Comparison and analysis of skiing injuries at ski resorts in Chongli, China and Japan / 中华创伤杂志(英文版)

PURPOSE@#The rapid development of winter sports requires investigation on injuries in Chongli district, Zhangjiakou city, one of the ski sites of the 2022 Winter Olympics. Careful evaluation is required to observe which injuries are caused under what circumstances, and then we can make corresponding preventive measures and recommendations based on the results.@*METHODS@#In this retrospective study, the data of injury cases at ski resorts in China (Chongli district) and Japan were analyzed to provide a reference for the ongoing injury prevention at ski resorts. We collected data on injuries at Wanlong and Fulong ski resorts in Chongli district during the 2017-2018 and 2018-2019 ski seasons. We referred to the skiing injury report issued in February 2020 of a nationwide ski safety statistical service - Japan Ski Safety Association. The causes of injury and specific injured body parts were analyzed based on the data of Chinese and Japanese ski resorts. Statistical significance has been calculated using the Chi-square test.@*RESULTS@#During the 2019-2020 ski season in Japanese ski resorts, the number of reported injuries per 10,000 skiers was 0.93, of which 457 (17.3%) were over 50 years old, accounting for a large proportion of injuries, meanwhile in Chongli ski resort, the injury rate of skiers aged 50 and over was 7.1%. The knee joint (23.7% at Wanlong ski resort and 28.4% in Japanese ski resorts) was the most injured body part among Chongli and Japanese skiers. Among snowboarders, shoulder joint injury (17.7% in Japanese ski resorts) was the most common, and injury on hands and fingers (16.3% in Wanlong ski resorts) was the most common. Head injury rates are similar in Chongli, China and Japanese ski resorts (8.2% and 8.7%, respectively).@*CONCLUSION@#Our analysis demonstrated that injury data recorded among young skiers was higher in Chinese ski resorts (Chongli district) than that in Japanese ski resorts, and elderly skiers made up a larger proportion of skiing injuries in Japanese resorts. Thus, according to our research, the protection of knee joints, shoulder joints, and hands and fingers should be taken seriously. It should pay attention to the teaching of ski poles (for finger protection), and use protective devices such as knee pads, helmets, etc.

Meniscus repair with simultaneous anterior cruciate ligament reconstruction: Clinical outcomes, failure rates and subsequent processing / 中华创伤杂志(英文版)

PURPOSE@#To retrospectively analyze the clinical outcomes of meniscus repair with simultaneous anterior cruciate ligament (ACL) reconstruction and explore the causes of failure of meniscus repair.@*METHODS@#From May 2013 to July 2018, the clinical data of 165 patients who were treated with meniscus surgery and simultaneous ACL reconstruction, including 69 cases of meniscus repair (repair group) and 96 cases of partial meniscectomy (partial meniscectomy group) were retrospectively analyzed. The exclusion criteria were as follows: (1) ACL rupture associated with fracture, collateral ligament injury, or complex ligament injury; (2) a history of knee surgery; or (3) a significant degree of osteoarthritis. The 69 patients in the repair group were divided into the non-failure group (62 cases) and the failure group (7 cases) depending on the repair effect. Postoperative outcomes of the repair group and the partial meniscectomy group were compared. General conditions and postoperative outcomes of the failure group and the non-failure group were compared. During the median follow-up period of 28 months (range, 4 - 65 months) after the second arthroscopy, postoperative outcomes of seven patients in the failure group were summarized. SPSS 25.0 statistical software was used for statistical analysis. A p value less than 0.05 was considered statistically significant.@*RESULTS@#Seven patients in the failure group who underwent the second arthroscopy were followed up for (30 ± 17.4) months and their postoperative outcomes were summarized. Compared with the partial meniscectomy group, the International Knee Documentation Committee scores of patients in the repair group improved significantly (p = 0.031). Compared with the non-failure group, more patients in the failure group were younger than 24 years (p = 0.030). The median follow-up period was 39.5 months. All patients recovered well after subsequent partial meniscectomy and relieved clinical symptoms. Visual analog scale scores decreased significantly (p = 0.026), and the International Knee Documentation Committee and Lysholm scores improved significantly (p = 0.046 for both).@*CONCLUSION@#The failure rate of meniscus repair in this study was 10.1% (7/69), all of which were medial meniscus tears. However, the surgical outcomes of ACL reconstruction were not affected, and there might be a role for graft protection. Therefore, meniscus retears can be successful treated by performing subsequent partial meniscectomy in patients with repair failure.

