Form-function changes (part 2)

Medical thinking is based on scientific knowledge and veterinary experience. In orthopaedics, the principles and insights of biology and the mechanics are of central importance.  For this reason, the transfer of the physical laws mechanics can be attributed to problems of orthopaedics. Therefore, it is possible to compare the emergences of stress symptoms; wear and tear processes (degenerative diseases) and deformations, with any known issues in the technological field.The joints of the dog, including the ones of human beings, are referred to as ball and hinge joints, whose overloading may well be mirrored on technical joints. Therefore, defective structures reflect form intereferences and affect permanently the function of the structures and, therefore, special attention is paid in the assessment of orthopaedic  diseases.  In this instance, I like to make my favourite comparison with a car: If the engine block on an 8-cylinder shows a quadrangular cylinder, the engine runs irregularly and the typical sound of the engine gets lost! If we, as veterinary surgeons and orthopaedists, have to assess the lameness of a dog, it is imperative to clearly consider and record the movement pattern of the dog. With today's means of video technology, absolutely no problem occurs whatsoever. The recording of the movement pattern allows us to document the course process, and to better estimate and assess  the success of the therapy.  Quite often a lameness changes within a therapy despite improvement, especially if such a lameness already exists for quite some time. In the equine medicine this is called "skip/jump" if the lameness of the supposedly sick leg is getting better, but instead another limb then shows a limp. In order to assess and evaluate the mechanical stress and resilience of the orthopaedic structures, it is essential to rely on other diagnostic tools such as X-ray; X-ray in an upright/standing position; orthopaedic ultrasound, or if need be, CT and MRT.

The orthopaedic tissue of the dog are not just technical structures, or a dead substance, as such. These are living structures which are very adaptable. This is visible regularly during the orthopaedic examination of a dog. Again and again, I examine dogs which show symptoms, such as limping or relief probably after only a few days to two weeks.  Upon closer examination, however, it can often be noticed that the musculature of the "sick" side of the affected joint is already clearly deformed. That refers to a so-called atrophy. This clearly captures the longer lasting relief of the joint or limb. This is also a clear indication of how the body first compensates for an orthopaedic problem, which means that the remaining (healthy) limbs endorse the function of the movement and the statics.  The layperson hardly  registers this movement change. An orthopaedist, however, is able to identify this change very quickly during the freedom of movement! The orthopaedic system of the dog is therefore a continuous adaptation and subject to change in biomechanics.

Example 1

The dog presented here came to me with an acute back problem. Two months earlier, the patient was violently jostled by another dog on the field. Since then, he repeatedly showed a raised back and had trouble jumping and pulled up again and again the right leg! He refused to jump into the car and, additionally, yelped time and again. The movement pattern shows a left curved spine and opposite bent hind legs. The back is also pulled up and the movement is rather wide apart. In the seating position, the left hindlimb is shifted and asymmetrical. In the video sequence, taken after the treatment, the seating position is immediately symmetrical and the movement patterns more even and much smoother! 

This example shows us how important the biomechanics of the spine is for a uniform and painless movement. If this basic requirement does not exist, a compensatory relief occurs resulting in changed movement patterns, which is reflected in the following video.

Example 2

In our second example, the altered biomechanics affects the behaviour of the dog. Due to the chronic pain the dog shows significant aggressive behaviour! The dog has a shifted axis of the spine, as well as a modified cross axis. Generally, it is clear that the dog has a strong forehand, however, the hindquarter is rather weak. During the examination, the extension of the hindquarters was painful to the dog and acknowledged by means of defensive movements! The aggressive behaviour manifested itself in the fact that he had a low threshold towards other people or children and immediately snapped. This behaviour immediately improved after successful pain therapy!  

At this point, attention is made to the conditioning. Pain therapy is not enough to erase the learned defense pattern "Attack is the best defense”.

Further information is available on our video about the Form-Function Changes.

https://www.youtube.com/watch?v=pp3QYp6vVVU&feature=player_embedded