Evolving Techniques: perfecting cam resection 5 essential steps in 5 minutes

1. Evolving Techniques: perfecting cam resection5 essential steps in 5 minutes John J Christoforetti, MD www.drchristo.com

2. Disclosures • Consultant: Arthrex, Inc • Royalty: Arthrex, Inc; Breg, Inc • Employed Physician: Allegheny Health Network • Board of Directors: ISHA The Hip Preservation Society • Editorial Board: Journal of Arthroscopy

3. The “Five Steps” • Understand 3 dimensional deformity AND patient activity demands • Create region-specific plan for arthroscopic access • Select technique that works in YOUR hands • Judicious Resection Assessment • Dynamic assessment of resection

4. Understand 3-D Deformity / Patient Demands • Proximal femur anatomy (version, offset, neck/shaft angle) • Regional bone topography • Benchmark to soft tissue structures identifiable at arthroscopy • Patient Sports/Life-related rotatory arc of motion in various planes of hip flexion/abduction Byrd. CORR. 2009

5. Create Region-Specific Plan • Proximal/lateral; Proximal/Posterior cam • Leg in relative extension, abduction, IR • View from MA Portal, work in AL portal • Distal medial cam • Leg in flexion, abduction, ER • View from AL Portal, work in MA portal • Cephalad resection zones require LESS bone resection to create a sphere! • Distal resection zones limited by true neck of femur • Lateral/distal zones limited by epiphyseal vessels

6. Select YOUR access technique • Soft tissue exposure is critical and options exist • Capsulectomy (Sampson) • Interportalcapsulotomy (Philippon) • Dynamic resection required • Mobile window benefits from retraction sutures • Spiker AM. Arthroscopy Tech. 2016 • Visualization of proximal/lateral and distal zones difficult • T-Capsulotomy (Kelly/Nho) • Likely can be accomplished with limited dynamic resection • Better visualization without capsular manipulation • Requires expert capsular management • Higher reported rates of instability early in learning curve • Sub-Zona Orbicularis (Dienst) • Does not require traction to start • Early results promising in expert hands • Some criticize compromise (thinning) of ZO • Use of 70 degree lens, un-hooded burr (round)

7. Judicious Resection and Assessment • Can obtain views with AP and cross table lateral (Larson) • Also can obtain with AP/angled and femur repositioning • Seek a tangential view • Define your resection goals preop, pre-resection, and post resection • Depth of resection pearls • Use cortical bone as guide • Atkins PR. CORR. 2017 • PRESERVE SUCTION SEAL of labrum throughout functional (ambulation) zones Atkins PR. CORR. 2017

8. Dynamic Assessment of Resection • Exam under anesthesia • Fluoro exam under anesthesia • Arthroscopic correlation to preoperative plan • Move limb through patient-specific motion extremes • Under-resection of “anteromedial” leads to less gain in IR post resection • Matsuda DK. Arthroscopy. 2015 • MORE HARM IS DONE WHEN TOO MUCH BONE IS RESECTED • Mansor et al. AJSM 2018 • 130 hips (revisions included) • Overresection >5% diameter is a problem for PRO’s! • BETTER OUTCOMES WHEN THE RESECTION IS “JUST RIGHT”

9. Thank you! John J Christoforetti, MD