Lucas A. Anderson

Acetabular Cartilage Delamination in Femoroacetabular Impingement: Risk Factors and Magnetic Resonance Imaging Diagnosis

BACKGROUND Delamination of acetabular articular cartilage is a common abnormality in hips with femoroacetabular impingement. The purpose of the present study was to identify clinical and radiographic factors predisposing to delamination and to assess the diagnostic accuracy of magnetic resonance arthrography for the detection of these lesions. METHODS Following a retrospective review of records, we determined that acetabular cartilage delamination had been present in twenty-eight of sixty-four hips that had undergone a surgical dislocation procedure for the treatment of femoroacetabular impingement. Multivariable logistic regression was performed to assess the correlation of radiographic findings (i.e., magnetic resonance imaging and computerized tomography findings) with the status of delamination. The preoperative interpretations of the magnetic resonance arthrograms for twenty-seven hips that underwent surgical dislocation were reviewed to assess the accuracy of detecting delamination. At the time of surgery, nine of these twenty-seven hips were found to have delamination. Magnetic resonance arthrography interpretations that did not correlate with operative findings were subjected to conspicuity assessment and error analysis. RESULTS The rate of delamination of the acetabular cartilage as noted at the time of surgical dislocation was 44% (twenty-eight of sixty-four). Delamination was strongly associated with male sex and femoral sided signs of impingement; however, it was not associated with acetabular overcoverage (center-edge angle, >40 degrees) (odds ratio = 0.16; p < 0.05). While there was no significant difference in the prevalence of labral lesions between groups, whenever labral and delamination lesions were found in the same hip, they were directly adjacent to one another. Preoperative magnetic resonance arthrography had a low sensitivity for delamination (22%) but had a high specificity (100%). Two-thirds of the delamination lesions were visible on retrospective review of these images when the reader was unblinded to the surgical findings. Delamination could most often be identified on the sagittal T1-weighted image and on the proton-density sequences with fat saturation. DISCUSSION There should be a high level of suspicion for articular cartilage delamination in men and in patients with primarily cam-type femoroacetabular impingement. Acetabular overcoverage may be protective against delamination. Preoperative high-quality magnetic resonance arthrograms should be carefully analyzed for evidence of delamination in this patient population.

Perioperative Closure-related Complication Rates and Cost Analysis of Barbed Suture for Closure in TKA

BackgroundThe use of barbed suture for surgical closure has been associated with lower operative times, equivalent wound complication rate, and comparable cosmesis scores in the plastic surgery literature. Similar studies would help determine whether this technology is associated with low complication rates and reduced operating times for orthopaedic closures.Questions/purposesWe compared a running barbed suture with an interrupted standard suture technique for layered closure in primary TKA to determine if the barbed suture would be associated with (1) shorter estimated closure times; (2) lower cost; and (3) similar closure-related perioperative complication rates.MethodsWe retrospectively compared two-layered closure techniques in primary TKA with either barbed or knotted sutures. The barbed group consisted of 104 primary TKAs closed with running barbed suture. The standard group consisted of 87 primary TKAs closed with interrupted suture. Cost analysis was based on cost of suture and operating room time. Clinical records were assessed for closure-related complications within the 6-week perioperative period.ResultsAverage estimated closure time was 2.3 minutes shorter with the use of barbed suture. The total closure cost was similar between the groups. The closure-related perioperative complication rates were similar between the groups.ConclusionsBarbed suture is associated with a slightly shorter estimated closure time, although this small difference is of questionable clinical importance. With similar overall cost and no difference in perioperative complications in primary TKA, this closure methodology has led to more widespread use at our institution.Level of EvidenceLevel III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Sequelae of Perthes Disease: Treatment with Surgical Hip Dislocation and Relative Femoral Neck Lengthening

