Publications by authors named "Adam K Lee"

14 Publications

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Treatment of tibial plateau fractures with a novel fenestrated screw system for delivery of bone graft substitute.

Eur J Orthop Surg Traumatol 2021 Jan 24. Epub 2021 Jan 24.

Department of Orthopaedic Surgery, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA.

Purpose: The purpose of this study was to describe the incidence of subsidence in patients with AO/OTA 41 (tibial plateau) fractures which were repaired with a novel fenestrated screw system to used to deliver CaPO4 bone substitute material to fill the subchondral void and support the articular reduction.

Methods: Patients with unicondylar and bicondylar tibial plateau fractures were treated according to the usual technique of two surgeons. After fixation, the Zimmer Biomet N-Force Fixation System®, a fenestrated screw that allows for the injection of bone substitute was placed and used for injection of the proprietary calcium phosphate bone graft substitute into the subchondral void. For all included patients, demographic information, operative data, radiographs, and clinic notes were reviewed. Patients were considered to have articular subsidence if one or more of two observations were made when comparing post-operative to their most recent clinic radiographs: > 2 mm change in the distance between the screw and the lowest point of the tibial plateau, > 2 mm change in the distance between the screw and the most superior aspect of the plate. Data were analyzed to determine if there were any identifiable risk factors for complication, reoperation, or subsidence using logistic regression. Statistical significance was set at p < 0.05.

Results: 34 patients were included with an average follow-up of 32.03 ± 22.52 weeks. There were no overall differences between height relative to the medial plateau or the plate. Two patients (5.9%) had articular subsidence. Six patients (15.2%) underwent reoperation, two (6%) for manipulations under anaesthesia due to arthrofibrosis, and four (12%) due to infections. There were 6 (19%) total infections as 2 were superficial and required solely antibiotics. One patient had early failure.

Conclusion: Use of a novel fenestrated screw system for the delivery of CaPO4 BSM results in articular subsidence and complication rates similar to previously published values and appears to be a viable option for addressing subchondral defects in tibial plateau fractures.

Level Of Evidence: IV.
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http://dx.doi.org/10.1007/s00590-021-02871-yDOI Listing
January 2021

A Survey to Assess Agreement Between Pelvic Surgeons on the Outcome of Examination Under Anesthesia for Lateral Compression Pelvic Fractures.

J Orthop Trauma 2020 09;34(9):e304-e308

Department of Orthopaedics, University of Southern California, Los Angeles, CA.

Objectives: To assess agreement among pelvic surgeons regarding the interpretation of examination under anesthesia (EUA), the methodology by which EUA should be performed, and the definition of a positive examination.

Design: Survey.

Patients/participants: Ten patients who presented to our Level 1 trauma center with a pelvic ring injury were selected as clinical vignettes. Vignettes were distributed to 15 experienced pelvic surgeons.

Intervention: Examination under anesthesia.

Main Outcome Measurements: Agreement regarding pelvic fracture stability (defined as >80% similar responses), need for surgical fixation, definition of an unstable EUA, and method of performing EUA.

Results: There was agreement that a pelvic fracture was stable or unstable in 8 (80%) of 10 cases. There was agreement that fixation was required or not required in 6 (60.0%) of 10 cases. Seven (46.7%) surgeons endorsed performing a full 15-part EUA, whereas the other 8 (53.3%) used an abbreviated or alternative method. Eight (53.3%) surgeons provided a definition of what constitutes a positive EUA, whereas the remaining 7 did not endorse adhering to a strict definition.

Conclusions: Pelvic surgeons generally agree on what constitutes a positive or negative EUA but not necessarily the implications of a positive or negative examination. There is no clear consensus among surgeons regarding the method of performing EUA nor regarding the definition of a positive EUA.

Level Of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.
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http://dx.doi.org/10.1097/BOT.0000000000001759DOI Listing
September 2020

Standard Versus Low-Dose Computed Tomography for Assessment of Acetabular Fracture Reduction.

J Orthop Trauma 2020 09;34(9):462-468

Department of Orthopaedic Surgery, University of Southern California, Keck School of Medicine, Los Angeles, CA.

Objective: First, to assess the impact of varying computed tomography (CT) radiation dose on surgeon assessment of postfixation acetabular fracture reduction and malpositioned implants. Second, to quantify the accuracy of CT assessments compared with the experimentally set displacement in cadaver specimens. We hypothesized that a CT dose would not affect the assessments and that CT assessments would show a high concordance with known displacement.

