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The subtalar joint has a possible compensatory mechanism for supramalleolar deformities; the failure of this mechanism causes the progression of ankle osteoarthritis. However, the reason for this failure has not been fully elucidated. This study aimed to evaluate the characteristics of the morphologic changes in the subtalar joint in varus ankle osteoarthritis using computed tomography. The study included 30 patients with severe osteoarthritis (modified Kellgren-Lawrence classification grade ≥ 3; mean age: 68.5 years) and 30 patients without- or with early osteoarthritis (grade 0-1; mean age: 43.0 years) as the control group. The location of cysts, osteophyte formation in the subtalar joint, and thickness of the subchondral bone plate were evaluated. In the osteoarthritis group, cyst formation was observed on the posterolateral side of the posterior facet of the calcaneus in 6 cases (20%) and of the talus in 7 cases (23.3%). Osteophyte formation was observed in the talus in 21 cases (70.0%) and in the calcaneus in 29 cases (96.6%). Osteophyte formation was observed on the posterior or lateral side of the posterior facet, and osteophyte contact between the talus and calcaneus was observed. The subchondral bone plate of the posterior medial side of the posterior facet of the talus was significantly thicker in the osteoarthritis group. The subtalar joint is less affected in severe varus ankle osteoarthritis containing a thickened subchondral bone plate in the posteromedial aspect of the posterior talar facet.

Aims Meniscal injuries are common and often induce knee pain requiring surgical intervention. To develop effective strategies for meniscus regeneration, we hypothesized that a minced meniscus embedded in an atelocollagen gel, a firm gel-like material, may enhance meniscus regeneration through cell migration and proliferation in the gel. Hence, the objective of this study was to investigate cell migration and proliferation in atelocollagen gels seeded with autologous meniscus fragments in vitro and examine the therapeutic potential of this combination in an in vivo rabbit model of massive meniscus defect. Methods A total of 34 Japanese white rabbits (divided into defect and atelocollagen groups) were used to produce the massive meniscus defect model through a medial patellar approach. Cell migration and proliferation were evaluated using immunohistochemistry. Furthermore, histological evaluation of the sections was performed, and a modified Pauli’s scoring system was used for the quantitative evaluation of the regenerated meniscus. Results In vitro immunohistochemistry revealed that the meniscus cells migrated from the minced meniscus and proliferated in the gel. Furthermore, histological analysis suggested that the minced meniscus embedded in the atelocollagen gel produced tissue resembling the native meniscus in vivo. The minced meniscus group also had a higher Pauli’s score compared to the defect and atelocollagen groups. Conclusion Our data show that cells in minced meniscus can proliferate, and that implantation of the minced meniscus within atelocollagen induces meniscus regeneration, thus suggesting a novel therapeutic alternative for meniscus tears. Cite this article: Bone Joint Res 2021;10(4):269–276.

Background: Rotational ankle instability (RAI) is associated with the faster onset of severe ankle osteoarthritis via dysfunction of the anterior talofibular ligament, calcaneofibular ligament, and deltoid ligament. No specific clinical examination is available for RAI, and diagnostic imaging has limitations in evaluating ligament degradation. This study investigated the deltoid ligament degeneration using Hounsfield unit (HU) values on computed tomography (CT) images. Methods: Patients were enrolled in this retrospective analysis if they had undergone magnetic resonance imaging (MRI) and CT scans of the ankle. The chronic ankle instability (CAI) group comprised 20 ankles with CAI (9 men, 11 women; mean age, 28.7 years) and the control group comprised 28 ankles (16 men, 12 women, mean age, 41.3 years). The average HU values of the deep posterior tibiotalar ligament (dPTL) that constitutes the deltoid ligament were measured on coronal CT images, and MRI results were used as a reference. All patients were subdivided based on the MRI findings of dPTL injury such as fascicular disruption, irregularity, and the loss of striation. Results: A strong negative correlation was identified between age and HU values for all patients (Spearman ρ = −0.63; P < .001). The mean HU values of the dPTL for participants aged Conclusion: In addition to the conventional imaging examination such as stress radiographs and MRI, HU measurements of CT images could be useful for quantitatively and noninvasively evaluating degenerative changes in the deltoid ligament for CAI patients to assist the diagnosis of RAI. Level of Evidence: Level III. case-control study.

Background The posterior cruciate ligament (PCL) is one of the essential stabilizers of the knee joint and it was demonstrated that its degenerative change related to the knee osteoarthritis (OA). We aimed to evaluate signal of the PCL in OA patients in comparison with healthy young and elderly volunteers using the ultra-short echo timeenhanced (UTE)-T2∗ mapping, and to validate these findings with histology. Methods Thirty asymptomatic volunteers, 13 young people (younger group) and 17 elderly people (elder group), and 27 patients who had undergone total knee arthroplasty (OA group) were enrolled in this study. UTE-T2∗ maps of PCL were obtained from all participants. The PCL was divided into proximal, middle, and distal parts and the UTET2∗ values obtained from each part were compared among the groups. In OA group, the sacrificed PCLs were evaluated histologically in each part corresponding to the part of UTE-T2∗ maps and compared. Results The UTE-T2∗ values in OA group were significantly higher than those in other groups except in distal part. In elder group, the UTE-T2∗ values were significantly higher than those in younger group only in the proximal part. Moreover, in OA group, the UTE-T2∗ values in proximal and middle parts were significantly higher than those in distal part. There was a moderate correlation between the UTE-T2∗ values and histological scores. Conclusions The specific signal intensity pattern of the PCL in patients with OA was demonstrated using UTE-T2∗ mapping, and these findings were related to histological degenerated status of the PCL.

Background Lateral ankle ligament repair for chronic lateral ankle instability is common, and arthroscopic repair of the anterior talofibular ligament (ATFL) has been widely performed. However, it is desirable to repair of calcaneofibular ligament (CFL) combined with arthroscopic ATFL repair to obtain good long term clinical outcomes. Repairing CFL through small skin incision, there is the possibility to interfere with ATFL and CFL anchors because of close attachment of ATFL and CFL at fibula. The purpose of this study is to determine the safety anchor insertion angles for ATFL and CFL on CT images and to achieve ATFL and CFL repair with minimally invasive technique. Methods Fifty ankles in 50 patients were included in this study. On a sagittal CT image, the anchor drill hole angles for ATFL and CFL were measured to avoid interference with these anchors. Then, arthroscopic ATFL repair combined with CFL repair was performed on 15 patients according to the safety insertion angles obtained by CT. CFL repair was performed through 1.5 cm length of accessory anterolateral portal. Clinical outcome was evaluated using the Japanese Society for the Surgery of the Foot (JSSF) ankle hindfoot scale and the Karlsson score before surgery and at final follow-up. Results On the CT image, the mean angles between the ATFL drill hole and anterior border of the fibula was 59.4 ± 6.5°, and those between the longitudinal axis of the fibula and ATFL drill hole, and the CFL drill hole were 34.6 ± 5.0°, and 15.1 ± 5.7°, respectively. Postoperative CT after arthroscopic ATFL repair combined with CFL repair showed that no interference with 2 anchors, and JSSF scale and the Karlsson score were significantly improved from preoperative to final follow-up. Conclusions This study showed how safety ATFL and CFL anchor insertion angles comprise a minimally invasive anatomical repair technique.

Arthroscopic ankle arthrodesis (AAA) has advantages of being less invasive and achieving a high bone union rate. However, there are still some nonunion or delayed union cases, especially those of high-grade deformity. During AAA, curettage of the subchondral bone using an abrader burr provides bone debris, and there is the possibility of bone debris being used as autograft to improve bone union. The purpose of this study is to analyze bone debris histologically, and the effect of its implantation on bone union of AAA. Bone debris from 6 patients was collected during AAA. Bone debris/atelocollagen composite was made and cultured for 4 weeks. Histological analyses were performed before and after culture. Twenty-six patients with AAA were divided into 2 groups with or without bone debris implantation, and the time to union after surgery was evaluated. In histological analysis of bone debris/atelocollagen composite, bone debris contained bone, cartilage and synovium fragment at time 0. After 4 weeks of culture, osteocalcin positive cells migrated and proliferated in the gel. Ki67 positive cells significantly increased after culture. In clinical cases, time to union was significantly shorter in the bone debris group (9.3 ± 1.3 weeks) than that in the control (12.4 ± 3.1 weeks). This study showed that bone debris contained the osteochonductive and osteoinductive properties, and there is the potential for its implantation into the ankle joint to improve bone union in ankle arthrodesis.

