A Cautionary Tale of Anatomy

Surgeons from Belgium have recently published research detailing the anatomy of a ligament in the knee joint. Whilst its existence was confirmed by a surgeon in 1879, it has taken 134 years to fully describe its anatomy. This study has illuminated a murky area of human anatomy: which structure connects the femur with the outer front of the tibia. While this enigma may now be understood, the functions of this structure (in terms of the biomechanics of the lower limb) are still unknown. What makes this research slightly unnerving is the amount of surgery that takes place in this area, to counteract the common sports injury of a tear to the anterior cruciate ligament. To put it plainly, this is surgery on an area of anatomy that is not fully understood... today... in 2013. While there are distinct regions of the body that remain a mystery for the time being (the brain being the most obvious choice) the structure of the knee is not one that quickly comes to mind.

There are other examples where a lack of anatomical knowledge is less of a restriction to surgery than one might hope. As recently as 2008, studies were created testing the optimal implantation angle for sacral nerve stimulation. This procedure is used to treat bladder dysfunction by supplying electric impulses to sacral nerves connected to the bladder, suppressing oversensitivity in this area. In order for the electrode to reach the nerve, it needs to be inserted into the 3^rd or 4^th sacral foramen (holes in the posterior bone), detectable only through palpating the area. The success of the procedure depends on how close the surgeon can insert the electrode into this small space and results vary. Considering the first study on sacral nerve stimulation was in 1988, a lot of time (and surgery) has passed, where a lack of anatomical knowledge has been detrimental to the success of the procedure. Fortunately, research is being undertaken into the best angle of insertion and the most successful methods of detecting the correct foramen (though the application of techniques practised on cadavers may still hold some problems in practise). To provide some comfort, this method is only undertaken as a last resort, when other forms of treatment, such as medication, no longer work or are unsuitable.

It is of interest that the medical marvels carried out every day, are performed on an anatomy that still retains some enigmas.  While we pride ourselves on the scientific leaps made since the time ailments were treated by bloodletting, any smugness we feel is reduced by the reminder that our understanding is not complete. I can only apologise for any worry caused to those soon to be going under the knife, however they may yet be placated with the knowledge that future researchers still have jobs to do.

Further reading:

• Bolton, J.F. & Harrison, S.C. (2009). Neuromodulation 10 years on: how widely should we use this technique in bladder dysfunction? Current Opinion in Urology, 19(4), pp. 375-379.
• Buchs, N.C. et al. (2008). Optimizing electrode implantation in sacral nerve stimulation- an anatomical cadaver study controlled by laparoscopic camera. International Journal of Colorectal Disease, 23(1), pp. 85-91.
• Claes, S. et al. (2013). Anatomy of the anterolateral ligament of the knee. Journal of Anatomy, 223(4), pp. 321-328. 

Credit:<a href="http://www.flickr.com/photos/50946274@N02/4849499648/">Rob Swatski</a> via <a href="http://compfight.com"> and </a> <a href="http://creativecommons.org/licenses/by-nc/2.0/">cc</a>