Simple production of resilin-like protein hydrogels using the Brevibacillus secretory expression system and column-free purification.

Resilin, an insect structural protein, has excellent flexibility, photocrosslinking properties, and temperature responsiveness. Recombinant resilin-like proteins (RLPs) can be fabricated into three-dimensional (3D) structures for use as cell culture substrates and highly elastic materials. A simplified, high-yielding production process for RLPs is required for their widespread application. This study proposes a simple production process combining extracellular expression using Brevibacillus choshinensis (B. choshinensis) and rapid column-free purification. Extracellular production was tested using four representative signal peptides; B. choshinensis was found to efficiently secrete Rec1, an RLP derived from Drosophila melanogaster, regardless of the type of signal peptide. However, it was suggested that Rec1 is altered by an increase in the pH of the culture medium associated with prolonged incubation. Production in a jar fermentor with controllable pH yielded 530 mg Rec1 per liter of culture medium, which is superior to productivity using other hosts. The secreted Rec1 was purified from the culture supernatant via (NH4 )2 SO4 and ethanol precipitations, and the purified Rec1 was applied to ring-shaped 3D hydrogels. These results indicate that the combination of secretory production using B. choshinensis and column-free purification can accelerate the further application of RLPs.

Synthesis of cinchona urea polymers using Yamamoto coupling and their application to asymmetric reaction.

Cinchona urea compounds having 3,5-diiodophenyl moieties were subjected to Yamamoto coupling polymerization to afford the chiral urea polymers. These polymers showed high activities as heterogeneous catalysts in asymmetric Michael reactions comparable with those of the corresponding monomeric catalyst in solution systems. Furthermore, the polymeric catalysts are easily recovered from their reaction mixtures due to their insolubility and can be reused several times without loss of catalytic activity.

Effects of sturgeon fillet intake on top-ranked Japanese female long-distance runners.

AIMS: The aim of this study is to investigate whether consumption of sturgeon fillets reduces the oxidative stress marker urinary 8-hydroxy-2'-deoxyguanosine (8OHdG) in top-ranked Japanese female long-distance runners. METHODS: In a before-and-after study, nine professional long-distance female athletes ate 100 g/day of sturgeon fillets for 2 weeks. Urinalysis (8OHdG, an oxidative stress marker, and creatinine), blood tests (fatty acids and 25-hydroxyvitamin D [25OHD]), exercise intensity, subjective fatigue, muscle elasticity, muscle mass, body fat mass, and nutritional intake using image-based dietary assessment (IBDA) were compared before, immediately after, and 1 month after the intervention. RESULTS: Consumption of sturgeon fillets suppressed 8OHdG (p < 0.05) in the increased exercise intensity female athletes. Eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and 25OHD levels in blood increased from before to immediately after and 1 month after the intervention (p < 0.05). IBDA showed that intake of n-3 fatty acid increased after and one month after the intervention, whereas DHA, imidazole dipeptide and vitamin D intake increased after the intervention (p < 0.05) and then decreased after 1 month (p < 0.05). There were no significant changes in subjective fatigue, muscle elasticity, muscle mass, and body fat. CONCLUSIONS: The results suggest that eating sturgeon fillets during intense training may increase blood levels of EPA, DHA, and 25OHD, which may suppress urinary oxidative stress (8OHdG) in top-ranked Japanese long-distance runners.

Fixation of the osteochondral talar fragment yields good results regardless of lesion size or chronicity.

