Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
Add more filters










Database
Language
Publication year range
1.
Mil Med ; 186(11-12): e1115-e1123, 2021 11 02.
Article in English | MEDLINE | ID: mdl-33242094

ABSTRACT

BACKGROUND AND OBJECTIVE: Porcine translational models have become the gold-standard translational tool to study the effects of major injury and hemorrhagic shock because of their similarity to the human immunologic response to trauma. Segmental bone defects (SBDs) typically occur in warfighters with associated severe limb trauma. The purpose of this study was to develop a translational porcine diaphyseal SBD model in Yucatan minipigs (YMPs), which could be used in bone healing investigations that simulate injury-relevant conditions. We were specifically working toward developing a critical sized defect (CSD). METHODS: We used an adaptive experimental design in which both 25.0 mm and 40.0 mm SBDs were created in the tibial mid-diaphysis in skeletally mature YMPs. Initially, eight YMPs were subjected to a 25.0 mm SBD and treated with intramedullary nailing (intramedullary nail [IMN] 25mm). Due to unanticipated wound problems, we subsequently treated four specimens with identical 25.0 mm defect with dual plating (open reduction with internal fixation [ORIF] 25mm). Finally, a third group of four YMPs with 40.0 mm defects were treated with dual plating (ORIF 40mm). Monthly radiographs were made until sacrifice. Modified Radiographic Union Score for Tibia fractures (mRUST) measurements were made by three trauma-trained orthopedic surgeons. CT scans of the tibias were used to verify the union results. RESULTS: At 4 months post-surgery, mean mRUST scores were 11.7 (SD ± 1.8) in the ORIF 25mm YMPs vs. 8.5 (SD ± 1.4) in the IMN 25mm YMPs (P < .0001). All four ORIF 25mm YMPs were clinically healed. In contrast, none of the IMN 25mm YMPs were clinically healed and seven of eight IMN 25mm YMPs developed delayed wound breakdown. All four of the ORIF 40mm YMPs had flail nonunions with complete hardware failure by 3 months after surgery and were sacrificed early. CT scanning confirmed that none of the IMN 25mm YMPs, none of the ORIF 40mm YMPs, and two of four ORIF 25mm YMPs were healed. A third ORIF 25mm specimen was nearly healed on CT scanning. Inter-rater and intra-rater reliability interclass coefficients using the mRUST scale were 0.81 and 0.80, respectively. CONCLUSIONS: YMPs that had a 40 mm segment of bone removed from their tibia and were treated with dual plating did not heal and could be used to investigate interventions that accelerate bone healing. In contrast, a 25 mm SBD treated with dual plating demonstrated delayed but successful healing, indicating it can potentially be used to investigate bone healing adjuncts or conversely how concomitant injuries may impair bone healing. Pigs treated with IMN failed to heal and developed consistent delayed wound breakdown presumably secondary to chronic limb instability. The porcine YMP SBD model has the potential to be an effective translational tool to investigate bone healing under physiologically relevant injury conditions.


Subject(s)
Diaphyses , Fracture Fixation, Intramedullary , Animals , Bone Nails , Bone Plates , Extremities , Reproducibility of Results , Retrospective Studies , Swine , Swine, Miniature , Tibia/surgery , Trauma Severity Indices , Treatment Outcome
2.
J Pediatr Orthop ; 40(1): e25-e29, 2020 Jan.
Article in English | MEDLINE | ID: mdl-30969199

ABSTRACT

BACKGROUND: Foot abduction orthoses (FAO) are believed to decrease recurrence following treatment of congenital talipes equinovarus (CTEV) as described by Ponseti. The purpose of this project is to examine the outcomes of FAO bracing following treatment by the Ponseti method in a cohort of idiopathic CTEV patients. METHODS: After IRB approval, a cohort of patients aged 3 to 46 days with idiopathic CTEV was identified in a previous prospective study of brace compliance by family report and sensor. Dimeglio score and family demographic information were collected. Initial treatment was by the Ponseti method, with or without Achilles tenotomy. Following correction, patients had three months of full-time FAO bracing during which parents kept a log of compliance. Patients were followed until recurrence (need for further treatment) or age 5. RESULTS: In total, 42 patients with 64 affected feet met the above criteria and were included in the final analysis. Twenty-six feet (40%) went on to develop recurrence requiring further treatment, including casting, bracing, or surgery. Because of poor tolerance of the original FAO, 20 feet were transitioned to an alternative FAO, and 14 of these (70%) went on to recur (P<0.01). The casting duration (P=0.02) had a statistically significant relationship to recurrence. Patients who were casted for 9 weeks or more had a higher rate of recurrence (57.1% vs. 27.8%; P=0.02). Age at treatment start, Dimeglio score, demographic factors, and compliance during full-time bracing, whether by report or sensor, did not show a significant relationship with recurrence. CONCLUSIONS: The study showed a statistically significant relationship between the difficulty of CTEV correction and the risk of recurrent deformity requiring treatment. This relationship could be used to provide prognostic information for patients' families. Caregiver-reported compliance was not significantly related to recurrence. LEVEL OF EVIDENCE: Level III-Prognostic Retrospective Cohort Study.


