Cellular senescence promotes meibomian gland dysfunction in a chronic graft-versus-host disease mouse model.

PURPOSE: Aging is a well-established risk factor for meibomian gland dysfunction (MGD). We previously reported an accelerated cellular senescence phenomenon in the lacrimal glands of a murine model of chronic graft-versus-host disease (cGVHD). Herein, we aimed to elucidate the relationship between cellular senescence and MGD in cGVHD mice, utilizing the senolytic agent ABT-263. METHODS: A cGVHD mouse model was established through allogeneic bone marrow transplantation (BMT) from B10.D2 to BALB/c mice. Subsequently, cGVHD mice were treated with either ABT-263 or vehicle. The eyelids of recipients were analyzed at 4-week intervals post-BMT in both groups. RESULTS: Meibomian gland (MG) area was significantly smaller in cGVHD mice than in syngeneic control mice. ABT-263-treated mice retained a significantly larger MG area than their vehicle-treated counterparts. Pathological and immunohistochemical examinations revealed significant reductions in eyelid tissue inflammation and pathological fibrosis in the ABT-263 group compared to that in the vehicle-treated group. Additionally, expression of DNA damage markers, senescent cell markers, and senescence-associated secretory phenotype (SASP) factors was elevated in the eyelids of cGVHD mice compared with that in syngeneic mice. The expression of these cellular senescence-associated molecules was considerably suppressed in ABT-263-treated eyelids compared to that in vehicle-treated ones. CONCLUSIONS: Cellular senescence, along with expression of SASP factors, exhibited increased activity in the eyelids, particularly in the MGs of cGVHD mice. ABT-263 mitigated the severity of MGD. These findings highlight the potential of targeting cellular senescence as an effective approach for MGD treatment in cGVHD.

Ten-Year Clinical Outcomes of Endoscope-Assisted Minimally Invasive Surgical Decompression for Lumbar Spinal Stenosis with Degenerative Spondylolisthesis and Comparison with Conservative Treatment.

Introduction: This study aimed to evaluate the 10-year clinical outcomes of endoscope-assisted, minimally invasive surgical (MIS) decompression for lumbar spinal canal stenosis (LSS) with lumbar degenerative spondylolisthesis (DS) and to compare the radiographic changes in patients who underwent this procedure with those who underwent conservative therapy at 10-year follow-up. Methods: Between April 2007 and April 2010, 347 consecutive patients with DS and evidence of LSS underwent conservative treatment first from 2 to 4 weeks. The 114 patients who failed conservative treatment were then treated surgically by endoscope-assisted MIS decompression. Of them, 91 patients were followed for more than 10 years (group S), and 146 of the 233 patients treated conservatively were followed for more than 10 years (group C). Clinical outcomes of endoscope-assisted MIS decompression were assessed using the Short Form Health Survey-36 score (SF-36), the Roland Morris Disability Questionnaire (RDQ), and the neurological leg symptoms of the Japanese Orthopaedic Association Score (JOA score). Radiographic changes of the two groups were assessed by %slip, dynamic %slip, range of motion (ROM), and the height of the disc (DH) on plain radiographs. Results: Significant improvements in clinical outcomes on the SF-36, RDQ, and neurological leg symptoms of the JOA were observed. Radiographic assessment did not show significant differences in the assessed items between the two groups at baseline and after last treatment. Both groups had significantly decreased ROM and DH. Conclusions: The 10-year clinical outcomes of endoscope-assisted MIS decompression for DS were generally good. Furthermore, on radiographic comparison, the progress of spondylolisthesis after this procedure was virtually the same as in the natural course of the disease at 10-year follow-up.

Ultrasonographic diagnosis of medial meniscus posterior root tear in early knee osteoarthritis: a comparative study.

