• Sports Medicine and Lower Extremity Division / Research

• Results

Sports Medicine and Lower Extremity Division

The Kobe University Orthopaedic Sports Medicine and Lower Extremity Division is served by five faculties: Prof. Ryosuke Kuroda, Dr. Takehiko Matsushita, Dr. Yuichi Hoshino, Dr. Noriyuki Kanzaki, and Dr. Daisuke Araki. Our treatment strategy is to restore normal joint function and kinematics by using comprehensive joint preserving techniques, such as ligament reconstruction, osteotomy, meniscal repair, or cartilage repair, including cell therapies. Once injuries occur, our sports medicine experts use the most advanced methods to evaluate and treat injuries in professional, nonprofessional, and recreational athletes of all ages. Our mission is returning patients to an active lifestyle based on our clinical and basic researches.

[Clinical research]

(1) Knee joint

Anterior cruciate ligament (ACL) and knee ligament reconstruction
Our division traditionally concentrates on the safe return to sports after ACL or knee ligament injuries. Once ACL is injured, ACL reconstruction is the gold standard for treatment due to its poor self-healing ability. To quantitatively assess knee joint laxity, we have developed the three-dimensional (3-D) electromagnetic measurement system (EMS) in 2004 and used this system to patients with knee ligament injury. This system can evaluate the Lachman and pivot shift tests non-invasively and quantitatively. Based on several biomechanical researches, anatomic double-bundle ACL reconstruction, which reproduces both the anteromedial and posterolateral bundles, is our first choice for patients with ACL injury. In addition, we also have some treatment options, such as bone-patellar tendon-bone graft ACL reconstruction with Kurosaka screws, selective single-bundle ACL reconstruction (ACL remnant preserved augmentation technique) or epiphyseal plate-preserving technique. These clinical researches have led many athletes to undergo surgical treatment in our division.

Articular cartilage injuries
For focal osteochondral lesions or osteochondritis dissecans, we select the treatment strategies, such as arthrosopic bone marrow stimulations (drilling, micro-fracture or abrasion chondroplasty), autogenous osteochondral graft transfer (mosaicplasty), or autologous chondrocyte implantation, based on osteochondral lesion size. To date, we have reported good clinical results of these treatments. For autogenous osteochondral graft transfer, we investigated the ideal matching patterns of articular surface profiles of the donor and recipient sites using a 3-D laser scanning method. For larger traumatic cartilage defects, autologous chondrocyte implantation is the first choice. Since 2012, we conducted the investigator-initiated clinical research of the 3rd generation of this treatment in collaboration with the Institute of Biomedical Research and Innovation Hospital (http://chuo.kcho.jp/foreign_page/eng/eng_index.html). The good outcome of this clinical research is now stepped onto the sponsor-initiated clinical research. We recently performed the 2nd generation of autologous chondrocyte implantation using JACCR (J-TEC, Japan), with good post-operative outcomes.

Meniscal injuries
To treat meniscal injuries, we are actively performing arthroscopic meniscal repair because meniscectomy leads to a high risk of osteoarthritis. Furthermore, we used fibrin clots for meniscal repair to enhance the clinical results. In animal studies, we reported that platelet-rich plasma (PRP) enhances the healing of meniscal defects. Based on this result, we will also consider clinical trials or either surgical treatments using PRP or intracapsular injection, with the goal of further improving our results.

Patellofemoral joint disorders
Patellar dislocation is a multifactorial problem because patellar stability relies on limb alignment, the osseous structure of the patella and trochlea, and the integrity of static and dynamic soft-tissue constraints. To treat these patellar dislocations, our first choice is medial patellofemoral ligament (MPFL) reconstruction. This technique is an operative procedure independently developed at our division, which has shown good clinical results. Furthermore, by developing 3-D analysis software in collaboration with the Kobe University Faculty of Engineering, we perform motion analysis of normal knees, adding the individual anatomy of each case to preoperative planning, with the aim of further improving postoperative results.

Early-stage osteoarthritis
As the sports population is growing, the importance of joint preservation surgery is highlighted. Recently, we actively select osteotomy, which improves pain and disability from isolated unicompartmental disease in the knee through surgical correction of weight-bearing alignment, as a treatment option for highly active and/or relatively young patients with osteoarthritis. Osteotomy includes distal femur osteotomy, high tibial osteotomy (open-wedge or hybrid), and double-level osteotomy, which combines the previous two procedures. The osteotomy type is selected by the deformity of each case. Our division has used computer navigation systems for obtaining more accurate alignment and advancing the state of our treatments.

(2) Foot and ankle joints

Only few hospitals have expertise on the treatments for foot and ankle surgery because of its specificity in orthopedics. For novel treatment strategies for foot and ankle joints, we aggressively perform not only conservative treatments, but also minimum invasive surgical treatments with the newest implements and surgical techniques.
Ankle lateral ligament injury is one of the most common sports injuries, and several surgical procedures have been developed and gradually spread. We also perform arthroscopic ligament repair (arthroscopic Brostrom procedure) and initiatively use the procedure. This technique can lead athletes to early recovery from the injury, with good clinical results compared with the conventional open technique.
For ankle osteoarthritis, arthroscopic synovectomy, low tibial osteotomy, ankle arthrodesis (open or arthroscopic), and total ankle arthroplasty are selected. We choose the optimal procedure for each patient, considering the degree of deformity, age, and activity. Particularly, total ankle arthroplasty, which requires high-level technique, is also one option in our division.