Recent reports have described midterm natural courses of osteochondral lesion of the talus (OLT) and lack of progression of ankle osteoarthritis (OA) in adult patients. The relationship between the OLT managed with nonoperative treatment and development of OA in children remains unknown. We report the long-term course of medial OLT in a 12-year-old female who was treated nonoperatively for 10 years. Radiographically, no osteoarthritic changes were observed at the first examination. She initially returned to her basketball club after nonoperative treatment. Although daily activities were not restricted, limitation of recreational activities began to appear at 4 years of follow-up. Subsequently, plain radiographs revealed bone absorption around the osteochondral fragment and osteophyte formation at the medial gutter, then ankle OA was advanced at the final follow-up.

To accomplish joint preservation, the osteochondral unit, which comprises articular cartilage and underlying subchondral bone, should be understood and treated accordingly. Articular cartilage plays a role in both smooth joint movement and weight-bearing capabilities, while subchondral bone supports the articular cartilage to maintain its homeostasis. Cartilage and subchondral bone interact (through crosstalk) within the osteochondral unit and cooperate to perform joint function. Therefore, it is appropriate to target articular cartilage and subchondral bone in the task of restoring joint function. The strategies for joint preservation aim to prevent the development of osteoarthritis (OA) and to treat joints which have already developed OA, by preserving or restoring joint function. Surgical procedures should be chosen based on which specific area of the osteochondral unit needs to treatment, such as the cartilage layer, subchondral bone, or both. The important thing to keep in mind is the concept of repairing the whole osteochondral unit, the purpose of which is to restore the function of the osteochondral unit for joint preservation.

Iatrogenic hallux varus is a difficult complication of hallux valgus surgery. Although tendon transfer combined with bony correction is performed for hallux varus, tendon transfer has several disadvantages, such as the complicated nature of the procedure and the donor site morbidity. We describe the case of a 70-year-old woman with iatrogenic hallux varus treated by lateral collateral ligament (LCL) reconstruction using a suture tape anchor with bony correction. Tarsometatarsal joint arthrodesis was performed to correct the narrow intermetatarsal angle (IMA), and the varus deformity of the great toe at the metatarsophalangeal joint was corrected by anatomical reconstruction of the LCL using the suture tape anchor. One year postoperatively, the Japanese Society for Surgery of the Foot Hallux Metatarsophalangeal-Interphalangeal Scale had improved from 37 to 90 points. Radiography confirmed that the hallux valgus angle had been corrected from -24° to 4° and the IMA from 0° to 8°. Reconstruction of the LCL using suture tape anchor is an easy procedure for iatrogenic hallux varus which can achieve good stabilization.

Background/objective: There is controversy regarding the biomechanical function of the anteromedial (AM) and posterolateral (PL) bundles in isolated tibiofemoral rotation during double-bundle anterior cruciate ligament (ACL) reconstruction. This study aimed to evaluate the biomechanical function of the AM and PL bundles of the ACL using a computer navigation system. Methods: This study involved 15 patients who underwent double-bundle ACL reconstruction. Anteroposterior and isolated rotational knee laxity were measured with a navigation system. The measurements were performed four times, namely, before fixation, after temporary PL bundle fixation, after AM bundle fixation, and after double-bundle reconstruction. With knee flexion ranging from 20° to 60°, we continuously measured the anterior tibial displacement under an anterior drawer stress (100 N using a spring balance). The total range of tibial rotation was also measured under an external and internal rotational torque of 3 Nm. Results: Fixation of either the AM or the PL bundle significantly reduced the anteroposterior displacement at all knee flexion angles. Although the anteroposterior displacement after AM bundle fixation was relatively similar throughout the range of motion (2.4–3.2 mm), the anteroposterior displacement after PL bundle fixation increased continuously with knee flexion (2.2–4.6 mm). With respect to the total range of tibial rotation under external and internal rotational torque, there was no significant difference between AM and PL bundle fixation throughout the range of motion. The total range of tibial rotation was significantly reduced only on double-bundle reconstruction at 20° and 25° knee flexion compared to the pre-reconstruction range (P = 0.015 and 0.036, respectively). Conclusion: The AM and PL bundles function differently for controlling anterior knee laxity throughout the range of motion. The function of the AM and PL bundles was similar for controlling isolated tibiofemoral rotation. Isolated tibiofemoral rotation was significantly controlled only on double-bundle reconstruction at knee flexion angles of 20° and 25°. Keywords: Anterior cruciate ligament, Double-bundle, Navigation system, Intraoperative kinematics, Isolated tibiofemoral rotation

Background: Fixation of an osteochondral lesion of the talus (OLT) can restore the natural congruency of the joint surface with hyaline cartilage. In this procedure, the bone condition of the osteochondral fragment is important for stabilizing the lesion, and it may affect clinical outcomes. The aim of this study was to explore the influence of the fragment’s bone condition on clinical outcomes. Methods: Eighteen ankles in 17 patients with a mean age of 20.1 years, which had undergone fixation of an OLT using bioabsorbable pins, were included. Based on the fragment’s bone condition on preoperative computed tomography scans, ankles were divided into 3 groups: normal, segmentation, and absorption. The American Orthopaedic Foot & Ankle Society (AOFAS) scale and magnetic resonance imaging (MRI) findings were evaluated both pre- and postoperatively. Second-look arthroscopic findings were evaluated in 15 ankles and were compared with biopsy specimens from the initial surgery. Results: The AOFAS scale significantly improved at the final follow-up in all groups with no significant differences among the 3 groups. MRI at 1 year showed good bone incorporation and a congruent cartilage surface in all groups, but the bone marrow lesion in the absorption group was significantly larger than that in the other groups. In second-look arthroscopy, all ankles showed stable and near-normal cartilage. There was no significant correlation between arthroscopic and histological findings. Conclusion: We found that fixation can be considered when there is a good cartilage surface on a large OLT, even if bone absorption in the fragment exists. Level of Evidence: Level III, comparative study.

Chronic lateral ankle instability (CLAI) is associated with osteoarthritis (OA). However, the characteristics of patients with CLAI who progress to OA are not clear. Measurement of Hounsfield Unit (HU) value on computed tomography (CT) is reported to be useful to evaluate the stress distribution. We aimed to evaluate the stress distribution in the ankle and subtalar joints and factors enhancing it in patients with CLAI. Thirty-three ankles with CLAI (CLAI group) and 26 ankles without CLAI (control group) were included. A mean age of CLAI was 35.2 years and control was 30.3 years. Color map was created in the ankle and subtalar joint according to the HU values using three-dimensional CT to identify the region with high HU values, and HU values in those regions were measured using two-dimensional CT and compared between control and CLAI groups. In CLAI group, the relationships between HU values and ankle activity score (AAS), OA, talar tilting angle (TTA), cartilage injury were assessed. The HU values in the anteromedial region of the talus and lateral region in the subtalar joint were higher than those in the control. In CLAI, patients with an AAS of ≧ 6, over 10° of TTA, cartilage injury, and OA changes in the medial gutter had significantly higher HU values in the lateral region of the subtalar joint than those with an AAS of ≦5, less than 10° of TTA without cartilage injury and OA change. CLAI patients, especially in the patients with high activity level, large TTA, cartilage injury, and OA changes at the medial gutter, have high HU values in the lateral region of the subtalar joint, which suggests that disruption of the subtalar compensation toward OA will occur. For these patients, instability should be completely eliminated to prevent ankle OA. Level III, comparative series.

Category: Ankle; Other Introduction/Purpose: Chronic lateral ankle instability (CLAI) that is developed after multiple lateral ankle ligament injury lead to ankle osteoarthritis. Although isolated deltoid ligament injury is rare compared to lateral ankle ligament injury, deltoid ligament tear, especially deep posterior tibiotalar ligament (PTT) can be observed arthroscopically in CLAI patients. Unphysiological loading of the ankle joint with CLAI might cause degradation of the deltoid ligament. This study aimed to investigate image findings of the deltoid ligament using computed tomography (CT) value for quantitative analysis of degenerative ligament changes in CLAI patients. Methods: Among the enrolled patients who underwent ankle magnetic resonance imaging (MRI) and CT scans of the ankle, this retrospective analysis included 24 ankles without ankle osteoarthritis, osteochondral lesion of the talus (OLT), flatfoot and ankle fractures (14 males and 10 females; mean age, 42.8 years) as a control group, and 14 CLAI ankles without OLT (7 males and 7 females; mean age, 31.1 years) as CLAI group. The CT scans were performed using a 64-slice multidetector row CT. Deep PTT was detected on coronal T2-weighted MR images. Both the coronal MR and CT images were matched for analysis, then average CT values were measured using the region of interest that was applied to the detected area of deep PTT on the CT images. Spearman’s correlation coefficient was used to evaluate the correlation between age and CT value in the control group. Results: The strong negative correlation was identified between age and CT value in the control group (Spearman ρ= -0.88; p < 0.001). The CT value of the deep PTT are degraded with aging. Mean CT value of deep PTT in participants under 60 years old were 79.9 HU (95% CI, 75.1-84.8) in the control group (18 ankles), and 66.5 HU (95% CI, 58.6-74.5) in the CLAI group (14 ankles) (Welch’s t test; p = 0.005). Conclusion: MRI techniques and protocols recently have been developed, however, some limitations remain such as a quantitative evaluation of the ligament. Our findings suggest that the CLAI can lead to degradation of the deltoid ligament via an overloading of medial ankle structures. Additionally, CT values should be useful for quantitatively evaluating ligament status including degenerative changes.