INTRODUCTION: This study aimed to detect medial meniscal posterior root tear (MMPRT) diagnostic methods with high sensitivity and specificity using dynamic ultrasonographic evaluation in patients with early knee osteoarthritis (OA) and demonstrate the usefulness of dynamic ultrasonographic medial meniscal extrusion (MME) evaluation in MMPRT diagnosis using a cutoff value. MATERIALS AND METHODS: Between 2018 and 2020, a total of 120 patients were diagnosed with early knee OA using clinical and radiographic findings. Dynamic ultrasonographic evaluations and magnetic resonance imaging were performed in all patients, and 47 patients who had and 73 patients who did not have MMPRT were classified into the MMPRT and non-MMPRT groups, respectively. Age, sex, femorotibial angle, MME of knee extension and flexion, and MME at weight-bearing were compared between the two groups. Additionally, the sensitivity and specificity of significant ultrasonographic findings were calculated using a receiver operating characteristic (ROC) curve. RESULTS: The MMEs under knee extension-flexion and weight-loading in the MMPRT group were significantly larger than those in the non-MMPRT group. ROC curve analysis for each ultrasonographic evaluation condition to diagnose MMPRT indicated that the sensitivity was 72-88% and the specificity was 66-85% when the cutoff values of MME under knee flexion at 0°, 90°, and weight-loading were set at 2.55 mm, 2.00 mm, and 3.55 mm, respectively. The highest sensitivity (88%) and specificity (85%) were exhibited upon > 2 mm MME at a knee flexion of 90° and were the most useful indicators for MME diagnosis. CONCLUSIONS: Ultrasonographic MME evaluations for MMPRT diagnosis showed relatively high sensitivity and specificity in patients with early knee OA. Dynamic ultrasonographic MME evaluation may lead to appropriate additional examinations, early diagnosis, and intervention for MMPRT in patients with early knee OA.

Differences in the microstructural and mechanical qualities of semitendinosus tendon grafts between skeletally immature and mature patients in anterior cruciate ligament reconstruction.

BACKGROUND: This study aimed to investigate the microstructural and mechanical properties of semitendinosus tendon graft tissues during anterior cruciate ligament reconstruction and the clinical outcomes in skeletally immature and mature patients. METHODS: Twenty-two patients who underwent primary anterior cruciate ligament reconstruction using a hamstring tendon graft were analyzed and divided into skeletally immature (n = 7) and mature groups (n = 15) based on magnetic resonance imaging findings of the epiphyseal plate of the distal femur. Tissue samples were collected from the mid-portion of the semitendinosus tendon. The collagen fibril diameter, maximum stress, and strain at maximum stress point in the semitendinosus tendon tissues were calculated for comparison of the microstructural and mechanical properties between the two groups. Postoperative outcomes were also assessed between the two groups. RESULTS: The mean and 60th and 80th percentiles of fibril diameters in the skeletally immature group were significantly smaller than those in the mature group (65.9 ± 13.0, 73.5 ± 19.3, and 91.3 ± 27.4 nm in the skeletally immature group; and 90.3 ± 14.7, 94.0 ± 18.4, and 125.3 ± 19.9 nm in the skeletally immature group; p = 0.001, 0.024, and 0.004, respectively). Additionally, the strain at maximum stress was higher in the skeletally immature group (237.2 ± 102.4% vs. 121.5 ± 51.9%, p = 0.024). However, there was no difference in maximum stress between the skeletally immature and mature groups (19.9 ± 14.3 MPa vs. 24.5 ± 23.4 MPa, p = 0.578). Strain was negatively correlated with the mean fibril diameter and the 60th and 80th percentiles of fibril diameters, whereas stress was positively correlated with the mean fibril diameter. The skeletally immature group had a higher pivot shift test-positive rate than the mature group at the last follow-up (p = 0.023). CONCLUSION: Semitendinosus tendon graft tissues differed microstructurally and mechanically between skeletally immature and mature patients. LEVEL OF EVIDENCE: Level Ⅳ.

Growth-related changes in the ultrastructure of the quadriceps tendon.

BACKGROUND: The purpose of this study was to investigate the effect of growth on the ultrastructural characteristics of the quadriceps tendon (QT). METHODS: Eighteen included patients were classified into three groups based on age and epiphyseal plate condition: the 'immature group' consisted of patients with open epiphyseal plates (11.5 ± 1.6 years old; mean ± standard deviation), the 'young group' consisted of patients aged <20 years with closed epiphyseal plates (15.8 ± 1.0 years), and the 'adult group' consisted of all patients aged >20 years (29.8 ± 11.3 years) irrespective of epiphyseal plate condition. Tendon tissue samples were used for ultrastructural analysis by transmission electron microscopy. Minimum collagen fibril diameters were measured from the cross sections of collagen fibril images using Image J software. The average number of collagen fibers per sample was 797 ± 109, and the average collagen fibril diameter of each sample was compared using one-way analysis of variance. RESULTS: The mean collagen fibril diameter was 89.7 ± 14.4 nm in the immature group, 94.8 ± 16.4 nm in the young group, and 107.2 ± 12.1 nm in the adult group, with significant differences between the immature and adult groups, and between the young and adult groups (P = 0.001 and P = 0.021, respectively); however, no significant differences were observed between the immature and young adult groups (P = 0.49). CONCLUSIONS: The collagen fibril diameter of the QT was found to have increased with growth. The study provided insights into graft selection.

