Carl T. Brighton Workshop on Hip Preservation Surgery

Acknowledgement

Videos from the ABJS Carl T. Brighton Workshop on Hip Preservation Surgery are made available by an unrestricted educational grant from the following sponsors.

Association of Bone and Joint Surgeons

CORR Articles

Thu May 17 12:40:22 PDT 2012

Articles on Hip Preservation Surgery and related topics from CORR.

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Led by co-chairs Christopher L. Peters, MD, and Klaus A. Siebenrock, MD, the renowned international faculty of the ABJS Carl T. Brighton Workshop on Hip Preservation Surgery explored the current state and future of hip preservation surgery in 11 key areas, focusing on femoroacetabular impingement, hip dysplasia, and pediatric hip diseases. Video presentations from the workshop, held November 16-19 in Tampa, Florida, are available on Orthopaedia®.

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Hip Development and Morphology

Goal: Better understand the relationships between hip development, abnormal hip morphology, and hip pathomechanics, emphasizing challenging conditions of acetabular retroversion and the deep acetabulum.

[Hip Ontogenesis - Susceptibility of the Developing Hip], Tom Hogervorst, MD Abstract

T. Hogervorst, MD, PhD (n), W. Eilander, MD (n), J.T. Fikkers (n), I. Meulenbelt, MD, PhD (n)

Compared to other mammalian hips, human hip development demonstrates several peculiar features. First, in the last trimester in utero, the human hip is progressively hyperflexed due to space constraints related to development of a large brain and long legs. Second, after quadrupedal crouching, human gait rapidly develops into an obligate bipedal gait. Further, humans age slowly: all life phases are markedly drawn out as compared to large apes. Hence, the growing human skeleton with open physes can undergo high loading for several years, e.g. in sports, and this applies particularly to the weight-bearing lower extremities. Through the years, mechanical loading has been suggested to contribute to developmental hip disorders. New imaging parameters that allow comprehensive quantification of proximal femoral morphology may further clarify hip development. In addition, genetic mechanisms of skeletal development have been defined more clearly in recent years, and may explain gender and ethnic disparities in prevalence of developmental hip disorders.

We performed a systematic review to clarify the relative strengths and weaknesses of the literature on the effects of mechanical loading and genetic factors during hip development. Discussion of the data focuses on developmental dysplasia of the hip, slipped capitis femoral epiphysis, and femoroacetabular impingement.

[Morphologic Considerations in Dysplasia and Acetabular Retroversion], Moritz Tannast, MD Abstract

M. Tannast, MD (n), P. Pfannebecker, MD (n), S.D. Steppacher, MD (n), K.A. Siebenrock, MD (n), L. Büchler, MD (9-Swiss Orthopaedic Society)

Acetabular dysplasia and retroversion represent two opposite pathomorphologies. We made the observation that (besides the acetabular) the pelvic morphology substantially differs with these two conditions. We therefore questioned if there are differences in terms of the pelvic dimensions ⁽¹⁾ the radiographic appearance of the obturator foramen ⁽²⁾ and the iliac wing ⁽³⁾.

The correctly centered anteroposterior pelvic radiograph of 102 patients (51 with dysplastic and 51 with retroverted hips) were analyzed. The pelvic dimensions were assessed by the pelvic height, width, diameter, and the interspinous/-tuberous/-teardrop distances. The obturator foramen was characterized by its height and width. The iliac wing was described by the radiographic appearance of the superior/inferior iliac spine and the iliac wing.

⁽¹⁾ The pelvic width was significantly increased in retroverted hips. The interspinous, interteardrop and intertuberous distance was increased in dysplastic hips. ⁽²⁾ The height and width of the obturator foramen was increased in dysplastic hips. ⁽³⁾ The anterior inferior and superior iliac spine and the iliac crest were significantly more often visible in retroverted hips.

Hips with a dysplasia significantly differ in terms of the pelvic morphology in comparison to hips with retroversion. The pathomorphology of the hip therefore is strongly associated with a pelvic pathomorphology.

[Morphology and Pathogenesis of Coxa Profunda and Coxa Protrusio], Martin Beck, MD Abstract

Martin Beck, MD, PD (3C-Mathys Ltd., Switzerland)

Coxa profunda and protrusio both are acetabular deformities that lead to pincer type FAI. Whereas the impingement mechanism is similar, the pathogenesis of profunda and protrusio hips are different, but both not well understood and subject to discussion and investigation. Already the definition is controversial and lets space for Coxa profunda cannot be defined on the basis of the radiographic morphology of the hip as it is currently done. The definition of acetabular depth based on the relation of the fossa acetabuli and/or femoral head to the ilioischial line only gives clues where the acetabulum is positioned in the pelvis but is not a good predictor of acetabular depth. The depth of the acetabulum has to be determined with currently used parameters (LCE, AI, extrusion index).

For protrusio hips, such values also exist. But the radiographic morphology shows additional features as width and orientation of the facies lunata, size and shape of the acetabular fossa. Protrusio hips are classified into primary (unknown) and secondary, explained by an underlying disease, ranging from infection and trauma to metabolic and genetic diseases.

For coxa profunda, such a classification does not exist. Based on the radiographic appearance, the division into primary and secondary (deepening of normal acetabulum through ossification of labrum) is proposed.

Imaging the Hip

Goal: Define optimum imaging protocol of patients with FAI/dysplasia. Outline future directions in imaging technology/protocols for patients with FAI and dysplasia.

[Plain Radiographic Examination Is Diagnostic for Most Patients], John Clohisy, MD Abstract

Jeffrey J. Nepple, MD (n), John M. Martell, MD (3B-Biomet, Smith & Nephew, Zimmer, Harris Foundation), Harish S. Hosalkar, MD (2-Synthes; 3B-SYNTAXIN; Synthes; 4-GlaxoSmithKline, Johnson & Johnson, Pfizer; 5-Zimmer; 7-Journal of Bone and Joint Surgery – American, Turner White), Young-Jo Kim, MD, PhD (5-Siemens), David A. Podeszwa, MD (n), Ernest L. Sink, MD (3B-Pivot Medical), Daniel J. Sucato, MD (7-Saunders/Mosby=Elsevier; 9-AAOS, Pediatric Orthopaedic Society of North America; Scoliosis Research Society), Ira Zaltz, MD (n), John C. Clohisy, MD (3C-Biomet Manufacturing Corp.; 5-Zimmer, Inc.)

Introduction: Three-dimensional imaging (CT and MRI) is the gold standard for detection of femoral head-neck junction malformations in femoroacetabular impingement (FAI), yet plain radiographs are used to screen for FAI. The purpose of this study was to compare the utility of plain radiographs with CT scanning in the detection of femoral head-neck malformations.

