Understanding Health Economics in Hand Surgery.

Rising health care costs in the United States, besides evolving payment models that place emphasis on value instead of volume, have led to an increasing number of studies evaluating hand surgery from an economic perspective. To better understand such economics-based studies, this review provides a foundational understanding of what value entails by defining its features of quality and cost. Principles of evaluating value through cost-benefit, cost-effectiveness, and cost-utility analyses are discussed. Models of discounting and clinical decision analyses are also discussed. Understanding such concepts and their evaluation in economic analyses will provide greater insight into the economic landscape of hand surgery and improving patient care.

Risk of Dislocation and Revision Following Primary Total Hip Arthroplasty in Patients With Prior Lumbar Fusion With Spinopelvic Fixation.

BACKGROUND: The effect of spinopelvic fixation in addition to lumbar spinal fusion (LSF) on dislocation/instability and revision in patients undergoing primary total hip arthroplasty (THA) has not been reported previously. METHODS: The PearlDiver Research Program was used to identify patients aged 30 and above undergoing primary THA who received (1) THA only, (2) THA with prior single-level LSF, (3) THA with prior 2-5 level LSF, or (4) THA with prior LSF with spinopelvic fixation. The incidence of THA revision and dislocation/instability was compared through logistic regression and Chi-squared analysis. All regressions were controlled for age, gender, and Elixhauser Comorbidity Index (ECI). RESULTS: Between 2010 and 2018, 465,558 patients without history of LSF undergoing THA were examined and compared to 180 THA patients with prior spinopelvic fixation, 5,299 with prior single-level LSF, and 1,465 with prior 2-5 level LSF. At 2 years, 7.8% of THA patients with prior spinopelvic fixation, 4.7% of THA patients with prior 2-5 level LSF, 4.2% of THA patients with prior single-level LSF, and 2.2% of THA patients undergoing only THA had a dislocation event or instability (P < .0001). After controlling for length of fusion, pelvic fixation itself was associated with higher independent risk of revision (at 2 years: 2-5 level LSF + spinopelvic fixation: aHR = 3.15, 95% CI 1.77-5.61, P < .0001 vs 2-5 level LSF with no spinopelvic fixation: aOR = 1.39, 95% CI 1.10-1.76, P < .0001). CONCLUSION: At 2 years, spinopelvic fixation in THA patients were associated with a greater than 3.5-fold increase in hip dislocation risk compared to those without LSF, and an over 2-fold increase in THA revision risk compared to those with LSF without spinopelvic fixation. LEVEL OF EVIDENCE: III.

Restoration of hamstring function following sciatic nerve resection at the greater sciatic foramen with reconstruction involving acellular nerve allograft and vascularized sural nerve autograft: A case report.

Segmental loss of the sciatic nerve secondary to oncologic resection or trauma is detrimental to hamstring and leg function. The diameter of this nerve and the length of its axons spanning the lower extremity create significant challenges in reconstruction and optimizing return of sensory or motor function. The purpose of this report is to describe outcomes of a free vascularized sural nerve graft to preserve hamstring function in a large proximal sciatic nerve defect beginning at the greater sciatic foramen. A 44-year-old female underwent neoadjuvant chemotherapy and radiation for treatment of a left sciatic nerve synovial cell sarcoma. The patient underwent R0 resection of the proximal left sciatic nerve resulting in a 15 cm defect. An ipsilateral vascularized sural nerve graft was used to reconstruct the medial aspect of the sciatic nerve, prioritizing the tibial division, in an effort to restore hamstring function and plantar sensation. A 5 cm allograft nerve was added to the cutaneous branches of the sural nerve graft to better span the large defect and reconstruct the lateral aspect of the nerve. The patient's postoperative course was uneventful. At 1-year follow-up, the patient showed MRC grade 4/5 strength with knee flexion and steady gait pattern with a left ankle-foot orthosis. Outcomes support the use of a single vascularized nerve graft alongside acellular nerve allograft to restore motor function in large diameter and large defect mixed nerve injuries.

