Fiber-reinforced fixation implant for proximal interphalangeal joint arthrodesis shows advanced implant bio-integration at 2-year follow-up.

BACKGROUND: A bio-integrative fiber-reinforced implant (OSSIOfiber® Hammertoe Fixation Implant, OSSIO Ltd., Caesarea, Israel) for proximal interphalangeal joint (PIPJ) correction-arthrodesis showed partial bio-integration at 1-year follow-up (1FU) in a previous study. The study was prolonged to assess the bio-integration at 2-year-follow-up (2FU). METHODS: Twenty-four patients with proximal interphalangeal joint (PIPJ) correction-arthrodesis using the fiber-reinforced implant and analysed at 1FU, completed 2FU. Follow-up included clinical examination, patient reported outcomes, radiographs, MRI and bio-integration scoring. Results were compared between the 1FU and 2FU (paired t-test). RESULTS: Radiographs confirmed fusion in 96 % (n = 23) at 2FU (1FU, 92 % (n = 22)). Implant was no longer visible in 21 % (n = 5), partially visible in 33 % (n = 8), and fully visible in 46 % (n = 11)(1FU, fully visible 100 % (n = 24)). The border between implant and surrounding bone was scored not visible in 88 % (n = 21) and partially visible in 12 % (n = 3) (1FU, border partially visible 100 % (n = 24)). There were no cyst formation or fluid accumulation findings 1FU/2FU. Mild bone edema was detected in 4 % (n = 1) (1FU, 29 % (n = 7)). None of the edema findings were considered as adverse implant related. The mean bio-integration score was 9.71 ± 0.69 at 2FU (1FU, 7.71 ± 0.46). The parameters of border between implant and bone and bone edema further improved at the 2FU compared to the 1FU, total bio-integration score was also higher at 2FU than 1FU (each p < 0.05). CONCLUSIONS: This study demonstrates 96 % PIPJ fusion rate and increased bio-integration from 1FU to 2FU, reaching advanced bio-integration of the fiber-reinforced implant at 2FU.

Fiber-reinforced fixation implant for proximal interphalangeal joint arthrodesis shows implant bio-integration at 1-year follow-up.

BACKGROUND: A new bio-integrative fiber-reinforced implant (OSSIOfiber® Hammertoe Fixation Implant, OSSIO Ltd., Caesarea, Israel) was developed for proximal interphalangeal joint (PIPJ) correction-arthrodesis. The main purpose of this clinical study was to assess implant bio-integration at 1-year follow-up. METHODS: Twenty-four patients, previously treated for a Hammertoe deformity using the bio-integrative, fiber-reinforced implant, were enrolled in this follow-up study. One-year follow-up included clinical examination, patient reported outcomes, radiographs, Magnetic Resonance Imaging (MRI) and bio-integration scoring. RESULTS: Proximal interphalangeal joint (PIPJ) radiographic fusion rate was 92% (n = 22). MRI was analyzed for 24 (100%) patients. In 100% of patients (n = 24), the border between implant and surrounding tissue was scored as partially visible. There were no cyst formation or fluid accumulation findings. Mild bone edema was detected in 29% (n = 7) and is attributed to the chronic distribution of forces due to chronic abnormal gait and pasture. None of the edema findings were considered as adverse implant-related finding. The mean bio-integration score was 7.71 ± 0.46. CONCLUSIONS: This study demonstrates safe bio-integration of the newly developed fiber-reinforced implant at 1-year follow-up without negative side effects.

Prospective, Multicenter, Clinical and Radiographic Evaluation of a Biointegrative, Fiber-Reinforced Implant for Proximal Interphalangeal Joint Arthrodesis.

BACKGROUND: A novel biointegrative implant was developed for proximal interphalangeal joint (PIPJ) arthrodesis to treat hammertoe deformity. Composed of continuous reinforcing mineral fibers bound by bioabsorbable polymer matrix, the implant demonstrated quiescent, gradual degradation with complete elimination at 104 weeks in animal models. This prospective trial assessed the implant's safety, clinical performance, and fusion rate of PIPJ arthrodesis for hammertoe correction. METHODS: Twenty-five patients (mean age 63.9±7.5 years) who required PIPJ arthrodesis were enrolled at 3 centers. Outcomes included radiographic joint fusion, adverse events, pain visual analog scale (VAS) score, Foot and Ankle Ability Measure (FAAM) Activities of Daily Living (ADL) score, and patient satisfaction. Patients were evaluated 2, 4, 6, 12, and 26 weeks postoperatively. RESULTS: Twenty-two patients (88%) achieved radiographic fusion at 26 weeks. All joints (100%) were considered clinically stable, with no complications or serious adverse events. Pain VAS improved from 5.3±2.5 preoperatively to 0.5±1.4 at 26 weeks postoperatively. FAAM-ADL total scores and level of functioning improved by mean 19.5±19.0 points and 24.4±15.7 percentage points, respectively, from preoperation to 26 weeks postoperation. Improvements in pain VAS and FAAM scores surpassed established minimal clinically important differences. All patients were very satisfied (84%) or satisfied (16%) with the surgery. Patient-reported postoperative results greatly exceeded (72%), exceeded (20%), or matched (8%) expectations. CONCLUSION: This prospective, multicenter, first-in-human clinical trial of a novel biointegrative fiber-reinforced implant in PIPJ arthrodesis of hammertoe deformity demonstrated a favorable rate of radiographic fusion at 12 and 26 weeks, with no complications and good patient-reported clinical outcomes. LEVEL OF EVIDENCE: Level IV, prospective case series.