Feasibility study on the use of single-port laparoscopic surgery for diagnosis and tumor sampling in advanced epithelial ovarian cancer - Case series of three cases.

INTRODUCTION: In advanced epithelial ovarian cancer (AEOC), it is often difficult to achieve optimal surgery at primary debulking surgery (PDS) due to intra-abdominal dissemination and/or metastasis. When it is determined that optimal surgery is not possible, neoadjuvant chemotherapy (NAC) is performed prior to subsequent debulking surgery. Also, a histological diagnosis of the tumor is very important before initiation of NAC. Laparoscopic surgery is thus useful to objectively diagnose whether an optimal primary debulking surgery is feasible and to obtain tumor biopsy samples. In order to minimize the invasive procedures at initial surgery, we performed laparoscopic surgery using a single-port method. CASE PRESENTATION: Three patients were diagnosed as stage IV ovarian cancer based on imaging and physical examination. Single-port laparoscopic surgery was performed. The intraabdominal findings were evaluated in all patients by predictive index scoring and objectively diagnosed as not ideal candidates for optimal surgery at PDS. Our use of single-port laparoscopic surgery (SPLS) allowed for safe surgical outcomes and sufficient tissue sampling for histological diagnosis. CLINICAL DISCUSSION: Laparoscopic surgery is not appropriate for tumor reduction surgery in AEOC; however, its use as an alternative method to laparotomy is recommended for tumor tissue biopsy and/or intraperitoneal observation. Previous studies have reported on the use of conventional multi-port laparoscopic surgery. The single-port method, when compared to conventional laparoscopic surgery, is less invasive with only one abdominal wound at the umbilicus. CONCLUSION: SPLS is feasible and clinically useful for diagnosis and tumor sampling in AEOC.

Pediatric chronic graft-versus-host disease-related dry eye disease and the diagnostic association of potential clinical findings.

Pediatric graft-versus-host-disease (GVHD)-related dry eye disease (DED) is often overlooked due to a lack of subjective symptoms and reliable testing, leading to irreversible corneal damage. To study the clinical findings contributing to the accurate detection of pediatric GVHD-related DED, a retrospective study of pediatric patients treated with hematopoietic stem cell transplantation (HSCT) at Keio University Hospital between 2004 and 2017 was conducted. Association and diagnostic values of ophthalmological findings for DED were analyzed. Twenty-six patients who had no ocular complications before HSCT were included in the study. Eleven (42.3%) patients developed new-onset DED. The cotton thread test showed excellent diagnostic accuracy in detecting DED (area under the receiver operating curve, 0.96; sensitivity, 0.95; specificity, 0.85) with a cut-off of 17 mm, which was higher than the conventional threshold of 10 mm. Additionally, the presence of filamentary keratitis (FK) and pseudomembranous conjunctivitis (PC) were significantly associated with the diagnosis of DED (p value, 0.003 and 0.001 for FK and PC, respectively) and displayed good diagnostic performance (sensitivity, 0.46 and 0.54; specificity, 0.97 and 0.97 for FK and PC, respectively). In conclusion, the cotton thread test with a new threshold, the presence of PC and FK, could be helpful for promptly detecting pediatric GVHD-related DED.

High initial graft tension is a post-operative risk factor for high UTE T2* value of the graft 6 months after anterior cruciate ligament reconstruction.

