Objective - To determine if an endoscopic-assisted foraminotomy significantly increases the area of the L7-S1 intervertebral foramen and if, over a 12-week time period, there is stenosis of the treated foramen. Study Design - Prospective, experimental study Animal Population - Six, clinically normal adult dogs. Methods - Using endoscopic assistance a unilateral L7-S1 foraminotomy was performed. Computed tomography of the region was performed in the pre-operative, immediately post-operative and 12-week post-operative time periods. Parasagittal area measurements were obtained at the entry, middle and exit zones of the treatment and control foramen for each period. Objective and subjective data were compared among dogs, by time period and treatment status. Results - Endoscopic assisted foraminotomy resulted in a significant increase in the mean parasagittal foramen area (mPFA) of the entry and middle zones in the immediate post-operative period. The exit zone was not made significantly larger at any time period. The foramen remained significantly larger at the 12-week post-operative period in the middle zone only. However, some decrease in the surgically created foramen enlargement occurred at all three levels. The dogs tolerated the procedure well, but did have a mild, temporary delay of functional return post-operatively. Conclusions - Endoscopic assisted foraminotomy in the canine patient can be performed for certain regions of the foramen allowing enhanced visibility in the spinal canal during the procedure. The foramen can be surgically enlarged at the entry and middle zones using this technique. There is some reduction of the foraminal enlargement at 12-weeks post-operative. The clinical significance of this reduction is not evident from this study. Clinical Relevance - Endoscopic assisted foraminotomy could be used to improve intra-operative visualization in dogs with foraminal stenosis as a component of degenerative lumbosacral stenosis. / Master of Science

Cette étude a été subventionnée par le Fonds de recherche du Québec - Santé (FRQ-S, grant # 21230 – 2) / Les infiltrations foraminales cervicales sont associées à un risque de complications neurologiques majeures. Cette étude compare l’efficacité des infiltrations facettaires, plus sécuritaires, à celle des infiltrations foraminales dans le traitement de la cervico-brachialgie secondaire à une spondylose et/ou à une hernie discale, à 4 semaines post traitement. Cinquante-six sujets ont été randomisés pour recevoir une infiltration foraminale (15 hommes, 13 femmes ; âge moyen 52 ans) ou facettaire (8 hommes, 20 femmes ; âge moyen 44 ans). L’issue principale était l’intensité de la douleur mesurée sur une échelle visuelle analogique (0 – 100). Les issues secondaires étaient le Neck Disability Index et le Medication Quantitative Scale. Suivant les analyses en intention-de-traiter et en intention-du-protocole, pour un score de douleur initial moyen, une réduction significative de l’intensité de la douleur a été observée avec les infiltrations facettaires [45.3% (95%CI: 21.4; 69.2) et 37.0% (95%CI: 9.2; 64.7)] contrairement aux infiltrations foraminales [9.8% (95%CI: +11.5; 31.2) et 17.8% (95%CI: +6.6; 42.2)]. Les infiltrations facettaires ont procuré une amélioration cliniquement (mais non statistiquement) significative du Neck Disability Index [24.3% (95%CI: +2.9; 51.5) et 20.7% (95%CI: +6.2; 47.6),], contrairement aux infiltrations foraminales [9.6% (95%CI: +15.2; 34.4) et 12.8% (95%CI: +11.2; 36.7)]. Les infiltrations facettaires étaient au moins aussi efficaces que les infiltrations foraminales pour un score initial de douleur ≤ 60, alors que l’analyse de non infériorité n’était pas concluante pour un score initial ≥ 80, de même que pour le Neck Disability Index. Les infiltrations n’ont pas été associées à une réduction du score de Medication Quantitative Scale. Les infiltrations facettaires sont efficaces dans le traitement de la névralgie cervico-brachiale et représentent une alternative valable et plus sécuritaire aux infiltrations foraminales. / Transforaminal corticosteroid injections can be performed in the management of cervical radiculopathy but carry the risk of catastrophic complications. This study compares the efficacy of transforaminal and facet corticosteroid injections at 4 weeks post treatment. We randomly assigned 56 subjects to receive CT-guided transforaminal (15 men, 13 women; mean age 52 years; range 28 – 72 years) or facet (8 men, 20 women; mean 44 years; range 26 – 60 years) injections. The primary outcome was pain severity rated on a visual analog scale (0-100). Secondary outcome measures were the Neck Disability Index and the Medication Quantitative Scale. In the intention-to-treat and as-treated analyses, for a mean baseline score, facet injections demonstrated a significant pain score reduction of 45.3% (95%CI: 21.4; 69.2) and 37.0% (95%CI: 9.2; 64.7), while transforaminal injections showed nonsignificant pain score reduction of 9.8% (95%CI: +11.5; 31.2) and 17.8% (95%CI: +6.6; 42.2). While facet injections demonstrated an improvement in Neck Disability Index score of [24.3% (95%CI: +2.9; 51.5); 20.7% (95%CI: +6.2; 47.6),] as opposed to transforaminal injections [9.6% (95%CI: +15.2; 34.4); 12.8% (95%CI: +11.2; 36.7)], the results did not reach statistical significance. Noninferiority of facet to transforaminal injections was demonstrated for baseline pain score ≤ 60, while noninferiority analysis was inconclusive for baseline pain score ≥ 80 and for the Neck Disability Index score. Neither intervention showed a significant medication intake score reduction over time. Facet injections are effective for the treatment of cervical radiculopathy and represent a valid and safer alternative to transforaminal injections.