To assess the clinical efficacy of medial patellofemoral ligament reconstruction (MPFL-R) combined with medial-approach derotational distal femoral osteotomy (DDFO) in the treatment of recurrent patellar dislocation (RPD). In this retrospective Level IV case series, we reviewed 45 patients with recurrent patellar dislocation (2 males, 43 females; age 13–44 years, mean 22.8 ± 6.0 years) and a femoral anteversion angle (FAA) > 30° as measured using the Jarrett method (Kaiser et al. in Arch Orthop Trauma Surg 136(9):1259, 2016), who underwent combined medial patellofemoral ligament reconstruction (MPFL-R) and medial-approach derotational distal femoral osteotomy (DDFO) between January 2018 and January 2022. Clinical and radiographic parameters were assessed preoperatively and at a minimum two-year follow-up, including J-sign grading, visual analogue scale (VAS) pain score, Caton–Deschamps index (CD-I), FAA, patellar tilt angle (PTA), tibial tubercle–trochlear groove (TT–TG) distance, and patient-reported outcome measures (PROM) scores (Tegner, Kujala, and Lysholm). A subgroup analysis compared outcomes between patients who did and did not undergo adjunctive tibial tubercle osteotomy (TTO). At the two-year follow-up, patients demonstrated significant improvements in J-sign grading, VAS pain scores, femoral anteversion angle, patellar tilt angle, TT–TG distance, and functional outcomes (Tegner, Kujala, and Lysholm scores) (all P < 0.05). The Caton–Deschamps index showed no significant change (P > 0.05). In subgroup analysis, the TTO cohort experienced a greater reduction in TT–TG distance than the non-TTO cohort (P < 0.05), whereas postoperative VAS, Kujala, and Lysholm scores did not differ significantly between groups (P > 0.05). Medial patellofemoral ligament reconstruction combined with medial-approach derotational distal femoral osteotomy effectively restores patellofemoral stability and enhances functional outcomes in patients with recurrent patellar dislocation and excessive femoral anteversion. The indication for concomitant tibial tubercle osteotomy should be individualized according to each patient’s specific anatomical and clinical characteristics.

Bucket-handle tears of the medial meniscus are a common knee injury. Meniscal repair restores stability, reduces degenerative changes, and improves clinical outcomes. Repair may be performed using all-inside, outside-in, or inside-out techniques. Among these, the inside-out technique is widely regarded as the gold standard because of its reliability and broad applicability. However, blind needle passage during inside-out repair carries a risk of semimembranosus tendon entrapment. The purpose of this technical note is to describe a step-by-step surgical technique for inside-out repair of medial meniscus bucket-handle tears that recognizes and addresses entrapment of the semimembranosus tendon.

To analyze the effects of different plate placement positions on the efficacy and safety of Derotational Distal Femoral Osteotomy (DDFO) combined with Medial Patellofemoral Ligament Reconstruction (MPFL) surgery in the treatment of Recurrent Patellar Dislocation (RPD). A retrospective analysis was conducted on 33 patients with Recurrent Patellar Dislocation (RPD) who underwent surgical treatment from January 2020 to January 2022. Preoperative general data were collected for both groups, as well as J-sign grading, VAS scores, Caton index, femoral anteversion angle, patellar tilt angle, TT–TG value, Tegner score, Kujala score, and Lysholm score measured preoperatively and at 1.5 years postoperatively. Bone healing was evaluated on follow-up radiographs, and the time to bone union was defined as the duration from surgery to the presence of continuous cortical bridging at the osteotomy site on at least three cortices. Delayed union was defined as bone union exceeding six months after surgery. In addition, effect sizes (Cohen’s h/d) and post hoc power analyses were performed to further evaluate the adequacy of the sample size, particularly for the comparisons between medial and lateral plating. At 1.5 years postoperatively, the incidence of discomfort related to plate placement was significantly lower in the medial plate group compared with the lateral plate group (P < 0.05). Additionally, the rate of plate removal was significantly lower in the medial plate group than in the lateral plate group (P < 0.05). Both groups showed significant improvements in J-sign grading, VAS scores, Caton index, femoral anteversion angle, patellar tilt angle, TT–TG value, Tegner score, Kujala score, and Lysholm score at 1.5 years postoperatively compared with preoperative values (P < 0.001). All osteotomy sites achieved bone union without nonunion, and the mean time to bone union was 5.9 ± 1.1 months in the medial plate group and 5.8 ± 0.5 months in the lateral plate group (P = 0.71). All patient incisions healed at stage I, and there were no complications such as knee joint stiffness, infection, or recurrent patellar dislocation. Post hoc power analysis further confirmed adequate statistical power (Cohen’s h = 1.01 for discomfort; 0.87 for plate removal, both with > 99

