How Does the Addition of Dexamethasone to a Brachial Plexus Block Change Pain Patterns After Surgery for Distal Radius Fractures? A Randomized, Double-blind Study

BACKGROUND

Although brachial plexus block in volar plating surgery for distal radius fractures is reportedly associated with lower postoperative pain scores, rebound pain has been reported to occur after the initial block wears off. Dexamethasone can be used in multimodal strategies for antiemesis and to control pain postoperatively. Although prior studies have suggested that anesthesia can be prolonged by adding dexamethasone to regional blocks, no randomized trials we are aware of have ascertained whether doing so will make a clinically important difference in pain after surgery for distal radius fractures.

QUESTIONS/PURPOSES

Do patients who receive supplemental dexamethasone in a brachial plexus block for volar plating of unstable distal radius fractures have (1) better pain scores at 4, 8, 24, and 48 hours postoperatively than patients who have not received dexamethasone, and (2) lower fentanyl consumption and administration of antiemetic drugs without change in serum blood glucose, as well as a longer analgesic duration from the block after surgery than patients who have not received dexamethasone?

METHODS

This randomized, double-blind trial included 69 patients undergoing surgery for distal radius fractures under ultrasound-guided supraclavicular brachial plexus blocks who were randomly allocated into two groups: a nondexamethasone group receiving a brachial plexus block with 0.5% ropivacaine and a dexamethasone group receiving 0.5% ropivacaine and 5 mg of dexamethasone. Thirty-four patients were allocated to the dexamethasone group and 35 were allocated to the nondexamethasone group. Nine patients (four in the dexamethasone group and five in the nondexamethasone group) were excluded after randomization because local anesthetics were used during their surgical procedures owing to an incomplete block or they requested patient-controlled analgesia after surgery. The treatment groups did not differ in any important ways, including age, gender, BMI, hand dominance, and AO/Orthopaedic Trauma Association classification. All patients received the same surgical procedure and perioperative care protocol, except for the injected agents during their brachial plexus block. The primary outcome was postoperative pain, evaluated using a 10-mm VAS at 4, 8, 12, 24, and 48 hours after surgery. The minimum clinically important difference for the VAS score was 2 of 10 points. Secondary outcome variables included fentanyl administration as a rescue analgesic, the number of patients receiving antiemetic medications because of fentanyl administration, and the duration of brachial plexus block. Serum blood glucose was measured 1 day before, immediately after, and 24 hours after surgery. Patients, surgeons, and outcome assessors were blinded to treatment allocation.

RESULTS

The only clinically important between-group difference in VAS pain scores was at 8 hours, favoring the group that received dexamethasone over the group that did not (1.9 ± 1.6 versus 4.7 ± 2.7; mean difference -2.8 [95% CI -3.9 to -1.6]; p < 0.001). After brachial plexus block, the most severe pain score in both groups was reported at 12 hours postoperatively and gradually diminished over time. There was no between-group difference in fentanyl use between those who received dexamethasone and those who did not (21 ± 38 mcg versus 31 ± 29 mcg; mean difference -10 [95% CI -27.4 to 7.4]; p = 0.26). Furthermore, the use of antiemetics did not differ between the groups (27% [eight of 30] versus 37% [11 of 30]; odds ratio 1.6 [95% CI 0.5 to 4.8]; p = 0.41). Baseline and 24-hour postoperative serum blood glucose level did not differ between the groups. However, the immediately postoperative serum blood glucose level was higher in the dexamethasone group than in the nondexamethasone group (121 ± 29 versus 104 ± 20; mean difference 16 [95% CI 3.3 to 28.8]; p = 0.02). The brachial plexus block duration was 3 hours longer (95% CI 0.8 to 5.2 hours) in the dexamethasone group than that in the nondexamethasone group (11 ± 5 hours versus 8 ± 3 hours; p = 0.01).

CONCLUSION

The postoperative pain level in patients who received supplemental dexamethasone in a regional block was not clinically different from that of patients who received conventional brachial plexus block anesthesia when undergoing volar plating for distal radius fractures. However, patients who received a brachial plexus block with dexamethasone experienced slight prolongation of their block and decrease in pain 8 hours after surgery.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Risk factors for hardware-related complications after extra-articular distal humerus fracture fixation using an anatomical locking plate

PURPOSE

We aimed to identify the incidence and risk factors of hardware-related complications in patients treated with anatomical locking plate fixation for extra-articular distal humerus fractures.

METHODS

From 2013 to 2020, patients with extra-articular distal humerus fractures who underwent open reduction and internal fixation with an extra-articular distal humerus locking plate (EADHP) were retrospectively reviewed and categorized according to the presence/absence of hardware-related complications. Hardware-related complications were defined as the occurrence of skin prominence on the plate and discomfort in activities of daily living. Patient demographics, the lateral condylar angle, lateral body length, shaft-condylar angle of the humerus, and plate length were analyzed.

RESULTS

Of the 29 patients, 10 (34%) did not develop hardware-related complications (group A), whereas 19 (66%) did (group B). Patient demographics did not differ between the groups. However, the number of patients who underwent hardware removal was significantly greater in group B (16/19) than in group A (4/10; p = 0.032). Radiologic assessment revealed no significant difference in the lateral condylar or shaft-condylar angle. However, the lateral body length was greater in group A than in group B (44.5 ± 4.8 vs. 39.5 ± 3.7, p = 0.007). The plate length significantly differed between the groups. Twelve of 19 (63%) patients in group B received short-hole plates (six holes), while nine of ten (90%) patients in group A received long-hole plates (eight holes). In the multivariable analysis, the lateral body length of the distal humerus (p = 0.047, odds ratio = 0.734, 95% confidence interval: 0.542-0.996) and plate length (p = 0.036, odds ratio = 0.076, 95% confidence interval: 0.542-0.996) were associated with hardware-related complications.

CONCLUSIONS

Most patients developed hardware-related complications, particularly with short plates, mainly because of the narrow lateral body length of the distal humerus. Surgeons should be careful to secure EADHP in the appropriate position, especially when short plates are used in patients with narrow lateral body length.

Is a Steroid Injection in Both Compartments More Effective than an Injection in the Extensor Pollicis Brevis Subcompartment Alone in Patients with de Quervain Disease? A Randomized, Controlled Trial

BACKGROUND

Ultrasonography (US)-guided steroid injections can improve the accuracy of injection in patients with de Quervain disease, especially in those with an intracompartmental septum. Although the main lesion of de Quervain disease in patients with a septum is a stenosing tenosynovitis of the extensor pollicis brevis (EPB), no report we know of has compared injection into the EPB subcompartment with an injection into both the abductor pollicis longus (APL) and EPB subcompartments. In this randomized trial, we compared the results of US-guided steroid injections targeting both subcompartments and the EPB subcompartment alone in patients with de Quervain disease.

QUESTIONS/PURPOSES

(1) Do patients who receive a steroid injection in the EPB subcompartment alone have lower pain scores at 6 weeks and at 3 months after US-guided injection compared with patients who receive an injection in both subcompartments? (2) Do patients who receive a steroid injection in the EPB subcompartment alone experience fewer steroid injection-related complications than patients who receive an injection in both subcompartments?

METHODS

A randomized controlled study was performed at a single center between August 2018 and March 2021. Patients with a diagnosis of de Quervain disease and with a complete intracompartmental septum between the APL and the EPB tendons were included. In total, 112 patients had a diagnosis of de Quervain disease during the study period. Definite, complete subcompartmentalization was seen in 50 patients. Patients were randomly assigned to US-guided injections targeting both subcompartments (n = 25) or the EPB subcompartment alone (n = 25). There were no between-group differences in age, gender, affected wrist, or disease duration, and all patients had US evidence of tendinosis of the EPB, with or without tendinosis of the APL. Although 33% of patients (16 of 48) showed tendinosis of the APL, no patient showed tendinosis of the APL alone. In all patients, a dorsal-to-palmar side injection of 0.5 mL of 2% lidocaine and 0.5 mL of triamcinolone acetonide (40 mg/mL) was administered by two experienced hand surgeons. In the both-subcompartments group, US-guided injections were performed in each of the APL and EPB subcompartments. In the EPB subcompartment group, US-guided injections were administered in the EPB subcompartment only. All patients underwent the same protocol after the procedure. Four percent (n = 2, 1 in each group) of patients were excluded after randomization because their pain level was not registered. Pre- and postinjection clinical outcome assessments were completed by orthopaedic surgery residents not involved in patient management. Patients were regularly examined at baseline, 6 weeks, and 3 months to evaluate the intensity of pain. We assessed pain by the VAS score, where 0 indicated no pain and 100 the most pain. At baseline, the VAS score was 67 ± 14 in the both-subcompartment group and 67 ± 16 in the EPB subcompartment group (mean difference 0.17 [95% CI -8.45 to 8.82]; p = 0.97). Complications related to the steroid injection, including numbness, tendon rupture, and skin hypopigmentation, were also recorded at final follow-up examinations. To determine statistical power, the VAS score for pain at 6 weeks after the injection was used as the primary outcome variable. The minimum clinically important difference for the VAS score was deemed to be 20 mm, and we estimated an SD of 23. A sample size calculation indicated that a sample of 21 patients per group would provide 80% power to detect an effect of this size between the groups at the p = 0.05 level using a t-test.

