Etsuo Chosa

Miyazaki University · Department of Orthopaedics

Background The evaluation of lateral ankle laxity remains challenging when diagnosing chronic lateral ankle instability (CLAI). Several studies have reported that internal rotation of the talus as an indicator of rotational lateral ankle laxity (RLAL) increases in patients with CLAI. However, there is no established method for detecting and evaluat...

Objective: This study evaluated new indices for quantitative assessment of mobility in orthopedic patients who underwent total hip and knee arthroplasties. Methods: This observational study evaluated three new indices, the 5-m walker gait, sitting-rising, and supine-to-sitting and sitting-to-supine times, for assessing the ambulatory function of 33...

Background Some patients with lateral ankle sprain (LAS) will experience chronic lateral ankle instability (CLAI). However, not all of those with residual increased lateral ankle laxity (ILAL) become symptomatic. There is a lack of evidence regarding the prevalence of undiagnosed ILAL in the general population. Purpose To evaluate the prevalence o...

Liver regeneration is a well-orchestrated compensatory process that is regulated by multiple factors. We recently reported the importance of the chromatin protein, a high-mobility group box 2 (HMGB2) in mouse liver regeneration. However, the molecular mechanism remains unclear. In this study, we aimed to study how HMGB2 regulates hepatocyte prolife...

Background Studies have evaluated types of retromalleolar groove using axial magnetic resonance imaging at the level of 10 mm above the tip of the lateral malleolus. However, no evidence is available to support that this level is appropriate for evaluating retromalleolar groove morphology. Purpose To assess the influence of the level of axial comp...

Posterior tibial translation (PTT) after double-bundle posterior cruciate ligament (PCL) reconstruction has sometimes occurred. Purpose of this study is to identify the risk factors for postoperative PTT after double-bundle PCL reconstruction with a hamstring autograft. Comparing the results of bilateral gravity sag view (GSV) at 12 months after su...

Background: A halo vest is an immobilization device widely used to stabilize the cervical spine. Pain and infection at the skull pin insertion site are common complications, but skull perforation is rare, and most published studies are case reports. This study aimed to identify risk factors for skull perforation by comparing patients who did and di...

Background The objective kinematic assessments of activities of daily living are desired. However, the limited knowledge regarding age- and sex-related differences prevents the adaptation of these measurements to clinical settings and in-home exercises. Therefore, this study aimed to determine the effects of age and sex on joint and endpoint kinema...

Purpose To investigate the efficacy of sagittal ultrasonography of the median nerve in diagnosing carpal tunnel syndrome (CTS). Methods Seventy‐six hands with idiopathic CTS and 80 hands of asymptomatic subjects were included. All patients with CTS underwent ultrasonographic examination, electrodiagnostic testing, and CTS‐6 assessment. In the sagi...

Purpose The purpose of this study was to investigate the morphological characteristics of the aortic valve and identify factors associated with the progression of aortic valve stenosis (AS) in osteoporosis patients. Methods In this single-center prospective cohort study, we recruited 10 patients (mean age: 75 ± 7 years, 90% female) who were taking...

Motion analysis during activities of daily living has been conducted in numerous studies. However, information is lacking regarding age-related differences that affect clinical assessment and treatment goals. This study aimed to examine the effect of age on kinematics during activities of daily living. Three-dimensional motions of the shoulder, elb...

Background and objectives: An accessory navicular (AN) bone is often classified into types 1–3 according to the Veitch classification, and symptomatic type 1 patients usually receive non-surgical treatment. However, there are cases in which AN cannot be classified into one of these three types using this classification system, and the small ossicle...

Posterior tibial translation (PTT) after double-bundle posterior cruciate ligament (PCL) reconstruction has sometimes occurred. Purpose of this study is to identify the risk factors for postoperative PTT after double-bundle PCL reconstruction with a hamstring autograft. Comparing the results of bilateral gravity sag view (GSV) at 12 months after su...

Objectives Meniscal tears are one of the common knee injuries. Large size of longitudinal-vertical tear is called bucket handle tear, and easily displaced and locked in the knee joint cavity. This type of injury is usually required arthroscopic intervention due to pain or dysfunction such as loss of range of motion of the knee. Recently, the arthro...

Background In kayaking, trunk motion is one of the important factors that prevent injury and improve performance. Kinematic studies in kayaking have been reported in laboratory settings using paddling simulators and ergometers. However, such studies do not reflect kayaking on water, the actual competitive environment. Therefore, we developed a vide...

Background: Medial meniscus posterior root (MMPR) tears have been reported to occur in middle-aged patients with minor trauma. However, the injury mechanism of MMPR tears remains unclear. The purpose of this study was to evaluate the shear stress in the MMPR during daily activities using a finite-element analysis. Methods: Subject-specific finit...

