Intramedullary (IM) pins are only suitable for relatively simple tibial fractures. Normograde pin placement is the only suitable method in the tibia. Tibial fractures should never have an IM pin placed by a retrograde method because the pin will pass into the articular part of the stifle joint. In these instances the pin commonly damages the cruciate ligaments, menisci and articular cartilage resulting in pain,

lameness and, ultimately, degenerative joint disease. For normograde IM pin placement, make a 1-2cm skin incision over the medial tibial condyle at the junction of the cranial and middle thirds (Figures 5a and 5b). The pin should be driven distally entering the medial ridge of the tibial plateau at that location. The fracture is held in reduction while the pin is driven into the distal fragment. Judge the correct depth of insertion by measuring with a second pin ofidentical length. It is essential to remember that the medial malleolus extends distally past the location of the talocrural joint. As the IM pin is being driven distally, it is important to remember this, it will help to prevent the pin from penetrating the talocrural joint. The base of the medial malleolus, rather than the tip, is the distal extent of maximum pin insertion. Flex and extend the hock joint to ensure that the pin has not been driven too far distally and penetrated the joint. Tibial pins should not be too large (they are usually 50 to 60% of the medullary diameter at its narrowest point); they need to curve slightly as they pass down the shaft of the tibia. Once seated, the pin must be cut short enough so that it will not touch the femoral condyles at full extension of the stifle joint. The reduced pin size means a consequent reduction in stability. Therefore, IM pins should only be used for tibial fractures where significant compressive and rotational forces are not present.

 Figure 5a: Site for intra-medullary pin insertion. Medial view of the proximal right tibia.

A; tibial crest, F; medial tibial condyle

 Figure 5b: Site for intramedullary pin insertion. Dorsal view of the tibial plateau of the right tibia. A; tibialcrest, B; Gurdey’s tubercle, C; musculargroove (of the long digital extensor tendon), D; Fibular head, E; intercondylar eminences, F; medial tibial condyle, G;lateral tibial condyle

External  Coaptation

 The use of external coaptation is only suitable in relatively simple tibial fractures. Full casts are reasonably good at preventing bending and rotational forces of low magnitude, which occur in simple transverse fractures in small or medium sized animals. External coaptation is unsuitable for use in fractures where bending and rotational forces of high magnitude (such as in large breed or very active dogs) are expected. External coaptation is also unsuitable in comminuted fractures or in long oblique fractures as it cannot prevent collapse and overriding of the fracture fragments.

Bone Plates

Bone plates are very useful for the repair of tibial fractures.They can be used for grade 1 open fractures although for more severe open fractures such as grade 2 or 3 fractures, external fixators are preferable. Bone plates are applied to the medial aspect of the tibia. The use of the plate-rod technique is possible for the tibia although this procedure is technically more difficult than when applied to the femur (the narrowest part of the tibia is in the distal half and the limited widening in the distal tibial metaphysis makes distal screw placement more difficult).

Make a skin incision on the cranial aspect of the crus for the medial approach to the tibia. This approach will simplify closure and prevent the skin being closed directly over the plate. Wound breakdown over the distal tibia is a problem if this is not done.  Intra-operative contouring of the bone plate, prior to application to the bone, is necessary due to the sigmoid shape of the tibia in a medi-olateral and craniocaudal plane.

The use of aluminium bending templates greatly simplifies contouring and they are a useful (and inexpensive) investment;

• When viewed from a medial aspect, the plate is applied to the line of ‘best fit’ and typically requires placement along the caudal edge of the proximal third;

• Bending of the plate can be done with either a bending press, bending pliers or bending irons;
• Slight twisting of the plate is usually necessary if the plate is applied to the full length of the tibia, to account for the 10-15o of tibial torsion. Whether twisting of the plate is necessary will be apparent from using a plate template and needs to be done with bending irons.

• Remember when applying bone plates to the distal tibia that the talocrural joint lies proximal to the medial malleolus by 0.5 to1cm. The distal tibial widens or flares at about a 20o angle to the long (sagital)axis of the tibia. If the most distal screw is placed perpendicular to thebone surface, rather than perpendicular to the long axis of the tibia, penetration of the talocrural joint may result.

External Fixator

External fixators (ESF) are the gold standard in the repair and management of open tibial fractures. The tibia is the easiest bone to which to apply an ESF. It is recommended that surgeons developing their ESF technique should work first on the tibia before repairing fractures of the radius and other long bones using this method. All types of ESF can be applied to the tibia. The most useful ESF for the repair of tibial fractures are the type II and modified type II ESF.

