Talar Neck Fractures With Associated Ipsilateral Foot and Ankle Fractures Have a Higher Risk of Avascular Necrosis

OBJECTIVES

To determine if talar neck fractures with concomitant ipsilateral foot and/or ankle fractures (TNIFAFs) are associated with higher rates of avascular necrosis (AVN) compared with isolated talar neck fractures (ITNs).

METHODS

DESIGN

Retrospective cohort.

SETTING

Single level I trauma center.

PATIENT SELECTION CRITERIA

Skeletally mature patients who sustained talar neck fractures from January 2008 to January 2017 with at least 6-month follow-up. Based on radiographs at the time of injury, fractures were classified as ITN or TNIFAF and by Hawkins classification.

OUTCOME MEASURES AND COMPARISONS

The primary outcome was the development of AVN based on follow-up radiographs, with secondary outcomes including nonunion and collapse.

RESULTS

There were 115 patients who sustained talar neck fractures, with 63 (55%) in the ITN group and 52 (45%) in the TNIFAF group. In total, 63 patients (54.7%) were female with the mean age of 39 years (range, 17-85), and 111 fractures (96.5%) occurred secondary to high-energy mechanisms of injury. There were no significant differences in demographic or clinical characteristics between groups ( P > 0.05). Twenty-four patients (46%) developed AVN in the TNIFAF group compared with 19 patients (30%) in the ITN group ( P = 0.078). After adjusting for Hawkins classification and other variables, the odds of developing AVN was higher in the TNIFAF group compared with the ITN group [odds ratio, 2.43 (95% confidence interval, 1.01-5.84); ( P = 0.047)].

CONCLUSIONS

This study found a significantly higher likelihood of AVN in patients with talar neck fractures with concomitant ipsilateral foot and/or ankle fractures compared to those with isolated talar neck fractures after adjusting for Hawkins classification and other potential prognostic confounders.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Non-Operative Treatment of Humeral Shaft Fractures with Immediate Functional Bracing versus Coaptation Splinting and Delayed Functional Bracing: A Retrospective Study

OBJECTIVES

To compare radiographic and clinical outcomes in non-operative management of humeral shaft fractures treated initially with coaptation splinting (CS) followed by delayed functional bracing (FB) versus treatment with immediate FB.

METHODS

Design: Retrospective cohort study.

SETTING

Academic Level 1 Trauma Center.

PATIENT SELECTION CRITERIA

Patients with closed humeral shaft fractures managed non-operatively with initial CS followed by delayed FB or with immediate FB from 2016 to 2022. Patients younger than 18 years and/or with less than 3 months follow-up were excluded.Outcome Measures and Comparisons: The primary outcome was coronal and sagittal radiographic alignment assessed at final follow-up. Secondary outcomes included rate of failure of non-operative management (defined as surgical conversion and/or fracture nonunion), fracture union, and skin complications secondary to splint/brace wear.

RESULTS

Ninety-seven patients were managed non-operatively with delayed FB (n=58) or immediate FB (n=39). Overall, the mean age was 49.9 years (range 18-94), and 64 (66%) patients were female. The immediate FB group had less smokers (p=0.003) and lower incidence of radial nerve palsy (p=0.025), with more proximal third humeral shaft fractures (p=0.001). There were no other significant differences in demographic or clinical characteristics (p>0.05). There were no significant differences in coronal (p=0.144) or sagittal (p=0.763) radiographic alignment between groups. In total, 33 (34.0%) humeral shaft fractures failed non-operative management, with 11 (28.2%) in the immediate FB group, and 22 (37.9%) in the delayed FB group (p=0.322). There were no significant differences in fracture union (p=0.074) or skin complications (p=0.259) between groups.

CONCLUSIONS

This study demonstrated that non-operative treatment of humeral shaft fractures with immediate functional bracing did not result in significantly different radiographic or clinical outcomes compared to treatment with coaptation splinting followed by delayed functional bracing. Future prospective studies assessing patient reported outcomes (PROs) will further guide clinical decision making.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

The Hawkins Sign of the Talus: The Impact of Patient Factors on Prediction Accuracy

BACKGROUND

Osteonecrosis is a complication of talar neck fractures associated with chronic pain and poor functional outcomes. The Hawkins sign, the radiographic presence of subchondral lucency seen in the talar dome 6 to 8 weeks after trauma, is a strong predictor of preserved talar vascularity. This study sought to assess the accuracy of the Hawkins sign in a contemporary cohort and assess factors associated with inaccuracy.

METHODS

A retrospective review of talar neck fractures at a level-I trauma center from 2008 to 2016 was conducted. Both the Hawkins sign and osteonecrosis were evaluated on radiographs. The Hawkins sign was determined on the basis of radiographs taken approximately 6 to 8 weeks after injury, whereas osteonecrosis was determined based on radiographs taken throughout follow-up. The Hawkins sign accuracy was assessed using proportions with 95% confidence intervals (CIs), and associations were examined with Fisher exact testing.

RESULTS

In total, 105 talar neck fractures were identified. The Hawkins sign was observed in 21 tali, 3 (14% [95% CI, 3% to 36%]) of which later developed osteonecrosis. In the remaining 84 tali without a Hawkins sign, 32 (38% [95% CI, 28% to 49%]) developed osteonecrosis. Of the 3 tali that developed osteonecrosis following observation of the Hawkins sign, all were in patients who smoked.

CONCLUSIONS

A positive Hawkins sign may not be a reliable predictor of preserved talar vascularity in all patients. We identified 3 patients with a positive Hawkins sign who developed osteonecrosis, all of whom were smokers. Factors impairing the restoration of microvascular blood supply to the talus may lead to osteonecrosis despite the presence of preserved macrovascular blood flow and an observed Hawkins sign. Further research is needed to understand the factors limiting Hawkins sign accuracy.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Does Scheduled Low-Dose Short-Term NSAID (Ketorolac) Modulate Cytokine Levels Following Orthopaedic Polytrauma? A Secondary Analysis of a Randomized Clinical Trial

OBJECTIVES

To determine whether scheduled low-dose, short-term ketorolac modulates cytokine concentrations in orthopaedic polytrauma patients.

METHODS

DESIGN

Secondary analysis of a double-blinded, randomized controlled trial.

SETTING

Single Level I trauma center from August 2018 to October 2022.

PATIENT SELECTION CRITERIA

Orthopaedic polytrauma patients between 18-75 years with a New Injury Severity Score greater than 9 were enrolled. Participants were randomized to receive 15 mg of intravenous (IV) ketorolac every 6 hours for up to 5 inpatient days or 2 mL of IV saline similarly.

OUTCOME MEASURES AND COMPARISONS

Daily concentrations of prostaglandin E2 (PGE2), interleukin (IL)-1a, IL-1b, IL-6, and IL-10. Clinical outcomes included hospital and intensive care unit (ICU) length of stay (LOS), pulmonary complications, and acute kidney injury (AKI).

RESULTS

Seventy orthopaedic polytrauma patients were enrolled, with 35 participants randomized to the ketorolac group and 35 to the placebo group. The overall IL-10 trend over time was significantly different in the ketorolac group (p = 0.043). IL-6 was 65.8% higher at enrollment compared to Day 3 (p < 0.001) when aggregated over both groups. There was no significant treatment effect for PGE2, IL-1a, or IL-1b (p > 0.05). There were no significant differences in clinical outcomes between groups (p > 0.05).

