What is the Radiographic Factor Associated with Meniscus Injury in Tibial Plateau Factures? Multicenter Retrospective (TRON) Study

Purpose

Tibial plateau fracture (TPF) is a complex intra-articular injury involving comminution and depression of the joint, which can be accompanied by meniscal tears. The aims of this study were (1) to demonstrate the rate at which surgical treatment for lateral meniscal injury and (2) to clarify the explanatory radiographic factors associated with meniscal injury in patients with TPF.

Methods

We extracted the patients who received surgical treatment for TPF from our multicenter database (named TRON) included from 2011 to 2020. We analyzed 79 patients who were received surgical treatment for TPF with Schatzker type II and III and evaluation for meniscal injury on arthroscopy. We investigated the rate at which surgical treatment of the lateral meniscus was required in patients with TPF and the explanatory radiographic factors associated with meniscal injury. Radiographs and CT scans were evaluated to measure the following parameters: tibial plateau slope, distance from lateral edge of the articular surface to fracture line (DLE), articular step, and width of articular bone fragment (WDT). Meniscus tears were classified according to whether surgery was necessary. The results were analyzed by multivariate Logistic analyses.

Results

We showed that 27.7% (22/79) of cases of TPF with Schatzker type II and III had lateral meniscal injury that required repair. WDT ≥ 10 mm (odds ratio 10.9; p = 0.005) and DLE ≥ 5 mm (odds ratio 5.7; p = 0.05) were independent explanatory factors for meniscal injury with TPF.

Conclusion

Bone fragment size and the location of fracture line on radiographs in patients with TPF are associated with meniscus injuries requiring surgery.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-023-00888-5.

Neutron resonance absorption imaging of simulated high-level radioactive waste in borosilicate glass

We performed a preliminary study of neutron resonance absorption imaging to investigate the spatial distribution of constituent elements in borosilicate glasses containing simulated high-level radioactive waste, in which elemental inhomogeneities affect the physical and chemical stabilities of the glass. Dips generated by the resonance absorptions of Rh, Pd, Na, Gd, Cs, and Sm were observed in the neutron transmission spectra of the glass samples. The spatial distributions of these elements were obtained from the neutron transmission images at the resonance energies. The distributions of Rh and Pd visualized the sedimentation of these platinum group elements. In contrast, the lanthanides (Gd and Sm) and Cs were uniformly dispersed. These results show that neutron resonance absorption imaging is a promising tool for characterizing borosilicate glasses and investigating the vitrification mechanism of high-level radioactive waste.

Risk factors for rupture of extensor tendons in the rheumatoid wrist

This study assessed the risk factors for spontaneous extensor tendon rupture in the rheumatoid wrist. The rupture group consisted of 25 wrists that had rupture of the extensor tendons and later received tendon reconstruction. The non-rupture group included 77 rheumatoid wrists without extensor tendon rupture. We assessed patients' pain at the distal radioulnar joint and swelling in the extensor tendon compartments clinically, matrix metalloproteinase-3 level in blood samples, and radiographic findings. We found that swelling in the extensor tendon compartments, the scallop sign, and severe dorsal subluxation are significantly associated with spontaneous extensor tendon rupture, but serum matrix metalloproteinase-3 level is not.Level of evidence: IV.

Platelet volume indices correlate to severity of heart failure and have prognostic value for both cardiac and thrombotic events in patients with congenital heart disease

Introduction

Patients with heart failure are reported to have activated platelets leading to thrombotic events. Consequently, immature giant platelets are produced, and platelet distribution width (PDW) and mean platelet volume (MPV) increase. These platelet indices are easily, reasonably, and safely available by routine blood test and recently have been proposed as potential markers of cardiac events. However, little is known about the usefulness of platelet indices in patients with congenital heart disease (CHD).

Purpose

To test whether the hypothesis that PDW and MPV correlate to the severity of heart failure and have prognostic value in both future heart failure-related admission and thrombosis formation in patients with CHD.

Methods

We performed a retrospective, single-centre study that included 400 patients with CHD (median age, 34 years [range: 12–76]; 49% males; 35% single ventricular morphology), who were admitted in our institute between April 2014 and June 2017. We reviewed patients' medical records to assess their clinical information including medical history, blood sample data, and echocardiologic parameters. At first, we assessed the correlation between platelet indices and patients' clinical parameters. Next, we compared platelet indices before and after treatment for heart failure. Finally, using logistic regression and Kaplan-Meier analyses, we assessed prognostic factors of future heart failure-related admission and thrombosis formation.

