Yoshikuni Mimata

Interleukin-6 upregulates expression of ADAMTS-4 in fibroblast-like synoviocytes from patients with rheumatoid arthritis

Aim:  A disintegrin‐like and metalloproteinase with thrombospondin type 1 motif (ADAMTS)‐4 and ADAMTS‐5 play crucial roles in the cleavage of aggrecan. Several recent studies have demonstrated the effect of cytokines such as interleukin (IL)‐1β, tumor necrosis factor‐α and transforming growth factor‐β on the expression of ADAMTS‐4 and ADAMTS‐5 in fibroblast‐like synoviocytes (FLS). However, the effect of IL‐6 remains unclear. The aim of this study is to investigate the expression of ADAMTS‐4 and ADAMTS‐5 in FLS of rheumatoid arthritis (RA) patients after IL‐6 stimulation.

Glenohumeral arthrodesis for malignant tumor of the shoulder girdle

BACKGROUND Arthrodesis of the shoulder joint using a free vascularized fibular graft has been performed as a reconstruction method after resection of bone sarcoma in the shoulder girdle. Postoperative fractures occasionally occur as a complication of arthrodesis of the shoulder joint using single-bone fusion (the conventional method). We hypothesized that the clinical results of shoulder arthrodesis using a double-barrel vascularized fibula graft for the malignant tumor of the shoulder girdle would achieve superior results compared with the conventional single-bone fusion method. METHODS The clinical results of 5 patients with a malignant bone and soft tissue tumor of the shoulder girdle were retrospectively reviewed. The factors evaluated were surgical margins, reconstruction procedures, postoperative complications, local recurrences, metastasis in lymph nodes or lung, or both, survival, and functional results assessed by the Musculoskeletal Tumor Society (MSTS) score. After surgical resection, arthrodesis of the shoulder joint was performed using a free vascularized fibula graft as a reconstructive procedure for the bone defect. Arthrodesis was by single-bone fusion in 3 of 5 patients, and a double-barrel vascularized fibula graft (dual-bone fusion) was used in 2 patients. RESULTS The average MSTS scores were 58.3% in the group with single-bone fusion and 85.0% in the group with dual-bone fusion. CONCLUSION The use of a double-barrel vascularized fibular graft may be useful in the reconstruction of large bone defects after wide excision of malignant tumors of the proximal humerus, with the advantage of avoiding postoperative fractures in shoulder arthrodesis.

Evaluation of Water Retention in Lumbar Intervertebral Disks Before and After Exercise Stress With T2 Mapping.

Study Design. T2 mapping was used to quantify moisture content of the lumbar spinal disk nucleus pulposus (NP) and annulus fibrosus before and after exercise stress, and after rest, to evaluate the intervertebral disk function. Objective. To clarify water retention in intervertebral disks of the lumbar vertebrae by performing magnetic resonance imaging before and after exercise stress and quantitatively measuring changes in moisture content of intervertebral disks with T2 mapping. Summary of Background Data. To date, a few case studies describe functional evaluation of articular cartilage with T2 mapping; however, T2 mapping to the functional evaluation of intervertebral disks has rarely been applied. Using T2 mapping might help detect changes in the moisture content of intervertebral disks, including articular cartilage, before and after exercise stress, thus enabling the evaluation of changes in water retention shock absorber function. Methods. Subjects, comprising 40 healthy individuals (males: 26, females: 14), underwent magnetic resonance imaging T2 mapping before and after exercise stress and after rest. Image J image analysis software was then used to set regions of interest in the obtained images of the anterior annulus fibrosus, posterior annulus fibrosus, and NP. T2 values were measured and compared according to upper vertebrae position and degeneration grade. Results. T2 values significantly decreased in the NP after exercise stress and significantly increased after rest. According to upper vertebrae position, in all of the upper vertebrae positions, T2 values for the NP significantly decreased after exercise stress and significantly increased after rest. According to the degeneration grade, in the NP of grade 1 and 2 cases, T2 values significantly decreased after exercise stress and significantly increased after rest. Conclusion. T2 mapping could be used to not only diagnose the degree of degeneration but also evaluate intervertebral disk function. Level of Evidence: 3

