Pathological Findings of Hourglass-Like Constriction in Spontaneous Posterior Interosseous Nerve Palsy.

We report the pathological findings of hourglass-like fascicular constriction (HLFC) under optical and electron microscopy. A 24-year-old man with spontaneous posterior interosseous nerve palsy was treated by interfascicular neurolysis at 29 weeks after onset. One fascicle in the radial nerve presented severe HLFC with torsion at 5 cm proximal to the elbow. Functional recovery was achieved by resection of the enlarged fascicle including HLFC and sural nerve grafting. Proximal to the HLFC, the endoneurium was filled with clusters of regenerating nerve fibers. At the level of the HLFC, a complete loss of myelinated nerve fibers and vascular occlusion of endo- and perineurial vessels were found. Few regenerating nerve fibers were observed. Distal to the HLFC, severe endoneurial edema, a complete loss of myelinated and unmyelinated nerve fibers, and bands of Büngner were noted. These electron microscopic findings demonstrated a detailed pathology of the nerve around the HLFC.

Nurse-like cells in rheumatoid arthritis: Formation of survival niches cooperating between the cell types.

Nurse-like cells (NLCs) established from bone marrow and synovial tissue of rheumatoid arthritis (RA) patients were found to promote maturation and differentiation of B lineage cells as well as T cells. In co-culture of RA-NLCs and B cells, tight physical interactions (pseudoemperipolesis) developed, which resulted in activation of both cell types. RA-NLCs also supported myeloid cell maturation, promoting their differentiation into tartrate-resistant acid phosphatase-positive mononuclear cells, which are precursor cells of osteoclasts. In RA synovial tissue, the characteristic dendritic-shaped cells (the DCs) were electron microscopically found to form direct physical interactions with adjacent plasma cells (PCs) suspecting to be pseudoemperipolesis. The numbers of PCs accumulating in various areas tended to correlate with the numbers of the DCs, which appeared to have RA-NLC functions forming survival niches for PCs. Immunohistochemical staining analysis indicated that CD14+ cells including the DCs formed survival niches for CD138+ PCs by RA-NLC functions. Quantitative dual immunofluorescence staining studies of these areas indicated that the majority of CD14+ cells were of myeloid lineage. These survival niches promoted by RA-NLCs appear to play important roles in supporting immunological functions in RA bone marrow and synovial tissues.

Cigarette Smoking Is Associated With Cubital Tunnel Syndrome.

INTRODUCTION: The aim of this study was to validate the potential association between cigarette smoking and cubital tunnel syndrome (CubTS). METHODS: One hundred patients with CubTS were compared with 100 controls with ulnar abutment syndrome matched for age, gender, and body mass index. The smoking status was compared between patients and controls using the sign test and the Wilcoxon signed rank test. Conditional logistic regression was used to calculate the association between CubTS and pack-years smoked. RESULTS: A significant association was found between increased pack-years smoked and CubTS. A significant difference in the number of never smokers and ever smokers was observed between the patients with CubTS and controls. The difference in mean pack-years in the patients and controls was highly significant. A dose-dependent association with pack-years was found between patients and controls. CONCLUSIONS: High cumulative cigarette smoking is associated with CubTS. Muscle Nerve 54: 1136-1138, 2016.

Risk factors associated with the occurrence of proximal humerus fractures in patients with rheumatoid arthritis: a custom strategy for preventing proximal humerus fractures.

To our knowledge, no prior report focused on the risk factors for proximal humerus fractures in patients with rheumatoid arthritis. The purpose of this study was to evaluate the association between potential risk factors and the occurrence of proximal humerus fractures in patients with rheumatoid arthritis. A total of 11,907 patients with rheumatoid arthritis were enrolled in our observational cohort rheumatoid arthritis study between 2000 and 2012. Self-reported proximal humerus fractures were verified using the patients' medical records. Cox proportional hazard models were used to analyze the independent contribution of risk factors to the occurrence of proximal humerus fractures. During follow-up (mean 5.6 years), 92 proximal humerus fractures were verified in 91 patients. Multivariate Cox regression analyses estimated that the hazard ratios of sustaining a proximal humerus fracture were 1.37 for every 10-year increase in age [95 % confidence interval (CI) 1.10-1.70; P < 0.01], 1.95 for increases in serum C-reactive protein levels (mg/100 mL; 95 % CI 1.15-3.34; P < 0.05), 2.13 for a history of fractures (95 % CI 1.34-3.40; P < 0.01), 1.07 for the daily prednisolone dose (per mg; 95 % CI 1.01-1.13; P < 0.05), and 1.97 for oral bisphosphonate use (95 % CI 1.20-3.23; P < 0.01). Better control of rheumatoid arthritis with a smaller daily prednisolone dose in elderly patients with a history of fractures may be important for preventing proximal humerus fractures.