Results

In multivariate analysis, a significant correlation was found between PDW and logBNP (brain natriuretic peptide) (p<0.001), haemoglobin (p=0.01), D-dimer (p=0.019), Fontan operation (p<0.001) and male sex (p<0.001); as well as between MPV and logBNP (p<0.001), D-dimer (p<0.001) and Fontan operation (p=0.002). Throughout treatment of heart failure, significant reduction was found both in PDW (average value before treatment = 14.2, after treatment = 13.2, p=0.002) and MPV (before = 11.2, after = 10.8, p=0.004). In multivariate logistic regression analysis, predictors of future heart failure-related admissions were PDW (hazard ratio [HR]: 1.365; 95% confidence interval [CI]: 1.005–1.768), MPV (HR: 1.472; 95% CI: 1.055–2.052), age (HR: 1.063; 95% CI: 1.010–1.119), and SpO2 under 85% (HR: 5.089; 95% CI: 1.350–19.18). Using the same analysis, predictors of thrombotic formation were PDW (HR: 1.998; 95% CI: 1.461–2.630), MPV (HR: 1.792; 95% CI: 1.155–2.781), logBNP (HR: 1.196, 95% CI: 1.085–1.320), D-dimer (HR: 1.024; 95% CI: 1.007–1.042) and male sex (HR: 3.071; 95% CI: 1.079–8.737). In addition, during median follow-up of 28 months, the Kaplan-Meier analysis showed an improvement in both heart failure and thrombosis-free survival in the low PDW, as well as the low MPV group.

Conclusion

Platelet volume indices correlate to severity of heart failure and have prognostic value for both cardiac and thrombotic events in patients with congenital heart disease.

Funding Acknowledgement

Type of funding source: None

Long-term prognosis in patients with non-type 1 Brugada ECG: results from a large Japanese cohort of Brugada syndrome

Background

Most recent consensus conference report recommends Brugada syndrome (BrS) is diagnosed in patients with ST segment elevation with spontaneous, drug-induced or fever-induced type 1 morphology. Prognosis in patients with type 2 or 3 ECG without drug-induced or fever-induced type 1 ECG is still unknown.

Purpose

To evaluate a long-term prognosis in patients with non-type 1 Brugada ECG in a large Japanese cohort of BrS (The Japan Idiopathic Ventricular Fibrillation Study [J-IVFS]).

Methods

From 528 patients in J-IVFS, a total of 28 consecutive non-type 1 patients (54±14 years, all male, previous sustained ventricular tachyarrhythmias (VTs) 1, syncope 11, asymptomatic 16) were enrolled. Cardiac events (CI: sudden cardiac death or VTs) during the follow-up period were evaluated, and risk factors for the cardiac events were assessed.

Results

During a mean follow-up period of 111±91 months (median 134 months), 4 patients experienced cardiac events (1.5%/yr), who all had received implantable cardioverter defibrillator implantation. There was no statistically significant clinical risk factor for cardiac events. However, the incidences of cardiac events tended to be higher in symptomatic patients (CI: 25.0, non-CI: 6.3%, p=0.17), those with wide QRS duration >90 msec in lead V2 (CI: 30.0, non-CI: 6.3%, p=0.11), and those with inducible VTs (CI: 21.1, non-CI: 0%, p=0.20), as determined by the Kaplan-Meier method. The annual incidences of cardiac events in patients with symptom, wide QRS duration >90msec in lead V2, or inducible VTs were 2.8, 3.5, and 2.0%/yr, respectively. The incidences of cardiac events were significantly higher in patients with all these 3 factors (9.9%/yr) than those without (p=0.01).

Conclusions

Our large-scaled multicentre study revealed long-term prognosis in patients with non-type 1 Brugada ECG. The combination of symptom, wide QRS duration in lead V2, and inducible VTs may be useful to evaluate risk for cardiac events. The patients with all these parameters showed high risk for cardiac events and need to be carefully followed.

Funding Acknowledgement

Type of funding source: None

An experimental setup for creating and imaging 4He2 * excimer cluster tracers in superfluid helium-4 via neutron-3He absorption reaction

For the purpose of future visualization of the flow field in superfluid helium-4, clusters of the triplet state excimer ⁴He₂ ^* are generated along the micro-scale recoil tracks of the neutron-absorption reaction n + ³He → ³T + p. This reaction is induced by neutron irradiation of the ³He fraction contained in natural isotopic abundance liquid helium with neutron beams either from the Japan Proton Accelerator Research Complex, Materials and Life Science Experimental Facility (JPARC)/Materials and Life Science Experimental Facility or from the Kyoto University Institute for Integrated Radiation and Nuclear Science. These ⁴He₂ ^* clusters are expected to be ideal tracers of the normal-fluid component in superfluid helium with several advantageous properties. Evidence of the excimer generation is inferred by detection of laser induced fluorescence emitted from the ⁴He₂ ^* clusters excited by a purpose-built short pulse gain-switched titanium:sapphire (Ti:sa) laser operating at a wavelength of 905 nm. The setup and performance characteristics of the laser system including the Ti:sa and two continuous wave re-pumping lasers are described. Detection at the fluorescence wavelength of 640 nm is performed by using optical bandpass filtered photomultiplier tubes (PMT). Electrical noise in the PMT acquisition traces could successfully be suppressed by post-processing with a simple algorithm. Despite other laser-related backgrounds, the excimer was clearly identified by its fluorescence decay characteristics. Production of the excimer was found to be proportional to the neutron flux, adjusted via insertion of different collimators into the neutron beam. These observations suggest that the apparatus we constructed does function in the expected manner and, therefore, has the potential for groundbreaking turbulence research with superfluid helium.