To evaluate the mid- to long-term clinical outcomes of all inside arthroscopic suture lateral meniscal allograft transplantation (MAT) combined with different cartilage repair techniques, microfracture (MF) or osteochondral autograft transplantation systems (OATS), in the treatment of lateral meniscal deficiency with concomitant lateral compartmental chondral lesions of the knee. A retrospective study was conducted on 22 patients who underwent arthroscopic lateral MAT combined with cartilage repair between June 2013 and December 2020 in the First Affiliated Hospital of Chongqing Medical University. All patients were diagnosed preoperatively by MRI and confirmed via arthroscopy to have lateral meniscal deficiency with local cartilage lesions of the lateral femoral condyle. The cartilage defects were less than 2 cm2 in size and classified as ICRS grade III–IV. Based on lesion characteristics, patient age, and activity level, either MF or OAT was performed in combination with lateral MAT. Postoperative assessments included knee function (Lysholm and Tegner scores), pain levels (VAS score), and MRI evaluation of meniscal graft integrity and cartilage repair status. All patients completed the follow-up. Lysholm, Tegner, and VAS scores improved significantly at 6 months, 1 year, 2 years, and 5 years postoperatively compared to preoperative values (P < 0.05), with sustained improvement observed through the final follow-up. MRI showed intact meniscal grafts in 20 cases (90.9

Objective: This study aims to compare the efficacy of scorpion-based versus all-inside suture device techniques for repairing lateral meniscus posterior root tears based on clinical, radiographic, and finite element analysis findings. Methods: A retrospective analysis included 98 patients (Scorpion group: n=51; suture device group: n=47) who underwent surgery between 2016 and 2022. Outcomes were assessed via knee function scores, stability tests (Lachman, anterior drawer, pivot shift), MRI (meniscal integrity at 1 year, MOAKS), and finite element analysis of stress/strain under load. Results: Among the 98 included patients, both the scorpion and suture device groups demonstrated significant improvements in subjective functional scores from preoperative to postoperative assessments ( P < 0.05). No significant differences were observed in subjective functional scores between the two groups. However, the Scorpion group demonstrated superior outcomes in meniscal extrusion (1.68 mm vs. 2.21 mm, P = 0.036), anterior tibial translation (4.37 mm vs. 5.40 mm, p = 0.016), and MOAKS scores (12.60 vs. 15.97, P = 0.014). Finite element analysis also indicated better displacement control and stress distribution in the Scorpion group. Conclusion: Both techniques improved postoperative knee stability and functional scores, with no significant early clinical differences. However, the Scorpion technique yielded superior MRI findings and biomechanical results, suggesting its potential advantage in lateral meniscus posterior root repair, thereby informing surgical planning and early prognosis.

