A Statistical Analysis of the Impact of Gun Ownership on Mass Shootings in the USA Between 2013 and 2022.

Mass shootings (incidents with four or more people shot in a single event, not including the shooter) are becoming more frequent in the United States, posing a significant threat to public health and safety in the country. In the current study, we intended to analyze the impact of state-level prevalence of gun ownership on mass shootings-both the frequency and severity of these events. We applied the negative binomial generalized linear mixed model to investigate the association between gun ownership rate, as measured by a proxy (i.e., the proportion of suicides committed with firearms to total suicides), and population-adjusted rates of mass shooting incidents and fatalities at the state level from 2013 to 2022. Gun ownership was found to be significantly associated with the rate of mass shooting fatalities. Specifically, our model indicated that for every 1-SD increase-that is, for every 12.5% increase-in gun ownership, the rate of mass shooting fatalities increased by 34% (p value < 0.001). However, no significant association was found between gun ownership and rate of mass shooting incidents. These findings suggest that restricting gun ownership (and therefore reducing availability to guns) may not decrease the number of mass shooting events, but it may save lives when these events occur.

Outcomes following total ankle total talus replacement: A systematic review.

BACKGROUND: Prosthetic substitution of the talus presents a significant challenge to the foot and ankle surgeon. The shear and compressive forces on the talus and its tenuous blood supply lead to high rates of avascular necrosis and eventual talar collapse. The purpose of this systematic review is to evaluate whether total ankle total talus replacement (TATTR) leads to improved clinical and radiographic outcomes with appropriate safety metrics in patients with a history of avascular necrosis or significant trauma. METHODS: We searched the concepts of talus, prosthesis, and arthroplasty in MEDLINE (PubMed), Embase (Elsevier), CINAHL Complete (EBSCOhost), and Scopus (Elsevier) from the database's inception through March 9, 2023. Inclusion Criteria were 1) previous trauma to the talus, 2) post-traumatic arthritis to the tibiotalar joint, 3) avascular necrosis of talus, 4) multiple failed prior interventions, 5) degenerative osteoarthritis to the tibiotalar joint, and 6) inflammatory arthropathy to tibiotalar joint. Patients less than 18 years of age and manuscripts in non-English languages were excluded. RESULTS: Of the 7625 references, 16 studies met the inclusion criteria, yielding data from 136 patients (139 ankles). The studies varied in design, with case reports and retrospective case series being predominant. The overall weighted average modified Coleman Methodology Score (mCMS) was 70.4 out of 100, indicating moderate flaws in study design that may be subject to various forms of bias and possible confounders. Demographics showed a diverse range of etiologies, with alumina ceramic being the primary prosthesis material. Functional scores demonstrated improvements in dorsiflexion and plantarflexion, although patient-reported outcome measures (PROs) were inconsistently reported. Complications included fractures, heterotopic ossification, prolonged wound healing, and infections. Revision details were sparsely reported. CONCLUSION: TATTR is a promising treatment modality for improving short-term functional outcomes for patients with avascular necrosis or trauma-related issues. However, this systematic review underscores the need for standardized reporting, longer-term follow-ups, and further research to establish the procedure's efficacy and safety, particularly in comparison to other treatment modalities. LEVEL OF EVIDENCE: III, Systematic Review of Level IV Studies.

Nuclear damage in LMNA mutant iPSC-derived cardiomyocytes is associated with impaired lamin localization to the nuclear envelope.

The LMNA gene encodes the nuclear envelope proteins Lamins A and C, which comprise a major part of the nuclear lamina, provide mechanical support to the nucleus, and participate in diverse intracellular signaling. LMNA mutations give rise to a collection of diseases called laminopathies, including dilated cardiomyopathy (LMNA-DCM) and muscular dystrophies. Although nuclear deformities are a hallmark of LMNA-DCM, the role of nuclear abnormalities in the pathogenesis of LMNA-DCM remains incompletely understood. Using induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) from LMNA mutant patients and healthy controls, we show that LMNA mutant iPSC-CM nuclei have altered shape or increased size compared to healthy control iPSC-CM nuclei. The LMNA mutation exhibiting the most severe nuclear deformities, R249Q, additionally caused reduced nuclear stiffness and increased nuclear fragility. Importantly, for all cell lines, the degree of nuclear abnormalities corresponded to the degree of Lamin A/C and Lamin B1 mislocalization from the nuclear envelope. The mislocalization was likely due to altered assembly of Lamin A/C. Collectively, these results point to the importance of correct lamin assembly at the nuclear envelope in providing mechanical stability to the nucleus and suggest that defects in nuclear lamina organization may contribute to the nuclear and cellular dysfunction in LMNA-DCM.

