Anterior talofibular ligament remnant quality is important for achieving a stable ankle after arthroscopic lateral ankle ligament repair.

PURPOSE: The relationship between ligament remnant quality and postoperative outcomes after arthroscopic lateral ankle ligament repair for chronic lateral ankle instability is controversial. This study aimed to determine whether the signal intensity of the anterior talofibular ligament on preoperative magnetic resonance imaging and ligament remnant quality identified on arthroscopy are associated with recurrent ankle instability after arthroscopic lateral ankle ligament repair. METHODS: A total of 68 ankles from 67 patients with chronic lateral ankle instability who underwent arthroscopic lateral ankle ligament repair were retrospectively studied. The signal intensity of the anterior talofibular ligament was evaluated using T2-weighted magnetic resonance imaging. Arthroscopy was used to evaluate the thickness and mechanical resistance of the anterior talofibular ligament by hook palpation and to classify ankles into two groups: the present anterior talofibular ligament group with adequate mechanical resistance and the absent anterior talofibular ligament group with no mechanical resistance. The outcomes included recurrent ankle instability (respraining of the operated ankle after surgery) and Self-Administered Foot Evaluation Questionnaire scores. RESULTS: Thirteen ankles were diagnosed with recurrent ankle instability. Patients with a high anterior talofibular ligament T2 signal intensity experienced more recurrent ankle instability than those with a low intensity. As determined via arthroscopy, the absent anterior talofibular ligament group had a higher rate of recurrent ankle instability than the present anterior talofibular ligament group. There were no significant differences in Self-Administered Foot Evaluation Questionnaire scores between patients with high and low anterior talofibular ligament T2 signal intensity, as well as between absent and present anterior talofibular ligament groups based on arthroscopy. CONCLUSION: Poor quality of the anterior talofibular ligament remnant could result in recurrent ankle instability after arthroscopic lateral ankle ligament repair. Therefore, when treating chronic lateral ankle instability, surgeons should consider ligament quality. LEVEL OF EVIDENCE: IV.

How does the postoperative medial arch height influence the patient reported outcomes of stage â ¡ acquired adult flatfoot deformity?

BACKGROUND: This study aimed to assess how the postoperative medial arch height influenced postoperative patient-reported clinical outcomes after surgery for stage Ⅱ acquired adult flatfoot deformity. METHODS: A total of 30 feet of 30 patients (7 males, 23 females) who underwent surgery for stage Ⅱ acquired adult flatfoot deformity and could be followed up for at least 2 years were included. The average age at surgery was 60.0 (standard deviation, 13.0) years, and the average follow-up period was 40 (standard deviation, 15.4) months. Among them, 16 patients underwent lateral column lengthening and 14 patients did not. Patient-reported clinical outcomes were evaluated using the Self-Administered Foot Evaluation Questionnaire. Radiographic alignment was evaluated by the talonavicular coverage angle, lateral talo-1st metatarsal angle, medial cuneiform height, medial cuneiform to 5th metatarsal height, and calcaneal pitch. The correlation between postoperative Self-Administered Foot Evaluation Questionnaire and radiographic alignment was assessed with Pearson's correlation analysis. RESULTS: Self-Administered Foot Evaluation Questionnaire and radiographic alignment significantly improved postoperatively in all patients (P < 0.0001). In patients with severe deformity who needed lateral column lengthening, lateral talo-1st metatarsal angle was negatively and medial cuneiform to 5th metatarsal height was positively correlated with physical functioning Self-Administered Foot Evaluation Questionnaire subscales (r = -0.56 and 0.55), and medial cuneiform height was positively correlated with physical functioning, social functioning and general health Self-Administered Foot Evaluation Questionnaire subscales (r = 0.70, 0.55 and 0.73, respectively). CONCLUSION: Postoperative medial arch height could influence physical functioning, social functioning, and general health in patients with severe stage II adult-acquired flatfoot deformity.

Hindfoot Alignment and Ankle Stability Following Arthroscopic Lateral Ankle Ligament Repair.

