Concentration of voxelotor in sickle cell disease can be estimated using electrophoresis and high-performance liquid chromatography.

OBJECTIVES: Voxelotor can increase hemoglobin levels in patients living with sickle cell disease (SCD). A clinician who is monitoring voxelotor response may want to know whole-blood voxelotor concentration, but this cannot be measured in most clinical settings. However, voxelotor has been demonstrated to cause "peak splitting" in common methods of hemoglobin measurement such as capillary zone electrophoresis (CZE) and high-performance liquid chromatography (HPLC). We hypothesized that we could use the size of the peak split to estimate the whole-blood concentration. METHODS: Blood from people with SCD was dosed with known concentrations of voxelotor, and multiparameter regression was used to derive the relationship of voxelotor concentration to the degree of peak splitting observed. To validate these equations, 21 patients started on voxelotor at 1500 mg/d had blood samples drawn at days 0, 14, 30, and 60. Samples were sent out for gold standard voxelotor concentration testing. The derived equations were then used to calculate voxelotor concentration. RESULTS: Calculated concentrations correlated strongly with measured concentrations for both CZE (R2 = 0.83, P < .001) and HPLC (R2 = 0.76, P < .001). Voxelotor concentration also had a significant effect on increases in hemoglobin (R2 = 0.40, P < .001). CONCLUSIONS: Thus, peak splitting CZE and HPLC can be used to estimate voxelotor concentration.

Trifocal femur fracture with intracapsular femoral neck, open diaphyseal, and distal complete articular fractures.

We describe a trifocal femur injury with intracapsular femoral neck fracture, diaphyseal fracture with bone loss, and distal complete articular (AO/OTA C type) fracture, an injury rarely described in the literature. Surgical management utilized a not-yet-reported implant combination: screw-side plate device for the intracapsular femoral neck, retrograde nail for the diaphysis, and lag screws plus mini fragment buttress plating for the distal fracture. The patient had uneventful fracture union with no changes in alignment. Given the rarity and complexity of this injury, there is little consensus on surgical technique and implant choice. This case demonstrates a modernized approach that may be useful for surgeons who encounter similar fracture patterns in their practice.

Interfragmentary strain measurement post-fixation to guide intraoperative decision making: a narrative review.

PURPOSE: Interfragmentary strain influences whether a fracture will undergo direct and indirect fracture healing. Orthopedic trauma surgeons modulate strain and create optimal biomechanical environments for specific fracture patterns using fixation constructs. However, objective intraoperative interfragmentary strain measurement does not currently inform fixation strategy in common practice. This review identifies potential methods and technologies to enable intraoperative strain measurement for guiding optimal fracture fixation strategies. METHODS: PubMed, Scopus, and Web of Science were methodologically queried for manuscripts containing terms related to "bone fracture," "strain," "measurement," and "intraoperative." Manuscripts were systematically screened for relevance and adjudicated by three reviewers. Relevant articles describing methods to measure interfragmentary strain intraoperatively were summarized. RESULTS: After removing duplicates, 1404 records were screened initially. There were 49 manuscripts meeting criteria for in-depth review. Of these, four reports were included in this study that described methods applicable to measuring interfragmentary strain intraoperatively. Two of these reports described a method using instrumented staples, one described optical tracking of Kirschner wires, and one described using a digital linear variable displacement transducer with a custom external fixator. CONCLUSION: The four reports identified by this review describe potential methods to quantify interfragmentary strain after fixation. However, further studies are needed to confirm the precision and accuracy of these measurements across a range of fractures and fixation methods. Additionally, described methods require the insertion and likely removal of additional implants into the bone. Ideally, innovations that measure interfragmentary strain intraoperatively would provide dynamic biomechanical feedback for the surgeon to proactively modulate construct stability.

Distal Tibia Apex Posterior Angulation: A Normal Anatomic Variant Related to Hindfoot Alignment With Side-to-Side Symmetry.

