Kenji Tsunoda

Radial wedge osteotomy for Kienböck disease.

A radial wedge osteotomy, with reduction of the inclination angle of the distal part of the radius, was performed in twenty-seven patients who had Kienböck disease. After two to five years of follow-up, all of the patients were free of pain or had only mild pain in the wrist with strenuous activity. Flexion-extension of the wrist improved by more than 10 degrees in about half of the patients, and in most of the patients the grip strength increased by five kilograms or more. All but two of the postoperative results were satisfactory, as evaluated by the criteria of Lichtman et al. The osteotomy was effective even in patients who had zero or positive ulnar variance.

The Sauvé-Kapandji procedure for chronic dislocation of the distal radio-ulnar joint with destruction of the articular surface

The Sauvé-Kapandji procedure has been performed in 15 non-rheumatoid patients with chronic distal radio-ulnar joint dislocation accompanied by joint damage or deformity. The clinical results were favourable; wrist pain improved in all patients, wrist flexion-extension was increased by more than 10° in nine patients, grip strength of at least 80% of the contralateral wrist was achieved in 11 patients, and forearm rotation was more than 150° in 12 patients. However, X-ray examination revealed an unstable proximal ulnar stump and radio-ulnar convergence in all patients similar to that associated with the Darrach procedure. Although the Sauvé-Kapandji procedure can preserve ulnar support of the wrist and is believed to yield more satisfactory results than the Darrach procedure, its extensive use is not recommended for non-rheumatoid distal radio-ulnar joint disorders, but it is recommended for chronic distal radio-ulnar joint dislocation with articular injury or deformity.

Proximal Row Carpectomy Versus Limited Wrist Arthrodesis for Advanced Kienböck’s Disease

The outcomes in 20 patients with advanced Kienböcks disease treated by proximal row carpectomy (seven patients) or limited wrist arthrodesis (13 patients) were reviewed retrospectivey. Postoperatively, the results were more satisfactory in terms of wrist pain, the range of wrist flexion–extension, and grip strength following limited wrist arthrodesis than after proximal row carpectomy, although the differences were not statistically significant. We recommend scaphotrapeziotrapezoid arthrodesis in selected patients with advanced Kienböcks disease who have a fragmented lunate.

Scaphoid Non-Union: Factors Affecting the Functional Outcome of Open Reduction and Wedge Grafting with Herbert Screw Fixation

50 patients with scaphoid non-union were treated by open reduction, anterior wedge bone grafting and internal fixation using the Herbert screw. Intra-operative image intensiner control enabled us to insert the screw into the scaphoid accurately. An excellent or good functional outcome was less likely when more than 5 years had elapsed since injury, the non-union was in the proximal third, when sclerosis of the proximal fragment was present, and when reduction of carpal and scaphoid deformity was unsatisfactory. These four factors are believed to be the primary determinants affecting the functional results of the surgical treatment of scaphoid non-union, even when bony union is achieved.

Biodegradable polymers based on renewable resources. IV. Enzymatic degradation of polyesters composed of 1,4:3.6‐dianhydro‐D‐glucitol and aliphatic dicarboxylic acid moieties

Enzymatic degradation of a series of polyesters prepared from 1,4:3.6-dianhydro-D-glucitol (1) and aliphatic dicarboxylic acids of the methylene chain length ranging from 2 to 10 were examined using seven different enzymes. Enzymatic degradability of these polyesters as estimated by water-soluble total organic carbon (TOC) measurement is dependent on the methylene chain length (m) of the dicarboxylic acid component for most of the enzymes examined. The most remarkable substrate specificity was observed for Rhizopus delemar lipase, which degraded polyester derived from 1 and suberic acid (m = 6) most readily. In contrast, degradation by Porcine liver esterase was nearly independent of the structure of the polyesters. Enzymatic degradability of the polyesters based on three isomeric 1,4:3.6-dianhydrohexitols and sebacic acid was found to decrease in the order of 1, 1,4:3.6-dianhydro-D-mannitol (2), and 1,4:3.6-dianhydro-L-iditol (3). Structural analysis of water-soluble degradation products formed during the enzymatic hydrolysis of polyester 5g derived from 1 and sebacic acid has shown that the preferential ester cleavage occurs at the O(5) position of 1,4:3.6-dianhydro-D-glucitol moiety in the polymer chain by enzymes including Porcine pancreas lipase, Rhizopus delemar lipase, and Pseudomonas sp. lipase.

Distal radioulnar joint subluxation and dislocation diagnosed by standard roentgenography.

