Parallel K-Wire Placement Leads to Fusion and Midcarpal Settling in Scaphoid Excision Four-Corner Fusion.

BACKGROUND: Scaphoid excision 4-corner fusion is a motion-sparing procedure in patients with advanced radioscaphoid arthritis. This study introduces an alternate technique for scaphoid excision 4-corner fusion using a parallel Kirschner wire (K-wire) construct across the midcarpal joints that leads to reliable fusion rates, and good patient outcomes. METHODS: This is a single-surgeon, retrospective study of patients who underwent scaphoid excision 4-corner fusion, using a parallel K-wire construct across the midcarpal joints. Once fusion was achieved, K-wires were removed. Radiographic union rate, time to union, capitolunate angle, capitolunate coverage, and amount of midcarpal settling are measured. Patient-reported outcome measures and descriptive statistics are presented. RESULTS: Sixty-five wrists were included in this study with a mean age of 50.1 years. One patient was lost to follow-up. All 64 wrists (100%) fused at an average of 2.6 months. The mean capitolunate angle was 7°, and capitolunate coverage was 99.2%. Fifty-two patients (81%) had adequate radiographs for measurement. Average midcarpal settling was 1.1 mm. Thirty-two patients (51%) were available for long-term follow-up at an average of 5.3 years (0.7-10.2 years), and participated in patient reported outcomes (PRO) surveys. The mean Quick Disabilities of the Arm, Shoulder, and Hand score was 16.6, and numeric pain rating scale score was 1.8. CONCLUSIONS: Parallel K-wire placement across the midcarpal joints with scaphoid leads to a high rate of fusion with good patient outcomes long term. Midcarpal settling that occurs through dynamic compression around the K-wires may have contributed to bony fusion. This technique may provide an alternative approach to achieving reliable fusion across the midcarpal joints.

Magnetic Resonance Imaging-Measured Cross-Sectional Area of the Median Nerve.

Purpose: The size of the median nerve may serve as a useful parameter to predict carpal tunnel syndrome (CTS) in a subset of patients. The purpose of this study was to evaluate magnetic resonance imaging-based measurements of median nerve cross-sectional area (CSA) to examine trends between patient subgroups and CSA that may assist in predicting the individuals who are most likely to develop CTS symptoms. Methods: A retrospective chart review of 1,273 wrist magnetic resonance images was performed, and the images were analyzed to evaluate the median nerve CSA at the level of the pisiform and the hook of hamate. The age, sex, height, weight, and body mass index (BMI) of the patients were collected from their medical records. Results: The median nerve size correlated with patient BMI. Additionally, patients with CTS had larger median nerves at the hook of hamate and pisiform than those without CTS. When subdividing patients on the basis of BMI, obese patients with CTS had larger median nerve CSA at the pisiform than those without CTS. Conclusions: This study demonstrated that increased BMI is associated with increased median nerve CSA at the hook of hamate and pisiform in patients with or without CTS. Additionally, patients with CTS had larger median nerve CSA than those without CTS. Measurements at these locations may help predict individuals who are likely to experience median nerve impingement. Type of study/level of evidence: Prognostic III.

A Novel Mouse Model for SNP in Steroid Receptor Co-Activator-1 Reveals Role in Bone Density and Breast Cancer Metastasis.

The steroid receptor coactivator-1 (SRC-1) is a nuclear receptor co-activator, known to play key roles in both estrogen response in bone and in breast cancer metastases. We previously demonstrated that the P1272S single nucleotide polymorphism (SNP; P1272S; rs1804645) in SRC-1 decreases the activity of estrogen receptor in the presence of selective estrogen receptor modulators (SERMs) and that it is associated with a decrease in bone mineral density (BMD) after tamoxifen therapy, suggesting it may disrupt the agonist action of tamoxifen. Given such dual roles of SRC-1 in the bone microenvironment and in tumor cell-intrinsic phenotypes, we hypothesized that SRC-1 and a naturally occurring genetic variant, P1272S, may promote breast cancer bone metastases. We developed a syngeneic, knock-in mouse model to study if the SRC-1 SNP is critical for normal bone homeostasis and bone metastasis. Our data surprisingly reveal that the homozygous SRC-1 SNP knock-in increases tamoxifen-induced bone protection after ovariectomy. The presence of the SRC-1 SNP in mammary glands resulted in decreased expression levels of SRC-1 and reduced tumor burden after orthotopic injection of breast cancer cells not bearing the SRC-1 SNP, but increased metastases to the lungs in our syngeneic mouse model. Interestingly, the P1272S SNP identified in a small, exploratory cohort of bone metastases from breast cancer patients was significantly associated with earlier development of bone metastasis. This study demonstrates the importance of the P1272S SNP in both the effect of SERMs on BMD and the development of tumor in the bone.