OBJECTIVES: The sagittal plane of the distal tibia has not been well-described. This study sought to characterize sagittal plane morphology, determine symmetry from side to side, and identify differences based on hindfoot alignment. METHODS: One hundred twelve bilateral lateral weight-bearing ankle radiographs were retrospectively evaluated (224 ankles). Hindfoot alignment was classified as neutral, planus, or cavus using the Meary angle. The angle between the diaphyseal and distal tibia axes was measured, and the apex location relative to the plafond was recorded. RESULTS: A mean distal tibia apex posterior angulation (DTAPA) of 2.0° (range -2° to 7°, SD = 2.06°) was located 8.0 cm proximal to the plafond. No difference was observed from side to side in DTAPA magnitude (P = 0.36) or location (P = 0.90). Planus alignment was associated with a significantly greater DTAPA (3.05°) as compared with neutral (1.89°) (P = 0.002) and cavus (1.25°) (P < 0.001) alignment. CONCLUSION: The distal tibia has an apex posterior angulation, suggesting that the true anatomic axis of the tibia terminates just posterior to the plafond center. Hindfoot alignment is related to distal tibia morphology. DTAPA symmetry indicates that contralateral imaging can be used to guide reconstruction of patient-specific anatomy and alignment. Knowledge of the DTAPA may help mitigate sagittal malalignment during distal tibia fracture surgery.

Updated Blocking Techniques for Lower Extremity Medullary Nailing: Beyond the Concavity of Deformity.

Modern blocking techniques are useful to achieve anatomic alignment and stable fixation during end-segment nailing. Whether with screws or drill bits, blocking implants can correct both angular and translational deformities. Understanding the biomechanics of blocking implants allows the surgeon to properly plan their placement based on principles rather than dogma. We use case examples to highlight updates in blocking techniques during acute surgical fixation and chronic deformity correction.

Irreducible posterior hip dislocation in the setting of a multifocal displaced pelvic ring injury: A case report.

Case report: Traumatic hip dislocations require prompt diagnosis and reduction to preserve the native joint. The classic irreducible posterior hip fracture-dislocation has been described as an immobile, slightly flexed, and internally rotated hip on physical exam. Classically, this irreducible pattern is associated with an ipsilateral femoral head fracture. The purpose of our report is to present an irreducible posterior hip dislocation with preserved motion in the setting of an unstable pelvic ring injury without associated femoral head pathology. Despite lacking clinical features of an irreducible hip, closed reduction in the emergency and operating rooms was unsuccessful, even after frame application for pelvis stability. Persistent irreducibility necessitated open reduction, where the femoral head was found to be buttonholed through the posterior hip capsule and blocking reduction. Conclusion: A posteriorly dislocated hip with preserved motion in the setting of a concomitant unstable pelvic ring injury may belie the true locked nature of the femoroacetabular dislocation and high suspicion for femoral head incarceration is required. The description of this unique irreducible fracture pattern and the stepwise approach used for reduction may be useful for other surgeons who may encounter similar patterns of injury.

Apex posterior angulation of the humerus: A characterization of normal sagittal plane anatomy with implications for surgical fixation.

INTRODUCTION: An understanding of the sagittal plane morphology of the humerus is relevant during surgical fixation of humeral fractures but is not well described in the literature. The purpose of this study was to better characterize the native sagittal plane morphology of the humerus. MATERIALS AND METHODS: 170 patients with uninjured full length lateral humerus radiographs were retrospectively evaluated. The angle between the proximal humeral diaphyseal axis and the distal humeral diaphyseal axis was identified and measured. The proximal axis was defined by two points equidistant from the anterior and posterior cortex 10 mm and 100 mm distal to the metaphyseal flare, and the distal axis by two points at 10 mm and 50 mm proximal to the capitellum/trochlea. The relative location of the center of rotation of angulation (CORA) was calculated as a percentage of humeral length. RESULTS: 114 radiographs were included in the analysis (66 right humeri, 48 left humeri). The average apex posterior angulation was 6.5 +/- 2.9°. The CORA occurred at an average of 80% (SD+/-13%) of the length of the humerus (proximal to distal). Total humeral length and absolute distance to CORA were greater in males compared to females (364 ± 50 mm versus 326 ± 30 mm; p<0.001; 290 ± 68 mm versus 260 ± 48 mm; p=0.003), but there were no significant sex differences with respect to magnitude of the apex posterior angulation (p=0.077) or location of CORA as a percentage of total humeral length (p=0.916). There were no statistically significant associations between age and total humeral length (p=0.056), distance to CORA (p=0.130), location of CORA as percentage of total humeral length (p=0.753), or magnitude of angulation (p=0.075). CONCLUSION: An apex posterior bow consistently exists in the distal one-quarter of the humerus that is consistent across ages and between sexes. This normal anatomic bow is important to recognize to avoid an extension malreduction and has implications for implant fit and contouring.

