The Effect of Learning Curve on the Results of Percutaneous Transforaminal Endoscopic Lumbar Discectomy
Chaisiri Chaichankul MD*, Sompob Poopitaya MD*, Warat Tassanawipas MD*
Affiliation : * Department of Orthopaedics, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand
Objective : To demonstrate the correlation of postoperative visual analog scale (VAS) of leg pain and adequacy of disc
decompression with the learning curve of the surgeon who performed PTELD.
Material and Method: The authors retrospectively reviewed 50 matched criteria patients arranged into 5 groups which were
categorized by the period of operation from January 2010 to May 2011 successively. Each patient’s preoperative and
postoperative VAS of leg pain at 1-week, 3-week, and 6-week follow-up were analyzed and demonstrated the correlation with
the learning curve. Additionally, the authors also showed the alteration of thecal sac expansion between the preoperative and
the postoperative MRI to demonstrate the learning curve during the different operative period.
Results : The VAS of leg pain as well as the mean differences of VAS of leg pain in each groups of patient were improved at each
postoperative period follow-up and have a statistically significant improvement at 6-week follow-up. When the authors
analyzed the mean differences VAS at pre- and post-operative 6-week follow-up among each groups of patients, it demon-
strated that the learning curve had the progressive effect on the result of the operation. Also for the adequacy of disc
decompression, the improvement of the thecal sac expansion was established when the amount of surgical volume was
increased.
Conclusion : The amount of surgical volume in focus of PTELD has an influence in the improvement of the VAS of leg pain
and the adequacy of disc decompression. However, the patient selection such as types of disc herniation is also play an
important role in accomplishment.
Keywords : Learning curve, Percutaneous transforaminal endoscopic lumbar discectomy (PTELD)