RESULTS

There were no differences in the VAS scores between the both-subcompartment group and the EPB group at 6 weeks (10 ± 6 versus 10 ± 7, mean difference -0.08 [95% CI -4.08 to 3.91]; p = 0.97). The same was true at 12 weeks (12 ± 13 versus 11 ± 15, mean difference 0.38 [95% CI -7.74 to 8.49]; p = 0.09). No adverse events related to treatment (such as tendon rupture, infections, and numbness) occurred in either group. However, skin hypopigmentation occurred at the final follow-up examination in both groups. The proportion of patients experiencing skin hypopigmentation in the EPB subcompartment group was lower than in the both-subcompartment group (33% [8 of 24] versus 67% [16 of 24]; odds ratio 0.25 [95% CI 0.08 to 0.83]; p = 0.02).

CONCLUSION

Our data suggest that a US-guided steroid injection targeting the EPB subcompartment alone is as effective in terms of pain reduction as targeting both subcompartments in patients with de Quervain disease who have complete septation. Furthermore, an injection targeting the EPB subcompartment alone can reduce the dose of steroids used, perhaps thereby decreasing complications related to steroid injections. We recommend using only single-compartment injections in this context, even among patients with an intracompartmental septum.

LEVEL OF EVIDENCE

Level I, therapeutic study.

The effect of leucocyte concentration of platelet-rich plasma on outcomes in patients with lateral epicondylitis: a systematic review and meta-analysis

HYPOTHESIS

The concentration of leukocytes influences the quality of platelet-rich plasma (PRP). However, there is no consensus on which type of PRP based on the concentration of leukocytes is the best for lateral epicondylitis (LE).

METHODS

We systematically searched the MEDLINE, Embase, and Cochrane Library databases until March 1, 2020. Studies involving randomized controlled trials, patients with LE, and treatment with PRP injections were included. PRP was classified into leukocyte-poor (LP) PRP and leukocyte-rich (LR) PRP. LR-PRP was defined as PRP with a white blood cell concentration exceeding that of whole blood (4.0-10.0 per μL³), whereas LP-PRP was defined as PRP with a lower white blood cell concentration than that of whole blood. The efficacy of PRP was assessed using the visual analog scale (VAS) and success rates.

RESULTS

Eleven randomized controlled trials (six involving LP-PRP and five involving LR-PRP) were eligible for inclusion in this review. Eight studies were included in the meta-analysis to evaluate the VAS score. Regarding short-term follow-up, there was no difference in the VAS scores between the LP-PRP and control groups (standard mean difference [SMD], 0.01; 95% confidence interval [CI], -0.29 to 0.30; P = 0.97), with no heterogeneity (I² = 0%). There was also no difference in the VAS scores between the LR-PRP and control groups (SMD, -0.19; 95% CI, -0.57 to 0.20; P = 0.34), with substantial heterogeneity (I² = 56.7%). Regarding long-term follow-up, there was no difference in the VAS scores between the LP-PRP and control groups (SMD, -0.73; 95% CI, -1.69 to 0.23; P = 0.134) with substantial heterogeneity (I² = 88.4%). The LR-PRP group had lower VAS scores than the control group (SMD, -1.06; 95% CI, -2.02 to -0.09; P = 0.032) with substantial heterogeneity (I² = 92%). In the LP-PRP group, there was no significant difference in the success rate (odds ratio, 1.08; 95% CI, 0.07-16.47; P = 0.956) with substantial heterogeneity (I² = 87.7%). In the LR-PRP group, however, the patients who received PRP had a higher success rate than those in the control group (odds ratio, 2.85; 95% CI, 1.67-4.85; P < 0.01) with substantial heterogeneity (I² = 82.9%).

CONCLUSION

LR-PRP may provide pain relief and successful outcomes for patients with LE compared with alternative local injections. Better results were observed with the use of LR-PRP than with the use of LP-PRP.

Platelet-rich plasma injection vs. operative treatment for lateral elbow tendinosis: a systematic review and meta-analysis

BACKGROUND

Although surgical treatment is considered reliable for lateral elbow tendinosis, local injection therapy may be preferable, as it avoids surgery. Among a number of local injections, platelet-rich plasma has been used successfully to treat lateral elbow tendinosis. The purpose of this study was to compare the outcomes in patients treated with either platelet-rich plasma injections or surgery for lateral elbow tendinosis using a systematic literature review and meta-analysis.

METHODS

MEDLINE, Embase, and Cochrane Library databases were systematically searched for studies published before March 1, 2021, that compared platelet-rich plasma with operative treatment for lateral elbow tendinosis. The pooled analysis was designed to compare the visual analog scale scores and the Patient-Related Tennis Elbow Evaluation scores between the platelet-rich plasma and surgical treatment groups at serial time points.

RESULTS

We included 5 studies involving 340 patients with lateral elbow tendinosis, comprising of 154 patients treated with platelet-rich plasma and 186 patients who underwent surgical treatment. The pooled analysis showed no statistically significant differences in the visual analog scale scores at any of the follow-up time points, namely, 2 months (mean difference [MD] 1.11, 95% confidence interval [CI] -2.51 to 4.74, P = .55, I² = 94%), 6 months (MD 0.80, 95% CI -2.83 to 4.42, P = .67, I² = 92%), and 12 months (MD -0.92, 95% CI -4.63 to 2.80, P = .63, I² = 93%) postintervention and in the Patient-Related Tennis Elbow Evaluation scores at 12 weeks (MD -1.86, 95% CI -22.30 to 18.58, P = .86, I² = 81%), 24 weeks (MD -3.33, 95% CI -21.82 to 15.17, P = .72, I² = 74%), and 52 weeks (MD -3.64, 95% CI -19.65 to 12.37, P = .66, I² = 69%) postintervention.

CONCLUSIONS

Local platelet-rich plasma injections and surgical treatment produced equivalent pain scores and functional outcomes in patients with lateral elbow tendinosis. Thus, platelet-rich plasma injections may represent a reasonable alternative treatment for patients who are apprehensive to proceed with surgery or for poor surgical candidates.

Postoperative immobilization using a short-arm cast in the semisupination position is appropriate after arthroscopic triangular fibrocartilage complex foveal repair

AIMS

The aim of this study was to assess and compare active rotation of the forearm in normal subjects after the application of a short-arm cast (SAC) in the semisupination position and a long-arm cast (LAC) in the neutral position. A clinical study was also conducted to compare the functional outcomes of using a SAC in the semisupination position with those of using a LAC in the neutral position in patients who underwent arthroscopic triangular fibrocartilage complex (TFCC) foveal repair.

METHODS

A total of 40 healthy right-handed volunteers were recruited. Active pronation and supination of the forearm were measured in each subject using a goniometer. In the retrospective clinical study, 40 patients who underwent arthroscopic foveal repair were included. The wrist was immobilized postoperatively using a SAC in the semisupination position (approximately 45°) in 16 patients and a LAC in 24. Clinical outcomes were assessed using grip strength and patient-reported outcomes. The degree of disability caused by cast immobilization was also evaluated when the cast was removed.

RESULTS

Supination was significantly more restricted with LACs than with SACs in the semisupination position in male and female patients (p < 0.001 for both). However, pronation was significantly more restricted with SACs in the semisupination position than with LACs in female patients (p = 0.003) and was not significantly different in male patients (p = 0.090). In the clinical study, both groups showed improvement in all parameters with significant differences in grip strength, visual analogue scale scores for pain, modified Mayo Wrist Score, the Disability of the Arm, Shoulder, and Hand (DASH) score, and the Patient-Rated Wrist Evaluation (PRWE) score. No significant postoperative differences were noted between LACs and SACs in the semisupination position. However, the disability caused by immobilization in a cast was significantly higher in patients who had a LAC on the dominant hand (p < 0.001).

CONCLUSION

We found that a SAC in the semisupination position is as effective as a LAC in restricting pronation of the forearm. In addition, postoperative immobilization with a SAC in the semisupination position resulted in comparable pain scores and functional outcomes to immobilization with a LAC after TFCC foveal repair, with less restriction of daily activities. Therefore, we recommend that surgeons consider using a SAC in the semisupination position for postoperative immobilization following TFCC foveal repair for dorsal instability of the distal radioulnar joint. Cite this article: Bone Joint J 2022;104-B(2):249-256.

Combined Approach for Intra-articular Distal Radius Fracture: A Case Series and Literature Review

Background

The purpose of this study was to classify the possible indications for a combined approach to distal radius fractures (DRFs) by investigating surgical outcomes of patients treated according to our treatment algorithm.

Methods

A combined approach was performed in 32 patients. Patients who were thought to need a combined approach were classified into three types according to the combined injuries associated with loss of volar cortical buttresses in DRFs. The classifications included the following: type 1, free intra-articular fragments; type 2, distally migrated dorsal fragments located beyond the wrist joint; and type 3, centrally impacted articular fragments and displaced dorsal fragments, not reduced by indirect methods.

Results

Seven patients had type 1 fractures treated with volar plates and excision of the intra-articular fragments. Fourteen patients had type 2 fractures: 12 were treated with volar plates and excision of dorsal fragments, and 2 with relatively large unstable dorsal fragments were treated with combined volar and dorsal plates. The remaining 11 patients had type 3 fractures treated with combined volar and dorsal plates. At the latest follow-up, the radiographs revealed an average of 16.9° of radial inclination, an average of 4.2° of volar tilt, and an average of 7.5 mm of radial height. According to the Garland and Werley scores, the functional results were excellent for 3 patients, good for 25, and fair for 4.

Conclusions

The classification system indicated when an additional dorsal approach was needed in unstable DRFs, and it may establish useful guidelines for appropriate surgical decision-making.

Validation of an Operational Definition to Identify Distal Radius Fractures in a National Health Insurance Database

PURPOSE

To develop and validate identification criteria for distal radius fractures (DRFs) and their treatment using a national health insurance database.

