Rotator Cuff Tears are Significantly More Frequent in Recurrent Shoulder Instability Patients With Initial Dislocation at Age 40 or Older.

PURPOSE: To investigate and compare the pathologies and clinical outcomes of patients with traumatic anterior shoulder instability who underwent arthroscopic stabilization at 40 years or older between shoulders with initial dislocation before age 40 years and at 40 years or after. METHODS: Shoulders that underwent arthroscopic stabilization for recurrent traumatic anterior shoulder instability at 40 years or older with a minimum of 2-year follow-up were included. The subjects were divided into 2 groups according to age at initial dislocation after propensity score matching to reduce potential bias: younger than 40 years (group 1) and 40 years or older (group 2). Radiographic findings, pathologies, clinical outcomes, and complications were compared between the groups. RESULTS: Group 1 included 56 shoulders in 56 patients (26 men and 30 women) with a mean age of 51 years (range, 40-77 years). Group 2 included 28 shoulders in 28 patients (13 men and 15 women) with a mean age of 51 years (range, 40-77 years). Glenoid bone loss was greater in group 1 than in group 2 (P = .004). Rotator cuff tears were more frequently observed in group 2 than in group 1 (P < .001). Both groups showed significant improvement in the West Ontario Shoulder Instability Index score (P < .001 for each) and flexion (P < .001 for each). The recurrence rate was 4% in group 1 and 7% in group 2. CONCLUSIONS: Rotator cuff tears are significantly more frequent in recurrent shoulder instability patients with initial dislocation at age 40 or older. Arthroscopic stabilization yielded a low recurrence rate and favorable outcomes with a good return-to-sport rate in patients 40 years or older. LEVEL OF EVIDENCE: Level III, retrospective comparative prognostic trial.

Prevalence and treatment rates of osteoporosis among individuals with rotator cuff tears.

BACKGROUND: The relationship between osteoporosis and rotator cuff tears has been reported previously. However, the treatment rate of osteoporosis in individuals with rotator cuff tear is still unknown. The aim of this study was to investigate the prevalence and treatment rate of osteoporosis in individuals with rotator cuff tears. METHODS: In this cross-sectional study, we enrolled 207 participants. Participants underwent comprehensive assessments, including shoulder ultrasonographic examinations and quantitative ultrasound measurements for bone status evaluation. Osteoporosis diagnosis was predicated on a calcaneus ultrasound bone densitometry, and the cutoff value was set as a T score of -1.455, with reference to a previous report. RESULTS: One hundred fifty-six participants were classified as individuals without rotator cuff tears (group A), and 51 participants were classified as those with (group B). The mean age in group A was significantly lower than that in group B (63 ± 10 vs. 68 ± 9, respectively; P = .003). In terms of the T score examined by quantitative ultrasound, the mean T score in group A was significantly higher than that in group B (-1.4 ± 1.3 vs. -1.9 ± 1.6, respectively; P = .0412). The percentage of subjects with a T score of -1.455 or less in group B was 60.8% (31/51). The proportion of subjects with a T score of -1.455 or less undergoing osteoporosis treatment was 14.5% (12/83) in group A and 12.9% (4/27) in group B, showing no significant difference. CONCLUSIONS: Participants with a rotator cuff tear had relatively high prevalence of osteoporosis. Among those with both a rotator cuff tear and osteoporosis, the proportion receiving osteoporosis treatment was l2.9%, a very low rate.

Potential of patellar height measurement methods in predicting recurrent patellar dislocation incidence: a case-control study.

