Short summary

The aim of this project is to make a detailed study of patients with distal femoral fractures, treated with a certain surgical technique called locking plates that minimizes the compressive forces exerted between plate and bone. In particular we wish to investigate:

- Risk of developing complications during admission, re-admission, and death, as well as the importance of risk factors. - Risk of re-operation as well as the influence of risk factors such as x-ray fracture classification.

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Rationale

The distal femur is defined as the distal 15 cm of the femur including the metaphyseal-diaphyseal junction, femoral condyles, and the articular surface of the knee (1, 2). The incidence of distal femoral fractures and periprosthetic distal femoral fractures have been reported to be 8.7 per 100,000 per year, and 2.4 per 100,000 per year respectively (1). There is especially a rapid, continuous increase in the incidence after the age of 60 years. As the population ages, the treatment of these fractures has correlated with poor outcomes as elderly patients often present with significant co-morbidities impacting their recovery and survival (1, 2). There is currently no treatment algorithm regarding native and periprosthetic distal femoral fractures, however many cases are treated with internal fixation such as a locked plating system. A locked plating system can be used minimally invasive and with a bridging fixation for relative stability. The angular and axial stability of the locking plate seems to minimize the risk of complications (3) Previous studies have reported data on patient outcomes after treatment of distal femur fractures with ORIF (open reduction and internal fixation) and prosthesis in the elderly.

Re-operation: Salazar et al. (4) found, in a systematic review of 30 studies, a failure rate (defined as complications requiring major re-operations) of 8.6% and 10.4% in the treatment of native distal femur fractures with ORIF and prosthesis respectively. In another systematic review of 56 studies, Wadwa et al. (5) reported a failure rate (complications requiring re-operations) of 15% and 14% in the treatment of periprosthetic distal fracture with ORIF and prosthesis respectively.

Patient safety: Studies investigating patient safety regarding mortality, LOS (length of hospital stay), and readmission have found varying outcomes. The one-year mortality after a native distal femoral fracture treated with ORIF has been assessed to span over 2-37% versus 0-10% in treatment with a prosthesis (6-12). The one-year mortality after a periprosthetic distal femoral fracture treated with a locked lateral plating has been assessed to be 22% versus 10% in treatment with a prosthesis (13). Reported data on postoperative LOS is also varying. The LOS after a native distal femoral fracture treated with ORIF or prosthesis has been found to be approximately 7 days for both groups (6-12). LOS of 5-15 days for periprosthetic fractures treated with ORIF and 6-27 days in treatment with a prosthesis have been reported (13-15). Data on readmission risk however is limited. In the following studies (13, 14) the readmission risk is found to vary between 28-56% in patients with periprosthetic distal femur fractures, treated with prosthesis while the readmission risk after surgical treatment for native fractures is yet to be assessed.

Hence, there is no consensus about the best way to treat distal femur fractures in different patient groups and data on patient safety and re-operation risk is still limited. The aim of this study is to report patient safety measured as risk of in-hospital complications, readmission, mortality as well as re-operation after treatment of distal femur fractures with ORIF (locking plate system).

References:

1. Elsoe R, Ceccotti AA, Larsen P. Population-based epidemiology and incidence of distal femur fractures. Int Orthop. 2018;42(1):191-6.

2. Coon MS, Best BJ. Distal Femur Fractures. StatPearls. Treasure Island (FL)2022.

3. Egol KA, Kubiak EN, Fulkerson E, Kummer FJ, Koval KJ. Biomechanics of locked plates and screws. J Orthop Trauma. 2004;18(8):488-93.

4. Salazar BP, Babian AR, DeBaun MR, Githens MF, Chavez GA, Goodnough LH, et al. Distal Femur Replacement Versus Surgical Fixation for the Treatment of Geriatric Distal Femur Fractures: A Systematic Review. J Orthop Trauma. 2021;35(1):2-9.

