Outcomes of isolated medial tibial plateau fractures by fracture morphology.

PURPOSE: To identify a cohort of isolated medial tibial plateau fractures treated with surgical fixation and to categorize them by Moore and Wahlquist classifications in order to determine the rate of complications with each fracture morphology and the predictive value of each classification system. We hypothesized there would be high rates of neurovascular injury, compartment syndrome, and complications overall with a higher incidence of neurovascular injury in Moore type III rim avulsion fractures and Wahlquist type C fractures that enter the plateau lateral to the tibial spines. METHODS: Patients who presented to six Level I trauma centers between 2010 and 2021 who underwent surgical fixation for isolated medial tibial plateau fractures were retrospectively reviewed. Data including demographics, radiographs, complications, and functional outcomes were collected. RESULTS: One hundred and fifty isolated medial tibial plateau fractures were included. All patients were classified by the Wahlquist classification of medial tibial plateau fractures, and 139 patients were classifiable by the Moore classification of tibial plateau fracture-dislocations. Nine percent of fractures presented with neurovascular injury: 5 % with isolated vascular injury and 6 % with isolated nerve injury. There were no significant differences in neurovascular injury by fracture type (Wahlquist p = 0.16, Moore p = 0.33). Compartment syndrome developed in two patients (1.3 %). The average final range of motion was 0.8-122° with no difference by Wahlquist or Moore classifications (p = 0.11, p = 0.52). The overall complication rate was 32 % without differences by fracture morphology. The overall rate of return to the operating room (OR) was 25 %. CONCLUSIONS: Isolated medial tibial plateau fractures often represent fracture-dislocations of the knee and should receive a meticulous neurovascular exam on presentation with a high suspicion for neurovascular injury. No specific fracture pattern was found to be predictive of neurovascular injuries, complications, or final knee range of motion. Patients should be counseled pre-operatively regarding high rates of return to the OR after the index surgery.

Incidence of Suboptimal Fluoroscopic Outlet Imaging of the Sacrum and Pelvic Retroversion Necessary for Optimal Views.

OBJECTIVES: To estimate the prevalence of suboptimal fluoroscopy of sacral outlet images due to anatomic and equipment dimensions. Pelvic retroversion is hypothesized to mitigate this issue. DESIGN: In silico simulations using retrospectively collected computed tomography (CT) data from human patients. SETTING: Level I trauma center. PATIENT SELECTION CRITERIA: Adults with OTA/AO 61 pelvic ring disruptions treated with posterior pelvic fixation between July and December 2021. OUTCOME MEASURES AND COMPARISONS: C-arm tilt angles required to obtain 3 optimal fluoroscopic sacral outlet images, defined as vectors from pubic symphysis to S2 and parallel to the first and second sacral neural foramina, were calculated from sagittal CT images. A suboptimal view was defined as collision of the C-arm radiation source or image intensifier with the patient/operating table at the required tilt angle simulated using the dimensions of 5 commercial C-arm models and trigonometric calculations. Incidence of suboptimal outlet views and pelvic retroversion necessary to obtain optimal views without collision, which may be obtained by placement of a sacral bump, was determined for each view for all patients and C-arm models. RESULTS: CT data from 72 adults were used. Collision between patient and C-arm would occur at the optimal tilt angle for 17% of simulations and at least 1 view in 68% of patients. Greater body mass index was associated with greater odds of suboptimal imaging (standard outlet: odds ratio [OR] 0.84, confidence interval [CI] 0.79-0.89, P < 0.001; S1: OR 0.91, CI 0.87-0.97, P = 0.002; S2: OR 0.85, CI 0.80-0.91, P < 0.001). S1 anterior sacral slope was associated with suboptimal S1 outlet views (OR 1.12, Cl 1.07-1.17, P < 0.001). S2 anterior sacral slope was associated with suboptimal standard outlet (OR 1.07, Cl 1.02-1.13, P = 0.004) and S2 outlet (OR 1.16, Cl 1.09-1.23, P < 0.001) views. Retroversion of the pelvis 15-20 degrees made optimal outlet views possible without collision in 95%-99% of all simulations, respectively. CONCLUSIONS: Suboptimal outlet imaging of the sacrum is associated with greater body mass index and sacral slope at S1 and S2. Retroversion of the pelvis by 15-20 degrees with a bump under the distal sacrum may offer a low-tech solution to ensure optimal fluoroscopic imaging for percutaneous fixation of the posterior pelvic ring. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Pelvic binder radiography detects occult instability in cadaveric simulated lateral compression type I (LC1) pelvic fractures.