The use of standard lateral roentgenography for diagnosing distal radioulnar joint (DRUJ) subluxation and dislocation was investigated. Using a wrist support, bilateral standard lateral roentgenograms of the wrist were obtained in 42 patients with normal wrists and in 56 patients with a unilateral wrist injury. In normal wrists the difference between the radioulnar distance in the right and the left wrist did not exceed 4 mm when the difference in the pisoscaphoid distance was less than 3 mm. Of the 36 patients with wrist injury whose difference in pisoscaphoid distance was less than 3 mm, 15 had a radioulnar distance of 5 mm or more, and computed tomography (CT) confirmed DRUJ dislocation in 14. Concordance between lateral roentgenograms and CT was present in 33 of 36 patients (92%). These results demonstrate the value of a standardized technique for bilateral lateral roentgenography in diagnosing DRUJ subluxation and dislocation.

Radial osteotomy for Kienböck's disease evaluated by magnetic resonance imaging: 24 cases followed for 1–3 years

24 patients with Kienböcks disease were followed with magnetic resonance imaging (MRI) for 1-3 years. 9 patients were treated with radial shortening, 10 with radial wedge osteotomy and 5 patients were treated non-operatively. Signal intensity of the lunate on T1-weighted or T2-weighted images increased postoperatively in all operated on patients, and normal or near-normal signal intensity was observed in 9 patients on T1-weighted images and in 15 patients on T2-weighted images postoperatively. Signal intensity did not increase in any patient treated non-operatively. The postoperative increase in signal intensity on MRI following radial shortening and radial wedge osteotomy presumably is due to revascularization of the lunate.

A novel evaluation method for biodegradability of poly(butylene succinate-co-butylene adipate) by pyrolysis-gas chromatography

Biodegradation behavior of poly(butylene succinate-co-butylene adipate) (PBSA) film samples during the soil burial degradation test was studied by pyrolysis-gas chromatography (Py-GC). In the pyrograms of the PBSA film sample residues, various ester compounds containing succinate and/or adipate units were observed as the main pyrolysis products along with some minor pyrolyzates such as fatty-acid esters comprising propionates and valerates which might be formed mostly from carboxyl end-groups existing in PBSA molecules. Although the relative yields of the major pyrolyzates were almost unchanged before and after the soil burial test, those of the fatty-acid esters decreased with the soil burial time almost correlating with the decrease in recovery as residue. Thus, the variation of the relative yields of the fatty-acid esters proved to be a good measure to evaluate the degree of PBSA biodegradation. Furthermore, the local structural changes for the biodegraded PBSA film samples were also evaluated from the relative yields of these specific esters observed on the pyrograms for tiny pieces of analyte (ca. 0.1 mg) sampled from local points.

The aetiological significance of work-load in the development of osteoarthritis of the distal interphalangeal joint

The incidence of Heberden’s nodes was determined in three groups of Japanese women with different occupations to investigate the role of work-load in their pathogenesis. School cooks (n = 260), each of whom prepared 150 to 450 lunches daily, pre-school cooks (n = 222), each of whom prepared 30 to 80 lunches daily, and municipal employees (n = 298) underwent physical examination and X-ray of the hand if pathology was present. The incidence of Heberden’s nodes and X-ray incidence of osteoarthritis was 19.2% and 13.5%, 8.6% and 5.4%, 5.9% and 2.0% among school cooks, pre-school cooks and municipal workers, respectively. The incidence of Heberden’s nodes and osteoarthritis was significantly higher among school cooks. These findings support the concept that work-load is an aetiological factor in the pathogenesis of Heberden’s nodes and also support Radin’s hypothesis that women’s daily work pattern explains the increased incidence of DIP joint osteoarthritis in women.

Changes in Carpal Alignment Following Radial Osteotomy for Kienböck’s Disease

Changes in carpal alignment following radial osteotomy were studied in 30 patients with Kienböck’s disease. The carpal height ratio and carpal-ulnar distance ratio were significantly less in wrists with Kienböck’s disease than unaffected wrists. This observation implies proximal-ulnar translation of the capitate. In addition, the lunate-covering ratio increased significantly, reflecting radial translation of the lunate. Radial osteotomy corrected ulnar translation of the capitate and increased the radial translation of the lunate, thus increasing the lunate-covering ratio. The increased lunate-covering ratio is believed to increase the area of distribution of the axial load through the lunate by increasing the contact area with the radius. The satisfactory clinical outcome of radial osteotomy is believed to be due to this effect on carpal alignment.