Takumi Nakagawa

Teikyo University Hospital, Edo, Tōkyō, Japan

Are you Takumi Nakagawa?

Claim your profile

Publications (25)79.95 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Background Medial collateral ligament tibial avulsion is rare. Consequently, diagnostic criteria and a treatment regimen for medial collateral ligament tibial side avulsions remain to be established. The purpose of this study is to clarify the clinical features of medial collateral ligament tibial side avulsions. Methods We performed a retrospective clinical and magnetic resonance imaging review of a consecutive series of 12 medial collateral ligament tibial side avulsions. All patients were treated operatively and the final diagnosis was made based on the intraoperative findings. Post-injury magnetic resonance imaging studies were reviewed to assess injury patterns with respect to the intraoperative findings. Results Eleven of 12 cases (92%) had grade III valgus laxity (unstable to valgus stress at both 0° and 30° of flexion) on an examination under anesthesia. Concomitant anterior cruciate ligament tear was noticed in all cases. Intraoperative findings were classified into 3 types depending on the location of the ruptured end of the superficial medial collateral ligament with respect to the pes anserinus tendons. Magnetic resonance imaging depicted characteristic waving (“wave sign”) of the superficial layer of medial collateral ligament in all cases. Conclusions “Wave sign” of the superficial layer of medial collateral ligament on magnetic resonance imaging is essential for diagnosing medial collateral ligament tibial side avulsions. Based on the clinical features and injury patterns, operative treatment is primarily recommended for medial collateral ligament tibial side avulsions. Level of evidence Case series, Level IV.
    The Knee 09/2014; · 2.01 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Recently, remnant-preserving anterior cruciate ligament (ACL) reconstruction has been increasingly performed to achieve revascularization, cell proliferation, and recovery of high-quality proprioception. However, poor arthroscopic visualization makes accurate socket placement during remnant-preserving ACL reconstruction difficult. This study describes a surgical technique used to create an anatomical femoral socket with a three-dimensional (3D) fluoroscopy based navigation system during technically demanding remnant-preserving ACL reconstruction.
    Knee surgery & related research. 09/2014; 26(3):168-76.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Purpose The purpose of this study was to retrospectively evaluate femoral tunnel widening (TW) and migration of the femoral tunnel aperture after anatomic anterior cruciate ligament (ACL) reconstructions with hamstring grafts and bone–patellar tendon–bone (BPTB) grafts. Methods Of the 105 consecutive patients who underwent ACL reconstruction, the 52 patients who underwent isolated ACL reconstruction and in whom tunnel measurement could be obtained by computed tomography were included in this study. In 26 patients, double-bundle reconstruction (DBR) of the ACL using hamstring tendons was performed. These patients were compared with 26 patients in whom rectangular tunnel ACL reconstruction using BPTB grafts (BPTBR) was performed. Femoral tunnel aperture positioning and TW were investigated postoperatively using 3-dimensional computed tomographic images, which were performed a week and a year after surgery in all patients. Results In DBR, the average diameter of the anteromedial (AM) femoral tunnel increased by 34.0% in the horizontal direction and 28.2% in the vertical direction, whereas that of the posterolateral (PL) femoral tunnel increased by 58.2% and 73.4%, respectively, at 1 year after surgery compared with 1 week after surgery. The percentage TW value of the PL tunnel was significantly greater than that of the AM tunnel. In BPTBR, the average diameter increased by 22.0% and 17.1%, respectively. The percentage TW value of the PL tunnel in DBR was significantly greater than that of the femoral tunnel in BPTBR. Each tunnel aperture migrated distally (“shallow”) in the horizontal direction and high in the vertical direction. AM and PL tunnel apertures in DBR migrated in the vertical direction significantly more than they did in BPTBR. No significant differences between the 2 groups were found in clinical outcomes. Conclusions The femoral PL tunnel aperture in DBR showed significantly more widening than did the AM tunnel aperture in DBR and the femoral tunnel aperture in BPTBR. Also, greater migration of the femoral tunnel aperture in the vertical direction because of TW was observed in DBR than in BPTBR. Level of Evidence Level IV, therapeutic case series.
