Acetabular Cartilage Delamination Research Articles

Acetabular cartilage delamination: performance of MRI using arthroscopy as the standard of reference.

Femoroacetabular impingement (FAI) frequently leads to acetabular chondral delamination. Early identification and treatment of these cases is crucial to prevent further damage to the hip. To evaluate the accuracy of morphological signs of cartilage acetabular delamination in non-arthrographic magnetic resonance imaging (MRI) using intra-articular arthroscopic findings in patients undergoing FAI surgery. All hip MRI scans were assessed individually by three independent radiologists. Images were assessed for signs of delamination including the presence of a linear area of bright signal intensity along the acetabular subchondral bone and an area of darker tissue at the surface of the acetabular cartilage. All FAI patients underwent surgery; arthroscopy served as the standard of reference. The mean age of participants was 36.1±10.9 years with 36 (48.6%) women. In the FAI group, arthroscopic surgery showed acetabular chondral delamination in 37 hips. In all hips (including the controls), MRI signs of acetabular cartilage delamination showed an average sensitivity across the three raters of 73.0% with a specificity of 71.0%. In a separate analysis of only the FAI patients, a slightly higher sensitivity (77.7%) but lower specificity (66.7%) was demonstrated. The interrater reliability showed a moderate agreement (average [k]) across the raters (0.450). Performance of non-arthrographic MRI in diagnosing acetabular chondral delamination showed good results, yet inter-observer reproducibility among different radiologists was only moderate. Our results suggest that an increased level of awareness, for signs of delamination using MRI, will be helpful for detecting chondral delamination in patients with a history of FAI.

Acetabular Cartilage Delamination in Femoroacetabular Impingement: The Underdiagnosis on MRA, Risk Factors and Radiologic Predictors

Objectives:Cartilage delamination (CD) is reported to be a very common (31.5%-75%) pathology in patients undergoing surgery for femoroacetabular impingement (FAI). Treatment options vary depending ...

Acetabular Cartilage Delamination in Femoroacetabular Impingement: The Underdiagnosis on MRA, Risk Factors and Radiologic Factors

Objectives:Cartilage delamination (CD) is reported to be a very common (31.5%-75%) pathology in patients undergoing surgery for femoroacetabular impingement (FAI). Treatment options vary depending on size and location of the CD and are very limited in patients with advanced CD. Therefore, it is necessary to diagnose CD pre-operatively to plan for surgical treatment. Magnetic resonance arthrography (MRA) is cited in the literature as the standard diagnostic tool of this pathology, but there are discrepancies in the literature as to the effectiveness of this diagnostic tool, with a variety of reported sensitivities and specificities. The objective of this study is to [1] to assess the frequency, size and location of acetabular CD in our FAI population, [2] to assess the sensitivity, specificity, negative prognostic value (NPV), and positive prognostic value (PPV) of the MRA, and [3] to determine risk factors and radiologic predictors for CD.Methods:This study is a single centre, retrospective review of 200 patients who previously underwent FAI surgery. Two trained assessors reviewed and reported on all surgical videos, clinical notes, x-rays and MRA images and reports. The presence of CD indicated on the MRA report was compared with the presence of CD reported intra-operatively. If CD was found during the operation, the size and location of the CD were measured. Multivariable logistic regression was used to check for correlations between CD and risk factors such as gender, side, age, BMI, length of symptoms before operation, as well as, radiologic factors, over-coverage of the femoral head, hip retroversion, acetabular and impingement cysts, presence and severity of osteoarthritis (OA), alpha angle, anatomy of the labrum and labral tear characteristics.Results:The patient population studied was 52.5% male and 47.5% female, with an overall mean age of 37.6 years. The average time period between the MRA and the surgical intervention was 0.88 years. 59% of men and 45.3% of women were reported to have CD at the time of surgery, for an overall 47.5% of the patient population. There was no significant difference between the mean age of patients with CD (36.8 years) and that of patients without CD (38.3 years). The mean size of the CD defects were 3.12 cm2 with mean shape, measured from the acetabular rim x sagittal extent, 0.6cm x 4.36cm. Most of the cartilage damage was located in the antero-superior quadrant. The MRA had an extremely low sensitivity of 4.11%, with a high specificity 97.40%. The NPV and PPV were calculated to be 68.18% and 42.86%, respectively.Conclusion:CD in patients with FAI is severely under-diagnosed with MRA. There is need for better standard diagnostic criteria to detect CD on MRA. Reliable prognostic clinical and radiological factors could contribute to the improved diagnosis and surgical planning, organizing adequately the intraoperative treatment options and informing and consenting properly the patient in order the operation to meet his expectations.

