Nonunion of Isolated Medial Cuneiform Fracture Fixed With a Compression Screw and Compression Staple: A Case Report.

Isolated cuneiform fractures are rare and account for only 1.7% of all midfoot fractures. Medial cuneiform fractures can be treated conservatively or surgically, with good clinical outcomes. However, nonunion is a rare complication of medial cuneiform fractures, and only a few cases have been reported in the literature. We report a case of a medial cuneiform fracture requiring surgical treatment that had a good clinical outcome. A 15-year-old boy presented to an orthopedic clinic with a complaint of pain in his right foot. The patient had landed on the foot during a handball game and was treated conservatively for several months. However, his symptoms persisted, and he was referred to our clinic for further evaluation, where he was diagnosed with medial cuneiform nonunion of the right foot. Open reduction and internal fixation surgery using a compression screw and staple and autologous bone grafting were performed. Postoperatively, bone union was observed, and the patient returned to full competition with no complaints of pain during exercise. The Self-Administered Foot Evaluation Questionnaire (SAFE-Q) score at 21 months after surgery was 100.0 for the following subscales: Pain & Pain-Related; Physical Functioning & Daily Living; Social Functioning; Shoe-Related; General Health & Well-Being; and Sport (handball). We encountered a case of an isolated medial cuneiform fracture that required surgical treatment. During the surgical treatment, fixation with a combination of compression staples and screws may be considered simple and useful for achieving strong fixation because the medial cuneiform fracture has a small bone fragment.

Morphology and deformity of the distal phalanx in hallux valgus.

BACKGROUND: Studies have shown that the first metatarsal contributes to hallux valgus. The proximal phalanx, another factor that defines the hallux valgus angle, also contributes to the development of hallux valgus. There have been no reports on the use of computed tomography to evaluate bone morphology of the proximal phalanx. The purpose of this study was to analyze the morphology and deformity of the proximal phalanx and its relationship to hallux valgus using computed tomography, and to consider the indications for proximal phalanx surgery in hallux valgus. METHODS: Patients who consulted at our clinic for foot and ankle disorders and underwent both weight-bearing radiography and computed tomography between May 2019 and March 2022 were included in the study. The hallux valgus angle, sesamoid subluxation, first metatarsal length, proximal phalanx length, metatarsal-proximal phalanx ratio, proximal phalanx valgus angle, metatarsal-proximal phalanx angle, proximal phalanx rotation angle, and distal phalanx-proximal phalanx angle were measured. These parameters were compared between the hallux valgus and control groups. In the hallux valgus group, the hallux valgus and proximal phalanx valgus angles were measured and compared using weight-bearing radiographs. RESULTS: A total of 83 feet in 65 patients were diagnosed with hallux valgus (hallux valgus group; mean age of 68.0 ± 13.8 years) and 30 feet in 22 patients without hallux valgus (control group; mean age of 67.0 ± 25.8 years) were included in the study. The proximal phalanx length, metatarsal-proximal phalanx ratio and angle, and distal phalanx-proximal phalanx angle were significantly greater in the hallux valgus group than in the control group. However, the proximal phalanx valgus and rotation angles were not significantly different between the groups. CONCLUSION: Since there was no significant difference in the proximal phalanx morphology, except length, between the hallux valgus and control groups, the indications for osteotomy of the proximal phalanx should be carefully considered.

Changes in the Subchondral Bone Affect Pain in the Natural Course of Traumatic Articular Cartilage Defects.

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.

Decreased Joint Position Sense of the Ankle Joint Is a Risk Factor for Falls in the Elderly.

BACKGROUND: Falls in the elderly are common causes of morbidity, mortality, loss of independence, and poor quality of life. We hypothesized that decreased ankle position sense is one among several risk factors that might lead to falls. METHODS: A total of 54 feet from 28 patients over 65 years of age and 10 feet from five healthy volunteers were included. Measurements of ankle position sense, medical history, and fall history within a year were obtained, which were compared between the groups. RESULTS: The mean replication error angle of internal and external rotation was significantly higher in the elderly, and the mean replication error angle of internal rotation was significantly higher in the group with a history of falls. CONCLUSION: The mean replication error angle of internal rotation and a history of fractures were significant risk factors for falls. Hence, an increase in the mean replication error angle of internal rotation may increase the risk of falls in the elderly population.

Characteristic Bone Morphology Change of the Subtalar Joint in Severe Varus Ankle Osteoarthritis.

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.

Therapeutic effect of targeting Substance P on the progression of osteoarthritis.