Limb function after excision of a deltoid muscle sarcoma

BACKGROUND Limb function after excision of deltoid muscle sarcomas has not been thoroughly investigated, although a large defect of soft tissue often causes some degree of dysfunction after wide excision. We formulated a hypothesis that the limb functional results depend on the volume of the excised deltoid muscle and examined the clinical outcomes in patients with a sarcoma in the deltoid muscle treated by surgical resection. METHODS The clinical outcomes of 8 patients with a malignant soft tissue tumor in the deltoid muscle were retrospectively reviewed. The following items were evaluated: type of excision of the deltoid muscle, including total excision, subtotal excision, and partial excision; surgical margins; reconstruction procedure used; postoperative complications; local recurrence; metastasis; survival; and functional results (determined by the Musculoskeletal Tumor Society scoring system). RESULTS After surgical resection, reconstruction in 6 of 8 patients was performed by pedicled latissimus dorsi musculocutaneous or muscle flap or pedicled trapezius musculocutaneous flap. Two patients did not undergo reconstruction because skin closure was possible. The partial excision group had a Musculoskeletal Tumor Society score of 100.0%, and the subtotal excision case and the total excision group had scores of 76.6% and 82.2%, respectively. None of the patients has demonstrated any evidence of local recurrence. CONCLUSION We conclude that the functional results may depend on the volume of the excised deltoid muscle. Latissimus dorsi and trapezius musculocutaneous flaps were found to be useful for covering a defect of the deltoid muscle, although these flaps did not contribute to function of the shoulder.

Core Needle Percutaneous Transpedicular Vertebral Body Biopsy: A Study of 128 Cases.

Study Design: We report an accurate technique for percutaneous transpedicular core needle biopsy of vertebral body lesions, and evaluate its effectiveness for histologic diagnosis retrospectively. Objective: The purpose of this study is to evaluate the effectiveness and accuracy of this method retrospectively. Summary of Background Data: Better knowledge of vertebral pedicle morphometry has led to the development of transpedicular fixation techniques in spinal surgery. After experience with these techniques, we have been performing percutaneous transpedicular vertebral body core needle biopsies (transpedicular biopsy) for histologic diagnosis since 1993. Methods: A total of 128 patients who had undergone transpedicular biopsy for T1–L5 vertebral body lesions were evaluated. The biopsies were carried out under local anesthesia, except in children, for whom general anesthesia was used. Biopsy specimens were obtained by passing 8 or 11 G needle biopsy instruments percutaneously through the pedicle into the site of the lesion under C-arm fluoroscopy guidance. Histologic analyses were performed, and the accuracy and effectiveness of this technique were evaluated. Results: The pathologic evaluations were definitive in 120 patients (93.8%) and not diagnostic in 8. The accuracy of the results differed among the diagnostic categories. Diagnostic accuracy was 78.6% for primary neoplasms and 97.0% for metastatic neoplasms. There was a significant difference in the diagnostic criteria and spinal segment. True positive rate was higher in the thoracic spine (92.2%) than that of lumbar spine (76.6%). Conclusions: Transpedicular biopsy is a useful procedure for evaluation of thoracic and lumbar vertebral body lesions.

Incidence of tendon rupture following volar plate fixation of distal radius fractures: A survey of 2787 cases

This study assessed the comprehensive incidence of tendon rupture following volar locking plate (VLP) surgery for a large number of patients with distal radius fractures (DRFs) at multiple facilities in one prefecture, Japan. During the 4-year period, 2787 patients with DRFs underwent fixation using VLP. The overall incidence rates of rupture of the FPL, the extensor pollicis longus, the flexor digitorum profundus of the index finger, and the extensor digitorum communis were 0.35% (10 patients), 0.29% (8 patients), 0.04% (1 patient), and 0.04% (1 patient), respectively.

Superficial Ulnar Artery Crossing Over the Palmaris Longus Tendon at the Wrist in a Cadaver: A Case Report

Superficial ulnar artery (SUA) is defined as arterial variation of an ulnar artery of high origin that lies superficially in the forearm. Because an SUA may be mistaken for a superficial vein, there is a risk of arterial damage. During routine dissection of the cadaver, we incidentally detected a case of unilateral SUA in the left arm. SUA arose from the axillary artery and descended superficial to the axillary artery and median nerve. At the wrist, the SUA crossed over palmaris longus (PL) tendon from the radial side to the ulnar side. In this cadaver, the PL tendon was located on the ulnar side and was thicker than the flexor carpi radialis tendon. Clinicians should check for the presence of SUA before any technical procedure, because lack of awareness of its presence can have serious consequences.

