Principal Investigator: Michael Dillon, PhD, BPO(Hons), La Trobe University, Australia
Co-Investigator: Stefania Fatone, PhD, BPO(Hons)
Research Assistant: Matthew Quigley, MCPO(Hons), La Trobe University, Australia
Funded by: American Orthotic and Prosthetic Association
Status: In Progress
While the incidence of lower limb amputation has remained constant over the last 15 years, there appears to have been a dramatic shift in the types of lower limb amputations performed. The incidence of transtibial amputation seems to have declined and there is some evidence that partial foot amputation has increased proportionately. If these trends hold true into the future, the incidence of partial foot amputation is expected to triple across the first half of this century.
Our uncertainty about these observations is a reflection of the way different health jurisdictions and researchers measure and report these data. For example, counting of first-ever (index) amputation underestimates the number of surgeries compared to counting all amputation procedures, but may better capture the number of people affected. This is particularly problematic in people with partial foot amputation given that one-third of amputations are revised to a higher level. Many studies only count major amputations (e.g., above-the-ankle) and underreport the incidence given that up to three-quarters of all lower limb amputations are partial foot amputations.
These variations in study design cloud our understanding of the true incidence of partial foot and transtibial amputation, the incidence of secondary amputations, as well as changes in both over time. A systematic review designed to critically appraise recent epidemiological research would provide a better understanding of changes in the population of people living with limb loss. These data are important to help plan for the projected increase in the number of people living with partial foot amputation and the specialist clinical services they require (e.g., wound care and high risk foot clinics, prosthetic, orthotic and pedorthic services). Notwithstanding the limitations of the epidemiology evidence, the shift from transtibial to partial foot amputation will be seen by many as a significant improvement; particularly given an understanding that preserving the ankle joint results in more normal gait, reduced energy expenditure, improved quality of life, and lower mortality. However, partial foot amputation has been associated with a significant rate of failure and numerous complications. Between 30-50% of people with partial foot amputation will experience complications including: dehiscence, ulceration or complete failure of the wound to heal. Only about 50% of all partial foot amputations heal, with no appreciable difference based on level of partial foot amputation. The rate of healing of partial foot amputations is only about 10% better in non-diabetic populations, which makes it difficult to conclude that the high failure rate is simply a reflection of advanced systemic disease. About one-third of people with an initial partial foot amputation will require revision surgery, most commonly within three months. The rates of failure and reamputation in people with partial foot amputation are disproportionately high when you consider that more than 80% of all transtibial amputations heal, and only about 10% require subsequent amputation surgery on the same limb.
The potential benefits and complications of partial foot amputation have recently been the focus of editorials by the PI and Co-Investigator (Drs. Dillon and Fatone). These commentaries challenge the long-held belief that the high rates of complications and reamputation are worth the potential benefits; particularly given that once the metatarsal heads are affected, the gait of people with partial foot and transtibial amputation is virtually indistinguishable. Similarly, measures of community mobility, energy expenditure, balance, and quality of life also appear to be comparable in people with partial foot and transtibial amputation.
While these editorials resulted in a number of letters to the editor and considerable media attention, concerns have been raised that require closer scrutiny of the evidence. For example, much of the literature focuses on people with mid-foot amputations and there is suggestion that outcomes may be better for people with toe amputations. Similarly, some studies report very high rates of wound healing in people with partial foot amputation - comparable to those for people with transtibial amputation - but it is unclear what made some surgical and rehabilitation programs so much more effective. There appears to have been little focus on the psychological and social outcomes, which is of particular concern given the experience of people with partial foot amputation. Isolated studies suggest that people with partial foot amputation report a pervasive fear and anxiety about the prospect of future amputations that has not been reported by people with transtibial amputation.
The aim of this project will be to compare the outcomes of people with partial foot and transtibial amputation secondary to peripheral vascular disease and/or diabetes as well as translate what we learn from this research to help clinicians and patients make well-informed decisions about amputation surgery.
Review Protocol Registration
Michael Dillon, Stefania Fatone, Matthew Quigley. Describing the outcomes of dysvascular partial foot amputation and how these compare to transtibial amputation: a systematic review protocol for the development of shared decision making resources. PROSPERO 2015:CRD42015029186 Available from http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42015029186
Dillon M, Quigley M, Fatone S (2017) Outcomes of dysvascular partial foot amputation and how these compare to transtibial amputation: a systematic review for the development of shared decision-making resources. Systematic Reviews, 6:54 DOI 10.1186/s13643-017-0433-7 http://systematicreviewsjournal.biomedcentral.com/articles/10.1186/s13643-017-0433-7
Dillon M, Fatone S, Quigley M (2016) Describe the outcomes of dysvascular partial foot amputation and how these compare to transtibial amputation: a systematic review protocol for the development of shared decision making resources. Systematic Reviews. doi:10.1186/s13643-015-0161-9
Dillon M, Fatone S (2017) Outcomes of Dysvascular Partial Foot Amputation. The 43rd Academy Annual Meeting & Scientific Symposium of the American Academy of Orthotists & Prosthetists (AAOP), March 1-4, Chicago, IL.
Dillon M, Fatone S, Hoffman T (2016) Symposium: Outcomes of partial foot amputation can inform difficult decisions about amputation surgery using a shared decision-making approach. American Orthotic and Prosthetic Association National Assembly, September 8-11, Boston, MA.
Michael Dillon, PhD, BPO(Hons), and Stefania Fatone, PhD, BPO(Hons), presented Outcomes of Dysvascular Partial Foot Amputation at the 43rd Academy Annual Meeting & Scientific Symposium of the American Academy of Orthotists & Prosthetists (AAOP), March 1-4, Chicago, IL.