Distal Femur Fractures

Distal Femur Fractures

Graeme Hoit MD1, Amir Khoshbin MD1 and Rudolf W. Poolman MD PhD2

1Department of Orthopaedic Surgery, University of Toronto, Toronto, ON, Canada

2Leiden University Medical Center, Amsterdam, The Netherlands

Clinical scenario

  • A 66‐year‐old woman presents to the Emergency Department with significant pain and deformity to her right lower thigh after falling off a step ladder. X‐rays demonstrate a distal femur fracture. You are consulted as the orthopedic surgeon on call.
  • She would like to know what the best way to fix her fracture is and is quite insistent on doing everything possible to avoid a second operation.
  • She has also recently heard about the expedited surgery of hip fracture are receiving on the news and wonders if this is applicable to her as well.

Top three questions

  1. In patients undergoing distal femoral fixation, do locking plates result in less construct failures and nonunions than nonlocking constructs?
  2. In geriatric patients with distal femur fractures, does early surgery result in improved morbidity and mortality in comparison with delayed surgery?
  3. In patients undergoing lateral locking plate fixation, are some patient and surgical factors, such as patient BMI, plate length, etc., more likely to result in nonunion and mechanical failure compared to other factors?

Question 1: In patients undergoing distal femoral fixation, do locking plates result in less construct failures and nonunions than nonlocking constructs?


Locking plates have become widely used throughout trauma orthopedics because of their assumed increased stability, ability to find fixation in osteoporotic bone, and often their precontoured nature.1 However, there is concern regarding a potential for nonunion when applied to distal femoral fractures.

Clinical comment

Distal femoral fractures have been reported to go onto nonunion at a rate of 6–24%.13 Nonunions have been demonstrated to have devastating consequences for patients’ physical, psychosocial, and financial wellbeing as well as lead to significant healthcare system costs.46 Additionally, mechanical failure (often contributory to nonunion) has been identified as a significant problem in distal femoral fractures, resulting in the need for re‐operation in 4% of cases.7 With this in mind, the surgical techniques used to fix distal femoral fractures should attempt to minimize the nonunion rate and requirement for re‐operation.

Available literature and quality of the evidence

A 2015 Cochrane review by Griffin et al. (level II) for distal femoral fractures included six studies examining surgical fixation methods, including preliminary data from two studies that compared locking plates versus intramedullary (IM) nailing and the dynamic condylar screw (DCS), respectively.8 No differences were found between locking plates and other interventions in this review in terms of union rates or mechanical failures. Similarly, a small randomized controlled trial (RCT) (level II) by the Canadian Orthopaedic Trauma Society of 52 patients with distal femoral fractures were randomized to either locked plating with the Less Invasive Stabilization System (LISS) or DCS.9 Significantly more DCS patients achieved bony union without subsequent intervention in comparison to LISS plating.

A meta‐analysis (level II) by Koso et al. synthesized the results of 11 level II and 3 distal femoral fracture studies including 505 patients.7 They found no significant differences in nonunion rates, reoperation rates, or mechanical failures when comparing plating constructs versus IM nails – they did not differentiate between locking and nonlocking plates. The LISS was compared specifically to other constructs, which included IM nails, other locking plates, DCS, and nonlocking plate constructs and was found to have significantly fewer mechanical failures.

The Southeast Fracture Consortium compared locking compression plating to LISS for distal femoral fixation in a retrospective review (level III) of 339 patients.10 No significant difference was found between the two constructs for mechanical failure or nonunion rates.


Based on the current available evidence, it is unclear if locking plates provide any benefit over other constructs. This is especially apparent as the predominant locking plate option reported on in the literature is the LISS, which is no longer as widely used with the advent of other commercial locking plates that are marketed as less rigid to avoid nonunion.9,11 There is a need for high‐quality evidence examining the optimal fixation method for distal femoral fractures.

Resolution of clinical scenario

  • Level II and III evidence provides mixed results for the benefit of locking plates over other constructs for distal femoral fractures. Given the current literature, no resolution was reached.

Question 2: In geriatric patients with distal femur fractures, does early surgery result in improved morbidity and mortality in comparison with delayed surgery?


Increasingly, attention has been drawn to the effect of surgical delay on the morbidity and mortality of geriatric orthopedic patients. Definitive evidence to this effect for hip fracture patients has changed the clinical landscape with clinical practice guidelines recommending early surgery.12,13 Whether or not a similar action should be applied to distal femur fractures in the geriatric population is an important question to answer.

Clinical comment

Distal femur fractures occur in a bimodal distribution in the population, with an increased frequency in young trauma patients and in elderly patients with osteoporotic bone.14,15 The patient profile of low‐energy distal femur fractures is similar to the hip fracture population in terms of demographics and comorbidities. Elderly patients who suffer a distal femur fracture are at significant risk of postoperative complications and/or mortality. The one‐year mortality rate has been reported as up to 38% post distal femur fracture,1618 which is similar to hip fractures.19 Several studies have evaluated patient and surgical factors affecting mortality of patients with distal femoral fractures, including surgical delay.

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Nov 28, 2021 | Posted by in ORTHOPEDIC | Comments Off on Distal Femur Fractures

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