Anteroinferior acetabular rim damage due to femoroacetabular impingement

Anteroinferior Hip Instability in Flexion During Dynamic Arthroscopic Examination Is Associated With Abnormal Anterior Acetabular Horn

Background:

The stabilization of the femoral head is provided by the distal acetabulum when the hip is in a flexed position. However, the osseous parameters for the diagnosis of hip instability in flexion are not defined.

Purpose/Hypothesis:

To determine whether the osseous parameters of the distal acetabulum are different in hips demonstrating anteroinferior subluxation in flexion under dynamic arthroscopic examination, compared with individuals without hip symptoms. The hypothesis was that the morphometric parameters of the anterior acetabular horn are distinct in hips with anteroinferior instability compared with asymptomatic hips.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

A total of 30 hips with anteroinferior instability in flexion under dynamic arthroscopic examination were identified. A control group of 60 hips (30 patients), matched by age and sex, was formed from individuals who had undergone pelvis magnetic resonance imaging (MRI) for nonorthopaedic reasons. Unstable and control hips were compared according to the following parameters assessed on axial MRI scans of the pelvis: anterior sector angle (ASA), anterior horn angle (AHA), posterior sector angle (PSA), posterior horn angle (PHA), acetabular version, lateral center-edge angle, acetabular inclination (Tönnis angle), and femoral head diameter.

Results:

The coverage of the femoral head by the anterior acetabular horn was decreased in unstable hips compared with the control group (mean ASA, 54.8° vs 61°, respectively; P < .001). Unstable hips also had a steeper anterior acetabular horn, with an increased mean AHA compared with controls (52.5° vs 46.8°, respectively; P < .001). An ASA <58° had a sensitivity of 0.8, a specificity of 0.68, a negative predictive value of 0.87, and a positive predictive value of 0.56 for anteroinferior hip instability. An AHA >50° had a sensitivity of 0.77, a specificity of 0.72, a negative predictive value of 0.86, and a positive predictive value of 0.57 for anteroinferior hip instability. There was no statistically significant difference in the mean PSA, PHA, acetabular version, lateral center-edge angle, acetabular inclination, or femoral head diameter between unstable hips and controls.

Conclusion:

Abnormal morphology of the anterior acetabular horn is associated with anteroinferior instability in hip flexion. The ASA and AHA can aid in the diagnosis of hip instability.

Trends in Hip Arthroscopic Labral Repair: An American Board of Orthopaedic Surgery Database Study

PURPOSE

The purpose of this study is to evaluate the trends in labral repair in American Board of Orthopaedic Surgery Part II candidates performing hip arthroscopy.

METHODS

Candidates who performed arthroscopic hip surgery between 2011 and 2015 during their American Board of Orthopaedic Surgery Part II board collection period were identified using Current Procedural Terminology codes (29860, 29861, 29862, 29863, 29914, 29915, 29916). The proportion of hip arthroscopy cases including labral repair (Current Procedural Terminology code 29916) were calculated for each year and analyzed by fellowship training experience. Trends in labral repair utilization were calculated using univariate and regression analyses, with significance set at P < .05.

RESULTS

During the study period, 1,606 hip labral repair cases were performed, with a 35% increase in utilization between 2011 and 2015. Overall, labral repair was performed in 64.8% (1,606/2,480) of hip arthroscopy cases, with a significant increase between 2011 and 2015 (47.4% vs 79.2%; P < .001). Of the hip arthroscopy cases including labral repair, 80.4% (1,291/1,606) were performed by candidates with sports medicine fellowship training. The proportion of hip arthroscopy cases including labral repair was highest for surgeons with sports medicine fellowship training compared with those without sports medicine fellowship training (66.1% vs 59.8%; P = .007). Candidates with sports medicine training performing at least 1 labral repair each year increased from 68% to 89% over the study period (P = .0007). The average number of labral repairs per candidate increased significantly over the duration of the study period (P = .0072).

CONCLUSIONS

Labral repair utilization during hip arthroscopy procedures nearly doubled from 2011 to 2015 for American Board of Orthopaedic Surgery Part II candidates, reflecting a significant change in practice. Current data suggest that nearly 80% of hip arthroscopy procedures include labral repair. These trends may reflect the current practice patterns at academic institutions with sports medicine fellowships.

Valgus Slipped Capital Femoral Epiphysis: Pathophysiology of Motion and Results of Intracapsular Realignment

OBJECTIVES

The purpose of this study was to report (1) a different but specific pattern of impingement in hips involved with valgus slipped capital femoral epiphysis (valgus SCFE) and (2) the results of surgical treatment using intracapsular realignment techniques.

DESIGN

Case series.

SETTING

Multiple academic centers.

PATIENTS

Six patients with 8 involved hips referred for valgus alignment of proximal femoral epiphysis (valgus SCFE).