Gorham Disease Limited to the Left Upper Extremity Without Hand Involvement.

In this case report, we present a young female patient with a history of Gorham disease, who sustained pathologic fractures of the left radius and ulna after a low-impact fall. Massive osteolysis of the left forearm and wrist was noted on plain radiographs. The patient had had 8 previous left upper-extremity fractures without evidence of disease in any other area of the body.

Human Cartilage-Derived Progenitors Resist Terminal Differentiation and Require CXCR4 Activation to Successfully Bridge Meniscus Tissue Tears.

Meniscus injuries are among the most common orthopedic injuries. Tears in the inner one-third of the meniscus heal poorly and present a significant clinical challenge. In this study, we hypothesized that progenitor cells from healthy human articular cartilage (chondroprogenitor cells [C-PCs]) may be more suitable than bone-marrow mesenchymal stem cells (BM-MSCs) to mediate bridging and reintegration of fibrocartilage tissue tears in meniscus. C-PCs were isolated from healthy human articular cartilage based on their expression of mesenchymal stem/progenitor marker activated leukocyte cell adhesion molecule (ALCAM) (CD166). Our findings revealed that healthy human C-PCs are CD166+, CD90+, CD54+, CD106- cells with multilineage differentiation potential, and elevated basal expression of chondrogenesis marker SOX-9. We show that, similar to BM-MSCs, C-PCs are responsive to the chemokine stromal cell-derived factor-1 (SDF-1) and they can successfully migrate to the area of meniscal tissue damage promoting collagen bridging across inner meniscal tears. In contrast to BM-MSCs, C-PCs maintained reduced expression of cellular hypertrophy marker collagen X in monolayer culture and in an explant organ culture model of meniscus repair. Treatment of C-PCs with SDF-1/CXCR4 pathway inhibitor AMD3100 disrupted cell localization to area of injury and prevented meniscus tissue bridging thereby indicating that the SDF-1/CXCR4 axis is an important mediator of this repair process. This study suggests that C-PCs from healthy human cartilage may potentially be a useful tool for fibrocartilage tissue repair/regeneration because they resist cellular hypertrophy and mobilize in response to chemokine signaling. Stem Cells 2019;37:102-114.

SDF-1 preconditioned HPC scaffolds mobilize cartilage-derived progenitors and stimulate meniscal fibrocartilage repair in human explant tissue culture.

Purpose: The purpose of this study was to characterize the influence of SDF-1 on cell migration/adhesion and temporal gene expression of human cartilage mesenchymal progenitor cells (C-PCs); and to utilize SDF-1 conditioned mesenchymal progenitors to stimulate reintegration of human meniscus fibrocartilage breaks.Materials and Methods: Characterization of SDF-1-induced cell migration was achieved using hydroxypropyl cellulose (HPC) scaffolds pretreated with SDF-1. Fluorescence microscopy and cell counting were used to visualize and quantify the extent of cell migration into scaffolds, respectively. Relative mRNA expression analysis was used to characterize the temporal effects of SDF-1 on C-PCs. Tissue reintegration experiments were conducted using cylindrical human meniscal tissue punches, which were then placed back together with an HPC scaffold embedded with C-PCs. Tensile testing was used to evaluate the extent of tissue reintegration stimulated by human mesenchymal progenitors.Results: C-PCs migrate into scaffolds in response to SDF-1 with the same efficiency as mesenchymal progenitors from human marrow (BM-MSCs). SDF-1 treatment of C-PCs did not significantly alter the expression of early and late stage chondrogenic differentiation genes. Scaffolds containing SDF-1 pre-conditioned C-PCs successfully adhered to fibrocartilage breaks and migrated from the scaffold into the tissue. Tensile testing demonstrated that SDF-1 preconditioned C-PCs stimulate reintegration of fibrocartilage tears.Conclusion: C-PCs migrate in response to SDF-1. Exposure to SDF-1 does not significantly alter the unique mRNA profile of C-PCs that make them desirable for cartilaginous tissue repair applications. SDF-1 pretreated mesenchymal progenitors successfully disperse into injured tissues to help facilitate tissue reintegration.

