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Papers - Sato, Kazuki

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Shoulder position increases ulnar nerve strain at the elbow of patients with cubital tunnel syndrome

Ochi Kensuke, Horiuchi Yukio, Horiuchi Koichi, Iwamoto Takuji, Morisawa Yasushi, Sato Kazuki

Journal of Shoulder and Elbow Surgery 24 ( 9 ) 1380 - 1385 2015.09

ISSN 1058-2746

Background: Previous studies have shown that the shoulder internal rotation elbow flexion (SIREF) test, which is a modified elbow flexion (EF) test, has significantly higher sensitivity than the EF test in patients with cubital tunnel syndrome (CubTS). Here, we hypothesized that this increase in sensitivity was due to increase in the ulnar nerve strain around the elbow introduced by the additional shoulder position. Methods: Ulnar nerve strain at the elbow was intraoperatively measured at both the EF test and SIREF test positions in 20 patients with CubTS before simple decompression. Statistical analysis was performed with the Wilcoxon signed rank test at a confidence level of 99% (. P < .001). Results: Mean ulnar nerve strain in the EF test position was 18.9% ± 12.1%, whereas that in the SIREF test position was 24.7% ± 14.0%. Ulnar nerve strain was higher in the SIREF than in the EF test position in all cases, and the difference was significant (mean, 5.8% ± 0.9%; 95% confidence interval, 3.90%-7.73%). Conclusion: This study indicated that increased sensitivity in the SIREF test compared with the EF test was due to the increase in ulnar nerve strain around the elbow. To the best of our knowledge, this is the first study showing that shoulder position changes the ulnar nerve strain around the elbow in living patients with CubTS.

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Comparison of surgical treatments for triple extensor tendon ruptures in rheumatoid hands

Suzuki Taku, Iwamoto Takuji, Ikegami Hiroyasu, Sakuma Y., Ikari Katsunori, Matsumura Noboru, Ochi Kensuke, Sato Kazuki, Nakamura Masaya, Matsumoto Morio, Momohara Shigeki

Modern Rheumatology 2015.08

ISSN 1439-7595

Objective. This retrospective study was designed to evaluate the outcomes of four different surgical reconstructions for extensor tendon ruptures in ulnar three fingers in 48 patients with rheumatoid arthritis. Methods. The following four techniques were performed; palmaris longus tendon grafting (PL group; n = 9), extensor indicis proprius (EIP) tendon transfers (EIP group; n = 8), end-to-side transfers with tension-reduced early mobilization (End-to-side group; n = 16), and a combination of end-to-side and EIP transfers (Combination group; n = 15). Loss of extension was evaluated to determine the mean postoperative range of motion of the metacarpophalangeal (MP) joint and clinical outcomes were categorized using modified Geldmacher criteria. Results. Combination group demonstrated the best mean MP joint extension (− 3°), followed by End-to-side group (− 12°), EIP group (− 16°), and PL group (− 21°). Combination group yielded the best clinical outcomes with all cases showing good results. Conclusions. The combination of end-to-side and EIP transfer was an effective surgical reconstruction procedure for triple fingers extension loss.

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Radial deviation of the finger caused by an occult intramuscular ganglion in a patient with rheumatoid arthritis

Kato Tomoyuki, Iwamoto Takuji, Matsumura Noboru, Sato Kazuki, Nakamura Toshiyasu, Toyama Yoshiaki

Modern Rheumatology 2015.06

ISSN 1439-7595

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Time course of osteonecrosis in rabbit articular intercalated bone

Obara Yukihiko, Nakamura Toshiyasu, Shinmoto Hiroshi, Osada Natsuya, Yamabe Eiko, Sato Kazuki, Toyama Yoshiaki