Traumatic Proximal Femoral Fractures during COVID-19 Pandemic in the US: An ACS NSQIP® Analysis.

In order to determine the impact of COVID-19 on the treatment and outcomes in patients with proximal femoral fracture's (PFF), we analyzed a national US sample. This is a retrospective review of American College of Surgery's (ACS) National Surgical Quality Improvement Program (NSQIP) for patients with proximal femoral fractures. A total of 26,830 and 26,300 patients sustaining PFF and undergoing surgical treatment were sampled during 2019 and 2020, respectively. On multivariable logistic regression, patients were less likely to have 'presence of non-healing wound' (p < 0.001), functional status 'independent' (p = 0.012), undergo surgical procedures of 'hemiarthroplasty'(p = 0.002) and 'ORIF IT, Peritroch, Subtroch with plates and screws' (p < 0.001) and to be 'alive at 30-days post-op' (p = 0.001) in 2020 as compared to 2019. Patients were more likely to have a case status 'emergent', 'loss of ≥10% body weight', discharge destination of 'home' (p < 0.001 for each) or 'leaving against medical advice' (p = 0.026), postoperative 'acute renal failure (ARF)' (p = 0.011), 'myocardial infarction (MI)' (p = 0.006), 'pulmonary embolism (PE)' (p = 0.047), and 'deep venous thrombosis (DVT)' (p = 0.049) in 2020 as compared to 2019. Patients sustaining PFF and undergoing surgical treatment during pandemic year 2020 differed significantly in preoperative characteristics and 30-day postoperative complications when compared to patients from the previous year.

A Single Proximal Interlocking Bolt May Be Sufficient for Retrograde Nailing of Extra-articular Femur Fractures.

OBJECTIVE: To evaluate whether a single proximal interlocking bolt was sufficient during the treatment of extra-articular femur fractures with retrograde medullary nailing. DESIGN: Retrospective comparative study. SETTING: Academic Level 1 trauma center. PATIENTS: The study included 136 patients with extra-articular femur fractures treated with retrograde medullary nailing who met inclusion and follow-up criteria. INTERVENTION: The intervention included surgical treatment for a femur fracture with retrograde medullary nailing, with comparisons made between those treated with a single proximal interlocking (1 IL) bolt and those treated with 2 proximal interlocking bolts (2 IL). MAIN OUTCOME MEASUREMENT: The main outcome measurements were as follows: (1) rate of nonunion and (2) rate of catastrophic implant failure. RESULTS: There was no difference in the rate of nonunion requiring surgical intervention between the 2 groups. There were no catastrophic failures in either group. CONCLUSIONS: A single proximal interlocking bolt may be sufficient when using retrograde nailing for the treatment of extra-articular femur fractures. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Triceps Surae Lengthening in Foot and Ankle Trauma: A Survey of OTA and AOFAS Members.

