[Study on clinical characteristics and surgical methods of bucket-handle meniscal tears].

Objective: To summarize the clinical features, surgical methods, and prognosis of bucket-handle meniscal tears (BHMTs), and provide guidance for clinical treatment. Methods: The clinical data of 91 BHMTs patients (91 knees), who met the selection criteria and were admitted between January 2015 and January 2021, was retrospectively analyzed. There were 68 males and 23 females. Age ranged from 16 to 58 years with an average of 34.4 years. The injury was caused by sports in 68 cases, traffic accident in 15 cases, and falls or sprains in 8 cases. There were 49 cases of left knee injury and 42 cases of right knee injury. The time from the onset of symptoms to the admission ranged from 1 day to 13 months (median, 18 days), including >1 month in 35 cases and ≤1 month in 56 cases. Medial BHMTs occurred in 52 cases and lateral BHMTs in 39 cases. There were 36 cases with ACL rupture and 12 cases with discoid meniscus. The knee extension was limited more than 10° in 55 cases. According to the condition of meniscus injury, the meniscus suture with Inside-out combined with All-inside techniques (54 cases) or meniscoplasty (37 cases) under arthroscopy were selected. ACL reconstruction was performed in all patients with ACL rupture with autogenous hamstring tendon. Postoperative complications were observed. International Knee Documentation Committee (IKDC) score, Lysholm score, and Tegner score were used to evaluate knee function, and clinical failure was recorded. Results: Two patients developed intermuscular venous thrombosis, which improved after oral anticoagulant therapy. No vascular injury, postoperative infection, joint stiffness, or other complications occurred in all patients. All patients were followed up 24-95 months, with a median of 64 months. A total of 12 cases (13.19%) failed the operation and were re-operated or given oral anti-inflammatory analgesics and rehabilitation therapy. At last follow-up, IKDC score and Lysholm score of 91 patients significantly increased when compared with those before operation ( P<0.05), while Tegner score significantly decreased ( P<0.05). The above indexes of patients treated with meniscus suture and meniscoplasty were also significantly different from those before operation ( P<0.05). Conclusion: BHMTs occurs mostly in young men and is one of the important reasons for the limitation of knee extension after trauma. Arthroscopic meniscus suture and meniscoplasty can obtain good effectiveness according to individual conditions of patients. But the latter can better preserve the shape and function of meniscus, and theoretically can obtain better long-term outcomes, which needs to be confirmed by further research with larger sample size.

Reliability of a Novel Automatic Knee Arthrometer for Measuring Knee Laxity After Anterior Cruciate Ligament Ruptures.

BACKGROUND: The accuracy of existing devices for measuring knee laxity is adversely affected by examiner reliability. PURPOSE: To compare the accuracy of a novel automatic knee arthrometer (AKA) to that of the KT-2000 arthrometer for measuring knee laxity after anterior cruciate ligament (ACL) ruptures. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: We measured anterior displacement and the anterior displacement difference (ADD) at 134 N of anterior force in 221 healthy volunteers and 200 patients with ACL ruptures. All trials were performed by the same 2 examiners. We first analyzed the effects of examiner, side assessed, and device type using the intraclass correlation coefficient (ICC), t test, and F test. We then used the receiver operating characteristic curve to compare the diagnostic value of the measurements between devices. RESULTS: In repeated measurements for a single healthy volunteer, there were no differences in the variance of the measurements between sides according to the AKA (standard deviation of right vs left knee for examiner A: 0.43 vs 0.58 mm, respectively [P = .39]; for examiner B: 0.49 vs 0.77 mm, respectively [P = .81]), while the KT-2000 measurements showed differences (standard deviation of right vs left knee for examiner A: 1.47 vs 0.80 mm, respectively [P = .02]; for examiner B: 1.78 vs 0.91 mm, respectively [P = .01]). The ADD assessed by the AKA was not significantly different between examiners A and B (0.50 vs 0.75 mm, respectively; P = .27; ICC = 0.83), but the KT-2000 showed a difference (1.07 vs 2.01 mm, respectively; P = .01; ICC = 0.55). The ADD of 20 healthy volunteers assessed by the AKA was less than that by the KT-2000 (0.98 vs 1.41 mm, respectively; P = .04). When comparing the diagnostic value of the 2 devices in the sample of 200 patients with ACL ruptures and 200 healthy controls, the area under the receiver operating characteristic curve for the AKA was larger than that for the KT-2000 (0.93 vs 0.87, respectively; P ≤ .01), and the threshold values were 1.75 and 2.73 mm, respectively. CONCLUSION: The AKA can be used to determine the degree of knee laxity in ACL injuries and to provide indications for treatment.