BACKGROUND: Hindfoot varus deformity is a known risk factor for chronic lateral ankle instability (CLAI). The impact of this deformity on clinical results following arthroscopic lateral ankle ligament repair (ALLR) for CLAI has not been studied. METHODS: Sixty-three ankles from 62 patients who received ALLR for CLAI were retrospectively examined. Preoperative plain radiographs were used to measure tibial articular surface (TAS) angles, and long axial hindfoot alignment radiographs were used to measure tibiocalcaneal angles (TCAs) pre- and postoperatively. Results included ratings on the Self-Administered Foot Evaluation Questionnaire (SAFE-Q) and recurrent ankle instability (respraining of the operated ankle following surgery). RESULTS: Recurrent ankle instability, defined as incidence of any new ankle sprain after surgery reported in the follow-up period, occurred in 13 ankles. The TAS angles of these patients were significantly low, and their preoperative TCA was significantly high. Multivariate analysis showed that preoperative TCA was an independent risk factor for recurrent ankle instability. The threshold values for preoperative TCA for recurrent instability were determined via the receiver operating characteristic curve analysis to be 3.4 degrees. Patients were assigned to a low- or high-TCA group based on the reported average TCA (2.7 degrees) of healthy patients. In the high-TCA group, recurrent instability was significantly more frequent, and the scores on the pain subscale of the postoperative SAFE-Q were significantly lower. CONCLUSION: Hindfoot varus alignment was associated with pooreroutcomes after ALLR. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Varus-Tilted Distal Tibial Plafond Is a Risk Factor for Recurrent Ankle Instability After Arthroscopic Lateral Ankle Ligament Repair.

BACKGROUND: Although varus-tilted distal tibial deformity is an established risk factor for chronic lateral ankle instability (CLAI), no studies have reported whether this deformity influences ankle instability after arthroscopic lateral ankle ligament repair (ALLR) for CLAI. METHODS: A total of 57 ankles from 57 patients who underwent ALLR for CLAI were retrospectively analyzed. Tibial articular surface (TAS) angles were measured on preoperative plain radiograph. After 12 months of follow-up, recurrent ankle instability and talar tilt angles on stress radiograph were evaluated as outcomes. Relationships between the TAS angle and these outcomes were assessed. RESULTS: Recurrent ankle instability was observed in 10 ankles. The TAS angles of patients with recurrent instability were significantly lower (85.2 degrees vs 87.9 degrees). The receiver operating characteristic curve analysis revealed that the cutoff value of TAS angle for recurrent instability was 86.2 degrees. Based on this cutoff value, our patients were divided into 2 groups: low-TAS and high-TAS group. Univariate and multivariate analysis revealed that low TAS was an independent risk factor for recurrent ankle instability and greater postoperative talar tilt angles. CONCLUSION: Varus-tilted distal tibial plafond appears to be a risk factor for recurrent ankle instability after ALLR.

Nonunion of a medial malleolar stress fracture in an adolescent athlete secondary to lateral ankle instability: A case report.

INTRODUCTION: Medial malleolar stress fractures are relatively uncommon. This report describes the successful treatment of nonunion of a medial malleolar stress fracture due to chronic lateral ankle instability. PRESENTATION OF CASE: A 13-year-old middle school student who belonged to a football club presented to our clinic with chronic medial left ankle pain lasting over a year. He had sprained his left ankle several times 6 years earlier. A plain anteroposterior ankle radiograph showed a vertical fracture line in the medial malleolus involving the epiphyseal plate, and computed tomography demonstrated the vertical fracture seen on the plain radiographs and bone sclerosis at the fracture site. We performed internal fixation for nonunion of the medial malleolar stress fracture with arthroscopic modified Broström for lateral ankle instability. Two years after surgery, the Self-Administered Foot Evaluation Questionnaire improved in all parameters, and both the anterior drawer and varus stress tests were negative. DISCUSSION: Early diagnosis of medial malleolar stress fracture is important for a rapid return to sports. Magnetic resonance imaging is helpful for early diagnosis. Because lateral ankle instability can cause medial malleolar stress fracture, arthroscopic modified Broström procedure is meaningful for medial malleolar stress fracture with lateral ankle instability. CONCLUSION: Internal fixation and the arthroscopic modified Broström procedure could achieve good clinical outcomes for medial malleolar stress fractures with lateral ankle instability.

Intra-articular administration of EP2 enhances the articular cartilage repair in a rabbit model.