Background: The prevalence, indications, and preferred methods for gastrocnemius recession and tendo-Achilles lengthening-grouped as triceps surae lengthening (TSL) procedures-in foot and ankle trauma are supported by a scarcity of clinical evidence. We hypothesize that injury, practice environment, and training heritage are significantly associated with probability of performing adjunctive TSL in the operative management of foot and ankle trauma. Methods: A survey was distributed to members of the American Orthopaedic Foot & Ankle Society and the Orthopaedic Trauma Association. Participants rated how likely they would be to perform TSL at initial management, definitive fixation, and after weightbearing in the presence and absence of a positive Silfverskiöld test in 10 clinical scenarios of closed foot and ankle trauma. Results: A total of 258 surgeons with median 14 years' experience responded. Eighty-five percent reported foot and ankle fellowship training, 24% reported traumatology fellowship training, 13% both, and 4% no fellowship. Ninety-nine percent reported performing TSL with a median 25 TSL procedures per year, 72% open gastrocnemius recession, and 17% percutaneous tendo-Achilles lengthening). Across all scenarios, we observed low overall 8% probability with fair agreement (κ = 0.246) of performing TSL (range, 1% at initial management of an unstable Weber B bimalleolar ankle fracture with negative contralateral Silfverskiöld test to 29% at definitive fixation of tongue-type calcaneus fracture with positive contralateral Silfverskiöld test). Silfverskiöld testing significantly influenced TSL probability at all time points. University of Washington training (ß = 1.5, P = .007) but not trauma vs foot fellowship training, years in practice, academic practice, urban setting, or facility trauma designation were significantly associated with likelihood of performing TSL. Conclusion: Orthopaedic traumatology and foot and ankle surgeons report similar indications, methods, and low perceived propensity to use TSL in the management of foot and ankle trauma. We found that graduates of 1 fellowship training site were more likely to perform TSL in the setting of acute trauma potentially indicating the need for better scientific data to support this practice. Level of Evidence: Level V, therapeutic.

Talus Fractures: An Update on Current Concepts in Surgical Management.

Talus fractures can be challenging injuries to treat because of complex talar shape, an abundance of articular cartilage, a potentially unforgiving soft-tissue envelope, and an easily injured blood supply. In addition, the spectra of energy involved, soft-tissue injury, and the fracture pattern are wide. Temporizing treatment is sometimes required, including débridement of open fractures, reduction of dislocations, and occasionally spanning external fixation. Definitive treatment first requires an understanding of the fracture pattern, including location and fracture line orientation. Multiple options for surgical exposure exist and are selected based on the fracture pattern and condition of the soft tissues. Newer fixation techniques, including the use of fixed-angle and minifragment implants, are useful in achieving stable fixation.

Musculoskeletal Educational Resources for the Aspiring Orthopaedic Surgeon.

Musculoskeletal (MSK) education is underemphasized in medical school curricula, which can lead to decreased confidence in treating MSK conditions and suboptimal performance on orthopaedic surgery elective rotations or subinternships. Given the low amount of formalized education in MSK medicine, students aiming to learn about orthopaedic surgery must gain much of their foundational knowledge from other resources. However, there are currently no centralized introductory educational resources to fill this need. We provide a framework for navigating the different types of resources available for trainees and highlight the unaddressed needs in this area.

To Fix or Revise: Differences in Periprosthetic Distal Femur Fracture Management Between Trauma and Arthroplasty Surgeons.