Rupture Site Location of Surgically Treated Thumb Metacarpophalangeal Ulnar and Radial Collateral Ligaments.

Purpose: Thumb metacarpophalangeal collateral ligament injuries occur in 50 per 100,000 people. The most frequent rupture site locations that are often cited are the thumb ulnar collateral ligament (UCL) occurring distally from the proximal phalanx and the radial collateral ligament (RCL) occurring proximally from the metacarpal head.2,16 In this study, we report the frequency of the rupture site location of both thumb UCL and RCL injuries. Methods: A retrospective analysis of 1,004 consecutive finger collateral ligament surgeries performed at a single academic institution over 17 years was conducted. The inclusion criteria were any patient who underwent either a thumb UCL or RCL surgical repair. Patients were excluded if the rupture etiology was secondary to a laceration or a congenital or chronic deformity. Descriptive statistics were presented. Results: Three hundred forty-seven patients were included in this study, including 288 thumb UCL injuries and 59 thumb RCL injuries. The rupture site location for the thumb UCL was proximal in 5.9% (n = 17) of the cases, distal in 92.7% (n = 267), and midsubstance in 1.4% (n = 4). Fifty-three (18.4%) Stener lesions were noted. The rupture site location for the thumb RCL was proximal in 69.5% (n = 41) of the cases, distal in 25.4% (n = 15), and midsubstance in 5.1% (n = 3). Conclusions: In thumb UCL ruptures, the rupture site occurred most often at the proximal phalanx, whereas RCL injuries occurred most often at the metacarpal head. Overall, there was greater heterogeneity of RCL rupture site location frequency. Careful surgical exposure should be performed when repairing either the UCL or RCL. Further studies will determine if differences in rupture site location portend a difference in prognosis. Type of study/level of evidence: Prognostic III.

Comparison of cachectic and non-cachectic sarcoma patients reveals an important role of Notch signaling in metastasis and myogenesis.

Cancer-associated cachexia is a wasting syndrome that affects up to 50% of cancer patients. It is defined as unintentional weight loss ≥5% over 6 months and characterized by muscle atrophy, fatigue, and anorexia that are refractory to nutritional support. Sarcoma describes a diverse group of malignancies arising from the connective tissues. Sarcoma patients are uniquely susceptible to cancer-associated cachexia given its origins in the musculoskeletal system. Our previous research suggests that sarcoma cells may contribute to sarcoma-associated cachexia (SAC) via establishment of TNF-α-mediated inflammation and dysregulation of muscle homeostasis by abnormal Notch signaling. Here, we examine the role of the Notch pathway and pro-inflammatory cytokines in cells derived from cachectic and non-cachectic human sarcoma patients. We observed increased expression of Notch pathway genes in the cachexia group while no differences in pro-inflammatory cytokines were observed. Co-culture of muscle-derived stem cells (MDSCs) and sarcoma cells demonstrated the inhibition of MDSC maturation with both cachectic and non-cachectic patient cells, corresponding to elevated Pax7 and Notch pathway expression in MDSCs. Our findings suggest that there is no difference in inflammatory profile between cachexia and non-cachexia sarcoma samples. However, Cachectic sarcoma samples express increased Notch that mediates muscle wasting possibly through inhibition of myogenesis.

