Approval status and characteristics of work-related musculoskeletal disorders among Korean workers in 2020.

Background: This study aimed to investigate the characteristics of work-related musculoskeletal disorders (WRMSDs) in occupational disease claims and identify patterns of WRMSDs for each body part by industry and occupation. Methods: This study analyzed the raw data of occupational disease claims for musculoskeletal disorders deliberated by the Occupational Disease Decision Committee of the Korea Workers' Compensation & Welfare Service in 2020. The data was classified into 6 body parts with the highest numbers of occupational disease cases by using the complete enumeration data on principal diagnoses and 4 types of subdiagnoses in the raw data. The characteristics and approval rates of WRMSDs by body part, industry and occupation were examined and summarized. Results: A total of 13,015 occupational disease cases for WRMSDs were classified, and lumbar spinal (back) diseases accounted for the largest proportion of claimed diseases, followed by shoulder, elbow, wrist, knee, and neck diseases in a descending order. The occupations with the highest and second highest numbers of occupational disease cases by body part were found to be automobile assemblers and production-related elementary workers for the neck, school meal service workers and cooks for the back, construction frame mold carpenters and school meal service workers for the shoulder, elementary workers in mining and food service workers for the elbow, food service workers and automobile parts assemblers for the wrist, and ship welders and school meal service workers for the knee. Conclusions: This study examined the characteristics and approval status of WRMSDs by body part and occupation. Based on the study results, management strategies for the prevention of WRMSDs should be established regarding occupations with a high risk of WRMSDs for each body part.

Analysis of the Change Patterns of Sagittal Alignment Values After Selective Thoracic Fusion in Lenke 1 Adolescent Idiopathic Scoliosis According to Preoperative Thoracic Kyphosis Status.

STUDY DESIGN: This was a retrospective study. OBJECTIVE: The objective of this study was to demonstrate the different change patterns in reciprocal sagittal alignment values after selective thoracic fusion (STF) in Lenke type 1 adolescent idiopathic scoliosis (AIS) according to preoperative thoracic kyphosis (TK). SUMMARY OF BACKGROUND DATA: Several studies have found significant increase in TK after STF, while other studies have reported decrease in TK postoperatively. Similar inconclusive results on changes in lumbar lordosis (LL) have been reported, showing LL increase, decrease, or no change. MATERIALS AND METHODS: Ninety-three patients presenting with Lenke type 1 AIS treated by posterior STF with a minimum follow-up of 2 years were included in this study. Using whole spine radiographs, sagittal parameters including TK, LL, and upper lumbar lordosis (ULL) were compared preoperatively and at the last follow-up between a hypokyphosis group (preoperative TK<20 degrees) and a normokyphosis group (preoperative TK≥20 degrees). Health-related quality of life (HRQOL) was assessed using scoliosis research society health-related quality of life-30 (SRS-30) and short from health survey-36 questionnaire at the last visit. RESULTS: The mean follow-up duration was 74.9 months. In the hypokyphosis group (35 patients), TK, LL, and ULL statistically significantly increased after surgery by mean 7.7, 5.1, and 3.7 degrees (P<0.001, <0.001, and 0.001). In the normokyphosis group (58 patients), these parameters did not show significant changes after STF. Final TK was significantly lower in hypokyphosis group than that in the normokyphosis group (21.2 vs. 30.9 degrees, P<0.001) while final LL did not differ between 2 groups (52.4 vs. 54.6 degrees, P=0.194). HRQOL did not differ significantly between the 2 groups. CONCLUSIONS: After STF in Lenke 1 AIS, TK, and LL statistically significantly increased through an increase in the mean ULL in the hypokyphosis group while those mean values did not change in the normokyphosis group. Despite the final mean value of the TK in the hypokyphosis group increasing by 7.7 degrees, it was statistically significantly lower than the final mean TK value in the normokyphosis group which did not increase after STF surgery by posterior approach. However, HRQOL showed no significant difference between the 2 groups.

Minimum Three-year Follow-up of Specific Functional Disabilities After Multilevel Lumbar Fusion: Comparison of Long-level and Short-level Fusion.

