Fractures of the tibia

Chapter 13 Fractures of the tibia

1 General principles (a): Mechanisms of injury: The tibia is vulnerable to torsional stresses (1) (e.g. sporting injuries), to violence transmitted through the feet (2) (e.g. falls from a height, road traffic accidents), and from direct blows (3) (e.g. road traffic accidents, blows from falling rock, masonry, etc.).

2 General principles (b): Isolated fractures of either the tibia or fibula may occur from direct violence (1) although this is comparatively uncommon. As in the case of the forearm bones, indirect violence leads to fracture of both tibia and fibula (2). Always obtain radiographs of the whole length of the limb to exclude a distal injury accompanying a proximal fracture (3).

3 General principles (c): Note that a third of the tibia is subcutaneous. There is little to resist the spiky end of a fractured tibia from penetrating the skin; again, any direct violence to the shin is uncushioned, and the skin is readily split; these factors account for the fact that tibial fractures are often open (either from within out or from without in).

4 General principles (d): Partly because of its triangular shape, and partly because of the frequency of injury caused by torsional forces, oblique and spiral fractures of the tibia are common. Muscle tone in the soleus (1), gastrocnemius (2) and tibialis anterior (3) tends to produce shortening and displacement in fractures of this type (4).

5 General principles (e): The popliteal artery (5) is anchored as it passes under the origin of the soleus at the soleal line (6). It is susceptible to damage in upper tibial fractures (7) and may cause Volkmann’s ischaemia of the calf with permanent flexion contracture of the ankle. Fractures of the tibia may be followed by ischaemia of the distal fragment (8) through interruption of the blood supply through the nutrient artery (9).

6 General principles (f): It is particularly important to correct angulation in fractures of this weight-bearing bone. Unlike angulation in femoral shaft fractures (1), which can be compensated at the hip (2), residual angulation in tibial fractures (3) will throw inevitable stress at the ankle (4) and/or the knee, perhaps leading to pain and secondary osteoarthritis.

7 Undisplaced fractures (a): In children, owing to the thickness of the subcutaneous fat and periosteum, and the elasticity of the bones, fractures are often of greenstick pattern and closed. In many cases, too, the fractures are minimally displaced. (Illus.: Greenstick fracture distal tibia and fibula, betrayed by fibular kinking and tibial cortical buckling.)

8 Undisplaced fractures (b): When deformity is minimal, apply a long leg plaster immediately over a generous layer of wool (1) (mild sedation only may be required). A sandbag under the buttocks (2) may be helpful, while an assistant holds the toes (3) and supports the calf (4). The knee is slightly flexed (5) and the plaster may be applied in one stage with or without a slab (6).

9 Undisplaced fractures (c): Elevation of the leg and a regular, careful check of the circulation is essential, and admission for this is desirable. In a child, non-weight bearing with crutches can usually be allowed as soon as there is no circulatory risk (say 2–3 days post injury). Thereafter the child should be seen every 2–3 weeks (the casualty rate in children’s plasters is high).

10 Undisplaced fractures (d): A walking heel can certainly be applied when there is evidence of early callus on the radiographs (e.g. after 3–4 weeks in a child of 9 years). Before that a heel may be applied if in your assessment there is no risk of displacement or problems from swelling. Any hesitation may sometimes be dispelled by the appearance of the sole of the plaster which often indicates premature successful weight bearing!

11 Undisplaced fracture (e): The fracture may be assessed for union after say 4–5 weeks in a child of 4 years, 8 weeks in a child of 8, and 8–12 weeks in a child of 12. On removal of the plaster no support for the limb is usually required, but confidence may be raised by a crepe bandage. Crutches for the first few days are advocated as the child often shows timidity in commencing weight bearing: and the parents may require reassurance.

12 Undisplaced fractures (f): The child should be reviewed 2 weeks after removal of the plaster. In most cases he will be walking unsupported, the movements in the knee and ankle will have returned, and the limb lengths will be equal. The child may then be discharged. The parents should be reassured that any residual limp will resolve, and that athletic activities may be resumed say in a further 2 months.

13 Angled fractures in children (a): These are reduced under general anaesthesia. One hand is placed over the fracture site (1) while the other, at the ankle (2), is used to correct the angulation. Although the AP plane only is illustrated, obviously any deformity in the lateral plane should be similarly corrected.

14 Angled fractures (b): The pressure of the hand at the ankle should be released, and any tendency for the deformity to recur noted (indicating springy intact periosteum). If this is found, particular care must be taken during the application of the plaster to maintain full correction; alternatively, complete tearing of the periosteum may be obtained by over-correction of the deformity.

15 Angled fractures (c): If there is little tendency to recurrence of angulation, the plaster may be applied as follows: wool roll is wound round the limb from toes to groin (1); one assistant supports the fracture and the toes (2) while the second takes the weight of the thigh (3). The knee is flexed to 15° (4) and the ankle maintained at right angles (5). The supporting hands are moved during the application of the plaster (6). Use a sandbag under the buttocks.

16 Angled fractures (d): If there is a tendency to re-angulation, the plaster must be moulded while it sets. Except in the smallest of children it is difficult to apply a full length plaster and mould the fracture within the setting time. A two-stage technique may be used: either apply a below knee plaster (1), mould and complete the thigh (2), or apply the thigh cuff first (3), complete the plaster (4) and then mould.

17 Displaced fractures of the tibia (a): An assistant applies strong traction in the line of the limb (1) while strong pressure is applied with the heels of the hands above (2) and below (3) the fracture to correct the displacement. The traction is then slackened off to allow the bone ends to engage.

