Objective:To evaluate knee biomechanics of patients about 12 months after anterior cruciate ligament(ACL)reconstruction during cutting and determine the abnormal biomechanical characteristics.Methods:Sixteen males about 12 months after ACL reconstruction were recruited for this study.Three-dimensional kinematic and kinetic data were collected during cutting movement.Knee joint angles and moments were calculated.Paired t-tests were used to compare the differences in knee biomechanics be-tween the surgical leg and nonsurgical leg.Results:The peak posterior ground reaction force(surgical leg:0.380±0.071;nonsurgical leg:0.427±0.069,P=0.003)and vertical ground reaction force(surgical leg:1.996±0.202,nonsurgical leg:2.110±0.182,P=0.001)were significantly smaller in the surgical leg than in the nonsurgical leg.When compared with the uninjured leg,the surgical leg demonstrated a smaller knee flexion angle(surgical leg:38.3°±7.4°;nonsurgical leg:42.8°±7.9°,P＜0.001)and larger external rotation angle(surgical leg:10.3°±2.4°;nonsurgical leg:7.7°±2.1°,P=0.008).The surgical leg also demonstrated a smaller peak knee extension moment(surgical leg:0.092±0.031;nonsurgical leg:0.133±0.024,P＜0.001)and peak knee external rotation moment(surgical leg:0.005±0.004;nonsurgical leg:0.008±0.004,P=0.015)when com-pared with the nonsurgical leg.Conclusion:The individuals with ACL reconstruction mainly showed asymmetrical movements in the sagittal and horizontal planes.The surgical leg demonstrated a smaller peak knee flexion angle,knee extension moment,and knee external rotation moment,with greater knee external rotation angle.

Background::Visual inputs are critical for locomotor navigation and sensorimotor integration in the elderly; however, the mechanism needs to be explored intensively. The present study assessed the gait pattern after cataract surgery to investigate the effects of visual restoration on locomotion.Methods::The prospective study recruited 32 patients (70.1 ± 5.2 years) with bilateral age-related cataracts in the Department of Ophthalmology at Peking University Third Hospital from October 2016 to December 2019. The temporal-spatial gait parameters and kinematic parameters were measured by the Footscan system and inertial measurement units. Paired t-test was employed to compare data normally distributed and Wilcoxon rank-sum test for non-normally distributed. Results::After visual restoration, the walking speed increased by 9.3% (1.19 ± 0.40 m/s vs. 1.09 ± 0.34 m/s, P=0.008) and exhibited an efficient gait pattern with significant decrease in gait cycle (1.02 ± 0.08 s vs. 1.04 ± 0.07 s, P=0.012), stance time (0.66 ± 0.06 s vs. 0.68 ± 0.06 s, P=0.045), and single support time (0.36 ± 0.03 s vs. 0.37 ± 0.02 s, P=0.011). High amplitude of joint motion was detected in the sagittal plane in the left hip (37.6° ± 5.3° vs. 35.5° ± 6.2°, P=0.014), left thigh (38.0° ± 5.2° vs. 36.4° ± 5.8°, P=0.026), left shank (71.9° ± 5.7° vs. 70.1° ± 5.6°, P=0.031), and right knee (59.1° ± 4.8° vs. 56.4° ± 4.8°, P=0.001). The motor symmetry of thigh improved from 8.35 ± 5.30% to 6.30 ± 4.73% ( P=0.042). Conclusions::The accelerated gait in response to visual restoration is characterized by decreased stance time and increased range of joint motion. Training programs for improving muscle strength of lower extremities might be helpful to facilitate the adaptation to these changes in gait.

