Magnetic resonance imaging of hip joint cartilage and labrum

Management of chondral and osteochondral lesions of the hip : A comprehensive review

Chondral and osteochondral lesions encompass several acute or chronic defects of the articular cartilage and/or subchondral bone. These lesions can result from several different diseases and injuries, including osteochondritis dissecans, osteochondral defects, osteochondral fractures, subchondral bone osteonecrosis, and insufficiency fractures. As the cartilage has a low capacity for regeneration and self-repair, these lesions can progress to osteoarthritis. This study provides a comprehensive overview of the subject matter that it covers. PubMed, Scopus and Google Scholar were accessed using the following keywords: "chondral lesions/defects of the femoral head", "chondral/cartilage lesions/defects of the acetabulum", "chondral/cartilage lesions/defects of the hip", "osteochondral lesions of the femoral head", "osteochondral lesions of the acetabulum", "osteochondral lesions of the hip", "osteochondritis dissecans," "early osteoarthritis of the hip," and "early stage avascular necrosis". Hip osteochondral injuries can cause significant damage to the articular surface and diminish the quality of life. It can be difficult to treat such injuries, especially in patients who are young and active. Several methods are used to treat chondral and osteochondral injuries of the hip, such as mesenchymal stem cells and cell-based treatment, surgical repair, and microfractures. Realignment of bony anatomy may also be necessary for optimal outcomes. Despite several treatments being successful, there is a lack of head-to-head comparisons and large sample size studies in the current literature. Additional research will be required to provide appropriate clinical recommendations for treating chondral/osteochondral injuries of the hip joint.

Is hip arthroscopy useful in the treatment of borderline dysplasia?: a case-control study

INTRODUCTION

Since arthroscopy remains a controversial treatment of hip dysplasia, our objective was to analyse its clinical and radiological results in a cohort of patients with dysplasia and compare them to controls with femoroacetabular impingement (FAI).

MATERIAL AND METHODS

We retrospectively analysed a series of patients who underwent hip arthroscopy for the treatment of labral pathology; 29 of them with borderline hip dysplasia and 197 with FAI, comparing reoperations and joint survival. The diagnosis of borderline dysplasia was made with a lateral centre-edge angle greater than 18° but less than 25°. The average follow-up was 43 months. We performed a multivariate regression analysis to evaluate the association of reoperations with different demographic, radiological and intraoperative variables.

RESULTS

Seven complications were registered in the FAI group (1 medically treated superficial wound infection, 3 pudendal nerve paraesthesias, 1 deep vein thrombosis and 2 heterotopic ossifications) and none in the dysplasia group. While 5 patients from the FAI group required a new surgery, none of the dysplasia group was re-operated (p=.38). After adjusting for confounders, reoperation showed a very strong association with the finding of osteochondral lesions during index surgery, with a coefficient of .12 (p<.001, 95%CI=.06-.17).

CONCLUSION

Hip arthroscopy was useful in the treatment of borderline dysplasia, without non-inferior survival compared to the FAI group. We suggest indicating it carefully in dysplasia cases, whenever the symptoms of femoroacetabular friction prevail over those of instability.

Comparison Between 3-Dimensional Multiple-Echo Recombined Gradient Echo Magnetic Resonance Imaging and Arthroscopic Findings for the Evaluation of Acetabular Labrum Tear

PURPOSE

To evaluate radially reconstructed 3.0-Tesla 3-dimensional multiple-echo recombined gradient echo (MERGE) magnetic resonance imaging (MRI) without arthrography for the assessment of acetabular labrum tears, using arthroscopic evaluation as the reference standard.

METHODS

A total of 71 consecutive hips, including 29 with femoroacetabular impingement, 26 with borderline developmental dysplasia of the hip, and 16 with early-stage osteoarthritis, were evaluated in this retrospective study. MERGE MRI findings were evaluated according to the modified Czerny classification for 3 regions of interest: anterior region, anterolateral region, and lateral region. Cases with severe degeneration that was not concordant with any stage in the original Czerny classification were defined as stage Ⅳ. MERGE MRI findings were compared with arthroscopic findings, and the sensitivity, specificity, positive predictive value, and negative predictive value in terms of the existence of labrum tears were calculated.

RESULTS

MERGE MRI findings revealed labrum tears more frequently in the anterolateral region than in the anterior and lateral regions (P < .01). In cases of femoroacetabular impingement and borderline developmental dysplasia of the hip in particular, labrum tears were more frequently observed on MRI in the anterolateral region than in the lateral region (P < .05). In comparison with MRI findings and arthroscopic findings, our newly defined stage IV in the modified Czerny classification was more frequently observed in cases with a Multicenter Arthroscopy of the Hip Outcomes Research Network (MAHORN) classification of degenerative or complex (P < .01). The average sensitivity and specificity of all regions for the existence of labrum tears were 85% and 56%, respectively. Sensitivity and specificity were 79% and 50%, respectively, in the anterior region; 96% and 50%, respectively, in the anterolateral region; and 70% and 57%, respectively, in the lateral region.

