A new instrument: a carpal tunnel knife

Carpal tunnel release by mini palmar incision

Background: Open carpal tunnel release is the gold standard treatment for carpal tunnel syndrome. However, there are complications related to the long incision.

Method: We report the results from a mini-incision open carpal tunnel release with simple instruments.

Results: There were no complications in our small series, improvement of scores was shown at four-week follow-up, and cosmetic results were satisfactory.

Conclusions: Mini-incision carpal tunnel release is one option to treat carpal tunnel syndrome.

CARPAL TUNNEL RELEASE WITH A LIMITED PALMAR INCISION: CLINICAL RESULTS AND PILLAR PAIN AT 18 MONTHS FOLLOW-UP

Limited open carpal tunnel release was performed in 58 hands (44 patients) using a single 1.5 cm palmar incision according to the technique described by Lee and Strickland.1The patients were assessed at regular intervals after surgery for hand functions and subjective symptoms, in particular pillar pain. There was rapid wound recovery with minimal post-operative pain and scarring, and return to functional activities within four weeks. At an average follow-up of 18 months (range 14–24 months), 91% of patients had complete or significant resolution of hand paraesthesia. No patient required further surgery. However, pillar pain was found in 48% of hands at four weeks, 21% at 12 weeks, 12% at six months, 9% at 12 months and 7% at the last follow-up. The significance of the incidence of pillar pain is discussed.

Minimally invasive carpal tunnel release

We prospectively compared the safety and effectiveness of mini-incision (group A) and a limited open technique (group B) for carpal tunnel release (CTR) in 185 consecutive patients operated between November 1999 and May 2001, with a 5-year minimum follow-up. Patients in Group A had a minimally invasive approach (<2 cm incision), performed using the KnifeLight (Stryker, Kalamazoo, Michigan) instrument. Patients in Group B had a limited longitudinal incision (3-4 cm). Patient status was evaluated with an Italian modified version of the Boston Carpal Tunnel questionnaire, administered preoperatively and at 19, 30, and 60 postoperative months. Mini-incision CTR showed advantages over standard technique in early recovery, pillar pain, and recurrence rate. The recovery period after mini-incision is shorter than after standard procedure.

Mini open carpal tunnel release using Knifelight: evaluation of the safety and effectiveness of using a single wrist incision (cadaveric study)

This cadaveric study evaluates the margin of safety and technical efficacy of mini open carpal tunnel release performed using Knifelight (Stryker Instruments) through a transverse 1 cm wrist incision. A single investigator released 32 wrists in 17 cadavers. The wrists were then explored to assess the completeness of release and damage to vital structures including the superficial palmar arch, palmar cutaneous branch and recurrent branch of the median nerve. All the releases were complete and no injury to the median nerve and other structures were observed. The mean distance of the recurrent motor branch to the ligamentous divisions was 5.7 +/- 2.4 mm, superficial palmar arch was 8.7 +/- 3.1 mm and palmar cutaneous branch to the ligamentous division was 7.2 +/- 2.4 mm. The mean length of the transverse carpal ligament was 29.3 +/- 3.7 mm. Guyon's canal was preserved in all cases.

Mini-open blind procedure versus limited open technique for carpal tunnel release: a 30-month follow-up study

PURPOSE

To evaluate prospectively the safety and effectiveness of a mini-open blind technique for carpal tunnel release (group A) when compared with a limited open technique (group B).

METHODS

From November 1999 to May 2001 (mean follow-up period, 30 mo) we performed 222 carpal tunnel release procedures on 185 consecutive patients. All patients were affected by mild to moderate median nerve compression. Patients in group A (82 patients, 99 procedures) had a short transverse incision at the wrist (length, 2 cm). We used a manual surgical instrument that helps in blindly dividing the flexor retinaculum because it has an integrated light source. The light makes it possible to locate precisely the tool blade by transillumination. Patients in group B (103 patients, 123 procedures) had a limited longitudinal incision (length, 3-4 cm). The preoperative and postoperative patient statuses were evaluated with an Italian modified version of the Boston Carpal Tunnel questionnaire with a mean of 30 months' follow-up after surgery (range, 24-39 mo).

RESULTS

Group A patients showed better results than group B patients in all of the sections of the Italian modified version of the Boston Carpal Tunnel questionnaire at a mean follow-up period of 19 months, whereas after a mean of 30 months of follow-up evaluation the differences between groups A and B tended to decrease. Disease recurred in 7 group B patients, whereas only 1 patient in group A experienced symptom recurrence at the latest office evaluation.

CONCLUSIONS

The blind mini-invasive technique has been shown to be as safe as traditional techniques but the recovery period is significantly shortened. With the technique we described a low recurrence rate was observed. All patients in group A reported great reduction in preoperative pain and numbness.

Carpal tunnel release using a short palmar incision and a new knife

A new knife with its own battery powered light source (Knifelight, Stryker Instruments, Kalamazoo, Michigan, USA) was used for carpal tunnel release in 31 wrists of 25 patients. Under local anaesthesia, a short palmar incision was used and the carpal tunnel contents were visualized during division of the flexor retinaculum. The mean operation time was 11 minutes and no major complications were seen. The patients could use their hands for self-care after 3 days and returned to work at a mean of 23 days. At a minimum follow-up of 6 months, all but one of the patients were satisfied with the final result. Mild scar tenderness was seen in two patients and pillar pain in one patient.

Safe carpal tunnel release via a limited palmar incision

Despite its demonstrated advantages in postoperative recovery, endoscopic carpal tunnel release has not been adopted by most surgeons because of the associated complications of neurovascular injury. A technique of carpal tunnel release is presented that utilizes a 1.0 to 1.5-cm palmar incision and a specially designed carpal tunnel "tome." Any aberrant anatomy of adjacent neurovascular structures may be identified under direct vision. Anatomic dissection in 28 cadaveric specimens following the procedure showed complete decompression of carpal tunnel and preservation with safe margins of the palmar cutaneous branch and thenar motor branch of median nerve, ulnar artery and nerve, and superficial palmar arch. Clinical experience with the technique in two centers consisted of 525 patients and 694 hands over a 29-month period. The great majority of patients derived complete (72.6 percent) or near-complete (19.6 percent) symptomatic relief from the procedure, and two complications (0.29 percent) of median nerve lacerations occurred. Postoperative incisional and pillar tenderness and grip, key pinch, and three-point pinch strengths were comparable with those in published series of endoscopic carpal tunnel release. We conclude that this technique of carpal tunnel release combines the simplicity and safety of traditional open release and the reduced tissue trauma and improved postoperative recovery of the endoscopic modality.

Endoscopic carpal tunnel decompression

A study of endoscopic carpal tunnel release was carried out in three parts, consisting of initial cadaveric dissections, a prospective pilot study of 20 patients and a prospective, randomized trial of 71 patients comparing endoscopic with open decompression. In the main trial, 25 patients with bilateral symptoms underwent simultaneous endoscopic and open release, with the remainder randomized to one or other technique. Both techniques effectively decompressed the median nerve. A significant improvement in group and pinch strength over 3 months was achieved in those undergoing endoscopic surgery. Average return to work was 14 days in the endoscopic series and 39 days in the open series. A complication rate of 35% was achieved with the transbursal endoscopic technique, 3.7% with the extrabursal endoscopic technique and 13.5% in the open series.