Genome-wide cancer-specific chromatin accessibility patterns derived from archival processed xenograft tumors.

Chromatin accessibility states that influence gene expression and other nuclear processes can be altered in disease. The constellation of transcription factors and chromatin regulatory complexes in cells results in characteristic patterns of chromatin accessibility. The study of these patterns in tissues has been limited because existing chromatin accessibility assays are ineffective for archival formalin-fixed, paraffin-embedded (FFPE) tissues. We have developed a method to efficiently extract intact chromatin from archival tissue via enhanced cavitation with a nanodroplet reagent consisting of a lipid shell with a liquid perfluorocarbon core. Inclusion of nanodroplets during the extraction of chromatin from FFPE tissues enhances the recovery of intact accessible and nucleosome-bound chromatin. We show that the addition of nanodroplets to the chromatin accessibility assay formaldehyde-assisted isolation of regulatory elements (FAIRE), does not affect the accessible chromatin signal. Applying the technique to FFPE human tumor xenografts, we identified tumor-relevant regions of accessible chromatin shared with those identified in primary tumors. Further, we deconvoluted non-tumor signal to identify cellular components of the tumor microenvironment. Incorporation of this method of enhanced cavitation into FAIRE offers the potential for extending chromatin accessibility to clinical diagnosis and personalized medicine, while also enabling the exploration of gene regulatory mechanisms in archival samples.

AAHKS Surgical Techniques & Technologies Award: Inferior Screw Fixation Decreases Acetabular Component Failure Following Revision Total Hip Arthroplasty.

BACKGROUND: Adjunctive screw fixation has been shown to be reliable in achieving acetabular component stability in revision total hip arthroplasty (THA). The purpose of this study was to assess the effect of inferior screw placement on acetabular component failure following revision THA. We hypothesized that inferior screw fixation would decrease acetabular failure rates. METHODS: We reviewed 250 patients who had Paprosky Type II or III defects who underwent acetabular revision between 2001 and 2021 across three institutions. Demographic factors, the number of screws, location of screw placement (superior versus inferior), use of augments and/or cup-cage constructs, Paprosky classification, and presence of discontinuity were documented. Multivariate regression was performed to identify the independent effect of inferior screw fixation on the primary outcome of aseptic rerevision of the acetabular component. RESULTS: At a mean follow-up of 53.4 months (range, 12 to 261), 16 patients (6.4%) required re-revision for acetabular loosening. There were 140 patients (56.0%) who had inferior screw fixation, all of whom did not have neurovascular complications during screw placement. Patients who had inferior screws had a lower rate of acetabular rerevision than those who only had superior screw fixation (2.1 versus 11.8%, P = .0030). Multivariate regression demonstrates that inferior screw fixation decreased the likelihood of rerevision for acetabular loosening when compared to superior screw fixation alone (odds ratio: 0.1, confidence interval: 0.03 to 0.5; P = .0071). No other risk factors were identified. CONCLUSIONS: Inferior screw fixation is a safe and reliable technique to reduce acetabular component failure following revision THA in cases of severe acetabular bone loss.

Assessment of variables that influence agreement between reviewers for Foot & Ankle International.

INTRODUCTION: A common criticism of the peer-review process is the often disparate nature of reviewer recommendations when a decision is rendered which belies the supposed uniformity of the process. The purpose of this investigation was to examine level of agreement between reviewers for Foot & Ankle International (FAI) and analyze variables which may have influenced agreement in order to better understand the peer-review process. METHODS: Approval to conduct this investigation was obtained from the Executive Board and Editor in Chief of FAI. All manuscripts submitted to FAI during the calendar year 2016 which underwent formal peer-review were included in the analysis. For each reviewed manuscript, demographic data was collected regarding specific reviewer and manuscript characteristics in a de-identified manner. RESULTS: 442 manuscripts underwent formal blinded peer-review by two independent reviewers during the study period. Only 199 manuscripts (45%) had a decision rendered in which both reviewers agreed on the same initial recommendation. There were no differences in demographic characteristics between the group of reviewers who agreed as compared to those who disagreed on the initial round of peer review. A similar number of indexed peer-reviewed publications between reviewers correlated with increased levels of agreement. CONCLUSIONS: During the study period, there was 45% initial agreement between reviewers for FAI when assessing the same manuscript. Aside from research productivity, no other reviewer-specific variables examined in this investigation were found to correlate with agreement. Specific recommendations and changes may be considered to increase the efficiency and effectiveness of the peer-review process.