Methods: We performed a retrospective review of 41 consecutive surgical patients with preoperative CT scans and plain radiographs (AP pelvis, 45 degree Dunn, frog lateral, cross-table lateral). Twenty-eight were female, 13 male and diagnoses included cam FAI (56.1%), combined cam-pincer FAI (36.6%), DDH (4.9%), and normal structural anatomy (2.4%). Radial CT reformations of the head-neck junction were generated at the 12, 1, 2, and 3 o’clock positions spanning the superior to anterior neck. Alpha angles were measured with a computer-assisted program. Alpha angle thresholds of 50 and 63 degrees were utilized as markers of any or severe deformity, respectively.

Results: The maximum alpha angle on plain radiographs was greater than that of CT reformats in 61.0% of cases. The complete radiographic series was 85.7-90.0% sensitive to detecting deformity on CT. Exclusion of the crosstable lateral did not affect the sensitivity (85.7-87.7%). The Dunn view was most sensitive (71.4-80.0%). The frog lateral showed the best specificity (90.9-100%).

Conclusions: Plain radiographs detect deformity seen on CT scan, and in some cases may overestimate the alpha angle. The combination of an AP pelvis, 45 degree Dunn, and frog lateral has excellent sensitivity in detecting head-neck malformations and can be diagnostic for most patients.

Summary: A three view radiographic hip series (AP pelvis, 45 degree Dunn, and frog lateral) has excellent sensitivity and specificity in detecting femoral head-neck junction malformations.

[MRI of Hip Cartilage - Joint Morphology, Structure, and Composition], Hollis Potter, MD
Abstract
Hollis Potter, MD (2-DePuy Orthopaedics, Inc., Metal Ion and MRI Imaging Web Cast; 3B-Smith & Nephew, Kensey Nash Corporation, BioMimetic Therapeutic, Inc., Biomet; 5-General Electric Healthcare, institutional research support; 8-Associate Editor for Imaging, Sports Health (AOSSM), Editorial Board for the International Cartilage Repair Society journal, Cartilage

Given the relatively thin cartilage of the hip joint, as well as the complex spherical anatomy, accurate assessment of hip cartilage poses a challenge for traditional MRI techniques. With the use of high in-plane and through-plane resolution, however, reproducible assessment of cartilage and labrum is clinically feasible with reported accuracy of 87-88% and weighted kappa measures of reproducibility of 0.8 (p<0.001)1. Specific features of femoroacetabular impingement are discussed, as well as findings suggestive of instability, particularly in the postoperative setting. In addition, high resolution, non-contrast techniques allow for superior depiction of the native synovium and may disclose proliferative synovial disorders that may be clinically mistaken for labral or chondral pathology2. More recent quantitative MR techniques also allow for noninvasive assessment of collagen orientation and proteoglycan content in articular cartilage. High levels of reproducibility and clinical feasibility has been demonstrated for both T1rho and T2 mapping of hip cartilage3, and these techniques provide important insight into early matrix degeneration from osteoarthritis in cohorts at risk.

References
1. Potter HG, Schachar J. High resolution noncontrast MRI of the hip. J Magn Reson Imaging 2010; 31:268-278
2. Mintz DN, Hooper TR, Connell DA, Buly R, Padgett DE, Potter HG. Magnetic resonance imaging of the hip: detection of labral and chondral abnormalities using non-contrast imaging. Arthroscopy 2005; 21(4):385-393.
3. Dillon AB, Joseph GB, Krug R, Li X, Majumdar S. Reproducibility of T1rho and T2 relaxation time and morphologic measurements of articular hip cartilage at 3T. Poster presentation. ISMRM 2011. Montreal, Canada.

[New Imaging Technology May Predict Outcome], Young-Jo Kim, MD, PhD Abstract

Young-Jo Kim, MD, PhD (5-Siemens)

Previous clinical studies have shown that outcome after correction of hip deformities such as acetabular dysplasia, acetabular retroversion, anterior overcoverage, coxa profunda, and femoral cam lesion is dependent on the extent of articular cartilage damage in the joint. A non-invasive and sensitive imaging technology should be able to help select the right patient for joint preserving surgery. The standard method of grading the amount of osteoarthritis in the hip is a plain radiograph. It is becoming clear that plain radiographs are insensitive to early articular cartilage damage. Magnetic resonance imaging has the ability to directly image the articular cartilage. Direct assessment of the gross tissue structure is possible. Additionally, the biochemical composition of the cartilage can be assessed by imaging techniques such as delayed Gadolinium Enhanced MRI of Cartilage (dGEMRIC), T1rho, and T2. dGEMRIC has been studied extensively in the hip. It has been shown to be a better predictor than plain radiographs for the short term clinical outcome after periacetabular osteotomy for acetabular dysplasia. dGEMRIC has demonstrated that the pattern of acetabular cartilage damage is different between femoroacetabular impingement and dysplasia. Future studies utilizing non-contrast techniques such as T1rho may show similar value in predicting clinical outcome after joint preservation surgery.

[Specialized Imaging Centers to Avoid Duplication and Poor Imaging], William Jiranek, MD Abstract

Curtis Hayes, MD (3B-BioClinica, Inc., Pfizer, Inc.; 7-Up To Date), Kevin Hoover, MD (3B-BioClinica, Inc.), William Jiranek, MD (1,3B-DePuy; 5-Stryker; 8-OKO; 9-Lifenet Health)

1. Personnel Needs of Imaging Center

2. Equipment Needs of Imaging Center

3. What are the forces incenting duplication (and dilution) of efforts?

4. Should an imaging center be part of a radiology department or a hospital cost center?

5. Should radiologists be involved in deciding which studies are appropriate for a given patient?

6. What evidence is there that imaging centers decrease cost and promote better outcomes?

There is ample data that specialized arthroplasty units within hospitals with higher volumes have less complications and better outcomes. There is less data in support of specialized imaging/diagnostic centers. It is clear, however, that duplication of expensive medical technology by competing hospitals has not always lowered costs or improved patient outcomes. This article evaluates current evidence of the utility of specialized centers, and presents guidelines by which these centers could be developed.

There is ample precedent for the development of specialized imaging centers. The National Comprehensive Cancer Center created the Specialized Imaging Research Center (SIRC) whose goal is to advance technology development to improve patient outcomes. Similar centers have been developed for ophthalmology, hemophilia, prostate and breast imaging, and numerous other disciplines.

The goals of a hip imaging and diagnostic center would be to improve diagnostic accuracy (and limit cost) by more appropriate selection of diagnostic studies, to increase experience with specific imaging studies such that they are performed with greater accuracy and efficiency, and to foster research into better evaluations by concentration of similar studies. Currently there is little systematic evaluation of plain radiographs for parameters of femoral and acetabular architecture. While there is some agreement in the literature about the use of MR arthrograms to evaluate labral pathology, there is little agreement on which cross sectional imaging is best suited to evaluation of femoral and acetabular architecture. Similar controversy exists for the imaging of articular cartilage.

Dysplasia Challenges/Controversies

Goal: Further define patient selection criteria for acetabular redirectional osteotomy and define optimum intraoperative treatment. Define the role of arthroscopy for dysplasia.