Objective:To investigate the correlation of isokinetic thigh muscle asymmetry with gait asymmetry at one year after anterior cruciate ligament (ACL) reconstruction.Methods:A retrospective case series analysis was made on 25 patients treated by ACL reconstruction in Third Hospital of Peking University from January 2014 to January 2019. All the subjects were male, aged 17-47 years [(29.4±5.2)years]. Standard rehabilitation treatment procedures were conducted after surgery. The isokinetic muscle strength of the thigh was collected at one year after operation to evaluate knee extensor and flexor concentric strength at 60°/s, 180°/s and 300°/s, and knee extensor and flexor eccentric strength at 60°/s. The maximum concentric and eccentric strength of the knee extensor and flexor were analysed between the injured and intact side. The three-dimensional motion information and ground reaction force was collected during the stance phase of gait, and knee kinematic and kinetic parameters were calculated by inverse dynamics analysis, including the peak flexion moment, peak extension moment, first and second peak adduction moment, peak external and internal rotation moment, peak flexion angle, peak extension angle during the terminal stance phase, flexion angle at heel strike, peak abduction angle, and peak external rotation angle during terminal stance phase. Spearman correlation analysis was used to study the correlation between limb symmetry index (LSI) of isokinetic muscle strength and LSI of gait parameters.Results:One year after ACL reconstruction, the maximum concentric strength of the knee extensor and flexor at 60°/s, 180°/s and 300°/s and maximum eccentric strength of the knee flexor and extensor at 60°/s on the injured side were significantly lower than those on the normal side (all P<0.01). Compared with the intact side, the peak knee extension moment on the injured side was significantly lower during the stance phase of gait ( P<0.01), and the extension angle was insufficient during the terminal stance phase ( P<0.01). There were no significant differences between the injured and intact side in terms of peak flexion moment, first and second peak adduction moment, peak external and internal rotation moment, peak flexion angle, flexion angle at heel strike, peak abduction angle, and peak external rotation angle during terminal stance phase (all P>0.05). One year after ACL reconstruction, Spearman correlation analysis during gait stance phase showed that the LSI of 60°/s concentric strength of the isokinetic knee extensor was significantly related to LSI of peak internal rotation moment ( R=0.42, P<0.05), the LSI of 180°/s concentric strength of the isokinetic knee extensor was significantly related to LSI of peak flexion moment ( R=0.45, P<0.05), the LSI of 180°/s concentric strength of the isokinetic knee flexor was significantly correlated with LSI of peak flexion angle ( R=0.46, P<0.05), the LSI of 300°/s concentric strength of the isokinetic knee extensor was significantly correlated with LSI of peak knee flexion angle ( R=0.42, P<0.05), and the LSI of 60°/s eccentric strength of the isokinetic flexor was significantly correlated with LSI of peak knee flexion angle ( R=0.54, P<0.01). Conclusions:For patients following ACL reconstruction at one year postoperatively, a significant correlation of isokinetic thigh extensor strength asymmetry with peak knee flexion and rotation moment and peak knee flexion angle, and that of isokinetic thigh flexor strength asymmetry with peak knee flexion angle are observed during the stance phase of gait, which suggests that patients with ACL reconstruction still need systematic rehabilitation training one year postoperatively to improve muscle strength and motor function so as to reduce the risk of ACL reinjury and secondary injury.

Lateral ankle avulsion fracture is a common sports injury that can lead to chronic lateral ankle instability and substantial deterioration of the joint function. Currently, problems such as misdiagnosis, inappropriate treatment, disparate outcomes and lack of standardization are usually met in the diagnosis and treatment of lateral ankle avulsion fracture. The Foot and Ankle Committee of Chinese Association of Sports Medicine Physicians thus organized a working group of experts in the field of sports medicine and ankle surgery from China to develop "An evidence-based clinical guideline for the diagnosis and treatment of lateral ankle avulsion fractures (2022 version)" in accordance with the principle of evidence-based medicine and scientificity and practicability. The guideline covered the topics of imaging diagnosis, indications and methods of non-operative and operative treatment as well as postoperative rehabilitation, in order to provide guidance for the diagnosis and treatment of lateral ankle avulsion fracture.

