Extracorporeal Shockwave Therapy With a Modified Technique on Tendon and Ligament for Knee Osteoarthritis: A Randomized Controlled Trial.

BACKGROUND: There have been no definitive guidelines on the treatment method and specific points in the body. PURPOSE: The aim of the study was to investigate the effects of extracorporeal shockwave therapy on treating the main tendons and ligaments of knee osteoarthritis. METHOD: A total of 36 patients with knee osteoarthritis were enrolled in trial and organized into two groups: 3-wk extracorporeal shockwave therapy for the intervention group and 3-wk sham extracorporeal shockwave therapy for control group. Both groups received the same physical therapies: (1) transcutaneous electrical nerve stimulation, (2) magnetic field treatment, and (3) quadricep muscle strength training. Evaluation was performed before the start of treatment, at third week after the start of treatment, and 1 wk after the end of treatment. The study used randomized controlled trials (level of evidence, 1). RESULT: Eextracorporeal shockwave therapy group had significant improvement in WOMAC pain score, physical function, and total score (mean difference = -2.8, P < 0.001; -5.1, P = 0.02; -8.3, P = 0.004, respectively), Visual Analog Scale score (mean difference = -2.3, P < 0.001), and the distance of 6-min walk test (mean difference = 28.7, P = 0.01) in the 1 wk after the end of treatment. Statistical significance in WOMAC pain, physical function, and total scores (mean difference = -3.0, P = 0.001; -5.6, P = 0.02; -9.3, P = 0.004, respectively) and Visual Analog Scale score (mean difference = -1.2, P = 0.027) was observed between the extracorporeal shockwave therapy group and control group. CONCLUSIONS: Extracorporeal shockwave therapy for the tendons and ligaments has clinical benefits for pain and physical function improvement in knee osteoarthritis. In addition, improvement in physical performance was observed in the short-term follow-up.

Suture augmentation of acromioclavicular and coracoclavicular ligament reconstruction for acute acromioclavicular dislocation.

ABSTRACT: The objective of this report was to introduce a new suture augmentation of coracoclavicular (CC) and acromioclavicular ligament reconstruction for acute Rockwood grade III to V acromioclavicular dislocations.From January 2015 to January 2019, 43 patients with Rockwood III to VI acute acromioclavicular dislocations were retrospectively reviewed. For comparison, another series of 28 patients treated with double Endobutton technique from January 2011 to December 2014 were reviewed. A P < .05 was considered statistical significance.The mean follow-up period of the 2 series were 39.69 ±â€Š7.42 months (range, 24-54 months) and 37.86 ±â€Š8.23 months (range, 26-48 months) (P > .05), respectively. There were significant differences regarding CC space (11.62 ±â€Š2.54 mm vs 16.78 ±â€Š5.53 mm; P < .05), CC reduction loss (5.56 ±â€Š4.73 mm vs 26.25 ±â€Š4.42 mm; P < .05), and acromioclavicular space (6.89 ±â€Š1.87 mm vs 7.95 ±â€Š2.37 mm; P < .05). There were significant differences regarding the disabilities of the arm, shoulder, and hand questionnaire (3.3 ±â€Š2.8 vs 5.32 ±â€Š4.37; P < .05) and University of California-Los Angeles shoulder rating scale (31.19 ±â€Š2.48 vs 29.24 ±â€Š2.48; P < .05). The excellent to good percentages were 100% (n = 32) and 85% (n = 23), respectively.In conclusion, the suture augmentation of acromioclavicular and CC ligament reconstruction is a reliable technique for acute acromioclavicular dislocation with minimal complications.Type of study/level of evidence: Therapeutic IIa.

Ligament of Marshall ablation for persistent atrial fibrillation.

Beyond pulmonary vein isolation, the two main additional strategies: Cox-Maze procedure or targeting of electrical signatures (focal bursts, rotational activities, meandering wavelets), remain controversial. High-density mapping of these arrhythmias has demonstrated firstly that a patchy lesion set is highly proarrhythmogenic, favoring macro-re-entry through conduction slowing and providing pivots for localized re-entry. Secondly, discrete anatomical structures such as the Vein or Ligament of Marshall (VOM/LOM) and the coronary sinus (CS) have epicardial muscular bundles that are more frequently involved in re-entry than previously thought. The Marshall Bundle can be ablated at any point along its course from the mid-to-distal coronary sinus to the left atrial appendage. If necessary, the VOM may be directly ablated using ethanol infusion to eliminate PV contributions and produce conduction block across the mistral isthmus. Ethanol ablation of the VOM, supplemented with RF ablation, may be more effective in producing conduction block at the mitral isthmus than repeat RF ablation alone.

