Graham Hughes1 and Shirish Sangle2
(1)
The London Lupus Centre, London Bridge Hospital, London, UK
(2)
Louise Coote Lupus Unit, St Thomas’ Hospital, London, UK
Abstract
A number of cases of “idiopathic” bone necrosis have been reported in aPL-positive individuals with no other risk factors and who have never received steroids. These include avascular lesions in the hip and shoulder, for example (Fig. 17.1).
17.1 Avascular Necrosis
A number of cases of “idiopathic” bone necrosis have been reported in aPL-positive individuals with no other risk factors and who have never received steroids. These include avascular lesions in the hip and shoulder, for example (Fig. 17.1).
Figure 17.1
Avascular necrosis of hip in Hughes Syndrome
A large, multinational study of lupus patients with avascular necrosis (AVN) showed twice the incidence in aPL-positive individuals despite comparable steroid histories.
Despite these observations, the jury is still out on the overall contribution of APS to bone necrosis, some studies so far failing to find a significant link. Yet logically, the link makes sense. The hip joint, for example, is an end-organ, ischaemia or obstruction of the vascular supply to the head of femur having major consequences. This author believes that the link with AVN will prove a strong one.
An interesting clinical observation has come from the management of APS patients with hip pain. A small number have noticed pain relief in the hip when anticoagulation was started. And in some of these patients, MRI has revealed early avascular necrosis.
Clearly these clinical observations, “soft” though they might be, raise the possibility that anti-aggregant or anticoagulant treatment might have a place in some cases of early AVN – especially in aPL-positive patients.
17.2 Bone Fracture
An important study reported a series of Hughes Syndrome patients with “idiopathic” fracture of the metatarsal – the so-called “march fracture” traditionally seen in army recruits.
It seems probable that these fractures in the foot bones of aPL-positive individuals are also secondary to arterial ischaemia. Not surprisingly, a number of the “idiopathic” bone fractures in APS have been reported, including rib and vertebral fractures (Fig. 17.2
Figure 17.2
Non-traumatic metatarsal fractures in Hughes syndrome - multiple partially healed (callus) metatarsal fractures (arrow)
).
17.3 Arthritis
True arthritis is rare in APS but common in lupus or Sjögren’s patients with positive aPL. Thus it is likely that the complaints of widespread arthralgias in an aPL-positive person are secondary to an associated underlying connective tissue disease such as lupus, or more likely, Sjögren’s Syndrome (see Chap. 23).
17.4 Reflex Dystrophy
This rare, bizarre condition, also known as “algodystrophy”, is characterised by pain and swelling in a joint (such as the wrist) accompanied by overlying skin changes – shininess and tenderness.
Although the condition usually follows a relatively minor trauma, it results in severe disability, the limb being clinically “paralysed,” the skin showing livedo and other possibly ischaemic changes (Fig. 17.3). The cause is unknown.
Figure 17.3
Increased uptake of isotope in left wrist in a patient with reflex dystrophy in Hughes syndrome. (Image reproduced with permission from Medscape.com, 2011. Available at: http://emedicine.medscape.com/article/394928-overview)
There are a small number of cases reported in APS and it is possible that an underlying ischaemic tendency such as that in APS could be a contributing factor in such cases.
17.5 Orthopaedic Surgery
The medical and financial cost of post-operative thrombosis following knee or hip surgery is huge. Testing for thrombophilia and prophylactic anticoagulant treatment, while becoming more widespread in orthopaedic practice, is still not routine. Testing for aPL should become a standard (inexpensive) part of the routine pre-op assessment in major surgery, particularly surgery to the knee or hip.