Articular cartilage has the ability to absorb the loading stress and create a low friction and high resistance to the wear and tear, which provides a smooth joint movement and weight-bearing capability to the joint. A loss of function of the articular cartilage due to trauma or osteoarthritis (OA) induces a functional disability of the joint. The subchondral bone plays a crucial role in the cartilage metabolism, load-bearing, and nourishment and is a warehouse of the cartilage cells and the growth factors. A damaged subchondral bone no longer maintains cartilage homeostasis, which leads to a loss of proteoglycan, glycoprotein, load-bearing capacity, and the vascularity [1]. In the treatment of articular cartilage, it is important to know the importance of the subchondral bone including the relationship of the articular cartilage and the subchondral bone.

Background: Chronic ankle instability (CAI) induces osteoarthritis (OA) by inflicting abnormal stresses on the medial gutter. It is important to detect early OA change and to explore factors likely to induce the OA. The purpose of this study was to evaluate subchondral bone change in the medial gutter of CAI using computed tomography (CT) scans. Methods: Thirty-five ankles with CAI (CAI group) and 35 ankles without CAI (control group) were included. The region of interest (ROI) in the subchondral bone of the medial gutter on CT axial images was set on the tibia and talus. The Hounsfield unit (HU) in ROIs was measured and corrected by the HU of the fibula in the same slice. HU ratios were compared between the CAI and control groups. In the CAI group, the relationship between the HU ratio and the talar tilt angle (TTA), OA change, and the anterior talofibular ligament (ATFL) remnant quality were analyzed. Results: The mean HU ratio in the CAI group was significantly higher than that in the control. In the CAI group, HU ratios in ≥10 degrees of TTA were significantly higher than those in Conclusion: CAI patients exhibited subchondral bone change in the medial gutter, which suggests that the elimination of instability may help to prevent or decrease the development and/or progression of osteoarthritis. Level of Evidence: Level III, comparative series.

Background Posterior cruciate ligament (PCL) degeneration is often seen in knee osteoarthritis (OA); however, there is no established method for its evaluation. The purpose of this study is to investigate whether the Hounsfield unit (HU) using computed tomography (CT) could be a useful scale to evaluate the degeneration of PCL in knee OA. Methods Knee OA treated with total knee arthroplasty (21 patients, 21 knees) and non-osteoarthritic knees (21 patients, 21 knees) were retrospectively observed and studied. All PCLs in the knees were analyzed using CT. The PCL in the sagittal section was divided into three regions: proximal, middle, and distal sections. The HU value of the PCL at each area was measured. In osteoarthritic knees, tissues from the PCL were collected and histologically graded. The correlation between the radiological classification by Kellgren and Lawrence and the histological grade was analyzed. The average CT HU values for each degenerative grade were also calculated and compared. Results The HU values in OA and non-OA were 70.7 and 88.4 HU (p p p > 0.05) in the distal region, respectively. The degeneration of PCL was graded as follows: one, three, and 17 mild, moderate, and severe cases at the proximal portion, and 16, 4, and one mild, moderate, and severe cases at the distal portion, respectively. The radiological classification and the grade of degeneration were not correlated in either the proximal (r = 0.047, p = 0.84) or the distal (r = − 0.21, p = 0.35) portions. The HU value was 84.5, 72.1, and 70.6 HU for mild, moderate, and severe grades, respectively (mild versus moderate: p p p > 0.05). Conclusions In knee OA, a lower HU value in the PCL indicates the progression of degeneration. The CT HU value could be a useful measurement to predict the grade of PCL degeneration.

Postoperative anterior and rotational stability are still controversial when compared with single-bundle (SB) and double-bundle (DB) anterior cruciate ligament (ACL) reconstruction. This study aimed to compare the central anatomical SB and anatomical DB ACL reconstruction in intraoperative knee kinematics during continuous knee flexion-extension. A total of 34 patients who underwent ACL reconstruction using the hamstring tendon were evaluated intraoperatively before and immediately after ACL reconstruction using OrthoPilot ACL Navigation System Version 3.0. The patients were prospectively randomized into the central anatomical SB (17 knees) and the anatomical DB reconstruction (17 knees) groups. The tibial translation and rotation were continuously measured during knee flexion-extension under conventional knee motion, anterior tibial load (100N), and internal-external torque (3 N·m). The anterior tibial translation and total range of tibial rotation were calculated from the measurement values from 20 to 50 degrees at each 5-degree point. The anterior tibial translation (p = 0.59; two-factor repeated measures analysis of variance; η 2G = 0.0077) and total range of tibial rotation (p = 0.95; η 2G = 0.0001) at each knee flexion angle showed no significant difference between the central anatomical SB and anatomical DB reconstruction groups. It is suggested that the central anatomical SB reconstruction is comparable with the anatomical DB reconstruction in biomechanical anteroposterior and rotational knee stability at time 0.

Arthroscopic repair of the lateral ankle ligament using the anchor system has been increasingly reported. We treated a 39-year-old woman who suffered from pain and instability in her left ankle joint. She was diagnosed with chronic ankle instability and an osteochondral lesion of the talar dome. For this patient, arthroscopic repair of the anterior talofibular ligament (ATFL) was performed. Standard anteromedial and anterolateral portals were placed, and excision of the osteochondral fragment and microfracture were performed. Then, an accessory anterolateral (AAL) portal was placed. No. 2 nylon sutures were inserted into the ATFL remnant through the AAL portal. Two bone tunnels were created at the footprint of the fibula attachment toward the posterior edge of the lateral malleolus using a passing pin, and nylon sutures anchored in the ATFL were retrieved toward the posterior fibula. The foot was held in neutral position with eversion, and nylon sutures were tied at the posterior fibula. At 1 year after surgery, the Japanese Society for Surgery of the Foot scale was improved from the preoperative value of 48 points to a postoperative value of 100 points. Stress radiography showed no difference of talar tilt angle between the involved and noninvolved ankles. Joint position sense was also improved at 3 and 6 months after surgery. This arthroscopic repair of the ATFL using the pull-out technique enabled achievement of an improved clinical score and stability of the ankle and proprioception, and there was no concern about complications of the anchor system.

Background: The microfracture (MF) technique is an established surgical treatment for cartilage injury. However, the early-phase histological changes in full-thickness cartilage defects (FTCDs) after MF and the concomitant changes in the subchondral bone are still unknown. Purpose: To determine the early-phase histological changes in FTCD associated with subchondral bone remodeling after MF in rat model. Study Design: Controlled laboratory study. Methods: Rats were subjected to FTCD, followed by MF at the trochlear groove. For histological analysis, experiment and untreated control rats were sacrificed at 0, 1, 3, 7, 14, 28, and 56 days postoperatively (n = 6 knees per time point). Cartilage healing response was evaluated with the Pineda score. Osteoclast activity was evaluated by counting and locating the number of tartrate-resistant acid phosphatase (TRAP)–positive cells in the subchondral bone. MF hole diameter and bone mineral density in the subchondral bone were measured sequentially in 3 rats (n = 6 knees) by 3-dimensional μ–computed tomography. Results: Pineda score showed no difference in cartilage response from day 0 to day 3 but a significant improvement from day 7 to day 56. Although the MF holes were filled with blood clots in all specimens, the defect sites were not. The number of TRAP-positive cells peaked at day 3, mostly accumulating around the deeper zone of the MF holes. Over time, the number of TRAP-positive cells decreased to preoperative levels, localizing around the aperture of the MF holes where there was active remodeling of the osteochondral unit. The MF hole diameter was largest at day 14, and most holes disappeared by day 28. Bone mineral density was also highest at day 14 and decreased to preoperative levels by day 56. Conclusion: Histological changes in the FTCD after MF were derived from endochondral ossification within the deeper zone of the MF holes. Clinical Relevance: The absence of healing by blood clot in the FTCD should be noted by surgeons performing MF, and indications for MF should be carefully considered not only for maximizing the postoperative clinical outcome but also minimizing potential complications, such as formation of subchondral bone cysts or intralesional osteophytes.