Results of arthroscopic treatment of chondral delamination in femoroacetabular impingement with bone marrow stimulation and BST-CarGel®.

Objectives: The purpose of this study is to show the preliminary results of using chitosan-based scaffold (BST-CarGel®) with microfracture for treatment of acetabular chondral delamination associated with femoroacetabular impingement. Methods: A prospective study was performed on 13 hips. Patients were selected in the age group between 18 and 50 years. Patients with delamination of acetabular cartilage associated with femoroacetabular impingement received arthroscopic debridement and microfracture technique. Then cases with defect > 2 cm2 were considered for the application of BST-CarGel® and included in the study. Also, reattachment of the torn labrum and resection of the cam deformity were performed according to the case. For evaluation of the functional outcome, the patients had completed the hip outcome score (HOS) pre- and post-operatively. For evaluation of the regeneration of the cartilage, delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) was used and the percentage of defect filling and type of cartilage studied. Results: Patients had a mean age of 41 years, with moderate to high level of activity (mean Tegner scale 7). The mean size of the chondral defect after debridement was 3.7 cm2. The mean HOS for daily live activities has been improved from 64.4 to 87.4 and for sports subscale from 35.2 to 75.2, which is statistically highly significant. All patients had > 90% of filling of chondral defect. Conclusion: The use of BST-CarGel® with microfracture for treatment of acetabular chondral delamination associated with femoroacetabular impingement can improve the functional outcome at two years, with a complete restoration of the cartilage defect in magnetic resonance images (MRI) with specific cartilage sequences.

The shape of the hip joint as a risk factor for osteoarthritis

Purpose: Cam-type femoroacetabular impingement characterized by extra bone formation at the anterolateral head-neck junction of the hip creates a non-spherical femoral head, known as a cam deformity. The cam deformity is forced into the acetabulum during flexion and internal rotation of the hip, leading to structural damage as acetabular labrum tears and cartilage delamination. This damage might gradually lead to osteoarthritis. Cam deformity and subtle acetabular dysplasia are recently recognized as relevant risk factors for hip osteoarthritis (HOA). In subtle acetabular dysplasia, the femoral head has contact with a small area of the shallowacetabulum. Therefore, more focal stress is put on this small area, which provides insufficient coverage for the femur. Cumulative articular surface contact stress above a critical threshold in dysplastic joints causes joint degeneration. However, the influence of these deformities on HOA incidence compared with other risk factors including age, gender, and body mass index (BMI) and the effect modification of other known determinants on these associations are not yet known. Methods: Participants of Rotterdam Study (RS-I: n = 2960, RS-II: n = 1470) including men and women aged >55 years with a Kellgren and Lawrence (K/L) grade ≥1 at baseline and mean follow-up of 9.2 years were included in the study. Incident radiographic HOA was defined as a K/L grade of ≥2 or a total joint replacement at follow-up. The shape of the proximal femur and the acetabulumwere outlined by a set of points (23 points, Figure 1) that were positioned on pre-defined anatomical landmarks on the anteroposterior pelvic radiographs using statistical shape modeling software. Using this point set, alpha and center-edge (CE) angles, parameters that quantify these deformities were calculated. Acetabular dysplasia and cam deformity were defined as the presence of a CE angle 60°, respectively (Figure 1). Using generalized estimating equation models, odds ratios were calculated to assess the associations between both hip deformities and the development of HOA. Results: At the follow-up times, 234 and 179 cases of HOAwere identified for RS-I and RS-II, respectively. Incident OA was defined in 281 hips within RS-I among that 12.2% (n = 34) had cam deformity and 8.3% (n = 23) had acetabular dysplasia, while out of 218 hips with incident OA in RS-II,16.1% (n = 35) had cam deformity and 7.3% (n = 16) had dysplasia. In pooled data analyses (Table 1), individuals with cam deformity had a two-fold increased risk for developing osteoarthritis (OR = 2.0, 95% CI= 1.48-2.71, p = 0.00001) compared with individuals without cam deformity. Moreover, subtle acetabular dysplasia was significantly associated with increased risk of HOA (OR = 1.96, 95% CI = 1.35-2.84, p = 0.0004). Both associations were independent of known risk factors of HOA such as age, sex, and BMI and were only significantly associated with development of OA in younger individuals. These bony deformities were independently related to the outcomewhen included in the samemodel (camdeformity: OR (95% CI) = 2.03 (1.50-2.76), hip dysplasia: OR (95% CI) = 2.03 (1.41-2.92)). The results were almost consistent in both cohorts. Conclusions: Individuals with cam deformity and acetabular dysplasia are strongly predisposed to progression to HOA independently from other well known risk factors of age, sex, and BMI. Interestingly, both deformities were only predisposing to OA in relatively young individuals. Therefore, early identification of these conditions is important and might provide an opportunity to prevent hip osteoarthritis. (Figure Presented).

