Long-term follow-up in a single-bundle arthroscopic acromioclavicular joint reconstruction after Rockwood III to VI dislocation.

This retrospective study presents the clinical and radiographic results of a single-bundle arthroscopic acromioclavicular joint reconstruction in 45 patients with a mean follow-up of 4.8 years. Patients with a Rockwood grade III or higher were included. Clinical results were based on satisfaction, pain and functional scores. These outcome scores were compared to coracoclavicular distance measurement on X-ray. Secondly, clinical outcome scores were compared between patients who had surgery in the first 6 weeks after trauma and patients treated after 6 weeks. Overall, X-ray showed a good reduction in 71.1% of the patients (less than 50% loss of reduction). These patients showed better clinical results than patients with radiographical failure in terms of satisfaction (p = .001), Constant (p = .001), DASH (p = .031) and SPADI (p = .005) scores. In total, 78% of the patient had surgery in the first 6 weeks after trauma. When treated later (mean time to surgery of 8.8 months), patients showed worse results for satisfaction (p = .003) and DASH score (p = .006), suggesting that treatment of chronic cases might warrant additional fixation techniques. As a conclusion, these results showed that, in the acute approach, single-bundle arthroscopic coracoclavicular fixation is a good treatment in acromioclavicular joint dislocation Rockwood grade III or higher.

Proximal row carpectomy versus four-corner arthrodesis in the treatment of SLAC and SNAC wrist: meta-analysis and literature review.

A systematic literature review was performed on 84 articles from 2000 to 2020 on proximal row carpectomy (PRC) or four-corner arthrodesis (FCA) in patients with posttraumatic wrist osteoarthritis. Qualitative assessment was conducted on 14 articles. Pain, range of motion (ROM), grip strength and complications were analyzed using weighted average means. Meta-analysis with a random effects model was performed for the flexion-extension arc and grip strength. A total of 1,066 PRCs and 2,771 FCAs were analyzed, with a mean follow-up of 9 and 7 years respectively. Mean flexion after PRC and FCA respectively was 36.2 ° and 31.1 °, mean extension 41.4 ° and 32.4 °, and mean grip strength 26.4 kg and 27.5 kg. PRC had a larger flexion-extension arc than FCA, with a standard mean difference (SMD) of 0.41 (range, 0.02-0.81). No significant difference was found for grip strength. Osteoarthritis occurred in 42.2% of PRC cases, independently of capitate shape. Conversion to wrist arthrodesis was performed in 10.1% of failed PRCs. Revision was chosen in 4.7% of FCAs and conversion to wrist arthrodesis in 4.6%. We conclude that the functional results of both techniques are similar, but prefer PRC to FCA because of the lower complications rate.

Keratinization of middle ear cholesteatomas. II. A histochemical study of epidermal transglutaminase substrates.

A histochemical study was performed to clarify further the role played by epidermal transglutaminase (ETgase) in the keratinization of aural cholesteatoma. Weakly and strongly keratinized epidermal tissues and healthy middle ear mucosa were included as references. A first assay revealed the distribution of non-specified acyl donor substrates. In a second assay, the topography of involucrin was assessed immunohistochemically. In both epidermal and cholesteatoma matrix tissues, the presence of acyl donors was not restricted to the sites of (E)Tgase activity, but was almost uniformly extended throughout living layers. In reference tissues, residual acyl donors were poorly detected in horny layers, while they were more abundant in the stratum corneum of the cholesteatomas studied. The presence of involucrin along the cell membrane was observed at varying distances throughout the spinous and granular layers, depending upon the epidermal and matrix configurations. In thick epithelia, involucrin rapidly became concentrated at the cell periphery (in spinous keratinocytes), while in thin epithelia it was usually associated with cell flattening. This latter staining profile was observed more frequently in cholesteatomatous tissues. In addition, we regularly noticed an immediately suprabasal accumulation of involucrin, suggesting a locally hyperproliferative state of the matrix. An insufficient availability of acyl donors, especially involucrin, could not be used to explain the defective ETgase-mediated cross-linking of cholesteatoma cell membranes during terminal stages of differentiation. The present investigation may be the first to demonstrate the presence of involucrin in middle ear mucosa.

Differentiation of nuclei during keratinization in middle ear cholesteatoma. DNA cytophotometry completed by computerized image analysis.

Quantitative DNA cytophotometric techniques were applied to judge the alteration (differentiation) and ultimate fate of nuclei during keratinization in human middle ear cholesteatoma. Compared with a healthy epidermis, a tendency towards postponed nuclear degradation was noticed. Two patterns governing the loss of DNA are recognized. In one group, the mean nuclear DNA content declines continuously, starting in the nearest suprabasal layers and continuing throughout the prickle and granular cell stages, where the ultimate degeneration of nuclei takes place. This pathway corresponds to that observed in epidermis, but evolves more slowly. In another group of samples, the onset of the DNA decline is delayed to the upper prickle cells, exceptionally to more terminal stages of keratinization. During matrix keratinization, a profound nuclear remodelling takes place, similar to that in epidermal tissues, as far as eu- and heterchromatin DNA and area data are concerned. However, euchromatinization of nuclei in matrix prickle cells is more pronounced than in epidermal tissues. The topography of residual heterochromatic clumps does not reflect a persistent margination as in epidermal nuclei, but is the result of more individualized rearrangements. The changes in karyotype are less elaborate when the complete decline of the nuclear DNA content only occurs during terminal keratinization.

Nuclear differentiation and ultimate fate during epidermal keratinization. Two-wavelength and cytofluorometric DNA investigations completed by computerized scanning image analysis.

