Immobilization-induced osteolysis and recovery in neuropathic foot impairments

Abstract

Background Neuropathic foot impairments treated with immobilization and off-loading result in osteolysis. In order to prescribe and optimize rehabilitation programs after immobilization we need to understand the magnitude of pedal osteolysis after immobilization and the time course for recovery. Objective To determine differences in a) foot skin temperature; b) calcaneal bone mineral density (BMD) after immobilization; c) calcaneal BMD after 33–53 weeks of recovery; and d) percent of feet classified as osteopenic or osteoporotic after recovery in participants with neuropathic plantar ulcers (NPU) compared to Charcot neuroarthropathy (CNA). Methods Fifty-five participants with peripheral neuropathy were studied. Twenty-eight participants had NPU and 27 participants had CNA. Bilateral foot skin temperature was assessed before immobilization and bilateral calcaneal BMD was assessed before immobilization, after immobilization and after recovery using quantitative ultrasonometry. Results Before immobilization, skin temperature differences in CNA between their index and contralateral foot were markedly higher than NPU feet (3.0 degree C versus 0.7 degree C, respectively, p < .01); BMD in NPU immobilized feet averaged 486 ± 136 mg/cm2, and CNA immobilized feet averaged 456 ± 138 mg/cm2, p >0.05). After immobilization, index NPU feet lost 27 mg/cm2; CNA feet lost 47 mg/cm2 of BMD, p < 0.05. After recovery, 61% of NPU index feet and 84% of CNA index feet were classified as osteopenic or osteoporotic. Conclusions There was a greater osteolysis after immobilization with an attenuated recovery in CNA feet compared to NPU feet. The attenuated recovery of pedal BMD in CNA feet resulted in a greater percentage of feet classified as osteoporotic and osteopenic.

Should weight-bearing activity be reduced during healing of plantar diabetic foot ulcers, even when using appropriate offloading devices?

“…Rather, so-called non-removable devices imply different physical or psychological thresholds that patients can accept to prevent their future self from removing the device [63]. It is also worth noting that of the reviewed studies only three investigated activity-related side-effects (reporting no [40] or few [55,56] falls and moderate satisfaction with performance of daily activities [41]), although other studies have found that prolonged immobilization of the ankle joint with knee-high devices results in muscle atrophy [64], reduced range of motion [65] and loss of calcaneal bone mass [66]. Thus, future studies should include side-effects of restricted weightbearing activity from a wider perspective, including both specific bodily side-effects (glycemic control, weight gain, loss of muscle mass, joint flexibility, and bone mass) and a wider health perspective, taking emotional and social aspects into account.…”

Accelerated Cortical Osteolysis of Metatarsals in Charcot Neuroarthropathy: A Cross‐Sectional Observational Study

“…Our previous work suggests that an acute or prolonged inflammation associated with CN is largely the incipient contributor of the 5% to 6% cortical osteolysis in the metatarsals because participants with DM and PN, but without CN, gained an average of 0.4% apparent BMD after 1‐year follow‐up . Also previously, participants with DMPN and a neuropathic plantar ulcer recovered QUS‐derived calcaneal BMD 1 year after immobilization, whereas participants with DMPN&CN did not recover calcaneal BMD after immobilization: This implies that diabetes and neuropathy are not the primary contributing factors in pedal bone loss and recovery …”

“…(10) Also previously, participants with DMPN and a neuropathic plantar ulcer recovered QUS-derived calcaneal BMD 1 year after immobilization, whereas participants with DMPN&CN did not recover calcaneal BMD after immobilization: This implies that diabetes and neuropathy are not the primary contributing factors in pedal bone loss and recovery. (29) Another limitation is when estimating the metatarsal strength indices, we assumed the metatarsals to be uniformly circular with a constant diameter (and radius). Similarly, we assumed the cortical width (and area) around the marrow cavity was uniform and therefore can be represented by a single average cortical width.…”

Rehabilitation for people wearing offloading devices for diabetes‐related foot ulcers: a systematic review and meta‐analyses

“…People with DFUs are generally advised to reduce weightbearing activity as much as possible to improve ulcer healing [8,9]. Knee-high devices reduce the range of motion at the ankle joint which increases the potential for muscle atrophy and bone mass loss over longer periods [10][11][12]. A recent systematic review (three trials; n = 139) concluded there was limited evidence to support non-weight bearing exercise as an intervention to directly improve ulcer healing, although none of the trials reported negative consequences of non-weight bearing exercise [8].…”