Effects of visual restoration on dynamic plantar pressure features in elder individuals / 北京大学学报(医学版)

OBJECTIVE@#To analyze the effects of visual restoration after cataract surgery on plantar pressure and biomechanics of foot in elder individuals.@*METHODS@#Thirty-two patients [male/female 5/27, (70.1±5.2) years old] with age-related cataract were recruited between October 2016 and December 2019. The footscan system was employed to record the data of plantar pressure during level walking before and 1-month after the cataract surgery. Parameters of peak pressure (PP), impulse (I), pressure-time integral (PTI) and time to peak pressure (TPP) from the regions of the 1st toe (T1), 2nd to 5th toes (T2-5), 1st to 5th metatarsal heads (M1-M5), midfoot (MF), medial hindfoot (HM) and lateral hindfoot (HL) were analyzed respectively.@*RESULTS@#Post-operatively, the visual function was effectively reconstructed with improved visual acuity in both eyes (Z=-4.878, -4.801; P < 0.001). The PP (t=2.266, P=0.031) and I (t=2.152, P=0.039) values in M2 region on the dominant side (right foot) increased statistically at post-operative phase, while the changes of pressure and temporal para-meters in other regions remained stable. There was laterality in plantar pressure at pre-operative phase, manifested as greater PP values in M1, M2, MF, and HM regions on the dominant sides (t=-2.414, -2.478, -2.144, -5.269; P < 0.05), greater PP values in T1, M3, M5 and HL regions on the non-dominant sides (t=4.830, 3.155, 2.686, 3.683; P < 0.05), greater I values in M1, MF, and HM regions on the dominant sides (t=-2.380, -2.185, -5.320; P < 0.05) and greater I values in T1, M3, M5 and HL regions on the non-dominant sides (t=4.489, 2.247, 2.838, 3.992; P < 0.05). post-operatively, the pressure tended to be compatible between the two sides in regions of M3 and MF, while the magnitude of laterality in regions of M1 (ZPP△= -2.721, P=0.007; ZI△=-2.581, P=0.010), M2 (ZPP△=-2.674, P=0.007; ZI△=-2.375, P=0.018) and M5 (ZPP△=1.991, P=0.046; ZI△=2.150, P=0.032) was further increased.@*CONCLUSION@#Changes in plantar pressure after cataract surgery were characterized as increased pressure in the 2nd metatarsal head area on the dominant side. Visual restoration might intensify the laterality in the medial of forefoot on the dominant side and the lateral of forefoot on the non-dominant side.

Changes of electroencephalography power spectrum during joint position perception test after anterior cruciate ligament rupture / 北京大学学报(医学版)

OBJECTIVE@#To measure the electroencephalography (EEG) of the patients with anterior cruciate ligament (ACL) rupture when performing joint position perception movement task, to compare the differences between the ACL rupture side and the unaffected side, to identify the EEG change in the power spectrum caused by the ACL rupture, and to provide evidence for the diagnosis, treatment and rehabi-litation for ACL injury as well as knee instability.@*METHODS@#Sixteen male patients, selected from the Department of Sports Medicine, Peking University Third Hospital from November 2014 to April 2015, with only ACL rupture on one side used isokinetic muscle strength testing equipment were enrolled in the study to perform unilateral active knee joint positional movement and passive knee joint positional movement tasks. EEG was recorded to compare between the affected and unaffected limb of ACL rupture patients when doing single leg movement tasks, including passive knee joint position test and active knee joint position sensation test. The target position of the active knee joint position movement task and the passive knee joint position movement task was 30 degrees of knee flexion.@*RESULTS@#During the passive knee joint position test, there was no significant difference in EEG power spectrum of Delta[F (1, 15)=0.003, P=0.957, ηP2 =0.001], Theta[F (1, 15)=0.002, P=0.962, ηP2 < 0.001], Alpha[F (1, 15)=0.002, P=0.966, ηP2 =0.001], Beta[F (1, 15)=0.008, P=0.929, ηP2 =0.001] at Fz, Cz, and Pz between the affected and unaffected limbs in the ACL patients. During the active knee joint position movement task, the EEG power spectrum of Delta, Theta, Alpha, Beta at Fz and Cz location, on the affected side was significant higher than on the unaffected side.@*CONCLUSION@#This study compared the differences between the ACL rupture side and the unaffected side during active knee position movement task and passive knee position movement task, and identifyied the EEG changes in the power spectrum caused by the ACL rupture, It was found that the central changes caused by unilateral ACL rupture still existed during contralateral (unaffected) side movement. The EEG power spectrum of the affected side during active exercise was significantly higher than that of the unaffected side This study provides new electrophysiological evidence for the study of ACL injury.

Finite element analysis of the graft stresses after anterior cruciate ligament reconstruction / 北京大学学报(医学版)

