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.

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.

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.

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.

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.

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.

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.

Four-Direction Procedures Involving Tibial Tubercle Osteotomy for Habitual Dislocation of the Patella: A Case Report.

CASE: A 22-year-old man with habitual dislocation of the patella (HDP), characterized by lateral dislocation in flexion with spontaneous relocation with extension, presented with right knee pain and inability to actively extend. Imaging revealed lateral patellar dislocation, flat articular surface of the patella, and trochlear dysplasia. His symptoms persisted despite physical therapy. A 4-directional patellar stabilization surgery, incorporating lateral release, medial tibial tuberosity osteotomy, quadriceps muscle lengthening, and medial patellofemoral ligament reconstruction, was performed, with significant improvement in pain and function postoperatively. CONCLUSION: The procedure could be feasible in cases of severe HDP when conservative measures failed to relieve the patient's symptoms.

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.

Trichostatin A inhibits TGF-ß1 induced in vitro chondrogenesis of hMSCs through Sp1 suppression.

Trichostatin A (TSA) is a histone deacetylase inhibitor (HDACi) known to modulate differentiation of many cells. However, its effect on chondrogenesis remains elusive. This study was aimed to investigate the effects of TSA on in vitro transforming growth factor-ß1 (TGF-ß1)-induced chondrogenesis of human mesenchymal stem cells (hMSCs). The pellet cultures of hMSCs in a chondrogenic medium were exposed to TGF-ß1 and TSA. Quantitative reverse transcription/polymerase chain reaction (PCR) analysis, Alcian blue staining, and immunohistochemistry staining were used to confirm and compare the differences in chondrogenesis by analyzing the mRNA of chondrogenic genes (Sox9, Aggrecan, and Col2A1), synthesis of chondrogenic proteins and type II collagen, respectively. TGF-ß1 signaling and its downstream targets were determined by western blot analysis. TGF-ß1 led to significant increases in chondrogenic gene expression and the synthesis of chondrogenic proteins. However, TSA significantly decreased chondrogenic gene expression and the synthesis of chondrogenic proteins in a dose-dependent manner. TGF-ß1 increased phosphorylation of Smad 2/3 and Sp1 expression around half an hour after induction. The increase of Sp1, but not Smad 2/3 activation was almost completely blocked by the addition of TSA. The chondrogenic effect of TGF-ß1 was also suppressed by the Sp1-binding inhibitor mithramycin A. Finally, overexpression of Sp1 abolished TSA-mediated inhibition of TGF-ß1-induced chondrogenesis. Our study showed that TSA inhibited chondrogenesis through inhibition of TGF-ß1-induced Sp1 expression. Furthermore, Sp1 could be a useful tool in future studies looking into biological mechanisms by which chondrogenesis of hMSCs can be augmented, especially in the area of clinical application.

Clinical outcome and imaging of arthroscopic single-row and double-row rotator cuff repair: a prospective randomized trial.

PURPOSE: The purpose of this study was to compare the clinical and imaging outcomes of single-row and double-row suture anchor fixation in arthroscopic rotator cuff repair with emphasis on analysis of the effect of various tear size on repair integrity. METHODS: Fifty-three patents were randomized to either single-row or double-row rotator cuff repair at the time of surgical intervention. The clinical results were evaluated by applying the UCLA score and the ASES index and assessing muscle strength in abduction and external rotation with a minimum 2-year follow-up. The postoperative rotator cuff integrity was evaluated by magnetic resonance arthrography at 6-month and minimum 2-year follow-up. RESULTS: We enrolled 27 patients in the single-row group and 26 patients in the double-row group. Statistically, the UCLA score; the ASES index; and muscle strength were significantly increased in both groups after surgery, but there was no significant difference between the 2 groups. At minimum 2-year follow-up, intact rotator cuffs were found in 17 patients in the single-row group and 20 in the double-row group, based on magnetic resonance arthrography results. Overall, there was no significant difference in postoperative structural integrity between the 2 groups at 6-month and 2-year follow-up. In patients with tear size larger than 3 cm, the muscle strength of the shoulder was significantly better in the double-row group. For the final imaging results, regardless of the tear size, there was no difference between the single-row and double-row groups. CONCLUSIONS: Arthroscopic rotator cuff repair with double-row fixation showed better shoulder strength in patients with larger tear size (>3 cm) in comparison with single-row fixation. However, the imaging results showed no significant difference in cuff integrity in both groups in patients with any tear size at 6-month and minimum 2-year follow-up. LEVEL OF EVIDENCE: Level II, lesser-quality randomized control trial.

