Combined vertical and external rotational force in plantarflexion position produces posterior pilon fracture: A preliminary cadaveric study.

BACKGROUND: Posterior pilon fracture is speculated to occur by a combination of rotation and axial load, which makes it different from rotational posterior malleolar fracture or pilon fracture, but is not validated in vitro. The aim of the current study is to investigate the injury mechanisms of posterior pilon fracture on cadaveric specimens. METHODS: Eighteen cadaveric specimens were mounted to a loading device to undergo solitary vertical loading, solitary external rotational loading, and combined vertical and external rotational loading until failure, in initial position of plantarflexion with or without varus. The fracture characteristics were documented for each specimen. RESULTS: Vertical loading force combined with external rotation force diversified the fracture types resulting in pilon fracture, tibial spiral fracture, rotational malleolar fracture, talar fracture or calcaneal fracture. Vertical violence combined with external rotational loading in position of 45° of plantarflexion and 0° of varus produced posterior pilon fracture in specimens No. 13 and 14. CONCLUSION: Combination of vertical and external rotational force in plantarflexion position on cadaveric specimens produce posterior pilon fracture.

Functional effects of arthroscopic modified Broström procedure on lateral ankle instability: A pilot study.

BACKGROUND: This study aims to assess the mechanical and functional effects of the arthroscopic modified Broström procedure (AMBP) on patients with lateral ankle instability. METHODS: Eight patients with unilateral ankle instability treated with AMBP and eight healthy subjects were recruited. Healthy subjects, preoperative and one-year postoperative patients were assessed using outcome scales and the Star Excursion Balance Test (SEBT) for dynamic postural control. One-dimensional statistical parametric mapping was performed to compare ankle angle and muscle activation curve during stair descent. RESULTS: The patients with lateral ankle instability showed good clinical outcomes and increased posterior lateral reach during the SEBT after the AMBP (p = 0.046). The medial gastrocnemius activation after initial contact was reduced (p = 0.049), and the peroneal longus activation after initial contact was promoted (p = 0.014). CONCLUSION: The AMBP has functional effects of promoting dynamic postural control and peroneal longus activation within one year of follow-up, which can benefit patients with functional ankle instability. However, the medial gastrocnemius activation was unexpectedly reduced post operation.

Use of Ankle Dorsiflexion and the Dimeglio and Pirani Scores in Predicting Relapse of Clubfoot Treated With the Ponseti Method.

Although Dimeglio and Pirani scores are frequently employed to rate the severities of clubfoot and to evaluate treatment outcomes, it is unclear if these scores predict relapse after treatment. Ankle dorsiflexion has been suggested in recent years to be a promising predictor of relapse. The aim of this study was to investigate ankle dorsiflexion and Dimeglio and Pirani scores in predicting the relapse of clubfoot after treatment with the Ponseti method. We included patients with clubfoot previously treated by the Ponseti method, and retrospectively analyzed their initial ankle dorsiflexion, Pirani and Dimeglio scores, number of castings, and the occurrence of relapse. We analyzed 218 feet of 176 infants with clubfoot who showed an incidence of relapse of 17.0% (30/176). The mean initial Pirani and Dimeglio scores of the feet showing recurrence were significantly higher than individuals with non-recurrence (p < .001 each). We observed a robust association between Pirani and Dimeglio scores and the recurrence of clubfoot at the last follow-up (γ = 0.53, p = .001). In contrast, ankle dorsiflexion was negatively correlated with recurrence of clubfoot (γ = -0.21, p = .001). Dimeglio scores significantly predicted the recurrence of clubfoot (p = .014). Receiver operating characteristic curve analysis exhibited slightly better performance regarding the Dimeglio score relative to the Pirani score and ankle dorsiflexion in predicting recurrence. Ankle dorsiflexion and Pirani and Dimeglio scores were related to recurrence in patients with clubfoot. However, the Dimeglio score reflected superior accuracy in predicting the prognosis of clubfoot treated with the Ponseti method.

Dynamic Reach Deficit Is a Predictive Factor of Inferior Outcomes After Modified Broström Procedure for Lateral Ankle Instability.