OBJECTIVE@#To explore the stress distribution characteristics of the graft after anterior cruciate ligament (ACL) reconstruction, so as to provide theoretical reference for the surgical plan of ACL reconstruction.@*METHODS@#Based on 3D MRI and CT images, finite element models of the uninjured knee joint and knee joint after ACL reconstruction were established in this study. The uninjured knee model included femur, tibia, fibula, medial collateral ligament, lateral collateral ligament, ACL and posterior cruciate ligament. The ACL reconstruction knee model included femur, tibia, fibula, medial collateral ligament, lateral collateral ligament, ACL graft and posterior cruciate ligament. Linear elastic material properties were used for both the uninjured and ACL reconstruction models. The elastic modulus of bone tissue was set as 17 GPa and Poisson' s ratio was 0.36. The material properties of ligament tissue and graft were set as elastic modulus 390 MPa and Poisson's ratio 0.4. The femur was fixed as the boundary condition, and the tibia anterior tension of 134 N was applied as the loading condition. The stress states of the ACL of the intact joint and the ACL graft after reconstruction were solved and analyzed, including tension, pressure, shear force and von Mises stress.@*RESULTS@#The maximum compressive stress (6.34 MPa), von Mises stress (5.9 MPa) and shear stress (1.83 MPa) of the reconstructed ACL graft were all at the anterior femoral end. It was consistent with the position of maximum compressive stress (8.77 MPa), von Mises stress (8.88 MPa) and shear stress (3.44 MPa) in the ACL of the intact knee joint. The maximum tensile stress of the graft also appeared at the femoral end, but at the posterior side, which was consistent with the position of the maximum tensile stress of ACL of the uninjured knee joint. More-over, the maximum tensile stress of the graft was only 0.88 MPa, which was less than 2.56 MPa of ACL of the uninjured knee joint.@*CONCLUSION@#The maximum compressive stress, von Mises stress and shear stress of the ACL graft are located in the anterior femoral end, and the maximum tensile stress is located in the posterior femoral end, which is consistent with the position of the maximum tensile stress of the ACL of the uninjured knee joint. The anterior part of ACL and the graft bore higher stresses than the posterior part, which is consistent with the biomechanical characteristics of ACL.

Mid-to-long term clinical outcomes and predictors after anterior cruciate ligament revision / 北京大学学报(医学版)

OBJECTIVE@#To assess the mid-to-long term clinical outcomes after anterior cruciate ligament (ACL) revision surgery and to analyze their predictors.@*METHODS@#The medical records of 235 patients undergoing ACL revision surgery between Jan. 2001 and Dec. 2015 at Department of Sports Medicine, Peking University Third Hospital were reviewed. Data were collected including demographic information, information related to revision surgery (time and cause of graft failure, date of revision surgery, surgical technique, combined injuries and management, etc.), as well as information related to primary ACL reconstruction (time, cause and mechanism of first-time ACL rupture, date of primary ACL reconstruction, surgical technique, combined injuries and management, etc.). Patients were followed up at least 2 years after revision surgery for clinical outcomes [Tegner score, Lysholm score, and International Knee Documentation Committee (IKDC) subjective knee score]. Post-revision surgeries on the involved knee and the contralateral knee joint were also documented. Multivariate regression model was used to analyze the predictors of clinical outcomes after ACL revision surgery.@*RESULTS@#A total of 166 (70.63%) patients were followed up at a mean of (4.44±2.40) years (2.03-14.63 years). Clinical outcomes improved significantly at the last follow-up from pre-operative level, with the Lysholm, Tegner, and IKDC scores improving from 70.51±21.25, 3.39±1.77, 63.78±15.04 to 88.64±14.36, 4.67±1.739, 80.23±13.31 (P < 0.05), respectively. Three (1.81%) patients experienced infection while 39 (23.49%) patients underwent surgery after revision surgery during the follow-up. Compared with that those occurred during sports, graft failure that occurred during daily activities or due to surgical technical errors that led to poorer clinical outcomes, with the Lysholm, Tegner, and IKDC scores of 9.90 (95%CI: 1.49-18.31), 1.41 (95%CI: 0.10-2.72), 10.35 (95%CI: 0.17-20.54), and 8.53 (95%CI: 1.31-15.75), 1.28 (95%CI: 0.14-2.43), 9.39 (95%CI: 1.03-17.74) lower, respectively. Compared with antero-medial portal, transtibial technique for placement of the femoral bone tunnel showed poorer Lysholm scores of 11.18 (95%CI: 4.73-17.63, P=0.001). Concurrent repair of medial meniscus yielded higher IKDC scores of 11.06 (95%CI: 1.21-20.92, P=0.029) than those with intact medical meniscus. Other factors showed no significant effect.@*CONCLUSION@#ACL revision surgery is able to restore knee stability and improve knee function. Graft failure caused by sports, concurrent repair of medical meniscus and antero-medial portal technique predicts better outcomes after revision surgery.

Management algorithm for septic arthritis after anterior cruciate ligament reconstruction / 北京大学学报(医学版)