[Basic research]

(1) Biomechanics

From 2004, 3-D EMS has been established and used for quantitative evaluation of knee laxity during the Lachman and pivot shift tests, which are widely used as manual examination methods for detecting ACL deficiencies and for postoperative evaluations. This system can record the 6 degrees of freedom of knee kinematics data quantitatively and non-invasively. To date, we have applied this system for both research purposes and clinical use. For biomechanical research projects, we are collaborating with the Department of Human and Artificial Intelligent Systems, Graduate School of Engineering, University of Fukui (https://eng.eng.u-fukui.ac.jp/hiseng/). In addition, we have developed the intra-articular ligament tension measurement system, which could detect ACL tension, the finger pressure measurement system wherein sensors are attached on the fingertip, and the system that could measure wall pressure that could record the applied force toward the bone tunnel for ligament reconstruction by embedding sensors. Furthermore, we have developed the software that could semi-automatically extract the bone tunnels after ACL reconstruction, and have investigated the changes over time of the bone tunnels.
We reported these research results at The Japanese Orthopaedic Association (JOA), The Japanese Orthopaedic Society of Knee Arthroscopy and Sports Medicine (JOSKAS), The Japanese Society for Clinical Biomechanics (JSCB), The Japanese Society of Clinical Sports Medicine (JSCSM), The American Association of Orthopaedic Surgeons (AAOS), The Orthopaedic Research Society (ORS), The American Orthopaedic Society for Sports Medicine (AOSSM), The European Society of Sports Traumatology, Knee Surgery and Arthroscopy (ESSKA), and The International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine (ISAKOS), and we are always trying to improve ligament reconstruction procedures.

(2) Biology

In our division, we collaborate with the Institute for Frontier Life and Medical Sciences, Kyoto University (http://www2.infront.kyoto-u.ac.jp/te02/index_en.html), researching on meniscus, ligament, and bone regeneration using various growth factors (b-FGF, BMP, G-CSF, statin, platelet-rich-plasma, etc.). We are also conducting collaborative research with the Institute of Biomedical Research and Innovation (http://chuo.kcho.jp/foreign_page/eng/eng_index.html), investigating on the promotion of remodeling of bone and reconstructed anterior cruciate ligament using vascular endothelial progenitor cells (called stem cells in peripheral blood).
With regard to the regeneration and metabolism of cartilage, because SIRT1 (silent information regulator two ortholog 1) is an essential factor for prolonging life span, we focus on SIRT1 that is a histone deacetylase, and analyze the relationship with osteoarthritis.
Since 2015, we have received human adipose-derived regenerative cells from Osaka Medical College and research on the application to bone fracture healing and osteoarthritis treatment.
We have reported these research results at The Orthopaedic Research Society (ORS), The Osteoarthritis Research Society International (OARSI), The International Cartilage Repair Society (ICRS), The Tissue Engineering and Regenerative Medicine International Society (TERMIS), and many other scientific fields.

• Sports Medicine and Lower Extremity Division / Results

• Research

Original Research Article

(1) Watanabe S, Nagai K, Hoshino Y, Kataoka K, Nakanishi Y, Araki D, Kanzaki N, Matsushita T, Kuroda R. Influence of Injury to the Kaplan Fibers of the Iliotibial Band on Anterolateral Rotatory Knee Laxity in Anterior Cruciate Ligament Injury: A Retrospective Cohort Study. Am J Sports Med. 2022;50(12):3265-3272.

(2) Yamashita T, Nagai K, Kanzaki N, Yamamoto T, Ibaraki K, Araki D, Hoshino Y, Matsushita T, Kuroda R. Short-term clinical outcomes following total ankle arthroplasty without concomitant osteotomy in ankles with severe preoperative varus deformity: comparison to ankles with preoperative neutral alignment. J Am Podiatr Med Assoc 2022;112(6):1-9.

(3) Kamada K, Nagai K, Nagamune K, Hoshino Y, Nakanishi Y, Araki D, Kanzaki N, Matsushita T, Kuroda R. Direct suturing quadriceps tendon to a continuous loop with a suspensory button provides biomechanically superior fixation in ACL reconstruction. Knee Surg Sports Traumatol Arthrosc. 2022;30(7):2307-2313.

(4) Byrne KJ, Rothrauff BB, Nagai K, Onishi K, Fu FH. Two-fragment Segond fracture validates historical descriptions of independent soft tissue attachments. Knee Surg Sports Traumatol Arthrosc 2022;30(1):71-77.

(5) Yamamoto T, Nagai K, Kanzaki N, Kataoka K, Nukuto K, Hoshino Y, Matsushita T, Kuroda R. Comparison of Clinical Outcomes Between Ceramic-Based Total Ankle Arthroplasty with Ceramic Total Talar Prosthesis and Ceramic-Based Total Ankle Arthroplasty. Foot Ankle Int. 2022;43(4):529-539.

(6) Matsushita T, Matsumoto T, Araki D, Nagai K, Hoshino Y, Niikura T, Kawamoto A, Go MJ, Kawamata S, Fukushima M, Kuroda R. A phase I/IIa clinical trial of third-generation autologous chondrocyte implantation (IK-01) for focal cartilage injury of the knee. Asia-Pac J Sports Med Arthrosc Rehabil Technol. 2022;28:6-12.

