Chronic calcaneal osteomyelitis secondary to heel ulceration is difficult to treat in patients with diabetes (Fraccalvieri et al, 2012). In these patients, diabetes is often complicated by peripheral vascular disease and/or neuropathy (National Institute for Health and are Care Excellence (NICE), 2022). They can cause significant morbidity and often have few treatment options other than major amputation. Calcanectomy can be a surgical alternative to below- or above-knee amputation (Bollinger and Thordarson, 2022). The calcanectomy involves resecting all infected and non-viable tissue to allow healing of the soft tissue. Patients require ongoing and intensive podiatry input for pressure relief, wound management debridement and infection control. In addition, holistic management of the diabetes and comorbidities, particularly blood glucose control, is also essential.
These case histories highlight the clinical challenges associated with calcaneal osteomyelitis and demonstrate that for many patients alternatives to a major amputation are limited unless limb sparing total or partial calcanectomy procedures are considered (Yammine et al, 2020) and suggest that calcanectomy is a reliable limb-sparing procedure for calcaneal osteomyelitis in selected patients.
Partial calcanectomy as an alternative to major amputation: case report 1
A 66-year-old male with uncontrolled type 2 diabetes mellitus, end-stage renal failure requiring haemodialysis, hypertension, retinopathy, peripheral neuropathy and chronic nephrotic syndrome was admitted to hospital for treatment of bilateral foot burns caused by a hot water bottle. The right heel had an extensive heel eschar with some additional maceration, for which he was provided with a heel cast for offloading. A magnetic resonance angiogram showed significant tibial vessel disease and he subsequently had an angioplasty which was only partially successful due to extensive calcification of the distal vessels.
Due to pre-existing comorbidity the patient was deemed a high risk for lower-limb bypass surgery. The right heel eventually became necrotic and a plain radiograph confirmed calcaneal osteomyelitis. The patient was admitted with right foot sepsis and commenced on intravenous antibiotics. However, there was clinical deterioration and extensive osteomyelitis within the heel. The patient declined a major amputation so underwent debridement of his right heel and a partial calcanectomy rather than a below-knee amputation. This was the patient’s choice and had the full support of the multidisciplinary diabetic foot team (MDFT). He was treated with negative pressure wound closure (NPWC) and intravenous antibiotics until the soft tissue infection had improved and then stepped down to oral antibiotics based on postoperative bone cultures. The wound made satisfactory progress while he continued to wear the heel cast. A subsequent magnetic resonance imaging (MRI) of the foot confirmed no further signs of osteomyelitis in the residual right calcaneum.
The patient re-presented at the hospital 2 years later with tissue loss from his left heel with exposed bone. There was clinical and radiological evidence of extensive osteomyelitis in his left calcaneum. The patient was offered a partial calcanectomy initially, but again counselled that there was a high risk of a below-knee amputation. He underwent a left partial calcanectomy and had vacuum assisted closure, which resulted in wound healing (Figure 1). During a follow up for the left heel, it was noted the patient had developed an ulcer on the right heel where he had previously had the calcanectomy. However, this was healed with conservative treatment. The patient continued with regular podiatry input in the multidisciplinary diabetic clinic with offloading via heel casts. He unfortunately died 2 and a half years after the final procedure and as per his wishes he did not have a major amputation.
Total calcanectomy in the treatment of calcaneal osteomyelitis: case history 2
A 58-year-old male patient presented with bilateral heel ulcerations with a background of poorly controlled type 2 diabetes requiring insulin. He also had a significant history of diabetic retinopathy, bilateral peripheral neuropathy, atrial fibrillation and dilated cardiomyopathy and was a current smoker.
The patient originally developed bilateral heel ulcers caused as a result of an injury from carpet grippers in his home. The right heel initially presented as a superficial, granulating wound which was healing well. However, the left heel probed to bone with a plain X-ray confirming osteomyelitis in the calcaneum. Initially, the patient was keen for a below-knee amputation rather than have prolonged treatment with intravenous antibiotics and topical wound care. However, after counselling from the multidisciplinary diabetic foot team about the long-term issues following a major amputation, he opted for the latter treatment. He underwent a left leg angioplasty with surgical debridement of the heel, with a bone biopsy. He had a 4-week course of intravenous antibiotics and then oral antibiotics as per bone cultures. The heel ulcer was non-healing mainly due a lack of concordance with both antibiotics and offloading. Subsequent deterioration of the left heel resulted in an emergency popliteal-distal bypass alongside further surgical debridement of the heel.