OBJECTIVE@#To summarize the experience in the diagnosis and management of septic arthritis after anterior cruciate ligament reconstruction.@*METHODS@#A retrospective review was conducted of all the arthroscopic anterior cruciate ligament reconstructions performed at Department of Sports Medicine, Peking University Third Hospital between January 2001 and December 2020. In the study, 65 of 27 867 patients experienced postoperative septic arthritis. The incidence, presentation, laboratory results, treatment, and outcome of all the infected patients were analyzed. The experiences of diagnosis and management of septic arthritis after anterior cruciate ligament reconstruction were summarized.@*RESULTS@#A total of 27 867 anterior cruciate ligament reconstructions were performed at our department between January 2001 and December 2020. In the study, 65 (0.23%) patients were identified with postoperative septic arthritis. The most common symptoms of the infected patients were fever (38.7±0.5) ℃, knee swelling, pain, and restricted motion. The mean peripheral white blood cell count (WBC) was (9.2±2.6)×109/L (range 4.2×109/L-19.4×109/L), with (72.5±6.3) % (range 54.9%-85.1%) polymorphonuclear neutrophils (N). The mean erythrocyte sedimentation rate (ESR) was (59.9±24.1) mm/h (range 9-108 mm/h), C-reactive protein (CRP) was (10.9±5.7) mg/dL (range 1.2-30.8 mg/dL), and fibrinogen (FIB) level was (7.0±1.6) g/L (range 3.7-10.8 g/L). All of the laboratory results were statistically higher in the infection group compared with the normal postoperative group (P＜0.001). The synovial white blood cell count (SWBC) of aspirated knee joint fluid was (45.0±29.8)×109/L (range 7.1×109-76.5×109/L). Polymorphonuclear cell percentage (PMNC) was (90.27±7.86) % (range 60%-97%). In the study, 45 patients (69.2%) had positive aspirate cultures. Microbiology showed coagulase-negative Staphylococcus (CNS) and Staphylococcus aureus (SA) were the most common bacterium (34 cases and 7 cases, individually). There were 26 methicillin-resistant Staphylococcus. Both conservative (16 patients) and operative (49 patients) treatments were effective, but conservative group had a longer recovery time (5.6 d vs. 1.6 d, P=0.042).@*CONCLUSION@#Septic arthritis after arthroscopic anterior cruciate ligament reconstruction is a rare but potentially devastating complication. The correct diagnosis relies on synovial fluid analysis and bacterial culture. Our proposed treatment protocol is arthroscopic debridement and antibiotic therapy as quickly as possible.

Comparison of acute sports injury between recreational skiers and skiers / 北京大学学报(医学版)

OBJECTIVE@#To compare and analyze the difference between the injuries of recreational skiers in public ski resorts and those of skiing athletes in official competitions, and to explore the suggestions of medical insurance for these two types of skiers.@*METHODS@#The injury data of recreational skiers in Chongli District, Zhangjiakou City, Hebei Province during 2018-2019 and 2019-2020 snow seasons, and the injury data of skiers in two official international skiing competitions during 2019-2020 snow season and domestic test events in Chongli District of 2021 Winter Olympic Games were analyzed retrospectively, and the similarities and differences were compared.@*RESULTS@#A total of 1 187 injuries occurred to recreational skiers in the two public ski resorts during the 2018-2019 snow season, with an injury rate of 0.3%.There were 1 277 injury sites in total, and the most frequent injury sites were head and neck (230 cases, 18.0%), followed by knee joint (204 cases, 16.0%) and lower extremity (131 cases, 10.3%). Thirty-one skiers were injured in the two official international skiing competitions in the 2019-2020 and 2020-2021 snow season, and in the domestic test competitions in the 2021 Winter Olympic Games, and the injury rates were 11.5%, 17.2% and 12.0%, respectively. There were 37 injury sites in total, among which 11 (29.7%) were in the head and neck, followed by 6 (16.2%) in the knee joint and 5 (13.6%) in the chest, rib and abdomen.@*CONCLUSION@#In order to better guarantee the safety of skiers and timely provide corresponding medical help, safety facilities and technical guidance should be added to the snow resort for leisure skiing, and medical stations should be set up in the snow resort. As the formal ski racing for skiing athletes during the game has 30 to 80 times higher injury ratesthan recreational skiers, and compared with the recreational skiing, head and neck injury rate is higher, and the damage is much heavier, more complete first aid facilities and experienced medical workers are, needed so the field should be equipped with the circuit inside the quantities, track fixed outside the clinic, surrounding referral hospitals set up trauma centers to provide athletes with more timely medical care.

Role of ski injury treatment system between the ski resort medical station of Winter Olympics and the nearby medical care hospital / 北京大学学报(医学版)

OBJECTIVE@#To make a retrospective analysis of the situation and process of treating skiers' injuries in the medical station of the Wanlong ski resort in Chongli and the nearest treatment hospital, and to provide a basis for the establishment and optimization of the treatment process between the medical station of the Winter Olympics ski resort and the nearest treatment hospital, and to gain experience for medical security of mass skiing.@*METHODS@#The data of all ski injuries in Chongli District were collected from the medical station of the Wanlong ski resort during the 2018-2019 snow season (November 2018 to April 2019) and the nearest treatment hospital during two periods (March 2019, and November 2019 to January 2020). The differences of injury causes, injury types, injury sites, and treatment effects of the injured skiers were analyzed.@*RESULTS@#A total of 755 cases of ski injuries were recorded in the medical station of Wanlong ski resort, the estimated incidence of injury was 2.02‰ per day. The nearest treatment hospital treated a total of 838 injured skiers from different ski resorts in Chongli District in the two periods. In the records of the ski resort medical station, the main causes of injury were technical defects and turnovers (53.6%). Knee joint injury rate was the highest (18.7%), followed by head and neck (12.9%) and lower limb (11.9%). The number of injuries on intermediate roads was the highest (40.0%), the greatest number of injuries (81.2%) occurred when the age of skiing was less than 5 years. In the records of the nearest treatment hospital, the injury types were fracture or fissure fracture, contusion and trauma, and muscle and soft tissue injury, accounting for 30.5%, 27.4%, and 21.2% respectively. 9.6% of the injured took the snow field ambulance to the hospital, and 50% of them suffered from fractures or fissure fractures.@*CONCLUSION@#The injury rate of skiing in the 2018-2019 snow season of the Wanlong ski resort in Chongli was higher than that reported by foreign literature. Severe trauma (including severe fractures and concussions) could occur and patients needed to be transferred to the nearest hospital for treatment. The ski resort medical station and the nearest treatment hospital should be strengthened with adequate medical staff and equipment, and promote cooperation in the timely referral of seriously injured patients, the organization and construction of ski patrols and the medical security of large-scale competitions, thus playing an important role in forming a grassroots network of medical security and treatment system for skiing.