BACKGROUND: To evaluate the risk factor of "ligamentization" using the ultrashort echo time (UTE)-T2* imaging. METHODS: Fifty-nine patients (23 males and 36 females, age of 21.9 ± 10.6 years old) who underwent anterior cruciate ligament (ACL) reconstruction with hamstring tendon were evaluated. The UTE T2* values of the reconstructed ACL at 6 months postoperatively were calculated. Circular regions of interest (5-10 mm2) were set at the proximal, mid-substance, and distal regions of the reconstructed ACL. The UTE T2* values of the entire reconstructed ACL were calculated as the average of these three points. Patients were divided into high (27 knees) and low (32 knees) UTE T2* groups by calculating whether their UTE T2* values were greater than the median of the UTE T2* values of all patients. Risk factors for high UTE T2* values were evaluated. Clinical outcomes were compared between the two groups. RESULTS: There were no significant differences in any measured parameters and clinical outcomes between the two UTE T2* groups. Logistic regression analysis revealed that graft tension was a significant risk factor for patients with high UTE-T2* values (P = 0.047, odds ratio [OR] = 2.285). The UTE-T2* values of the 20 N graft tension using the Tension loc system were significantly lower than those of the 40 N using double-spike plate (DSP) with screws at each site and the 30 N using the Tension loc system at the distal site. CONCLUSIONS: Higher graft tension was an independent risk factor for high UTE T2* values of the reconstructed ACL.

Regeneration Using Adipose-Derived Stem Cell Sheets in a Rabbit Meniscal Defect Model Improves Tensile Strength and Load Distribution Function of the Meniscus at 12 Weeks.

PURPOSE: The purpose of this study was to evaluate the mechanical properties, such as the tensile strength and load distribution function, of the meniscus tissue regenerated using adipose-derived stem cell (ADSC) sheets in a rabbit meniscal defect model. METHODS: ADSC sheets were prepared from adipose tissue of rabbits. The anterior half of the medial meniscus was removed from both knees. One knee was transplanted with an ADSC sheet; the contralateral knee was closed without transplantation. Mechanical tests were performed at 4 and 12 weeks posttransplantation. In the tensile test, tensile force was applied to the entire medial meniscus, including the normal area (n = 10/group). Compression tests were performed on the entire knee, with soft tissues other than the ligament removed. A pressure-sensitive film was inserted under the medial meniscus and a 40-N load was applied (n = 5/group). RESULTS: In the tensile test, the elastic modulus in ADSC-treated knees was higher at 12 weeks (ADSC: 70.30 ± 18.50 MPa, control: 43.71 ± 7.11 MPa, P = .009). The ultimate tensile strength (UTS) in ADSC-treated knees at 12 weeks was also higher (ADSC: 22.69 ± 5.87 N, control: 15.45 ± 4.08 N, P = .038). In the compression test, the contact area was larger in the ADSC group at 4 weeks (ADSC: 31.60 ± 8.17 mm2, control: 20.33 ± 2.86 mm2, P = .024) and 12 weeks (ADSC: 41.07 ± 6.09 mm2, control: 30.53 ± 5.47 mm2, P = .04). Peak pressure was significantly lower in ADSC-treated knees at 12 weeks (ADSC: 11.91 ± 1.03 MPa, control: 15.53 ± 2.3 MPa, P = .002). CONCLUSIONS: The regenerated meniscus tissue, 12 weeks after transplantation of the ADSC sheets into the meniscal defect area, had high elastic modulus and UTS. In the meniscus-tibia compartment, the contact area was large and the peak pressure was low. CLINICAL RELEVANCE: ADSC sheets promoted regeneration of meniscus. ADSC sheet transplantation for meniscal defects could be an effective regenerative therapy.

Relationship between anatomical injury site of rectus femoris muscle strain and time taken to return to play in Japanese professional soccer players.

PURPOSE: The rectus femoris has three myotendinous or myoaponeurosis junctions and causes three types of muscle strain anatomically. We aimed to investigate the anatomical injury site of the rectus femoris muscle strain in professional soccer players as well as the characteristic findings on magnetic resonance imaging (MRI) and to evaluate its relationship with the time taken to return to play at competition levels. METHODS: Thirteen Japanese professional soccer players who sustained injuries to the rectus femoris were included in this study. The mechanism of injury, anatomical injury site, severity, absence of hematomas, and time taken to return to competition were evaluated. RESULTS: Ten patients were injured while kicking and three while sprinting. The anatomical injury site was the origin aponeurosis in two cases, intramuscular tendon in eight cases, and distal aponeurosis in three cases. The severity was one-degree in three cases and two-degree in 10 cases. Hematomas were observed in five cases. Cases with injuries caused by sprinting, two-degree injuries, or clear hematomas were associated with significantly longer periods of return to play than the other cases. Additionally, patients with distal aponeurosis-type injuries tended to take a long time to return to the competition. CONCLUSIONS: In rectus femoris muscle strain, it is important to evaluate the anatomical injury site, severity, and absence of hematomas on MRI. Not only the injury mechanism, a clear hematoma, and high severity but also distal aponeurosis injuries may be associated with long periods of return to play at competition levels.