Quantitative DNA cytophotometric investigations were performed to clarify some aspects of the differentiation and fate of nuclei in bovine snout and human epidermis representing various sites and different degrees of keratinization. We elaborated optimal conditions for hydrolysis and Feulgen staining. Diverse cytophotometric techniques, including computerized scanning cytophotometry and image analysis were applied. This approach provided the first quantitative data concerning changes of nucleotype during soft keratinization. Cytophotometric DNA measurements provide evidence for a continuous decline of nuclear DNA content from immediately beyond the basal layer to the transition zone. The overall loss of DNA is an orderly process that intensifies gradually and culminates in the stratum granulosum. Gradual nuclear degeneration, however, is not a general phenomenon, and a significant number of nuclei retains a DNA content within the diploid limits throughout the entire stratum spinosum and part of the stratum granulosum. At any level of differentiation or decay, residual nucleoprotein complexes remain intact, as judged from their resistance to acid hydrolysis. Karyological features change completely during keratinization. Basal cell nuclei are rather compact, ellipsoid and heterochromatic. Beyond the basal layer, nuclei enlarge, round up and obviously evolve to an extremely euchromatic state, with preferential localization of the dispersed heterochromatic clumps at the more peripheral sites. In the upper stratum spinosum, nuclei undergo even more drastic changes: nuclear area and volume shrink, nuclei partially regain the ellipsoid shape and revert to heterochromasia. Nevertheless, euchromatin remains the major constituent of decaying nuclei. Terminal differentiation stages, except in human sole, are marked by heterochromatin clumping. In human sole, persistence or even progression of heterochromatin dispersion is observed. Heterochromatic dots are situated along the nuclear membrane in human terminal keratinocytes, but are almost randomly distributed in bovine stratum granulosum nuclei. Finally, nuclear contrast analysis partially reveals statistically significant changes throughout keratinization.

A quantitative histochemical study of sulphydryl and disulphide content during normal epidermal keratinization.

A quantitative histochemical study was carried out on the distribution of protein thiol and disulphide groups in normal human plantar epidermal tissue. Histochemical demonstration of reactive groups was achieved by addition of N-(4-aminophenyl) maleimide, subsequent diazotization and final coupling with a Nitro Red or chromotropic acid label as first described by Sippel. The quantitative reliability of the method was tested by absorption cytophotometry, and evaluated on the basis of the internal consistency of the results reported. Our histological observations and histophotometric data support accepted views on epidermal keratinization. A limited, though reproducible, amount of disulphide bonds was observed near the basement membrane. The free thiol concentration in basal and prickle cells was low and almost constant, but was higher in the granular cells, where deposition of sulphur-containing proteins on cell membranes is initiated. In Malpighian layers, disulphide cross-links only occurred just beneath the transition zone in thickened cell membranes. The staining pattern of the inner stratum corneum resembled a mosaic and was characterized by a Sharp rise of the disulphide content, which exceeded the decrease in free thiol groups. The free thiol concentration decreased further throughout the cornified layers whilst the disulphide content remained fairly constant. Staining of thiol and disulphide groups together corresponded, within the limits of the standard error, to the sum of the thiol and disulphide concentrations when they were assayed separately in living ahd horny cells. These results confirm that living cells are the main site of free thiol groups, while horny cells are the most prominent of site of disulphide cross-links.

Quantitative determination of free thiol and disulphide groups by a fluorescent maleimide procedure.

To determine the quantitative reliability of thiol histofluorometry, the distribution of protein thiol and disulphide groups was reinvestigated in normal human epidermis, labelled with DACM-3 after cryocutting. Microscopical observations roughly confirmed, that living keratinocytes and inner stratum corneum are the main sites of free thiol groups, while disulphide crosslinks are almost exclusively found in cornified cells. Histofluorometric quantitation led to free--SH, --S--S-- or combined --SH and --S--S-profiles through the different strata, that were not compatible with previous absorption-histophotometric studies and lacked internal consistency. The difficulties reside mainly at the methodological level and may partially be resolved--at least in keratinocytes--by extraction of nonstructural SH-groups in a prerinsing step. Permanent mounting further contribute to the realization of normal fluorescence behaviour, as visualized by the decay curves. DACM-saturation of structural protein reactive groups was only reached after prolonged staining.

Structural and topological studies of cholesteatoma proteins, in relation to the keratinization process.

For the extraction of soft keratins from bovine snout or human epidermis the best results were obtained with a detergent (sodium dodecyl sulphate, SDS) or hydrogen bond breaking agent (urea) in a reducing medium (2-mercaptoethanol, 2-ME). N-acetylcysteine was a little less effective. Keratins from both sources gave typical sets of protein bands with molecular weights between 40.000 and 70.000 daltons. Upon electrofocusing special precautions had to be taken to avoid reoxidation and reaggregation of protein subunits. Keratins from aural cholesteatomas were obtained by extraction with SDA and 2-ME, with N-acetylcysteine alone and to a lesser extent with urea and 2-ME. The pattern of these keratins on SDS-gel is less complicated than that obtained from human skin or bovine snout. Histophotometric results argue for a clear analogy between the nuclear DNA metabolism in normal skin epidermis and cholesteatoma matrix. The only differences of potential relevance are the much wider range of the nuclear DNA amount in cholesteatoma stratum basale cells compared with basal cells in normal epidermis, and the higher persistence of nuclear DNA in cholesteatoma stratum granulosum, indicating postponement of keratinocyte terminal differentiation.