Surgical Hip Dislocation is Safe and Effective Following Acute Traumatic Hip Instability in the Adolescent.

A traumatic hip dislocation in the pediatric patient is a rare but potentially catastrophic injury. The purpose of this study was to review our early clinical results and radiographic morphology of hips treated with a surgical hip dislocation (SHD) approach for intra-articular hip pathology resulting from traumatic instability in pediatric and adolescent patients. This is a retrospective analysis of a consecutive series of patients presenting with nonconcentric reduction after traumatic hip instability. All patients were treated with a transtrochanteric SHD with concomitant procedures based on intra-articular findings. Radiographic evaluations and Harris Hip Scores were completed at final follow-up. Eleven male patients, mean age of 12.3 years (range, 9.3 to 16.1 y) and mean body mass index 19.6 kg/m (range, 15.4 to 28.0 kg/m). Intraoperative findings included: labral tear (8), femoral cartilage injury (5), acetabular rim fracture (4), acetabular cartilage delamination (3), loose body (2), and femoral head osteochondral fracture (1). Postoperatively, 1 patient developed a transient peroneal nerve palsy. At a mean 24.5 months (range, 12.0 to 48.1 mo) postoperatively, no hips have radiographic evidence of osteonecrosis. The mean lateral center edge angle was 20 degrees (range, 9 to 38 degrees) with 6 hips of <20 degrees; mean acetabular index 9 degrees (range, -2 to 23 degrees) with 5 hips of >10 degrees; mean α-angle 56 degrees (range, 48 to 62 degrees) with 6 hips of >55 degrees; mean acetabular version 12 degrees (range, 8 to 16 degrees) with 8 hips of <15 degrees. At 1-year follow-up, the mean Harris Hip Score was 95.8 (range, 84.7 to 100). Early results suggest that SHD is a safe approach to treat an incomplete reduction following posterior hip instability and is effective for identification and treatment of acute intra-articular pathology. Acetabular dysplasia, relative acetabular retroversion, and/or decreased femoral offset may be risk factors for posterior hip instability in adolescents. Level IV.

Femoroacetabular impingement: Association between the overcoverage and acetabular cartilage delamination areas

