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Review: AAOS Clinical Practice Guideline Summary

American Academy of Orthopaedic Surgeons Clinical Practice Guideline Summary for Limb Salvage or Early Amputation

Potter, Colonel B. K. MD; Bosse, Michael J. MD

Author Information
Journal of the American Academy of Orthopaedic Surgeons: July 1, 2021 - Volume 29 - Issue 13 - p e628-e634
doi: 10.5435/JAAOS-D-20-00188
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Abstract

The American Academy of Orthopaedic Surgeons (AAOS) and the Major Extremity Trauma and Rehabilitation Consortium, with input from representatives from the Orthopaedic Trauma Association, the Society of Military Orthopaedic Surgeons, the American Orthopaedic Foot & Ankle Society, the Musculoskeletal Tumor Society, the American Society for Plastic Surgeons, the Society of Critical Care Medicine, and the Society for Vascular Surgery, recently published their clinical practice guideline (CPG), Limb Salvage or Early Amputation.1 This CPG was approved by the AAOS Board of Directors in December 2019. The purpose of this CPG is to treat patients with limb-threatening lower extremity injuries based on current best evidence.

The true frequency of limb-threatening, high-energy lower extremity trauma (HELET), in general, or as defined for purposes of this CPG, specifically, remains difficult to accurately quantify, but thousands of patients per year are subject to this life-changing event. Providing affected patients and their families with the best counseling, to facilitate shared decision making and set realistic expectations, and the best treatment, based on the best available evidence, is critical toward achieving optimal outcomes.

The LEAP study demonstrated poor, but similar, functional outcomes in a civilian population of HELET patients at both 2 and 7 years after injury and treated by either limb salvage or amputation.2,3 Based on this and the higher lifetime costs of amputation, the LEAP authors recommended that limb salvage be pursued whenever reasonably possible.4 However, the more recent METALS (Military Extremity Trauma Amputation/Limb Salvage) study of a cohort of combat-injured military patients demonstrated better outcomes after amputation.5 Similarly, LEAP patients requiring ankle arthrodesis or flap coverage had worse outcomes than those treated with transtibial amputation,6 and a series of combat-related open calcaneal fractures reported an amputation rate of 43% and better outcomes in those patients treated with amputation.7 These discrepancies highlight the difficult decisions facing both survivors of HELET and the multidisciplinary teams treating them.

Other areas of related uncertainty abound. Scoring systems to guide treatment decisions after HELET are lacking,8,9 and the specific patient and injury factors which should encourage one treatment strategy versus the other remain poorly defined. Awareness of and emphasis on patient resilience assessment and facilitation after HELET have increased, but whether this should also affect treatment decisions remains unclear. Furthermore, although the costs of amputation exceed those of limb salvage, the costs of late amputation are greater than either, and in a worst-case scenario, this outcome suggests that patients may have been subjected to potentially unnecessary or futile procedures. These issues say nothing of the medicolegal implications of making the “wrong” decision for a given patient.

Therefore, the Department of Defense partnered with the AAOS to develop an evidence-based CPG to aid practitioners in the treatment of severe HELET.1 Furthermore, the CPG represents a call for continued research directions to improve the initial and subsequent evaluation and decision-making elements for limb salvage or amputation after severe lower extremity trauma. An exhaustive literature search was conducted resulting initially in over 830 manuscripts for full review. The articles were then graded for quality and aligned with the work group's patients, interventions, and outcomes of concern. For CPG PICO (ie, population, intervention, comparison, and outcome) questions that returned no evidence from the systematic literature review, the work group used the established AAOS CPG methodology to generate three companion consensus statements regarding the evaluation and treatment of severe lower extremity trauma.

In summary, the limb salvage or early amputation guideline involved reviewing over 3,800 abstracts and more than 830 full-text articles to develop 11 recommendations supported by 36 research articles meeting stringent inclusion criteria. Each recommendation is based on a systematic review of the research-related topic, which resulted in one recommendation classified as high, six recommendations classified as moderate, and four recommendations classified as limited. The strength of recommendation is assigned based on the quality of the supporting evidence. The strength of recommendation also takes into account the quality, quantity, and trade-offs between the benefits and harms of a treatment; the magnitude of a treatment's effect; and whether data on critical outcomes are available.