PURPOSE: Osteochondral talar lesions, regardless of their size and/or chronicity, are, at our hospital, now treated by fixation of the fragment if the talar dome cartilage is judged to be healthy. The retrospective study described herein was conducted to assess clinical outcomes of this treatment strategy. METHODS: The study group comprised 44 patients (18 men and 26 women) with 45 such talar lesions. In all cases, the osteochondral fragment was reduced and fixed with bone harvested from the osteotomy site and shaped into peg(s) (one to four pegs per lesion). Median follow-up was 2.1 years (1-9 years). The lesion area was measured on computed tomography arthrographs, and the Japanese Society for Surgery of the Foot (JSSF) ankle/hindfoot scale was used to evaluate postoperative outcomes. Clinical failure was defined as a JSSF score < 80 points. RESULTS: The mean JSSF score improved significantly from 63.5 points preoperatively to 93.0 postoperatively (p < 0.001). Treatment failure occurred in only one ankle (0.02%). The mean lesion area was 51.2 mm2 (range 5-147 mm2). Correlation between lesion areas and the postoperative JSSF scores was weak (r = - 0.133). Correlation between the time of the trauma to the time of fixation surgery and the postoperative JSSF scores was also weak (r = 0.042). Radiographic outcomes were good for 28 ankles, fair for 10, and poor for 7. CONCLUSION: Fixation of the lesion fragment, regardless of size and/or chronicity, appears to be appropriate in cases of an osteochondral talar lesion. LEVEL OF EVIDENCE: IV.

T1ρ mapping of articular cartilage grafts after autologous osteochondral transplantation for osteochondral lesions of the talus: A longitudinal evaluation.

BACKGROUND: Clinical results of autologous osteochondral transplantation (AOT) for treatment of osteochondral lesions of the talus have been mixed. T1ρ imaging can be used to noninvasively detect early cartilage degeneration. PURPOSE OR HYPOTHESIS: To quantitatively assess, by means of T1ρ imaging, changes over time in the biochemical health of grafted cartilage after AOT for osteochondral lesions of the talus. STUDY TYPE: Retrosepctive case series. POPULATION: The study group comprised nine patients who underwent AOT for an osteochondral lesion of the talus and in whom T1ρ mapping was performed 1 and 2 years postoperatively. FIELD STRENGTH/SEQUENCE: 3 Tesla. T1ρ-weighted turbo field echo. ASSESSMENT: The mean T1ρ value of full-thickness cartilage at the repair site and that of full-thickness cartilage elsewhere in the same image (far-field cartilage) were determined. Clinical assessment was based on the American Orthopaedic Foot & Ankle Society (AOFAS) scale. Correlation between the T1ρ ratios (grafted-to-far-field cartilage T1ρ values) and clinical outcomes was examined. STATISTICAL TESTS: Mixed effects model. Pearson correlation analysis. RESULTS: At 1 year, a significant difference existed between the mean T1ρ value of the grafted cartilage (57.0 ± 7.7 ms) and that of the far-field cartilage (41.8 ± 4.6 ms) (P < 0.001). At 2 years, the mean T1ρ value of the grafted cartilage (49.1 ± 6.4 ms) was significantly lower than that at 1 year (P = 0.011). Moderate negative correlation was found between the 1-year T1ρ ratio and 1-year AOFAS score (r = -0.60) and between the 2-year T1ρ ratio and 2-year AOFAS score (r = -0.50). DATA CONCLUSION: Our observation of substantial restoration of the proteoglycan content of the grafted cartilage approximately 2 years after AOT for osteochondral lesions of the talus indicates that the content changes gradually and that the cartilage reparation process is slower than previously believed. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 3 J. MAGN. RESON. IMAGING 2018;48:398-403.

Responsiveness of the Self-Administered Foot Evaluation Questionnaire (SAFE-Q) in patients with hallux valgus.

