Platelet-rich plasma pretreatment protects anterior cruciate ligament fibroblasts correlated with PI3K-Akt-mTOR pathway under hypoxia condition.

Background: /Objective: Biological factors such as platelet-rich plasma (PRP) combined with anterior cruciate ligament (ACL) primary repair technology are used to treat ACL injury. However, the protective mechanism of PRP for ACL fibroblasts under hypoxia condition is still unknown. The aim of this study was to investigate the protective effect of PRP on ACL fibroblasts under hypoxia condition and illustrate the mechanism of PRP regulating the ACL fibroblasts under hypoxia condition. Methods: The cells were divided into three groups: control group, hypoxia group and PRP pretreatment group. Lethal dose (LD) 50 for hypoxia induction time and the maximum efficacy of PRP concentration were confirmed by CCK-8 assay. The ability of cell apoptosis, cell proliferation, and cell migration were tested by flow cytometry, scratch assay and transwell assay, respectively. Extracellular matrix (ECM) synthesis and hypoxia-inducible factor 1α (HIF-1α) were identified by immunofluorescence staining, Masson's staining and transmission electron microscope analysis. Inflammatory cell infiltration was assessed by hematoxylin and eosin staining as well as immunofluorescence staining. Western blot analysis and real-time PCR were performed to assess the associated gene and protein expression, respectively. The ratio of phosphorylated/total PI3K, Akt and mTOR were also assessed by western blot analysis. Results: ① LD 50 of hypoxia was 48 â€‹h and the maximum efficacy of PRP concentration was 600 â€‹× â€‹109/L. ② ANNEXIN V-FITC/PI flow cytometry showed that the hypoxia condition significantly increased the apoptosis of cells (P â€‹< â€‹0.001) whereas PRP pretreatment significantly decreased the apoptosis of cells under hypoxia (P â€‹< â€‹0.001). The expressions of gene and protein of Bax, Bcl-2, cleaved-caspase 3 were consistent with the results of flow cytometric analysis. ③ Cell cycle analysis for flow cytometry showed the inhibitory effect of hypoxia and promotive effect of PRP pretreatment. ④ Immunofluorescence staining (HIF-1α, collagen I and III) showed the positive effect of hypoxia and negative effect of PRP on these parameters. Real-time PCR showed that type I and III collagen were 2.1 folds and 2.5 folds higher after 48 â€‹h hypoxia induction compared to the control group. PRP pretreatment significantly reduced the type I and III collagen mRNA expression of the hypoxia induced ACL fibroblasts to 78.5% and 77.7% at 48 â€‹h compared to hypoxia group (P â€‹< â€‹0.001), respectively.⑤ Cell migration assay showed that hypoxia condition significantly restrained cell migration compared with the control group. PRP could alleviate the inhibitory effect of hypoxia on fibroblasts. ⑥ Western blot analysis showed the ratio of phosphorylated/total PI3K, Akt and mTOR in hypoxia group increased to 31%, 20% and 44/% compared to control group, respectively. ⑦ The results of in vivo analysis was in accordance with the results of in vitro analysis. Conclusion: PRP can protect ACL fibroblasts via decreasing apoptosis and increasing cell viability, cell migration and cell proliferation under hypoxia condition. And such PRP protective effect was correlated with PI3K/Akt/mTOR pathway. The translational potential of this article: PRP can be used to treat patients with ACL tear by injection under arthroscopy or ultrasound guiding.

Derotational distal femoral osteotomy yields satisfactory clinical outcomes in pathological femoral rotation with failed medial patellofemoral ligament reconstruction.

PURPOSE: The purpose of this study was to evaluate the clinical outcomes of de-rotational distal femoral osteotomy (DDFO) in patients who underwent primary medial patellofemoral ligament reconstruction (MPFLR) failure with increased femoral anteversion along with high-grade J sign. METHODS: Between 2011 and 2019, 14 patients underwent DDFO revision surgery due to failed MPFLR. The pre- and postoperative J sign grade, Caton-Deschamps index (CDI), tibial tuberosity-trochlear groove (TT-TG) distance, femoral anteversion angle (FAA), patellar lateral tilt angle (PLTA), MPFL graft laxity, and patient-reported outcomes (Kujala, Lysholm, Tegner, and International Knee Documentation Committee (IKDC) subjective scores) were collected. The anterior-posterior and proximal-distal distances between the actual point and the Schöttle point were also calculated. RESULTS: Fourteen patients underwent MPFLR revision by DDFO combined with MPFLR. The mean PLTA improved from 40.7° ± 11.9° to 20.5° ± 8.7° (P < 0.001). The mean FAA significantly decreased from 42.7° ± 12.0° to 14.1° ± 5.2° (P < 0.001). The mean patellar laxity index (PLI) decreased from 82.4% preoperatively to 15.1% postoperatively (P < 0.001). None of these patients experienced subluxation or re-dislocation during follow-up of 29.7 ± 5.0 months after revision surgery. Meanwhile, the Tegner score at the last follow-up ranged from 3 to 6, with a median of 5. The Kujala, Lysholm, and IKDC subjective scores showed significant improvements, from a mean of 51.0 ± 6.8 preoperatively to 75.4 ± 5.1 postoperatively (P < 0.001), 49.2 ± 7.9 to 75.2 ± 7.2 (P < 0.001), and 42.9 ± 6.2 to 76.8 ± 6.0 (P < 0.001), respectively. The proportion of patients with a high-grade J sign was significantly lower postoperatively than preoperatively (100% vs. 14%). Four out of 14 patients (29%) showed femoral tunnel mal-positioning. CONCLUSION: MPFLR revision by DDFO combined with MPFLR achieved favorable clinical outcomes in patients with increased femoral anteversion along with high-grade J sign. LEVEL OF EVIDENCE: IV.