Guideline Summary

These recommendations are designed to create a decision-making framework for the evaluation and treatment of patients who have sustained HELET and by definition are at some risk of requiring, or in some cases being best managed with, amputation. The strength of each of the 11 guidelines is graded based on the quality of the available evidence. For many of the guidelines, additional high-quality research is needed to further refine our conclusions and/or improve the strength of the recommendations. Indeed, of 3,846 abstracts reviewed, only 36 manuscripts met the stringent criteria for inclusion herein.

At both Time0 (initial surgical management) and Time1 (all points thereafter), the guidelines recommend that the physician team should evaluate the overall systemic injury burden and patient physiology in the process of determining whether pursuit of limb salvage is advisable. In the absence of strong evidence (but accounting for a good measure of common sense), the guidelines also recommend that “life” be prioritized over “limb” and, if additional efforts at definitive limb salvage would increase the risk of mortality, that damage-control measures or immediate amputation be pursued. Certain injury patterns such as associated pelvic fractures or traumatic amputations have been associated with increased risk of mortality10; others such as multiple amputations have been associated with increased risk of potentially fatal events such as pulmonary embolism.11

For Time1 and beyond, the CPG further recommends that the cumulative injury burden to the patient, the involved extremity, and the various tissue types be considered when counseling patients on anticipated outcomes and decision making regarding the pursuit of either limb salvage or amputation treatment. For example, a severe tibial injury with no other distal injuries may be appropriately and optimally treated with limb salvage, but that same injury may be best treated with amputation whether it is associated with a severe hindfoot injury or requires flap coverage around the foot or ankle.

Regardless of treatment decisions or pathways, the CPG strongly recommends that all patients sustaining HELET be evaluated for psychosocial risk factors affecting patient outcomes, such as PTSD, anxiety, or low self-efficacy. The importance of this cannot be overstated because the LEAP study determined that the greatest determinants of patient functional outcomes were beyond surgeon control.2 Furthermore, low self-efficacy, for example, has been associated with worse functional outcomes,2,3 and even the costs of prosthetic management are increased among amputees with PTSD.12

We recommend that patients sustaining HELET participate in a multidisciplinary rehabilitation program including physical and occupational therapy and behavioral health interventions in an effort to improve both psychological and functional outcomes. In addition to the abundant attention that psychological factors have received in recent years as a determinant of outcomes,3,13 these studies further suggest that behavioral health interventions can improve outcomes. Furthermore, psychosocial adaptation after injury has been associated with greater mobility and independence.14

The guidelines also attempt to address specific injury factors which should (or should not) be factored into the decision to pursue limb salvage or amputation. Specifically, absent plantar sensation at presentation and documented major nerve (eg, tibial) transection should not be a major factor in treatment pathway decisions. Multiple studies have shown that plantar examination at presentation is unreliable and not necessarily correlated with eventual outcome, and/or neurologic deficit did not predictably affect functional recovery.15,16 Furthermore, a goal of either protective or functional sensation recovery can often be achieved with nerve repair or grafting long after injury even in the setting of overt transection. Although neurologic status does factor into the compositive assessment and reconstructive requirements of the injured limb, it should not be viewed as an absolute or major criterion for decision making.

Although certain findings remain intuitive, limited available evidence suggests that composite soft-tissue loss and prolonged limb ischemia adversely affect outcomes. Accordingly, the recommendations note that specific mechanisms of injury, such as blunt, crush, or blast, leading to either degloving or volumetric muscle loss, defined as the traumatic or surgical loss of skeletal muscle with resulting functional impairment, may increase the risk of poor outcomes. Volumetric muscle loss was associated with worse functional outcomes in the LEAP study3 but did not affect successful limb salvage. Other studies have similarly reported limited or no impact on limb salvage versus amputation. Accordingly, the CPG later recommends that massive muscle damage should not be considered an absolute indication for amputation at Time0.

