Can the Acetabular Labrum Be Reconstructed With a Meniscal Allograft? An In Vivo Pig Model.

BACKGROUND: No single graft type has been shown to have a benefit in acetabular labral reconstruction. The native labrum and lateral meniscus share many similarities, suggesting that the meniscus may be a promising source of graft material in labral reconstruction. QUESTIONS/PURPOSES: Using a pig model, we sought to evaluate the healing process of fresh-frozen meniscus allograft for acetabular reconstruction by assessing (1) MRI and macroscopic observations of the meniscus allograft; (2) histologic appearance and immunohistologic evaluation of the meniscus allograft, native meniscus, and labrum; (3) microscopic assessment of the native labrum and meniscus via scanning electron microscopy; and (4) biomechanical assessment of tensile properties. METHODS: Twelve skeletally mature male miniature Bama pigs (24 hips) were randomly divided into two groups: labral defect group (control) and lateral meniscus allograft group. The selection of Bama pig specimens was based on the similarity of their acetabular labrum to that of the human acetabular labrum, characterized by the presence of fibrocartilage-like tissue lacking blood vessels. The pigs underwent bilateral hip surgery. Briefly, a 1.5-cm-long section was resected in the anterior dorsal labrum, which was left untreated or reconstructed using an allogeneic lateral meniscus. The pigs were euthanized at 12 and 24 weeks postoperatively, and then evaluated by macroscopic observations and MRI measurement to assess the extent of coverage of the labral defect. We also performed a histologic analysis and immunohistologic evaluation to assess the composition and structure of meniscus allograft, native labrum, and meniscus, as well as scanning electron microscopy assessment of the microstructure of the native labrum and meniscus and biomechanical assessment of tensile properties. RESULTS: Imaging measurement and macroscopic observations revealed that the resected area of the labrum was fully filled in the lateral meniscus allograft group, whereas in the control group, the labral defect remained at 24 weeks. The macroscopic scores of the meniscus allograft group (8.2 ± 0.8) were higher than those of the control groups (4.8 ± 1.0) (mean difference 3.3 [95% CI 1.6 to 5.0]; p < 0.001). Moreover, in the meniscus allograft group, histologic assessment identified fibrocartilage-like cell cluster formation at the interface between the graft and acetabulum; cells and fibers arranged perpendicularly to the acetabulum and tideline structure that were similar to those of native labrum could be observed at 24 weeks. Immunohistochemical results showed that the average optical density value of Type II collagen at the graft-acetabulum interface was increased in the meniscus allograft group at 24 weeks compared with at 12 weeks (0.259 ± 0.031 versus 0.228 ± 0.023, mean difference 0.032 [95% CI 0.003 to 0.061]; p = 0.013). Furthermore, the tensile modulus of the lateral meniscus allograft was near that of the native labrum at 24 weeks (54.7 ± 9.9 MPa versus 63.2 ± 11.3 MPa, mean difference -8.4 MPa [95% CI -38.3 to 21.4]; p = 0.212). CONCLUSION: In a pig model, lateral meniscus allografts fully filled labral defects in labral reconstruction. Regeneration of a fibrocartilage transition zone at the graft-acetabulum interface was observed at 24 weeks. CLINICAL RELEVANCE: The use of an autograft meniscus for labral reconstruction may be a viable option when labral tears are deemed irreparable. Before its clinical implementation, it is imperative to conduct a comparative study involving tendon grafts, which are extensively used in current clinical practice.

Additional suture augmentation to anterior cruciate ligament reconstruction with hamstring autografts bring no benefits to clinical results, graft maturation and graft-bone interface healing.

BACKGROUND: From the perspective of graft protection and early rehabilitation during the maturation and remodeling phases of graft healing, suture augmentation (SA) for anterior cruciate ligament reconstruction (ACLR) has attracted more and more attention. STUDY DESIGN: Retrospective study. PURPOSE: To determine whether the additional SA affects clinical results, graft maturation and graft-bone interface healing during two years follow-up after ACLR. METHODS: 20 ACLRs with additional SA (ACLR-SA group) and 20 ACLRs without additional SA (ACLR group) were performed between January 2020 and December 2021 by the same surgeon and were retrospectively analyzed. Pre- and postoperative International Knee Documentation Committee (IKDC) scores, Lysholm scores, graft failure and reoperation were evaluated. The signal/noise quotient (SNQ) of autografts and the signal intensity of graft-bone interface were analyzed. All 40 patients in ACLR-SA group and ACLR group completed 2-years follow-up. RESULTS: There was no patient in the two cohorts experienced graft failure and reoperation. The postoperative IKDC and Lysholm scores have been significantly improved compared with preoperative scored in both ACLR-SA group and ACLR group, however, there was no significant difference between two groups. The SNQ of proximal graft of ACLR-SA group (14.78 ± 8.62 vs. 8.1 ± 5.5, p = 0.041) was significantly greater while the grades of graft-bone interface healing of posterior tibial was significantly lower than that of ACLR group at 1-year postoperatively (p = 0.03), respectively. There were no significant differences between the two groups of the SNQ of proximal, distal medial graft segments, and the graft-bone interface healing grades of anterior femoral, posterior femoral, anterior tibial and posterior tibial at other time points (p>0.05). CONCLUSIONS: The additional SA in ACLR had no effect on IKDC scores, Lysholm scores, graft maturation and graft-bone interface healing at 2-year postoperatively. Our research does not support the routine use of SA in ACLR.