BACKGROUND: Recurrent patellar dislocation (RPD) is a multifactorial disease that affects young and active people. Patellar height measurements are used clinically to screen and diagnose knee conditions. However, there are no known studies that have assessed and compared the performance of patellar height indices for predicting the incidence of RPD, which could be used to recommend surgical treatment after primary patellar dislocation. This case-control study aimed to determine if the patellar height index could be used to predict the incidence of RPD, and to identify the optimal method in terms of its diagnostic ability for RPD. METHOD: Altogether, 133 patients (52 patients with RPD [Group R] and 81 sex- and age-matched controls [Group C]) were enrolled in this study. The Insall-Salvati (IS), Blackburne-Peel (BP), Caton-Deschamps (CD), and modified IS (mIS) methods were used to measure the patellar height index. The intra-observer and inter-observer reliabilities of these four methods were determined using intraclass correlation coefficients. A receiver operating characteristic curve analysis was performed to evaluate the predictive ability of each index and identify the cut-off values that indicated significantly increased risk of RPD. RESULTS: Patient demographics were similar between the two groups. The inter-observer and intra-observer reliabilities were good for all four methods. In patients with RPD, the mean index values for the four methods were significantly higher than those in the matched controls. The area under the curve (AUC) values for IS, BP, CD, and mIS were 0.91 (standard error [SE], 0.03; 95% confidence interval [CI], 0.84-0.96), 0.72 (SE, 0.05; 95% CI, 0.63-0.81), 0.86 (SE, 0.03; 95% CI, 0.79-0.92), and 0.96 (SE, 0.01; 95% CI, 0.94-0.99), respectively. CONCLUSION: Patellar height indices had high predictive performance for the incidence of RPD. The mIS method had the highest AUC.

Activated FGFR3 suppresses bone regeneration and bone mineralization in an ovariectomized mouse model.

BACKGROUND: Postmenopausal osteoporosis is a widespread health concern due to its prevalence among older adults and an associated high risk of fracture. The downregulation of bone regeneration delays fracture healing. Activated fibroblast growth factor receptor 3 (FGFR3) accelerates bone regeneration at juvenile age and downregulates bone mineralization at all ages. However, the impact of FGFR3 signaling on bone regeneration and bone mineralization post-menopause is still unknown. This study aimed to evaluate the impact of FGFR3 signaling on bone regeneration and bone mineralization during menopause by developing a distraction osteogenesis (DO) mouse model after ovariectomy (OVX) using transgenic mice with activated FGFR3 driven by Col2a1 promoter (Fgfr3 mice). METHODS: The OVX or sham operations were performed in 8-week-old female Fgfr3 and wild-type mice. After 8 weeks of OVX surgery, DO surgery in the lower limb was performed. The 5-day-latency period followed by performing distraction for 9 days. Bone mineral density (BMD) and bone regeneration was assessed by micro-computed tomography (micro-CT) scan and soft X-ray. Bone volume in the distraction area was also evaluated by histological analysis after 7 days at the end of distraction. Osteogenic differentiation and mineralization of bone marrow-derived mesenchymal stem cells (BMSCs) derived from each mouse after 8 weeks of the OVX or sham operations were also evaluated with and without an inhibitor for FGFR3 signaling (meclozine). RESULTS: BMD decreased after OVX in both groups, and it further deteriorated in Fgfr3 mice. Poor callus formation after DO was also observed in both groups with OVX, and the amount of regenerated bone was further decreased in Fgfr3 mice. Similarly, histological analysis revealed that Fgfr3 OVX mice showed lower bone volume. Osteogenic differentiation and mineralization of BMSCs were also deteriorated in Fgfr3 OVX mice. An inhibitor for FGFR3 signaling dramatically reversed the inhibitory effect of OVX and FGFR3 signaling on BMSC mineralization. CONCLUSION: Upregulated FGFR3 decreased newly regenerated bone after DO and BMD in OVX mice. FGFR3 signaling can be a potential therapeutic target in patients with postmenopausal osteoporosis.

Arthroscopic Bankart repair with peeling osteotomy of the anterior glenoid rim preserves glenoid morphology.

