Interposition of acellular amniotic membrane at the tendon to bone interface would be better for healing than overlaying above the tendon to bone junction in the repair of rotator cuff injury.

PURPOSE: The retear rate of rotator cuff (RC) after surgery is high, and the rapid and functional enthesis regeneration remains a challenge. Whether acellular amniotic membrane (AAM) helps to promote the healing of tendon to bone and which treatment is better are both unclear. The study aims to investigate the effect of AAM on the healing of RC and the best treatment for RC repair. METHODS: Thirty-three Sprague Dawley rats underwent RC transection and repair using microsurgical techniques and were randomly divided into the suturing repair only (SRO) group (n = 11), the AAM overlaying (AOL) group (n = 11), and the AAM interposition (AIP) group (n = 11), respectively. Rats were sacrificed at 4 weeks, then examined by subsequent micro-CT, and evaluated by histologic and biomechanical tests. The statistical analyses of one-way ANOVA or Kruskal-Wallis test were performed using with SPSS 23.0. A p < 0.05 was considered a significant difference. RESULTS: AAM being intervened between tendon and bone (AIP group) or overlaid over tendon to bone junction (AOL group) in a rat model, promoted enthesis regeneration, increased new bone and cartilage generation, and improved collagen arrangement and biomechanical properties in comparison with suturing repair only (SRO group) (AOL vs. SRO, p < 0.001, p = 0.004, p = 0.003; AIP vs. SRO, p < 0.001, p < 0.001, p < 0.001). Compared with the AOL group, the AIP group had better results in micro-CT evaluation, histological score, and biomechanical testing (p = 0 0.039, p = 0.011, p = 0.003, respectively). CONCLUSION: In the RC repair model, AAM enhanced regeneration of the tendon to bone junction. This regeneration was more effective when the AAM was intervened at the tendon to bone interface than overlaid above the tendon to bone junction.

The effect of cooking temperature on the aggregation and digestion rate of myofibrillar proteins in Jinhua ham.

BACKGROUND: In order to evaluate the effect of cooking temperature on the nutrition quality of dry-cured hams, 60 biceps femoris samples from 16 Jinhua hams were divided into four groups (control, 70, 100 and 120 °C) and cooked for 30 min. Carbonyl content, sulfhydryl groups, surface hydrophobicity, microstructure, protein aggregation and digestibility of myofibrillar proteins were investigated. RESULTS: Cooking promoted carbonylation and decreased sulfhydryl groups in a temperature-dependent way. Scanning electron microscopy and Nile Red revealed that protein aggregation became a main phenomenon at 120 °C; it coincided with surface hydrophobicity. The increased carbonyl content and decreased sulfhydryl groups contributed to the formation of aggregates. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles showed the initial difference in proteolysis rate among four groups. The in vitro digestibility of pepsin and of trypsin and α-chymotrypsin increased from the control to 100 °C and decreased from 100 to 120 °C. CONCLUSION: The increased digestibility could be attributed to the oxidation of proteins and exposing recognition sites of digestive enzymes, while the decreased digestibility was due to the formation of aggregates. Cooking was a main factor that affected the digestibility of Jinhua ham, and cooking at 100 °C could be an ideal way to gain the highest digestibility of Jinhua ham. © 2018 Society of Chemical Industry.

Correlation Between Improvement in Pain After Ultrasound-Guided Intra-articular Hip Injection and Outcomes After Arthroscopy in Patients With Femoroacetabular Impingement.