(7) Hiranaka Y, Muratsu H, Tsubosaka M, Matsumoto T, Maruo A, Miya H, Kuroda R, Matsushita T. Influence of posterior tibial slope on sagittal knee alignment with comparing contralateral knees of anterior cruciate ligament injured patients to healthy knees. Sci Rep. 2022 Aug 18;12(1):14071.

(8) Kamada K, Matsushita T, Nagai K, Hoshino Y, Araki D, Kanzaki N, Matsumoto T, Niikura T, Kuroda R. Risk factors of residual pivot-shift after anatomic double-bundle anterior cruciate ligament reconstruction. Arch Orthop Trauma Surg. 2022 Apr 1. doi: 10.1007/s00402-022-04428-y. Epub ahead of print.

(9) Hong CK, Hoshino Y, Watanabe S, Nagai K, Matsushita T, Su WR, Kuroda R. The coronal lateral collateral ligament sign in the anterior cruciate ligament-injured knees was observed regardless of the knee laxity based on the quantitative measurements. Knee Surg Sports Traumatol Arthrosc. 2022;30(10):3508-3514.

(10) Zakharia A, Lameire DL, Abdel Khalik H, Kay J, Uddandam A, Nagai K, Hoshino Y, de SA D. Quadriceps tendon autograft for pediatric anterior cruciate ligament reconstruction results in promising postoperative function and rates of return to sports: A systematic review. Knee Surg Sports Traumatol Arthrosc. 2022;30(11):3659-3672.

(11) Ueda Y, Matsushita T, Shibata Y, Takiguchi K, Ono K, Kida A, Ono R, Nagai K, Hoshino Y, Matsumoto T, Sakai Y, Kuroda R. Association Between Meeting Return-to-Sport Criteria and Psychological Readiness to Return to Sport After Anterior Cruciate Ligament Reconstruction. Orthop J Sports Med. 2022;10(5):23259671221093985.

(12) Mori A, Matsushita T, Miyaji N, Nagai K, Araki D, Kanzaki N, Matsumoto T, Niikura T, Hoshino Y, Kuroda R. Analysis of popliteal artery location for high tibial and distal tuberosity osteotomy using contrast-enhanced computed tomography. Knee Surg Relat Res. 2022;34(1):25.

(13) Matsushita T, Mori A, Watanabe S, Kataoka K, Oka S, Nishida K, Nagai K, Matsumoto T, Hoshino Y, Kuroda R. Analysis of bone union after medial closing wedge distal femoral osteotomy using a new radiographic scoring system. Arch Orthop Trauma Surg. 2022;142(9):2303-2312.

(14) Nakanishi Y, Nagai K, Kay J, Zakharia A, Nukuto K, Hoshino Y, Matsushita T, Kuroda R, de SA D. The Incidence of Tibial Tunnel Coalition is Higher Than Femoral Tunnel Coalition in Double-Bundle Anterior Cruciate Ligament Reconstruction Using Hamstring Autografts: A Systematic Review. Orthop Traumatol Surg Res. 2022;108(8):103407.

(15) Eliya Y, Qureshi AR, Kay J, Nagai K, Hoshino Y, de Sa D. Anatomical double-bundle anterior cruciate ligament reconstruction moderately improved tegner scores over the long-term: a systematic review and meta-analysis of randomized controlled trials. Knee Surg Sports Traumatol Arthrosc. 2022 Jul 15. doi: 10.1007/s00167-022-07046-8. Epub ahead of print.

(16) Nukuto K, Matsushita T, Kamada K, Nishida K, Nagai K, Kanzaki N, Hoshino Y, Matsumoto T, Niikura T, Kuroda R. Development and analysis of mouse medial meniscus posterior root tear model. Calcif Tissue Int. 2022 Oct 15. doi: 10.1007/s00223-022-01028-1. Epub ahead of print. PMID: 36242608.

(17) Singh H, Glassman I, Sheean A, Hoshino Y, Nagai K, de SA D. Less than 1% risk of donor-site quadriceps tendon rupture post-ACL reconstruction with quadriceps tendon autograft: a systematic review. Knee Surg Sports Traumatol Arthrosc. 2022 Oct 18. doi: 10.1007/s00167-022-07175-0. Epub ahead of print.

(18) Kataoka K, Nagai K, Hoshino Y, Shimabukuro M, Nishida K, Kanzaki N, Matsushita T, Kuroda R. Steeper lateral posterior tibial slope and greater lateral-medial slope asymmetry correlate with greater preoperative pivot-shift in anterior cruciate ligament injury. J Exp Orthop 2022;9(1):117.

(19) Mir B, Vivekanantha P, Dhillon S, Cotnareanu O, Cohen D, Nagai K, de SA D. Fear of reinjury following primary anterior cruciate ligament reconstruction: a systematic review. Knee Surg Sports Traumatol Arthrosc. 2022 Dec 23. doi: 10.1007/s00167-022-07296-6. Epub ahead of print. PMID: 36562808.

(20) Araki S, Tsubosaka M, Muratsu H, Inokuchi T, Maruo H, Miya H, Kuroda R, Matsushita T. Evaluation of morphological characteristics for incomplete discoid medial meniscus with an oversized posterior segment. J Orthop Surg Res. 2022 Apr 20;17(1):245.

(21) Gyemi LA, Bednar ED, Sheean AJ, Kuroda R, de Sa D. The quadriceps tendon autograft is an option for primary PCL reconstruction: a systematic review. J ISAKOS. 2022;7(1):27-34.

