The role of the oblique medial osteotomy angle during osteochondral fragment fixation in patients with a posteromedial osteochondral lesion of the talus.

BACKGROUND: Medial malleolar osteotomy has been widely performed for posteromedial osteochondral lesions of the talus (OLT) to expose the lesion. In osteochondral fragment fixation, bioabsorbable pins should be inserted as perpendicular as possible to obtain the rigid fixation. However, the exposure of the lesion may depend on the osteotomy angle, which affects the pin insertion angles. This study aimed to analyze the relationship between pin insertion and osteotomy angles in the medial malleolar osteotomy. METHODS: Twenty-four ankles of 23 patients were included. The malleolar bisector angle which was calculated from radiographs and actual osteotomy angles were measured on radiographs, and the pin insertion and osteotomy angles were measured using MRI. The intersection angle was defined by the tangential line of the tibial plafond and medial malleolar articular facet, and the bisector of this angle was defined as the malleolar bisector angle. The relationship between pin insertion and osteotomy angles was analyzed. RESULTS: There was no significant difference between the actual osteotomy (55.7° ± 6.6°) and malleolar bisector angles (57.4° ± 4.3°) on the radiograph. There was a significant correlation between pin insertion and osteotomy angles (rs = 0.601). The pin insertion angle (54.3° ± 5.9°) in the lower actual osteotomy angle than the malleolar bisector angle was smaller than those in the higher actual osteotomy angle (63.4° ± 8.2°). CONCLUSIONS: This study showed the osteotomy angle affected pin insertion angle. The osteotomy angle should not be smaller than the malleolar bisector angle at medial malleolar osteotomy to insert pins as perpendicular as possible for fixation of posteromedial OLTs.

Inverted V-Shaped High Tibial Osteotomy Decreases the Posterior Tibial Slope More but Shortens the Tibia Less Than Closed-Wedge High Tibial Osteotomy.

PURPOSE: To assess the postoperative anatomical changes in the lower extremity after inverted V-shaped high tibial osteotomy (IVHTO) using 3-dimensional (3D) computed tomography (CT) bone models and compare those changes after closed-wedge high tibial osteotomy (CWHTO). METHODS: Preoperative and 3-week postoperative CT scanning of the lower extremity were obtained from patients who underwent IVHTO and CWHTO between October 2019 and March 2021. 3D CT bone models were reconstructed using ZedKnee software. The postoperative changes (Δ) in (1) posterior tibial slope (PTS), (2) knee rotation angle (KRA), (3) tibial torsional angle (TTA), (4) patella tilt (PT), (5) Insall-Salvati ratio (ISR), and (6) tibial length (TL) were compared between IVHTO and CWHTO. RESULTS: Thirty-seven knees (18 IVHTO and 19 CWHTO) in 34 patients were retrospectively enrolled in this study. ΔPTS at the medial and lateral tibial plateau in the IVHTO group (-6.5° and -5.0°) was larger compared with that in the CWHTO group (-3.3° and -2.0°; P = .024 and P = .002, respectively). No significant differences exist between the IVHTO and CWHTO groups in ΔKRA (0.8 ± 4.5° and -1.5 ± 6.5°; P = 0.631), ΔTTA (-3.9 ± 6.2° and -4.1 ± 7.3°; P = .951), ΔPT (-2.0 ± 4.8° and -0.6 ± 4.1°; P = .353), and ΔISR (0.0 and 0.0; P = .829). ΔTL in the IVHTO group (-1.6 ± 2.3 mm) was smaller compared with that in the CWHTO group (-4.1 ± 1.6 mm; P < .001). CONCLUSIONS: (1) The postoperative PTS in the IVHTO group was further decreased compared to the CWHTO group; (2) no significant differences in ΔKRA, ΔTTA, ΔPT, and ΔISR exist between the 2 groups; and (3) the ΔTL in the IVHTO group was significantly smaller compared with the CWHTO group. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

The Benefit of Minced Cartilage Over Isolated Chondrocytes in Atelocollagen Gel on Chondrocyte Proliferation and Migration.

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-ß, 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.

Increase in medial meniscal extrusion in the weight-bearing position observed on ultrasonography correlates with lateral thrust in early-stage knee osteoarthritis.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Repair of an Osteochondral Defect With Minced Cartilage Embedded in Atelocollagen Gel: A Rabbit Model.

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.

Application of a peripheral vein illumination device to reduce saphenous structure injury caused by screw insertion during arthroscopic ankle arthrodesis.

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.

MRI Tracking of the Effect of Bioabsorbable Pins on Bone Marrow Edema After Fixation of the Osteochondral Fragment in the Talus.

BACKGROUND:: Large osteochondral lesions of the talus (OLT) with good articular cartilage can be fixed by using bioabsorbable pins. These pins have various advantages but they can have adverse effects such as foreign body inflammation. This negative impact of pins on subchondral bone can be seen as bone marrow edema (BME) on magnetic resonance imaging (MRI). The purpose of this study was to investigate the course of change in BME on MRI, including osteolytic change around pins in OLT treated with pin fixation. METHODS:: This study comprised 13 ankles in 12 patients, who underwent surgeries to fix an OLT using poly-l-lactide acid pins. MRIs were taken at preoperative, 3, 6, and 12 months after surgery. The area of BME was measured at each time point, and osteolytic change around pins was evaluated. Moreover, pin insertion angle was measured. RESULTS:: BME significantly decreased from preoperative to 6 and 12 months. At 1 year, 28.1% of pins exhibited osteolytic change around them. Pin insertion angle was significantly lower in those with osteolytic change than those with no osteolytic change. At 3 and 6 months and 1 year postoperatively, BME with osteolytic change was significantly greater than those patients with no osteolytic change. The American Orthopaedic Foot & Ankle Society score significantly improved from preoperative (76.6±3.4 points) to 1 year after surgery (98.5±3.8 points). CONCLUSION:: A shallow pin insertion angle was associated with osteolytic change around pins and persistence of BME on MRI, although excellent results were obtained at 1 year after surgery. LEVEL OF EVIDENCE:: Level III, retrospective comparative series.

