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Dive into the research topics where Yoshinori Ohashi is active.

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Featured researches published by Yoshinori Ohashi.


Journal of Pediatric Orthopaedics | 2013

Outcomes and failure factors in surgical treatment for osteochondritis dissecans of the capitellum

Masahiro Kosaka; Junsuke Nakase; Ryohei Takahashi; Tatsuhiro Toratani; Yoshinori Ohashi; Katsuhiko Kitaoka; Hiroyuki Tsuchiya

Background: Osteochondritis dissecans (OCD) of the capitellum is an intra-articular lesion and one of the leading causes of permanent elbow disability. The treatment of advanced capitellar OCD remains challenging because of the limited potential of the articular cartilage for self-repair. The purpose of this study was to investigate the outcome of surgical treatment for OCD of the capitellum. Methods: From 2000 to 2010, 32 male patients who had advanced lesions of capitellar OCD were treated operatively. The mean age of the patients was 14.4 years at the time of surgery. Twenty-nine patients played baseball and 3 played other sports. The lesions were of the centralized type in 9 patients, the lateral type in 4 patients, and the widespread type in 19 patients. For the surgical procedure, osteochondral peg fixation was selected for 13 patients and osteochondral autograft transplantation for 19 patients. Clinical outcome was measured with the elbow rating system including range of motion, and the number of patients who returned to active sports participation within 1 year after surgery was determined. Results: The mean total arc of elbow motion increased from 123±17 degrees preoperatively to 132±14 degrees postoperatively. The mean clinical score improved significantly from 133±24 to 177±27. Within the first year after surgery, 81.3% of the patients returned to active sports playing. However, 4 of 8 patients (50%) in which osteochondral peg fixation was performed for lesions of the lateral widespread type required reoperation. Conclusions: Our results indicate that osteochondral peg fixation and osteochondral autograft transplantation may improve elbow rating score, and may facilitate a return to active sports participation. However, osteochondral peg fixation may be insufficient for lesions of the widespread type because of their poor stability. The large lateral condyle lesions had a worse outcome, and future studies will need to develop improved treatment for these defects. Level of Evidence: Level IV (case series).


Knee Surgery, Sports Traumatology, Arthroscopy | 2013

Roles of ACL remnants in knee stability

Junsuke Nakase; Tatsuhiro Toratani; Masahiro Kosaka; Yoshinori Ohashi; Hiroyuki Tsuchiya

PurposeThis study evaluated knee laxity in anterior tibial translation and rotation following removal of anterior cruciate ligament (ACL) remnants using a computer navigation system.MethodsThis prospective study included 50 knees undergoing primary ACL reconstruction using a navigation system. ACL remnants were classified into four morphologic types: Type 1, bridging between the roof of the intercondylar notch and tibia; Type 2, bridging between the posterior cruciate ligament and tibia; Type 3, bridging between the anatomical insertions of the ACL on the lateral wall of the femoral condyle and the tibia; and Type 4, no bridging of ACL remnants. Anterior tibial translation and rotatory laxity were measured before and after remnant resection using a navigation system at 30°, 60°, and 90° of knee flexion. The amount of change in anterior tibial translation and rotatory laxity of each type was compared among the types.ResultsThe different morphologic types of ACL remnants were as follows: Type 1, 15 knees; Type 2, 9 knees; Type 3, 6 knees; and Type 4, 20 knees. The amount of change in anterior tibial translation and rotatory laxity at 30° knee flexion in Type 3 was significantly larger than in the other types. There were no significant differences in either tibial translation or rotatory laxity at 60° and 90° knee flexion among the types.ConclusionsIn Type 3, ACL remnants contributed to anteroposterior and rotatory knee laxity evaluated at 30° knee flexion. The bridging point of the remnants is important to knee laxity. The Type 3 remnant should be preserved as much as possible when ACL reconstruction surgery is performed.Level of evidencePrognostic study, Level II.