[Defining Hip Dysplasia in 2011], Michael Millis, MD Abstract

Michael B. Millis, MD (n)

The term “hip dysplasia”, since the advent of X-ray, has been defined by certain radiographic features: deficiency of anterior or lateral rims; obliquity of the acetabular weight-bearing zone; or subluxation of the femoral head. With the mechanically-destabilizing insufficiency of the acetabulum as part of the definition of dysplasia, the mechanical environment in such hips tends toward instability. The most useful terminology will accommodate our evolving understanding of the functional consequences of subtle variations in version and shape of the hip’s bony elements, and in the structure of its non-bony elements. MR and other imaging should be considered. Classification of hips is useful in treatment selection. As a simplistic one word description of a group of hips with certain features, “dysplasia” suggests a hip with rim overload by the femoral head in extension/external rotation, with variable labral hypertrophy or tears. More precise categorization of hips is needed and might parallel the TNM Classification of Malignant Tumors. An analogous hip classification schema might contain elements briefly describing acetabular deformity with a versional modifier; the femoral deformity if any with a versional modifier; a congruity parameter; and an arthrosis parameter.

[Patient Selection Criteria for PAO or RAO], Yuji Yasunaga, MD Abstract

Yuji Yasunaga, MD¹ (n) Takuma Yamasaki, MD² (n), Mitsuo Ochi, MD ² (n)
¹Department of Artificial Joints & Biomaterilas, Hiroshima University, Japan
²Department of Orthopaedic Surgery, Hiroshima University, Japan

Dysplasia of the hip is the most common cause of secondary osteoarthritis (OA). Periacetabular osteotomy (PAO) or rotational acetabular osteotomy (RAO) have been utilized as joint-preserving procedures to prevent the early onset of OA. Many authors reported satisfactory mid- and long-term results in patients with pre- or early stage OA, younger age and good postoperative joint congruency.

The success of PAO or RAO depends on articular cartilage that is sufficiently healthy to sustain normal load transmission. Even at the early stage radiographically, severe degeneration of articular cartilage with subchondral exposure may be present. Since the introduction of femoroacetabular impingement (FAI), secondary FAI after PAO which could be associated with an unfavorable outcome has been noticed.

For more satisfactory outcome after these procedures, preoperative precise evaluation of articular cartilage and prevention of postoperative FAI should be solved. For cases with degenerated cartilage, intraarticular tratment such as microfracture or drilling combined with osteotomy may have a potential for the regeneration of articular cartilage.

[Reorientation Is the Preferred Treatment], Klaus A. Siebenrock, MD

[Role of Arthroscopy in Dysplasia], Damian Griffin, MA(Cantab), MPhil (Oxon), FRCS (Tr&Orth) Abstract

Damian Griffin, MA, Mphil, FRCS, (Tr & Orth) (3B-Conmed Linvatec; 5-Wright Medical, Smith & Nephew, Corin, Zimmer)

Background: Rotational osteotomies of the acetabulum are established treatments for acetabular dysplasia; the potential role of hip arthroscopy is controversial.

Purpose: The authors sought to determine whether arthroscopy was valuable in the management of patients with acetabular dysplasia in whom indications for periacetabular osteotomy were not clear-cut.

Study design: Case series. Level of evidence, 4.

Patients and Methods: 28 patients (28 hips) with symptomatic acetabular dysplasia who did not clearly meet the criteria for peri-acetabular osteotomy (PAO), and who had hip arthroscopy, were reviewed. Radiographic and arthroscopic findings were tabulated with outcome including PAO, hip arthroplasty or prospectively collected change in Non-Arthritic Hip Score (NAHS) in those where no further surgery was performed.

Results: The majority of these patients were women (25/28) with a mean age of 37 years (16-52). Most had radiographic degeneration, and a mean NAHS of 51 (11-65). Arthroscopic evidence of rim failure (anterosuperior labral or chondral degeneration) was found in all but one patient. A particular pattern of ‘outside-inside’ labrochondral tear was present in 18/28, markedly distinct from the pattern of labrochondral failure seen in cam-type femoro-acetabular impingement. 9/28 had hip arthroplasty and 11/28 a PAO as a result of findings at arthroscopy. 8/28 had neither procedure, being treated only by arthroscopic chondroplasty, conservative labral debridement or labral repair. NAHS in this later group increased from a mean of 59 to 81 at two years.

Conclusion: Hip arthroscopy was useful in supporting decision making to perform PAO or hip arthroplasty in this group of patients who were often older and had more degenerated hips than would be ideal for PAO. In those managed only with arthroscopy, there was moderate improvement in symptoms for at least two years. A particular pattern of ‘outside-inside’ labrochondral tear was recognised which the authors suggest may be pathognemonic of acetabular dysplasia.

Dysplasia Outcome

Goal: Further define patient selection criteria for acetabular redirectional osteotomy and define optimum preoperative imaging algorithm. Define best intra-articular treatment methodology and the role of PAO for retroversion.

[The Bernese Experience], Moritz Tannast, MD

[The Japanese Experience with RAO], Yuji Yasunaga, MD Abstract

Yuji Yasunaga, MD¹ (n), Takuma Yamasaki, MD² (n), Mitsuo Ochi, MD² (n)
¹Department of Artificial Joints & Biomaterilas, Hiroshima University, Japan
²Department of Orthopaedic Surgery, Hiroshima University, Japan

In Japan, the rotational acetabular osteotomy (RAO) is a common procedure for dysplastic hip. The RAO was developed by Tagawa H. in 1968. Thereafter, the curved periacetabular osteotomy, which is a modified periacetabular osteotomy (PAO) and the eccentric rotational acetabular osteotomy, which is a modified RAO, were developed.

Many authors reported satisfactory mid- and long-term results in patients with pre- or early stage OA, younger age and good postoperative joint congruency. Patient selection criteria for the RAO or PAO in Japan is equivalent to that in the western world. However, Japanese patients with moderate or severe dysplasia (e.g. center-edge angle of around 0 degree) are characteristic compared to those in the western world. Japanese surgeons had not taken care of FAI in these procedures before the introduction of FAI, and there are few reports on postoperative FAI. The incidence of postoperative FAI and the relation to OA progression after surgery in Japan should be evaluated.

FAI General Concepts

Goal: Define the parameters that influence the prognosis of patients with FAI.

[Femoroacetabular Impingement - Cam Alpha Angle and Cartilage Delamination] Paul Beaulé, MD, FRCSC
Abstract
Paul E. Beaulé, MD, FRCSC (2-MEDACTA, Smith & Nephew; 3B-MEDACTA, Smith & Nephew, Corin)

The presence of acetabular cartilage damage at the time of FAI surgery is well-documented ranging from 44-75%1-3². The acetabular cartilage damage has been classified by Beck et al¹ with the majority being Type 3 (cartilage is debonded from acetabular surface but there is no visible cleft) and Type 4 (same as Type 3 but with cleavage of the flap). The etiology of these lesions is felt to be secondary to an “outside-in” damage of the acetabular cartilage and/or its avulsion from the labrum and the subchondral bone in a rather constant anterosuperior rim area⁴.