Mechanics of Uterosacral Ligaments: Current Knowledge, Existing Gaps, and Future Directions.

The uterosacral ligaments (USLs) are important anatomical structures that support the uterus and apical vagina within the pelvis. As these structures are over-stretched, become weak, and exhibit laxity, pelvic floor disorders such as pelvic organ prolapse occur. Although several surgical procedures to treat pelvic floor disorders are directed toward the USLs, there is still a lot that is unknown about their function. This manuscript presents a review of the current knowledge on the mechanical properties of the USLs. The anatomy, microstructure, and clinical significance of the USLs are first reviewed. Then, the results of published experimental studies on the in vivo and ex vivo, uniaxial and biaxial tensile tests are compiled. Based on the existing findings, research gaps are identified and future research directions are discussed. The purpose of this exhaustive review is to help new researchers navigate scientific literature on the mechanical properties of the USLs. The use of these structures remains very popular in reconstructive surgeries that restore and augment the support of pelvic organs, especially as synthetic surgical mesh implants continue to be highly controversial.

A biomechanics study on ligamentous injury in anterior-posterior compression type II pelvic injury.

BACKGROUND: Anterior-posterior compression (APC) type II pelvis fracture is caused by the destruction of pelvic ligaments. This study aims to explore ligaments injury in APC type II pelvic injury. METHOD: Fourteen human cadaveric pelvis samples with sacrospinous ligament (SPL), sacrotuberous ligament (SBL), anterior sacroiliac ligament (ASL), and partial bone retaining unilaterally were acquired for this study. They were randomly divided into hemipelvis restricted and unrestricted groups. We recorded the separation distance of the pubic symphysis and anterior sacroiliac joint, external rotation angle, and force when ASL ruptured. We observed the external rotation damage to the pelvic bone and ligaments. RESULT: When ASL failed, there was no significant difference in pubic symphysis separation (28.6 ± 8.4 mm to 23.6 ± 8.2 mm, P = 0.11) and anterior sacroiliac joint separation (11.4 ± 3.8 mm to 9.7 ± 3.9 mm, P = 0.30) between restricted and unrestricted groups. The external rotation angle (33.9 ± 5.5° to 48.9 ± 5.2°, P < 0.01) and force (553.9 ± 82.6 N to 756.6 ± 41.4 N, P < 0.01) were significantly different. Pubic symphysis separation between two groups ranged from 14 to 40 mm. In the restricted group, both SBL and SPL were injured. SPL ruptured first, and then SBL and the interosseous sacroiliac ligament were damaged while the posterior ligament remained unharmed. In the unrestricted group, interosseous sacroiliac ligament and posterior sacroiliac ligaments were damaged, while SBL and SPL were not. When the ASL, SBL, and SPL all failed, pubic symphysis and anterior sacroiliac joint separation between two groups increased significantly (from 28.6 ± 8.4 to 42.0 ± 7.6 mm, 11.4 ± 3.8 to 16.7 ± 4.2 mm respectively, all P < 0.05). CONCLUSION: Pelvic external rotation injury is either hemipelvic restricted or unrestricted, which can result in different outcomes. When the ASL ruptures, the unrestricted group needs greater external rotation angle and force, without SBL or SPL injury, while both SBL and SPL were injured in another group. When ASL fails in two groups, pubic symphysis separation fluctuates considerably. Finally, when the ASL ruptures, SBL and SPL may be undamaged.

Techniques for In Vivo Measurement of Ligament and Tendon Strain: A Review.

