Does the Sagittal Radiographic Morphology of Subtalar Joint Affect the Alignment of Foot?

OBJECTIVES: The etiology of flatfoot and cavus foot is multicausal and controversial. So far, no literature reports the relationship between the sagittal morphology of subtalar joint and the alignment of foot. The purpose of this study was to explore whether the subtalar alignment would influence the configuration of foot. METHODS: From January 2017 to January 2020, we included 109 feet in the flatfoot group, 95 feet in the cavus group, and 104 feet in the control group in this retrospective comparative study. The Gissane angle and calcaneal posterior articular surface inclination angle represented the sagittal morphology of the subtalar joint. Meary's angle, calcaneal pitch angle, and talar pitch angle reflected the alignment of foot. They were measured in the weightbearing foot X-rays. The angles in different groups were compared via Mann-Whitney U test. We calculated the correlation between the sagittal alignment of subtalar joint and the alignment of foot using Spearman's correlation analysis. Interobserver and intraobserver reliability were calculated. RESULTS: The Gissane angle, calcaneal posterior articular surface inclination angle, Meary's angle, talar pitch angle, and calcaneal pitch angle were significantly different in the three groups. The Gissane angle had an excellent correlation with the Meary's angle (r = 0.850, p < 0.0001), and the talar pitch angle (r = -0.825, p < 0.0001), and a good correlation with the calcaneal pitch angle (r = 0.638, p < 0.0001). The calcaneal posterior articular surface inclination angle had an excellent correlation with the Meary's angle (r = -0.902, p < 0.001), and the talar pitch angle (r = 0.887, p < 0.0001), and a good correlation with the calcaneal pitch angle (r = -0.702, p < 0.0001). The interobserver and intraobserver reliability for all radiographic measurements was good to excellent. CONCLUSION: A subtalar joint with a larger Gissane angle and a more horizontal calcaneal posterior articular surface angle tended to have a higher foot arch and vice versa. The inspiration from this study was that the deformities of flatfoot and cavus foot may relate to the subtalar deformity.

Does a rupture of the lateral ankle ligament need to be repaired in supination-adduction type II (OTA/AO 44A2) fractures?

PURPOSE: To evaluate the outcomes of patients with supination-adduction (SAD) type II (OTA/AO 44A2) fractures who had a lateral ankle ligament rupture repaired compared with patients who did not have a lateral ankle ligament repaired using patients who underwent fibula fracture fixation as a control group. METHODS: A retrospective analysis of all 104 patients diagnosed with SAD type II fractures from January 2011 to December 2020 and managed operatively was performed. The patients were divided into three groups: 32 patients with ruptures of the lateral ligaments that were not repaired (group A), 34 patients with ruptures of the lateral ligaments that were repaired (group B), and 38 patients with fibula fracture fixation acting as the control group (group C). The objective outcomes including radiographic findings, the ankle range of motion, the manual ankle stress tests, and complications were gained from the record of the last time in outpatient clinics. The functional outcomes including the identification of functional ankle instability (IdFAI) scores were collected postoperatively at 12-month intervals to assess clinical outcomes. The Manchester Oxford Foot Questionnaire (MOXFQ) and Karlsson scoring scale were also recorded at the last follow-up. RESULTS: The mean follow-up of the objective and subjective functional outcomes was 23.4 (range, 13-42) and 76.9 (range, 25-134) months, respectively. There was no significant difference in the radiographic findings, the ankle range of motion and complications between the three groups. All ankles were found to be stable using the manual ankle stress test in both group A and group B. The IdFAI scores showed a significant difference between group A and group B (1.12 ± 1.3 vs 0.35 ± 0.69; p < 0.001) in the first year of follow-up and no significant difference after the first year. No differences were noted in MOXFQ scores or Karlsson scores among the groups. CONCLUSION: Directly repairing the lateral ligament could minimize the proportion of the first year of postoperative functional ankle instability, although the final stability of the ankle and clinical outcomes were not significantly different in SAD type II fractures. LEVEL OF EVIDENCE: Level III, retrospective comparative case series.

Mechanism and Practice of Multifracturing Using Dynamic Loads in a Low-Permeability Coal Reservoir.