Recent literature has shown the alpha angle to be predictive of developing hip pain with alpha angle >60º having an odds ratio of 2.55⁵. In addition, alpha angle was found to be an independent risk factor for the presence of acetabular cartilage delamination in two retrospective studies looking at operative findings of acetabular cartilage damage and alpha angle6,7⁶. In a series of 102 hips, Johnston et al⁷ reported that the alpha angle measured on the cross-table lateral was significantly higher in patients with full-thickness delamination: 60° vs v 51°, p=.034. In a larger series of 355 hips, Nepple et al³ found that an alpha angle greater than 50 measured on the frog lateral, was associated with an odds ratio of 2.8 (p<.001) to have significant acetabular cartilage delamination.

In our prospective data base of our surgically treated FAI patients from September 2005 to August 2011, 190 patients with a mean age of 38.5 (17-59); 145 males and 45 females were identified. The mean alpha angle at the time of surgery was 65º (30-90). 47.4% of patients had acetabular cartilage delamination either Beck type 3 or type 4 cartilage damage. Age and alpha were both significantly correlated to Beck Grade of acetabular cartilage damage although weak r=0.14 (p=.01) and r=0.20 (p=.04), respectively. With a multivariate regression analysis, alpha angle> 65º was significantly correlated with Beck Grading of acetabular cartilage with an Odds ratio of 1.42 (p<0.005). More recently, high resolution cartilage imaging was been able to show early proteoglycan depletion in asymptomatic volunteers with a CAM deformity and more importantly, a moderate association was noted between the severity of the CAM deformity and dGEMRIC values⁸. Severity of CAM deformity as measured with the alpha angle correlates to acetabular cartilage damage having said that determining optimal timing for intervention prior to damage needs to be defined.

References
1. Beck M, Leunig M, Parvizi J, Boutier V, Wyss D, Ganz R. Anterior Femoroacetabular Impingement. Part II. Midterm Results of surgical treatment. Clin.Orthop. 2004;418:67-73.
2. Beaule PE, LeDuff MJ, Zaragoza EJ. Quality of Life outcome of femoral head/neck offset correction for femoroacetabular impingement. J Bone Joint Surg. 2007;89A:773-79.
3. Nepple JJ, Carlisle JC, Nunley RM, Clohisy J.C. Clinical and radiographic predictors of intra-articular hip disease in arthroscopy. Am J Sports Med 2011;39:296-303.
4. Ganz R., Leunig M, Leunig-Ganz K, Harris WH. The etiology of osteoarthritis of the hip : an integrated mechanical concept. Clin.Orthop.Rel.Res. 2008;466:264-72.
5. Allen DJ, Beaule PE, Ramadan O, Doucette S. Prevalence of associated deformities and hip pain in patients with cam type femoroacetabular impingement. J Bone Joint Surg 2009;91B:589-94.
6. Anderson LA, Peters CL, Park BB, Stoddard GJ, Erickson JA, Crim JR. Acetabular cartilage delamination in femoroacetabular impingement. Risk factors and magnetic resonance imaging diagnosis. J Bone Joint Surg 2009;91:305-13.
7. Johnston TL, Schenker ML, Briggs KK, Philippon MJ. Relationship between offset angle alpha and hip chondral injury in femoroacetabular impingement. Arthroscopy 2008;24:669-75.
8. Pollard TC, McNally EG, Wilson DC, Wilson DR, Madler B, Watson M, Gill HS, Carr AJ. Localized cartilage assessment with three-dimensional dGEMRIC in asymptomatic hips with normal morphology and cam deformity. J Bone Joint Surg Am 2010;92:2557-69.

[Does Mixed-Type Impingement Exist?] Damian Griffin, MA(Cantab), MPhil (Oxon), FRCS (Tr&Orth) Abstract

Damian Griffin, MA, Phil, FRCS (Tr & Orth) (3B-Conmed Linvatec; 5-Wright Medical, Smith & Nephew, Corin, Zimmer)

Background: Femoro-acetabular impingement (FAI) is an important cause of hip pain and hip degeneration. Two major types are recognised: cam and pincer. Open or arthroscopic treatment may be directed at either or both, so it is important to know whether a patient has evidence of both and whether both need to be treated.

Purposes: The authors set out to determine whether cam and pincer related shapes of the femur and acetabulum could be identified and classified in patients with a diagnosis of FAI, whether these shapes predicted chondral and labral injury patterns, and whether there were patients in whom cam and pincer-types of FAI occurred together.

Study design: Case series. Level of evidence, 4.

Patients and Methods: The authors developed a process to map the profile of cam and pincer shapes on reconstructed circumferential radial CT images. This was applied to 119 patients (91 male, 28 female) having surgery for symptomatic FAI on 146 hips, and to 22 trauma patients (44 ‘normal’ hips) who had no previous history of hip problems. FAI hips were compared to normal hips to establish criteria for diagnosis of cam and pincer shapes, and imaging findings were compared with operative findings.

Results: 92% of FAI hips had evidence of cam shapes, and all of these had chondral injury patterns consistent with these shapes. They were classified into Type 1: anterior (29%), Type 2: superior (8%), Type 3: anterior and superior (42%) and Type 4: widespread (13%). 39 hips had evidence of pincer shapes, and all of these had labral injury patterns consistent with this type of impingement. They were classified into Type 1: anterosuperior over-coverage (12%), type 2: retroversion (7%) and type 3: circumferential over-coverage (8%). 18% of patients had anteversion >15°, and 9% were dysplastic with undercoverage. 16% of hips had evidence of both cam and pincer shapes, with the majority showing a combination of a Type 3 cam and a Type 1 pincer. At surgery, all of these hips had been judged to need femoral and acetabular reshaping surgery in order to relieve impingement on dynamic range of movement testing.

Conclusion: Mixed cam and pincer-type FAI does exist, most commonly a combination of Type 3 cam (anterior and superior) and Type 1 pincer (anterosuperior over-coverage).

[Pincer Issues - Does Coverage Matter?] Rafael Sierra, MD Abstract

Michael R. Pagnotto, MD (4-MAKO Surgical Corp., Bayer AG; 7-Mindworks Communications, A Wyanoke Group Company), Gregory R. Boone, BS, Justin A. Walker, MD (n), Robert T. Trousdale, MD (1,3B-DePuy, A Johnson & Johnson Company, Wright Medical Technology, Inc. ortho development, MAKO), Rafael J. Sierra, MD (1,2-Biomet; 5-Biomet, Stryker, DePuy, Zimmer; 9-Midamerica, AAHKS, Maurice Mueller Foundation)

Not all deformities associated with femoroacetabular impingement (FAI) can be treated arthroscopically. A select group of patients may differentially benefit from open vs. arthroscopic techniques. To better understand who may benefit from surgical hip dislocation (SHD) vs. arthroscopy the results of SHD after failed arthroscopy in a single institutional series is reported with an emphasis on reporting the reasons for failure of the hip arthroscopy. Furthermore, the significance pre-operative lateral center edge angle as a predictor of the need for acetabular rim trimming was examined in a consecutive series of patients undergoing SHD for FAI. A consecutive series of 155 patients (178 hips) treated with SHD between 8/2002 and 2/2011 for FAI were reviewed. Twenty-three patients (25 hips) who had undergone previous hip arthroscopy prior to SHD were identified and 75 patients (85 hips) with concurrent coxa profunda were identified from the series. The primary mode of failure of arthroscopy was found to be the under correction of hip pathology at the time of initial arthroscopy. Lateral center edge (LCE) angle ? 40º was predictive of the need for acetabular rim trimming. When deciding between open and arthroscopic techniques for the treatment of FAI surgeons should appreciate that under correction of hip structural pathology at the time of arthroscopy was found to be the major mode of failure and that LCE ? 40º is highly predictive of the need to perform acetabular rim trimming.