Risk of Revision Shoulder Surgery, Complications, and Prolonged Opioid Use in Patients Undergoing Shoulder Arthroscopy Who Have Previously Undergone Anterior Cervical Discectomy and Fusion.

PURPOSE: To compare postoperative complications, rates of revision, and opioid use of those who undergo shoulder arthroscopy with and without previous anterior cervical discectomy and fusion (ACDF). METHODS: The PearlDiver database from 2007 to 2017 was used to query all patients who underwent shoulder arthroscopy as determined by Current Procedural Terminology (CPT). Patients were then separated among those who had a previous instance of ACDF and those who did not as filtered by CPT. Postoperative complications within 30 days, readmission rates, opioid use, and revision procedures were assessed for each cohort using a mix of International Classification of Diseases Ninth and Tenth Revision Clinical Modification codes, CPT, as well as generic drug codes. RESULTS: A total of 91,029 patients undergoing shoulder arthroscopy were identified, of whom 1,267 (1.4%) had a history of ACDF. Compared with patients without previous ACDF, patients with a history of ACDF had significantly greater respiratory complication rates (1.3% vs 0.5%: adjusted odds ratio [aOR] 2.16, 95% confidence interval [CI]1.30-3.59, P = .003), 30-day complication rates (3.7% vs 2.2%: aOR 1.48, 95% CI 1.10-1.99, P = .011), 1-year revision rates (15.2% vs 7.7%: aOR 2.00, 95% CI 1.71-2.33, P < .0001), and greater opioid use at 1 month, 3 months, 6 months, and 12 months (P < .0001). CONCLUSIONS: This study revealed that patients who undergo shoulder arthroscopy with a history of ACDF are twice as likely to undergo revision arthroscopy within 2 years of surgery and are at an increased risk of complications within 30 days postoperatively as well as prolonged opioid use compared with those without a history of ACDF. With these findings, both spine and shoulder surgeons should aim to be more aware of surgical history, especially of the cervical spine, to better counsel patients' clinical course and expected outcomes following shoulder arthroscopy. LEVEL OF EVIDENCE: III, retrospective cohort study.

Distal-Less Homeobox 5 Is a Therapeutic Target for Attenuating Hypertrophy and Apoptosis of Mesenchymal Progenitor Cells.

Chondrocyte hypertrophy is a hallmark of osteoarthritis (OA) pathology. In the present study, we elucidated the mechanism underlying the relationship between the hypertrophy/apoptotic phenotype and OA pathogenesis in bone marrow-derived mesenchymal stem cells (BM-MSCs) via gene targeting of distal-less homeobox 5 (DLX5). Our primary objectives were (1) to determine whether DLX5 is a predictive biomarker of cellular hypertrophy in human osteoarthritic tissues; (2) To determine whether modulating DLX5 activity can regulate cell hypertrophy in mesenchymal stem/progenitor cells from marrow and cartilage. Whole transcriptome sequencing was performed to identify differences in the RNA expression profile between human-cartilage-derived mesenchymal progenitors (C-PCs) and bone-marrow-derived mesenchymal progenitors (BM-MSCs). Ingenuity Pathway Analysis (IPA) software was used to compare molecular pathways known to regulate hypertrophic terminal cell differentiation. RT-qPCR was used to measure DLX5 and hypertrophy marker COL10 in healthy human chondrocytes and OA chondrocytes. DLX5 was knocked down or overexpressed in BM-MSCs and C-PCs and RT-qPCR were used to measure the expression of hypertrophy/terminal differentiation markers following DLX5 modulation. Apoptotic cell activity was characterized by immunostaining for cleaved caspase 3/7. We demonstrate that DLX5 and downstream hypertrophy markers were significantly upregulated in BM-MSCs, relative to C-PCs. DLX5 and COL10 were also significantly upregulated in cells from OA knee joint tissues, relative to normal non-arthritic joint tissues. Knocking down DLX5 in BM-MSCs inhibited cell hypertrophy and apoptotic activity without attenuating their chondrogenic potential. Overexpression of DLX5 in C-PCs stimulated hypertrophy markers and increased apoptotic cell activity. Modulating DLX5 activity regulates cell hypertrophy and apoptosis in BM-MSCs and C-PCs. These findings suggest that DLX5 is a biomarker of OA changes in human knee joint tissues and confirms the DLX5 mechanism contributes to hypertrophy and apoptosis in BM-MSCs.

