2015 ISAKOS Biennial Congress ePoster #2302

Description of a New Posterior Approach to Posterior Bone Block Arthroscopically

Mirouse Guillaume, MD, Paris FRANCE
Laurent Casabianca, MD, Paris FRANCE
Loriaut Philippe, MD, Paris FRANCE
Nourissat Geoffroy, PhD, Paris FRANCE
Nollet-Maussins Clinical, Paris, Paris, FRANCE

FDA Status Not Applicable

Summary: We performed an anatomic study to describe a new posterior approach between infraspinatus and teres minor respecting muscles and nerves anatomy and permitting a good position of the bone block.

Abstract:

To Purpose : The conventionnal approach to the posterior bone block of shoulder is responsable of damage muscles and to put the bone block on a good position is difficult. Arthroscopy seems to prevent these risks. No specific surgical approach has been described to respect the muscles and to avoid injuries of the suprascapular nerve. We performed an anatomic study to describe a new posterior approach between infraspinatus and teres minor respecting muscles and nerves anatomy and permitting a good position of the bone block.

Methods

8 shoulders cadavers were used. We did a posterior capsulectomy arthroscopically and a glenoid bony bed of 2 cm was prepared using a burr. The bony bed should show capillary bleeding and have a flat surface. The 6, 9 and 12 o`clock positions are marked for precise graft positioning at the end. A guide wire placed in the soft point (SP) on rotator interval direction. A posterior approach is performed, to find the split between infra-spinatus (IS) and teres minor (TM). A guide wire placed into the split parallel to the first one, to report the new posterior arthrocopic approach. After, we found the suprascapular nerve (NSC). Ten distances were measured : soft point-split IS-TM, bord spinal-split IS-TM, split IS-TM –posterior glenoid, split IS-TM –posterior glenoid 6 o’clock, split IS-TM –posterior glenoid 9 o’clock, split IS-TM –posterior glenoid 12 o’oclock, NSC-posterior glenoid 6 o’clock, NSC-posterior glenoid 9 o’clock, NSC-posterior glenoid 12 o’clock, NSC-split IS-TM.

Results

The mean distances were : soft point-split IS-TM : 2 cm (2-2.8), bord spinal-split IS-TM : 5 cm ( 3-6.2) , split IS-TM –posterior glenoid : 1.2 cm(0.8-1.4), split IS-TM –posterior glenoid 6 o’clock : 1.3 cm ( 0.6-1.6), split IS-TM –posterior glenoid 9 o’clock : 1.5 cm(1-1.9), split IS-TM –posterior glenoid 12 o’oclock : 2 cm( 2.1-2.4), NSC-posterior glenoid 6 o’clock : 2.4 cm(2.1-2.6), NSC-posterior glenoid 9 o’clock : 1.7 cm ( 1.5-1.8), NSC-posterior glenoid 12 o’clock : 1.5 cm (1.2-2.1), NSC-split IS-TM : 2cm ( 1.2-2.1). One time, the wire placed into the split did an injury of the NSC.

Conclusion

This is a preliminary anatomic study to evaluate a new posterior arthroscopic approach to the posterior bone block procedure respecting the split IS-TM and the suprascapular nerve. The posterior bone block is more safety on the lower part of the glenoid for the suprascapular nerve (2.6cm) and the acromion doesn’t interfere with the good positionning of the bone block.