Methods: We created posterior wall acetabular fractures in 8 fresh-frozen cadaver hips and reduced them with varying combinations of step and gap displacement. The insertion of an intra-articular screw was randomized. Each specimen had a CT with standard (120 kV), intermediate (100 kV), and low-dose (80 kV) protocols, with and without metal artifact reduction postprocessing. Reviewers quantified gap and step displacement, overall reduction, quality of the scan, and identified intra-articular implants.

Results: There were no significant differences between the CT dose protocols for assessment of gap, step, overall displacement, or the presence of intra-articular screws. Reviewers correctly categorized displacement as anatomic (0-1 mm), imperfect (2-3 mm), or poor (>3 mm) in 27.5%-57.5% of specimens. When the anatomic and imperfect categories were condensed into a single category, these scores improved to 52.5%-82.5%. Intra-articular screws were correctly identified in 56.3% of cases. Interobserver reliability was poor or moderate for all items. Reviewers rated the quality of most scans as "sufficient" (60.0%-72.5%); reviewers more frequently rated the low-dose CT as "inferior" (30.0%) and the standard dose CT as "excellent" (25%).

Conclusion: A CT dose did not affect assessment of displacement, intra-articular screw penetration, or subjective rating of scan quality in the setting of a fixed posterior wall fracture.
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http://dx.doi.org/10.1097/BOT.0000000000001778DOI Listing
September 2020

Morphology of the Posterior Malleolar Fracture Associated With a Spiral Distal Tibia Fracture.

J Orthop Trauma 2019 Apr;33(4):185-188

Department of Orthopaedic Surgery and Rehabilitation, Vanderbilt University Medical Center, Nashville, TN.

Objective: To define the pathoanatomy of the posterior malleolus fracture associated with a spiral distal tibia fracture to guide clamp and implant placement when treating these common injuries.

Design: Retrospective cohort.

Setting: Level I trauma center.

Patients/participants: One hundred twenty-two spiral infraisthmal tibia fractures identified from a cohort of 922 tibia fractures undergoing intramedullary nailing over a 7-year period.

Main Outcome Measurements: We collected instances of intra-articular extension seen on preoperative, intraoperative, or postoperative imaging. For patients with a posterior malleolus fracture and computed tomography imaging, we used an axial image 2-3 mm above the articular surface to create a fracture map.

Results: Intra-articular extension was present in 84 patients (68.9%), with posterior malleolus fractures occurring most commonly (n = 59, 48.4%). Other fractures included plafond fractures (n = 8), medial malleolus fractures (n = 7), anterior-inferior tibiofibular ligament avulsions (n = 5), and other anterior fractures (n = 5). Forty-one of 44 (93%) posterior malleolus fractures with cross-sectional imaging were Haraguchi type I (posterolateral-oblique type) with an average angle of 24 degrees off the bimalleolar axis. The remaining 3 were type II (transverse-medial extension type) fractures. Posterior malleolus fractures were visible 61% of the time on preoperative radiographs.

Discussion: Posterior malleolus fractures occur in approximately half of spiral distal tibia fractures and are consistently posterolateral in their morphology. This study can be used to enhance evaluation of the posterior malleolus intraoperatively (eg, ∼25 degrees external rotation view), and if the typical variant of posterior malleolus is identified, clamps and lag screws might be applied accordingly.
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http://dx.doi.org/10.1097/BOT.0000000000001398DOI Listing
April 2019

Early Comparative Outcomes of Carbon Fiber-Reinforced Polymer Plate in the Fixation of Distal Femur Fractures.

J Orthop Trauma 2018 08;32(8):386-390

Department of Orthopaedic Surgery and Rehabilitation, Vanderbilt University Medical Center, Nashville, TN.

Objective: To evaluate the early clinical results of distal femur fractures treated with carbon fiber-reinforced polyetheretherketone (CFR-PEEK) plates compared with stainless steel (SS) lateral locking plates.

Design: Retrospective comparative cohort study.

Setting: ACS Level I trauma center.

Patients/participants: Twenty-two patients (11 SS, 11 CFR-PEEK) with closed distal femur fractures treated by a single surgeon over a 6-year period.

Main Outcome Measurements: Nonunion, hardware failure, reoperation, time to full weight-bearing, and time union were assessed.