The patient was prescribed intravenous antibiotics and a subsequent MRI confirmed persistent osteomyelitis. He was discharged from hospital on oral antibiotics and NPWC therapy with heel cast offloading. However, he was unfortunately readmitted to hospital a few weeks later with sepsis of the left foot secondary to an infected left calcaneum. The heel was further surgically debrided to healthy bone but due to continued purulent discharge a total calcanectomy was performed; this was 18 months after the initial injury (Figure 2). This healed with no clinical issues and the patient was subsequently managed with offloading of the heel.
Four years later, the patient was admitted to hospital with an acutely ischaemic left leg due to occlusion of his bypass and a below-knee amputation was performed at this point. Due to the patient developing a gangrenous below-knee stump secondary to trauma at home, this was revised to an above-knee amputation.
The left leg was intact for 5 years post-total calcanectomy and limb loss was secondary to occlusion of the bypass. The right foot heel ulcer deteriorated within a few months of the left major limb amputation and the patient underwent a partial calcanectomy on this heel due to the presence of exposed bone. Unfortunately, the postoperative wound deteriorated 6 months later and requiring further debridement and subsequent below-knee amputation 1 month later.
Discussion
Heel ulceration is a common and difficult to treat, with limited specific or universally successful treatment options in the diabetic foot clinic (Jeffcote, 2014). Chronic calcaneal osteomyelitis is particularly resistant to treatment, especially in patients with diabetes mellitus with associated peripheral vascular disease, and/or peripheral sensory neuropathy carrying with it the significant risk of major amputation (Ignatiadis et al, 2010).
It is important that the treatment of foot ulcers associated with diabetes should be part of a comprehensive care plan that should also include eradication of infection, frequent debridement (if deemed appropriate by a skilled specialist clinician), biomechanical offloading, blood glucose control and treatment of associated comorbidity (Turns, 2013). Many podiatrists utilise bespoke, removable, lightweight fibreglass total contact casts or heel casts in order to promote healing (Baker and Osman, 2016) by reducing both pressure and shear in the healing wound, as well as reducing potential discomfort and pain (Jeffcoate et al, 2014) and have been shown to result in healing in approximately 84% of heel ulcers in patients with and without diabetes (Stuart et al, 2009).
The surgical procedure
Introduced by Gaenslen in 1931, calcanectomy surgery is aimed at reducing the bulkiness of the bony prominence of the calcaneum and to allow for closure of the overlying soft tissues, thereby avoiding the need for lower-limb amputation (Gaenslen, 1931; Walsh and Yates, 2013). The relative simplicity and low morbidity of the procedure make it an appealing and limb-sparing option, (Han and Ezquerro, 2011) with advantages including preservation of the heel pad for weight-bearing, decreased oxygen demand and decreased energy costs (Bragdon and Baumhauer, 2008).
The aim of the calcanectomy is therefore to eradicate non-viable soft tissue and infected bone whilst preserving the weight-bearing function of the foot (Ignatiadis, 2010) which may be achieved by either a total or partial calcanectomy procedure. Such surgery is suggested as a reliable and credible alternative for major amputation in order to ensure limb salvage and reduce mortality (Schade, 2012). It is important as shown in these cases that the multidisciplinary team should be involved to allow the patient to make an informed choice and achieve good outcomes.
The two patients in this case report both had chronic heel wounds and underwent calcanectomy surgery as an alternative to below knee amputation. The first patient avoided a below-knee amputation, although before dying 2 and half years after surgery. which was in keeping with his wish not to have a major amputation. The second had successful bilateral calcanectomies and remained amputation free for 5 years after his first procedure before undergoing bilateral major amputations. These cases both demonstrate the patient’s significant additional time with both limbs before the requirement for more extensive surgery in one patient and death in the second patient, which further illustrates the morbidity and mortality associated with patients with high-risk diabetes foot complications.
Conclusion
These case histories also demonstrate that the remaining foot and contralateral limb require regular and vigilant podiatric surveillance and monitoring to avoid the risks of subsequent tissue damage and ulceration due to vulnerability of the remaining limb.
It is important that the patient is fully aware and understands the implications of a major limb amputation and this case series highlights the importance of multidisclipinary diabetes foot team involvement with patients who may otherwise opt for a major amputation rather than explore calcaneal surgery, wound debridement and long-term antibiotics as a treatment for calcaneal ulceration and osteomyelitis.
Calcanectomy is, therefore, been suggested as a viable alternative to below knee amputation with a high degree of patient satisfaction but has traditionally been underutilised.
