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result(s) for
"Nauth, Aaron"
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Comparing Entry Points for Antegrade Nailing of Femoral Shaft Fractures
by
Tim Dwyer
,
Jaskarndip Chahal
,
Chetan Gohal
in
Bone Nails
,
Cohort analysis
,
Diaphyses - diagnostic imaging
2016
The optimal entry point for antegrade intramedullary nailing of femoral shaft fractures remains controversial. The purpose of this systematic review was to determine whether there is a difference in operative parameters, healing, and functional outcome when comparing the greater trochanter (GT) and piriformis fossa (PF) entry points. A systematic search of multiple databases and 3 major orthopedic meetings (American Academy of Orthopaedic Surgeons, Canadian Orthopaedic Association, and Orthopaedic Trauma Association) was conducted. Four studies (570 patients) met the inclusion criteria. Mean patient age was 34.5 years, and 60.4% were male. The GT entry point was associated with significantly shorter operative (mean difference [MD], −20.05 minutes [95% confidence interval (CI), −23.09 to −17.02]; The optimal entry point for antegrade intramedullary nailing of femoral shaft fractures remains controversial. The purpose of this systematic review was to determine whether there is a difference in operative parameters, healing, and functional outcome when comparing the greater trochanter (GT) and piriformis fossa (PF) entry points. A systematic search of multiple databases and 3 major orthopedic meetings (American Academy of Orthopaedic Surgeons, Canadian Orthopaedic Association, and Orthopaedic Trauma Association) was conducted. Four studies (570 patients) met the inclusion criteria. Mean patient age was 34.5 years, and 60.4% were male. The GT entry point was associated with significantly shorter operative (mean difference [MD], −20.05 minutes [95% confidence interval (CI), −23.09 to −17.02];
P
<.00001) and fluoroscopy times (MD, −24.55 seconds [95% CI, −43.23 to −5.86];
P
=.01). There was no significant difference in nonunion (risk ratio [RR], 0.74 [95% CI, 0.35 to 1.58];
P
=.44) and delayed union rates (RR, 0.94 [95% CI, 0.41 to 2.14];
P
=.88) between the 2 entry points. Heterogeneity in outcome measures reported prevented pooled analysis of functional outcomes. This review supports the use of the GT entry point during antegrade nailing of femoral shaft fractures over the PF entry point, with regard to shorter operative and fluoroscopy times. Healing and complication rates were not related to the entry point. Further study is required to determine the effect of each entry point on the surrounding soft tissue structures and ultimately its impact on postoperative function. [
Orthopedics.
2016; 39(1):e43–e50.]
Journal Article
Subtypes of endothelial progenitor cells affect healing of segmental bone defects differently
by
Lin, Tony
,
Nauth, Aaron
,
Schemitsch, Emil H.
in
Animals
,
Bone marrow
,
Bone Morphogenetic Protein 2 - metabolism
2017
Purpose
Treating fracture nonunion with endothelial progenitor cells (EPCs) is a promising approach. Nevertheless, the effect of different EPC-related cell populations remains unclear. In this study, we compared the therapeutic potential of early (E-EPCs) and late EPCs (L-EPCs).
Methods
Male Fischer 344 rats were used for cell isolation and in vivo experiments. Bone marrow-derived E-EPCs and L-EPCs were kept in culture for seven to ten days and four weeks, respectively. For each treatment group, we seeded one million cells on a gelatin scaffold before implantation in a segmental defect created in a rat femur; control animals received a cell-free scaffold. Bone healing was monitored via radiographs for up to ten weeks after surgery. In vitro, secretion of vascular endothelial growth factor (VEGF) and bone morphogenetic protein (BMP)-2 was quantified by ELISA for both cell populations. Tube formation assays were also performed.
Results
Final radiographs showed complete (four out of five rats) or partial (one out of five rats) union with E-EPC treatment. In contrast, complete healing was achieved in only one of five animals after L-EPC implantation, while control treatment resulted in nonunion in all animals. In vitro, E-EPCs released more VEGF, but less BMP-2 than L-EPCs. In addition, L-EPCs formed longer and more mature tubules on basement membrane matrix than E-EPCs. However, co-culture with primary osteoblasts stimulated tubulogenesis of E-EPCs while inhibiting that of L-EPCs.