[Objective Parameters for Measuring Coverage], Klaus A. Siebenrock, MD Abstract

K.A. Siebenrock, MD (n), L. Kistler, MD (n), J. Schwab, MD (n), L. Büchler, MD (9-Swiss Orthopaedic Society), M. Tannast, MD (n)

Substantial alterations of the anterior and posterior acetabular coverage were proven to be associated with hip pain and joint degeneration. To date, there is no simple parameter for quantification of the absolute anterior and posterior acetabular coverage that can be used in daily clinical practice. We introduce and validate the acetabular wall index as a new parameter to assess the absolute anterior and posterior coverage on non-calibrated anteroposterior pelvic radiographs.

The acetabular wall index was measured on the anteroposterior radiographs of 86 patients (21 normal, 26 dysplastic, 14 pincer, 25 protrusio hips) for the anterior and posterior wall by two observers. The acetabular wall index was then compared to the actual percentage of acetabular coverage which was determined with a validated computerized methods.

The inter- and intraobserver variability was very good for the (anterior and posterior) acetabular wall index. There was a strong correlation for the anterior/posterior acetabular wall index with the actual anterior and posterior acetabular coverage.

The acetabular wall index is a reliable, reproducible and accurate parameter for assessment of the anterior and posterior acetabular coverage.

FAI - Establishing Who Is at Risk

Goal: Better define the patients who are at risk for developing FAI and the relationship between early sporting activity and FAI.

[Prevalence of Cam Deformity in the Asymptomatic Population], Paul Beaulé, MD, FRCSC

[Athletes Are at High Risk for Femoroacetabular Impingement], Christopher L. Peters, MD Abstract

Ashley Kapron, BS (n), Andrew E. Anderson, PhD (n), Stephen Aoki, MD (3B-Smith & Nephew; 5-Biomet, Musculoskeletal Transplant Foundation, Arthrex, Inc.; 9-American Orthopaedic Society for Sports Medicine), Lee Phillips, MD (n), Bob Toth, PA-C (n), David Petron, MD (n), Lucas Anderson, PA (n), Christopher L. Peters, MD (1,2,3B-Biomet, 8-Journal of Arthroplasty; 9-AAOS Adult Reconstruction Subcommittee)

Introduction: Due to increased loading of the hip during sport, the prevalence of femoroacetabular impingement (FAI) in athletes may be greater than the normal population. This study used radiographic measures to identify morphologic abnormalities associated with FAI in an athletic population. Additionally, physical exams commonly used in the clinical diagnosis of FAI were evaluated to quantify their ability to predict underlying abnormalities in asymptomatic subjects.

Methods: Prospective, IRB approved study of 67 male collegiate football players.

Both hips (n=134) were evaluated for radiographic signs of pincer and cam FAI on AP and frog-lateral films. Each subject’s past and present hip condition was assessed with a questionnaire.

Standard clinical exams, including the impingement and FABER exam, were performed. Max hip range of motion in flexion (supine) and internal/external rotation (supine, sitting, and prone) measured using a goniometer.

The correlation between each range of motion and radiographic measure was determined by a random-effects linear regression model.

Results: 95% (127 hips) had at least 1 sign of cam or pincer FAI. Hip internal rotation in the supine, sitting and prone positions was significantly correlated to two measures of cam FAI (alpha angle and head-neck offset).

Conclusion: Morphologic abnormalities associated with cam/pincer FAI were common in these athletic males. The prevalence was substantially higher than previously reported values for normal populations. Supine and prone internal rotation can predict radiographic findings of cam FAI in athletic males with repeatable radiographic and physical measures. Screening athletes may identify hips at risk for the development of osteoarthrosis due to FAI.

[Estimates in an Active Male Population], Michael Leunig, MD Abstract

Michael Leunig, MD (3B-Biomet, Smith & Nephew; 4-Pivot Medical; 7-Springer)

Background: Clinically, cam impingement is often seen in young active male individuals referred to an orthopedic surgeon because of groin pain, and internal rotation is usually found to be diminished. However, it remains unclear how often a cam-type deformity with a non-spherical femoral head and decreased head-neck offset can be found in the general population of young males. We therefore aimed to examine the prevalence of cam-type deformities in a population-based inception cohort study of young males.

Objective: To determine the prevalence of cam-type deformities on hip magnetic resonance imaging (MRI) in young males.

Methods: This was a population-based cross-sectional study in young asymptomatic male individuals who underwent clinical examination and completed a self-report questionnaire. A random sample of participants was invited for MRI of the hip. We graded the maximal offset at the femoral head-neck junction on radial sequences using grades from 0 to 3, where 0 = normal, 1 = possible, 2 = definite, and 3 = severe deformity. The prespecified main analyses were based on definite cam-type deformity grades 2 or 3. We estimated the prevalence of the cam-type deformity adjusted for the sampling process overall and according to the extent of internal rotation. Then we determined the location of the deformity on radial MRI sequences.

Results: A total of 1,080 subjects were included in the study and 244 asymptomatic males with a mean age of 19.9 years attended MRI. Sixty-seven definite cam-type deformities were detected. The adjusted overall prevalence was 24% (95% confidence interval [95% CI] 19--30%). The prevalence increased with decreasing internal rotation (P < 0.001 for trend). Among those with a clinically decreased internal rotation of < 30°, the estimated prevalence was 48% (95% CI 37--59%). Sixty-one of 67 cam-type deformities were located in an anterosuperior position.

Conclusion: Cam-type deformities can be found on MRI in every fourth young asymptomatic male individual and in every second male with decreased internal rotation. The majority of deformities are located in an anterosuperior position.

FAI Treatment - Labral Issues

Goal: Better define the influence of the labrum and identify labral treatment variables that may affect the outcome in FAI.

[Labral Repair, Refixation Improves Outcome], Martin Beck, MD Abstract

Martin Beck, MD, PD (3C-Mathys Ltd., Switzerland)

Labral tears can be classified by etiology (traumatic; degenerative; idiopathic; congenital) morphology (chondro-labral dissociation; intrasubstance, radial, fibrillated) location and by their stability (stable; unstable). Besides, the labrum often undergoes degenerative changes (intrasubstance degeneration, ossification, etc.). In rare situations an aplastic labrum can be observed already in early stages of life.

The variability of labral pathology makes it very difficult to assess the efficacy of surgical treatment.