Results: The CFR-PEEK cohort was on average older (71 vs. 57 years, P = 0.03) and more likely to have diabetes (P = 0.02). Nonunion was diagnosed in 4/11 (36%) patients in the SS group and 1/11 (9%) patients in the CFR-PEEK group (P = 0.12). Hardware failure occurred in 2 SS patients (18%) compared with none in the CFR-PEEK group (P = 0.14). Time to full weight-bearing was similar between groups, occurring at 9.9 and 12.4 weeks in the CFR-PEEK and SS groups, respectively (P = 0.23). Time to radiographic union averaged 12.4 weeks in the SS group and 18.7 weeks in the CFR-PEEK group (P = 0.26). There were 4 reoperations in the SS group and 1 in the CFR-PEEK group (P = 0.12).

Conclusions: CFR-PEEK plates show encouraging short-term results in the treatment of distal femur fractures with a comparable nonunion, reoperation, and hardware failure rates to those treated with SS plates. This data suggest that CFR-PEEK plates may be a viable alternative to SS plates in fixation of these fractures.

Level Of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
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http://dx.doi.org/10.1097/BOT.0000000000001223DOI Listing
August 2018

Bicondylar Tibial Plateau Fractures: A Critical Analysis Review.

JBJS Rev 2018 02;6(2):e4

Department of Orthopedic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee.

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http://dx.doi.org/10.2106/JBJS.RVW.17.00050DOI Listing
February 2018

The Effect of Insertion Technique on Temperatures for Standard and Self-Drilling External Fixation Pins.

J Orthop Trauma 2017 Aug;31(8):e247-e251

*Mechanical Engineering, Bucknell University, Lewisburg, PA; and †Orthopaedics, Geisinger Health System, Danville, PA.

Objectives: No studies have assessed the effects of parameters associated with insertion temperature in modern self-drilling external fixation pins. The current study assessed how varying the presence of irrigation, insertion speed, and force impacted the insertion temperatures of 2 types of standard and self-drilling external fixation half pins.

Methods: Seventy tests were conducted with 10 trials for 4 conditions on self-drilling pins, and 3 conditions for standard pins. Each test used a thermocouple inside the pin to measure temperature rise during insertion.

Results: Adding irrigation to the standard pin insertion significantly lowered the maximum temperature (P <0.001). Lowering the applied force for the standard pin did not have a significant change in temperature rise. Applying irrigation during the self-drilling pin tests dropped average rise in temperature from 151.3 ± 21.6°C to 124.1 ± 15.3°C (P = 0.005). When the self-drilling pin insertion was decreased considerably from 360 to 60 rpm, the temperature decreased significantly from 151.3 ± 21.6°C to 109.6 ± 14.0°C (P <0.001). When the force applied increased significantly, the corresponding self-drilling pin temperature increase was not significant.

Conclusions: The standard pin had lower peak temperatures than the self-drilling pin for all conditions. Moreover, slowing down the insertion speed and adding irrigation helped mitigate the temperature increase of both pin types during insertion.
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http://dx.doi.org/10.1097/BOT.0000000000000859DOI Listing
August 2017

Locking Compression Pilon Plate for Fixation of Comminuted Posterior Wall Acetabular Fractures: A Novel Technique.

J Orthop Trauma 2017 Jan;31(1):e32-e36

*Orthopaedic Institute, Geisinger Medical Center, Danville, PA; and †Memorial University Medical Center, Savannah, GA.

Posterior wall acetabular fractures involving a large portion the wall's width and with extensive comminution are difficult fractures to manage operatively. Cortical substitution with a pelvic reconstruction plate and supplemental spring plates has been the traditional means of fixation for these fractures. This option, however, requires the use of multiple, unlinked plates and provides no reliable option for peripheral fixation in comminuted fragments. We describe a novel technique for operative fixation of large, comminuted posterior wall fractures using a single distal tibia pilon plate with the option for peripheral locking screw fixation and report on a series of 20 consecutive patients treated with this method.
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http://dx.doi.org/10.1097/BOT.0000000000000675DOI Listing
January 2017

Corrigendum to "Adverse cardiac events in 56,000 orthopaedic trauma patients: Does anatomic area make a difference?" [Injury 47 (2016) 1856-1861].

Injury 2016 12 5;47(12):2838-2840. Epub 2016 Oct 5.