BACKGROUND: Only a few studies have analyzed functional predictive factors for inferior outcomes after modified Broström procedure (MBP). The aim of the current study is to identify the influence of the preoperative dynamic reach deficit on the surgical outcomes of MBP. METHODS: Sixty-one patients with lateral ankle instability who underwent MBP were included in the current study and followed up for a median of 24 months. The Karlsson scores and the reaches of the Star Excursion Balance Test (SEBT) were evaluated before surgery and during the last follow-up. A total of 19 prognostic factors were analyzed. The relationship between the variables and inferior outcomes (Karlsson score < 90) in the bivariate analysis was tested through the Mann-Whitney U test or the Fisher exact test. A multivariate logistic regression model was developed to investigate the influence of the selected factors on inferior outcomes. RESULTS: Thirty-two of the patients had superior outcomes, and the rest had inferior outcomes. The age, gender, and body mass index of the groups with superior and inferior outcomes did not differ. Preoperative dynamic reach deficit (P = .032), osteochondral lesion of the talus (P = .004), and decreased preoperative Karlsson score (P = .004) were independent predictors of inferior outcomes. CONCLUSION: Patients with preoperative dynamic reach deficit, osteochondral lesion of the talus, or decreased preoperative Karlsson score have inferior outcomes after MBP. LEVEL OF EVIDENCE: Level III, case-control study.

Epidemiological Characteristics of Patients Operated for Achilles Tendon Rupture in Shanghai.

OBJECTIVE: To reflect the potential epidemiological characteristics of Achilles tendon (AT) rupture in Shanghai, China, which has been rarely reported before. METHODS: This work is a descriptive epidemiology study. A total of 302 cases of AT rupture admitted to our department between 01/2013 and 02/2020 are analyzed according to telephone follow-up and medical records. Male to female ratio is 10.3 and the average age is 37.5 years. The record of each case includes age, gender, Body mass index (BMI), quinolone use, corticoid exposure and related medical history/comorbidities. If the case is sports-related (SR), details including kind of sports, intensity of exercise, exercise time before rupture, specific action that causes rupture and situation of warm-up are collected. Two independent sample t-tests and Pearson chi-square tests are used for statistical analysis. RESULTS: A total of 252 ruptures are SR. Male to female ratio is 15.6 in SR cases. Most SR ruptures occur in patients aged 25-39 years. Ball games are major sports responsible for rupture: basketball in 95 (37.7%), badminton in 68 (27.0%) and soccer in 62 (24.6%). Acceleration and running start is the specific action that cause most (37.7%) ruptures. AT cases are observed in 91 patients with warm-up and 161 without preparation before exercise. As a result, more ruptures happened within 10 min' sports in 161 unprepared (22.4%) than in 91 prepared (5.5%) cases. In SR cases, 107 and 145 cases are observed on weekends and weekdays. Of the 302 total cases, 64 are associated with Achilles tendinopathy. Frequently reported factors such as quinolone use and corticoid exposure are found only in two and 11 of all cases, respectively. CONCLUSION: Middle-aged males are common victims of AT rupture in Shanghai. Sports including basketball, badminton, soccer and actions involving in sudden and severe contraction of AT cause most ruptures. Warm-up before exercise reduces rupture in short time. Factors such as quinolone, corticoid and Achilles tendonitis still need attention.

Surgical management of concurrent lateral ankle instability and osteochondral lesions of the talus increases dynamic sagittal ankle range of motion.