Background: An accurate and objective criterion is needed to determine candidates who are suitable for hip arthroscopy in patients with femoroacetabular impingement (FAI). Purpose: To determine whether improvement in pain after ultrasound (US)-guided intra-articular hip injection during standardized examinations can be used to predict the outcomes of hip arthroscopy in patients with FAI. Study Design: Cohort study; Level of evidence, 3. Methods: We enrolled 119 patients with FAI who underwent US-guided intra-articular hip injection of local anesthesia during standardized examinations, carried out from May 2018 to February 2020 (within 2 weeks before hip arthroscopy). All patients had undergone a minimum of 6 months of nonoperative treatment without remission and had 2-year follow-up data. Pain visual analog scale (VAS) scores (0-10) were recorded for 7 different physical examination tests, and a total score (0 [best] to 70 [worst]) was obtained. In addition, International Hip Outcome Tool-12 (iHOT-12) and modified Harris Hip Score (mHHS) scores were recorded before hip arthroscopy and at final follow-up. According to whether patients achieved the substantial clinical benefit (SCB) on the iHOT-12, they were divided into SCB and non-SCB groups, and the improvement in VAS pain scores from preinjection to postinjection (ΔVAS pain) was compared between the 2 groups. Logistic regression analysis was used to predict the achievement of SCB, and the area under the receiver operating characteristic curve (AUC) was used to estimate the accuracy of the prediction. Results: There was a significant pre- to postoperative increase in iHOT-12 (31.6 points; P < .001) and mHHS (20.0 points; P < .001) scores, and 84 (70.6%) patients achieved the SCB. The ΔVAS pain score was significantly greater in the SCB versus the non-SCB group (16.0 vs 7.0 points; respectively; P < .001). Logistic regression analysis demonstrated an optimal cutoff value of 8.5 points for ΔVAS pain (AUC, 0.772; 95% CI, 0.687-0.858). For patients with more severe symptoms (total preinjection VAS pain score of >10 out of 70), the accuracy of the prediction for ΔVAS pain had a better evaluation value (AUC, 0.834; 95% CI, 0.676-0.992). Conclusion: Improvement in pain after US-guided intra-articular hip injection predicted the outcomes of hip arthroscopy in patients with FAI in this study, especially for patients with more severe pain.

[Experimental study of tendon graft fixation in anterior cruciate ligament reconstruction with cortical press-fit bolt in rabbits].

OBJECTIVE: To explore the histological outcomes of tendon-bone healing in anterior cruciate ligament (ACL) reconstruction with cortical press-fit bolt (CPB). METHODS: Twenty-four healthy female or male New Zealand White rabbits (2-3 months old) underwent bilateral ACL reconstruction with extensor digitorum longus tendon. A random method was used to decide one knee would receive the routine ACL reconstruction (control group) and another cortical press-fit bolt fixation (experimental group). After general anesthesia, extensor digitorum longus tendon was harvested and ACL reconstruction performed. All animals were sacrificed at 4, 8 and 12 weeks postoperation. Radiological and histological examinations were made at each timepoint. The specimens were stained with different methods to observe the pathological changes of tendon graft, bone tunnel and cortical press-fit bolt. RESULTS: More revascularization and massive new bone were found in tendon-bone junction of experimental group at 4, 8 and 12 weeks postoperation. The circum-graft new vessel proportion of the experimental and control groups were 0.48 ± 0.12 and 0.26 ± 0.05 respectively (P < 0.05). In the experimental group, more cartilage cells were present in tendon-bone junction at 12 weeks and the circum-graft new bone areas in two groups were 0.41 ± 0.11 and 0.21 ± 0.10 mm(2) respectively (P < 0.05). CONCLUSION: Cortical press-fit blot may improve tendon-bone healing after ACL reconstruction in rabbits. The application prospects of this procedure are promising.

Evaluation the food safety of cultured fat via detection of residues of adipogenic differentiation cocktail in cultured fat with high performance liquid chromatography and enzyme-linked immunosorbent assay.

Cultured fat is inducing adipose progenitor cells (APCs) to differentiate into mature adipocytes for consumption. The traditional adipogenic differentiation cocktail, including insulin, dexamethasone, indomethacin, isobutylmethylxanthine and rosiglitazone, has potential food safety problems in cultured fat. Therefore, the detection of these residues is necessary to ensure food safety. In this research, a method of high performance liquid chromatography (HPLC) was established to quantitatively analyze the potential residual content of dexamethasone, indomethacin, isobutylmethylxanthine and rosiglitazone in cultured fat and medium. Quantitative analysis showed that the content of four residues in cultured fat decreased to zero on Day 10. Subsequently, enzyme-linked immunosorbent assay (ELISA) was performed to detect the insulin content in the cultured fat and found that the insulin content in the cultured fat on Day 10 was 2.78 ± 0.21 µg/kg. After soaking with phosphate buffered saline (PBS), the insulin content decreased to 1.88 ± 0.54 µg/kg. In conclusion, this research provided an effective approach to clarify the content of potential residual components in cultured fat and it will provide reference for the safety of cultured fat in the future.

Synthesis and antidiabetic activity of 5,7-dihydroxyflavonoids and analogs.

