High Variability of Mesenchymal Stem Cells Obtained via Bone Marrow Aspirate Concentrate Compared With Traditional Bone Marrow Aspiration Technique.

BACKGROUND: Bone marrow aspirate (BMA) is a common source for harvesting mesenchymal stem cells (MSCs), other progenitor cells, and associated cytokines and growth factors to be used in the biologic treatment of various orthopaedic pathologies. The aspirate is commonly centrifuged into a concentrated volume that can be immediately administered to a patient using commercially available kits. However, the handling and efficacy of BMA concentrate (BMAC) are still controversial. PURPOSE: To characterize BMA versus BMAC for MSC quantity, potency, and cytokine profile. STUDY DESIGN: Controlled laboratory study. METHODS: From 8 participants (age, 17-68 years), 30 mL of bone marrow was aspirated by a single surgeon from either the proximal humerus or distal femur and was separated into 2 equal samples. One sample was kept as BMA, and the other half was centrifuged into BMAC. The 2 samples then underwent flow cytometry for detection of MSCs, cell analysis for colony-forming units (CFUs), and cytokine profiling. A 2-tailed t test was used to detect differences between MSCs, CFUs, and cytokine density concentrations between BMA and BMAC. RESULTS: The average concentration of MSCs in both BMA and BMAC was 0.001%. Average MSC events detected by flow cytometry were significantly higher in BMA versus BMAC (15.1 and 8.1, respectively; P < .045). Expanded MSCs demonstrated similar phenotypes, but CFUs were significantly increased in BMA compared with BMAC (104 vs 68 CFUs, respectively; P < .001). Total protein concentration and cytokine profiling demonstrated great variability between BMA and BMAC and between patients. Most importantly, BMAC failed to concentrate MSCs in 6 of 8 samples. CONCLUSION: There is great variability in MSC concentration, total protein concentration, and cytokine profile between BMA and BMAC. CLINICAL RELEVANCE: When studying the clinical efficacy of BMAC, one must also evaluate the sample itself to determine the presence, concentration, and potency of MSCs if this is to be considered a cell-based therapy. Further standard operating procedures need to be investigated to ensure reproducible results and appropriate treatments.

Increased Survivorship of Cementless versus Cemented TKA in the Morbidly Obese. A Minimum 5-Year Follow-Up.

BACKGROUND: Total knee arthroplasty (TKA) in the morbidly obese patients can be challenging with an increased risk of complications. Studies have shown increased aseptic failures with well-aligned cemented TKAs in the obese patient. The purpose of this study is to determine if TKA in the morbidly obese (body mass index [BMI] ≥ 40) using cementless implants would demonstrate improved results and survivorship compared to cemented TKA at a minimum 5-year follow-up. METHODS: This is a retrospective study comparing clinical results of cemented vs cementless primary TKA with a posterior stabilized design TKA in morbidly obese (BMI ≥ 40) patients with minimal 5-year follow-up. There were 108 patients in the cementless group with a mean BMI of 45.6. In the cemented cohort, there were 85 cemented TKAs with a mean BMI of 45.0. Demographic, clinical, surgical, and radiographic data along with complications were extracted for all study patients. RESULTS: There were 5 failures requiring revision in the cementless group, including 1 for aseptic tibial loosening (0.9%). In the cemented group, there were 22 failures requiring revision, including 16 implants for aseptic loosening (18.8%; P = .0001). Survivorship with aseptic loosening as the endpoint was 99.1% in the cementless group vs 88.2% in the cemented cohort at 8 years (P = .02). CONCLUSION: Morbidly obese patients (BMI ≥ 40) have a higher failure due to aseptic loosening with cemented TKA with decreasing survivorship over time. The use of cementless TKA in morbidly obese patients with the potential of durable long-term biologic fixation and increased survivorship appears to be a promising alternative to mechanical cement fixation.

Behavioral Economics and Physician Board Meetings: Opportunity Cost, Regret, and Their Mitigation in Orthopaedic Surgery.