BACKGROUND: In this study, we investigated the responsiveness of the Self-Administered Foot Evaluation Questionnaire (SAFE-Q) for patient's assessment before and after hallux valgus surgery. METHODS: Patient-reported answers on the SAFE-Q and Short Form-36 (SF-36) before and at a mean of 3-4 and 9-12 months after hallux valgus surgery were analyzed. Data of 100 patients (92 women, eight men) from 36 institutions throughout Japan were used for analysis. RESULTS: In all subscales of the SAFE-Q, the trend of increased scores after surgery was statistically significant (P < 0.001). Among the patients with available scores both before and at 9-12 months after surgery (n = 66), the largest effect sizes (ESs) were observed for shoe-related (1.60), pain and pain-related (1.05), and general health and well-being (0.84) scales. In the SF-36 (n = 64), the largest ES was observed for the bodily pain scale (0.86). Less notable changes were observed for the remaining SF-36 domains. CONCLUSION: The SAFE-Q is the first patient-reported outcome measure which includes a quality of life assessment of shoes. In our cohort, the most remarkable responsiveness was observed for the shoe-related subscale. Based on its responsiveness, the SAFE-Q appears to be sufficient for evaluation of foot-related quality of life before and after surgery.

An Evidence-Based Update on Fixation Procedures for Acute and Chronic Osteochondral Lesions of the Talus.

Osteochondral lesions of the talus (OLT) involve the subchondral bone and the overlying articular cartilage. Various surgical treatments for these lesions are available, such as bone marrow stimulation (BMS), autologous osteochondral grafting, and fixation of an osteochondral fragment. Treatment choice depends on the condition of the lesion, which includes lesion size, morphology, location, and the presence of cysts. Among the surgical procedures available to date, in situ fixation of the osteochondral fragment has the advantage of restoring the articular surface while preserving the native hyaline cartilage and its subchondral bone. Fixation for OLT has been shown to be clinically successful for the treatment of both acute and chronic lesions. Moreover, the indication for osteochondral fragment fixation is expanding as recent studies have found good clinical outcomes in relatively small-sized lesions. The present article describes the current evidence on fixation for acute and chronic OLT.

Validity and reliability of a self-administered foot evaluation questionnaire (SAFE-Q).

BACKGROUND: The Japanese Society for Surgery of the Foot (JSSF) is developing a QOL questionnaire instrument for use in pathological conditions related to the foot and ankle. The main body of the outcome instrument (the Self-Administered Foot Evaluation Questionnaire, SAFE-Q version 2) consists of 34 questionnaire items, which provide five subscale scores (1: Pain and Pain-Related; 2: Physical Functioning and Daily Living; 3: Social Functioning; 4: Shoe-Related; and 5: General Health and Well-Being). In addition, the instrument has nine optional questionnaire items that provide a Sports Activity subscale score. The purpose of this study was to evaluate the test-retest reliability of the SAFE-Q. PATIENTS AND METHODS: Version 2 of the SAFE-Q was administered to 876 patients and 491 non-patients, and the test-retest reliability was evaluated for 131 patients. In addition, the SF-36 questionnaire and the JSSF Scale scoring form were administered to all of the participants. Subscale scores were scaled such that the final sum of scores ranged between zero (least healthy) to 100 (healthiest). RESULTS: The intraclass correlation coefficients were larger than 0.7 for all of the scores. The means of the five subscale scores were between 60 and 75. The five subscales easily separated patients from non-patients. The coefficients for the correlations of the subscale scores with the scores on the JSSF Scale and the SF-36 subscales were all highly statistically significantly greater than zero (p < 0.001). The means for the five JSSF Scale classification groups fell within a relatively narrow range, indicating that the SAFE-Q labels are sufficiently similar to permit their use for all of the JSSF Scale classifications. CONCLUSION: The present study revealed that the test-retest reliability is high for each subscale. Consequently, the SAFE-Q is valid and reliable. In the future, it will be beneficial to test the responsiveness of the SAFE-Q.

Nutritional Status Is Associated With Survival Following Spinal Surgery in Patients With Metastatic Spinal Tumors.

