Distal interphalangeal joint arthrodesis with the intramedullary Lync^® implant: Prospective study of 22 cases

Several techniques have been described for fusion of the distal interphalangeal joint. The intramedullary Lync^® implant (Novastep™) may be superior to other options as it is available in straight or bent configurations, does not need to be removed and does not require fingertip incisions. The objective of our prospective study was to determine the effectiveness of finger distal interphalangeal (DIP) arthrodesis with Lync^® implants. Between February 2016 and June 2017, we performed 22 cases of DIP arthrodesis with this implant. Pain was assessed with a visual analog scale, the joint range of motion was measured using a digital goniometer, the pulp to palm distance was measured using a ruler, and the QuickDASH Questionnaire was filled out. AP and lateral X-rays were used to look for secondary displacement at 3 weeks and joint fusion at 6 weeks, 3 months, 6 months and 12 months. The primary endpoint was clinical and radiological union defined as the presence of trabecular bone bridges across the arthrodesis site. The patients' mean age was 57.8 years ± 9.9 (36-73). The mean follow up was 10 months ± 4.9 (3-15). The pre-operative pain level was 6/10 ± 2.4 (0-10) and it was 1.3/10 ± 1.7 (0-6) at 3 months post-operative (P < 0.0001). The mean pre-operative DASH Score was 64/100 ± 16 (15.9-86.3) and it was 19/100 ± 14 (2.3-45.4) at 3 months post-operative (P < 0.0001). At the end of the study, 20 DIP joints were fused (91%); 18 joints had fused at the 3 month follow-up visit (82%). Three cases required reoperation. DIP arthrodesis with the Lync^® implant resulted in DIP fusion in 91% of cases. When fusion was achieved, it provided pain relief and improved function. The Lync^® implant is less bulky than other arthrodesis devices and does not need to be removed.