Subject(s)
Casts, Surgical , Clubfoot/therapy , Foot Orthoses , Achilles Tendon/surgery , Braces , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Patient Compliance , Prospective Studies , Recurrence , Retrospective Studies , Tenotomy , Treatment Outcome
3.
J Orthop Trauma ; 33(5): e183-e189, 2019 May.
Article in English | MEDLINE | ID: mdl-30640295

ABSTRACT

OBJECTIVES: To compare the compressive force achieved and retained with the lag versus positional screw technique at various angles of screw application. METHODS: Sixty humeral sawbones were stratified into 6 groups based on the technique (lag or positional) and fixation angle (30, 60, or 90 degrees relative to the fracture plane). A sensor was placed between fragments to record compressive force. Absolute screw force is the final screw force. Normalized force is the final screw force minus force generated by reduction forceps. Retained force is the quotient of absolute force relative to reduction forceps force. RESULTS: Lag screws attained higher force than positional at 60 degrees (absolute force 41% higher, P = 0.041; normalized force 1300% higher, P = 0.008; retained force 60% higher, P = 0.008) and 90 degrees (absolute force 86% higher, P = 0.006; normalized force 730% higher, P = 0.005; retained force 70% higher, P = 0.011), but not at 30 degrees. For lag screws, compressive force was similar at 60 and 90 degrees (absolute force P = 0.174, normalized force P = 0.364, and retained force P = 0.496), but not 30 degrees. For positional screws, no difference was found between the 3 angles of fixation for absolute force (P = 0.059). Normalized force and retained force were similar at 60 and 90 degrees (P = 0.944 and P = 0.725, respectively), but not 30 degrees. CONCLUSIONS: Lag screw technique compressive force was superior to positional screw technique at 60 and 90 degrees. Comparison of force at angles of 60 and 90 degrees showed no significant difference for both techniques. Indicating 30 degrees deviation from perfect technique is tolerated without significant decrease in compressive force.


Subject(s)
Bone Screws , Compressive Strength , Fracture Fixation, Internal/methods , Humeral Fractures/surgery , Materials Testing/methods , Humans , Pressure
4.
J Arthroplasty ; 32(8): 2325-2331, 2017 08.
Article in English | MEDLINE | ID: mdl-28390881

ABSTRACT

BACKGROUND: Current patient selection criteria and medical risk stratification methods for outpatient primary total joint arthroplasty (TJA) surgery are unproven. This study assessed the predictive ability of a medically based risk assessment score in selecting patients for outpatient and short stay surgery. METHODS: A retrospective review of 1120 consecutive primary TJAs in an early discharge program was performed. An Outpatient Arthroplasty Risk Assessment ("OARA") score was developed by a high-volume arthroplasty surgeon and perioperative internal medicine specialist to stratify patients as "low-moderate risk (≤59)" and "not appropriate" (≥60) for early discharge. OARA, American Society of Anesthesiologists Physical Status Classification System (ASA-PS), and Charlson comorbidity index (CCI) scores were analyzed with respect to length of stay. RESULTS: The positive predictive value of the OARA score was 81.6% for the same or the next day discharge, compared with that of 56.4% for ASA-PS (P < .001) and 70.3% for CCI (P = .002) scores. Patients with OARA scores ≤59 were 2.0 (95% confidence interval [CI], 1.4-2.8) times more likely to be discharged early than those with scores ≥60 (P < .001), while a low ASA-PS score was 1.7 (95% CI, 1.2-2.3) times more likely to be discharged early (P = .001). CCI did not predict early discharge (P ≥ .301). With deliberate patient education and expectations for outpatient discharge, the odds of early discharge predicted by the OARA score, but not the ASA-PS score, increased to 2.7 (95% CI, 1.7-4.2). CONCLUSION: The OARA score for primary TJA has more precise predictive ability than the ASA-PS and CCI scores for the same or next day discharge and is enhanced with a robust patient education program to establish appropriate expectations for early discharge. Early results suggest that the OARA score can successfully facilitate appropriate patient selection for outpatient TJA, although consideration of clinical program maturity before adoption of the score is advised.


Subject(s)
Ambulatory Surgical Procedures , Arthroplasty, Replacement, Hip , Arthroplasty, Replacement, Knee , Patient Selection , Aged , Female , Humans , Male , Middle Aged , Outpatients/statistics & numerical data , Patient Discharge/statistics & numerical data , Retrospective Studies , Risk Assessment/methods
SELECTION OF CITATIONS
SEARCH DETAIL
...