To investigate whether posteromedial safety-incision inspection and release of intraoperatively confirmed semimembranosus tendon-related sutures is associated with improved postoperative pain, functional recovery, and reduced posteromedial knee pain after arthroscopic inside-out repair of medial meniscal bucket-handle tears. We retrospectively reviewed 65 patients with medial meniscal bucket-handle tears treated at Fujian Medical University Union Hospital and the First Affiliated Hospital of Chongqing Medical University between January 2023 and November 2024. Patients were divided into a release group and a control group according to whether posteromedial safety-incision inspection and release of semimembranosus tendon-related sutures was performed (release group, n = 29; control group, n = 36). In the release group, semimembranosus tendon-related suture entrapment or tethering was confirmed intraoperatively through the posteromedial safety incision and then released. In the control group, no posteromedial exploration was performed; therefore, the presence or absence of semimembranosus tendon-related suture involvement was unknown. All patients underwent arthroscopic inside-out repair and were followed for 12 months. Lysholm, visual analog scale (VAS), and Tegner scores were compared preoperatively and at 3, 6, and 12 months postoperatively. The incidence of posteromedial knee pain was also recorded. There were no significant between-group differences in preoperative Lysholm, VAS, or Tegner scores (P > 0.05). In the release group, semimembranosus tendon-related suture entrapment or tethering was identified in all included patients during safety-incision inspection, and 1 to 3 sutures per patient required release. During follow-up, the release group demonstrated significantly better Lysholm and VAS scores than the control group at 3, 6, and 12 months postoperatively (P < 0.05). Tegner scores did not differ significantly between groups at any time point (P > 0.05). At 12 months, no patients in the release group reported posteromedial knee pain, whereas 8 patients in the control group experienced posteromedial pain. In both groups, all postoperative scores improved significantly compared with preoperative values (P < 0.05). Posteromedial safety-incision inspection and release of intraoperatively confirmed semimembranosus tendon-related sutures during arthroscopic inside-out repair of medial meniscal bucket-handle tears was associated with better pain relief, improved early knee function, and a lower incidence of posteromedial knee pain. Intraoperative safety-incision inspection can directly identify semimembranosus tendon-related suture entrapment or tethering in selected cases. However, because the control group was not explored and postoperative MRI or second-look arthroscopy was not routinely performed, the role of semimembranosus tendon-related suture involvement in control-group symptoms should still be interpreted cautiously.

Rotator cuff injuries are common, particularly among older adults, and are often treated with arthroscopic repair. However, retear rates remain high. This study compares clinical and structural outcomes between arthroscopic double-row suture bridge repairs using either suture tape anchors (STAs) with knotless medial fixation, or traditional knotted suture anchors (TSAs) with knotted medial fixation. This retrospective cohort study compared arthroscopic double-row suture bridge repairs performed from January 2021 to July 2023 using either knotless STAs or knotted TSAs. Eligible patients had medium (1–3 cm), large (3–5 cm), or massive (> 5 cm) full-thickness rotator cuff tears (DeOrio-Cofield classification) with no greater than Goutallier grade 3 fatty infiltration. Clinical outcomes were measured using VAS, Constant, UCLA, and ASES scores, both preoperatively and at 1-year postoperative follow-up. Muscle strength was assessed using manual muscle testing (0–5 scale) with the arm positioned at 30° scapular elevation. Structural outcomes were evaluated via MRI, where two trained surgeons assessed tendon thickness using the Sugaya classification and identified retears according to the Cho classification. Statistical analysis was conducted using SPSS. The study included 86 consecutive patients undergoing arthroscopic rotator cuff repair, with 36 patients in the STA group (median follow-up 15.0 months, range 12–19 months) and 50 patients in the traditional suture anchor (TSA) group (median follow-up 16.5 months, range 12–20 months). Both groups showed significant improvements in functional scores (VAS, Constant, UCLA, ASES) postoperatively (P < 0.05), with no significant differences between the two groups (P > 0.05). The STAs group had significantly lower tendon thinning and higher tendon thickness and supraspinatus muscle strength compared to the TSAs group (P < 0.05). The retear rate was similar between the two groups (12.0