BACKGROUND: A decrease in the glenoid size after arthroscopic Bankart repair (ABR) was common in shoulders without osseous fragments compared with those with osseous fragments. For cases of chronic recurrent traumatic anterior glenohumeral instability without osseous fragments, we have performed ABR with peeling osteotomy of the anterior glenoid rim (ABRPO) to make an intentional osseous Bankart lesion. The aim of this study was to compare the glenoid morphology after ABRPO with it after simple ABR. METHODS: The medical records of patients who underwent arthroscopic stabilization for chronic recurrent traumatic anterior glenohumeral instability were retrospectively reviewed. Patients with an osseous fragment, with revision surgery and without complete data were excluded. Patients were assigned to 1 of 2 groups: Group A, ABR without peeling osteotomy procedure or Group B, with ABRPO procedure. Computed tomography was performed preoperatively and 1 year after surgery. The size of the glenoid bone loss was investigated by the assumed circle method. The following formula was used to calculate the decreased size of the glenoid: (Δ) = (postoperative size of the glenoid bone loss) - (preoperative size of the glenoid bone loss). The size of the glenoid 1 year after surgery was assessed to determine if it had decreased (Δ > 0%) or not decreased (Δ ≤ 0%) relative to the preoperative size. RESULTS: This study evaluated 39 shoulders divided into 2 groups: 27 shoulders in Group A and 12 shoulders in Group B. In Group A, postoperative glenoid bone loss was significantly greater than preoperative glenoid bone loss (7.8 ± 6.2 vs. 5.5 ± 5.3, respectively, P = .02). In Group B, postoperative glenoid bone loss was significantly lower than preoperative glenoid bone loss (5.6 ± 5.4 vs. 8.7 ± 4.0, respectively, P = .02). The P value for the interaction of group (A or B) × time (preoperative or postoperative) was 0.001. The decreased size of the glenoid was significantly larger in Group A than in Group B (2.1 ± 4.2 vs. -3.1 ± 4.5, respectively, P = .001). The rate of shoulders in which the size of the glenoid decreased 1 year after surgery relative to the preoperative size was significantly higher in Group A than in Group B (63% [17/27] vs. 25% [3/2], respectively, P = .04). CONCLUSIONS: The study showed that ABRPO preserved the glenoid size better than simple ABR without a peeling osteotomy procedure.

Biceps tenotomy versus soft-tissue tenodesis in females aged 60 years and older with rotator cuff tears.

BACKGROUND: Recently, to treat the long head of the biceps tendon lesions in addition to rotator cuff repair has been recommended. However, the differences in clinical outcomes between biceps tenotomy and tenodesis for middle-aged and elderly females remains unclear. The purpose of this study was to compare the outcomes of biceps tenotomy and soft-tissue tenodesis that were performed concurrently with arthroscopic rotator cuff repair in ≥60-year-old females. METHODS: Female shoulders that underwent arthroscopic rotator cuff repair in our institute in 2016 were retrospectively reviewed. This study included 66 shoulders with concurrent biceps tenotomy or soft-tissue tenodesis: tenotomy group, 41 shoulders; soft-tissue tenodesis group, 25 shoulders. Clinical scores, biceps pain (visual analogue scale, VAS), Popeye deformity, and biceps strength (%contralateral side) were compared between the two groups. RESULTS: The mean age was significantly higher in the tenotomy group than the soft-tissue tenodesis group (72 ± 4 and 68 ± 6 years, respectively; P = 0.002). There were no significant differences in post-operative JOA and UCLA scores between the groups. VAS for biceps pain was significantly higher at postoperative 6 months in the tenotomy group than the soft-tissue tenodesis group (2.9 ± 2.5 and 1.7 ± 1.6, respectively, P = 0.03), though there were no significant differences at postoperative 3, 12, and ≥24 months. Subjective evaluation of Popeye deformity was not significantly different between the groups. Postoperative biceps strength was significantly lower in the tenotomy group than the soft-tissue tenodesis group (89.9% and 102.8%, respectively, P = 0.02). CONCLUSIONS: Both biceps tenotomy and soft-tissue tenodesis concurrent with rotator cuff repair in ≥60-year-old female patients resulted in good outcomes. Shoulders with soft-tissue tenodesis demonstrated earlier improvement in postoperative biceps pain and better postoperative biceps strength than those with tenotomy. There were no differences in objective and subjective Popeye deformity between tenotomy and soft-tissue tenodesis. The LHB procedures, tenotomy or tenodesis, can be selected depending on surgeons' preference.

