The correlation between hip alpha angle and acetabular labral tear location and size: A cross-sectional study.

BACKGROUND: Explore the correlation between hip morphology and labral tear location/size. METHODS: This retrospective study analyzed patients with hip pain who received magnetic resonance (MR) arthrography at our institution, between January 2017 and December 2020. Imaging analysis includes labral tear location and size, and hip morphology measurement with alpha angle, lateral center-edge (CE) angle, anterior CE angle, and femoral neck version. The correlation between hip morphology angles and labral tear location/size was evaluated using multiple regression, followed by stratification analysis with Chi-square test to investigate interactions between the variables. RESULTS: A total of 103 patients (105 hips) with hip pain who received MR arthrography (mean age, 50 years ± 15 [SD]) were included, with mean alpha angle of 57.7° ± 9.9° [SD], mean lateral CE angle of 32.6° ± 6.8° [SD], mean anterior CE angle of 58.2° ± 8.1° [SD], mean femoral neck version of 17.1° ± 8.2° [SD]. Large alpha angle (>57°) and older age were both correlated with superior and posterosuperior labral tear incidence ( p < 0.05) and larger tear size ( p < 0.05). Furthermore, alpha angle is significantly correlated with superior labral tear incidence in young-age subgroup (age <45 years) ( p < 0.05), also significantly correlated with posterosuperior labral tear incidence and larger tear size in middle-age subgroup (45 ≤ age ≤ 60 years) ( p < 0.05). CONCLUSION: A large alpha angle (>57°) is significantly correlated with increased incidence of superior and posterosuperior labral tear, and larger tear size in patients with hip pain, and the relationships depend on age.

Global Compressive Loading from an Ultra-Thin PEEK Button Augment Enhances Fibrocartilage Regeneration of Rotator Cuff Enthesis.

A PEEK button is developed to improve the tendon-to-bone compression area. In total, 18 goats were divided into 12-week, 4-week, and 0-week groups. All underwent bilateral detachment of the infraspinatus tendon. In the 12-week group, 6 were fixed with a 0.8-1 mm-thick PEEK augment (A-12, Augmented), and 6 were fixed with the double-row technique (DR-12). Overall, 6 infraspinatus were fixed with PEEK augment (A-4) and without PEEK augment (DR-4) in the 4-week group. The same condition was performed in the 0-week groups (A-0 and DR-0). Mechanical testing, immunohistochemistry assessment, cell responses, tissue alternation, surgical impact, remodeling, and the expression of type I, II, and III collagen of the native tendon-to-bone insertion and new footprint areas were evaluated. The average maximum load in the A-12 group (393.75 (84.40) N) was significantly larger than in the TOE-12 group (229.17 (43.94) N) (p < 0.001). Cell responses and tissue alternations in the 4-week group were slight. The new footprint area of the A-4 group had better fibrocartilage maturation and more type III collagen expression than in DR-4 group. This result proved the novel device is safe and provides superior load-displacement to the double-row technique. There is a trend toward better fibrocartilage maturation and more collagen III secretions in the PEEK augmentation group.

Anterior mid-portion capsular tear with Bankart lesion in recurrent anterior shoulder dislocation: outcome report and bone defect evaluation.

INTRODUCTION: This study aimed to report the incidence of anterior mid-portion capsular tears identified during arthroscopic Bankart repair (ABR), the clinical outcomes of repairing this combined lesion, and to evaluate the associated bone defects. METHODS: We retrospectively reviewed the records of patients undergoing ABR between January 2014 and December 2017. Data from patients with capsular tears identified during ABR were included and analyzed. Age, number of dislocations, repair technique, follow-up results, and X-rays were reviewed. The size of the glenoid defect and Hill-Sachs lesion were reviewed via magnetic resonance imaging or magnetic resonance arthrography (MRA). RESULTS: Records of 95 patients undergoing ABR during the study period were reviewed, and nine were included. The overall incidence of capsular tears was 9.5% and the mean age at surgery was 45.3 ± 14.3 years. All cases had > 3 dislocations before treatment. All patients had labral lesions, and one had a glenoid defect. Hill-Sachs lesions were observed in eight patients. Seven patients underwent MRA examination, and all seven showed axillary pouch disruption. Over 3.9 ± 1.1 years of follow-up, there was no instability recurrence, and Rowe scores improved from 42.2 to 96.7 (p < 0.001). CONCLUSIONS: There was no recurrent shoulder instability after combined arthroscopic repair of capsular and Bankart lesions. There were Rowe score improvements over at least three years of follow-up. Although our case number was small, we found that mid-portion capsular tear occurred in patients over 30 years with multiple recurrent dislocations, with or without small glenoid bone defects, and with axillary pouch disruption on MRA images.

