VCOM Carolinas Research Day 2023

Clinical Studies

A Single Surgeon Experience with Lateral Malleolar Fracture Fixation Over A 9 Year Period, the Effectiveness of Non-locking Plates: A Descriptive Analysis Muir S.M. BS, Rizzieri T. BS, Nkemakolam C. BS, Brown A. BS, Lombardozzi S., Wilsom A. MBA, Mack T. BSN, Lombardozzi K MD, Broderick JS MD. Spartanburg Regional Healthcare System, Spartanburg, SC. Co-authorship should be given to collaborators such as a Statistician, who have made intellectual contribution in terms of writing, research design, study implementation, and data analysis and interpretation. Abstract Methods

CLIN-6

Results/Conclusions

• All adult patients (≥18 years of age) who underwent operative fixation of an ankle fracture by a single orthopedic surgeon at Spartanburg Medical Center over a 9-year period, from May 2013 through June 2021, were screened for eligibility inclusion. Patients were included if they underwent an operative fixation of a lateral malleolar fracture. Pregnant women and prisoners were excluded • Since we only compared to the results published in the literature and defined pool of patients based on time frame, no power analysis was done. Descriptive statistics will be utilized and compared with previously published data. • Data gathering was done by chart review. Data collected included demographic data, BMI, smoking status, coexisting diagnosis of diabetes mellitus, peripheral artery disease, osteoporosis, type of operative fixation performed, and intraoperative assessment of bone quality. • Complications including wound complication, infection requiring oral antibiotics, infection requiring IV antibiotics, infection requiring operation, hardware removal and/or revision were also assessed. • The data was assessed after fixation with an average time of follow up of 8 months.

B ackground : 187 per 100,000 ankle fractures occur each year and are one of the most common types of lower extremity fractures. Over the last 10-15 years, locking plates have been introduced as an alternative method of fixation of lateral malleolar fractures compared to the gold standard non-locking plates. A locking plate differs from a non-locking plate in that the screw is locked in place by the plate at a fixed angle, while a non-locking plate does not lock the screw into place therefor, can allow "toggling" of the screw. Locking plates increased in popularity because they demonstrated biomechanical advantages in cadaver studies, especially in osteoporotic bone. However, this demonstration has not been translated clinically. Plate failure, pain, malunion/non union, and patient satisfaction has not been statistically different between locking and non-locking plates. Even without statistical superiority orthopedic surgeons defer to locking plates in patients with and without osteoporotic bone. This study is a single center, single surgeon, effectiveness trial of adult patients undergoing operative fixation of lateral malleolar fractures, over a nine-year period, to describe the efficacy of repair and complication rates with non-locking and locking plates. Hypothesis : Non-locking plates provide an efficacious fixation with equivalent complication rate when compared to use of locking plates. Methods : 579 retrospective chart reviews were completed for patients 18 years of age and older, who underwent operative fixation of an ankle fracture by single orthopedic surgeon at Spartanburg Regional Medical Center, from May 2013 through June 2021. 282 patients were excluded from analysis. Baseline demographics, type of operative fixation performed, construct failure, and post operative infections were collected. Non-locking and locking plate complications were compared using descriptive analysis. Results : Anticipated results are that non-locking plates provide an efficacious fixation with equivalent complication rate when compared to use of locking plates, as reported in the literature. Conclusion : While locking plates have become increasingly common, clinical superiority has yet to be established. In our single center, single surgeon study, complication rates have shown to be similar between non-locking and locking plates. Integration of locking and non-locking plates in clinical practice warrants further study. • Biomechanical studies have hypothesized that locking plates are superior to nonlocking plates in some circumstances. • The design of a locking plate arose to provide a better stabilizing construct in bridging fixation and has since been used in other instances where non locking plates have had lower fixation rates; some of these include osteopenic, pathological, union, or non-union fractures. • One of the most widely supportive remarks in favor of locking plates is the ability to fix bone while resting above the cortical bone layer, unlike a nonlocking plate which is flush with the cortical bone. Laying flush with the cortical bone layer has been demonstrated to be the source of necrosis induced bone loss, and a potential for infection. • Other studies have demonstrated that laying flush with the bone causes sheer stress on the cortical bone layer, possibly playing a role in fixation failure and the potential source of cortical necrosis. • Many of these claims in biomechanical studies have not been correlated in clinical studies. • In fact, studies like Tsukada et al., a randomized control trial comparing nonlocking a locking plate in lateral malleolar fractures, Hasami et al., a meta-analysis and systemic review, Odak et al., a systematic review, and Lyle et al., a retrospective review comparing locking and nonlocking plates, demonstrated no difference in clinical or radiographic outcomes between locking and non-locking plates. • Even with these outcomes, many orthopedic surgeons still prefer locking plates over non-locking plates. Background Introduction