The critical clinical and scientific insights achieved through knowledge of in vivo musculoskeletal soft tissue strains has motivated the development of relevant measurement techniques. This review provides a comprehensive summary of the key findings, limitations, and clinical impacts of these techniques to quantify musculoskeletal soft tissue strains during dynamic movements. Current technologies generally leverage three techniques to quantify in vivo strain patterns, including implantable strain sensors, virtual fibre elongation, and ultrasound. (1) Implantable strain sensors enable direct measurements of tissue strains with high accuracy and minimal artefact, but are highly invasive and current designs are not clinically viable. (2) The virtual fibre elongation method tracks the relative displacement of tissue attachments to measure strains in both deep and superficial tissues. However, the associated imaging techniques often require exposure to radiation, limit the activities that can be performed, and only quantify bone-to-bone tissue strains. (3) Ultrasound methods enable safe and non-invasive imaging of soft tissue deformation. However, ultrasound can only image superficial tissues, and measurements are confounded by out-of-plane tissue motion. Finally, all in vivo strain measurement methods are limited in their ability to establish the slack length of musculoskeletal soft tissue structures. Despite the many challenges and limitations of these measurement techniques, knowledge of in vivo soft tissue strain has led to improved clinical treatments for many musculoskeletal pathologies including anterior cruciate ligament reconstruction, Achilles tendon repair, and total knee replacement. This review provides a comprehensive understanding of these measurement techniques and identifies the key features of in vivo strain measurement that can facilitate innovative personalized sports medicine treatment.

The ligament of Marshall and arrhythmias: A review.

The ligament of Marshall (LOM) is a remnant of the embryonic sinus venosus and left cardinal vein, and contains fat and fibrous tissues, blood vessels, muscle bundles, nerve fibers, and ganglia. The complexity of LOM's structure makes it as a source of triggers and drivers as well as substrates of re-entry for atrial arrhythmias, especially for atrial fibrillation (AF). LOM also serves as a portion of left atrial macro-re-entrant circuit, especially peri-mitral isthmus re-entrant circuit. Experimental studies demonstrate that the LOM acts as a sympathetic conduit between the left stellate ganglion and the ventricles, and participates in the initiation and maintenance of ventricular arrhythmias. Endocardial or epicardial catheter ablation or ethanol infusion into the vein of Marshall may serve as an important adjunct therapy to pulmonary vein isolation in patients with advanced stage of AF, and may help alleviate ventricular arrhythmias as well.

Volar and Dorsal Blood Supply to the Lunate: A Cadaveric Study.

Although various studies have proposed vascular and mechanical factors, the etiology of Kienböck disease is unknown. Kienböck theorized that lunatomalacia resulted from traumatic disruption of blood supply and bony nutrition to the lunate. Extraosseous supply to the lunate, as far as volar or dorsal vessels are concerned, is still controversial. This study evaluated the extraosseous nutrient foramina from the dorsal and volar aspects of lunate specimens. A total of 913 specimens from the Hamann-Todd Osteological Collection in Cleveland, Ohio, were examined. The nutrient artery foramina on left and right lunate specimens were examined from dorsal and volar aspects. The number of nutrient artery foramen was tabulated. Age, sex, and race data were collected. Specimens were divided into groups according to the number of nutrient artery foramina, and the dorsal and volar foramina were compared. The average number of foramina on the dorsal aspect of the lunate (1.71) was greater than the volar aspect (1.64), except in specimens younger than 35 years. A greater number of specimens had 3 or more foramina on the dorsal side compared with the volar aspect. Based on this study, there was significant contribution of dorsal arterial vessels to the blood supply of lunate specimens older than 35 years, which contrasts with findings in earlier studies. The disruption of dorsal intercarpal and radiocarpal ligaments leading to the disruption of the dorsal arterial arches may contribute to vascular insufficiency of the lunate and should be evaluated further in the etiopathogenesis of Kienböck disease. [Orthopedics. 2021;44(2):e243-e247.].

Using the novel pelvic organ prolapse histologic quantification system to identify phenotypes in uterosacral ligaments in women with pelvic organ prolapse.