ß-Arrestin2 Inhibits the Apoptosis and Facilitates the Proliferation of Fibroblast-like Synoviocytes in Diffuse-type Tenosynovial Giant Cell Tumor.

BACKGROUND/AIM: Diffuse-type tenosynovial giant cell tumor (TGCT) is a rare benign proliferative synovial neoplasm of uncertain etiology, and the efficacy of surgical resection is not satisfactory. Therefore, there is an urgent need to explore the pathogenesis and identify novel therapeutic targets for TGCT. MATERIALS AND METHODS: Synovial tissues were collected from patients with TGCT and osteoarthritis (OA). Differences of mRNA expression between TGCT and OA were explored using mRNA-seq. In addition, fibroblast-like synoviocytes (FLS) were treated with small interfering RNA (siRNA) or adenovirus in order to knockdown or overexpress ß-arrestin2 (Arrb2), respectively. FLS proliferation and apoptosis were evaluated using the MTT assay and the caspase 3 activity assay, respectively. RESULTS: The expression of Arrb2 in TGCT was significantly higher than that in OA. The overexpression of Arrb2 promoted the proliferation of FLS and inhibited its apoptosis, while knocking down Arrb2 had the opposite effect. Further studies showed that Arrb2 can activate the PI3K-Akt signaling pathway, leading to increased proliferation of TGCT. CONCLUSION: Arrb2 facilitates the proliferation and inhibits the apoptosis of TGCT FLS through activating the PI3K-Akt cell survival pathway, providing new insight into the molecular mechanism of TGCT.

Cadherin-11 cooperates with inflammatory factors to promote the migration and invasion of fibroblast-like synoviocytes in pigmented villonodular synovitis.

Rationale: Pigmented villonodular synovitis (PVNS) is a destructive benign tumor-like hyperplastic disease that occurs in synovial tissue. Fibroblast-like synoviocytes (FLS) are the predominant cell type comprising the structure of the PVNS synovial lining layer. Due to a high recurrence rate, high invasion, migration, and cartilage destruction ability, PVNS causes substantial damage to patients and the efficacy of surgical resection is not satisfactory. Therefore, exploring the pathogenesis and identifying novel therapeutic targets for PVNS are urgently required. Currently, the pathogenesis of PVNS remains unclear, and there is uncertainty and controversy regarding whether PVNS is an inflammatory or a neoplastic disease. Cadherin-11 is a classical molecule that mediates hemophilic cell-to-cell adhesion in FLS and plays an important role in the normal synovium lining layer formation. This study aimed to explore the role of inflammation and cadherin-11 in PVNS pathogenesis and determine the effects of cadherin-11 as a molecular target for PVNS treatment. Methods: FLS were primarily cultured from PVNS patients during arthroscopic synovectomy. The level of cytokines in the PVNS synovial fluid was evaluated using a human antibody array. Cadherin-11 expression of PVNS FLS was detected by qPCR, Western blots, tissue immunohistochemistry, and cell immunofluorescence. Cadherin-11 was down-regulated by siRNA or up-regulated with a plasmid, with or without inflammatory factor stimulation, and PI3K/Akt was inhibited with LY294002. The capacity of migration and invasion of PVNS FLS was tested using Transwell and wound-healing assays. Activation of the nuclear factor-kappaB (NF-κB) and mitogen-activated protein kinase (MAPK) pathways was detected by Western blots. Chondrocyte damage by PVNS FLS was assessed with a co-culture assay. Results: Inflammatory factors (IL-1ß and TNF-α) in the synovial fluid of PVNS patients were significantly up-regulated. Cadherin-11 was highly expressed in the FLS of PVNS patients, and positively correlated with recurrence, extra-articular migration, and cartilage destruction of PVNS. Knocking down of cadherin-11 inhibited the migration and invasion of PVNS FLS. Moreover, inflammatory factors up-regulated the expression of cadherin-11, which activated the NF-κB and MAPK signaling pathways and led to cartilage destruction. Inhibition of cadherin-11 blocked IL-1ß- and TNF-α-induced activation of the above pathways, migration and invasion of PVNS FLS, and damage of chondrocyte. In addition, the elevation of cadherin-11 expression, together with the migration and invasion, of PVNS FLS was down-regulated by the inhibition of the PI3K/Akt signaling pathway. Conclusions: Cadherin-11 plays an important role in the pathogenesis of PVNS and forms a positive feedback loop with inflammatory factors, which further activates the NF-κB and MAPK pathways to trigger an inflammatory cascade. Cadherin-11-mediated inflammation results in PVNS with high recurrence, invasiveness, and strong cartilage destruction ability, and eventually promotes the transformation of PVNS from the initial inflammatory disease to neoplastic disease. Thus, inhibition of cadherin-11 together with its related inflammatory reaction, represents a new therapeutic strategy for PVNS.