Historical treatment of labral tears alone yielded good results in 46% to 80%, depending on the joint degeneration. Biomechanical studies showed the importance of the intact labrum for joint sealing and stress distribution and the potential disadvantage of removing the labrum. More recent studies, comparing debridement with preservation of the labrum, report about superior clinical and radiographic short term results in hips where the labrum was reattached.

Based on current knowledge, preservation of the labrum seems to be mandatory whenever possible.

[The Biomechanical Case for Labral Debridement], Ira Zaltz, MD Abstract

Ira Zaltz, MD (n)

The entire hip and acetabular labrum develop from mesenchymal tissue. The labrum covers proportionally more femoral head prenatally. In the mature hip the labrum extends the articulating surface and deepens the acetabulum. The labrum is composed primarily of radial oriented type II collagen fibers. In a normal acetabulum the labrum transmits very little weight. Its external surface is richly innervated with sensory nerve fibers, a finding that may be associated with labral proprioceptive function. The labrum is thought to seal the femoroacetabular joint allowing pressurization of interstitial fluid and decreasing stress within the articular cartilage. MRI and pathologic examination suggest age related degenerative changes are prevalent in the majority of humans.

Long-term studies on selective labral debridement suggest prolonged improvement in hip symptoms. Recent clinical follow-up data derived from patients who underwent open and arthroscopic acetabular rim resection suggest that labral repair is associated with superior clinical outcomes. There are currently no data supporting labral repair when the acetabular rim does not require modification. Significant circumstantial evidence suggests that undersurface labral resection preserves the majority of circumferentially oriented collagen fibers and that minor labral disruptions have negligible detrimental biomechanical effects upon the stability or strain measured within the labrum and acetabular cartilage.

At the present time available clinical and biomechanical data do not support repairing the labrum if the acetabulum is not structurally unstable and if resection preserves a rim of labral tissue.

[Labral Reconstruction: Is It Necessary?], Rafael Sierra, MD Abstract

J.A. Walker, MD (n), M.R. Pagnotto, MD (4-MAKO Surgical Corp., Bayer AG; 7-Mindworks Communications, A Wyanoke Group Company), R.T. Trousdale, MD (1,3B-DePuy, A Johnson & Johnson Company, Wright Medical Technology, Inc. ortho development, MAKO), R.J. Sierra, MD (1,2-Biomet; 5-Biomet, Stryker, DePuy, Zimmer; 9-Midamerica, AAHKS, Maurice Mueller Foundation)

Summary: The short term results of surgical hip dislocation and labral reconstruction reveal that 18/20 patients noticed improvement in their hip pain, with 2/21 hips progressing to total hip arthroplasty.

Introduction: The published results of both open and arthroscopic FAI surgery are better when the labrum is preserved rather than resected. When the labrum is absent, degenerated or is irreparable, reconstruction of the labrum may provide a better biomechanical environment for the hip joint and could lead to improved clinical outcomes. The objective of this study is to report the short term outcome of labral reconstruction in patients undergoing impingement surgery through a surgical hip dislocation (SHD).

Methods: 155 patients (178 hips) underwent SHD for FAI between 8/2002 and 2/2011. Twenty-one hips in twenty patients were identified as having a labral reconstruction at the time of SHD. All reconstructions were performed after January 2007. Indications for labral reconstruction were prior resection (3 hips), advanced labral degeneration (13 hips), and acetabular rim trimming requiring augmentation of native labrum (9 hips). Of the 21 hips, 16 were in females, and 5 in males with an average age at the time of surgery of 28.8 years (16-50). Clinical outcomes, including persistent pain, limp, need for additional surgery, and conversion to THA, were determined by review of clinical notes and patient questionnaires.

Results: The average time from the surgical procedure was 23.5 (3-50) months, with an average clinical follow-up of 12.5 (2-47) months. At latest follow-up 14 hips experienced no pain, mild pain was present in 5 hips, and significant pain was present in 2 hips (both converted to THA). Six patients were reported as walking with a limp at latest follow-up. In 19/21 hips, the patients were satisfied with the operation at latest follow-up. Two hips underwent lysis of adhesions in between the capsule and femoral head-neck junction. Eleven hips underwent trochanteric screw removal for symptomatic hardware. Two hips in 2 patients were converted to total hip arthroplasty at 13 and 18 months, both for continued hip pain and progression in hip arthritis. In both hips, significant chondral damage of the femoral head or acetabulum was noted at the time of SHD. There were no complications associated with the labral reconstruction itself. During the only arthroscopic procedure, as well as during both total hip arthroplasties, the graft was noticed to be healed to the acetabular rim and functioning as a pseudolabrum.

Conclusion: Acetabular labra found to be deficient, ossified, or irreparably torn may be reconstructed with ligamentum teres capitis or fascia lata autograft at the time of SHD. 19 of 21 hips had no or mild pain at last followup and there were no complications associated with the graft. It is unknown whether labral reconstruction will decrease the progression or prevent hip arthritis. Persistent symptoms and conversion to total hip arthroplasty after open offset procedure and labral reconstruction may be related to the degree of cartilage damage noted at surgery.

FAI Treatment - Cartilage Lesions - Current Practice and Future Directions

Goal: Define optimum treatment of hyaline cartilage/labral injury associated with FAI. Outline future treatment methods.

[Chondral Injury in FAI - Where and How Does It Occur?] William Jiranek, MD Abstract

Curtis Hayes, MD (3B-BioClinica, Inc., Pfizer, Inc.; 7-Up To Date), Kevin Hoover, MD (3B-BioClinica, Inc.), William Jiranek, MD (1,3B-DePuy; 5-Stryker; 8-OKO; 9-Lifenet Health)

The chondral damage that results from abnormal hip mechanics can be acute, chronic, or acute on chronic. The mechanism of chondral injury in the posterior medial section of the acetabulum and femoral head is similar between the 2 described types of femoroacetabular impingement. These two types differ in the vector forces in the anterior portion of the joint at the site of contact. In pincer impingement the predominant forces occur superior to the joint and induce a traction moment on the labrum and secondarily the articular cartilage on the edge of the socket, producing the delaminating lesions often described. In contradistinction, the anterior moment of cam impingement is more “train hitting wall” with a shearing moment induced on the anterior femoral head. In pincer impingement the cartilage matrix is often intact but separated from subchondral bone, whereas the adhesive wear of cam impingement usually removes all articular cartilage in the affected area.

This narrative will review existing data regarding inciting factors and progression of chondral injury.

[The Role of Microfracture], Bryan Kelly, MD Abstract

Bryan T. Kelly, MD (3C,4-A2 Surgical, Pivot Medical)

To date, there are no prospective trials that have looked at the efficacy of microfracture for treatment of focal chondral injuries in the hip. Nonetheless, a review of the literature suggests that the indications for microfracture of the hip are similar to the knee and include focal and contained lesions, typically less than 2 to 4 cm in size.