BackgroundFemoroacetabular impingement (FAI) is a clinical syndrome relatively recently recognised as source of hip mechanic pain and early osteoarthritis. Two types of FAI have been described, based on the bone morphology and pattern of chondral and labral damage; the cam type is frequently associated with chondral delamination; and the pincer type is associated with a contre-coup injury of the posteroinferior acetabulum. A close relationship between the zone of acetabular overcoverage or retroversion and the area of acetabular chondral delamination has been observed. ObjectiveTo evaluate the relationship between the acetabular overcoverage or retroversion zone, and the cartilage delamination area; and whether by treating the overcoverage zone, the cartilage delamination area itself is also treated. MethodsA prospective evaluation was conducted for 16 patients (17 hips) with FAI and chondral delamination treated with acetabular trimming and labral reinsertion, and femoral bump resection. ResultsAll the cases had chondral delamination in the anterosuperior acetabular area, corresponding to the overcoverage or retroversion zone. In the 16 patients (94% of the hips) after the acetabular overcoverage bone resection, the remaining cartilage was stable and without delamination. Only one case (6%) required microfractures to treat the exposed subchondral bone after delaminated cartilage debridement. ConclusionThe acetabular chondral delamination area has a very close relationship with the acetabular overcoverage zone, meaning that the delamination area can be treated by trimming the overcoverage zone.

Can the Alpha Angle Assessment of Cam Impingement Predict Acetabular Cartilage Delamination?

Substantial acetabular cartilage damage is commonly present in patients suffering from femoral acetabular impingement (FAI). A better understanding of which patient is at risk of developing substantial cartilage damage is critical for establishing appropriate treatment guidelines. We asked: (1) Does the cam deformity severity in FAI as assessed by alpha angle predict acetabular cartilage delamination? And (2) what are the clinical and radiographic findings in patients with acetabular cartilage delamination? One hundred sixty-seven patients (129 males, 38 females) with a mean age of 38 years (range, 17-59 years) underwent joint preservation surgery for cam-type FAI. All data were collected prospectively. We assessed center-edge angle and Tönnis grade on AP radiographs and alpha angle on specialized lateral radiographs. Acetabular cartilage damage was assessed intraoperatively using the classification of Beck et al., with Type 3 and greater qualifying as delamination. For all hips, mean alpha angle was 65.5° (range, 41°-90°), and mean center-edge angle was 33.3° (range, 21°-52.5°). Patients with an alpha angle of 65° or greater had an odds ratio (OR) of 4.00 (95% CI, 1.26-12.71) of having Type 3 or greater damage. Increased age (OR, 1.04; 95% CI, 1.01-1.07) and male sex (OR, 2.24; 95% CI, 1.09-4.62) were associated with Type 3 or greater damage, while this was the opposite for acetabular coverage as assessed by center-edge angle (OR, 0.94; 95% CI, 0.89-0.99). Patients with cam-type FAI and an alpha angle of 65° or more are at increased risk of substantial cartilage damage while increasing acetabular coverage appears to have a protective effect. Level III, prognostic study. See the Instructions for Authors for a complete description of levels of evidence.

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

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

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

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

MR Arthrography of Acetabular Cartilage Delamination in Femoroacetabular Cam Impingement

MR Arthrography of Acetabular Cartilage Delamination in Femoroacetabular Cam Impingement

Open Treatment of Femoroacetabular Impingement is Associated with Clinical Improvement and Low Complication Rate at Short-term Followup

Since the modern description of femoroacetabular impingement (FAI) a decade ago, surgical treatment has become increasingly common. Although the ability of open treatment of FAI to relieve pain and improve function has been demonstrated in a number of retrospective studies, questions remain regarding predictability of clinical outcome, the factors associated with clinical failure, and the complications associated with treatment. We therefore described the change in clinical pain and function after open treatment, determined whether failure of treatment and progression of osteoarthritis was associated with Outerbridge Grade IV hyaline cartilage injury, and described the associated complications. We retrospectively reviewed all 94 patients (96 hips) (55 males and 39 females; mean age, 28 years) who underwent surgical dislocation for femoroacetabular impingement between 2000 and 2008. Seventy-two of the 96 hips had acetabular articular cartilage lesions treated with a variety of methods, most commonly resection of damaged hyaline cartilage and labral advancement. Patients were followed for a minimum of 18 months (mean, 26 months; range, 18-96 months). Mean Harris hip scores improved from 67 to 91 at final followup. Six of the 96 hips (6%) were converted to arthroplasty or had worse Harris hip score after surgical recovery. Four of these six had Outerbridge Grade IV acetabular cartilage lesions and two had Legg-Calvé-Perthes disease or slipped capital epiphysis deformities. Two hips (2%) had refixation of the greater trochanter. At short-term followup, open treatment for femoroacetabular impingement in hips without substantial acetabular hyaline cartilage damage reduced pain and improved function with a low complication rate. Treatment of Outerbridge Grade IV acetabular cartilage delamination remains the major challenge. Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Arthroscopic Repair of Delaminated Acetabular Articular Cartilage in Femoroacetabular Impingement