CONCLUSIONS

Scheduled low-dose, short-term, IV ketorolac was associated with significantly different mean trends in IL-10 concentration in orthopaedic polytrauma patients with no significant differences in PGE2, IL-1a, IL-1b, or IL-6 levels between groups. The treatment did not have an impact on clinical outcomes of hospital or ICU LOS, pulmonary complications, or AKI.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

A multi-institutional study of short-term mortality in COVID-positive patients undergoing hip fracture surgery: is survival better than expected?

PURPOSE

Early reports of 30-day mortality in COVID-positive patients with hip fracture were often over 30% and were higher than historical rates of 10% in pre-COVID studies. We conducted a multi-institutional retrospective cohort study to determine whether the incidence of 30-day mortality and complications in COVID-positive patients undergoing hip fracture surgery is as high as initially reported.

METHODS

A retrospective chart review was performed at 11 level I trauma centers from January 1, 2020 to May 1, 2022. Patients 50 years or older undergoing hip fracture surgery with a positive COVID test at the time of surgery were included. The primary outcome measurements were the incidence of 30-day mortality and complications. Post-operative outcomes were reported using proportions with 95% confidence interval (C.I.).

RESULTS

Forty patients with a median age of 71.5 years (interquartile range, 50-87 years) met the criteria. Within 30-days, four patients (10%; 95% C.I. 3-24%) died, four developed pneumonia, three developed thromboembolism, and three remained intubated post-operatively. Increased age was a statistically significant predictor of 30-day mortality (p = 0.01), with all deaths occurring in patients over 80 years.

CONCLUSION

In this multi-institutional analysis of COVID-positive patients undergoing hip fracture surgery, 30-day mortality was 10%. The 95% C.I. did not include 30%, suggesting that survival may be better than initially reported. While COVID-positive patients with hip fractures have high short-term mortality, the clinical situation may not be as dire as initially described, which may reflect initial publication bias, selection bias introduced by testing, or other issues.

LEVELS OF EVIDENCE

Therapeutic Level III.

Retrograde intramedullary nailing of the femur: identifying the true anatomic axis for the ideal start point

PURPOSE

Retrograde femoral intramedullary nailing (IMN) is commonly used to treat distal femur fractures. There is variability in the literature regarding the ideal starting point for retrograde femoral IMN in the coronal plane. The objective of this study was to identify the ideal starting point, based on radiographs, relative to the intercondylar notch in the placement of a retrograde femoral IMN.

METHODS

A consecutive series of 48 patients with anteroposterior long-leg radiographs prior to elective knee arthroplasty from 2017 to 2021 were used to determine the femoral anatomic axis. The anatomic center of the isthmus was identified and marked. Another point 3 cm distal from the isthmus was marked in the center of the femoral canal. A line was drawn connecting the points and extended longitudinally through the distal femur. The distance from the center of the intercondylar notch to the point where the anatomic axis of the femur intersected the distal femur was measured.

RESULTS

On radiographic review, the distance from the intercondylar notch to where the femoral anatomic axis intersects the distal femur was normally distributed with an average distance of 4.1 mm (SD, 1.7 mm) medial to the intercondylar notch.

CONCLUSION

The ideal start point, based on radiographs, for retrograde femoral intramedullary nailing is approximately 4.1 mm medial to the intercondylar notch. Medialization of the starting point for retrograde intramedullary nailing in the coronal plane aligns with the anatomic axis. These results support the integration of templating into preoperative planning prior to retrograde IMN of the femur, with the knowledge that, on average, the ideal start point will be slightly medial. Further investigation via anatomic studies is required to determine whether a medial start point is safe and efficacious in patients with distal femur fractures treated with retrograde IMNs.

Comparison of post-op opioid use and pain between short and long cephalomedullary nails in elderly intertrochanteric fractures

PURPOSE

It remains unknown if cephalomedullary nail (CMN) length has an impact on pain and opioid use following fixation. Given the lack of level I evidence favoring a specific CMN length to prevent adverse surgical outcomes, we investigated if CMN length impacts acute postoperative pain and opioid use. The authors hypothesize that the use of longer CMNs results in increased pain scores and morphine milligram equivalents (MME) intake during the 0-24 h (h) and 24-36 h postoperative period.

METHODS

A retrospective chart review was performed from 2010 to 2020 of patients ≥ 65 years-old who underwent CMN for IT fractures and fractures with subtrochanteric extension (STE). We compared patients who received short and long CMNs using numeric rating scale (NRS) pain scores and MME intake at 0-24 h and 24-36 h postoperatively.

RESULTS

330 patients receiving short (n = 155) and long (n = 175) CMNs met criteria. CMN length was found to not be associated with higher pain scores in the early postoperative phase. However, patients with long CMNs received higher MME from 0-24 h (25.4% estimated mean increase, p value = 0.02) and 24-36 h (22.3% estimated mean increase, p value = 0.04) postoperatively, even after adjusting for covariates, gender, and age.

CONCLUSION

Patients with long CMNs received greater MME postoperatively. Additionally, differences in pain and MME were not significantly different between patients with and without STE, suggesting our findings were not influenced by this pattern. These results suggest longer CMNs are associated with higher acute postoperative opioid intake among patients with IT fractures.

LEVEL OF EVIDENCE

Therapeutic level III.

Low-Dose Short-Term Scheduled Ketorolac Reduces Opioid Use and Pain in Orthopaedic Polytrauma Patients: A Randomized Clinical Trial

OBJECTIVE

To determine whether scheduled low-dose, short-term ketorolac is associated with reduced length of stay, opioid use, and pain in orthopaedic polytrauma patients.

DESIGN

Double-blinded, randomized controlled trial.

SETTING

One Level 1 trauma center.

PATIENTS

From August 2018 to October 2022, 70 orthopaedic polytrauma patients between 18-75 years-old with a New Injury Severity Score (NISS) > 9 were randomized. 70 participants were enrolled, with 35 randomized to the ketorolac group and 35 to the placebo group.

INTERVENTION

15 mg of intravenous (IV) ketorolac every 6 hours for up to 5 inpatient days or 2 mL of IV saline in a similar fashion.

MAIN OUTCOME MEASUREMENTS

Length of Stay (LOS), Morphine Milligram Equivalents (MME), Visual Analogue Scale (VAS), and Complications.

RESULTS

Study groups were not significantly different with respect to age, BMI, and NISS (p>0.05). Median LOS was 8 days (interquartile range [IQR], 4.5 to 11.5) in the ketorolac group compared to 7 days (IQR, 3 to 10) in the placebo group (p = 0.275). Over the 5-day treatment period, the ketorolac group experienced a 32% reduction in average MME (p = 0.013) and a 12-point reduction in baseline-adjusted mean VAS (p = 0.037) compared to the placebo group. There were no apparent short-term adverse effects in either group.

