BACKGROUND: Cam type femoroacetabular impingement (FAI) is an anatomical disorder that can lead to osteoarthritis (OA) of the hip joint. With existing surgical options there is invariably a tendency for under-resection or over-resection of the cam lesion, both having dire consequences. This study assessed the application of robotic technology in the surgical management of cam FAI. METHODS: Three different dry-bone femur models (14 in each) with severe cam deformity underwent corrective surgery using a haptic robot with active constraints. The 'post surgery', models were CT scanned and 3-D alpha angles and head/neck ratios (HNRs) were compared with pre-operative plans. RESULTS: In all models, the robotic resection resulted in a measured reduction of the maximum alpha angle to an angle indicative of no clinical impingement (first model 91° vs 49° ± 3°, second 91° vs 55° ± 5°, and third 87° vs 47° ± 2° P < 0.001). Similarly, the HNRs for all models reduced substantially following resection surgery. CONCLUSIONS: This dry bone study validates the use of robotic technology to perform cam FAI corrective surgery. A more accurate bony resection may minimize complications due to over- and under-resection.
BACKGROUND:Cam type femoroacetabular impingement (FAI) is an anatomical disorder that can lead to osteoarthritis (OA) of the hip joint. With existing surgical options there is invariably a tendency for under-resection or over-resection of the cam lesion, both having dire consequences. This study assessed the application of robotic technology in the surgical management of cam FAI. METHODS: Three different dry-bone femur models (14 in each) with severe camdeformity underwent corrective surgery using a haptic robot with active constraints. The 'post surgery', models were CT scanned and 3-D alpha angles and head/neck ratios (HNRs) were compared with pre-operative plans. RESULTS: In all models, the robotic resection resulted in a measured reduction of the maximum alpha angle to an angle indicative of no clinical impingement (first model 91° vs 49° ± 3°, second 91° vs 55° ± 5°, and third 87° vs 47° ± 2° P < 0.001). Similarly, the HNRs for all models reduced substantially following resection surgery. CONCLUSIONS: This dry bone study validates the use of robotic technology to perform cam FAI corrective surgery. A more accurate bony resection may minimize complications due to over- and under-resection.