Research-Track Residency Programs in Orthopaedic Surgery: A Survey of Program Directors and Recent Graduates.

BACKGROUND: The importance of research in resident education has been emphasized in the orthopaedic surgery community, and a number of residency programs have incorporated a year or more of protected research time into their training. However, limited information exists as to what programs are looking for in applicants to research-track residency programs or the perceived benefits of completing such a program. METHODS: We identified orthopaedic surgery programs that have tracks involving at least 1 year of protected research time and sent surveys to their program directors and to the 2012 through 2016 research-track graduates. RESULTS: Twenty-three programs with research tracks were identified, and 19 program directors (83%) responded to the survey. The survey revealed that only 2 (11%) of these program directors were willing to accept lower scores and grades among applicants to their research track compared with their primary clinical (categorical) track. While most of the program directors (14 [74%]) preferred that applicants have an interest in academics, only a few (3 [16%]) considered it a failure if their research-track residents did not pursue academic careers. We obtained the e-mail addresses of 82 research-track graduates, and 66 (80%) responded to the survey. The survey revealed that those who went into academic careers were more likely than those who went into private practice to view completing a research track as beneficial for fellowship (73% versus 35%, respectively) and job (73% versus 22%, respectively) applications, believed that the income lost from the additional year of residency would be compensated for by opportunities gained from the research year (50% versus 17%, respectively), and said that they would pursue a research-track residency if they had to do it over again (81% versus 39%, respectively; all p values <0.05). CONCLUSIONS: The majority of program directors preferred that applicants to their research-track program have an interest in academics, although most did not consider it a failure if their research-track residents entered nonacademic careers. Graduates of research-track residency programs who entered academics more frequently viewed the completion of a research track as being beneficial compared with those who went into private practice.

Prophylactic perioperative dexamethasone decreases the incidence of postoperative C5 palsies after a posterior cervical laminectomy and fusion.

BACKGROUND CONTEXT: Postoperative C5 palsy is a well-known complication of cervical decompression procedures. Studies have shown that posterior laminectomy and fusions confer the greatest risk of C5 palsy. Despite this, pharmacologic preventive measures remain unknown. We hypothesize that prophylactic perioperative dexamethasone (DEX) will decrease the rate of postoperative C5 palsy in patients undergoing a multilevel posterior cervical laminectomy and fusion. PURPOSE: The purpose of this study was to assess the safety and efficacy of prophylactic perioperative DEX in decreasing the rate of postoperative C5 palsy. DESIGN: This is a retrospective, single-institution clinical study. PATIENT SAMPLE: The patient population included all patients undergoing multilevel posterior cervical laminectomy and instrumented fusion procedures for myeloradiculopathy or myelopathy, who also received a course of perioperative dexamethasone. Surgeries occurred between 2012 and 2017 at a single tertiary care center by a single surgeon with at least 1 year of follow-up. Patients who underwent decompression procedures other than multilevel posterior cervical laminectomy and instrumented fusions; had trauma, fracture; underwent decompression not including C5-level, insulin-dependent diabetes mellitus; and had documented adverse reactions to steroids were excluded. OUTCOME MEASURES: Preoperative demographics and postoperative complications, including development of postoperative C5 palsy, were considered as outcome measures. MATERIALS AND METHODS: A total of 189 consecutive patients who underwent multilevel posterior cervical laminectomy and instrumented fusion and received prophylactic perioperative DEX were reviewed. The rate of C5 palsy was investigated and compared with our historical control rate of C5 palsy before the institutional implementation of perioperative DEX. Demographics were reviewed, and risk factor stratification was analyzed. The safety of using DEX was investigated by examining postoperative complications. The clinical course of patients who developed C5 palsy was then reported. RESULTS: Postoperative C5 palsy occurred in 5 of the 138 patients (3.6%) meeting the inclusion criteria. Patients receiving perioperative DEX had a significantly decreased rate of postoperative C5 palsy compared with those who did not (3.6% vs. 9.5%, p=.01). Age was the only risk factor that was significantly correlated with development of C5 palsy (72.71±7.76 vs. 61.07±10.59, p=.02). Infection, seroma, and wound complication rates were 2.8%, 2.17%, and 1.44%, respectively, in patients receiving prophylactic DEX. All five patients receiving DEX who developed C5 palsy recovered with no residual deficits at an average of 16.8 weeks postoperatively. CONCLUSIONS: Perioperative prophylactic DEX therapy is a safe and effective way to decrease the incidence of C5 palsies in patients who undergo multilevel posterior laminectomy and fusion for myeloradiculopathy or myelopathy.