AimsTo investigate the risk factors for progression of articular cartilage damage after anatomical anterior cruciate ligament (ACL) reconstruction.Patients and MethodsA total of 174 patients who underwent second-look arthroscopic evaluation after anatomical ACL reconstruction were enrolled in this study. The graded condition of the articular cartilage at the time of ACL reconstruction was compared with that at second-look arthroscopy. Age, gender, body mass index (BMI), ACL reconstruction technique, meniscal conditions, and other variables were assessed by regression analysis as risk factors for progression of damage to the articular cartilage.ResultsIn the medial compartment, multivariable logistic regression analysis indicated that partial medial meniscectomy (odds ratio (OR) 6.82, 95% confidence interval (CI) 2.11 to 22.04, p = 0.001), pivot-shift test grade at the final follow-up (OR 3.53, CI 1.39 to 8.96, p = 0.008), BMI (OR 1.15, CI 1.03 to 1.28, p = 0.015) and medial meniscal repair (OR 3.19, CI 1.24 to 8.21, p = 0.016) were significant risk factors for progression of cartilage damage. In the lateral compartment, partial lateral meniscectomy (OR 10.94, CI 4.14 to 28.92, p < 0.001) and side-to-side differences in anterior knee laxity at follow-up (OR 0.63, p = 0.001) were significant risk factors.ConclusionPartial meniscectomy was found to be strongly associated with the progression of articular cartilage damage despite r anatomical ACL reconstruction. Cite this article: Bone Joint J 2018;100-B:285–93.

Background Osteochondral lesions of the talus (OLT) are recognized as being commonly associated with trauma. However, the etiology of OLT remains unclear. In the case of a posteromedial lesion of OLT (medial OLT), the deep layer of the deltoid ligament is located close to the medial OLT, and this relationship between a medial lesion and deltoid ligament could be a risk factor for medial OLT. The purpose of this study is to investigate the unique anatomic feature of the deep deltoid attachment to the talus in patients with medial OLT compared with patients with non-medial OLT. Methods Forty ankles with medial OLT and 40 ankles without medial OLT were retrospectively reviewed in this study. On the coronal images of MRI, the attachment of deltoid ligament was measured. The continuity of the osteochondral fragment and its bed was evaluated on MRI and arthroscopic findings. Results Coronal MRI images showed that the attachment of the deep deltoid ligament to the medial OLT was broader and located more proximally than in non-medial OLT. The continuity of fibers from the insertion site of deltoid ligament to the talus to the osteochondral fragment was observed (76.7%). In the arthroscopic findings, the osteochondral fragment was obviously connected to the talus at the medial site in 85.2% of feet. Conclusions The location of the deep deltoid ligament attachment to the medial OLT was more proximal and there was the possibility of these anatomic feature might contribute to the pathogenesis of medial OLT.

Ankle arthroscopy is a minimally invasive technique for ankle joint treatment. However, injury to the intermediate dorsal cutaneous nerve (IDCN) and the medial dorsal cutaneous nerve (MDCN) is a common complication during anterior portal placement. To prevent injuries, methods such as palpating the nerves topographically and marking the nerves by transilluminating the skin with an arthroscope have been proposed. Easier and more definitive methods of identifying the IDCN and MDCN should result in a reduction of complications. Recently, a vein imaging system was developed that projects images of subcutaneous vasculature directly onto the skin with the use of near-infrared (NIR) light. Because anatomic studies have shown that superficial veins accompany the IDCN and MDCN, protecting the subcutaneous veins could lower the risk of nerve injury. We introduce our technique for the creation of an ankle arthroscopic portal using an NIR imaging system, which displays the vein image on the skin, to prevent injury to the superficial veins and, consequently, reduce IDCN and MDCN injuries. This is the first technical report on the prevention of vein and nerve injuries using an NIR imaging system. Our technique for avoiding vein injury using a peripheral vein illumination device during anterior portal placement in ankle arthroscopy could lower the risk of complications.

Importance Several studies have shown a statistically significant decrease in proprioceptive function in anterior cruciate ligament (ACL)-deficient knees. The effects of ACL reconstruction on knee proprioception have continued to be a matter of debate. Objective The main aim of this review was to verify whether there is impaired proprioceptive function of the lower extremity in subjects with ACL reconstruction when compared with uninjured external controls. Evidence review A comprehensive search was performed using PubMed and Scopus to search for relevant studies on knee proprioception after ACL reconstruction on 10 September 2016. The studies that used only a patient's contralateral leg as a control were excluded. A modified Cochrane Methods Group on Screening and Diagnostic Tests Methodology was used to grade the quality of the studies. Findings A total of 11 studies involving 213 patients and 204 controls were included. In the threshold to detect passive motion measurement, five of the six studies showed no significant differences between the ACL-reconstructed knees and the uninjured external control knees. In the joint position sense measurement, only one of six studies showed that ACL-reconstructed knees had significantly lower proprioceptive function than those of uninjured external control knees. Conclusions and relevance This review demonstrated that there was no evidence of impaired proprioceptive function in subjects with ACL reconstruction when compared with the uninjured external controls. Higher quality studies and homogenisation on clinical assessment are needed to perform a more definitive analysis in the future. Level of evidence III, systematic review of level II and III studies

Large differences in tibial tubercle-posterior cruciate ligament (TT-PCL) distance were described in several reports between countries, suggesting that abnormal TT-PCL distance is variable due to individual patient size. This study aimed to clarify the relationship between TT-PCL distance and patient size, and to determine a method for describing individualized TT lateralization.We analyzed 41 patients with recurrent patellar dislocation (RPD) and 41 age-matched patients without patellar instability who underwent primary anterior cruciate ligament reconstruction (control). TT-PCL distance and tibia width (TW) were measured based on preoperative T2-weighted magnetic resonance imaging. Then, TT-PCL distance was standardized based on TW (TT-PCL ratio), and TT-PCL distance and ratio were compared between groups. Correlations were investigated among TT-PCL distance, TT-PCL ratio and each measurement (patient height, weight, TW).Strong positive correlations were observed between TW and patient height, and weak or moderate positive correlations were found between TT-PCL distance and each parameter. The mean TT-PCL distance was 21.2 and 20.6 mm (P = .39), while the mean TT-PCL ratio was 31.6% and 29.0% (P = .0093) in the RPD and control groups, respectively. The TT-PCL ratio was34% in 39 of 41 knees (95.1%) in the control group. No correlation was indicated between the TT-PCL ratio and patient size.Our findings demonstrate that the TT-PCL ratio is not affected by patient size, although the TT-PCL distance is associated with knee size and patient height. The TT-PCL ratio could be an important index for identifying patients for whom distal realignment surgery should be considered.

Category: Ankle, Basic Sciences/Biologics Introduction/Purpose: Usefulness of ultrasonographic guided saphenous nerve block is well known for perioperative pain management of foot and ankle surgery. However, in some cases it may be impossible to identify the saphenous nerve, especially women or obese patients, so successful rate of ultrasonographic guided saphenous nerve block was reported 70 to 80%. Previous reports demonstrated that the saphenous nerve is running adjacent to the greater saphenous vein, which suggests that the greater saphenous vein can be an indicator to identify the saphenous nerve. The purpose of this study was to examine anatomical relationship between the saphenous nerve and the greater saphenous vein which is depicted using the near-infrared (NIR) vascular imaging system, the Vein Viewer Flex®. Methods: Thirty legs as 15 healthy subjects (13 males, 2 females) were included in this study. Average age was 34.2 ± 3.2 years old. In a supine position, the knee joint was flexed 60 degrees with mild flexion, abduction, and external rotation of the hip joint, and the greater saphenous vein was depicted using the Vein Viewer Flex® on the skin of the lower extremity. The vein visualized as a green light was then marked using the skin marker. (Figure 1). After marking the greater saphenous vein, the greater saphenous vein and saphenous nerve were identified under ultrasonography at 5 cm distal from the medial knee joint space (Figure 2). The distance between the greater saphenous vein which was marked using the Vein Viewer Flex® and the saphenous nerve was measured in the ultrasonography images. The circumference of the leg (COL) was also measured. Results: The course of the greater saphenous vein could be depicted by the Vein Viewer Flex® in all cases, and it was confirmed by ultrasonography. It was confirmed that the saphenous nerve was located under the sartorius fascia and it was running posteromedially in parallel of the greater saphenous vein. The mean distance from the saphenous nerve and the greater saphenous vein was 7.9 ± 2.7 mm. There was no significant difference between left and right legs (right: 7.9±2.8 mm, left: 8.0±3.0 mm, P=0.95). The mean COL was 34.2 ± 1.9 mm, and there was a moderate positive correlation (r = 0.45). Conclusion: This study revealed that the saphenous nerve is running in parallel of the greater saphenous vein which can be depicted by the Vein Viewer Flex®. Ultrasonography after depicting greater saphenous vein enabled to confirm the saphenous nerve with certainly and noninvasive. These findings suggested that the combination of the Vein Viewer Flex® and ultrasonography enables the saphenous nerve block to be more reliable procedure even the saphenous nerve is hardly identified by the ultrasonography.