We have reported the usefulness of chondrocyte sheets on articular cartilage repair in animal experiments. Here, we investigated the regenerative effects of EP2 signalling with or without chondrocyte sheets. Forty-five rabbits were used, with six rabbits in each of the six groups and nine rabbits for chondrocytes and synovial cells harvesting to fabricate triple-layered chondrocyte sheets: osteochondral defect only (control, Group A), EP2 agonist (Group B), EP2 antagonist (Group C), chondrocyte sheets (Group D), EP2 agonist and chondrocyte sheets (Group E), and EP2 antagonist and chondrocyte sheets (Group F). After surgery, the weight distribution ratio was measured as an indicator of pain alleviation. Injections of the EP2 agonist or EP2 antagonist were given from 4 weeks after surgery. The rabbits were sacrificed at 12 weeks, and the repaired tissues were evaluated for histology. The weight distribution ratio and International Cartilage Repair Society grading were as follows: Group A: 40.5% ± 0.2%, 14.8 ± 0.5; Group B: 43.4% ± 0.7%, 25.4 ± 0.8; Group C: 38.7% ± 0.7%, 13.7 ± 0.3; Group D: 48.6% ± 0.6%, 40.2 ± 0.5; Group E: 49.1% ± 0.3%, 40.5 ± 0.4; and Group F; 46.8% ± 0.4%, 38.7 ± 0.5. Significant differences in histology and pain alleviation were observed between groups except between Groups A and C, between Groups D and E, and between Groups D and F. These findings show that the intra-articular administration of an EP2 agonist achieved pain alleviation and tissue repair. However, no synergistic effect with chondrocyte sheets was observed.

Rabbit xenogeneic transplantation model for evaluating human chondrocyte sheets used in articular cartilage repair.

Research on cartilage regeneration has developed novel sources for human chondrocytes and new regenerative therapies, but appropriate animal models for translational research are needed. Although rabbit models are frequently used in such studies, the availability of immunocompromised rabbits is limited. Here, we investigated the usefulness of an immunosuppressed rabbit model to evaluate directly the efficacy of human chondrocyte sheets through xenogeneic transplantation. Human chondrocyte sheets were transplanted into knee osteochondral defects in Japanese white rabbits administered with immunosuppressant tacrolimus at a dosage of 0.8 or 1.6 mg/kg/day for 4 weeks. Histological evaluation at 4 weeks after transplantation in rabbits administered 1.6 mg/kg/day showed successful engraftment of human chondrocytes and cartilage regeneration involving a mixture of hyaline cartilage and fibrocartilage. No human chondrocytes were detected in rabbits administered 0.8 mg/kg/day, although regeneration of hyaline cartilage was confirmed. Histological evaluation at 12 weeks after transplantation (i.e., 8 weeks after termination of immunosuppression) showed strong immune rejection of human chondrocytes, which indicated that, even after engraftment, articular cartilage is not particularly immune privileged in xenogeneic transplantation. Our results suggest that Japanese white rabbits administered tacrolimus at 1.6 mg/kg/day and evaluated at 4 weeks may be useful as a preclinical model for the direct evaluation of human cell-based therapies.

Effects of a cell-free method using collagen vitrigel incorporating TGF-ß1 on articular cartilage repair in a rabbit osteochondral defect model.

We studied the ability of collagen vitrigel material to repair cartilage in vivo when used alone or with transforming growth factor-ß (TGF-ß). We measured the time course and quantity of TGF-ß1 released from the collagen vitrigel in vitro to quantify the controlled release of TGF-ß1. Over 14 days, 0.91 ng of TGF-ß was released from the collagen vitrigel. Osteochondral defects were made in the femoral trochlear groove in 36 Japanese white rabbits, which were divided into three groups: untreated group (group A), collagen vitrigel-implanted group (group B), and TGF-ß1-incorporated collagen vitrigel-implanted group (group C). The weight distribution ratio between the affected and unaffected limbs served as an indicator of pain. Animals were sacrificed at 4 and 12 weeks after surgery, and their tissues were assessed histologically. The weight distribution ratio increased in all groups and did not differ significantly between groups at 12 weeks. Group A needed 6 weeks to attain maximum improvement, and groups B and C showed near-maximum improvement at 4 and 2 weeks, respectively. The International Cartilage Repair Society II score improved significantly in group C relative to the other groups. These findings suggest that sustained, slow release of TGF-ß caused early pain mitigation and cartilage repair. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2592-2602, 2017.