Growth Plate Fractures of the Tibia Bone

Avulsion fracture the tibial tuberosity occurs in young animal , usually between 4-8 months of age. The tibial tuberosity serves as the insertion point of the quadriceps muscles through the patellar ligament, and avulsion result from contaction of the muscle while stifle is flexed and the foot firmly on the ground, Such mechanism could easily occur during jumping or running and perhaps in a fall.

Surgery: Open reduction and internal fixation technique.

• A longitudinal incision is made just medial to the patella, the patellar ligament, and the tibial tuberosity.
• The blood clot and fibrin clot is removed from the original location of the tuberosity. Fracture is reduced and anchored in place with three Kirschner wires.

AfterCare:

• Exercise should be restricted for 6-8 weeks until fracture have healed
• In animal has a considerable amount of growth potential remaining, the fixation should be removed as early as possible to avoid premature fusion of the tuberosity to the shaft of tibia(shin bone)
• Pin fixation need not be removed unless it loosens and migrates.

• Radiographs (x-rays) should be taken about 2 months after surgery to evaluate healing of the fracture

 Physeal fractures  usually Salter type 1 or type 11 injuries occur in young animal.  After skeletal maturity, fractures in this region are slightly more distal. The entire epiphysis and tibial tuberosity are usallu involved, and the tendency is for dislocation in a caudolateral direction in relation to the tibial shalft

Surgery: Open reduction and internal fixation technique.

A longitudinal skin inciosion is made on the craniomedial surface of the proximal tibia and  stifle. After open reduction, transfixed by multiple Kirschner wires. The medial and lateral pins are started near the periphery of the tibial plateau, where they do not interfere with the femoral condyles.These pins pushed to penetrate the opposite cortex for the best stability.

AfterCare:

• Exercise should be restricted for 6-8 weeks until fracture have healed.
• In animal has a considerable amount of growth potential remaining, the fixation should be removed as early as possible to help avoid interference with the growth plate.
• Pin fixation need not be removed unless it loosens and migrates.

• Radiographs (x-rays) should be taken about 2 months after surgery to evaluate healing of the fracture.

Mid-shift tibial fracture repaired:

• The entire limb is shaved
• An incision is made on the inner side of the tibia
• The fracture is reduced and stabilized with one of the following
  1. Bone Plate and Screws
  2. Bone Plate and Pin Combination
  3. Intra-medullary Pins
  4. External skeletal fixator
  5. Combination of above

Make a skin incision on the cranial aspect of the crus for the medial approach to the tibia. This approach will simplify closure and prevent the skin being closed directly over the plate.Wound breakdown over the distal tibia is a problem if this is not done. Intraoperative contouring of the bone plate, prior to application to the bone, is necessary due to the sigmoid shape of the tibia in a mediolateral and craniocaudal plane.

• The use of aluminium bending templates greatly simplifies contouring and they are auseful (and inexpensive) investment;
• When viewed from a medial aspect, the plate is applied to the line of ‘best fit’ and typically requires placement along the caudal edge of the proximal third;
• Bending of the plate can be done with either a bending press, bending pliers or bending irons;
• Slight twisting of the plate is usually necessary if the plate is applied to the full length of the tibia, to account for the 10-15o of tibial torsion. Whether twisting of the plate is necessary will be apparent from using a plate template and needs to be done with bending irons.

AfterCare:

• Ideally the animal would be allowed early, limited active use of the limb to promote healing
• This requires totally stable internal fixation, good owner compliance with confinement and exercise restrictions, and a patient that will not overstress the repair because of hyperactivity.
• Exercise should be severely restricted for 6weeks, with a gradual return to unrestricted activity 3-4 weeks after clinical union.
• Radiographs should be taken at 6 or 8 weeks to confirm clinical union before any increase in exercise is allowed.

  Distal tibial fracture;

This fracture is observed primarily in the immature animal as a physeal fracture of  Salter type 1 or type 11.

Reduction and fixation vary with the individual case. In some patient s, reduction may be accomplished closed by a combination of traction, countertraction,  and manipulation.

An open reduction may be mandatory for satisfactory reduction in most case: the approach is usually made on the medial side. Because the distal tibial has no muscular covering, the bone is virtually subcutaneous.

Surgery: Open reduction and internal fixation technique.

• After reduction, the insertion of two small, diagonally placed pins starting at the medial and Lateral malleoli is often the only practical methods of fixation because of the shortness of the fragment.
• Supplemental fixation using a short lateral splint is applied.
• Additional Rotational stability can also be achieved by a tension wire placed between the protruding pins on one or both side.

AfterCare:

• Activity is restricted during the healing period.
• The external fixation can be removed when adequate primary callus has formed ( in about 3 weeks)
• The transfixation pins are usually removed after clinical union has been reached.