Background Preoperative and postoperative nutritional statuses are reported to influence the outcomes and complications of multidisciplinary treatment, including patient survival. However, a causal relationship between nutritional status and survival following spinal surgery has not been demonstrated in patients with metastatic spinal tumors. The present study was, therefore, designed to evaluate the correlation between the nutritional status and survival following spinal surgery in patients with metastatic spinal tumors. Methods Nutritional status was evaluated using the Japanese version of the modified Glasgow prognostic score (JmGPS), C-reactive protein-to-albumin ratio (CAR), prognostic nutrition index (PNI), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR), which were calculated from the results of preoperative laboratory tests. The survival period was defined as the interval between the day preoperative data were obtained and the day of death. Results Data from 57 of 113 consecutive surgeries were retrieved. The CAR, JmGPS, and PNI were significantly correlated with the survival period (CAR, r = -0.576, P < 0.01; JmGPS, r = -0.537, P < 0.01; PNI, r = 0.316, P = 0.02). Furthermore, patients with 0 points on the JmGPS had significantly longer survival. Using receiver operating characteristic curves, CAR cutoffs of ≥0.880 and ≤0.220 were found to be optimal in predicting the 90- and 180-day postoperative survival, respectively. Conclusions The findings of the present study indicate that preoperative assessment of the JmGPS, CAR, and PNI has utility in estimating nutritional status and predicting survival following spinal surgery in patients with metastatic spinal tumors.

Active Consumption of Konjac and Konjac Products Improves Blood Glucose Control in Patients with Type 2 Diabetes Mellitus.

OBJECTIVE: Konjac is a food mainly consumed in Asian countries with high fiber and low energy. Although glucomannan, a component of konjac, have been used for several clinical studies, there is few reports using konjac itself. This study examined the effects of the active consumption of konjac in patients with type 2 diabetes mellitus (T2DM). METHODS: The study included 26 Japanese patients with T2DM. Participants were recommended to take konjac at least once a day using free konjac products (various noodles, rice, and desserts) and plate konjac for 12 weeks. RESULTS: HbA1c and fasting plasma glucose levels significantly decreased from 8.3 ± 0.9% to 8.0 ± 0.8% and from 173.2 ± 44.4 to 152.8 ± 36.7 mg/dL, respectively. No significant changes were observed in body weight and insulin resistance indices, but the index for insulin secretion significantly increased. Serum high molecular weight adiponectin levels significantly increased. Plasma ghrelin, leptin and glucagon-like peptide-1 levels tended to decrease (p = 0.084), decrease (p = 0.057) and increase (p = 0.071), respectively. Actual konjac intake positively correlated with age (r = 0.61, p = 0.001). Body weight and HbA1c significantly decreased in patients aged ≥50 years than in those aged <50 years, and the changes significantly inversely correlated with age. CONCLUSION: Active consumption of konjac and konjac products seems to be a useful dietary therapy with multifaceted action for T2DM. Further studies with greater sample size and long-term are needed to confirm these findings.

Molecular design of chiral quaternary ammonium polymers for asymmetric catalysis applications.

Repeated reaction between a chiral quaternary ammonium dimer and disodium disulfonate gave a chiral ionic polymer, which showed excellent catalytic activity in the asymmetric benzylation of N-diphenylmethylene glycine tert-butyl ester.

Synthesis of main-chain chiral quaternary ammonium polymers for asymmetric catalysis using quaternization polymerization.

Main-chain chiral quaternary ammonium polymers were successfully synthesized by the quaternization polymerization of cinchonidine dimer with dihalides. The polymerization occurred smoothly under optimized conditions to give novel type of main-chain chiral quaternary ammonium polymers. The catalytic activity of the polymeric chiral organocatalysts was investigated on the asymmetric benzylation of N-(diphenylmethylidene)glycine tert-butyl ester.

Analysis of Whole Limb Alignment in Ankle Arthritis.