Ligamentization of the reconstructed ACL differs between the intraarticular and intraosseous regions: A quantitative assessment using UTE-T2* mapping.

BACKGROUND: The purpose of this study was to prospectively observe the trends of ultrashort echo time (UTE)-T2* values for the intraarticular and intraosseous regions of reconstructed anterior cruciate ligaments from 6 to 12 months after anterior cruciate ligament reconstruction by using UTE-T2* mapping, and to investigate the changes and differences over time in each region. METHODS: Ten patients underwent UTE-T2* mapping of the operated knee at 6, 9, and 12 months after anterior cruciate ligament reconstruction. The UTE-T2* values of intraarticular and intraosseous regions of reconstructed anterior cruciate ligaments at 6, 9, and 12 months postoperatively were statistically compared. RESULTS: The UTE-T2* values of the intraarticular region at 6 months postoperatively were significantly higher than those at 9 and 12 months. There were no significant differences in the UTE-T2* values at 6, 9, and 12 months postoperatively in the intraosseous region. At 6 months postoperatively, the UTE-T2* values of the intraarticular region were significantly higher than those of the intraosseous region. The UTE-T2* values of the intraosseous region at the tibia were significantly lower than those of the other sites at any postoperative time point. CONCLUSIONS: According to UTE-T2*mapping-based findings, histological maturation of reconstructed ACLs is faster in the intraosseous region than in the intraarticular region. In particular, the intraarticular region is still undergoing rapid histologic changes at 6 months postoperatively, and its tissue structure is less substantial than normal. The findings of this study may provide clues to determine the optimal timing for safe return to sports in terms of ligamentaization of reconstructed ACLs.

Incidence and temporal changes in lumbar degeneration and low back pain in child and adolescent weightlifters: A prospective 5-year cohort study.

This study was conducted to investigate the incidence of lumbar degeneration findings and low back pain (LBP) in children and adolescent weightlifters using magnetic resonance imaging (MRI) and medical questionnaires over a 5-year period. Moreover, we aimed to reveal the temporal changes in the lumbar vertebrae caused by long-term weightlifting training during the growth period. Twelve children and adolescent weightlifters who participated in weightlifting for >2 years (six boys, six girls, 11.4±2.0 years) were enrolled. Participants underwent annual medical questionnaire surveys, including data on practice frequency, competition history, presence of LBP, and lumbar examinations using MRI during the 5-year follow-up. Lumbar disc degeneration was detected in all the participants after 4 years, and lumbar disc herniation findings were detected in 33% of participants after 5 years; one underwent herniotomy during the follow-up period. Lumbar spondylolysis was detected in 58% of patients at 5 years. Although there were three participants who had LBP in the final year, none had LBP that prevented them from returning to weightlifting. This 5-year cohort study of 12 children and adolescent weightlifters detected lumbar degeneration in all participants. High frequency weightlifting training over a long period during the growth period may increase the risk of developing current and future LBP.

Suture Bridge Fixation for Posterior Cruciate Ligament Tibial Avulsion Fracture in Children.

Posterior cruciate ligament (PCL) tibial avulsion fractures in children are extremely rare. Due to the rarity of these injuries, careful attention to the specific physical examination and imaging findings is necessary for a proper diagnosis. PCL avulsion fractures can be missed on plain radiography in skeletally immature patients. Magnetic resonance imaging should be considered if sagging or posterior drawer sign is positive after a strong hit to the anterior aspect of the lower leg. With this knowledge, clinicians can formulate treatment plans that can return patients to their original functionality while avoiding potential morbidity from misdiagnoses. We treated these patients using the suture bridge method. In children, ossification is incomplete, and they possess a lot of cartilage, so screw fixation easily destroys avulsed fragment. The suture bridge method can firmly fix the avulsed fragments, reducing the risk of damage to the bone fragment; therefore, a secondary surgery for implant removal is not needed. Arthroscopic surgery also was expected to be technically difficult in children due to the limited scope of the operation. We used open fixation because the outcome was unaffected by open surgery and arthroscopic surgery, and all patients returned to full sporting activity postoperatively.