Vanderbilt Orthopaedics Institute Center for Health Policy, Vanderbilt University Medical Center, Nashville, TN, United States. Electronic address:

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http://dx.doi.org/10.1016/j.injury.2016.09.035DOI Listing
December 2016

Adverse cardiac events in 56,000 orthopaedic trauma patients: Does anatomic area make a difference?

Injury 2016 Aug 8;47(8):1856-61. Epub 2016 Jun 8.

Vanderbilt Orthopaedics Institute Center for Health Policy, Vanderbilt University Medical Center, Nashville, TN, United States. Electronic address:

Purpose: Postoperative cardiac events in orthopaedic trauma patients constitute severe morbidity and mortality. It is therefore increasingly important to determine patient risk factors that are predictive of postoperative myocardial infarctions and cardiac arrests. This study sought to assess if there is an association between anatomic area and cardiac complications in the orthopaedic trauma patient.

Patients And Methods: From 2006-2013, a total of 361,402 orthopaedic patients were identified in the NSQIP database using Current Procedural Terminology (CPT) codes. Of these, 56,336 (15.6%) patients were identified as orthopaedic trauma patients broken down by anatomic region: 11,905 (21.1%) upper extremity patients (UE), 29,009 (51.5%) hip/pelvis patients (HP), and 15,422 (27.4%) lower extremity patients (LE) using CPT codes. Patients were defined as having adverse cardiac events if they developed myocardial infarctions or cardiac arrests within 30days after surgery. Chi-squared analysis was used to determine if there was an association between anatomic area and rates of cardiac events. Multivariate logistical analysis was used with over 40 patient characteristics including age, gender, history of cardiac disease, and anatomic region as independent predictors to determine whether anatomic area significantly predicted the development of cardiac complications.

Results: There were significant differences in baseline demographics among the three groups: HP patients had the greatest average age (77.6 years) compared to 54.8 years for UE patients and 54.1 years in LE patients (p<0.001). HP patients also had the highest average ASA score (3.0) (p<0.001). There was a significant difference in adverse cardiac events based on anatomic area: 0.27% (32/11,905) UE patients developed cardiac complications compared to 2.15% (623/29,009) HP patients and 0.61% (94/15,422) LE patients. After multivariate analysis, HP patients were significantly more likely to develop cardiac complications compared to both UE patients (OR: 6.377, p=0.014) and LE patients (OR: 2.766, p=0.009).

Conclusion: There is a significant difference in adverse cardiac events following orthopaedic trauma based on anatomic region. Hip/Pelvis surgery appeared to be a significant risk factor in developing an adverse cardiac event. Further studies should investigate why hip/pelvic patients are at a higher risk of adverse cardiac events.
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http://dx.doi.org/10.1016/j.injury.2016.06.013DOI Listing
August 2016

Trauma-Induced Resolution of Solitary Osteochondroma of the Distal Femur.

Orthopedics 2016 Sep 24;39(5):e1001-4. Epub 2016 Jun 24.

Osteochondromas are benign lesions manifested as bony protrusions capped by cartilage. The exact cause of these growths is not known, and there is no treatment other than surgical excision if the lesion becomes symptomatic. Spontaneous resolution is an uncommon phenomenon that is not completely understood. A 12-year-old girl presented with a mass behind the left knee diagnosed as an osteochondroma. She was followed with serial radiographs because the lesion was minimally symptomatic. At 2.5 years after presentation, the patient reported feeling a "pop" with knee hyperflexion, and radiographic follow-up confirmed a decrease in the size of the growth. The protrusion continued to decrease in size until it was no longer detectable with radiographs, physical examination, and advanced imaging. Spontaneously resolving osteochondromas have been previously documented, but the literature is limited. There were just over 20 cases reported as of the writing of this article, and only 1 other case includes postresolution magnetic resonance imaging. This report of localized trauma inducing spontaneous resolution provides additional evidence and insight supporting previous theories on spontaneous resolution of osteochondromas, which may assist in counseling patients and their families regarding expected natural history. [Orthopedics.2016; 39(5):e1001-e1004.].
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http://dx.doi.org/10.3928/01477447-20160616-09DOI Listing
September 2016

Measuring temperature rise during orthopaedic surgical procedures.

Med Eng Phys 2016 09 28;38(9):1016-20. Epub 2016 May 28.

Geisinger Health System, 100 N Academy Ave, Danville, PA 17822, USA.