    Arthroscopy The Journal of Arthroscopic and Related Surgery 01/2014; · 3.10 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A case of recurrent hemarthrosis initially presenting after the fifth postoperative month is described. Because of recurrent pain and swelling, the patient underwent an arthroscopy 14months after total knee arthroplasty (TKA). A remnant posterior lateral meniscus was found to be impinged between the femoral component and the tibial liner, and there was oozing from the hypertrophied synovium around the remnant meniscus. The remnant meniscus and the synovium were carefully cauterized and completely excised. Following the arthroscopy, hemarthrosis has not recurred. A remnant lateral meniscus may be a cause of recurrent hemarthrosis after TKA. Accordingly, in cases of recurrent hemarthrosis after TKA, exploration by arthroscopy should be considered.
    The Knee 10/2013; · 2.01 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this study was to evaluate the clinical results of anatomic double-bundle (DB) anterior cruciate ligament (ACL) reconstruction in which anatomic position of femoral socket apertures was validated using three-dimensional (3D) computed tomography (CT) modelling. Anatomic DB ACL reconstructions with hamstring autografts were performed in 34 patients. Two femoral sockets were created through a far anteromedial (AM) portal behind the lateral intercondylar ridge with the assistance of intraoperative 3D fluoroscopic navigation. Femoral tunnel aperture positioning was investigated postoperatively using 3D CT images in all patients. Clinical results were also evaluated subjectively and objectively at least up to 2 years. Measurement of the AM and the posterolateral (PL) femoral socket locations on the 3D CT images using the quadrant method showed that the centre of the AM socket aperture was located at a depth of 21.0 ± 4.1 % and a height of 30.5 ± 9.3 % and that of the PL socket aperture was located at a depth of 31.3 ± 5.8 % and a height of 57.2 ± 7.7 %. The femoral socket locations were considered as anatomic in accordance with previous cadaveric studies examining the positions of ACL femoral insertion site. Subjectively, the mean Lysholm score was 96.9 ± 4.0 points. According to IKDC final objective scores, 26 knees (76 %) were objectively graded as normal, 8 (24 %) as nearly normal, and 0 (0 %) as abnormal or severely abnormal. Postoperative side-to-side anterior translation measured with a KT-2000 arthrometer averaged 0.7 ± 1.2 mm. DB ACL reconstructions in which femoral socket apertures were validated anatomically using 3D CT provided satisfactory short-term results. Case series, Level IV.
    Knee Surgery Sports Traumatology Arthroscopy 10/2013; · 2.68 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Two patients underwent arthroscopic anatomic double-bundle anterior cruciate ligament (ACL) reconstruction using the EndoButton for femoral fixation. The femoral tunnels were created by the inside-out technique through a far anteromedial portal. The patients postoperatively developed moderate lateral knee pain without instability. At the second-look arthroscopic evaluation, the two EndoButtons were removed. Both patients were completely asymptomatic several months after implant removal, implying that the EndoButtons caused the mechanical irritation in the iliotibial band. This is the first report describing removal of EndoButtons because of pain caused by friction with the iliotibial band. In anatomic ACL reconstruction, if the femoral tunnel exit is positioned near the lateral femoral epicondyle, care should be taken to prevent iliotibial band friction syndrome that could result because of the EndoButton.
    The Knee 08/2013; 20(4):291-294. · 2.01 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: The purpose of this study was to evaluate the influence of image-free computer-assisted navigation system update on outcome in total knee arthroplasty. METHODS: Thirty-three knees were replaced using the Stryker 3.1 image-free navigation system and 49 knees were replaced using the Stryker 4.0 system. One surgeon took part in all procedures as chief surgeon or first assistant. All patients received the Stryker Scopio NRG CR total knee prosthesis. We compared the accuracy of component positioning measured using radiographs and CT scans, operating time and clinical outcome 1 year after surgery. RESULTS: The mean hip-knee-ankle, frontal femoral and tibial component angle were 179.8[degree sign] (ideally implanted 85%), 89.8[degree sign] (88%), 90.4[degree sign] (88%) respectively for the 3.1 group and 179.5[degree sign] (96%), 90.6[degree sign] (92%), 90.2[degree sign] (94%) for the 4.0 group. The mean sagittal tibial component angle was 85.5[degree sign] (82%) for the 3.1 group and 85.6[degree sign] (92%) for the 4.0 group. The mean rotational femoral and tibial component angle were -0.5[degree sign] (81%), -0.7[degree sign] (73%) for the 3.1 group and 0.0[degree sign] (84%), 0.4[degree sign] (72%) for the 4.0 group. There were no statistically significant findings with regard to component positioning.Operating time was significantly longer in the 3.1 group (3.1 group: 137 min, 4.1group: 125 min, P < 0.01).No significant difference was detected in postoperative clinical outcome. CONCLUSION: The navigation system update from Stryker 3.1 to Stryker 4.0 reduced operating time by 12 min. However, there were no statistically significant findings with regard to component positioning and clinical outcome.