Incidence, Timing, and Risk Factors for Secondary Revision After Primary Revision of Traumatic Digit Amputations.

PURPOSE: Primary revision amputation is the most common treatment method for traumatic digit amputations in the United States. Few studies have reported secondary revision rates after primary revision amputation. The primary aim of our study was to identify risk factors for secondary revision within 1 year of the index procedure. Secondarily, we describe the incidence and timing of complications requiring secondary revision. METHODS: Our institution's emergency department (ED) database was reviewed for traumatic digit amputations over a 6-year period. Patients were reviewed for demographic characteristics, comorbidities, site of treatment (ED versus operating room), and complications requiring secondary revision. Conditional Cox Proportional Hazard regression was used to model hazard of revision within 1 year of index procedure relative to site of initial management, mechanism of injury, injury characteristics, and patient demographics. RESULTS: Five hundred and thirty-seven patients with 677 digits were managed with primary revision amputation. Five hundred and eighty-six digits (86.6%) were revised in the ED, and 91 (13.4%) in the operating room. Ninety-one digits required secondary revision, including 83 within 1 year. No increased risk of secondary revision amputation within 1 year of the index procedure was observed for patients treated in the ED compared with the operating room. Relative to crush injuries, bite and sharp laceration amputations had 4.8 times and 2.6 times increased risk of secondary revision, respectively. The index finger had a 5.3-fold increased risk of revision with the thumb as the reference digit. Work-related injuries had a 1.9-fold increased risk of secondary revision compared with non-work-related injuries. CONCLUSIONS: No evidence was found indicating that traumatic digit amputations primarily revised in the ED had an increased risk of secondary revision. Patients may be counseled on the risk of secondary procedures based on the mechanism of injury, injury characteristics and demographics, as well as the timing of complications. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Obesity's Influence on Operative Management of Pediatric Supracondylar Humerus Fractures.

BACKGROUND: As childhood obesity remains an ongoing issue for the United States there has been an increasing number of studies detailing its effect on fracture complexity, management, and outcomes. This study utilizes a national database to examine whether obese children with supracondylar humerus fractures are more likely to require open reduction and internal fixation than nonobese children. METHODS: The Healthcare Cost and Utilization Project Kid's Inpatient Database of 2003, 2006, 2009, 2012 were queried for pediatric supracondylar humerus fractures [International Classification of Disease (ICD-9), 812.41] between 2 and 12 years. Patients were separated into those undergoing closed reduction percutaneous pinning (CRPP), open reduction internal fixation (ORIF), or both. Obesity was determined by comorbidity and ICD-9 coding (ICD-9, 278.00, 278.01). Univariable and multivariable logistic regression models were utilized with P<0.05 considered significant. RESULTS: Between 2003 and 2012, 31,905 patients between the ages of 2 and 12 years sustained supracondylar humerus fractures. In total, 105 patients (0.3%) were obese. A majority of patients, 27,658 (86.7%), underwent CRPP. Odds for ORIF increased in association with age, obesity, white race, and private insurance. Significant association was found between age and obesity (P<0.05) in those undergoing ORIF. Obese children between 2 and 7 years of age had no difference in ORIF or CRPP compared with normal-weight children. Those between 8 and 12 years who were obese were significantly more likely to undergo ORIF (OR, 4.29; 95% confidence interval, 1.78-10.36). CONCLUSIONS: Supracondylar humerus fractures sustained in obese children between 8 and 12 years are over 4 times more likely to require ORIF compared with normal-weight children of the same age. Providers should identify and counsel older obese children and their families regarding the potential for increased difficulty in fracture management that may require open surgical intervention. LEVEL OF EVIDENCE: Level IV-case series.