N-3 polyunsaturated fatty acids block the trimethylamine-N-oxide- ACE2- TMPRSS2 cascade to inhibit the infection of human endothelial progenitor cells by SARS-CoV-2.

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) is a novel coronavirus that infects many types of cells and causes cytokine storms, excessive inflammation, acute respiratory distress to induce failure of respiratory system and other critical organs. In this study, our results showed that trimethylamine-N-oxide (TMAO), a metabolite generated by gut microbiota, acts as a regulatory mediator to enhance the inerleukin-6 (IL-6) cytokine production and the infection of human endothelial progenitor cells (hEPCs) by SARS-CoV-2. Treatment of N-3 polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) could effectively block the entry of SARS-CoV-2 in hEPCs. The anti-infection effects of N-3 PUFAs were associated with the inactivation of NF-κB signaling pathway, a decreased expression of the entry receptor angiotensin-converting enzyme 2 (ACE2) and downstream transmembrane serine protease 2 in hEPCs upon the stimulation of TMAO. Treatment of DHA and EPA further effectively inhibited TMAO-mediated expression of IL-6 protein, probably through an inactivation of MAPK/p38/JNK signaling cascades and a downregulation of microRNA (miR)-221 in hEPCs. In conclusion, N-3 PUFAs such as DHA and EPA could effectively act as preventive agents to block the infection of SARS-CoV-2 and IL-6 cytokine production in hEPCs upon the stimulation of TMAO.

Comparison of the Infant and Adult Adipose-Derived Mesenchymal Stem Cells in Proliferation, Senescence, Anti-oxidative Ability and Differentiation Potential.

BACKGROUND: Infant adipose-derived mesenchymal stem cells (ADSCs) collected from excised polydactyly fat tissue, which was surgical waste, could be cultured and expanded in vitro in this study. In addition, the collecting process would not cause pain in the host. In this study, the proliferation, reduction of senescence, anti-oxidative ability, and differentiation potential in the infant ADSCs were compared with those in the adult ADSCs harvested from thigh liposuction to determine the availability of infant ADSCs. METHODS: Proliferation was determined by detecting the fold changes in cell numbers and doubling time periods. Senescence was analyzed by investigating the age-related gene expression levels and the replicative stress. The superoxide dismutase (SOD) gene expression, adipogenic, neurogenic, osteogenic, and tenogenic differentiation were compared by RT-qPCR. The chondrogenic differentiation efficiency was also determined using RT-qPCR and immunohistochemical staining. RESULTS: The proliferation, SOD (SOD1, SOD2 and SOD3) gene expression, the stemness-related gene (c-MYC) and telomerase reverse transcriptase of the infant ADSCs at early passages were enhanced compared with those of the adults'. Cellular senescence related genes, including p16, p21 and p53, and replicative stress were reduced in the infant ADSCs. The adipogenic genes (PPARγ and LPL) and neurogenic genes (MAP2 and NEFH) of the infant ADSC differentiated cells were significantly higher than those of the adults' while the expression of the osteogenic genes (OCN and RUNX) and tenogenic genes (TNC and COL3A1) of both demonstrated opposite results. The chondrogenic markers (SOX9, COL2 and COL10) were enhanced in the infant ADSC differentiated chondrogenic pellets, and the expression levels of SODs were decreased during the differentiation process. CONCLUSION: Cultured infant ADSCs demonstrate less cellular senescence and replicative stress, higher proliferation rates, better antioxidant defense activity, and higher potential of chondrogenic, adipogenic and neurogenic differentiation.