Similarly, neither hard signs of vascular injury nor duration of limb ischemia should represent absolute indications for amputation although the guidelines recommend that the duration of limb ischemia be minimized to the greatest extent possible. Six studies, all of low quality, reflected an impact of vascular injury on outcomes. One study found that coagulopathy and having two or more hard signs of vascular injury increased mortality.17 Two other studies found that vascular injury increased the risk of limb salvage complications and/or failure of attempted limb salvage. However, three additional studies reported no notable effect of vascular injury on complications, outcomes, or late amputation.

This CPG recommends that physicians should not consider a patient's smoking/nicotine status as a major criterion for decision making at Time0. However, smoking cessation interventions should be pursued thereafter because of compelling evidence that smoking status adversely affects functional and psychological outcomes.18 In addition, higher risk of wound healing problems, infection, delayed union, and nonunion have been consistently reported among smokers/nicotine users.

As mentioned above, the so-called limb salvage scoring systems have been demonstrated not to be reliable guides for limb salvage versus amputation or to reliably predict patient outcomes. The guidelines therefore recommend against the routine use of these systems in clinical decision making and counseling. Although these systems are generally highly specific for amputation, they are not adequately sensitive for clinical use.8 That is, although a low score can predict successful limb salvage, a higher score (where such objective guidance would be most useful) cannot reliably predict amputation. The same scoring systems were also not predictive of outcomes at either 6 months or 2 years,19 and a study of military patients similarly found insufficient sensitivity or accuracy of mangled extremity severity score (MESS).9

Conversely, some specific injury patterns should prompt early discussion of amputation. Severe ankle or hindfoot injuries requiring either arthrodesis or free-tissue coverage demonstrated inferior functional outcomes with limb salvage versus amputation in the LEAP study.6 Three military studies found poor functional outcomes and high rates of eventual amputation in these patients with transtibial amputees generally achieving better outcomes than patients treated with limb salvage.7,16,20 The guidelines therefore recommend that the physician team engages in shared decision making with such patients regarding consideration for transtibial amputation at Time1 (ie, in the nonacute treatment phase or as soon as practicable after Time0).

A number of recommendations were made by the work group in the absence of reliable evidence. For example, although no reliable evidence was found and we further advocate that patient physiology and mortality risk be considered, the work group felt that preexisting medical comorbid conditions should be considered in the decision to pursue limb salvage versus amputation. Similarly, the work group felt that patients sustaining or requiring lower extremity amputation should be fit with an appropriate prosthesis, and limb salvage patients with residual deficits should be evaluated and/or fitted with an appropriate orthosis. There is no question that ambulatory potential is improved with a prosthesis after amputation, and a growing body of literature suggests that limb salvage outcomes may be improved with appropriate bracing treatment. Both groups of patients may thus benefit from long-term clinical follow-up to assess the need for and adequacy of these devices in an effort to improve functional outcomes.

This guideline summarizes that the best recommendations the work group felt were possible on the basis of the current published evidence for limb salvage versus amputation treatment decisions after HELET. The recommendations herein are not intended to be interpreted rigidly as if correct or ideal for every patient or injury pattern. As per any evidence-based recommendation, the physician team should also rely on their own clinical judgment, experience, available resources, and the desires of their patients and patients' families. Furthermore, these recommendations were limited in some areas, as noted, based on low quality or inadequate evidence, and they highlight areas requiring diligent future study and investigation. Our hope is that these recommendations will serve as a useful template for both clinical and shared decision making with patients and patients' families affected by HELET and that future research will permit revision, refinement, improvement, and expansion of these recommendations toward this worthy end. These efforts can help guide our treatment of patients with HELET toward the goal of providing each patient with both the best treatment options and the best outcome for their specific injury pattern and circumstances.

Recommendations

This summary of recommendations of the AAOS/Major Extremity Trauma and Rehabilitation Consortium CPG for Limb Salvage or Early Amputation contains a list of evidence-based treatment recommendations. Discussions of how each recommendation was developed and the complete evidence report are contained in the full guideline at www.aaos.org/lsacpg. Readers are urged to consult the full guideline for the comprehensive evaluation of the available scientific studies. The recommendations were established using methods of evidence-based medicine that rigorously control for bias, enhance transparency, and promote reproducibility.