Three-Dimensional Printed Silk Fibroin/Hyaluronic Acid Scaffold with Functionalized Modification Results in Excellent Mechanical Strength and Efficient Endogenous Cell Recruitment for Articular Cartilage Regeneration.

Treatment of articular cartilage remains a great challenge due to its limited self-repair capability. In tissue engineering, a scaffold with both mechanical strength and regenerative capacity has been highly desired. This study developed a double-network scaffold based on natural biomaterials of silk fibroin (SF) and methacrylated hyaluronic acid (MAHA) using three-dimensional (3D) printing technology. Structural and mechanical characteristics of the scaffold was first investigated. To enhance its ability of recruiting endogenous bone marrow mesenchymal stem cells (BMSCs), the scaffold was conjugated with a proven BMSC-specific-affinity peptide E7, and its biocompatibility and capacity of cell recruitment were assessed in vitro. Animal experiments were conducted to evaluate cartilage regeneration after transplantation of the described scaffolds. The SF/HA scaffolds exhibited a hierarchical macro-microporous structure with ideal mechanical properties, and offered a 3D spatial microenvironment for cell migration and proliferation. In vitro experiments demonstrated excellent biocompatibility of the scaffolds to support BMSCs proliferation, differentiation, and extracellular matrix production. In vivo, superior capacity of cartilage regeneration was displayed by the SF/MAHA + E7 scaffold as compared with microfracture and unconjugated SF/MAHA scaffold based on macroscopic, histologic and imaging evaluation. In conclusion, this structurally and functionally optimized SF/MAHA + E7 scaffold may provide a promising approach to repair articular cartilage lesions in situ.

[Comparison of the early analgesic efficacy of three different drugs after anterior cruciate ligament reconstruction].

OBJECTIVE: The pain-relieving effect and safety of compound aminopyrine phenacetin tablets, tramcontin (tramadol hydrochloride sustained-release tablets) and dolantin in the early stage of autologous tendon reconstruction of the anterior cruciate ligament (ACL) of the knee joint were compared. METHODS: Retrospective analysis of postoperative pain and drug analgesia in 45 patients performed by the same group from November 2018 to February 2019. The random area group design was divided into two groups according to whether ACL rupture was combined with meniscal injury, group A was 24 patients with ACL reconstruction of knee joint and group B was 21 patients with ACL fracture combined with meniscus injury. The two groups were divided into three subgroups respectively according to the actual treatment of postoperative analgesic drugs received by the patients, including 4 cases of compound aminopyrine phenacetin tablets, 11 cases of oral tramcontin, 9 cases of intramuscular dolantin combined with phenergan in group A; 3 cases of compound aminopyrine phenacetin tablets, 10 cases of oral tramcontin, and 8 cases of intramuscular dolantin combined with phenergan in group B. When the early postoperative patients complain about pain and actively ask for analgesia. When the patients complained about pain after the operation and actively asked for analgesia, they were randomly given painkillers, tramcontin or dolantin combined with phenergan to relieve pain. Pain visual analogue scale (VAS) was used to evaluate pain relief and observe the occurrence of adverse reactions. RESULTS: There were no significant dif-ferences in gender, age, body mass index, and time of hospital stay between the two groups of patients (P > 0.05). In the patients who used tramcontin and dolantin combined with phenergan to relieve pain judging by VAS score before and 1 h after taking the drug, it was found that the pain situation of the patient was significantly relieved, and the difference before and after taking the drug had statistical significance (P < 0.05). Pairwise comparisons of the three drugs applied in the two groups showed significantly greater pain relief in the dolantin combined with phenergan group than in the remaining two drugs. There was no significant difference (P > 0.05). Dolantin was prone to nausea and vomiting, but the application of phenergan was also used to reduce side effects. In terms of adverse reactions, only 1 case of nausea occurred in the tramcontin group for simple ACL reconstruction, and none of the patients in the other groups showed serious complications and allergic reactions. CONCLUSION: Whether in cruciate ligament reconstruction alone or combined with meniscus molding or suture, compound aminopyrine phenacetin tablets, tramcontin, dolantin combined with phenergan can effectively relieve pain. Among the three drugs, dolantin caused the largest pain relief. At the same time, the combination of phenergan effectively reduced the adverse reactions, such as vomiting and nausea, and increased the drug safety.

[Biomechanics during cutting movement in individuals after anterior cruciate ligament reconstruction].