A magnetoencephalographic study of longitudinal brain function alterations following carpal tunnel release

We investigate changes in brain function before and after carpal tunnel release. Magnetoencephalography (MEG), during which we recorded somatosensory evoked cortical magnetic fields (SEFs), and a clinical evaluation were performed before surgery and 6 months after. The distance on the vertical axis between the equivalent current dipoles (ECDs) for the first and third digits before surgery was significantly less than after surgery. There were no significant differences in values between the control participant and patients after surgery. In terms of distal motor latency, there was a negative correlation with the distance. The recovery function of the root mean square (RMS) before surgery for the N20m was less suppressed at 10 ms of ISI in patients, compared to controls. There were no significant differences in the RMS values for patients before and after surgery. Our results indicate that treating peripheral nerve lesions, such as in carpal tunnel release, positively modifies brain function.

P5029Inducibility of ventricular tachyarrhythmias by up to two extrastimuli does not predict future cardiac events in asymptomatic Brugada patients: results from long-term follow-up

Background

Most recent consensus conference report recommends Implantable Cardioverter Defibrillator (ICD) implantation for asymptomatic Brugada patients with spontaneous or fever-induced type-1 ECG (A-BrS) and inducible ventricular tachyarrhythmias (VTs) by up to two extrastimuli as class IIb indication. However, the validity of the inducible VTs by up to two extrastimuli in A-BrS is still unknown.

Purpose

To evaluate the validity of the inducibility by up to two extrastimuli in A-BrS in a large Japanese cohort of BrS (The Japan Idiopathic Ventricular Fibrillation Study [J-IVFS]).

Methods

A total of 193 consecutive A-BrS patients performed programmed electrical stimulation (PES) with non-aggressive uniform protocol (mean age 50±13 years, 180 males) were enrolled. PES protocol was using 2 basic pacing cycles and the order of introduction of up to 2 ventricular extra-stimuli from right ventricular apex [RVA] first, then right ventricular outflow tract [RVOT], 3 ventricular extra-stimuli from RVA then RVOT down to the minimum of 200ms. Clinical outcomes during the follow-up period were compared between A-BrS patients with and without inducible VTs by up to two extrastimuli.

Results

Thirty-five A-BrS (18%) had inducible VTs by up to two extrastimuli. During a mean follow-up period of 101±48 months, 7 A-BrS experienced cardiac events (sudden cardiac death [SCD] or VTs, 0.4%/yr). None of the 7 A-BrS had inducible VTs by up to two extrastimuli. The incidences of cardiac events tended to be higher in A-BrS without inducible VTs by up to two extrastimuli than in those with inducible VTs (p=0.10), as determined by the Kaplan-Meier method. In the A-BrS, the annual incidences of cardiac events in A-BrS with family history of SCD, inferolateral J wave, wide QRS duration >90msec in lead V2, or inducible VT/VF by 3 extrastimuli were 0.7, 0.7, 0.6, and 0.3%/yr, respectively.

Conclusions

Our large-scaled multicentre study with long-term follow-up revealed the inducibility of ventricular tachyarrhythmias by up to two extrastimuli does not predict future cardiac events in A-BrS, even using non-aggressive uniform protocol. Rather, other parameters such as family history of SCD or inferolateral J wave might be helpful for risk assessment in A-BrS.

4090Maximum standardized uptake value of pericardial fat for prediction of ventricular arrhythmias in patients with cardiac sarcoidosis

Background

Cardiac sarcoidosis is a cause of epicarditis and sustained life-threatening ventricular arrhythmias. These arrhythmias occasionally arise from epicardial. Positron emission tomogramphy-comututed tomography (PET-CT) is useful for diagnosis with sarcoidosis. However, the usefulness for prediction of ventricular arrhythmias in patients with cardiac sarcoidosis is unknown.

Objective

We hypothesized that the evaluation of pericardial fat inflammation could identify high-risk sarcoidosis patients for ventricular arrhythmias.

Methods

We enrolled 20 consecutive patients with cardiac sarcoidosis performed PET-CT between August 2016 and December 2018. In each case, we measured the maximum standardized uptake value (SUVmax) of pericardial fat around the left atrium, both ventricules, atrioventricular groove, and left main coronary.

Results

Seven patients experienced ventricular tachycardia (VT) or ventricular fibrillation (VF). VT/VF patients had significantly more complete right bundle branch block (P=0.035), larger left atrial dimension (P=0.021), larger left ventricular end-diastolic dimension (P=0.005), lower ejection fraction (P=0.007), and higher E/e' (P=0.004). SUVmax of pericardial fat in the roof of left atrium (LA) and left ventricular (LV) with VT/VF patients were significantly higher than non-VT/VF patients (LA: 1.63 vs 1.32, P=0.0311; LV: 1.84 vs 1.26, P=0.045). The cut-off values of SUVmax derived from the ROC curve in the roof of LA and LV are 1.47 and 1.59 respectively. The Kaplan Meire estimator showed that high SUVmax patients in the roof of LA had significantly more detection of NSVT.

Conclusions

Our results suggest the relationship between SUVmax and VT/VF occurrence in patients with cardiac sarcoidosis. The evaluateon of SUVmax may be useful for VT/VF risk stratification.

P1628Angiopoietin-like protein (Angptl) 2 secreted from epicardial adipose tissue induces atrial myocardial fibrosis

Background

Using excised human left atrial appendage samples, we previously demonstrated that epicardial adipose tissue (EAT) are highly associated with atrial myocardial fibrosis as a substrate of atrial fibrillation (AF). We also reported the relationship between Angptl2 in EAT and atrial fibrosis. However, the mechanism is not clear. The purpose is to clarify the mechanisms underlying the effect of EAT on the atrial myocardium.