Reinvestigation of the Morphological Characteristics of the Lateral Ulnar Collateral Ligament in Humans

To clarify the cause of posterolateral rotatory instability after damage to the lateral ulnar collateral ligament (LUCL), the morphological characteristics of the LUCL were reinvestigated and three-dimensional (3D) image of the ligament was reconstructed using 35 human elbows. The results were as follows: 1) the insertion point of the LUCL on the humerus was almost at the center of the capitellum, and its width was 2.61 ± 1.02 mm. The insertion point of the LUCL on the ulna was located from the lesser sigmoid notch to the supinator crest and had a width of 9.0 ± 2.8 mm. The proximal insertion of the LUCL on the ulna was 7.0 ± 3.0 mm, and the distal part was on the articular surface of the radial head. 2) Three-dimensional imaging of the LUCL revealed an anterior curved shape that covered the radial head. Based on these results, it was clear that both the supinator crest and the lesser sigmoid notch could be useful as osseous landmarks. We think that these anatomical results are useful for surgeons performing LUCL reconstruction.

Importance of latissimus dorsi muscle preservation for shoulder function after scapulectomy

BACKGROUND Scapulectomy is an inevitable treatment for sarcomas of the scapula. This procedure is unavoidable because it reduces the local recurrence rate but can impair shoulder movements and affect the activities of daily living. This study investigated the factors influencing functional outcomes after scapulectomy. MATERIALS AND METHODS The clinical results of 8 patients (5 males, 3 females) who were diagnosed with primary or metastatic sarcomas of the scapula were retrospectively reviewed. The mean age was 49 years (range, 11-86 years). We examined the correlation between the type of excision of the scapula (total, subtotal, or partial) and postoperative functional outcomes according to the Musculoskeletal Tumor Society (MSTS) score. In partial excision, the glenohumeral joint was preserved; in subtotal excision, the glenoid was completely resected and some bony components were preserved; and in total excision, the entire bony component of the scapula was resected. The average follow-up period was 55 months (range, 9-142 months). RESULTS The partial, subtotal, and total excision groups had mean functional scores of 96.7%, 76.7%, and 62.2%, respectively. Although the mean functional scores were lower in patients who underwent total and subtotal excisions, 3 patients in whom the latissimus dorsi muscle was preserved had better function (mean MSTS score, 76.7%) than the 2 patients in whom it was not preserved (mean MSTS score, 55.0%). CONCLUSION These results suggest that the latissimus dorsi muscle, along with the deltoid and pectoralis major muscles, is one of the stabilizers of the proximal humerus after scapulectomy.

Morphology of the Lateral Ulnar Collateral Ligament of the Elbow

Objective: The lateral ulnar collateral ligament (LUCL) is considered to be the main factor against posterolateral rotatory instability (PLRI). The aim of this study was to clarify the morphological features of the LUCL and the related osseous landmarks on 3-dimensional (3D) images. We hypothesized that the characteristic features of the LUCL and related structures can be identified, which may assist surgeons in performing LUCL reconstruction with a more anatomic perspective. Materials and Methods: Thirty-five nonpaired, formalin-fixed human cadaveric elbows were evaluated in this study. After the identification of the LUCL, the outlines of the ligament were marked by using soft stainless wires. 3D images were created, and the insertions and running route of the LUCL and related osseous landmarks were analyzed. Results: The LUCL originated from the anterior edge of the prominence at the lateral epicondyle and inserted from the lesser sigmoid notch to the supinator crest with increasing width. In the 3D images, the LUCL formed an anterior curved shape and covered the radial head like a hammock. The insertion of the LUCL at the humerus was nearly at the center of the capitellum, with a width of 2.61 ± 1.02 mm. The insertion of the LUCL at the ulna was located from the lesser sigmoid notch to the supinator crest, with a width of 9.0 ± 2.8 mm. The proximal end of the LUCL insertion at the ulna was 7.0 ± 3.0 mm distal to the articular surface of the radial head. On the horizontal plane, the LUCL was located on the radial head at 99.5° ± 10.3° to 126.1° ± 12.4°. Conclusions: The LUCL insertion at the humerus was nearly at the center of the capitellum, and the LUCL insertion at the ulna was located from the lesser sigmoid notch to the supinator crest. This study showed that both the supinator crest and lesser sigmoid notch could be useful as osseous landmarks. The LUCL was attached to the annular ligament at 8 to 9 o’clock position in the radial head, which stabilizes the radial head. On the basis of these morphological features, the LUCL might act a posterior buttress for the radial head and the ulna to prevent its subluxation, and therefore it is considered to be the principal constraint of the elbow joint against PLRI. The results of this study may assist surgeons in performing LUCL reconstruction with a more anatomic perspective.