Munekazu Kanemitsu

Morphological change of OLT after excision of osteochondral fragment with microfracture on MRI

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.

Relationship between osteophyte and arthroscopic findings in osteoarthritis of ankle

Category: Ankle Introduction/Purpose: Mortise view weight-bearing radiograph is widely used for the diagnosis of osteoarthritis of ankle. Thickness of the articular cartilage cannot be accurately evaluated in the evaluation of joint space from weight-bearing radiograph, because lateral tibiotalar joint space is maintained in valgus type osteoarthritis in some cases. There are few reports on the relation between osteophyte and the articular cartilage injury. We considered that it might be possible to estimate the cartilage injury more accurately by examining osteophytes. The purpose of this study is to analyze the relationship between the location and grade of osteophytes in weight-bearing radiograph and cartilage injury in arthroscopic findings was analyzed. Methods: Twenty-one anklets of 21 patients consisted of 10 males and 10 females, with mean age of 61.4 years (31-79 years), who underwent arthroscopic surgery for osteoarthritis in our department were included. Weight-bearing radiograph were taken before surgery. Location and grade of osteophytes were evaluated using Ankle and Hindfoot Radiographic Osteoarthritis Scoring reported by Kraus et al. Arthroscopic findings were evaluated with International Cartilage Repair Society (ICRS) Grade at a total of 20 sites (9 areas of tibia and talar in tibiotalar joint, medial malleolus and lateral malleolus). The correlation between radiographic findings and arthroscopic findings were analyzed. Results: In Mortise view, strong correlations were found between lateral tibial osteophyte grade and ICRS grade of the center (talus R = 0.69, tibia R = 0.76), the central lateral (tibia R = 0.79), the posterior center (talus R = 0.72, tibia R = 0.74) and the posterior lateral of the tibiotalar joint (talus R = 0.63, tibia R = 0.76). There are moderate correlations between distal fibular osteophyte grade and ICRS grade of the medial inner (tibia R = 0.74) and the posterior medial of the tibiotalar joint (talus R = 0.61, tibia = 0.63). In lateral view, there are moderate correlations between posterior talar osteophyte grade and ICRS grade at the center of the tibiotalar joint (talus R = 0.61, tibia R = 0.60). Conclusion: From this study, there was a strong correlation between location and grade osteophyte and the articular cartilage injury. Osteoarthritis progression is caused by degeneration of the cartilage because of the joint instability, and osteophytes were formed by traction force or impaction. This study showed that local cartilage injury is thought to be related to osteophytes. By evaluating the location and size of osteophytes, the articular cartilage injury might be predicted accurately before arthroscopic surgery.

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.

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.

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-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.