Delayed anterior cruciate ligament reconstruction increases the incidence of medial meniscal bucket handle tears and medial compartment chondral injuries in patients aged 40 years and older.

INTRODUCTION: No widely accepted evidence-based indications exist for the initial surgical management of patients with anterior cruciate ligament (ACL) injuries ≥ 40 years old, and treatment for these patients remains controversial. This study aimed to evaluate the association between elapsed time from ACL injury to surgery and the incidence of meniscal tears and chondral injury in patients aged ≥ 40 years. MATERIALS AND METHODS: The patients who underwent primary ACL reconstruction were divided into two groups based on elapsed time from injury to surgery: early group, < 12 months; and delayed group, ≥ 12 months. Patient records were reviewed for incidence and types of meniscal tears and chondral injuries in each group. Chondral injury grades were evaluated with International Cartilage Regeneration and Joint Preservation Society (ICRS) Criteria. RESULTS: This study evaluated 67 knees in the early group and 33 knees in the delayed group. Mean ages in each group were 46.9 ± 6.5 and 46.9 ± 6.0. The delayed group showed significantly higher rates of medial meniscal tear [31 of 33, 93.9% vs 29 of 67, 43.3%; P < 0.0001; odds ratio (OR), 20.31; 95% confidence interval (CI), 4.49-91.9], medial femoral condyle chondral injuries ≥ ICRS grade II (15 of 33, 45.5% vs 8 of 67, 11.9%; P < 0.001; OR, 6.15; 95% CI 2.24-16.83), and medial tibial chondral injuries ≥ ICRS grade II (7 of 33, 21.2% vs 3 of 67, 4.5%; P < 0.05; OR, 5.74; 95% CI 1.38-23.9) compared with the early group. With respect to types of medial meniscal tear, the delayed group showed a significantly higher frequency of bucket handle tears (11 of 33, 33.3%) compared with the early group (2 of 67, 3.0%; P < 0.0001; OR, 16.25; 95% CI 3.34-79.1). CONCLUSIONS: Delayed ACL reconstruction was associated with increased incidence of chondral injuries and medial meniscal tears, particularly bucket handle tears in this cohort. LEVEL OF EVIDENCE: Level III.

Spontaneous Pneumomediastinum in an Adolescent Soccer Player.

Spontaneous pneumomediastinum (SPM) is an uncommon and usually benign self-limiting clinical disorder found in young people, often without apparent precipitating factors or diseases. A pressure gradient exists between the peripheral pulmonary alveoli and the hilum, and increased intra-alveolar pressure causes rupture of the terminal alveoli. We present the case of a 15-year-old male soccer player who presented with a complaint of anterior chest pain and dysphagia after stopping the strong ball with his chest. His symptom gradually progressed over hours. We can make the diagnosis of SPM using by chest X-ray and computed tomography (CT) scanning. His symptoms were gradually resolved over the course of approximately one week with no exercise and careful observation. We believe that our case provides very useful information to alert clinicians and coaches regarding this rare disease that may occur in anyone including adolescent soccer players.

Recurrent fifth metatarsal stress fractures in a professional soccer player with hypoparathyroidism: a case report.