Other indications that have been applied to the knee and may be considered for chondral injuries in the hip include full thickness loss of articular cartilage in weight-bearing areas and unstable cartilage flaps overlying intact subchondral bone. Other considerations for performing the procedure include patient age, activity level, and the ability to comply with the postoperative rehabilitation protocol. Microfracture in the hip is most commonly performed in cases of cam impingement where there is associated focal chondral damage on the acetabular side due to transition zone delamination. It has been less commonly used for chondral defects on the femoral head.

The same technical considerations for microfracture of the knee should be applied to microfracture in the hip including: debridement of all remaining unstable cartilage from the exposed bone; meticulous preparation of the defect through the creation of a smooth, perpendicular, shouldered border; removal of the calcified cartilage layer; and maintenance of the subchondral plate. After preparation of the bed, angled arthroscopic awls are used to penetrate the microfracture holes deep to the subchondral bone.

Prospective literature on the efficacy of microfracture techniques for the treatment of focal chondral defects in the hip compared to alternative treatment options are currently unavailable in the literature, so recommendations regarding the use of this technique are currently based upon extrapolation of data from the knee literature.

[Cartilage Repair Improves Results], Michael Leunig, MD Abstract

Michael Leunig, MD (3B-Biomet, Smith & Nephew; -Pivot Medical; 7-Springer)

Background: Most secondary cartilaginous lesions in patients suffering from FAI are localized on the acetabular side and will be addressed during acetabular rim trimming. There are, however, cases where these lesions cannot be addressed by this procedure and which require specific treatment. Current surgical options include simple debridement, bone marrow stimulation techniques such as microfracture, cell-based techniques such as autologous chondrocyte implantation (ACI), tissue transplantation techniques such as the osteoarticular transfer system (OATS), or a combination with the use of scaffolds such as the matrix-induced autologous chondrocyte implantation (MACI) or autologous matrix-induced chondrogenesis (AMIC). AMIC was developed for the treatment of larger sized cartilage defects in the knee which were not suitable for ACI. Compared to other cell-based techniques, AMIC is a one stage procedure and less cost intensive. AMIC might be, therefore, of particular interest for the treatment of larger sized cartilage lesions in the hip.

Purposes: To determine if large focal chondral or osteochondral lesions in the hip can be successfully treated by the AMIC technique as assessed by MRI and clinical outcome.

Methods: Between 2009 and 2011, seven patients underwent surgical hip dislocation and AMIC for the treatment of large chondral or osteochondral defects of the femoral head or acetabulum (mean defect size 5.3 cm2). Five patients were prospectively followed-up for a mean of 15.5 months. Clinical and radiographic outcomes including MRI were determined.

Results: All five patients were subjectively improved. Hip flexion and internal rotation significantly increased from pre- to postoperative. The MRI analysis revealed remodeling of all lesions with moderate to complete filling of the defects and a resolved surrounding bone marrow edema.

Conclusions: AMIC appears to be a promising technique for the treatment of large chondral and osteochondral defects in the hip joint. However, longer follow-up investigations in larger patient cohorts are required to substantiate the present findings.

Childhood Hip Disease - SCFE

Goal: Define the natural history and optimum treatment of adolescents with SCFE.

[SCFE - Prevalence, Pathogenesis, Natural History], Michael Millis, MD Abstract

Michael B. Millis, MD (n)

Slipped capital femoral epiphysis(SCFE), a condition of the immature hip in which anatomic disruption occurs through the proximal femoral physis, is associated with highly variable degree of displacement between the proximal femoral neck and the epiphysis. In SCFE, there is a spectrum of each of the following elements: temporal acuity; physical stability of the slipping physis; amount of deformity that the protruding anterior metaphyseal prominence presents to the anterior acetabular cartilage in flexion.

Prevalence of SCFE varies widely among ethnic groups. Pathogenesis includes any factors which either reduce the resistance to shear or which increase the stresses across the proximal femoral physis: for example, hormonal changes of preadolescence, obesity, femoral or acetabular retroversion, and coxa profunda.

Natural history in past reports seemed largely dependent on both the degree of deformity and any complications of treatment, with most long-term studies showing some loss of function over time with all degrees of deformity. Contemporary analysis suggests FAI as the major pathomechanical element in SCFE-related dysfunction in both short and long terms.

[SCFE - In Situ Pinning Offers the Best Risk and Reward], Young-Jo Kim, MD, PhD Abstract

Young-Jo Kim, MD, PhD (5-Siemens)

Slipped capital femoral epiphysis leads to femoroacetabular impingement, which will eventually lead to osteoarthritis. Surgical correction of the impingement may be accomplished but there are associated risks, which include the risk of developing avascular necrosis. In situ pining is a low risk surgical procedure that stabilizes the slipping physis but does not correct the deformity. The risk/benefit analysis will depend on the relative risk of these two surgical approaches.

To date, long term follow-up data exists for the results of in situ pinning. The risk of developing osteoarthritis is dependent on the severity of the slip, i.e. more severe the slip, the higher the probability of osteoarthritis. The observation has been made that even in mild SCFE, significant damage can be present in the joint early on, hence the case for early realignment. The surgical observation and long term data are discordant. At present, without data showing an improved long term outcome with early realignment surgery and a low rate of iatrogenic avascular necrosis, evidence suggest in situ pinning is the best surgical treatment.

[SCFE - Anatomic Correction Is Best], Moritz Tannast, MD

Childhood Hip Disease - Perthes Sequelae

Goal: Define the pathoanatomy associated with Perthes and optimum treatment of associated femoral and acetabular deformities.

[Post-Perthes Morphology - Associated FAI and Dysplasia], Ernest Sink, MD Abstract

Ernest L. Sink, MD (3B-Pivot Medical)

Residual deformity secondary to Legg-Calvé-Perthes disease (LCPD) in a skeletally mature individual presents treatment challenges to the surgeon. Management is complex owing to significant pathomechanical concerns, notably co-existent femoroacetabular impingement and dysplasia, as well as the unique morphological characteristics of each hip.

In this paper we seek to describe the varied pathomechanics in LCPD, with consideration given to the characteristic aspherical femoral head, short femoral neck and large greater trochanter and the resultant impingement, poor cartilage quality, instability and incongruence of the joint. Second, we discuss indications for appropriate surgical management, the goal of which is correction of the residual hip deformity at maturity. Further, selection of femoral-sided procedures (relative neck lengthening, osteotomy and femoral head reduction) and acetabular-sided procedures (periacetabular and Shelf/Chiari osteotomies) is described in detail. Finally, we present a systematic review of the known outcomes of treatment, which reveals short-term pain reduction and functional improvement.

A comprehensive understanding of the symptomatic healed Perthes hip and the stepwise approach to its management are vital in correcting the complex femoral and acetabular deformities that contribute to impingement and instability in this population of patients. Long-term outcomes remain a fundamental concern, as patients with LCPD are at risk for severe osteoarthritis and poor clinical outcomes by the fourth and fifth decade.

[Correct the Femoral Pathomorphology], Klaus A. Siebenrock, MD

[When to Correct Associated Acetabular Dysplasia], John Clohisy, MD Abstract

John C. Clohisy, MD (3C-Biomet Manufacturing Corp.; 5-Zimmer, Inc.)