Hamstring graft sizes differ between Chinese and Caucasians.

PURPOSE: The use of hamstring tendon autografts for anterior cruciate ligament (ACL) surgery has become more and more common. The purposes of this study were to determine whether anthropomorphic measurement correlated with tendon sizes in Chinese patient group and whether tendon sizes in Chinese and Caucasian patient groups differed. METHODS: From 2008 to 2009, 100 patients that received double-bundle ACL reconstruction with autologous hamstring tendons were prospectively enrolled. The original lengths and triple-folded graft diameters of the individual semitendinosus (ST) and gracilis (Gr) tendons were recorded and correlated with the anthropometric data (height, weight, body mass index, gender, thigh length, shank length, leg length and bilateral thigh circumference) of the patients. Later, using height for predictions, the original heights of patients were added to the equations previously used for regression models to compare the tendon lengths in different ethnic groups. RESULTS: After stepwise multiple linear regression analysis, the height and leg lengths showed greatest correlation with the lengths of both tendons. The lengths of both the semitendinosus and gracilis tendons in Caucasian patients were significantly longer than in the Chinese patients. CONCLUSIONS: The results of this study showed that anthropomorphic measurements (height and leg length) correlated with tendon lengths. In addition, Caucasians had significantly longer hamstring tendons than the Chinese patients. LEVEL OF EVIDENCE: Prospective cohort study (prevalence), Level I.

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.

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.

Fibromatosis stem cells rather than bone-marrow mesenchymal stem cells recapitulate a murine model of fibromatosis.

Palmar fibromatosis is a benign fibroproliferative tumor of unknown etiology, with a high rate of recurrence after excision. The offending cells of palmar fibromatosis are myofibroblasts and the cellular origin of other myofibroblasts has previously been reported to be the bone marrow. However, further clarification of the relationship between bone marrow precursors and palmar fibromatosis is required. Stem cells (SCs) are known to exist in various tissues, but whether SCs can be isolated from fibromatosis tissue is still unclear. The purpose of this study was to isolate and identify stem cells from human palmar fibromatosis, and to evaluate the differences in the differentiation and fibrogenic capacities of bone marrow stem cells (BMSCs) and fibromatosis-derived stem cells (FSCs). We found that FSCs had better fibrogenic differentiation potential than BMSCs, whereas BMSCs had better adipogenic and chondrogenic differentiation capacities. Treatment with transforming growth factor-ß1 increased the expression of α-smooth muscle actin, and types III and I collagen significantly more in FSCs than in BMSCs. An in vivo study further confirmed the results of fibrogenesis and suggested that FSCs can recapitulate the fibromatosis nodule. In summary, their myofibroblastic differentiation both in vivo and in vitro makes FSCs a potential cell source for future applications in murine models of fibromatosis or fibrogenesis.

Comparison of articulating and static spacers regarding infection with resistant organisms in total knee arthroplasty.

INTRODUCTION: The result of treatment of infections involving antibiotic-resistant organisms in total knee arthroplasty (TKA) is often poor. We evaluated the efficacy of 2-stage revision in TKAs infected with resistant organisms and compared the clinical outcomes with articulating and conventional static spacers, in terms of both infection control and function. METHODS: In a prospective manner, from June 2003 to January 2007 selected patients with a TKA infected with resistant organisms were enrolled and treated with 2-stage re-implantation. The 45 patients were divided into 2 groups: group A (23 patients) implanted with the articulating spacers and group S (22 patients) implanted with static spacers. All patients followed the same antibiotic protocols and had the same re-implantation criteria. The efficacy of infection control was evaluated using re-implantation rate, recurrence rate, and overall success rate. The functional and radiographic results were interpreted with the Hospital of Special Surgery (HSS) knee score and the Insall-Salvati ratio. RESULTS: With mean 40 (24-61) months of follow-up, 22 of 23 knees were re-implanted in group A and 21 of 22 were re-implanted in group S. Of these re-implanted prostheses, 1 re-infection occurred in group A and 2 occurred in group S. Range of motion after re-implantation, the final functional scores, and the satisfaction rate were better in group A. One third of the patients in group S, and none in group A, had a patella baja. INTERPRETATION: After 2-stage re-implantation of TKAs originally infected with resistant organisms, the clinical outcome was satisfactory-and similar to that reported after treatment of TKAs infected with low-virulence strains. Treatment with an articulating spacer resulted in better functional outcome and lower incidence of patella baja.

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.

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.

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.