BACKGROUND: Hypoparathyroidism is characterized by low or inappropriately normal levels of parathyroid hormone leading to hypocalcemia. In this report, a case of recurrent fifth metatarsal stress fractures in a professional soccer player with hypoparathyroidism is presented. CASE PRESENTATION: A 23-year-old male professional soccer player developed left foot pain. He had no specific medical or family history. He was diagnosed with a fifth metatarsal stress fracture and underwent osteosynthesis with a cannulated cancellous screw 3 days after the injury. After three and a half months, the X-ray showed bone union, and he returned to full sports activity. However, he felt pain in his left foot again, and a re-fracture was found on X-ray a week later. Osteosynthesis was performed again. Two months after re-operation, the cause of re-fracture was investigated. Laboratory results showed abnormally low levels of serum calcium (8.4 mg/dL) and intact parathyroid hormone (i-PTH: 19.0 pg/mL). However, other laboratory examinations were normal. Therefore, he was diagnosed with primary hypoparathyroidism according to the diagnostic criteria. Medical treatment was started with alfacalcidol 1.0 µg/day. One month after starting medication, the serum calcium improved to 9.4 mg/dL. Four months after the re-operation, the X-ray showed bone union, and he was therefore allowed to play soccer. While he played professional soccer, there were no new subjective complaints. CONCLUSIONS: Hypoparathyroidism may be one of the risk factors for stress fractures. We believe that serum calcium levels should be checked in patients with stress fractures, and if the serum calcium is low, hypoparathyroidism should be considered.

Treatment of open ankle dislocation without associated fractures in a young athlete using external fixation and ligament repair with suture tape augmentation.

BACKGROUND: Ankle dislocation without fracture is an extremely rare injury because it is usually accompanied by concomitant malleolar fractures from the anatomical and mechanical viewpoints. CASE PRESENTATION: We report the case of a 17-year-old woman who was injured while playing basketball. Her ankle was swollen and deformed. Plain X-ray revealed tibiotalar dislocation in the medial direction without any fractures. Immediate reduction and ligament repair using suture tape augmentation were performed. CONCLUSIONS: At 5 months postoperatively, the patient returned to playing basketball without any complaints. After an additional 2 months, the patient participated and played in the Winter Cup 2019 (the national high school basketball tournament in Japan) at the previous performance level.

Outcomes of pediatric anterior cruciate ligament reconstructions in patients with and without bucket handle meniscus repairs.

The purpose of this study was to report the outcomes of concomitant bucket handle meniscal tear (BHMT) repair and anterior cruciate ligament (ACL) reconstruction and to compare the outcomes with those after isolated ACL reconstruction in patients aged ≤16 years. Patients in our database from 2013 to 2017 were retrospectively analyzed. Patients were assigned to one of two treatment groups based on the presence of BHMTs: no meniscal tear group (group A) and BHMT group (group B). All BHMTs were repaired using the combined inside-out with all-inside technique. This study included 64 knees divided into two groups: 47 knees in group A and 17 knees in group B. There was a significant difference in the interval between ACL injury and surgery between groups A and B (69 vs. 150 days, respectively; P < 0.001). Mean postoperative International Knee Documentation Committee and Lysholm scores in group A were slightly, although significantly, improved compared to those in group B (96.5 vs. 92.6, respectively; P < 0.05, and 98 vs. 95, respectively; P < 0.05). There were no significant differences in postoperative anteroposterior laxity and graft failure rate between the groups. In group B, four patients (23.5%) required surgery for incomplete meniscal healing. Postoperative International Knee Documentation Committee and Lysholm scores of patients with BHMTs were significantly lower than those of patients without any meniscal tear, although with significant improvement in the amount of instability. Level of evidence was Level III.

Incidence of teres minor muscle atrophy in young and middle-aged populations.

