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Vail, Colorado, United States

Stull J.D.,Steadman Philippon Research Institute
The American journal of sports medicine | Year: 2011

Femoroacetabular impingement (FAI) is becoming a prevalent overuse injury diagnosis among hockey players. In the adult ice hockey stride, the "at-risk" hip position, defined by internal rotation during flexion and external rotation during abduction, reportedly increases hip vulnerability to labral injury as a result of FAI. Peewee youth ice hockey players display the kinematics for both described at-risk hip positions (internal rotation during flexion and external rotation during abduction) in the ice hockey sprint start. Descriptive laboratory study. Twelve healthy male Peewee ice hockey players (mean age, 10.8 ± 0.6 years) participated in this study. Thirty-five anatomic landmarks were used to analyze the 3-dimensional kinematic and kinetic variables of the hip associated with the ice hockey sprint start. Ten high-speed (120-Hz) infrared cameras recorded the trials, which were subsequently analyzed with Motion Monitor software. The sprint start was recorded over 4 defined periods of motion: start, push, swing, and even. In the "push" period, 11.5° of external rotation was observed concurrently with 13.2° of abduction in the push leg, and 6.8° of internal rotation occurred with 33.8° of flexion in the lead leg. During the recovery phase of the "swing" period, maximum internal rotation was 5.6° with concurrent hip flexion of 44.2° in the push leg, while lead leg internal rotation reached a maximum of 10.8° with hip flexion of 35.1° during the "even" period. During the sprint start, youth ice hockey players externally rotate in abduction during the push-off phase and internally rotate through increasing hip flexion during the recovery phase, displaying the at-risk hip positions of the ice hockey skating stride. During the sprint start, youth ice hockey players position their hips in a manner that can cause impingement of the femoral neck against the acetabulum and potentially lead to labral tears and/or articular cartilage damage. This knowledge could be applied to assist in the prevention of overuse injuries of the hip as youth hockey players mature and increase in skill level.

Briggs K.K.,Steadman Philippon Research Institute
The journal of knee surgery | Year: 2012

The purpose of this study was to determine if short form (SF)-12 physical component would increase with unloader brace use. Patient expectations and predictors of significant improvement were determined. Our hypothesis was that patients with unloader braces will have increases in general physical health (SF-12) and function (Western Ontario and McMaster Universities Arthritis Index [WOMAC]). Patients were enrolled in institutional review board-approved prospective cohort study. They completed a self-administered questionnaire (SF-12; WOMAC, Tegner activity scale, expectations) at enrollment, 3 weeks, 6 weeks, and 6 months. In this study, 39 patients, 23 males and 16 females (average age = 61 years [range 44 to 87]), were prescribed an unloader brace. Patients had significant improvement in quality of life (SF-12) (p < 0.05). There was significant improvement in pain, stiffness, and function (WOMAC) (p < 0.05). Patients who reported Tegner of 3 or greater at final follow-up had significantly higher SF-12 physical component (48 vs. 37; p = 0.023). Return to recreational sports was very important in 83% and somewhat important in 17%. Improving ability to walk was very important in 89%. Pain relief was very important in 69%, somewhat important in 17%. Of these, 39% expected most pain to be relieved and 57% expected all pain to be relieved. The most important expectations were to have confidence in knee (97% very important), avoid future knee degeneration (90% very important), and improve ability to maintain general health (93% very important). Patients demonstrated a significant decrease in pain and disability. Patients saw improvement in SF-12 physical component. Braces specifically designed to unload the degenerative compartment of the knee can be an effective treatment to decrease pain and maintain activity level to increase overall physical health. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Lertwanich P.,Steadman Philippon Research Institute
The American journal of sports medicine | Year: 2011