The geological conditions of coal reservoirs in China are complex, and the reservoir permeability is generally lower. Multifracturing is an effective method of improving reservoir permeability and coalbed methane (CBM) production. In this study, two types of dynamic loads, CO2 blasting and a pulse fracturing gun (PF-GUN), were used to conduct multifracturing engineering tests in nine surface CBM wells in the Lu'an mining area in the central and eastern parts of the Qinshui Basin. The curves of pressure versus time of the two dynamic loads were obtained in the laboratory. The prepeak pressurization time of the PF-GUN was 200 ms, and that of the CO2 blasting was 2.05 ms, which just falls in the optimum pressurization time of multifracturing. The microseismic monitoring results revealed that, in terms of the fracture morphology, both the CO2 blasting and PF-GUN loads produced multiple sets of fractures in the near-well zone. In the six wells used for the CO2 blasting tests, an average of three branch fractures were produced outside of the main fracture, and the average angle between the main fracture and the branch fractures exceeded 60°. In the three wells stimulated by PF-GUN, an average of two branch fractures were produced outside of the main fracture, and the average angle between the main fracture and the branch fractures was 25-35°. The multifracture characteristics of the fractures formed via CO2 blasting were more obvious. However, a coal seam is a multifracture reservoir with a large filtration coefficient; the fracture will not extend after reaching the maximum scale under a certain gas displacement condition. Compared with the traditional hydraulic fracturing technique, the nine wells used in the multifracturing tests exhibited an obvious stimulation effect with an average increase of 51.4% in daily production. The results of this study provide an important technical reference for the efficient development of CBM in low- and ultralow-permeability reservoirs.

Anatomic reconstruction of the lateral ligaments using allograft tendon and suspensory fixation for chronic lateral ankle instability with poor remnant quality: results and complications.

PURPOSE: Treatment of chronic lateral ankle instability (CLAI) with poor remnant quality is challenging. The aim of the present study was to evaluate clinical results and complications of anatomic reconstruction of the lateral ligaments using allograft tendon and suspensory fixation in the treatment of such patients. METHODS: One hundred and eight patients with CLAI, who were treated surgically using anatomic reconstruction with allograft tendon and suspensory fixation between April 2016 and January 2018 at our hospital, were retrospectively analysed. None of the patients had sufficient ligament remnants for the modified Broström procedure during the intraoperative evaluation. Eighteen patients were excluded. Seventeen patients were lost to follow-up and 73 patients completed the study. The mean duration of instability symptoms was 39.1 months (range, 6-480 months). The mean follow-up time was 57.5 months (range, 48-69 months). Clinical results were evaluated using the Karlsson scoring scale, American Orthopaedic Foot and Ankle Society-Ankle and Hindfoot (AOFAS-AH) score, visual analogue scale (VAS), patients' subjective satisfaction, and incidence of complications. Mechanical stability was evaluated using the varus talar tilt angle (TTA) and anterior talar displacement (ATD). RESULTS: The AOFAS-AH scores significantly improved from 67.7 ± 8.5 points to 89.8 ± 9.5 (p < 0.001). The Karlsson scoring scales evolved from 58.8 ± 16.5 to 88.4 ± 11.2 (p < 0.001). VAS scores significantly decreased from 2.9 ± 1.3 to 1.1 ± 1.0 (p < 0.001). On stress radiographs, TTA decreased from 15.1 ± 2.5 degrees to 5.8 ± 2.1 degrees (p < 0.001), whereas ATD reduced from 13.4 ± 2.9 mm to 5.7 ± 1.5 mm (p < 0.001). Patients' subjective satisfaction indicated 46 excellent, 20 good, 5 fair, and 2 bad results. Postoperatively, 15 cases (20.5%) did not achieve complete relief of discomfort or swelling, 9 cases (12.3%) experienced joint stiffness or decreased range of motion, and 6 cases (8.2%) had soft tissue irritation. Residual instability and reoperation are rare. Allograft rejection or wound infection was not observed. CONCLUSION: For the CLAI patients with poor remnant quality, anatomic reconstruction of the lateral ligaments using allograft tendon and suspensory fixation is an effective procedure, while the top three complications in incidence were residual discomfort, joint stiffness, and soft tissue irritation. LEVELS OF EVIDENCE: Level IV, retrospective case series.

Revision lateral ankle ligament reconstruction for patients with a failed modified Brostrom procedure.

