Search

Objective Articular cartilage defect causes joint pain and finally progresses to osteoarthritis. Although the subchondral bone condition affects clinical outcomes of cartilage defects, the natural course of changes in subchondral bone and associated pain in full-thickness cartilage defects remain unknown. Therefore, we investigated the natural course of histological changes in subchondral bone and joint pain in cartilage defects using a rat model. Design Full-thickness cartilage defects were created at the medial femoral condyle of 10-week-old male Sprague-Dawley rats. Rats were sacrificed at 3, 7, 14, 28, and 56 days postoperatively, and histological including immunohistochemistry and tartrate-resistant acid phosphatase (TRAP) staining and micro-computed tomography (μCT) analyses of their knees were performed. Pain was evaluated using behavioral analysis and immunofluorescence staining of the dorsal root ganglion (DRG). Results The contour of the subchondral bone plate was maintained until day 3, but it was absorbed just under the cartilage defect from day 7 to 14. Starting on day 28, sclerotic changes surrounding the bone absorption area were detected. In the subchondral bone, the number of TRAP-positive cells peaked on day 14. Osteocalcin-positive cells were observed at 7 days, and their number gradually increased till day 56. Behavioral analysis showed that the total distance and the number of getting up by hind legs decreased on day 14. The number of calcitonin gene-related peptide-positive fibers in the DRG increased and was the highest on day 14. Conclusions The subchondral bone condition under cartilage defects dynamically changes from bone resorption to sclerosis and is related to pain level.

The cause of osteochondral lesions of the talus (OLT) in patients without a history of trauma remains unclear, and almost all nontraumatic lesions appear to involve the medial talar dome. This study aimed to investigate the relationship between foot alignment, deltoid morphology, and medial OLT in pediatric patients. In total, 28 patients (31 feet) with medial OLT (17 boys, 11 girls, mean age: 14.9 years), and 50 patients without OLT (50 feet, 31 boys, 19 girls, mean age: 14.5 years) were included in this study. The OLT patients were subdivided into traumatic and nontraumatic groups. Radiographic parameters of the foot arch were measured on weight-bearing lateral images. The extent of the OLT was measured on computed tomographic images. The ratio of deep deltoid attachment length of the talus to talar height was examined as deltoid ligament position index (DPI) on coronal magnetic resonance imaging. Nontraumatic medial lesions were frequently observed in pediatric patients (54.8%) compared to traumatic lesions. The depression of the foot arch was commonly identified in pediatric patients with resistant medial lesions. The lesion size was moderately correlated with DPI (rho = 0.48; P = 0.0086). The attachment of the deep deltoid ligament to the medial talar dome was located more proximally in nontraumatic lesions than in traumatic lesions and the control group. Our findings suggest that a combination of foot alignment and the anatomic variations in the attachment of the deep deltoid ligament contributes to the incidence of nontraumatic medial OLT in the pediatric population. Level of evidence: level IV.

Background: The bone marrow stimulation (BMS) technique is performed for osteochondral lesions of the talus (OLTs) with a lesion size of 2. The lesion defect is covered with fibrocartilage, and the clinical outcomes deteriorate over time. In contrast, the osteochondral fragment fixation can restore the native articular surface. The difference in clinical outcomes between these procedures is unclear. Purpose: To compare the clinical outcomes of BMS and osteochondral fragment fixation for OLTs and examine the characteristics of patients with poor clinical outcomes of BMS. Study Design: Cohort study; Level of evidence, 3. Methods: In total, 62 ankles in 59 patients with OLTs were included. BMS was performed for 26 ankles, and fixation was performed for 36 ankles. Clinical outcomes, including the American Orthopaedic Foot & Ankle Society (AOFAS) Ankle Hindfoot Scale and bone marrow edema (BME) as identified on magnetic resonance imaging, were compared between the 2 groups. On computed tomography scans, the lesion location was compared with or without BME in each group. Results: The AOFAS scores in the fixation group (97.3 ± 4.3 points) were significantly higher than those in the BMS group (91.3 ± 7.7 points), even when the lesion size was 2 ( P < .05). When comparing the ankles with or without BME in each group, the AOFAS scores at the final follow-up were significantly lower for the ankles with BME (88.6 ± 7.8 points) than for those without BME (95.0 ± 6.1 points) in the BMS group ( P < .05). Lesions with BME in the sagittal plane were located more centrally than those without BME in the BMS group. In the fixation group, there were no significant differences in AOFAS scores and location of the lesion in ankles with or without BME. Conclusion: The clinical outcomes of osteochondral fragment fixation are superior to those of BMS in OLTs, even for lesions sized 2. Fixation is recommended even for small lesions, especially for more centralized lesions in the medial and lateral sides of the talus.

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.

