[Our experience with repair of the scapholunate ligament using the MITEK bone anchor]

A complete rupture of the scapholunate (SL) interosseal ligament results in palmar flexion of the scaphoid and dorsiflexion of the lunate that leads to disintegration of the carpal circle and the development of scapholunate dissociation with dorsal intercalary segment instability. If the injury is not treated properly or early, the abnormal position of the scaphoid and lunate results in degenerative changes of the wrist shown by X-ray and referred to as scapholunate advanced collapse (SLAC). The aim of this study was to evaluate the results of our method used for reconstruction of the SL ligament by means of MITEK bone anchors in acute injury.

The group included 17 patients, 12 male and 5 female, aged 18 to 49 years, with complete SL ligament ruptures. The dominant hand was affected in 10 patients. After the diagnosis had been confirmed, we performed reconstructive surgery involving re-attachment of the SL ligament to the scaphoid by means of the MITEK Mini G2 anchor. The patients were examined by X-rays at 3, 6, 12 and 24 months after the operation to assess the SL angle, capitolunate (CL) angle, SL distance and signs of SLAC. Hand function and pain were evaluated on the basis of the Wrightington Hospital Wrist Scoring (WHWS) system.

The average preoperative value of the SL angle was 79 degrees and was corrected to 38 degrees by surgery. By subsequent physical therapy for 12 months, an SL angle of 51 degrees was achieved and increased to 52 degrees during the following year. The CL angle, showing a preoperative average value of 34 degrees, was corrected by surgery to 6 degrees, further increased to 9 degrees by exercising and then remained unchanged. The average SL distance of 5.25 mm preoperatively was reduced to 2.75 mm by surgery with no further change. At 24 months of follow-up, the results of pain evaluation were excellent, good and satisfactory in 41 %, 47 % and 12 % of the patients, respectively, with no poor outcome indicating restriction of the patient's daily activities. Functioning of the hand was excellent in 47 %, good also in 47 % and satisfactory in 6 % of the patients. The range of motion was excellent, good and satisfactory in 24 %, 64 % and 12 % of the patients, respectively. No stiff wrist was recorded after reconstruction of the SL ligament by our method. The hand grip was evaluated as excellent in 47 %, good in 35 % and satisfactory in 18 % of the patients.

The results show that by reconstruction of the SL ligament with the use of MITEK anchors, radiographic values of the SL and CL angles and SL distance can reach the normal levels within 24 months of the operation. As assessed by the WHWS system, excellent and good results were achieved in 88 % of the wrists treated. Similarly, at 24 months of followup, excellent or good functional outcomes were reported by 94 % of the patients, and excellent or good results in relation to the range of motion and hand grip were experienced by 88 % and 82 % of the patients, respectively.

When treating complete SL ligament ruptures within 4 weeks of injury, stabilization with Kirschner's wires, re-attachment of the SL ligament and suture of the articular capsule are adequate procedures leading to the best results. The ligament reconstruction with MITEK anchors, as presented here, is a relatively simple method giving good results. For treatment of chronic instability it is necessary to use other surgical procedures that, however, will reduce wrist mobility to a greater extent.