Nature nanotechnology. Detecting bacteria on implants. Timing!

NATURE NANOTECHNOLOGY | ARTICLE

• 
  

A magneto-DNA nanoparticle system for rapid detection and phenotyping of bacteria

• Hyun Jung Chung,
• Cesar M. Castro,
• Hyungsoon Im,
• Hakho Lee
• & Ralph Weissleder

• Nature Nanotechnology
   
  8,
   
  369–375
   
  (2013)
   

One of the most devastating experiences that an orthopaedic surgeon encounters is the infected implant. More importantly, the patient goes through extensive surgery that most of time is of inferior result compared to the first surgery. The socioeconomic cost of the infections in orthopaedics is tremendous. The annual cost of infected revisions to US hospitals is projected to exceed $1.62 billion by 2020.

Often times it is difficult to confirm the presence of bacteria in a wound just by inspecting the color of the fluid, the odor or the macroscopic appearance of the membranes on the implants. There is promising technology being developed that will give us the opportunity to detect an infection in less than 2 hours when currently a standard microbiology lab can give us an answer in 2-3 days and sometimes depending on the micro-organism in 14-21 days.

The magneto-DNA nanoparticle system provides an answer in less than 2 hours. The ideal test would have been similar to a pregnancy test that will give us an answer at the time of surgery. In that scenario orthopaedic surgeons will be able to manage periprosthetic infections more effectively, develop better algorithms and lower the cost of revision arthroplasty care from a financial and social perspective.

http://www.nature.com/nnano/journal/v8/n5/full/nnano.2013.70.html#f5

My experience at the AANA Masters Elbow Course 2015

Recently, I had the honor to be an invited instructor at theLearning Center of the American Academy of Orthopaedics Surgeons. Masters Course AANA 2015 on elbow arthroscopy.

I recall that in the 1990s many surgeons thought that arthroscopy will be something temporary, a trend that will go away as many "new technologies" do. I also recall that arthroscopic surgery was approached with negativity or even skepticism even in the 1990s. During the time I spend at the AAOS Learning Center as an instructor on elbow arthroscopy I thought that being negative has no place in science and medicine. I remember the lecture of Dr Gary Poehling on elbow arthroscopy at the institution where I was trained (WFUBMC) and the first arthroscopes that were introduced in the US and imported from Japan. They were bulky, they will break and they will not be suitable for small joints. In addition, the quality of imaging was poor for diagnosis.  I do not think anyone would have imagined the potential of arthroscopic surgery at that point. 

Thirty years later arthroscopy of small joints has come long ways. While I was teaching fellows how to establish portals safely around the elbow, which is considered a difficult joint to scope, I realized that arthroscopy has even greater potential. I believe that the cameras and instruments will become smaller in size in the future, the ability to navigate the elbow will improve and the arthroscopic repair of collateral ligament ruptures or even fixation of shear fractures of the capitellum will become a reality. Some may think that I am very optimistic. The ones who belong to the arena of electronics and computer science know that we are not far away from manufacturing surgical instruments and arthroscopes that will have the diameter of a spinal needle. In my opinion it is exciting what the future will bring us. Negativity has no place in medicine.  

Subluxating ulnar nerve

Subluxation of the ulnar nerve at the elbow can be seen in 12-15% of the normal population and can be asymptomatic. The nerve usually subluxes in flexion as seen in this video. If the patient has no symptoms and no neurologic findings then surgery is not indicated. It may be associated with snapping of the medial triceps.

The clinical importance of this condition is the following:

1. In case elbow arthroscopy is planned the proximal medial portal can result in ulnar nerve damage which may lead to permanent dysfunction of the hand/arm

2. If symptomatic and presentation mimics cubital tunnel syndrome findings then it is important to evaluate intra-operatively what makes the ulnar nerve sublux. This is performed by exposing the ulnar nerve proximal to the medial epicondyle and flexing the elbow while inspecting the wound. Sometimes snapping over the medial triceps or intermuscular septum may be seen.

It is commonly seen in throwers and bodybuilders and surgery is necessary if symptomatic.