(22) Matsushita T, Akiyama T, Osano K, Yokoyama Y, Okazaki K. Biomechanical analysis of the role of hinge support fixators on hinge stability in medial closing wedge distal femoral osteotomy. Clin Biomech. 2022;91:105528.

(23) Nishida K, Xu C, Gale T, Anderst W, Fu F. Symmetry and sex differences in knee kinematics and ACL elongation in healthy collegiate athletes during high-impact activities revealed through dynamic biplane radiography. J Orthop Res. 2022;40(1):239-251.

(24) Kataoka K, Hoshino Y, Nagamune K, Nukuto K, Yamamoto T, Yamashita T, Kanzaki N, Kakutani K, Matsushita T, Kuroda R. The quantitative evaluation of anterior drawer test using an electromagnetic measurement system. Sports Biomech. 2022;21(4):550-561

(25) Nishida K, Gale T, Chiba D, Suntaxi F, Lesniak B, Fu F, Anderst W, Musahl V. The effect of lateral extra-articular tenodesis on in vivo cartilage contact in combined anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 2022;30(1):61-70.

(26) Kamada K, Nagai K, Nagamune K, Hoshino Y, Nakanishi Y, Araki D, Kanzaki N, Matsushita T, Kuroda R. Direct suturing quadriceps tendon to a continuous loop with a suspensory button provides biomechanically superior fixation in ACL reconstruction. Knee Surg Sports Traumatol Arthrosc. 2021 Nov 22. doi: 10.1007/s00167-021-06805-3. Epub ahead of print.

(27) Yamamoto T, Nagai K, Kanzaki N, Kataoka K, Nukuto K, Hoshino Y, Matsushita T, Kuroda R. Comparison of Clinical Outcomes Between Ceramic-Based Total Ankle Arthroplasty with Ceramic Total Talar Prosthesis and Ceramic-Based Total Ankle Arthroplasty. Foot Ankle Int. 2021 Nov 18:10711007211051353. doi: 10.1177/10711007211051353. Epub ahead of print.

(28) Matsushita T, Akiyama T, Osano K, Yokoyama Y, Okazaki K. Biomechanical analysis of the role of hinge support fixators on hinge stability in medial closing wedge distal femoral osteotomy. Clin Biomech. 2021 Nov 15;91:105528. doi: 10.1016/j.clinbiomech.2021.105528. Epub ahead of print.

(29) Nagai K, Kamada K, Kay J, Hoshino Y, Matsushita T, Kuroda R, de Sa D. Clinical Outcomes After Anterior Cruciate Ligament Reconstruction in Patients With a Concomitant Segond Fracture: A Systematic Review. Am J Sports Med. 2021 Oct 20;3635465211045689. doi: 10.1177/03635465211045689. Epub ahead of print.

(30) Nishida K, Xu C, Gale T, Anderst W, Fu F. Symmetry and sex differences in knee kinematics and ACL elongation in healthy collegiate athletes during high-impact activities revealed through dynamic biplane radiography. J Orthop Res. 2021 Aug 13. doi: 10.1002/jor.25162. Epub ahead of print.

(31) Kataoka K, Hoshino Y, Nagamune K, Nukuto K, Yamamoto T, Yamashita T, Kanzaki N, Kakutani K, Matsushita T, Kuroda R. The quantitative evaluation of anterior drawer test using an electromagnetic measurement system. Sports Biomech. 2021 May 20:1-12. doi: 10.1080/14763141.2021.1918754. Epub ahead of print.

(32) Nishida K, Gale T, Chiba D, Suntaxi F, Lesniak B, Fu F, Anderst W, Musahl V. The effect of lateral extra-articular tenodesis on in vivo cartilage contact in combined anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 2021 Feb 12. doi: 10.1007/s00167-021-06480-4. Epub ahead of print.

(33) Yamamoto T, Miyaji N, Kataoka K, Nishida K, Nagai K, Kanzaki N, Hoshino Y, Kuroda R, Matsushita T. Knee Osteoarthritis Progression Is Delayed in Silent Information Regulator 2 Ortholog 1 Knock-in Mice. Int J Mol Sci. 2021;22(19):10685.

(34) Kamada K, Matsushita T, Yamashita T, Matsumoto T, Iwaguro H, Sobajima S, Kuroda R. Attenuation of Knee Osteoarthritis Progression in Mice through Polarization of M2 Macrophages by Intra-Articular Transplantation of Non-Cultured Human Adipose-Derived Regenerative Cells. J Clin Med. 2021;10(19):4309.

(35) Kataoka K, Watanabe S, Nagai K, Kay J, Matsushita T, Kuroda R, de Sa D. Patellofemoral Osteoarthritis Progresses After Medial Open-Wedge High Tibial Osteotomy: A Systematic Review. Arthroscopy. 2021;37(10):3177-3186.

(36) Ueda Y, Matsushita T, Shibata Y, Takiguchi K, Ono K, Kida A, Ono R, Nagai K, Araki D, Hoshino Y, Matsumoto T, Niikura T, Sakai Y, Kuroda R. Satisfaction with playing pre-injury sports 1 year after anterior cruciate ligament reconstruction using a hamstring autograft. Knee. 2021;33:282-289.

(37) Yamamoto T, Nagai K, Araki D, Miyaji N, Nakanishi Y, Hoshino Y, Kanzaki N, Matsumoto T, Niikura T, Kuroda R, Matsushita T. Influence of selected plane on the evaluation of tibial tunnel locations using a three-dimensional bone model in double-bundle anterior cruciate ligament reconstruction. Knee. 2021;29:298-304.