    BMC sports science, medicine and rehabilitation. 05/2013; 5(1):10.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Few studies have demonstrated improvement in accuracy of rotational alignment using image-free navigation systems mainly due to the inconsistent registration of anatomical landmarks. We have used an image-free navigation for total knee arthroplasty, which adopts the average algorithm between two reference axes (transepicondylar axis and axis perpendicular to the Whiteside axis) for femoral component rotation control. We hypothesized that addition of another axis (condylar twisting axis measured on a preoperative radiograph) would improve the accuracy. One group using the average algorithm (double-axis group) was compared with the other group using another axis to confirm the accuracy of the average algorithm (triple-axis group). Femoral components were more accurately implanted for rotational alignment in the triple-axis group (ideal: triple-axis group 100%, double-axis group 82%, P<0.05).
    The Journal of arthroplasty 03/2013; · 1.79 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Individual skeletal elements of the vertebrate limbs arise through a segmentation process introducing joints in specific locations. However, the molecular pathways controlling joint formation and subsequent joint maintenance are largely unknown. In this study, we focused on SOX11, and its contribution to the regulation of GDF5, a secreted signal necessary for proper joint formation and postnatal joint homeostasis. RESULTS: Sox11 is initially expressed broadly in the murine cartilage condensations at early stages of skeletal development, but its expression is specifically increased in the forming joint interzone as is forms. SOX11 overexpression can directly activate GDF5 expression both in vitro and in micromass cell cultures prepared from chick limb buds. Conserved SOX family binding sites are present in the 5' UTR region of the GDF5 gene and we show SOX11 can specifically bind to one of them. While misexpression of Sox11 in developing chick limbs through RCAS virus infection does not induce Gdf5 expression in ectopic locations, it does enhance its expression. To explore the roles of Sox11 in joint homeostasis, we analyzed adult knee joints in an osteoarthritis mouse model where the medial meniscus and the medial collateral ligament were removed. We also analyzed knee joints from human subjects who underwent total knee replacement surgery. We find that SOX11 is mainly expressed in the weight-bearing areas of knee joints, and its expression is decreased in degraded cartilage during progression of knee osteoarthritis in both mice and humans. CONCLUSIONS: This work implicates SOX11 as a potential regulator of GDF5 expression in joint maintenance and suggests a possible role in the pathogenesis of osteoarthritis.
    BMC Developmental Biology 01/2013; 13(1):4. · 2.73 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Articular chondrocytes undergo an obvious phenotypic change when cultured in monolayers. During this change, or dedifferentiation, the expression of type I and type III procollagen is induced where normal chondrocytes express little type I and type III procollagen. In this study, we attempted to determine the mechanism(s) for the induction of such procollagen expression in dedifferentiating chondrocytes. All experiments were performed using primary-cultured human articular chondrocytes under approval of institutional review boards. Integrin(s) responsible for the induction of type I and type III procollagen expression were specified by RNAi experiments. The signal pathway(s) involved in the induction were determined by specific inhibitors and RNAi experiments. Adenovirus-mediated experiments were performed to identify a small GTPase regulating the activity of integrins in dedifferentiating chondrocytes. The effect of inhibition of integrins on dedifferentiation was investigated by experiments using echistatin, a potent disintegrin. The effect of echistatin was investigated first with monolayer-cultured chondrocytes, and then with pellet-cultured chondrocytes. In dedifferentiating chondrocytes, α5β1 integrin was found to be involved in the induction of type I and type III procollagen expression. The induction was known to be mediated by v-akt murine thymoma viral oncogene homolog (AKT) signaling. Among the three AKT isoforms, AKT1 seemed to be most involved in the signaling. Elated RAS viral (r-ras) oncogene homolog (RRAS) was considered to regulate the progression of dedifferentiation by modulating the affinity and avidity of α5β1 integrin to ligands. Echistatin inhibited dedifferentiation of monolayer-cultured chondrocytes. Furthermore, the matrix formed by pellet-cultured chondrocytes more closely resembled that of normal cartilage compared with the controls. The result of this study has shown, for the first time, that α5β1 integrin may be responsible for the induction of non-cartilaginous collagen expression in chondrocytes undergoing dedifferentiation. Again, this study has shown that the inhibition of ligand ligation to integrins may be an effective strategy to inhibit phenotypic change of cultured chondrocytes, and to improve the quality of matrix synthesized by primary cultured chondrocytes.