In a study to evaluate the structural elements essential for the antidiabetic activity of flavonoids, we synthesized two series of flavonoids, 5,7-dihydroxyflavanones and 5,7-dihydroxyflavones. In a screening for potential antidiabetic activity, most of the flavonoids showed a remarkable in vitro activity, and compounds 1f, 2d, and 3c were significantly more effective than the positive control, metformin. The biological activity was mainly affected by structural modification at the ring B moiety of the flavonoid skeleton. The results suggest that 5,7-dihydroxyflavonoids can be considered as promising candidates in the development of new antidiabetic lead compounds.

Desmin as molecular chaperone for myofibrillar degradation during freeze-thaw cycles.

This study investigated the relationship of secondary protein structures with textural attributes of chicken breast subjected to 6 freeze (-20 °C) thaw (4 °C for 12 h) cycles. 2DE identified 78 distinct protein spots. Moreover, WB indicated a remarkable increase in the degree of desmin degradation during multiple freeze-thaw (MFT). In addition, the TEM micrographs revealed that MFT remarkably increased the spacing between the muscle fibers, especially from cycles 3 to 5, slightly decreased H-zone, but a remarkable shrinkage of Z-lines, as well as degradation of myofibril structures (Z-line, I-bands, and M-lines). DSC showed shifts in first and second endothermic transition peaks during the 3rd and 5th cycles. Viscoelastic graphs revealed a cycle-dependent decrease in gel-forming ability (G') during MFT. Finally, the MFT chicken breast samples exhibited significantly decreased shear force in a cycle-dependent manner. This study highlighted the critical role of desmin in regulating myofibrillar degradation through various routes and mechanisms.

Production of cultured meat by culturing porcine smooth muscle cells in vitro with food grade peanut wire-drawing protein scaffold.

Cultivating meat is a promising solution to the negative problems brought by traditional animal husbandry. To make cultured meat have the sensory and nutritional characteristics of conventional meat as much as possible, many studies have been conducted on various cell types and scaffold characteristics. Therefore, this study aims to produce a low-cost cultured meat with a quality closer to that of conventional meat. Tissue generation requires three-dimensional (3D) scaffolds to support cells and simulate extracellular matrix (ECM). Here, we used peanut wire-drawing protein (a biomaterial based on edible porous protein) as a new culture meat scaffold to culture cells. The scaffold can support cell attachment and proliferation to create 3D engineered porcine muscle tissue. The differentiation of smooth muscle cells (SMCs) was induced by a low serum medium to produce more extracellular matrix proteins. After differentiation, it was found that peanut wire-drawing protein scaffolds could be used for porcine smooth muscle cell adhesion and growth. The ECM protein and muscle protein produced by SMCs can endow cultured meat with better quality. This technology provides an innovative pathway for the industrialized production of cultured meat.

Subspine Hypertrophy: Higher Incidence of Symptomatic versus Asymptomatic Hips in Patients with Unilateral Femoroacetabular Impingement.

OBJECTIVE: To compare the difference of anterior inferior iliac spine (AIIS) and subspine hypertrophic deformity between symptomatic and asymptomatic hips in patients traditionally diagnosed with femoroacetabular impingement (FAI), and investigate the correlation of subspine decompression with AIIS variation and subspine hypertrophic deformity. METHODS: We retrospectively reviewed 70 patients with unilateral symptomatic FAI who underwent hip arthroscopy. The operative hips and contralateral hips naturally formed the symptomatic groups and asymptomatic control groups, respectively. The morphometric comparison of the hip joint was performed between the operative and contralateral sides of each patient. Radiological assessment was performed by two observers (an experienced musculoskeletal radiologist and an experienced surgeon). Three-dimensional (3D)-CT images of each patient were blindly reviewed to determine the AIIS variation and subspine hypertrophic deformity. Reformatted two-dimensional (2D)-CT images and anterior-posterior (AP) pelvic plain radiographs were blindly reviewed to determine FAI-related morphological measurements. Moreover, the surgical assessment was reviewed by one experienced surgeon to interpret whether subspine decompression was performed. The correlation of subspine decompression with AIIS variation and subspine hypertrophy was analyzed. RESULTS: Out of 70 patients with unilateral symptomatic FAI, 37 were males (52.9%) and 23 (32.9%) had symptoms involving the left hip. The mean age was 39.3 ± 10.4 years and the mean BMI was 24.3 ± 3.6. The distribution of AIIS variants in symptomatic hips did not differ significantly from that in asymptomatic hips (χ2 = 3.092, P = 0.213). Twenty-nine hips in the symptomatic group (41.4%) and 12 hips in the asymptomatic group (17.1%) were identified as positive for subspine hypertrophy. The incidence of positive subspine hypertrophy was significantly higher in the symptomatic hips compared to the asymptomatic hips (χ2 = 9.968, P = 0.002). FAI-related morphological parameters including α angle, lateral center-edge angle, acetabular anteversion, crossover sign, and Tonnis grade were highly symmetrical and did not show significant differences between symptomatic and asymptomatic hips. Fifty-four of 70 hips (77.1%) had labral tears extended to the acetabular rim corresponding to the AIIS. Forty-seven hips of 70 hips (67.1%) underwent subspine decompression, which was significantly correlated with AIIS variation and subspine hypertrophic deformity (P = 0.019 and 0.001, respectively). CONCLUSION: Subspine hypertrophic deformity was found to be more common in symptomatic side vs asymptomatic side in patients with unilateral symptomatic femoroacetabular impingement. Subspine hypertrophy may be considered as an underlying indication for subspine decompression besides low-lying AIIS.

