Joint Expert Course series
KNEE EXPERT COURSE – Hannover May 2011
Topic:    “The degenerative knee”
Surgical techniques: Cartilage Procedures / Osteotomy / Hemicompartimental Arthroplasty

Knee Expert Course
Innsbruck 21 – 22 May 2010

ACL / PCL INJURIES and PATELLA DISLOCATION
Two days with the European top knee experts

ACL

The first topic of the meeting was the anterior cruciate ligament. Dr. Rainer Siebold from Heidelberg (G) presented some new insight into the ACL anatomy. Insertion sites are important for both single and double bundle reconstruction. There is still considerable variation which can not be duplicated by one single solution. Dr. Hermann Mayr from Munich (G), the current president of the German Speaking Arthroscopy Association (AGA), gave an overview of the history of ACL reconstruction. It was interesting to see that several techniques have been around for years before they became clinical routine.

Six of the top experts in ACL surgery presented than their indications and techniques of ACL double bundle surgery. Although in general agreement the technique is able to provide superior biomechanical function over single bundle techniques there are small differences between each surgeons approach. The indication for double bundle technique is dependent on the size of the ACL insertions. The larger the insertion sites are the more advantages these techniques are.

Dr. Jürgen Eichhorn from Straubing (G) has performed double bundle operations over the last 14 years having probably the most experience in Europe. He has designed several instruments with Aesculap. Dr. Thore Zantop from Münster, a young, but extremely innovative and productive surgeon, presented his instrument developments with STORZ and later on demonstrated his excellent techniques in a live surgery.

Dr. Hermann Anetzberger , Munich (G) has also a long time experience with double bundle. Opposite to the previous speakers who use cortical graft fixation Dr. Anetzberger advocates aperture fixation using resorbable ARTHEX screws.Dr. Rainer Siebold has also some interesting additions using bone block fixation techniques for the tibial graft sites. Dr. Philipp Lobenhoffer from Hannover (G) demonstrated a reconstruction technique using a prototype from MITEC developed by his partners Dr. Markus Tröger and Dr. Jens Agneskirchner. It’s a perfect modification of the current Rigid fix which allows for save and secure fixation for both bundles.

Dr. Christian Fink from Innsbruck (A) demonstrated that patellar tendon and quadriceps tendon are still a useful alternative to hamstring grafts. With new technical developments like a squared bone tunnel compared to a round one, these grafts are able to duplicate the biomechanical parameters close to the native ACL and to single bundle reconstruction techniques. This technique has later been demonstrated in a life surgery by Dr. Christian Hoser.

ACL reconstruction in children with open growth plates gained a lot of interest during the last few years. Dr. Robert Smigelsky from Warsau (PL) has most likely the largest series in Europe. He demonstrated the benefit of early reconstruction in this population with minimal risk for growth disturbances if you stick to some rules in surgery (cortical fixation, small and step bone tunnels (no double bundle) and soft tissue grafts).If grafts fail reoperation is most of the times necessary. Its no only trauma but more likely surgical errors in the first place causing this situation. Dr. Christian Hoser from Innsbruck (A) demonstrated the algorithm from diagnosis to surgical planning. A single stage revision should be preferred for the patient but this necessitates knowledge of different fixation techniques as well as usage of all different graft sources.

Since more and more double bundle reconstructions are performed new challenges await the revision surgeon. Dr. Jürgen Eichhorn showed some tricks to overcome difficult revision situations.

PCL

Treatment of PCL injuries remains a challenge. The surgical indications for ACL ruptures are relatively clear however there is still discrepancy amongst surgeons concerning PCL lesions. Dr. Roland Becker described a clear treatment algorithm, advocating surgery if posterior laxity is exceeding 10mm. The anatomy of the PCL and especially that of the posterolateral corner is always difficult. Dr. Steffano Zaffanini from Bologna (I) gave some insights into all aspects of this area.

Reconstruction techniques today are mostly performed arthroscopically. There are two distinct differences placing the tibial tunnel: transtibial from anterior or as a tibial inlay technique. The latter has traditionally been an open technique necessitating an approach to the back of the knee. Dr. KP Benedetto developed an elegant arthroscopic technique together with ARTHREX for an inlay technique using quadriceps tendon. Dr. Philipp Lobenhoffer demonstrated the transtibial technique using hamstring grafts. Currently double bundle reconstruction does not seen to be advantages compared to single bundle techniques. The aim is to rather reconstruct the ACL – bundle and leaving as much of the PCL remnants in place as possible.

Open techniques are a valuable adjunct for PCL revision surgery as well as the treatment for bony PCL avulsions. The posterior approach can be either between the heads of the gastrocnemius muscles or dorsomedial. The latter approach can be performed in a lateral decubitus position allowing excellent access to the posterior tibia. In PCL revision surgery osteotomy correcting mainly varus alignment is an important consideration before thinking of ligamentous revision. Dr. KP Benedetto presented several cases documenting his vast experience with difficult revision situations.

PATELLA DISLOCATION

The Patellofemoral joint is probably still the most difficult area of the knee. The focus of the meeting was limited to patellofemoral instability. Again, anatomy and biomechanics of these joint are the guidelines for further treatment options. Dr. Katja Tecklenburg from Munich (G) gave an overview of anatomical variations and measurements helping us to distinguish between normal and abnormal. Treatment of patella dislocations although very frequent is still under discussion. Conservative treatment is associated with a recurrence rate >40% and surgical indications are not clear.  A detailed analysis of risk factors facilitating patella instability (TT-TG distance, patella height, trochlear groove) should therefore performed in every case of acute patella dislocation in order to pick the right candidate who would benefit from surgical intervention (Dr. Christian Hoser).

The medio patellofemoral ligament (MPFL) is the most important passive restrain to lateral patellar dislocation. Therefore, MPFL reconstruction techniques have been popularized recently to compensate for patellar instability. Most commonly the gracilis tendon is utilized fixed to the medial patellar rim either with resorbale screws (ARTHREX) or bone ankers (SMITH & NEPHEW, MITEK). It can although be placed trough bone tunnels and sutured on the lateral aspect of the patella (STORZ). The pros and cons of these techniques have been presented by Dr. Lobenhoffer and Dr. Zantop).

A new and interesting technique for MPFL reconstruction has been advocated by Dr. Velesko from Ljubljana (SL). He uses a strip of quadriceps tendon (approx 2mm thick and 12mm wide) which perfectly mimics the original MPFL. It stays attached on the patella and is then fixed (like the gracilis tendon) in a bone tunnel using a resorbable interference screw. Dr. David Dejour from Lyon (F) is one of the leading world experts on patellofemoral pathology. He recently popularized distalization of the patellar insertion in case of patella alta associated with instability. He has although became famous for his classification on trochlear dysplasia and the corrective operations (trochleaplasty).  This operation is extremely effective correcting instability in case of severe trochlea dysplasia but although risky and needs an experienced surgeon.

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