Magnetic Resonance in Medical Sciences 14 ( 1 ) 57 - 64 2014.12

ISSN 1347-3182

Purpose: Magnetic resonance (MR) imaging offers the highest sensitivity for detecting bone necrosis. We evaluated osteonecrosis in rabbit models by calculating the percentage of fat to (fat + water) [F/(F+W)] on MR spectroscopy (MRS) and compared MR spectroscopy and imaging findings with corresponding histological results. Methods: To model the natural course of articular osteonecrosis, we removed the fourth tarsal bone in 45 rabbits, froze it for 5 min in liquid nitrogen to produce complete cellular necrosis, and then replaced the bone into the knee joint. We performed Carr-Purcell- Meiboom-Gill proton spectroscopic imaging to assess necrotic bone at 3 days and one, 2, 3, 4, 8, 12, 16, and 20 weeks after osteonecrosis and calculated the percentage of F/ (F+W) of each bone. We also performed conventional T1- and T2-weighted imaging and compared all data to histological findings to analyze the natural course of necrosis. Results: T1-weighted MR imaging demonstrated obvious low signal intensity at 2 to 8 weeks and recovery at 12 to 20 weeks, whereas T2-weighted imaging demonstrated inconsistent intensities throughout the period. The postoperative percentage of F/(F+W) measured using line scan MRS decreased to 8.88% at 3 weeks, 6.22% at 8 weeks, and 34.40% at 20 weeks results that were mostly consistent with MR imaging findings. Histological findings demonstrated complete absence of osteocyte nuclei and loss of osteoid-osteogenesis at 3 to 8 weeks. Recovery of bone marrow was identified as an increase in the area of fat after 12 weeks. Conclusion: Osteonecrosis delineated by T1-weighted MR imaging demonstrated fat content in the bone marrow that correlated with histology. The present MRS modality can be used to calculate the percentage of F/(F+W) of osteonecrosis to enable objective assessment of recovery and quantification of osteonecrosis to provide a numerical value for osteonecrosis.

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How Does Ulnar Shortening Osteotomy Influence Morphologic Changes in the Triangular Fibrocartilage Complex?

Yamanaka Yoshiaki, Nakamura Toshiyasu, Sato Kazuki, Toyama Yoshiaki

Clinical Orthopaedics and Related Research 472 ( 11 ) 3489 - 3494 2014.10

ISSN 0009-921X

Background: Ulnar shortening osteotomy often is indicated for treatment of injuries to the triangular fibrocartilage complex (TFCC). However, the effect of ulnar shortening osteotomy on the changes in shape of the TFCC is unclear. In our study, quantitative evaluations were performed using MRI to clarify the effect of ulnar shortening on triangular fibrocartilage (TFC) thickness attributable to disc regeneration of the TFC and TFC angle attributable to the suspension effect of ulnar shortening on the TFC.Questions/purposes: The purposes of this study were (1) to compare preoperative and postoperative TFC thickness and TFC angle on MR images to quantitatively evaluate the effect of ulnar shortening osteotomy on disc regeneration and the suspension effect on the TFC; and (2) to assess whether changes in TFC thickness and TFC angle correlated with the Mayo wrist score.Methods: Between 1995 and 2008, 256 patients underwent ulnar shortening osteotomy for TFCC injuries. The minimum followup was 24 months (mean, 51 months; range, 24–210 months). A total of 79 patients (31%) with complete followup including preoperative and postoperative MR images and the Mayo wrist score was included in this retrospective study. Evaluation of the postoperative MR images and the Mayo wrist score were performed at the final followup. The remaining 177 patients did not undergo postoperative MRI, or they had a previous fracture, large tears of the disc proper, or were lost to followup. Two orthopaedists, one of whom performed the surgeries, measured the TFC thickness and the TFC angle on coronal MR images before and after surgery for each patient. Correlations of the percent change in the TFC thickness and the magnitude of TFC angle change with age, sex, postoperative MR images, extent of ulnar shortening, preoperative ulnar variance, and postoperative Mayo wrist score were assessed.Results: Stepwise regression analysis showed a correlation between the percent change in TFC thickness and preoperative ulnar variance (R² = 0.21; β = −0.33; 95% CI, −0.11 to 0.01; p = 0.01) and between the magnitude of change in the TFC angle and the extent of ulnar shortening (R² = 0.18; β = −0.29; 95% CI, −5.8 to 0.29; p = 0.03). The Mayo wrist score was not correlated with the percent change in TFC thickness or the magnitude of change in the TFC angle.Conclusions: These results suggest that, in patients with TFCC injury with a smaller preoperative ulnar variance, a high residual potential for regeneration in the disc proper was seen after ulnar shortening osteotomy, and correlated with the extent of ulnar shortening and the suspension effect on TFC. However, there was no correlation between disc regeneration or the suspension effect on TFC and the Mayo wrist score.Level of Evidence: Level IV, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