Objective:To evaluate the clinical value of endoscopic release therapy for fecal impaction in the colorectal diverticulum.Methods:Data of patients with fecal impaction in the colorectal diverticulum who received endoscopy in Shantou Central Hospital from January 2018 to September 2020 were included in this study. Among them, 85 patients treated with endoscopic release therapy were assigned to the observation group (2 patients were excluded from the observation group due to acute appendicitis), and 43 patients receiving no treatment were assigned to the control group. The relief of abdominal symptoms was used as an index to evaluate the clinical value of endoscopic release therapy for fecal impaction in the colorectal diverticulum.Results:In the observation group, 42.2% (35/83) were successfully released at one time. The successful comprehensive measures accounted for 25.0% (12/48) of the first release failure, and the total success rate was 56.6% (47/83). There were no complications related to endoscopy in the observation group. One week after the treatment, patients in the observation group were followed up by telephone. Among the 45 patients who were successfully released, positive symptoms of 30 patients disappeared or significantly improved with the effective rate of 90.9% (30/33). Among the 38 patients who failed to release the fecal impaction, 19 had positive symptoms and 16 improved in varying degrees with the effective rate of 55.2% (16/29). The overall effective rate of the observation group was higher than that of the control group [55.4% (46/83) VS 7.0% (3/43)], showing significant difference( χ2=23.354, P<0.01). The effective rate were significant differences in the successful release group [65.2% (30/46)], unsuccessful release group [29.7% (11/37)] and the control group [7.0% (3/43), χ2=33.792, P<0.01]. By pairwise comparison, the effective rate of the successful release group was the highest, followed by the unsuccessful release group, and that of the control group was the lowest with significant difference ( P<0.017). Conclusion:The endoscopic release therapy for fecal impaction in the colorectal diverticulum is relatively simple, which can relieve and reduce related symptoms, avoid complications, missed diagnosis and misdiagnosis, and show definite curative effects. When colorectal diverticulum with fecal impaction is found in the process of endoscopy, it is of great practical significance to release the incarcerated feces by means of different methods.

Objective Gait analysis plays an important role in the description of the site and degree of injury in the lower limbs, and symmetry is an important indicator of gait characteristics. The aim of this study is to quantitatively describe gait information and its asymmetry in three-dimensional space, dig deeper into gait information and improve the analysis of abnormal gait characteristics.Methods The information about the change of coronal-sagittal plane angle in different parts was obtained based on the inertial gait sensor, and the gait space vector was inverted to build the movement curve and form a motion symmetry detection method based on three-dimensional space angle vector distance. The characteristics of normal subjects (control group) and the anterior cruciate ligament (ACL) rupture patients (patients group) were analyzed from July, 2017 to January, 2018, and its effectiveness was verified.Results There was a better discrimination effect in the calf, thigh and knee asymmetry, etc., between the control group and the patient group (P<0.05). The characteristics of the calf space motion vector were highest among the control group and the patient group, and the discrimination was relatively stable, and not various with gender, age, height or body mass index.Conclusion The time-coronal-sagittal vector diagrams of left and right limbs were obtained by inertial sensor and the average of the square of the Euclidean distances in space at the selected gait cycle time points was calculated in three-dimensional space, which could be used as a gait asymmetry analysis method.

Objective To identify the differences of three-dimensional knee kinematics of unilateral anterior cruciate ligament (ACL) deficient patients with and without the meniscus injury.Methods A total of 39 subjects including unilateral isolate ACL-deficient patients (ACL group,n=13),ACL deficient patients combined with meniscus tear (ACL+M group,n=13) and healthy controls (C group,n=13) participated in this study.In the gait analysis,three-dimensional knee kinematic and kinetic parameters were collected synchronously and compared.Results The peak knee flexion angles were greater in the ACL+M group and C group compared with the ACL group (P=0.001,P=0.001),with no significant differences between the former two groups (P=0.847).Lower first peak vertical ground reaction force,peak posterior ground reaction force,sagittal plane knee excursions and peak knee extension moment were found in ACL-injured side compared with the contralateral side (P=0.001,P＜0.001,P=0.006,P=0.001).Greater peak knee abduction moment was found in group ACL+M compared with both the ACL and C groups (P=0.045,P=0.014).However,no significant difference was observed between the ACL group and C group in peak knee abduction moment (P=0.616).Conclusions The altered loading in unilateral ACL deficient patients can lead to lower ground reaction force in injured knee and greater ground reaction force in the contralateral side,which may increase the risk of developing knee osteoarthritis.The greater internal knee abduction moment in ACL deficient patients combined with meniscus injury may be a risking factor for the knee osteoarthritis.