(38) Yamamoto T, Nagai K, Kanzaki N, Nukuto K, Yamashita T, Ibaraki K, Araki D, Hoshino Y, Matsushita T, Kuroda R. Anterior placement of the talar component in total ankle arthroplasty: A risk factor for talar component subsidence. Foot Ankle Surg. 2021;27(3):311-315.

(39) Matsushita T, Watanabe S, Araki D, Nagai K, Hoshino Y, Kanzaki N, Matsumoto T, Niikura T, Kuroda R. Differences in preoperative planning for high-tibial osteotomy between the standing and supine positions. Knee Surg Relat Res. 2021;33(1):8.

(40) Buerba RA, Zaffagnini S, Kuroda R, Musahl V. ACL reconstruction in the professional or elite athlete: state of the art. J ISAKOS. 2021;6(4):226-236.

(41) Chiba D, Gale T, Nishida K, Suntaxi F, Lesniak BP, Fu FH, Anderst W, Musahl V. Lateral Extra-articular Tenodesis Contributes Little to Change In Vivo Kinematics After Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial. Am J Sports Med. 2021;49(7):1803-1812.

(42) Sasaki Y, Fujii M, Araki D, Marshall BD, Linde MA, Smolinski P, Fu FH. Effect of Percentage of Femoral Anterior Cruciate Ligament Insertion Site Reconstructed With Hamstring Tendon on Knee Kinematics and Graft Force. Am J Sports Med. 2021;49(5):1279-1285.

(43) Matsui T, Kumai T, Shinohara Y, Kanzaki N, Noguchi K, Tanaka H, Sugimoto T, Yabiku H, Higashiyama I. A false-pouch closure technique with an intact superior peroneal retinaculum for recurrent dislocation of the peroneal tendon. J Exp Orthop. 2021;8(1):22.

(44) Nukuto K, Hoshino Y, Yamamoto T, Miyaji N, Nagai K, Araki D, Kanzaki N, Matsushita T, Kuroda R. Anatomic double-bundle anterior cruciate ligament reconstruction could not achieve sufficient control of pivot-shift when accompanying tibial tunnel coalition. Knee Surg Sports Traumatol Arthrosc. 2021;29(11):3743-3750.

(45) Yamamoto T, Nagai K, Kanzaki N, Nukuto K, Yamashita T, Ibaraki K, Araki D, Hoshino Y, Matsushita T, Kuroda R. Anterior placement of the talar component in total ankle arthroplasty: A risk factor for talar component subsidence. Foot Ankle Surg. 2021;27(3):311-315.

(46) Miyaji N, Araki D, Hoshino Y, Kanzaki N, Nagai K, Matsumoto T, Niikura T, Kuroda R, Matsushita T. The sagittal cutting plane affects evaluation of the femoral bone tunnel position on three-dimensional computed tomography after anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 2021;29(2):398-404.

(47) Miyaji N, Nishida K, Tanaka T, Araki D, Kanzaki N, Hoshino Y, Kuroda R, Matsushita T. Inhibition of Knee Osteoarthritis Progression in Mice by Administering SRT2014, an Activator of Silent Information Regulator 2 Ortholog 1. Cartilage. 2020:1947603519900795. doi: 10.1177/1947603519900795. Epub ahead of print.

(48) Byrne KJ, Rothrauff BB, Nagai K, Onishi K, Fu FH. Two-fragment Segond fracture validates historical descriptions of independent soft tissue attachments. Knee Surg Sports Traumatol Arthrosc 2021 Epub ahead of print. doi: 10.1007/s00167-021-06515-w.

(49) Longo UG, Nagai K, Salvatore G, Cella E, Candela V, Cappelli F, Ciccozzi M, Denaro V. Epidemiology of anterior cruciate ligament reconstruction surgery in Italy: a 15-year nationwide registry study. J Clin Med 2021;10(2):223.

(50) Nakanishi Y, Hoshino Y, Nagamune K, Yamamoto T, Nagai K, Araki D, Kanzaki N, Matsushita T, Kuroda R. Radial Meniscal Tears Are Best Repaired by a Modified "Cross" Tie-Grip Suture Based on a Biomechanical Comparison of 4 Repair Techniques in a Porcine Model. Orthop J Sports Med. 2020;8(7):2325967120935810.

(51) Yamamoto T, Hoshino Y, Kanzaki N, Nukuto K, Yamashita T, Ibaraki K, Nagamune K, Nagai K, Araki D, Matsushita T, Kuroda R. Plantar pressure sensors indicate women to have a significantly higher peak pressure on the hallux, toes, forefoot, and medial of the foot compared to men. J Foot Ankle Res. 2020;13(1):40.

(52) Hoshino Y, Hiroshima Y, Miyaji N, Nagai K, Araki D, Kanzaki N, Kakutani K, Matsushita T, Kuroda R. Unrepaired lateral meniscus tears lead to remaining pivot-shift in ACL-reconstructed knees. Knee Surg Sports Traumatol Arthrosc. 2020;28(11):3504-3510.

(53) Hiroshima Y, Hoshino Y, Miyaji N, Tanaka T, Araki D, Kanzaki N, Matsushita T, Kuroda R. No difference in postoperative rotational laxity after ACL reconstruction in patients with and without anterolateral capsule injury: quantitative evaluation of the pivot-shift test at 1-year follow-up. Knee Surg Sports Traumatol Arthrosc. 2020;28(2):489-494.