OBJECTIVE: To evaluate knee biomechanics of patients about 12 months after anterior cruciate ligament (ACL) reconstruction during cutting and determine the abnormal biomechanical characteristics. METHODS: Sixteen males about 12 months after ACL reconstruction were recruited for this study. Three-dimensional kinematic and kinetic data were collected during cutting movement. Knee joint angles and moments were calculated. Paired t-tests were used to compare the differences in knee biomechanics between the surgical leg and nonsurgical leg. RESULTS: The peak posterior ground reaction force (surgical leg: 0.380±0.071; nonsurgical leg: 0.427±0.069, P = 0.003) and vertical ground reaction force (surgical leg: 1.996±0.202, nonsurgical leg: 2.110±0.182, P = 0.001) were significantly smaller in the surgical leg than in the nonsurgical leg. When compared with the uninjured leg, the surgical leg demonstrated a smaller knee flexion angle (surgical leg: 38.3°± 7.4°; nonsurgical leg: 42.8°± 7.9°, P < 0.001) and larger external rotation angle (surgical leg: 10.3°± 2.4°; nonsurgical leg: 7.7°± 2.1°, P = 0.008). The surgical leg also demonstrated a smaller peak knee extension moment (surgical leg: 0.092 ± 0.031; nonsurgical leg: 0.133 ± 0.024, P < 0.001) and peak knee external rotation moment (surgical leg: 0.005 ± 0.004; nonsurgical leg: 0.008 ± 0.004, P = 0.015) when compared with the nonsurgical leg. CONCLUSION: The individuals with ACL reconstruction mainly showed asymmetrical movements in the sagittal and horizontal planes. The surgical leg demonstrated a smaller peak knee flexion angle, knee extension moment, and knee external rotation moment, with greater knee external rotation angle.

Comparison between primary repair and augmented repair with gastrocnemius turn-down flap for acute Achilles tendon rupture: a retrospective study with minimum 2-year follow-up.

BACKGROUND: To explore and compare the clinical outcomes in patients undergoing primary repair versus augmented repair with a gastrocnemius turn-down flap for acute Achilles tendon rupture. METHODS: From 2012 to 2018, the clinical data of 113 patients with acute Achilles tendon rupture who were treated with primary repair or augmented repair with a gastrocnemius turn-down flap by the same surgeon were retrospectively reviewed. The patients' preoperative and postoperative scores on the visual analog scale (VAS), American Orthopaedic Foot and Ankle Society Ankle⁃Hindfoot (AOFAS) score, the Victorian Institute of Sport Assessment⁃Achilles (VISA-A), the Achilles tendon total rupture score (ATRS), and the Tegner Activity Scale were examined and compared. The postoperative calf circumference was measured. A Biodex isokinetic dynamometer was used to evaluate the plantarflexion strength on both sides. The time to return to life and exercise as well as the strength deficits in both groups were recorded. Finally, the correlation analyses between patient characteristics and treatment details with clinical outcomes were conducted. RESULTS: In total, 68 patients were included and completed the follow-up. The 42 and 26 patients who were treated with primary repair and augmented repair were assigned to group A and B, respectively. No serious postoperative complications were reported. No significant between-group differences in any outcomes were observed. It was found that female sex was correlated with poorer VISA-A score (P = 0.009), complete seal of paratenon was correlated with higher AOFAS score (P = 0.031), and short leg cast was correlated with higher ATRS score (P = 0.006). CONCLUSIONS: Augmented repair with a gastrocnemius turn-down flap provided no advantage over primary repair for the treatment of acute Achilles tendon rupture. After surgical treatment, females tended to had poorer outcomes, while complete seal of paratenon and short leg cast contributed to better results. LEVEL OF EVIDENCE: Cohort study; Level of evidence, 3.

Balance training benefits chronic ankle instability with generalized joint hypermobility: a prospective cohort study.

BACKGROUND: Balance training is the first choice of treatment for chronic ankle instability (CAI). However, there is a lack of research on the effects of balance training in CAI with generalized joint hypermobility (GJH). This study is to compare the outcomes of balance training in CAI patients with and without GJH. METHODS: Forty CAI patients were assigned into the GJH group (Beighton ≥ 4, 20) and non-GJH group (Beighton < 4, 20) and they received same 3-month supervised balance training. Repeated measure ANOVA and independent t test were used to analyze self-reported questionnaires (Foot and ankle ability measure, FAAM), the number of patients experiencing ankle sprain, isokinetic muscle strength and postural control tests (Star excursion balance test, SEBT and Balance errors system, BES) before training, post-training immediately, and post-training 3 months, respectively. RESULTS: At baseline, no differences were found between groups with except for GJH group having poorer SEBT in the posteromedial direction (83.6 ± 10.1 vs 92.8 ± 12.3, %) and in the posterolateral direction (84.7 ± 11.7 vs 95.7 ± 8.7, %). Following the balance training, GJH group demonstrated lower re-sprain ratio (immediately after training, 11.1% vs 23.5%, 3 month after training, 16.7% vs 29.4%) than non-GJH group, as well as greater FAAM-S score, plantarflexion strength and dorsiflexion strength at post-training immediately and 3 months, and both groups improved similarly in the FAAM-A score, muscle strength and balance control (SEBT in the posterior-lateral and posterior-medial directions, and BES scores) compared with baseline. CONCLUSIONS: CAI patients with GJH gained equally even better postural stability and muscle strength after the balance training than the non-GJH patients. Balance training could still be an effective treatment for CAI patients with GJH before considering surgery. TRIAL REGISTRATION: ChiCTR1900023999, June 21st, 2019.