Cavitation Enhancement Increases the Efficiency and Consistency of Chromatin Fragmentation from Fixed Cells for Downstream Quantitative Applications.

One of the most sensitive, time-consuming, and variable steps of chromatin immunoprecipitation (ChIP) is chromatin sonication. Traditionally, this process can take hours to properly sonicate enough chromatin for multiple ChIP assays. Further, the length of sheared DNA is often inconsistent. In order to faithfully measure chemical and structural changes at the chromatin level, sonication needs to be reliable. Thus, chromatin fragmentation by sonication represents a significant bottleneck to downstream quantitative analysis. To improve the consistency and efficiency of chromatin sonication, we developed and tested a cavitation enhancing reagent based on sonically active nanodroplets. Here, we show that nanodroplets increase sonication efficiency by 16-fold and provide more consistent levels of chromatin fragmentation. Using the previously characterized chromatin in vivo assay (CiA) platform, we generated two distinct chromatin states in order to test nanodroplet-assisted sonication sensitivity in measuring post-translational chromatin marks. By comparing euchromatin to chemically induced heterochromatin at the same CiA:Oct4 locus, we quantitatively measure the capability of our new sonication technique to resolve differences in chromatin structure. We confirm that nanodroplet-assisted sonication results are indistinguishable from those of samples processed with traditional sonication in downstream applications. While the processing time for each sample was reduced from 38.4 to 2.3 min, DNA fragment distribution sizes were significantly more consistent with a coefficient of variation 2.7 times lower for samples sonicated in the presence of nanodroplets. In conclusion, sonication utilizing the nanodroplet cavitation enhancement reagent drastically reduces the amount of processing time and provides consistently fragmented chromatin of high quality for downstream applications.

Syndesmotic Screw Breakage May Be More Problematic Than Previously Reported: Increased Rates of Hardware Removal Secondary to Pain With Intraosseous Screw Breakage.

BACKGROUND: The majority of retained syndesmotic screws will either loosen or break once the patient resumes weight-bearing. While evidence is limited, anecdotal experience suggests that intraosseous screw breakage may be problematic for some patients due to painful bony erosion. This study seeks to identify the incidence of intraosseous screw breakage, variables that may predict intraosseous screw breakage, and whether intraosseous screw breakage is associated with higher rates of implant removal secondary to pain. METHODS: Five hundred thirty-one patients undergoing syndesmotic stabilization were screened, of which 43 patients (with 58 screws) experiencing postoperative screw breakage met inclusion criteria. Patient charts were retrospectively reviewed for demographic data, comorbidities, time to screw breakage, location of screw breakage, and implant removal. Several radiographic parameters were evaluated for their potential to influence the site of screw breakage. RESULTS: Intraosseous screw breakage occurred in 32 patients (74.4%). Screw breakage occurred exclusively in the tibiofibular clear space in the remaining 11 instances (25.6%). Intraosseous screw breakage was significantly associated with eventual implant removal after breakage (P = .034). Screws placed further from the tibiotalar joint were at less risk for intraosseous breakage (odds ratio 0.818, P = .002). Screws placed at a threshold height of 20 mm or greater were more likely to break in the clear space (odds ratio 12.1, P = .002). CONCLUSION: Syndesmotic screw breakage may be more problematic than previously described. Intraosseous breakage was associated with higher rates of implant removal secondary to pain in this study. Placement of screws 20 mm or higher from the tibiotalar joint may decrease risk of intraosseous breakage.Levels of Evidence: Level III: Retrospective study.

No Difference in Perioperative Complications for Bilateral Total Knee Arthroplasty Staged at 1 Week Compared With Delayed Staging.