[Current diagnosis and treatment of posterior shoulder instability].

The incidence of posterior instability of shoulder joint was significantly lower than that of anterior instability, but the clinical diagnosis and treatment was difficult, and the misdiagnosis and missed diagnosis rate were high. Its etiology, clinical manifestation and treatment strategy are totally different from the anterior instability. Therefore, the deep understanding of the anatomical structure around the shoulder joint, the mastery of the examination method, and the classification of the shoulder instability based on the anatomy and injury mode are of great importance to improve the accuracy of diagnosis. CT three-dimensional reconstruction is helpful to evaluate the defect of humeral head and glenoid bone, and MRA is helpful for the accurate diagnosis of posterior glenoid lip and joint capsule. The treatment was divided into conservative treatment and surgical treatment. Conservative treatment is recommended for muscular instability. Surgical treatment is recommended for traumatic and dysplastic instability. Different operative methods should be performed according to the injury of glenoid side or humeral head side. According to the condition of bone defect, soft tissue operation, bone grafting or osteotomy were performed to reconstruct the posterior stable structure of the glenoid injury; according to the area of the anterior bone defect, bone grafting or subscapular muscle packing were performed to the head of humerus defect. The former has the advantages of short learning curve and firm fixation, while the latter has the advantages of minimally invasive operation and the ability to observe the lesions from multiple angles and accurately control the location of bone masses. This paper summarizes the above problems.

Evaluating the effect of cooking temperature and time on collagen characteristics and the texture of hog maw.

This study evaluated the texture of hog maw and the degradation of Types I and III collagen in the intramuscular connective tissue (IMCT) of hog maw at different cooking temperatures (75-95°C) and times (50-130 min). The cooking loss, shear force, collagen content, collagen solubility, and IMCT strength of hog maw cooked in water baths were measured. The instrumental texture profile analysis showed that the brittleness, springiness, chewiness and hardness of the cooked hog maw significantly increased with the increase of cooking temperature, while the hardness, springiness and chewiness increased first and then decreased with increasing cooking time. Cooking loss exhibited a 38% increase between the raw meat and meat cooked at 95°C. The collagen solubility significantly increased from 5.5 mg/g for raw meat to 8.6 mg/g for meat cooked at 95°C, accompanied by decreases in the shear force and IMCT strength associated with the increase in cooking temperature and time. These results show that the texture and collagen characteristics of hog maw are dramatically affected by the cooking temperature and time. Sodium dodecyl sulfate electrophoresis and immunofluorescence staining further showed that collagen degradation occurred after cooking, and the degradation of Type I collagen was higher than that of Type III collagen. These results indicated that the degradation of Type I collagen was mainly responsible for the sensory and textural improvements of the cooked hog maw.

Arthroscopic Treatment for Femoroacetabular Impingement Syndrome with External Snapping Hip: A Comparison Study of Matched Case Series.