Arthroscopic Anatomical Double-Bundle Medial Patellofemoral Complex Reconstruction Improves Clinical Outcomes in Treating Recurrent Patellar Dislocation Despite Trochlear Dysplasia, Elevated Tibial Tubercle-Trochlear Groove Distance, and Patellar Alta.

PURPOSE: To evaluate the clinical outcomes of arthroscopically assisted double-bundle medial patellofemoral complex reconstruction (MPFC-R). METHODS: A retrospective review was carried out among adult patients who experienced at least 2 patellar dislocations and underwent primary arthroscopically assisted MPFC-R between January 2014 and November 2019. Dejour classification, tibial tubercle-trochlear groove (TT-TG) distance, and patellar height (with Insall-Salvati index) were measured. Pre- and postoperative patellar tilt were compared. Information on outcome scores, ability to return to sports, postoperative recurrent dislocations, and complications was recorded. RESULTS: A total of 42 MPFC-Rs in 39 patients were included. Mean age at surgery was 22.2 ± 7.6 years; 69.2% of patients were female. Mean follow-up was 47.3 ± 20.2 months. Seventy-four percent of cases had Dejour B (19.0%), C (33.3%), and D (21.4%) trochlear dysplasia; mean TT-TG distance was 19.6 ± 3.5 mm, and mean Insall-Salvati index was 1.21 ± 0.17. Mean patellar tilt decreased from 27.6 ± 11.6° to 9.4 ± 6.5° (P < .001). All patients had statistically significant (P < .001) improvement in mean International Knee Documentation Committee (IKDC) (44.9 ± 18.2 to 87.5 ± 6.9), Lysholm (61.4 ± 16.6 to 94.1 ± 6.4), Kujala (56.0 ± 16.8 to 92.9 ± 5.3), and Tegner score (2.7 ± 1.3 to 4.6 ± 1.4). The majority of patients (96.9%) returned to sports, with 90.3% returning to the same or greater level of activity. No postoperative dislocations or subluxations were reported. CONCLUSIONS: Arthroscopically assisted double-bundle MPFC-R is a promising procedure to treat recurrent patellar instability at 2- to 7-year mid-term follow-up, despite the presence of trochlear dysplasia, elevated TT-TG distance and patellar alta. The improvement of IKDC score exceeded the minimal clinically important difference in 95.2% patients, and 66.7% surpassed the patient acceptable symptomatic state based on postoperative IKDC score with no redislocations being reported at latest follow-up. LEVEL OF EVIDENCE: Level IV, case series, retrospective.

Efficacy of Platelet-Rich Plasma Versus Placebo in the Treatment of Tendinopathy: A Meta-analysis of Randomized Controlled Trials.

OBJECTIVE: To evaluate the efficacy of platelet-rich plasma (PRP) injections versus placebo in the treatment of tendinopathy. DATA SOURCES: We performed a systematic literature search in MEDLINE, Embase, Scopus, CINAHL, Cochrane Library, and ClinicalTrials.gov through November 2020 to identify randomized controlled trials (RCTs) that evaluated the clinical efficacy of PRP versus placebo for the treatment of tendinopathy. Outcomes were analyzed on an intention-to-treat basis with random-effects models. MAIN RESULTS: A total of 13 RCTs were included in this meta-analysis. The pooled analysis showed no significant difference in pain relief at 4 to 6 weeks (standard mean difference [SMD]: -0.18, 95% confidence intervals [CI]: -0.62 to 0.26), 12 weeks (SMD: -0.14, 95% CI: -0.55 to 0.26), and ≥24 weeks (SMD: -0.56, 95% CI: -1.16 to 0.05) or function improvement at 4 to 6 weeks (SMD: 0.11, 95% CI: -0.13 to 0.35), 12 weeks (SMD: 0.18, 95% CI: -0.13 to 0.49), and ≥24 weeks (SMD: 0.26, 95% CI: -0.14 to 0.66) for PRP compared with placebo in the treatment of tendinopathy. The sensitivity analysis indicated no significant difference in pain relief or function improvement at 12 weeks between PRP and placebo for different types of tendinopathies, treatment regimens, leukocyte concentrations, or cointerventions. CONCLUSIONS: Platelet-rich plasma injection was not found to be superior to placebo in the treatment of tendinopathy, as measured by pain relief and functional improvement at 4 to 6, 12, and ≥24 weeks.

The apex of the deep cartilage is a stable landmark to evaluate the femoral tunnel position in ACL reconstruction.

