The role of radiology in nerve function impairment and its musculoskeletal complications in leprosy.

Conventional techniques, such as plain radiography and bone-scintigraphy, were used in the past to evaluate skeletal changes in patients with leprosy. More recent publications focus on radiological imaging of affected nerves, and involve advanced modalities such as Computed Tomography (CT-scan), Ultrasonography (US), and Magnetic Resonance Imaging (MRI). US and MRI can play an especially important role in the evaluation of nerve involvement in newly diagnosed patients, and also during leprosy reactions. This is important, because when nerve involvement is diagnosed in time, it may be reversible with adequate treatment. Radiological modalities can also play an important role during the followup of patients with leprosy with nerve function impairment. Skeletal and soft-tissue abnormalities occur, even after treatment. The so-called neuropathic foot is a well known consequence. Because of nerve function impairment, there is a constant risk of developing ulcers and subsequent osteomyelitis, or neuro-osteoarthropathy (Charcot foot or tarsal disintegration), which can lead to the amputation of the affected limb. Different radiological modalities can be used during the evaluation and follow-up of patients with leprosy with a neuropathic foot. With this up-to-date review, we highlight the importance and potential role of radiological imaging techniques in leprosy.

Radiological changes in hands and feet in disabled leprosy patients: a clinico-radiological correlation.

Seventy-six consecutive leprosy patients with disabilities were subjected to radiological examination of hands and feet, and bone changes were found in 63 of them (82.9%). Specific, nonspecific and osteoporotic bone changes were observed in 22.4%, 78.9% and 28.9% of cases respectively. Bone cysts (10.5%), subarticular erosions (10.5%) and enlargement of nutrient foramina (5.3%) were the common specific bone changes whereas bone absorptive changes (59.2%), soft tissue changes (39.5%) and concentric absorption (39.5%) were the most frequent nonspecific bone changes. Specific bone changes were more common in older patients (age 40 years) and nonspecific bone changes correlated with duration of disease, duration of deformity, and disability index. Osteoporotic bone changes were found to be affected by ageing and severity of disability of hands and feet.

Neuroarthropathy of the foot in leprosy.

Among 449 patients with leprosy, 40 had clinical and radiographic evidence of neuroarthropathy in 50 feet. These changes were classified into four types according to the joints first involved by major lesions: ankle (25 feet), midtarsal (15 feet), tarsometatarsal (7 feet) and subtalar (3 feet). The progression of joint destruction was different in each type, but despite the severe destructive changes seen in radiographs, the patients had relatively few complaints. The muscles innervated by the peroneal nerve were severely paralysed in ankle and midtarsal types and it seems that, over a long term, repeated trauma and/or abnormal stress may lead to these types of neuroarthropathy. Neuropathy was less severe in the tarsometatarsal type of joint degeneration; the pathogenesis in this type seemed to be mainly direct trauma to the forefoot.

Spina bifida occulta with atrophy of toes.

A case of lumbosacral spina bifida occulta presented with resorption of toes which started at six years of age. Its differential diagnosis with neural leprosy is discussed.

Seronegative arthropathies in the foot.

It has been seen that involvement of the foot in the seronegative arthropathies forms a regular and varied part of the clinical picture. This is often quite different from that seen in rheumatoid arthritis; its components, whether in joints, periarticular structures, or as surface manifestations, may be characteristic enough to raise the diagnosis of 'spondarthritis'. The features described, though characteristic of the spondarthritides, are, however, not pathognomonic. Thus, the osteolysis in psoriatic arthritis also occurs in neuropathic arthritis (e.g. syringomyelia, leprosy), psoriatic periosteal changes may mimic osteosarcomatous proliferations, and the calcaneal enthesitis so typical of spondylitis, Reiter's disease and psoriatic arthritis, may also be seen in metabolic arthropathies. It should also be mentioned here that the severe erosive osteolytic changes leading to psoriatic arthritis mutilans may also be seen, albeit rarely, in rheumatoid arthritis. Ankylosis, too, is not totally confined to the spondarthritides, having also been reported in occasional patients with rheumatoid arthritis. Calcaneal erosions, sometimes envisaged as a spondarthritic feature, also occur in rheumatoid patients. Within the spondarthritis matrix, a striking overlap is seen in the pattern of arthritis. Thus, involvement of the feet in psoriatic arthritis and in Reiter's disease shows many similarities, particularly the tendency to involve IP joints in asymmetrical oligoarticular fashion. In the hindfoot, too, parallels can be drawn between the tendency to Achilles and plantar insertion enthesitis in ankylosing spondylitis and Reiter's disease. On the other hand, the arthropathies of the chronic inflammatory bowel diseases, ulcerative colitis, Crohn's disease, and Whipple's disease, share with Behçet's syndrome an asymmetrical involvement of knees and ankles, but relative freedom from foot involvement. Regarding the surface features in the foot of spondarthritides, there is overlap here, too. For example, the nail dystrophy of psoriasis can be indistinguishable from that of Reiter's disease, and pustular psoriasis in its severe form cannot be differentiated from keratoderma blenorrhagica, even at the histological level. Other surface manifestations affecting the lower limb in general distribution may spread to the feet and thus fall within the ambit of this discussion. Such features include the lesions of erythema nodosum, patches of pyoderma gangrenosum, and the tender cords of thrombophlebitis, all of which have a higher prevalence in seronegative arthritis than in seropositive disease.(ABSTRACT TRUNCATED AT 400 WORDS)

Bone changes in leprosy. A study of 50 cases.

The radiological bone changes have been studied in 50 patients comprising of lepromatous, tuberculoid, mixed (borderline lepromatous, borderline tuberculoid, dimorphous) and polyneuritic (neural) types of leprosy of which the former formed the largest group. The overall incidence of non-specific bone changes is higher as compared to specific bone changes. These were found to have highest incidence in the lepromatous type of leprosy, in the occupational group of manual workers and from 3rd to 6th decade of life. With the longer duration of the disease, the incidence of non-specific bone changes is also more.