OBJECTIVES: Substance P (SP) modulates NK1 and has various functions such as regulation of pain response, bone metabolism, and angiogenesis, which are recognized as important factors in osteoarthritis (OA). We aimed to evaluate the therapeutic effect of targeting SP on OA progression. METHODS: SP expression patterns were analysed histologically in articular cartilage and subchondral bone of human knees from OA patients and autopsy donors as non-OA samples and in mouse articular cartilage. Moreover, to examine the effect of SP on the progression of OA, we administered drugs to mice following the surgical destabilization of the medial meniscus: Phosphate-buffered saline (PBS), septide (NK1 receptor agonist), or aprepitant (NK1 receptor antagonist). Histological analysis and bone morphologic analysis using micro-computed tomography were performed. RESULTS: In human analysis, the expression of SP in mild OA samples was significantly higher than that in severe OA, and that in healthy cartilage was significantly higher than that in OA. In mouse analysis, Osteoarthritis Research Society International scores in the septide group were significantly lower than those in the control group. Computed tomography analysis showed that the subchondral bone's epiphysis in the control group had sclerotic change, not observed in the septide group. CONCLUSIONS: The administration of septide ameliorates OA progression through preventing subchondral bone sclerosis.

Association between medial meniscus extrusion under weight-bearing conditions and pain in early-stage knee osteoarthritis.

PURPOSE: This study aimed to investigate the association between the severity of medial meniscus extrusion (MME) under weight bearing and pain in patients with early-stage knee osteoarthritis (OA). METHODS: Twenty-eight patients with symptomatic early-stage knee OA (Kellgren and Lawrence grade ≤ 2) who visited our outpatient clinic between 2016 and 2018 were included in this cross-sectional study (mean age: 58.0 ± 11.6 years, female: n = 10). MME was evaluated under weight-bearing conditions using ultrasonography. Patients were divided into two groups according to the severity of MME under weight bearing: those with MME ≥ 3 mm were assigned to the severe group, whereas those with MME < 3 mm were assigned to the mild group. The knee injury osteoarthritis outcome score (KOOS) system was used to evaluate knee pain. The incidence of bone marrow lesions (BMLs) was evaluated using magnetic resonance images. RESULTS: The KOOS pain score was significantly lower in the severe group than in the mild group (P < 0.05). The incidence of BMLs was significantly higher in the severe group (69%) than in the mild group (7%) (P < 0.001). CONCLUSION: Patients with early-stage knee OA who have greater MME under weight-bearing have more intense knee pain and a higher incidence of BMLs.

The correlation between osteoarthritis stage and the effect of the lateral wedge insole for 3 months on medial meniscus extrusion in the knee joint.

BACKGROUND: Medial meniscus extrusion (MME) leads to symptomatic knee osteoarthritis (OA) due to increased mechanical stress. MME increases with weight-bearing, and the difference in MME between non-weight-bearing and weight-bearing status (ΔMME) is a factor that causes greater MME. The lateral wedge insole (LWI) is an ideal approach for decreasing the amount of ΔMME associated with the reduction of medial loading stress in the early stage of knee OA. However, the effect of the LWI for 3 months on the ΔMME and its response to OA stage have not been elucidated. OBJECTIVE: To investigate the effects of the LWI for 3 months on MME and the ΔMME in each stage of OA. METHODS: Participants were divided into three groups: no intervention with the LWI (control group; n = 9) and intervention with the LWI in early OA (early OA group: Kellgren-Lawrence (K/L) stage = 2, n = 17) and late OA (late OA group: K/L stage > 2, n = 13). MME was evaluated using ultrasound, and the ΔMME was obtained as the difference in MME from non-weight-bearing and weight-bearing conditions. These measurements were performed at two time points: the initial office visit as a baseline and post-3 months. RESULTS: The weight-bearing MME and ΔMME values post-3 months were significantly decreased compared with those at baseline in the early OA group but not in the control or late OA groups. CONCLUSIONS: The use of the LWI for 3 months decreased weight-bearing MME and ΔMME values, and its effectiveness was more pronounced in the early stage of knee OA.

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.

Safe angles of ATFL and CFL anchor insertion into anatomical attachment of fibula in a lateral ankle ligament repair.

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 triple arthrodesis for the patient with rheumatoid arthritis; a case report.

We treated a 60 - year - old man with pes planovalgus due to rheumatoid arthritis. He had been suffering from left foot pain with swelling. Despite drug therapy, his foot pain and deformity had got worsen. Taking into consideration his skin and bone quality, arthroscopic triple arthrodesis was performed. To access the subtalar joint, 2 portals were applied at the sinus tarsi, and decortication was performed. For calcaneocuboid joint, 1.5 cm portal was applied along with joint line at calcaneocuboid joint. Calcaneocuboid joint was fully decorticated, then, 1.5 cm portal was applied at the joint line of talonavicular joint in parallel. Synovectomy and decortication under arthroscopy were performed. Once each joint was sufficiently prepared, it was fixed using screws via a percutaneous stab incision with an autologous bone graft from the iliac crest to the calcaneocuboid and talonavicular joint. At 12 weeks postoperatively, bone union was confirmed. The Japan Society for Surgery of the Foot (JSSF) RA foot and ankle scale had improved from the postoperative value of 38 points to a postoperative score of 86 points at one year. Plain radiographs showed that good alignment of the patient's hindfoot was maintained. We found that arthroscopic approach was able to achieve satisfactory outcome and minimise soft tissue trauma in a compromised patient.