OBJECTIVE: To determine the effectiveness of hip arthroscopy combined with endoscopic iliotibial band (ITB) release in patients with both femoroacetabular impingement (FAI) syndrome and external snapping hip (ESH). METHODS: Retrospectively review the preoperative and minimum of 2-year follow-up data of patients with both FAI syndrome and ESH who underwent endoscopic ITB release during hip arthroscopy (FAI + ESH group) from January 2014 to December 2018. The same number of age- and gender-matched FAI syndrome patients without ESH undergoing hip arthroscopy were enrolled in the control group (FAI group). Patient-reported outcomes (PROs) including international Hip Outcome Tool (iHOT-33), modified Harris Hip Score (mHHS), visual analog scale for pain (VAS-pain), and abductive force of affected hip at 3 month and 2 years postoperatively were comparatively analyzed. The VAS-satisfaction score of two groups at 2 years postoperatively were also analyzed. RESULTS: The prevalence of ESH in FAI syndrome patients undergoing hip arthroscopy in our institution was 5.5% (39 of 715 hips), including nine males (10 hips) and 29 females (29 hips). The mean age at the time of surgery was 32.1 ± 6.9 years (range, 22-48 years). According to inclusion and exclusion criteria, 23 patients were enrolled in FAI + ITB group. Twenty-three age- and sex-matched FAI syndrome patients were enrolled in FAI group. At 24 months postoperatively, no patient still suffered ESH symptoms and painful palpation at lateral region in FAI + ITB group. The iHOT-33, mHHS, and VAS-pain score of patients in FAI + ESH group were significantly severer than patients in FAI group preoperatively (41.6 ± 7.5 vs 48.8 ± 7.2, 54.8 ± 7.2 vs 59.2 ± 6.9, 5.5 ± 0.9 vs 4.7 ± 1.0; P < 0.05), while there was no significant difference in these scores between the patients in FAI + ESH group and FAI group at 3-month and 24-month follow-up (73.6 ± 8.5 vs 76.1 ± 6.9, 85.3 ± 7.8 vs 84.2 ± 6.6, 0.8 ± 0.9 vs 0.6 ± 0.9; P > 0.05). At 3 months after surgery, the abductive force of operated hip was significantly smaller than that in FAI group (82.4 ± 12.4 N vs 91.9 ± 16.1 N, P < 0.05), whereas there was no significant difference at 24 months after surgery (101.6 ± 14.9 N vs 106.5 ± 13.7 N, P > 0.05). The VAS-satisfaction scores of patients in the two groups were at a similarly high level (90.5 ± 6.8 vs 88.8 ± 7.3, P > 0.05). There was no complication and no arthroscopic revision in either group until 2-year follow-up. CONCLUSION: Although abductive force recovery of the hip was delayed, hip arthroscopy combined with endoscopic ITB release addressed hip snapping in patients with both FAI syndrome and ESH, and could get similar functional improvement, pain relief, recovery speed, as well as patient satisfaction compared with the pure hip arthroscopy in FAI syndrome patients without ESH.

The Evaluation of Sagittal Pelvic-Femoral Kinematics in Patients with Cam-Type Femoracetabular Impingement.

OBJECTIVE: To investigate the sagittal hip-pelvic kinematics in symptomatic cam-type femoroacetabular impingement (FAI) patients in the process of sitting down and compare their difference between patients with sitting pain complaint and those without. METHODS: Twenty-nine symptomatic cam-type FAI patients were recruited from our clinic between May 2018 and October 2018. Patients were categorized into two groups depending on whether they complain of pain in prolonged sitting or not. The pelvic-femoral measurements were assessed with a set of lateral pelvic radiography in sitting and standing respectively. Pelvic incidence (PI), sacral slope (SS), and proximal femoral shaft angle (PFSA) were measured on lateral pelvic radiography, and then pelvic tilting, apparent hip flexion, true hip flexion, and the pelvic-femoral ratio were calculated to investigate the kinematic change from standing to sitting position. Demographic measurements, hip morphology measurements, functional measurements, visual analog scale (VAS), and pelvic-femoral measurements were compared between the two groups. RESULTS: Thirteen cases without sitting pain complaint and 16 cases with sitting pain complaint were stratified to Group N and Group P respectively. No was significant difference in age, body mass index (BMI), and gender between the two groups. Hip morphology measurements (α angle and lateral center-edge angle) and functional measurements (iHOT-12) showed no significant difference between the two groups. However, the mean VAS of pain while sitting was 0.5 ± 0.4 and 1.6 ± 0.6 in Group N and Group P respectively (P = 0.005). Patients with sitting pain complaint have increased pelvic PI compared to those without (50.1° ± 6.5° and 44.2° ± 7.6°, P = 0. 042). The changes in SS (pelvic tilting) from standing to sitting in Group N was significantly larger than that in Group P (21.8° ± 7.0° and 15.1° ± 6.5°, P = 0.012). Although no significant difference in apparent hip flexion and true hip flexion was found. Patients without sitting pain complaint demonstrated a higher pelvic-femoral ratio (22.8% ± 7.9% and 16.1% ± 7.5%, P = 0.010) compared to those with sitting pain complaint. CONCLUSION: Sagittal pelvic-femoral kinematics could have an influence on the symptomology of cam-type FAI. The small PI and insufficient sagittal pelvic tilting in the process of sitting down could be related to the complaint of sitting pain in patients with symptomatic cam-type FAI.