Background The application of tibial tunnel compaction-drilling technique in anterior cruciate ligament reconstruction (ACL-R) is controversy. The purpose of this study was to evaluate the impact of tibial tunnel compaction-drilling technique and extraction-drilling technique used in single‑bundle ACL reconstruction on bone tunnel enlargement value, ACL graft maturation and clinical outcomes. Methods In this retrospective cohort study, 62 patients receiving ACL-R were screened and divided into two groups based on the technique of tibial tunnel drilling: compaction-drilling group (CD group, n = 31) and extraction-drilling group (ED group, n = 31). The bone tunnel enlargement was analysed based on the multislice computerised tomography at 12 months postoperatively. The ACL graft maturation was evaluated by the signal/noise quotient (SNQ) value on magnetic resonance imaging at 12 months postoperatively. Subjectively clinical outcomes were assessed by Lysholm score and International Knee Documentation Committee (IKDC) subjective score at 12 months postoperatively. Pivot-shift test was performed at 12 months postoperatively. The instrumental laxity measurement using the KT-1000 arthrometer was performed at 12 and 24 months postoperatively. Results The tibial bone tunnel diameters were enlarged by 9–15% in CD group ( p < 0.001) and enlarged by 15–22% in ED group ( p < 0.001). The CD group showed significantly smaller bone tunnel enlargement value than the ED group at 12 months follow up ( P < 0.05). In addition, significantly decreased KT-1000 measurement was found in CD group at 12 months (3.7 ± 1.8 vs. 5.0 ± 1.8 mm) ( P = 0.003) and 24 months follow up (3.4 ± 1.6 vs. 5.4 ± 2.0 mm) ( P < 0.001) compared to the ED group. No statistically significant differences of the SNQ value ( p = 0.255), IKDC subjective score ( p = 0.599) and Lysholm score ( p = 0.378) were found between two groups at 12 months postoperatively. Conclusion This study demonstrated that bone tunnel compaction-drilling technique could reduce the tibial bone tunnel enlargement and improve knee stability compared with extraction-drilling technique in ACL-R objectively.

This study compared partial (PMAT) and total meniscus allograft transplantation (TMAT) in rabbits, assessing their impact on meniscus function preservation and degeneration delay. In 18 rabbits with induced meniscus defects, PMAT better preserved meniscus morphology, collagen fibers, and showed less inflammation and better cartilage protection than TMAT. Histological staining and RNA sequencing revealed PMAT maintained collagen distribution and certain gene expression patterns closer to normal tissues. These findings suggest PMAT may offer advantages in reducing inflammation, delaying degeneration, and protecting cartilage, providing a potential new clinical approach for meniscus injuries and a foundation for further exploration of meniscal repair mechanisms.

Lateral meniscus tears are common knee injuries, but a tight lateral joint space, significantly smaller than the average 5.63 mm, can hinder visualization and surgical access to the posterior horn and root. Forceful instrumentation in such a narrow compartment risks damaging the articular cartilage, potentially increasing the likelihood of osteoarthritis. In the present study, we describe a technique involving partial osteotomy of the lateral collateral ligament femoral insertion to widen the tight lateral joint compartment, improving visualization and instrumentation for surgical procedures. This surgical technique is simple, effective, safe, and worth promoting.

Objective: To assess the clinical efficacy of arthroscopic medial patellofemoral ligament reconstruction (MPFL-R) combined with medial-approach derotational distal femoral osteotomy (DDFO) in the treatment of recurrent patellar dislocation (RPD). Methods: We retrospectively reviewed 45 patients with recurrent patellar dislocation (2 males, 43 females; age 13–44 years, mean 22.8 ± 6.0 years) and a femoral anteversion angle (FAA) > 30°, who underwent combined arthroscopic medial patellofemoral ligament reconstruction (MPFL-R) and medial-approach derotational distal femoral osteotomy (DDFO) at the First Affiliated Hospital of Chongqing Medical University between January 2018 and January 2022. Clinical and radiographic parameters were assessed preoperatively and at a minimum two-year follow-up, including J-sign grading, visual analogue scale (VAS) pain score, Caton–Deschamps index (CD-I), FAA, patellar tilt angle (PTA), tibial tubercle–trochlear groove (TT–TG) distance, and functional scores (Tegner, Kujala, and Lysholm). A subgroup analysis compared outcomes between patients who did and did not undergo adjunctive tibial tubercle osteotomy (TTO). Results: At the two-year follow-up, patients demonstrated significant improvements in J-sign grading, VAS pain scores, femoral anteversion angle, patellar tilt angle, TT–TG distance, and functional outcomes (Tegner, Kujala, and Lysholm scores) (all P < 0.05). The Caton–Deschamps index showed no significant change (P > 0.05). In subgroup analysis, the TTO cohort experienced a greater reduction in TT–TG distance than the non-TTO cohort (P < 0.05), whereas postoperative VAS, Kujala, and Lysholm scores did not differ significantly between groups (P > 0.05). Conclusion Arthroscopic medial patellofemoral ligament reconstruction combined with medial-approach derotational distal femoral osteotomy effectively restores patellofemoral stability and enhances functional outcomes in patients with recurrent patellar dislocation and excessive femoral anteversion. The indication for concomitant tibial tubercle osteotomy should be individualized according to each patient’s specific anatomical and clinical characteristics.