A reliable means for measuring temperatures generated during surgical procedures is needed to recommend best practices for inserting fixation devices and minimizing the risk of osteonecrosis. Twenty four screw tests for three surgical procedures were conducted using the four thermocouples in the bone and one thermocouple in the screw. The maximum temperature rise recorded from the thermocouple in the screw (92.7±8.9°C, 158.7±20.9°C, 204.4±35.2°C) was consistently higher than the average temperature rise recorded in the bone (31.8±9.3°C, 44.9±12.4°C, 77.3±12.7°C). The same overall trend between the temperatures that resulted from three screw insertion procedures was recorded with significant statistical analyses using either the thermocouple in the screw or the average of several in-bone thermocouples. Placing a single thermocouple in the bone was determined to have limitations in accurately comparing temperatures from different external fixation screw insertion procedures. Using the preferred measurement techniques, a standard screw with a predrilled hole was found to have the lowest maximum temperatures for the shortest duration compared to the other two insertion procedures. Future studies evaluating bone temperature increase need to use reliable temperature measurements for recommending best practices to surgeons.
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http://dx.doi.org/10.1016/j.medengphy.2016.05.003DOI Listing
September 2016

Do Politics Matter to an Orthopaedic Surgeon? (They Should!).

J Orthop Trauma 2015 Nov;29 Suppl 11:S3-4

*Department of Orthopaedics, Geisinger Medical Center, Danville, PA; and †VOI Center for Health Policy, Vanderbilt University Medical Center, Nashville, TN.

Orthopaedic trauma care is intimately tied with health policy, and current changes with health care reform may change how trauma care is delivered. This article offers a brief history of modern health care and the implications of new policies on the practice of orthopaedic trauma.
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http://dx.doi.org/10.1097/BOT.0000000000000428DOI Listing
November 2015

Incidence and Risk Factors for Extensor Pollicis Longus Rupture in Elastic Stable Intramedullary Nailing of Pediatric Forearm Shaft Fractures.

J Pediatr Orthop 2016 Dec;36(8):810-815

*Geisinger Medical Center, Danville, PA †Washington Hand Surgery, Kirkland, WA.

Background: Elastic stable intramedullary nailing (ESIN) is an effective means of fixation for unstable, pediatric forearm shaft fractures with the benefit of smaller incisions, less soft tissue manipulation, and ease of removal. This study was designed to evaluate the incidence of and risk factors for extensor pollicis longus (EPL) rupture after fixation of pediatric radial shaft fractures with ESIN.

Methods: A retrospective review of all patients younger than 19 years who had a repair of a forearm fracture with flexible intramedullary nailing between 2006 and 2011 was performed. Nineteen consecutive patients were identified from the electronic medical record. All patients were treated with a titanium elastic nailing system using a dorsal approach to the radius. The patients were followed postoperatively for at least 2 years, and all fractures healed. An extensive chart review assessing for persistent pain, EPL function, and risk factors for EPL rupture was performed. Implants were removed in all but 1 patient.

Results: Seventeen records were available for review. Fourteen (82%) were male, and the mean age at time of fracture was 10 years old (range, 5 to 14 y). Follow-up averaged 5.5 years (range, 2.9 to 7.8 y). The mean weight was 32.7 kg for males and 50.6 kg for females corresponding to the 61st and 60th percentile respectively of weight-for-age (range, 8th to 99.9th percentile). Hardware was removed in all but 1 case, and the median time from surgery to hardware removal was 21 weeks (range, 8 to 63). Three of the 17 patients (18%) experienced rupture of the EPL. Two were treated with additional surgery following hardware removal, and one was untreated due to patient preference. None of the 17 patients (including those with rupture) had independent risk factors for tendon rupture: inflammatory arthritis, diabetes, or prior steroid use. Time to removal, patient age, and percentile of weight-for-age did not correlate with EPL rupture.

Conclusions: Although ESIN of pediatric forearm shaft fractures has gained acceptance as a treatment option, our series of 17 patients revealed an 18% rate of EPL rupture. With this small patient cohort, no patient characteristics proved to be significant risk factors for predicting tendon rupture. However, awareness should be raised for an increased risk of EPL rupture with this fixation method.

Level Of Evidence: Level IV-Therapeutic.
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http://dx.doi.org/10.1097/BPO.0000000000000568DOI Listing
December 2016