Characteristics and related factors of plantar pressure in the chronic ankle instability individuals / 北京大学学报(医学版)

OBJECTIVE@#To analyze characteristics and related factors of the plantar pressure during the level walking and single leg standing in the chronic ankle instability (CAI) individuals.@*METHODS@#From April 2019, 75 CAI individuals and 40 healthy individuals were enrolled in this study. Both of the static and dynamic plantar pressure were measured during six times level walking and three times single leg standing testing. The data including peak force, time to peak force in various foot contact areas and the time to boundary (TTB) and velocity of center of pressure (COP) were measured and compared between the affected side and the unaffected side and between the CAI cases and the healthy individuals. The correlations between the plantar pressure and the gender, Beighton score, affected side and body mass index (BMI) were analyzed.@*RESULTS@#The characteristics of plantar pressure distribution in the CAI individuals included: (1) During the level walking, the affected side showed the similar pressure contribution as the unaffected side (P>0.05). While compared with healthy individuals, there was a significantly higher peak force in the 5th metatarsal area (t=-3.86, P=0.03) of the affected side, lower peak force in the 1st (t=2.99, P=0.02), 2nd metatarsal head areas (t=2.09, P=0.01) of the affected side, medial hindfoot areas of both sides (affected, t=2.33, P=0.01; unaffected, t=3.74, P=0.02) and toes areass of both sides (affected, t=2.23, P=0.01; unaffected, t=3.28, P=0.02) and a delay to peak force in the 4th metatarsal head area (t=3.33, P=0.01) of the affected side. (2) During the single leg standing, the CAI individuals showed significantly worse balance control in the anterior/posterior direction (P < 0.05) and lateral/medial direction (P < 0.05) compared with the healthy controls, and the affected side had more severe balance control deficit in the lateral/medial direction (P < 0.05). (3) The women (P < 0.05) and the individuals with higher Beighton scores (P < 0.05) showed worse balance control deficit in the lateral/medial direction.@*CONCLUSION@#CAI individuals showed significantly a more lateral shifted plantar distribution during the level walking compared with the healthy individuals and the tendency was worse on the affected sides, and showed worse balance control in the anterior/posterior direction and lateral/medial direction during the single leg standing. The women and those with generalized ligament laxity showed significantly worse balance control.

Analysis of the mass skiers' injury in a large ski resort in Chongli, China / 北京大学学报(医学版)

OBJECTIVE@#To make a retrospective analysis of the injuries of skiing population in a large ski resort in Chongli, China and provide a basis for predicting the rapidly increasing medical needs for ski injuries in the context of the 2022 Winter Olympic Games.@*METHODS@#The basic data of all injured skiers who were treated in a medical station of a large ski resort in Chongli during the snow season from November 2017 to March 2018 and from November 2018 to March 2019 were collected. The number of skiers, the number of injuries, the causes of injuries, the types of injuries and the locations of injuries were compared.@*RESULTS@#A total of 753 skiers were injured in two snow seasons, and the estimated average incidence of injury was 4.53 and 4.46 per 1 000 skier days at the resort respectively. The average daily injury rate per 1 000 skiers in November of the two snow seasons was relatively low, with 2.20 and 1.38 cases respectively. The difference of injury rate in different months might have little to do with snowfall and more to do with passenger flow. In both the snow seasons, men accounted for more injuries than women, and injured skiers aged between 21 and 30 accounted for the largest proportion, reaching 36.8%. The main causes of injuries were falls (76.6%). The highest rate of injury was in the head and neck (17.9%), followed by the knee (17.4%) and wrist and fingers (13.3%). The most common types of injuries were contusion and trauma (29.5%) and joint and/or ligament injuries (22.2%). Children (2-12 years old) accounted for 12.7% of all the injured skiers. The rate of moderate to severe injuries (including fractures, concussions, etc.) was 34.8% among the injured patients over 50 years of age.@*CONCLUSION@#The snow resort should focus on injuries to children and elderly skiers and carry out targeted guidance and rescue work. In order to better ensure the medical safety of skiers, the ski resort medical station and nearby treatment hospitals should be equipped with a corresponding number of medical personnel and equipment, and the ski resort should further improve its safety management and rescue system.