PURPOSE: A biomechanical study, in which imaging modalities are used to strictly include patients with concurrent lateral ankle instability (LAI) and osteochondral lesions of the talus (OLT), is needed to demonstrate the static and dynamic ankle range of motion (ROM) restriction in these patients, and determine whether ankle ROM restriction can be corrected postoperatively. METHODS: Eight patients with concurrent LAI and OLT treated with the arthroscopic modified Broström procedure and microfracture were recruited from June 2019 to January 2020. Patients were assessed using outcome scales, static ankle ROM, and a stair descent gait analysis for dynamic ankle ROM, a day prior to surgery and one year postoperatively. Eight healthy subjects were assessed using the same modalities upon recruitment. Operative outcomes and variables during stair descent were documented and compared among the preoperative, postoperative, and healthy groups. A curve analysis, one-dimensional statistical parametric mapping, was performed to compare the dynamic ankle kinematics and muscle activation curves over the entire normalised time series. RESULTS: The functional outcomes of patients with concurrent LAI and OLT were significantly worse than those of healthy subjects preoperatively, but were partially improved postoperatively. Patients had decreased static and dynamic ROM preoperatively, and static ROM did not significantly increase postoperatively (preoperative, 39.6 ± 11.3; postoperative, 44.9 ± 7.1; healthy, 52.0 ± 4.6; p = 0.021). Patients showed increased dynamic ankle flexion ROM (preoperative, 41.2 ± 11.6; postoperative, 53.6 ± 9.0; healthy, 53.9 ± 3.4; p = 0.012) postoperatively, as well as increased peroneus longus activation (preoperative, 35.8 ± 12.0; postoperative, 55.4 ± 25.1; healthy, 71.9 ± 13.4; p = 0.002) and muscle co-contraction of the tibialis anterior and peroneus longus (preoperative, 69.4 ± 23.4; postoperative, 88.4 ± 9.3; healthy, 66.2 ± 18.1; p = 0.045). CONCLUSIONS: Patients with concurrent LAI and OLT had decreased static and dynamic sagittal ankle ROM and altered neuromuscular activation patterns. The arthroscopic modified Broström procedure and microfracture did not significantly increase the static sagittal ankle ROM. However, the dynamic sagittal ankle ROM, peroneus longus activation and muscle co-contraction of the tibialis anterior and peroneus longus increased postoperatively. LEVEL OF EVIDENCE: IV.

Quantitative analysis with load-displacement ratio measured via digital arthrometer in the diagnostic evaluation of chronic ankle instability: a cross-sectional study.

BACKGROUND: Arthrometry has been introduced to evaluate the laxity of ankle joint in recent years. However, its role in the diagnosis of chronic ankle instability is still debatable. Therefore, we assessed the diagnostic accuracy of a digital arthrometer in terms of sensitivity and specificity. METHODS: According to the inclusion and exclusion criteria proposed by the International Ankle Consortium, we recruited 160 uninjured ankles (control group) and 153 ankles with chronic ankle instability (CAI group). Ankle laxity was quantitively measured by a validated digital arthrometer. Data of loading force and joint displacement were recorded in a continuous manner. Differences between the control and CAI groups were compared using 2-tailed independent t test. A receiver operating characteristic curve analysis was used to calculate area under a curve, sensitivity and specificity. RESULTS: Load-displacement curves of the two groups were depicted. Differences of joint displacement between the control and CAI groups were compared at 30, 45, 60, 75, 90, 105 and 120 N, which were all of statistical significance (all p < 0.001) with the largest effect size at 90 N. Statistical significance was found in the differences between the two groups in load-displacement ratio at 10-120 N, 10-40 N, 40-80 N and 80-120 N (all p < 0.001), with the largest effect size at 10-40 N. Load-displacement ratio at the interval of 10-40 N had the highest area under a curve (0.9226), with sensitivity and specificity of 0.804 and 0.863, respectively, when the cutoff point was 0.1582 mm/N. CONCLUSION: The digital arthrometer measurement could quantitively analyze the ankle laxity with high diagnostic accuracy. The load-displacement ratio would be a reliable and promising approach for chronic ankle instability diagnosis. Level of evidence level II.

The effect of partial deltoid ligament injuries on the external rotation stability: A cadaveric study.

BACKGROUND: The anterior and posterior part of the deltoid ligament have different functions during ankle flexion motion. Partial ligament injuries have been demonstrated in previous clinical reports. However, the efficacy of external rotation stress test in partial injured cases is unavailable till now. METHODS: Thirty-two fresh cadaveric specimens were included and allocated into two destabilization groups. In the first group, the anterior portion of deltoid ligament (DL) and syndesmotic ligament were sequentially severed, while in the second group, the posterior portion of DL and syndesmotic ligament were sequentially severed. Mortise view radiographs were taken after each destabilization stage when the ankles were placed at plantarflexion and dorsiflexion positions and stressed in standard external rotation force. The medial clear space (MCS) and talar tilt (TT) angle were measured and compared among different destabilization stages. RESULTS: When the ankles were placed at neutral position, the TT significantly increased in all destabilization stages. The MCS significantly increased after the partial deltoid ligament ruptures only with presence of syndesmotic ligament injuries. There was no significant difference of MCS at plantarflexion for all stages of destabilization if the anterior portion of DL is preserved. Similarly, no significant increase of MCS was detected at dorsiflexion if the posterior portion of DL and posterior inferior tibiofibular ligament are intact. CONCLUSION: Partial DL rupture causes ankle rotational instability at different ankle joint positions, especially when combined with syndesmotic injuries. The neutral position is recommended for diagnosis of partial DL ruptures under external rotation stress.