Tibial graft fixation methods and bone tunnel enlargement: A comparison between the TensionLoc implant system and the double-spike plate.

Background/objective: TensionLoc (Arthrex, Naples, Florida, USA), a tibial graft fixation system for anterior cruciate ligament (ACL) reconstruction, is expected to apply the preoperatively determined level of graft tension and allow setting of lower initial tension. Considering its mechanism, we hypothesised that TensionLoc would prevent postoperative bone tunnel enlargement (TE) through fixation with lower initial tension. Therefore, the present study aimed to compare TE between ACL reconstructions using the double-spike plate (DSP; Smith and Nephew, Andover, Massachusetts) and TensionLoc implant system. Methods: A total of 40 patients who underwent anatomical single-bundle ACL reconstruction with a hamstring tendon graft were retrospectively analysed. In the group in which DSP and screw were used, the initial graft tension was set to 40 N at 20° of knee flexion (group D). In the other group in which TensionLoc was used, the initial graft tension was set to 30 N at 20° of knee flexion (group T). Both groups included 20 patients each. Tunnel areas were measured using computed tomography images at one week and three months after surgery, and the TE ratio was calculated according to the following equation: TE ratio (%) = (tunnel area at three months after surgery - tunnel area at one week after surgery)/tunnel area at one week after surgery × 100. Results: The femoral TE ratios were significantly higher in group T (80.5% ± 28.8%) than in group D (45.5% ± 34.6%) (p = 0.001). However, the tibial TE ratios did not significantly differ between the two groups. Conclusion: Compared with ACL reconstruction using DSP and screw, ACL reconstruction using TensionLoc fixed the graft with lower initial tension but showed greater femoral TE and restricted knee extension in the early postoperative period.

Evaluation of skeletal muscle activity during foot training exercises using positron emission tomography.

The foot exercises "rock-paper-scissors" and "towel gathering" are widely used in patients with lower limb disorders; however, there are no detailed reports on muscle activity during such training. We quantitatively evaluated the difference in skeletal muscle activity between the two exercises using positron emission tomography. Eight university student athletes were included. Four participants each were assigned to the foot rock-paper-scissors and towel gathering groups. Participants in each group underwent continuous training for 15 min, and received an intravenous injection of 18F-fluorodeoxyglucose. After retraining for 15 min, participants rested for 45 min. Regions of interest were defined in 25 muscles. The standardized uptake value (SUV) in the trained limb was compared with that in the non-trained control limb. SUVs increased in four skeletal muscles (tibialis anterior, peroneus brevis, extensor hallucis brevis, and abductor hallucis) in the rock-paper-scissors group, and in four muscles (flexor digitorum longus, extensor hallucis brevis, extensor digitorum brevis, and quadratus plantae) in the towel gathering group. Thus, foot rock-paper-scissors and towel gathering involved skeletal muscles related to the medial longitudinal arch and toe grip strength, respectively. Given that the two exercises target different skeletal muscles, they should be taught and implemented according to their respective purposes.

Adipose-Derived Stem Cell Sheets Promote Meniscus Regeneration Regardless of Whether the Defect Involves the Inner Half or the Whole Width of the Anterior Half of the Medial Meniscus in a Rabbit Model.