A full-length standing posteroanterior radiograph that includes the calcaneus (hip-to-calcaneus radiograph) is obtained for evaluation of the mechanical axis of the entire lower limb in patients with a lower limb condition involving malalignment. Such evaluation clarifies several pathomechanical aspects of hindfoot disorders, facilitates surgical planning, and elucidates factors contributing to unsatisfactory results of a particular operation. Whole limb alignment is influenced not only by the knee joint but also by the ankle joint; thus, knee realignment influences hindfoot alignment and vice versa. It is essential to analyze alignment of the whole limb in planning corrective lower limb surgery.

Synthesis of homo- and copolymer containing sulfonic acid via atom transfer radical polymerization.

Well-defined functional poly(p-phenyl styrenesulfonate) and poly(p-phenyl styrene-sulfonate-co-styrene) were successfully synthesized by the atom transfer radical polymerization (ATRP) using CuBr/bpy(PMDETA) catalyst and 1-phenylethyl bromide (1-PEBr) as an ATRP initiator in diphenyl ether (DPE) or dimethyl formamide (DMF). In both homo- and copolymers, the CuBr/PMDETA catalytic system in DPE or DME showed higher yield than CuBr/bpy and the polydispersity index (PDI) of polymer was low. Using PMDETA or bpy as a ligand in DMF, the high yield with high PDI was obtained than in DPE. We found that the CuBr/PMDETA catalyzed ATRP of p-phenyl styrenesulfonate and copolymerization with styrene comonomer in DPE proceeded in a controlled manner. The polymers containing sulfonic acid were obtained by the chemical deprotection of protecting group, followed by acidification. The molecular structure, molecular weights and thermal properties of the copolymers were determined by nuclear magnetic resonance (1H NMR) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, size exclusion chromatography (SEC), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively.

Supramalleolar Lateral Opening-Wedge Osteotomy in Conjunction With Progressive Collapsing Foot Deformity Reconstruction for PCFD With Ankle Instability.

BACKGROUND: Reconstruction of progressive collapsing foot deformity (PCFD) with ankle instability (PCFD class E) remains a substantial challenge to orthopaedic surgeons. We report the outcomes of PCFD class E treated by means of a relatively standard PCFD foot reconstruction approach with the addition of a supramalleolar lateral opening-wedge osteotomy. METHODS: We conducted a retrospective study of 13 patients (15 ankles) who underwent this procedure for PCFD class E between 2010 and 2021. Mean follow-up time was 3.8 (range, 2-6.3) years. Clinical assessment was based on the Japanese Society for Surgery of the Foot (JSSF) ankle/hindfoot scale as well as a Self-Administered Foot Evaluation Questionnaire (SAFE-Q). Radiographic assessments, including identification of the mechanical ankle joint axis point and a modified valgus Takakura-Tanaka osteoarthritis grade, were recorded. RESULTS: The mean JSSF score improved significantly from 45.2 preoperatively to 83.9 postoperatively (P < .001). SAFE-Q scores at the final follow-up were 70.1 for the pain and pain-related subscale, 75.4 for the physical functioning and daily living subscale, 83.0 for the social functioning subscale, 74.4 for the shoe-related subscale, and 78.1 for the general health and well-being subscale. Radiographic measurements showed improvement in the tibiotalar tilt angle (average improvement: 5.4 degrees); orientation of the talus joint line relative to the ground (average improvement: 14.0 degrees); anteroposterior talus-first metatarsal angle (average improvement: 11.2 degrees), talonavicular coverage angle (average improvement: 21.6 degrees), and lateral talus-first metatarsal angle (average improvement: 17.0 degrees). Postoperatively, the mechanical ankle joint axis point moved medially for all patients and into the medial half of the ankle joint for 7 patients. The modified osteoarthritis stage improved postoperatively in most cases. CONCLUSION: In this select and relatively small group of patients who had a supramalleolar lateral opening-wedge osteotomy combined with PCFD reconstruction, we measured general improvement in JSSF scores and radiographic variables. Long-term durability of the procedure remains unknown. This procedure may be an option for preserving the ankle joint in treatment of PCFD class E with osteoarthritis of the ankle. LEVEL OF EVIDENCE: Level IV, therapeutic.