Repairing Complete Radial Tears of the Lateral Meniscus: Arthroscopic All-Inside Double Vertical Cross-Suture Technique Is Effective and Safe With 2-Year Minimum Follow-Up.

PURPOSE: To assess the failure rate and clinical outcomes of the all-inside, double-vertical, cross-suture technique in repairing complete radial tears of the lateral meniscus. METHOD: We retrospectively reviewed records of patients with this injury on whom the present technique was employed at our institution between 2011 and 2018, with at least 24 months of follow-up. Six months postoperatively, the meniscus healing and extrusion status were evaluated through magnetic resonance imaging. Preoperative and postoperative knee function, measured through IKDC, Lysholm knee, and Tegner activity scale scores, were compared. RESULTS: In total, 27 patients underwent the procedure. The preoperative mean (standard deviation) IKDC score, Lysholm knee score, and Tegner activity scale scores were 53.4 ± 5.3, 63.2 ± 9.3, and 4 ± .7, respectively. At the last follow-up (≥24 months postoperatively), these scores increased to 92.1 ± 2.6, 90.8 ± 4.2, and 6.1 ± 1.3, respectively (all P < .05). Complete healing of the meniscus was observed in 23 patients, and 4 patients had meniscus retear or nonhealing. The overall retear or nonhealing rate was 14.8%. Healing rates between those with isolated radial tears (87.5%) and those with combined anterior cruciate ligament rupture (84.2%; P = .826) were comparable. No difference was observed in the progression of coronal and sagittal meniscus extrusion (P = .133 and .797, respectively). CONCLUSION: In patients with complete radial tears of the lateral meniscus, the arthroscopic all-inside double vertical cross-suture repair technique resulted in an 85.2% healing rate, improvements in functional outcomes and activity levels, and no identifiable progression of meniscus extrusion. The all-inside double vertical cross-suture technique is effective and safe for the repair of radial tears of the meniscus. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Comparison of the Confluence-Initiated Neurogenic Differentiation Tendency of Adipose-Derived and Bone Marrow-Derived Mesenchymal Stem Cells.

Adipose-derived mesenchymal stem cells (ADSCs), which tended to neurogenically differentiate spontaneously after achieving high confluence, were observed. Human ADSCs reaching 80% confluence were cultured in DMEM without an inducing factor for 24 h and then maintained in DMEM plus 1% FBS medium for 7 days. The neurogenic, adipogenic, and osteogenic genes of the factor-induced and confluence-initiated differentiation of the ADSCs and bone marrow-derived mesenchymal stem cells (BMSCs) at passages 3 to 5 were determined and compared using RT-qPCR, and the neurogenic differentiation was confirmed using immunofluorescent staining. In vitro tests revealed that the RNA and protein expression of neuronal markers, including class III ß-tubulin (TUBB3), microtubule-associated protein 2 (MAP2), neurofilament medium polypeptide (NEFM), neurofilament heavy polypeptide (NEFH), and neurofilament light polypeptide (NEFL), had been enhanced in the confluence-initiated differentiation of the ADSCs. In addition, the expressions of neurotrophins, such as the nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and glial cell-derived neurotrophic factor (GDNF), were also elevated in the confluence-initiated differentiation of the ADSCs. However, the confluent ADSCs did not show a tendency toward spontaneous adipogenic and osteogenic differentiation. Moreover, compared with the confluent ADSCs, the tendency of spontaneous neurogenic, adipogenic, and osteogenic differentiation of the confluent human bone marrow mesenchymal stem cells (BMSCs) was not observed. The results indicated that ADSCs had the potential to spontaneously differentiate into neuron-like cells during the confluent culture period; however, this tendency was not observed in BMSCs.

Editorial Commentary: Tranexamic Acid Is Beneficial in the Very Early Postoperative Period in Anterior Cruciate Ligament Reconstruction Patients.