Residual Perthes-like hip deformities are complex disorders involving both the acetabulum and the proximal femur. This presentation will: 1) review the characteristic of Perthes-like hip deformities, 2) outline surgical treatment for residual Perthes-like hip deformities, and 3) present factors associated with the need for PAO when managing residual Perthes deformities. The acetabular anatomy in Perthes hips variably involves acetabular dysplasia with retroversion and insufficient femoral head coverage. Proximal femoral deformities are characterized by an aspheric femoral head, short neck, and high greater trochanter. Surgical treatment encompasses a surgical dislocation of the hip followed by intraoperative assessment of hip structure and stability. PAO is considered when the hip has 1) adequate range of motion, 2) maintained or improved congruency with functional radiographs, and 3) instability upon dynamic examination. If PAO is used, care should be taken to avoid overcorrection and secondary FAI.

Summary: Residual Perthes deformities are complex. These disorders can be managed effectively with surgical dislocation and PAO in carefully selected cases.

Is Hip Preservation an Emerging Orthopaedic Subspecialty?

Goal: Establish a strategy for defining the best individual care/provider models for treatment of adult/pediatric hip preservation surgery. Outline current and optimum training.

[Patient Outcomes Are Improved with a Dedicated Hip Preservation Service], Christopher L. Peters, MD Abstract

Christopher L. Peters, MD (1,2,3B-Biomet; 8-Journal of Arthroplasty; 9-AAOS Adult Reconstruction Subcommittee), Lucas Anderson, MD (n), Jill Erickson, PA-C (n), Stephen Aoki, MD (3B-Smith & Nephew; 5-Biomet, Musculoskeletal Transplant Foundation, Arthrex, Inc.; 9-American Orthopaedic Society for Sports Medicine)

Introduction: The field of hip preservation surgery has grown substantially over the past decade coincident with the recognition that most young adult hip problems are associated with altered hip morphology. Although open hip procedures such as surgical dislocation (SD) and periacetabular osteotomy (PAO) have proven efficacy, arthroscopic treatment has increasingly become an attractive alternative to open hip approaches. In an effort to circumvent the “either/or” approach, our center established a comprehensive service incorporating both arthroscopic and open hip surgery tailored to specific operative indications. The hypothesis was that the service would better address patient demand, define operative indications, and improve clinical outcome.

Materials and Methods: In 2008 hip arthroscopy was formally incorporated into the Hip Preservation Service. Indications for operative intervention included FAI, dysplasia, and prearthritic hip disease. All operative hip preservation cases were shown at a multidisciplinary indications conference. Clinical outcome was measured with the HHS, SF-36, Lower Extremity Function Score (LEFS), Rapid Assessment of Physical Activity Score (RAPA) and conversion to THA. The mean age of all patients was 28 years (range 13-59).

Results: From 2008-2010, 147 hip arthroscopy and 106 open procedures were performed (59 SD, 47 PAO). The HHS improved from 76 to 91 (p<0.05). The physical component of the SF-36 improved from 36.8 to 47.8, and the mental component from 49.9 to 50.1. The LEFS improved from 35.7 to 65.5. The RAPA improved from 3 to 6 (max 7). 11/253 hips (4%) have progressed to THA. Specific operative indications based upon the extent of abnormal hip morphology and chondrolabral damage have been developed and each case is discussed at a multidisciplinary conference.

Conclusion/Discussion: A comprehensive hip preservation service offering a variety of open and arthroscopic treatments tailored to specific operative indications is associated with improved clinical/functional outcome. The approach offers distinct advantages that include refining indications, optimizing surgical selection, maximizing clinical outcomes, and improving the educational model.

[Specialized Training in Open and Arthroscopic Techniques Is Essential], Ernest Sink, MD / Bryan Kelly, MD Abstract

Bryan T. Kelly, MD (3C,4-A2 Surgical, Pivot Medical)

While hip preservation surgery continues to be an area of rapid development, procedures such as periacetabular osteotomy, surgical hip dislocation, and arthroscopic impingement surgery can be very complex and time-consuming, and require a steep learning curve. As such, hip preservation surgeries may not lend themselves to the surgeon who only occasionally sees patients who meet the indications for such interventions.

So the question arises: who among us should perform these hip preservation surgeries, and is specialty training required?

Our belief is that general orthopaedic residency programs and even specialized fellowship training in Adult Hip Reconstruction, Pediatric Orthopaedics, Trauma Surgery, and Sports Medicine, do not provide enough of a comprehensive overview of the assessment and management of patients with these oftentimes subtle and complex injury patterns. The formation of specialized training fellowships and curriculum are critical to the safe and effective advancements in the field of hip preservation.

Without such specialized training and monitoring of the quality of procedures that are being performed by our peers, we are at risk of having a continued increase in poorly performed hip preservation surgeries that will ultimately lead to poor outcomes and compromise the integrity of the field.

[Strategies for Optimizing Outcome with a Single-Surgeon Approach], Ira Zaltz, MD Abstract

Ira Zaltz, MD (n)

The practice of hip preservation surgery requires significant basic knowledge of hip development, childhood hip disease, normal hip anatomy, cartilage biology, and pathomechanics. Proficiency in many types of open-surgical and arthroscopic procedures is necessary in order to provide the full spectrum of hip preservation care. Both open and arthroscopic procedures as well as basic understanding of hip mechanobiology continue to undergo significant evolution. There are potentially serious complications that are associated with open and arthroscopic hip procedures especially during early implementation. The learning curve for hip preservation procedures is not well defined and probably varies depending upon individual surgeon background and training. There is evidence that surgeon mentoring may facilitate learning these procedures and may minimize complications during the early learning curve.

[Multicenter Collaboration to Improve Hip Preservation Outcome-Based Research], John Clohisy, MD Abstract

John C. Clohisy, MD (3C-Biomet Manufacturing Corp.; 5-Zimmer, Inc.)

Over the past decade we have observed major expansion of the knowledge-base regarding FAI. In addition to new information, this has provided clinical and scientific data resulting in new controversies regarding the etiology, natural history, optimal treatment, clinical outcomes, and economic value of orthopaedic treatments. There is a major need to resolve these profound controversies.

To do so, we have developed a multicenter hip joint preservation study group. Academic Network of Conservational Hip Outcomes Research (ANCHOR) is focused on establishing large patient cohorts undergoing hip preservation treatment with timely reporting of clinical outcomes data. In this presentation we will review the structure of ANCHOR and our preliminary FAI cohort. This cohort encompasses over 900 hips. The average patient age is 27 years, more females than males and the average BMI is 25. FAI is associated with major hip dysfunction, activity limitation and reduced quality of life. Intraarticular degeneration (labrum and articular cartilage) is present in 96% of patients.

Future studies will focus on clinical outcomes of surgical treatment and identification of factors associated with success or failure of treatment. These studies will be accomplished in a timely manner as a result of the patient cohort size and uniform data collection.