Metal Hypersensitivity Following Total Ankle Arthroplasty: Case Series and Literature Review.

Metal hypersensitivity following total ankle arthroplasty (TAA) is an underreported complication that can manifest as dermal, systematic, and orthopaedic-specific symptoms. It is critical to recognize that metal hypersensitivity is a diagnosis of exclusion; only after all other potential sources of failure, such as loosening or infection are ruled out, can this diagnosis be considered. Aside from imaging and common laboratory analysis, skin patch testing, leukocyte migration inhibition test (LMIT), and lymphocyte transformation test (LTT) are the testing options available for metal allergy. With regards to management of metal hypersensitivity, nonoperative modalities involving topical dermatological management are generally preferred. Severe cases of metal allergy may necessitate operative management consisting of explantation of the implant and either revision TAA with a custom hypoallergenic implant or conversion to an ankle fusion. We present 3 cases of presumed metal hypersensitivity following TAA. In all 3 cases, other forms of TAA failure were carefully ruled out. One patient underwent explantation and conversion to hypoallergenic implant, 1 patient underwent explantation and ankle arthrodesis with hypoallergenic hardware, and 1 patient elected for conservative care. In patients who underwent explantation and conversion to hypoallergenic hardware, no further symptoms associated with metal allergy were noted. Additional research is necessary to improve diagnostic accuracy of metal allergy and make treatment options more effective and accessible.Level of Evidence: Retrospective case series, IV.

Team Approach: Metal Hypersensitivity in Total Joint Arthroplasty.

¼: As total joint arthroplasty volume continues to grow nationwide, more uncommon complications such as metal implant hypersensitivity are reported with greater frequency in the literature. ¼: Metal hypersensitivity is a challenging diagnosis given the potentially vague symptomology. It should be considered a diagnosis of exclusion, necessitating careful consideration of other potential etiologies of a failing implant before arriving at the final diagnosis of metal hypersensitivity. ¼: Patients can experience substantial morbidity from implant rejection and in severe, refractory cases may even require revision arthroplasty and conversion to a hypoallergenic implant. ¼: Given the complex nature of the condition, successful treatment of metal hypersensitivity to orthopaedic implants is best achieved through the use of a multidisciplinary, team-based approach. Immunologists, radiologists, and infectious disease physicians as well as orthopaedic surgeons and mechanical engineers are all vital in appropriate diagnosis and treatment of the condition.

Three-Year Follow-Up of a Traumatic Critical-Sized Tibial Bone Defect Treated with a 3D Printed Titanium Cage: A Case Report.

CASE: We report a case involving a 21-year-old woman who sustained a Grade III open pilon fracture of the left ankle during a motor vehicle accident that resulted in a 12-cm critical-sized bone defect (CSD) that was successfully treated with a three-dimensional (3D) printed titanium alloy (Ti-6Al-4V) cage, a tibiotalocalcaneal intramedullary nail, and autogenous and allograft bone. The patient's reported outcome measures were comparable with those reported for non-CSD injuries at 3-year follow-up. The authors conclude that 3D printed titanium cages offers a unique approach to traumatic limb salvage for tibial CSD. CONCLUSIONS: 3D printing offers a novel solution to CSDs. To the best of our knowledge, this case report details the largest 3D printed cage, to date, used to treat tibial bone loss. This report describes a unique approach to traumatic limb salvage with favorable patient-reported outcomes and evidence of radiographic fusion at a 3-year follow up.

The efficacy of platelet-rich plasma in osseous foot and ankle pathology: a review.

The purpose of this review is to develop evidence-based practices for the use of platelet-rich plasma (PRP) to treat osseous pathologies of the lower extremity. There is moderate high-quality evidence to support the efficacy of PRP as a surgical augment to microfracture in osteochondral lesions of the talus (OLT). The literature supports a conceivable positive impact on bony union and osseous healing. There is insufficient evidence to support PRP injections in the conservative management of OLT or symptomatic ankle osteoarthritis. PRP may serve as a viable treatment method in the surgical augmentation of microfracture surgery in OLT and has promise for increasing bony union following surgical operations. Further high-quality, comparative studies with longer clinical follow-up are required.

