Edward K. Rodriguez

Predictive factors of distal femoral fracture nonunion after lateral locked plating: a retrospective multicenter case-control study of 283 fractures.

INTRODUCTION Reported initial success rates after lateral locked plating (LLP) of distal femur fractures have led to more concerning outcomes with reported nonunion rates now ranging from 0 to 21%. Reported factors associated with nonunion include comorbidities such as obesity, age and diabetes. In this study, our goal was to identify patient comorbidities, injury and construct characteristics that are independent predictors of nonunion risk in LLP of distal femur fractures; and to develop a predictive algorithm of nonunion risk, irrespective of institutional criteria for clinical intervention variability. PATIENTS AND METHODS A retrospective review of 283 distal femoral fractures in 278 consecutive patients treated with LLP at three Level1 academic trauma centers. Nonunion was liberally defined as need for secondary procedure to manage poor healing based on unrestricted surgeon criteria. Patient demographics (age, gender), comorbidities (obesity, smoking, diabetes, chronic steroid use, dialysis), injury characteristics (AO type, periprosthetic fracture, open fracture, infection), and management factors (institution, reason for intervention, time to intervention, plate length, screw density, and plate material) were obtained for all participants. Multivariable analysis was performed using logistic regression to control for confounding in order to identify independent risk factors for nonunion. RESULTS 28 of the 283 fractures were treated for nonunion, 13 were referred to us from other institutions. Obesity (BMI>30), open fracture, occurrence of infection, and use of stainless steel plate were significant independent risk factors (P<0.01). A predictive algorithm demonstrates that when none of these variables are present (titanium instead of stainless steel) the risk of nonunion requiring intervention is 4%, but increases to 96% with all factors present. When a stainless plate is used, obesity alone carries a risk of 44% while infection alone a risk of 66%. While Chi-square testing suggested no institutional differences in nonunion rates, the time to intervention for nonunion varied inversely with nonunion rates between institutions, indicating varying trends in management approach. DISCUSSION Obesity, open fracture, occurrence of infection, and the use of stainless steel are prognostic risk factors of nonunion in distal femoral fractures treated with LLP independent of differing trends in how surgeons intervene in the management of nonunion.

A Dendritic Thioester Hydrogel Based on Thiol–Thioester Exchange as a Dissolvable Sealant System for Wound Closure†

A dissolvable dendritic thioester hydrogel based on thiol-thioester exchange for wound closure is reported. The hydrogel sealant adheres strongly to tissues, closes an ex vivo vein puncture, and withstands high pressures placed on a wound. The hydrogel sealant can be completely washed off upon exposure to thiolates based on thiol-thioester exchange and allow gradual wound re-exposure during definitive surgical care.

Does late night hip surgery affect outcome

BACKGROUND There is a perception that after-hours hip surgery may result in increased complication rates. Surgeon fatigue, decreased availability of support staff, and other logistical factors may play an adverse role. However, there are little data supporting this perception in the hip fracture literature. We present a retrospective study comparing outcomes of hip fracture surgeries performed after hours versus regular daytime hours and outcomes before and after implementation of a dedicated orthopedic trauma room staffed by a fellowship trained traumatologist. METHODS A retrospective study of 767 consecutive patients with intertrochanteric, subtrochanteric, or femoral neck fractures was performed for the years 2000 to 2006. Surgeries were stratified by time of incision into two groups: day (07:00 AM-05:59 PM) and night (06:00 PM-06:59 PM). Each group was further divided into a period before the implementation of a trauma room and the period after (August 2004). Records were examined for procedure length, intraoperative blood loss, complications (nonunion, implant failure, infection, deep vein thrombosis, pulmonary embolus, and refracture), reoperation, and mortality. RESULTS Four hundred ninety-nine patients were included the day group and 268 in the night group. There were no differences in terms of age, ethnicity, American Society of Anesthesiologists status, total number of comorbidities, and fracture type between groups. There were significantly more females in the night group than the day group. Intertrochanteric fractures were 64% of all fractures, femoral neck fractures were 34%, and subtrochanteric fractures were 2%. Duration of surgery for Dynamic Hip System procedures was significantly longer in the night group and also before the trauma room became available. These differences in duration of surgery also correlate with blood loss differences between the groups. Intramedullary nails also took longer to do at night. Hemiarthroplasties demonstrated no significant differences. The 1-year and 2-year mortalities of hip fracture patients operated during daytime hours in a trauma room (13 and 15%, respectively) were significantly less than they were before the implementation of the trauma room (25 and 37%, respectively). When the effect of the trauma room was eliminated, there were no significant differences between overall daytime and nighttime mortalities at 1 month, 1 year, and 2 years. There were no significant differences in other complications noted between the different groups. CONCLUSIONS We recommend that nighttime surgery should not be dismissed in hip fracture patients that would otherwise benefit from an early operation. However, there seems to be a decreasing trend in mortality when hip fractures are operated in a dedicated daytime trauma room staffed by a dedicated traumatologist.