Anatomical and finite element analysis of anterior cruciate ligament reconstruction within biomechanical insertion / 北京大学学报(医学版)

OBJECTIVE@#To provide new concepts of anterior cruciate ligament (ACL) reconstruction by anatomical gross observation of ACL tibial insertion and finite element analysis of distribution of ACL mechanical insertion.@*METHODS@#In the anatomical study, ten fresh adult cadaveric knees were dissected, including 6 males and 4 females, all knees were generally observed through standard medial parapatellar approaches, paying attention to the close anatomical relationship of tibial insertion and anterior horn of lateral meniscus, and ACL was exposed and gradually removed from the inside. The shape of tibial insertion of ACL was observed and recorded, and anterior-posterior diameters and left-right diameters of tibial insertion were measured with vernier caliper. For the study of finite element analysis, three-dimensional thin-layer magnetic resonance imaging of normal knee joint was used to establish knee joint model. Three-dimensional reconstruction software MIMICS and finite element analysis software ANSYS were used to establish knee joint model, subsequently, clinical physical examination Lachman test and pivot-shift test were simulated to observe the force distribution of ACL tibial insertion and femoral insertion.@*RESULTS@#The ACL tibial mechanical insertion was rather flat and long similar as an arc shape without a clear separation between anterior medial bundle (AMB) and posterolateral bundle (PLB) in gross observation. The dense fibers lies belonged to the medial intercondylar ridge and ended up anterior with the osseous landmark of anterior ridge. Its average anterior-posterior diameter was (13.8±2.0) mm, the average left-right diameter of midsubstance was (5.3±0.6) mm, and the average left-right diameter of anterior margin was (11.5±1.2) mm. The finite element analysis showed that distribution on the femoral side was oval shape mainly below the residents' ridge, while the tibial side was rather flat mainly along the medial intercondylar ridge, which was consistent with the anatomical observation. The biomechanical characteristics of ACL attachments were verified theoretically.@*CONCLUSION@#Anatomical study and finite element analysis have confirmed the flat arc shape of ACL tibial insertion. The ideal reconstruction technique of ACL should be based on its biomechanical insertion. Based on anatomical study and biomechanical analysis, we have proposed the idea of ACL biomechanical insertion reconstruction (BIR) and established a surgical model with oval femoral tunnel and rounded-rectangle tibial tunnel.

The Hug-up Test: A New, Sensitive Diagnostic Test for Supraspinatus Tears / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The supraspinatus tendon is the most commonly affected tendon in rotator cuff tears. Early detection of a supraspinatus tear using an accurate physical examination is, therefore, important. However, the currently used physical tests for detecting supraspinatus tears are poor diagnostic indicators and involve a wide range of sensitivity and specificity values. Therefore, the aim of this study was to establish a new physical test for the diagnosis of supraspinatus tears and evaluate its accuracy in comparison with conventional tests.</p><p><b>METHODS</b>Between November 2012 and January 2014, 200 consecutive patients undergoing shoulder arthroscopy were prospectively evaluated preoperatively. The hug-up test, empty can (EC) test, full can (FC) test, Neer impingement sign, and Hawkins-Kennedy impingement sign were used and compared statistically for their accuracy in terms of supraspinatus tears, with arthroscopic findings as the gold standard. Muscle strength was precisely quantified using an electronic digital tensiometer.</p><p><b>RESULTS</b>The prevalence of supraspinatus tears was 76.5%. The hug-up test demonstrated the highest sensitivity (94.1%), with a low negative likelihood ratio (NLR, 0.08) and comparable specificity (76.6%) compared with the other four tests. The area under the receiver operating characteristic curve for the hug-up test was 0.854, with no statistical difference compared with the EC test (z = 1.438, P = 0.075) or the FC test (z = 1.498, P = 0.067). The hug-up test showed no statistical difference in terms of detecting different tear patterns according to the position (χ2 = 0.578, P = 0.898) and size (Fisher's exact test, P > 0.999) compared with the arthroscopic examination. The interobserver reproducibility of the hug-up test was high, with a kappa coefficient of 0.823.</p><p><b>CONCLUSIONS</b>The hug-up test can accurately detect supraspinatus tears with a high sensitivity, comparable specificity, and low NLR compared with the conventional clinical tests and could, therefore, improve the diagnosis of supraspinatus tears in clinical settings.</p>

Anterior cruciate ligament reconstruction using the bone-posterior cruciate ligament-bone allograft / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Allografts were widely used in anterior cruciate ligament (ACL) reconstruction for patients with ACL rupture of the knee. This study was to approve the feasibility of bone-posterior cruciate ligament-bone (BPCLB) allograft transplantation in ACL reconstruction.</p><p><b>METHODS</b>Eight patients underwent ACL reconstructions with BPCLB allografts and were followed up for an average period of 32 months after operation.</p><p><b>RESULTS</b>Subjective parameters including International Knee Documentation Committee (IKDC), modified Larson knee ligament, Lysholm, and Tegner rating scales were much improved and side to side KT-2000 arthrometer difference was much less postoperatively. Pivot shift test was negative in all patients. The reconstructed ACL had satisfactory shape and tension.</p><p><b>CONCLUSIONS</b>BPCLB allograft is an optional choice for ACL reconstruction.</p>