Tranexamic acid (TXA) has been administrated in many orthopaedic surgical procedures to decrease perioperative and postsurgical bleeding. Relatively scant literature exists regarding the effect of TXA in patients after anterior cruciate ligament reconstruction. Currently, most evidence shows that within about 1 month after anterior cruciate ligament reconstruction, TXA can effectively reduce postoperative joint swelling and pain, as well as the aspiration rate. However, there are still controversies regarding the optimal dosage, timing, and route of administration of TXA in these patients. In addition, the potential chondrotoxic effect of TXA needs to be further clarified with longer clinical follow-up.

Adipose-Derived Mesenchymal Stem Cells From a Hypoxic Culture Improve Neuronal Differentiation and Nerve Repair.

Hypoxic expansion has been demonstrated to enhance in vitro neuronal differentiation of bone-marrow derived mesenchymal stem cells (BMSCs). Whether adipose-derived mesenchymal stem cells (ADSCs) increase their neuronal differentiation potential following hypoxic expansion has been examined in the study. Real-time quantitative reverse transcription-polymerase chain reaction and immunofluorescence staining were employed to detect the expression of neuronal markers and compare the differentiation efficiency of hypoxic and normoxic ADSCs. A sciatic nerve injury animal model was used to analyze the gastrocnemius muscle weights as the outcomes of hypoxic and normoxic ADSC treatments, and sections of the regenerated nerve fibers taken from the conduits were analyzed by histological staining and immunohistochemical staining. Comparisons of the treatment effects of ADSCs and BMSCs following hypoxic expansion were also conducted in vitro and in vivo. Hypoxic expansion prior to the differentiation procedure promoted the expression of the neuronal markers in ADSC differentiated neuron-like cells. Moreover, the conduit connecting the sciatic nerve gap injected with hypoxic ADSCs showed the highest recovery rate of the gastrocnemius muscle weights in the animal model, suggesting a conceivable treatment for hypoxic ADSCs. The percentages of the regenerated myelinated fibers from the hypoxic ADSCs detected by toluidine blue staining and myelin basic protein (MBP) immunostaining were higher than those of the normoxic ones. On the other hand, hypoxic expansion increased the neuronal differentiation potential of ADSCs compared with that of the hypoxic BMSCs in vitro. The outcomes of animals treated with hypoxic ADSCs and hypoxic BMSCs showed similar results, confirming that hypoxic expansion enhances the neuronal differentiation potential of ADSCs in vitro and improves in vivo therapeutic potential.

Adipose Derived Mesenchymal Stem Cells from a Hypoxic Culture Reduce Cartilage Damage.

The method to benifit tissue engineering of adipose-derived stem cells (ADSCs) to cartilage has been an objective of intense research in treating increasing cartilage-related disease. In this study, whether hypoxic expansion would enhance the proliferation and in vitro chondrogenic differentiation of ADSCs was studied, and then hypoxic expansion was applied to reduce cartilage damage in a rat model in vivo. Hypoxic expansion increased the proliferation and decreased the expression of aging-related genes, including p16, p21, and p53, of human ADSCs in comparison with normoxic expansion. In addition, the γH2AX expression was reduced in the hypoxic ADSCs. The chondrogenic markers were enhanced in the hypoxic ADSC differentiated chondrogenic pellets, including SOX9 on day 7 and gene expressions of COL 2 and COL 10 on day 21. To determine the in vitro chondrogenic differentiation potential of ADSCs, ADSC differentiated 21-day chondrogenic pellets were stained by Alcian blue staining and the immunostaining of COL 2 and COL 10, the results of which confirmed the enhancement of differentiation potential after the hypoxic expansion. Moreover, cartilage injury in a rat model was reduced by hypoxic ADSC treatment that was determined by histological and immunohistochemical staining detections. The effects of hypoxic expansion of ADSCs and bone marrow-derived stem cells (BMSCs) on chondrogenic differentiation potential were also compared. Smaller sizes were presented in the in vitro hypoxic BMSC differentiated chondrogenic pellets, whereas the chondrogenic marker expressions were significantly higher than those of the hypoxic ADSCs. However, there was no significant difference between the treatments of the hypoxic ADSCs and BMSCs in the cartilage injury in vivo. In conclusion, hypoxic expansion increases the chondrogenic differentiation potential of ADSCs and BMSCs in vitro and enhances them to reduce cartilage damage in vivo. Although the hypoxic BMSCs showed compact chondrogenic pellet formation and higher potential of chondrogenesis, the easy access and large resources of ADSCs still uplifted the application.