PURPOSE: The Brostrom-Gould procedure has been considered as a gold standard operative technique for chronic lateral ankle instability. Despite the popularity and excellent outcomes of the modified Brostrom procedure, some patients still experience recurrence of ankle instability. Few studies reported outcomes of revision reconstruction for patients with a failed modified Brostrom procedure. This study aimed to evaluate the outcomes of a percutaneous anatomic revision lateral ankle ligament reconstruction for patients with a failed modified Brostrom procedure. METHODS: From March 2017 to April 2020, 21 patients with persistent ankle instability after a modified Brostrom procedure underwent revision lateral ankle ligament reconstruction. The operation was performed through minimally invasive incisions. Functional assessment was performed using the Karlsson-Peterson ankle scoring system (KP) and the Visual Analogue Scale (VAS). The questionnaires of KP and VAS were completed before surgery and at the last follow-up. Patients' subjective satisfaction level was graded as excellent, good, fair, and poor. Preoperative and postoperative anterior talar displacement and varus talus tilt angle in stress radiographs were recorded. RESULTS: The average age at the revision surgery time was 39.6years. The mean follow-up was 39.2months. The VAS score improved from 4.1 ± 1.5 preoperatively to 1.3 ± 1.3 at the final follow-up (p < .05). The KP score improved from 59.0 ± 20.2 preoperatively to 88.2 ± 9.6 at the last follow-up (p < .05). The mean varus talar tilt angle was 14.1 ± 3.9 mm preoperatively versus 4.9 ± 4.7 mm at the final follow-up (p < .05). The mean anterior talar displacement was 12.8 ± 2.2 mm versus 5.6 ± 3.7 mm at the last follow-up (p < .05). CONCLUSIONS: The revision anatomic reconstruction of the lateral ligaments of the ankle is effective for patients with recurrent instability after a failed modified Broström procedure.

Therapeutic efficacy analysis of distal tibia varus syndrome with different classification and different therapy: a cross-sectional study.

Background: We often attribute the lateral ankle impingement to the valgus calcaneus, while ignoring the varus distal tibia. The diagnostic criteria, severity and treatment of distal tibia varus syndrome (DTVS) have not been reported. This retrospective study sought to propose a diagnosis and classification system for DTVS based on patients' clinical symptoms and imaging findings. Methods: A total of 76 symptomatic patients with varus distal tibia and congruent ankle examined between 2010 and 2018 were involved to evaluate clinically based on their SF-36 scores, AOFAS ankle-hindfoot scores, and VAS scores. Each patient's history, symptoms, and MRI images were analyzed retrospectively, and their weight-bearing ankle radiographs were observed to measure the tibial anterior surface angle (TAS) and tibial tilt angle (TTA). Paired t-test and Kruskal-Wallis test were used to compare the results above. Results: Forty-three men and 33 women with an average age of 46 years (range, 28-68 years) included. Besides the same symptom of intermittent subfibular pain, 3 types of DTVS were defined: (I) Type I: a sloped surface of the distal tibia with the congruent tibiotalar joint on radiographs; (II) Type II: a sloped surface of the distal tibia with the congruent tibiotalar joint on radiographs, and soft-tissue edema inferior to the lateral malleolus on MRI images; and (III) Type III: the same symptoms as Type II, plus osteochondral lesions of the talus on MRI images. Under our proposed classification system, 26 patients were classified as Type I, requiring conservative treatment, 22 as Type II, and 28 as Type III under supramalleolar valgus osteotomy. The ankle functional evaluation scores, such as the SF-36 (74.14±12.50 preoperatively and 85.22±8.83 postoperatively), AOFAS (71.14±15.19 preoperatively and 87.53±8.62 postoperatively), and VAS (5.41±1.10 preoperatively and 1.82±1.08 postoperatively) scores for all types were significantly improved (P<0.01). The TAS (80.38°±4.80° preoperatively and 90.44°±3.96° postoperatively) and TTA (13.02°±3.41° preoperatively and 0.62°±2.67° postoperatively) of all the patients on the weight-bearing ankle radiographs were significantly improved (P<0.01). Conclusions: DTVS, causing lateral ankle impingement, can be diagnosed based on clinical manifestations and imaging findings. Our classification system can aid in the decision-making process in relation to the appropriate form of conservative or surgical treatments.