Patient Positioning in Arthroscopic Management of Posterior-Inferior Shoulder Instability: A Systematic Review Comparing Beach Chair and Lateral Decubitus Approaches.

PURPOSE: To analyze the available literature pertaining to clinical outcomes and complications of posterior-inferior shoulder stabilization performed arthroscopically in either the beach chair (BC) or lateral decubitus (LD) position. METHODS: According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), 3 databases (PubMed, EMBASE, and Medline) were searched up to January 2018 for English-language studies on posterior shoulder instability. Descriptive statistics are presented. The Methodological Index for Non-Randomized Studies (MINORS) scale was used to assess quality. RESULTS: Twenty-five studies were included, examining 1,085 patients (n = 140 BC; n = 945 LD), of mean age 25.0 years, 27.1% female, and mean 3.1 years of follow-up. MINORS scores for BC and LD were 11.2 and 9.8, respectively. Regardless of positioning, patients did not differ across numerous outcomes and various surgical factors (e.g., number of portals, anchors, anchor types, concomitant pathology, or postoperative rehabilitation protocol). Postoperative patient satisfaction ranged from 85% to 87.5% and 93% to 100% for patients treated in BC and LD positions, respectively. Although not reported for BC, overall and preinjury return-to-play (RTP) rates in LD patients ranged from 72% to 100% and 55% to 100%, respectively, returning from 3 to 7.6 months postoperatively. Failure rates in the BC and LD positions ranged from 0% to 9.4% and 0% to 29%, respectively. There were no differences in reported incidences of neuropraxia, stroke, nonfatal pulmonary embolus, vision loss, cardiac arrest, or other positioning-related complications. CONCLUSIONS: Arthroscopic management of posterior-inferior shoulder instability has a successful track record and minimal complication profile. Although patient positioning appears to influence results, with those treated in the LD position experiencing marginally higher patient satisfaction and failure rates, the current data prevent any conclusions being made regarding the superiority of one approach over another. As the clinical relevance of patient positioning remains to be determined, larger, higher-level study designs with long-term follow-up are required. LEVEL OF EVIDENCE: Level IV, systematic review of Level II, III, and IV studies.

Tumor Resection Guided by Intraoperative Indocyanine Green Dye Fluorescence Angiography Results in Negative Surgical Margins and Decreased Local Recurrence in an Orthotopic Mouse Model of Osteosarcoma.

BACKGROUND: Surgical resection with negative margins is the foundation of extremity sarcoma management. Failure to achieve negative surgical margins can result in local recurrence (LR), a potentially devastating complication. Indocyanine green (ICG) is a US FDA-approved fluorophore previously used to guide carcinoma resections. We investigated the potential of ICG as an intraoperative guide during experimental sarcoma resection. METHODS: Fifty 6-week-old immunocompetent Balb/c female mice received left proximal tibia paraphyseal injections of 5 × 105 K7M2 murine osteosarcoma cells. Animals were separated into two groups (n = 25 each): (1) ICG-assisted surgical resection; and (2) no ICG-assisted resection. Resections were performed 4 weeks after primary tumor engraftment. All animals received 7.5 ug ICG via retro-orbital injection 12 h prior to surgery. ICG fluorescence measurements and clinical evaluations were performed 4 weeks after resection to detect LR. RESULTS: Eleven of 25 animals from each group developed gross tumors. Four weeks after resection, group 1 had 0/11 tumor recurrences, while group 2 had recurrences in 9/11 (81.8%) experimental mice (p < 0.0002) (Fig. 2). There was a 100% NPV in group 1, and no tumor recurrence with fluorescence-free margins after the primary surgery. Group 2 had a 100% positive predictive value for the development of an LR if any fluorescent signal was present at the surgical margin after resection. CONCLUSION: Intraoperative ICG guidance led to reliably negative surgical margins and a diminished LR rate. Given the benign safety profile of ICG and its prior clinical success, these results could be immediately translatable to the clinical realm.