Modified Extensor Pollicis Longus Rerouting Technique for Boutonniere Deformity of the Thumb in Rheumatoid Arthritis.

PURPOSE: To assess the outcomes of a modified extensor pollicis longus (EPL) rerouting technique for boutonniere deformity of the thumb in patients with rheumatoid arthritis. METHODS: A total of 21 thumbs in 18 patients with a mean age of 63 years were retrospectively analyzed after an average follow-up period of 3.2 years. The preoperative deformities were classified as either mild (5 thumbs) or moderate (16 thumbs). After either metacarpophalangeal (MCP) joint synovectomy or implant arthroplasty, the ulnarly dislocated EPL tendon was reduced dorsally and sutured to the dorsal base of the proximal phalanx. If the interphalangeal (IP) joint extended with manual traction on the proximal portion of the extensor pollicis brevis tendon, no further treatment was considered. If the IP joint did not extend with this maneuver, the insertion of the extensor pollicis brevis tendon was dissected and transferred to the distal portion of the EPL tendon. RESULTS: The average MCP joint extensor lag improved from 62° (range, 32° to 85°) before surgery to 17° (range, active extension 12° to extensor lag 70°) at the final follow-up (P < .05), whereas average MCP joint flexion decreased from 83° (range, 52° to 95°) to 68° (range, 30° to 90°) (P < .05). Hyperextension at the IP joint was improved from 30° (range, 10° to 50°) before surgery to an average extensor lag of 2° (range, extensor lag 24° to hyperextension 20°) at the final follow-up. The average combined MCP and IP motion did not significantly change. The boutonniere deformity was improved in 18 of 21 thumbs. The 3 failures all had moderate-stage deformity prior to treatment. CONCLUSIONS: A modified EPL rerouting technique provided satisfactory results together with a low risk of IP joint extension loss. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Three-dimensional anthropometric analysis of the glenohumeral joint in a normal Japanese population.

BACKGROUND: An understanding of normal glenohumeral geometry is important for anatomical reconstruction in shoulder arthroplasty. Unfortunately, the details of the glenohumeral joint in Asian populations have not been sufficiently evaluated. The purpose of this study was to evaluate the 3-dimensional geometry of the glenohumeral joint in the normal Japanese population and to clarify its morphologic features. METHODS: Anthropometric analysis of the glenohumeral joint was performed using computed tomography scans of 160 normal shoulders from healthy Japanese volunteers. The glenohumeral dimensions and orientation were analyzed 3-dimensionally. Sex differences and correlations between sides and among the respective parameters in the glenohumeral dimensions were evaluated. RESULTS: The normal Japanese humeral head has an average width of 41.4 mm, thickness of 13.2 mm, diameter of 42.9 mm, retroversion of 32°, and inclination of 135°. The glenoid has an average height of 31.5 mm, width of 23.1 mm, diameter of 62.0 mm, retroversion of 0°, and inferior inclination of 2°. The values of the glenohumeral dimensions were uniform in men and women, and the humeral head and glenoid were larger in men than in women. The glenohumeral size was well correlated between the 2 sides, and there were direct correlations among the heights, humeral length, humeral head size, and glenoid size. CONCLUSIONS: The present study revealed the glenohumeral geometry in the normal Japanese population. The present results would be useful to determine the size of implants and to improve the design of shoulder prostheses that reflect the normal anatomy of the Asian glenohumeral joint.

Association between position of the fixed ulnar head and carpal translocation after the Sauvé-Kapandji procedure in patients with rheumatoid arthritis.

OBJECTIVE: The Sauvé-Kapandji procedure is a common surgical procedure for rheumatoid wrist, which involves fixing dissected ulnar head to the distal radius in order to provide "bony support" to the carpus. The purpose of this study was to investigate whether the position of the fixed ulnar head was associated with postsurgical carpus translocation. METHODS: We retrospectively reviewed radiographs of 40 patients who underwent the Sauvé-Kapandji procedure and were subsequently followed up for over two years. The association between the fixed ulnar head position and postsurgical carpus translocation was statistically analysed with a confidence interval of 95% (p < 0.05). RESULTS: Multiple regression analysis suggested that the radial inclination of the fixed ulnar head, the absence of increases in ulnar variance, and wide "bony support" were significantly associated with less postsurgical carpal translocation. CONCLUSION: Our study indicated that good concordance between the "bony support" and the carpus might be important in reducing postsurgical carpus translocation.