18 Displaced fractures of the tibia (b): Checking the reduction clinically can be difficult. Try palpating the fracture line along the subcutaneous border (1) or in the case of a transverse fracture confirm that a hitch is present by noting resistance to attempted telescoping (2).

19 Displaced fractures of the tibia (c): If the reduction obtained by manipulation is somewhat precarious and it is feared that the fracture might slip during the application of plaster, place the limb on a firm pillow (4), steady the leg by holding the toes (5) and apply a thick, anterior, plaster slab (6) tucking the edges well round the limb. When it has set, the leg can then be carefully bandaged into the slab.

20 Wedging (a): Ultimately, if necessitated by circumstance, displacement and even off-ending may be accepted in children. If, however, the radiographs indicate residual angulation, this should be corrected. This may usually be done by wedging. Begin by marking the plaster circumferentially at the level of the fracture (1) using the radiographs as a guide.

21 Wedging (b): Now carefully work out where the plaster must hinge to correct the deformity. For example, where there is medial angulation (2) and the lateral projection is normal (3), the hinge should lie medially (4). Where there is lateral angulation (5) along with posterior angulation (6) the hinge should be positioned posterolaterally (7).

22 Wedging (c): Cut through 7/8 of the circumference of the plaster at the marked level, sparing the hinge; use a plaster saw or a hacksaw with a fine blade. Now spring the plaster 1–2 cm open; maintain the position temporarily by placing a suitably sized piece of previously prepared cork into the mouth of the wedge.

23 Wedging (d): Check radiographs should be taken, and any adjustment made on the result. If a satisfactory correction has been obtained, wool should be packed lightly into the gap on either side of the cork, and the plaster reconstituted locally with a 15 cm (6″) plaster bandage.

(Illus.: A badly angled fracture in the distal third of the tibia has been corrected by wedging. Although the level of the wedge is more distal than it should be, an almost anatomical position has been achieved.) General anaesthesia is not required for wedging, but mild sedation is desirable. Aftercare should follow the lines described for undisplaced fractures.

24 Flexible intramedullary nails (Nancy nails): As an alternative to conservative treatment some surgeons prefer to internally fix severely displaced or unstable fractures of the tibia in children using flexible intramedullary nails. The triangular cross-section of the tibia makes it difficult to place the nails in the configuration required to satisfy the principles of this technique, and the proximal metaphyseal flare and the presence of the proximal tibio-fibular joint make antegrade insertion difficult. The rigidity of the fixation is often far from perfect, and additional support with a cast is usually required (so that some critics might say that the benefits of this treatment are often at best somewhat marginal).

Technique: Two nails are selected. Their diameter should be in the order of 2/5th of that of the medullary canal, and their lengths determined from the radiographs. An allowance is made for some protrusion of the nails at their point of insertion (to facilitate their subsequent removal). Then the first nail is pre-bent in such a way that the apex of its bend will be level with the fracture. The second nail is similarly treated so that its curve will lie diametrically opposite. An opening is then made in the cortex with an awl or small broach, and the appropriate nail inserted; it is tapped along the canal until it reaches the level of the fracture. This is repeated on the other side. The fracture is then reduced under intensifier control and the nails then tapped across the fracture site. The aim is for the tips to lie on either side of the metaphyseal flare with the apices of their curves at the level of the fracture; there should be a sufficient length protruding from bone to allow removal of the nails after the fracture has healed. Due to the lack of rigidity the early formation of abundant callus at the fracture site is the rule.

25 Tibial fractures in the adult (a): In the adult many tibial fractures may be treated conservatively, and where good results with few complications are the rule some consider it unwise to advocate surgery with its additional risks. Conservative treatment may with good reason always be advised for stress, isolated (Illus.) and undisplaced fractures, and for slightly displaced stable fractures.

26 Minimally displaced fractures in the adult (b): A long leg plaster is applied, check radiographs are taken, and the limb elevated (1) for 3–7 days until swelling subsides. The plaster is checked for slackness and changed if required. As soon as the patient has mastered crutches he may be allowed home (2). A walking heel is applied (3) usually after 3–6 weeks (depending on your assessment of stability) and the plaster retained till union.

27 Sarmiento plaster (a): Alternatively, at 4–6 weeks post injury, the long leg plaster is removed and a Sarmiento cast applied. The patient sits on the edge of the plaster table (1), the foot being steadied by the lap of the operator. Stockingette (2) and wool roll are applied, and the plaster extended over the knee (3). It is firmly moulded (before setting) round the patellar ligament (4).

28 Sarmiento plaster (b): The plaster is then trimmed from the upper pole of the patella (5) round to the upper part of the calf (6); check that knee movement is free before turning down the stockingette and finishing in the usual way. A rocker sole may then be applied (7) and weight bearing and knee flexion commenced. The plaster is retained until union is sound.

29 Functional bracing with a gaiter: In the later stages of fixation, or even as early as 4 weeks when instability is not a problem, a supporting gaiter may be used instead of plaster. The type illustrated may be fashioned from perforated Orthoplast^™ (Johnson & Johnson) thermoplastic sheet (1). For additional support a plastic heel seat (2) may be secured to the brace with polyethylene hinges (3) and a garter strap (4).

30 Aftercare: 1. Intervals between hospital attendances should not exceed 4 weeks, and the fixation – plaster or brace – changed if it becomes unduly slack. 2. Tibial fractures take an average 16 weeks to unite, but union may be sought in 8–12 weeks in the case of a hairline crack, and after 12 weeks in a transverse fracture. Radiographs should be taken (Illus. advanced union in tibial fracture) preferably out of plaster.

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Tags: Practical Fracture Treatment

Mar 20, 2017 | Posted by admin in ORTHOPEDIC | Comments Off

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