STUDY DESIGN: Retrospective case-control study. OBJECTIVE: To evaluate specific functional disabilities after short- and long-level lumbar fusion. SUMMARY OF BACKGROUND DATA: The Oswestry Disability Index (ODI) cannot represent all types of functional disabilities observed after lumbar fusion and a region-specific Functional Disability Index (SFDI) is necessary. METHODS: We examined the differences in postoperative functional disability between 81 patients who underwent ≥3-level lumbar fusion (group I) and 70 age- and sex-matched patients who underwent one- or two-level lumbar fusion (group II). The ODI and Visual Analogue Scale (VAS) were assessed pre- and postoperatively. The SFDI was assessed after lumbar fusion. We evaluated intergroup differences in postoperative VAS, ODI, and SFDI scores during 3-year follow-up. Each mean score was evaluated separately for the 10 ODI and the 12 SFDI items, and we evaluated the changes observed in these scores over the 3-year follow-up. RESULTS: The mean intergroup preoperative ODI and VAS scores were similar. The mean postoperative intergroup VAS scores were similar; however, the mean postoperative ODI and SFDI scores were significantly higher in group I than in group II at 1-year (P<0.001, P<0.001, respectively) and 3-year follow-up (P = 0.037, P<0.001, respectively). Among 10 ODI items, group I showed significant disability with regard to six items at the 1-year follow-up compared with group II, but only showed significant disability with regard to one item at the 3-year follow-up. Among the 12 SFDI items, group I showed significant disability with regard to all 12 items at 1-year follow-up compared with group II, as well as significant disability with regard to nine items at 3-year follow-up. CONCLUSION: The SFDI is more sensitive than the ODI in assessing functional disabilities based on the levels of fusion. Most SFDI items indicated continued significant disability in patients with long-level lumbar fusion even 3 years postoperatively. LEVEL OF EVIDENCE: 3.

Radiological and clinical long-term results of heterotopic ossification following lumbar total disc replacement.

BACKGROUND: The long-term results of heterotopic ossification (HO) following lumbar total disc replacement (TDR) and the corresponding clinical and radiological outcomes are unclear. PURPOSE: This study aimed to report the long-term results of HO following lumbar TDR and to analyze the clinical and radiological outcomes. STUDY DESIGN/SETTING: A retrospective case review was performed for the consecutive patients who underwent lumbar TDR. PATIENT SAMPLE: The study included 48 patients (60 segments) who underwent lumbar TDR. OUTCOME MEASURES: The time and location of HO development, segmental range of motion (ROM) of index level, the visual analog scale (VAS), and the Oswestry Disability Index (ODI) were analyzed. METHODS: Forty-eight patients (60 segments) were divided into HO and non-HO groups, and radiographs were used to measure the time and location of HO development. We compared segmental ROM between two groups using flexion-extension radiographs. Clinical outcomes were assessed using the VAS and the ODI. Furthermore, the segmental ROM, VAS, and ODI scores of each HO class were compared with those of the non-HO group. RESULTS: The mean follow-up duration was 104.4 months. Heterotopic ossification was detected in 30 of 60 segments following lumbar TDR, and HO progression was noted in six segments. The mean segmental ROM was significantly lower in the HO group than in the non-HO group. The mean VAS and ODI scores were not significantly different between the two groups. Segmental ROM was significantly lower in the class III and IV of the HO group than in the non-HO group. The VAS and ODI scores were not significantly different among the different classes. CONCLUSIONS: We found that the incidence of HO is the highest within 12 months after lumbar TDR, and the incidence might increase 5 years after surgery. Furthermore, HO progressed over time. Segmental ROM was decreased in the HO groups; however, the limitation in motion might have little clinical influence.

Characteristics and Efficacy of a New 3-Dimensional Printed Mesh Structure Titanium Alloy Spacer for Posterior Lumbar Interbody Fusion.

This study evaluated the characteristics of a newly developed 3-dimensional printed mesh structure titanium spacer and its efficacy for posterior lumbar interbody fusion. Posterior lumbar interbody fusion with this spacer was performed at 53 segments (40 patients; mean age, 64 years; range, 51-73 years). Data were collected prospectively. Radiographic characteristics were analyzed with changes in interbody height, instability of the segments, formation of bone bridges around the implants, and pseudarthrosis, as determined by dynamic radiographs and postoperative computed tomography scans. Clinical outcomes were evaluated with the visual analog scale for the low back and extremities, the Oswestry Disability Index, and the 36-Item Short Form Survey. Radiographically, preoperative anterior and posterior interbody height was significantly increased immediately postoperatively (P<.05), and this increase was maintained until the last follow-up. No segmental motion of 3° or greater was noted at the last follow-up. Sagittal computed tomography images showed complete anterior bone bridges for 94.3% of cases and complete posterior bone bridges for 86.7% of cases. Coronal computed tomography images showed bilateral complete bone bridges for 94.3% of cases and unilateral bone bridges for 5.7% of cases without incomplete bilateral bone bridges. No pseudarthrosis or revision, particularly including posterior lumbar interbody fusion at L5-S1, was noted. Compared with preoperative values, the visual analog scale score for the low back and extremities, the Oswestry Disability Index, and the 36-Item Short Form Survey score showed significant improvement at the last follow-up (P<.05). Posterior lumbar interbody fusion with a newly developed 3-dimensional printed mesh structure titanium spacer showed satisfactory radiographic and clinical results, with no cases of pseudarthrosis or revision, including posterior lumbar interbody fusion at L5-S1. [Orthopedics. 2017; 40(5):e880-e885.].