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Associations between ulnar nerve strain and accompanying conditions in patients with cubital tunnel syndrome

Ochi Kensuke, Horiuchi Yukio, Nakamura Toshiyasu, Sato Kazuki, Morita Kozo, Horiuchi Koichi

Hand surgery : an international journal devoted to hand and upper limb surgery and related research : journal of the Asia-Pacific Federation of Societies for Surgery of the Hand 19 ( 3 ) 329 - 333 2014

ISSN 0218-8104

Pathophysiology of cubital tunnel syndrome (CubTS) is still controversial. Ulnar nerve strain at the elbow was measured intraoperatively in 13 patients with CubTS before simple decompression. The patients were divided into three groups according to their accompanying conditions: compression/adhesion, idiopathic, and relaxation groups. The mean ulnar nerve strain was 43.5 ± 30.0%, 25.5 ± 14.8%, and 9.0 ± 5.0% in the compression/adhesion, idiopathic, and relaxation groups respectively. The mean ulnar nerve strains in patients with McGowan's classification grades I, II, and III were 18.0 ± 4.2%, 27.1 ± 22.7%, and 33.7 ± 24.7%, respectively. The Jonckheere-Terpstra test showed that there were significant reductions in the ulnar nerve strain among the first three groups, but not in the three groups according to McGowan's classification. Our results suggest that the pathophysiology, not disease severity, of CubTS may be explained at least in part by the presence of ulnar nerve strain.

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Reply to the Letter to the Editor

Yamanaka Yoshiaki, Nakamura Toshiyasu, Sato Kazuki, Toyama Yoshiaki

Clinical Orthopaedics and Related Research 473 ( 1 ) 399 - 400 2014

ISSN 0009-921X

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Slow progression predicts poor prognoses in patients with spontaneous posterior interosseous nerve palsy

Ochi Kensuke, Horiuchi Yukio, Tazaki Kenichi, Takayama Shinichiro, Nakamura Toshiyasu, Sato Kazuki

Journal of Plastic Surgery and Hand Surgery 47 ( 6 ) 493 - 497 2013.12

ISSN 2000-656X

There are still no factors that predict the prognoses of patients with spontaneous posterior interosseous nerve palsies who are in an early phase of the illness. This paper reviewed 39 patients with this type of palsy. Seventeen patients who requested surgery for possible earlier recovery underwent interfascicular neurolysis because no signs of recovery were seen more than 3 months after onset. A Medical Research Council muscle power grade over 4 at their final visit was considered a good result, while a power less than grade 4 was considered a poor result. The clinical outcomes were significantly worse for the patients who had palsies with slow progressions (for more than 1 month) compared with those who had palsies with rapid progressions (completed within 1 month), regardless of their treatment. No significant difference was seen between the prognoses of patients with complete and incomplete palsies. We, therefore, recommend that interfascicular neurolysis is performed together with tendon transfer as the primary surgical procedures for patients with palsies with slow progression. © 2013 Informa Healthcare.