The summary of recommendations is not intended to stand alone. Medical care should be based on evidence; a physician's expert judgment; and the patient's circumstances, values, preferences, and rights. For treatment procedures to provide benefit, mutual collaboration with shared decision making between patient and physician/allied healthcare provider is essential.

A strong recommendation means that the quality of the supporting evidence is high. A moderate recommendation means that the benefits exceed the potential harm (or that the potential harm clearly exceeds the benefits in the case of a negative recommendation), but the quality/applicability of the supporting evidence is not as strong. A limited recommendation means that there is a lack of compelling evidence that has resulted in an unclear balance between benefits and potential harm. A consensus recommendation means that expert opinion supports the guideline recommendation although there is no available empirical evidence that meets the inclusion criteria of the guideline's systematic review.

- Strength of Recommendation Descriptions
Strength of Recommendation Overall Strength of Evidence Description of Evidence Quality Strength Visual
Strong Strong Evidence from two or more “high” quality studies with consistent findings for recommending for or against the intervention. Also requires no reasons to downgrade from the EtD framework.
Moderate Moderate or strong Evidence from two or more “moderate” quality studies with consistent findings or evidence from a single “high” quality study for recommending for or against the intervention. Also requires no or only minor concerns addressed in the EtD framework.
Limited Limited, moderate, or strong Evidence from one or more “low” quality studies with consistent findings or evidence from a single “moderate” quality study recommending for or against the intervention. Also, higher strength evidence can be downgraded to limited because of major concerns addressed in the EtD framework.
Consensus No reliable evidence There is no supporting evidence, or higher quality evidence was downgraded because of major concerns addressed in the EtD framework. In the absence of reliable evidence, the guideline work group is making a recommendation based on their clinical opinion.

Burden of Injury

Nonlimb-Specific Injury

Time0 and Time1

A. The Physician team should evaluate overall burden of injury and patient physiology when considering if initial limb salvage is advisable.

Strength of recommendation: Moderate.

Implication: Practitioners should generally follow a moderate recommendation but remain alert to new information and be sensitive to patient preferences.

Nonlimb-Specific Injury

Time0 and Time1

B. In the absence of reliable evidence, the work group suggests that the physician team should prioritize patient survival in the limb reconstruction versus amputation decision. Limb-specific damage control measures (ie, temporizing) or immediate amputation should be considered when additional attempts at definitive salvage will increase the risk of mortality.

Strength of recommendation: Moderate.

Implication: Practitioners should generally follow a moderate recommendation but remain alert to new information and be sensitive to patient preferences.

Limb-Specific Injury

Time1 and Beyond

C. Physicians should consider the cumulative injury burden (soft tissue, vascular, nerve, bone, and joint) of the limb when counseling patients on anticipated outcomes of and making recommendations on when to pursue limb salvage or amputation treatment.

Strength of recommendation: Moderate.

Implication: Practitioners should generally follow a moderate recommendation but remain alert to new information and be sensitive to patient preferences.

Psychosocial Factors

Clinicians should screen all patients with high-energy lower extremity trauma for psychosocial risk factors (eg, depression, PTSD, anxiety, low self-efficacy, and poor social support) affecting patient outcomes.

Strength of recommendation: Strong.

Implication: Practitioners should follow a strong recommendation unless a clear and compelling rationale for an alternative approach is present.

Rehabilitation

Clinicians should recommend patients with high-energy lower extremity trauma injuries participate in a rehabilitation program (eg, PT, OT, and behavioral health) to improve psychological and functional outcomes.

Strength of recommendation: Moderate.

Implication: Practitioners should generally follow a moderate recommendation but remain alert to new information and be sensitive to patient preferences.

Nerve Injury

The evidence suggests that plantar sensation or an observed nerve transection is not a factor in the decision for limb salvage versus amputation.

Strength of recommendation: Limited.

Implication: Practitioners should feel little constraint in following a recommendation labeled limited, exercise clinical judgment, and be alert for emerging evidence that clarifies or helps to determine the balance between benefits and potential harm. Patient preference should have a substantial influencing role.