Heterotopic ossification after arthroscopy for hip impingement syndrome.

BACKGROUND: Heterotopic ossification (HO) is a known complication of hip arthroscopy. We investigated incidence of HO after hip arthroscopy and determined whether revision for HO improved outcome. METHODS: A retrospective study was conducted on 242 patients (140 men and 102 women, mean age: 36.2 ±â€Š9.5 years) who underwent hip arthroscopy for femoroacetabular impingement (FAI) between January 2016 and January 2018. The average follow-up period was 22.88 ±â€Š11.74 months (range: 11-34 months). Thirteen (5.37%) cases of HO (six men and seven women, five left hips and eight right hips; mean age: 37.5 ±â€Š4.7 years) were observed. Among them, four cases with HO with obvious pain symptoms and persistent non-remission underwent revision surgery to remove HO. Monthly follow-up was conducted. Visual analog scale (VAS), modified Harris Hip Score (mHHS), and non-Arthritis Hip Score (NAHS) were evaluated and compared between HO and non-HO patients. Independent sample t test, Mann-Whitney U test and the Chi-square test were used for inter-group comparisons. HO degree was evaluated using Brooker classification. Symptoms and function were evaluated before and after revision. RESULTS: A total of 242 patients were involved in this study. Thirteen cases (5.4%) had imaging evidence of HO. Nine (9/13) were classified as Brooker stage I, three (3/13) Brooker stage II, and one (1/13) Brooker stage III. HO was detected by ultrasonography as early as 3 weeks after operation. After primary surgery, the mHHS of the HO group and non-HO group increased by 13.00 (8.50, 25.50) and 24.00 (14.00, 34.50) points (Z = -1.80, P = 0.08), NAHS increased by 18.00 (9.50, 31.50) and 26.00 (13.50, 36.00) points (Z = -1.34, P = 0.18), and VAS decreased by 3.00 (2.00, 4.00) and 4.00 (3.00, 4.50) points (Z = -1.55, P = 0.12). Average follow-up time after revision was 9.00 ±â€Š2.94 months; mHHS increased by 34.75 points (t = -55.23, P < 0.01) and NAHS by 28.75 points (t = -6.03, P < 0.01), and VAS decreased by 4 points (t = 9.80, P < 0.01). HO and non-HO patients were similar for demographic and surgical data, and clinical and functional scores. CONCLUSION: HO incidence after arthroscopic treatment of FAI is similar to that found in previous studies. Most HO have no effect on clinical symptoms. Patients who undergo revision HO resection show improvement in pain and joint function.