To establish a histopathological scoring system for changes in subchondral bone in murine models of knee osteoarthritis (OA), three key parameters, subchondral bone plate (Subcho.BP) consisting of the combination of Subcho.BP.thickness (Subcho.BP.Th) and angiogenesis, bone volume (BV/TV) and osteophytes, were selected. The new grading system was tested in two mouse OA models, (1) senescence accelerated mouse (SAM)-prone 8 (SAMP8) as spontaneous OA model with SAM-resistant 1 (SAMR1) as control; (2) destabilization of the medial meniscus in C57BL/6 mice as surgical OA model. Results of the spontaneous OA model showed that Subcho.BP.Th was significantly wider, angiogenesis was greater, and BV/TV was higher in SAMP8 than SAMR1. Notably, subchondral bone score was dramatically higher in SAMP8 at 6 weeks than SAMR1, while OARSI cartilage scores became higher only at 14 weeks. In the surgical OA model, the results were similar to the spontaneous OA model, but osteophytes appeared earlier. There were strong correlations both in Subcho.BP.Th and BV/TV between this scoring system and µCT (r = 0.89, 0.84, respectively). Inter-rater reliabilities for each parameter using this system were more than 0.943. We conclude that this new histopathological scoring system is readily applicable for evaluating the early changes in aging and OA-affected murine subchondral bone.

Objective Osteoarthritis (OA) is a progressive joint disorder, with abnormal remodeling of subchondral bone linked to the disruption of cartilage metabolism. Nerves also play an important role in bone remodeling in OA progression, and vasoactive intestinal peptide (VIP), one of the neuropeptides, plays an important role in bone metabolism. The aim of this study was to analyze the expression pattern of VIP in subchondral bone, and its potential as a therapeutic target for OA progression. Design The pattern of VIP expression in the human tibia was histologically evaluated. The effect of VIP on angiogenesis was investigated using human umbilical vein endothelial cells (HUVECs). Knee OA was induced by the resection of the medial meniscotibial ligament in C57BL/6 mice. A VIP receptor antagonist was intraperitoneally administered postoperatively, and therapeutic effects were analyzed at 4 and 8 weeks. Results VIP expression in the subchondral bone increased as OA progressed in human tibia. VIP was also expressed in the vascular channels into the cartilage layer. The total length and branch points were significantly increased, due to the VIP receptor agonist in HUVECs. In OA mice, the VIP receptor antagonist could prevent cartilage degeneration and subchondral bone sclerosis. The Osteoarthritis Research Society International score in the VIP receptor antagonist group was significantly lower than in the control group. Conclusion VIP is involved in the progression of OA through its effect on subchondral bone sclerosis and angiogenesis. Inhibition of VIP signaling has the potential to be a therapeutic target to prevent OA progression.

Background:Autologous chondrocyte implantation (ACI) is often performed for large cartilage defects. Because this technique has several disadvantages, including the need for second-stage surgery, cartilage repair using minced cartilage has been suggested. However, this technique could be improved using 3-dimensional scaffolds.Purpose:To examine the ability of chondrocyte migration and proliferation from minced cartilage in atelocollagen gel in vitro and evaluate the repairable potential of minced cartilage embedded in atelocollagen gel covered with a periosteal flap in a rabbit model.Study Design:Controlled laboratory study.Methods:Minced cartilage or isolated chondrocytes from rabbits were embedded in atelocollagen gel and cultured for 3 weeks. Chondrocyte proliferation and matrix production were evaluated in vitro. An osteochondral defect at the trochlear groove was created in 56 rabbits, which were divided into 4 groups. The defect was left empty (defect group), filled with allogenic minced cartilage (minced cartilage group), filled with isolated allogenic chondrocytes embedded in atelocollagen gel (ACI group), or filled with atelocollagen gel (atelocollagen with periosteal flap group). At 4, 12, and 24 weeks after surgery, repair of the defect was evaluated in these 4 groups.Results:In vitro, the number of chondrocytes and abundant matrix on the surface of the gel significantly increased in the minced cartilage group compared with the ACI group ( P < .05). In vivo, the minced cartilage and ACI groups showed good cartilage repair compared with the empty defect and atelocollagen/periosteal flap groups ( P < .05); there was no significant difference in the Pineda score between the minced cartilage and ACI groups.Conclusion:Minced cartilage in atelocollagen gel had good chondrocyte migration and proliferation abilities in vitro, and osteochondral defects were well repaired by implanting minced cartilage embedded in the atelocollagen gel in vivo. Implantation of minced cartilage embedded in atelocollagen gel showed good cartilage repair equivalent to ACI.Clinical Relevance:Implantation of minced cartilage embedded in atelocollagen gel as a 1-step procedure has outcomes similar to those of ACI but is cheaper and more convenient than ACI.

Autologous fibrin clots derived from peripheral blood (pb-fibrin clot) and bone marrow (bm-fibrin clot) are thought to be effective for tissue regeneration. However, there is no report detailing the amount of growth factors in pb-/bm-fibrin clot. In this study we evaluated the amount of growth factors in human pb-/bm-fibrin clot, and prove the validity of fibrin clot for clinical use.Human pb-/bm-fibrin clots were obtained during surgery. In the first experiment, enzyme-linked immunosorbent assay (ELISA) was performed for detecting the amount of vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), insulin-like growth factor-1 (IGF-1), fibroblast growth factor basic (bFGF), hepatocyte growth factor (HGF), transforming growth factor-beta (TGF-β), platelet derived-growth factors-AB (PDGF-AB), and stromal cell-derived factor-1 (SDF-1). In the second experiment, the efficacy of fibrin clot on the osteogenic differentiation and fibroblast proliferation was evaluated. Pb-/bm-fibrin clots were incubated in human osteoblast derived from mesenchymal stromal cells (MSCs) or human skin fibroblast. Alizarin red staining and real-time PCR (COL1A1, RUNX2) were performed for the detection of osteogenic potential. Cell-growth assay (WST-8) and real-time PCR (COL1A1) were also performed for the detection of the potential of fibroblast proliferation.ELISA analysis revealed that the amount of VEGF, HGF, bFGF, IGF-1, and SDF-1 of bm-fibrin clot group is higher than that of pb-fibrin clot group with statistical differences. Besides, we confirmed that bm-fibrin clot has much potential for the osteogenic differentiation and fibroblast proliferation.The positive outcomes confirm the efficacy of pb-/bm-fibrin clot, and bm-fibrin clot was proved to have much potential for tissue regeneration compared with pb-fibrin clot. The current study showed the potential of a strategy for regenerative medicine using bm-fibrin clot.

Lateral thrust is known to be risk factors for knee osteoarthritis progression. Medial meniscus extrusion is also known to be risk factors for knee osteoarthritis progression; moreover, the amount of change in medial meniscus extrusion from non-weight bearing to weight bearing is an important factor for the progression of knee osteoarthritis. This study aimed to investigate the correlation between lateral thrust and the change in medial meniscus extrusion.In total, 44 knees from 44 patients (mean age, 68.9 years) with knee osteoarthritis were divided into two groups according to the Kellgren-Lawrence grade: early-stage osteoarthritis (Kellgren-Lawrence = 2) and severe osteoarthritis (Kellgren-Lawrence = 3 or 4). The lateral thrust during gait, represented as the lateral acceleration peak immediately after heel strike, was recorded by an inertial sensor. The amount of change in medial meniscus extrusion, which was the difference between weight-bearing (unipedal standing) and non-weight-bearing (supine) conditions, was evaluated using ultrasonography.The mean value of the lateral acceleration peak in the severe osteoarthritis group was higher than that of the early-stage osteoarthritis group (p 0.05). The non-weight-bearing and weight-bearing medial meniscus extrusion in the severe OA group were significantly higher than those of the early-stage osteoarthritis group (p 0.001). However, the amount of change in medial meniscus extrusion in severe osteoarthritis group was significantly lower than in the early-stage osteoarthritis group (p 0.05). The amount of change in medial meniscus extrusion showed a significant correlation with the lateral acceleration peak in the early-stage osteoarthritis group (r = 0.56, p 0.001). On the other hand, there was no significant correlation in the severe osteoarthritis group.The lateral thrust shows a positive correlation with the amount of change in medial meniscus extrusion by weight bearing in patients with early-stage knee osteoarthritis.