Core Decompression with Local Administration of Zoledronate and Enriched Bone Marrow Mononuclear Cells for Treatment of Non-Traumatic Osteonecrosis of Femoral Head.

OBJECTIVE: To investigate the efficacy and safety of core decompression (CD) with local administration of zoledronate and enriched bone marrow mononuclear cells (BMMCS) for the treatment of non-traumatic osteonecrosis of femoral head (ONFH). METHODS: A total of 17 patients (30 hips) diagnosed with stage II and III ONFH according to the 2019 revised Association for Research on Osseous Circulation (ARCO) staging criteria from 2012 to 2014 were retrospectively reviewed. The patients received the following therapy: the BMMCs and zoledronate were injected into the necrotic zone, respectively, along with CD. The mean age of the patients was 36.8 years; 14 were men and three were women. All patients included had non-traumatic ONFH and a minimum follow-up of 5 years, which ended when total hip arthroplasty (THA) was performed. Imaging modalities, including plain radiography, computed tomography (CT), and magnetic resonance imaging (MRI) were taken pre- and postoperatively. Harris hip score (HHS) was used to evaluate the functional outcomes of femoral head necrosis. Kaplan-Meier analysis was adopted to determine the probability of survivorship with THA as the end point in this series of patients. The correlation between radiological progression or THA and related risk factors were further analyzed. All complications were recorded. RESULTS: With THA as the follow-up endpoint, All patients were followed up for an average of 69.1 ± 20.5 months (range, 18-95 months). Preoperative imaging found six hips (20%) at ARCO stage II, 14 hips (46.7%) at stage IIIA, 10 hips (33.3%) at stage IIIB. Fourteen hips (46.7%) shown progression radiologically, while six hips (20%) underwent TKA among these patients with hip preservation. The cumulative survival was 80% (95% CI, 0.608-905) at 5 years with THA as the end point. HHS improved from 63.3 ± 8.7 preoperatively to 74.6 ± 20.6 postoperatively (P = 0.000). Radiological progression was found to be associated with ARCO stage, Japanese Investigation Committee (JIC) type, and corticosteroid exposure (P = 0.047; P = 0.012; P = 0.031). However, no correlation was found between conversion to THA and the known risk factors. No major complication was reported, with only four patients complaining about general weakness and muscle soreness, and all disappeared within 2-3 days. CONCLUSIONS: The novel treatment modality could relieve pain, delay the progression of collapse, which might be an effective and safe method for hip preservation of early and mid-term ONFH. However, the effect of this method may be related to ARCO stage, JIC type, and corticosteroid exposure.

Evaluation of the effect of smooth muscle cells on the quality of cultured meat in a model for cultured meat.

While the research on improving the meat quality of cultured meat is in full swing, few studies have focused on the effect of smooth muscle cells (SMCs) on the meat quality of cultured meat. Therefore, this study aimed at building a cultured meat model containing smooth muscle cells, and further evaluating the effect of smooth muscle cells on the quality of cultured meat, so as to reveal the contribution of smooth muscle cells in the production of cultured meat. In this study, we isolated high purity of smooth muscle cells from vascular tissues. The addition of basic fibroblast growth factor (bFGF) to the medium significantly increased the growth rate of smooth muscle cells and the expression of extracellular matrix related genes, especially collagen and elastin. Smooth muscle cells were seeded in a collagen gel to construct a culture meat model. It was found that the pressure loss of the model meat significantly decreased from 98.5 % in control group to 54 % with the extension of culture time for 9 days, while the total collagen content of model meat increased significantly (P < 0.05). In addition, the hydrogel tissue with smooth muscle cells compacted more dramatically and were more tightly, accompanied by significantly increased hardness, springiness and chewiness compared to the control one (P < 0.05). These results indicate that smooth muscle cells can secrete extracellular matrix proteins such as collagen, which can significantly enhance the texture of cultured meat models prepared by hydrogel.

[Case-control study on remnant-preserving strategy for preservation and reconstruction of anterior cruciate ligament].