Background After a total hip arthroplasty (THA), standing and walking balance are greatly affected in the early stages of recovery, so it is important to increase the weight-bearing amount (WBA) on the operated side. Sometimes, traditional treatments may not be enough to improve WBA and weight-bearing ratio (WBR) on the operated side in a satisfact...

Osteochondral lesions of the talus (OLT) are common injuries in young athletes. Various kinds of surgical procedures are available for orthopaedic surgeons, but which surgical technique is the best remains controversial. Many surgical procedures require malleolar osteotomy to obtain appropriate surgical exposure to the OLT because of the anatomic c...

Background: Ureteral injury during lateral lumbar interbody fusion (LLIF) is uncommon. However, it is a serious complication that may require additional surgery should it occur. The objective of this study was to evaluate whether there was any change in the position of the left ureter between preoperative biphasic contrast-enhanced CT scanned in t...

Recent physiological studies have shown that the deep fascia has received much attention concerning clinical medicine; however, histological examination of the deep fascia has not been well established. In this study, we aimed to clarify and visualize the structure of the deep fascia by taking advantage of cryofixation techniques and low-vacuum sca...

Standing up from a chair is a mechanically demanding daily motion, and its biomechanics represent motor performance. In older adults with locomotive syndrome (LS), sit-to-stand (STS) movement with adequate postural control is essential to prevent falls. This study evaluated the characteristics of dynamic balance during STS movement on older adults...

Background: Partial meniscectomy is commonly performed for symptomatic patients with discoid lateral meniscus (DLM) if conservative treatment fails. However, the development of knee osteoarthritis and osteochondral lesion are detrimental postoperative complications. This study aimed to evaluate the effect of the volume of resected DLM on the conta...

Abstract Background Clavicle fractures are common injuries, especially in young, active individuals. Operative treatment is recommended for completely displaced clavicle shaft fractures, and plate fixation is stronger than the use of intramedullary nails. Few studies have reported on iatrogenic injuries to the muscle attached to the clavicle during...

Background: Few studies have retrospectively analyzed the relationship between joint range of motion (ROM) and muscle flexibility and shoulder and elbow throwing injuries in a large number of elementary school baseball players. The purpose of this study was to retrospectively identify the physical factors related to shoulder and elbow throwing inj...

Muscle herniation of the lower extremity, such as tibialis anterior muscle herniation (TAMH), is not a rare cause of leg pain in athletes. However, a few studies have reported surgical treatment for TAMH, and the optimal surgical procedure remains controversial. Fasciotomy was reported to be effective for patients with TAMH. However, this procedure...

This study aimed to evaluate the influence of various posterior tibial slopes (PTSs) and tibial tunnel angles (TTAs) on “killer turn” in posterior cruciate ligament (PCL) reconstruction by using three-dimensional finite element analysis (FEA). The study models were created using computed tomography images of a healthy young Asian male. Using SolidW...

A novel and fun exercise robot (LOCOBOT) was developed to improve balance ability. This system can control a spherical robot on a floor by changing the center of pressure (COP) based on weight-shifting on a board. The present study evaluated leg muscle activity and joint motion during LOCOBOT exercise and compared the muscle activity with walking a...

The biological mechanism of action for osteoprotegerin (OPG), a soluble decoy receptor for the receptor activator of nuclear factor kappa-B ligand (RANKL) in the vascular structure, has not been elucidated. The study aim was to determine if OPG affects aortic structural integrity in angiotensin II-induced hypertension. Mortality was higher (P < 0.0...

Background Recently, cryotherapy has become a common practice for postoperative pain management. The current accepted practice in Japan is the use of cryotherapy at 5 °C after arthroscopic shoulder surgery. However, this therapy has been reported to be highly intense because the sustained low temperature causes discomfort for patients. The optimum...

Background High-Mobility Group Box 1 (HMGB1) and HMGB2 are chromatin-associated proteins that belong to the HMG protein family, and are involved in the regulation of DNA transcription during cell differentiation, proliferation and regeneration in various tissues. However, the role of HMGB2 in ovarian folliculogenesis is largely unknown. Methods We...

Few studies have reported injuries and physical characteristics in adolescent weightlifters. The purpose of this study was to report the results of orthopaedic medical examinations in adolescent amateur weightlifters that were performed cross-sectionally from 2012 to 2019. The orthopaedic medical examination included physical examinations, generali...

Osteochondral lesion (OCL) of the patellofemoral (PF) joint is not an uncommon cause of knee pain, and surgery is needed when conservative treatment fails. However, there is a lack of evidence regarding the optimal surgical treatment for OCL of the PF joint. Fixation of OCLs using autogenous osteochondral grafts has been reported to be effective fo...

Backgroud: To evaluate the influence of intra-articular hemarthrosis on activities of a disintegrin and metalloprotease with thrombospondin motifs (ADAMTS) family and matrix metalloproteases (MMPs) in the acute phase after anterior cruciate ligament reconstruction (ACLR). Methods: Intra-articular hemarthrosis was collected from 17 patients who unde...