CONCLUSION

Scheduled low-dose, short-term IV ketorolac was associated with significantly reduced inpatient opioid use and pain in orthopaedic polytrauma patients with no significant difference in LOS and no apparent short-term adverse effects. The results support the use of scheduled low-dose, short-term IV ketorolac for acute pain control among orthopaedic polytrauma patients. Further studies are needed to delineate lasting clinical effects and potential long-term effects, such as fracture healing.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Association of Talar Neck Fractures With Body Extension and Risk of Avascular Necrosis

BACKGROUND

The objective of this study was to determine whether talar neck fractures with proximal extension (TNPE) into the talar body are associated with higher rates of avascular necrosis (AVN) compared to isolated talar neck (TN) fractures.

METHODS

A retrospective review of patients sustaining talar neck fractures at a level I trauma center from 2008 to 2016 was performed. Demographic and clinical data were collected from the electronic medical record. Fractures were characterized as TN or TNPE based on initial radiographs. TNPE was defined as a fracture that originates on the talar neck and extends proximal to a line subtended from the junction of the neck and the articular cartilage dorsal to the anterior portion of the lateral process of the talus. Fractures were classified according to the modified Hawkins classification for analysis. The primary outcome was the development of AVN. Secondary outcomes included nonunion and collapse. These were measured on postoperative radiographs.

RESULTS

There were 137 fractures in 130 patients, with 80 (58%) fractures in the TN group and 57 (42%) in the TNPE group. Median follow-up was 10 months (interquartile range, 6-18 months). The TNPE group was more likely to develop AVN as compared to the TN group (49% vs 19%, P < .001). Similarly, the TNPE group had a higher rate of collapse (14% vs 4%, P = .03) and nonunion (26% vs 9%, P = .01). Even after adjusting for open fracture, Hawkins fracture type, smoking, and diabetes, AVN still remained significant for the TNPE group as compared to the TN group with an odds ratio of 3.47 (95% CI, 1.51-7.99).

CONCLUSION

We found a higher rate of AVN, subsequent collapse, and nonunion in patients with TNPE compared to isolated TN fractures.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Functional Outcomes of Primary Arthrodesis (PA) versus Open Reduction and Internal Fixation (ORIF) in the Treatment of Lisfranc Injuries

OBJECTIVES

To determine whether PA or ORIF results in better functional outcomes via patient-reported outcome measures (PROMs). Reoperation rates and surgical characteristics amongst the two groups are evaluated as well.

DESIGN

A retrospective cohort study.

SETTING

Level 1 trauma center.

PATIENTS

Eighty-one patients treated via PA or ORIF for Lisfranc injuries between January 2010 and January 2019.

MAIN OUTCOME MEASUREMENTS

PROMs were collected via the validated Foot and Ankle Ability Measure (FAAM) questionnaire. Follow-up ranged from one to ten years post-treatment.

RESULTS

Two hundred patients underwent ORIF and 72 patients underwent PA. Eighty-one out of 272 patients responded to the questionnaire. The FAAM revealed ADL subscores for PA and ORIF of 69.78 ± 18.61 and 73.53 ± 25.60, respectively (P = 0.48). The Sports subscore for PA (45.81 ± 24.65) and ORIF (56.54 ± 31.13) were not significantly different (P = 0.11). Perceived levels of ADL (P = 0.32) and Sports (P = 0.81) function, compared to pre-injury levels, were also not significantly different between the two groups. Rates of reoperation were nearly identical for PA (28.1%) and ORIF (30.6%) (P = 1.00).

CONCLUSION

Our results suggest that neither PA nor ORIF is superior with regards to functional outcomes or rates of re-operation in the surgical treatment of Lisfranc injuries when appropriately triaged by the treating surgeon.Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Does prophylactic local tobramycin injection lower open fracture infection rates?

Objective: To determine whether local aqueous tobramycin injection in combination with systemic perioperative IV antibiotic prophylaxis will reduce the rate of fracture-related infection (FRI) after open fracture fixation. Other Outcomes of Interest: (1) To compare fracture nonunion rates and report differences between treatment and control groups and (2) compare bacterial speciation and antibiotic sensitivity among groups that develop FRI. Design: Phase 3 prospective, randomized clinical trial. Setting: Two level 1 trauma centers. Participants: Six hundred subjects (300 in study/tobramycin group and 300 in control/standard practice group) will be enrolled and assigned to the study group or control group using a randomization table. Patients with open extremity fractures that receive definitive internal surgical fixation will be considered. Intervention: Aqueous local tobramycin will be injected into the wound cavity (down to bone) after debridement, irrigation, and fixation, following closure. Main Outcome Measurements: Outcomes will look at the presence or absence of FRI, the rate of fracture nonunion, and determine speciation of gram-negative and Staph bacteria in each group with a FRI. Results: Not applicable. Conclusion: The proposed work will determine whether local tobramycin delivery plus perioperative standard antibiotic synergism will minimize the occurrence of open extremity FRI. Level of Evidence: Level 1.

Outcomes of Reamed Intramedullary Nailing for Lower Extremity Diaphyseal Fractures in COVID-Positive Patients: A Multi-institutional Observational Study

OBJECTIVE

To determine if reamed intramedullary nailing (IMN) of tibial and femoral shaft fractures exacerbated the hypercoagulable state of COVID infection, resulting in increased thromboembolic and pulmonary complications.

DESIGN

Retrospective chart review.

SETTING

Eleven Level I trauma centers.

PATIENTS

From January 1, 2020, to December 1, 2022, 163 patients with orthopaedic trauma and COVID positivity and 36 patients with tibial and femoral shaft fractures were included.

INTERVENTION

Reamed IMN.

MAIN OUTCOME MEASURES

Incidence of postoperative thromboembolic and respiratory complications.

RESULTS

Thirty-six patients with a median age of 52 years (range, 18-92 years; interquartile range, 29-72 years) met criteria. There were 21 and 15 patients with femoral and tibial shaft fractures. There were 15 patients sustaining polytrauma; of which, 10 had a new injury severity score of >17. All patients underwent reamed IMN in a median of 1 day (range, 0-12 days; interquartile range = 1-2 days) after injury. Two patients developed acute respiratory distress syndrome (ARDS) and 3 pneumonia. No patients had pulmonary embolism, deep vein thrombosis, or died within 30 days.

CONCLUSION

In this multi-institutional review of COVID-positive patients undergoing reamed IMN, there were no thromboembolic events. All patients developing pulmonary complications (ARDS or pneumonia) had baseline chronic obstructive pulmonary disease, were immune compromised, or sustained polytraumatic injuries with new injury severity score of >20. Given this, it seems reasonable to continue using reamed IMN for tibial and femoral shaft fractures after evaluation for COVID severity, comorbidities, and other injuries.

LEVELS OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

An Off-Label Use of a Tensioned Proximal Humerus Plate for Tibiotalar Fusion: A Case Report

CASE

A 70-year-old man presented with a left pilon fracture after a 10-foot fall from a ladder. The severe amount of comminution, joint destruction, and impaction from this injury eventually resulted in a tibiotalar fusion. Owing to multiple tibiotalar fusion plates not being long enough to span the extent of the fracture, a tensioned proximal humerus plate was used as an alternative.

CONCLUSION

We do not endorse the off-label use of a tensioned proximal humerus plate for all tibiotalar fusions; however, we do believe that this is a useful technique in certain situations with large zones of distal tibial comminution.