Prevalence of Lateral Meniscal Extrusion for Posterior Lateral Meniscal Root Lesion With and Without Concomitant Midbody Radial Tear in Anterior Cruciate Ligament Injury.

PURPOSE: To investigate the prevalence of lateral meniscal extrusion for patients with posterior lateral meniscal root lesions (PLMRLs) and for those with concomitant midbody radial tears (MRTs) in anterior cruciate ligament (ACL) injuries. METHODS: A database of consecutive patients undergoing primary ACL reconstruction between 2011 and 2013 was retrospectively reviewed to identify patients with isolated ACL injuries and those with associated PLMRLs. Patients with (1) unavailable preoperative magnetic resonance imaging scans, (2) other concomitant ligamentous injuries, (3) severe degeneration or malalignment, (4) infection or tumor, or (5) history of surgery on the injured side were excluded. For patients with associated PLMRLs (study group), degree of concomitant MRTs and status of meniscofemoral ligaments (MFLs) were verified arthroscopically. Prevalence of lateral meniscal extrusion was compared between (1) patients in the study group and those with isolated ACL injuries and between (2) those with and without concomitant MRTs in the study group. RESULTS: Of the 1,021 consecutive patients, 412 met the inclusion and exclusion criteria. Of those, 52 (5.1%) had an associated PLMRL (study group) and another 52 were randomly chosen from the 360 isolated ACL injuries as the control group. In the study group, 33 (63.5%) were arthroscopically verified to have concomitant MRTs. Prevalence of lateral meniscal extrusion was significantly higher (P < .0001) in the study group (30.8%; 95% confidence interval [CI], 18.3 to 43.3) than in the control group (1.9%; 95% CI, -1.8 to 5.6), whereas there was no significant difference (P = .758) between patients with (33.3%; 95% CI, 17.3 to 49.3) and without (26.3%; 95% CI, 6.5 to 46.1) concomitant MRTs in the study group. However, the 7 patients who showed either complete concomitant MRTs or absence of MFLs were all diagnosed to have lateral meniscal extrusion. CONCLUSIONS: The PLMRLs, identified in 5.1% of ACL injuries, appeared to result in lateral meniscal extrusion. Although the presence of a concomitant MRT did not further increase the prevalence of lateral meniscal extrusion in the setting of a PLMRL, surgical repair might still be necessary if a complete concomitant MRT or an absence of MFL was identified to restore normal meniscal functions. LEVEL OF EVIDENCE: Level III, prognostic case-control study.

The "lateral gutter drive-through" sign revisited: a cadaveric study exploring its real mechanism based on the individual posterolateral structure of knee joints.