References Anticipated results include: • No difference in rates of nonunion between locking and nonlocking plates • No difference in hardware removal rates between locking and nonlocking plates • No difference in hardware loosening rates between locking and nonlocking plates • No difference in infection rates between locking and nonlocking plates This study demonstrates no significant difference in successful fixation and complication rates between those treated for lateral malleolar fractures with a locking vs. a nonlocking plate. This study further supports the data produced by Tsukada et al, Hasami et al., Odak et al., and Lyel et al. This suggests that careful consideration may need to be taken when choosing a locking v. nonlocking plate for lateral malleolar fixation, contrary to the current belief. One limitation of this study is adherence to treatment plan. Patients are often instructed for multiple weeks of non-weightbearing ambulation, with a gradual increase in weight-bearing activities over the course of months. Some patients adhere strictly to the plan while others loosely abide by it, or disregard it completely. Non-adherence to the treatment plan can significantly impact bone healing, movement of hardware, and infection rate. Similarly, wound disruption was a potential confounding factor. During the course of healing, some patients had additional trauma, which could cause failed fixation and increased complications. However, wound disruption was accounted for in the data analysis with this subset of patients sub-stratified in order to limit this variable. 1. AO Surgery Reference. “Locking Plate Principles.” SurgeryReference , surgeryreference.aofoundation.org/cmf/basic-technique/locking-plate principles#design. Accessed22 Jan. 23, 2023. 2. Hasami NA, Smeeing DPJ, Pull Ter Gunne AF, Edwards MJR, Nelen SD. Operative Fixation of Lateral Malleolus Fractures with Locking Plates vs Nonlocking Plates: A Systematic Review and Meta-analysis. Foot Ankle Int. 2022 Feb;43(2):280-290. doi: 10.1177/10711007211040508. Epub 2021 Sep 28. PMID: 34581226; PMCID: PMC8841627. 3. Court-Brown CM, Caesar B. Epidemiology of adult fractures: A review. Injury. 2006 Aug;37(8):691-7. doi: 10.1016/j.injury.2006.04.130. Epub 2006 Jun 30. PMID: 16814787. 4. Lyle SA, Malik C, Oddy MJ. Comparisonof Locking Versus Nonlocking Plates for Distal Fibula Fractures. J Foot Ankle Surg. 2018 Jul-Aug;57(4):664-667. doi: 10.1053/j.jfas.2017.11.035. Epub 2018 Apr 19. PMID: 29681437. 5. MacLeod AR, SimpsonAH, Pankaj P. Reasons whyuncomp dynamic compressionplates are inferior to locking plates in osteoporotic bone: a finite element explanation. Comput Methods BiomechBiomed Engin. 2015;18(16):1818-25. doi: 10.1080/10255842.2014.974580. Epub 2014 Dec 4. PMID: 25473732. 6. Tsukada S, Otsuji M, Shiozaki A, Yamamoto A, KomatsuS, Yoshimura H, Ikeda H, Hoshino A. Locking versus non-locking neutralization plates for treatment of lateral malleolar fractures: a randomized controlled trial. Int Orthop. 2013 Dec;37(12):2451-6. doi: 10.1007/s00264-013-2109-9. PMID: 24077867; PMCID: PMC3843202. 7. Schepers T, Van Lieshout EM, De Vries MR, Van der Elst M. Increased rates of wound complications with locking plates in distal fibular fractures. Injury. 2011 Oct;42(10):1125-9. doi: 10.1016/j.injury.2011.01.009. Epub 2011 Feb 16. PMID: 21329921. 8. Shih CA, Jou IM, Lee PY, Lu CL, Su WR, Yeh ML, Wu PT. Treating AO/OTA44B lateral malleolar fracture in patients over 50 years of age: periarticular locking plate versus non-locking plate. J Orthop Surg Res. 2020 Mar 20;15(1):112. doi: 10.1186/s13018-020-01622-9. PMID: 32197662; PMCID: PMC7082938. This project was approved by Spartanburg Regional Healthcare System IRB committee. The authors would like to thank Edward Via College of Osteopathic Medicine and their team for their support and editorial revisions, and WilliamMuir, DVM. PhD. for his poster and abstract guidance. Acknowledgements

Nonlocking v. Locking

Nonlocking Plate

• A nonlocking plate is a simple construct in which there are no threads built into the holes of the plate. Congruently, there are no threads within the head of the screw. Therefore, as the screw is tightened into a hole of the plate bone is compressed against the plate. This concept was one of the original ways in which fractures were plated.

Image 1. Nonlocking Plate

AO Surgery Reference [1]

Locking Plate

• Locking plates were developed in the early 1880s by Carl Hansman, however, were not expanded upon until the 1930s by Paul Reinhold. The plate was designed so that the holes within the plate contain threads themselves that will lock into the threads within the screw head. The ingenuity behind this construct is to prevent bone from being compressed into the plate (like the nonlocking plate). The goal of this mechanism was to provide stronger fixation and prevent screw dislodgement, thus preventing plate failure. Image 2. Locking Plate AO Surgery Reference [1]

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