METHODS

Patients who had at least 1 wrist radiograph taken in 2018 were recruited from a single academic referral hospital. After excluding patients who lacked immobilization code for wrist pathology, we collected data on the overall population. Because some patients might have undergone wrist radiography at another institution or had DRFs without an immobilization code, we additionally included patients who had a DRF diagnosis code at our institution. Reviews of medical records and wrist radiographs were considered for the diagnosis of DRF. We evaluated the sensitivity, specificity, and positive predictive value (PPV) of 3 operational definitions of fractures that were based on a single primary or secondary diagnosis code; all diagnosis codes, including primary and secondary codes; and all diagnosis and procedure codes.

RESULTS

Among 768 patients included in the study, true DRFs were confirmed in 305. The sensitivity, specificity, and PPV for definition 1 were 91.5% (95% CI, 88.3%-94.6%), 97.5% (95% CI, 95.9%-99.1%), and 96.9% (95% CI, 94.9%-98.9%), respectively. Although the sensitivity of definition 2 was higher (92.1%; 95% CI, 89.1%-95.2%), its specificity and PPV were lower (96.4% [95% CI, 94.4%-98.3%] and 95.6% [95% CI, 93.2%-97.9%], respectively). The sensitivity of definition 3 was the lowest (88.2%; 95% CI, 84.6%-91.8%), but its specificity and PPV were the highest among the 3 definitions (98.6% [95% CI, 97.4%-98.8%] and 98.2% [95% CI, 96.6%-99.8%], respectively).

CONCLUSIONS

Patients with DRFs can be identified from claims databases with high accuracy using an operational definition based on DRF diagnosis and procedure codes, including codes for surgical and nonoperative methods.

CLINICAL RELEVANCE

Verified operational definitions will increase the consistency of results in future national health insurance database studies related to DRFs.

Analysis of Fracture Characteristic and Medial Collateral Ligament Injury Relationships in Terrible Triad Elbow Injuries

PURPOSE

The objectives of this study were to identify the relationship between fracture characteristics and medial collateral ligament (MCL) injuries in terrible triad injuries of the elbow.

METHODS

Between 2010 and 2018, 60 patients who underwent surgery for terrible triad elbow injuries were retrospectively reviewed. Using magnetic resonance imaging (MRI) assessments, patients were stratified into those who had intact or low-grade partial MCL tears (low-grade MRI-MCL group) and those who had high-grade partial or full-thickness MCL tears (high-grade MRI-MCL group). We also analyzed patients according to whether they underwent MCL repair surgery. Fractures of the radial head were assessed according to Mason's classification system and measurements of fracture fragment arc on axial cuts. Fractures of the coronoid processes were assessed according to the system of Regan and Morrey and measurements of coronoid process volumes.

RESULTS

Patients in the high-grade MRI-MCL group (28 patients) had a more comminuted and higher fragment arc of radial head fractures than those in the low-grade MRI-MCL group (32 patients) (143º ± 45º vs 119º ± 31º). However, the volume of coronoid fracture fragments was smaller in the high-grade MRI-MCL than in the low-grade MRI-MCL group (359 ± 325 mm³ vs 722 ± 448 mm³). The MCL repair group (22 patients) also had a more comminuted and higher fragment arc in radial head fractures (153º ± 44º vs 117º ± 31º) and a smaller coronoid process fracture volume (236 ± 224 mm³ vs 735 ± 419 mm³) than the non-MCL repair group (38 patients).

CONCLUSIONS

Our results demonstrated that high-grade MCL injuries are associated with comminuted and larger-sized radial head fractures, as well as smaller-sized coronoid process fractures in terrible triad injuries. In making a decision regarding surgical treatment, these fracture characteristics could help to predict the severity for MCL injury in terrible triad injuries.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Clinical comparison of the over-the-top and flexor carpi ulnaris split approaches for the treatment of anteromedial facet fracture of the coronoid process

BACKGROUND

The flexor carpi ulnaris (FCU)-split approach and the over-the-top approach have been used frequently for the fixation of anteromedial facet (AMF) fractures of the coronoid process. Clinical studies have not compared functional recovery and complication rates associated with these approaches. This study aimed to compare the clinical effectiveness of the over-the-top and FCU-split approaches for the treatment of AMF fractures of the coronoid process.

METHODS

Thirty-two patients who underwent surgery for AMF fractures between January 2013 and August 2019 were divided into the FCU-split and over-the-top groups. The FCU-split approach was used from January 2013 to March 2016, and the over-the-top approach was used from April 2016 to August 2019. Bony union, radiographic signs of osteoarthritis (Broberg and Morrey classification), and development of heterotopic ossification were evaluated. Postoperative pain score (visual analog scale at 2 days after the operation), surgical time (minutes), range of motion of the elbow, elbow function (Mayo Elbow Performance Score [MEPS]), and the presence of postoperative ulnar neuropathy were also compared between the 2 groups.

RESULTS

The FCU-split and over-the-top approaches were performed in 15 and 17 patients, respectively. The mean age was 46 ± 13 years (range, 22-67 years), and the mean follow-up duration was 19± 6.7 months (range, 13-38 months). All coronoid fractures had a solid osseous union during the follow-up, and no subluxation or dislocation was observed in the 2 groups. The occurrence of heterotopic ossification and the grade of post-traumatic arthritis did not differ significantly between the groups (all P > .05). There were also no significant differences between the groups in terms of postoperative pain score, range of motion, and MEPS (all P > .05). However, the surgical time was shorter for the over-the-top approach than that for the FCU-split approach (79± 23 vs. 101 ± 14, P = .008), and the surgical time was significantly associated with the fracture classification and surgical approach (P = .001 and .003, respectively). In addition, postoperative ulnar neuropathy occurred less with the over-the-top approach than with the FCU-spilt approach (5.9% vs. 46%, P = .013).

CONCLUSION

Both the FCU-split and over-the-top approaches were appropriate for performing the buttress plate fixation for AMF fractures of the coronoid process and for restoring the elbow stability. The fixation of AMF fractures through the over-the-top approach was technically easier and had less incidence of postoperative ulnar neuropathy.

Arthroscopic Transosseous Repair of Foveal Tears of the Triangular Fibrocartilage Complex: A Systematic Review of Clinical Outcomes

PURPOSE

To determine whether arthroscopic transosseous foveal repair of the triangular fibrocartilage complex (TFCC) results in significant and clinically relevant improvement in clinical outcomes including pain and function with low complication and reoperation rates.

METHODS

We reviewed studies investigating the clinical outcomes of arthroscopic transosseous foveal repair of the TFCC through MEDLINE, Embase, and the Cochrane Library. Studies on TFCC repair performed with an open or capsular technique and combined with other procedures, such as ulnar shortening osteotomy and a wafer procedure, were excluded. Methodologic quality was assessed using the Methodological Index for Non-randomized Studies score. Clinical outcomes were assessed using range of motion, grip strength, and patient-reported outcomes. Clinically relevant improvement was determined using the minimal clinically important difference (MCID).

RESULTS

A total of 443 unique studies were identified, of which 7 (131 patients) met the inclusion criteria. The mean age ranged from 27 to 37 years, and the mean follow-up period ranged from 23.5 to 31.1 months. The grip strength (as a percentage) increased after foveal repair of the TFCC in all studies (mean difference range, 11.8% to 22.3%). All studies also reported an improvement in the visual analog scale score (mean difference range, -9.8 to -1.88); Modified Mayo Wrist Score (mean difference range, 10.5 to 27); and Disabilities of the Arm, Shoulder and Hand score (mean difference range, -51.8 to -24.48). Considering clinically relevant improvements based on the MCID, 4 of 5 studies reporting the visual analog scale score showed improvements in this score (MCID, 2) and all studies reporting the Disabilities of the Arm, Shoulder and Hand score showed improvements in this score (MCID, 10). Most complications recovered without any treatment, and 3 patients (2.29%) needed a reoperation.

CONCLUSIONS

Arthroscopic transosseous foveal repair of the TFCC resulted in improvements in grip strength and functional outcomes with low complication and reoperation rates. However, the evidence for which technique produces better clinical outcomes remains limited.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III and IV studies.

Osteoporosis and Osteoporotic Fracture Fact Sheet in Korea

BACKGROUND

The socioeconomic burdens of osteoporosis and related fractures have increased in parallel with population aging. The Korea Society of Bone and Mineral Research published fact sheets on these topics in 2017, 2018, and 2019. This study provides complied epidemiological data based on these fact sheets for understanding current status of osteoporosis in Korea.

METHODS

Data from the Korea National Health and Nutrition Examination Survey (2008-2011) performed by the Korea Centers for Disease Control and Prevention and from National Health Information database (2008-2016) by National Health Insurance Service of Korea was used for analyzing the prevalence and incidence of osteoporosis and related fractures, respectively, fatality rates after fractures, and prescription status of anti-osteoporotic medications (AOMs).

RESULTS

Among Korean adults aged ≥50 years, 22.4% and 47.9% had osteopenia or osteoporosis, respectively. Incidences of osteoporotic hip, vertebral, humerus, and distal radius fractures plateaued in 2013. The cumulative incidence of subsequent fractures gradually increased over 4 years of follow-up once an osteoporotic fracture occurred. Crude fatality rates in the first 12 months after hip fracture were 14.0% for women and 21.0% for men. Only 33.5% of patients with osteoporosis took AOMs, and even after an osteoporotic fracture, only 41.9% of patients took AOMs within the following 12 months. Despite a steady increase in AOM prescriptions of ~6% per annum, only 33.2% of patients were medication compliant (medication possession ratio ≥80%) at 12 months after treatment initiation.