Objectives: To identify the specific serum biochemical markers that exhibit causal associations with the risk rheumatoid arthritis (RA) Methods: A cross-sectional study based on the NHANES database was conducted to investigate which serum biochemical markers were significantly associated with RA. Two-sample Mendelian randomization (MR) and Generalized summary data-based Mendelian randomization (GSMR) analysis were employed to analyze the causal relationships between biomarkers exhibiting differential expression identified within the NHANES database. The primary MR analysis utilized the inverse variance weighted (IVW) method. Restricted cubic spline (RCS) regression was conducted to explore non-linear associations between variables. Results: The NHANES cohort included 1,416 participants with clinically diagnosed RA and 3,744 control participants without RA. GSMR analysis revealed a significant causal relationship between serum albumin and RA risk (OR = 0.80, 95% CI: 0.72-0.89, P = 3.67×10−5). The IVW meta-analysis also confirmed that decreased albumin expression significantly associated with decreased risk of RA (P = 0.002). A four-node RCS model demonstrated non-linear correlations between albumin, uric acid, and RA (all P non-linear < 0.05), while calcium, globulin, and lactate dehydrogenase (LDH) exhibited linear relationships (all P non-linear > 0.05). However, multiple MR methods did not show any significant causal association between calcium, LDH, urate, and RA risk. Conclusion: This study found a linear association between calcium, globulin, LDH, and RA risk, while a U-shaped non-linear relationship between albumin, uric and RA was observed. MR analysis revealed a significant causal association between albumin and RA. However, the molecular mechanisms by which albumin affects the risk of RA remain to be further elucidated.

Current suturing techniques used in meniscal allograft transplantation pose risks of damaging blood vessels and nerves, and they conflict with patients’ esthetic needs, impacting the prognosis of the graft and patient satisfaction. This article introduces an all-inside all-suture technique for suturing and securing grafts during meniscal allograft transplantation procedures. This technique offers a more physiological alignment and fixation for the graft and joint capsule, ensuring graft stability while significantly reducing the risk of vascular and neural injuries in the knee joint and postoperative complications. Additionally, it eliminates the need for extra safety incisions, improving postoperative esthetics and patient satisfaction.

Abstract Background A variety of measurement methods and imaging modalities are in use to quantify the morphology of lateral femoral condyle (LFC), but the most reliable method remains elusive in patients with lateral patellar dislocation (LPD). The purpose of this study was to determine the intra- and inter-observer reliability of different measurement methods for evaluating the morphology of LFC on different imaging modalities in patients with LPD. Methods Seventy-three patients with LPD were included. Four parameters for quantifying the morphology of LFC were retrospectively measured by three observers on MRI, sagittal CT image, conventional radiograph (CR), and three-dimensional CT (3D–CT). The intra-class correlation coefficient was calculated to determine the intra- and inter-observer reliability. Bland–Altman analysis was conducted to identify the bias between observers. Results The lateral femoral condyle index (LFCI) showed better intra- and inter-observer reliability on MRI and 3D–CT than on CR and sagittal CT images. The mean difference in the LFCI between observers was lowest on 3D–CT (0.047), higher on MRI (0.053), and highest on sagittal CT images (0.062). The LFCI was associated with the lateral femoral condyle ratio (ρ = 0.422, P = 0.022), lateral condyle index (r = 0.413, P = 0.037), and lateral femoral condyle distance (r = 0.459, P = 0.014). The LFCI could be reliably measured by MRI and 3D–CT. Conclusion The LFCI could be reliably measured by MRI and 3D–CT. The LFCI was associated with both the height and length of LFC and could serve as a comprehensive parameter for quantifying the morphology of LFC in patients with LPD.