Methods

Human peri-left atrial EAT and abdominal subcutaneous adipose tissue (SAT) samples were obtained from 6 cases (2 females, 70.2±13.2 years). 50 mg of EAT and SAT were quickly washed with PBS and centrifuged 1min at 1200rpm. After 3 times this procedures, adipose tissues were cultured in DMEM F12 medium with Fetal bovine Serum (FBS) overnight.

After pre-incubation, EAT and SAT tissues were washed and centrifuge d three times and cultured in medium without FBS for 24hours. Finally, we collected oozed medium (conditioned medium) and used for experiments.

Concentrations of Angptl2 in conditioned medium were measured by ELISA.

To study the effects of conditioned medium, we used “organo-culture” system. Isolated atrium from 8week old male Sprague-Dawley rats were placed on the porous membrane with the endothelial face toward the membrane. After that, loading medium (conditioned medium:culture medium = 1:4), culture medium (control), or recombinant Angptl2 were dropped onto the epicardial face of the atrium once a day and incubated for 7 days (37°C, 5% CO2).

Then, histological and immunohistochemical analysis were performed. We also performed quantitative reverse transcription–polymerase chain reaction (RT–PCR) analysis.

Next, we isolated and cultured neonatal rat fibroblast and loaded Angptl2 for 24 hours.After collected these cells, we performed western blotting analysis.

Results

Atria organo-culture incubated for 7 days with conditioned medium showed global fibrosis. At epicardial side, fibrotic area of EAT group was significantly greater compared to that of SAT and control group (P<0.05).

mRNA of Col1a1, col3a1 and TGFβ1 were significantly increased in EAT group compared with the SAT and control group.

And, the concentration of conditioned medium created from EAT was significant higher than that from SAT (P<0.05).

Then, we dropped 500 ng/ml of recombinant Angptl2 onto the rat atria. Fibrotic area of Angptl22 group significantly greater than that of control with increasing number of α-SMA positive cells, and mRNA of col3a1 and TGFβ1 were significantly increased in Angptl2 group compared with control group.

In cultured fibroblasts, α-SMA and p-ERK expression were increased in Angptl2 group measured by western blotting analysis.

Conclusions

Our results demonstrated that EAT rather than SAT induces atrial myocardial fibrosis. There is a possibility that Angptl2 effused from EAT plays a part in atrial fibrosis thought EAT paracrine effect.

Acknowledgement/Funding

ONO PHARMACEUTICAL CO

Incomplete Ossification of the Scaphoid Mimicking Obvious Radiographic Scapholunate Dissociation: A Case Report

We report a patient of Scapholunate (SL) injury in which radiography revealed obvious SL dissociation with dorsal intercalated segment instability deformity, but arthroscopy showed a SL gap of less than 2 mm. Radiographs of the uninjured wrist showed a SL interval of 3.0 mm and a SL angle of 80°. Preoperative magnetic resonance imaging showed low signal intensity in the proximal portion of the scaphoid and a mild SL gap on T1-, T2-weighted, and T2-weighted fat-suppressed images. Midcarpal wrist arthrography revealed a small amount of contrast media leakage through the SL interval. It was considered that incomplete ossification of the scaphoid mimicked obvious radiographic SL dissociation.

Distal radius nonunion after volar locking plate fixation of a distal radius fracture: a case report

We describe a 59-year-old man who had nonunion of a right distal radius fracture after volar locking plate fixation. He underwent open reduction and internal fixation with a volar locking plate system for a dorsally displaced, unstable distal radius fracture at a previous hospital 5 months ago. Radiographs of the injured wrist showed nonunion of the distal radius with 1.5-mm ulnar minus variance. Radiographs of the unaffected wrist showed 3.5-mm ulnar plus variance. Intraoperative findings of surgical revision showed an unstable nonunion; thus, debridement of the nonunion, autogenous inlay bone grafting, and internal fixation using another type of volar locking plate system were performed. Healing of the re-operative site was confirmed radiographically 3 months postoperatively. We considered that volar locking plate fixation with excessive distraction of the fracture may lead to nonunion.

Wrist Swelling in Kienböck's Disease

Background and Purpose  Wrist swelling is a frequent clinical manifestation of Kienböck's disease, but no study has reported the site and pathology of wrist swelling in this disease. The aim of this study is to elucidate the site and pathology of wrist swelling in Kienböck's disease. Materials and Methods  Dorsal and palmar soft tissue thicknesses of the wrist were measured on standard lateral radiographs of the wrist in 26 patients with Kienböck's disease and 30 subjects without intra-articular lesion. Axial magnetic resonance imaging (MRI) views were examined to detect the site of swelling. The dorsal capsular ligament in three patients with Kienböck's disease underwent histological examination. Results  Radiographic study confirmed dorsal wrist swelling in 24 of 26 (92%) patients examined compared with the contralateral unaffected wrists. MRI demonstrated thickening of the dorsal capsular ligament and extensor layer with synovial proliferation. Histological examination revealed nonspecific chronic inflammation. Conclusion  Dorsal wrist swelling in Kienböck's disease is a common manifestation and constitutes a part of pathology of Kienböck's disease, although further study is required to clarify the relation between wrist swelling and etiology of Kienböck's disease. Level of Evidence  This is a Level III study.