Disulfiram reduces metastatic osteosarcoma tumor burden in an immunocompetent Balb/c or-thotopic mouse model.

INTRODUCTION: The overall survival rate of patients with osteosarcoma (OS) and pulmonary metastases has remained stagnant at 15-30% for several decades. Disulfiram (DSF) is an FDA-approved aldehyde dehydrogenase inhibitor that reduces the metastatic phenotype of OS cells in vitro. Here we evaluate its in vivo efficacy, as compared to doxorubicin chemotherapy, in a previously-validated orthotopic model of metastatic OS. RESULTS: All treatment groups displayed a significantly reduced quantitative OS metastatic burden compared with controls. The metastatic burden of Lo DSF-treated animals was equivalent to the DXR group. Ninety-five percent of control animals displayed evidence of metastatic disease, which was significantly greater than all treatment groups. DISCUSSION: Disulfiram treatment resulted in a reduced burden of OS metastatic disease compared with controls. This was statistically-equivalent to doxorubicin. No additive effect was observed between these two therapies. MATERIALS AND METHODS: One-hundred twenty immunocompetent Balb/c mice received proximal tibia paraphyseal injections of 5 × 105 K7M2 murine OS cells. Therapy began three weeks after injection: saline (control), low-dose disulfiram (Lo DSF), high-dose disulfiram (Hi DSF), doxorubicin (DXR), Lo DSF + DXR, and Hi DSF + DXR. Transfemoral amputations were performed at 4 weeks. Quantitative metastatic tumor burden was measured using near-infrared indocyanine green (ICG) angiography.

Comparison of prognostic indices in patients who undergo melanoma brain metastasis radiosurgery.

OBJECTIVE The goal of this study was to use 4 prognostic indices to compare survival times of patients who underwent Gamma Knife stereotactic radiosurgery (SRS) to treat melanoma brain metastases. METHODS The authors analyzed 422 consecutive patients (1440 brain metastases) who underwent Gamma Knife SRS. The median total brain tumor volume was 4.7 cm3 (range 0.3-69.3 cm3), and the median number of metastases was 2 (range 1-32). One hundred thirty-two patients underwent whole-brain radiation therapy. Survival times were compared using recursive partitioning analysis (RPA), the Score Index for Radiosurgery (SIR), the Basic Score for Brain Metastases (BSBM), and the Diagnosis-Specific Graded Prognostic Assessment (DS-GPA). RESULTS The overall survival times after SRS were compared. With the RPA index, survival times were 2.6 months (Class III, n = 27), 5.5 months (Class II, n = 348), and 13.0 months (Class I, n = 47). With the DS-GPA index, survival times were 2.8 months (Scores 0-1, n = 67), 4.2 months (Scores 1.5-2.0, n = 143), 6.6 months (Scores 2.5-3.0, n = 111), and 9.4 months (Scores 3.5-4.0, n = 101). With the SIR, survival times were 3.2 months (Scores 0-3, n = 56), 5.8 months (Scores 4-7, n = 319), and 12.7 months (Scores 8-10, n = 47). With the BSBM index, survival times were 2.6 months (BSBM0, n = 47), 5.4 months (BSBM1, n = 282), 11.0 months (BSBM2, n = 86), and 8.8 months (BSBM3, n = 7). The DS-GPA index was the most balanced by case numbers in each class and provided the overall best prognostic index for overall survival. CONCLUSIONS The DS-GPA index proved most balanced and predictive of survival for patients with melanoma who underwent SRS as part of management for brain metastases. Patients whose DS-GPA score was ≥ 2.5 had predictably improved survival times after SRS.