Avascular Necrosis of the Talus Following Subchondroplasty: A Case Report and Review of Literature

CASE

Avascular necrosis (AVN) of the talus in a 45-year-old female following subchondroplasty with calcium phosphate bone filler for treatment of anterolateral and posteromedial talar dome bone marrow lesions (BMLs). The patient subsequently presented as consultation, 18 months postoperatively, with AVN of the talus. After failing conservative management, the patient underwent a total ankle arthroplasty at 46 months after subchondroplasty with resolution of pain.

CONCLUSION

There are few studies that have reported on the safety of subchondroplasty of the talus. Given the tenuous blood supply to the talar body and poor patient outcomes associated with AVN, caution should be taken before extrapolating the generally positive results of subchondroplasty in the knee.

LEVEL OF EVIDENCE

Level IV.

Inflammatory cytokines associated with outcomes in orthopedic trauma patients independent of New Injury Severity score: A pilot prospective cohort study

Traumatic injury is the leading cause of mortality in patients under 50. It is associated with a complex inflammatory response involving hormonal, immunologic, and metabolic mediators. The marked elevation of cytokines and inflammatory mediators subsequently correlates with the development of posttraumatic complications. The aim was to determine whether elevated cytokine levels provide a predictive value for orthopedic trauma patients. A prospective cohort study of patients with New Injury Severity Score (NISS) > 5 was undertaken. IL-6, IL-8, IL-10, and migration inhibitory factor levels were measured within 24-h of presentation. Demographic covariates and clinical outcomes were obtained from the medical records. Fifty-eight patients (83% male, 40 years) were included. Addition of IL-6 to baseline models significantly improved prediction of pulmonary complication (LR = 6.21, p = 0.01), ICU (change in R²  = 0.31, p < 0.01), and hospital length of stay (change in R²  = 0.16, p < 0.01). The addition of IL-8 significantly improved the prediction of acute kidney injury (LR = 9.15, p < 0.01). The addition of postinjury IL-6 level to baseline New Injury Severity Score model is better able to predict the occurrence of pulmonary complications as well as prolonged ICU and hospital length of stay.

Rethinking the Coronal Anatomic Axis of the Distal Tibia for Intramedullary Nail Placement: A Cadaveric Study

Background: Recent studies have reported that targeting a center-center position at the distal tibia during intramedullary nailing (IMN) may result in malalignment. Although not fully understood, this observation suggests that the coronal anatomic center of the tibia may not correspond to the center of the distal tibia articular surface. Questions/Purposes: To identify the coronal anatomic axis of the distal tibia that corresponds to an ideal start site for IMN placement utilizing intact cadaveric tibiae. Methods: IMN placement was performed in 9 fresh frozen cadaveric tibiae. A guidewire was used to identify the ideal start site in the proximal tibia and an opening reamer allowed access to the canal. Each nail was then advanced without the use of a reaming rod until exiting the distal tibia plafond. Cadaveric and radiographic measurements were performed to determine the center of the nail exit site in the coronal plane. Results: Cadaveric and radiographic measurements identified the IMN exit site to correspond with the lateral 59.5% and 60.4% of the plafond, respectively. Conclusions: Tibial nails inserted using an ideal start site have an endpoint that corresponds roughly to the junction of the lateral and middle third of the plafond. Further studies are warranted to better understand the impact of IMN endpoint placement on the functional and radiographic outcomes of tibia shaft fractures.

Patient-Specific Precision Injury Signatures to Optimize Orthopaedic Interventions in Multiply Injured Patients (PRECISE STUDY)

SUMMARY

Optimal timing and procedure selection that define staged treatment strategies can affect outcomes dramatically and remain an area of major debate in the treatment of multiply injured orthopaedic trauma patients. Decisions regarding timing and choice of orthopaedic procedure(s) are currently based on the physiologic condition of the patient, resource availability, and the expected magnitude of the intervention. Surgical decision-making algorithms rarely rely on precision-type data that account for demographics, magnitude of injury, and the physiologic/immunologic response to injury on a patient-specific basis. This study is a multicenter prospective investigation that will work toward developing a precision medicine approach to managing multiply injured patients by incorporating patient-specific indices that quantify (1) mechanical tissue damage volume; (2) cumulative hypoperfusion; (3) immunologic response; and (4) demographics. These indices will formulate a precision injury signature, unique to each patient, which will be explored for correspondence to outcomes and response to surgical interventions. The impact of the timing and magnitude of initial and staged surgical interventions on patient-specific physiologic and immunologic responses will be evaluated and described. The primary goal of the study will be the development of data-driven models that will inform clinical decision-making tools that can be used to predict outcomes and guide intervention decisions.

Most orthopaedic trauma patients are using the internet, but do you know where they're going?

PURPOSE

The Internet is a resource that patients can use to learn about their injuries, treatment options, and surgeon. Previously, it was demonstrated that orthopaedic trauma patients are unlikely to use a reliable, provided source. It is unknown however, if patients are seeking information from elsewhere. The purpose of this study was to determine if orthopaedic trauma patients utilize the Internet and what websites are utilized. Our hypothesis was that the majority of patients use the Internet and when they do, are unlikely to use a reliable source.

METHODS

Orthopaedic trauma patients were surveyed in clinic at a Level I trauma center in the United States. The survey queried demographics, injury information, Internet access, and eHealth Literacy Scale (eHEALS). Data were analyzed using t-tests, Chi-squared tests, and a multivariate logistic regression, as appropriate.

RESULTS

138 patients with a mean age of 47.1 years (95% confidence interval: 44.0-50.3; 51.1% female) were included in the analysis. Despite 94.1% reporting access, only 55.8% of trauma patients used the Internet for information about their injury. Of those, 64.5% used at least one unreliable source. WebMD (54.8%) was the highest utilized website. Age, sex, employment, and greater eHEALS score were associated with increased Internet use (p<0.001).

CONCLUSION

The Internet has potential to be a useful, low cost, and readily available informational source for orthopaedic trauma patients. This study illustrates that a majority of patients seek information from the Internet after their injury, including unreliable websites like Wikipedia and Facebook. Our study emphasizes the need for active referral to trusted websites and initiation of organizational partnerships (e.g. OTA/AAOS) with common content providers (e.g. WebMD) to provide patients with accurate information about their injury and treatment.

LEVEL OF EVIDENCE

Prognostic, Level II.

Hypercoagulable Disorders in Orthopaedics: Etiology, Considerations, and Management

»

Hypercoagulable disorders (HCDs) can be inherited or acquired. An HCD of either etiology increases the chance of venous thromboembolic events (VTEs).

»

Patients with an HCD often have the condition discovered only after surgical complications.

»

We recommend that patients with a concern for or a known HCD be referred to the appropriate hematological specialist for workup and treatment.

»

Tourniquet use in the orthopaedic patient with an HCD is understudied and controversial. We recommend that tourniquets be avoided in the surgical management of patients with an HCD, if possible. When tourniquets are applied to patients with unknown HCD status, close follow-up and vigilant postoperative examinations should be undertaken.

Maintaining the Neutral Axis in the Treatment of Distal Femur Fractures Via Dual Plate or Nail Plate Combination Technique: When and How?