Background: Teres minor atrophy can be seen in shoulders both with and without a rotator cuff tear, even among the young population. The purpose of this study was to retrospectively investigate the incidence of teres minor atrophy in young and middle-aged patients with or without a rotator cuff tear. Methods: Patient records were reviewed to identify 10-39-year-old patients (Group Y) and 60-69-year-old patients (Group O) who underwent MRI because of shoulder disorders. The exclusion criteria were as follows: (1) prior surgeries, (2) neurological disorders in the cervical spines or shoulder girdle, (3) global atrophy of all four cuff muscles without a rotator cuff tear, (4) acute trauma, and (5) poor image quality due to artifacts. An experienced shoulder surgeon evaluated teres minor atrophy on T1-weighted oblique sagittal images. Statistical analysis was performed using the chi-square test for comparison of Groups Y and O. Results: Group Y consisted of 528 shoulders in 520 patients, including 406 males and 114 females with a mean age of 26 years. Group O consisted of 884 shoulders in 837 patients, including 394 males and 443 females with a mean age of 65 years. Rotator cuff tears were seen in 33 shoulders (6.3 %) in Group Y, and 411 shoulders (46.5%) in Group O. Teres minor atrophy was more present in Group O (59 shoulders [6.7%]) than Group Y (11 shoulders [2.1%], P < .001). Among shoulders with teres minor atrophy, the incidence of intact cuff tended to be higher in Group Y than O (7 shoulders [64%] and 21 shoulders [36%], P = .08). However, the ratio of the intact cuff to the number of patients in each group was not significantly different (Group Y, 7 of 528 [1.3%]; Group O, 21 of 884 [2.3%]). Teres minor muscle atrophy tended to be more common in athletes than nonathletes in Group Y, although the difference was not significant (P = .057). Conclusion: The incidence of teres minor atrophy was significantly higher in middle-aged patients than young patients. Middle-aged patients with teres minor atrophy were more associated with rotator cuff tears. The common cause of teres minor atrophy may be rotator cuff tears. Teres minor atrophy in young patients might be associated with sports-related factors such as infraspinatus hypertrophy or axillary nerve injury.

The impact of vitamin D supplementation on body fat mass in elite male collegiate athletes.

BACKGROUND: Whether vitamin D supplementation has any effect on body fat percentage, especially among elite athletes, remains unclear. The aim of this study was to evaluate the effect of vitamin D supplementation on serum vitamin D level in elite male collegiate athletes and to analyze its effect on body fat percentage. METHODS: We enrolled a total of 42 elite male collegiate athletes in this prospective cohort study. In March 2020, body composition monitoring and blood test were performed. All athletes were provided with vitamin D3 supplement tablets of 25 µg/day. The use of the supplement was dependent on athletes' preference. During the study period, their club activities were stopped for 2 months due to the coronavirus disease 2019 outbreak. A second examination, similar to the first one, was performed after approximately 3 months. Supplement usage by each athlete was also confirmed. The participants were divided into a non-supplement group (without supplementation, n = 15) and a supplement group (with supplementation, n = 27). RESULTS: Regarding baseline data at initial examination, the non-supplement and supplement groups showed significant differences in the mean body fat percentage (9.0% and 12.1%, respectively; P = 0.03) and serum 25(OH)D level (22.7 and 18.5 ng/mL, respectively, P = 0.02). At the time of the second examination, there were no significant differences in the results of both the groups. In terms of mean change value from the first to the second examination, there were significant differences in body fat percentage (1.9 and 0.2%, respectively, P = 0.02) and serum 25(OH)D level (1.7 and 7.2 ng/mL, respectively, P < 0.001) between the two groups. A significant negative correlation was observed between the change ratio of body fat percentage and change value of serum 25(OH)D level (r = - 0.37, P = 0.02). CONCLUSIONS: Vitamin D supplementation of 25 µg/day significantly increased the serum 25(OH)D level in elite male collegiate athletes. Vitamin D supplementation may play a role in maintaining athletes' body fat percentage under circumstances where sports activity has decreased.

Assessment of the Preserved Biceps Tendon After Arthroscopic Rotator Cuff Repair in Patients ≤ 55 Years.

