Traction



Introduction

Traction produces a reduction through the surrounding soft parts which align the fragments by their tension.

When the shaft of a long bone is fractured the elastic retraction of muscles surrounding the bone tends to produce over-riding of the fragments. This tendency is greater when the muscles are powerful and long bellied as in the thigh, when the fracture is imperfectly immobilised so that there is pain and therefore muscle spam and when the fracture is mechanically unstable because the fragments are not in apposition or because the fracture line is oblique.

Continuous traction generated by weights and pulleys in addition to causing reduction of a deformity will also produce a relative fixation of the fragments by the rigidity conferred by the surrounding soft tissue structures when under tension. It also enables maintenance of alignment while at the same time it is possible to devise apparatus which permit joint movement.

Traction may be applied through traction tapes attached to skin by adhesives or by direct pull by transfixing pins through or onto the skeleton.

Traction must always be apposed by counter traction or the pull exerted against a fixed object, otherwise it mealy pulls the patient down or off the bed.

Traction requires constant care and vigilance and is costly in terms of the length of hospital stay and all the hazards of prolonged bed rest - thromboembolism, decubiti, pneumonia and atelectasis must be considered when traction is used

Excessive traction which leads to distraction of the fracture is undesirable. Once the fracture is reduced a decreasing amount of weight is required to maintain a reduction once the muscle stretch reflex has been overcome and the fracture immobilised. For a femoral fracture no more than 10lbs should be used and for fractures of the tibia and upper limb less weight is required.

 

Skin Traction

Traction is applied to the skeleton through its attached soft tissued and in the adult should be used only as a temporary measure.

Skin is designed to bear compression forces and not shear. If much more than 8lbs is applied for any length of time it results in superficial layers of skin pulled off. Other difficulties such as migration of the bandage may occur with lower weights.

 

Skeletal Traction

First achieved by the use of tongs.

The application of traction applied by a pin transfixing bone was introduced by Fritz Steinmann. Now a threaded Denham pin is preferred to prevent early loosening of the device.

The threaded portion of the Denham pin is offset, closer to the end of the pin held in the drill chuck and should engage only the proximal cortex of the recipient long bone.

 

Traction by Gravity

Really only applies to fractures of the upper limb (hanging cast)

 

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Definitions

Traction on a limb demands either a fixed point from which the traction may be exerted (fixed traction) or an equal counter-traction in the opposite direction (balanced traction)

 

Fixed Traction

The length of the limb remains constant and there is continuous diminution of traction force as the tone in the muscles diminishes and no further stimuli results in activation of the muscle stretch reflex.

Pull is exerted against a fixed point for example tapes are tied to the cross piece of a Thomas splint and the leg pulled down until the root of the limb abuts against the ring of the splint.

Pins in plaster is a form of fixed traction

 

Balanced Traction

In weight traction it is the tension in the apparatus which remains constant and the length depends on the amount of tearing of the intermuscular septum and fibrous tissue of the limb

The pull is exerted against an opposing force provided by the weight of the body when the foot of the bed is raised.

 

Combined Traction

May be used in conjunction with fixed traction where the weight takes up any slack in the tapes or cords while the splint maintains a reduction.

This combination facilitates less frequent checks and adjustment of the apparatus

 

Sliding Traction

First introduced by Pugh by applying traction tapes to the limb and fastening them to the raised foot of the bed which was then inclined head down.

He utilised this traction in the treatment of conditions such as Perthes where only one limb was fastened to the end of the bed enabling the pelvis on the opposite side to slide down the bed more thus creating traction and abduction.

The extent to which the patient slides down the bed is limited by the friction of the body against the mattress.

The traction was subsequently modified by Hendry using a mattress on a sliding frame which resulted in the same amount of traction with an inclination of 10o as that with that on a normal mattress at 30 - 40o inclination.

This is also really a form of balance traction where the amount of weight is determined by the inclination of the bed.

 

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Specific Types of Traction

Thomas Splint Traction

Hugh Owen Thomas introduced his splint which he called "The Knee Appliance" in 1875.