Conclusions
We demonstrated that bone marrow-derived E-EPCs are a better alternative than L-EPCs for treatment of nonunion. We hypothesize that the expression profile of E-EPCs and their adaptation to the local environment contribute to superior bone healing.
Journal Article
Delayed Endothelial Progenitor Cell Therapy Promotes Bone Defect Repair in a Clinically Relevant Rat Model
by
Nauth, Aaron
,
Schemitsch, Emil H.
,
Bates, Brent D.
in
Animal models
,
Biomechanics
,
Bone marrow
2017
The repair of segmental bone defects remains a significant challenge for orthopaedic surgeons. Endothelial progenitor cells (EPCs) have successfully promoted the repair of acute defects in animal models; however, the ability of EPCs to induce the repair of chronic nonhealing defects, such as those often encountered clinically, has not been investigated. Therefore, the purpose of this study was to investigate the ability of EPCs delivered in delayed fashion to induce the repair of nonhealing defects in a clinically relevant model. In order to simulate delayed treatment, 5 mm segmental defects in Fischer 344 rat femora were treated with bone marrow-derived EPCs on a Gelfoam scaffold at 3 weeks post creation of the defect. At ten weeks posttreatment, 100% of EPC-treated defects achieved union, whereas complete union was only achieved in 37.5% of defects treated with Gelfoam alone. Furthermore, significant increases in ultimate torque (p=0.022) and torsional stiffness (p=0.003) were found in EPC-treated defects compared to controls. Critically, no differences in outcomes were observed between acute and delayed EPC treatments. These results suggest that EPCs can enhance bone healing when applied in an acute or delayed fashion and that their use may represent a clinically translatable therapy for bone healing in humans.
Journal Article
Regional anesthesia and acute compartment syndrome: principles for practice
2021
Acute compartment syndrome (ACS) is a potentially reversible orthopedic surgical emergency leading to tissue ischemia and ultimately cell death. Diagnosis of ACS can be challenging, as neither clinical symptoms nor signs are sufficiently sensitive. The cardinal symptom associated with ACS is pain reported in excess of what would otherwise be expected for the underlying injury, and not reasonably managed by opioid-based analgesia. Regional anesthesia (RA) techniques are traditionally discouraged in clinical settings where the development of ACS is a concern as sensory and motor nerve blockade may mask symptoms and signs of ACS. This Education article addresses the most common trauma and elective orthopedic surgical procedures in adults with a view towards assessing their respective risk of ACS and offering suggestions regarding the suitability of RA for each type of surgery.
Journal Article
Accelerated surgery versus standard care in hip fracture (HIP ATTACK): an international, randomised, controlled trial
by
González-Osuna, Aránzazu
,
Patel, Ameen
,
Sharma, Achal
in
Activities of Daily Living
,
Aged
,
Aged, 80 and over
2020
Observational studies have suggested that accelerated surgery is associated with improved outcomes in patients with a hip fracture. The HIP ATTACK trial assessed whether accelerated surgery could reduce mortality and major complications.
HIP ATTACK was an international, randomised, controlled trial done at 69 hospitals in 17 countries. Patients with a hip fracture that required surgery and were aged 45 years or older were eligible. Research personnel randomly assigned patients (1:1) through a central computerised randomisation system using randomly varying block sizes to either accelerated surgery (goal of surgery within 6 h of diagnosis) or standard care. The coprimary outcomes were mortality and a composite of major complications (ie, mortality and non-fatal myocardial infarction, stroke, venous thromboembolism, sepsis, pneumonia, life-threatening bleeding, and major bleeding) at 90 days after randomisation. Patients, health-care providers, and study staff were aware of treatment assignment, but outcome adjudicators were masked to treatment allocation. Patients were analysed according to the intention-to-treat principle. This study is registered at ClinicalTrials.gov (NCT02027896).