Massive Soft-Tissue and Muscle Damage

Time1

Limited evidence suggests that these etiologies may lead to increased risk of adverse events or decreased functional outcomes as follows:

  • (1) Crush
  • (2) Blunt
  • (3) Blast
  • (4) Penetrating
  • (5) Degloving
  • (6) Volumetric muscle loss/soft-tissue loss

Strength of recommendation: Limited.

Implication: Practitioners should feel little constraint in following a recommendation labeled limited, exercise clinical judgment, and be alert for emerging evidence that clarifies or helps to determine the balance between benefits and potential harm. Patient preference should have a substantial influencing role.

Vascular Injury/Limb Ischemia

The evidence suggests that neither hard signs of vascular injury nor duration of limb ischemia are absolute factors in the decision for limb salvage versus amputation. However, the panel recognizes that prolonged ischemia is detrimental, and the interval to reperfusion should be kept to a practical minimum. The duration of lower extremity ischemia is directly correlated with adverse events.

Strength of recommendation: Limited.

Implication: Practitioners should feel little constraint in following a recommendation labeled limited, exercise clinical judgment, and be alert for emerging evidence that clarifies or helps to determine the balance between benefits and potential harm. Patient preference should have a substantial influencing role.

Smoking

Physicians should not consider a patient's smoking/nicotine use as a critical decision-making factor at time zero. Physicians should recommend nicotine education/cessation (abstinence of nicotine) for all patients with high-energy lower limb trauma because there is moderate evidence to suggest that smoking/nicotine use has a detrimental effect on outcomes for both amputation and limb salvage.

Strength of recommendation: Moderate.

Implication: Practitioners should generally follow a moderate recommendation but remain alert to new information and be sensitive to patient preferences.

Lower Extremity Injury Scores

Physicians should not use extremity-specific scores to select limb salvage versus amputation or to predict outcomes for patients with high-energy lower extremity trauma.

Strength of recommendation: Moderate.

Implication: Practitioners should generally follow a moderate recommendation but remain alert to new information and be sensitive to patient preferences.

Amputation/Limb Salvage

Injury patterns requiring ankle arthrodesis or foot free-tissue transfer may be an indication for amputation in the nonacute phase and should be addressed in shared decision making with the patient.

Strength of recommendation: Limited.

Implication: Practitioners should feel little constraint in following a recommendation labeled limited, exercise clinical judgment, and be alert for emerging evidence that clarifies or helps to determine the balance between benefits and potential harm. Patient preference should have a substantial influencing role.

Orthotics/Prosthetics

In the absence of reliable evidence, it is the consensus of the work group that all patients with lower extremity amputation be fitted with an appropriate prosthesis.

Similarly, all lower extremity limb salvage patients with residual deficits should be evaluated for and/or fitted with an appropriate orthosis.

These conditions are lifelong and require periodic reevaluation and device adjustments and/or replacement.

Strength of recommendation: Consensus.

Implication: In the absence of reliable evidence, practitioners should remain alert to new information because emerging studies may change this recommendation. Practitioners should weigh this recommendation with their clinical expertise and be sensitive to patient preferences.

Massive Muscle Damage

Time0

In the absence of reliable evidence, the work group suggests that massive muscle damage requiring extensive débridement is not an absolute factor in the decision for limb salvage versus amputation.

Strength of recommendation: Consensus.

Implication: In the absence of reliable evidence, practitioners should remain alert to new information because emerging studies may change this recommendation. Practitioners should weigh this recommendation with their clinical expertise and be sensitive to patient preferences.

Comorbidities

In the absence of reliable evidence, it is the opinion of the work group that preexisting comorbid conditions should be considered in the decision of limb salvage versus amputation.

Strength of recommendation: Consensus.

Implication: In the absence of reliable evidence, practitioners should remain alert to new information because emerging studies may change this recommendation. Practitioners should weigh this recommendation with their clinical expertise and be sensitive to patient preferences.

References

References printed in bold type are those published within the past 5 years.