5. Wadhwa H, Salazar BP, Goodnough LH, Van Rysselberghe NL, DeBaun MR, Wong HN, et al. Distal Femur Replacement Versus Open Reduction and Internal Fixation for Treatment of Periprosthetic Distal Femur Fractures: A Systematic Review and Meta-Analysis. J Orthop Trauma. 2022;36(1):1-6.

6. Brodke DJ, Devana SK, Upfill-Brown A, Lee C. Cost-effectiveness of fixation versus arthroplasty for geriatric distal femur fractures. Injury. 2022;53(2):661-8.

7. Poole WEC, Wilson DGG, Guthrie HC, Bellringer SF, Freeman R, Guryel E, et al. 'Modern' distal femoral locking plates allow safe, early weight-bearing with a high rate of union and low rate of failure: five-year experience from a United Kingdom major trauma centre. Bone Joint J. 2017;99-B(7):951-7.

8. Konda SR, Pean CA, Goch AM, Fields AC, Egol KA. Comparison of Short-Term Outcomes of Geriatric Distal Femur and Femoral Neck Fractures: Results From the NSQIP Database. Geriatr Orthop Surg Rehabil. 2015;6(4):311-5.

9. Smith JR, Halliday R, Aquilina AL, Morrison RJ, Yip GC, McArthur J, et al. Distal femoral fractures: The need to review the standard of care. Injury. 2015;46(6):1084-8.

10. Kammerlander C, Riedmuller P, Gosch M, Zegg M, Kammerlander-Knauer U, Schmid R, et al. Functional outcome and mortality in geriatric distal femoral fractures. Injury. 2012;43(7):1096-101.

11. Streubel PN, Ricci WM, Wong A, Gardner MJ. Mortality after distal femur fractures in elderly patients. Clin Orthop Relat Res. 2011;469(4):1188-96.

12. Wolfstadt JI, Atrey A, Nowak LL, Stavrakis A, Melo LT, Backstein D, et al. A Comparison of Acute Complications and Mortality Between Geriatric Knee and Hip Fractures: A Matched Cohort Study. J Am Acad Orthop Surg. 2021;29(21):929-36.

13. Hoellwarth JS, Fourman MS, Crossett L, Goodman M, Siska P, Moloney GB, et al. Equivalent mortality and complication rates following periprosthetic distal femur fractures managed with either lateral locked plating or a distal femoral replacement. Injury. 2018;49(2):392-7.

14. Corap Y, Brix M, Emmeluth C, Lindberg-Larsen M. Patient safety in distal femoral resection knee arthroplasty for non-tumor indications: a single-center consecutive cohort study of 45 patients. BMC Musculoskelet Disord. 2022;23(1):199.

15. Quinzi DA, Ramirez G, Kaplan NB, Myers TG, Thirukumaran CP, Ricciardi BF. Early complications and reoperation rates are similar amongst open reduction internal fixation, intramedullary nail, and distal femoral replacement for periprosthetic distal femur fractures: a systematic review and meta-analysis. Arch Orthop Trauma Surg. 2021;141(6):997-1006.

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Description of the cohort

The study population includes a consecutive cohort of all patients treated with locking plate after distal femur fracture in Odense University Hospital (OUH) in Odense, Denmark in a period from 2011-2022 (approximately 400 procedures). The population is identified by specific diagnosis codes (DS723, DS724, DS728, DS729) in combination with procedure codes (KNFJ64, KNFJ65, KNFJ84, KNFJ85) in the period of January 2011 to December 2021. The data analysis will take place at the Orthopedic Research Unit, OUH-SDU in collaboration with Open Patient data Explorative Network (OPEN).

Data and biological material

The index population is identified by specific procedures and diagnosis codes from the hospitals administrative database. Patients treated with locking compression plates at OUH will be investigated on patient file level. Fracture classification and quality of osteosynthesis will be determined by radiographic imaging. Follow-up data on risk of in-hospital complications, readmission, reoperations, and mortality will be available from all patients from Region of Southern Denmark on patient file level.