(54) Nakanishi Y, Matsushita T, Nagai K, Araki D, Kanzaki N, Hoshino Y, Matsumoto T, Niikura T, Kuroda R. Greater knee joint laxity remains in teenagers after anatomical double-bundle anterior cruciate ligament reconstruction compared to young adults. Knee Surg Sports Traumatol Arthrosc. 2020;28(8):2663-2667.

(55) Kanzaki N, Chinzei N, Yamashita T, Kumai T, Kuroda R. A Novel Technique of Arthroscopic Ankle Lateral Ligament Repair Using a Knotless Suture Anchor. Orthop J Sports Med. 2020;8(11):2325967120962079.

(56) Nishida K, Matsushita T, Hoshino Y, Araki D, Matsumoto T, Niikura T, Kuroda R. The Influences of Chronicity and Meniscal Injuries on Pivot Shift in Anterior Cruciate Ligament-Deficient Knees: Quantitative Evaluation Using an Electromagnetic Measurement System. Arthroscopy. 2020;36(5):1398-1406.

(57) Lian J, Diermeier T, Meghpara M, Popchak A, Smith CN, Kuroda R, Zaffagnini S, Samuelsson K, Karlsson J, Irrgang JJ, Musahl V; PIVOT Study Group. Rotatory Knee Laxity Exists on a Continuum in Anterior Cruciate Ligament Injury. J Bone Joint Surg Am. 2020;102(3):213-220.

(58) Diermeier T, Meredith SJ, Irrgang JJ, Zaffagnini S, Kuroda R, Hochino Y, Samuelsson K, Smith CN, Popchak A, Musahl V; PIVOT Study Group, Sheean A, Burnham JM, Lian J, Smith C, Popchak A, Herbst E, Pfeiffer T, Araujo P, Oostdyk A, Guenther D, Ohashi B, Irrgang JJ, Fu FH, Nagamune K, Kurosaka M, Kuroda R, Hoshino Y, Grassi A, Muccioli GMM, Lopomo N, Signorelli C, Raggi F, Zaffagnini S, Horvath A, Svantesson E, Senorski EH, Sundemo D, Bjoernsson H, Ahlden M, Desai N, Samuelsson K, Karlsson J. Patient-Reported and Quantitative Outcomes of Anatomic Anterior Cruciate Ligament Reconstruction With Hamstring Tendon Autografts. Orthop J Sports Med. 2020;8(7):2325967120926159.

(59) Horvath A, Meredith SJ, Nishida K, Hoshino Y, Musahl V. Objectifying the Pivot Shift Test. Sports Med Arthrosc Rev. 2020;28(2):36-40.

(60) Nagai K, Rothrauff BB, Li RT, Fu FH. Over-the-top ACL reconstruction restores anterior and rotatory knee laxity in skeletally immature individuals and revision settings. Knee Surg Sports Traumatol Arthrosc 2020;28(2):538-43.

(61) Naendrup JH, Pfeiffer TR, Chan C, Nagai K, Novaretti JV, Sheean AJ, Shafizadeh ST, Debski RE, Musahl V. Effect of Meniscal Ramp Lesion Repair on Knee Kinematics, Bony Contact Forces, and In Situ Forces in the Anterior Cruciate Ligament: Response. Am J Sports Med 2020;48(2):NP25-NP7.

(62) Matsushita T, Araki D, Matsumoto T, Niikura T, Kuroda R. Changes in knee extensor strengths before and after medial patellofemoral ligament reconstruction. Phys Sportsmed. 2019;47(2):220-226.

(63) Hoshino Y, Miyaji N, Nishida K, Nishizawa Y, Araki D, Kanzaki N, Kakutani K, Matsushita T, Kuroda R. The concomitant lateral meniscus injury increased the pivot shift in the anterior cruciate ligament-injured knee. Knee Surg Sports Traumatol Arthrosc. 2019;27(2):646-651.

(64) Kanzaki N, Chinzei N, Yamamoto T, Yamashita T, Ibaraki K, Kuroda R. Clinical Outcomes of Total Ankle Arthroplasty With Total Talar Prosthesis. Foot Ankle Int. 2019;40(8):948-954.

(65) Araki D, Matsushita T, Hoshino Y, Nagai K, Nishida K, Koga H, Nakamura T, Katakura M, Muneta T, Kuroda R. The Anterolateral Structure of the Knee Does Not Affect Anterior and Dynamic Rotatory Stability in Anterior Cruciate Ligament Injury: Quantitative Evaluation With the Electromagnetic Measurement System. Am J Sports Med. 2019;47(14):3381-3388.

(66) Nishida K, Matsushita T, Araki D, Sasaki H, Tanaka T, Hoshino Y, Kanzaki N, Matsumoto T, Nagamune K, Niikura T, Kurosaka M, Kuroda R. Analysis of anterior tibial subluxation to the femur at maximum extension in anterior cruciate ligament-deficient knees. J Orthop Surg (Hong Kong). 2019;27(1):2309499019833606.

(67) Tanaka T, Matsushita T, Miyaji N, Ibaraki K, Nishida K, Oka S, Araki D, Kanzaki N, Hoshino Y, Matsumoto T, Kuroda R. Deterioration of patellofemoral cartilage status after medial open-wedge high tibial osteotomy. Knee Surg Sports Traumatol Arthrosc. 2019;27(4):1347-1354.