SUMMARY

Distal femur fractures in the elderly have been historically treated with locked plating or retrograde intramedullary nailing with good, reliable results. However, in certain more complex fracture patterns (native or periprosthetic), increased density of fixation via dual-plate or nail plate combination can help achieve immediate weight-bearing. It can also potentially increase rates of union by shifting and maintaining the neutral axis, distributing forces more evenly across the fracture site. Here, we discuss the indications, pros and cons of both dual-plate and nail plate combination techniques in a concise case-based format.

Dorsal Thompson: Approach to the Proximal Radial Shaft

Treatment principles in the management of radial shaft fractures, congruent with all fracture care, are to restore anatomy and function of the limb. Radial shaft fractures are unique in that preserving the anatomic bow of the radius, which allows for its rotation around the ulna during pronation and supination, is essential for proper function. The 2 main approaches for exposure of the proximal or middle third radial diaphyseal fractures are the volar "Henry" and the dorsal "Thompson." This article highlights the benefits of the dorsal Thompson approach, describes the key points of the operative technique, which allow for protection of the posterior interosseous nerve, and provides an overview of the measurable outcomes when using this approach. In the accompanying video, the steps of operative exposure to the proximal radial shaft with careful avoidance of the posterior interosseous nerve are demonstrated.

Is supplemental regional anesthesia associated with more complications and readmissions after ankle fracture surgery in the inpatient and outpatient setting?

BACKGROUND

There is concern that regional anesthesia is associated with increased risk of complications, including return to the hospital for uncontrolled pain once the regional anesthetic wears off.

METHODS

Retrospective database review of patients who underwent open reduction and internal fixation of a closed ankle fracture from 2014-16 who received general anesthesia alone (GA) or general anesthesia plus regional anesthesia (RA).

RESULTS

9459 patients met inclusion criteria. Patients in the RA group had significantly longer operative duration in both inpatient (GAI=71min vs RAI=79min, p=0.002) and outpatient setting (GAO=66min vs RAI=72min, p<0.001), lower overall LOS (GA=1.7 days vs RA=1.1 days, p<0.001), and higher readmission rate for pain (RAO=4 [0.3%] vs GAO=1 [0.0%], p=0.007).

CONCLUSIONS

Patients who received supplemental regional anesthesia had shorter hospital LOS, increased operative time, and increased readmission rates for rebound pain. However, the small number of patients needing readmission are not clinically significant demonstrating that regional anesthesia is safe, effective and readmission for rebound pain should not be a concern.

LEVEL OF EVIDENCE

III.

Newer generation of proximal tibia locking plates demonstrate large variability in their ability to capture the posteromedial fragment in bicondylar tibial plateau fractures

INTRODUCTION

The early generations of proximal tibial locking plates demonstrated inferior results when compared to dual plating in bicondylar tibial plateau fractures with posteromedial fragments (PMF). Modern plates have multiple rows of locking screws and variable angle technology -which tote the ability to capture the PMF. The purpose of this study was to determine if the modern plates could capture the PMF in a large series of bicondylar tibial plateau fractures.

MATERIALS & METHODS

Axial computer topography (CT) scans of 114 bicondylar tibial plateau fractures with PMF were analyzed. Five proximal tibia locking plates-in seven total configurations-were applied to radiopaque tibiae models. All possible screws were placed. Templates of screw trajectories were created based on the model CT scans. These were superimposed onto patient CT scan images to assess for screw penetration into the PMF. Number of screws fully within the PMF were recorded. Capture of the PMF was defined as having at least two screws within the fragment.

RESULTS

On average, all plates were able to capture 81.6% of PMF with an average of 3.77 [95% Confidence Interval (CI): 3.47-4.07] screws. However, their ability to capture all fragments varied greatly, from 55.7%-95.2% in fixed angle constructs. Overall, variable angle constructs had a significantly higher capture rate (98.5% vs. 74.9%; p<0.0001) and more screws in the PMF (5.88 [95% CI: 5.58-6.17] vs 2.93 [95% CI: 2.62-3.24]; p<0.0001) when compared to fixed angle constructs.

CONCLUSION

Newer generation locking plates vary greatly in their ability to capture the PMF. Variable angle technology dramatically increases the ability to capture the majority of PMFs. Prior biomechanical and clinical studies may yield substantially different results if repeated with these newer implants. Use of newer generation locked plates should not replace thorough preoperative planning.

A Review of Impact of Textile Research on Protective Face Masks

COVID-19, classified as SARS-CoV-2, is causing an ongoing global pandemic. The pandemic has resulted in the loss of lives and has caused economic hardships. Most of the devices used to protect against the transmission of the novel COVID-19 disease are related to textile structures. Hence, the challenge for textile professionals is to design and develop suitable textile structures with multiple functionalities for capturing viruses, passivating them, and, at the same time, having no adverse effects on humans during the complete period of use. In addition to manufacturing efficient, biocompatible, and cost-effective protective face masks, it is also necessary to inform the public about the benefits and risks of protective face mask materials. The purpose of this article is to address the concerns of efficiency and efficacy of face masks by primarily reviewing the literature of research conducted at the Technical University of Liberec. The main focus is on the presentation of problems related to the specification of aims of face mask applications, mechanisms of capture, durability, and modes of sterilization. The recommendations, instead of conclusions, are addressed to the whole textile society because they should be leading players in the design, creation, and proper treatment of face masks due to their familiarity with the complex behavior of textile structures and targeted changes of structural hierarchy starting from polymeric chains (nano-level) and ending in planar textile structures (millimeter level) due to action by mechanical, physical and chemical fields. This becomes extremely critical to saving hundreds of thousands of lives from COVID-19.

Leveraging Existing Institutional Resources to Maintain Quality Assurance Practices in Anatomic Pathology in the Era of Social Distancing

Introduction/Objective

Due to the COVID-19 pandemic, hospitals had to adapt practices to incorporate social distancing while maintaining quality assurance (QA) in anatomic pathology (AP). Prior to this, our general surgical pathology (SP) and cytopathology (CP) services held daily consensus conferences (CC) at a multi-headed microscope. Implementing social distancing meant only a few faculty were present onsite and avoidance of interactions at the multi-headed scope. In an effort to preserve QA through CC, faculty exploited the use of web conferencing through our HIPAA-compliant Zoom. We describe the utility of this new practice.

Methods

From 3/25-4/30/20, all SP and CP cases selected for CC were presented by respective pathologists (n=8) in their own offices by using individual microscopes with cameras, image acquisition software, and screen-sharing through Zoom. One pathologist was responsible for sending out a new CC Zoom link daily and recording the consensus diagnosis. All onsite pathologists and those at home participated.

Results

We presented 95 SP and 31 CP cases through Zoom compared to 300 SP and 60 CP cases presented at a similar timeframe prior to social distancing. This 68% and 48% decline could be attributed to elective procedure cancellation. We assigned a consensus diagnosis to all cases, with 77% overall being malignant diagnoses, and breast being the most common SP specimen type (22%). Additionally, all participating pathologists felt comfortable with the new format irrespective of being onsite or at home. Apart from minor audio issues, we did not notice significant lag time or visual disturbances that interfered with diagnostic abilities. Importantly, the transition did not involve investing in new technology.

