Tenon Medical announced compelling 12-month interim results from its ongoing MAINSAIL study, demonstrating that the Catamaran SI Joint Fusion System achieved an 83% fusion rate while delivering statistically significant improvements in pain and disability scores for patients with sacroiliac joint dysfunction. The prospective, single-arm, multi-center post-market clinical trial evaluated 24 consecutive patients across six U.S. clinical sites.
Significant Clinical Improvements Sustained at 12 Months
The study revealed robust clinical outcomes with mean VAS SI joint pain intensity scores decreasing significantly from pre-operative levels of 78.8mm to 23.0mm (p<0.001). Oswestry Disability Index (ODI) scores, measuring patient-perceived disability, showed substantial improvement from pre-operative values of 51.6% to 20.8% (p<0.001). Notably, 83.3% of subjects demonstrated an ODI improvement exceeding 15%, indicating clinically meaningful functional recovery.
"I am extremely encouraged by the ongoing clinical outcomes we are seeing at 12 months with the Catamaran SI Joint Fusion System," said Matthew Davies, MD, a board-certified neurosurgeon at Orthopaedic Associates of Duluth and principal investigator. "Patients in the study continue to achieve clinically meaningful reductions in both VAS pain and ODI disability scores, and the high fusion rates observed at 12 months further validate the Catamaran as a reliable, minimally invasive solution for treating SI joint dysfunction."
High Fusion Rates Confirmed by Independent Review
Of the 23 patients who reached 12-month follow-up with CT radiographic imaging, 19 patients (83%) showed unequivocal evidence of fusion with bridging bone across the SI joint and no radiolucency, as identified by an independent radiology reviewer. This fusion rate demonstrates the device's effectiveness in achieving the primary therapeutic goal of joint stabilization.
Superior Safety Profile and Patient Satisfaction
The study reported no serious adverse events, re-operations, or re-interventions throughout the 12-month follow-up period. Importantly, no vascular or nerve injuries were associated with the inferior-posterior surgical approach used to deliver the Catamaran implant. Patient satisfaction remained consistently high, with 83.3% of patients reporting high satisfaction with their treatment at 12 months.
Efficient Surgical Workflow
The minimally invasive procedure demonstrated operational efficiency, with 45.7% of procedures completed in under 45 minutes and the shortest procedural time recorded as 24 minutes. All procedures were performed in an outpatient setting, potentially reducing healthcare costs and improving patient convenience.
Benchmark-Exceeding Performance
The MAINSAIL study results significantly exceeded established literature benchmarks for SI joint fusion procedures. The 57.8-point improvement in VAS and 30.4% improvement in ODI surpassed averages reported in comprehensive reviews by Martin et al., which showed weighted mean improvements of 48.1 points in VAS and 21.8% in ODI at 12 months across lateral and posterior approaches.
Novel Device Technology
The Catamaran SI Joint Fixation Device is a single-piece titanium implant featuring two pontoons connected by an osteotome bridge, engineered to transfix the SI joint along its longitudinal axis for immediate stabilization and long-term fusion. Developed according to AO principles of arthrodesis, the device is placed via a minimally invasive inferior-posterior approach into the dense cortical bone of the sacrum and ilium. More than 1,000 devices have been implanted to date across various indications.
"These results highlight our ability to deliver consistent, reliable fusion with the Catamaran Fixation Device using the inferior posterior approach, while offering physicians a solution that combines ease of use, safety, and meaningful patient outcomes," said Steven M. Foster, President and CEO of Tenon Medical. "Coupled with our recent acquisition of SiVantage's innovative technology, Tenon is now uniquely positioned to lead the sacro-pelvic market with a comprehensive, multi-approach portfolio."
The MAINSAIL study is designed to enroll up to 50 patients, each followed for up to 24 months, with the current analysis representing the second interim publication from this ongoing investigation.