CONCLUSIONS

Continuous efforts are required to diagnose patients at high risk of fracture and ensure proper management in Korea.

The correlation between shape of the sigmoid notch of the distal radius and the risk of triangular fibrocartilage complex foveal tear

Aims

The aim of this study was to analyze the association between the shape of the distal radius sigmoid notch and triangular fibrocartilage complex (TFCC) foveal tear.

Methods

Between 2013 and 2018, patients were retrospectively recruited in two different groups. The patient group comprised individuals who underwent arthroscopic transosseous TFCC foveal repair for foveal tear of the wrist. The control group comprised individuals presenting with various diseases around wrist not affecting the TFCC. The study recruited 176 patients (58 patients, 118 controls). The sigmoid notch shape was classified into four types (flat-face, C-, S-, and ski-slope types) and three radiological parameters related to the sigmoid notch (namely, the radius curvature, depth, and version angle) were measured. The association of radiological parameters and sigmoid notch types with the TFCC foveal tear was investigated in univariate and multivariate analyses. Receiver operating characteristic curves were used to estimate a cut-off for any statistically significant variables.

Results

Univariate analysis showed that the flat-face type was more prevalent in the patients than in the control group (43% vs 21%; p = 0.002), while the C-type was lower in the patients than in the control group (3% vs 17%; p = 0.011). The depth and version angle of sigmoid notch showed a negative association with the TFCC foveal tear in the multivariate analysis (depth: odds ratio (OR) 0.380; p = 0.037; version angle: OR 0.896; p = 0.033). Estimated cut-off values were 1.34 mm for the depth (area under the curve (AUC) = 0.725) and 10.45° for the version angle (AUC = 0.726).

Conclusion

The proportion of flat-face sigmoid notch type was greater in the patient group than in the control group. The depth and version angle of sigmoid notch were negatively associated with TFCC foveal injury. Cite this article: Bone Joint J 2020;102-B(6):749–754.

Subclinical thyroid dysfunction, bone mineral density, and osteoporosis in a middle-aged Korean population

Thyroid dysfunction is associated with the loss of bone density (osteoporosis). However, the connection between subclinical thyroid dysfunction and osteoporosis remains controversial. This study found no apparent association between subclinical hypothyroidism or subclinical hyperthyroidism and bone mineral density (BMD) in the lumbar spine and femur.

INTRODUCTION

The present study examined the relationship between subclinical thyroid dysfunction and BMD in healthy middle-aged adults.

METHODS

A total of 25,510 healthy Koreans with normal free thyroxine levels were enrolled from January 2011 to December 2016, and 91% of subjects visited only once. The average age of the 15,761 women was 45, and the average age of the 9749 men was 48. Levels of thyroid-stimulating hormone (TSH) and BMD were recorded in all subjects. BMD was measured using dual-energy X-ray absorptiometry.

RESULTS

No apparent association was found between subclinical thyroid dysfunction and BMD in the lumbar spine, femur-neck, and proximal femur sites compared with a euthyroid group. Age, body mass index (BMI), and postmenopausal status affected BMD in women, and only BMI affected BMD in men. Subclinical hypothyroidism was independently associated with a lower risk of osteoporosis (odds ratio 0.657, 95% confidence interval 0.464-0.930) in 4710 postmenopausal women.

CONCLUSIONS

No apparent association was found between subclinical hypothyroidism or subclinical hyperthyroidism defined on single TSH measurement and BMD at the lumbar spine and femur in a large cohort of middle-aged men and women. Subclinical hypothyroidism was independently associated with a lower risk of osteoporosis in postmenopausal women.

Necessity of acceptable radiologic alignment by preoperative closed reduction for unstable distal radius fractures treated with volar locking plates

PURPOSE

The purpose of this study was to demonstrate the necessity of achieving acceptable radiographic alignment by preoperative closed reduction in unstable distal radius fractures (DRFs) to improve preoperative pain and obtain satisfactory outcomes after surgery.

METHODS

From 2013 to 2016, patients who received volar locking plates for DRFs were retrospectively reviewed. Patients were classified into acceptable and non-acceptable reduction groups based on immediate post-reduction radiographs. To avoid potential bias, a matched-pair analysis was performed, and paired patients were categorized into non-acceptable reduction (group A) and acceptable reduction (group B) groups. Preoperative pain level, mean length of stay, operation time, postoperative complications, and surgical outcomes were analysed. The preoperative pain level and functional results were assessed by the visual analogue scale (VAS) and Disabilities of the Arm, Shoulder and Hand (DASH) scores.

RESULTS

Of the 239 patients, 80 had non-acceptable and 159 had acceptable reductions. Among these patients, 201 (66 in group A vs. 135 in group B) were matched in a 1:2 matched ratio. Although the radiological parameters after closed reduction were better in group B, there were no significant differences in the preoperative pain VAS score, mean length of stay, operation time, and postoperative complications between the groups. In addition, radiologic parameters and the DASH score at a 1-year follow-up were also not significantly different between the groups.

CONCLUSION

Our results suggest that obtaining acceptable radiologic alignment by closed reduction is not necessary for patients who make an informed decision to undergo volar plating for unstable DRFs.

How Many Screws Are Needed for Reliable Stability of Extra-articular Nonosteoporotic Distal Radius Fractures Fixed with Volar Locking Plates?

Background

We hypothesized that volar locking pate fixation using a minimum number of screws-four in the distal row and two in the shaft of the plate-will provide sufficient stability for unstable extra-articular fractures of the distal radius. We aimed to compare the biomechanical properties of different numbers and locations of screws in volar locking plate fixation and describe the clinical and radiological outcome of plate fixation using a minimum number of screws for distal radius fractures.

Methods

We divided 48 artificial radius fracture bones into four groups (group A-D) based on the number and location of screws used for fixation with volar locking plates. The artificial bone models were subjected to axial compression and volar bending load with a force of 250 N and 80 N, respectively, for 1,000 cycles at a frequency of 1 Hz. We also retrospectively reviewed 42 patients with unstable, extra-articular, distal radius fractures who were treated with volar locking plate fixation using a minimum number of screws.

Results

Group A (seven distal screws and three proximal screws) had the highest mean stiffness: 303.7 N/mm under axial compression and 61.1 N/mm under volar bending. Compared with group A, group D (four screws in the distal part and two screws in the shaft) showed significantly lower stiffness; therefore, group D was considered inferior in terms of stability. However, in the fatigue test, neither deformation of the metal plate nor detachment or breakage of the metal screws was observed in all groups. In the clinical study, all fractures united without displacement and satisfactory clinical outcome was obtained.

Conclusions

In the dorsally comminuted, extra-articular, nonosteoporotic distal radius fractures, the minimum number of screws-four in the distal row and two in the shaft-in volar locking plate fixation can provide sufficient stability. Further biomechanical studies involving osteoporotic bone will be necessary to confirm the results because volar plate fixation is most commonly used in patients with osteoporosis.

Use of the Bridge Plate Technique for the Treatment of Hamatometacarpal Fracture-Dislocations

Background: This study aimed to describe a novel surgical technique in which a bridge plate was used for the treatment of hamatometacarpal fracture-dislocations and to assess its radiologic and clinical outcomes. Methods: A retrospective review of 16 patients treated with the bridge plate technique for hamatometacarpal fracture-dislocations was performed between 2010 and 2015. Clinical and radiographic evaluations were performed at months 3, 6, and 12 postoperatively. Active wrist and metacarpophalangeal joint ranges of motion and Quick Disabilities of Arm, Shoulder, and Hand (DASH) scores were recorded for the injured hands. Grip strength data were collected for both the injured hands and the contralateral uninjured hands. Results: All patients included in our study were male (mean age 31 years). The average Quick DASH score was 24.3 ± 9.1 at 3 months, 12.3 ± 7.3 at 6 months, and 6.2 ± 6.6 at 12 months. All patients returned to their original jobs within 5 weeks of the procedure. Grip strength eventually recovered to 90% of that of the uninjured hand, and none of the patients complained of finger or wrist joint stiffness. Conclusions: The use of the bridge plate technique may be an effective alternative treatment for patients with comminuted hamatometacarpal fracture-dislocations.

Survival rates and risk factors for failure using an interposition vein graft for fingertip amputations with segmental vessel defects

PURPOSE

This study aimed to compare survival rates and risk factors of replantation failures using an interposition vein graft in fingertip amputations with segmental vessel defects with those using simple end-to-end anastomosis in amputations.

PATIENTS AND METHODS

Between 2004 and 2015, 776 (647 males and 129 females) with single Zone I or II amputations of digits underwent replantation. Among these, simple end-to-end anastomosis was performed in 698 replantations, while interposition vein grafts were used for either arterial or venous repair or both in 78 amputated fingertips. The survival rate was compared between the groups. Logistic regression analysis was performed to identify risk factors predicting replantation failure in all study subjects.

RESULTS

Among 776 replantations, 713 (91.9%) survived. At latest follow-up, of 698 cases in the simple anastomosis group, 650 (93.1%) survived; of 78 cases in the vein graft group, 63 (80.8%) survived (p > .001). Logistic regression analysis revealed that avulsion type (odds ratio [OR] 3.121; 95% confidence interval [CI], 1.211-8.064; p = .018) and zone II amputation (OR, 2.370; 95% CI, 1.382-4.065; p = .002) were significant risk factors for replantation failure.