Tenosynovial giant cell tumour encompasses a group of lesions that present with synovial differentiation and most commonly occur in the joint synovium, bursae, and tendon sheaths. Diffuse-type tenosynovial giant cell tumour, previously known as pigmented villonodular synovitis, is one of the most common benign soft tissue tumours of the foot and ankle and usually affects young adults. The differential diagnosis of diffuse-type tenosynovial giant cell tumours remains a clinical problem because its clinical symptoms are similar to those of inflammatory arthritis, including rheumatoid arthritis. Moreover, persistent diffuse-type tenosynovial giant cell tumours can lead to articular deterioration, including osseous erosions and subchondral bone cysts. Joint-preserving procedures are considered optimal for treating younger patients with ankle osteoarthritis because the indication of ankle arthrodesis and total ankle arthroplasty is limited. Thus, ankle distraction arthroplasty could be an alternative for treating diffuse-type tenosynovial giant cell tumour with articular deterioration in young patients. Here, we report about a woman in her early 30s who presented with ankle pain owing to a diffuse-type tenosynovial giant cell tumour with an articular cartilage defect and subchondral bone cysts. We performed ankle distraction arthroplasty combined with an autologous bone graft. A follow-up examination at 2 years revealed preservation of physical function and pain alleviation. These findings suggest that distraction arthroplasty is a viable treatment option for remedying the destruction of the articular cartilage and subchondral bone owing to diffuse-type tenosynovial giant cell tumours in young adults.

Objectives To analyse the microstructural changes of subchondral trabecular bone in patients with osteonecrosis of the femoral head (ONFH) using multi-detector row computed tomography (MDCT). Methods We retrospectively investigated 76 hips in 50 patients diagnosed with ONFH between 2017 and 2021. Groups 1, 2, 3, and 4 comprised hips without ONFH, ONFH without femoral head collapse (FHC), ONFH with mild collapse (2 mm), respectively. All patients underwent MDCT, and the subchondral trabecular bone microstructure was assessed. Regions of interests were set at the lateral boundary of the femoral head necrotic lesion and centre of the acetabular weight-bearing portion. Results In both the femoral head and the acetabular regions, there were significant differences in Groups 2 and 3 compared to Group 1, with increased volumetric bone mineral density and apparent bone volume fraction, and more plate-like with increased connectivity, indicating that osteosclerotic changes were occurring. Conclusions In both the femoral head and the acetabular regions, osteosclerotic changes of subchondral trabecular bone microstructure were present before FHC.

Fixation of the osteochondral fragment has the advantage to restore the naturally congruent morphology of the talar dome with native hyaline cartilage in the treatment of the osteochondral lesion of the talus (OLT). Surgical treatment of medial talar osteochondral lesions is commonly done through a medial malleolar osteotomy. However, a medial malleolar osteotomy is an invasive procedure and gives negative impacts on clinical outcomes. Fixation for the posteromedial lesion of the OLT without the medial malleolar osteotomy may provide good clinical outcomes. We showed arthroscopic fixation for medial OLT without the medial malleolar osteotomy. Curettage and bone grafting between the fragment and its bed were performed, and then 2-mm bone tunnel in the medial malleolus was created. Bioabsorbable pins were inserted through the tunnel to fix the osteochondral fragment. Three cases (mean age 18.6 years) were treated using this technique for medial OLT and followed at 16 months (range, 12-24 months). The Japanese Society for Surgery of the Foot scale improved from 73.3 ± 1.2 points before surgery to 95.7 ± 7.5 points at the final follow-up. Bone union of the osteochondral fragment was confirmed on magnetic resonance imaging (MRI). Arthroscopic fixation for medial OLT is less invasive and yields good clinical outcomes. Levels of Evidence: Level V

It is unclear whether osteochondral lesions of the talus (OLTs) without chronic lateral ankle instability (CLAI) progress to osteoarthritis, which affects the therapeutic strategy. Especially, the efficacy of conservative treatment for OLT remains controversial. Since various anatomical abnormalities have been reported, there may be abnormal movement of the talus in the mortise, causing ankle instability. We hypothesized that OLTs have frequent osteoarthritic changes even without CLAI. This study aimed to evaluate the incidence of osteoarthritic changes and stress distribution on the talus in OLT.Fifty-eight ankles with medial OLT without CLAI were retrospectively reviewed. Osteophytes and joint space narrowing on radiographs were scored using Kraus's classification and compared to ankles without OLTs. OA scores were compared between over 18 years and less than 17 years in OLTs. On computed tomography images, the area of OLTs was measured. Besides, Hounsfield Units (HU) of the talus in patients with and without OLTs were measured and compared.Osteoarthritic changes were observed in 54 of the 58 ankles (94.8%) in the OLT patients. Osteophytes were frequently observed at the medial gutter and anterior tibial plafond. The OA score in patients aged over 18 years was significantly higher than that in patients aged less than 17 years (P 0.05). HU values in the talus were significantly higher than those in non-OLT patients. OLTs more than 100 mmMedial OLT without CLAI has frequently osteoarthritic changes, especially large lesions. Osteoarthritic changes in OLTs will progress over time, which needs to be considered when deciding whether to perform the surgical or non-surgical treatment.