PURPOSE: We assessed hypertrophy of preserved long head of the biceps tendon (LHBT) and vascularity in the bicipital groove after arthroscopic rotator cuff repair in ≤55-year-old patients and compared postoperative pain between shoulders with or without vascularity in the bicipital groove. METHODS: Patients who underwent arthroscopic rotator cuff repair between 2015 and 2017 were reviewed. Inclusion criteria were arthroscopic rotator cuff repair and ≤55 years old. Exclusion criteria were a history of contralateral rotator cuff repair, revision surgery, partial repair or superior capsular reconstruction, shoulder dislocation or fracture, torn LHBT at surgery, LHBT tenodesis, retears, <1-year follow-up, and incomplete follow-up data. Cross-sectional area (CSA) of the LHBT and vascularity in the bicipital groove were examined preoperatively and 1 year after surgery using ultrasonography. Shoulder pain at postoperative 1 year was assessed using the pain subscore of the University of California at Los Angeles scale. The data were compared between shoulders with negative and positive vascularity. RESULTS: Fifty-seven shoulders were included in this study. There was no side-to-side difference in preoperative CSA. No difference was found between preoperative and postoperative CSA in the affected shoulders. Postoperative vascularity was identified in 28 (49%) shoulders. Mean pain score was significantly higher in the negative vascularity group than the positive vascularity group (9 and 8, respectively; P = .002). CONCLUSIONS: The preserved LHBT did not show hypertrophy 1 year after arthroscopic repair of medium-sized or smaller posterosuperior rotator cuff tear in ≤55-year-old patients. However, 49% of the shoulders postoperatively demonstrated lower-grade vascularity in the bicipital groove. Healthy LHBT can be preserved in ≤55-year-old patients with posterosuperior medium-sized or smaller rotator cuff tears. LEVEL OF EVIDENCE: III, retrospective comparative prognostic trial.

Comparison of vitamin D sufficiency between indoor and outdoor elite male collegiate athletes.

This study compared vitamin D sufficiency between indoor and outdoor elite athletes. We also evaluated the association between vitamin D level, body composition, and stress fractures incidence. 27 outdoor elite male collegiate athletes (field hockey players) and 21 indoor elite male collegiate athletes (fencing players) were enrolled. Participants' demographic information including past fractures were recorded. Furthermore, all the athletes' body compositions including percentage of body fat were measured. Blood samples were collected to test serum calcium, phosphorus, and 25(OH)D. levels. Participants were classified into three groups: vitamin D sufficiency (serum 25(OH)D levels of ≥30 ng/ml), vitamin D insufficiency (serum 25(OH)D levels of <30 ng/ml), and vitamin D deficiency (serum 25(OH)D levels of <20 ng/ml). The indoor athletes showed significantly higher mean percentage of body fat than outdoor athletes, 12.2 ± 3.2% and 9.7 ± 3.7%, respectively. The serum 25(OH)D levels of indoor athletes were significantly lower than those of outdoor athletes, 15.3 ± 3.3 ng/mL and 24.9 ± 4.5 ng/ml, respectively (P < 0.001). Furthermore, the indoor athletes showed a significantly higher rate of vitamin D deficiency than the outdoor athletes, 19 of 21 (90.5%) and 5 of 27 (18.5%), respectively (P < 0.001). The cohort of outdoor athletes with stress fractures' history had significantly lower serum 25(OH)D levels than those without history of any fractures, 21.1 ± 4.3 ng/ml and 26.4 ± 3.0 ng/ml, respectively (P < 0.05). In conclusion, a majority of the indoor elite athletes were vitamin D-deficient. The serum 25(OH)D levels were significantly higher in outdoor elite athletes. However, lower serum 25(OH)D levels might be associated with stress fractures among outdoor athletes.

Association Between Knee Alignment and Meniscal Tear in Pediatric Patients with Anterior Cruciate Ligament Injury.