OBJECTIVE: To investigate and compare the clinical efficacies of remnant-preserving and remnant-non-preserving, remnant-non-preserving remnant segment preserving and remnant root preserving with anterior cruciate ligament reconstruction. METHODS: From March 2014 to December 2017, 204 patients with anterior cruciate ligament (ACL) injuries were treated by single-bundle ACL reconstruction with hamstring tendon autograft. According to the different methods of remnant preservation, the procedures were divided into remnant segment preserving group (A), remnant root preserving group (B), and remnant-non-preserving group (C). There were 37 males and 39 femalesin group A aged from 16 to 43 years old with an average of (28.80±5.41) years old. The time from injury to operation ranged from 2 to 11 weeks with an average of (3.68±1.04) weeks. In group B, there were 39 males and 25 females aged from 18 to 41 years old with an average of (28.42±5.60) years old. The time from injury to operation ranged from 2 to 10 weeks with an average of (3.36±1.68) weeks. In group C, there were 37 males and 27 females aged from 18 to 43 years old with an average of (29.10±6.11) years old. The time from injury to operation ranged from 3 to 11 weeks with an average of (3.54±1.46) weeks. The range of motion (ROM) of the knee was used to assess the range of extension and flextion of the knee at pre-operation and 24 months after operation. Lysholm score and the international knee documentation committee (IKDC) score were used to assess the knee function. The differences among three procedures were judged by comparing among the three groups at 6, 12 and 24 months postoperatively. RESULTS: All incisions got a one stage healing, and no complications, such as vascular injury, nerve damage and articular infect or the like, occurred. All the patients were followed up, and the follow-up duration of group A ranged from 24.00 to 45.96 months with a mean of (35.52±14.40) months;the follow up duration of group B ranged from 27.96 to 48.00 months with a mean of (37.56±10.68) month;and the follow up duration of group C ranged from 24.00 to 66.00 months with a mean of (37.08±13.44) month. There were no significant differences in follow up time among three groups (P>0.05). Six months after operation, Lysholm score 80.74±3.14 and IKDC score 79.92±3.44 in group A were higher than those in group B 80.74±3.14 and 78.21±4.63, and higher than those in group C 79.22±3.63 and 76.63±3.80 (P<0.05);12 months after operation, Lysholm score 89.84± 5.13 and IKDC score 87.90±3.93 in group A were higher than those in group B 85.74±6.04 and 83.62±5.64, and higher than those in group C 82.83±3.43 and 79.21±4.04(P<0.05). CONCLUSION: Compared with remnant-non-preserving group, the residual tissue of anterior cruciate ligament is preserved, which is conducive to promote the healing and remodeling of tendon graft and accelerate the recovery of joint function. Proper fixation of residual tissue and restoration of its tension are the key factors affecting the postoperative efficacy.

The Application of Arthroscopic Techniques in the Diagnosis and Treatment of Hip-Related Conditions in China.

The hip joint is the largest weight-bearing joint in the body and is surrounded by dense capsules and thick muscles. Hip arthroscopic techniques are suitable for the treatment of hip-related conditions. These minimally invasive techniques have rapidly developed in China since 2007. Moreover, they have been used in the treatment of gluteal muscle contracture, snapping hip syndrome, femoral acetabular impingement, acetabular labral injury, hip labral calcification, synovial chondroma, osteoid osteoma, synovitis, osteonecrosis of the femoral head, and developmental dysplasia of the hip. This technique has showed its advantage in the total debridement of lesions, precision treatment, and less trauma. However, we lack understanding of the overall development of arthroscopic techniques in China. This review illustrates the recent development of hip arthroscopic techniques in China and related research progress.

Clinical Outcomes of Hip Arthroscopy for Hip Labrum Calcification in Young and Middle-Aged Patients.