Objective:To evaluate the change in hamstring ( H ):quadriceps ( Q ) ratio following anterior cruciate ligament ( ACL) rupture during isokinetic knee extension and flexion at 30 degrees of flexion which is important for knee dynamic function .Methods:A study was performed in 25 male com-plete unilateral ACL ruptures .Isokinetic concentric and eccentric quadriceps and hamstring muscle tests in both the deficient knees and intact knees were performed at 60°/s, respectively.At 30 degrees of flexion, the average torque of quadriceps and hamstring , Qe∶Qc ratios ( ratios of eccentric quadriceps to concentric quadriceps muscle torque ) , He∶Hc ratios ( eccentric hamstring to concentric hamstring ) , Hc∶Qc ratios ( concentric hamstring to concentric quadriceps ) , He∶Qc ratios ( eccentric hamstring to con-centric quadriceps ) , and Hc∶Qe ratios ( concentric hamstring to eccentric quadriceps ) were calculated . Wilcoxon matched-pairs signed-ranks test was used .Results:At 30 degrees of knee flexion , a significant reduction ( P<0.05) in the average torque of quadriceps was observed at concentric and eccentric 60°/s produced by the deficient-side compared with the intact side .In addition, Hc∶Qc, He∶Qc, and Qe∶Qc significantly increased on the ACL-deficient side .Conclusion:The change in H ∶Q ratio in the mode of isokinetic 60 °/s at 30 degrees of knee flexion might therefore be a new tool to objectively document muscle function in ACL-deficient knee .

OBJECTIVE To describe the clinical, CT or MRI, pathological characteristics of desmoplastic fibroblastoma for helping the diagnosis and treatment. METHODS The clinical data of 4 cases with desmoplastic fibroblastoma were retrospectively analyzed. RESULTS The tumors of all 4 cases were found in the compartment of muscles, and can be removed by conservative excision. The 4 cases were followed up for 38, 7, 6, 3 months respectively, and no local recurrences were found. CONCLUSION Desmoplastic fibroblastoma is a benign fibroblastic neoplasm with distinctive clinical, CT or MRI imaging and pathological characteristics. Optimal management is conservative excision with functional preservation. Needle aspiration cytology and immunohistochemistry are of non-diagnostic value.

Objective To study the effects of continuous passive motion(CPM)on tissue blood oxygen saturation(StO2)in the edge of wound after anterior cruciate ligament(ACL)reconstruction in rabbits.Methods Twenty male New Zealand rabbits,aged 8 months,received an ACL reconstruction by using double semitendinous tendon autograft in the right hind leg.The rabbits were randomly divided into 2 groups postoperatively,namely Cage activity group(n=10)and CPM group(n=10),treated with cage activity and activity by rabbit knee joint continuous passive motion apparatus respectively.On the following day after operation,a near-infrared optical device and ODISseyTM Tissue Oximeter were applied to measure the changes of tissue oxygen saturation(StO2)in the edge of the wound in each cycle(with flexion of 30?-110?)and various CPM speeds(2.35?/s,3.2?/s,and 8?/s),and the optimal CPM range and speed was thus selected for analyzing the changes of StO2 in local tissues of wounds with various angles of CPM in knee joint before the operation and on the 2nd,4th,6th,8th,10th,and 14th postoperative days.Results There was a significant difference with regard to StO2 between CPM group and Cage activity group(P0.05),however,a significant difference was observed among different time points(before the operation,and 2,4,6,8,10,14 days after the operation)(P