INTRODUCTION: Controversy exists regarding the safety of simultaneous bilateral total knee arthroplasty (TKA) versus two TKA procedures staged months apart in patients with bilateral knee arthritis. Here, we investigated a third option: bilateral TKA staged 1 week apart. In this study, we examined the rate of complications in patients undergoing bilateral TKA staged at 1 week compared with longer time intervals. METHODS: A retrospective review of 351 consecutive patients undergoing bilateral TKA at our institution was conducted. Patients underwent a 1-week staged bilateral procedure with planned interim transfer to a subacute rehabilitation facility (short-staged) or two separate unilateral TKA procedures within 1 year (long-staged). Binary logistic regression was used to compare outcomes while controlling for year of surgery, patient age, body mass index, and Charlson Comorbidity Index. RESULTS: Two hundred four short-staged and 147 long-staged bilateral TKA patients were included. The average interval between procedures in long-staged patients was 200.9 ± 95.9 days. Patients undergoing short-staged TKA had a higher Charlson Comorbidity Index (3.0 ± 1.5 versus 2.6 ± 1.5, P = 0.017) with no difference in preoperative hemoglobin ( P = 0.285) or body mass index ( P = 0.486). Regression analysis demonstrated that short-staged patients had a higher likelihood of requiring a blood transfusion (odds ratio 4.015, P = 0.005) but were less likely to return to the emergency department within 90 days (odds ratio 0.247, P = 0.001). No difference was observed in short-term complications ( P = 0.100), 90-day readmissions ( P = 0.250), or 1-year complications ( P = 0.418) between the groups. CONCLUSION: Bilateral TKA staged at a 1-week interval is safe with a comparable complication rate with delayed staged TKA, but allows for a faster total recovery time. LEVEL OF EVIDENCE: Level III.

Validation of a combined ultrasound and bioluminescence imaging system with magnetic resonance imaging in orthotopic pancreatic murine tumors.

Preclinical mouse solid tumor models are widely used to evaluate efficacy of novel cancer therapeutics. Recent reports have highlighted the need for utilizing orthotopic implantation to represent clinical disease more accurately, however the deep tissue location of these tumors makes longitudinal assessment challenging without the use of imaging techniques. The purpose of this study was to evaluate the performance of a new multi-modality high-throughput in vivo imaging system that combines bioluminescence imaging (BLI) with robotic, hands-free ultrasound (US) for evaluating orthotopic mouse models. Long utilized in cancer research as independent modalities, we hypothesized that the combination of BLI and US would offer complementary advantages of detection sensitivity and quantification accuracy, while mitigating individual technological weaknesses. Bioluminescent pancreatic tumor cells were injected into the pancreas tail of C57BL/6 mice and imaged weekly with the combination system and magnetic resonance imaging (MRI) to serve as a gold standard. BLI photon flux was quantified to assess tumor activity and distribution, and US and MRI datasets were manually segmented for gross tumor volume. Robotic US and MRI demonstrated a strong agreement (R2 = 0.94) for tumor volume measurement. BLI showed a weak overall agreement with MRI (R2 = 0.21), however, it offered the greatest sensitivity to detecting the presence of tumors. We conclude that combining BLI with robotic US offers an efficient screening tool for orthotopic tumor models.

Development of a Robotic Shear Wave Elastography System for Noninvasive Staging of Liver Disease in Murine Models.