Treatment with the MAPK kinase inhibitor U0126 during the first two hours of in vitro maturation improves bovine oocyte developmental competence

This study examined the effects of treatment with U0126, which inhibits MAPK by inhibiting MAPK kinase, during the first 2 hr of in vitro maturation on bovine developmental competence and on gap junction (GAPJ) communication between the oocyte and cumulus cells. The percentage of oocytes developing to the blastocyst stage in the group treated with 5 μM U0126 (28%) was significantly higher than that in controls (15%, p < .05), while that in the group treated with 10 μM U0126 (18%) was not. Breakdown of the GAPJs was delayed in the group treated with 5 μM U0126 when compared to controls, as estimated by immunohistochemical examination of connexin 43, which is a primary constituent of the GAPJs. These results indicate that treatment with 5 μM U0126 during in vitro maturation delays GAPJ breakdown and improves bovine oocyte developmental competence.

Anterior interosseous nerve palsy mimicking rupture of the index flexor digitorum profundus after volar locking plate fixation of a distal radius fracture

We describe the case of a patient with distal radius fracture who became unable to flex the distal interphalangeal joint of the index finger after internal fixation using a volar locking plate. There was palpable crepitus with active thumb motion, and wrist radiographs showed prominence of the volar plate at the watershed line. Therefore, our initial diagnosis was plate-induced closed rupture of the flexor digitorum profundus tendon of the index finger. However, upon surgical removal of the plate, no tendon rupture was found. Magnetic resonance imaging after plate removal showed diffuse increased signal intensity in the index flexor digitorum profundus on T2-weighted fat-suppressed images, which indicated muscle denervation. Based on the above findings, we changed the diagnosis to anterior interosseous nerve palsy with isolated paralysis of the flexor digitorum profundus of the index finger. Finger flexion disability following volar plate fixation of distal radius fracture should always be investigated carefully..

Clinical effects of internal fixation for ulnar styloid fractures associated with distal radius fractures: A matched case-control study

BACKGROUND

Ulnar styloid fractures are often associated with distal radius fractures. However, controversy exists regarding whether to treat ulnar styloid fractures. This study aimed to evaluate clinical effects of internal fixation for ulnar styloid fractures after distal radius fractures were treated with the volar locking plate system.

METHODS

We used prospectively collected data of distal radius fractures. 111 patients were enrolled in this study. A matched case-control study design was used. We selected patients who underwent fixation for ulnar styloid fractures (case group). Three control patients for each patient of the case group were matched on the basis of age, sex, and fracture type of distal radius fractures from among patients who did not undergo fixation for ulnar styloid fractures (control group). The case group included 16 patients (7 men, 9 women; mean age: 52.6 years; classification of ulnar styloid fractures: center, 3; base, 11; and proximal, 2). The control group included 48 patients (15 men, 33 women; mean age: 61.1 years; classification of ulnar styloid fractures: center, 10; base, 31; and proximal, 7). For radiographic examination, the volar tilt angle, radial inclination angle, and ulnar variance length were measured, and the union of ulnar styloid fractures was judged. For clinical examination, the range of motions, grip strength, Hand20 score, and Numeric Rating Scale score were evaluated.

RESULTS

There was little correction loss for each radiological parameter of fracture reduction, and these parameters were not significantly different between the groups. The bone-healing rate of ulnar styloid fractures was significantly higher in the case group than in the control group, but the clinical results were not significantly different.

CONCLUSIONS

We revealed that there was no need to fix ulnar styloid fractures when distal radius fractures were treated via open reduction and internal fixation with a volar locking plate system.

Mid- to long-term outcomes after surgical treatment of chronic anterior dislocation of the radial head in children

BACKGROUND

To evaluate the mid- to long-term clinical and radiographic outcomes after surgical treatment of chronic anterior dislocation of the radial head in children.

METHODS

Open reduction was performed in 16 children (mean age, 9.3 years [range, 2.6-13.6 years]) with chronic anterior dislocation of the radial head. Twelve patients had a history of preceding injuries, with a mean interval between injury and surgery of 24 months (range, 2-86 months); 4 patients did not have injuries. Eight patients who had undergone reduction within 16 months were treated by open reduction and ulnar osteotomy. The other 8 patients who had not sustained trauma or had been injured >2 years previously required either annular ligament reconstruction or radial shortening in addition to ulnar osteotomy.

RESULTS

The average preoperative Kim's elbow performance score was 77.2 ± 10.5, which significantly improved to 97.5 ± 5.8 at the final follow-up. The radial head was maintained in a reduced position in 14 patients and was subluxed in 2. Slight osteoarthritic changes of the elbow were observed in 2 patients with good reduction. The functional results were excellent in 15 and were good in 1 patient with an average follow-up of 6.5 years (range, 2.6-15.1 years).

CONCLUSIONS

Our surgical procedure provided good mid- to long-term clinical and radiographic outcomes.