CONCLUSION

This study demonstrates that the survival rate (80.8%) of the vein graft in fingertip amputation with segmental vessel defects was shown to be a possible option to increase the survival rates in case with segmental vessel defects where simple anastomosis could not be performed. However, avulsion type and zone II amputation are important risk factors of replantation failures.

Proton Shell Evolution below ^{132}Sn: First Measurement of Low-Lying β-Emitting Isomers in ^{123,125}Ag

The β-delayed γ-ray spectroscopy of neutron-rich ^{123,125}Ag isotopes is investigated at the Radioactive Isotope Beam Factory of RIKEN, and the long-predicted 1/2^{-} β-emitting isomers in ^{123,125}Ag are identified for the first time. With the new experimental results, the systematic trend of energy spacing between the lowest 9/2^{+} and 1/2^{-} levels is extended in Ag isotopes up to N=78, providing a clear signal for the reduction of the Z=40 subshell gap in Ag towards N=82. Shell-model calculations with the state-of-the-art V_{MU} plus M3Y spin-orbit interaction give a satisfactory description of the low-lying states in ^{123,125}Ag. The tensor force is found to play a crucial role in the evolution of the size of the Z=40 subshell gap. The observed inversion of the single-particle levels around ^{123}Ag can be well interpreted in terms of the monopole shift of the π1g_{9/2} orbitals mainly caused by the increasing occupation of ν1h_{11/2} orbitals.

Incidence of Osteoporotic Refractures Following Proximal Humerus Fractures in Adults Aged 50 Years and Older in Korea

Background

The purpose of this study was to investigate the incidence and characteristics of osteoporotic refractures after proximal humerus fracture in Korean adults aged above 50 years.

Methods

Patients aged 50 years or older with initial proximal humerus fractures reported in 2012 were enrolled and followed up until 2016 using the Korean National Health Insurance data. Based on the last claim date, the refractures were classified as osteoporotic fractures including spine, hip, distal radius, and humerus 6 months after the index fracture involving the proximal humerus. Each osteoprotic fracture was identified using specific International Classification of Diseases, 10th Revision codes and site-specific physician claims for procedures.

Results

A total of 5,587 first-time fractures involving proximal humerus were reported in 2012. Among them, a total of 1,018 osteoporotic refractures occured between 2012 and 2016. The total cumulative incidence of osteoporotic refractures was 4.85% (271/5,587) at 1 year, 9.61% (537/5,587) at 2 years, 14.21% (794/5,587) at 3 years, and 18.22% (1,018/5,587) at 4 years. In terms of site by year, the incidence of associated refractures was as follows: spine, 48.62% (495/1,018); hip, 25.83% (263/1,018); wrist 18.57% (189/1,018); and humerus 6.97% (71/1,018) during all the follow-up periods.

Conclusions

Our study showed that the cumulative incidence of osteoporotic refractures following proximal humerus fractures in the elderly population has been increasing over the years. Given that osteoporotic refractures are associated with an increased mortality risk, a public health strategy to prevent the refracture after proximal humerus fracture in the elderly is imperative.

The effect of PPARγ agonist on SGLT2 and glucagon expressions in alpha cells under hyperglycemia

BACKGROUND

Although sodium glucose cotransporter 2 (SGLT2) inhibitors have many beneficial effects for type 2 diabetes, including decreased cardiovascular death, recent reports that they increased glucagon through SGLT2 inhibition raised some concern. Troglitazone, Peroxisome proliferator-activated receptor γ (PPAR-γ) agonist, was reported to increase SGLT2 in renal proximal tubule cells, but its role on pancreatic alpha cells have not been reported. We investigated the effect of troglitazone on SGLT2 expression in alpha cells and subsequent glucagon regulation in hyperglycemia.

METHODS

An Alpha TC1-6 cell line was cultured in control (5 mM) or hyperglycemia (HG, 15 mM) for 72 h. We applied troglitazone with or without PPARγ antagonist (GW9662 10 μM). To investigate the involvement of PI3K/Akt pathway, we applied troglitazone with or without Wortmanin. We measured sodium glucose transporter 2 (SGLT2) and glucagon (GCG) mRNA and protein expression. PPAR gamma, PI3K and Akt protein were also measured.

RESULTS

Exposure of alpha TC cells to HG for 72 h increased glucagon mRNA and protein expression. HG decreased SGLT2 mRNA and protein expression. Troglitazone significantly reversed HG-induced reduction of SGLT2 expression and increase of glucagon secretion. PPARγ antagonist (GW9662 10 μM) decreased the expression of SGLT2 and increased glucagon as HG did. Hyperglycemia increased PI3K and pAkt expression in alpha cells. Wortmanin (PI3K inhibitor, 1 μM) reversed HG-induced SGLT2 decrease and glucagon increase. Troglitazone treatment decreased PI3K and pAkt expression in HG.

CONCLUSION

In conclusion, PPARγ agonist, troglitazone improved glucose transport SGLT2 dysfunction and subsequent glucagon dysregulation in alpha cell under hyperglycemia. Those effects were through the involvement of PI3K/pAkt signaling pathway. This study may add one more reason for the ideal combination of PPARγ agonist and SGLT2 inhibitor in clinical practice.

Shell Evolution towards ^{78}Ni: Low-Lying States in ^{77}Cu

The level structure of the neutron-rich ^{77}Cu nucleus is investigated through β-delayed γ-ray spectroscopy at the Radioactive Isotope Beam Factory of the RIKEN Nishina Center. Ions of ^{77}Ni are produced by in-flight fission, separated and identified in the BigRIPS fragment separator, and implanted in the WAS3ABi silicon detector array, surrounded by Ge cluster detectors of the EURICA array. A large number of excited states in ^{77}Cu are identified for the first time by correlating γ rays with the β decay of ^{77}Ni, and a level scheme is constructed by utilizing their coincidence relationships. The good agreement between large-scale Monte Carlo shell model calculations and experimental results allows for the evaluation of the single-particle structure near ^{78}Ni and suggests a single-particle nature for both the 5/2_{1}^{-} and 3/2_{1}^{-} states in ^{77}Cu, leading to doubly magic ^{78}Ni.

Is a short arm cast appropriate for stable distal radius fractures in patients older than 55 years? A randomized prospective multicentre study

We conducted a prospective randomized, multicentre study to compare short arm and long arm plaster casts for the treatment of stable distal radius fracture in patients older than 55 years. We randomly assigned patients over the age of 55 years who had stable distal radius fracture to either a short arm or long arm plaster cast at the first review 1 week after their injury. Radiographic and clinical follow-up was conducted at 1, 3, 5, 12 and 24 weeks following their injury. Also, degree of disability caused by each cast immobilization was evaluated at the patient's visit to remove the cast. There were no significant differences in radiological parameters between the groups except for volar tilt. Despite these differences in volar tilt, neither functional status as measured by the Disabilities of the Arm, Shoulder and Hand, nor visual analogue scale was significantly different between the groups. However, the mean score of disability caused by plaster cast immobilization and the incidence rate of shoulder pain were significantly higher in patients who had a long plaster cast. Our findings suggest that a short arm cast is as effective as a long arm cast for stable distal radius fractures in the elderly. Furthermore, it is more comfortable and introduces less restriction on daily activities.

LEVEL OF EVIDENCE

II.

Aminophylline Effect on Renal Ischemia-Reperfusion Injury in Mice

BACKGROUND

Aminophylline increases the intracellular concentration of cAMP and exerts an anti-inflammatory effect. The aim of this study was to investigate the effect of aminophylline on renal ischemia-reperfusion (I/R) injury in mice.

METHODS

Thirty C57BL/6 mice were divided into 3 groups. In the sham group (group S, n = 10), only right nephrectomy was performed. In the control group (group C, n = 10), after right nephrectomy, the mice were subjected to 30 minutes of left renal ischemia. In the aminophylline group (group A, n = 10), an intraperitoneal injection of aminophylline (5 mg/kg) was performed before renal ischemia. Twenty-four hours after reperfusion, the mice were euthanized, and plasma and kidney samples were obtained to analyze the serum creatinine, renal histology, and expression levels of nuclear factor-kappa B (NF-kB) and pro-inflammatory cytokines.

RESULTS

The serum creatinine concentration in group C was markedly elevated at 24 hours after reperfusion. Aminophylline treatment significantly reduced serum creatinine, compared with group C. Aminophylline also reduced the histological evidence of renal damage. The expression levels of NF-kB, tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-2 (MIP-2), and intercellular adhesion molecule-1 (ICAM-1) mRNA were significantly increased in group C (P < .001). Group A showed lower expression of NF-kB, TNF-α, MCP-1, MIP-2, and ICAM-1 mRNA than group C (P < .01).

CONCLUSIONS

Aminophylline treatment improved the renal function and indexes of renal inflammation, which suggests that it provided reno-protection against renal I/R injury.

Russian Caucasians have a higher risk of erosive reflux disease compared with East Asians: A direct endoscopic comparison

BACKGROUND

Erosive reflux disease (ERD) is prevalent in the West, and its incidence is increasing in the East. The differences between the West and East, especially in body composition, have not been investigated thoroughly.

METHODS

Subjects who underwent esophagogastroduodenoscopy and body composition analysis during health screening were analyzed retrospectively. Russian Caucasians who visited Korea were propensity matched with native Koreans. Endoscopy results were analyzed to identify ERD and gastroesophageal flap valve (GEFV) status. Body composition and laboratory results were compared to identify risk factors for ERD.