(68) Tanaka T, Matsushita T, Nishida K, Takayama K, Nagai K, Araki D, Matsumoto T, Tabata Y, Kuroda R. Attenuation of osteoarthritis progression in mice following intra-articular administration of simvastatin-conjugated gelatin hydrogel. J Tissue Eng Regen Med. 2019;13(3):423-432.

(69) Miyaji N, Hoshino Y, Tanaka T, Nishida K, Araki D, Kanzaki N, Matsushita T, Kuroda R. MRI-determined anterolateral capsule injury did not affect the pivot-shift in anterior cruciate ligament-injured knees. Knee Surg Sports Traumatol Arthrosc. 2019;27(11):3426-3431.

(70) Ueda Y, Matsushita T, Shibata Y, Takiguchi K, Kida A, Araki D, Kanzaki N, Hoshino Y, Ono R, Sakai Y, Kuroda R. Longitudinal Quadriceps Strength Recovery After Anterior Cruciate Ligament Reconstruction With Hamstring Autograft: Patients Stratified by Preoperative Quadriceps Strength Deficit. J Sport Rehabil. 2019;16:1-20.

(71) Shibata Y, Matsushita T, Araki D, Kida A, Takiguchi K, Ueda Y, Ono K, Matsumoto T, Niikura T, Sakai Y, Kuroda R. Prediction of quadriceps strength recovery after anterior cruciate ligament reconstruction with a hamstring autograft: Decision tree analysis. J Orthop Sci. 2019;24(2):301-305.

(72) Katakura M, Koga H, Nakamura T, Araki D, Nagai K, Nishida K, Kuroda R, Muneta T.　Biomechanical Effects of Additional Anterolateral Structure Reconstruction with Different Femoral Attachment Sites on Anterior Cruciate Ligament Reconstruction. Am J Sports Med 2019;47(14):3373-3380.

(73) Naendrup JH, Pfeiffer TR, Chan C, Nagai K, Novaretti JV, Sheean AJ, Shafizadeh ST, Debski RE, Musahl V. Effect of Meniscal Ramp Lesion Repair on Knee Kinematics, Bony Contact Forces, and In Situ Forces in the Anterior Cruciate Ligament. Am J Sports Med 2019;47(13):3195-3202.

(74) Takenaga T, Yoshida M, Albers M, Nagai K, Nakamura T, Fu FH, Onishi K. Preoperative sonographic measurement can accurately predict quadrupled hamstring tendon graft diameter for ACL reconstruction. Knee Surg Sports Traumatol Arthrosc 2019;27(3):797-804.

(75) Nagai K, Yang S, Fu FH, Anderst W. Unloader knee brace increases medial compartment joint space during gait in knee osteoarthritis patients. Knee Surg Sports Traumatol Arthrosc 2019;27(7):2354-60.

(76) Nagai K, Gale T, Chiba D, Su F, Fu FH, Anderst W. The Complex Relationship Between In Vivo ACL Elongation and Knee Kinematics During Walking and Running. J Orthop Res 2019;37(9):1920-1928.

(77) Tanaka T, Hoshino Y, Miyaji N, Ibaragi K, Nishida K, Nishizawa Y, Araki D, Kanzaki N, Matsushita T, Kuroda R. The diagnostic reliability of the quantitative pivot-shift evaluation using an electromagnetic measurement system for anterior cruciate ligament deficiency was superior to those of the accelerometer and iPad image analysis. Knee Surg Sports Traumatol Arthrosc. 2018;26(9)2835-2840.

(78) Matsushita T, Araki D, Hoshino Y, Oka S, Nishida K, Tanaka T, Miyaji N, Kanzaki N, Ibaraki K, Matsumoto T, Kurosaka M, Kuroda R. Analysis of Graft Length Change Patterns in Medial Patellofemoral Ligament Reconstruction via a Fluoroscopic Guidance Method. Am J Sports Med. 2018;46(5):1150-1157.

(79) Nishida K, Matsushita T, Takayama K, Tanaka T, Miyaji N, Ibaraki K, Araki D, Kanzaki N, Matsumoto T, Kuroda R. Intraperitoneal injection of the SIRT1 activator SRT1720 attenuates the progression of experimental osteoarthritis in mice. Bone Joint Res. 2018;7(3):252-262.

(80) Kirizuki S, Matsumoto T, Ueha T, Uefuji A, Inokuchi T, Takayama K, Hashimoto S, Hayashi S, Matsushita T, Kuroda R. The Influence of Ruptured Scar Pattern on the Healing Potential of Anterior Cruciate Ligament Remnant Cells. Am J Sports Med. 2018;46(6):1382-1388.

(81) Zaffagnini S, Signorelli C, Grassi A, Hoshino Y, Kuroda R, de Sa D, Sundemo D, Samuelsson K, Musahl V, Karlsson J, Sheean A, Burnham JM, Lian J, Smith C, Popchak A, Herbst E, Pfeiffer T, Araujo P, Oostdyk A, Guenther D, Ohashi B, Irrgang JJ, Fu FH, Nagamune K, Kurosaka M, Marcheggiani Muccioli GM, Lopomo N, Raggi F, Svantesson E, Hamrin Senorski E, Bjoernsson H, Ahlden M, Desai N. Anatomic Anterior Cruciate Ligament Reconstruction Using Hamstring Tendons Restores Quantitative Pivot Shift. Orthop J Sports Med. 2018;6(12):2325967118812364.

(82) Musahl V, Burnham J, Lian J, Popchak A, Svantesson E, Kuroda R, Zaffagnini S, Samuelsson K; PIVOT Study Group. High-grade rotatory knee laxity may be predictable in ACL injuries. Knee Surg Sports Traumatol Arthrosc. 2018;26(12):3762-3769.

