Skeletal fluorosis phases

[tirath]

Osteosclerotic phase Ash concentration (mgF/kg) Symptoms and signs
Normal Bone 500 to 1,000 Normal
Preclinical Phase 3,500 to 5,500 Asymptomatic; slight radiographically-detectable increases in bone mass
Clinical Phase I 6,000 to 7,000 Sporadic pain; stiffness of joints; osteosclerosis of pelvis and vertebral spine
Clinical Phase II 7,500 to 9,000 Chronic joint pain; arthritic symptoms; slight calcification of ligaments’ increased osteosclerosis and cancellous bones; with/without osteoporosis of long bones
Phase III: Crippling Fluorosis 8,400 Limitation of joint movement; calcification of ligaments of neck vertebral column; crippling deformities of the spine and major joints; muscle wasting; neurological defects/compression of spinal cord

        

[sushantpatel_doc]

X-ray Diagnosis of Skeletal fluorosis:

In 1937, Kaj Roholm published his seminal study Fluorine Intoxication. Based on observations of skeletal fluorosis in fluoride-exposed workers, Roholm described three phases of bone changes detectable via x-ray. Roholm’s description of the x-ray picture of skeletal fluorosis has been widely used as a diagnostic tool in detecting the disease. It is not, however, without its limitations.

In 1958, the German scientist Fritz expanded on Roholm’s description of the x-ray picture, by defining two additional phases (“subtle signs” & “stage O-I”) of bone changes that occur prior to Roholm’s 3 phases.

Other researchers have called attention to a more diverse range of radiological findings, beyond the predominantly osteosclerotic form of the disease which Roholm described.

In addition, others have reported that the symptoms of skeletal fluorosis can occur before the development of bone changes detectable by x-ray. This latter research has emphasized the problems of relying on x-ray analysis to diagnose fluorosis, as x-rays are bound to overlook individuals suffering from the early, “pre-skeletal” stage of fluorosis.

Diagnosing Skeletal Fluorosis – Roholm’s 3 Phases of Bone Changes Detectable by X-Ray:

“From the X-ray picture it is possible to differentiate between three phases of the same osteosclerotic process, each overlapping the next without any sharp boundary.

1st Phase.

“The changes are observed in pelvis and columna, but are doubtful or absent elsewhere. The density of bone is very little increased. The trabeculae are rough, blurred and give deep shadows; this is often distinct in corpora of the lower lumbar vertebrae. The bone has both a more prominent and a more blurred structure at the same time, which is very characteristic when the operator is familiar with the phenomenon, but otherwise is easily overlooked. The bone contour is sharp. In some few cases there is incipient osteophyte formation on the edge of corpora of the lumbar vertebrae. The boundary against the normal bone structure is not sharp, and in an isolated case it will be difficult to decide whether the change is a normal variation or a pathological finding. In serial examinations, however, the difference is distinct.

2nd Phase.

“The bone structure is blurred, the trabeculae merging together. Over often rather large areas the bone gives a diffuse, structureless shadow. At first glance the negative seems to have been underexposed, but it is difficult or impossible to distinguish details even when the time of exposure or the tension is increased. The bone contours are uneven and somewhat blurred. The changes are most distinct in pelvis and columna, but also in the ribs and in the bones of the extremities, even if there they are less pronounced and often resemble the changes described as 1st phase. In the extremity bones the medullary cavity is usually moderately narrowed. In columna there are incipient or moderate ligament calcifications, especially caudally; they appear in the form of pointed, beaked osteophytes with an inclination to form bridges between vertebral bodies or as a diffuse blur lying posteriorly to corpora. In some cases (particularly among the younger individuals) the ligament calcifications are absent, though the bone structure is so changed that the case must be placed to the 2nd phase.

3rd Phase.

“On the negative the bone presents itself as a more or less diffuse marble-white shadow, in which the details cannot be distinguished. Changes are observable in all bones but are still greatest centrally, being most conspicuous in bones with cancellous structure, pelvis, columna, ribs and sternum. In the bones of the extremities there are changes in the structure that recall the 2nd phase, or fairly often only the 1st phsase. Among the worst affected individuals changes are to be seen in the cranium, usually rather moderate in intensity. Theca is denser and gives a deeper shadow than normally, sutures and vessel grooves are indistinct, and the same applies to impressiones digitatae. The air-sinuses in the cranial bones are diminished in size. The region around sella turcica gives a deep shadow but is normal as to contour. No distinct thickening of the processus clinoidei was observed.

The bone contours almost everywhere are wooly and blurred. Very often the bones or certain parts of them have a rough and slightly enlarged appearance, but otherwise the shape is not altered. On the extremity bones are irregular periosteal thicknesses, some flats, others more rough. The interosseous membrane in antibrachium and crus are calcified to a greatewr or smaller extent. The normal cristae corresponding to the muscle attachments are increased in size and resemble exostoses. On costae, especially vertebrally, there is calcification of the insertions of the intercostal muscles, which appear like “rime frost needles” or irregular shadows to both sides. There are considerable ligament calcifications, varying up to very severe, in columna, particularly in pars lumbalis and thoracalis. In columna cervicalis these changes are less pronounced, but distinct. The ligament calcifications appear partly in the form of bridge-like connections with fairly sharp borders between corpora, partly as a diffuse opacity and density round about the intervertebral and costovertebral articulations. Processus transversi and spinosi are rough and thickened; between the latter are considerable ligament calcifications with irregular borders. In the pelvis, ligamentum sacrotuberosum is sometimes calcified. The intensity of the calcification and the diffuse density of the bone usually are in conformity with each other; in some elderly workers, however, there is a density of the osseous tissue which does not attain to the extreme degree, side by side with very pronounced ligament calcification.

In the extremity bones, both short and long, the medullary cavity is diminished in width and the boundary against compacta is less sharp than normally. The width of compacta is correspondingly increased. In tibia and femur the width of the medullary cavity sometimes decreases to half the normal, in metacarpals and phalanges there is sometimes a partial occlusion of the cavity.

The interarticular spaces are of normal width everywhere and the contours are sharp. Limited calcifications of the capsule in hip and knee joints are seen. The intervertebral disks are not visibly changed and the calcification of the costal cartilage does not exceed the normal.

If the result of the Rontgen examination is to be summarized, the first thing to emphasize is the fact that the affection is a system-disease, for it attacks all bones, though it has a predilection for certain places. The pathological process may be characterized as a diffuse osteosclerosis, in which the pathological formation of bone starts both in periosteum and in endosteum. Compacta densifies and thickens; thet spongiosa trabecula thicken and fuse together. The medullary cavity decreases in diameter. There is a considerable new-formation of bone from periosteum, and ligaments that normally do not calcify or only in advanced age undergo a considerable degree of calcification. All signs of bone destruction are absent from the picture.”

        

[Author]

Posts