1. American Academy of Orthopaedic Surgeons: Clinical Practice Guideline for Limb Salvage or Early Amputation. Available at: http://www.assoc.org/lsacpg.
2. Bosse MJ, MacKenzie EJ, Kellam JF, et al.: An analysis of outcomes of reconstruction or amputation of leg-threatening injuries. New Engl J Med 2002;24:1924-1931.
3. MacKenzie EJ, Bosse MJ, Pollak AN, et al.: Long-term persistence of disability following severe lower-limb trauma. Results of a seven-year follow-up. J Bone Joint Surg Am 2005;8:1801-1809.
4. MacKenzie AS, EJ, Bosse MJ, Castillo RC, et al.: Health-care costs associated with amputation or reconstruction of a limb-threatening injury. J Bone Joint Surg Am 2007;8:1685-1925.
5. Doukas WC, Hayda RA, Frisch HM, et al.: The military extremity trauma amputation/limb salvage (METALS) study: Outcomes of amputation versus limb salvage following major lower-extremity trauma. J Bone Joint Sug Am 2013;2:138-145.
6. Ellington JK, Bosse MJ, Castillo RC, MacKenzie EJ: The mangled foot and ankle: Results from a 2-year prospective study. J Orthop Trauma 2013;1:43-48.
7. Dickens JF, Kilcoyne KG, Kluk MW, Gordon WT, Shawen SB, Potter BK: Risk factors for infection and amputation following open, combat-related calcaneal fractures. J Bone Joint Surg Am 2013;5:e24.
8. Bosse MJ, MacKenzie EJ, Kellam JF, et al.: A prospective evaluation of the clinical utility of the lower-extremity injury-severity scores. Jbone Joint Surg Am 2001;1:3-14.
9. Sheean AJ, Krueger CA, Napeierala MA, et al.: Evaluation of the mangled extremity severity score in combat-related type III open tibia fracture. J Orthop Trauma 2014;9:523-526.
10. Webster CE, Clasper J, Stinner DJ, Eliahoo J, Masouros SD: Characterization of lower extremity blast injury. Mil Med 2018;183:e448-e453.
11. Hutchison TN, Krueger CA, Berry JS, Aden JK, Cohn SM, White CE: Venous thromboembolism during combat operations: A 10-y review. J Surg Res 2014;2:625-630.
12. Bhatnagar V, Richard E, Melcer T, Walker J, Galarneau M: Lower-limb amputation and effect of posttraumatic stress disorder on Department of Veterans Affairs outpatient cost trends. J Rehabil Res Dev 2015;7:827-838.
13. O'Toole RV, Castillo RC, Pollak AN, MacKenzie EJ, Bosse MJ: Determinants of patient satisfaction after severe lower-extremity injuries. J Bone Joint Surg Am 2008;6:1206-1211.
14. Wen PS, Randolph MG, Elbaum L, De la Rosa M: Gender differences in psychosocial and physical outcomes in Haitian amputees. Am J Occup Ther 2018;3:7203205090p1-7203205090p8.
15. Bosse MJ, McCarthy ML, Jones AL, et al.: The insensate foot following severe lower extremity trauma: An indication for amputation? J Bone Joint Surg Am 2005;12:2601-2608.
16. Bennett PM, Stevenson T, Sargeant ID, Mountain A, Penn-Barwell JG: Outcomes following limb salvage after combat hindfoot injury are inferior to delayed amputation at five years. Bone Joint Res 2018;2:131-138.
17. Asensio JA, Kuncir EJ, Garcia-Nunez LM, Petrone P: Femoral vessel injuries: Analysis of factors predictive of outcomes. J Am Coll Surg 2006;4:512-520.
18. MacKenzie EJ, Bosse MJ, Kellam JF, et al.: Early predictors of long-term work disability after major limb trauma. J Trauma 2006;3:688-694.
19. Ly TV, Travison TG, Castillo RC, Bosse MJ, MacKenzie EJ: Ability of lower-extremity injury severity scores to predict functional outcome after limb salvage. J Bone Joint Surg Am 2008;8:1738-1743.
20. Bevevino AJ, Dickens JF, Potter BK, et al.: A model to predict limb salvage in severe combat-related open calcaneus fractures. Clin Orthop Relat Res 2014;10:3002-3009.
Copyright 2021 by the American Academy of Orthopaedic Surgeons.