Hyaluronan metabolism in overloaded temporomandibular joint

This study aimed to examine hyaluronan (HA) metabolism in relation to the onset and progression of temporomandibular joint osteoarthritis (TMJ-OA) induced by mechanical overloading. Two-month-old and 6-month-old C57BL/6N mice were divided into experimental and untreated control groups (n = 5/group). A sliding plate was attached to the maxillary incisors of the experimental mice for 10 days to overload the condylar cartilage in TMJ. In experimental group, profound cartilage degradation was detected in haematoxylin-eosin, Safranin-O-Fast Green-stained sections. It was also shown that the cartilage degradation was greater in older mice in both the control and the experimental groups. The number of HABP-positive cells was decreased by mechanical overloading and with age. The reduction of HA expression was correlated with the progression of cartilage degradation induced by mechanical overloading. The absolute quantification of the mRNA expression related to HA synthesis and HA degradation was also performed in each group. The mRNA expression levels of HA synthase (HAS) 2 and 3 were lower in the experimental group compared with the control group in the younger mice. In contrast, the mRNA expression levels of the HA degradation gene, HYAL2 and KIAA1199, were higher in the experimental group compared with the control group in the older mice. Thus, mechanical overload differently affected the balance of HA degradation and HA synthesis in the older and younger mice, respectively. In conclusion, mechanical overloading affects HA metabolism and it might initiate or amplify the condylar cartilage degradation.

Carpal tunnel syndrome associated with Kienböck disease

We retrospectively reviewed 12 patients (3 men and 9 women, with a mean age of 72 years) who were surgically treated for carpal tunnel syndrome associated with Kienböck disease. All patients except 1 were incidentally diagnosed with Kienböck disease and had little or no wrist pain. Radiographic tests revealed advanced Kienböck disease in all patients. Intraoperative findings indicated that the site of maximum compression on the median nerve was located at the level of the carpal tunnel inlet in 11 patients, and the volar dislocated fragment of the lunate was located proximally adjacent to the floor of the carpal tunnel inlet. This disorder is most prevalent in elderly women, and even advanced Kienböck disease can present without wrist pain. Our findings suggest that palmar protrusion of the lunate may be the primary cause of carpal tunnel syndrome associated with Kienböck disease.

Recovery function of somatosensory evoked brain response in patients with carpal tunnel syndrome: A magnetoencephalographic study

OBJECTIVE

The recovery function of somatosensory evoked magnetic fields (SEFs) was recorded to investigate excitatory and inhibitory balance in the somatosensory cortex of patients with carpal tunnel syndrome.

METHODS

SEFs were recorded in patients and controls. Recordings were taken following median nerve stimulation with single and double pulses with interstimulus intervals of 10-200ms. The root mean square for the N20m component following the second stimulation was analyzed. SEFs following stimulation of the first and middle digits were also recorded and the location for the equivalent current dipoles was estimated in three-dimensional planes.

RESULTS

Distances on the vertical axis between the equivalent current dipoles for the first and third digits were shorter in patients than in control participants. The root mean square for the N20m recovered earlier in patients compared to controls; this was statistically significant at an interstimulus interval of 10ms. There was no relationship between N20m recovery and the equivalent current dipole location in the primary somatosensory cortex.

CONCLUSIONS

Carpal tunnel syndrome was associated with functional disinhibition and destruction of the somatotopic organization in the primary somatosensory cortex.

SIGNIFICANCE

Disinhibitory changes might induce a maladaptation of the central nervous system relating to pain.

Ulnar impaction syndrome: incidence of lunotriquetral ligament degeneration and outcome of ulnar-shortening osteotomy

PURPOSE

We hypothesized that most patients with ulnar impaction syndrome have degenerative changes of the proximal lunotriquetral (LT) membrane and that ulnar-shortening osteotomy is an effective procedure in these patients.

METHODS

We retrospectively reviewed 50 wrists of 49 patients with idiopathic ulnar impaction syndrome who underwent an arthroscopic evaluation at the time of ulnar-shortening osteotomy, and subsequently at plate removal. Based on the Geissler classification, patients were divided into group A, normal, and group B, grades I to IV. The degree of degeneration of the proximal LT membrane at first-look arthroscopy was compared with that at second-look arthroscopy.

RESULTS

After ulnar-shortening osteotomy, both groups improved significantly in wrist range of motion and grip strength. According to the Mayo wrist score, 29, 18, and 3 patients showed excellent, good, and fair results, respectively. Of the 50 wrists, 25 had degenerative changes (group B) in the proximal LT membrane at the time of first-look arthroscopy. Of the 25 wrists in group B, 11 wrists improved based on the Geissler grade, 9 wrists showed no changes, and 2 wrists became worse. Clinically, patients demonstrated improvement after ulnar-shortening osteotomy regardless of the degree of degenerative LT ligament changes.