Objective Autologous chondrocyte implantation is a necessary procedure for the repair of articular cartilage defects; however, isolated chondrocyte implantation requires a 2-step procedure (for harvesting and implantation) and is limited by cytotoxicity due to enzymatic digestion. Therefore, in this in vitro study, we evaluated the possible benefit of using minced cartilage embedded in a 3-dimensional culture scaffold and fixed with fibrin glue, in comparison with isolated chondrocytes in atelocollagen, to induce cell migration, proliferation, and matrix production, using cartilage from patients with knee joint osteoarthritis. Design Cartilage fragments were obtained from 7 female patients with knee osteoarthritis (OA) and embedded in atelocollagen gels. As a control, chondrocytes were isolated and embedded in gels in the same manner. These composites were cultured for 3 weeks, and cell proliferation and matrix production were evaluated using histology and immunochemistry. Results Histologically, minced cartilage showed cell migration from the cartilage fragments into the gel, with the Bern score and cell count in the minced cartilage group being significantly higher than those in the control group. Immunohistochemistry revealed that the number of Ki67-positive cells, the expression of LECT-1 and TGF-β, and the glycosaminoglycan content were significantly higher in the minced cartilage than in the control group. Minced cartilage exhibited superior cell migration, proliferation, and glycosaminoglycan content than isolated chondrocytes. Conclusion Our findings support that minced cartilage has a favorable potential for cell proliferation and matrix production compared with the isolated chondrocytes after enzymatic treatment.

Category: Ankle Introduction/Purpose: Osteochondral lesion of talus (OLT) is treated by several procedures such as bone marrow stimulation technique, cartilage fragment fixation, or autologous osteochondoral bone implantation. The choice of surgical methods depends on the size of lesion and cartilage condition. For unstable small lesion, excision of osteochondral fragment is usually performed. Good clinical results after this procedure is reported, but it is unclear that the morphological repair of subchondral bone and cartilage like tissue at the lesion. The purpose of this study is to evaluate the restoration of subchondral bone and cartilage like tissue after arthroscopic microfracture with excision of osteochondral fragment, and to investigate the clinical outcomes of this operation for the athletes. Methods: From 2005 to 2015, 11 patients (6 men and 5 women) were performed arthroscopic microfracture with excision of osteochondral fragment for OLT. Average age was 28.6 years old (17 - 59 years old). The site of OLT was 10 medial and 1 lateral. The cases of athletes were 7 of 11 cases. The size of preoperative OLT by MRI, measure the depth of the resected site on 3-month postoperative MRI. And we evaluated the appearance of the repair site on 1 year postoperative MRI, clinical outcome using American Orthopaedic Foot and Ankle Society Clinical Rating System (AOFAS), return rate to sports, and period of return to the sports. Results: Preoperative size of lesion on MRI was 9.8 mm in sagittal view, and 6.0 mm in coronal view. Depth of the resected site in 3 months postoperative MRI was 3.1 mm. On one year postoperative MRI, the resected site was filled with cartilage like tissue, and the shape of restored site was good that mimicked the original shape (Figure 1). As for clinical outcome, AOFAS score was 65.4 points preoperatively, and it improved to 93.4 points 1 year postoperatively. In clinical outcomes of the athletes, all cases could return to sports. Average period to return sports was 5.6 months. Only in 1 case, mild pain during sports activity was remained. Preoperative AOFAS score of athletes was 71.4 points and it improved to 98.5 points postoperatively. Conclusion: According to this study, even if a symptom is mild, an early operation will be more likely to result in the early return to sports and good outcomes. In addition, these good outcomes and good congruency on 1 year postoperative MRI suggest that the restored cartilage like tissue is enough for the high activities. The cartilage is repaired with maintaining original shape of talus cartilage. And this method was effective for athletes and was able to get them return to sports with good outcome.

Category: Ankle Arthritis Introduction/Purpose: Ankle arthrodesis is still the primary treatment for end-stage arthritis of the ankle that does not respond to conservative treatment. However, comparative studies demonstrated that the patients’ functional outcomes remain significantly lower than normal, progression of subtalar and midfoot arthritis and there could be measurable abnormalities in their gait parameters. Previous studies demonstrated gait analysis after ankle arthrodesis using 3D motion capture system. These studies used a single segment foot model, which had the limitation of detailed motion analysis. 3D multi-segmental foot model enables to perform detailed analysis segmentally such as fore foot and hind foot. The purpose of this study was to examine foot kinematics during walking after ankle arthrodesis using 3D multi-segment foot model as compared with a healthy control group. Methods: Between 2014 and 2016, nine patients who underwent an isolated ankle arthrodesis were followed for a mean 2 years after surgery, and five control subjects were included for comparison. Physical examination, radiographic examination and gait examination were performed. For gait analysis Vicon Nexus system with 16 MX-Cameras was used to capture foot kinematics during barefoot walking at self-selected speed along a 10 m walkway. Markers were placed according to the Oxford Foot Model (OFM). Patients completed preoperative and annual postoperative functional outcome scores including the Japanese Society for Surgery of the Foot (JSSF) scale. Results: JSSF scale was significantly improved from pre-operation to post-operation (50 points versus 85 points; pConclusion: In this study, detailed motion of foot after ankle arthrodesis could be analyzed by using OFM. Range of sagittal motion in hind foot in arthrodesis group during one gait cycle was significantly smaller than that in healthy group. However, no significant difference was observed in the forefoot. The same result was also obtained on the frontal plane. In arthrodesis group, forefoot tended to be more plantarflexion than healthy group in gait, especially there was significant difference at heel contact. These findings suggested to cause lower functional outcomes and the progression of subtalar and midfoot arthritis after ankle arthrodesis.

Category: Ankle Introduction/Purpose: Previous studies have described the damage of sensori-motor control in ankle sprain as being a possible cause of functional instability. The methods to demonstrate the functional instability, have included the postural balance test, peroneal muscle reaction time to sudden ankle inversion, peroneal nerve conduction velocity, and joint position sense of the ankle. On the other hand, isokinetic fatigue of ankle plantar flexion and dorsiflexion exhibits the correlation with postural instability. We hypothesize muscle fatigue around ankle joint causes abnormality of joint position sense, especially inversion at ankle joint, and it will be one of the causes of the ankle sprain. The aim of this study was to evaluate the inversion angle replication errors of before fatigue and after fatigue. Methods: 11 subjects were included in this study. The subjects were placed in a sitting position with the knee flexed at 70°. Each subject placed the foot on a goniometer footplate with the ankle at 20° planter flexion. Subjects were blindfolded to eliminate visual input and to facilitate concentration during testing. The foot was passively rotated internally at random to one of six positions (5°to 30°), always starting from 0°. The footplate was rotated manually to the index angle in approximately 1 s, and held in position for 5 s. Then the ankle was returned to the 0° position. After that, the subjects moved their ankle to match the previous test angle actively. The difference between the index angle and replication angle was measured. Ankles were enforced planter and dorsiflexion according to previous reports, and replication error was measured before and after fatigue. Results: The side-to-side difference of the replication errors was 1.9±1.7° in the before-fatigue group and 2.6±1.8° in the after-fatigue group. There was a statistically significant difference between both the groups (pConclusion: This study revealed the deficit of joint position sense in ankle inversion induced by fatigue. Fatigue may be one of the risk factor of ankle sprain through the deficit of joint position sense in inversion angle during sports activity.

Background Arthroscopic ankle arthrodesis (AAA) is minimally invasive surgery, whereby percutaneous screw fixation is used through the medial aspect of the distal tibia to fusion the ankle, but it carries the risk of the saphenous vein and nerve injuries. The near-infrared (NIR) vascular imaging system, the VeinViewer® Flex, projects an image of the vein onto the skin, and the visualization of the vein may reduce the vein and nerve injuries. The purpose of this study is to investigate the risk of the saphenous vein injury by the percutaneous screw insertion during AAA, and to evaluate the effectiveness of the NIR vascular imaging system in the reduction of the saphenous vein injury. Methods Ten patients with the ankle osteoarthritis underwent AAA. Three screw insertion sites (proximal as number 1, anterior distal as number 2, and posterior distal as number 3) were marked and then the vein was depicted on the medial malleolus using the VeinViewer® Flex. The distance between the screw insertion sites and the closest vein was measured. Additionally, the pattern of the vein course on the medial aspect of the distal tibia was investigated in 32 ankles using the VeinViewer® Flex. Results The distance of number 1, 2, and 3 from the vein was 2.4 ± 1.4 mm (range from 0 to 5 mm), 6.3 ± 6.6 mm (range from 0 to 20 mm) and 3.5 ± 3.1 mm (range from 0 to 11 mm) respectively. In anterior screw insertion site, 3 of 10 cases showed just on the vein. The veins were observed at the anterior region from the center axis of the tibia more than 75% of ankles which was suspected as the greater saphenous vein with closely running of the saphenous nerve, but also other regions had the crossing vein. Conclusions Percutaneous screw fixation during AAA runs the risk of causing the saphenous structure injury. The NIR light imaging system is beneficial in reducing the complications of saphenous structure damage in AAA.