Injury and Biological Factors Impact Shoulder Function following Autogenous Grafting of Spinal Nerves for Pan-Brachial Plexus Reconstruction.

BACKGROUND: Shoulder function following spinal nerve grafting in pan-brachial plexus injuries(Pan-BPI) is not well described. The purpose of this study was twofold: 1)to evaluate shoulder abduction(ABD) and external rotation(ER) after grafting of viable spinal nerves to the suprascapular nerve(SSN), axillary nerve(AxN), or posterior division of the upper trunk(PDUT); and 2)to determine patient characteristics, injury severity/characteristics, and nerve graft factors that influenced outcomes. METHODS: 362 Pan-BPI reconstruction patients from a single institution were reviewed for those who underwent spinal nerve grafting for shoulder reanimation between 2001 and 2018. Patient demographics, injury severity scores(ISS), graft characteristics, strength, range of motion for shoulder ABD and ER, and patient-reported outcomes were recorded. Patients were divided into three groups based on the recovery of shoulder function: no return, ABD only, and ABD and ER. RESULTS: 110 patients underwent spinal nerve grafting, with 41 meeting inclusion criteria. 17(41.5%) had no return of shoulder function, 14(34.1%) had ABD alone, and 10(24.4%) had ABD and ER. Patients with recovery of both ABD and ER were significantly younger(18.6±5.56), had lower BMI(22.4±4.0), and lower ISS(10.5±6.24, p=0.003). Multivariable analysis found that with increasing age(OR:0.786, 95%CI:0.576,0.941) and ISS(OR:0.820, 95%CI:0.606-0.979), odds for return of ABD and ER significantly decreased. CONCLUSIONS: In Pan-BPI, 24.4% of patients demonstrated return of both ABD and ER following spinal nerve grafting to SSN and either AxN or PDUT. Age, BMI, and ISS were associated with poorer recovery of shoulder function. Careful patient selection and consideration of age, BMI, and ISS may improve outcomes of spinal nerve grafting for shoulder reanimation. LEVEL OF EVIDENCE: III.

Update to Management of Acute Scaphoid Fractures.

The scaphoid is the most commonly fractured carpal bone. With high clinical suspicion and negative radiographs, expedient evaluation by CT or MRI has been recommended. When treating nondisplaced or minimally displaced scaphoid waist and distal pole fractures, immobilization below the elbow without inclusion of the thumb is an option. Comparatively, early surgical intervention for nondisplaced or minimally displaced scaphoid waist fractures allows for quicker return of function, but with increased risk of surgical complications and no long-term outcomes differences compared with cast immobilization. For most patients with such fractures, consideration for aggressive conservative treatment involving 6 weeks of immobilization with CT assessment to guide the need for continued casting, surgical intervention, or mobilization is advocated. Determination of union is best done with a CT scan at 6 weeks and at least 50% continuous trabecular bridging across the fracture site deemed sufficient to begin mobilization. Nonsurgical and surgical management of scaphoid fractures requires a thorough understanding of fracture location, fracture characteristics, and patient-specific factors to provide the best healing opportunity of this notoriously difficult fracture and return the patient to full function.

Matrilin-2 within a three-dimensional lysine-modified chitosan porous scaffold enhances Schwann cell migration and axonal outgrowth for peripheral nerve regeneration.