CONCLUSIONS

We validated the diagnostic performance of 3.0-Tesla 3-dimensional MERGE MRI for evaluating acetabular labrum tears and made comparisons with arthroscopic findings. Radially reconstructed MERGE magnetic resonance images showed excellent sensitivity for the diagnosis of labrum tears, particularly in the anterolateral region. The newly defined stage IV was distinctive of early-stage osteoarthritis cases with degeneration and/or complex arthroscopic findings. The noninvasive imaging modality of radially reconstructed MERGE MRI may be an alternative to magnetic resonance arthrography for evaluating labrum tears.

LEVELS OF EVIDENCE

Level Ⅱ, development of diagnostic criteria.

Arthroscopic acetabuloplasty without labral detachment for focal pincer-type impingement: a minimum 2-year follow-up

In order to access and resect the acetabular rim, arthroscopic acetabuloplasty was described with labral detachment. When the chondrolabral junction remains intact, acetabuloplasty and labral refixation can be performed maintaining an unharmed labrum. We aimed to evaluate the outcome of a group of patients treated with arthroscopic acetabuloplasty without labral detachment. During the study period, we retrospectively analysed 44 patients with pincer-type o combined impingement and an intact chondroblabral junction, with an average follow-up of 32 months (range: 27-38). We excluded patients with isolated CAM-type impingement and previous hip pathology. Radiographs were analysed to define impingement and classify grade of osteoarthritis. Clinical evaluation consisted of pre-operative and post-operative modified Harris hip score (mHHS) and WOMAC as well as post-operative visual analogue scale (VAS) of pain and satisfaction. Reoperations were considered surgical failures for purposes of survival analysis. Mean mHHS changed from 51.06 (SD 4.81) pre-operatively to 84.97 (SD 12.79) post-operatively. Pre-operative WOMAC was 29.18 (SD 8) and post-operative, 13.10 (SD 11). Post-operative VAS was 7.5 and 2.27 for satisfaction and pain, respectively. When comparing patients with Tönnis 0 to those with Tönnis 1, the former showed better results regarding post-operative mHHS (89.9 s versus 77.85, P = 0.03), pain VAS (1.5 versus 6.3, P = 0.03) and satisfaction VAS (8.2 versus 6.3, P = 0.01). Survival was 100% at 24 months and 76% at 40 months (95% CI: 35-98%). Arthroscopic acetabuloplasty without labral detachment achieved good clinical outcomes. Slight degenerative changes on radiographs correlated with poorer clinical outcomes.

Femoro-acetabular impingement clinical research: is a composite outcome the answer?

Femoro-acetabular impingement (FAI) is increasingly recognized as an important cause of hip pain in the young adult. However, the methods of evaluating the efficacy of surgical intervention are often not validated and/or inconsistently reported. Important clinical, gait, radiographic and biomarker outcomes are discussed. This article (1) presents the rationale for considering a composite outcome for FAI patients; (2) examines a variety of important end points currently used to evaluate FAI surgery; (3) discusses a strategy to generate a composite outcome by combining these end points; and (4) highlights the challenges and current areas of controversy that such an approach to evaluating symptomatic FAI patients may present.

"Crevasse" Lesions: A Unique Pattern of Femoral Head Chondral Damage

OBJECTIVE

The purpose of this article is to report on a distinctive pattern of linear femoral head chondral lesions that were observed in 7 patients who underwent hip arthroscopy for the treatment of mixed-type femoroacetabular impingement (FAI).

DESIGN

Between 2010 and 2012, 702 patients were treated with hip arthroscopy at our institution for symptomatic FAI. Among those patients, 7 were found to have a unique vertical chondral fissure located on the posterior femoral head. A retrospective review of the preoperative history, physical examination, and radiographic findings in addition to the intraoperative findings and surgical procedures performed was carried out for each patient.

RESULTS

All patients were diagnosed with mixed-type FAI by dynamic examination intraoperatively. The femoral head cartilage lesions were noted to be both linear and deep and resembled the appearance of a crevasse. Three of the 7 patients in whom these lesions were identified reported an acute event preceding their pain. Of the other 4 patients, 3 were involved in sports that involved vigorous rotational hip movements: golf, tennis, and wrestling. Notably, none of these lesions were identifiable on preoperative 3-T MRI scans.

CONCLUSIONS

This series reports on a previously undefined femoral head cartilage lesion. It is hypothesized that increased pathologic translational movements and perching of the femoral head on the posterior rim of the acetabulum create this pattern of chondral damage. Recognition of this pattern of damage on the femoral head is important in the setting of mixed-type FAI.