INTERVENTION

Intracapsular realignment osteotomy combined with periacetabular osteotomy if needed.

MAIN OUTCOME MEASUREMENT

The clinical and radiographical results and pathophysiology of motion.

RESULTS

Eight hips in 6 patients were treated with subcapital (5 hips) or femoral neck (3 hips) osteotomy for realignment. The medially prominent metaphysis created an inclusive impingement at the anterior acetabular wall, whereas the high coxa valga favored impacting impingement at the posterior head-neck junction. The mean preoperative epiphyseal-shaft angle of 110.5 (range 90-125 degrees) was reduced to 62 degrees (range 55-70 degrees) postoperatively. At the last follow-up, all but 1 hip were pain-free and impingement-free, with normal range of motion. One hip was replaced after repeated attempts of correction. The overall hip functional result using modified Merle d'Aubigne scoring system was excellent in 5 hips (18-16 points), good in 2 hips (16-15 points), and poor in 1 hip (6 points).

CONCLUSIONS

Impingement in valgus SCFE deformity is specific and complex. Anatomical realignment can lead to favorable results by the restoration of normal morphology and impingement-free range of motion.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

[Impingement of the hip]

Femoroacetabular impingement (FAI) describes the repetitive painful contact between the acetabulum, the pelvis and the proximal femur. This bony abutment can lead to a characteristic pattern of chondrolabral damage and is one of the main etiological factors in the development of juvenile osteoarthritis of the hip joint. This article describes the current treatment concepts of FAI and the radiological assessment including an overview of standard measurement methods, coxometric parameters and cut-off values. Furthermore, the authors stress the importance of a profound understanding of the entire configuration of the pelvis and the dynamic interplay of its components.

Surgical treatment of femoroacetabular impingement following slipped capital femoral epiphysis: A systematic review

Objectives

The purpose of this study was to evaluate the existing literature from 2005 to 2016 reporting on the efficacy of surgical management of patients with femoroacetabular impingement (FAI) secondary to slipped capital femoral epiphysis (SCFE).

Methods

The electronic databases MEDLINE, EMBASE, and PubMed were searched and screened in duplicate. Data such as patient demographics, surgical technique, surgical outcomes and complications were retrieved from eligible studies.

Results

Fifteen eligible level IV studies were included in this review comprising 261 patients (266 hips). Treatment groups included arthroscopic osteochondroplasty, surgical hip dislocation, and traditional open osteotomy. The mean alpha angle corrections were 32.14° (standard deviation (sd) 7.02°), 41.45° (sd 10.5°) and 6.0° (sd 5.21°), for arthroscopy, surgical hip dislocation, and open osteotomy groups, respectively (p < 0.05). Each group demonstrated satisfactory clinical outcomes across their respective scoring systems. Major complication rates were 1.6%, 10.7%, and 6.7%, for arthroscopy, surgical dislocation and osteotomy treatments, respectively.

Conclusion

In the context of SCFE-related FAI, surgical hip dislocation demonstrated improved correction of the alpha angle, albeit at higher complication and revision rates than both arthroscopic and open osteotomy treatments. Further investigation, including high-quality trials with standardised radiological and clinical outcome measures for young patients, is warranted to clarify treatment approaches and safety.

Cite this article: K. O. Oduwole, D. de Sa, J. Kay, F. Findakli, A. Duong, N. Simunovic, Y. Yi-Meng, O. R. Ayeni. Surgical treatment of femoroacetabular impingement following slipped capital femoral epiphysis: A systematic review. Bone Joint Res 2017;6:472–480. DOI: 10.1302/2046-3758.68.BJR-2017-0018.R1.

Parameters for assessment of the inferior acetabulum morphology in 300 adult hips

The inferior acetabulum (IA) has been studied as a stabilizer of the hip in flexed positions with potential implications in femoroacetabular impingement and hip instability. However, there is a paucity of studies considering the normal morphology and parameters for assessment of the IA. The purpose of this study was to define parameters to assess the IA morphology and their normal range. Specifically, the objectives were to assess: (i) the width of the anterior horn (AH) and posterior horn (PH) of the acetabulum; (ii) the inclination of the articular surface of the AH angle (AHA) and PH angle (PHA) in the axial plane; (iii) the anterior opening angle of the IA and differences between genders. One hundred and fifty adult skeletons were utilized in this study. Measurements were taken directly from acetabula in 300 innominate bones utilizing digital calipers. In sequence, the innominate bones were assembled to sacrum and 150 pelvises were digitally photographed in standardized positions. Angular parameters of the acetabulum were then measured utilizing the Adobe Photoshop software. The mean width of the AH was 14.80 ± 2.35 mm (range 9.44–20.88). The mean width of the PH was 19.72 ± 2.61 mm (range 13.16–25.86). The AHA was on average 43.58 ± 7.10° (range 24.70–64) and the PHA was on average 36.07 ± 7.54° (16.10–53.20). The mean anterior opening angle of the IA was 25.33 ± 5.40° (10.90–43.10). The IA morphology can be evaluated in all anatomical planes through quantitative parameters. The assessment of the osseous morphology of the IA is the first step to elucidate abnormalities of the IA as potential source of hip pain.