BACKGROUND: Pelvic organ prolapse is common, but the underlying etiologies are poorly understood, which limits our current prevention and treatment options. OBJECTIVE: Our primary objective was to compare the uterosacral ligament histologic features in women with and without prolapse using the novel pelvic organ prolapse histologic quantification system. Our secondary aim was to determine whether composite histologic findings in uterosacral ligaments are associated with prolapse risk factors. STUDY DESIGN: This was a prospective cohort study in which paracervical uterosacral ligament biopsies were performed at the time of hysterectomy for primary prolapse or other benign gynecologic indications and processed for histologic evaluation. The pelvic organ prolapse quantification system was used to determine the prolapse stage. In this study, 9 prominent histologic features were semiquantitatively scored using the pelvic organ prolapse histologic quantification system in a blinded fashion and compared between prolapse and control groups. Unbiased principal component analysis of these scores was independently performed to identify potential relationships between histologic measures and prolapse risk factors. RESULTS: The histologic scores of 81 prolapse and 33 control ligaments were analyzed. Compared with the control group, women in the prolapse group were significantly older and more likely to be in the menopausal phase. There was no difference in the number of vaginal deliveries, body mass index, hormone use, or smoking status between the groups. To control for baseline differences, patients were also stratified by age over 40 years and menopausal status. Compared with the control group, the prolapse ligaments in the premenopausal group had significantly more loss of smooth muscle fibers within the fascicles (P<.001), increased inflammatory infiltrates of neutrophils within the tissue and perineural inflammatory cells (P<.01 and P=.04, respectively), and reduced neointimal hyperplasia (P=.02). Prolapse ligaments in the postmenopausal group exhibited elevated adipose content compared with that of the control group (P=.05). Amount of fibrillar collagen, total nonvascular smooth muscle, and muscle fiber vesicles of prolapse ligaments did not differ in either the premenopausal or postmenopausal group compared with that of the control group. Unbiased principal component analysis of the histologic scores separated the prolapse ligaments into 3 phenotypes: (1) increased adipose accumulation, (2) increased inflammation, and (3) abnormal vasculature, with variable overlap with controls. Posthoc analysis of these subgroups demonstrated a positive correlation between increasing number of vaginal deliveries and body mass index with increasing adipose content in the adipocyte accumulation and inflammatory phenotype and increasing neointimal hyperplasia in the vascular phenotype. However, only the relationship between vaginal delivery and adipocytes was significant in the adipose phenotype (R2=0.13; P=.04). CONCLUSION: Histologic phenotypes exist in pelvic support ligaments that can be distinguished using the pelvic organ prolapse histologic quantification system and principle component analysis. Vaginal delivery is associated with aberrant adipose accumulation in uterosacral ligaments. Our findings support a multifactorial etiology for pelvic organ prolapse contributing to altered smooth muscle, vasculature, and connective tissue content in crucial pelvic support structures. To confirm these associations and evaluate the biomechanical properties of histologic phenotypes of prolapse, larger studies are warranted. Closing this gap in knowledge will help optimize personalized medicine and help identify targets for prevention and treatment of this complex condition.

Molecular mechanism of extracellular matrix disorder in pelvic organ prolapses.

Pelvic organ prolapses (POP) notably reduces the quality of life in elderly populations due to bladder and bowel dysfunction, incontinence, and coital problems. Extracellular matrix (ECM) disorder is a pivotal event in the progression of POP, but to date, its specific underlying mechanism remains unclear. The ligaments of patients with POP and healthy controls were collected to compare the expression of Homeobox11 (HOXA11) and transforming growth factor ß (TGF­ß1) via immunohistochemical analysis. HOXA11 and TGF­ß1 were overexpressed or knocked down in fibroblast cells to explore their effects on the expression of collagen and matrix metalloproteinases (MMPs). HOXA11 and TGF­ß1 were greatly reduced in the ligaments of patients with POP. The overexpression and downregulation of HOXA11 and TGF­ß1 can mediate ECM disorder via regulating expression of collagen (Col) and MMPs. In addition, HOXA11 and TGF­ß1 exerted synergistic effect on the expression of Col and MMPs. The present study identified that HOXA11 and TGF­ß1 serve critical roles in mediating ECM disorders, which may be of clinical significance for the diagnosis and treatment of patients with POP.

Massage of the Hepatoduodenal Ligament Recovers Portal Vein Flow Immediately After the Pringle Maneuver in Hepatectomy.

BACKGROUND: The Pringle maneuver is often used in liver surgery to minimize bleeding during liver transection. Many authors have demonstrated that intermittent use of the Pringle maneuver is safe and effective when performed appropriately. However, some studies have reported that the Pringle maneuver is a significant risk factor for portal vein thrombosis. In this study, we evaluated the effectiveness of portal vein flow after the Pringle maneuver and the impact that massaging the hepatoduodenal ligament after the Pringle maneuver has on portal vein flow. MATERIALS AND METHODS: Patients treated with the Pringle maneuver for hepatectomies performed to treat hepatic disease at our hospital between August 2014 and March 2019 were included in the study (N = 101). We divided these patients into two groups, a massage group and nonmassage group. We measured portal vein blood flow with ultrasonography before and after clamping of the hepatoduodenal ligament. We also evaluated laboratory data after the hepatectomy. RESULTS: Portal vein flow was significantly lower after the Pringle maneuver than before clamping of the hepatoduodenal ligament. The portal vein flow after the Pringle maneuver was improved following massage of the hepatoduodenal ligament. After hepatectomy, serum prothrombin time was significantly higher and serum C-reactive protein was significantly lower in the massage group than in the nonmassage group. CONCLUSION: Massaging the hepatoduodenal ligament after the Pringle maneuver is recommended in order to quickly recover portal vein flow during hepatectomy and to improve coagulability.