Conclusion

The new virtual CC allowed our department to maintain QA practices in AP without sacrificing quality and serves as a starting point to investigating the use of this technology to other applications in AP, such as overnight frozen sections.

Pulmonary Granuloma Associated with Pneumocystis Jirovecii in a Patient with Peripheral T-Cell Lymphoma: Presentation of a Rare Case with Review of the Literature

Casestudy: Although Pneumocystis jirovecii (PJ) is a known opportunistic pulmonary infection among immunocompromised patients, it is a rare (&lt;5%) cause of pneumonia in this cohort. Majority of cases are observed in patients with HIV or solid organ transplant recipients. Granuloma formation in patients infected with PJ is even rarer. We present a case of multiple pulmonary granulomas associated with PJ in a non-HIV patient. A 49-year-old female with a history of asthma presented with worsening dyspnea. Initial imaging revealed multifocal bilateral areas of consolidation and a diagnostic bronchoalveolar lavage (BAL) demonstrated PJ organisms. Additional investigation was pursued to determine the etiology of this infection in a seemingly immunocompetent patient. New findings noted during hospitalization included a new maculopapular skin rash, significant weight loss, and lymphopenia. A bone marrow biopsy revealed a clonal proliferation of plasma cells. Subsequent imaging revealed mediastinal adenopathy. There was no improvement in symptoms despite treatment for pneumonia and a month later, a lung wedge biopsy revealed organizing acute lung injury and multiple non-caseating granulomas without lymphoid rimming, asteroid, or Schaumann bodies. Silver stain highlighted numerous PJ organisms within and outside of the granulomas. An inguinal lymph node and skin biopsies eventually revealed involvement by peripheral T-cell lymphoma (PTCL). Repeat BAL revealed clearance of organisms after additional therapy; however, the PTCL was refractory to chemotherapy and palliative care was pursued. To date, we could only find &lt;30 cases of pulmonary PJ granulomas in patients with hematologic malignancies. Most are in patients with B cell lymphomas and just 1 report in a patient with adult T-cell leukemia/lymphoma. In summary, this case highlights that PJ associated pulmonary granulomas are uncommon, can be a harbinger of an underlying immunocompromised state, such as a lymphoma, and are even rarer to be associated with PTCL.

The synergistic effect of preoperative opioid use and many associated preoperative predictors of poor outcome in the trauma patient population

OBJECTIVE

The purpose of this study is to investigate if preoperative opioid use is associated with other predictors of poor outcome and the effect of these factors on complications. We hypothesized that preoperative opioid use (POU) is associated with increased rates of postoperative complications.

DESIGN

Retrospective case control study.

SETTING

Academic level-1 trauma center.

PATIENTS/PARTICIPANTS

Patients with long bone, lower extremity fractures requiring operative fixation.

INTERVENTION

N/A.

MAIN OUTCOME MEASURES

Postoperative hospital admissions, emergency room (ER) visits, and reoperations.

RESULTS

399 patients (opioid naïve [ON] 80.2%, Age 38, 95% CI 35.9-39.6) were reviewed. Patients who had POU were older (P = 0.004), had higher BMI (P = 0.03), proportion of females (P < 0.001), tobacco use (P < 0.001), proportion of American Society of Anesthesiologist (ASA) class ≥ 3 (P < 0.001), and rates of substance use disorder (SUD) (P < 0.001). POU was associated with prolonged opiate use at 6 months (60.8%), 1 year (43.0%), higher rates of postoperative readmissions (18.1%), ER visits (17.2%), reoperations (17.5%), and complications (Odds Ratio [OR]: 2.4, P < 0.01). The risk of complication increased synergistically with the addition of other predictors: less than a high school education (OR: 4.6, P = 0.001); ASA class ≥3 (OR: 5.6, P < 0.001). All three factors combined also increased risk of complication synergistically (OR: 9.1, P = 0.003).

CONCLUSIONS

Our study demonstrates that many predictors of poor outcome frequently accompany POU. POU combined with many of these predictors synergistically increases the risk of complication. Outcomes-based payment models should reflect this expected rate of readmissions, ER visits and complications in this group. Patients with POU should be targeted with multi-disciplinary interventions aimed to modify these risk factors.

Below-Knee Amputation Resulting from an Arterial Thrombosis from Tourniquet Use in a Patient with Undiagnosed Factor V Leiden: A Case Report

CASE

A 38-year-old woman presented with previously undiagnosed factor V Leiden (FVL), who suffered a complete superficial femoral arterial thrombosis after tourniquet use during the surgical repair of one of her bilateral tibial plafond fractures. This patient's injury eventually resulted in a below-knee amputation.

CONCLUSION

We recommend expanding hypercoagulable screening on patients with risk factors based on a detailed history and physical examination. We also recommend limiting or negating tourniquet use in patients with FVL or other hypercoagulable disorders.

Anterolateral distal tibia locking plate osteosynthesis and their ability to capture OTAC3 pilon fragments

BACKGROUND

Intra-articular Pilon fractures remain therapeutically challenging due to osteochondral fracturing and comminution, marginal impaction, and insult to the soft tissue envelope. The purpose of this study was to compare the efficacy of anterolateral distal tibial locking plates in capturing main fracture fragments in tibial plafond fractures.

METHODS

From May 2011 to Dec 2015, 169 OTA C-type pilon fractures met inclusion and exclusion criteria with computed tomographic (CT) scans performed prior to definitive fixation. For each patient, the fracture lines were mapped, digitized, and graphically superimposed to create a compilation of fracture lines. Based on these average measurements, three distal tibia sawbones had three different anterolateral plates applied. Axial CT scan images were used to determine the efficacy of screw purchase in main fracture fragments in pilon fractures.

RESULTS

The Smith & Nephew PERI-LOC plate secured the largest number of fracture lines (90.1%) but missed the Volkmann fragment with greatest frequency at 3.6%. The Synthes 2.7/3.5 mm VA-LCP captured 87.3% of the fracture lines while missing the Volkmann fragment 3.2% of the time. The Synthes 3.5 mm LCP captured 86.5% of the fracture lines but was the best at securing the Volkmann fragment (1.2% missed). All three implants were deficient in capturing the medial malleolar fragment. The PERI-LOC and 2.7/3.5 mm VA-LCP did not differ with respect to percentage of fragments captured (p = 0.721) but both outperformed the 3.5 mm LCP (p = 0.021 and p = 0.05, respectively).

CONCLUSIONS

This study was consistent with prior literature in defining three main fracture fragments: anterior, medial, and posterior. All three plates were deficient in capturing the medial malleolar fragment. The Smith and Nephew PERI-LOC plate secured the most number of fracture lines, while the Synthes 3.5 mm LCP was least likely to miss the Volkmann fragment and most likely to miss the medial malleolar fragment. No plate was found to be superior to the other in capturing all fracture lines of the OTAC3 pilon fragments.

LEVEL OF EVIDENCE

Three.