PURPOSE: To develop a simple and effective method for evaluating the femoral tunnel position using the apex of the deep cartilage (ADC) as the landmark. METHODS: A total of 52 patients who underwent arthroscopic ACL reconstruction were recruited between June and September 2021. The femoral tunnel was placed on the central point of the anteromedial footprint with an accessory anteromedial and a high anterolateral portal. Then, the length from the ADC to the shallow cartilage margin (L1) and to the center of the femoral tunnel (l1), as well as the center to the low cartilage margin (H1, intraoperative height), was measured under arthroscopy and on postoperative CT scans (L2, l2 and H2). Moreover, intraoperative and postoperative cartilage ratios were equivalent to l1/L1 and l2/L2, respectively. Linear regression, Pearson correlation and Bland-Altman analysis were performed to evaluate the consistency between these two measurements of cartilage ratio (l/L) and height (H). RESULTS: The mean age at the time of surgery was 28.7 years; 42 patients were male, and 17 patients were hurt in the left knee among 52 patients. The intraoperative cartilage ratio was 0.37 ± 0.04, and the height was 8.1 ± 1.1 mm with almost perfect inter-observer reproducibility. After the surgery, the cartilage ratio and height were measured as 0.39 ± 0.04 and 8.2 ± 1.3 mm on 3D-CT, respectively, with almost perfect intra- and inter-observer reproducibility. Significant positive correlations and linear regression were detected in the cartilage ratio (r = 0.844, p < 0.001), and height (r = 0.926, p < 0.001) intraoperatively and postoperatively. The Bland-Altman plot also showed excellent consistency between arthroscopy and 3D-CT. CONCLUSIONS: The ADC is a good landmark in the assessment of femoral tunnel position, with excellent consistency between intraoperative arthroscopic measurements and postoperative 3D-CT. CLINICALTRIALS: gov Identifier: NCT04937517. LEVEL OF EVIDENCE: Level III.

Comparison and analysis of skiing injuries at ski resorts in Chongli, China and Japan.

PURPOSE: The rapid development of winter sports requires investigation on injuries in Chongli district, Zhangjiakou city, one of the ski sites of the 2022 Winter Olympics. Careful evaluation is required to observe which injuries are caused under what circumstances, and then we can make corresponding preventive measures and recommendations based on the results. METHODS: In this retrospective study, the data of injury cases at ski resorts in China (Chongli district) and Japan were analyzed to provide a reference for the ongoing injury prevention at ski resorts. We collected data on injuries at Wanlong and Fulong ski resorts in Chongli district during the 2017-2018 and 2018-2019 ski seasons. We referred to the skiing injury report issued in February 2020 of a nationwide ski safety statistical service - Japan Ski Safety Association. The causes of injury and specific injured body parts were analyzed based on the data of Chinese and Japanese ski resorts. Statistical significance has been calculated using the Chi-square test. RESULTS: During the 2019-2020 ski season in Japanese ski resorts, the number of reported injuries per 10,000 skiers was 0.93, of which 457 (17.3%) were over 50 years old, accounting for a large proportion of injuries, meanwhile in Chongli ski resort, the injury rate of skiers aged 50 and over was 7.1%. The knee joint (23.7% at Wanlong ski resort and 28.4% in Japanese ski resorts) was the most injured body part among Chongli and Japanese skiers. Among snowboarders, shoulder joint injury (17.7% in Japanese ski resorts) was the most common, and injury on hands and fingers (16.3% in Wanlong ski resorts) was the most common. Head injury rates are similar in Chongli, China and Japanese ski resorts (8.2% and 8.7%, respectively). CONCLUSION: Our analysis demonstrated that injury data recorded among young skiers was higher in Chinese ski resorts (Chongli district) than that in Japanese ski resorts, and elderly skiers made up a larger proportion of skiing injuries in Japanese resorts. Thus, according to our research, the protection of knee joints, shoulder joints, and hands and fingers should be taken seriously. It should pay attention to the teaching of ski poles (for finger protection), and use protective devices such as knee pads, helmets, etc.

3D-printed regenerative polycaprolactone/silk fibroin osteogenic and chondrogenic implant for treatment of hip dysplasia.

Hip dysplasia is a developmental disorder that resulted in insufficient acetabular coverage. Current surgical treatments are technically demanding, complex, invasive, and often lead to associated complications. Therefore, the development of regenerative implants that fit to the bone and induce osteogenesis and chondrogenesis is in high demand. In this study, an implant was developed in which the osteogenic part was 3D printed using polycaprolactone (PCL), crosslinked with dopamine, and subjected to surface mineralization; while the chondrogenic part was prepared using silk fibroin (SF) and bone morphogenetic protein 2. Physical and chemical characterization of the implant was conducted using energy dispersive spectrometry (EDS) and scanning electron microscopy (SEM). The viability of rabbit adipose-derived mesenchymal stem cell (ADSCs) was evaluated by LIVE/DEAD staining and alamarBlue. SEM showed crosslinked polydopamine and crystals produced by mineralization on the surface of the implant, while EDS revealed the deposition of calcium and phosphorus on its surface. LIVE/DEAD staining and alamarBlue assay demonstrated that both the PCL and SF parts exhibit good biocompatibility. An in vivo hip dysplasia model was established in rabbits using a bone rongeur to make acetabular defects. Macroscopic observation, histological analysis, postoperative imaging, and biomechanical analysis of this model demonstrated the osteogenic and chondrogenic effects of the implant, and revealed that it provided good coverage of the femoral head, restoring the anatomical morphology of the acetabulum. Thus, this novel regenerative and cytocompatible implant provides a potentially viable strategy for the treatment of hip dysplasia.