KEY RESULTS

32 279 subjects underwent health screening with 1496 Russian Caucasians propensity matched with 1496 Koreans. ERD prevalence was 20.2% for Caucasians and 9.8% for Koreans (P<.001). Caucasians had significantly greater body mass index (BMI) and were more sarcopenic. Significant risk factors for ERD were Caucasian ethnicity (OR 1.629, 95% CI 1.265-2.099, P<.001), male gender (OR 2.374, 95% CI 1.883-2.993, P<.001), greater BMI (OR 1.067, 95% CI 1.041-1.093, P<.001), and abnormal GEFV (OR 2.730, 95% CI 2.194-3.397, P<.001). H. pylori seropositivity (OR 0.614, 95% CI 0.488-0.774, P<.001) and atrophic gastritis (OR 0.547, 95% CI 0.411-0.728, P<.001) were significantly preventive.

CONCLUSIONS & INFERENCES

Caucasian ethnicity is a significant risk factor for ERD. Greater BMI, male gender and abnormal GEFV are associated with ERD, and H. pylori seropositivity and atrophic gastritis are preventive. Further studies are needed to assess the differences in ERD between Caucasians and East Asians.

UTE-ΔR2 -ΔR2 * combined MR whole-brain angiogram using dual-contrast superparamagnetic iron oxide nanoparticles

The ability to visualize whole-brain vasculature is important for quantitative in vivo investigation of vascular malfunctions in cerebral small vessel diseases, including cancer, stroke and neurodegeneration. Transverse relaxation-based ΔR2 and ΔR2 * MR angiography (MRA) provides improved vessel-tissue contrast in animal deep brain with the aid of intravascular contrast agents; however, it is susceptible to orientation dependence, air-tissue interface artifacts and vessel size overestimation. Dual-mode MRA acquisition with superparamagnetic iron oxide nanoparticles (SPION) provides a unique opportunity to systematically compare and synergistically combine both longitudinal (R1 ) and transverse (ΔR2 and ΔR2 *) relaxation-based MRA. Through Monte Carlo (MC) simulation and MRA experiments in normal and tumor-bearing animals with intravascular SPION, we show that ultrashort TE (UTE) MRA acquires well-defined vascularization on the brain surface, minimizing air-tissue artifacts, and combined ΔR2 and ΔR2 * MRA simultaneously improves the sensitivity to intracortical penetrating vessels and reduces vessel size overestimation. Consequently, UTE-ΔR2 -ΔR2 * combined MRA complements the shortcomings of individual angiograms and provides a strategy to synergistically merge longitudinal and transverse relaxation effects to generate more robust in vivo whole-brain micro-MRA. Copyright © 2016 John Wiley & Sons, Ltd.

Robot-assisted thoracoscopic esophagectomy with extensive mediastinal lymphadenectomy: experience with 114 consecutive patients with intrathoracic esophageal cancer

The study aims to report the operative outcomes of robot-assisted thoracoscopic esophagectomy (RATE) with extensive mediastinal lymphadenectomy (ML) for intrathoracic esophageal cancer. We analyzed a prospective database of 114 consecutive patients who underwent RATE with lymph node dissection along recurrent laryngeal nerve (RLN) followed by cervical esophagogastrostomy. The study included 104 men with a mean age of 63.1 ± 0.8 years. Of these, 110 (96.5%) had squamous cell carcinoma, and the location of the tumor was upper esophagus in 7 (6.1%), middle in 62 (54.4%), and lower in 45 (39.5%). Preoperative concurrent chemoradiation was performed in 15 patients (13.2%). All but one patient underwent successful RATE, and R0 resection was achieved in 111 patients (97.4%). Extended ML and total ML were performed in 24 (21.1%) and 90 (78.9%) patients, respectively. Total operation time was 419.6 ± 7.9 minutes, and robot console time was 206.6 ± 5.2 minutes. The mean number of total, mediastinal, and RLN nodes was 43.5 ± 1.4, 24.5 ± 1.0, and 9.7 ± 0.7, respectively. The most common complication was RLN palsy (30, 26.3%), followed by anastomotic leakage (17, 14.9%) and pulmonary complications (11, 9.6%). Median hospital stay was 16 days, and 90-day mortality was observed in three patients (2.5%). On multivariate analysis, preoperative concurrent chemoradiation was a risk factor for pulmonary complications (odds ratio 7.42, 95% confidence interval 1.91-28.8, P = 0.004). RATE with extensive ML could be performed safely with acceptable postoperative outcomes. Long-term survival data should be followed in the future to verify the oncological outcome of the procedure.

Unique Imaging Features of Spinal Neurenteric Cyst

A 50-year-old male presented with acutely progressed paraplegia. His magnetic resonance imaging demonstrated two well-demarcated components with opposite signals in one cystic lesion between the T1- and T2-weighted images at the T1 spine level. The patient showed immediately improved neurological symptoms after surgical intervention and the histopathological exam was compatible with a neurenteric cyst. On operation, two different viscous drainages from the cyst were confirmed. A unique similarity of image findings was found from a review of the pertinent literature. The common findings of spinal neurenteric cyst include an isointense or mildly hyperintense signal relative to cerebrospinal fluid for both T1- and T2-weighted images. However, albeit rarer, the signals of some part of the cyst could change into brightly hyperintensity on T1-weighted images and hypointensity on T2-weighted images due to the differing sedimentation of the more viscous contents in the cyst.

Pathway for the Production of Neutron-Rich Isotopes around the N=126 Shell Closure

Absolute cross sections for isotopically identified products formed in multinucleon transfer in the (136)Xe+(198)Pt system at ∼8  MeV/nucleon are reported. The isotopic distributions obtained using a large acceptance spectrometer demonstrated the production of the "hard-to-reach" neutron-rich isotopes for Z<78 around the N=126 shell closure far from stability. The main contribution to the formation of these exotic nuclei is shown to arise in collisions with a small kinetic energy dissipation. The present experimental finding corroborates for the first time recent predictions that multinucleon transfer reactions would be the optimum method to populate and characterize neutron-rich isotopes around N=126 which are crucial for understanding both astrophysically relevant processes and the evolution of "magic" numbers far from stability.

β-Decay Half-Lives of 110 Neutron-Rich Nuclei across the N=82 Shell Gap: Implications for the Mechanism and Universality of the Astrophysical r Process

The β-decay half-lives of 110 neutron-rich isotopes of the elements from _{37}Rb to _{50}Sn were measured at the Radioactive Isotope Beam Factory. The 40 new half-lives follow robust systematics and highlight the persistence of shell effects. The new data have direct implications for r-process calculations and reinforce the notion that the second (A≈130) and the rare-earth-element (A≈160) abundance peaks may result from the freeze-out of an (n,γ)⇄(γ,n) equilibrium. In such an equilibrium, the new half-lives are important factors determining the abundance of rare-earth elements, and allow for a more reliable discussion of the r process universality. It is anticipated that universality may not extend to the elements Sn, Sb, I, and Cs, making the detection of these elements in metal-poor stars of the utmost importance to determine the exact conditions of individual r-process events.

Robust MR assessment of cerebral blood volume and mean vessel size using SPION-enhanced ultrashort echo acquisition

Intravascular superparamagnetic iron oxide nanoparticles (SPION)-enhanced MR transverse relaxation rates (∆R2(⁎) and ∆R2) are widely used to investigate in vivo vascular parameters, such as the cerebral blood volume (CBV), microvascular volume (MVV), and mean vessel size index (mVSI, ∆R2(⁎)/∆R2). Although highly efficient, regional comparison of vascular parameters acquired using gradient-echo based ∆R2(⁎) is hampered by its high sensitivity to magnetic field perturbations arising from air-tissue interfaces and large vessels. To minimize such demerits, we took advantage of the dual contrast property of SPION and both theoretically and experimentally verified the direct benefit of replacing gradient-echo based ∆R2(⁎) measurement with ultra-short echo time (UTE)-based ∆R1 contrast to generate the robust CBV and mVSI maps. The UTE acquisition minimized the local measurement errors from susceptibility perturbations and enabled dose-independent CBV measurement using the vessel/tissue ∆R1 ratio, while independent spin-echo acquisition enabled simultaneous ∆R2 measurement and mVSI calculation of the cortex, cerebellum, and olfactory bulb, which are animal brain regions typified by significant susceptibility-associated measurement errors.

Optimizing broadband terahertz modulation with hybrid graphene/metasurface structures

We demonstrate efficient terahertz (THz) modulation by coupling graphene strongly with a broadband THz metasurface device. This THz metasurface, made of periodic gold slit arrays, shows near unity broadband transmission, which arises from coherent radiation of the enhanced local-field in the slits. Utilizing graphene as an active load with tunable conductivity, we can significantly modify the local-field enhancement and strongly modulate the THz wave transmission. This hybrid device also provides a new platform for future nonlinear THz spectroscopy study of graphene.

Amelioration of high fat diet-induced glucose intolerance by blockade of Smad4 in pancreatic beta-cells

BACKGROUND

In this study, we investigated whether Smad4 signaling is involved in the regulation of beta-cell function using a high fat diet (HFD)-induced obesity mouse model.

METHODS

Beta-cell-specific Smad4-knockout mice (Smad4(-/-)RIP-Cre(+); β-Smad4KO) were generated by mating Smad4 (flox/flox) mice with rat insulin promoter (RIP)-Cre mice. Mice were fed a HFD beginning at 6 weeks of age for 16 weeks. Body weight, food intake, fasting and fed glucose levels, and glucose and insulin tolerance were measured.