Shear wave elastography (SWE) is an ultrasound-based stiffness quantification technology that is used for noninvasive liver fibrosis assessment. However, despite widescale clinical adoption, SWE is largely unused by preclinical researchers and drug developers for studies of liver disease progression in small animal models due to significant experimental, technical, and reproducibility challenges. Therefore, the aim of this work was to develop a tool designed specifically for assessing liver stiffness and echogenicity in small animals to better enable longitudinal preclinical studies. A high-frequency linear array transducer (12-24 MHz) was integrated into a robotic small animal ultrasound system (Vega; SonoVol, Inc., Durham, NC) to perform liver stiffness and echogenicity measurements in three dimensions. The instrument was validated with tissue-mimicking phantoms and a mouse model of nonalcoholic steatohepatitis. Female C57BL/6J mice (n = 40) were placed on choline-deficient, L-amino acid-defined, high-fat diet and imaged longitudinally for 15 weeks. A subset was sacrificed after each imaging timepoint (n = 5) for histological validation, and analyses of receiver operating characteristic (ROC) curves were performed. Results demonstrated that robotic measurements of echogenicity and stiffness were most strongly correlated with macrovesicular steatosis (R2  = 0.891) and fibrosis (R2  = 0.839), respectively. For diagnostic classification of fibrosis (Ishak score), areas under ROC (AUROCs) curves were 0.969 for ≥Ishak1, 0.984 for ≥Ishak2, 0.980 for ≥Ishak3, and 0.969 for ≥Ishak4. For classification of macrovesicular steatosis (S-score), AUROCs were 1.00 for ≥S2 and 0.997 for ≥S3. Average scanning and analysis time was <5 minutes/liver. Conclusion: Robotic SWE in small animals is feasible and sensitive to small changes in liver disease state, facilitating in vivo staging of rodent liver disease with minimal sonographic expertise.

Amphiphilic phospholipid-iodinated polymer conjugates for bioimaging.

Amphiphilic phospholipid-iodinated polymer conjugates were designed and synthesized as new macromolecular probes for a highly radiopaque and biocompatible imaging technology. Bioconjugation of PEG 2000-phospholipids and iodinated polyesters by click chemistry created amphiphilic moieties with hydrophobic polyesters and hydrophilic PEG units, which allowed their self-assemblies into vesicles or spiked vesicles. More importantly, the conjugates exhibited high radiopacity and biocompatibility in in vitro X-ray and cell viability measurements. This new type of bioimaging contrast agent with a Mn value of 11 289 g mol-1 was found to have a significant X-ray signal at 3.13 mg mL-1 of iodine equivalent than baseline and no cytotoxicity after 48 hours incubation of with HEK and 3T3 cells at 20 µM (20 picomoles) concentration of conjugates per well. The potential of adopting the described macromolecular probes for bioimaging was demonstrated, which could further promote the development of a field-friendly and highly sensitive bioimaging contrast agent for point-of-care diagnostic applications.

Medial tenderness revisited: Is medial ankle tenderness predictive of instability in isolated lateral malleolus fractures?

INTRODUCTION: Determining deltoid ligament incompetence in supination external rotation (SER) injuries commonly relies on stress radiography, given several studies demonstrating low predictive value of physical examination. Stress radiography can be difficult to obtain and may result in suboptimal radiographs with equivocal determination of stability. This study revisits the concept of medial ankle tenderness and its association with mortise instability. METHODS: Patients who presented with an isolated lateral malleolus fracture underwent prospective data collection. VAS scores were recorded with palpation at the lateral malleolar fracture site, anterior deltoid ligament, and posterior deltoid ligament. Three non-weightbearing radiographs of the ankle and a gravity stress view were obtained. Statistical analysis was performed to determine a correlation between tenderness and instability defined as MCS widening > 4 mm on gravity stress x-ray. RESULTS: 51 patients met inclusion criteria. Group I (stable) and Group II (unstable) demonstrated no difference in tenderness over the lateral malleolus (p = 0.94) or anterior deltoid (p = 0.12), but patients in Group II reported significantly more tenderness over the posterior deltoid (p = 0.03). Taking the higher pain score from either anterior or posterior deltoid palpation, patients with unstable ankle fractures reported significantly more tenderness with medial palpation (p = 0.02). The relative risk of having an unstable ankle fracture with any tenderness to palpation over either the anterior or posterior deltoid ligament was 1.77 (95% CI 1.03 - 3.06, P = 0.039). When comparing no pain versus the presence of any pain with palpation medially, the sensitivity for any medial tenderness to detect an unstable ankle fracture was 0.76 (specificity 0.59, PPV 0.79, NPV 0.56). CONCLUSION: Patients with any medial tenderness were at significantly higher risk of having an unstable SER ankle fracture in this study, but strict reliance on the presence or absence of medial tenderness without stress radiographs would lead to an unacceptable number of both false positive and false negative determinations of instability. However, our findings suggest that medial tenderness is associated with instability. The 0.79 PPV of any medial tenderness for instability may be useful to cast doubt on equivocal stress radiography and prompt surgeons to repeat stress radiography or shorten the interval for radiographic follow up. LEVEL OF EVIDENCE: Diagnostic study, Level II-1 (development of diagnostic criteria on basis of consecutive patients [with universally applied reference "gold" standard]).