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An obliquely placed headless compression screw for distal interphalangeal joint arthrodesis

Iwamoto Takuji, Matsumura Noboru, Sato Kazuki, Momohara Shigeki, Toyama Yoshiaki, Nakamura Toshiyasu

Journal of Hand Surgery 38 ( 12 ) 2360 - 2364 2013.12

ISSN 0363-5023

Purpose To assess the outcomes of our technique involving oblique headless compression screw for arthrodesis of the thumb interphalangeal joint and the distal interphalangeal joints of the other digits. Methods A total of 28 joints (19 thumb interphalangeal and 9 distal interphalangeal) in 23 patients with a mean age of 65 years (range, 58-74 y) were retrospectively analyzed. All operations were performed with the Acutrak2 micro-screw. After the resection of synovium and joint cartilage by a dorsal approach, a 0.88-mm diameter guide wire was inserted at the ulnar side of the proximal phalanx in the thumb and radial side of the middle phalanx in the other digits from proximal to distal to fix the joint obliquely. We verified its position under fluoroscopic control and placed the cannulated screw from proximal to distal over the guide wire. Results Intraoperative rigid fixation was obtained except for 1 case, which required additional K-wire fixation. The overall union rate was 96%. Average time to fusion was 11 weeks (range, 8-30 wk), with 76% achieving union within 3 months. There were 2 complications, 1 nonunion and 1 late infection. Other complications such as dorsal skin necrosis, nail deformity, and paresthesia did not occur. Conclusions Efforts to avoid invasion of the nailbed can be technically demanding. We believe that our proximal to distal technique with oblique placement of the headless compression screw is a straightforward and effective method with a relatively low risk of complication. Type of study/level of evidence Therapeutic IV. © 2013 by the American Society for Surgery of the Hand. All rights reserved.

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The effects of dorsally angulated distal radius fractures on distal radioulnar joint stability

Saito T., Nakamura T., Nagura T., Nishiwaki M., Sato K., Toyama Y.

Journal of Hand Surgery: European Volume 38 ( 7 ) 739 - 745 2013.09

ISSN 1753-1934

Relationship between dorsal tilt of the distal radius and distal radioulnar joint stability was examined. Stiffness in dorsopalmar displacement of the radius (distal radioulnar joint stiffness) was recorded at 10° intervals until 30° of dorsal angulation from 10° of palmar tilt. Tests were repeated after partial sectioning of the radioulnar ligament, then after complete sectioning of the radioulnar ligament. All data were compared with control (intact triangular fibrocartilage complex, 10° of palmar tilt). The distal radioulnar joint stiffness in dorsal translation decreased significantly with dorsal tilt 10° and 20° in pronation. Partial sectioning of the radioulnar ligament indicated a decrease of the distal radioulnar joint stiffness in the dorsal translation at neutral tilt to 20° of dorsal tilt in the neutral position and in pronation. Distal radioulnar joint stiffness decreased significantly in both dorsal and palmar translations in all forearm positions at 10° and 20° of dorsal tilt. From these findings, the dorsal angulation of the radius should be corrected to less than 10° of dorsal tilt. © 2013 The Author(s).

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Ulnar nerve strain at the elbow in patients with cubital tunnel syndrome

Ochi K., Horiuchi Y., Nakamura T., Sato K., Arino H., Koyanagi T.

Journal of Hand Surgery: European Volume 38 ( 5 ) 474 - 480 2013.06

ISSN 1753-1934

Simple decompression of the ulnar nerve at the elbow has not been shown to reduce nerve strain in cadavers. In this study, ulnar nerve strain at the elbow was measured intraoperatively in 11 patients with cubital tunnel syndrome, before and after simple decompression. Statistical analysis was performed using a paired Student's t-test. Mean ulnar nerve strain before and after simple decompression was 30.5% (range 9% to 69%) and 5.5% (range -2% to 11%), respectively; this difference was statistically significant (p < 0.01) with a statistical power of 96%. Simple decompression reduced ulnar nerve strain in all patients by an average of 24.5%. Our results suggest that the pathophysiology of cubital tunnel syndrome may be multifactorial, being neither a simple compression neuropathy nor a simple traction neuropathy, and simple decompression may be a favourable surgical procedure for cubital tunnel syndrome in terms of decompression and reduction of strain in the ulnar nerve. © The Author(s) 2012.