Lesions to articular cartilage can be difficult to treat and directly impact surgical outcome in hip arthroscopy. This article describes a direct cartilage suture repair technique for a young, active individual with full-thickness acetabular cartilage delamination. Lesions of this type are commonly seen with femoroacetabular impingement. A 17-year-old boy presented with bilateral hip pain greater in the right than left. Arthroscopic intervention for the right hip included direct cartilage repair for the cartilage lesion, osteoplasty for femoroacetabular impingement, repair for an anterior labral tear, capsular plication for iliofemoral ligament laxity, and psoas lengthening. Twelve weeks postoperatively, a standard capsular plication, osteoplasty, and chondroplasty were performed on the left hip. At follow-up, the patient reported feeling 95% normal. He noted that the right and left hips were essentially the same. Symptoms consisted of stiffness after prolonged sitting and mild pain following sports. The patient reported being pain free 90% of the time, with pain 2/10 at worst. He scored a 96 on the modified Harris Hip Score, 93 on the Hip Outcome Score Activities of Daily Living subscale, and 81 on the Hip Outcome Score Sports subscale. Overall, the patient was satisfied with the outcome. The direct cartilage repair, in addition to osteoplasty, anterior superior labral repair, iliofemoral capsular plication, and psoas lengthening, produced an excellent outcome in this young, active patient.

Acetabular Cartilage Delamination in Femoroacetabular Impingement

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. 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. 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. 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.

Magnetic Resonance Imaging with Gadolinium Arthrography to Assess Acetabular Cartilage Delamination

Recent reports have demonstrated magnetic resonance imaging (MRI) as a promising technique in detecting articular cartilage lesions of the hip joint. The purpose of our study was to evaluate the diagnostic performance of MRI with gadolinium arthrography in detecting acetabular cartilage delamination in patients with pre-arthritic hip pain. 46 patients (48 hips) underwent surgical dislocation of the hip. Mean age was 38.8 (range 17-56). There were 26 males and 20 females. All patients had Magnetic Resonance Imaging with gadolinium arthrography (MRA) before undergoing open hip surgery where the acetabular cartilage was inspected. Acetabular cartilage delamination on MRA was seen on sagittal images as a linear intra-articular filling defect of low signal intensity >1mm in thickness on T1 weighted images and surrounded by contrast. On MRA all hips had a labral tear confirmed at surgery. At surgery 30 hips had evidence of acetabular cartilage delamination, 4 hips had ulceration and 14 had no articular cartilage damage. The majority of labral tears and cartilage damage were located in the antero-superior quadrant. The sensitivity and specificity of MRA detection of cartilage delamination confirmed at surgery were 97% and 84%, respectively. The positive and negative predictive values of the MRA finding were 90% and 94%, respectively. The presence of the acetabular cartilage delamination represents an early stage of articular cartilage degeneration. When evaluating a young adult with hip pain, labral tears in association with cartilage delamination should be considered. MRA represents an effective diagnostic tool.

Delamination Cysts: A Predictor of Acetabular Cartilage Delamination in Hips with a Labral Tear

The treatment and prognosis of labral tears of the hip depend primarily on whether there is concomitant injury of the adjacent acetabular articular cartilage. We asked whether a delamination cyst on the preoperative plain radiographs correlated with delamination of the acetabular articular cartilage at the time of hip arthroscopy. We reviewed the preoperative radiographs of 125 consecutive hips that had a labral tear at hip arthroscopy for the presence of a delamination cyst. A delamination cyst was defined as an acetabular subchondral cyst either directly adjacent to a lateral acetabular cyst or in relation to a subchondral crack in the anterosuperior portion of the acetabulum. All patients with acetabular cartilage delamination at arthroscopy were identified. There were 16 patients with delamination cysts on radiographs and 15 patients with cartilage delamination at arthroscopy. A delamination cyst on the preoperative anteroposterior and/or frog lateral radiographs of the hip accurately predicted acetabular cartilage delamination, especially in hips with labral tears not caused by a major trauma. A delamination cyst is a previously unrecognized and novel radiographic sign that can preoperatively identify acetabular cartilage delamination in patients with labral tears, thereby facilitating the selection of the appropriate surgery and determining prognosis. Level II, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