Staged surgical management of sinus tarsi syndrome: our experience of 273 cases.

BACKGROUND: The sinus tarsi syndrome (STS) is a common foot and ankle disease with controversial pathogenesis and treatment procedures. This long-term study aimed to analyze the effect of a staged surgical strategy for STS. METHODS: Clinical data were retrospectively analyzed in 273 STS patients [129 men and 144 women; mean age: 36 years (10-60 years)] treated between 2006 and 2016. The 89 patients underwent different surgeries, including sinus tarsal debridement, subtalar joint stabilization, sinus tarsal denervation, tarsal coalition resection, or subtalar arthrodesis. The patients' American Orthopedic Foot & Ankle Society (AOFAS) ankle-hindfoot scores, visual analogue scale (VAS) scores for pain during daily activities, and 36-item short-form health survey (SF-36) scores at the first visit and latest follow-up were assessed by paired T-test. RESULTS: The 89 patients who failed conservative treatments first underwent tarsal sinus soft tissue debridement, with 52 patients remaining in remission after 2 years. The other 37 patients with relapse underwent further surgeries. Five of the 19 patients with subtalar instability were cured following ligament reconstruction surgery. Two of the four patients with severe neurological signs recovered after nerve release surgery. Five of the 10 patients with tarsal coalition were cured by resection of the talocalcaneal bridge. A total of 21 patients failed their second operations due to peroneal spasm, and were eventually successfully treated by subtalar arthrodesis. In addition, subtalar arthrodesis was directly performed in the remaining four patients with peroneal spastic flatfoot. After the final operations, all patients achieved satisfactory results. The AOFAS ankle-hindfoot scores increased from 34.83±12.21 preoperatively to 85.52±7.07 postoperatively (t=-24.62, P<0.01), the VAS scores decreased from 8.14±1.52 to 2.14±1.00 (t=24.65, P<0.01), and the SF-36 scores increased from 36.58±11.36 to 86.22±9.17 (t=-28.13, P<0.01). CONCLUSIONS: In this study, we observed that 67% (184/273) of patients with STS need a staged surgical management. According to the etiology, symptoms, and severity, soft tissue surgery is the first choice. However, simple soft tissue surgeries may fail to achieve long-term results. Once the symptoms recur and become difficult to cure, the staged surgical strategy for STS we proposed can be the best choice to achieve long-term results.

Outcomes of ossicle resection and anatomic reconstruction of lateral ligaments for chronic ankle instability with large malleolar accessory ossicles.

BACKGROUND: Malleolar accessory ossicles can be found in patients with chronic lateral ankle instability (CLAI). Ossicle resection combined with the modified Broström procedure is the most commonly used surgical method. However, an unrepairable gap after ossicle resection often occurs in patients with large ossicles. PURPOSE: This study analysed the clinical outcomes of ossicle resection and anatomic ligament reconstruction (ALR) for CLAI with large malleolar accessory ossicles. METHODS: This study was a retrospective case series. Since 2014, we have adopted ALR for patients with difficulties using the modified Broström procedure after ossicle resection. Sixteen patients with chronic ankle instability and malleolar accessory ossicles were treated with this method between December 2014 and February 2018. The average age of the patients at the time of surgery was 28.9 (range, 16-65) years. They were followed up for an average time of 26.9 (range, 12-47) months. The clinical outcomes were evaluated using the Visual Analogue Scale, Karlsson-Peterson ankle scoring system, subjective satisfaction of patients, and radiographic parameters. RESULTS: All unrepairable cases occurred in patients with ossicles larger than or equal to 10 mm. The VAS score improved from 3.5 ± 1.6 preoperatively to 1.4 ± 1.0 at the final follow-up (p < 0.05), and the Karlsson-Peterson score improved significantly from 52.7 ± 15.1 to 86.4 ± 8.2 (p < 0.05). There was also an obvious change in the varus talar tilt angle (15.4 ± 2.0° vs 6.2 ± 1.6°, p < 0.05) and anterior talar displacement (14.3 ± 2.1 mm vs 6.3 ± 1.4 mm, p < 0.05). Fourteen patients (87.5%) were satisfied (excellent or good) with their clinical outcomes. CONCLUSION: If modified Broström procedure is difficult to accomplish effectively after ossicle resection for chronic ankle instability with large malleolar accessory ossicles, ALR is a viable option with satisfactory clinical results.