Background: Although chondral or osteochondral injuries are usually assessed by magnetic resonance imaging, its accuracy can be low, presumably related to the relatively thin cartilage layer and the close apposition of the cartilage of the talus and tibial plafond. We hypothesized that axial traction could provide a contrast between the articular cartilage and joint cavity, and it enabled the simultaneous evaluation of cartilage and subchondral bone. The purpose of this study was to assess the feasibility of using computed tomography (CT) imaging with axial traction for the diagnosis of articular cartilage injuries. Methods: Chondral lesions in 18 ankles were evaluated by CT with axial traction using a tensioning device and ankle strap for enlargement of the joint space of the ankle. CT was done in 3-mm slices and programmed for gray scale, and then CT images were allocated colors to make it easier to evaluate the cartilage layer. The International Cartilage Repair Society (ICRS) grades on CT were compared with those on arthroscopic findings. Results: The respective sensitivity and specificity of CT imaging with traction using ICRS grading were 74.4%, and 96.3%. The level of agreement of the ICRS grading between CT images and arthroscopic findings was moderate (kappa coefficient, 0.547). Adding axial traction to CT increased the delineation of the cartilage surface, including chondral thinning, chondral defect, and cartilage separation. Conclusions: CT with axial traction produced acceptable levels of sensitivity and specificity for the evaluation of articular cartilage injuries, in addition to the assessment of subchondral bone. Level of Evidence: Level III, comparative case series.

Osteoarthritis (OA) is a progressive joint disorder which affects cartilage and subchondral bone. Calcitonin gene-related peptide (CGRP) plays a role in bone metabolism. The purpose of this study is to examine the therapeutic effect of the blocking CGRP on OA progression in mice by inhibition of subchondral bone sclerosis. OA was induced by the resection of the medial meniscotibial ligament of the knee in C57/BL6 mice. An intraperitoneal injection of the CGRP receptor antagonist (BIBN4096) was administered after OA surgery. At 1, 4, and 8 weeks after injection, histological analysis were performed. In vitro, the effect of CGRP and BIBN4096 on osteogenesis and osteoclastogenesis was analyzed. BIBN4096 could prevent cartilage degeneration and subchondral bone sclerosis. The OARSI score in the BIBN4096 group was significantly lower than that in the control. In vitro, CGRP up regulated osteocalcin expression, but its expression was down regulated by BIBN4096. CGRP inhibited osteoclastogenesis of raw 267.4 cells, but its effect was reduced by the addition of BIBN4096.The current study showed that subchondral bone sclerosis and increasing expression of CGRP occurs in the early phase of OA in relation to cartilage degeneration, and that BIBN4096 could effectively attenuate OA progression. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1177-1184, 2016.

Background: Injury to the medial collateral ligament (MCL) of the knee joint is the most common ligament injury of the knee. Ligament healing generally takes a long time. Micro-ribonucleic acid (miRNA) is one of the noncoding RNAs and plays a crucial role in physiological function; miRNA (miR)-210 is known as a potent factor of angiogenesis, which is an important initiator of ligament healing. The purpose of this study is to examine the effect of local injection of double-stranded (ds) miR-210 on the healing of the MCL of rat knee joint. Methods: MCLs of Sprague-Dawley rats were cut transversely. After the fascia and skin were sutured, dsmiR-210 or control dsRNA was injected into the injured site of MCL. At 2 weeks and 4 weeks, histological analysis and immunofluorescence staining of vascular endothelial growth factor, isolectin B4, collagen type 1, and Ki67 as well as a mechanical test were performed. Analysis of complementary deoxyribonucleic acid (cDNA) microarray data was performed at 1 week. Results: Histological analysis showed that parallel fibres in the injured site were organised at 2 weeks and became thicker at 4 weeks in the miR-210-treated group, whereas the injured site in controls was filled with loose fibrous tissues and was thinner than that in the miR-210-treated group. The number of blood vessels in the miR-210-treated group was significantly higher than that in controls (p < 0.05), and vascular endothelial growth factor, Ki67, and collagen type 1 in the miR-210-treated group were intensely expressed in the repaired site as compared to the control group. The mechanical test indicated that the ultimate failure load in the miR-210-treated group was significantly higher than that in the control group at 2 weeks. The cDNA microarray analysis showed significant upregulation of genes related to cell proliferation and cell differentiation, and genes involved in negative regulation of apoptosis. Conclusion: This study showed that local injection of dsmiR-210 could accelerate MCL healing in rat, which is likely due to stimulation of angiogenesis at the healing site.

The present study investigated intra-articular injection of bone-marrow-derived mesenchymal stem cells (MSCs) combined with articulated joint distraction as treatment for osteochondral defects. Large osteochondral defects were created in the weight-bearing area of the medial femoral condyle in rabbit knees. Four weeks after defect creation, rabbits were divided into six groups: control group, MSC group, distraction group, distraction + MSC group, temporary distraction group, and temporary distraction + MSC group. Groups with MSC received intra-articular injection of MSCs. Groups with distraction underwent articulated distraction arthroplasty. Groups with temporary distraction discontinued the distraction after 4 weeks. The rabbits were euthanized at 4, 8, and 12 weeks after treatment except temporary distraction groups which were euthanized at only 12 weeks. Histological scores in the distraction + MSC group were significantly better than in the control, MSC group or distraction group at 4 and 8 weeks, but showed no further improvement. At 12 weeks, the temporary distraction + MSC group showed the best results, demonstrating hyaline cartilage repair with regeneration of the osteochondral junction. In conclusion, joint distraction with intra-articular injection of MSCs promotes early cartilage repair, and compressive loading of the repair tissue after temporary distraction stimulates articular cartilage regeneration.

Mesenchymal stem cell (MSC) transplantation is used for treatment of many diseases. The paracrine role of MSCs in tissue regeneration is attracting particular attention. We investigate the role of MSC exosomes in skeletal muscle regeneration. MSC exosomes promote myogenesis and angiogenesis in vitro, and muscle regeneration in an in vivo model of muscle injury. Although MSC exosomes had low concentrations of muscle-repair-related cytokines, a number of repair-related miRNAs were identified. This study suggests that the MSC-derived exosomes promote muscle regeneration by enhancing myogenesis and angiogenesis, which is at least in part mediated by miRNAs such as miR-494.

We treated a 39-year-old female who had experienced destruction of her ankle joint owing to rheumatoid arthritis. This relatively young patient wished to avoid ankle fusion and joint replacement. Therefore, distraction arthroplasty with arthroscopic microfracture was performed to improve her symptoms and preserve motion. A microfracture procedure specifically for cartilage defects of the tibial plafond and talar dome was performed with the arthroscope, after which a hinged external fixator was applied to distract the ankle joint. The ankle joint space was enlarged by the external device and joint movement allowed. After 3 months, removal of the external device and repeat arthroscopy revealed newly formed fibrocartilage on the surfaces of both the tibia and the talus. At 2 years after the surgery, a radiograph showed that the joint space enlargement of the ankle had been maintained. The American Orthopaedic Foot and Ankle Society score improved from 37 points preoperatively to 82 points at 2 years postoperatively. Our findings suggest that good clinical results can be achieved with distraction arthroplasty and arthroscopic microfracture in a relatively young patient with rheumatoid arthritis.

Background Patients with discoid lateral meniscus (DLM) are prone to meniscal injuries related to its shape and abnormal mobility. The anatomical joint inclination of the proximal tibiofibular joint (PTFJ) can also affect joint movement in knee motion. However, an association between PTFJ morphology and DLM remains unclear. The purpose of this study was to investigate the morphology of the PTFJ on MRI and how this differs between patients with and without DLM. Materials and methods Fifty-eight patients with DLM and 58 age-matched controls (normal meniscus) were included in this study. Slices from preoperative MRI sagittal images that clearly showed the PTFJ were used for measurements. The angle between the PTFJ and the perpendicular line of the fibula axis was measured as the inclination angle, and patients were classified as horizontal-type ( 20°). The inclination angle was also compared among patients with open and closed epiphysis in both groups to assess the effect of age. Results Patients in the horizontal-type PTFJ group frequently had DLM. Before epiphyseal closure, most patients had a horizontal-type PTFJ, with or without DLM. However, in older patients with a closed epiphysis, most with a normal meniscus had an oblique-type PTFJ, and those with DLM retained the horizontal-type joint. Conclusion The horizontal-type PTFJ was significantly associated with DLM, and patients with DLM tended to retain a horizontal-type PTFJ after epiphyseal closure. In contrast, in patients with a normal meniscus, the PTFJ may change from a horizontal-type to an oblique-type PTFJ in line with bone maturity.