OBJECTIVE: To investigate the methods and outcomes of hip arthroscopy for hip labrum calcification, and to discuss the clinical, imaging, and intraoperative findings of hip labrum calcification. METHODS: This is a therapeutic case series study. From January 2015 to June 2018, 15 patients who met the inclusion and exclusion criteria were followed up for at least 2 years for an analysis on the outcomes of arthroscopy in the treatment of hip labrum calcification and the clinical, imaging, and intraoperative findings of the patients. There were eight males and seven females, with an average age of 38.9 ± 8.8 years (range, 23-50 years). The visual analog scale (VAS), the modified Harris hip score (mHSS), and the international hip outcome tool (iHOT-12) were used to evaluate the outcomes of surgery. RESULTS: A total of 15 patients were followed up for at least 2 years (28.1 ± 2.9 months). The average calcified volume was 118.0 mm3 (range, 19.4-609.2 mm3 ) and calcified volume was related to the preoperative hip function score. Thirteen patients had pain in the groin area (86.7%). Labrum calcifications were located (according to the clock distribution) as follows: 14 patients were anterior and superior (11:00-3:00); 12 cases of femoroacetabular impingement (FAI) were observed during operation, including five cases of pincer type, two cases of cam type, and five cases of mixed type. VAS pain score means were 7.73 ± 1.28 before surgery, decreasing to 2.0 ± 0.89 and 1.73 ± 0.79 at 1 and 2 years post-surgery, respectively. mHSS scores were 57.40 ± 6.23 before surgery and 82.10 ± 4.76 and 83.18 ± 4.07, 1 and 2 years post-surgery, respectively; iHOT-12 mean score pre-surgery was 37.67 ± 4.85, increasing to 67.64 ± 5.30 and 72.18 ± 4.49, 1 and 2 years post-surgery, respectively. Compared with preoperative values, postoperative VAS, mHSS, and iHOT-12 scores were significantly improved (P < 0.01); iHOT-12 scores also significantly decreased from 1 to 2 years postoperatively (P = 0.034). No patient had complications. CONCLUSION: Hip arthroscopy is an effective method for the treatment of hip labrum calcification. The size of calcification influenced preoperative symptoms and function. Long-term irritation from FAI may be one important cause of labrum calcification.

[Classification and arthroscopic surgery of chronic achilles tendinitis].

OBJECTIVE: To investigate the clinical classification of chronic achilles tendinitis and analyze the surgical technique and efficacy of arthroscopic surgery. METHODS: Twenty-two patients (16 males, 6 females) with chronic achilles tendinitis were recruited. The average age was 33.5 years old (range: 17 - 53). Sixteen cases were caused by sport injury while 6 cases had no definite etiological factor. The Achilles tendinopathy was divided into three types according to clinical characteristics and the results of X ray, CT scan and MRI examination of ankle: Type 1, hypertrophy (n = 10); Type 2, calcified tubercle (n = 5); Type 3, fiber tear (n = 7). All cases were treated with endoscopic debridement of ventral neovascularized area, peritendineum and Achilles tendon by shaver and radiofrequency (RF) probe. RESULTS: The patients were followed-up for a mean of 14 months (range: 9 - 15). Evaluated by our criteria and visual analogue scale, the post-operative efficacy was excellent in 12 cases, good in 8 and fair in 2. No postoperative complications, such as neurovascular injury, infection and rupture of Achilles tendon, was recorded. CONCLUSION: This scheme of classifying is helpful to the diagnosis and effective treatment of chronic Achilles tendonitis. With a high safety and a satisfactory efficacy, arthroscopic surgery has the advantages of minimally invasiveness.

[Modified arthroscopic anterior approach for the treatment of shoulder Bankart lesion].

OBJECTIVE: To explore the effects of single anterior approach under shoulder arthroscopy in the treatment of Bankart injury, and to provide a scheme to overcome the difficulties and simplify the operation process. METHODS: From July 2016 to January 2019, 62 patients with recurrent dislocation caused by Bankart leision were treated under shoulder arthroscopy, including 50 males and 12 females, ranging in age from 19 to 44 years old with an average age of (26.5±6.1) years old. There were 25 cases of left shoulder and 37 cases of right shoulder. The patients were divided into two groups according to the operation mode, 35 patients in the front modified single approach group (experimental group) and 27 patients in the traditional double approachgroup (control group). The results of the operation were evaluated by assessing the preoperative and postoperative ASES scores of the shoulder joint, and the time of the approach establishment and the overall operation process was recorded to evaluate whether the operation time of the experimental group was shortened. RESULTS: Three patients were lost during the follow-up after operation, and except for one case of re-dislocation, all patients achieved satisfactory results without neurovascular injury and other complications. The patients were followed up before operation and 3, 6, 12 months after operation, and the ASES scores were significantly enhanced at the latest follow-up compared with those of before operation. The time of establishing surgical approach in the experimental group was (7.5±1.5) minutes, which was shorter than that of control group (13.7±1.2) minutes. CONCLUSION: The improved technique of single-channel anterior approach has the advantages of reducing the surgical incision and shortening the operationtime while ensuring the quality of the operation, which is worthy of popularization and application.