| dc.description.abstract | Five brands of plaster of Paris casting bandages including Nairobi
Enterprises'b', Salvagypsv", Helm®, Plasrun-gyps'P and Veronese'P, which are
available on the Kenyan market were evaluated based on breaking strength,
resistance to abrasion and radioluscency. Eight layer rectangular slabs (10 X 4
em) were loaded at the center with a metal rod anchored onto a Tensile machine
until they broke. Load versus displacement curves were recorded on a chart
recorder and used to calculate the mean maximum load for each plaster product.
The mean slab thickness was also determined and used to calculate load per unit
thickness which was compared. For abrasion testing, rectangular plaster slabs
(17 XlO em) were initially weighed on a Sartorius balance and clamped onto the
flat non - abrading surface of the Abrasion tester. A circular waterproof
abrasive paper was then secured on the abrasive disc of known diameter and a
load of 10 Newtons placed over it. The slabs were weighed again after being
subjected to abrasion of 300 revolutions and the mean loss in mass per square
meter calculated and compared. The mean maximum load and mean loss in
mass per square meter of the various plaster products were tested for
significance using Analysis of Variance at 95 %. Radiographic clarity, mottling
and fiber pattern interference were subjectively evaluated after radiographing a
bone sandwiched between two plaster slabs of equal number of layers for each
brand of plaster bandages.
The ease of cast breakage, the extent of cast wearing at the foot, the
ability to bear weight on the cast limb, the severity of lameness and cast related
complications (fever, recumbency and pneumonia) were compared clinically in
three groups of six calves each, using Plasrun- gyps®, Veronese® and
Salvagyps'P. These parameters were monitored daily for twenty one days and a
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Salvagyps®. These parameters were monitored daily for twenty one days and a
semi quantitative score recorded for each. In each group five rolls of bandage
material of equal dimension were applied over a double layer of polypropylene
stockinette. This was done in a spiral fashion, to enclose the left forelimb of
each calf up to about four centimeters above the carpal joint. The casts were
applied following aseptic joint surgery for immobilization.
Helm® plaster of Paris had a significantly higher mean maximum
load (110.33 N) compared to the other products (p < 0.05). Although the mean
maximum load for the other plaster casts appeared different, (Veronese'P
(101.33 N), Plasrun - 'gyps® (99.3 N), Salvagyps's' (92.4 N) and Nairobi
Enterprises'P (89.17 N)), this was not statistically significant. Plasrun - gyps®
had a maximum load of 21.8412 N/mm thickness while Salvagyps® had
19.8198 N/mm followed by Helm® (19.7907 N/mm), Nairobi Enterprises'f
(18.309 N/mm) and Yeronese® (18.2648 N/mrn). The mean loss in mass per
square meter for Nairobi Enterprises's' and Salvagyps'l'', (133.1761 and
129.87421 g/m2 respectively), were significantly lower (p < 0.05) indicating
that these two types 'of plaster were more resistant to abrasion than the others
(Veronese'P 231.60377 g/m2, Plasrun - gyps® 260.06289 gjm2 and Helm®
265.56604 g/m2), under the test conditions. No product was consistently the
best in all the three radiographic features evaluated. The overall radiographic
score for Salvagyps®, Yeronese® and Helm® was similar and all were found
to show a clear outline of the bone that was radiographed. Cast breakage was
seen in only one case in which Plasrun - gyps® was used but was observed in
most of the cases cast with Salvagyps® and Yeronese® although they still
provided joint immobilization. Cast breakage was most often seen at the
midshaft of the metacarpus than at the fetlock, contrary to previous reports.
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There was marked cast wearing at the foot, the cast completely worn out up to
the coronary area of the claws, everted and appearing as a hanging tube, in all
plaster casts and this made the casts not useful for fracture treatment. However,
for the temporary immobilization of joints or in cases where casts are required
for short durations, these plaster casts would still be useful. All casts enabled
weight bearing in all calves and when lameness was seen to be severe this was
due to broken casts with the edges impinging on soft tissue to cause pain.
No single product was superior In all the criteria that were
investigated. Helm® plaster of Paris casting bandage was suitable for use on
calves on the basis of its superior breaking strength. Plasrun - gyps® could
support higher mean maximum load per millimeter thickness. The radiographs
for all the plaster casts were generally clear and with minimal mottling and
would be satisfactory in case fracture healing assessment was needed.
Salvagyps® plaster was the most satisfactory for the physical properties, but
performed poorly on clinical evaluation (multiple cast breakages and loss of cast
integrity). The wearing properties of the plaster casts at the foot was marked, a
finding that was consistent with previous reports. On the basis of its ability to
support more load per millimeter and having minimal breakages on clinical
application, Plasrun - gyps® was the most suitable for LIseon the limbs of
calves. | en |