Background Sequelae of Perthes disease commonly manifests as complex hip pathomorphology including coxa magna, coxa brevis, and acetabular dysplasia. These abnormalities contribute to femoroacetabular impingement and early osteoarthritis. This report describes our experience with correction of the proximal femoral deformity associated with Perthes disease through surgical dislocation, osteochondroplasty (SDO), trochanteric advancement, and treatment of intraarticular chondrolabral injury. Methods Between January 2003 and January 2009, 14 patients with Perthes disease (4 female and 10 male patients) with an average age of 19.6 years (range 14 to 28 y) were treated with SDO and trochanteric advancement. One patient had a subsequent staged periacetabular osteotomy to improve acetabular coverage. Patient histories, physical examinations, operative findings, and preoperative and postoperative radiographs were evaluated. Results Operative findings showed 6 acetabular cartilage lesions, 6 labral lesions, and 4 femoral osteochondritis dissecans (OCD) lesions treated with autografts. The mean of center-trochanteric distance improved from −20 mm to −1 mm. Approximately 4 of 14 hips deteriorated to Tönnis grade 1 and 1 of 14 hips deteriorated 2 Tönnis grades. The Harris hip scores improved from an average of 62 preoperatively (range 51 to 72) to 95 postoperatively (range 93 to 97) with OCD lesions versus 71 (range 65 to 76) to 88.6 (range 63 to 100) in the hips without OCD lesions. There was no statistically significant difference in the age, preoperative or postoperative HHSs between the OCD and non-OCD groups. The mean follow-up was 45 months. There were no major perioperative complications, and all the patients in both the groups have their native hip to date. Conclusions The typical adult sequelae of Perthes disease predispose the hip to the development of chondrolabral injury and poor clinical function. Treatment with SDO and trochanteric advancement reduces impingement, improves hip biomechanics, and allows the treatment of intraarticular pathology. This approach is associated with clinical improvement without major perioperative complications. In addition, we have found a high rate of OCD lesions of the femoral head in Perthes hips undergoing surgical dislocation. Osteochondral autograft transfer from the resected femoral head-neck junction been found in the 4 patients treated thus far to be safe and effective with comparable clinical and radiographic outcomes to those hips without OCD lesions. Level of Evidence Level IV (Case series).

Hip-preserving surgery: understanding complex pathomorphology.

Recent evidence suggests that abnormal hip morphology may be the primary cause of osteoarthritis of the hip in young adults1-5. Hip pathomorphology is manifested as acetabular deficiency or malorientation, or as femoral deformity or malorientation, and most commonly as a combination of these problems6,7. Contemporary surgical intervention for hip preservation has been directed toward correction of these malformations and associated chondrolabral injuries and has shown promise as a way of alleviating hip pain and possibly retarding the progression of osteoarthritis8,9. With the increasing number of available surgical methodologies (e.g., surgical dislocation, osteochondroplasty, hip arthroscopy, and redirectional acetabular osteotomy) that are directed at hip preservation, the importance of understanding the pathologic process that results in a painful hip has become paramount. In an effort to augment the basic information obtained from clinical examination, two-dimensional plain radiography, and magnetic resonance arthrography, we have utilized a validated three-dimensional modeling protocol to serve as a diagnostic and surgical planning tool for hip-preservation surgery. Three-dimensional modeling has helped to emphasize the complex pathomorphology that is evident in patients with hip dysplasia and femoroacetabular impingement and may have a future role in the classification and treatment of hip maladies in young adults. The goals of this study were to describe the typical presentation of the young adult with a painful hip and to offer corresponding case examples of the common morphologic abnormalities of the femur and acetabulum. The case examples illustrate the value of a comprehensive imaging protocol to facilitate diagnosis and management of patients who have complex femoroacetabular impingement and dysplasia. In addition, we describe our experience with three-dimensional computational model development as a function of a subset of work focused on the biomechanics of the dysplastic hip, and we outline future streams …

Center Edge Angle Measurement for Hip Preservation Surgery: Technique and Caveats

Anterior and lateral center edge angles have traditionally been used to determine acetabular coverage, and thereby strongly influence the decision to perform acetabular reorientation versus osteochondroplasty in patients with dysplasia and/or femoroacetabular impingement. We propose templating the center of the contained articular femoral head in aspherical hips to provide reliable assessment of acetabular coverage. Digital radiographs of 30 patients with various combinations of femoral and acetabular morphologies were evaluated using 2 methods to identify the anterior center edge angle and lateral center edge angle. The control method used an estimated femoral head center for angle apex. The study technique determined the center of the femoral head by templating the congruent aspect of the femoral head contained by the acetabulum while ignoring the increasing lateral and anterior radius associated with cam deformities. Four readers measured lateral center edge angles on anteroposterior radiographs and anterior center edge angles on false-profile radiographs. Two reads were performed by each reader using both the estimated and the templated methods for a total of 4 reads. Interobserver reliability using the proposed method compared to the standard was much improved for anterior center edge angles (intraclass correlation coefficient of 0.76 vs 0.55) as well as with lateral center edge angles (ICC of 0.80 vs 0.42). Decreased correlation was most commonly associated with abnormal sourcil morphology, posterior wall deficiency combined with calcified labra, and os acetabuli. Including the anterolateral cam deformity in identifying the center of the femoral head for measuring center edge angles leads to an underestimation of acetabular coverage, which may negatively affect hip preservation surgical decision making.