Percutaneous Inferior Extensor Retinaculum Augmentation Technique for Chronic Ankle Instability.

OBJECTIVE: To specify indications and contraindications of the modified percutaneous inferior extensor retinaculum augmentation (PIERA) technique for chronic ankle instability cases, and to introduce technique details and report surgical outcomes and complications. METHODS: The PIERA technique was performed on seven patients with chronic ankle instability (four females and three males, 36.4 ± 15.1 years of age, and course of symptoms of 33.7 ± 8.8 months) from June to October 2018 in this retrospective study of case series. All patients demonstrated attenuated ligamentous tissue quality, which was confirmed using preoperative ankle MRI. IER were drew up to the distal fibula using suture anchors with the ankle in neutral position for all cases, to engage the entire IER in reconstructing the stability of the ankle. Patients were assessed using American Orthopaedic Foot and Ankle Society Ankle-Hindfoot (AOFAS) score and Cumberland Ankle Instability Tool (CAIT) scores pre- and postoperatively at the last follow-up examination. Preoperative and postoperative outcome scores of patients were compared using paired t-test. A p value of less than 0.05 was regarded statistically significant. RESULTS: Mean follow-up duration was 16.7 ± 1.6 months. The mean AOFAS score significantly improved from 66.9 ± 11.2 preoperatively to 93.7 ± 8.5 postoperatively (P = 0.001). Mean CAIT score significantly improved from 13.1 ± 4.7 preoperatively to 26.3 ± 1.8 postoperatively (P = 0.001). Patients did not report any wound healing problem, numbness, swelling, or instability at the last follow-up examination, except for one patient who reported pain and minimal stiffness, and presented an AOFAS score of less than 80 and a CAIT score below 24. All patients returned to at least recreational sport activity level. CONCLUSION: The PIERA technique can improve the functional outcomes of patients with chronic ankle instability with few complications.

Length change pattern of the ankle deltoid ligament during physiological ankle motion.

BACKGROUND: Length change pattern of the ankle deltoid ligament during physiological ankle motion is still confused currently and had not been studied in vivo. METHODS: The deltoid ligaments from 7 cadaveric specimens were dissected. Lengths of each band during 30° plantarflexion to 20° dorsiflexion were measured. A dual fluoroscopy imaging system was utilized to capture the images of hindfoot joint of 7 healthy subjects during the stance phase of walking. 3D bone models were reconstructed from CT images. Lengths of each band were calculated after model-image registration utilizing a solid modeling software. Percentage of length variation and poses when the bands were in maximum extension were documented among each band. RESULTS: The anterior border of tibiocalcaneal ligament (TCL) had only 1.7% length variation in vitro and 5.7% length variation in vivo. The tibionavicular ligament, tibiospring ligament, and deep anterior tibiotalar ligament were in maximum extension at 30° plantarflexion, however, superficial posterior tibiotalar ligament, deep posterior tibiotalar ligament, and the posterior border of TCL were in maximum extension at 20° dorsiflexion. The tibionavicular ligament, tibiospring ligament, and deep anterior tibiotalar ligament were in maximum extension during foot flat. The TCL was in maximum extension during midstance. The superficial posterior tibiotalar ligament and deep posterior tibiotalar ligament were in maximum extension during heel off and toe off. CONCLUSION: The length of TCL did not change during ankle dorsiflexion and plantarflexion. The bands anterior to and posterior to the TCL showed different length change pattern during physiological ankle dorsiflexion and plantarflexion.

Influence of Achilles tendon rupture site on surgical repair outcomes.

PURPOSE: This study aims to measure the distance between the common site of Achilles tendon rupture and calcaneal insertion through ultrasound and to compare the outcomes between proximal and distal rupture groups. METHODS: We investigated the electronic medical records of 117 patients and preoperative ultrasound describing the rupture site. Among 88 patients, we compared the patient-reported outcome and re-rupture rate of proximal and distal rupture groups. RESULTS: The mean rupture site of the 117 included subjects was 4.5 ± 1.3 cm. The rupture site had a weak negative correlation with body mass index (ρ = -0.230, P = 0.013). Furthermore, 77% of the patients with distal rupture reported good outcome (Achilles Tendon Rupture Score > 80) compared to 56% of the patients with proximal rupture (P = 0.041). CONCLUSION: Patients with proximal rupture had less satisfactory postoperative outcomes than those with distal rupture.