Coronal Plane Deformity Correction in Distal Radius Fracture Fixation With the Volar Locking Plate

The goal of treatment for distal radius fractures is anatomic articular reduction and restoration of coronal and sagittal plane alignment, rotation, and angulation of the metadiaphyseal component of these fractures. This article presents a reproducible technique for restoring coronal plane alignment of the metadiaphyseal component of the fracture using an indirect reduction maneuver leveraging the volar locking plate as an indirect reduction aid. After applying an appropriately sized volar locking plate, the first screw is placed in the center of the shaft of the plate. Next, the distal row of subarticular locking screws is placed to neutralize a reduced articular surface. The shaft screw is subsequently loosened, and two Freer elevators are used to rotate the plate, indirectly translating the distal articular block and achieving improved coronal plane alignment. Last, the remaining diaphyseal screws are applied to appropriately neutralize the fracture. (Journal of Surgical Orthopaedic Advances 27(2):160-163, 2018).

Use of Volar Plate for Indirect Coronal Plane Reduction in an Intraarticular Distal Radius Fracture

Management of intraarticular distal radius fractures requires precise reconstruction of the articular surface to optimize outcomes. Treatment goals also include restoration of alignment, rotation, and angulation in both the coronal and sagittal planes of the metaphyseal component of these fractures. Surgical management with open reduction and internal fixation with a volar plate is often the preferred method of open treatment. However, a variety of different techniques have been described, and the preferred technique may be determined on an individual basis by the fracture characteristics, patient-dependent factors, or surgeon experience.

Thromboembolic Disease in Patients with Metastatic Femoral Lesions: A Comparison Between Prophylactic Fixation and Fracture Fixation

BACKGROUND

We are not aware of any previous studies that have compared the rate of venous thromboembolic events in patients who underwent prophylactic intramedullary nailing because of an impending fracture with the rate in patients who underwent intramedullary nailing after a pathological fracture. The objective of the present study was to determine if the rate of venous thromboembolic events varies between patients who are managed with prophylactic fixation and those who are managed with fixation after a pathological fracture.

METHODS

We performed a retrospective comparative study in which the Nationwide Inpatient Sample database was used to identify all patients who had undergone femoral stabilization, either for a pathological femoral fracture or for prophylactic fixation of femoral metastatic lesion, over a period of 10 consecutive years (between 2002 and 2011) in the United States. Demographic data, comorbidities, venous thromboembolic event rates, and other common postoperative complications were compared between the 2 groups.

RESULTS

Patients who were managed with prophylactic fixation had significantly higher rates of pulmonary embolism (p < 0.001; adjusted odds ratio, 2.1) and deep-vein thrombosis (p = 0.03; adjusted odds ratio, 1.5). Patients who were managed with fixation after a pathological fracture had a significantly greater need for blood transfusion, higher rates of postoperative urinary tract infection, and a decreased likelihood of being discharged to home (p < 0.001 for all).

CONCLUSIONS

Patients with metastatic disease who undergo prophylactic intramedullary nailing have higher observed rates of venous thromboembolic events than those who undergo nailing for the treatment of a pathological fracture and should be actively and vigilantly managed in the postoperative period.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Utility of portable monitoring in the diagnosis of obstructive sleep apnea

Obstructive sleep apnea (OSA) is a common but underdiagnosed sleep disorder, which is associated with systemic consequences such as hypertension, stroke, metabolic syndrome, and ischemic heart disease. Nocturnal laboratory-based polysomnography (PSG) is the gold standard test for diagnosis of OSA. PSG consists of a simultaneous recording of multiple physiologic parameters related to sleep and wakefulness including electroencephalography (EEG), electrooculography (EOG), surface electromyography (EMG), airflow measurement using thermistor and nasal pressure transducer, pulse oximetry and respiratory effort (thoracic and abdominal). Multiple alternative and simpler methods that record respiratory parameters alone for diagnosing OSA have been developed in the past two decades. These devices are called portable monitors (PMs) and enable performing sleep studies at a lower cost with shorter waiting times. It has been observed and reported that comprehensive sleep evaluation coupled with the use of PMs can fulfill the unmet need for diagnostic testing in various out-of-hospital settings in patients with suspected OSA. This article reviews the available medical literature on PMs in order to justify the utility of PMs in the diagnosis of OSA, especially in resource-poor, high-disease burden settings. The published practice parameters for the use of these devices have also been reviewed with respect to their relevance in the Indian setting.

Life-stage Analysis of Solvent Induced Fissures under Static Stress in PET Fibers

The paper discusses the impact of drawing poly(ethylene terephthalate) (PET) fibers in the presence of solvents, which consist of the first five homologues of aliphatic primary alcohols, namely methanol to amyl alcohol. The solvent induced deformation under tensile load leads to surface fissures characterized by four stages: fissure formation (birth), incipient draw (neck formation), partial draw, and full draw. This process results in internal void formation in the presence of a propagating neck. A design of experiment (DOE) was performed to screen out the process parameters critical for understanding surface fissure formation. Four process parameters were investigated: initial material properties (orientation); environment of draw (i.e. type of alcohols used as solvent); rate of extension; and amount of extension. The response of solvent induced deformation were characterized by the natural draw force reduction; number of fissures formed at time of birth, fissure width at time of formation, and neck angle. Of all the four process parameters involved, the analysis indicates that the material properties and amount of extension were the best predictors of solvent induced fissure formation. Organic solvents reduce the tension required for draw and create internal voids, a porous network, with possibly the penetrant being “sucked” into the interior of PET fibers drawn in the presence of alcohols.

The effects of sustained delivery of alendronate on the kidney in ovariectomized female rats

Bisphosphonates are indicated for the treatment and prevention of osteoporosis in adults; the treatment and prevention of glucocorticoid-induced osteoporosis; the treatment of Paget’s disease; and the treatment of multiple myeloma in patients with documented bone metastases. Two long-term trials in cancer patients demonstrated an increase in serum creatinine (SCr) when 8 mg of bisphosphonate was administered, prompting a recommendation to reduce the dose to 4 mg. The risk for renal toxicity remains a possibility following chronic administration of bisphosphonate treatment for osteoporosis. The goal of the study was to evaluate the kidney of osteoporotic female rats following chronic administration of alendronate using a drug delivery device for 4 weeks and compare the finding with control non-ovariectomized animals, ovariectomized control animals (OVX), and ovariectomized animals with an empty drug delivery system. The results of the study showed significant increases in body weights in the ovariectomized animals compared with non-ovariectomized animals. The organ wet-weights were not statistically different between the control and treatment groups or the ovariectomized and non-ovariectomized animals. Histological and histomorphometric analysis of the kidney revealed significant changes in the glomerular area on alendronate treated animals at 4 weeks when compared with ovx, ovx-sham and control non-ovariectomized animals. The results indicate chronic use of alendronate for osteoporosis may impair renal function or increase renal related problems in patients with existing kidney disease.