Between March 14, 2014, and May 24, 2019, 27 701 patients were screened, of whom 7780 were eligible. 2970 of these were enrolled and randomly assigned to receive accelerated surgery (n=1487) or standard care (n=1483). The median time from hip fracture diagnosis to surgery was 6 h (IQR 4–9) in the accelerated-surgery group and 24 h (10–42) in the standard-care group (p<0·0001). 140 (9%) patients assigned to accelerated surgery and 154 (10%) assigned to standard care died, with a hazard ratio (HR) of 0·91 (95% CI 0·72 to 1·14) and absolute risk reduction (ARR) of 1% (−1 to 3; p=0·40). Major complications occurred in 321 (22%) patients assigned to accelerated surgery and 331 (22%) assigned to standard care, with an HR of 0·97 (0·83 to 1·13) and an ARR of 1% (−2 to 4; p=0·71).
Among patients with a hip fracture, accelerated surgery did not significantly lower the risk of mortality or a composite of major complications compared with standard care.
Canadian Institutes of Health Research.
Journal Article
Total Hip Arthroplasty After Acetabular Fracture Is Associated With Lower Survivorship and More Complications
by
Morison, Zachary
,
Waddell, James P.
,
Nauth, Aaron
in
Acetabulum - injuries
,
Acetabulum - physiopathology
,
Acetabulum - surgery
2016
Background
Despite modern fracture management techniques allowing for near anatomic reduction of acetabular fractures, there continues to be a risk of posttraumatic arthritis and need for total hip arthroplasty (THA). Few well-controlled studies have compared THA after acetabular fractures with THAs performed for other indications in terms of survivorship or complications, and none, to our knowledge, present 10-year survivorship data in this setting.
Questions/purposes
(1) How does the 10-year survival of THA compare between those patients who underwent THA after an acetabular fracture and those who underwent THA for primary arthritis or avascular necrosis (AVN)? (2) Is there an increased risk of serious complications like infection, dislocation, and aseptic loosening as well as heterotopic ossification associated with a THA performed after a previous acetabular fracture?
Methods
This retrospective case-control study compared findings of patients who underwent THA after acetabular fracture versus a matched cohort of patients who had received a primary THA for primary osteoarthritis or AVN. Between 1987 and 2011, we performed 95 THAs after acetabular fracture; of those, 74 (78%) met inclusion criteria and had documented followup beyond 2 years in our institutional registry. We selected 74 matched patients based on an algorithm that matched patients based on preoperative diagnosis, date of operation, age, gender, and type of prosthesis. During this time, we performed approximately 8000 THAs that were potentially available for matching based on complete followup beyond 2 years. We compared cases and control subjects using the Kaplan-Meier survivorship estimator as well as a comparison of the proportions in each group that developed major complications (including infection, dislocation, loosening, and heterotopic ossification) based a retrospective chart review.
Results
The 10-year survivorship after THA was lower in patients with a previous acetabular fracture than in the matched cohort (70%, 95% confidence interval [CI], 64%–78%, versus 90%, 95% CI, 86–95%; p < 0.001). There was no difference in the 10-year survival rate for those patients whose acetabular fracture was initially treated conservatively and those treated by open reduction and internal fixation. Patients with previous acetabular fracture had a higher likelihood of developing infection (7% [five of 74] versus 0% [zero of 74]; odds ratio [OR], 11.79; p = 0.028), dislocation (11% [eight of 74] versus 3% [two of 74]; OR, 4.36; p = 0.048), or heterotopic ossification (43% [32 of 74] versus 16% [12 of 74]; OR, 3.93; p < 0.001).
Conclusions
In this case-control study, patients with a prior acetabular fracture had markedly inferior 10-year survivorship and more frequent serious complications when compared with patients undergoing THA for primary osteoarthritis or AVN. Given these findings, management of these complex cases should be in highly specialized units where the expertise of arthroplasty and trauma reconstruction is available.
Level of Evidence
Level III, therapeutic study.
Journal Article