Imaging of the knee: Common acute presentations to general practice.

BACKGROUND: Knee pain is a common symptom in the community. There is a wide range of conditions that can cause pain. Identifying the type and severity of the condition is important for effective management. There are several guidelines for the appropriate imaging of patients presenting with knee pain. Presentation is generally divided into a post-traumatic group and those without known trauma (including arthritis). OBJECTIVE: The aim of this article is to discuss the approach to imaging of the knee with reference to Diagnostic Imaging Pathways and illustrate some of the conditions that may be encountered. DISCUSSION: The initial workup is typically done in general practice to determine which patients require referral for specialist management and which patients can be cared for in the community. Most cases presented in this article are patients referred from primary care to a metropolitan radiology practice during a six-month period, and they represent examples of some of the more common pathologies.

Comparison of Biaxial Biomechanical Properties of Post-menopausal Human Prolapsed and Non-prolapsed Uterosacral Ligament.

Uterosacral ligaments (USLs) provide structural support to the female pelvic floor, and a loss of USL structural integrity or biomechanical function may induce pelvic organ prolapse (POP). Alterations in extracellular matrix composition and organization dictate USL mechanical function. Changes in USL microstructure and corresponding mechanical properties, however, are not fully understood, nor is it understood how microstructure and mechanics change with onset and progression of POP. This is due, in part, as USL properties are primarily characterized along a single direction (uniaxial test), whereas the USL is loaded in multiple directions simultaneously within the body. Biaxial testing permits the acquisition of biomechanical data from two axes simultaneously, and thus simulates a more physiologic assessment compared to the traditional uniaxial testing. Therefore, the objective of this study was to quantify the biaxial biomechanical properties and histological composition of the USL in post-menopausal women with and without POP at various stages. Potential correlations between tissue microstructural composition and mechanical function were also examined. Tangential modulus was lower and peak stretch higher in POP III/IV compared to non-POP and POP I/II in the main in vivo loading direction; however, no significant differences in mechanical properties were observed in the perpendicular loading direction. Collagen content positively correlated to tangential modulus in the main in vivo loading direction (r = 0.5, p = 0.02) and negatively correlated with the peak stretch in both the main in vivo (r = -0.5, p = 0.02) and perpendicular loading directions (r = -0.3, p = 0.05). However, no statistically significant differences in USL composition were observed, which may be due to the small sample size and high variability of small sections of human tissues. These results provide first step towards understanding what microstructural and mechanical changes may occur in the USL with POP onset and progression. Such information may provide important future insights into the development of new surgical reconstruction techniques and graft materials for POP treatment.

Tendon tissue engineering: biomechanical considerations.

Engineered soft tissue products-both tendon and ligament-have gained tremendous interest in regenerative medicine as alternatives to autograft and allograft treatments due to their potential to overcome limitations such as pain and donor site morbidity. Tendon engineered grafts have focused on the replication of native tendon tissue composition and architecture in the form of scaffolds using synthetic or natural biomaterials seeded with cells and factors. However, these approaches suffer due to static culture environments that fail to mimic the dynamic tissue environment and mechanical forces required to promote tenogenic differentiation of cultured cells. Mechanical stimulation is sensed by cellular mechanosensors such as integrins, focal adhesion kinase, and other transmembrane receptors which promote tenogenic gene expression and synthesis of tendon extracellular matrix components such as Type I collagen. Thus, it is imperative to apply biological and biomechanical aspects to engineer tendon. This review highlights the origin of tendon tissue, its ability to sense forces from its microenvironment, and the biological machinery that helps in mechanosensation. Additionally, this review focuses on use of bioreactors that aid in understanding cell-microenvironment interactions and enable the design of mechanically competent tendon tissue. We categorize these bioreactors based on functional features, sample size/type, and loading regimes and discuss their application in tendon research. The objective of this article is to provide a perspective on biomechanical considerations in the development of functional tendon tissue.

Intraoperative physiological lateral laxity in extension and flexion for varus knees did not affect short-term clinical outcomes and patient satisfaction.