Online Ratings and Reviews of American Orthopaedic Foot and Ankle Surgeons.

Background. Utilization of physician rating websites continues to expand. There is limited information on how these websites function and influence patient perception and physicians' practices. No study to our knowledge has investigated online ratings and comments of orthopaedic foot and ankle surgeons. We identified factors impacting online ratings and comments for this subset of surgeons. Methods. 210 orthopaedic foot and ankle surgeons were selected from the American Orthopaedic Foot and Ankle Society (AOFAS) website. Demographic information, ratings, and comments were reviewed on the 3 most visited public domain physician ratings websites: HealthGrades.com , Vitals.com, and Ratemds.com. Content differences between positive and negative comments were evaluated. Results. The mean review rating of 4.03 ± 0.57 out of 5 stars. 84% of the total number of ratings were either 1 star (17%) or 5 stars (67%). Most positive comments related to outcome, physician personality, and communication, whereas most negative comments related to outcome, bedside manner, and waiting time. χ2 Analyses revealed statistically significant proportions of positive comments pertaining to surgeon-dependent factors (eg, physician personality, knowledge, skills) and negative comments concerning surgeon-independent factors (eg, waiting time, logistics). Conclusion. This study examined online ratings and written comments of orthopaedic foot and ankle surgeons. Surgeons had a generally favorable rating and were likely to have positive comments. Patients were likely to write positive comments about surgeon personality and communication, and negative comments pertaining to bedside manner and waiting time. Knowledge and management of online content may allow surgeons to improve patient satisfaction and online ratings. Level of Evidence: Level IV.

Prevalence of Incidental Benign and Malignant Lesions on Radiographs Ordered by Orthopaedic Surgeons.

BACKGROUND: Radiographs are the most commonly available diagnostic imaging modalities used to evaluate orthopaedic conditions. In addition to suspected findings based on the initial indication to obtain radiographic images, incidental findings may be observed as well, some of which may have notable medical and legal ramifications. This study evaluates the number of incidental findings reported from orthopaedic radiographs ordered in an academic orthopaedic multispecialty group over 1 year. METHODS: A retrospective review was conducted of 13,948 eligible radiographs recorded at our institution over a 12-month period. Reports were categorized based on examination type. Incidental findings were categorized as having concern for possible malignancy versus likely benign conditions. The possibly malignant findings were then further subdivided into either bone or lung malignancies. The benign findings were subcategorized by etiology and anatomic location. RESULTS: Thirteen thousand nine hundred forty-eight radiographs were evaluated, and 289 (2.07%) incidental findings were identified. The three study categories with the highest prevalence of incidental findings were spine (3.96%), leg length alignment (3.94%), and pelvic and hip (2.81%) radiographs. The three most common types of incidental findings identified were for possible malignancy or metastases in bone (30.1%), benign bone disease (24.9%), and gastrointestinal conditions (6.57%). Follow-up was recommended for 122 (42.2%) incidental findings. DISCUSSION: This study describes the prevalence of incidental findings on orthopaedic radiographs in adults. Axial radiographs such as of the spine and pelvis are more likely to report an incidental finding as opposed to appendicular radiographs of distal extremities. The exception is leg alignment radiographs that include the entire lower extremity and pelvis and image a larger area of the body. Nearly one-third of incidental findings were suspicious for possible malignancy or metastases. Additional diagnostic workup with focused imaging is often recommended. This information is useful to orthopaedic surgeons who read their own radiographs (without formal radiologist interpretation) to increase awareness of common, concerning incidental findings that may be missed and warrant additional follow-up. LEVEL OF EVIDENCE: Level III.

