Optimal fracture compression and fixation device without screws: Preliminary account

OPTIMAL FRACTURE COMPRESSION SCREWS: PRELIMINARY ACCOUNT For the open surgical treatment of fractures of the long bones several methods may be employed, extramedullary as well as intramedullary, both principles having been perfected during many decades of individual treatment. The first open fracture plate fixation is supposed to have been performed in the mid eighteenhundreds’. For extramedullary fracture fixation the well documented A0 method and its adapted instruments are successMly used2 as also is the A0 HoffmanAdrey transmedullary-extramedullary procedure. Both principles unavoidably compromise the neuro-vascular structures within and around the bones, but they do stabilize the fracture, which is the major prerequisite for healing. Various techniques have been tried in order to avoid or minimize bone damage caused by the osteosynthesis (Figure 1 ). The A0 plate-and-screws method may still be that most widely used for open fractures, but it is hazardous to the bone. The X-plate method described by the authors includes theoretical improvements4 but is unsatisfactory for several reasons: insufficient counterplate and side stability of the fracture fixation for postoperative mobilization, even after optimal fixation; insufficient stability for fixation of a cornminuted fracture and insufficient fracture stability for axial loading. The original X-plate

Figure 1 Obvious advantages of the extramedullary X-plate to intramedullary space compromising rod and plateandscrews 0 1986 Butterworth 0141~5425/86/020178-02 178

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J. Biomed Eng. 1986, Vol. 8, April

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AND FIXATION DEVICE WITHOUT

method may satisfy the need for the care of the vascular structures, but its draw-backs make the widespread use of the method hazardous, unreliable and impracticable. The awareness of the weaknesses of the method made it necessary to select only non-cornminuted fractures of the fore-arm bones for X-plate treatment. All treated fractures healed without delay or other complication and often primary fracture healing occurred3*5*6. These results encouraged the development of a similar procedure, one which did not interfere with the intramedullary space. Several improvements of the basic X-plate were introduced4. The new device consists of two parallel steel bars, or plates (Figure 3 ). The bars form a semi-circular frame for four or more wedges which act on the rims of predrilled holes in the cortical bone. The bars are brought together by two transverse screws which prevent rotation and instability which might otherwise occur when the screws are tightened to create fracture compression and fixation. The shallow holes must be made with precision, before the transverse screws are finally tightened. The wedge-shaped tips force the fracture fragments against each other and against the under surface of the device, the interconnected bars, and the semicircular framework of the wedges. Pre- bending of the device to acquire bone-plate Congruency is possible (Figure 3 ).

Figure 2 X-plate

Principle

of shaft fracture

fixation

with the wedged

Fracture fiwation: H. G. Edeland

Principle and function of the L-plate with the fracture compression Figure 3 parallel stabilising non-rigid bars which are screwed together to create fracture

The nrinciole of fracture comnression fixation with the c’ompo’site L-plate is the same as that for the Xplate, by wedge effects; fracture stabilization by the L-plate is more predictable and reliable. Construction of a model device is in progress and fracture tests of the same character as were performed with the original X-plateS are planned.

REFERENCES 1

2

3

4 H. G. Edeland Volvo PV AB, S-40508 Gateborg, Sweden

and fragment fixation wedges, based on the two compression and fixation

5 6

Hansmann, H. Verein Deutsches Gesellsctij ftir Chirurgiz, 1886, 15, 134 Muller, M., Aflgbwer, M., Willenegger, H. Manual of Internal Fixation Springer, Berlin, Heidelberg, New York, 1970 Edeland, H.G., Sonnerup, L, Nikhasson, B., Persson, E. A fracture compression clamp without screws. Exp. Mech. 1976, 16, 61-65 Edeland, H.G. Bifurcated fracture compression clamps. In: Current Concepts of Internal Fixation of Fractures Springer, Berlin, Heidelberg, New York, 1980, 228-234 Edeland, H. G. The X-Plate Fixation of Forearm Shaft Fractures. Thesis, Gijteborg, 1974, 95 Dank, R Ttiorie et Pratique de I’Ostkosynthese, 1949, Masson, Paris

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