Background: Osteochondral lesions of the talar dome (OLT) involve the articular cartilage and/or subchondral bone. The subchondral bone plate plays an important role in cartilage metabolism. We hypothesized that the findings of subchondral bone on CT image would be related to the cartilage damage of OLT. The purpose of this study was to evaluate the relationship between the arthroscopic and CT findings focused on subchondral bone. Methods: Thirty-one ankles diagnosed as OLT were analyzed. All patients underwent CT, MRI, and arthroscopic surgery. The CT findings for both the cystic and fragment lesions were classified into 3 types. The 3 types for the cystic lesion ankles were irregular shape, round shape with sclerotic wall, and irregular shape with opening to an articular cavity. The 3 types for the fragment lesion were no bone absorption, bed absorption without fragment absorption, and bed sclerosis and fragment absorption. The subchondral bone findings on CT were compared with International Cartilage Repair Society (ICRS) grades and arthroscopic grading. Results: All round and sclerotic cystic lesions revealed cartilaginous flap lesions with a nearly normal cartilage surface. An irregular shape with opening revealed an unstable lesion with severely damaged cartilage. As for fragment lesions, no absorption revealed a stable lesion with a nearly normal cartilage surface. Bed absorption revealed an unstable lesion with a nearly normal cartilage surface. Fragment absorption with bed sclerosis showed an unstable lesion with severely damaged cartilage. There was a significant difference between CT findings and ICRS grade or arthroscopic findings (both P < .01), while there was no significant difference with MRI grading. The diagnosis of cartilage status by CT was better than MRI. Conclusion: CT findings for OLT based on subchondral bone related to cartilage damage. This study showed that CT was a useful tool for evaluating cartilage damage in OLT. Level of Evidence: Level III, comparative case series.

Background Osteochondral lesions of the talar dome (OLT) involve the articular cartilage and subchondral bone. The subchondral bone plate (SBP) plays a crucial role in cartilage metabolism, and its disruption no longer maintains cartilage homeostasis. Computed tomography (CT) can provide more precise information on subchondral bone. CT image prediction of the histological findings on OLT will be useful to determine the most appropriate therapeutic strategy. We hypothesized that the clarification of the relationship between CT image of subchondral bone and histological findings of articular cartilage in osteochondral fragment will predict the cartilage degeneration in OLT. The purpose of this study is to evaluate the unique features of the CT findings that relate to the condition of the articular cartilage in OLT. Methods Thirty ankles in 29 patients, who had OLT with an osteochondral fragment were retrospectively reviewed. At surgery, the osteochondral fragment of 19 ankles could be preserved (preservation group) by fixation or drilling, and in the remaining 10 ankles the osteochondral fragment was removed (excision group). Preoperative CT findings were compared between the 2 groups. Biopsies of the osteochondral fragment from 13 ankles were performed. The relationship between the CT and histological findings were evaluated. Results The area of lesion in the preservation group was significantly larger than that in the excision group. The CT images of the lesion showed the rate of absorption of the SBP in the preservation group to be lower than that in the excision group. As for the lesion bed absorption, it was higher in the preservation group than in the excision group. In the excision group, all cases showed bed sclerosis while bed sclerosis was observed in 42.1% of cases in the preservation group. The specimens with disruption of the subchondral bone plate exhibited cartilage degeneration and abundant chondrocyte cloning. OLT with absorption of the SBP on CT showed severe cartilage degeneration, while the remaining SBP on CT showed low-grade cartilage degeneration. Conclusions This study shows the features of preoperative CT and histological findings in OLT with osteochondral fragments. The condition of the subchondral bone plate affects the cartilage degeneration. CT findings provide important information for the determination of surgical treatment.

Category: Ankle Arthritis, Arthroscopy Introduction/Purpose: Ankle trauma is highly implicated in the etiology of osteoarthritis (OA) of the ankle, and posttraumatic ankle OA is often observed in younger patients. In advanced stages, ankle arthrodesis has been considered as a gold standard treatment, and total ankle arthroplasty is also developed over the past decade for older patients. However, the surgical treatment of severe ankle OA for younger, active patients remains challenging. Ankle distraction arthroplasty is an alternative option for treatment of severe ankle OA in younger patients. The distraction device enables joint distraction with ankle motion that induces cartilage repair of the ankle. This study aimed to clarify the clinical outcome of the ankle distraction arthroplasty with arthroscopic microfracture for ankle OA in younger patients. Methods: This retrospective analysis included 7 ankle OA patients who underwent distraction arthroplasty with arthroscopic microfracture, in 5 men and 2 women, with a mean age of 45.9 years (range, 39-62). Range of motion (ROM) and American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score were evaluated as the clinical outcomes. The talotibial joint space was identified as anterior, center and posterior segment on lateral view. The width of joint space in each segment was measured on pre- and post-operative weight-bearing radiographs. The distraction device was removed at 3 months after initial surgery, and second look arthroscopy was also performed at the same time. The arthroscopic findings were assessed retrospectively. Results: All 7 patients were followed with a mean follow-up period of 4.2 years. One patient who had the worst preoperative AOFAS score of 19 converted to arthroscopic ankle arthrodesis at 2 years after the initial surgery. The mean total ROM and AOFAS score improved from 29.3 to 37.1 (p = 0.028), from 41.7 to 76.1 (p = 0.018), respectively. Weight-bearing radiographs showed a width of ankle joint space with anterior, center and posterior of 1.9 mm, 1.8 mm, 2.0 mm at preoperative status and 2.9 mm, 2.8 mm, 2.9 mm at final follow-up status. Second look arthroscopy revealed that the fibrous cartilage like tissue covered the cartilage defect area at the talotibial joint in all patients. Conclusion: Our findings suggest that the distraction arthroplasty with arthroscopic microfracture could be a useful option for active patients with advanced stage of ankle OA. Good clinical status and the width of joint space had been preserved for a maximum of seven years. Further follow-up was required to elucidate the long-term clinical results.

AbStrA ct Aim: until recently, only fibrin glue has been available for clinical usage to repair articular cartilage, although its adhesiveness is not strong enough for use with articular cartilage, and it is derived from human blood and thus carries the risk of contamination. recently, LYdEX, a new biodegradable hydrogel glue, has come onto the market. t he purpose of this study was to evaluate the adhesive strength and cytotoxicity of LYdEX when used on articular cartilage. Materials and Methods: t he differing adhesive strengths of collagen membrane and articular cartilage with LYdEX versus with fibrin glue were measured using a tensile tester. In addition, the cytotoxity of LYdEX in vitro was evaluated. t he cytotoxity of LYdEX for the articular cartilage of rats was evaluated histopathologically. Results: t he adhesive strength of LYdEX was significantly stronger than that of fibrin glue, giving values about 3.8 times higher. LYdEX has no discernible effect on normal articular cartilage. Conclusions: our study is the first to assess the usefulness and safety of LYdEX for use on articular cartilage.

Objectives MicroRNAs, a class of noncoding RNAs, play roles in human diseases. MicroRNA-223 (miR-223) is reported to play critical roles in osteoclastogenesis. The purpose of this study was to analyze the expression pattern of miR-223 in rheumatoid arthritis (RA) synovium and examine the suppression of osteoclastogenesis from human peripheral blood mononuclear cells (PBMC) by overexpression of miR-223.Methods Expression of miR-223 in synovium from RA patients was analyzed by quantitative reverse transcription polymerase chain reaction (RT-PCR) and section in situ hybridization. MiR-223 was overexpressed in an osteoclastogenesis coculture system with PBMC and RA synovial fibroblast. At 3 weeks after transfection of double-stranded miR-223, the formation of tartrate-resistant acid phosphatase (TRAP)-stained multinucleated cells was analyzed to evaluate the inhibitory effect of miR-223 on osteoclastogenesis.Results MiR-223 was more highly expressed in RA synovium than in osteoarthritis (OA) synovium ...

The etiology of the osteochondral lesion of the talar dome (OLT) remains unclear. A joint position sense deficit of the ankle is reported to be a possible cause of ankle disorder. Repeated contact of the articular surface of the talar dome with the plafond during inversion might be a cause of OLT. The aim of the present study was to evaluate the joint position sense deficit by measuring the replication error of the inversion angle in patients with OLT. The replication error, which is the difference between the index angle and replication angle in inversion, was measured in 15 patients with OLT. The replication error in 15 healthy volunteers was evaluated as a control group. The side to side differences of the replication errors between the patients with OLT and healthy volunteers and the replication errors in each angle between the involved and uninvolved ankle in the patients with OLT were investigated. Finally, the side to side differences of the replication errors between the patients with OLT with a traumatic and nontraumatic history were compared. The side to side difference in the patients with OLT (1.3° ± 0.2°) was significantly greater than that in the healthy subjects (0.4° ± 0.7°) (p ≤ .05). Significant differences were found between the involved and uninvolved sides at 10°, 15°, 20°, and 25° in the patients with OLT. No significant difference (p > .05) was found between the patients with traumatic and nontraumatic OLT. The present study found that the patients with OLT have a joint position sense deficit during inversion movement, regardless of a traumatic history. Although various factors for the etiology of OLT have been reported, the joint position sense deficit in inversion might be a cause of OLT.