Development of the patient-based outcome instrument for foot and ankle: part 2: results from the second field survey: validity of the Outcome Instrument for the foot and ankle version 2.

BACKGROUND: The Clinical Outcomes Committee of the Japanese Society for Surgery of the Foot (JSSF) has conducted the second Field Survey of the Outcome Instrument for the Foot and Ankle version 2. METHODS: The survey of the Outcome Instrument version 2, which was composed of 43 items, was performed in 313 patients (154 men and 159 women) who had pathological conditions related to the foot and ankle. Optional sports items in the Outcome Instrument version 2 were analyzed in 123 patients. Internal consistency and construct validity of the Outcome Instrument version 2 were assessed. Correlation of the Outcome Instrument version 2 score with Short Form 36 (SF36) and JSSF scores was analyzed to evaluate criterion validity. RESULTS: Both the EFA and CFA demonstrated good alignment of questionnaire items with their intended subscales in most cases. Sports items were not clearly classified into subgroups. Therefore, it seemed reasonable to use those as a set of questions in a single subscale. The present subscales, having similar names as the SF36 subscales, were closely correlated with the respective subscales. In those cases, the magnitude of the correlation coefficient was >0.6 (p < 0.001) except the present subscale called General Health and Well-being. Comparison of the present scores with JSSF evaluation scores showed satisfactory results except in patients with rheumatoid arthritis. CONCLUSIONS: The Outcome Instrument version 2 demonstrated acceptable psychometric performances as outcome measures for patients with pathological conditions related to the foot and ankle. This outcome instrument would be helpful to evaluate patients with foot and/or ankle impairment. However, the analyses of the test-retest reliability and the influence of background factors such as age and gender, etc., on Outcome Instrument version 2 are needed in the third field survey.

Development of the patient-based outcome instrument for the foot and ankle. Part 1: project description and evaluation of the Outcome Instrument version 1.

BACKGROUND: The Clinical Outcomes Committee of the Japanese Society for Surgery of the Foot conducted a field survey using a novel foot and ankle outcome instrument. We report the development and evaluation of the Outcome Instrument version 1. MATERIALS AND METHODS: A total of 108 potential questions were extracted from literature published in the interval between 1990 and 2006. Tentative subscales proposed were "Degree of Foot Pain," "Foot Pain-related," "Physical Functioning and Daily Living," "Social Functioning" and "General Health and Well-being." After pre-testing in two different groups of patients, the Outcome Instrument version 1, which was composed of 46 items selected from the 108 questions, was administered to 256 patients (111 men and 145 women) with foot-and-ankle-related pathologic conditions and 243 healthy volunteers (125 men and 118 women). Cronbach's alpha coefficients were used for assessment of internal consistency of the instrument. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were utilized for evaluation of construct validity. RESULTS: Neither a ceiling nor floor effect was observed in the responses from the patients. Significant differences were found in the responses to all of the questions between the patients and volunteers (P < 0.01 each). The Cronbach's alpha coefficients for each of the expected subscales indicated high reliability for most of the items and subscales. However, EFA extracted an additional subscale that should be interpreted as something related to shoe or shoe-fit. Further, both EFA and CFA indicated that "Degree of Foot Pain" and "Foot Pain-related" subscales were barely discernable with a factor correlation coefficient of 0.927. CONCLUSIONS: The Committee partly revised the instrument, and the new subscales are as follows: "Foot Pain and Pain-related," "Physical Functioning and Daily Living," "Social Functioning," "General Health and Well-being" and "Shoe-related." Evaluation of the Outcome Instrument version 2 will be reported in the following paper.

Main-chain ionic chiral polymers: synthesis of optically active quaternary ammonium sulfonate polymers and their application in asymmetric catalysis.