Arthrofibrosis of the Ankle.

Arthrofibrosis is a common, but often overlooked, condition that imparts significant morbidity following injuries and surgery to the foot and ankle. The most common etiologies are related to soft tissue trauma with subsequent fibrotic and contractile scar tissue formation within the ligaments and capsule of the ankle. This leads to pain, alterations in gait, and ankle dysfunction. Initial treatment often includes extensive physical therapy, however, if severe enough surgical options exist. Although the literature regarding ankle arthrofibrosis is scarce, this review article provides a greater understanding of the pathogenesis of arthrofibrosis and describes the current and future therapeutic options to treat fibrotic joints. Level of Evidence: Level V, expert opinion.

Getting the Starting Point Right: Prevention of Skiving and Fibular Cortical Breach During Suture Button Placement for Syndesmotic Ankle Injuries.

The use of suture button (SB) devices in the treatment of syndesmotic ankle injuries is increasing. These constructs have demonstrated better syndesmotic reduction, improved clinical outcomes, and lower rates of hardware removal compared with screw fixation. However, placing a SB device without a fibular plate can be technically challenging. In this technique tip, we use an illustrative case to demonstrate a technique tip that minimizes the risk of anterior or posterior cortical breach of the fibula and helps facilitate more accurate placement of a SB device.Levels of Evidence: Level V: Expert opinion.

Peri-implant fractures around hindfoot fusion nails: A systematic literature review and classification system.

BACKGROUND: Tibio-talo calcaneal (TTC) arthrodesis is increasingly performed for hindfoot arthrosis and other indications. Peri-implant fracture around hindfoot fusion nails has been previously reported and can be problematic to treat given multiple surgical considerations including the status of hindfoot arthrodesis at time of fracture. We present a systematic review of the literature regarding peri-implant fractures around hindfoot fusion nails and propose a classification system to help guide treatment based on findings from the current literature as well as the collective experience of the senior authors. METHODS: A review of the literature was conducted in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to identify clinical investigations in which peri-implant fractures or other hardware failures were observed as complications following TTC arthrodesis using hindfoot nails. The electronic database of PubMed/Medline/Cochrane Library was explored using specific search terms. Inclusion criteria was any clinical investigation that reported on outcomes after TTC arthrodesis using a hindfoot nail in at least one patient. Cadaveric and non-clinical investigations were excluded. RESULTS: A total of 36 studies were identified which met inclusion criteria and reported clinical outcomes after TTC arthrodesis using a hindfoot fusion nail. Of the 36 studies, there was a total of 13 intraoperative fractures, 43 tibial stress fractures and 24 peri-implant fractures recorded in 12 of the 36 studies. CONCLUSION: Peri-implant fracture following tibio-talo calcaneal arthrodesis using a hindfoot intramedullary nail is an uncommon but problematic condition to treat. General heterogeneity of patients and indications as well as a lack of descriptive detail in the current literature makes meta-analysis difficult. Given the lack of consensus on treatment, a classification system may be helpful to guide clinical practice.

Gunshot-Related Injuries to the Foot & Ankle: Review Article.

Gunshot-related injuries remain a significant and important cause of global morbidity and cost. The foot and ankle has certain anatomic and functional considerations that make gunshot-related injuries challenging to manage. While the scientific literature regarding gunshot-related injuries is extensive, little of the existing literature focuses on the foot and ankle. While principles of management can be somewhat extrapolated from the current literature, an understanding of the body of work specific to the foot and ankle is valuable. Therefore, this review provides an overview of ballistic injuries to the foot and ankle as well as specific guidelines to aid surgeons in treating these difficult injuries. Level of Evidence: Level V, expert opinion.

Syndesmotic Fixation Utilizing a Novel Screw: A Retrospective Case Series Reporting Early Clinical and Radiographic Outcomes.

