project work FOR STUDENTS IN THEIR DAILY.pptx

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1. PRINCIPLES OF TREATMENT Angelo Villa Introduction Many factors may interfere with normal fracture repair, resulting in nonunion, the persistence of mobility between fracture fragments, mechanical and biological factors certainly contribute to retard fracture healing. Stable osteosynthesis with early return of normal function motion and load) is felt to be the biological Stimulus for repair.

2. Nonunion may be classified according to the local trophism of the fractured bone ends and the presence or absence of infection. This classification of nonunion determines the treatment modality. In simplest terms, nonunions may be hypertrophic vascular and stiff or hypotrophic avascular and lax. These two groups can be further subdivided based on the presence or absence of local sepsis .

3. The hypertrophic failure of fracture repair is more related to mechanical factors, while the hypotrophic failure includes poor local biology. Traditional methods utilize stable loading internal fixation for hypertrophic nonunions and local bone graft with fixation for hypotrophic nonunions .

4. The presence of an infection further exacerbates the failure of local-biology to produce osteogenesis. Septic nonunions are difficult to treat with traditional methods of sequestrectomy and late bone grafting. Even newer techniques, including antibiotic beads and osteoinductive substances, have been unreliable. Axial load is, in fact, the force which the Ilizarov frame, if correctly applied, can reestablish in bone. After transosseous osteosynthesis the reintegration of function, in the presence of renewed vascularization, promotes osteogenesis and local tissue trophism. The corticotomy is the biological stimulus for neovascularization and the correctly applied external fixator introduces a mechanical environment which facilitates function loading and motion.

5. The marriage of revascularization and local tissue trophism under mechanical load has been shown by Ilizarov to reliably heal infected nonunions and hypotrophic nonunions, the most difficult challenges. Additionally deformities such as angulation and shortening can be corrected with the Ilizarov methods described in this chapter. A fracture is usually transformed into a nonunion by the absence of stability, function or vascularization. Thus, in the treatment of nonunion, these parameters must be regained. Ilizarov distinguishes between two essential types of nonunion: Stiff without evident movement and mobile with considerable movement, between segments. This distinction, which is essentially clinical, is very important for the type of treatment to be initiated.

6. A stiff nonunion radio graphically almost always appears as hypertrophic. Local vascularity is well-evidenced by voluminous new bone formation. The soft tissues interposed in the area of nonunion fibro-cartilage), when submitted to axial compression-distraction, are directed to transform into solid bone. For the correct function of a limb, it is necessary to reestablish the load axis. The nonunion should be exposed to pure compression-distraction loads shear stress, which is thought to be a detriment to callus formation, should be completely eliminated. A mobile nonunion radio logically identified as an atrophic nonunion is a fracture where there has been devascularization of the segments. In addition to the reestablishment of fracture stability, these nonunions often require some form of biologic stimulation.

7. According to the Ilizarov method, this stimulation is represented by a bone corticotomy in distraction and progressive compression on the nonunion center Corticotomy, followed by distraction, increases vascularization in the entire segment, while compression at the site of nonunion increases the stability of the bone segments.

8. CLASSIFICATION AND TREATMENT OF NONUNION Maurizio Catagni ASEPTIC NONUNION WITHOUT BONE DEFECT Type A1: Mobile ( Atrophic/Hypotrophic) The Recommended treatment is bifocal osteosynthesis (Fig. 14.1). A corticotomy with gradual distraction and simultaneous gradual compression of the non-union in its proper axis is performed with the appropriate frame. Biologically, this technique makes sense and clinically, the results have been good.

9. Type A2: Stiff without Deformity (Hypertrophic) The biological treatment for hypertrophic nonunion is monofocal osteosynthesis by compression (Fig. 14.2) The biology of a stiff nonunion (fibrous union) strongly resembles the fibrous interzone demonstrated in Chapter 4, “ Biology of distraction osteogenesis.” Osteogenesis should, therefore be re-stimulated, by primary distraction.

10. Despite this, Ilizarov recommends ten to twenty days of primary compression, then distraction and finally compression to bridge the nonunion. The later sequence makes more sense for a synovial nonunion which will not respond to primary distraction but must first be converted to inflammatory tissue prior to distraction. Our clinical trials following Ilizarov method had fair results. Therefore, corticotomy is recommended for bifocal treatment.

11. Type A3: Stiff With Deformity (Hypertrophic)   The recommended treatment is monofocal osteosynthesis in distraction and compression with simultaneous correction of the deformity. In refractory cases, bifocal treatment by addition of corticotomy can be used

12. VARIATIONS IN TREATMENT HYPERTROPHIC WITH DEFORMITY   Type A3.1: with hinges   A four-level assembly is preferable, in order to have more stability and to avoid slipping of the wires. Fo ur olive wires must be used, two close to the non union on the convex side, and two far from the nonunion on the concave side (Fig. 14.4). In the tibia, where this type of assembly is most frequently used, resection of the fibula equal to at least one centimeter is required so that it does not oppose correction .