Characteristics of Osteochondral Lesions of the Talus in Different Age Groups.

We analyzed the characteristics of 112 consecutive patients who were operatively treated for osteochondral lesions of the talus from August 2014 to April 2019 in our hospital. The patients were divided into three age groups: young-adult (<40 years), middle-age (40-60 years) and old-age (>60 years). The basic clinical features, localization and size of the lesions, Hepple stage, and surgical procedures were compared among groups. Several significant differences were found on the characteristics of osteochondral lesions of the talus among age groups. There were more female patients in the old-age group (p<0.01), and old patients had a longer duration of symptoms (p<0.05). The OLTs in middle- and old-age patients were mostly located in the medial part of the talus with larger depth (p<0.01). Hepple stage 5, the cystic type, was very common in the old-age group (p<0.01). With regard to surgical procedures, more osteochondral autograft transplantations were applied in the old-age group (p<0.01). Female and deep medial talar subchondral cyst is the typical characteristics of patients over 60 years old. Age is an important factor that must be considered when choosing surgery procedure for patients with osteochondral lesions of the talus.

Diagnosis of tibiofibular syndesmosis instability in Weber type B malleolar fractures.

OBJECTIVE: This study was performed to analyze the clinical value of X-ray, computed tomography (CT), and magnetic resonance imaging (MRI) examinations for the diagnosis of distal tibiofibular syndesmosis injuries in Weber type B ankle fractures with reference to the ankle arthroscopic findings. METHODS: This retrospective clinical study involved 52 patients with type B ankle fractures from August 2014 to January 2018. We analyzed the patients' preoperative imaging data and judged the stability of the distal tibiofibular syndesmosis using X-ray, CT, and MRI examinations. We also evaluated the syndesmosis stability with arthroscopy both statically and dynamically. RESULTS: With the arthroscopic findings as the standard, the sensitivity of X-ray for diagnosing syndesmosis instability was 52.8%, the specificity was 100%, and the diagnostic efficiency was 67.3%. The sensitivity of CT for diagnosing syndesmosis instability was 77.8%, the specificity was 100%, and the diagnostic efficiency was 84.6%. The sensitivity of MRI for diagnosing syndesmosis instability was 100%, the specificity was 81.3%, and the diagnostic efficiency was 94.2%. CONCLUSION: This study suggests that an arthroscopic examination may be recommended when the X-ray or CT features are different from the MRI findings while diagnosing tibiofibular syndesmosis instability in Weber type B malleolar fractures.

Surgical management of chronic lateral ankle instability: a meta-analysis.

BACKGROUND: A key point to surgical treatment of chronic lateral ankle instability is choosing a suitable surgical procedure. The purpose of this meta-analysis was to compare different surgical techniques for management of chronic lateral ankle instability. METHODS: We searched the Cochrane Library, MEDLINE, and EMBASE. All identified randomized and quasi-randomized controlled trials of operative treatment for chronic lateral ankle instability were included. Two review authors independently extracted data from each study and assessed risk of bias. Where appropriate, results of comparable studies were pooled. RESULTS: Seven randomized controlled trials were included for analysis. They fell in five clearly distinct groups. One study comparing two different kinds of non-anatomic reconstruction procedures (dynamic and static tenodesis) found two clinical outcomes favoring static tenodesis: better clinical satisfaction and fewer subsequent sprains. Two studies compared non-anatomic reconstruction versus anatomic repairment. In one study, nerve damage was more frequent in non-anatomic reconstruction group; the other one reported that radiological measurement of ankle laxity showed that non-anatomic reconstruction provided higher reduction of talar tilt angle. Two studies comparing two anatomic repairment surgical techniques (transosseous suture versus imbrication) showed no significant difference in any clinical outcome at the follow-up except operation time. One study compared two different anatomic repairment techniques. They found that the double anchor technique was superior with respect to the reduction of talar tilt than single anchor technique. One study compared an anatomic reconstruction procedure with a modified Brostrom technique. Primary reconstruction combined with ligament advanced reinforcement system results in better patient-scored clinical outcome, at 2 years post-surgery, than the modified Brostrom procedure. CONCLUSIONS: There is limited evidence to support any one surgical technique over another surgical technique for chronic lateral ankle instability, but based on the evidence, we could still get some conclusions: (1) There are limitations to the use of dynamic tenodesis, which obtained poor clinical satisfaction and more subsequent sprains. (2) Non-anatomic reconstruction abnormally increased inversion stiffness at the subtalar level as compare with anatomic repairment. (3) Multiple types of modified Brostrom procedures could acquire good clinical results. (4) Anatomic reconstruction is a better procedure for some specific patients.