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Conditional Inactivation of TNFα-Converting Enzyme in Chondrocytes Results in an Elongated Growth Plate and Shorter Long Bones

Saito Kenta, Horiuchi Keisuke, Kimura Tokuhiro, Mizuno Sakiko, Yoda Masaki, Morioka Hideo, Akiyama Haruhiko, Threadgill David, Okada Yasunori, Toyama Yoshiaki, Sato Kazuki

PLoS ONE 8 ( 1 ) 2013.01

TNFα-converting enzyme (TACE) is a membrane-bound proteolytic enzyme with essential roles in the functional regulation of TNFα and epidermal growth factor receptor (EGFR) ligands. Previous studies have demonstrated critical roles for TACE in vivo, including epidermal development, immune response, and pathological neoangiogenesis, among others. However, the potential contribution of TACE to skeletal development is still unclear. In the present study, we generated a Tace mutant mouse in which Tace is conditionally disrupted in chondrocytes under the control of the Col2a1 promoter. These mutant mice were fertile and viable but all exhibited long bones that were approximately 10% shorter compared to those of wild-type animals. Histological analyses revealed that Tace mutant mice exhibited a longer hypertrophic zone in the growth plate, and there were fewer osteoclasts at the chondro-osseous junction in the Tace mutant mice than in their wild-type littermates. Of note, we found an increase in osteoprotegerin transcripts and a reduction in Rankl and Mmp-13 transcripts in the TACE-deficient cartilage, indicating that dysregulation of these genes is causally related to the skeletal defects in the Tace mutant mice. Furthermore, we also found that phosphorylation of EGFR was significantly reduced in the cartilage tissue lacking TACE, and that suppression of EGFR signaling increases osteoprotegerin transcripts and reduces Rankl and Mmp-13 transcripts in primary chondrocytes. In accordance, chondrocyte-specific abrogation of Egfr in vivo resulted in skeletal defects nearly identical to those observed in the Tace mutant mice. Taken together, these data suggest that TACE-EGFR signaling in chondrocytes is involved in the turnover of the growth plate during postnatal development via the transcriptional regulation of osteoprotegerin, Rankl, and Mmp-13. © 2013 Saito et al.

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An experimental study on costal osteochondral graft

Sato K., Moy O. J., Peimer C. A., Nakamura T., Howard C., Ko S. H., Lee T. C., Nishiwaki Y.

Osteoarthritis and Cartilage 20 ( 2 ) 172 - 183 2012.02

ISSN 1063-4584

Objective: To investigate usefulness of osteochondral grafting from the costo-osteochondral junction as a repair technique for articular cartilage defects histologic and biochemical analysis of grafted cartilage in rabbit knees was evaluated up to 48. weeks after transplantation. Methods: Twenty New Zealand White rabbits were used. A costal osteochondral plug was harvested from a middle rib. After trimming, it was transplanted into a cylindrical osteochondral 2.5. mm diameter and 5. mm deep defect created in the knee. The animals were sacrificed at 6, 12, 24, and 48. weeks after transplantation. Defect sites were inspected macroscopically, and then by light microscopy. Samples were evaluated for cell viability using a fluorescent. in situ double-staining protocol with confocal laser microscopic analysis. Samples were also processed to assess type I and II collagen and aggrecan mRNA expression using reverse transcription-polymerase chain reaction (RT-PCR). Results: Histologically, bone union was achieved in all plugs. Confocal microscopic analysis revealed chondrocyte viability in the 48-week grafts; the distribution of chondrocytes was similar to surrounding articular cartilage. The expression of type II collagen and aggrecan mRNA in the grafted cartilage was consistent with normal articular cartilage and normal costal cartilage. These results were observed over 6-48. weeks. Conclusions: Our study revealed that chondrocytes in the grafted cartilage were viable at least up to 48. weeks and that mRNA expression of type II collagen and aggrecan was also similar to that of normal articular cartilage. These results suggest that costal osteochondral grafting can be a useful alternative in the treatment of osteochondral defects. © 2011 Osteoarthritis Research Society International.