13. After progressive correction has been carried out (either in distraction or neutral or in compression pending on the position of the hinges), it is possible to further increase stability by progressive compression equal to 1/4 millimeter twice weekly until bone f callus occurs at the site of nonunion (see chapter 7).

14. Type A3.2: with transverse wires After proximal and distal fixation of the segment, two ; wires are inserted exactly perpendicular to the plane Of the deformity. Using two half-rings and a long connection plate, we push progressively from the convex )side of the deformity. To help direct this movement, two hinges push on the assembly (Fig. 14.5). This assembly is preferred for the correction of the femur

15. Type A3.3: with olive wire alone This technique is used for thin bones where the de­formity does not exceed five to eight degrees, for inst­ance in the forearm where forceful loading of the seg­ment is not required. Dynamometric tensioners are used on the intermediate wires until the axis is corrected during surgery. The intermediate wires are fixed and compression is carried out during the days that follow at 1/4 millimeter twice weekly (Fig. 14.6).

16. B.ASEPTIC NONUNION WITH BONE DEFECT: Bone defects are defined as losses of length or inter­calary substance exceeding four centimeters. In most cases, nonunion with loss of substance results in a mobile nonunion (atrophic) because of significant soft tissue injury resulting I poor vascularity and excessive instability. Secondary operations performed in order to eliminate the nonunion (e.g., resections, grafts) often increase local scarring. In these cases, there are three main problems: nonunion, discrepancy in length, and atrophy of the segments. Thus, in all types of treatment, a bifocal method must used to gain back the length of the bone and to increase the vascularization of the segments ( Fig . 14.7 ).

17. Variations in treatment - Length of Limb Preserved with Bone Gap Type Bl.l For loss of substance up to five centimeters, we proceed with proximal and distal fixation and bone transportation. A single corticotomy creates a mobile bone fragment with good vascularity that can be transported linearly along the gap by transverse wire fixation . Distraction osteogenesis fills the trailing gap while the nonunion is reunited by compression at eventual bone contact. Transportation is carried out at one millime­ter per day in four increments and compression of the nonunion continued at 1/4 millimeter every three days to maintain stability until callus is visible radiographically . Fibulotomy is not required with this technique (Fig. 14.8a ).

18. Type B1.2 For loss of substance exceeding five centimeters, in order to accelerate healing time, two levels of corticotomy may be performed with centripetal bifocal bone transportation. The transport segments are generally each held by two transverse wires (1.5 millimeter) tensioned to the ring (Fig. 14.8b).

19. Type B1.3 If the loss of substance is considerable (exceeding eight to ten centimeters) or local scarring may inter­fere with bone transport using transverse wires, the transport may be performed by means of crossed lon­gitudinal olive or bent (corkscrew) wires to increase surface area (Fig. 14.8c). When the nonunion frag­ments come into contact, the crossed transportation wires must be substituted for by transverse wires as in treatment B 1.1 in order to increase stability and inter-­fragmentary compression forces. Free rings should be left in the initial construct for this eventuality.

20. Variations in treatment - Segments in Contact with Shortening of the Limb   TypeB2.1 In case of shortening up to five centimeters, a bifocal osteosynthesis is performed, with compression of the nonunion and lengthening by means of corticotomy. For the tibia, it is necessary to perform an osteotomy and fixation of the fibula, in order to allow for adequ­ate lengthening of the segment. In addition to the reestablishment of fracture stability, these nonunions often require some form of biologic stimulation.

21. This is most often performed distally because of the re­latively easy surgical access. The fibula is fixed with wires only at the proximal- and distal-most rings, thus allowing distraction at the distal corticotomy (Fig. 14.9a).

22. Type B2.2 If the shortening exceed five centimeters, the healing time may be accelerated by performing a double cor­ticotomy, carrying out trifocal osteosynthesis by dou­ble distraction osteogenesis and compression at the nonunion. In this case, also, it is necessary to carry out partial fibulectomy . Note that only the tibia is fixed by wires at the central two rings (Fig. 14.9b).

23. Variation in treatment • Combined-Shortening With Gap   Type B3 . This type of nonunion requires treatment similar to that in Type Bl. The only difference is that after bone transportation eliminates the gap, distraction must be continued at the site of the corticotomy, in order to eliminate the shortening of the segment. Nonunion compression is continued as in Types Bl and B2. For the tibia, lengthening should be initiated before compression, so as to avoid premature consolidation of the fibula. If this occurs further lengthening would be impossible, and a second fibular osteotomy would be necessary (Fig. 14.9c).