Inhibition of LDL receptor-related protein 3 suppresses chondrogenesis of stem cells, inhibits proliferation, and promotes apoptosis.

Articular cartilage defects remain the most common and challenging joint disease. Cartilage lacks the self-healing capacity after injury due to its avascularity. Recently, stem cell-based therapy has been applied for cartilage regeneration. However, the critical target for stem cells during chondrogenesis remains unclear. We first reported that LDL receptor-related protein 3 (LRP3) expression was markedly increased during chondrogenesis in stem cells. Furthermore, LRP3 was an effective chondrogenic stimulator, as confirmed by knockdown and overexpression experiments and RNA sequencing. In addition, inhibition of LRP3 suppressed proliferation and induced apoptosis. Therefore, our study first defined a new chondrogenic stimulator, LRP3, with detailed clarification, which provided a novel target for stem cell-based cartilage regeneration.

High prevalence of acetabular rim osteophytes after hip arthroscopy for treatment of FAI.

BACKGROUND: Few studies mentioned acetabular rim osteophytes (ARO) after arthroscopy for femoroacetabular impingement (FAI) in follow-up after primary hip arthroscopy. We found that many patients had postoperative ARO, which may lead to recurrent or secondary pincer-type deformity after primary hip arthroscopy for FAI and postoperative ARO sometimes even led to revision surgery. It is necessary to carry out related research on ARO. METHODS: We respectively evaluated consecutive cases who underwent hip arthroscopy in our hospital between January 2008 and January 2020. Radiographic examination was obtained for all patients preoperatively and postoperatively. Another CT scan was performed at least 6 months after surgery at final follow-up. Preoperative patient-reported outcomes (PROs) and PROs at final follow-up were obtained, including visual analog scale (VAS) for pain and modified Harris Hip Score (mHHS). The volume of ARO was calculated using mimics 21.0 software. According to the material of anchors and whether the anchors were used, patients were divided into absorbable group, non-absorbable group and no anchor group. RESULTS: A total of 71 patients were finally included in this study. Patients with postoperative ARO had higher VAS at final follow-up (P<0.05). Patients without postoperative ARO had higher mean mHHS at final follow-up (P = 0.08) and higher percentage of passing minimal clinical important difference. The percentage and volume of postoperative ARO was significantly higher in patients who underwent acetabuloplasty and labral repair (P<0.05). The percentage and volume of postoperative ARO in absorbable group were significantly higher than the other groups (P<0.05). CONCLUSION: There is a high percentage of ARO after hip arthroscopy for treatment of FAI and patients who have undergone labral repair and acetabuloplasty are more likely to have postoperative ARO. Using of absorbable anchors may increase the possibility and volume of postoperative ARO. Postoperative ARO may predict a worse clinical outcome.

Variations in postoperative electrolyte concentrations and influential factors in hip arthroscopy.

BACKGROUND: Different from arthroscopy in other joints, more perfusion is required for a better access to perform surgical procedures in hip arthroscopic operations. The significant fluid perfused may lead to complications of partial tissue injury and electrolyte imbalance. However, there were few studies on the change of serum electrolyte after hip arthroscopy and the influential factors were still unknown. METHODS: We evaluated consecutive patients who underwent hip arthroscopy in our hospital between October 2021 and February 2022. Age, sex, and BMI matched patients who underwent arthroscopic anterior cruciate ligament (ACL) reconstruction at the same time were also included as the control group. Preoperative and postoperative serum electrolyte of sodium (Na +), potassium (K +), chloride (Cl-), magnesium (Mg2 +), and carbon dioxide capacity (CO2CP) were analyzed. The correlations between influential factors like perfusion volume, operating time, BMI and hip circumference, and changes in serum electrolyte were also analyzed. RESULTS: A total of 79 patients were involved in this study, including 49 patients who underwent hip arthroscopy and 30 patients who underwent knee arthroscopy. For hip arthroscopy, decrease of potassium levels was observed in 40.8% of the patients, and postoperative hypokalemia was found in 10.2% patients. There were significant variations in postoperative sodium, magnesium, chloride and carbon dioxide capacity in hip arthroscopy (p < 0.05). No correlations were found between each of the electrolyte concentrations and influential factors like perfusion volume, operating time, BMI, sex and hip circumference. The significant variations were found in chloride and carbon dioxide capacity in knee arthroscopy (p < 0.05). CONCLUSIONS: Hip arthroscopy would significantly influence postoperative serum electrolyte, and hypokalemia could be a postoperative complication. The correlation between serum electrolyte and fluid perfusion volume is remained to be investigated. We therefor advocate that performing a systematic care of preoperative and postoperative serum electrolyte analysis as perioperative management is necessary.