BACKGROUND: Although the validity of the "lateral gutter drive-through" (LGDT) test has been proved to offer high sensitivity and specificity in diagnosing the posterolateral rotational instability of knee joints, the real mechanism on how the injury pattern of individual posterolateral knee structure triggers the positive LGDT sign still remains unknown. HYPOTHESIS: A certain amount of popliteus tendon (POP-T) laxity resulted from specific injury patterns of individual posterolateral knee structure or some degree of medial structural injury will lead to positive LGDT sign. STUDY DESIGN: Controlled laboratory study. METHODS: Seven non-paired intact cadaveric knees were divided into four groups and tested under unique sequential sectioning sequences including: (1) distal POP-T and popliteofibular ligament (PFL) (n = 2); (2) PFL and distal POP-T (n = 3); (3) lateral collateral ligament (LCL), distal POP-T and PFL (n = 1); (4) superficial medial collateral ligament (sMCL), deep MCL, posterior oblique ligament (POL), anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) (n = 1). The LGDT tests and the measurements of external tibial rotational angle (ETRA) were first performed on all the intact knees and then at each time point when an additional structure was sectioned. Results of each LGDT test and the absolute value of increased ETRA compared with the intact knee were recorded. Each knee was tested at 30° of flexion. A navigation system was used to measure motion changes of the tibia with respect to the femur. RESULTS: Initially, the LGDT tests all showed negative on each of the intact knee. Isolated sectioning of the distal POP-T, PFL or the LCL produced increased but insignificant ETRA with the LGDT tests still negative. However, simultaneous sectioning of the distal POP-T and PFL produced significantly increased ETRA with the LGDT tests changed to positive. In addition, for the knee with medial structural injuries, the LGDT test could also be positive only when the posteromedial structures (sMCL, deep MCL, POL) and the cruciate ligaments (ACL and PCL) were all sectioned. CONCLUSION: In this cadaveric sequential sectioning study, the LGDT test showed positive merely at the following two situations: (1) the distal POP-T and PFL were both sectioned; (2) the posteromedial structures (sMCL, deep MCL and POL) and the cruciate ligaments (ACL and PCL) were all sectioned. CLINICAL RELEVANCE: Accuracy of the LGDT test in diagnosing acute or chronic posterolateral corner (PLC) injuries will improve with the information in this study. It was the combined POP-T and PFL injuries that finally led to a positive LGDT sign. However, one should be cautious to use the LGDT test in diagnosing the PLC injuries when posteromedial structures and cruciate ligaments were all involved.

[Validity of a novel arthroscopic test to diagnose posterolateral rotational instability of the knee joint: the lateral gutter drive-through test].

OBJECTIVE: To assess the validity of the lateral gutter drive-through (LGDT) test in diagnosing posterolateral rotational instability (PLRI) of the knee joint. METHODS: Between October 2009 and February 2012, 115 consecutive patients were enrolled into this prospective diagnostic study. The tibia external rotation dial test was used as the gold standard for diagnostic reference. According to the dial test, the patients were divided into a study group (35 patients) and a control group (80 patients). The LGDT test was performed on all patients during arthroscopic surgery. The sensitivity and specificity of the LGDT test were calculated. The statistical difference of sensitivities in patient subgroups defined by injury patterns was tested using χ(2) test. And the correlation between the extent of tibia external rotational instability and the sensitivity of LGDT test was analyzed using logistic regression. RESULTS: The sensitivity and specificity of the LGDT test were calculated as 91.4% and 93.8%, respectively. The sensitivity of detection for acute PLRI was 9/10 vs. 92.0% in chronic cases (χ(2) = 0.036, P = 0.849). Popliteus femoral "peel off" lesions were detected with a sensitivity of 100% vs. 87.0% in cases of non "peel off" lesions (χ(2) = 1.712, P = 0.536). The sensitivity of detecting isolated external rotational instability vs. combined instability (rotational and varus) was 90.5% and 13/14, respectively (χ(2) = 0.062, P = 0.805). The sensitivity of the LGDT test was correlated with the extent of tibial external rotational instability (r = 1.000, P = 0.011). CONCLUSIONS: The LGDT test is a reliable method to diagnose PLRI of the knee joint. The highest sensitivity is observed for patients with the femoral "peel off" injury pattern. The sensitivity of the LGDT test is correlated with the extent of tibia external rotational instability.

Validity of a novel arthroscopic test to diagnose posterolateral rotational instability of the knee joint: the lateral gutter drive-through test.

PURPOSE: The purpose of this study was to assess the validity of a newly developed arthroscopic test, termed the lateral gutter drive-through (LGDT) test, to diagnose posterolateral rotational instability (PLRI) of the knee joint. METHODS: Between October 2009 and February 2012, 115 consecutive patients were enrolled into this prospective diagnostic study. The dial test was used as the gold standard for diagnostic reference. According to the dial test, the patients were divided into a study group (35 patients) and a control group (80 patients). The LGDT test was performed on all patients during arthroscopic surgery. The sensitivity and specificity of the LGDT test were calculated. Sensitivities were also calculated in subgroups defined by injury patterns and extents of tibial external rotational instability. RESULTS: The sensitivity and specificity of the LGDT test were calculated as 91.4% and 93.8%, respectively. In subgroup analyses the sensitivity of detection for acute PLRI was 90% versus 92% in chronic cases (P = .849). Popliteus femoral "peel-off" lesions were detected with a sensitivity of 100% versus 87.0% in cases of non-peel-off lesions (P = .536). The sensitivity of detecting isolated external rotational instability versus combined instability (rotational and varus) was 90.5% versus 92.8% (P = .805). The sensitivity of the LGDT test was correlated with the extent of tibial external rotational instability (P < .001). CONCLUSIONS: This study showed that the LGDT test is a reliable method and can be used for diagnosing PLRI of the knee joint. The highest sensitivity was observed in patients with the femoral peel-off injury pattern. The sensitivity of the LGDT test was correlated with the extent of tibial external rotational instability and was significantly higher in patients with an increase in tibial external rotation by more than 10°. LEVEL OF EVIDENCE: Level I, diagnostic study: testing of previously developed criteria in a series of consecutive patients.