Characteristic morphology of the proximal tibiofibular joint in patients with discoid lateral meniscus.

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°) or oblique-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.

Evaluation of Articular Cartilage Injury Using Computed Tomography With Axial Traction in the Ankle Joint.

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.

Relationship Between Bone Marrow Lesions on MRI and Cartilage Degeneration in Osteochondral Lesions of the Talar Dome.

BACKGROUND: In the evaluation of osteochondral lesions of the talar dome (OLT), bone marrow lesions (BML) are commonly observed in the subchondral bone on magnetic resonance imaging (MRI). However, the significance of BML, such as the histology of the overlying cartilage, is still unclear. The purpose of this study was to investigate the relationship between the BML and cartilage degeneration in OLT. METHODS: Thirty-three ankles with OLT were included in this study. All ankles underwent CT and MRI and had operative treatment. The ankles were divided into 2 groups, depending on the presence of bone sclerosis (ie, with or without) in the host bone just below the osteochondral fragment (nonsclerosis group and sclerosis group). The area of BML was compared between the 2 groups. Biopsies of the osteochondral fragment from 20 ankles were performed during surgery, and the correlation between the BML and cartilage degeneration was analyzed. The remaining 13 ankles had the CT and MRI compared with the arthroscopic findings. RESULTS: The mean area of BML in the nonsclerosis group was significantly larger than that in the sclerosis group. In the histologic analysis, there was a significant and moderate correlation between the Mankin score and the area of BML. The mean Mankin score in the nonsclerosis group was significantly lower than that in the sclerosis group. CONCLUSIONS: This study revealed that a large area of BML on MRI exhibited low degeneration of cartilage of the osteochondral fragment, while a small area of BML indicated sclerosis of the subchondral bone with severe degeneration of cartilage. The evaluation of BML may predict the cartilage condition of the osteochondral fragment. LEVEL OF EVIDENCE: Level III, comparative series.

A Technique for the Reduction of Complications Associated With Anterior Portal Placement During Ankle Arthroscopy Using a Peripheral Vein Illumination Device.

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.

Added Value of Preoperative Computed Tomography for Determining Cartilage Degeneration in Patients With Osteochondral Lesions of the Talar Dome.

BACKGROUND: Osteochondral lesions of the talar dome (OLTs) involve the articular cartilage and subchondral bone. The subchondral bone plate (SBP) plays a crucial role in cartilage metabolism, and 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. PURPOSE: To evaluate the unique features of the CT findings that relate to the condition of the articular cartilage in OLT. STUDY DESIGN: Cohort study; Level of evidence, 3. 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 11 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. All cases in the excision group showed bed sclerosis, compared with 42.1% in the preservation group. The specimens with disruption of the SBP 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. CONCLUSION: This study shows the features of preoperative CT and histological findings in OLT with osteochondral fragments. The condition of the SBP affects the cartilage degeneration. CT findings provide important information for the determination of surgical treatment.

Anatomic feature of deltoid ligament attachment in posteromedial osteochondral lesion of talar dome.

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.

In-vivo imaging of the sentinel vein using the near-infrared vascular imaging system in hallux valgus patients.

BACKGROUND: A high incidence of dorsomedial cutaneous nerve (DMCN) damage in hallux valgus surgery has been reported. Identification of the vein around 1st metatarsal head is reported to be helpful to reduce the DMCN damage during surgery. The near-infrared (NIR) vascular imaging system, the VeinViewer® Flex, projects the vein onto the skin. The purpose of this study was to investigate the difference of the vein course between normal and hallux valgus foot using the VeinViewer® Flex, and to validate that the DMCN was accompanied with its vein. METHODS: Twenty-seven feet with the hallux valgus and 27 feet in healthy subjects were included. The vein was projected onto the skin at the metatarsal head by the VeinViewer® Flex. The distance between the vein and the mid-line of the metatarsal head was measured. The correlation of the distance and hallux valgus angle or 1-2 intermetatarsal angle (IMA) was analyzed. The vein depicted by the VeinViewer® Flex and operative findings was compared in 4 patients during surgery. RESULTS: The vein in the hallux valgus patients shifted toward the dorsolateral side on the metatarsal bone head compared to that in healthy subjects. The distance from the midline of the 1st metatarsal bone to the vein in the hallux valgus (12.1 mm) was significantly higher than that in healthy subjects (2.7 mm) (p < 0.05). There was a significant correlation between the shift of the vein course toward dorsolateral and IMA. Surgical exploration revealed that the vein depicted by VeinViewer® Flex could be easily identified and the nerve was along with this vein in all 4 surgical cases. CONCLUSIONS: The vein in the hallux valgus patients shifted toward the dorsolateral on the metatarsal bone and it could be a landmark to identify DMCN. The NIR vascular imaging system would be useful to reduce the risk of nerve damage in great toe surgery.