External fixation is widely used in orthopaedic
and trauma surgery. Infections around pin or wire sites, which are usually
localised, non-invasive, and are easily managed, are common. Occasionally,
more serious invasive complications such as necrotising fasciitis
(NF) and toxic shock syndrome (TSS) may occur. We retrospectively reviewed all patients who underwent external
fixation between 1997 and 2012 in our limb lengthening and reconstruction
programme. A total of eight patients (seven female and one male)
with a mean age of 20 years (5 to 45) in which pin/wire track infections
became limb- or life-threatening were identified. Of these, four
were due to TSS and four to NF. Their management is described. A
satisfactory outcome was obtained with early diagnosis and aggressive
medical and surgical treatment. Clinicians caring for patients who have external fixation and
in whom infection has developed should be aware of the possibility
of these more serious complications. Early diagnosis and aggressive
treatment are required in order to obtain a satisfactory outcome. Cite this article:
Manoli and Schaeffer in 1987, showed that fixation by antiglide plate demonstrated superior static biomechanical properties compared to lateral plating. However there are some shortcomings in their study and hence we decided to perform our biomechanical study. The shortcomings of the Manoli study are. They did not use an interfragmentary lag screw for lateral plate fixation. It was a cadaveric study where the bone does not accurately represent the live bone. The quality of the bone ranging from normal to osteoporotic bone varies from cadaver to cadaver and hence there is no uniformity between the samples.
These bones were custom made for the experiment. We used two sets of bones, one representative of normal bone (Set A n=10) and the other of osteoporotic bone quality (Set B n=10). Each of the sets A &
B will have two types of fixations for artificially created Weber B Fractures.
Lateral plate with interfragmentary lag screw. Antiglide plate with interfragmentary lag screw. The strength of the fixation was measured by restressing the bone until the fixation failed using an Instron machine which simultaneously applied torque and compressive forces to the fibular construct. The resulting data was analysed on a computer and statistical analysis was performed.
The concept of tension band wiring is based on the fact that the distractive force applied to one surface of the bone will result in compression on the opposite articular surface. Clinical outcomes of TBW are not equivocal. It is associated with significant morbidity such as non union, failure of fixation, especially in osteoporotic bone and infection which sometimes leads to amputation. Often a second procedure for removal of prominent metal work is required. In our biomechanical study we investigated this concept as we believe that the forces generated by TBW construct do not generate significant compressive forces required for healing of fracture.
The advantage of using 4th generation composite bone model is that it provides uniformity which is not achievable in cadaveric studies. Two different bone models representative of Olecranon and patella were used. Transverse fractures were created in the bones and fixed with TBW technique as described in A.O. manual. Two 0.062-inch Kirschner wires and figure of eight configuration of 18G Stainless steel wire with single knot technique was used. Micro motion transducers (DVRT: MicroStrain, Williston, Vermont) with an accuracy of ± 1μm were placed across the fracture site both anteriorly and posteriorly. Continuous information regarding fracture distraction and compression, as determined by the transducers was recorded from both sites simultaneously during the experiment. The tension band wire construct was loaded up to a maximum force of 4000 Newtons for patella and 500 for the olecranon. The fractures were subjected to cyclic loading at 1Hz using a servo hydraulic materials-testing system (model 8500; Instron, Canton, Massachusetts). The results were analysed on a computer and statistical analysis performed.
A further study was undertaken to verify the results on composite material with biomechanical properties similar to human bone.
A study on cadaver ankles was performed; two methods of ‘Danis-Weber type B’ lateral malleolar fracture fixation were compared.
In conclusion, the fixation done in Group II was found to be better.
Statistical analysis was performed on the data collected through DASH questionnaires along with multivariate and univariate analysis and t-tests.
48 % of patients showed a rise in DASH scores after the fracture healing, indicating decrease shoulder function. This was statistically analysed and failed to reach any significance p=0.867. There was no difference between the two techniques in terms of complications and union rates.
In conclusion, the fixation done in Group II was found to be biomechanically more stable.
We retrospectively reviewed medical records and radiographs of 82 children who presented within 12 months of their birth, with unilateral dislocated/subluxed hips and required treatment in from of traction, closed/open reduction, pelvic osteotomy and maintenance. The purpose of the study was to assess if HE angle could be utilized as a prognostic indicator fro assessing reduction of the affected hip. Hilgenreiner epiphyseal angle was measured by two observers for the normal as well as the abnormal side and differences noted. The measurements of the primary presentation and follow-up films were then correlated. Two groups of patients emerged, those in who the difference between the normal and abnormal hips was less than 10 degrees and those in whom was greater than or equal to 10 degrees, on initial presentation. Their management transpired to be quite different (p=0.000), with open reduction/pelvic osteotomy being required in all cases in the latter group.