24. Special Variations ( Limited Indications) Type A2.4 Monofocal osteosynthesis with compression and suc­cessive distraction, is carried out when there is a mo­derate amount of shortening with good preservation of local vascularity evidenced by voluminous callus. Compression (as in Treatment A2) is applied until bone callus appears. Distraction is carried out at the nonunion which, under, the effect of tension, will transform into solid bone tissue, For the tibia, it is necessary to carry out resection of the fibula at the Time of distraction so that it opposes neither compres­sion nor distraction (Fig. 14.10 ).

25. Based upon the experience of the Lecco Hospital, this treatment must be used exclusively in cases where there is good vascularization of the segments and in patients who have not previously submitted to open surgery. Even when these criteria are met, extended periods of compression often do not produce sufficient cal­lus to allow for distraction osteogenesis. In these ca­ses a second surgical procedure with corticotomy must be resorted to bifocal treatment.

26. Type B1.3 Lateral bone transportation may be used in two-bone segments such as the forearm or lower leg for massive loss of bone substance. When the bone ends are short and atrophic, bone regeneration by longitudinal trans­port is unlikely. Thus, for the tibia, the fibula or part of the fibula is transported laterally for the recon­struction of the loss; in the forearm, depending upon which bone is deficient, longitudinal segments of the intact bone are transported transversely to eliminate the gap (Fig. 14.11).

27. The technical execution of this method presents con­siderable difficulties, so that it is best to use it only in cases where it is absolutely impossible to apply other variations. This method is recommended for use in the leg to reinforce a tibia which is thin due to longi­tudinal bone loss.

28. C. TREATMENT OF INFECTED NONUNION   Selection of a treatment technique for an infected non- union depends on various factors such as the type of nonunion (usually atrophic), the extent of the infection and trophic skin changes. Traditional concepts dictate that devitalized bone is I more prone to infection; the wider the bone necrosis, I the more widespread will be the infection. According to Ilizarov, to eliminate the infection, vascularization of the osteomyelitic center must be in­creased by the biological stimulation of a corticoto­my. " Osteomyelitis burns in the fire of regeneration ."

29. In our clinical application of this concept, there was healing of the nonunion but, unfortunately, infection was not always eliminated. Thus, to be sure that in­fection is eliminated, in cases of massive necrosis, we now routinely perform open debridement to totally remove the necrotic and infected segments and then proceed with bifocal osteosynthesis, in order to elimi­nate the bone gap (Fig. 14.12).

30. The treatment for hypertrophic nonunion with a mini­mum amount of infection and no sequestered bone is monofocal compression (Treatment A2). The stabili­zation of nonunion favors the formation of repair cal­lus and thus there is a revascularization of the seg­ments with an increase in the local humoral and cellu­lar defenses, with the spontaneous elimination of in­fection.

31. In infected hypertrophic nonunion with deformity, treatment by monofocal compression is used with eli­mination of the deformity at the same time (Treat- ment A3). For the reason stated above, the regenera­ted bone callus also eliminates the infection. In atrophic nonunion with diffuse infection or the presence of sequestered bone, open resection of the infected segments must be carried out so as to trans­form the type of nonunion into a loss of substance (Type Bl or B3). Therefore, bifocal methods are most suitable for treatment.

32. In some cases, where resection does not exceed one to two centimeters, it is possible to carry out acute shortening, placing the resection segments in contact and in compression and thus acting as in Type B2. When an infected nonunion also has poor skin quality with numerous fistulae, stabilization with the appara­tus following necrotic bone resection is enough. The skin is not closed, but rather is cleansed daily with peroxide and betadine followed by wound packing, leaving the skin defect to heal on its own.

33. When the skin conditions have improved and the in­fection has regressed, we proceed with corticotomy and bifocal treatment. The skin defect may close with a depression so that it becomes interposed like a pocket between the two segments of nonunion, thus ob­structing contact. If this is the case, skin resection must be performed and, if necessary, further bone re­section carried out so as to make the segments of non­union more congruent for wider surface contact (Fig. 14.13).

34. To increase the stability of the assembly, during bifo­cal treatment following bone resection, and to decrease the risk of displacement of the bone fragments dur­ing transportation, we sometimes place a central guide wire. During open surgery, we place a percutaneous olive wire (1.5 millimeter diameter) from later­al to medial into the medullary cavity of the frag­ments of nonunion, crossing the defect. This wire is maintained until there is contact between the bone fragments and callus forms at the nonunion center (Fig. 14.14 ).