A new minimally invasive method for anatomic reconstruction of the lateral ankle ligaments with a Tightrope system.

BACKGROUND: Several minimally invasive anatomic reconstruction techniques of the lateral ligaments have been introduced for the treatment of chronic lateral ankle instability. However, these strategies may not always follow accurate ligament anatomic attachments, especially in the construction of the fibular bone tunnels. OBJECTIVES: This study reported a new percutaneous technique for reconstruction of the ligaments of lateral ankle anatomically with a Tightrope system. METHODS: From April 2016 to August 2016, 25 ankles of 24 patients with chronic ankle instability underwent our new percutaneous anatomic reconstruction of the lateral ligaments with a Tightrope system. The operation was performed through several small incisions. The fibular tunnel was made obliquely from the anteromedial side of lateral malleolus tip towards retro-malleolar cortex. The graft was fixed in the tunnel with the help of a Tightrope system. The calcaneal tunnel and talar tunnel were made as our previous method. The mean final follow-up was 12.2 months (range 10-14). Visual Analogue Scale for pain, American Orthopaedic Foot and Ankle Society score, and patients' subjective satisfaction were used to measure clinical outcomes. Preoperative and postoperative stress tests were performed and radiographic parameters were measured. RESULTS: The Visual Analogue Scale decreased from 3.0 ± 1.4 to 1.3 ± 0.8 at the last follow-up (p < 0.01). The American Orthopaedic Foot and Ankle Society score was improved from 70.2 ± 5.4 preoperatively to 92.4 ± 5.3 at the final follow-up (p < 0.01). Radiologically, the mean anterior talar displacement was 13.1 ± 2.7 mm preoperatively versus 5.6 ± 1.3 mm at last follow-up (p < 0.01),and the mean varus talar tilt angle was 15.0° ± 2.4° preoperatively versus 5.6° ± 1.9° at the last follow-up (p < 0.01). Patients were satisfied ('excellent' or 'good') in 23 ankles (92%). Two patients reported residual instability but less apprehension than the preoperative condition. CONCLUSIONS: Percutaneous anatomic reconstruction of the lateral ligaments of the ankle with a Tightrope system is an anatomic and effective procedure for the treatment of chronic lateral ankle instability.

Internal fixation combined with bone grafting for large intraosseous calcaneal lipoma: A case report.

Intraosseous lipoma is a rare benign bone tumor that has been reported to occur in the calcaneus and long bones. The etiology of intraosseous lipoma is unknown, although several theories have been proposed. The majority of the cases of intraosseous calcaneal lipoma reported in the literature were localized in the anterior portion of the calcaneus and were treated by curettage and bone grafting. However, for larger lipomas, no specific treatment protocol has been developed to date. We herein present a rare case involving a large intraosseous lipoma of the calcaneus in a 36-year-old man following hindfoot trauma. The lesion was treated by decortication followed by bone grafting and internal fixation, a surgical approach that, to the best of our knowledge, has not been previously described in the literature.

Double calcaneal osteotomy for severe adolescent flexible flatfoot reconstruction.

