Is there a need for diabetic foot orthopaedic surgery as a sub-specialty?

The diabetic foot burden worldwide has been progressively increasing and this is expected to continue to increase in the coming decades. Initial observations showed the benefits of providing access to a structured multi-disciplinary service that directs a coordinated assessment and treatment for patients presenting with diabetic foot problems.¹ There has been progressive modernisation of this concept in the years since resulting in continued improvements in the outcomes of common diabetic foot presentations.² There is a wide variation in the delivery of diabetic foot care globally. However, diabetic foot screening and treatment of minor lesions are generally delivered in the community, whereas complex or limb-threatening care is provided by multi-disciplinary foot teams (MDFT) in the secondary or tertiary care. The MDFT should be skilled and equipped to deal with the full spectrum of presentations-from apical toe ulcers to the rapidly progressive infection of a deformed diabetic foot that can potentially lead to a major lower limb loss. The aim of such treatments should be to preserve the limb and its function. The MDFT is comprised of a diabetic foot physician, podiatrist, orthotist, and a surgeon (general, orthopaedic, vascular, plastic) as the core members, along with contributions from other surgeons, microbiologist, radiologist, and other specialists. Recently, there has been increasing and specialised contribution from the orthopaedic surgeon to indicate that orthopaedic surgery of the diabetic foot should be specific subspeciality within orthopaedics.

The patient with diabetic foot disease is complex and vulnerable. Up to 70% of diabetes patients who undergo an amputation will not be alive in 5 years.¹² Thus major amputation for advanced diabetic foot disease is known to be associated with a mortality rate that is greater than most common cancers, and the patients often die from medical complications related to poor mobility.³ This is frequently due to poor rehabilitation progression, and limited prosthetic uptake has been seen in this group of patients. It is critical that these patients with advanced diabetic foot disease receive appropriate interventions to maintain their ambulation status and hence functional limb salvage is offered whenever possible.

There are three pathological processes that often present in combination, contributing to lower extremity amputation in a neuropathic diabetic foot. These are infection, ischemia, and deformity. Infection surgery has seen major advancements recently. Aggressive surgical debridement that removes most infection burden, followed by a modern protocol-based and targeted antibiotic therapy measures are known to achieve infection eradication even in severe infection presentations. Phyo et al. described high rates of infection clearance and limb salvage among 29 patients presented with infected heel ulcers in a background of diabetic neuropathy.⁴ Rapid reconstruction of the soft-tissue defects following debridement is also critical, to prevent recurrence of infection and achieve ambulatory status, and appropriate plastic surgical or podoplastic procedures are now increasingly offered to these patients with greater success.Infection clearance and soft tissue reconstruction, combined with deformity correction or stabilisation in a circular frame have introduced a newer holistic approach to diabetic foot management.⁵ Associated vascular insufficiency, that often requires far-distal revascularisation in this group of patients is also increasingly managed by endovascular and open surgical techniques, thereby improving the success rates further.⁶

The orthopaedic surgeon is often the specialist surgical member of the MDFT and is responsible for delivering functional limb salvage treatment for diabetic foot deformities. The recent outcomes of surgical treatment of complex Charcot foot deformities using modern techniques are promising.^{7, 8, 9} This partly is due to a better understanding of the fixation principles used for Charcot foot reconstruction, using internal and external fixation methods, and the availability of dedicated fixation devices. The role of soft tissue balancing in deformity corrections, by performing release or lengthening of contracted tendon and other tissues is now much better understood. Tiruveedhula et al. reported the association of tight Achilles-gastrocnemius-soleus complex in midfoot Charcot deformities and noted good outcomes with Achilles tendon lengthening for such presentations in a series of 33 patients.¹⁰ Froekjaer reported satisfactory outcomes of midfoot Charcot reconstructions in 20 patients performed using ‘super construct’ internal fixation technique, with a 100% fusion rate.⁸ Another recently published studies revealed 100% limb salvage and high functional outcomes in a large series of Charcot hindfoot and midfoot reconstructions performed using internal fixation, that included two-stage procedures for infected presentations.¹¹

Most diabetic foot deformities also present with infected ulcerations and significant vascular compromise. Such deformity corrections require a coordinated and staged surgical approach, that addresses the infection, vascular, soft tissue cover, and deformity correction components delivered by different members of the surgical team of the MDFT. It is imperative that the treating orthopaedic member works closely with other surgeons in the team and becomes familiar with the non-orthopaedic surgical procedures needed for such presentations and their outcomes.

In addition to being competent in providing comprehensive assessment and contributing to the generic management of all diabetic foot presentations, it is critical that the specific role of an orthopaedic surgeon in an MDFT is well defined, and this should ideally include providing common and generic surgical treatment and complex orthopaedic reconstructive service. All surgical members of the MDFT should be competent in delivering the common and generic surgical procedures such as ulcer debridement, flexor tenotomies for toe deformities, Achilles tendon release for forefoot overload related ulcers, exostectomy, debridement diabetic foot attack and minor foot and major lower limb amputations. All surgical members should also have up to date knowledge on the surgical principles of management in other specialities delivered by other surgical team members.

With the continued advancement of diabetic foot surgical care, there is a greater understanding of the required knowledge base and skill set for the orthopaedic or foot and ankle surgeon member of the MDFT in a set up that delivers complex and functional limb salvage service. It is perhaps time to consider orthopaedic surgery of the diabetic foot as a specific subspeciality within orthopaedics, like bone tumour surgery!