Impaired blood pressure recovery to hemorrhage in obese Zucker rats with orthopedic trauma

We have shown that obese Zucker rats with orthopedic trauma (OZT) exhibit a loss of arteriolar tone in skeletal muscle. We hypothesize that the loss of arteriolar tone in OZT blunts vasoconstrictor responses to hemorrhage, resulting in an impaired blood pressure recovery. Orthopedic trauma was induced with soft tissue injury and local injection of bone components in both hindlimbs in lean (LZT) and OZT (11-13 wk). One day after the orthopedic trauma, blood pressure responses following hemorrhage were measured in conscious control lean, control obese, LZT, and OZT. In another set of experiments, the spinotrapezius muscle of control and trauma animals was prepared for microcirculatory observation. Arteriolar responses to phenylephrine (PE) or hemorrhage were determined. Hemorrhage resulted in similar blood pressure responses in control animals and LZT, but the blood pressure recovery following hemorrhage was blunted in the OZT. In the spinotrapezius, OZT exhibited decreased arteriolar tone and blunted vasoconstrictor responses to PE and hemorrhage. Treatment with glibenclamide improved the blood pressure recovery in the conscious OZT and improved the arteriolar tone, and PE induced vasoconstriction in the spinotrapezius of the OZT. Thus, ATP-dependent K(+) channel-mediated loss of arteriolar tone in OZT blunts the arteriolar constriction to hemorrhage, resulting in impaired blood pressure recovery.

Orthopedic trauma-induced pulmonary injury in the obese Zucker rat

OBJECTIVE

Obese subjects with orthopedic trauma exhibit increased inflammation and an increased risk of pulmonary edema. Prostaglandin E(2) (PGE(2) ) production is elevated during inflammation and associated with increased vascular permeability. We hypothesize that pulmonary edema in obesity following orthopedic trauma is due to elevated PGE(2) and resultant increases in pulmonary permeability.

METHODS

Orthopedic trauma was induced in both hindlimbs in lean (LZ) and obese Zucker rats (OZ). On the following day, plasma interleukin-6 (IL-6) and PGE(2) levels, pulmonary edema, and pulmonary gas exchange capability were compared between groups: LZ, OZ, LZ with trauma (LZT), and OZ with trauma (OZT). Vascular permeability in isolated lungs was measured in LZ and OZ before and after application of PGE(2) .

RESULTS

As compared with the other groups, the OZT exhibited elevated plasma IL-6 and PGE(2) levels, increased lung wet/dry weight ratio and bronchoalveolar protein concentration, and an impaired pulmonary gas exchange. Indomethacin treatment normalized plasma PGE(2) levels and pulmonary edema. Basal pulmonary permeability in isolated lungs was higher in OZ than LZ, with a further increase in permeability following treatment with PGE(2) .

CONCLUSIONS

These results suggest that pulmonary edema in OZ following orthopedic trauma is due to an elevated PGE(2) and resultant increases in pulmonary permeability.

Use of demineralized bone matrix protein in osteoporotic rats: a histological evaluation - biomed 2009

Osteoporosis is a disease characterized by structural deterioration of bone tissue, leading to fragile bone with an increased risk for fractures. Bone morphogenetic proteins (BMPs) are supplemental bone graft materials that have osteoconductive properties of serving as a scaffold for bone to grow on and osteoinductive capability of stimulating the patient's own stem cells and growth factors to grow new bone. Osteoblast cells in osteoporotic bone have the ability to produce BMPs and other factors needed for adequate bone formation when activated, demonstrating that there are factors that can serve as stimulus for fracture repair in osteoporosis. The objective of this study was to deliver a cascade of growth factors from demineralized bone (DBM), a rich composite of BMP-2, BMP-4, and BMP-7, to the fracture defect site in an effort to enhance osteoporotic fracture healing. 72 female ovariectomized (OVX) rats were divided into six treatment groups: intact control, OVX control, intact + drill defect (sham), OVX + drill defect (sham), intact + drill defect + DBM, and OVX + drill defect + DBM. Ovariectomy induced osteoporosis. DBM was delivered in a sustained manner via a novel local drug delivery device, tricalcium phosphate combined with lysine (TCPL). At 2 and 4 weeks post implantation, animals in each group were sacrificed, the femurs were retrieved and underwent histological analysis. Other surrounding and vital organs were also harvested and analyzed to study the systemic effects of DBM. The results suggest that DBM was effective in increasing osteocyte number en route to restoring periosteal and endosteal area in both intact and OVX animal populations.

Analysis of tobramycin release from beta tricalcium phosphate drug delivery system

The purpose of this pilot study was to determine the in-vitro release properties of tobramycin by tricalcium phosphate (TCP) delivery capsules. In addition, two different forms of TCP capsules, matrix and reservoir, were characterized. Three types of TCP ceramic capsules were constructed: six sham matrix capsules (Group A), six tobramycin loaded matrix capsules (Group B), and four hollow tobramycin loaded reservoir capsules (Group C). The capsules were submerged in PBS and 1 mL of elutant was collected, centrifuged, and analyzed via spectrometry for 14 days. In addition, elutant from selected capsules was bleached onto bacterial discs and placed on confluent Staphylococcus aureus agar plates to evaluate zones of inhibition. Their was a statistically significant difference in the concentration of tobramycin released between Group A versus Group B and Group C capsules and a statistically significant difference in the concentration of tobramycin released between Group B and Group C capsules over a 14 day period. Bacterial discs containing Group A elutant did not have a visible zone of inhibition, while both Groups B and C elutant discs had an appreciable zone of inhibition for the duration of the study. Group A sham capsules eluted no antibiotics implying that TCP by itself lacks antibacterial properties. Group B matrix and Group C reservoir capsules eluted sustained tobramycin concentrations that were bactericidal for the duration of the study. The data from this study demonstrates that the sustained release property of tobramycin loaded TCP matrix and reservoir capsules make them a suitable mode for local antibiotic delivery.

Suture plication, thermal shrinkage, and sclerosing agents: effects on rat patellar tendon length and biomechanical strength

BACKGROUND

Shortening or tightening of dense, collagenous tissues is often desirable in the treatment of laxity.

PURPOSE

To compare the effect of stress-protection suture, radiofrequency thermal shrinkage combined with stress-protection suture, and a 5% sodium morrhuate sclerosing injection on the length and biomechanical strength of the rat patellar tendon.

HYPOTHESIS

Sclerosing agents will increase tendon mechanical strength. Thermal shrinkage combined with stress-protection suture and stress-protection suture only will cause a short-term decrease in tendon strength. All 3 methods will produce equivalent shortening of the tendon.

STUDY DESIGN

Controlled laboratory study.

METHODS

Forty-six female retired breeder rats were split into 4 groups, each receiving 1 of the 3 aforementioned treatments plus a control group that received a saline injection. After 4 weeks' survival, the length and biomechanical properties of the patellar tendons were measured and compared to the contralateral untreated tendon.

RESULTS

Rats treated with stress-protection suture had shorter tendons. Radiofrequency thermal shrinkage combined with stress-protection suture yielded tendons that were both shorter and stronger than were the untreated contralateral tendons. The sodium morrhuate-injected tendons were stronger whereas the saline-treated tendons were weaker than were their respective untreated contralateral tendons.

CONCLUSION

Surgical stress-protection suture without radiofrequency shrinkage is most effective at shortening the length of the rat patellar tendon, whereas radiofrequency thermal shrinkage combined with stress-protection suture as well as sodium morrhuate are effective at increasing the strength of rat patellar tendons.

CLINICAL RELEVANCE

Judicious use of thermal shrinkage in combination with stress protection may improve ligament strength and decrease laxity.