CONCLUSIONS

Degenerative LT membrane changes that were seen in about half of our patients were mostly of a mild nature, and the clinical outcomes of ulnar-shortening osteotomy were acceptable.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Simple debridement has little useful value on the clinical course of recalcitrant ulnar wrist pain

The purpose of this study was to evaluate treatment results following arthroscopic triangular fibrocartilage complex (TFCC) debridement for recalcitrant ulnar wrist pain. According to the treatment algorithm, 66 patients (36 men and 30 women with a mean age of 38.1 years (15 to 67)) with recalcitrant ulnar wrist pain were allocated to undergo ulnar shortening osteotomy (USO; n = 24), arthroscopic TFCC repair (n = 15), arthroscopic TFCC debridement (n = 14) or prolonged conservative treatment (n = 13). The mean follow-up was 36.0 months (15 to 54). Significant differences in Hand20 score at 18 months were evident between the USO group and TFCC debridement group (p = 0.003), and between the TFCC repair group and TFCC debridement group (p = 0.029). Within-group comparisons showed that Hand20 score at five months or later and pain score at two months or later were significantly decreased in the USO/TFCC repair groups. In contrast, scores in the TFCC debridement/conservative groups did not decrease significantly. Grip strength at 18 months was significantly improved in the USO/TFCC repair groups, but not in the TFCC debridement/conservative groups. TFCC debridement shows little benefit on the clinical course of recalcitrant ulnar wrist pain even after excluding patients with ulnocarpal abutment or TFCC detachment from the fovea from the indications for arthroscopic TFCC debridement.

Evaluation of floating impeller phenomena in a Gyro centrifugal pump

The Gyro centrifugal pump developed as a totally implantable artificial heart was designed with a free impeller, in which the rotational shaft (male bearing) of the impeller was completely separated from the female bearing. For this type of pump, it is very important to keep the proper magnet balance (impeller-magnet and actuator-magnet) in order to prevent thrombus formation and/or bearing wear. When the magnet balance is not proper, the impeller is jerked down into the bottom bearing. On the other hand, if magnet balance is proper, the impeller lifted off the bottom of the pump housing within a certain range of pumping conditions. In this study, this floating phenomenon was investigated in detail. The floating phenomenon was proved by observation of the impeller behavior using a transparent acrylic pump. The impeller floating phenomenon was mapped on a pump performance curve. The impeller floating phenomenon is affected by the magnet-magnet coupling distance and rotational speed of the impeller. In order to keep the proper magnet balance and to maintain the impeller floating phenomenon at the driving condition of right and left pump, the magnet-magnet coupling distance was altered by a spacer which was installed between the pump and actuator. It became clear that the same pump could handle different conditions (right and left ventricular assist), by just changing the thickness of the spacer. When magnet balance is proper, the floating impeller phenomenon occurs automatically in response to the impeller rev. It is called "the dynamic RPM suspension".

Clinical, radiographic, and arthroscopic outcomes after ulnar shortening osteotomy: a long-term follow-up study

PURPOSE

Previous studies have investigated the long-term outcomes of ulnar shortening osteotomy (USO) in the treatment of ulnocarpal abutment syndrome (UCA), but none have used arthroscopic assessments. The purpose of this study was to investigate the long-term clinical outcomes of USO with patient-based, arthroscopic, and radiographic assessments.

METHODS

We retrospectively reviewed 30 patients with UCA after a minimum follow-up of 5 years, with arthroscopic evaluations at the time of both USO and plate removal. We confirmed the initial diagnosis of UCA by radiography and arthroscopy. Mean age at the time of index surgery was 37 years. Mean duration of follow-up was 11 years (range, 5-19 y). We obtained Disabilities of the Arm, Shoulder, and Hand and Hand20 self-assessments postoperatively for all patients. Bony spur formation was evaluated postoperatively from plain radiographs.

RESULTS

We detected triangular fibrocartilage complex (TFCC) disc tear in 13 wrists arthroscopically at the time of USO. Of these, 10 showed no evidence of TFCC disc tear at second-look arthroscopy. The remaining 17 cases showed no TFCC disc tear at either first- or second-look arthroscopy. Follow-up radiography revealed that bony spurs at the distal radioulnar joint had progressed in 13 wrists. Disabilities of the Shoulder, Arm, and Hand and Hand20 scores did not significantly correlate with the presence of bony spurs or TFCC disc tears. Range of motion decreased significantly with age only. Lower grip strength correlated with bony spur and lower radial inclination. Triangular fibrocartilage complex tear, male sex, and advanced age were associated with lower Disabilities of the Shoulder, Arm, and Hand and Hand20 scores.

CONCLUSIONS

Ulnar shortening osteotomy achieved excellent long-term results in most cases. Most TFCC disc tears identified at the initial surgery had healed by long-term arthroscopic follow-up. We suggest that UCA with a TFCC disc tear is a good indication for USO.

Results of ulnar shortening osteotomy for ulnocarpal abutment after malunited distal radius fracture

Surgical correction for ulnocarpal abutment syndrome after malunited distal radius fracture remains controversial. We reviewed sixteen patients (7 men, 9 women) who underwent isolated ulnar-shortening osteotomy for ulnar wrist pain as their main complaint. Mean age was 48 years. The range of flexion-extension increased from 81 degrees to 103 degrees, and range of supination-pronation from 120 degrees to 142 degrees after osteotomy. Mean grip strength increased from 49% to 69%. Mayo wrist score was excellent in 2 cases, good in 7 cases, fair in 6 cases, and poor in 1 case. Grip strength was found to correlate with radial inclination and flexion-extension range with the amount of ulna shortening.