OBJECTIVES: Occult instability in minimally displaced lateral compression (LC) pelvic ring injuries may have clinical relevance for treatment. We describe two novel LC pelvis fracture stress examinations - pelvic binder stress radiography (PBR) and pelvic binder stress bladder manometry (PBM) - which do not require sedation, anesthesia, patient transport, or radiation of personnel. METHODS: A biomechanical study was performed with five fresh elderly cadavers. Sequential osteotomies of the pelvis simulated increasingly unstable LC pelvis fracture patterns (OTA/AO 61A2.2, 61B1.1a, 61B1.1b, 61B2.1). Compressive force was quantitatively applied using a pelvic binder and scale. Pelvis fracture displacement was measured on AP and inlet fluoroscopic views. Pelvic bladder pressure (PBM) was measured using a Foley catheter as a water column. RESULTS: Fracture displacement strongly correlated with force applied (R2=0.600-0.963). PBR discriminated between simulated LC injuries. Mean displacement of 61B1.1b injuries >1cm was observed at 3.8kg on AP view and 5kg on inlet view. Mean displacement of 61B1.1a injuries >1cm was observed at 8.2kg on AP view and 9.3kg on inlet view. 61A2.2 injuries did not displace >1cm at forces up to 10kg. >95% of 61B1.1a and 61B1.1b injuries displaced >1cm at 10kg. PBM moderately correlated with force applied (R2=0.517-0.842) but did not discriminate between LC injuries. CONCLUSIONS: PBR is feasible, precisely quantified occult mechanical instability in simulated LC pelvis fractures in response to reproducible applied force, and discriminated between simulated LC pelvis fractures. PBM did not discriminate between simulated LC fractures. A clinical trial to validate the safety and efficacy of PBR for assessing occult instability in LC pelvis fracture is warranted.

Drill Bone with Both Hands: Plunge Depth and Accuracy with 4 Bracing Positions.

Bone drilling is a critical skill honed during orthopaedic surgical education. How a bone drill is held and operated (bracing position) may influence drilling performance. Methods: A prospective study with randomized crossover was conducted to assess the effect of 4 bracing positions on orthopaedic surgical trainee performance in a simulated bone drilling task. Linear mixed effects models considering participant training level, preferred bracing position, height, weight, and drill hole number were used to estimate pairwise and overall comparisons of the effect of each bracing position on 2 primary outcomes of drilling depth and accuracy. Results: A total of 42 trainees were screened and 19 were randomized and completed the study. Drill plunge depth with a 1-handed drilling position was significantly greater by pairwise comparison to any of the 3 double handed positions tested: a soft tissue protection sleeve in the other hand (0.41 mm, 95% confidence interval [CI] 0.80-0.03, p = 0.031), a 2-handed position with the contralateral small finger on bone and the thumb on the drill (0.42 mm, 95% CI 0.06-0.79, p = 0.018), and a 2-handed position with the contralateral elbow braced against the table (0.40 mm, 95% CI 0.02-0.78, p = 0.038). No position afforded a significant accuracy advantage (p = 0.227). Interactions of participant height with plunge depth and accuracy as well between drill hole number and plunge depth were observed. Conclusion: Orthopaedic surgical educators should discourage trainees from operating a bone drill using only 1 hand to reduce the risk of iatrogenic injury due to drill plunging. Level of Evidence: Therapeutic Level II.

Feasibility of Capturing Orthopaedic Trauma Research Outcomes Using Personal Mobile Devices.

INTRODUCTION: Patients with orthopaedic trauma are frequently lost to follow-up. Personal mobile devices have been used to ascertain clinical research outcomes. The prevalence of mobile device ownership, use patterns, and attitudes about research among patients with orthopaedic trauma would inform clinical research strategies in this population. METHODS: A total of 1,434 consecutive unique adults scheduled for an orthopaedic trauma outpatient clinic from December 2019 through February 2020 at a metropolitan level 1 trauma center were identified. Associations of demographic data with clinic attendance and mobile phone registration were explored by logistic regression. One hundred one patients attending clinic were then prospectively surveyed from June 2021 through August 2021 about housing stability, personal mobile device ownership, capabilities, use patterns, and openness to communicating via the device with for orthopaedic care and research. RESULTS: The prevalence of personal mobile device ownership was 91% by registration data and 90% by a survey. Ninety-nine percent of survey respondents with mobile devices reported cell service always or most of the time. Ninety-three percent kept their devices charged always or most of the time. Ninety-two percent reported e-mail access. Eighty-three percent reported video capability. Ninety-one percent would communicate with their orthopaedic trauma care team by text message. Eighty-seven percent would answer research questions by phone call, 79% by text, and 61% by video. Eighty-five percent reported stable housing, which was not associated with mobile device ownership or use, but was associated with clinic nonattendance (29% vs. 66%, P < 0.01) and changing phone number at least once in the previous year (28% vs. 58%, P = 0.04). DISCUSSION: Personal mobile devices represent a feasible platform for screening and collecting outcomes from patients with orthopaedic trauma. Nine in 10 patients own personal mobile devices, keep them charged, have text and e-mail service, and would use the device to participate in research. Housing instability was not associated with mobile device ownership or use patterns.

Antibiotic bead pouch versus negative pressure wound therapy at initial management of AO/OTA 42 type IIIB open tibia fracture may reduce fracture related infection: A retrospective analysis of 113 patients.