Health care is a business. Health care providers must become familiar with terms such as opportunity costs, the potential loss or gain when one choice is made in lieu of another. The purpose of this study was to calculate the opportunity cost of two orthopaedic surgery society board meetings and discuss these in the context of behavioral economics and regret. A literature search was conducted to determine an orthopaedic surgeon's average yearly salary, hours worked per week, and weeks worked per year. The details of two orthopaedic surgery professional society meetings that one senior author (CSR) attended were used to calculate opportunity cost. Although the true benefits are multifactorial and difficult to objectively quantify, awareness of the cost-benefit ratio can help guide time and resource management to maximize the return on investment while minimizing buyer's remorse and perhaps influence the media by which medical meetings are held in the future. (Journal of Surgical Orthopaedic Advances 27(1):10-13, 2018).

Biomechanics of the Injured Fibula Following Plate Fixation of a Concomitant Tibia Fracture To Fix or Not to Fix?

BACKGROUND: The mechanical role of supplemental fibula fixation in both bone lower leg fractures is not well defined. The benefit of fibula plate fixation in this context is controversial. The purpose of this study was to ascertain the mechanical contributions of the fibula under three conditions (intact, fractured, or plated fibula) following standard tibia locked plating. METHODS: A laboratory fracture model was created with 10 cadaveric legs (5 matched pairs) with no known history of lower extremity trauma or other musculoskeletal conditions. A both bone lower leg fracture was simulated by performing distal osteotomies, 3 to 5 cm above the tibia plafond, leaving a bony defect to simulate an unstable fracture (AOTrauma OTA classification 43-A3). Coronal and sagittal gauge-pins were placed above and below the fracture sites to measure relative displacement across three planes of motion. Axial and torsional loads were applied to the leg under the following conditions: tibia intact and fibula intact (control 1), tibia fracture and fibula intact, tibia fracture and fibula fracture (control 2), and the three conditions of primary interest: tibia plated and fibula intact, tibia plated and fibula fracture (osteotomy), and tibia plated and fibula plated. The load applied for level 1 was 75 N of axial compression and 0.3 Nm of torque, and the load for level 2 was 175 N of axial compression and 1.3 Nm of torque. RESULTS: There were significant differences in motion across the fracture site of the injured leg when the tibia was not plated compared with an intact and plated tibia, p < 0.05. However, when the tibia was plated, there were no significant differences in fracture motion when the fibula was left either intact, osteotomized, or underwent supplemental plate fixation, p > 0.05. This was true regardless of the loads applied. CONCLUSION: The mechanical stability of supplemental fibula fixation in a both bone lower leg fracture model was not significantly improved from standalone distal tibia fixation in this laboratory model. The clinical effects of these findings are yet to be demonstrated.

Outcomes after plating of olecranon fractures: A multicenter evaluation.

INTRODUCTION: The aim of this study was to report the physical and functional outcomes after open reduction internal fixation of the olecranon in a large series of patients with region specific plating across multiple centres. PATIENTS/METHODS: Between January 2007 and January 2014, 182 consecutive patients with a displaced olecranon fracture treated with open reduction internal fixation were included in this study. Retrospective review across four trauma centres collected elbow range of motion, DASH scores, hardware complications, and hardware removal. Postoperative visits in the outpatient clinic were at two, six, and twenty-four weeks. After 24 weeks, patients were eligible for hardware removal if symptomatic. All patients were contacted, at least 1 year following surgery, to determine if hardware was removed. RESULTS: 182 patients (75 women, 105 men) average age 50 (16-89) with 162 closed and 19 open displaced olecranon fractures were treated with one region specific plate. Nineteen were lost to followup leaving 163 for analysis with all patients united. The most common deficiency was a lack of full extension with 39% lacking at least 10° of extension. Hardware was asymptomatic in 67%, painful upon leaning in 20%, and restricted activities in 11% resulting in a 15% rate of hardware removal. Hardware complaints were more common if a screw was placed in the corner of the plate (P=0.004). When symptomatic, the area of the plate that was bothersome encompassed the whole plate in 39%, was at the edge of the plate in 33%, and was a screw head in 28%. The DASH scores, collected at final follow-up of 24 weeks, was 10.1±16, indicating moderate disability was still present. Patients who lacked 10° of extension had a DASH of 12.3 as compared with 10.5 for those with near full extension, but this was not significant (P=0.5). CONCLUSION: Plating of the olecranon leads to predictable union. The most common complication was lack of full extension with 39% lacking more than 10°, although this did not have any effect on DASH scores. Overall results indicate that disability still exists after 6 months with an average DASH score of 10. LEVEL OF EVIDENCE: Therapeutic level III.