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Radial and volar perilunate trans-scaphoid fracture dislocation

Nishiyama Yuichiro, Sato Kazuki, Nakamura Toshiyasu, Okazaki Masato, Toyama Yoshiaki, Ikegami Hiroyasu

Hand surgery : an international journal devoted to hand and upper limb surgery and related research : journal of the Asia-Pacific Federation of Societies for Surgery of the Hand 17 ( 1 ) 93 - 97 2012

ISSN 0218-8104

Gene expression profiling of mouse growth plate cartilage by laser microdissection and microarray analysis

Isshiki Honoka, Sato Kazuki, Horiuchi Keisuke, Tsutsumi Shuichi, Kano Makoto, Ikegami Hiroyasu, Abe Hitoshi, Umezawa Akihiro, Aburatani Hiroyuki, Toyama Yoshiaki

Journal of Orthopaedic Science 16 ( 5 ) 670 - 672 2011.09

ISSN 0949-2658

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Vertical locking of the metacarpophalangeal joint in young adults

Tajima Kosuke, Sato Kazuki, Sasaki Takashi, Peimer Clayton A.

Journal of Hand Surgery 36 ( 9 ) 1482 - 1485 2011.09

ISSN 0363-5023

Locking of the metacarpophalangeal joints has been occasionally reported in older adults, but reports of this problem are rare in younger individuals. We report 8 young adult patients with a metacarpophalangeal joint locked in 90° flexion after minor trauma. The cases included 6 little fingers and 2 thumbs in 1 male and 7 female patients aged 16 to 39 years. All were easily reduced closed. We postulate the mechanism of injury. Type of study/level of evidence: Therapeutic IV. © 2011 American Society for Surgery of the Hand.

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Repair of foveal detachment of the triangular fibrocartilage complex

Nakamura Toshiyasu, Sato Kazuki, Okazaki Masato, Toyama Yoshiaki, Ikegami Hiroyasu

Hand Clinics 27 ( 3 ) 281 - 290 2011.08

ISSN 0749-0712

Because the radioulnar ligament attaches to the ulnar fovea and base of the ulnar styloid, foveal detachment of the triangular fibrocartilage complex (TFCC) induces severe distal radioulnar joint instability. This article describes both an arthroscopic and open repair technique to reattach the TFCC to the fovea. Both techniques reanchor the detached TFCC to the fovea. Both techniques are reliable and promising techniques in the repair of a foveal detachment of the TFCC. © 2011 Elsevier Inc.

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Steroid-induced osteonecrosis of bilateral distal humerus treated by arthroplasty using costal osteochondral graft

Watanabe Ryuichi, Sato Kazuki, Nakamura Toshiyasu, Obara Yukihiko, Toyama Yoshiaki, Ikegami Hiroyasu

Journal of Hand Surgery 36 ( 5 ) 816 - 819 2011.05

ISSN 0363-5023

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Costo-osteochondral graft for post-traumatic osteonecrosis of the radial head in an adolescent boy

Iwai S., Sato K., Nakamura T., Okazaki M., Itoh Y., Toyama Y., Ikegami H.

Journal of Bone and Joint Surgery - Series B 93 B ( 1 ) 111 - 114 2011.01

ISSN 0301-620X

We present a case of post-traumatic osteonecrosis of the radial head in a 13-year-old boy which was treated with costo-osteochondral grafts. A satisfactory outcome was seen at a follow-up of two years and ten months. Although costo-osteochondral grafting has been used in the treatment of defects in articular cartilage, especially in the hand and the elbow, the extension of the technique to manage post-traumatic osteonecrosis of the radial head in a child has not previously been reported in the English language literature. Complete relief of pain was obtained and an improvement in the range of movement was observed. The long-term results remain uncertain. ©2011 British Editorial Society of Bone and Joint Surgery.

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Avulsion of flexor digitorum profundus secondary to recurrent enchondroma.

Nomura T., Nakamura T., Sato K., Toyama Y., Ikegami H.

ISSN 0218-8104

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