BACKGROUND: The present study aimed to evaluate the association between elapsed time from anterior cruciate ligament (ACL) injury to surgical treatment and the incidence of meniscal tears in a cohort of patients ≤16 years old with varus-aligned and non-varus-aligned knees. METHODS: The study cohort included 123 patients ≤16 years old who underwent primary ACL reconstruction between January 2016 and March 2020. Knee alignment was expressed as the hip-knee-ankle angle (HKAA), as measured preoperatively on an anteroposterior view of 3-dimensional computed tomography of the full length of the lower limb. Varus alignment was defined as an HKAA ≥181.0°, and non-varus alignment was defined as an HKAA <181.0°. Patients were divided into groups according to knee alignment and the elapsed time from injury to surgical treatment: early-treatment group (<60 days) and delayed-treatment group (≥60 days). RESULTS: A total of 64 varus-aligned and 59 non-varus-aligned knees were identified. Among patients with varus-aligned knees, those in the delayed-treatment group showed a significantly lower rate of lateral meniscal tears (6 of 30, 20%) compared with those in the early-treatment group (17 of 34, 50%; p = 0.015). Among patients with non-varus-aligned knees, there was no significant difference in meniscal tears of any type between the early and delayed-treatment groups. Among patients without medial meniscal injury identified on initial magnetic resonance imaging, those with varus-aligned knees in the delayed-treatment group showed a significantly higher rate of medial meniscal tears at the time of the surgical procedure (8 of 20, 40%) compared with those with non-varus-aligned knees (1 of 18, 6%; p = 0.015). CONCLUSIONS: Delayed ACL reconstruction in patients ≤16 years old with varus-aligned knees might be associated with an increased incidence of secondary medial meniscal tears. Accordingly, earlier ACL reconstruction in patients with varus-aligned knees should be considered. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Scapular Winging following Sports-Related Injury in a Rugby Player.

The most common cause of medial scapular winging is long thoracic nerve palsy (LTN) and subsequent serratus anterior muscle dysfunction. A 16-year-old right-handed male high-school rugby player developed severe right-sided neck and shoulder pain after tackling an opponent while playing rugby. Six weeks after initial injury, the patient observed shoulder muscle weakness when performing his daily activities. On physical examination, limited active elevation of the right shoulder in the scapular plane and scapular winging was observed. Magnetic resonance imaging revealed atrophy of both the SA and subclavius muscles on the right side, and we initially suspected an LTN injury sustained. However, while detailing his history, the patient explained that he also had noted difficulty sucking high viscosity drinks such as shakes and smoothies since childhood. In addition, physical examination showed weakness of the orbicularis oculi muscle. Considering the facial muscle weakness, facioscapulohumeral dystrophy (FSHD) was also suspected, and genetic testing showed chromosome 4q35 deletion with restriction fragments 17 kb and 3 tandem repeated DNA confirming the diagnosis of FSHD. Clinicians should be aware that FSHD could be one of the differential diagnoses of scapular winging after sports injury, and surgeons should rule out the diagnosis of FSHD before performing any surgical treatment for SA palsy.

4-Methylumbelliferone suppresses catabolic activation in anterior cruciate ligament-derived cells via a mechanism independent of hyaluronan inhibition.

BACKGROUND: The anterior cruciate ligament (ACL) has a key role as a dynamic stabilizer of the knee joints, and ACL dysfunction caused by traumatic or degenerative rupture accelerates osteoarthritis progression. Thus, it is important to prevent the degenerative rupture of the ACL. 4-Methylumbelliferone (4-MU), a pre-approved drug, exerts anti-inflammatory effects in osteoarthritis chondrocytes. It was originally used as an inhibitor of hyaluronan synthesis in chondrocytes. METHODS: In this study, we investigated whether 4-MU affects the expression of catabolic factors, such as matrix metalloproteinase (MMP)-1, MMP-3, and interleukin (IL)-6, in ACL-derived cells and ACL explant cultures using immunohistochemistry, real-time RT-qPCR, and capillary western immunoassay. Furthermore, the hyaluronan concentration was evaluated using a colorimetric assay. Statistical analyses were conducted using analysis of variance for multi-group comparisons, followed by Tukey or Tukey-Kramer post hoc test. RESULTS: Our results revealed, for the first time, that 4-MU suppressed the IL-ß-induced upregulation of pro-catabolic factors, such as MMP-1, MMP-3, and IL-6, in ACL-derived cells. This suppressive effect was also observed in the cultured ligament tissues in ex vivo experiments. 4-MU also reversed an enhanced dependence on glycolysis in IL-1ß-activated ACL-derived cells. Furthermore, we found that the suppressive effects of 4-MU were exerted directly and not through the inhibition of hyaluronan synthesis. CONCLUSIONS: We conclude that 4-MU could be an effective and useful treatment for knee osteoarthritis, owing to its anti-inflammatory effect on, not only chondrocytes but also on ligament cells.