    Arthritis research & therapy 01/2013; 15(5):R127. · 4.27 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Revision anterior cruciate ligament (ACL) reconstruction is accompanied by several technical challenges that must be addressed, such as a primary malpositioned bone tunnel, pre-existing hardware, or bone defects due to tunnel expansion. We describe a surgical technique used to create an anatomic femoral socket using a 3-dimensional (3D) fluoroscopy-based navigation system in technically demanding revision cases. After a reference frame is rigidly attached to the femur, an intraoperative image of the distal femur is obtained, which is transferred to a navigation system and reconstructed into a 3D image. A navigation computer helps the surgeon to visualize the whole image of the lateral wall of the femoral notch, even if the natural morphology of the intercondylar notch has been destroyed by the primary procedure. In addition, the surgeon can also confirm the position of the previous bone tunnel aperture, the previous exit of the femoral tunnel, and the presence of any pre-existing hardware on the navigation monitor. When a new femoral guidewire for the revision procedure is placed, the virtual femoral tunnel is overlaid on the reconstructed 3D image in real time. At our institution, 12 patients underwent 1-stage revision ACL procedures with the assistance of this computer navigation system, and the grafts were securely fixed in anatomically created tunnels in all cases. This technology can assist surgeons in creating anatomic femoral tunnels in technically challenging revision ACL reconstructions.
    Arthroscopy techniques. 09/2012; 1(1):e95-9.
  • [Show abstract] [Hide abstract]
    ABSTRACT: To elucidate the molecular mechanism underlying the endochondral ossification process during the skeletal growth and osteoarthritis (OA) development, we examined the signal network around CCAAT/enhancer-binding protein-β (C/EBPβ, encoded by CEBPB), a potent regulator of this process. Computational predictions and a C/EBP motif-reporter assay identified RUNX2 as the most potent transcriptional partner of C/EBPβ in chondrocytes. C/EBPβ and RUNX2 were induced and co-localized in highly differentiated chondrocytes during the skeletal growth and OA development of mice and humans. The compound knockout of Cebpb and Runx2 in mice caused growth retardation and resistance to OA with decreases in cartilage degradation and matrix metalloproteinase-13 (Mmp-13) expression. C/EBPβ and RUNX2 cooperatively enhanced promoter activity of MMP13 through specific binding to a C/EBP-binding motif and an osteoblast-specific cis-acting element 2 motif as a protein complex. Human genetic studies failed to show the association of human CEBPB gene polymorphisms with knee OA, nor was there a genetic variation around the identified responsive region in the human MMP13 promoter. However, hypoxia-inducible factor-2α (HIF-2α), a functional and genetic regulator of knee OA through promoting endochondral ossification, was identified as a potent and functional inducer of C/EBPβ expression in chondrocytes by the CEBPB promoter assay. Hence, C/EBPβ and RUNX2, with MMP-13 as the target and HIF-2α as the inducer, control cartilage degradation. This molecular network in chondrocytes may represent a therapeutic target for OA.
    Human Molecular Genetics 11/2011; 21(5):1111-23. · 7.69 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A young female athlete suffered from the residual instability of the knee after anterior cruciate ligament (ACL) reconstruction with hamstring autograft. The 3-dimensional (3-D) CT scan showed the "high noon" positioning of the primary femoral bone tunnel. The revision surgery with anatomic double-bundle technique was performed two years after the primary surgery and the femoral tunnels were created with the assistance of the 3-D fluoroscopy-based navigation. An arthroscopic examination confirmed the ACL graft impingement against posterior cruciate ligament (PCL) when the knee was deeply flexed. The histological analysis of the resected primary ACL graft showed local inflammatory infiltration, enhanced synovial coverage and vascularization at the impinged site. The enhanced expression of vascular endothelial growth factor (VEGF) at the impinged area when compared with non-impinged area was observed on immunohistochemical analysis. Abnormal mechanical stress by the impingement against PCL might have induced chronic inflammation and VEGF overexpression.