A review of factors that affect artifact from metallic hardware on multi-row detector computed tomography.

Artifact arising from metallic hardware can present a major obstacle to computed tomographic imaging of bone and soft tissue and can preclude its use for answering a variety of important clinical questions. The advent of multirow detector computed tomography offers new opportunities to address the challenge of imaging in the presence of metallic hardware. This pictorial essay highlights current strategies for reducing metallic hardware artifacts and presents some illustrative clinical cases.

Driving after musculoskeletal injury. Addressing patient and surgeon concerns in an urban orthopaedic practice

Patient and public safety concerns make the timing of return to driving after musculoskeletal injury or orthopaedic surgery an important decision that is made by orthopaedic surgeons on a daily basis. Neither the American Academy of Orthopaedic Surgeons nor any other orthopaedic specialty society has endorsed recommendations, policies, or practice guidelines that address when a patient is able to return to driving after a musculoskeletal injury. To our knowledge, there are no specific guidelines available on how the decision should be made, who should be involved, or to what extent retesting of driving abilities after an injury should be required. The only and most recent guidelines available were developed in 2003 by the National Highway Traffic Safety Administration (NHTSA) in cooperation with the American Medical Association specifically to assess the ability to return to driving in older patients1. While these guidelines address to a limited degree musculoskeletal disability in older individuals, they are not specific to musculoskeletal injury or orthopaedic surgery and they are not entirely applicable to younger age groups. They also fail to incorporate a substantial part of the already limited orthopaedic literature on the topic2-10. The American Occupational Therapy Association (AOTA) is the only organization that has addressed the issue and actually offers Driving and Community Mobility Specialty Certification for occupational therapists who seek the training (www.aota.org). Comprehensive evaluation of driving abilities, as recommended by the AOTA, involves both an office evaluation and a behind-the-wheel assessment administered in a properly equipped test vehicle. Unfortunately, such specialized programs are not standard in conventional occupational therapy practices and are not always geographically or financially accessible to all patients recovering from musculoskeletal injury or orthopaedic surgery. To address the issue of return to driving in our practice, we formulated a return-to-driving policy that takes …

Short versus long cephalomedullary nails for the treatment of intertrochanteric hip fractures in patients older than 65 years.