The Hill-Sachs interval to glenoid track width ratio is comparable to the instability severity index score for predicting risk of recurrent instability after arthroscopic Bankart repair.

PURPOSE: The purpose of this study was to clinically validate the Hill-Sachs interval to glenoid track width ratio (H/G ratio) compared with the instability severity index (ISI) score for predicting an increased risk of recurrent instability after arthroscopic Bankart repair. METHODS: A retrospective evaluation was performed using data from patients with anteroinferior shoulder instability who underwent arthroscopic Bankart repair with a follow-up period of at least 24 months. A receiver operating characteristic (ROC) curve was used to determine the optimal cut-off values for the H/G ratio and the ISI score to predict an increased risk of recurrent instability. The area under the ROC curve (AUC) of the two methods and the sensitivity and specificity of their optimal cut-off values were compared. RESULTS: A total of 222 patients were included, among whom 31 (14.0%) experienced recurrent instability during the follow-up period. The optimal cut-off values for predicting an increased risk of recurrent instability were an H/G ratio of ≥ 0.7 and ISI score of ≥ 4. There were no significant differences between the AUC of the two methods (H/G ratio AUC = 0.821, standard error = 0.035 and ISI score AUC = 0.792, standard error = 0.04; n.s.) nor between the sensitivity and specificity of the optimal cut-off values (n.s. and n.s., respectively). CONCLUSIONS: The H/G ratio is comparable to the ISI score for predicting an increased risk of recurrent instability after arthroscopic Bankart repair. Surgeons are recommended to consider other strategies to treat anterior shoulder instability if H/G ratio is ≥ 0.7. LEVEL OF EVIDENCE: III.

Mesenchymal stem cells from a hypoxic culture improve nerve regeneration.

Repairing the peripheral nerves following a segmental defect injury remains surgically challenging. Because of some disadvantages of nerve grafts, nerve regeneration, such as conduits combined with bone marrow-derived mesenchymal stem cells (BMSCs), may serve as an alternative. BMSCs expand under hypoxic conditions, decrease in senescence, and increase in proliferation and differentiation potential into the bone, fat, and cartilage. The purpose of this study was to investigate whether BMSCs increased the neuronal differentiation potential following expansion under hypoxic conditions. Isolated human BMSCs (hBMSCs) expand under hypoxia or normoxia, and neuronal differentiation proceeds under normoxia. in vitro tests revealed hypoxia culture enhanced the RNA and protein expression of neuronal markers. The electrophysiology of hBMSC-differentiated neuron-like cells was also enhanced by the hypoxia culturing. Our animal model indicated that the potential treatment of hypoxic rat BMSCs (rBMSCs) was better than that of normoxic rBMSCs because the conduit with the hypoxic rBMSCs injection demonstrated the highest recovery rate of gastrocnemius muscle weights. There were more toluidine blue-stained myelinated nerve fibers in the hypoxic rBMSCs group than in the normoxic group. To sum up, BMSCs cultured under hypoxia increased the potential of neuronal differentiation both in vivo and in vitro.

Intra-articular Injection of Tranexamic Acid Reduced Postoperative Hemarthrosis in Arthroscopic Anterior Cruciate Ligament Reconstruction: A Prospective Randomized Study.