Knee | 2014

Oblique coronal and oblique sagittal MRI for diagnosis of anterior cruciate ligament tears and evaluation of anterior cruciate ligament remnant tissue

Masahiro Kosaka; Junsuke Nakase; Tatsuhiro Toratani; Yoshinori Ohashi; Katsuhiko Kitaoka; Hiroshi Yamada; Koji Komura; Shinji Nakamura; Hiroyuki Tsuchiya

BACKGROUND The purpose of this study was to investigate the efficacy of additional oblique magnetic resonance imaging (MRI) for the diagnosis of anterior cruciate ligament (ACL) tear and evaluation of ACL remnant tissue. METHODS We retrospectively reviewed the records of 54 knees. Three independent readers evaluated the MR images by the use of three methods: orthogonal sagittal images only (method A); orthogonal sagittal and additional oblique sagittal images (method B); and orthogonal sagittal and oblique coronal images (method C). The sensitivity, specificity, and accuracy for the diagnosis of an ACL tear and the detection of the condition of the ACL remnant tissue by the use of each method were calculated in comparison with arthroscopic findings as the reference standard. RESULTS The arthroscopic records revealed 27 knees with intact ACLs and 27 with torn ACLs. Among the 27 knees with torn ACLs, 9 did not have continuous remnant tissue and 18 had certain remnant tissue attached to the femur or the posterior cruciate ligament. The specificities and accuracies of methods B and C for diagnosing an ACL tear were higher than those for method A. The sensitivity, specificity, and accuracy of method C for the detection of ACL remnant tissue were higher than those for method A and B. CONCLUSIONS Additional use of oblique MRI improved the accuracy of diagnosis of ACL tear and showed a reasonable level of efficacy in detecting ACL remnant tissue. LEVEL OF EVIDENCE Level IV (case series).


PLOS ONE | 2013

Whole body muscle activity during the FIFA 11+ program evaluated by positron emission tomography.

Junsuke Nakase; Takafumi Mochizuki; Tatsuhiro Toratani; Masahiro Kosaka; Yoshinori Ohashi; Junichi Taki; Tetsutaro Yahata; Seigo Kinuya; Hiroyuki Tsuchiya

Purpose This study investigated the effect of the FIFA 11+ warm-up program on whole body muscle activity using positron emission tomography. Methods Ten healthy male volunteers were divided into a control group and a group that performed injury prevention exercises (The 11+). The subjects of the control group were placed in a sitting position for 20 min and 37 MBq of 18F-fluorodeoxyglucose (FDG) was injected intravenously. The subjects then remained seated for 45 min. The subjects of the exercise group performed part 2 of the 11+for 20 min, after which FDG was injected. They then performed part 2 of the 11+for 20 min, and rested for 25 min in a sitting position. Positron emission tomography-computed tomography images were obtained 50 min after FDG injection in each group. Regions of interest were defined within 30 muscles. The standardized uptake value was calculated to examine the FDG uptake of muscle tissue per unit volume. Results FDG accumulation within the abdominal rectus, gluteus medius and minimus were significantly higher in the exercise group than in the control group (P<0.05). Conclusion The hip abductor muscles and abdominal rectus were active during part 2 of the FIFA 11+ program.


Journal of orthopaedic surgery | 2014

Grafted tendon healing in femoral and tibial tunnels after anterior cruciate ligament reconstruction

Junsuke Nakase; Katsuhiko Kitaoka; Tatsuhiro Toratani; Masahiro Kosaka; Yoshinori Ohashi; Hiroyuki Tsuchiya

Purpose. To evaluate tendon-to-bone healing after anterior cruciate ligament (ACL) reconstruction in the fibrous interzone (FIZ) of the femoral and tibial tunnels using magnetic resonance imaging (MRI). Methods. Five men and 5 women (mean age, 29 years) underwent arthroscopic ACL reconstruction by a single surgeon, using the semitendinosus and gracilis tendon. The tendon-to-bone healing in the FIZ was evaluated using sagittal and coronal MRI at 1, 3, 6, 9, 12, and 24 weeks, with the knee flexed at 60° and the tendon graft straight in both images. The signal intensity of the FIZ was visually assessed by comparing it with anatomic landmarks in the same patients knee, and classified into 4 grades. It was grade 3 when similar to that of the patellar tendon, grade 2 when similar to that of skeletal muscle, grade 1 when greater than that of muscle but less than that of joint fluid, and grade 0 when similar to that of joint fluid. At 24 weeks, subjective and objective functional outcomes were evaluated using the Lysholm score and the International Knee Documentation Committee score. Results. At 24 weeks, no patient had knee laxity. All patients had an International Knee Documentation Committee score of A, and their mean Lysholm score was 98.5. In the femoral tunnel, the FIZ did not change during the first 9 weeks (in particular the anterior part), but healing occurred rapidly thereafter. In the tibial tunnel, the FIZ healed over time in all locations, and healing was complete in the lateral and posterior parts at 12 weeks, and in all locations at 24 weeks. The mean signal intensity grade was significantly higher in the tibial than femoral FIZ at 3 to 12 weeks (p<0.01). Conclusion. After ACL reconstruction, the tendon-to-bone healing in the FIZ of the tibial tunnel was faster than that of the femoral tunnel.


