Background: The purpose of this study was to retrospectively analyze the clinical outcomes of patients with recurrent patellar dislocation who underwent arthroscopic medial patellofemoral ligament (MPFL) reconstruction using gracilis tendon autograft and a modified double-patellar tunnel method. We hypothesized that our modified method would provide good clinical outcomes. Methods: Patients who underwent arthroscopic MPFL reconstruction with autograft gracilis tendon and modified double-patellar tunnels technique for recurrent patellar dislocation and were followed up for a minimum of 5 years were identified, and the clinical and follow-up data were retrospectively analyzed. Preoperatively, joint hypermobility was assessed with the Beighton score. The Insall–Salvati ratio, TT–TG distance, and Q angle were measured on radiographic images. Patient-reported outcomes including the Kujala, Lysholm, and Tegner scores were collected preoperatively and postoperatively. Patient satisfaction was assessed at the end of 5 years. Complications and recurrent dislocation occurring after surgery were recorded. Results: A total of 79 patients (94 knees) were enrolled; of these, 13 (16.5%) were lost to follow-up. The data of 66 patients (80 knees) were available for final analysis. Mean age at surgery was 21.3 ± 7.8 years. Mean follow-up time was 66.1 ± 5.5 months (range, 60–78 months). Postoperative patient-reported outcome was not associated with Beighton score, Insall–Salvati ratio, or TT–TG distance. Q angle was negatively correlated to Kujala scores and Lysholm scores. Severity of trochlear dysplasia was not associated with postoperative patient-reported outcome. The mean Kujala score increased from 69.4 ± 7.9 to 96.1 ± 1.9, the mean Tegner score increased from 3.1 ± 1.3 to 5.9 ± 1.3, and the mean Lysholm score increased from 73.5 ± 14.6 to 95.3 ± 3.4. Two patients experienced recurrent patellar dislocation during follow-up. Conclusions: MPFL reconstruction using autologous gracilis tendon under arthroscopy appears to be a reliable and safe method for treating recurrent patellar dislocation. Level of evidence: Level IV.

The effective and translational strategy to regenerate knee meniscal fibrocartilage remained challenging. Herein, we first identified vascular smooth muscle cells (VSMCs) transdifferentiated into fibrochondrocytes and participated in spontaneous meniscal regeneration using smooth muscle cell lineage tracing transgenic mice meniscal defect model. Then, we identified low-intensity pulsed ultrasound (LIPUS) acoustic stimulus enhanced fibrochondrogenic transdifferentiation of VSMCs in vitro and in vivo. Mechanistically, LIPUS stimulus could up-regulate mechanosensitive ion channel Piezo1 expression and then activate the transforming growth factor β1 (TGFβ1) signal, following repression of the Notch signal, consequently enhancing fibrochondrogenic transdifferentiation of VSMCs. Finally, we demonstrated that the regular LIPUS stimulus enhanced anisotropic native-like meniscal fibrocartilage tissue regeneration in a beagle canine subtotal meniscectomy model at 6 months postoperatively. The single-cell RNA sequencing analysis confirmed the role of VSMC fibrochondrogenic transdifferentiation in meniscal regeneration.

Background: To better restore the anatomy of the native anterior cruciate ligament (ACL) attachment and fiber arrangement, researchers have developed techniques for changing the shape of the ACL bone tunnel during ACL reconstruction. Purpose: To compare the coverage of the ACL tibial footprint and influence on the anterior root of lateral meniscus (ARLM) between a rounded-rectangular tibial tunnel and a conventional round tibial tunnel for ACL reconstruction. Study Design: Controlled laboratory study. Methods: A total of 16 (8 matched-paired) fresh-frozen human cadaveric knees were distributed randomly into 2 groups: a rounded-rectangular tunnel (RRT) group and a round tunnel (RT) group. One of the knees from each pair was reamed with rounded-rectangular tibial tunnel, whereas the other was reamed with round tibial tunnel. Coverage of the ACL tibial footprint and areas of ARLM attachment before and after reaming were measured using 3-dimensional isotropic magnetic resonance imaging. Results: In the RRT group, the average percentage of ACL tibial footprint covered by the tunnel was 70.8% ± 2.5%, which was significantly higher than that in the RT group (48.2% ± 6.4%) ( P = .012). As for the ARLM attachment area, in the RT group, there was a significant decrease (22.5% ± 5.9%) in ARLM attachment area after tibial tunnel reaming compared with the intact state ( P < .001). Conversely, in the RRT group, the ARLM attachment area was not significantly affected by tibial tunnel reaming. Conclusion: Rounded-rectangular tibial tunnel was able to better cover the native ACL tibial footprint and significantly lower the risk of iatrogenic injury to the ARLM attachment than round tibial tunnel during ACL reconstruction.

Rotator cuff tear is a common type of injury. For the treatment of rotator cuff tears, arthroscopic surgery is widely used. However, for massive rotator cuff tears, the rate of recurrent tears after arthroscopic surgical repair is higher. This article describes an improved double‐row suture technique combining vertical mattress suture and double‐pulley techniques. This technique increases the strength and stability of the suture and reduces cutting damage to the tendon so as to reduce the risk of retear. Technique Video: video See video under supplementary data.