Background: Matrilin-2 is a key extracellular matrix protein involved in peripheral nerve regeneration. We sought to develop a biomimetic scaffold to enhance peripheral nerve regeneration by incorporating matrilin-2 within a chitosan-derived porous scaffold. We hypothesized that the use of such a novel biomaterial delivers microenvironmental cues to facilitate Schwann cell (SC) migration and enhance axonal outgrowth during peripheral nerve regeneration. Materials and Methods: The effect of matrilin-2 on SC migration was evaluated with agarose drop migration assay on matrilin-2 coated dishes. SC adhesion was determined with SCs cultured atop tissue culture dishes coated with matrilin-2. Various formulations of chitosan vs matrilin-2 in scaffold constructs were examined with scanning electron microscopy. The effect of the matrilin-2/chitosan scaffold on SC migration in the collagen conduits was determined by capillary migration assays. Neuronal adhesion and axonal outgrowth were evaluated with three-dimensional (3D) organotypic assay of dorsal root ganglions (DRG). DRG axonal outgrowth within the scaffolds was determined by immunofluorescence staining of neurofilaments. Results: Matrilin-2 induced SC migration and enhanced its adhesion. A formulation of 2% chitosan with matrilin-2 demonstrated an optimal 3D porous architecture for SC interaction. Matrilin-2/chitosan scaffold enabled SCs to migrate against gravity within conduits. Chemical modification of chitosan with lysine (K-chitosan) further improved DRG adhesion and axonal outgrowth than the matrilin-2/chitosan scaffold without lysine modification. Conclusion: We developed a matrilin-2/K-chitosan scaffold to mimic extracellular matrix cues and provide a porous matrix to enhance peripheral nerve regeneration. Taking advantage of matrilin-2's capability to stimulate SC migration and adhesion, we formulated a porous matrilin-2/chitosan scaffold to support axongal outgrowth. Chemical modification of chitosan with lysine further improved matrilin-2 bioactivity in the 3D scaffold. The 3D porous matrilin-2/K-chitosan scaffolds have high potential for enhancing nerve repair by stimulating SC migration, neuronal adhesion, and axonal outgrowth.

Complications and Reoperation Following Surgery for Concurrent Carpal Tunnel and Cervical Spine Compression.

BACKGROUND: Patients with carpal tunnel syndrome (CTS) may also have cervical radiculopathy (CR) or vice versa, potentially requiring carpal tunnel release (CTR) and anterior cervical discectomy and fusion (ACDF). This study evaluates whether there is an increased risk of complications following CTR or ACDF in patients with concurrent CTS and CR (CTS-CR) compared with those with only CTS or CR. METHODS: A multipayer database was used to identify patients with CTS-CR. From this cohort, patients who underwent CTR and/or ACDF were identified. Patients with CTS-CR undergoing surgery were compared with those undergoing surgery with only CTS or CR. Multivariable logistic regression was used to compare matched populations to assess postoperative complications and risk of undergoing both procedures. RESULTS: A total of 110 379 patients with CTS-CR were identified. Carpal tunnel release was performed in 21 152 patients (19.2%) with CTS-CR, from which 835 (0.76%) underwent ACDF. Anterior cervical discectomy and fusion was performed in 6960 patients (6.31%) with CTS-CR followed by CTR in 1098 patients (0.99%). Patients with CTS-CR were at greater risk of reoperation and complex regional pain syndrome following CTR. In ACDF, patients with CTS-CR were at greater risk of reoperation. Obesity and tobacco use were significant risk factors in patients with CTS-CR who underwent both CTR and ACDF rather than a single surgery. CONCLUSIONS: Examination of more than 100 000 patients with CTS-CR found a greater likelihood of reoperation and perioperative complications following surgery than those without concurrent diagnoses. Obesity and smoking increased the risk for patients undergoing both procedures. Patients presenting with CTS-CR are high risk and should be counseled on risk of complication and reoperation and optimized to reduce risk of undergoing both CTR and ACDF.

Effect of Hospital Characteristics on Performance of Pediatric Digit Replantation in the United States.

