[Modified SLAM (scapholunate axis method) technique for secondary SL reconstruction: preliminary results]

The common techniques for scapholunate (SL) ligament reconstruction achieve pain relief and maintenance of reposition at the expense of mobility and grip strength. In contrast, the scapholunate axis method (SLAM) technique seems to stabilise the scaphoid and lunate bones without a loss of function. We modified the technique with an additional anchor fixation of the tendon graft to the capitate bone in order to prevent palmar dislocation of the scaphoid bone.

This study aimed to examine whether or not it is possible to stabilise the scaphoid and lunate bones and to reduce pain without a loss of function and grip strength using the modified SLAM technique.

The SLAM technique was performed on 5 male patients aged between 36 and 60 years with an SL ligament lesion (3-10 months old). Preoperatively and after 12 months, the postoperative range of motion, grip strength, pain, SL angle, DASH Score and Mayo Wrist Score were assessed and compared to each other.

An improvement of the DASH Score (60.4 to 34.4 on average) and the Mayo Wrist Score (41 to 74 on average) was observed at the 12-month follow-up. Grip strength was enhanced from an average of 24.6 kg to 38 kg. Pain was improved from an average of 1.4 to 0.2 (at rest) and from 5.4 to 1.4 (under load). The SL angle changed only marginally from an average of 64.8° preoperatively to 63.2° postoperatively. The average range of motion was improved (extension/flexion: 58-0-60 vs. 50-0-49; radial/ulnar duction: 19-0-45 vs. 15-0-25 und supination/pronation: 87-0-90 vs. 81-0-81): However, function did not improve in every patient and all planes.

The modified SLAM technique improved the DASH Score, the Mayo Wrist Score, grip strength and pain. However, the SL angle and range of motion did not improve in every patient and plane. Consequently, it cannot be confirmed that the modified SLAM technique ensures a reliable stabilisation of the scaphoid and lunate bones and reduction of pain without a loss of function.