The loss of knee range of motion (ROM) is not an uncommon complication after anterior cruciate ligament reconstruction (ACLR). However, the risk factors of loss of knee ROM remain debatable. The purpose of this study was to evaluate the incidence and risk factors of loss of knee ROM at 12 months after primary ACLR performed after regaining full kne...

Purpose: This study aimed to evaluate the relationship between generalized joint laxity (GJL) and stress ultrasonographic (US) findings of the anterior talofibular ligament (ATFL) of healthy young men. Methods: The ATFL lengths of healthy young men were consecutively measured in the stress and nonstress positions. The ATFL ratio was calculated a...

Liver regeneration is an extraordinarily complex process involving a variety of factors; however, the role of chromatin protein in hepatocyte proliferation is largely unknown. In this study, we investigated the functional role of high-mobility group box 2 (HMGB2), a chromatin protein in liver regeneration using wild-type and HMGB2-knockout (KO) mic...

Epithelial protein lost in neoplasm (EPLIN) is an actin-associated cytoskeletal protein that plays an important role in epithelial cell adhesion. EPLIN has two isoforms: EPLINα and EPLINβ. In this study, we investigated the role of EPLINβ in osteoblasts using EPLINβ-deficient (EPLINβGT/GT ) mice. The skeletal phenotype of EPLINβGT/GT mice is indist...

This study was conducted to present remnant-preserving anterior cruciate ligament (ACL) augmentation as a useful option for partial ACL injury in multiligament knee injury (MLKI) cases, which may also contribute to conserving graft resources. The present study involved patients diagnosed with MLKI at our institute from Spring 2006 to February 2021....

Head Injury Assessment (HIA) is the screening tool for head injury during a rugby game. The purpose of this study was to investigate the epidemiology of HIA in the Japan Rugby Top League (JRTL). The incidences of HIA, defined concussion (per 1,000 player-hours) and repeated concussions were evaluated in three seasons (2016-17, 2017–18, 2018–19; tot...

Purpose: To evaluate the preoperative deterioration of an isolated meniscal tear in patients aged 40 years or older, and whether time from injury to surgery is associated with worsening of a meniscal tear. Methods: Patients aged 40 years or older who underwent arthroscopic surgery for isolated meniscal tear between 2014 and 2019 were retrospecti...

Background The biological mechanism of action for osteoprotegerin, a soluble decoy receptor for the receptor activator of nuclear factor‐kappa B ligand in the vascular structure, has not been elucidated. The study aim was to determine if osteoprotegerin affects aortic structural integrity in angiotensin II (Ang II)‐induced hypertension. Methods an...

Background Different methods of acetabular reconstruction with total hip arthroplasty (THA) for Crowe II and III of adult developmental dysplasia of the hip (DDH) acetabular bone defect have been implemented clinically. However, the biomechanical effect of different augmented materials for acetabular reconstruction in THA on shell stability has nev...

The Beighton score (BS) is widely used to evaluate generalized joint laxity. However, the association between the BS and lateral ankle laxity is unclear. This study compared the ultrasonographic (US) findings of the anterior talofibular ligament (ATFL) between high- (≥6) and low- (≤3) BS groups of healthy young women. The ATFL lengths of healthy yo...

High-mobility group box 2 (HMGB2) is a chromatin-associated protein that is an important regulator of gene transcription, recombination, and repair processes. The functional importance of HMGB2 has been reported in various organs, including the testis, heart, and cartilage. However, its role in the ovary is largely unknown. In this study, ovary tis...

Background Knee extensor structure disruption is sometimes combined with multi-ligament knee injury (MLKI). These cases could not be classified into the previous classification for knee dislocation or MLKI. To propose a new classification of MLKI that addresses both femorotibial and patellofemoral (PF) factors.Methods The present study involved pat...

[Purpose] Exercise guidance is an effective measure against locomotive syndrome. Appropriate nutritional management is also considered necessary in order to maintain the motor function. This study is the first exploratory and prospective research on the effects of exercise guidance and feeding high-protein foods in order to improve locomotive syndr...

Background: Before corrective surgery for idiopathic scoliosis, the stress X-rays are indispensable to collect information regarding the reducibility of deformity, deciding fusion levels, and categorizing curve types and so on. The hanging radiograph has not been conducted preoperatively so far as known. The objective of this study was to investig...

MEL1 (MDS1/EVI1-like gene 1/PRDM16), a zinc finger protein, is located near the chromosomal breakpoint at 1p36 in human acute myeloid leukemia (AML) cells with the t (1; 3) (p36; q21) translocation. Mel1/Prdm16 is not only a causative gene of leukemia, but also has multiple regulatory functions, such as the regulation of fat metabolism. To investig...