Objectives: To compare failure rates between short and long cephalomedullary nails used for the treatment of intertrochanteric hip fractures in patients over 65 years of age. Design: Retrospective cohort study. Data were collected from medical records and radiographs. Setting: Three level 1 trauma centers. Patients/Participants: Patients aged 65 years or older who underwent treatment of an intertrochanteric hip fracture with a cephalomedullary nail between January 2004 and December 2010. Intervention: Open reduction and internal fixation of intertrochanteric hip fracture with either short or long cephalomedullary nail. Main Outcome Measurement: Postoperative treatment failure rate, defined as periprosthetic fracture or reoperation requiring removal or revision of nail, including conversion to arthroplasty. Results: Incidence of treatment failure (periprosthetic fracture and reoperation requiring removal of nail) was 30 of 559 (5.4%) for the entire cohort; 13 of 219 (5.9%) occurred after placement of a short nail compared with 17 of 340 (5.0%) after placement of a long nail (P = 0.70). There were 11 of 559 (2.0%) patients who sustained a periprosthetic fracture after nailing, 6 of 219 (2.7%) after short nails and 5 of 340 (1.5%) after long nails (P = 0.35). The remaining 19 treatment failures were major reoperations requiring removal of nail, 7 of 219 (3.2%) after short nails and 12 of 340 (3.5%) after long nails (P = 0.81). The reasons for these 19 revision procedures were: screw/helical blade cutout (16), progressive arthritis with conversion to arthroplasty (1), avascular necrosis of femoral head with conversion to arthroplasty (1), and symptomatic leg length discrepancy with conversion to arthroplasty (1). Median follow-up period for patients living at least 1 year postoperatively was 30 months (range, 12–85 months). Overall, 175 of 698 (25%) patients died within 1 year after index surgery. Conclusions: When using contemporary cephalomedullary implants, short and long nails exhibit similar treatment failure rates. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

On-Demand Dissolution of a Dendritic Hydrogel-based Dressing for Second-Degree Burn Wounds through Thiol-Thioester Exchange Reaction.

An adhesive yet easily removable burn wound dressing represents a breakthrough in second-degree burn wound care. Current second-degree burn wound dressings absorb wound exudate, reduce bacterial infections, and maintain a moist environment for healing, but are surgically or mechanically debrided from the wound, causing additional trauma to the newly formed tissues. We have developed an on-demand dissolvable dendritic thioester hydrogel burn dressing for second-degree burn care. The hydrogel is composed of a lysine-based dendron and a PEG-based crosslinker, which are synthesized in high yields. The hydrogel burn dressing covers the wound and acts as a barrier to bacterial infection in an in vivo second-degree burn wound model. A unique feature of the hydrogel is its capability to be dissolved on-demand, via a thiol-thioester exchange reaction, allowing for a facile burn dressing removal.

A novel methodology for the study of injury mechanism: ankle fracture analysis using injury videos posted on YouTube.com

Purpose: An inherent deficiency in the understanding of the biomechanics of fractures is the reliance on cadaveric or other nonphysiological injury models resulting from the prohibitive ethical and practical considerations of conducting injury studies in live participants. We describe a novel methodology for studying injury mechanisms using in vivo injury videos obtained from Youtube.com demonstrating injuries as they occur in real time and correlating them with the resulting injury radiographs. Methods: Over 1000 video clips of potential ankle fractures were assessed for clear visualization of the mechanism of injury, including the foot position and deforming force. Candidate videos were selected if the mechanism of injury was classifiable by those described by Lauge-Hansen and there appeared to be a significant mechanism to likely cause fracture. X-rays were then requested from the individuals posting the video clips. Videos and x-rays were reviewed and classified using the Lauge-Hansen system in a blinded manner. The deforming mechanism in the video clips was classified as supination external rotation, supination adduction (SAD), pronation external rotation (PER), or pronation abduction. X-ray fracture patterns were similarly classified. Results: Two hundred forty videos were selected and individuals posting the videos were contacted. Of 96 initial positive responses, we collected 15 videos with their corresponding radiographs. Eight had SAD-deforming trauma and seven had PER-deforming trauma as appreciated in the videos. There were 12 true ankle fractures. All five fractures judged by video to be SAD injuries resulted in a corresponding SAD pattern radiographic ankle fractures. Of the seven fractures judged by video to be PER injuries, only two resulted in PER pattern radiographic ankle fractures. Five PER injuries resulted in supination external rotation ankle fracture patterns. Conclusion: Our series shows that when in vivo injury videos are matched to their corresponding x-rays, the Lauge-Hansen system is only 58% overall accurate in predicting fracture patterns from deforming injury mechanism as pertaining to SAD and PER injury mechanisms. All SAD injuries correlated but only 29% of PER injuries resulted in a PER fracture pattern. This study illustrates the ethical and practical difficulties of using public access Internet YouTube videos for the study of injury dynamics. The current case series illustrates the methods potential and may lead to future research analyzing the validity of the Lauge-Hansen classification system as applied to in vivo injuries.