Reliability and validity of different ankle MRI scanning planes for the anterior talofibular ligament injury diagnosis: a cadaveric study.

BACKGROUND: The objective of the current study is to compare reliability, accuracy, sensitivity, and specificity in magnetic resonance imaging (MRI) evaluation of anterior talofibular ligament (ATFL) among the routine axial scanning plane, oblique axial-coronal scanning plane, and oblique axial-sagittal scanning plane. METHODS: Twenty cadaveric feet were studied. ATFL was exposed before scanning. Routine axial, oblique axial-coronal, and oblique axial-sagittal MRI scanning of 20 ATFL-intact cadaveric feet were acquired utilizing a 1.5-T MRI unit. The scans were repeated on the 20 cadaveric feet after the ATFL was artificially injured. In total, 120 sets of MR images were obtained and were randomly numbered. Three independent observers who were blinded to the experiment evaluated the images. Interobserver agreement, sensitivity, specificity, and accuracy were calculated and compared between different scanning planes utilizing the McNemar test. RESULTS: The interobserver agreement was fair to good (kappa, 0.55 to 0.65) in the routine axial plane, fair to good (kappa, 0.557 to 0.75) in the oblique axial-sagittal plane, and excellent (kappa, 0.85 to 0.95) in the oblique axial-coronal plane. The accuracy was significantly higher when utilizing oblique axial-coronal MRI scanning than routine axial MRI scanning (reader 1: p = .018; reader 2: p = .005). CONCLUSIONS: The diagnostic accuracy of oblique axial-coronal plane MRI was higher than the routine axial plane concerning ATFL injury, and the interobserver agreement was excellent. The oblique axial-coronal plane could be added to the MRI scanning protocol during clinical practices to improve the diagnostic accuracy of ATFL injury.

Imaging diagnosis for chronic lateral ankle ligament injury: a systemic review with meta-analysis.

BACKGROUND: Various imaging techniques have been utilized for the diagnosis of chronic lateral ankle ligament injury. This systemic review will explore the effectiveness of different imaging techniques in diagnosing chronic lateral ankle ligament injury. METHODS: Relative studies were retrieved after searching 3 databases (MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trails). Eligible studies were summarized. Data were extracted to calculate pooled sensitivity and specificity of magnetic resonance imaging (MRI), ultrasonography (US), stress radiography, and arthrography. RESULTS: Fifteen studies met our inclusion and exclusion criteria. A total of 695 participants were included. The pooled sensitivities in diagnosing chronic ATFL injury were 0.83 [0.78, 0.87] for MRI, 0.99 [0.96, 1.00] for US, and 0.81 [0.68, 0.90] for stress radiography. The pooled specificities in diagnosing chronic ATFL injury were 0.79 [0.69, 0.87] for MRI, 0.91 [0.82, 0.97] for US, and 0.92 [0.79, 0.98] for stress radiography. The pooled sensitivities in diagnosing chronic CFL injury were 0.56 [0.46, 0.66] for MRI, 0.94 [0.85, 0.98] for US, and 0.90 [0.73, 0.98] for arthrography. The pooled specificities in diagnosing chronic CFL injury were 0.88 [0.82, 0.93] for MRI, 0.91 [0.80, 0.97] for US, and 0.90 [0.77, 0.97] for arthrography. CONCLUSION: This systematic review with meta-analysis investigated the accuracy of imaging for the diagnosis of chronic lateral ankle ligament injury. Ultrasound manifested high diagnostic accuracy in diagnosing chronic lateral ankle ligament injury. Clinicians should be aware of the limitations of MRI in detecting chronic CFL injuries.

Histone deacetylase inhibitor chidamide induces growth inhibition and apoptosis in NK/T lymphoma cells through ATM-Chk2-p53-p21 signalling pathway.