We aimed to investigate the mechanism of high mobility group box 1 (HMGB1) in the accelerated fracture healing process during Traumatic brain injury (TBI). The lateral ventricles of mice in the TBI model group were injected with adenovirus-packaged short hairpin RNA (shRNA)-HMGB1 or overexpressing (ov)-HMGB1 vector. We found HMGB1 levels were higher in bone tissue at the fracture end of TBI combined with fracture model mice. Compared with the TBI combined with fracture model mice, the mice in the ov-HMGB1 group healed faster and the expression levels of mitochondrial autophagy-related proteins were higher. Compared to the ov-HMGB1 group, mice in the ov-HMGB1 + autophagy inhibitor cyclosporin A (CsA) and ov-HMGB1 + shRNA-phosphatase and tensin homolog-induced kinase 1 (PINK1) groups showed slower healing and lower expression of mitochondrial autophagy-associated proteins. The expression of osteocalcin (OCN), SOX9, and bone morphogenetic protein (BMP)-2 in bone tissue at the fracture end of the ov-HMGB1 + shRNA-PINK1 group was lower than that in the ov-HMGB1 group. The mRNA expression levels of chondrogenic differentiation markers in bone tissue at the fracture end of the ov-HMGB1 + shRNAPINK1 group were lower than those in the ov-HMGB1 group. Fracture healing was accelerated during TBI, especially when HMGB1 was highly expressed, and HMGB1 promote accelerated fracture healing during TBI through PINK1/Parkin-mediated mitochondrial autophagy.

The subsequent dislocation of a contralateral patellofemoral joint sometimes occurs after a first-time lateral patellar dislocation (LPD). However, the anatomic risk factors for subsequent contralateral LPD remain elusive. This study included 17 patients with contralateral LPD and 34 unilateral patellar dislocators. The anatomic parameters of the contralateral patellofemoral joints were measured using CT images and radiographs that were obtained at the time of the first dislocation. The Wilcoxon rank-sum test was performed, and a binary regression model was established to identify the risk factors. The receiver operating characteristic curves and the area under the curve (AUC) were analyzed. The tibial tubercle-Roman arch (TT-RA) distance was significantly different between patients with and without contralateral LPD (24.1 vs. 19.5 mm, p < 0.001). The hip–knee–ankle (HKA) angle, patellar tilt, congruence angle, and patellar displacement were greater in the study group than in the control group (p < 0.05). The TT-RA distance revealed an OR of 1.35 (95% CI (1.26–1.44]), p < 0.001) and an AUC of 0.727 for predicting contralateral LPD. The HKA angle revealed an OR of 1.74 (95% CI (1.51–2.00), p < 0.001) and an AUC of 0.797. The Patellar tilt, congruence angle, and patellar displacement had AUC values of 0.703, 0.725, and 0.817 for predicting contralateral LPD, respectively. In conclusion, the contralateral patellofemoral anatomic parameters were significantly different between patients with and without subsequent contralateral LPD. Increased TT-RA distance and excessive valgus deformity were risk factors and could serve as predictors for contralateral LPD. At first-time dislocation, the abnormal position of the patella relative to the trochlea may also be an important cause of subsequent LPD.