PURPOSE: Medial release during total knee arthroplasty (TKA) is used to correct ligament imbalance in knees with varus deformity. However, questions remain on whether residual ligament imbalance would be related to inferior clinical results. The purposes of the present study were to measure the intraoperative joint gap and to evaluate the effect of intraoperative soft tissue condition on the new Knee Society Score (KSS 2011) at 2-year follow-up, without the maneuver of additional medial release to correct the asymmetrical gap balance. METHODS: Varus-valgus gap angle and joint gap were measured using a tensor device without medial release for 100 knees with preoperative varus deformity. The knees were categorized according to the varus-valgus gap angle and the laxity. The preoperative and postoperative clinical outcomes using KSS 2011 were compared between the groups. RESULTS: The average varus-valgus angles had a residual imbalance of 2.8° varus and 1.3° varus in extension and flexion, respectively. In comparison, according to varus-valgus joint gap angle and knee laxity in extension and flexion, no significant differences were found in postoperative range of motion and subscale of KSS 2011 among the groups. CONCLUSION: Intraoperative asymmetrical joint gap and physiological laxity do not affect early clinical results after TKA. LEVEL OF EVIDENCE: III.

Changes in Scaphoid and Lunate Position and Loading at Two Wrist Pushup Positions.

BACKGROUND: Scapholunate interosseous ligament (SLIL) injury following a fall on an outstretched hand may lead to carpal instability and in some cases require long-term rehabilitation following repair. Rehabilitation, especially in athletes, may include pushups, but little is known as to what type of pushup may be safer. OBJECTIVE: To determine biomechanical differences between two pushup positions (neutral or extended). METHODS: Six fresh cadaver wrists with pre-existing SLIL damage were uni-axially loaded in neutral and extension in order to simulate two different pushup styles. The motions of the scaphoid and lunate in relation to the radius were measured. The dorsal, proximal, and volar insertion sites of the SLIL were identified and, using the collected kinematic data, gap distances were calculated for each site. RESULTS: Gap distance between the proximal SLIL insertion points was significantly greater in neutral than in extension. There was a trend that the dorsal and volar SLIL insertion points were also greater in neutral than in extension. After the wrist was extended 90o, the scaphoid extended 70.1o and the lunate extended 28.6o compared to their positions with the wrist in neutral. CONCLUSION: The larger gap distances between the scaphoid and lunate in neutral suggest that a neutral style pushup could put higher forces on a wrist with pre-existing SLIL damage and may thus hinder recovery for a person with a repaired SLIL. A pushup in extension, in these injured wrists, may be less detrimental.

From molecular to macro: the key role of the apical ligaments in uterovaginal support.

To explain the pathophysiology of pelvic organ prolapse, we must first understand the complexities of the normal support structures of the uterus and vagina. In this review, we focus on the apical ligaments, which include the cardinal and uterosacral ligaments. The aims of this review are the following: (1) to provide an overview of the anatomy and histology of the ligaments; (2) to summarize the imaging and biomechanical studies of the ligament properties and the way they relate to anterior and posterior vaginal wall prolapse; and (3) to synthesize these findings into a conceptual model for the progression of prolapse.

Could an isolated human body lower limb model predict leg biomechanical response of Chinese pedestrians in vehicle collisions?

PURPOSE: The purpose of the current study was to investigate whether an isolated human body lower limb FE model could predict leg kinematics and biomechanical response of a full body Chinese pedestrian model in vehicle collisions. METHODS: A human body lower limb FE model representing midsize Chinese adult male anthropometry was employed with different upper body weight attachments being evaluated by comparing the predictions to those of a full body pedestrian model in vehicle-to-pedestrian collisions considering different front-end shapes. RESULTS: The results indicate that upper body mass has a significant influence on pedestrian lower limb injury risk, the effect varies from vehicle front-end shape and is more remarkable to the femur and knee ligaments than to the tibia. In particular, the upper body mass can generally increase femur and knee ligaments injury risk, but has no obvious effect on the injury risk of tibia. The results also show that a higher attached buttock mass is needed for isolated pedestrian lower limb model for impacts with vehicles of higher bonnet leading edge. CONCLUSIONS: The findings of this study may suggest that it is necessary to consider vehicle shape variation in assessment of vehicle pedestrian protection performance and leg-form impactors with adaptive upper body mass should be used for vehicles with different front-end shapes, and the use of regional leg-form impactor modeling the local anthropometry to evaluate the actual lower limb injury of pedestrians in different countries and regions.