The purpose of this review is to develop evidence-based practices for the use of platelet-rich plasma (PRP) to treat bony pathologies of the lower extremity. There is moderate high-quality evidence to support the use of PRP in surgery to treat damage of both cartilage and bone in the foot. The literature supports a conceivable positive impact on bony healing after fracture. There is insufficient evidence to support PRP injections in the conservative management symptomatic ankle osteoarthritis. PRP may augment bone stimulation surgery in cases of cartilage and bone defects with promise for increasing bone to bone healing following surgical operations. Further high-quality, comparative studies with longer clinical follow-up are required.

Tibiopedal Motion Following Tendo-Achilles Lengthening or Gastrocnemius Recession in Total Ankle Replacement: A Comparative Cohort Study.

BACKGROUND: End-stage ankle arthritis is a debilitating condition often necessitating total ankle replacement (TAR). Tendo-Achilles lengthening (TAL) and gastrocnemius recession (GR) are commonly performed with TAR to improve ankle dorsiflexion (DF). No studies to date have radiographically analyzed tibiopedal motion to guide surgical management. The purpose of this study is to determine the effect of a TAL or GR during TAR on radiographic tibiopedal range of motion (ROM). METHODS: A retrospective review of a prospectively maintained database was conducted followed by a propensity score-matched analysis of 110 patients who underwent TAL (n = 26), GR (n = 29), or no lengthening procedure (n = 55) with TAR. Minimum of 1-year ROM radiographic follow-up was required. Exclusion criteria included (1) calcaneal osteotomies, (2) simultaneous or previous hindfoot or midfoot arthrodesis, (3) prior ankle arthrodesis, or (4) revision TAR. Demographic data were extracted from the TAR database. Radiographic assessment included tibiopedal dorsiflexion (DF) and plantarflexion (PF). RESULTS: DF improved by 2.8 degrees (P = .0286) and by 6.0 degrees (P < .0001) in the TAL and GR cohorts, respectively, with no difference in the control group (+0.7 degrees, P = .3764). PF was decreased by 4.5 degrees (P = .0152) and by 7.2 degrees (P = .0002) in the TAL and GR cohorts, respectively, with no difference in the control group (-0.2 degrees, P = .8546). Minimal differences were observed for total arc of motion for all 3 groups (control 0.5 degrees, GR -1.2 degrees, TAL -1.7 degrees), all of which were nonsignificant (all P > .05). There was no between-group difference in the change in overall arc of motion between the groups (P = .3599). GR resulted in a greater increase in DF (6.0 vs 2.8 degrees; P = .1074), with a reciprocal greater decrease in PF (7.2 vs 4.5 degrees; P = .2416) compared with the TAL cohort. CONCLUSION: Both TAL and GR increased postoperative DF; however, this was accompanied by a reciprocal loss in PF. Minimal differences were observed for total arc of motion. Patients should be counseled that concomitant procedures performed to increase DF will do so at the expense of PF. LEVEL OF EVIDENCE: Level III, retrospective review of prospectively collected data.

Efficacy of Platelet-Rich Plasma in Soft Tissue Foot and Ankle Pathology.

➢: The preparation methodology for platelet-rich plasma (PRP) may have important clinical implications with varying effectiveness with leukocyte, platelet, and growth factor concentrations. ➢: There is high-quality evidence to support the superiority of PRP over corticosteroids in the case of chronic plantar fasciitis. ➢: There is moderate-quality to high-quality evidence for PRP's ability to increase tendon thickness with no capacity to decrease pain, increase function, or augment percutaneous tenotomy in Achilles tendinopathy. ➢: There is insufficient evidence to support PRP injections in the definitive treatment of Achilles tendon rupture. However, PRP may contribute to postoperative recovery after tendon rupture repair, but this requires further research. ➢: The biochemical theory supporting the clinical use of PRP must be reinforced with high-level evidence research. Based on the current literature, PRP may serve as a viable treatment method in chronic plantar fasciitis. Further high-quality, comparative studies with longer clinical follow-up are required to support recommendations for use of PRP in the treatment of Achilles tendon pathology.