PURPOSE: To evaluate the effect of intra-articular injection of tranexamic acid (TXA) in patients receiving arthroscopic anterior cruciate ligament reconstruction (ACLR). METHODS: A total of 304 patients were included in this study, which was performed between August 2017 and April 2018. Single-bundle reconstructions using autologous hamstring tendon grafts were performed in all patients. Patients were randomized into 2 groups: Group 1 patients (TXA group) received the index procedure with a 10-mL intra-articular injection of TXA (100 mg/mL). Group 2 patients (control group) received the index procedure without TXA injections. An intra-articular suction drain was placed in the joint and clamped for 2 hours after the procedure. The volume of drainage was recorded 24 hours after surgery. Clinical evaluations using the International Knee Documentation Committee functional score, range of motion, and a visual analog scale pain score were performed on day 3 and at week 4 postoperatively. RESULTS: Twenty-four hours after surgery, a significant decrease in the amount of drainage was observed in patients receiving intra-articular injections (TXA group, 56.1 ± 34.1 mL; control group, 80.1 ± 48 mL; P < .05). On day 3 and at week 4, significantly reduced pain scores were reported in the TXA group. However, at week 4, clinical function scores did not show significant differences between the 2 groups. CONCLUSIONS: Intra-articular injection of TXA could significantly reduce postoperative intra-articular bleeding in the first 24 hours in patients receiving arthroscopic ACLR. TXA injection may also decrease pain and the grade of hemarthrosis in the early postoperative period. No systemic side effects or need for aspiration was noted during the follow-up period. Therefore, intra-articular injection of TXA could be considered an effective and relatively safe solution to reduce postoperative bleeding and pain in ACLR patients. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Use of Allogeneic Hypoxic Mesenchymal Stem Cells For Treating Disc Degeneration in Rabbits.

Intervertebral discs (IVDs) are important biomechanical components of the spine. Once degenerated, mesenchymal stem cell (MSC)-based therapies may aid in the repair of these discs. Although hypoxic preconditioning enhances the chondrogenic potential of MSCs, it is unknown whether bone marrow MSCs expanded under hypoxic conditions (1% O2 , here referred to as hypoxic MSCs) are better than bone marrow MSCs expanded under normoxic conditions (air, here referred to as normoxic MSCs) with regards to disc regeneration capacity. The purpose of this study was to compare the therapeutic effects of hypoxic and normoxic MSCs in a rabbit needle puncture degenerated disc model after intra-disc injection. Six weeks after needle puncture, MSCs were injected into the IVD. A vehicle-treated group and an un-punctured sham-control group were included as controls. The tissues were analyzed by histological and immunohistochemical methods 6 and 12 weeks post-injection. At 6 and 12 weeks, less disc space narrowing was evident in the hypoxic MSC-treated group compared to the normoxic MSC-treated group. Significantly better histological scores were observed in the hypoxic MSC group. Discs treated with hypoxic MSCs also demonstrated significantly better extracellular matrix deposition in type II and XI collagen. Increased CD105 and BMP-7 expression were also observed upon injection of hypoxic MSCs. In conclusion, hypoxic MSC injection was more effective than normoxic MSC injection for reducing IVD degeneration progression in vivo. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1440-1450, 2019.

Does Arthroscopic Suture-Spanning Augmentation of Single-Row Repair Reduce the Retear Rate of Massive Rotator Cuff Tear?

BACKGROUND: Several surgical techniques have been proposed for massive rotator cuff tears (MRCTs), but the failure rates remain high. The suture-spanning augmentation technique of single-row (SSA-SR) repair was shown to reduce failure rates in cadaveric studies, but the outcome in vivo remains unclear. PURPOSE: To determine if adding spanning sutures to SR repair during MRCT repairs can improve functional outcome and reduce failure rates. STUDY DESIGN: Randomized controlled trial; Level of evidence, 2. METHODS: The study included 71 patients with a diagnosed MRCT. The study group (n = 35) received SSA-SR repair. The control (n = 36) received SR repair. The American Shoulder and Elbow Surgeons (ASES) score, Constant score, UCLA (University of California, Los Angeles) score, and visual analog scale for pain were assessed preoperatively and 24 months postoperatively. Magnetic resonance imaging was arranged at 6 months postoperatively to evaluate the rotator cuff. RESULTS: At 6 months postoperatively, the overall retear rate was 31.0%. The retear rate was lower in the SSA-SR group (14.3%) than in the SR group (47.2%, P = .002). At 24 months, the SSA-SR group had markedly improved ASES, Constant, and UCLA scores in comparison with the SR group ( P < .05). Within both groups, all scores had significant improvement as compared with the preoperative status ( P < .05). CONCLUSION: The SSA-SR repair technique showed improved functional and radiologic results. Based on the superior postoperative outcome of this technique, the SSA-SR repair technique can be a potential treatment option for MRCT repair. REGISTRATION: NCT03609164 (ClinicalTrials.gov identifier).