Correlation of AO and Lauge-Hansen Classification Systems for Ankle Fractures to the Mechanism of Injury

Background: Our aim was to assess whether the Lauge-Hansen (LH) and the Muller AO classification systems for ankle fractures radiographically correlate with in vivo injuries based on observed mechanism of injury. Methods: Videos of potential study candidates were reviewed on YouTube.com. Individuals were recruited for participation if the video could be classified by injury mechanism with a high likelihood of sustaining an ankle fracture. Corresponding injury radiographs were obtained. Injury mechanism was classified using the LH system as supination/external rotation (SER), supination/adduction (SAD), pronation/external rotation (PER), or pronation/abduction (PAB). Corresponding radiographs were classified by the LH system and the AO system. Results: Thirty injury videos with their corresponding radiographs were collected. Of the video clips reviewed, 16 had SAD mechanisms and 14 had PER mechanisms. There were 26 ankle fractures, 3 nonfractures, and 1 subtalar dislocation. Twelve fractures with SAD mechanisms had corresponding SAD fracture patterns. Five PER mechanisms had PER fracture patterns. Eight PER mechanisms had SER fracture patterns and 1 had SAD fracture pattern. When the AO classification was used, all 12 SAD type injuries had a 44A type fracture, whereas the 14 PER injuries resulted in nine 44B fractures, two 44C fractures, and three 43A fractures. Conclusion: When injury video clips of ankle fractures were matched to their corresponding radiographs, the LH system was 65% (17/26) consistent in predicting fracture patterns from the deforming injury mechanism. When the AO classification system was used, consistency was 81% (21/26). The AO classification, despite its development as a purely radiographic system, correlated with in vivo injuries, as based on observed mechanism of injury, more closely than did the LH system. Level of Evidence: Level IV, case series.

Detection of Orthopaedic Implants in Vivo by Enhanced-Sensitivity, Walk-Through Metal Detectors

BACKGROUND Since the September 11, 2001, World Trade Center terrorist attack, airports worldwide have heightened their security standards in efforts to discourage terrorist attacks. Patients have become increasingly concerned about whether their metallic implants will set off airport metal detectors. The purpose of this study was to assess rates of detection of various orthopaedic implants by airport detectors with the new security sensitivities. METHODS One hundred and twenty-nine volunteers with a total of 149 implants were asked to walk through an M-Scope three-zone metal detector at two sensitivity settings. Low sensitivity was equivalent to the United States Transportation Security Administration setting for regular security, and high sensitivity was equivalent to its standard for high security. RESULTS Of the 149 implants in 129 patients who were screened, eighty-four (56%) were trauma hardware, including intramedullary nails, plates, screws, and Kirschner wires, and sixty-five (44%) were arthroplasty implants. Seventy-seven (52%) of the 149 implants were detected by the metal detector at one or both settings. Multivariate analysis revealed that the type (p < 0.001), material (p < 0.001), and location (p < 0.001) of the implant were independent predictors of detection. The overall rate of detection was 88% for prosthetic replacements compared with 32% for plates, with the likelihood of detection being fifteen times greater (odds ratio = 15.0, 95% confidence interval = 5.9 to 39.1) for the prosthetic replacements. All total hip replacements and 90% of the total knee replacements were detected at the low-sensitivity setting. Intramedullary nails and Kirschner wires were not detected. The overall detection rate was 67% for implants in the lower extremity, 17% for those in the upper extremity, and 14% for those in the spine. The detection rate for implants in the lower extremity was ten times higher than that for implants in the upper extremity and eleven times higher than that for implants in the spine. CONCLUSIONS More than half of all orthopaedic implants may be detected by metal detectors used at commercial airports. Total joint prostheses will routinely set off the detector, whereas nails, plates, screws, and wires are rarely detected. Cobalt-chromium and titanium implants are more likely to be detected than stainless-steel implants.