Published papers

Frozen shoulder is a relatively common disorder that leads to severe pain and stiffness in the shoulder joint. Although this disorder is self-limiting in nature, the symptoms often persist for years, resulting in severe disability. Recent studies using human specimens and animal models have shown distinct changes in the gene expression patterns in frozen shoulder tissue, indicating that novel therapeutic intervention could be achieved by controlling the genes that are potentially involved in the development of frozen shoulder. To achieve this goal, it is imperative to develop a reliable animal joint contracture model in which gene expression can be manipulated by gene targeting and transgenic technologies. Here, we describe a novel shoulder contracture mouse model. We found that this model mimics the clinical presentation of human frozen shoulder and recapitulates the changes in the gene expression pattern and the histology of frozen shoulder and joint contracture in humans and other larger animal models. The model is highly reproducible, without any major complications. Therefore, the present model may serve as a useful tool for investigating frozen shoulder etiology and for identifying its potential target genes.

Background: Neovessels and accompanying nerves are possible sources of pain. We postulated that transcatheter arterial embolization of abnormal neovessels would relieve pain and symptoms in patients with adhesive capsulitis. Methods: Adhesive capsulitis was treated by transcatheter arterial embolization in 7 patients. Adverse events, changes in visual analog scale scores for night pain and overall shoulder pain, and changes in range of motion and American Shoulder and Elbow Surgeons scores were assessed at 1 week and at 1, 3, and 6 months after the procedure. Results: Abnormal neovessels were identified at the rotator interval in all patients. No major or minor adverse events were associated with the procedures. Transcatheter arterial embolization rapidly decreased nighttime pain scores from 67 ± 14 mm to 27 ± 14 mm at 1 week after the procedure, with further improvement at 1 and 6 months (6 ± 8 mm and 2 ± 5 mm, respectively). The American Shoulder and Elbow Surgeons score significantly improved from 17.8 ± 4.5 to 39.8 ± 12.0, 64.3 ± 13.9, and 76.2 ± 4.4 at 1, 3, and 6 months, respectively. Conclusion: All patients with adhesive capsulitis had abnormal neovessels at the rotator interval. Transcatheter arterial embolization was feasible, relieved unrelenting pain, and restored shoulder function. © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees.

Background: Management of massive chronic rotator cuff tears remains controversial, with no clearly defined clinical presentation as yet. The purpose of the study was to evaluate the effect of tear size and location on active motion in patients with chronic and massive rotator cuff tears with severe muscle degeneration. Methods: One hundred patients with massive rotator cuff tears accompanied by muscle fatty infiltration beyond Goutallier stage 3 were prospectively included in this study. All patients were divided into 5 groups on the basis of tear pattern (supraspinatus, superior subscapularis, inferior subscapularis, infraspinatus, and teres minor). Active range of shoulder motion was assessed in each group and differences were analyzed. Results: Active elevation was significantly decreased in patients with 3 tear patterns involved. Pseudoparalysis was found in 80% of the cases with supraspinatus and complete subscapularis tears and in 45% of the cases with tears involving the supraspinatus, infraspinatus, and superior subscapularis. Loss of active external rotation was related to tears involving the infraspinatus and teres minor; loss of active internal rotation was related to tears of the subscapularis. Conclusions: This study revealed that dysfunction of the entire subscapularis and supraspinatus or 3 rotator cuff muscles is a risk factor for pseudoparalysis. For function to be preserved in patients with massive chronic rotator cuff tears, it may be important to avoid fatty infiltration with anterior extension into the lower subscapularis or involvement of more than 2 rotator cuff muscles. © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees.

Here, we describe a modified osteotomy for malunion of the greater tuberosity that facilitates bone union and prevents symptom recurrence. The 3 most important features of this technique are: (1) osteotomizing the displaced fragment that includes the bed of the fracture, (2) placing figure-of-eight sutures by passing suture threads from inside the medullary cavity through osseous holes made in the metaphysis, and (3) pushing the distal end of the osteotomized fragment into the medullary cavity and fixing it in place. This procedure was performed on 10 patients who complained of clinical symptoms derived primarily from greater tuberosity malunion after fractures of various morphologies. Eight of these patients were available for follow-up examinations over 2 postoperative years. Constant score ratios comparing the repaired side to the uninjured side ranged from 82% to 100%. These results support the use of this modified osteotomy in achieving favorable bone union and in creating sufficient subacromial space to resolve most symptoms caused by these malunited proximal humeral fractures.