Modified metacarpal shortening osteotomy of the midcarpal bone for preserving metacarpophalangeal joints in patients with rheumatoid arthritis.

Recent advances in medication choices have strikingly improved the management of rheumatoid arthritis. However, medication alone cannot place back already deformed joints. Thus, to prevent metacarpophalangeal (MP) joint destruction, joint deformity correction should be considered since mechanical stress induced by finger motions will eventually destruct the undestructed joint, with a possibility of recurrence and future implant arthroplasty in mind since RA still remains as a progressive disease. We report a modified metacarpal shortening osteotomy for correcting MP joint deformity. The advantage of our technique over previous osteotomies is that it easily allows for subsequent implant arthroplasty even after the recurrence of joint deformity/destruction. Major modifications include that the metacarpal is shortened at its mid-shaft and the osteotomy is performed vertical to the shaft and fixed with surgical wiring. We believe that combination therapy consisting of medication and surgery is preferable to prevent joint destruction, even in this age of biological agents.

Subcutaneous flexor tendon rupture in patients with rheumatoid arthritis.

OBJECTIVE: We examined the clinical features and functional outcomes of surgically repaired subcutaneous flexor tendon ruptures in patients with rheumatoid arthritis (RA). METHODS: This retrospective study included 41 fingers of 24 RA patients who underwent surgical treatment for flexor tendon ruptures. Evaluations performed at the time of presentation following rupture were C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and disease activity score in 28 joints (DAS28)-ESR, as well as Larsen grading for carpal bone destruction. The ruptured tendon and postoperative active range of motion (ROM) of digits were also examined. RESULTS: The mean CRP was 2.4 mg/dl, ESR was 52 mm/h, and the DAS28-ESR was 4.5. Carpal bone destruction according to Larsen grade IV-V was observed in 18/24 patients. Affected digits were most commonly the thumb (12) and the ring and little fingers (9 each). Tendon ruptures were most common in the carpal tunnel in zone IV. The mean postoperative finger ROM (flexion/extension) was 38°/2° for the interphalangeal (IP) joint of the thumb and 23°/-2° for the distal interphalangeal joint of the other four fingers. CONCLUSIONS: Patients with flexor tendon ruptures present with high disease activity and advanced bone destruction. It is important to reduce the risk of progressive bone destruction and subsequent tendon rupture via tight control of disease activity.

Comparison of surgical treatments for triple extensor tendon ruptures in rheumatoid hands: A retrospective study of 48 cases.

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.

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

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.

Construct validity, reliability, response rate, and association with disease activity of the quick disabilities of the arm, shoulder and hand questionnaire in the assessment of rheumatoid arthritis.

OBJECTIVE: First objective is to validate the Disabilities of the Arm, Shoulder and Hand (DASH) and Quick DASH (QuickDASH) questionnaire in rheumatoid arthritis (RA) patients with functional upper extremity impairment. Next is to clarify which clinical factor is associating with QuickDASH using a large cohort of RA. METHODS: The QuickDASH and DASH were applied to our 94 RA patients who underwent surgery for functional upper extremity impairment. Next, the QuickDASH was applied to our cohort of 5191 Japanese patients with RA. RESULTS: In the first cohort of 94 RA patients, both QuickDASH and DASH displayed excellent reliability and validity. The response rate of patients < 65 and ≥ 65 years of age showed significant difference in the DASH but not in the QuickDASH. In the second cohort with 5191 RA patients, QuickDASH showed a high response rate (93%) and good to moderate correlation with Japanese version of the Health Assessment Questionnaire (r = 0.88) and disease activity score of 28 (DAS28, r = 0.53). Change in QuickDASH score and DAS28-based European League Against Rheumatism response showed significant correlation. CONCLUSION: QuickDASH seems suitable for evaluating upper extremity impairment, disability index, and disease control in a large cohort of RA patients including elderly patients.

Validity and responsiveness of a self-administered foot evaluation questionnaire in rheumatoid arthritis.

