gms | German Medical Science

Objectives/Interrogation: After a recent revisions of the insurance system for ambulatory treatment, certain operations have become a financial burden. Currently, the reimbursement for open release of the A1 pulley in stenosing tendosynovitis only covers 78% of the cost at our clinic. Percutaneous release of the A1 pulley has been around for many years with ever evolving techniques and instruments. Combined with sonography, we are able to visualize the A1 pulley, pinpoint the location of nerves and vessels and therefore safely release the A1 pulley percutaneously. Performed in the outpatient clinic, we expect percutaneous A1 release to be cost effective.

Methods: To establish a treatment protocol, 20 cadaver hands were used. The A1 pulley was evaluated sonographically, specifically noting the extent of the A1 pulley as well as the relative position of the nerves and vessels. Through a small incision just distal to the palmodigital fold, a cone tipped probe was inserted into the tendon sheath just distal to the A1 pulley and advanced between tendon and A1 pulley under sonographic guidance. Once correctly placed, a hook knife was inserted through a groove in the probe and the probe removed. After advancement of the knife to the proximal end of the A1 pulley the knife was retracted and in doing so the A1 pulley was released. Open inspection allowed for documentation of possible injuries.

With very promising results in cadaver hands, we intend to proceed to a clinical trial series.

Results and Conclusions: Percutaneous release was attempted in all A1 pulleys except for the A1 pulley of the thumb (n=80). The A1 pulley was released in 64 attempts (80%). Upon open inspection, no injuries to the nerves or vessels were noted. 9 lesions of the tendons were found, of which 4 were suspected sonographically (1 ulnar slip FDS, 2 partial (60%, 5%) lesions FDP, 2 longitudinal FDS splits, 4 perforations FDS). However, these results include our very early experience and inadequate instruments. The final 24 procedures were performed with improved instruments, resulting in 100% pulley release rate and without injuries.

As of yet, no clinical data has been collected. We intend to report on our first experience, as soon as they're available.

We propose a sonographically guided, percutaneous A1 pulley release suitable for the outpatient clinic. However, as the results represent only preclinical experience many limitations apply. Furthermore, contrary to the open release, no inspection of the tendon and no synovectomy can be performed.