Background. Syndesmotic disruption occurs in 20% of ankle fractures and requires anatomical reduction and stabilization to maximize outcomes. Although screw breakage is often asymptomatic, the breakage location can be unpredictable and result in painful bony erosion. The purpose of this investigation is to report early clinical and radiographic outcomes of patients who underwent syndesmotic fixation using a novel metal screw designed with a controlled break point. Methods. We performed a retrospective review of all patients who underwent syndesmotic fixation utilizing the R3lease Tissue Stabilization System (Paragon 28, Denver, CO) over a 12-month period. Demographic and screw-specific data were obtained. Postoperative radiographs were reviewed, and radiographic parameters were measured. Screw loosening or breakage was documented. Results. 18 patients (24 screws) met inclusion criteria. The mean follow-up was 11.7 months (range = 6.0-14.7 months). 5/24 screws (21%) fractured at the break point. No screw fractured at another location, nor did any fracture prior to resumption of weight bearing; 19 screws did not fracture, with 8/19 intact screws (42.1%) demonstrating loosening. There was no evidence of syndesmotic diastasis or mortise malalignment on final follow-up. No screws required removal during the study period. Conclusion. This study provides the first clinical data on a novel screw introduced specifically for syndesmotic fixation. At short-term follow up, there were no complications and the R3lease screw provided adequate fixation to allow healing and prevent diastasis. Although initial results are favorable, longer-term follow-up with data on cost comparisons and rates of hardware removal are needed to determine cost-effectiveness relative to similar implants.Level of Evidence: Level IV: Retrospective case series.

Does fracture obliquity in Weber B fibula fractures correlate with mortise instability?

BACKGROUND: The diagnosis of instability in the apparent, isolated distal fibula fracture can be challenging and often necessitates stress radiography. Danis & Weber classified lateral malleolar fractures based on the level of the fracture in relation to the syndesmosis. While Weber B fractures occur at the level of the syndesmosis, some such injuries present with a long, oblique pattern extending well above the syndesmosis. Given the well-established literature demonstrating that fractures above the syndesmosis correlate with a higher level of concomitant syndesmotic and deltoid ligament injury, we hypothesize that increased fracture obliquity, length and height of Weber B fibula fractures similarly correlates with increased mortise instability. METHODS: All patients with isolated Weber B fibula fractures who underwent gravity stress radiography met inclusion criteria. Fracture height was measured on mortise radiographs as: (1) the distance from the distal tip of the fibula to fracture apex, (2) the distance to the fracture apex as measured on a line drawn perpendicular to a line parallel to the plafond, (3) an angle subtended by a line drawn parallel to the plafond and a line drawn to the fracture apex and (4) a ratio of the absolute length as compared to fibular width. RESULTS: 51 patients were included in the study. The group of 39 patients with stable ankles had a mean medial clear space of 3.12 ±â€¯0.65 mm (range, 1.5 mm to 4.0 mm). The group of 12 patients with unstable ankles had a mean medial clear space of 6.29 ±â€¯3.11 mm (range, 4.1 mm to 14.0 mm). These groups showed no significant difference in fracture angle (p = 0.93), fracture height from plafond (p = 0.49), fracture height from tip of fibula (p = 0.42), and as a ratio of absolute length to fibular width (p = 0.85). CONCLUSION: Increased fracture obliquity, length and height of Weber B fibula fractures did not correlate with a higher incidence of mortise instability. Despite the lack of positive correlation, future studies should continue to investigate and identify radiographic parameters of distal fibula fractures that are most predictive of instability.

Flexible fixation for ligamentous lisfranc injuries.

Lisfranc injuries require anatomic reduction and stabilization of the tarsometatarsal joints. We describe a novel technique that provides flexible fixation that is simple, cost-effective and that may offer certain advantages over more traditional techniques.

Ankle gravity stress view in the seated position: A technical tip.

The ankle gravity stress view (GSV) is often utilized to elucidate instability in patients with an apparent, isolated lateral malleolus fracture. While this has been demonstrated to have advantages over the manual external rotation stress test, positioning in the lateral decubitus position can be difficult, uncomfortable and time-intensive. We report a simple and safe technique that allows one to obtain a gravity stress view of the ankle with the patient seated.