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.

A Well-Differentiated Liposarcoma in the Digit: A Case Report of the 5-Year Post-Surgical Follow-Up.

A liposarcoma is extremely rare in the digits. A 73-year-old woman was diagnosed with a lipoma in her middle finger 10 years ago. As this tumor increased in size and presented with imaging findings that were atypical of lipomas, careful marginal resection biopsy outside the pseudo-capsule was performed, and the tumor was diagnosed as a well-differentiated liposarcoma. At the 5-year follow-up, the patient showed no evidence of local recurrence or metastasis, with no loss of hand function. The findings from this case suggest that even for a lipomatous tumor in the digits, further imaging examination and resection biopsy should be considered if the tumor presents with features that are atypical of lipomas.

Osteoid Osteoma of the Distal Phalanx of the Ring Finger with Clubbed Finger Deformity: A Case Report.

Osteoid osteoma of the distal phalanx is very rare. We describe a case of osteoid osteoma of the distal phalanx of the ring finger with clubbed finger deformity that improved after tumour removal. A 50-year-old left-handed man presented with a history of right ring finger pain without any trauma. The distal phalanx of the ring finger had tender, redness, and a clubbed finger deformity. Plain radiography indicated a circular radiolucent area in the centre of the lesion. Computed tomography and gadolinium enhanced magnetic resonance imaging indicated presence of a nidus. The lesion was removed via the transungual approach. Histopathological examination confirmed the presence of an osteoid osteoma. His pain was immediately relieved after surgery. At the 2-year followup, he had no pain and the clubbed finger deformity had improved. In cases where clubbed finger deformity involves only one finger, the possibility of chronic osteomyelitis or osteoid osteoma should be considered.

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.

Osteochondritis dissecans on the medial aspect of the humeral head.

The case of a 29-year-old man who had osteochondritis dissecans on the medial aspect of the humeral head is reported. Repetitive micro-trauma at a low elevated arm position was thought to have induced the osteochondral lesion.

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.

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.

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.

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.

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 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.

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.

Reconstruction of the Scapholunate Ligament Using Capitohamate Bone-Ligament-Bone.

Background The biomechanical properties of the capitohamate (CH) ligament are equivalent to those of the scapholunate (SL) interosseous ligament. We reconstructed the SL ligament using the CH bone-ligament-bone substitute for chronic injury of the SL ligament. Patients and Methods Beginning in 2008, 15 wrists of 14 patients with an average age of 38 years underwent this procedure with a minimum follow-up of 2 years. Thirteen wrists had an SL joint gap more than 3 mm, and two had a complete SL ligament disruption with a severe dorsal intercalated segment instability (DISI) deformity. Kirschner wires (K-wires) were removed 8 weeks after the surgery, then active ROM exercise began. Pain (on visual analog scale [VAS]), wrist motion (angle), radiographic characteristics, such as SL gap (mm) and SL angle, and Modified Mayo Wrist Score (MMWS) were evaluated. Technique The SL joint was reduced by manipulation or with the use of joysticks, then temporary fixed with K-wires. A dorsal trough was then made between the scaphoid and the lunate. The proximal half of the CH ligament was harvested with attached bone from the capitate and hamate (CH bone-ligament-bone), inset into the SL trough, and fixed firmly with 1.2-mm diameter titanium screws in the scaphoid and lunate, respectively. Results The VAS improved from 77 preoperatively to 12 postoperatively. The average wrist extension/flexion was 74°/60°. There was no ossification of the reconstructed SL at the final follow-up. The SL gap improved from an average of 4.8 mm to an average of 2.1 mm, and the SL angle changed from 67° to 55°. The MMWS improved to 82 points postoperatively from a preoperative average of 47 with eight excellent, five good, and two fair results.

Interfascicular Neurolysis for Incomplete Spontaneous Posterior Interosseous Nerve Palsy with a Surgical Delay of 17 Years: Is It Still Effective?

A 55-year-old woman with incomplete spontaneous posterior interosseous nerve (PIN) palsy underwent interfascicular neurolysis and tendon transfer, 17 years after its onset. After one year, her nerve function partially recovered electrophysiologically. This case suggests that incomplete spontaneous PIN palsy may recover by interfascicular neurolysis, even with a long preoperative delay.

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.