Anterior cruciate ligament remnants nodule: potential factor causing extension loss / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Extension loss caused by anterior cruciate ligament (ACL) remnants nodule was usually reported by case reports. There is no systematic report analyzing ACL remnants nodule. The purpose of this study was to investigate the characteristics of extension loss caused by remnants of ACL after injury.</p><p><b>METHODS</b>From June 2008 to December 2011, ACL remnants were observed by arthroscopy in 1012 cases with ACL injuries at the time of primary reconstruction. ACL remnants nodules were recorded. The time of extension loss occurrence caused by ACL remnants nodule, associated symptom and sign, magnetic resonance imaging (MRI), and arthroscopic findings were observed. Histological examination was performed on the lesion resected.</p><p><b>RESULTS</b>Twenty-four cases with ACL remnants nodules were found by arthroscopy. Among them extension loss caused by remnants of ACL happened in 19 cases (male 13; female 6). The average extension loss were 9.1° (range, 5° - 20°). The average time from injury to operation was 8.9 weeks (range, 3 - 26 weeks). The remnants of ACL depressed in the inter-condylar notch were found on MRI in 15 cases with extension loss. The rupture locations of ACL were all close to the upper insertion of ACL. The microscopic examination of the resected remnants of ACL revealed disorganized fibrous connective tissue and tissue of ACL ligament.</p><p><b>CONCLUSIONS</b>Among 1012 ACL injury cases, 24 ACL remnants nodules were found with arthroscopy and 19 nodules could cause knee extension loss. ACL remnants nodule should be paid attention to as a potential cause of extension loss.</p>

Remnant-preserving posterior cruciate ligament reconstruction with graft tension-relieving: a comparative study with conventional technique / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Posterior cruciate ligament (PCL) tear is a severe injury to the knee joint and often requires surgical reconstruction. A number of PCL reconstruction techniques have been reported. However, the problem of residual laxity after surgery is not unusual with conventional techniques. This study aims to introduce a modified PCL reconstruction with remnant preservation and graft tension relieving.</p><p><b>METHODS</b>Between December 2008 and June 2011, 36 cases of PCL reconstruction were performed in our institute, 20 with conventional technique (Group I) and 16 with modified technique (Group II). Pre- and post-operative results of the international knee documentation committee knee evaluation form (IKDC), Lysholm, Tegner, and KT2000 side-to-side difference were obtained.</p><p><b>RESULTS</b>Significant improvements of IKDC, Lysholm, Tegner, and KT2000 results after surgery were found in both groups. Group II showed better improvement in all subjective examinations and significantly more decrease of KT 2000 side-to-side difference.</p><p><b>CONCLUSION</b>Modified PCL reconstruction with remnant preservation and graft tension relieving showed better results in restoration of posterior stability compared to conventional technique.</p>

Comparison of single and double bundle isolate posterior cruciate ligament reconstruction with hamstring autograft / 中华外科杂志

<p><b>OBJECTIVE</b>To determine if double bundle hamstring autograft posterior cruciate ligament (PCL) reconstruction could bring better outcomes than single bundle.</p><p><b>METHODS</b>From June 2007 to June 2009, there were 22 subjects, including 16 male and 6 female patients with an average (37 ± 13) years old (16-54 years old) were reconstructed with single bundle PCL reconstruction (single bundle group), 24 subjects, including 18 male and 6 female patients with an average (37 ± 10) years old (17 - 52 years old) were reconstructed with double bundle PCL reconstruction (double bundle group). There were no differences between the two groups on patients' demographics and the duration from the injury to the operation (P > 0.05). Clinical outcomes, KT2000 and tunnel placements of all the patients were measured and analyzed.</p><p><b>RESULTS</b>The two groups were retrospectively studied and compared with a (29 ± 9) months (24 - 55 months) follow-up. Operation duration of double bundle group was (92 ± 8) minutes which was significantly longer than the single bundle group (78 ± 13) minutes (t = 2.474, P < 0.05). IKDC, Lysholm and Tegner scores were all significantly improved at the last follow-up of both groups (single bundle group: t = 9.578, 13.115 and 8.165, P < 0.01; double bundle group: t = 4.390, 5.522 and 4.313, P < 0.05). Post operative KT2000 side-to-side difference of the double bundle group was significantly smaller than that of the single bundle group under maximum posterior force with the knee in 90° flexion ((1.5 ± 1.5) mm vs. (4.0 ± 2.9) mm, t = 2.538, P = 0.019). There were 66.7% of the patients of double bundle group were normal which was significantly higher than 31.8% of the single bundle group on the IKDC knee examination form (χ² = 5.576, P = 0.018).</p><p><b>CONCLUSIONS</b>Single or double bundle PCL reconstruction could restore the knee's stability and function satisfied. There are no differences between two groups in clinical scores, but double group manifestes a better anterior-posterior stability.</p>

