Volume 200 - Issue 5
Partial foot amputation may not always be worth the risk of complications
Authors: Michael P Dillon, Stefania Fatone and Meg E Morris
Med J Aust 2014; 200 (5): 252-253. || doi: 10.5694/mja13.11104
Published online: 17 March 2014
Published online: 17 March 2014
Similarity in functionality with partial foot and transtibial amputation focuses attention on complication rates
Similarity in functional outcomes with partial foot and transtibial amputation focuses attention on complication rates
Partial foot amputation is increasingly common in Australia,1 and the rates of complications are disproportionately high compared with people who have transtibial (below-knee) amputation.2We draw attention to these recent observations in our publications, highlighting that contemporary beliefs about partial foot amputations do not always result in optimal outcomes, especially for older people.1,3
A lower limb amputation is performed in Australia nearly every hour. Of the 8000 lower limb amputations in Australia each year,1 many are the end result of the long-term complications of diabetes such as peripheral vascular disease, neuropathy and chronic non-healing ulceration of the foot.
There has been a considerable shift in the types of lower limb amputations performed in Australia over the past decade.1 The incidence of transfemoral and transtibial amputation has declined and the incidence of partial foot amputation has increased.1 In Australia three-quarters of all lower limb amputations are now at the partial foot level.1
The shift to more distal amputation could be seen by some as a positive outcome. However, partial foot amputation can be associated with disproportionately high rates of complications and revision surgery. Between 30% and 50% of people with partial foot amputation experience complications such as dehiscence, ulceration or wound failure.4,5 However, these sorts of wound complications seem to affect just 10%–20% of people with transtibial amputation.6-8 Only around half of all partial foot amputations heal adequately.4,7 Efforts to achieve wound healing after partial foot amputation often occur over many months and cost between $27 000 and $36 000 depending on the treatment approach used.9 In comparison with the low rates of healing in partial foot amputation, around 80% of transtibial amputations heal.10,11 Subsequent amputation on the same limb is necessary in about one-third of people with an initial partial foot amputation; more than double that observed in people with an initial transtibial amputation.2,4
The high risk of complications and secondary amputation are sometimes considered reasonable when weighed against the functional benefits of partial foot amputation.12,13 Implicit in this reasoning is the belief that, if successful, partial foot amputation will lead to improved outcomes compared with transtibial amputation.
Emerging research suggests that many functional outcomes are similar in people with partial foot and transtibial amputation. For example, once the metatarsal heads are removed, people with partial foot and transtibial amputations have a strikingly similar gait pattern: power generation at the ankle is negligible and the hip joints provide the compensatory work required to walk.3 Similarly, walking speed and energy expenditure are also much the same.3 In terms of quality of life, only descriptive data are available. While these data suggest that quality of life is similar in both groups,3 we do not know whether the purported benefits of partial foot amputation, like walking short distances without a prosthesis,5 are important from the patient's perspective. The lower mortality associated with partial foot amputation may have nothing to do with the amputation procedure per se.14 It is likely that people considered suitable candidates for partial foot amputation live longer because they have less advanced vascular disease than those requiring a transtibial amputation.
Considering that the functional outcomes for people with partial foot and transtibial amputation are similar, it is difficult to understand why the high risk of complications and secondary amputation associated with partial foot amputation do not weigh more heavily in decisions about amputation surgery. Arguably, minimising complications and repeat surgeries should be the primary goal given that most people are in the last years of their life, are often chronically unwell and have limited mobility.
When viewed from the patient's perspective, it is perhaps easier to understand: individuals faced with the difficult reality of lower limb amputation often choose the procedure that preserves as much of their foot as possible. Yet when informing these decisions, clinicians have an obligation to provide information consistent with the emerging evidence, which suggests that people with partial foot amputation have very similar functional outcomes compared with those with transtibial amputation, yet markedly greater risks of complications and secondary amputation on the same limb.3
With a better understanding of the research data, we contend that more people might initially choose a more invasive procedure to minimise the risk of complications and further amputation surgery in the future.
If further research supports our interpretation of the emerging evidence,1,3 there will be a strong case for choosing between partial foot and transtibial amputation based on the likelihood of healing rather than perceived functional benefits. With this approach, more first amputations are more likely to be final ones.
Competing interests
No relevant disclosures.
References
- Dillon MP, Kohler F, Peever V. Incidence of lower limb amputation in Australian hospitals from 2000 to 2010. Prosthet Orthot Int 2013; 24 Jun [Epub ahead of print]. doi: 10.1177/0309364613490441. _ENREF_1
- Dillingham TR, Pezzin LE, Shore AD. Reamputation, mortality, and health care costs among persons with dysvascular lower-limb amputations. Arch Phys Med Rehabil 2005; 86: 480-486. _ENREF_8
- Dillon MP, Fatone S. Deliberations about the functional benefits and complications of partial foot amputation: do we pay heed to the purported benefits at the expense of minimizing complications? Arch Phys Med Rehabil 2013; 94: 1429-1435. 3
- Pollard J, Hamilton GA, Rush SM, Ford LA. Mortality and morbidity after transmetatarsal amputation: retrospective review of 101 cases. J Foot Ankle Surg 2006; 45: 91-97. _ENREF_3
- Dudkiewicz I, Schwarz O, Heim M, et al. Trans-metatarsal amputation in patients with diabetic foot: reviewing 10 years experience. Foot (Edinb) 2009; 19: 201-204. _ENREF_4
- Ploeg AJ, Lardenoye JW, Vrancken Peeters FM, Breslau PJ. Contemporary series of morbidity and mortality after lower limb amputation. Eur J Vasc Endovasc Surg 2005; 29: 633-637. _ENREF_5
- Stone PA, Back MR, Armstrong PA, et al. Midfoot amputations expand limb salvage rates for diabetic foot infections. Ann Vasc Surg 2005; 19: 805-811. 7
- Belmont PJ Jr, Davey S, Orr JD, et al. Risk factors for 30-day postoperative complications and mortality after below-knee amputation: a study of 2,911 patients from the national surgical quality improvement program. J Am Coll Surg 2011; 213: 370-378. 8
- Apelqvist J, Armstrong DG, Lavery LA, Boulton AJ. Resource utilization and economic costs of care based on a randomized trial of vacuum-assisted closure therapy in the treatment of diabetic foot wounds. Am J Surg 2008; 195: 782-788. _ENREF_6
- Nehler MR, Coll JR, Hiatt WR, et al. Functional outcome in a contemporary series of major lower extremity amputations. J Vasc Surg 2003; 38: 7-14. 10
- Keagy BA, Schwartz JA, Kotb M, et al. Lower extremity amputation: the control series. J Vasc Surg 1986; 4: 321-326. _ENREF_7
- Landry GJ, Silverman DA, Liem TK, et al. Predictors of healing and functional outcome following transmetatarsal amputations. Arch Surg 2011; 146: 1005-1009. _ENREF_9
- McCallum R, Tagoe M. Transmetatarsal amputation: a case series and review of the literature. J Aging Res 2012; 2012: 797218. _ENREF_10
- Evans KK, Attinger CE, Al-Attar A, et al. The importance of limb preservation in the diabetic population. J Diabetes Complications 2011; 25: 227-231. lefthere
Provenance: Not commissioned; externally peer reviewed.