Knee | 2016

Technique of anatomical single bundle ACL reconstruction with rounded rectangle femoral dilator

Junsuke Nakase; Tatsuhiro Toratani; Masahiro Kosaka; Yoshinori Ohashi; Hitoaki Numata; Takeshi Oshima; Yasushi Takata; Hiroyuki Tsuchiya

BACKGROUND This study aimed to present a new technique for anatomical single bundle anterior cruciate ligament (ACL) reconstruction. We developed an original rounded rectangular dilator set to create rounded rectangular femoral tunnels. This technique can increase the femoral tunnel size without roof impingement, and has the potential to reduce the graft failure rate. We investigated the tunnel position and the incidence of intraoperative complications. METHOD The presented technique is anatomical single bundle ACL reconstruction using a semitendinosus graft (with or without the gracilis tendon). The tunnel was drilled via an additional medial portal. Rounded rectangular tunnels were created using a special dilator. Tibial tunnels were created using conventional rounded tunnels. Fixation was achieved using a suspensory device on the femoral side and a plate and screw on the tibial side. PATIENTS Fifty patients underwent this surgery, and intraoperative complications were investigated. The femoral tunnel positions were documented postoperatively from computed tomography scans using the quadrant method. The tibial tunnel positions (anterior-to-posterior, medial-to-lateral) were documented using intraoperative X-ray scans. RESULTS Only one patient had a partial posterior tunnel wall blowout. The femoral tunnel length varied between 30 and 40mm (mean, 34.9±3.3mm). All femoral and tibial tunnels were located within the area of the anatomical ACL insertions. CONCLUSION We did not experience any serious intraoperative complications during anatomical single bundle ACL reconstruction using a rounded rectangle dilator, and the resulting locations of the femoral and tibial tunnels were within the anatomical ACL footprint. LEVEL OF EVIDENCE Level IV.


Journal of orthopaedic case reports | 2016

Ipsilateral Medial and Lateral Discoid Meniscus with Medial Meniscus Tear

Kengo Shimozaki; Junsuke Nakase; Yoshinori Ohashi; Hitoaki Numata; Takeshi Oshima; Yasushi Takata; Hiroyuki Tsuchiya

Introduction: Discoid meniscus is a well-documented knee pathology, and there are many cases of medial or lateral discoid meniscus reported in the literature. However, ipsilateral concurrent medial and lateral discoid meniscus is very rare, and only a few cases have been reported. Herein, we report a case of concurrent medial and lateral discoid meniscus. Case Report: A 27-year-old Japanese man complained of pain on medial joint space in his right knee that was diagnosed as a complete medial and lateral discoid meniscus. In magnetic resonance imaging, although the lateral discoid meniscus had no tear, the medial discoid meniscus had a horizontal tear. Arthroscopic examination of his right knee similarly revealed that the medial discoid meniscus had a horizontal tear. In addition, the discoid medial meniscus also had an anomalous insertion to the anterior cruciate ligament, and there was also mild fibrillation of the medial tibial cartilage surface. We performed arthroscopic partial meniscectomy for the torn medial discoid meniscus but not for the asymptomatic lateral discoid meniscus. The latest follow-up at 18 months indicated satisfactory results. Conclusion: We report a rare case of ipsilateral medial and lateral discoid meniscus with medial meniscus tear. The medial discoid meniscus with tear was treated with partial meniscectomy, whereas the lateral discoid meniscus without tear was only followed up.


Orthopaedic Journal of Sports Medicine | 2014

High Psychological Competitive Ability Is Related to Incidence of Anterior Cruciate Ligament Injury in High School Female Athletes.