The method of Hugh Owen Thomas uses fixed traction with the counter traction being applied against the perineum by the ring of the splint. This is in contrast to other methods using weight traction which is countered by the weight of the body.

Backward angulation of the distal fragment can never be corrected by traction in the axis of the femur which only results in elongation with persistence of the deformity.

A Thomas splint and fixed traction is only capable of maintaining a reduction previously achieved by manipulation. The use of supports enables correction of angulation caused by muscle tension.

Placement of a large pad behind the lower fragment acts as a fulcrum over which backward angulation is then corrected by the traction force. The pad should be ~ 6" in width, 9" long and 2" thick applied transversely across the splint under the distal fragment and popliteal fossa

It is the splint which controls alignment and not the traction.

The tension in the apparatus should only be that sufficient to balance resting muscle tone.

Suspension of the splint using an overhead beam in such a way to enable the splint to move easily with the patient when they move in bed.

Its use in combination with a Peason Knee-flexion piece enables mobilisation of the knee while maintaining traction, alignment and splintage of the fracture.

 

Hamilton Russell Traction

Robert Hamilton Russell wrote "Fracture of the femur: A clinical study" in which he described his traction in 1924.

Sling under the distal 1/3 of the thigh providing upward lift as well as longitudinal traction in the line of the tibia.

The sling under the distal fragment controls posterior angulation and the lifting force is related to the main traction force through the medium of pullies. No rigid splintage is used in this method

Combines a means of suspending the lower extremity and a means of applying traction in the axis of the femur.

Many other varieties of both skeletal and skin traction result in a similar effect.

 

Buck Traction

Buck introduced simple horizontal traction in 1861.

Traction is analogous to Pugh's traction only the inclination of the bed is replaced by the application of weights over a pulley.

 

Bryant's traction

Vertical extension traction was described by Bryant in 1873 and applied to the management of femoral fractures.

The development of ischaemia of the lower leg through reduced perfusion resulted in limitation of its application to the short term management of a fractured femur.

A modification of his traction has been shown to reduce the risk of limb ischaemia and may be applicable where prolonged traction is required in an infant.

 

Braun Frame

This is mearly a cradle for the limb but a disadvantage is that the position of the pulleys cannot be altered and the size of the splint often does not fit the limb as might be wished.

Lateral bowing is common as the splint and the distal fragment are fixed to the frame while the patient and the proximal fragment can move sideways leaving the frame behind.

 

Perkins Traction

Here no splintage is used at all, the posterior angulation of the thigh is controlled by a pillow and the alignment and fixation depend entirely on the action of continuous traction

 

Fisk Traction

Hinged version of a Thomas splint is arranged to allow 90o of knee movement. It is particularly attractive as it allows active extension of the knee joint. Fixation and alignment is dependent entirely on the weight traction and the splint merely applies the motive power for assisted knee movement.

 

90 - 90 Traction

The thigh is suspended in the vertical plane by weight traction pulling vertically upwards. The ill effect of gravity as the cause of backward angulation of the fragments is thus eliminated.

 

Charnley

Strongly recommends the use of a BK POP incorporating the Steinmann or Denham pin in the upper end in order to reduce pressure on the soft structures around the knee.

Benefits of POP/Traction unit: (Charnley)

 

  1. Foot supported at right angles to the tibia

     

  2. Common peroneal nerve and calf muscles protected from pressure against the slings of the splint and the splint itself. The tibia is suspended from the skeletal pin inside the POP so that an air space develops under the tibia as the calf muscles loose their bulk.

     

  3. External rotation of the foot and distal fragments is controlled.

     

  4. The tendo achilles is protected from pressure sores

     

  5. Comfort; The patient is unaware of the traction when applied through the medium of a nail

Upper Limb

A number of skin traction methods have been described and a number more utilised without documentation in the literature. Ingerbrightsen's overhead skin traction (A); Dunlop's sidearm skin traction (B); and Graham's extension skin traction (C) are but a few.

Skeletal pin traction can also be utilised. Overhead (A); Overhead with secondary distal forearm traction directed cephalad (B); and side arm pin traction (C).

 

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