PURPOSE: To investigate the regenerative effect of adipose-derived stem cell (ADSC) sheets in two different rabbit models of meniscal defects. METHODS: Forty-two rabbits were randomly divided into two groups: the whole (Group 1) or the inner half (Group 2) of anterior half of the medial meniscus was removed from both knees. The ADSC sheets were transplanted into one knee, whereas in the other knee the meniscal defect was left untreated (self-control). The histological score and expression of genes encoding collagen type I and II (COL1/2), SRY-box transcription factor 9 (SOX9), and aggrecan (ACAN) were compared between the ADSC sheet-treated and untreated menisci at 4 and 12 weeks. The ADSC sheet-treated menisci at 12 weeks were also analyzed immunohistochemically to assess the collagen component. RESULTS: The histological score was significantly higher in the treated side than in the control side at 4 and 12 weeks in both groups (Group 1; P = .016 and .032; Group 2; P = .030 and .016, respectively). All genes evaluated showed significantly higher expression in the treated side than in the control side in both groups, except COL2 and SOX9 at 4 weeks and COL2 at 12 weeks in Group 1, and COL1 in Group 2 at 4 weeks. The ADSC sheet-treated meniscus in Group 1 contained mostly COL1, whereas the Group 2 had less COL1, but was rich in COL2. CONCLUSIONS: ADSC sheets can promote meniscal regeneration regardless of whether the defect involves the inner half or whole width of the anterior half of the medial meniscus. However, the collagen component of the ADSC sheet-treated tissue differs depending on the defect site. CLINICAL RELEVANCE: ADSCs may help meniscal regeneration due to meniscal defects after meniscectomy. This study suggests longer-term follow-up and mechanical analysis as next steps.

Anterior cruciate ligament reconstruction with ultrasound-guided femoral nerve block does not adversely affect knee extensor strength beyond that seen with intravenous patient-controlled analgesia at 3 and 6 months postoperatively.

BACKGROUND: This study aimed to investigate the effect of anterior cruciate ligament (ACL) reconstruction with an ultrasound-guided femoral nerve block (FNB) on knee extensor strength weakness 3 and 6 months, and graft rupture in the 1 year following ACL reconstruction. METHODS: One hundred and seven patients who underwent ACL reconstruction were included in this retrospective study. The patients were divided into two groups stratified by the method of postoperative pain management. The FNB group included 66 patients, and there were 41 patients in the intravenous patient-controlled analgesia (iv-PCA) group. The isokinetic peak torque of knee flexor and extensor was measured preoperative, 3 and 6 months after ACL reconstruction. Muscle strength measurements were performed using the BIODEX dynamometer at a velocity of 60°/s and 180°/s. Peak torque of knee extensor and flexor strength, estimated pre-injury capacity (EPIC), body weight ratio (BW), and graft rupture incidence were compared between the two groups. RESULTS: There were no statistically significant differences in the knee extensor and flexor strength for all items at 3 and 6 months after ACL reconstruction. There was also not a statistically significant difference in the graft rupture incidence between the two groups: FNB group was two patients, 3.0% vs. iv-PCA group was one patient, 2.4% (p = 0.86). CONCLUSION: ACL reconstruction with ultrasound-guided FNB does not affect knee extensor strength at 6 months, nor graft rupture at 1 year postoperatively.

Differences in cellular and microstructural properties of the semitendinosus muscle tendon between young and adult patients.

BACKGROUND: Poor outcomes associated with anterior cruciate ligament reconstruction in paediatric patients are a major concern. The tendon structure and its cellular characteristics are key factors that affect the mechanical properties of tendons. This study aimed to evaluate the effects of growth on the cellular and microstructural properties of the tendon of the semitendinosus muscle in humans. METHODS: Semitendinosus muscle tendon samples from 76 patients who underwent ligament reconstruction were examined and divided into three groups: immature (10.8 ± 2.7 years old), young (16.5 ± 1.8 years old), and adult (35.2 ± 8.6 years old), based on age and the state of the epiphyseal plate in the distal femur. The number of tendon cells per unit area was assessed, and the major-to-minor-length ratio of the tendon cell nuclei was calculated to evaluate the shape of the nuclei using haematoxylin and eosin staining. The collagen fibril diameter and distribution were determined using electron microscopy. RESULTS: The major-to-minor-length ratio of the tendon cell nuclei significantly increased with age (p-value; immature vs. young: 0.018, young vs adult: 0.001, immature vs adult: 0.001). The shape of the tendon cell nuclei was rounder in the immature group and more elongated in the adult group. A significant decrease in the number of tendon cells was observed with age (immature: 565 ± 134/mm2, young: 356 ± 105/mm2, adult: 272 ± 81/mm2; p-value: immature vs young: 0.001, young vs adult: 0.012, immature vs adult: 0.001). The mean fibril diameter in the immature group was significantly smaller (p-value: immature vs young: 0.018, young vs adult: 0.001, immature vs adult: 0.001). The distribution of the collagen fibrils changed from right skewed in the immature group to flat in the adult group. CONCLUSIONS: The characteristics of the tendon cells and the microstructure of collagen in muscle tendons significantly changed with age.