We investigated the anti-tumour effects and the underlying molecular mechanisms of a new oral histone deacetylase inhibitor (HDACi), chidamide, in NK/T cell lymphoma (NKTCL), a rare and highly aggressive non-Hodgkin lymphoma with poor outcomes. SNT-8 and SNK-10 NKTCL cell lines were exposed to different concentrations of chidamide for the indicated time. The treated cells were analysed for cell proliferation, cell cycle progression, and cell apoptosis. Proteins in the AKT/mTOR and MAPK signalling pathways and the DNA damage response (DDR) cell cycle checkpoint pathway were measured by Western blotting. Chidamide inhibited cell proliferation in a dose- and time-dependent manner, arrested cell cycle progression at the G0/G1 phase, and induced apoptosis in the NKTCL cell lines. In addition, we found that chidamide suppressed the phosphorylation levels of proteins in the AKT/mTOR and MAPK signalling pathways and activated the DDR cell cycle checkpoint pathway, that is, the ATM-Chk2-p53-p21 pathway. Expression of EBV genes was also assessed by Real-Time PCR. Chidamide induced EBV lytic-phase gene expression in EBV-positive NKTCL. Our results provide evidence that chidamide shows antitumour effects by inhibiting the AKT/mTOR and MAPK signalling pathways and activating the ATM-Chk2-p53-p21 signalling pathway in vitro.

Resveratrol inhibits Extranodal NK/T cell lymphoma through activation of DNA damage response pathway.

BACKGROUND: Extranodal NK/T cell lymphoma (NKTCL) is a highly aggressive non-Hodgkin lymphoma with poor prognosis. Resveratrol (RSV, 3,5,4'-trihydroxystilbene), a natural nontoxic phenolic compound found in the skin of grapes and some other spermatophytes, performs multiple bioactivities, such as antioxidant activity, anti-aging activity, reduction of cardiovascular disease risk and anticarcinogenic effect. Here we report the anti-tumor effect of RSV in NKTCL cell lines SNT-8, SNK-10 and SNT-16. RESULTS: RSV inhibited NKTCL cell proliferation in a dose- and time-dependent manner and arrested cell cycle at S phase. It induced NKTCL cells apoptosis through mitochondrial pathway, shown as down-regulation of MCl-1 and survivin, up-regulation of Bax and Bad, and activation of caspase-9 and caspase-3. In addition, we found that RSV suppressed the phosphorylation level of AKT and Stat3, and activated DNA damage response (DDR) pathway directly or through up-regulation of Zta of Epstein-Barr virus (EBV). Furthermore, using KU55933 as the inhibitor of pATM, we verified that DDR played an important role in RSV inducing NKTCL apoptosis. RSV also showed synergistic effect on activating DDR pathway in combination with etoposide or ionizing radiation, which resulted in cell proliferation inhibition and apoptosis. CONCLUSIONS: Our results provide in vitro evidence that RSV produces anti-tumor effect by activating DDR pathway in an ATM/Chk2/p53 dependent manner. So we suggest that RSV may be worthy for further study as an anti-tumor drug for NKTCL treatment.

Steroidogenic Acute Regulatory Protein (StAR) Overexpression Reduces Inflammation and Insulin Resistance in Obese Mice.

Steroidogenic acute regulatory protein (StAR), a mitochondrial cholesterol delivery protein, plays a beneficial role in hyperlipidemia, NAFLD, and endothelial inflammation. Elevated circulating fatty acids and low grade inflammation are known as key risk factors of insulin resistance and type 2 diabetes. In the present study, C57BL/6J mice were fed with HFD and infected with recombinant adenovirus expressing StAR by tail-vein injection. Intraperitoneal glucose/insulin tolerance test was performed to assess the insulin sensitivity. Morphological analysis and intramuscular lipid determination were used to illustrate the adipose hypertrophy and ectopic fat accumulation in skeletal muscle. The levels of inflammatory factor and nitric oxide were determined by ELISA and classic Griess reagent methods, respectively. The fatty acids composition was analysis using gas chromatography-mass spectrometry (GC-MS). The expression of genes associated with inflammation and insulin resistance were determined by Western blotting and qPCR to elucidate the underlying mechanism. We demonstrated that StAR overexpression ameliorated insulin resistance and systemic inflammatory response with the reduction of adipose hypertrophy and intramuscular lipid in HFD-fed mice. In addition, StAR overexpression increased serum unsaturated fatty acids (UFAs) and PPARγ expression in muscle and adipose tissue of obese mice. In conclusion, StAR may activate PPARγ by increasing UFAs, which leads to a protective role in systemic inflammation and insulin resistance in obese mice. J. Cell. Biochem. 118: 3932-3942, 2017. © 2017 Wiley Periodicals, Inc.