OBJECTIVES: A self-administered foot evaluation questionnaire (SAFE-Q) was developed by the Japanese Society for Surgery of the Foot (JSSF). The aim of this study is to evaluate the validity and responsiveness of the SAFE-Q in patients with rheumatoid arthritis (RA). METHODS: In total, 180 patients with RA answered the SAFE-Q. Of 180 patients, 34 answered the SAFE-Q twice, preoperatively and postoperatively, to assess responsiveness. Construct validity was tested by comparing the 5 SAFE-Q subscales and the JSSF standard rating system for the RA foot and ankle scale (JSSF-RA), a Japanese version of the Health Assessment Questionnaire (JHAQ), disease activity score in 28 joints (DAS28), simplified disease activity index (SDAI), and clinical disease activity index (CDAI). Responsiveness was examined by calculating the standardized response mean (SRM) and effect size (ES) 3 months after surgery. RESULTS: There were moderate correlations between the SAFE-Q and the JSSF-RA and JHAQ. Conversely, a low correlation was observed between the SAFE-Q and DAS28, SDAI, and CDAI. The responsiveness was high, with an SRM of 0.9 and ES of 0.7 for pain subscales. CONCLUSION: SAFE-Q is a useful tool for assessing the foot and ankle in RA patients.

Risk factors for established vertebral fractures in Japanese patients with rheumatoid arthritis: Results from a large prospective observational cohort study.

OBJECTIVE: The aim of this study was to evaluate the associations between potential risk factors and the occurrence of established vertebral fractures in Japanese patients with rheumatoid arthritis (RA). METHODS: A total of 10,469 patients with RA were enrolled in a prospective, observational study from 2000 to 2011. Self-reported vertebral fractures were verified using patient's medical records and radiographs. Cox proportional hazards models were used to analyze independent contributions of various risk factors for established vertebral fracture occurrence. RESULTS: During a mean follow-up of 5.8 years, established vertebral fractures in 170 patients were verified with medical records and radiographs. Multivariate Cox regression analyses estimated that the hazards ratios of sustaining vertebral fractures increased by 1.84 for female gender, 1.72 for every 10 years of increased age, 1.26 for Disease Activity Score in 28 joints (DAS28), 1.44 for Japanese Health Assessment Questionnaire-Disability Index (J-HAQ-DI), 2.21 for history of any previous fractures, and 1.09 for daily prednisolone dose (mg/day). CONCLUSION: We confirmed the associations between vertebral fractures and advanced age, J-HAQ-DI, and high daily prednisolone dose; and found significant correlations between vertebral fractures and female gender, DAS28, and history of any previous fracture in Japanese RA patients.

Polyarthritis and posterior interosseous nerve palsy associated with gastric carcinoma.

Cancer polyarthritis is a very rare condition. Here, we present a case of cancer polyarthritis, who also had mononeuritis simplex as a manifestation of paraneoplastic neuralgic syndrome. A 71-year-old man, who initially presented symmetrical polyarthritis and unilateral posterior interosseous nerve palsy, was subsequently diagnosed to have gastric cancer. Total gastrectomy was performed, and his polyarthritis and the palsy simultaneously disappeared within 2 weeks after the resection. His gastric cancer was found to be metastasized to his liver 16 months after the total gastrectomy; however, the polyarthritis and the palsy did not recurrent throughout his course. The polyarthritis in this case was diagnosed as a cancer polyarthritis from its features. On the other hand, the isolated posterior interosseous nerve palsy in this case met the diagnostic criteria for paraneoplastic neurological syndrome. This case was also unique in that the manifestations of paraneoplastic syndromes did not recur even after the metastasis of the primary cancer, suggesting that some specific clones in the cancer were responsive to the manifestations of paraneoplastic syndromes. Our case suggested that relapse of the manifestations of paraneoplastic syndromes may not always herald the recurrence of primary or metastatic tumour, and other tumour markers and signs should be periodically followed to search for the recurrence of the tumours.

A modification of the palmaris longus-to-extensor pollicis longus transfer for radial nerve palsy.