Background and Objectives: Various predisposing factors for lateral patellar dislocation (LPD) have been identified, but the relation between femoral rotational deformity and the tibial tubercle–Roman arch (TT-RA) distance remains elusive. Materials and Methods: We conducted this study including 72 consecutive patients with unilateral LPD. Femoral anteversion was measured by the surgical transepicondylar axis (S-tAV), and the posterior condylar reference line (P-tAV), TT-RA distance, trochlear dysplasia, knee joint rotation, patellar height, and hip–knee–ankle angle were measured by CT images or by radiographs. The correlations among these parameters were analyzed, and the parameters were compared between patients with and without a pathological TT-RA distance. Binary regression analysis was performed, and receiver operating characteristic curves were obtained. Results: The TT-RA distance was correlated with S-tAV (r = 0.360, p = 0.002), but the correlation between P-tAV and the TT-RA distance was not significant. S-tAV had an AUC of 0.711 for predicting a pathological TT-RA, with a value of >18.6° indicating 54.8% sensitivity and 82.9% specificity. S-tAV revealed an OR of 1.13 (95% CI [1.04, 1.22], p = 0.003) with regard to the pathological TT-RA distance by an adjusted regression model. Conclusions: S-tAV was significantly correlated with the TT-RA distance, with a correlation coefficient of 0.360, and was identified as an independent risk factor for a pathological TT-RA distance. However, the TT-RA distance was found to be independent of P-tAV.

Authors’ Response: We thank Dr Nizić for his interest for our recently published study. The tibial tubercle–Roman arch (TT-RA) distance has landmarks on the tibia and femur. Therefore, the translation of the tibia or the rotation of knee joints would alter the value of TT-RA distance. We have also performed studies to investigate the difference in the TT-RA distance between CT and MRI. We found that the value of TT-RA distance is affected by the rotation or flexion of the knee joint, which is also the case for the current gold standard tibial tubercle–trochlear groove (TT-TG) distance. Therefore, the TT-RA distance is a mixed imaging test. We do agree with Dr Nizić that a test of tibial tuberosity lateralization that is independent of femorotibial rotation may be a more reliable assessment. Some measurements such as tibial tuberosity–tibial intercondylar midpoint (TT-TIM) distance, or tibial tubercle–posterior cruciate ligament (TT-PCL) distance can evaluate pure tibial tubercle lateralization. However, the clinical value of these measurements remains uncertain. TT-PCL distance reflects the true lateralization of the tibial tubercle, and the TT-TG distance reflects the mixed tibial tubercle lateralization. We compared the clinical application value between TT-TG and TT-PCL distance in our previously published study and found the difference in the TT-PCL distance between patients with patellar dislocation and healthy controls to be only 1.11 mm. In addition, the TT-PCL distance was found to have a poor capacity to predict patellar dislocation (area under the receiver operating curve [AUC] 1⁄4 0.627). Therefore, the role of true tibial tubercle lateralization in the evaluation of patellar dislocation patients warrants further assessment. As mixed imaging tests, the TT-RA distance (AUC 1⁄4 0.8) and TT-TG distance (AUC 1⁄4 0.8) had higher capacity than TT-PCL distance (AUC1⁄4 0.6) to distinguish patients with patellar dislocation from healthy individuals, which indicate that the mixed imaging tests would be more suitable to evaluate patellar dislocation. As for the question of the accuracy of the TT-RA distance. We used the intraclass correlation coefficient to evaluate the precision of the measurements, and found that the TT-RA distance showed higher interand intraobserver reliability than the TT-TG distance (Table 2 of our study), especially in patients with patellar dislocation (Figure 6 of our study). When regarding the precision of TT-RA distance to distinguish patellar dislocation patients from healthy individuals, the AUC was comparable to that of the TT-TG distance (Figure 8 of our study). The sex difference of TT-RA distance was not investigated in the present study. It is hard to determine any sex-based differences in the TT-RA distance with a small sample size. Thank you for your kind thoughts and interest.