The Potential of Bone Debris as a Bioactive Composite for Bone Grafting in Arthroscopic Ankle Arthrodesis.

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.

Bone Mineralization Changes in the Subchondral Bone of the Medial Gutter in Chronic Lateral Ankle Instability.

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 <10 degrees. But there was no significant difference in the HU ratios with or without OA change in the medial gutter. A good-quality ATFL remnant showed a low HU ratio compared with that with poor quality. 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.

Relationship of T2 Value of High-signal Line on MRI to the Fragment in Osteochondral Lesion of the Talus.

BACKGROUND: Magnetic resonance imaging (MRI) is useful for evaluating the stability of an osteochondral lesion of the talus (OLT). A T2 high-signal line between the fragment and its bed on MRI is known as a reliable indicator of an unstable lesion. However, the lesion exhibits various conditions even if a T2 high-signal line is observed. The purpose of this study was to evaluate the relationship between the T2 value of a high-signal line and the condition of the area between the fragment and its bed in OLT. METHODS: T2 values of the T2 high-signal line and those of joint fluid were measured from preoperative MRI images in 46 ankles with OLT and the T2 ratio (high-signal line / joint fluid) was calculated. The relationship between the T2 ratio and CT, arthroscopic, and histologic findings was examined. RESULTS: The mean T2 ratio was 0.48. T2 ratios of cystic lesions (0.62) or bone absorption (0.67) in the bed were significantly higher than those without a cyst (0.40) or no absorption (0.40). The T2 ratio of an unstable lesion (0.51) was significantly lower than that of a stable lesion (0.29). In histologic findings, there were 2 separate patterns: chondral and subchondral bone separations. The T2 ratio of the chondral separation (0.60) was significantly higher than that of bone separation (0.48). CONCLUSION: This study showed that the T2 ratio on a high-signal line was a predictor of stability, cyst, and bone absorption in OLT. LEVEL OF EVIDENCE: Level III, comparative series.

Role of vasoactive intestinal peptide in the progression of osteoarthritis through bone sclerosis and angiogenesis in 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.

Retrograde Drilling for Osteochondral Lesion of the Talus in Juvenile Patients.

BACKGROUND: Retrograde drilling (RD) is generally used for treating osteochondral lesion of the talus (OLT) with a stable osteochondral fragment and nearly normal articular cartilage surface. Previous studies that included participants of various ages have reported good clinical results. This study aimed to clarify the clinical outcomes of RD for OLT in juvenile patients whose bone-forming ability and physical activity might affect the healing process. METHODS: This retrospective study included 8 juvenile patients who underwent RD for OLT (5 boys and 3 girls, mean age 14.9 years, mean follow-up 2 years, 7 medial and 1 central lesion). American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score and ankle activity score were evaluated, and arthroscopic findings were graded according to the International Cartilage Research Society (ICRS) classification system. The condition of the underlying bone was assessed on preoperative computed tomographic images. The stability, incorporation, and subsidence of the osteochondral fragment, articular surface congruity, and the area of the bone marrow lesion (BML) were evaluated using magnetic resonance imaging (MRI). RESULTS: AOFAS ankle-hindfoot score and ankle activity score significantly improved postoperatively. Arthroscopically, the lesions were classified as ICRS grade 0 or 1. Bone sclerosis or multiple small cysts of the underlying bone were observed in all patients. MRI demonstrated no signs of osteochondral fragment instability or subsidence, good or fair fragment incorporation, good articular surface congruity, or slight irregularity. The postoperative BML was reduced; however, these BMLs were still detectable at 1 year after surgery. CONCLUSION: Our data suggested that RD is an option for treating juvenile patients with OLT refractory to nonoperative treatment at short-term follow-up. Although bone sclerosis or multiple small cysts were identified in the underlying bone preoperatively and the BML under the osteochondral fragment remained postoperatively, clinical status such as pain and physical activity level were improved by RD. LEVEL OF EVIDENCE: Level IV, retrospective case series.

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.

Clinical Results of Bioabsorbable Pin Fixation Relative to the Bone Condition for Osteochondral Lesion of the Talus.

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.

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.