Coordination of trunk and pelvis in young and elderly individuals during axial trunk rotation.

It has been well known that complex tasks such as walking and arm reaching can be achieved by the coordination of the trunk and pelvis. However, understanding of the effect of aging on the coordination of the trunk and pelvis during axial trunk rotation is still lacking. The present study examined relative phase of the trunk and pelvis during axial trunk rotation, and compared it between young and older groups. 22 healthy young (age: 23.9±4.6, gender: 11 male and 11 female) and 22 healthy elderly (age: 68.4±4.9, gender: 11 male and 11 female) individuals participated in the experiment and performed axial trunk rotation. Relative phase between the trunk and pelvis was calculated based on the angular displacements of the two segments. The results demonstrated age-related changes in coordination pattern of the trunk and pelvis during axial trunk rotation.

Tendon impingement of the extensor digiti minimi: clinical cases series and cadaveric study.

The authors describe two unique clinical cases of closed extensor digiti minimi (EDM) tendon injuries after hyperflexion of the wrist with full finger flexion and one case of chronic tenosynovitis around the EDM tendon. All three cases were thought to be related to the bifurcation of the EDM tendon and synovial septum. Subsequently, variations in EDM tendons were investigated in 49 cadaveric hands with a focus on patterns of tendon bifurcation and their relationships with the surrounding synovial sheath. The EDM tendon was found to be bifurcated in 74% (n = 36) of hands and all of these hands contained a synovial septum. In 9 (25%) hands, the EDM tendon bifurcated proximal to the retinaculum, in 15 (42%), it bifurcated distal to the retinaculum, and in the other 12 hands (33%), the tendon bifurcated at the retinacular level. In 6 of the 15 hands with an infraretinacular bifurcation, the tendon was found to impinge on the synovial septum during passive flexion of the wrist with full finger flexion, and the mean distance between the synovial septum and the bifurcation point in these specimens was 0.6 cm (range, 0.4-0.7 cm), which was differed significantly from hands not showing impingement (P = 0.01). This study shows that distal bifurcation of the EDM tendon may lead to tendon impingement on the septum and suggests that this is a potential etiology of chronic tenosynovitis of the fifth compartment and of acute closed tendon injuries.

A case of sparganosis in the leg.

The life-span of the sparganum in humans is not exactly known, but it may survive longer than 5 years in some patients. We experienced a case infected with a sparganum that is presumed to have lived for 20 years in a patient's leg. The patient was a 60-year-old woman, and she was admitted to a hospital due to ankle pain that was aggravated on dorsiflexion. She had noticed a mass on her knee some 20 years ago, but she received no medical management for it. The mass moved into the ankle joint 3 months before the current admission, and then the aforementioned symptoms appeared. A living sparganum was recovered by surgery, and the calcified tract near the knee was proved to be the pathway along which the larva had passed.

The rust fungus Gymnosporangium in Korea including two new species, G. monticola and G. unicorne.

A survey was conducted of the rust fungus Gymnosporangium in Korea. We recollected previously known species, namely Gymnosporangium asiaticum, G. clavariiforme, G. globosum, G. japonicum and G. yamadae. Gymnosporangium nidus-avis and G. sabinae are reported for the first time from Korea, and two new species, G. monticola sp. nov. and G. unicorne sp. nov., are recognized. Previous single reports of G. miyabei and G. shiraianum could not be confirmed. The LSU rDNA was sequenced from freshly collected specimens. Phylogenetic analyses show that species of Gymnosporangium form a monophyletic group with strong bootstrap support within the rust fungi. The two new species are unique based on both A and B molecular as well as morphological characteristics. Analyses of phenotypic characters mapped onto the phylogenetic tree show that teliospore length followed by telia shape and telia length are conserved; these are morphological characters useful in differentiating species of Gymnosporangium. Each of the nine species of Gymnosporangium in Korea is described and illustrated, and keys based on aecia and telia stages are provided. Lectotype specimens for several names described in Gymnosporangium are designated.

Identification of genes upregulated by pinewood nematode inoculation in Japanese red pine.

Pine wilt disease caused by the pinewood nematode (PWN), Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle, has destroyed huge areas of pine forest in East Asia, including Japan, China and Korea. No protection against PWN has been developed, and the responses of pine trees at the molecular level are unrecorded. We isolated and analyzed upregulated or newly induced genes from PWN-inoculated Japanese red pine (Pinus densiflora Sieb. et Zucc.) by using an annealing control primer system and suppression subtractive hybridization. Significant changes occurred in the transcript abundance of genes with functions related to defense, secondary metabolism and transcription, as the disease progressed. Other gene transcripts encoding pathogenesis-related proteins, pinosylvin synthases and metallothioneins were also more abundant in PWN-inoculated trees than in non-inoculated trees. Our report provides fundamental information on the molecular mechanisms controlling the biochemical and physiological responses of Japanese red pine trees to PWN invasion.