    Sports Medicine Arthroscopy Rehabilitation Therapy & Technology 11/2011; 3(1):26.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To investigate the chondroprotective effect of cyclooxygenase 2 (COX-2) inhibition in experimental osteoarthritis (OA). The expression of prostaglandin E2 synthetic enzymes was examined by immunostaining of tibial cartilage from mice with surgically induced knee joint instability and from OA patients undergoing total knee arthroplasty. The effect of orally administered celecoxib (10 mg/kg/day and 30 mg/kg/day) or vehicle alone in mice was examined 12 weeks after the induction of OA. To investigate the involvement of COX-1 and COX-2 in OA development, we also created the model in COX-1-homozygous-knockout (Ptgs1-/-) mice and COX-2-homozygous-knockout (Ptgs2-/-) mice. OA severity was assessed using a grading system developed by our group and by the Osteoarthritis Research Society International scoring system. In mouse and human OA cartilage, the expression of the inducible enzymes COX-2 and microsomal prostaglandin E synthase 1 (mPGES-1) was enhanced, while that of the constitutive enzymes COX-1, cytosolic PGES, and mPGES-2 was suppressed. Daily celecoxib treatment did not prevent cartilage degradation or osteophyte formation during OA development in the mouse model. Furthermore, neither Ptgs1-/- mice nor Ptgs2-/- mice exhibited any significant difference in OA development as compared to wild-type littermates. The two COX enzymes differ in terms of regulation of their expression during OA development. Nevertheless, experiments using inhibitor and genetic deficiency demonstrated a lack of chondroprotective effect of COX-2 inhibition in the mouse surgical OA model.
    Arthritis & Rheumatology 09/2011; 64(1):198-203. · 7.48 Impact Factor
  • Journal of Orthopaedic Science 05/2011; 17(4):507-11. · 0.96 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this study was to know which tunnel--the anteromedial (AM) bundle or the posterolateral (PL) bundle--should be prepared first to create the 2 femoral tunnels accurately in anatomic double-bundle (DB) anterior cruciate ligament (ACL) reconstruction. Thirty-four patients were divided into 2 groups of 17 depending on the sequence of preparation of the 2 femoral tunnels. In group A, the AM tunnel was prepared first, whereas the PL tunnel was prepared first in group P. ACL reconstruction was performed using a three-dimensional (3-D) fluoroscopy-based navigation system to place the double femoral tunnels through an accessory medial portal. The double femoral socket positioning was evaluated by 3-D computed tomography (CT) scan image. The non-anatomical placement of the femoral sockets occurred in 5 patients (29%) in group A, whereas the 2 sockets were placed anatomically in all patients in group P (P < 0.05). Evaluation of the AM and the PL socket location on the 3-D CT images using the quadrant method showed more similar values to the laboratory data in a literature in group P than in group A. No complication occurred in group A, whereas complications such as socket communications or back wall blowout occurred in 5 patients (29%) in group P (P < 0.05). The sequence of creating 2 femoral tunnels through accessory medial portal affected the resultant location of the sockets and the rate of the complications. When femoral tunnels are prepared with a transportal technique, PL tunnel first technique seems to be superior to AM first technique regarding anatomic placement. However, PL tunnel first technique accompanies the risk of socket communication.
    Knee Surgery Sports Traumatology Arthroscopy 03/2011; 19(3):424-31. · 2.68 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Articular cartilage defects in the knee of young or active individuals remain a problem in orthopaedic practice. These defects have limited ability to heal and may progress to osteoarthritis. The prevalence of knee osteoarthritis among athletes is higher than in the non-athletic population. The clinical symptoms of osteoarthritis are joint pain, limitation of range of motion and joint stiffness. The diagnosis of osteoarthritis is confirmed by the symptoms and the radiological findings (narrowing joint space, osteophyte formation and subchondral sclerosis). There is no strong correlation between symptoms and radiographic findings. The aetiology of knee osteoarthritis is multifactorial. Excessive musculoskeletal loading (at work or in sports), high body mass index, previous knee injury, female gender and muscle weakness are well-known risk factors. The high-level athlete with a major knee injury has a high incidence of knee osteoarthritis. Cartilage injuries are frequently observed in young and middle-aged active athletes. Often this injury precedes osteoarthritis. Reducing risk factors can decrease the prevalence of knee osteoarthritis. The prevention of knee injury, especially anterior cruciate ligament and meniscus injury in sports, is important to avoid progression of knee osteoarthritis.