Wrist arthroscopy is now widely indicated for diagnosis and treatment of acute or chronic wrist pain, especially for triangular fibrocartilage complex (TFCC) lesions, as a gold standard. In most cases radiocarpal and midcarpal arthroscopy was performed, while DRUJ arthroscopy has been rarely performed because of its difficulties. Recent anatomic and biomechanical studies demonstrated that the radioulnar ligament (RUL), which is the proximal component of the TFCC facing to the DRUJ, is the primary stabilizer of the distal radioulnar joint (DRUJ). Rupture of the radioulnar ligament (RUL) at the fovea area, where it is the main attaching portion to the ulna and is the isometric point during forearm rotation as the rotation axis passes, is responsible for DRUJ instability. Although physical examination and imaging diagnosis may indicate a foveal detachment of the TFCC, DRUJ arthroscopy is potential for visualizing the RUL at the fovea. Role of DRUJ arthroscopy should be more important not only for diagnosis of rupture of the RUL but also for decision making of treatment option for RUL tear. DRUJ arthroscopy also demonstrates the joint surface of both the sigmoid notch and ulnar head, and the proximal surface of the TFCC.

Background: The morphologic features and clinical significance of version of the humeral head and glenoid remain unclear. The purpose of this study was to evaluate the normal values of humeral head version and glenoid version on computed tomography scans and to clarify their features in the normal glenohumeral joint. Methods: Images for analysis were computed tomography scans of 410 normal shoulders from healthy volunteers. Values of humeral head and glenoid version were measured. In glenoid version measurement, 3-dimensionally corrected slices were reconstructed to eliminate scapular inclination. Differences in humeral head version and glenoid version were assessed between dominant and nondominant shoulders and between men and women. Correlation analyses were also performed in the values of version between dominant and nondominant shoulders and between humeral head version and glenoid version. Results: The values of humeral head retroversion were widely distributed from -2° to 60°, with an average of 26°±11°. Average glenoid retroversion was 1°±3°, ranging from -9° to 13°. Both humeral head retroversion and glenoid retroversion were significantly higher on the dominant side than on the nondominant side and significantly higher in men than in women. Humeral head version and glenoid version values were well correlated with those of the contralateral shoulder. No correlation was found between humeral head version and glenoid version. Conclusions: This study found differences in humeral head version and glenoid version by sex and shoulder dominance in a large sample. Both the humeral head and glenoid are thought to be more retroverted in high-demand shoulders.

Here we describe a modified osteotomy for malunion of the greater tuberosity that facilitates bone union and prevents symptom recurrence. The three most important features of this technique are: 1) osteotomizing the displaced fragment, which includes the bed of the fracture, 2) placing figure-of-eight sutures by passing suture threads from inside the medullary cavity through osseous holes made in the metaphysis, and 3) pushing the distal end of the osteotomized fragment into the medullary cavity and fixing it in place. This procedure was performed on 10 patients who complained of clinical symptoms derived primarily from greater tuberosity malunion following fractures of various morphologies. Eight of these patients were available for follow-up examinations over two postoperative years. Constant score ratios comparing the repaired side to the uninjured side ranged from 82 to 100%. These results support the use of this modified osteotomy in achieving favorable bone union and in creating sufficient subacromial space to resolve most symptoms caused by these malunited proximal humeral fractures.

Background: The conventional measuring method for glenoid version is greatly influenced by the scapular body shape that varies widely between patients. We postulated that the glenoid vault version could be more useful than the conventional glenoid version in clinical cases.Objectives: The purposes of this study were to compare the values of glenoid version measured with the conventional method to those with the vault method and to investigate the feasibility of the glenoid vault version.Methods: Computed tomography scans of 150 normal shoulders and 150 arthritic shoulders were analyzed. Three-dimensionally corrected slices were reconstructed from the Digital Imaging and Communications in Medicine (DICOM) data, and glenoid version was measured with both the conventional and vault methods. After determining intra- and interrater reliabilities, differences in glenoid version values between the conventional and vault methods were assessed. In the normal shoulder group, side-to-side differences of glenoid version values were also evaluated in both methods.Results: Both measuring methods demonstrated high intra- and interrater reliabilities. The normal glenoid had 1.1° ± 3.2° retroversion with the conventional method and 8.9° ± 2.7° retroversion with the vault method. The average glenoid retroversion of arthritic shoulders was 10.8° ± 9.3° measured with the conventional method and 18.2° ± 9.1° with the vault method. The vault method showed significantly larger glenoid retroversion than the conventional method in both normal and arthritic shoulder groups. Both conventional glenoid retroversion and glenoid vault retroversion were significantly larger on dominant sides than on nondominant sides in the normal shoulders.Conclusions: The glenoid vault version could be used as an alternative measuring method for glenoid version with high reliability. In clinical use, the glenoid vault version appears to be more useful than the conventional glenoid version to assess the severity of arthritis and difficulty of glenoid replacement. The glenoid vault is not symmetric, but usually retroverted in both normal and arthritic shoulders. © 2014 Matsumura et al.; licensee BioMed Central Ltd.