Arthroscopic subacromial decompression improves long-term functional outcome in patients with subacromial impingement: A systematic review and meta-analysis of randomized controlled trials.

PURPOSE: The effect of arthroscopic subacromial decompression for impingement syndrome is still under debate. The purpose of this study was to evaluate short-term and long-term effects of arthroscopic decompression in patients with subacromial impingement. METHODS: A systematic literature search was performed in Pubmed, Embase, Scopus, Cochrane Library, and ClinicalTrials.gov through March 2021 to identify randomized controlled trials (RCTs) that evaluated the clinical effects of arthroscopic decompression versus placebo surgery or exercise therapy for patients with subacromial impingement. Outcomes were analyzed on an intention-to-treat basis with random-effects models. RESULTS: Nine RCTs were included in the meta-analysis. The pooled analysis showed that arthroscopic decompression was associated with significantly better function improvement at 24-36 months and ≥ 60 months (24-36 months: SMD: 0.29, 95% CI: 0.10 to 0.48, P = 0.002; ≥ 60 months: SMD, 0.65, 95% CI, 0.20 to 1.09, P=0.004) compared with control group. Moreover, the effect size of function improvement ≥ 60 months exceeded the minimum clinically important difference (MCID). Additionally, sensitivity analysis indicated that compared with either exercise therapy or placebo surgery, arthroscopic decompression was associated with significantly better function improvement ≥ 60 months follow-up. However, there was no significant difference regarding pain relief at 6 months, 12 months, 24-36 months, ≥ 60 months, and function improvement at 6 months, 12 months for arthroscopic decompression compared with control group. CONCLUSION: After ≥ 60 months of follow-up, arthroscopic decompression in patients with subacromial impingement appears to render better function results than exercise therapy and placebo surgery. LEVEL OF EVIDENCE: I, systematic review and meta-analysis of level I studies.

Flat-Tunnel Technique With Independently Tensioned Bundles Better Restores Rotational Stability Than Round-Tunnel Technique in Anatomic Anterior Cruciate Ligament Reconstruction Using Hamstring Graft: A Cadaveric Biomechanical Study.

PURPOSE: To investigate the kinematics differences between round-tunnel (ROT) and flat-tunnel (FLT) techniques in anterior cruciate ligament (ACL) reconstruction when using hamstring graft. METHODS: Nine matched pairs of fresh-frozen cadaveric knees were evaluated for the kinematics of intact, ACL-sectioned, and either ROT or FLT reconstructed knees. The graft bundles for FLT technique were separately tensioned. A 6 degrees of freedom robotic system was used to assess knee laxity: (1) 134-N anterior tibial load at 0°, 15°, 30°, 60°, and 90°of knee flexion; (2) 10 Nm of valgus torque followed by 5 Nm of internal rotation torque simulates a pivot-shift test at 15° and 30°; (3) 5-Nm internal and external rotation torques at 0°, 15°, 30°, 60°, and 90°; (4) 10-Nm varus and valgus torques at 15° and 30°. RESULTS: Significant differences were found for ROT versus FLT techniques in terms of the simulated pivot-shift test at 15° (2.5 mm vs 1.4 mm, respectively, difference from intact; P =.039) and the internal rotation test at 15° (2.5° vs 0.5°, respectively, difference from intact; P =.034) and 30° (2.0° vs 0.4°, respectively, difference from intact; P =.014). No significant differences were found between groups during 134-N anterior tibial load, external rotation and valgus/varus rotation. Neither technique was able to reproduce the intact state during an anterior tibial load and simulated pivot-shift test. CONCLUSIONS: The FLT technique with independently tensioned bundles shows the same anterior control as the ROT technique but better restores rotational stability in terms of the simulated pivot-shift test and the internal rotation test in anatomic ACL reconstruction at time zero. CLINICAL RELEVANCE: The FLT technique with independently tensioned bundles of ACL reconstruction appears to be a viable, more anatomic technique than the ROT technique in mimicking flat anatomy and rotational stability of native ACL.

Arthroscopic modified Broström procedure achieves faster return to sports than open procedure for chronic ankle instability.