BACKGROUND: The timing and strategy of treatment for flatfoot still remain controversial. It is a difficult problem when facing severe adolescent flexible flatfoot because a single procedure cannot realign flatfoot deformity effectively. METHODS: We reviewed 13 adolescent flexible flatfoot patients who underwent double calcaneal osteotomy during May 2012 to June 2015. The mean age of patients was 15.2 ± 1.8 (range, 10-18) years. The American Orthopaedic Foot and Ankle Society Ankle-Hindfoot (AOFAS-AH) scores and SF-36 score were adopted to evaluate the preoperative and postoperative functions of the foot. Changes of hindfoot valgus angles, talonavicular uncoverage angles on AP view and talo-first metatarsal angles, and talar pitch angles and calcaneal pitch angles on the lateral film before and after surgery were measured. RESULTS: All 13 patients (15 ft) were followed. The mean duration of follow-up was 34.5 ± 15.7 (range, 21-60) months. The hindfoot valgus angle improved from 16.5 ± 4.1 to 2.9 ± 1.6. On the foot AP view, the mean preoperative and postoperative talonavicular coverage angles were 24.9 ± 8.5 and 6.5 ± 3.6. On the lateral view of the foot, the average preoperative and postoperative talo-first metatarsal angles were 18.1 ± 5.5 and 4.9 ± 4.4. The mean preoperative and postoperative talar pitch angles were 36.4 ± 4.7 and 24.0 ± 5.6. The AOFAS-AH score improved from 68.9 ± 12.3 preoperatively to 94.6 ± 3.9 postoperatively. CONCLUSION: With additional procedures, double calcaneal osteotomy was an effective method for severe adolescent flexible flatfoot.

Proinflammatory Cytokines Stimulate Mitochondrial Superoxide Flashes in Articular Chondrocytes In Vitro and In Situ.

OBJECTIVE: Mitochondria play important roles in many types of cells. However, little is known about mitochondrial function in chondrocytes. This study was undertaken to explore possible role of mitochondrial oxidative stress in inflammatory response in articular chondrocytes. METHODS: Chondrocytes and cartilage explants were isolated from wild type or transgenic mice expressing the mitochondrial superoxide biosensor - circularly permuted yellow fluorescent protein (cpYFP). Cultured chondrocytes or cartilage explants were incubated in media containing interleukin-1ß (10 ng/ml) or tumor necrosis factor-α (10 ng/ml) to stimulate an inflammatory response. Mitochondrial imaging was carried out by confocal and two-photon microscopy. Mitochondrial oxidative status was evaluated by "superoxide flash" activity recorded with time lapse scanning. RESULTS: Cultured chondrocytes contain abundant mitochondria that show active motility and dynamic morphological changes. In intact cartilage, mitochondrial abundance as well as chondrocyte density declines with distance from the surface. Importantly, sudden, bursting superoxide-producing events or "superoxide flashes" occur at single-mitochondrion level, accompanied by transient mitochondrial swelling and membrane depolarization. The superoxide flash incidence in quiescent chondrocytes was ∼4.5 and ∼0.5 events/1000 µm(2)*100 s in vitro and in situ, respectively. Interleukin-1ß or tumor necrosis factor-α stimulated mitochondrial superoxide flash activity by 2-fold in vitro and 5-fold in situ, without altering individual flash properties except for reduction in spatial size due to mitochondrial fragmentation. CONCLUSIONS: The superoxide flash response to proinflammatory cytokine stimulation in vitro and in situ suggests that chondrocyte mitochondria are a significant source of cellular oxidants and are an important previously under-appreciated mediator in inflammatory cartilage diseases.

Central role of E3 ubiquitin ligase MG53 in insulin resistance and metabolic disorders.

Insulin resistance is a fundamental pathogenic factor present in various metabolic disorders including obesity and type 2 diabetes. Although skeletal muscle accounts for 70-90% of insulin-stimulated glucose disposal, the mechanism underlying muscle insulin resistance is poorly understood. Here we show in mice that muscle-specific mitsugumin 53 (MG53; also called TRIM72) mediates the degradation of the insulin receptor and insulin receptor substrate 1 (IRS1), and when upregulated, causes metabolic syndrome featuring insulin resistance, obesity, hypertension and dyslipidaemia. MG53 expression is markedly elevated in models of insulin resistance, and MG53 overexpression suffices to trigger muscle insulin resistance and metabolic syndrome sequentially. Conversely, ablation of MG53 prevents diet-induced metabolic syndrome by preserving the insulin receptor, IRS1 and insulin signalling integrity. Mechanistically, MG53 acts as an E3 ligase targeting the insulin receptor and IRS1 for ubiquitin-dependent degradation, comprising a central mechanism controlling insulin signal strength in skeletal muscle. These findings define MG53 as a novel therapeutic target for treating metabolic disorders and associated cardiovascular complications.