Coxa Profunda: Is the Deep Acetabulum Overcovered?

BackgroundCoxa profunda, or a deep acetabular socket, is often used to diagnose pincer femoroacetabular impingement (FAI). Radiographically, coxa profunda is the finding of an acetabular fossa medial to the ilioischial line. However, the relative position of the acetabular fossa to the pelvis may not be indicative of acetabular coverage.Questions/purposesWe therefore determined the incidence of coxa profunda and evaluated associations between coxa profunda and other radiographic parameters of acetabular coverage commonly used to diagnose pincer FAI and acetabular dysplasia.MethodsWe evaluated the radiographs of three cohorts for coxa profunda, lateral center edge (LCE) angle, acetabular index, posterior wall sign, and crossover sign. Data from 67 collegiate football players were collected prospectively (Cohort 1). We identified two patient cohorts through retrospective review of all 179 hips undergoing hip preservation surgery from 2002 to 2008 (83 periacetabular osteotomies [Cohort 2] and 96 surgical dislocation and osteochondroplasties [Cohort 3]).ResultsIn all three cohorts, we detected no difference in the LCE angle or acetabular index between hips with and without coxa profunda. Coxa profunda existed in hips representing the spectrum of acetabular coverage measured by LCE angle (−18° to 60°) and acetabular orientation determined by the crossover sign.ConclusionsCoxa profunda was a common radiographic finding in both symptomatic patients and asymptomatic football players. Coxa profunda existed in hips representing the spectrum of acetabular coverage and was not associated with an overcovered acetabulum. We conclude coxa profunda is unrelated to overcoverage and suggest its use in diagnosis of pincer FAI be abandoned in favor of other determinants of focal or general overcoverage.Level of EvidenceLevel III, diagnostic study. See Instructions for Authors for a complete description of levels of evidence.

An algorithmic approach to surgical decision making in acetabular retroversion.

The optimum treatment for the young adult patient with symptomatic femoroacetabular impingement due predominately to acetabular retroversion remains unknown. The retroversion deformity can be associated with a volumetrically deficient or sufficient acetabulum based on the adequacy of lateral and posterior coverage. We prospectively collected clinical data from 2001 to 2006 on 60 hips with symptomatic femoroacetabular impingement that had radiographic evidence of acetabular retroversion defined as a crossover sign on an adequate anteroposterior radiograph or retroversion on magnetic resonance imaging or computed tomography. Our treatment algorithm for acetabular retroversion used measurements of acetabular coverage (lateral center edge angle and the posterior wall sign) and condition of acetabular cartilage to direct treatment of acetabular retroversion. The algorithm directed the surgeon to perform a periacetabular osteotomy in 30 hips and a surgical dislocation and osteochondroplasty of the femoral head-neck junction and acetabular rim in 30 hips. Harris Hip Score improved from 52 to 90 in the hips treated with surgical dislocation and osteochondroplasty and 72 to 91 in the hips treated with periacetabular osteotomy, with an overall survivorship of 96% at 4 years. Patient follow-up averaged 46 months (range, 24-75 months). Elimination of the crossover sign and correction of the posterior wall sign occurred in >90% of all patients when present. The results indicate that hips with acetabular retroversion, deficient posterior and/or lateral acetabular coverage, and intact hyaline cartilage can be effectively treated with acetabular reorientation, while retroverted hips with anterior overcoverage but sufficient posterior coverage are effectively treated with osteochondroplasty of the acetabulum and proximal femur.

Barbed Versus Standard Sutures for Closure in Total Knee Arthroplasty: A Multicenter Prospective Randomized Trial

Barbed suture has been associated with improved closure efficiency and safety in TKA in prior studies. We performed a multicenter randomized controlled trial to determine the efficiency and safety of this technology in TKA. We prospectively randomized 411 patients undergoing primary TKA to either barbed running (n=191) or knotted interrupted suture closure (n=203). Closure time was measured intra-operatively. Cost analysis was based on suture and OR time costs. Closure time was shorter with barbed suture (9.8 vs. 14.5 min, p<0.001). Total closure cost was less with barbed suture (

Correlation between radiographic measures of acetabular morphology with 3D femoral head coverage in patients with acetabular retroversion

324 vs.

Biomechanical Analysis of Acetabular Revision Constructs: Is Pelvic Discontinuity Best Treated With Bicolumnar or Traditional Unicolumnar Fixation?

419, p<0.001). Early complications and outcomes were similar between groups. The use of barbed suture in TKA is associated with shorter closure time, lower cost and similar outcomes and complications when compared with standard sutures.