SaphenoUs Nerve block Reduces length of Stay after Epiphysiodesis of the knee - a triple blind randomised superiority trial

Rationale: Percutan epiphysiodesis of the genual growth plates is a routinely
performed surgery in the pediatric orthopedic department of the Wilhelmina
Hospital Assen in the Netherlands. We hypothesize that a single shot saphenous
nerve block in combination with general anesthesia would be superior to general
anesthesia alone regarding opioid consumption, pain scores, recovery and length
of stay.

Objective: The primary outcome objective of this trial will be length of stay
in the hospital after surgery. We further will analyze intra- and postoperative
opioid consumption, NRS pain scores, time in the post anesthetic care unit,
time to walk (with crutches), strength of the quadriceps muscle and overall
patient satisfaction as secondary outcome measures.

Study design: The study will be randomized, placebo-controlled triple blind:
anesthesiologist and orthopedic surgeon as well as the patient, all nurses
taking care of the patient and physiotherapist are blinded.

Intervention: All patients of the interventional group receive bilateral
saphenous nerve block with 10ml of Ropivacaine 0,5% for each leg. The placebo
group will receive saphenous nerve block with Sodiumchloride 0,9%. Both groups
will than undergo general anesthesia and standardized postoperative analgesics.

Nature and extent of the burden and risks associated with participation,
benefit and group relatedness: As the epiphysiodesis of the knee can only take
place once the growth plates are still open and active it is evident, that this
study enrolls patients in their teenage years. None of the possible risks like
allergic reaction to Ropivacaine, cardiotoxic or central nervous effects
following intravascular injection, local anesthetic systemic toxicity (LAST)
after overdosing, hematoma of deeper structures such as muscles, nerve damage
of muscle weakness have been observed in the pilot study. The expected benefits
for patients undergoing epiphysiodesis of the knee like earlier discharge from
the hospital, less opioid consumption, less PONV, reduced time in the
post-anesthetic care unit and reduced pain scores shall outweigh the risks.