Introduction Utilize a national pediatric database to assess whether hospital characteristics such as location, teaching status, ownership, or size impact the performance of pediatric digit replantation following traumatic digit amputation in the United States. Materials and Methods The Kid's Inpatient Database (KID) was used to query pediatric traumatic digit amputations between 2000 and 2012. Ownership (private and public), teaching status (teaching and non-teaching), location (urban and rural), hospital type (general and children's), and size (large and small-medium) characteristics were evaluated. Replantations were then divided into those that required subsequent revision replantation or amputation. Fisher's exact tests and multivariable logistic regressions were performed with p <0.05 considered statistically significant. Results Overall, 1,015 pediatric patients were included for the digit replantation cohort. Hospitals that were privately owned, general, large, urban, or teaching had a significantly greater number of replantations than small-medium, rural, non-teaching, public, or children's hospitals. Privately owned (odds ratio [OR]: 1.80; 95% confidence interval [CI]: 1.06-3.06; p = 0.03) and urban (OR: 2.29; 95% CI: 1.41-3.73; p = 0.005) hospitals were significantly more likely to perform replantation. Urban (OR: 4.02; 95% CI: 1.90-8.47; p = 0.0003) and teaching (OR: 2.11; 95% CI: 1.17-3.83; p = 0.014) hospitals were significantly more likely to perform a revision procedure following primary replantation. Conclusion Private and urban hospitals were significantly more likely to perform replantation, but urban and teaching hospitals carried a greater number of revision procedures following replantation. Despite risk of requiring revision, the treatment of pediatric digit amputations in private, urban, and teaching centers provide the greatest likelihood for an attempt at replantation in the pediatric population. The study shows Level of Evidence III.

Upper Extremity Neuropathies Following Severe COVID-19 Infection: A Multicenter Case Series.

OBJECTIVE: The purpose of the study is to examine presentation, injury patterns, and clinical course, for COVID-19-related peripheral nerve injury following mechanical ventilation. METHODS: A multicenter retrospective study of patients with COVID-19 complicated by acute respiratory distress syndrome (ARDS) that required mechanical ventilation was undertaken. Patient records were reviewed for intensive care unit and intubation characteristics, prone or lateral decubitus positioning, and the onset of neuropathy diagnosis. RESULTS: Between September 2020 and January 2022, 11 patients were diagnosed with peripheral neuropathy, including 9 with brachial plexopathy following COVID-19 infection. Each patient developed ARDS requiring mechanical ventilation for a median of 39 days. Six patients (54.5%) underwent prone positioning and 1 lateral decubitus. Neuropathies involved 5 brachial pan-plexopathies, 2 incomplete brachial plexopathies, 2 lower trunk plexopathies, 1 radial neuropathy, and 1 bilateral ulnar neuropathy. At a mean follow-up of 10.2 months, patients with brachial pan-plexopathies demonstrated signs of reinnervation proximally, and 1 resolved to a radial mononeuropathy; however, the majority have demonstrated minimal clinical improvements. CONCLUSIONS: Our series demonstrates that peripheral neuropathies and especially brachial plexopathies have occurred following mechanical ventilation for ARDS-related COVID-19 infections. Contrary to prior COVID-19 studies, only 54.5% of these patients underwent prone positioning. Aside from a traumatic disturbance of prone positioning, the increased incidence of neuropathy may involve an atraumatic effect of COVID-19 via direct invasion of nerves, autoantibody targeting of nervous tissue, or hypercoagulation-induced microthrombotic angiopathy.

Tumor: Stroma Interaction and Cancer.

The understanding of how normal cells transform into tumor cells and progress to invasive cancer and metastases continues to evolve. The tumor mass is comprised of a heterogeneous population of cells that include recruited host immune cells, stromal cells, matrix components, and endothelial cells. This tumor microenvironment plays a fundamental role in the acquisition of hallmark traits, and has been the intense focus of current research. A key regulatory mechanism triggered by these tumor-stroma interactions includes processes that resemble epithelial-mesenchymal transition, a physiologic program that allows a polarized epithelial cell to undergo biochemical and cellular changes and adopt mesenchymal cell characteristics. These cellular adaptations facilitate enhanced migratory capacity, invasiveness, elevated resistance to apoptosis, and greatly increased production of ECM components. Indeed, it has been postulated that cancer cells undergo epithelial-mesenchymal transition to invade and metastasize.In the following discussion, the physiology of chronic inflammation, wound healing, fibrosis, and tumor invasion will be explored. The key regulatory cytokines, transforming growth factor ß and osteopontin, and their roles in cancer metastasis will be highlighted.