Masahiro Kosaka; Junsuke Nakase; Yoshinori Ohashi; Hitoaki Numata; Yosuke Shima; Katsuhiko Kitaoka; Hiroyuki Tsuchiya

Objectives: In a competitive sport situation, not only the exertions of performance but also the incidence of injury can be influenced by psychological factors. In recent years, the focus on anterior cruciate ligament (ACL) injury prevention has increased and many studies exploring risk factors for ACL injury have been published. However, the influence of psychological factors on ACL injuries is poorly documented. The purpose of this study was to investigate the relationship between psychological competitive ability and incidence of ACL injury among high school female athletes. Methods: A 3-year prospective cohort study was conducted with 220 high school female handball or basketball players. All subjects were 15 years old and included 77 handball players and 143 basketball players. At baseline, psychological competitive ability was assessed by a self-administered questionnaire, the Diagnostic Inventory of Psychological Competitive Ability (DIPCA.3). This inventory measures an athlete’s psychological abilities to fully display their skills and talents during competition via 52 questions categorized into 12 scales: Patience, Aggressiveness, Volition for self-realization, Volition for winning, Self-control, Ability to relax, Concentration, Confidence, Decision, Predictive ability, Judgment, and Cooperation. After the baseline examination was performed at high school entry, all players were followed for 36 months to register any subsequent incidence of ACL injury. We compared the differences in psychological competitive ability between injured and uninjured players using an unpaired t-test. Values of p < 0.05 were considered statistically significant. The purpose of this study was explained to the subjects and their parents and written informed consent to participate was obtained from them. This study was approved by the ethics committee of our institution. Results: In the present study, 20 of the 220 players (9.1%) suffered an ACL injury during the 3-year observation period. Eighteen of the 20 injured players sustained a non-contact injury to her knee. Eleven players were injured during the game and 9 players were injured during the practice. Between injured and uninjured players, injured players had significantly higher total DIPCA.3 scores [172.7 ± 18.3 points in injured players and 157.9 ± 20.9 points in uninjured players (p<0.001)]. Regarding the specific scales, injured players scored significantly higher on Patience, Aggressiveness, Volition for self-realization, Predictive ability, Judgment, and Cooperation. However, no significant differences were observed on Volition for winning, Self-control, Ability to relax, Concentration, Confidence and Decision. Conclusion: It is reported that players displaying higher competitive levels of performance or players with higher self-esteem in their own performance score higher on DIPCA.3. In the present study, DIPCA.3 scores were significantly higher in injured players compared with uninjured players. Among the high-scoring players, a strong emphasis on improvement of their performance may force them into situations associated with injury risk. The results of the present study suggest that psychological factors are associated with the incidence of ACL injury.


British Journal of Sports Medicine | 2014

YOUNG FEMALE ATHLETES HAVE CHANGED CONSIDERABLY IN THE TWO YEARS AFTER BASELINE EVALUATION IN A PROSPECTIVE STUDY

Yosuke Shima; Katsuhiko Kitaoka; Junsuke Nakase; Kenichi Goshima; R Takahashi; Tatsuhiro Toratani; Masahiro Kosaka; Yoshinori Ohashi; Hiroyuki Tsuchiya; T Munehiro; T Aiba

Background A 3-year prospective cohort study has been initiated in Japanese young female handball and basketball players to identify risk factors for non-contact ACL injuries. Although we examined the baseline data of the players at their first year of high school, it raises concern about the use of the individual baseline data as the characteristics of the players (might be identified as a risk factor) in cases where the players get injured during their senior year of high school. Objectives To compare the players data examined at the first year and the senior year of high school. Design Case-control study. Participants 21 of 84 high school female players (handball: 4 players, basketball: 17 players) who participated in our prospective cohort study. Methods Body compositions, static balance (locus length per unit area examined by stabilometer), dynamic balance (star excursion balance test; SEBT), isokinetic hamstrings/quadriceps strength, isometric hipabduction strength, hamstrings flexibility, knee laxity (KT1000), navicular drop, generalized joint laxity (Beighton index), and psychological-competitive ability (DIPCA-3) were examined. Results Significantly better result of isokinetic hamstrings/quadriceps strength, isometric hip abduction strength, and hamstrings flexibility were found at the senior. Significantly lower result of navicular drop was found at the senior. No significant differences were found between the groups in body compositions, static and dynamic balance, and DIPCA-3. Generalized joint laxity in the senior was significantly higher level of the index than that at the first. Conclusions During two years after baseline evaluation, the players increased their hip and knee strength without matching increases of static and dynamic balance ability. Considering that even generalized joint laxity which assumed to be consistent had changed, careful interpretation is needed to use the baseline data as a risk factor in a prospective cohort study.


Knee Surgery, Sports Traumatology, Arthroscopy | 2014

Relationship between the skeletal maturation of the distal attachment of the patellar tendon and physical features in preadolescent male football players

Junsuke Nakase; Tomohiro Aiba; Kenichi Goshima; Ryohei Takahashi; Tatsuhiro Toratani; Masahiro Kosaka; Yoshinori Ohashi; Hiroyuki Tsuchiya

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