Ligament quality can affect clinical outcomes of ligament repair in chronic lateral ankle instability (CLAI). Magnetic resonance imaging (MRI) is used to assess the morphological changes of ligaments, but the measurement of signal intensity enables quantitative evaluation, which can evaluate the degree of the ligament quality. This study aimed to evaluate the qualitative diagnostic capacity for anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) injuries of the signal intensity on MRI.Thirty-eight and 20 ankles with and without CLAI, respectively, were included. The regions of interest (ROIs) were set in the ATFL, CFL, and tibialis anterior tendon (TAT) on MRI, and the signal intensities were measured. The signal intensities of the ATFL and CFL were corrected using TAT as the signal intensity ratio (SIR). The SIRs of the ATFL and CFL in the control and CLAI groups were compared. The relationship between the SIR of the ATFL and the arthroscopic findings was analyzed. Finally, the SIRs of the CFL in CLAI with and without CFL repair were compared.The mean SIR of the ATFL in the CLAI group (6.1 ± 2.4) was significantly higher than that in the control (2.1 ± 0.4) (P 0.01). The SIR of the ATFL was associated with the arthroscopic grading. The mean SIR of the CFL in the CLAI groups (4.1 ± 2.5) was significantly higher than that in the control (1.7 ± 0.4) (P 0.01). The SIR of the CFL in patients with the requirement of the CFL repair (6.2 ± 1.9) was significantly higher than that without the CFL repair (2.1 ± 0.5) (P 0.05).The SIR is useful for evaluating the quality of the ATFL and CFL, which enables the decision of the treatment strategy of the CLAI.

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.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.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°).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.

Although arthroscopic anterior talofibular ligament (ATFL) repair for chronic lateral ankle instability (CLAI) has been widely performed, there are several issues such as the efficacy of the isolated ATFL repair for the ATFL and calcaneofibular ligament (CFL) injury and the influence of the poor remnant on the clinical outcomes to be discussed. This study aimed to evaluate clinical outcomes of the arthroscopic ATFL repair with the stepwise decision regarding the requirement of CFL repair and the influence of remnant qualities on clinical outcomes.Forty-four ankles underwent arthroscopic surgery to repair the lateral ankle ligament for CLAI. After arthroscopic ATFL repair, CFL repair was performed if instability remained. Clinical outcomes including the Karlsson-Peterson (KP) scores, Japanese Society for Surgery of the Foot (JSSF) scale, and the Self-Administered Foot Evaluation Questionnaire (SAFE-Q) were assessed at the final follow-up. ATFL remnants were classified into excellent, moderate, and poor according to the arthroscopic findings, and the clinical outcomes of each remnant group were compared.Twenty-five ankles were required for CFL repair after ATFL repair. K-P score was significantly improved from 66.1 ± 5.3 to 94.8 ± 6.5 points (p 0.01). JSSF scale was significantly improved from 70.5 ± 4.5 to 95.9 ± 6.0 points (p 0.01). The SAFE-Q was also significantly improved on all subscales. There were no significant differences in clinical outcomes among excellent, moderate, and poor remnants.Stepwise decision for CFL repair in addition to arthroscopic ATFL repair gave satisfactory clinical outcomes in CLAI regardless of the remnant quality.

Background: Arthroscopic anterior talofibular ligament (ATFL) repair is widely performed for chronic lateral ankle instability (CLAI). Although many studies have reported excellent outcomes with this procedure, the recurrence of instability remains a common concern. Therefore, this study aimed to analyze the risk factors for the recurrence of instability after arthroscopic repair for CLAI. Methods: Fifty-six ankles of 53 patients with a mean age of 31.8 ± 14.7 years were retrospectively reviewed. All patients underwent arthroscopic ATFL repair. If instability remained immediately after ATFL repair, calcaneofibular ligament (CFL) repair was performed. The Ankle Activity Score (AAS) was assessed preoperatively, and clinical outcomes including the Japanese Society for Surgery of the Foot scale, Karlsson-Peterson scores, and the Self-Administered Foot Evaluation Questionnaire (SAFE-Q) were evaluated preoperatively and at the final follow-up. Talar tilt angle (TTA) was assessed preoperatively and 1 year postoperatively. Ankles were divided into 2 groups—nonrecurrence (postoperative TTA, Results: Sixteen ankles showed recurrent instability, whereas 40 did not. AAS, TTA, and social functioning in the SAFE-Q were significantly higher in the recurrence group than those in the nonrecurrence group preoperatively. In addition, the rate of poor ATFL remnant quality and the number of CFLs not repaired despite the preoperative injury diagnosis were significantly higher in the recurrence group than in the nonrecurrence group. Conclusion: Arthroscopic repair for ATFL and CFL deficiencies with preoperative high activity, poor remnant quality, and neglected CFL injury can result in the recurrence of instability. Appropriate surgical procedures to prevent the recurrence of instability should be selected for these ankles. Level of Evidence: Level IV, retrospective case series.