RESULTS

The expression of Smad4 mRNA was significantly decreased in the islets of β-Smad4KO mice. In wild-type mice, Smad4 mRNA was significantly decreased at 18 weeks of age as compared with 8 weeks of age. On a regular chow diet, β-Smad4KO mice showed no differences in body weight, fed and fasting blood glucose levels, and glucose tolerance compared with wild-type mice. When fed a HFD, body weight gain was significantly reduced in β-Smad4KO mice as compared with wild-type mice, although the amount of food intake was not different. During the HFD, fed and fasting blood glucose levels, glucose stimulated insulin secretion, disposition index and glucose tolerance were significantly improved in β-Smad4KO mice as compared with wild-type mice. However, insulin tolerance tests showed no differences between the 2 groups.

CONCLUSION

Inhibition of Smad4 in beta-cells conferred mild but significant improvements in glucose levels and glucose tolerance in HFD-induced obese mice. Therefore, regulation of Smad4 expression may be one of the mechanisms regulating physiological expansion of beta-cells during development of type 2 diabetes.

Yrast 6⁺ seniority isomers of (136,138)Sn

Delayed γ-ray cascades, originating from the decay of (6⁺) isomeric states, in the very neutron-rich, semimagic isotopes (136,138)Sn have been observed following the projectile fission of a ²³⁸U beam at RIBF, RIKEN. The wave functions of these isomeric states are proposed to be predominantly a fully aligned pair of f(7/2) neutrons. Shell-model calculations, performed using a realistic effective interaction, reproduce well the energies of the excited states of these nuclei and the measured transition rates, with the exception of the B(E2;6⁺→4⁺) rate of ¹³⁶Sn, which deviates from a simple seniority scheme. Empirically reducing the νf(7/2)(2) orbit matrix elements produces a 4₁⁺ state with almost equal seniority 2 and 4 components, correctly reproducing the experimental B(E2;6⁺→4⁺) rate of ¹³⁶Sn. These data provide a key benchmark for shell-model interactions far from stability.

Monopole-driven shell evolution below the doubly magic nucleus 132Sn explored with the long-lived isomer in 126Pd

A new isomer with a half-life of 23.0(8) ms has been identified at 2406 keV in (126)Pd and is proposed to have a spin and parity of 10(+) with a maximally aligned configuration comprising two neutron holes in the 1h(11/2) orbit. In addition to an internal-decay branch through a hindered electric octupole transition, β decay from the long-lived isomer was observed to populate excited states at high spins in (126)Ag. The smaller energy difference between the 10(+) and 7(-) isomers in (126)Pd than in the heavier N=80 isotones can be interpreted as being ascribed to the monopole shift of the 1h(11/2) neutron orbit. The effects of the monopole interaction on the evolution of single-neutron energies below (132)Sn are discussed in terms of the central and tensor forces.

1p3/2 proton-hole state in 132Sn and the shell structure along N = 82

A low-lying state in 131In82, the one-proton hole nucleus with respect to double magic 132Sn, was observed by its γ decay to the Iπ=1/2- β-emitting isomer. We identify the new state at an excitation energy of Ex=1353  keV, which was populated both in the β decay of 131Cd83 and after β-delayed neutron emission from 132Cd84, as the previously unknown πp3/2 single-hole state with respect to the 132Sn core. Exploiting this crucial new experimental information, shell-model calculations were performed to study the structure of experimentally inaccessible N=82 isotones below 132Sn. The results evidence a surprising absence of proton subshell closures along the chain of N=82 isotones. The consequences of this finding for the evolution of the N=82 shell gap along the r-process path are discussed.

Second-look arthroscopy after surgical treatment of Schatzker type II plateau fractures through the lateral submeniscal approach

MAIN PROBLEM

To evaluate cartilage healing using second-look arthroscopic examination in tibia plateau fracture patients who have undergone open reduction and internal fixation with a submeniscal approach technique.

METHODS

Between January 2007 and January 2010, we used second-look arthroscopy during 18-24-month follow-up of 20 patients with Schatzkar type II tibial plateau fractures who had undergone open reduction and internal fixation with a submeniscal approach technique. We classified patients according to step-off, knee range of motion, and Knee Society Score, and compared the results with those obtained by arthroscopy.

RESULTS

Radiologically, 16 cases (80 %) were reduced within 2 mm of step-off. In 11 of these cases, according to the Outerbridge classification, we checked for chondromalacia from grade II to III. We observed 2 mm of step-off in four cases, and each had chondromalacia of at least grade III. The Knee Society Score was associated with chondromalacia grade (p < 0.05).

CONCLUSION

Even in patients with normal joint range of motion and good clinical and radiological results, the actual condition of the articular cartilage varied significantly. Therefore, more long-term and regular follow-up is needed for proximal plateau fractures.

First case report of an intracortical lipoma in an adult tibia

The current case report describes an adult male with an intracortical lipoma accompanied by cystic changes in the tibial diaphysis. To the best of our knowledge, intracortical lipoma in an adult tibia has not been previously described. An anteroposterior radiograph of the tibia revealed an osteolytic lesion on the diaphysis. Magnetic resonance imaging and computed tomography revealed that the lesion was located in the cortex and consisted of fat and cyst tissue. Surgical excision of the lesion confirmed diagnosis of an intracortical lipoma.

Isomers in 128Pd and 126Pd: evidence for a robust shell closure at the neutron magic number 82 in exotic palladium isotopes

The level structures of the very neutron-rich nuclei 128Pd and 126Pd have been investigated for the first time. In the r-process waiting-point nucleus 128Pd, a new isomer with a half-life of 5.8(8) μs is proposed to have a spin and parity of 8(+) and is associated with a maximally aligned configuration arising from the g(9/2) proton subshell with seniority υ=2. For 126Pd, two new isomers have been identified with half-lives of 0.33(4) and 0.44(3) μs. The yrast 2(+) energy is much higher in 128Pd than in 126Pd, while the level sequence below the 8(+) isomer in 128Pd is similar to that in the N=82 isotone 130Cd. The electric quadrupole transition that depopulates the 8(+) isomer in 128Pd is more hindered than the corresponding transition in 130Cd, as expected in the seniority scheme for a semimagic, spherical nucleus. These experimental findings indicate that the shell closure at the neutron number N=82 is fairly robust in the neutron-rich Pd isotopes.

Immune modulation effect of porcine placenta extracts in weaned the pig

In a previous study, we established a collection of appropriate porcine placental extracts using PBS at 80°C (PE-PBS80) as a food supplement to increase immune activities in a mice model. In this study, piglets were treated with 0.1%, 0.3%, and 0.5% PE-PBS80 for 3 wk after weaning. Experiments were performed at 2 separate farms using 2 different pig varieties. Composition of white blood cells, lymphocyte activation, and cytokine concentrations were analyzed to assess the immune modulation effect. In Exp. 1, the number of white blood cells increased significantly in the PE-PBS80 treatment and T- and B-cell activation increased as well (P < 0.01). Interestingly, piglets in all treatments in Exp. 2 were naturally infected by a rotavirus at the third day of the experiment but recovered after d 10. Increased lymphocyte activation was observed in the PE-PBS80 treatment (P < 0.01) regardless of viral infection. Additionally, unlike in Exp. 1, the percentage of granulocytes and concentrations of interferon-γ, IL-1β, and IgG increased in the PE-PBS80 treatment (P < 0.01) and were more active in the 0.3% PE-PBS80 treatment compared with the control and the other treatment. In conclusion, 0.3% PE-PBS80 treatment modulated immune activities in antigen-infected piglets. Therefore, the PE-PBS80 pig placental extract, particularly the 0.3% supplement to the normal diet, could be useful as an alternative feed supplement to modulate immune activity during the early piglet period.

A comparison of intra-operative blood loss and acid-base balance between vasopressor and inotrope strategy during living donor liver transplantation: a randomised, controlled study

Administration of vasopressors or inotropes during liver transplant surgery is almost universal, as this procedure is often accompanied by massive haemorrhage, acid-base imbalance, and cardiovascular instability. However, the actual agents that should be used and the choice between a vasopressor and an inotrope strategy are not clear from existing published evidence. In this prospective, randomised, controlled and single-blinded study, we compared the effects of a vasopressor strategy on intra-operative blood loss and acid-base status with those of an inotrope strategy during living donor liver transplantation. Seventy-six adult liver recipients with decompensated cirrhosis were randomly assigned to receive a continuous infusion of either phenylephrine at a dose of 0.3-0.4 μg.kg(-1).min(-1) or dopamine and/or dobutamine at 2-8 μg.kg(-1).min(-1) during surgery. Vascular resistance was higher over time in the phenylephrine group than in the dopamine/dobutamine group. Estimated blood loss was significantly lower in the phenylephrine group than in the dopamine/dobutamine group (mean (SD) 4.5 (1.8) l vs 6.1 (3.4) l, respectively, p=0.011). Patients in the phenylephrine group had lower lactate levels in the late pre-anhepatic and the early anhepatic phase and needed less bicarbonate administration than those in the dopamine/dobutamine group (median (IQR [range]) 40 (0-100 [0-160]) mEq vs 70 (40-163 [0-260]) mEq, respectively, p=0.018). Postoperative clinical outcomes and laboratory-measured hepatic and renal function did not differ between the groups. Increased vascular resistance and reduction of portal blood flow by intra-operative phenylephrine infusion is assumed to decrease the amount of intra-operative bleeding and thereby ameliorate the progression of lactic acidosis during liver transplant surgery.

