2015 ISAKOS Biennial Congress ePoster #902

Does Femoral Osteochondroplasty Restore Adequate Motion for All Athletes to Perform Their Sports Without Bony Impingement

Joshua D. Harris, MD, Houston, TX UNITED STATES
Jonathan Gold, BA, Houston, TX UNITED STATES
Sabir K. Ismaily, BS, Houston, TX UNITED STATES
Philip C. Noble, PhD, Houston, TX UNITED STATES

Houston Methodist Orthopedics & Sports Medicine, Houston, TX, USA

FDA Status Not Applicable

Summary: Femoral osteochondroplasty significantly improves hip range of motion in cadaveric specimens with cam impingement, permitting impingement-free gait, stooping, and certain sports activities. However, not all sport- and position-specific movements were improved to the magnitude necessary to successfully compete, especially those involving high flexion and internal rotation.

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Abstract:

Background

Clinical outcomes of patients with hip symptoms secondary to cam femoroacetabular impingement (FAI) and labral injury are significantly improved with femoral osteochondroplasty and labral refixation. However, despite bony correction, impingement symptoms during vigorous sport-specific activities may persist. This suggests that a standard pre-operative resection plan for osteochondroplasty may place athletes at risk for relative under-correction in meeting the demands of their sport. Research Question: Does osteochondroplasty, performed according to a standardized plan, restore adequate motion for all athletes to perform their sports without bony impingement? Methods: 3D computer models were reconstructed from CT scans of eight (8) male hips with a cam FAI deformity without degenerative arthrosis . Each hip model was placed in a series of positions characterizing the pure planar hip motions (flexion/extension; abduction/adduction; internal and external rotation), gait, stooping, ice hockey goalie butterfly position, baseball catcher squatting, and seven principal positions of classical ballet. Each specimen was placed in each of these positions and the occurrence of impingement was evaluated using collision detection routines. One component of joint orientation (for example, flexion) was then altered until the point of impingement. A total of 19 measurements of hip motion were performed with each specimen. A virtual osteochondroplasty was then performed to reduce the alpha angle of the head/neck junction to 50° or less from 6 o’clock to 12 o’clock and the range-of–motion routines were repeated. The change in each component of joint motion to impingement was calculated before and after bone resection. Results: In every position simulated, the range of motion of the hip increased following osteochondroplasty by an average of 53° in abduction, 41° in adduction, 7° in extension, 37° in flexion and 17° internal rotation. Several demanding activities were able to be successfully performed without bony impingement following osteochondroplasty: stooping, baseball catcher squatting position, and 2 of the ballet movements (développé devant and grand écart latéral). However, 9 of the 19 positions could not be attained without impingement and subluxation, even after osteochondroplasty, including the hockey butterfly position, and 5 of the positions of ballet. All of these positions involved flexion>100°, and/or internal rotation>10° with the exception of two ballet positions that required extreme abduction (>60°). The improvement in hip motion after osteochondroplasty was highly position specific. In the 9 postures that remained unattainable after resection, 6 were due to inadequate flexion which did not increase after resection compared to an average increase of 36° for positions that did not generate impingement. The 3 remaining impinging activities were all limited by internal rotation which increased by 15° in the joint positions affected. Conclusions: Femoral osteochondroplasty significantly improves hip range of motion in cadaveric specimens with cam impingement. This permits impingement-free gait, stooping, and certain sports activities. However, not all sport- and position-specific movements were improved to the magnitude necessary to successfully compete, especially those involving high flexion and internal rotation.