Comparison of Tunnel Enlargement and Clinical Outcome Between Bioabsorbable Interference Screws and Cortical Button-Post Fixation in Arthroscopic Double-Bundle Anterior Cruciate Ligament Reconstruction: A Prospective, Randomized Study With a Minimum Follow-Up of 2 Years.

PURPOSE: To investigate the tunnel enlargement rate and clinical function by comparing double-bundle anterior cruciate ligament reconstruction (ACLR) using different fixation devices. METHODS: Patients receiving primary arthroscopic double-bundle ACLR were screened and divided into 2 groups on the basis of the method of graft fixation: bioabsorbable interference screw (BS) group and cortical button (CB) group. Bone tunnel size was assessed digitally using magnetic resonance imaging, which was performed a minimum of 2 years postoperatively. Clinical evaluations were performed using the Knee Injury and Osteoarthritis Outcome Score, International Knee Documentation Committee score, and KT-1000 arthrometer 2 years postoperatively. RESULTS: Sixty patients receiving primary arthroscopic double-bundle ACLR were included. Overall, the BS group showed greater tunnel enlargement than the CB group, as well as a significantly increased rate of tunnel communication (P = .029). The average anteromedial tunnel enlargement rates for the BS and CB groups were 50% and 28%, respectively. The enlargement rate of the posterolateral (PL) femoral tunnel was similar in both groups. In the PL tibial tunnel, the CB group showed a significant increase in enlargement compared with the BS group (64% vs 45%, P = .0001). Both groups showed functional improvement in the Knee Injury and Osteoarthritis Outcome Score and International Knee Documentation Committee score. No significant difference in postoperative functional outcomes was found between the 2 groups. CONCLUSIONS: The BS group showed significantly greater tunnel enlargement in anteromedial tunnels and an increased tunnel communication rate compared with the CB group. On the other hand, the CB group showed greater tunnel enlargement in tibial PL tunnels. Tunnel communication was observed mostly on the tibial side in the BS patients. Equivalent clinical function outcomes were noted at 2 years after surgery in both groups of patients. LEVEL OF EVIDENCE: Level II, randomized controlled clinical trial.

Correlation of Meniscal Tear with Timing of Anterior Cruciate Ligament Reconstruction in Patients without Initially Concurrent Meniscal Tear.

The incidence of meniscal tear was reported to increase with the delay of anterior cruciate ligament reconstruction (ACLR). The tear may occur concurrently with the ACL injury or after the ACL injury. Few studies had focused on the patients whose meniscus is intact during ACL injury. We determined the correlation between timing of surgery and incidence of meniscal tears in ACL-deficient knees with initially intact meniscus. We retrospectively reviewed 387 patients who had undergone primary ACLR. Time of initial ACL injury, magnetic resonance imaging (MRI) examination, and surgery was recorded. The MRI was reviewed by experienced radiologic and orthopaedic doctors. Intraoperative arthroscopic images were also obtained and reviewed. The type of tear noted during surgery was classified according to the modification of International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine classification of meniscal tears. Patients were divided into early (surgery within 12 months from injury) and late surgery group (surgery at more than 12 months from injury). There were 216 patients with intact medial meniscus and 257 patients with intact lateral meniscus on the postinjury MRI study. The incidence of medial meniscus tear (MMT) was significantly higher than lateral meniscus tear (LMT) during the ACLR (33.8 vs. 19.8%, p < 0.001). The incidence of MMT is higher in late group than in early group (53.7 vs. 29.1%, p = 0.004, odds ratio= 2.815). The incidence of LMT is mildly higher in late group but without statistics significance (23.8 vs. 18.6%, p = 0.364). In both MMT and LMT, the most common injury pattern observed was a longitudinal tear. The incidence of each type is not different between early and late group. For patients without concurrent meniscal injuries with the ACL tear, the incidence of MMT significantly increased if ACLR was performed more than 12 months after injury. The medial meniscus was more prone to injury than the lateral meniscus in chronic ACL-deficient knee. ACLR should be performed earlier to reduce the risk of meniscal tears for patients without initially concurrent meniscal tear.