Counting small hypointense spots confounds the quantification of functional islet mass based on islet MRI

Iron-containing fragmented islets or free iron released from dying cells could confound the interpretation of MRI of iron nanoparticle-labeled islets. Exclusion of small hypointense spots could be a useful strategy to avoid such artifact. We investigated whether this strategy could improve the estimation of functioning islet mass after islet transplantation. Using a rat syngeneic intraportal islet transplantation model, we quantitatively assessed the relationships between total area, number of hypointense spots on MRI that belong to each size quartile and glycemic control of the recipients. The total area of hypointense spots on MRI was greater in the recipients that achieved diabetes reversal (p = 0.002), whereas the total number of hypointense spots was not different (p = 0.757). Exclusion of small hypointense spots improved the association between the number of hypointense spots and the blood glucose level of the recipients (p < 0.001). Ex-vivo imaging and histologic study confirmed that some small hypointense spots represent the phagocytosed free iron. Exclusion of small hypointense spots improved the quantification of the functional islet mass based on islet MRI. This would be a useful principle in the development of an algorithm to estimate functioning islet mass based on islet MRI.

Immunohistochemical analysis of pulpal regeneration by nestin expression in replanted teeth

AIM

To investigate dental pulp healing after tooth replantation in rats using nestin as an odontoblastic marker for immunohistochemical analysis.

METHODOLOGY

  Twenty-five maxillary right first molars from 25 female Sprague-Dawley rats, aged 4 weeks post-natally, were extracted and immediately repositioned in the original socket within 5 s. Five rats each were later killed on days 3, 5 and weeks 1, 2 and 4. The maxillae were removed en bloc and the tissue samples containing the maxillary right first molars were decalcified, sectioned, mounted and stained with anti-nestin antibody to be observed under a light microscope.

RESULTS

  At 3 days after replantation, there was a localized inflammatory reaction, but pulp revascularization and healing had begun in the root area. At 5 days after replantation, odontoblast-like cells were observed. Reparative dentine deposition was observed beneath the pulp-dentine border from 1 week after replantation, and gradually increased until 2 weeks after replantation. The presence of odontoblast-like cells and the formation of reparative dentine continued from the first week throughout the experimental period. At week four, deposition of osteodentine and cementum-like tissues were observed.

CONCLUSIONS

Pulpal mineralization after replantation initially occurred via the deposition of reparative dentine, followed by the deposition of osteodentine and cementum-like tissues in rat teeth.

Detection of Merkel cell polyomavirus in Merkel cell carcinomas and small cell carcinomas by PCR and immunohistochemistry

Recently, the clonal integration of a new human polyomavirus (Merkel cell polyomavirus or MCPyV) has been reported in Merkel cell carcinoma (MCC). In order to investigate the presence of MCPyV in small cell carcinomas (SCCs) and small round cell tumors (SRCTs), we collected formalin-fixed paraffin-embedded tissue specimens including 14 MCCs, 24 SCCs, 7 Ewing sarcoma/primitive neuroectodermal tumors (ES/PNETs) and 5 neuroblastomas. We also collected specimens of other cancers including 12 malignant melanomas, 10 breast, 10 ovarian and 20 gastric cancers. We used 3 primer sets for which the sequences were previously published (LT1, LT3, and VP1) and 3 newly designed primer sets (LT1-1, LT1-1a, and LT3a). Quantitative real-time PCR was also performed with the LTq primer set. Nested PCR using the LT3a primer set detected more cases of MCPyV infection in MCC. In total, 12 of 14 (85.7%) MCC cases were positive for MCPyV by PCR, which was consistent with published data. Some SCC specimens were also positive for MCPyV (37.5%) by PCR. PCR products from MCC and SCC cases showed premature truncation and frameshift mutation. Furthermore, one case of ES/PNET and one gastric carcinoma showed MCPyV DNA. However, MCPyV DNA and transcript were only detected in MCCs with quantitative real-time PCR analysis. In addition, 11 of 13 (84.6%) MCC cases and 6 of 23 (26.1%) SCC cases showed immunoreactivity with monoclonal antibodies against MCPyV large T-antigen. Considering both PCR and IHC results, MCPyV was detected in all MCCs tested. The presence of MCPyV in all MCC cases tested and in some SCC cases suggests that MCPyV may be involved in the malignant transformation.

Importance of Sox2 in maintenance of cell proliferation and multipotency of mesenchymal stem cells in low-density culture

OBJECTIVES

This study has aimed to repopulate 'primitive' cells from late-passage mesenchymal stem cells (MSCs) of poor multipotentiality and low cell proliferation rate, by simply altering plating density.

MATERIALS AND METHODS

Effects of low density culture compared t high density culture on late-passage bone marrow (BM)-derived MSCs and pluripotency markers of multipotentiality were investigated. Cell proliferation, gene expression, RNA interference and differentiation potential were assayed.

RESULTS AND CONCLUSIONS

We repopulated 'primitive' cells by replating late-passage MSCs at low density (17 cells/cm(2) ) regardless of donor age. Repopulated MSCs from low-density culture were smaller cells with spindle shaped morphology compared to MSCs from high-density culture. The latter had enhanced colony-forming ability, proliferation rate, and adipogenic and chondrogenic potential. Strong expression of osteogenic-related genes (Cbfa1, Dlx5, alkaline phosphatase and type Ι collagen) in late-passage MSCs was reduced by replating at low density, whereas expression of three pluripotency markers (Sox2, Nanog and Oct-4), Osterix and Msx2 reverted to levels of early-passage MSCs. Knockdown of Sox2 and Msx2 but not Nanog, using RNA interference, showed significant decrease in colony-forming ability. Specifically, knockdown of Sox2 significantly inhibited multipotentiality and cell proliferation. Our data suggest that plating density should be considered to be a critical factor for enrichment of 'primitive' cells from heterogeneous BM and that replicative senescence and multipotentiality of MSCs during in vitro expansion may be predominantly regulated through Sox2.

Comparison of an Intraoperative Infusion of Dexmedetomidine or Remifentanil on Perioperative Haemodynamics, Hypnosis and Sedation, and Postoperative Pain Control

This prospective, randomized, double-blind study compared the effects of dexmedetomidine and remifentanil on haemodynamic stability, sedation and postoperative pain control in the postanaesthetic care unit (PACU). Fifty consecutive patients scheduled for total laparoscopic hysterectomy were randomly assigned to receive infusions of either dexmedetomidine (1 μg/kg) i.v. over 10 min followed by 0.2-0.7 μg/kg per h continuous i.v. infusion or remifentanil (0.8-1.2 μg/kg) i.v. over 1 min followed by 0.05-0.1 μg/kg i.v. per min, starting at the end of surgery to the time in the PACU. Modified observer's assessment of alertness scores were significantly lower in the dexmedetomidine group than in the remifentanil group at 0, 5 and 10 min after arrival in the PACU. Blood pressure and heart rate in the dexmedetomidine group were significantly lower than that recorded in the remifentanil group in the PACU. Dexmedetomidine, at the doses used in this study, had a significant advantage over remifentanil in terms of postoperative haemodynamic stability.

Viral agents associated with acute gastroenteritis in Seoul, Korea

BACKGROUND

The present study was carried out to describe the epidemiologic characteristics of viral gastroenteritis and determine the phylogenetic composition of norovirus strains detected in hospitalized children with acute gastroenteritis in Seoul, Korea.

METHODS AND RESULTS

In total, 10,603 stool samples were collected from 2004 to 2008 and tested by RT-PCR or ELISA. In 4,170 (39.3%) samples at least one viral pathogen was present. Rotavirus (RoV) (1,864, 17.5%) was found to be the causative agent followed by norovirus (NoV) (1,845, 17.4%), human adenovirus (HAdV) (266, 2.5%), human astrovirus (HAstV) (194, 1.8%), and sapovirus (SV) (1, 0.009%). Five GI genotypes (GI-1, GI-3, GI-4, GI-8, and GI-9) and eight GII genotypes (GII-2, GII-3, GII-4, GII-6, GII-7, GII-12, GII-16, and GII-17) of NoV were identified in acute gastroenteritis patients in 2008.

CONCLUSIONS

The genetic characteristics of norovirus and the epidemiologic patterns of a viral pathogen from acute gastroenteritis patients may give potentially effective data for epidemiological studies in Seoul, Korea.

Role of autophagy in β-cell function and mass

Type 2 diabetes (T2D) is characterized by decreased insulin secretion and action. Decreased insulin secretion results from a reduction in pancreatic β-cell mass and/or function. Apoptosis, oxidative stress, mitochondrial dysfunction and endoplasmic reticulum (ER) stress responses including JNK activation have been suggested as mechanisms for the changes of pancreatic β-cells in T2D; however, the underlying causes were not clearly elucidated. Autophagy is an intracellular process that plays crucial roles in cellular homeostasis through degradation and recycling of organelles. We have reported increased apoptosis and decreased proliferation of β-cells with resultant reduction in the β-cell mass in β-cell-specific autophagy-deficient mice. Morphological analysis of β-cells revealed accumulation of ubiquitinated proteins, swollen mitochondria and distended ER. Insulin secretory function ex vivo was also impaired. As a result, β-cell-specific autophagy-deficient mice showed hypoinsulinaemia and hyperglycaemia. These results suggested that autophagy is necessary to maintain the structure, mass and function of pancreatic β-cells. In addition, as autophagy may play a protective role against ER stress and rejuvenates organelle function, impaired autophagy may lead to mitochondrial dysfunction and ER stress, which have been implicated as potential causes of insulin resistance. Therefore, in addition to β-cell homeostasis, dysregulated autophagy may possibly be involved in diverse aspects of the pathogenesis of diabetes.