MR Arthrography of Acetabular Cartilage Delamination in Femoroacetabular Cam Impingement1

To retrospectively assess the frequency and performance of magnetic resonance (MR) arthrography to help diagnose acetabular cartilage delamination in femoroacetabular impingement (FAI). Institutional review board approval and informed consent were waived for this retrospective study. Forty-four consecutive patients with FAI of the cam type were included (mean age, 30.7 years; range, 16-49 years), including 30 men (mean age, 30.5 years; range, 16-49 years) and 14 women (mean age, 31.4 years; range, 18-48 years). The inclusion criteria were no previous surgery, surgery within 3 months after MR imaging, and availability of a detailed surgical report with acetabular cartilage findings. MR arthrographic findings were assessed independently by two blinded readers. Findings at surgery served as reference standard. Sensitivity, specificity, accuracy, and kappa statistics for interobserver agreement were calculated. At surgery, acetabular cartilage delamination was seen in 23 (52%) of 44 patients (mean size of cartilage flap from acetabular rim, 7.6 mm; range, 2-30 mm). At MR, patients with fluid signal intensity under the cartilage delamination had a respective sensitivity, specificity, and accuracy of 22%, 95%, and 57% for reader 1 and 30%, 95%, and 61% for reader 2. A hypointense line in the acetabular cartilage on sagittal three-dimensional double-echo steady-state images with water excitation demonstrated moderate diagnostic performance (respective sensitivity, specificity, and accuracy were 70%, 57%, and 64% for reader 1 and 70%, 62%, and 66% for reader 2). Hypointense areas in the acetabular cartilage were quite specific on both coronal intermediate-weighted fat-saturated images (respective sensitivity, specificity, and accuracy were 52%, 90%, and 70% for reader 1 and 74%, 90%, and 82% for reader 2) and coronal T1-weighted images (respective sensitivity, specificity, and accuracy were 35%, 90%, and 61% for reader 1 and 61%, 95%, and 77% for reader 2). Cartilage delamination is common in patients undergoing surgery for FAI. Fluid under the cartilage delamination is a specific but rare finding. Hypointense areas in the acetabular cartilage seen on intermediate-weighted fat-saturated or T1-weighted images appear to be helpful diagnostic criteria.

Femoroacetabular Impingement: Early Results of Arthroscopic Management (SS-57)

The treatment of Femoroacetabular impingement (FAI) has thus far been documented extensively only with an extensile open approach. In the last few years, the treatment has been expanded to include arthroscopic management in selected cases. In this study, a series of 24 patients with a diagnosis of FAI were treated arthroscopically and reviewed retrospectively. Patients were identified retrospectively after having completed a non-athritic hip score (NAHS) and a WOMAC scale prospectively. The average age of the 24 patients was 36 years (range 21-54). There were 18 men and 6 women in the study. The average follow-up was 16 months (range 8- 22). Radiographs were assessed for evidence of femoral or acetabular impingement as well as degenerative changes via the Tnnis classification. The average preoperative WOMAC and NAHS were 63 and 75, respectively. At six months follow-up the average scores were 97 and 95, respectively. 19 patients with evidence of FAI and Tonnis grade I degenerative disease did substantially better than the 5 who had more advanced grades. In 17 patients there anterosuperior acetabular cartilage delamination lesions. There were no surgical complications noted in the group and no development of avascular necrosis. It appears that the arthroscopic management of patients with clinically evident FAI is certainly reasonable and provides good early results. Whether the outcomes will delay the onset of osteoarthritic changes or provide long-lasting relief of symptoms is the subject of further study.