(83) Sundemo D, Blom A, Hoshino Y, Kuroda R, Lopomo NF, Zaffagnini S, Musahl V, Irrgang JJ, Karlsson J, Samuelsson K; PIVOT Study Group. Correlation between quantitative pivot shift and generalized joint laxity: a prospective multicenter study of ACL ruptures. Knee Surg Sports Traumatol Arthrosc. 2018;26(8):2362-2370.

(84) Nagai K, Gale T, Herbst E, Tashiro Y, Irrgang JJ, Tashman S, Fu FH*, Anderst W. Knee hyperextension does not adversely affect dynamic in vivo kinematics after anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc 2018;26(2):448-454.

(85) Tashiro Y, Lucidi GA, Gale T, Nagai K, Herbst E, Irrgang JJ, Nakashima Y, Anderst W, Fu FH*. Anterior cruciate ligament tibial insertion site is elliptical or triangular shaped in healthy young adults: high-resolution 3-T MRI analysis. Knee Surg Sports Traumatol Arthrosc 2018;26(2):485-490.

(86) Hoshino Y*, Kuroda R, Nishizawa Y, Nakano N, Nagai K, Araki D, Oka S, Kawaguchi S, Nagamune K, Kurosaka M. Stress distribution is deviated around the aperture of the femoral tunnel in the anatomic anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc 2018;26(4):1145-1151.

(87) Albers M, Shaikh H, Herbst E, Onishi K, Nagai K, Musahl V, Fu FH*. The iliotibial band and anterolateral capsule have a combined attachment to the Segond fracture. Knee Surg Sports Traumatol Arthrosc 2018;26(5):1305-1310.

(88) Pfeiffer TR, Kanakamedala AC, Herbst E, Nagai K, Murphy C, Burnham JM, Popchak A, Debski RE, Musahl V*. Female sex is associated with greater rotatory knee laxity in collegiate athletes. Knee Surg Sports Traumatol Arthrosc 2018;26(5):1319-1325.

(89) Ferrer GA, Guenther D, Pauyo T, Herbst E, Nagai K, Debski RE, Musahl V*. Structural properties of the anterolateral complex and their clinical implications. Clin Sports Med 2018;37:41-47.

(90) Nagai K, Herbst E, Gale T, Tashiro Y, Irrgang JJ, Anderst W, Fu FH. Patient-reported outcome measures following anterior cruciate ligament reconstruction are not related to dynamic knee extension angle. Journal of ISAKOS: Joint Disorders & Orthopaedic Sports Medicine 2018;3(1):33-37.

(91) Nagai K, Gale T, Irrgang JJ, Tashman S, Fu FH, Anderst W. Anterior cruciate ligament reconstruction affects tibiofemoral joint congruency during dynamic functional movement. Am J Sports Med 2018;46(7):1566-1574.

(92) Nagai K, Muratsu H Kanda Y, Tsubosaka M, Kamenaga T, Miya H, Matsushita T, Niikura T, Kuroda R, Matsumoto T. Intraoperative soft tissue balance using novel medial preserving gap technique in posterior-stabilized total knee arthroplasty: comparison to measured resection technique. Knee Surg Sports Traumatol Arthrosc 2018 ;26(11):3474-3481.

(93) Nagai K, Tashiro Y, Herbst E, Gale T, Wang JH, Irrgang JJ, Anderst W, Fu FH. Steeper posterior tibial slope correlates with greater tibial tunnel widening following anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc 2018;26(12):3717-3723.

(94) Patel NK, Murphy CI, Nagai K, Canton S, Herbst E, Naendrup J-H, Debski RE, Musahl V. Passive teaching is not as effective as active teaching for learning the standard technique of pivot shift test. Journal of ISAKOS: Joint Disorders & Orthopaedic Sports Medicine 2018;3(4):193-197.

(95) Offerhaus C, Albers M, Nagai K, Arner JW, Hoher J, Musahl V, Fu FH. Individualized Anterior Cruciate Ligament Graft Matching: In Vivo Comparison of Cross-sectional Areas of Hamstring, Patellar, and Quadriceps Tendon Grafts and ACL Insertion Area. Am J Sports Med 2018;46(11):2646-2652.

(96) Nagai K, Nakamura T, Fu FH. The diagnosis of early osteoarthritis of the knee using magnetic resonance imaging. Annals of Joint 2018;3(2):110.

Book Chapter

(1) Nagai K, Kuroda R, Zaffagnini S, Núñez M. Patellofemoral Instability in the Adult Female with Recurrent Instability, Chondrosis of Patella and Trochlea. In: Koh JL, Kuroda R, Espregueira-Mendes J, Gobbi A, eds. The Patellofemoral Joint. Springer, Cham.; 2022:137-147.

(2) Hoshino Y, Barnechea A. How to Assess Patient’s Outcome?. In: Musahl V, Karlsson J, Hirschmann MT, et al., eds. Basic Methods Handbook for Clinical Orthopaedic Research: Springer, Berlin, Heidelberg; 2019:83-88.

(3) Patel NK, Yeung M, Nagai K, Musahl V. How to Review a Clinical Research Paper? In: Musahl V, Karlsson J, Hirschmann MT, et al., eds. Basic Methods Handbook for Clinical Orthopaedic Research: Springer, Berlin, Heidelberg; 2019:255-262.