The effect of gracilis tendon harvesting in addition to semitendinosus tendon harvesting on knee extensor and flexor strength after anterior cruciate ligament reconstruction.

INTRODUCTION: Anterior cruciate ligament (ACL) reconstruction using hamstring tendons may involve harvesting of the gracilis tendon in addition to the semitendinosus tendon (ST) depending on the size of the ST graft. However, the effect of gracilis harvesting in addition to ST harvesting on muscle strength, such as the hamstring-to-quadriceps (HQ) ratio, remains unclear. Hence, this study aimed to investigate the effect of gracilis harvesting on subsequent knee muscle strength. MATERIALS AND METHODS: Eighty-two patients who underwent ACL reconstruction were included in this retrospective study. They were divided into the following two groups depending on the tendon graft used for ACL reconstruction: the ST group (41 patients) and the semitendinosus tendon/gracilis tendon (STG) group (41 patients). The isokinetic peak torque of the knee extensor and flexor was measured using a BIODEX dynamometer at a velocity of 60°/s and 180°/s, respectively, 3 and 6 months after ACL reconstruction. The groups were compared in terms of the limb symmetry index (LSI) and HQ ratio. RESULTS: The significant difference in the knee flexor of the LSI at 6 months after ACL reconstruction was as follows: ST group, 120.3 ± 28.3 vs STG group, 105.6 ± 19.0 (p < 0.01) at 60°/s and ST group, 122.9 ± 35.2 vs STG group, 106.2 ± 24.6 (p = 0.02) at 180°/s. There were significant differences in the HQ ratio at 180°/s as follows: ST group, 0.67 ± 0.15 vs STG group, 0.60 ± 0.13 (p < 0.01) at 3 months and ST group, 0.67 ± 0.13 vs STG group, and 0.59 ± 0.12 (p < 0.01) at 6 months after ACL reconstruction. CONCLUSIONS: Gracilis tendon harvesting may contribute to a decrease in knee flexor strength and HQ ratio with fast contraction. Thus, the need for gracilis tendon harvesting in ACL reconstruction should be carefully considered. LEVEL OF EVIDENCE: III.

Eyelid blood vessel and meibomian gland changes in a sclerodermatous chronic GVHD mouse model.

PURPOSE: To investigate pathological changes in blood vessels and meibomian glands (MGs) in the eyelids of sclerodermatous chronic graft-versus-host disease (cGVHD) model mice. METHODS: We used an established major histocompatibility complex compatible, multiple minor histocompatibility antigen-mismatched sclerodermatous cGVHD mouse model. Blood vessels and MGs of eyelids from allogeneic bone marrow transplantation (allo-BMT) recipient mice and syngeneic bone marrow transplantation (syn-BMT) recipient mice were assessed by histopathology, immunohistochemistry and transmission electron microscopy. Peripheral blood samples from the recipients were examined by flow cytometry. RESULTS: Allo-BMT samples showed dilating, tortuous and branching vessels and shrunk MGs in the eyelids; showed significantly higher expression of VEGFR2 (p = 0.029), CD133 (p = 0.016), GFP (p = 0.006), and α-SMA (p = 0.029) in the peripheral MG area; showed endothelial damage and activation, fibrotic change, and immune cell infiltration into MGs compared with syn-BMT samples. Fewer Ki-67+ cells were observed in allo- and syn-BMT samples than in wild-type samples (p = 0.030). Ultrastructural changes including endothelial injury and activation, fibroblast activation, granulocyte degranulation, immune cell infiltration into MGs, and necrosis, apoptosis of MG basal cells were found in allo-BMT samples compared with syn-BMT samples. CONCLUSION: A series of our studies indicated that cGVHD can cause eyelid vessel and MGs changes, including endothelial injury and activation, neovascularization, early fibrotic changes, immune cell infiltration, MG basal cell necrosis and apoptosis, and resultant MG atrophy.