PURPOSE: To compare the clinical outcomes, rate of return to sports, postural control, and muscle strength between the arthroscopic and open modified Broström procedure for chronic lateral ankle instability (CLAI) patients. METHODS: From September 2018 to April 2019, 70 patients diagnosed with CLAI were prospectively included with arthroscopic modified Broström procedure (n = 36) and open modified Broström procedure (n = 34). They were evaluated at five time points (preoperation and 3 months, 6 months, 1 year and 2 years postoperatively). The main results examined the rate of return to sports, American Orthopaedic Foot and Ankle Society Score (AOFAS), Foot and Ankle Ability Measure (FAAM), visual analogue scale (VAS), centre of pressure (COP) excursion velocity, time to boundary (TTB), plantar pressure, isokinetic muscle strength and complications. RESULTS: Compared with the open group, the arthroscopic group demonstrated a significantly shorter period of return to the preinjury sport (13.2 ± 2.4 weeks vs. 18.7 ± 3.1 weeks, P = 0.023) and a higher early sport ratio (80.6 vs. 61.8%, P = 0.011) combined with better FAAM sports and AOFAS at 3 months and 6 months postoperatively and VAS at 3 months postoperatively. In addition, better anterior-posterior postural control stability, less time to peak force under lateral hindfoot and better dorsiflexion strength were shown in the arthroscopic group at 6 months postoperatively. No significant difference was found in clinical scores, posture control or muscle strength at the 1- or 2-year follow-up between the two groups. CONCLUSIONS: Shorter period and higher rates of return to sport activities and better clinical scores, posture control and muscle strength were achieved in the arthroscopic group at 6 months postoperatively, and no clinical differences were found between arthroscopic and open modified Broström procedure 1 year or 2 years postoperatively. Arthroscopic modified Broström procedure is a reliable procedure for CLAI injuries with the demand for fast exercise recovery. CLINICAL REGISTRATION: ChiCTR1900023999. LEVEL OF EVIDENCE: II.

Meniscus repair with simultaneous anterior cruciate ligament reconstruction: Clinical outcomes, failure rates and subsequent processing.

PURPOSE: To retrospectively analyze the clinical outcomes of meniscus repair with simultaneous anterior cruciate ligament (ACL) reconstruction and explore the causes of failure of meniscus repair. METHODS: From May 2013 to July 2018, the clinical data of 165 patients who were treated with meniscus surgery and simultaneous ACL reconstruction, including 69 cases of meniscus repair (repair group) and 96 cases of partial meniscectomy (partial meniscectomy group) were retrospectively analyzed. The exclusion criteria were as follows: (1) ACL rupture associated with fracture, collateral ligament injury, or complex ligament injury; (2) a history of knee surgery; or (3) a significant degree of osteoarthritis. The 69 patients in the repair group were divided into the non-failure group (62 cases) and the failure group (7 cases) depending on the repair effect. Postoperative outcomes of the repair group and the partial meniscectomy group were compared. General conditions and postoperative outcomes of the failure group and the non-failure group were compared. During the median follow-up period of 28 months (range, 4 - 65 months) after the second arthroscopy, postoperative outcomes of seven patients in the failure group were summarized. SPSS 25.0 statistical software was used for statistical analysis. A p value less than 0.05 was considered statistically significant. RESULTS: Seven patients in the failure group who underwent the second arthroscopy were followed up for (30 ± 17.4) months and their postoperative outcomes were summarized. Compared with the partial meniscectomy group, the International Knee Documentation Committee scores of patients in the repair group improved significantly (p = 0.031). Compared with the non-failure group, more patients in the failure group were younger than 24 years (p = 0.030). The median follow-up period was 39.5 months. All patients recovered well after subsequent partial meniscectomy and relieved clinical symptoms. Visual analog scale scores decreased significantly (p = 0.026), and the International Knee Documentation Committee and Lysholm scores improved significantly (p = 0.046 for both). CONCLUSION: The failure rate of meniscus repair in this study was 10.1% (7/69), all of which were medial meniscus tears. However, the surgical outcomes of ACL reconstruction were not affected, and there might be a role for graft protection. Therefore, meniscus retears can be successful treated by performing subsequent partial meniscectomy in patients with repair failure.

Secondary Effects of the Rupture and Reconstruction of the Interosseous Talocalcaneal Ligament on the Peritalar Joints.

BACKGROUND The interosseous talocalcaneal ligament (ITCL) is the main soft-tissue contributor to subtalar joint stability. The role of ITCL reconstruction in retaining this stability is minimally reported. Therefore, we conducted this study to investigate the effects of rupture and reconstruction of the ITCL on the subtalar and peritalar joints. MATERIAL AND METHODS This experimental study randomly divided 72 rabbits into 3 equal groups of 24 rabbits each. Group I underwent reconstruction surgery, group II underwent resection, and group III was the control group. The cartilages between the talocrural and calcaneocrural joints, and between the subtalar and talonavicular joints on both sides were assessed by gross observation, ink staining, histology, and immunohistochemistry at weeks 4, 8, 16, and 32, postoperatively. RESULTS In group II, the quantitative ink staining analysis revealed degeneration of the articular cartilages on the talonavicular joint (T=2.070, P=0.038) and the posterior subtalar joint (T=2.121, P=0.034) compared with the 2 sides of the same rabbit at 4 and 8 postoperative weeks. Comparing the operated sides of all the groups showed the posterior subtalar joints (Hc=9.563, P=0.008) and talonavicular joints (Hc=9.714, P=0.008) had an obvious difference at postoperative week 4; and in the calcaneocrural joints (Hc=6.750, P=0.034), it was noticed at postoperative week 8. Histology and immunohistochemistry findings confirm these observations. CONCLUSIONS An ITCL resection can lead to the progressive degeneration of the talonavicular and posterior subtalar joints, while an ITCL reconstruction can be beneficial in restoring the stability of these joints, preventing or postponing their degeneration, and protecting the articular cartilages.