INTRODUCTION: This study sought to determine the effect of trauma fellowship training on the surgical decision to fix or revise to distal femoral replacement in periprosthetic distal femur fractures. METHODS: An anonymous online survey including nine cases of geriatric periprosthetic distal femur fractures was distributed through the Orthopaedic Trauma Association website. Respondents were asked whether they would recommend fixation or revision to distal femoral replacement. Fractures were classified by the location relative to the anterior flange (proximal or distal) and the presence or absence of comminution. Recommendations were compared between type of fellowship completed (trauma, arthroplasty, or both), practice setting, and number of periprosthetic distal femur fractures treated monthly. RESULTS: One hundred fifty-one surgeon survey responses were included. Completion of a trauma fellowship was associated with a higher likelihood of recommending fixation for any periprosthetic distal femur fracture compared with arthroplasty training (odds ratio [OR] 2.55, 95% confidence interval [CI] 1.97 to 3.29; P < 0.0001). Disagreement was significant for comminuted proximal (OR 6.90, 95% CI 3.24 to 14.68; P < 0.0001), simple distal (OR 20.90, 95% CI 6.41 to 67.71; P < 0.001), and comminuted distal fractures (OR 2.47, 95% CI 1.66 to 3.68; P < 0.0001). Dual fellowship-trained surgeons were less likely to recommend fixation than surgeons who completed a trauma fellowship alone (OR 0.60, 95% CI 0.39 to 0.93; P = 0.027) and more likely to recommend fixation than surgeons who completed an arthroplasty fellowship alone (OR 1.70, 95% CI 1.13 to 2.63; P = 0.012). Surgeons who treat three or more periprosthetic distal femur fractures monthly showed a significant preference for fracture fixation compared with lower volume surgeons (OR 2.45, 95% CI 1.62 to 3.68; P < 0.0001). DISCUSSION: Fellowship-trained trauma surgeons show a notable preference for fracture fixation over distal femoral replacement for periprosthetic distal femur fractures, as compared with arthroplasty-trained surgeons. Additional research is needed to clarify surgical indications that maximize outcomes for these injuries.

Long-term sequelae of septic arthritis after tibial plateau fracture fixation: does timing matter?

INTRODUCTION: Septic arthritis following surgical treatment of a tibial plateau fracture is a rare complication, but it does occur, and the impact on long-term function is relatively unknown. The purpose of this study was to determine the long-term sequelae of septic arthritis among patients treated with internal fixation for a tibial plateau fracture and to determine the effect of timing (early or late infection) on the rate of such sequela. MATERIALS AND METHODS: A retrospective comparative study was designed using the trauma database of a single level I academic trauma center. Patients who developed culture-positive septic knee arthritis after internal fixation of a tibial plateau fracture, with 1-year follow-up, were included in the study. The number of debridement procedures required was recorded. Rates of long-term complications and implant removal were identified. Complications rates were compared between patients who developed early (within 30 days of definitive fixation) and late (more than 30 days) septic arthritis. RESULTS: The mean number of debridement procedures per patient was six. Fourteen patients (88%) required implant removal, and thirteen (81%) developed knee arthritis. There was a significantly lower rate of complications in the early septic arthritis group compared to the late group (3 of 6 patients or 50%, vs 10 of 10 patients or 100%; p = 0.036). CONCLUSIONS: Patients who developed septic arthritis following internal fixation of a tibial plateau fracture were likely to endure long-term sequelae. Early infection and detection led to fewer complications. Surgeons treating infectious complications in tibial plateau fracture patients should specifically seek to rule out septic arthritis, anticipate that implant removal may be necessary, and counsel these patients appropriately regarding the anticipated natural history of their condition. LEVEL OF EVIDENCE: III.

Simultaneous Posterolateral and Posteromedial Approaches for Fractures of the Entire Posterior Tibial Plafond: A Safe Technique for Effective Reduction and Fixation.

OBJECTIVE: To determine the short-term results of surgical treatment with dual posterolateral and posteromedial approaches for fractures of the entire posterior tibial plafond and secondarily to identify common fracture characteristics. DESIGN: Retrospective. SETTING: Single academic Level 1 trauma center. PATIENTS: Thirty-five patients with posterior pilon fractures followed until fracture union (minimum 3 months). INTERVENTION: Surgical treatment using simultaneous combined posterolateral and posteromedial exposures for fracture reduction and internal fixation. MAIN OUTCOME MEASUREMENT: (1) Surgical outcomes including rate of wound complications and accuracy of the articular reduction. (2) Fracture characteristics including the incidence of articular impaction, comminution interfering with reduction, syndesmosis injury, and the type of fibula fracture. RESULTS: The rate of wound problems was low (6%), and 94% of patients had an articular reduction with less than 1 mm of step or gap. There were high rates of articular comminution (83%) and posteromedial articular impaction (63%) and a 17% rate of syndesmosis injury requiring repair. CONCLUSIONS: Surgical fixation using simultaneous, combined posterolateral and posteromedial approaches for posterior pilon fractures had a low rate of wound complications and was an effective strategy for obtaining an accurate reduction. The rate of syndesmotic instability requiring fixation was lower than previous work reporting on fixation using a single approach. This may be a useful technique for surgeons who treat these injuries. Careful assessment of the preoperative imaging is required in patients with posterior pilon fractures. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Efficacy of booster doses in augmenting waning immune responses to COVID-19 vaccine in patients with cancer.