PURPOSE: The standard palmaris longus (PL)-to-rerouted extensor pollicis longus (EPL) transfer was modified by taking the PL with an extension of the palmar aponeurosis (PA) and performing the transfer at the level of the thumb metacarpal. Our purpose was to evaluate whether this modified transfer could restore both the extension and the radial abduction of the thumb without rerouting the EPL. METHODS: We restored thumb function of 5 patients with unrecovered radial nerve palsy (4 men and 1 women; mean age at surgery, 47 years; mean duration between onset of palsy and surgery, 13 months; and mean follow-up period after surgery, 17 months). The PA was dissected in continuity with the PL (PA/PL) tendon, as is done in Camitz thumb opponensplasty. Another skin incision was made on the dorsal side of the thumb metacarpal, and the EPL tendon was exposed. The PA/PL tendon was drawn into this skin incision, passing under the abductor pollicis longus and extensor pollicis brevis tendons. The PA/PL tendon was woven into the undivided EPL tendon and immobilized for 3 weeks. RESULTS: The mean values of active hyperextension and flexion of the interphalangeal joint, radial abduction, palmar abduction of the thumb, grip strength, and tip pinch strength of the involved/contralateral sides were 3°/7°, 41°/49°, 59°/65°, 65°/70°, 37 kg/47 kg, and 4.0 kg/5.2 kg, respectively. DISCUSSION: We used the PA to lengthen the PL tendon, to transfer it to the EPL at a level distal to the Lister tubercle. Because our procedure is based on the concept of standard transfer, it should yield similar long-term results. Our procedure should be a good alternative, especially in cases of closed radial nerve injury, because it preserves the paralyzed EPL for possible future recovery.

Shoulder internal rotation elbow flexion test for diagnosing cubital tunnel syndrome.

BACKGROUND: Shoulder internal rotation enhances symptom provocation attributed to cubital tunnel syndrome. We present a modified elbow flexion test--the shoulder internal rotation elbow flexion test--for diagnosing cubital tunnel syndrome. METHODS: Fifty-five ulnar nerves in cubital tunnel syndrome patients and 123 ulnar nerves in controls were examined with 5 seconds each of elbow flexion, shoulder internal rotation, and shoulder internal rotation elbow flexion tests before and after treatment (surgery in 18; conservative in others). For the shoulder internal rotation elbow flexion test position, 90° abduction, maximum internal rotation, and 10° flexion of the shoulder were combined with the elbow flexion test position. The test was considered positive if any symptom for cubital tunnel syndrome developed <5 seconds. Influence of the shoulder internal rotation elbow flexion test was evaluated by nerve conduction studies in 10 cubital tunnel syndrome nerves and 7 control nerves. RESULTS: The sensitivities/specificities of the 5-second elbow flexion, shoulder internal rotation, and shoulder internal rotation elbow flexion tests were 25%/100%, 58%/100%, and 87%/98%, respectively. Sensitivity differences between the shoulder internal rotation elbow flexion test and the other two tests were significant. Shoulder internal rotation elbow flexion test results and cubital tunnel syndrome symptoms were significantly correlated. Influence of the shoulder internal rotation elbow flexion test on the ulnar nerve was seen in 8 of 10 cubital tunnel syndrome nerves but not in controls. CONCLUSIONS: The 5-second shoulder internal rotation elbow flexion test is specific, easy and quick provocative test for diagnosing cubital tunnel syndrome.

Distal radius fracture after Sauvé-Kapandji procedure in a rheumatoid arthritis patient.

We report a case of distal radius fracture after a Sauvé-Kapandji procedure combined with synovectomy and tendon transfer in a rheumatoid arthritis patient. This case shared several unusual features that were also seen in a previously reported case. Based on these features, we discuss favorable surgical treatment for the rheumatoid wrist with extensor tendon rupture, and also the optimal treatment for distal radius fracture after such procedures.

Association between the elbow flexion test and extraneural pressure inside the cubital tunnel.

PURPOSE: The elbow flexion test is a standard, provocative diagnostic test for cubital tunnel syndrome (CubTS). The purpose of this study was to investigate the association between the elbow flexion test and the degree of extraneural pressure in the cubital tunnel of CubTS patients. METHODS: Extraneural pressure on the ulnar nerve in the cubital tunnel was evaluated using 0.7-mm thickness catheter during surgery of 25 CubTS cases and compared with the results of preoperative elbow flexion testing. Statistic analysis was performed using Student's t-test with a confidence level of 95% (p < .05). RESULTS: Forty-eight percent of the patients were positive for the elbow flexion test. Mean extraneural pressure was significantly higher in maximum elbow flexion than in maximum elbow extension (p < .001). No significant association was seen between the result of 45 seconds of the elbow flexion test and the extraneural pressure in the cubital tunnel induced by maximum elbow flexion (p = .45). CONCLUSIONS: Our results suggested that the mechanism of provocation of symptoms of CubTS by the elbow flexion could not be explained simply by dynamic pressure in the cubital tunnel, and other pathophysiological factors could also be contributing. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic III.