Despite the importance of eating movements to the rehabilitation of neurological patients, information regarding the normal kinematics of eating in a realistic setting is limited. We aimed to quantify whole-body three-dimensional kinematics among healthy individuals by assessing movement patterns in defined phases while eating real food with the do...

Background: It remains unclear what percentage of isolated meniscal tears deteriorates before surgery, especially in older patients. We aimed to evaluate the preoperative deterioration of an isolated meniscal tear in patients aged 40 years or older, and whether time from injury to surgery is associated with worsening of a meniscal tear. Methods: Pa...

High-mobility group box 2 (HMGB2), a chromatin-associated protein that interacts with DNA, is implicated in multiple biological processes, including gene transcription, replication, and repair. HMGB2 is expressed in several tissues, including the testis; however, its functional role is largely unknown. Here, we elucidated the role of HMGB2 in sperm...

Objectives Multi-ligament knee injury (MLKI) shows very varied symptoms which was depended on the combination of injured ligaments. Schenck`s knee dislocation classification which was one of useful classifications for surgeon in decision making. However, Schenck`s classification is only referred to the factors of cruciate ligament and collateral li...

Background Lateral ankle sprain (LAS) is one of the most common musculoskeletal injuries. Numerous studies regarding LAS have been performed. However, there are few studies evaluating the current clinical practice of orthopaedic surgeons regarding LAS. The purpose of this study was to evaluate the current clinical practice of general orthopaedic su...

Background Intertrochanteric curved varus osteotomy (CVO) has been widely used to remove the necrotic bone away from the weight-bearing portion in the treatment of osteonecrosis of the femoral head (ONFH). However, whether all types of necrosis will benefit from CVO, in terms of the stress level, the effect of different center-edge (CE) angles of a...

Study design: A retrospective analysis of a prospective, non-randomized cohort dataset. Objective: To cross-sectionally examine the prevalence of sarcopenia and the association between spine-pelvic deformity and skeletal muscle volume loss and ectopic fat infiltration into lumbar paravertebral muscles (PVMs) in patients who underwent lumbar surg...

Purpose: The purpose of this study is to investigate the treatment efficacy of total knee arthroplasty (TKA) on locomotive syndrome (LS) focusing on total clinical decision limit (CDL) stage 3 leading to revealing the motor function indicators that can predict LS improvement in knee osteoarthritis patients who had received TKA. Methods: This pro...

Background Aging is characterized by biological changes, such as reductions in muscle strength and the loss of mobility and balance. The Japanese Orthopaedic Association proposed the term “locomotive syndrome” (LS) to define people at risk of requiring nursing care because of problems with locomotive system. A need exists to develop simple methods...

Objectives Intra-articular hematoma are caused by articular injury such as ligament rupture or intra-articular fracture and following knee surgery. It has been reported that intra-articular hematoma leads to cartilage degeneration. Exposure of articular cartilage to low concentrations of blood for a period as short as 2 days has been confirmed to i...

PurposeDiscoid meniscus is a congenital abnormality of the lateral meniscus and is seen more frequently in East Asia. The purpose of this study was to retrospectively assess the relationship between discoid lateral meniscus (DLM) types and tear patterns and causes of age-specific clinical symptom onset.Methods Of 1650 arthroscopic surgeries over a...

Background The purpose of the present study was to evaluate the usefulness of the median nerve stenosis rate (MNSR) measured on sagittal sonographic images of the median nerve in the diagnosis of carpal tunnel syndrome (CTS). Methods The study population consisted of 45 hands from 37 patients with idiopathic CTS (CTS group), and 60 hands from 35 a...

Non-anatomical placement may occur during the surgical implantation of the meniscal implant, and its influence on the resulting biomechanics of the knee joint has not been systematically studied. The purpose of this study was to evaluate the biomechanical effects of non-anatomical placement of the meniscal implant on the knee joint during a complet...

Background Turner’s syndrome, discoid meniscus, and Blount’s disease have all been studied in isolation, but, to the best of our knowledge, there have been no studies reporting a patient with all three. Thus, the first case of Turner’s syndrome with discoid meniscus and Blount’s disease is presented. Case presentation A 5-year-old Japanese girl wi...

Swinging a baseball bat at a pitched ball takes less than half of a second. A hitter uses his lower extremities to generate power, and coordination of the swing motion gradually transfers power through the trunk to the upper extremities during bat–ball impact. The most important instant of the baseball swing is at the bat–ball impact, after which t...

Background Spondylolysis and undiagnosed mechanical low back pain (UMLBP) are the main causes of low back pain (LBP) in adolescent athletes. No studies have evaluated the difference in clinical and radiographic factors between these 2 conditions. Furthermore, it remains unclear which adolescent athletes with LBP should undergo advanced imaging exam...