Residual wrist pain after volar locking plate fixation of distal radius fractures

A prospective multicenter clinical study evaluated, using the Hand20 and hand diagram, the disability, incidence, location, and predictive factors of residual wrist pain 18 months after volar locking plate fixation of distal radius fracture in 122 patients. The average Hand20 score and numeric rating scores for pain were 13.1 +/- 18.2 and 2.1 +/- 23, respectively. Fifty-seven patients indicated that they had pain. Among those patients, 25 had ulnar pain and 45 had radial pain. The incidence of radial-sided wrist pain was higher than ulnar-sided wrist pain. Logistic regression analysis showed that female sex and intra-articular fracture significantly correlated with radial-sided wrist pain. Volar locking plate fixation maintained anatomical reduction; however, a significant number of patients complained of residual wrist pain.

Sonography-guided arthroscopy for wrist ganglion

PURPOSE

To describe how to combine the complementary features of sonography and arthroscopy to make the arthroscopic resection of wrist ganglions a safer and more reliable surgery.

METHODS

A total of 22 patients with wrist ganglions had sonography-assisted arthroscopic resection. Sonographic visualization of ganglions, adjacent structures (ie, vessels, nerves, and tendons), and the cycling tip of the arthroscopic shaver was assessed. Arthroscopic visualization of the ganglions or ganglion stalk was also assessed. Clinical outcome measures included wrist range of motion, grip strength, and our patient-rated Hand 20 questionnaire.

RESULTS

Sonographic visualization of the ganglion stalk, adjacent structures, and the cycling tip of the arthroscopic shaver was possible in all 22 cases. However, ganglion stalks were visualized by arthroscopy in only 4 cases. The mean range of motion and grip strength were not significantly changed following surgery. However, the mean Hand 20 score was significantly improved from 17 to 6 at final follow-up. Ganglion recurrence was seen in 2 cases at 6 and 8 months after surgery.

CONCLUSIONS

Sonography-guided wrist arthroscopy provides several advantages for surgeons, including visualization of the ganglions and ganglion stalk, as well as of the arthroscopic shaver and adjacent structures such as nerves, vessels, and tendons to perform surgery safely.

[Rib-originated fibrous dysplasia: report of a case]

The incidence of fibrous dysplasia (FD) is not frequent in the case of benign bone tumors of the chest wall, and differential diagnosis between FD and the malignancy on the basis of imaging findings is difficult. We report a case of a painful FD lesion (size, 9×8 cm) that originated from the 5th rib of a 52-year-old man and was surgically resected. His symptoms improved after the operation. Painful and large FD lesions should be resected because of a difficulty in differential diagnosis from malignant tumors.

Sonography-assisted arthroscopic resection of volar wrist Ganglia: a new technique

Although satisfactory arthroscopic resection of volar wrist ganglia has been reported recently, the risk of damage to arteries, nerves, and tendons remains. Furthermore, ganglia and their stalks cannot be visualized arthroscopically in many cases, and surgeons must perform a blind resection of the joint capsule until ganglion cysts or their stalks appear. Sonography has limited resolution, but recent improvements in hardware and software have made it an excellent noninvasive and dynamic imaging technique for assessing the musculoskeletal system. Ganglia, tendons, nerves, and vessels around the lesion can be clearly observed by sonography. Furthermore, the cyclic motion of the arthroscopic shaver tip makes identification by sonography easy and assists in guiding the surgeon to the lesion.

Tilt of the radius from forearm rotational axis reliably predicts rotational improvement after corrective osteotomy for malunited forearm fractures

Forearm rotation occurs around an axis connecting the center of the radial head and the fovea of the distal ulna. The purpose of the present study was to demonstrate the usefulness of the difference between forearm and proximal radial axis in the treatment of malunited forearm fractures. We reviewed the results of eight corrective osteotomies for malunited fractures of the forearm without dislocations of the wrist or elbow. Subjects were 6 men and 2 women (mean age, 15 years; range, 10-21 years). Corrective osteotomy was performed at the fracture site. Preoperatively and at final follow-up, the are of forearm rotation was recorded and anteroposterior and lateral X-rays were taken. Proximal radius tilt was defined as the angle between the rotational axis of the forearm and the axis of the proximal radius. Corrective osteotomy improved proximal radius tilt in all cases. Three patients were considered to have malrotation. Postoperative rotational are correlated with proximal radial tilt (r = -0.83). No significant difference in rotational arc was evident between malunited cases and the remaining cases. To improve forearm rotation, corrective osteotomy should be planned to minimize proximal radius tilt.

Proximal row carpectomy for chronic unreduced perilunate dislocations

We evaluated the results of proximal row carpectomy (PRC) for unreduced perilunate dislocation in 6 patients. The average period from the injury to the operation was 24 weeks. The modified Mayo wrist score was used for clinical evaluation. Radiological evaluation was based on the radius-capitate alignment. Pain disappeared in 4 cases; mild pain during activity persisted in 2 cases. The average flexion-extension are was 59% of the values on the unaffected side. The average grip strength was 72% of the unaffected side, and the average modified Mayo wrist score was 71 points. Three patients showed favourable radius-capitate alignment, while the other 3 patients showed poor radius-capitate alignment on the radiographs. The postoperative radius-capitate alignment was related to the preoperative position of the capitate on the lateral view. Those with poor radius-capitate alignment tended to obtain lower scores compared to those with favourable alignment.