Anti-COVID-19 immunity dynamics were assessed in patients with cancer in a prospective clinical trial. Waning of immunity was detected 4-6 months post-vaccination with significant increases in anti-spike IgG titers after booster dosing, and 56% of seronegative patients seroconverted post-booster vaccination. Prior anti-CD20/BTK inhibitor therapy was associated with reduced vaccine efficacy.

The Lines That Held Us: Assessing Racial and Socioeconomic Disparities in SARS-CoV-2 Testing.

BACKGROUND: Racial disparities in SARS-CoV-2 prevalence are apparent. Race is a sociocultural construct, necessitating investigation into how sociocultural factors contribute. METHODS: This cross-sectional study linked laboratory data of adult patients between February 29 and May 15, 2020 with socio-demographics variables from the 2018 American Community Survey (ACS). Medical sites included healthcare organizations in Michigan, New York, North Carolina, California, Florida, Pennsylvania, and Washington. Race was treated as a proxy for racism and not biological essentialism. Laboratory data included patient age, sex, race, ethnicity, test result, test location, and residential ZIP code. ACS data included economic and educational variables contributing to an SES Index, population density, proportion Medicaid, and racial composition for corresponding ZIP code. Associations between race/socioeconomic variables and test results were examined using odds ratios (OR). RESULTS: Of 126 452 patients [mean (SD) age 51.9 (18.4) years; 52 747 (41.7%) men; 68 856 (54.5%) White and 27 805 (22.0%) Black], 18 905 (15.0%) tested positive. Of positive tests, 5238 (SD 27.7%) were White and 7223 (SD 38.2%) were Black. Black race increased the odds of a positive test; this finding was consistent across sites [OR 2.11 (95% CI 1.95-2.29)]. When subset by race, higher SES increased the odds of a positive test for White patients [OR 1.10 (95% CI 1.05-1.16)] but decreased the odds for Black patients [OR 0.92 (95% CI 0.86-0.99)]. Black patients, but not White patients, who tested positive overwhelmingly resided in more densely populated areas. CONCLUSIONS: Black race was associated with SARS-CoV-2 positivity and the relationship between SES and test positivity differed by race, suggesting the impact of socioeconomic status on test positivity is race-specific.

Mater Artium Necessitas: The Birth of a COVID-19 Command Center.

In February of 2020, New York City was unprepared for the COVID-19 pandemic. Cases of SARS-CoV-2 infection appeared and spread rapidly. Hospitals had to repurpose staff and establish diagnostic testing for this new viral infection. In the background of the usual respiratory pathogen testing performed in the clinical laboratory, SARS-CoV-2 testing at the Montefiore Medical System grew exponentially, from none to hundreds per day within the first week of testing. The job of appropriately routing SARS-CoV-2 viral specimens became overwhelming. Additional staff was required to triage these specimens to multiple in-house testing platforms as well as external reference laboratories. Since medical school classes and many research laboratories shut down at the Albert Einstein College of Medicine and students were eager to help fight the pandemic, we seized the opportunity to engage and train senior MD-PhD students to assist in triaging specimens. This volunteer force enabled us to establish the "Pathology Command Center," staffed by these students as well as residents and furloughed dental associates. The Pathology Command Center staff were tasked with the accessioning and routing of specimens, answering questions from clinical teams, and updating ever evolving protocols developed in collaboration with a team of Infectious Disease clinicians. Many lessons were learned during this process, including how best to restructure an accessioning department and how to properly onboard students and repurpose staff while establishing safeguards for their well-being during these unprecedented times. In this article, we share some of our challenges, successes, and what we ultimately learned as an organization.