Arthroscopic Bankart repair combined with remplissage technique for the treatment of anterior shoulder instability with engaging Hill-Sachs lesion: a report of 49 cases with a minimum 2-year follow-up.

BACKGROUND: Engaging Hill-Sachs lesions are known to be a risk factor for recurrence dislocation after arthroscopic repair in patients with anterior shoulder instability. For a large engaging Hill-Sachs lesion, arthroscopic remplissage is a solution. HYPOTHESIS: Arthroscopic Bankart repair combined with the Hill-Sachs remplissage technique can achieve good results without significant impairment of shoulder function. STUDY DESIGN: Case Series; Level of evidence, 4. METHODS: Forty-nine consecutive patients who underwent arthroscopic Bankart repair and Hill-Sachs remplissage for anterior shoulder instability were followed up for a mean duration of 29.0 months (range, 24-35 months). There were 42 males and 7 females with a mean age of 28.4 years (range, 16.7-54.7 years). All patients had diagnosed traumatic unidirectional anterior shoulder instability with a bony lesion of glenoid and an engaging Hill-Sachs lesion. Physical examination, radiographs, and magnetic resonance imaging were performed during postoperative follow-up. The American Shoulder and Elbow Surgeons (ASES) score, Constant score, and Rowe score were used to evaluate shoulder function. RESULTS: The active forward elevation increased a mean of 8.0° (range, -10° to 80°) postoperatively. However, the patients lost 1.9° (range, -40° to 30°) of external rotation to the side. Significant improvement was detected with regard to the ASES score (84.7 vs 96.0, P < .001), Constant score (93.3 vs 97.8, P = .005), and Rowe score (36.8 vs 89.8, P < .001).There were 1 redislocation, 2 subluxations, and 1 patient with a positive apprehension test; the overall failure rate was 8.2% (4 of 49). Successful healing of the infraspinatus tendon within the Hill-Sachs lesion was shown by magnetic resonance imaging. CONCLUSION: Arthroscopic Bankart repair combined with Hill-Sachs remplissage can restore shoulder stability without significant impairment of shoulder function in patients with engaging Hill-Sachs lesions.

Locking intramedullary nails and locking plates in the treatment of two-part proximal humeral surgical neck fractures: a prospective randomized trial with a minimum of three years of follow-up.

BACKGROUND: locking intramedullary nails and locking plates specially designed for proximal humeral fractures are widely used. The purpose of our study was to compare the outcomes between these two types of implants in patients with a two-part surgical neck fracture. The advantages and shortcomings of each method were analyzed. METHODS: a prospective randomized study was performed. Fifty-one consecutive patients with a fresh two-part surgical neck fracture were randomized to be treated with a locking intramedullary nail (n = 25) or a locking plate (n = 26). Clinical and radiographic assessments were conducted at one year and three years after the surgery. A visual analog scale (VAS) was used to assess shoulder pain. The American Shoulder and Elbow Surgeons (ASES) scores and Constant-Murley scores were recorded to evaluate shoulder function. RESULTS: fracture union was achieved in all patients within three months after the surgery. At one year postoperatively, a significant difference (p = 0.024) was found with regard to the complication rate between the locking plate group (31%) and the locking nail group (4%). The average ASES score, median VAS score, and average strength of the supraspinatus were significantly better in the locking plate group (90.8 compared with 83.6 points [p = 0.021], 1.0 compared with 0.5 point [p = 0.042], and 77.4% compared with 64.3% [p = 0.032]). At three years postoperatively, no significant difference could be found in terms of any parameter between the two groups. Significant improvement in the VAS pain scores, ASES scores, and Constant-Murley scores were found between the one-year and three-year follow-up examinations in each group. CONCLUSIONS: satisfactory results can be achieved with either implant in the treatment of two-part proximal humeral surgical neck fractures. There was no difference regarding the ASES scores between these two implants at the time of the final, three-year follow-up. The complication rate was lower in the locking intramedullary nail group, while fixation with a locking plate had the advantage of a better one-year outcome. LEVEL OF EVIDENCE: therapeutic Level I. See Instructions to Authors for a complete description of levels of evidence.