Failed anterior cruciate ligament reconstruction: analysis of factors leading to instability after primary surgery / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Revision anterior cruciate ligament (ACL) surgery can be expected to become more common as the number of primary reconstruction keeps increasing. This study aims to investigate the factors causing instability after primary ACL reconstruction, which may provide an essential scientific base to prevent surgical failure.</p><p><b>METHODS</b>One hundred and ten revision ACL surgeries were performed at our institute between November 2001 and July 2012. There were 74 men and 36 women, and the mean age at the time of revision was 27.6 years (range 16 - 56 years). The factors leading to instability after primary ACL reconstruction were retrospectively reviewed.</p><p><b>RESULTS</b>Fifty-one knees failed because of bone tunnel malposition, with too anterior femoral tunnels (20 knees), posterior wall blowout (1 knee), vertical femoral tunnels (7 knees), too posterior tibial tunnels (12 knees), and too anterior tibial tunnels (10 knees). There was another knee performed with open surgery, where the femoral tunnel was drilled through the medial condyle and the tibial tunnel was too anterior. Five knees were found with malposition of the fixation. One knee with allograft was suspected of rejection and a second surgery had been made to take out the graft. Three knees met recurrent instability after postoperative infection. The other factors included traumatic (48 knees) and unidentified (12 knees).</p><p><b>CONCLUSION</b>Technical errors were the main factors leading to instability after primary ACL reconstructions, while attention should also be paid to the risk factors of re-injury and failure of graft incorporation.</p>

Clinical characteristics of 4355 patients with anterior cruciate ligament injury / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Clinical features of anterior cruciate ligament (ACL) injury are important for its prevention, diagnosis and treatment. However, few studies have reported such data, especially in China. The purpose of this study was to describe the clinical characteristics of ACL injury on a large cohort.</p><p><b>METHODS</b>Between 1993 and 2007, a total of 4355 ACL deficient inpatients (612 athletes and 3743 non-athletes) were registered. Data were collected using a special database system. And the distributions of characteristics in different groups were compared and analyzed statistically.</p><p><b>RESULTS</b>All subjects were confirmed with ACL tear during surgery. Statistical analysis revealed that the percentage of females in Athlete Group was significantly higher than that in Non-athlete Group (56.05% vs. 24.95%, P < 0.001). This study also found that sports trauma was the main cause of ACL tears. Soccer, basketball, judo, wrestling and track and field were the five most responsible activities for athletes. The average injury time for athletes was significantly shorter than that for non-athletes (413.3 days vs. 717.5 days, P < 0.001). Three thousand nine hundred and eight cases were ordered ACL reconstruction (76.04% single-bundle, 18.30% double-bundle). Three hundred and forty-five patients (7.92%) were combined with other ligaments injuries, 2667 (61.24%) were found with various grades of cartilage lesions, and 3377 (77.54%) were found with meniscal injury.</p><p><b>CONCLUSIONS</b>Sports trauma was the main cause of ACL tears in China, and reconstruction had become the principal surgical choice. In order to restore knee joint stability and reduce the incidence of cartilage and meniscal injury, patienttailored ACL reconstruction should be suggested at the right moment.</p>

Anatomical study of the anterolateral and posteromedial bundles of the posterior cruciate ligament for double-bundle reconstruction using the quadruple bone-tunnel technique / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Several techniques have been described for posterior cruciate ligament (PCL) reconstruction. However, double-bundle PCL reconstruction using the quadruple bone-tunnel technique has been seldom reported. The current study investigated this technique, focusing on the anatomy of the femoral and tibial insertions of the anterolateral (AL) and posteromedial (PM) bundles of the PCL.</p><p><b>METHODS</b>Twenty-two fresh, healthy adult cadaveric knees were dissected and measured. The PCL was divided into the AL bundle and PM bundle at the insertion footprint. The insertion footprints of the AL and PM bundles, their location, size, and the clock positions were measured and described.</p><p><b>RESULTS</b>On the femur, the clock position of the footprint of the AL bundle was 11:21 ± 0:23 (left) or 0:39 ± 0:23 (right), and the PM bundle was 9:50 ± 0:18 (left) or 2:10 ± 0:18 (right), with the knee flexed at 90 degrees. The distances from the center of the femoral insertions of the AL and PM bundles to the anterior cartilage margins of the medial femoral condyle were (7.79 ± 1.22) mm and (8.36 ± 1.63) mm, respectively. On the tibia, the vertical distances from the center of the tibial insertions of the AL and PM bundles to the tibial articular surface were (3.25 ± 1.20) mm and (6.91 ± 1.57) mm, respectively.</p><p><b>CONCLUSIONS</b>These results have led to a better definition of the anatomy of the AL and PM bundle footprint of the PCL. The technique of double-bundle PCL reconstruction using quadruple bone-tunnel is feasible. Application of these data during PCL reconstruction using the quadruple bone-tunnel technique may help optimize knee stability.</p>