A condensation reaction between quaternary ammonium halide and sulfonate was first successfully applied to the synthesis of the chiral polymers. Reaction of bis(quaternary ammonium halide) with disulfonate afforded a polymer containing ionic bonds in its main chain. The chiral ionic polymers were applied to the asymmetric benzylation of N-diphenylmethylidene glycine tert-butyl ester to prepare (S)-phenylalanine derivatives in high yield with a high level of enantioselectivity.

Proposed novel unified nomenclature for range of joint motion: method for measuring and recording for the ankles, feet, and toes.

The Ad Hoc Committee of Terminology of the Japanese Society for Surgery of the Foot (JSSF) proposes novel terminology for motion of the ankle, foot, and toe because there are some ambiguities in the current terminology. Articles were identified by searching the electronic databases of PubMed that compared definitions of American Orthopaedic Foot and Ankle Society (AOFAS), International Society of Biomechanics (ISB), and in the textbook of Kapandji as well as the American Academy of Orthopaedic Surgeons (AAOS). A total of 11 articles described the transverse (horizontal) plane motion in the hindfoot as external rotation/internal rotation and 10 as abduction/adduction. In all, 2 articles described the transverse (horizontal) plane motion in midfoot as external rotation/internal rotation and 10 as abduction/adduction. Another 4 articles described the transverse (horizontal) plane motion in the forefoot as external rotation/internal rotation and 8 as abduction/adduction. Altogether, 109 articles described the sagittal plane motion of the foot/ankle as dorsiflexion/plantarflexion and 20 as extension/flexion. In all, 99 articles described the frontal (coronal) plane motion of the foot/ankle as inversion/eversion and 4 as supination/pronation. Furthermore, 12 articles described the sagittal plane motion of toes as dorsiflexion/plantarflexion and 15 as extension/flexion. Another 16 articles described the frontal (coronal) plane motion of toes as supination/pronation and 1 as inversion/eversion. The transverse (horizontal) plane motion of the foot/ankle was defined as abduction/adduction in the hindfoot, midfoot, and forefoot; the sagittal plane motion of the foot/ankle was defined as dorsiflexion/plantarflexion; and the frontal (coronal) plane motion of the foot/ankle as inversion/eversion. The transverse (horizontal) plane motion of toes was defined as abduction/adduction; the sagittal plane motion of toes was defined as extension/flexion; and the frontal (coronal) plane motion of toes was defined as supination/pronation.

Mechanism of posterior malleolar fracture of the ankle: A cadaveric study.

OBJECTIVES: Ankle fracture treatment involves reduction of the bone fragments and stabilization of the joint by reversing the mechanics of injury. For posterior malleolar fracture however, the true mechanism is not understood, leading to a lack of consistent guidance on how to best treat this injury. METHODS: Fifteen cadaver ankles were subjected to fracture loading that replicated the Lauge-Hansen pronation-external rotation mechanism. An axial load was applied to each specimen, which was mounted on a materials testing machine, and the foot was rotated externally to failure. Digital video cameras recorded the failure sequence of specific anatomic structures. RESULTS: Posterior malleolar fracture occurred in 7 specimens. Of these, 1 was an intra-articular fracture, another was a fracture involving the entire posterior tibial margin consisting of 2 fragments: that of the posterior tubercle and that of the posteromedial margin of the tibial plafond, with the former judged to be a consequence of avulsion by the posterior inferior tibiofibular ligament and the latter a consequence of axial loading from the talus. In the remaining 5 specimens, the posterior malleolar fracture was a small extra-articular avulsion fracture. CONCLUSIONS: Fractures at the posterolateral corner of the distal tibia were shown to be avulsion fractures attributed to the posterior inferior tibiofibular ligament and produced by external rotation of the talus. A fracture involving the entire posterior tibial margin consisting of 2 fragments can be produced by a combination of avulsion by the posterior inferior tibiofibular ligament and axial loading from the talus.