Corticosteroid inhibits differentiation of palmar fibromatosis-derived stem cells (FSCs) through downregulation of transforming growth factor-ß1 (TGF-ß1).

Treatment for musculoskeletal fibromatosis remains challenging. Surgical excision for fibromatosis is the standard therapy but recurrence remains high. Corticosteroids, an anti-fibrogenic compound, have been used to treat early stage palmar fibromatosis, but the mechanism is unknown. We investigated the inhibitory mechanism effect of corticosteroids in the murine model of fibromatosis nodule as well as in cultured FSCs. Quantitative reverse transcription/polymerase chain reaction (PCR) analysis and immunofluorescence (IF) staining for markers of myofibroblasts (α-smooth muscle actin and type III collagen) were used to examine the effect of dexamethasone on myofibroblasic differentiation of FSCs both in vitro and in vivo. Transforming growth factor-ß1 (TGF-ß1) signaling and its downstream targets were examined using western blot analysis. TGF-ß1 expression in FSCs before and after dexamethasone treatment was compared. In addition, inhibition of TGF-ß1 expression was examined using RNA interference (RNAi) on FSCs, both in vitro and in vivo. Treating FSCs with dexamethasone inhibited FSCs' myofibroblastic differentiation in vitro. Treating FSCs with dexamethasone before or after implantation further inhibited formation of fibromatosis nodules. Dexamethasone suppressed expression of TGF-ß1 and pSmad2/3 by FSCs in vitro. TGF-ß1 knockdown FSCs showed reducing myofibroblastic differentiation both in vitro and in vivo. Finally, addition of TGF-ß1 abolished dexamethasone-mediated inhibition of myofibroblastic differentiation. Dexamethasone inhibits the myofibroblastic differentiated potential of FSCs both in vitro and in vivo through inhibition of TGF-ß1 expression in FSCs. TGF-ß1 plays a key role in myofibroblastic differentiation.

Arthroscopic Partial Repair of Irreparable Rotator Cuff Tears: Factors Related to Greater Degree of Clinical Improvement at 2 Years of Follow-Up.

PURPOSE: This study aimed to evaluate the clinical outcomes of irreparable rotator cuff tears (RCT) treated with an arthroscopic partial repair, as well as the preoperative factors that may be related to greater improvement of clinical outcomes at short-term follow-up. METHODS: We retrospectively reviewed patients with irreparable RCT who underwent arthroscopic partial rotator cuff repair between January 2011 and April 2014. Minimal follow-up of 24 months was required. Partial repair was defined as repairing the less retracted posterosuperior rotator cuff with a residual defect of the tendon-footprint junction. Tearing involving the subscapularis tendon was excluded. Factors collected included age, sex, diabetes, smoking, night pain, duration of symptoms, pain visual analog scale (VAS) score, acromiohumeral distance (AHD), and American Shoulder and Elbow Surgeons (ASES) score. Magnetic resonance images without intra-articular contrast were assessed for healing 6 months after surgery for all patients. Functional outcome was evaluated with ASES score. Degree of functional improvement was defined as the difference of ASES scores pre- and postoperatively (d-ASES). Paired t-test and simple linear analysis were used for statistical analysis. RESULTS: Thirty-seven patients were included with a mean follow-up period of 29.6 ± 6.6 months. VAS score improved from 5.22 to 1.51 (P < .001). ASES score improved from 46.0 to 78.6 (P < .001). The incidence of night pain improved from 70.3% to 8.1% (P < .001). Only a preoperative lower ASES score, higher VAS score, and night pain were related to the higher d-ASES score (P < .001, P = .005, P = .017, respectively). The rate of repair failure was 41.6% at a mean follow-up of 6.4 months. CONCLUSIONS: Arthroscopic partial repair of irreparable RCTs is an effective treatment to improve the shoulder function and decrease the pain, despite the high repair failure rate of 41.6%. Patients with preoperative lower functional score, higher VAS score, or night pain experienced a greater degree of functional improvement from the surgery. LEVEL OF EVIDENCE: Level IV, therapeutic case series.