    British journal of sports medicine 02/2011; 45(4):304-9. · 3.67 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Chondrocyte hypertrophy followed by cartilage matrix degradation and vascular invasion, characterized by expression of type X collagen (COL10A1), matrix metalloproteinase-13 (MMP-13) and vascular endothelial growth factor (VEGF), respectively, are central steps of endochondral ossification during normal skeletal growth and osteoarthritis development. A COL10A1 promoter assay identified hypoxia-inducible factor-2alpha (HIF-2alpha, encoded by EPAS1) as the most potent transactivator of COL10A1. HIF-2alpha enhanced promoter activities of COL10A1, MMP13 and VEGFA through specific binding to the respective hypoxia-responsive elements. HIF-2alpha, independently of oxygen-dependent hydroxylation, was essential for endochondral ossification of cultured chondrocytes and embryonic skeletal growth in mice. HIF-2alpha expression was higher in osteoarthritic cartilages versus nondiseased cartilages of mice and humans. Epas1-heterozygous deficient mice showed resistance to osteoarthritis development, and a functional single nucleotide polymorphism (SNP) in the human EPAS1 gene was associated with knee osteoarthritis in a Japanese population. The EPAS1 promoter assay identified RELA, a nuclear factor-kappaB (NF-kappaB) family member, as a potent inducer of HIF-2alpha expression. Hence, HIF-2alpha is a central transactivator that targets several crucial genes for endochondral ossification and may represent a therapeutic target for osteoarthritis.
    Nature medicine 06/2010; 16(6):678-86. · 27.14 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The reproducibilities of various measurements of thumb abduction were compared. Two independent observers measured the thumb abduction in 30 volunteers by the following four methods: distance between the thumb tip and the flexion crease of the index finger proximal interphalangeal joint; distance between the flexion crease of the thumb interphalangeal joint and the proximal palmar crease; angle between the thumb and index metacarpals; and angle between the thumb and index proximal phalanx. Measurements were repeated in three weeks and their reproducibility was assessed by the intraclass correlation coefficient (ICC). Intra-observer reproducibilities by distances were high with ICCs between 0.74 and 0.89, compared with those by angles with ICCs between 0.28 and 0.71. Inter-observer reproducibilities by distances were also high (ICCs = 0.79 and 0.81) compared with those by angles (ICCs = 0.28 and 0.42). Assessment of thumb abduction based on distance in the first web is recommended in terms of reproducibility.
    Hand Surgery 01/2010; 15(1):7-10.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Traumatic injury and surgical meniscectomy of a medial meniscus are known to cause subsequent knee osteoarthritis. However, the difference in the prevalence of osteoarthritis caused by the individual type of the medial meniscal tear has not been elucidated. The aim of this study was to investigate what type of tear is predominantly responsible for the degradation of articular cartilage in the medial compartment of knee joints. Five hundred and forty eight cadaveric knees (290 male and 258 female) were registered in this study. The average age of cadavers at death was 78.8 years old (range: 52-103 years). The knees were macroscopically examined and their medial menisci were classified into four groups according to types of tears: "no tear", "radial tear of posterior horn", "other types of tear" and "worn-out meniscus" groups. The severity of cartilage degradation in their medial compartment of knee joints was evaluated using the international cartilage repair society (ICRS) grading system. We statistically compared the ICRS grades among the groups using Mann-Whitney U test. The knees were assigned into the four groups: 416 "no tear" knees, 51 "radial tear of posterior horn" knees, 71 "other types of tear" knees, and 10 "worn-out meniscus" knees. The knees with substantial meniscal tears showed the severer ICRS grades of cartilage degradation than those without meniscal tears. In addition, the ICRS grades were significantly severer in the "radial tear of posterior horn" group than in the "other types of tear" group, suggesting that the radial tear of posterior horn in the medial meniscus is one of the risk factors for cartilage degradation of joint surface. We have clarified the relationship between the radial tear of posterior horn in the medial meniscus and the severer grade of cartilage degradation. This study indicates that the efforts should be made to restore the anatomical role of the posterior horn in keeping the hoop strain, when patients' physical activity levels are high and the tear pattern is simple enough to be securely sutured.
    Sports Medicine Arthroscopy Rehabilitation Therapy & Technology 01/2010; 2:1.

Publication Stats

204 Citations
79.95 Total Impact Points

Institutions

  • 2014
    • Teikyo University Hospital
      Edo, Tōkyō, Japan
  • 2006–2013
    • The University of Tokyo
      • • Department of Orthopaedic Surgery and Spinal Surgery
      • • Department of Surgical Sciences
      Tokyo, Tokyo-to, Japan