Treatment Failures in Diabetic Foot Osteomyelitis Associated with Concomitant Charcot Arthropathy: The Role of Underlying Arteriopathy

Abstract

Objective: Therapy for diabetic foot osteomyelitis (DFO) with Charcot neuroosteoarthropathy is challenging. In patients with diabetic Charcot osteomyelitis (DCO), both the anatomic deformity and infection must be addressed. This study assessed the outcomes of DCO therapy and variables associated with treatment failure and compared them with outcomes of DFO cases. Methods: A single-center, retrospective, case-control study was performed to compare 93 DCO episodes with 530 DFO episodes, using Kaplan-Meier survival curves and multivariate Cox regression analyses. Results: Clinical failure occurred in 21.5% of DCO compared with 22.3% in DFO episodes ( p = 0.89) and was associated with peripheral arterial disease (PAD) stages 3 or 4 (HR 6.1; CI 2.0-18.1) and chronic treatment with immunosuppressives (HR 7.4; CI 2.0-27.1). Major amputations were significantly more frequent in DCO (28% versus 13.6%; p < 0.01) and associated with PAD stages 3 and 4 (HR 8.0; CI 2.2-29.4), smoking (HR 5.4; CI 1.2-24.6), alcohol abuse (HR 3.5; CI 1.1-10.6), and renal dialysis (HR 4.9; CI 1.3-18.9). Conclusions: Clinical treatment failures did not differ between DCO and DFO. However, patients with DCO underwent major amputation twice as often as those with DFO. Unlike widespread belief, treatment failure in DCO patients may, similar to DFO, be associated with a striking epidemiological link to severe PAD.

Timing of Revascularization and Parenteral Antibiotic Treatment Associated with Therapeutic Failures in Ischemic Diabetic Foot Infections

“…The Balgrist University Hospital is a tertiary orthopedic clinic that cooperates with the Department of Angiology at the “University Hospital Zurich”. The Diabetic Foot Unit runs several registers regarding DFIs, assessing episodes since 1 January 2000 [ 5 , 7 , 33 , 35 ]. The first, bedside angiologic examinations (ABI, pressures, pulse palpability) are initiated by the specialized orthopedic surgeons of the Diabetic Foot Unit.…”

“…Most below-knee amputations are predominantly necessitated by the presence of peripheral arterial disease related ischemia, whereas toe amputations are more often necessitated by factors such as destructive bone lesions, hammer toe deformities, and the presence of refractory DFUs, which can be further complicated by acute ischemia [ 1 , 2 , 3 , 4 , 5 , 6 ]. While appropriately administered medical and surgical therapy can often cure DFIs, clinical failures during or after treatment can be as high as 25%, even in specialized centers in resource-rich settings [ 5 , 6 , 7 ]. Reasons for these clinical failures are often complex and may be caused by the presence of multiple and simultaneous clinical entities [ 8 , 9 , 10 , 11 ].…”

“…Among all clinical failures, only 5–15% are true infection recurrences, which have previously been called the microbiological failure [ 5 , 6 ]. This is a subset of clinical failure in which the majority of the causative pathogens in the recurrence are identical to those of the prior infection [ 5 , 7 ]. This relatively infrequent type of infectious recurrence is most often attributed to poor patient compliance or clinicians selecting the wrong empirical antimicrobial therapy.…”

“…The reduced blood supply impairs the wound healing [ 21 ] as well as the delivery of antibiotics to the infected site. We have found that in DFIs the likelihood of both clinical failure (hazard ratio (HR) 6.1) and major amputation (HR 8.0) is significantly associated with the advanced PAD [ 7 ]. This leads many clinicians to view the presence of severe PAD as an indication for prolonged initial intravenous antibiotic therapy in DFI, despite the associated increased costs, and impaired postsurgical mobilization [ 18 ].…”

No Difference in Risk of Amputation or Frequency of Surgical Interventions Between Patients With Diabetic and Nondiabetic Charcot Arthropathy

“…There was a possible susceptibility bias, because a higher percentage of patients with diabetic CN smoked cigarettes, and patients in that group were also younger. There are reports that smoking is associated with an increased frequency of major amputation in diabetic CN osteomyelitis [33] and delayed healing in patients with diabetic CN who undergo reconstruction [5]. However, because patients who smoke have a 30% to 40% higher risk of experiencing diabetes than patients who do not smoke [24], we believe the demographics of the diabetic CN group reflect the realworld demographics of patients with this condition.…”