Canaletto device cuts postoperative pain, improves function in patients with carpal tunnel syndrome
The Canaletto implant, when used in combination with the Dynavics antiadhesion gel, is an effective intervention for resistant or recurrent carpal tunnel syndrome (CTS), according to a recent study.
“The Canaletto device was placed through a relatively small incision, which was sufficiently long to allow accurate release of the median nerve and sufficiently short to avoid extensive dissection,” said researchers, pointing out that this current technique is less invasive than others while conferring minimal morbidity.
Forty hands from 39 patients (mean age 56 years) who underwent revision surgery for recurrent CTS were included in the present analysis. Twenty-one (group 1) received the Canaletto device alone while 19 (group 2) received the implant in combination with Dynavics. All patients underwent surgery under regional anaesthesia; flexor tendon synovitis was present in 30 hands. [Hand Surg Rehabil 2018;doi:10.1016/j.hansur.2018.10.244]
The pre-to-postoperative differences in the Douleur Neuropathique 4 (DN4) questionnaire were 0.55 and 2.25 in groups 1 and 2, respectively. The resulting difference in average improvement was –1.863, which achieved statistical significance.
Similar findings were reported for the Quick DASH (Disabilities of the Arm, Shoulder and Hand) score. The difference between pre- and postoperative scores was 18.98 in group 1 and 19.06 in group 2, yielding a significant average improvement difference of –14.503.
Improvements in grip strength were likewise significant, in favour of the combination therapy. Groups 1 and 2 showed an average difference of 19.55 percent and 28.53 percent, respectively, between preoperative and postoperative values. The obtained improvement difference was –7.168.
“The main hypothesis of our study was proven since the difference between the preoperative and postoperative neuropathic pain assessed with the DN4 Score in the group of patients who underwent revision surgery with the combination of Canaletto and Dynavics was higher than the difference in patients treated with Canaletto alone,” said researchers.
In contrast, no significant differences were reported for Pain Score, sensory nerve conduction velocity and distal motor latency. Similarly, the proportion of patients who successfully recovered from hypoaesthesia and who regained good trophism of the thenar muscles were comparable between the treatment groups.
The Canaletto device has a silicone body which acts as a gliding surface, preventing median nerve elongation. In addition, by recreating a wider retinaculum, the implant prevents anterior nerve subluxation. When combined with the Dynavics, a two-polymer compound with high absorbability, the Canaletto implant may confer significant benefits to CTS patients
“In general, our findings suggest that when a resistant or recurrent CTS is diagnosed, secondary nerve release with combined application of Dynavics gel around the median nerve and a Canaletto implant lead to satisfactory clinical and functional results,” said researchers.
“Compared to other techniques described in the literature, our technique had the advantage of using a small incision which avoids the local morbidity associated with harvesting a wrapping flap for the median nerve,” they added, however noting that the benefits of using Dynavics alone still have to be investigated.