To verify that lateral trochlear inclination (LTI) measured by the transepicondylar axis can reliably be used to evaluate trochlear dysplasia (TD) on MRI and can serve as an objective indication of trochleoplasty for patients with lateral patellar dislocation (LPD). Eighty patients with recurrent LPD and eighty healthy subjects were included. TD, posterior condylar angle (PCA), and LTI measured by the posterior condylar reference line (LTIp), surgical transepicondylar axis (LTIs), and anatomical transepicondylar axis (LTIa) were assessed on MRI. The intraclass correlation coefficient (ICC) and Bland–Altman analysis were performed, the correlations and differences amongst the parameters were identified, and a binary logistic regression model was established. Each measurement had excellent inter- and intra-observer agreement. The LTIp, LTIs and LTIa were smaller in the study group than in the control group, with mean differences of 9.0°, 7.2° and 7.0°, respectively (P < 0.001). The PCA was larger in patients with LPD than in the control group (P < 0.001). LTIp was associated with PCA in the study group (r = − 0.41, P < 0.001). The pathological values of LTIp, LTIs and LTIa were 11.7°, 15.3° and 17.4°, respectively. LTIs and LTIa were independent risk factors for LPD, with ORs of 7.33 (95

目的 探讨高迁移率族蛋白1(HMGB1)通过PTEN诱导假定激酶1(PINK1)/帕金蛋白(Par-kin)介导的线粒体自噬对骨髓干细胞的趋化及成骨分化的影响.方法 将人骨髓间充质干细胞(hBM-SCs)分为7组:control组、siRNA-NC组、siRNA-HMGB1组、pcDNA-NC组、pcDNA-HMGB1组、pcDNA-HMGB1+siRNA-NC组、pcDNA-HMGB1+siRNA-PINK1组.采用Transwell检测细胞迁移能力;茜素红染色检测各组细胞中钙结节数目;ELISA检测骨桥蛋白(OPN)、碱性磷酸酶(ALP)的含量;RT-qPCR检测各组细胞中成骨细胞特异性转录因子(Osterix)、HMGB1及Runt相关转录因子2(RUNX2)、转录因子CCAAT/增强子结合蛋白(C/EBPα)、过氧化物酶体增殖物激活受体γ(PPARγ)水平;透射电镜检测线粒体自噬小体数目;Western Blot检测hBMSCs中Parkin及微管相关蛋白1A/1B-轻链3(LC3Ⅱ/Ⅰ)、选择性自噬接头蛋白62(P62)和自噬关键分子酵母Atg6同系物(Beclin1)等线粒体自噬相关蛋白的表达.结果 HMGB1通过PINK1/Parkin介导的线粒体自噬对hBMSCs的趋化作用研究表明:与pcDNA-NC组相比,pcDNA-HMGB1组HMGB1表达、细胞迁移率、线粒体自噬数目及自噬相关蛋白Beclin-1、LC3B-Ⅱ/Ⅰ的表达增加,Parkin、P62等蛋白的表达降低(P＜0.05);与siRNA-NC组相比,siRNA-HMGB1组HMGB1表达、细胞迁移率、线粒体自噬数目及Beclin-1、LC3B-Ⅱ/Ⅰ等表达降低,Parkin、P62表达增高(P＜0.01).HMGB1通过PINK1/Parkin介导的线粒体自噬对hBMSCs的成骨分化作用研究结果显示:与pcDNA-NC组相比,pcDNA-HMGB1组钙结节数量、Osterix及RUNX2含量、ALP及OPN的表达升高(P＜0.01),PPARγ、C/EBPα的表达降低(P＜0.05);与pcDNA-HMGB1+siRNA-NC组相比,pcDNA HMGB1+siRNA-PINK1组钙结节数量、Osterix及RUNX2含量、ALP及OPN的表达降低(P＜0.05),PPARγ、C/EBPα的表达升高(P＜0.05).结论 HMGB1高表达能通过PINK1/Parkin介导的线粒体自噬促进hBMSCs的趋化、成骨细胞分化及抑制成脂细胞分化,可能是骨质疏松症的潜在治疗靶点.