INTRODUCTION: Fracture related infection (FRI) may be a devastating complication of open tibial shaft fractures. We sought to determine if antibiotic bead pouch, negative pressure wound therapy, or negative pressure wound therapy over antibiotic beads as the initial coverage method for type IIIB open tibial shaft fractures is associated with risk of FRI. PATIENTS AND METHODS: Retrospective cohort study with radiograph and chart review of patients aged ≥16 years with isolated, displaced, extra-articular, Gustilo-Anderson type IIIB open diaphyseal AO/OTA 42 tibial fractures requiring rotational or free tissue transfer for soft tissue coverage at one Level 1 trauma center between 2007 and 2020. An association of dressing applied at the first surgical debridement (application of antibiotic bead pouch, negative pressure wound therapy, or combined therapy) with a primary outcome of FRI requiring debridement or amputation was analyzed by multivariable logistic regression considering demographic, injury, and treatment characteristics. RESULTS: 113 patients met eligibility criteria. Median follow-up was 33 months (interquartile range 5-88). 41 patients were initially treated with NPWT, 59 with ABP, and 13 with ABP+NPWT at the initial surgical debridement. 39 (35%) underwent subsequent debridement or amputation for FRI. One amputation occurred in the ABP group for refractory deep surgical site infection (p = 0.630). Initial wound management with an antibiotic bead pouch versus either negative pressure wound therapy alone or negative pressure wound therapy combined with an antibiotic bead pouch was associated with lower odds of debridement or amputation for FRI (ß = -1.08, 95% CI -2.00 to -0.17, p = 0.02). CONCLUSIONS: In our retrospective analysis, antibiotic bead pouch for initial coverage of type IIIB open tibial shaft fractures requiring flap coverage was associated with a lower risk of FRI requiring debridement or amputation than negative pressure wound therapy applied with or without antibiotic beads. A prospective clinical trial is warranted.

Current and Future Advanced Imaging Modalities for the Diagnosis of Early Osteoarthritis of the Hip.

Hip osteoarthritis (OA) can be idiopathic or develop secondary to structural joint abnormalities of the hip joint (alteration of normal anatomy) and/or due to a systemic condition with joint involvement. Early osteoarthritic changes to the hip can be completely asymptomatic or may cause the development hip symptomatology without evidence of OA on radiographs. Delaying the progression of hip OA is critical due to the significant impact of this condition on the patient's quality of life. Pre-OA of the hip is a newly established term that is often described as the development of signs and symptoms of degenerative hip disease but no radiographic evidence of OA. Advanced imaging methods can help to diagnose pre-OA of the hip in patients with hip pain and normal radiographs or aid in the surveillance of asymptomatic patients with an underlying hip diagnosis that is known to increase the risk of early OA of the hip. These methods include the delayed gadolinium-enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC), quantitative magnetic resonance imaging (qMRI- T1rho, T2, and T2* relaxation time mapping), 7-Tesla MRI, computed tomography (CT), and optical coherence tomography (OCT). dGEMRIC proved to be a reliable and accurate modality though it is limited by the significant time necessary for contrast washout between scans. This disadvantage is potentially overcome by T2 weighted MRIs, which do not require contrast. 7-Tesla MRI is a promising development for enhanced imaging resolution compared to 1.5 and 3T MRIs. This technique does require additional optimization and development prior to widespread clinical use. The purpose of this review was to summarize the results of translational and clinical studies investigating the utilization of the above-mentioned imaging modalities to diagnose hip pre-OA, with special focus on recent research evaluating their implementation into clinical practice.

Assessment of Human Natural Killer Cell Events Driven by FcγRIIIa Engagement in the Presence of Therapeutic Antibodies.

One mechanism of action for clinical efficacy by therapeutic antibodies is the promotion of immune-related functions, such as cytokine secretion and cytotoxicity, driven by FcγRIIIa (CD16) expressed on natural killer (NK) cells. These observations have led to research focusing on methods to increase Fc receptor-mediated events, which include removal of a fucose moiety found on the Fc portion of the antibody. Further studies have elucidated the mechanistic changes in signaling, cellular processes, and cytotoxic characteristics that increase ADCC activity with afucosylated antibodies. Additionally, other studies have shown the potential benefits of these antibodies in combination with small molecule inhibitors. These experiments demonstrated the molecular and cellular mechanisms underlying the benefits of using afucosylated antibodies in combination settings. Many of these observations were based on an artificial in vitro activation assay in which the FcγRIIIa on human NK cells was activated by therapeutic antibodies. This assay provided the flexibility to study downstream effector NK cell functions, such as cytokine production and degranulation. In addition, this assay has been used to interrogate signaling pathways and identify molecules that can be modulated or used as biomarkers. Finally, other therapeutic molecules (i.e., small molecule inhibitors) have been added to the system to provide insights into the combination of these therapeutics with therapeutic antibodies, which is essential in the current clinical space. This manuscript aims to provide a technical foundation for performing this artificial human NK cell activation assay. The protocol demonstrates key steps for cell activation as well as potential downstream applications that range from functional readouts to more mechanistic observations.