Stem Cells and Bone Tissue Engineering.

Segmental bone defects that are caused by trauma, infection, tumor resection, or osteoporotic fractures present significant surgical treatment challenges. Host bone autograft is considered the gold standard for restoring function but comes with the cost of harvest site comorbidity. Allograft bone is a secondary option but has its own limitations in the incorporation with the host bone as well as its cost. Therefore, developing new bone tissue engineering strategies to treat bone defects is critically needed. In the past three decades, the use of stem cells that are delivered with different scaffolds or growth factors for bone tissue engineering has made tremendous progress. Many varieties of stem cells have been isolated from different tissues for use in bone tissue engineering. This review summarizes the progress in using different postnatal stem cells, including bone marrow mesenchymal stem cells, muscle-derived stem cells, adipose-derived stem cells, dental pulp stem cells/periodontal ligament stem cells, periosteum stem cells, umbilical cord-derived stem cells, peripheral blood stem cells, urine-derived stem cells, stem cells from apical papilla, and induced pluripotent stem cells, for bone tissue engineering and repair. This review also summarizes the progress using exosomes or extracellular vesicles that are delivered with various scaffolds for bone repair. The advantages and disadvantages of each type of stem cell are also discussed and explained in detail. It is hoped that in the future, these preclinical results will translate into new regenerative therapies for bone defect repair.

Surgeon Preference for Prophylactic Contralateral Fixation in Slipped Capital Femoral Epiphysis (SCFE) Patients: A Nationwide POSNA Survey Study.

BACKGROUND: It is estimated that 11% to 60% of unilateral slipped capital femoral epiphysis (SCFE) patients will develop contralateral pathology, usually within 18 months after the first event. Despite this, prophylactic fixation remains controversial, and there is significant variability in surgeon preferences. Thus, this study aimed to determine which factors predict surgeon preferences for prophylactic contralateral pinning in SCFE patients. METHODS: We designed a survey for pediatric orthopedic surgeons to collect data on (1) surgeon and hospital characteristics, (2) individual preference for contralateral SCFE pinning in three disparate hypothetical scenarios, and (3) personal risk-aversion traits. The questionnaire was distributed across the United States by the POSNA Evidence-Based Orthopaedics Committee. All POSNA members were eligible to respond. We performed analyses to evaluate the role of patient risk factors in hypothetical surgical decision-making and to determine if surgical training, hospital characteristics, and geographic region influenced prophylactic pinning in a surgeon's real-life practice. RESULTS: A total of 126 POSNA members responded to the survey. In the last year, a median of 6.5 SCFE patients was seen per surgeon (1243 patients total). A median of 10% of those patients underwent prophylactic contralateral fixation. In multiple analyses, surgeons were influenced by body mass index, open triradiate cartilage, patient race, various endocrine abnormalities, and specific radiographic measurements when deciding to fix the contralateral side prophylactically. Moreover, in multivariate regression, more years in practice and a hospital size of 500+ beds predicted fewer prophylactic fixation procedures (all P <0.05). Surgeons practicing in the South Atlantic, New England, and Mountain regions of the United States estimated the highest rate of contralateral pinning. CONCLUSIONS: This study's findings suggest that multiple factors influence surgeons' decisions to prophylactically fix the contralateral side in SCFE patients. Surgical training, hospital characteristics, and geographical regions played a role in decision-making. LEVEL OF EVIDENCE: N/A.

An Evaluation of the Impact of Mental Illness on Postoperative Breast Reconstruction Revision Surgery.

Breast cancer impacts millions of people yearly affecting various aspects of their lives-including but not limited to mental health. Patients with a known psychiatric history, specifically generalized anxiety disorder (GAD) and/or depression, have previously been shown to have an increased number of revisions after breast reconstruction. Methods: A commercially available database of 91 million unique patients, PearlDiver, was used to identify patients with breast cancer who underwent autologous free flap breast reconstruction. An average number of revisions were calculated from each group of patients-those with a history of anxiety and/or depression and patients without a history of anxiety and/or depression. A logistic regression was performed to determine risk factors associated with patients undergoing revision surgery. Results: A total of 39,683 patients with a history of breast cancer underwent autologous breast reconstruction between 2010 and 2020, of which 6308 (15.9%) patients had a history of GAD and/or depression before autologous reconstruction. A total of 13,422 (33.8%) patients received at least one revision surgery. Patients with GAD only, depression only, and concomitant GAD and depression received 1.40 revisions each with no significant differences between the control and any of the study groups (P = 0.956). Logistic regression did not find psychiatric history to be associated with patients undergoing revision surgery (OR, 0.94; 95% CI, 0.89-1.00). Conclusion: Patients who underwent autologous reconstruction for breast cancer demonstrated no difference in rates of secondary surgical revision, regardless of a concurrent mental health history.