Variability in Hand Surgery Training Among Plastic and Orthopaedic Surgery Residents.

BACKGROUND: A career in hand surgery in the United States requires a 1-year fellowship after residency training. Different residency specialty programs may vary in case volume. The purpose of this study was to characterize variation in hand surgery training within and between orthopaedic and plastic surgery residents. METHODS: Publicly available hand surgery case logs for graduating orthopaedic and plastic surgery residents during the 2010 to 2011 to 2018 to 2019 academic years were obtained through the Accreditation Council of Graduate Medical Education. Student t-tests were used to compare mean case volumes among several categories between plastic surgery (PRS) and orthopaedic surgery (OS) residents. Intraspecialty variation was assessed by comparing the 90th and 10th percentiles in each category. RESULTS: A total of 6,254 orthopaedic and 1,070 plastic surgery graduating residents were included. The mean hand surgery case volume for orthopaedic residents (OS 247.0) was significantly lower than that for plastic surgery residents (PRS 412.0) (P < 0.0001). Orthopaedic residents performed more trauma cases (OS 133.2, PRS 54.5; P < 0.0001) but fewer nerve repairs (OS 3.3, PRS 28.5 P < 0.0001) and amputations (OS 6.4, PRS 15.8; P < 0.0001). Nerve decompression case volumes were similar between the two specialties (OS 50.2, PRS 47.3; P = 0.34). Case volumes among orthopaedic residents varied considerably in amputations and among plastic surgery residents in replantation/revascularization procedures. CONCLUSIONS: Orthopaedic surgery residents performed significantly more trauma cases than plastic surgery residents did, but fewer overall cases, nerve repairs, and amputations, while nerve decompression volumes were similar between specialties. This information may help inform residency and fellowship directors regarding areas of potential training deficiency.

Understanding Health Economics in Joint Replacement Surgery.

The number of arthroplasty procedures has been rising at a significant rate, contributing to a notable portion of the nation's health care spending. This growth has contributed to an increase in the number of health care economic studies in the field of adult reconstruction surgery. Although these articles are filled with important information, they can be difficult to understand without a background in business or economics. The goal of this review is to define the common terminology used in health care economic studies, assess their value and benefit in the context of total joint arthroplasty, and highlight shortcomings in the current literature. [Orthopedics. 2022;45(4):e174-e182.].

A Nationwide Epidemiological Analysis of Finger Infections Presenting to Emergency Departments in the United States From 2012 to 2016.

Background: There is a paucity of literature exploring the epidemiology of finger infections presenting to emergency departments (EDs) on a national scale. The purpose of this study was to determine the national incidence of and risk factors for finger infections. Methods: Finger infections presenting to EDs between 2012 and 2016 were identified in the National Electronic Injury Surveillance System database. Finger infections were characterized by mechanism and type, with subanalyses for sex, race, and age. Results: Over this 5-year period, finger infections accounted for 80 519 visits to EDs in the United States. The annual incidence increased significantly from 4.4 per 100 000 person-years in 2012 to 6.2 in 2016. The 3 most common causes of finger infections were nail manicuring tools, knives, and doors. The most common diagnosis was finger cellulitis (46.3%). Significantly more men developed finger infections than women (relative risk of 1.4). The highest overall incidence was observed in 40- to 59-year-old men (7.8 per 100 000 person-years). Tenosynovitis resulted in the largest proportion of admissions (25%). Conclusions: We have demonstrated a rising incidence of finger infections presenting to EDs, with 40- to 59-year-old patients most at risk. The most common mechanism was the use of nail manicuring tools, such as nail clippers. Patient education may decrease finger infection incidence from these activities, and early detection of finger infections may be crucial to minimizing hospital admissions and invasive treatments.