Suture anchors are commonly used to reattach a torn labrum to the acetabular rim. The acetabular rim anatomy is not uniform, and the safety margin for inserting suture anchors is unknown. The acetabular rim angle is an anatomic measurement that is indicative of the safety margin for inserting suture anchors. To investigate the acetabular rim angle as a function of clock position, to evaluate the effect of drill depth on the acetabular rim angle, and to evaluate the effect of rim trimming on the acetabular rim angle. Descriptive laboratory study. Three-dimensional acetabular models were reconstructed from computed tomography scans of 20 nonpaired cadaveric hip specimens, and the acetabular rim angle, which quantifies the angle between the subchondral margin and the outer cortex of the acetabulum, was measured from the 8- to 4-o'clock positions. At each position, the acetabular rim angle was measured for 5 drill depths (10, 12.5, 15, 20, and 25 mm) to simulate different lengths of suture anchors or drill bit depths on the acetabular rim angle. To simulate rim trimming, the acetabular rim angle was measured at the points that would become the suture anchor insertion points after 2.5- and 5-mm rim trimming. Clock position, drill depth, and rim trimming all had significant effects on the acetabular rim angle (P < .0001). The acetabular rim angle was largest at the 2-o'clock and smallest at the 3-o'clock position. Greater drill depths provided smaller acetabular rim angles, whereas rim trimming provided larger acetabular rim angles. The acetabular rim angle varied significantly as a function of the location on the acetabular rim. A shorter drill depth and a greater amount of rim trimming provided a larger acetabular rim angle. Surgeons should be aware of the acetabular rim variations, especially in the anterosuperior quadrant, as well as the effects of drill depth and rim trimming, when selecting the optimal insertion angle for suture anchor placement to avoid articular cartilage penetration. The acetabular safety angle was smallest at the 3-o'clock position. Therefore, extra care must be taken when drilling or inserting anchors around the 3-o'clock position.

Foad A.,Quality Care Clinic and Surgery Center | Wijdicks C.A.,Steadman Philippon Research Institute
Arthroscopy - Journal of Arthroscopic and Related Surgery | Year: 2012

Purpose: The main purpose of this study was to evaluate the accuracy of preoperative magnetic resonance imaging (MRI) in detecting subscapularis tears identified during the gold standard of arthroscopy and determine whether MRI can reliably predict which patients have subscapularis tears. A second purpose was to determine whether magnetic resonance (MR) arthrograms could better identify a subscapularis tear than conventional MRI. Methods: This was a retrospective study evaluating 39 consecutive patients (40 shoulders) who had a preoperative 1.5-T MRI study and underwent an arthroscopic subscapularis tendon repair. All cases were performed between December 2007 and November 2010. Results: Subscapularis tears were missed on preoperative MR scanning in 25 of 40 shoulders (62.5%). The sensitivity of noncontrast MRI was 40%, the sensitivity of MR arthrography was 36%, and the overall MR sensitivity was 37.5%. Conclusions: Preoperative 1.5-T MRI of the shoulder does not reliably predict subscapularis tendon tears, regardless of whether conventional MRI or MR arthrography is used. Level of Evidence: Level II, development of diagnostic criteria on basis of consecutive patients with universally applied gold standard. © 2012 Arthroscopy Association of North America.

Myers C.A.,Steadman Philippon Research Institute
The American journal of sports medicine | Year: 2011

Recent biomechanical reports have described the function of the acetabular labrum and iliofemoral ligament in providing hip stability, but the relative stability provided by each structure has not been well described. Both the iliofemoral ligament and acetabular labrum are important for hip stability by limiting external rotation and anterior translation, with increased stability provided by the iliofemoral ligament compared with the acetabular labrum. Controlled laboratory study. Fifteen fresh-frozen male cadaveric hips were utilized for this study. Each specimen was selectively skeletonized down to the hip capsule. Four tantalum beads were embedded into each femur and pelvis to accurately measure hip translations and rotations using biplane fluoroscopy while either a standardized 5 N·m external or internal rotation torque was applied. The hips were tested in 4 hip flexion angles (10° of extension, neutral, and 10° and 40° of flexion) in the intact state and then by sectioning and later repairing the acetabular labrum and iliofemoral ligament in a randomized order. External rotation significantly increased from the intact condition (41.5° ± 7.4°) to the sectioned iliofemoral ligament condition (54.4° ± 6.6°) and both-sectioned condition (61.5° ± 5.7°; P < .01), but there was no significant increase in external rotation when the labrum alone was sectioned (45.6° ± 5.9°). The intact and fully repaired conditions were not significantly different. External rotation and internal rotation significantly decreased when the hip flexion angle decreased from 40° of flexion to 10° of extension (P < .01) regardless of sectioned condition. Anterior translation varied significantly across sectioned conditions but not across flexion angles (P < .001). The ligament-sectioned (1.4 ± 0.5 mm), both-sectioned (2.2 ± 0.2 mm), and labrum-repaired (1.1 ± 0.2 mm) conditions all resulted in significantly greater anterior translation than the intact condition (-0.4 ± 0.1 mm) (P < .001). The iliofemoral ligament had a significant role in limiting external rotation and anterior translation of the femur, while the acetabular labrum provided a secondary stabilizing role for these motions. These results suggest that, if injured, both the acetabular labrum and iliofemoral ligament should be surgically repaired to restore native hip rotation and translation. In addition, a careful repair of an arthroscopic capsulotomy should be performed to avoid increased external hip rotation and anterior translation after arthroscopy.

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