behavior of metals as well as the main features of the ideal forming theory are briefly summarized. Then, application of the strain-rate potential to the design of a blank shape for a circular cup drawn from an anisotropic Al-Li sheet is presented. It is shown that the design code efficiently predicts the shape of the blank needed to obtain a cup with minimal earing from a highly anisotropic material.     

Applying epidemiological principles to ergonomics: a checklist for incorporating sound design and interpretation of studies

A radiologic and tomographic study was made of the cranioencephalic topography of canary goats of medium weight and size. In a first step, the exocranialis references corresponding to an axis designed at the level of the meatus acusticus externus and parallel to the basicranial axis were anatomically and radiologically defined. Conventional stereotaxic techniques were then used to reach the standard position of the head in order to obtain macroscopical cross sections at different levels perpendicular to the base of the cranium. In a second step, a tomographic study was made to confirm the design of the axis.     

Rational design of a functional metalloenzyme: introduction of a site for manganese binding and oxidation into a heme peroxidase

The design of a series of functionally active models for manganese peroxidase (MnP) is described. Artificial metal binding sites were created near the heme of cytochrome c peroxidase (CCP) such that one of the heme propionates could serve as a metal ligand. At least two of these designs, MP6.1 and MP6.8, bind Mn2+ with Kd congruent with 0.2 mM, react with H2O2 to form stable ferryl heme species, and catalyze the steady-state oxidation of Mn2+ at enhanced rates relative to WT CCP. The kinetic parameters for this activity vary considerably in the presence of various dicarboxylic acid chelators, suggesting that the similar features displayed by native MnP are largely intrinsic to the manganese oxidation reaction rather than due to a specific interaction between the chelator and enzyme. Analysis of pre-steady-state data shows that electron transfer from Mn2+ to both the Trp-191 radical and the ferryl heme center of compound ES is enhanced by the metal site mutations, with transfer to the ferryl center showing the greatest stimulation. These properties are perplexingly similar to those reported for an alternate model for this site (1), despite rather distinct features of the two designs. Finally, we have determined the crystal structure at 1.9 A of one of our designs, MP6.8, in the presence of MnSO4. A weakly occupied metal at the designed site appears to coordinate two of the proposed ligands, Asp-45 and the heme 7-propionate. Paramagnetic nuclear magnetic resonance spectra also suggest that Mn2+ is interacting with the heme 7-propionate in MP6.8. The structure provides a basis for understanding the similar results of Yeung et al. (1), and suggests improvements for future designs.     

Frog chromaffin and adrenocortical cell co-cultures: a model for the study of medullary control of corticosteroidogenesis

Phylogenetic, physiological and morphological evidence indicates that interactions between chromaffin and adrenocortical cells are involved in the differentiation and maintenance of function of both cell types. Chromaffin-adrenocortical interaction has become recognized as an important component of adrenocortical regulation; however, the mechanisms by which chromaffin cells modulate adrenocortical function are not well understood. To study directly chromaffin-adrenocortical cellular interactions, we developed primary frog (Rana pipiens) adrenal co-cultures. In these co-cultures, chromaffin cells extend processes that project towards or onto adrenocortical cells, mimicking their organization in vivo and indicating a potential for interaction between the two cell types. Cell survival and differentiation were optimized using a combination of NGF, FGF and histamine to enhance neurite outgrowth and fetal calf serum plus 10(-10) M ACTH to maintain steroidogenesis. Characterization of the cells by immunocytochemistry and histochemistry showed that chromaffin cells maintain expression of catecholamine biosynthetic enzymes and that adrenocortical cells maintain expression of steroidogenic enzymes. Furthermore, chromaffin cells release catecholamines upon stimulation with carbamylcholine or potassium while adrenocortical cells sustain a basal secretion rate of aldosterone and corticosterone that is augmented 10-40-fold by 0.1 nM to 10 nM ACTH. We therefore propose that these co-cultures serve as a useful model system to study the cellular and molecular mechanisms by which chromaffin cells modulate adrenocortical cell function.