Ultrasound-guided intra-articular tenotomy of the long head of the biceps: a cadaveric feasibility study

Isolated tenotomy of the long head of the biceps (LHB) is known to improve function in patients with massive and non-reparable cuff tears without osteoarthritis. This two step cadaveric study was performed with the purpose to identify the best surgical technique for isolated LHB tenotomy under USG guidance (pilot study) and evaluate its feasibility (subsequent study). Pre-operative ultrasonographic evaluation of the rotator cuff was performed and any specimens whose long head of the biceps was not found to be intact during the pre-operative ultrasound evaluation were excluded. In the pilot study, nine scar-free cadaveric shoulders underwent ultrasound-guided tenotomy through a single percutaneous portal to determine the best instrument and approach which ensure elective and complete LHB tenotomy. Using it, a second series of 12 cadaveric shoulders were operated following a similar protocol to evaluate the feasibility of this technique. Pilot study: The use of a backward endoscopic cutter through a posterior percutaneous portal was found to be the safest. Control of the tenotomy was possible by manipulating the intra-articular part of the tendon with the instrument ("Groove Alone" test). Subsequent study: The tenotomy of the LHB was complete in all cases. Mean length of the proximal LHB stump was 0.3 cm (range, 0-0.8 cm). No iatrogenic lesion was observed when using the backward endoscopic cutter. On the other hand, the use of straight endoscopic scissors led to severe damage to the rotator cuff and the conjoined tendon. The "Groove Alone" test checked against iatrogenic injury. This was not done in one of the cases and it led to a partial section of the superior half of the tendon of the subscapularis. By the use of both appropriate endoscopic instrumentation and the newly described "Groove Alone" test, ultrasound-guided LHB tenotomy through a single percutaneous portal appears to be a feasible and reliable procedure that could be an alternative to isolated arthroscopic tenotomy. The choice of a posterior portal (soft point) may increase the safety and precision of this procedure and decrease the length of the proximal stump of the LHB.