Characterization of primary chondrocytes harvested from hips with femoroacetabular impingement

OBJECTIVE

Acetabular chondral lesions are common in patients with femoroacetabular impingement (FAI) syndrome. The aim of this study was (1) to evaluate the proliferation potential of primary human chondrocytes (hC) derived from both acetabular and femoral site and (2) to validate cellular differentiation during three-dimensional (3D) cultivation as a prerequisite for autologous matrix-assisted cartilage regeneration of the hip joint.

METHODS

hC were isolated from cartilage samples obtained from N = 6 patients during offset reconstruction. Proteoglycan content was assessed by Safranin-O staining. Proliferation and cell viability were quantified by microscopic cell counting and Trypan Blue exclusion. Messenger ribonucleic acid (mRNA) expression levels of collagen type 1 and 2, aggrecan (ACAN), and interleukin-1β (IL-1β) genes were assessed upon monolayer cultivation, after 48 h/4-10°C - transport simulation and after 14 days of 3D hydrogel cultivation.

RESULTS

Primary hC from acetabular and femoral damaged sites were viable. No significant intergroup differences were observed concerning cell viability (>95%) after monolayer cultivation and transport simulation. Harvest yields from acetabular and femoral cartilage samples were comparable to that known from knee joints (mean ± standard deviation (SD), 13.4 × 10(6) ± 5 × 10(6) cells per culture vs 20 × 10(6) cells). Redifferentiation was induced during 3D hydrogel cultivation as observed by increased levels of collagen II (1000-fold) and ACAN (10-fold) gene vs monolayer cultivation (P < 0.001).

CONCLUSION

hC derived from damaged acetabular and femoral site are qualified for autologous matrix-assisted cartilage transplantation paving the way for cell-based cartilage regeneration in FAI patients.

Joint Instability After Anatomic Reconstruction of Severe, Chronic Slipped Capital Femoral Epiphysis: A Report of 3 Cases, with High Femoral Anteversion in 1 and Adaptive Acetabular Roof Deformation in 3

CASES

Joint instability after slipped capital femoral epiphysis (SCFE) reorientation through the physis has been attributed to a combination of capsulotomy and chondrolabral rim damage. We report on 3 hips with severe SCFE with closed physes, in which anatomic correction with femoral neck osteotomy led to joint instability. All 3 had acetabular roof flattening; 1 showed slight additional acetabular retroversion but also increased femoral anteversion.

CONCLUSION

We speculate that the slight roof flattening in all 3 cases and/or the high femoral anteversion in 1 case had contributed to joint instability. Femoral derotation osteotomy was performed in 1 and periacetabular osteotomy was performed in 2 for joint restabilization.

Indications and Outcomes for Microfracture as an Adjunct to Hip Arthroscopy for Treatment of Chondral Defects in Patients With Femoroacetabular Impingement: A Systematic Review

PURPOSE

To evaluate the indications, preoperative workup outcomes, and postoperative rehabilitation of patients with femoroacetabular impingement (FAI) receiving microfracture as an adjunct to hip arthroscopy for chondral defects.

METHODS

The electronic databases MEDLINE, EMBASE, and PubMed were searched and screened in duplicate for studies involving patients with FAI treated arthroscopically with microfracture of the hip for chondral defects either solely or as an adjunct to hip arthroscopy. Data regarding indications, investigations, outcomes, and postoperative rehabilitation were abstracted from eligible studies. The references of included studies were additionally searched, and descriptive statistics are provided.

RESULTS

There were 12 studies included in this review, involving 267 patients. With the exception of a single, one-patient case report, 11 of the 12 studies reported positive outcomes after hip arthroscopy with microfracture. Only 0.7% of the total patients experienced a complication, and 1.1% required further surgery on the basis of outcomes evaluated at a mean follow-up of 29.5 (range, 4 to 60) months across the studies. Eight of 12 studies discussed the preoperative workup of these patients, with X-rays and magnetic resonance imaging being the most common preoperative imaging used. There was little reported on weight-bearing status during postoperative rehabilitation.

CONCLUSIONS

The outcomes reported in the literature after hip arthroscopy with microfracture for chondral defects are, in general, positive, with a very low percentage of patients requiring further surgery or experiencing complications. The most common indication used in the literature for microfracture is a full-thickness, focal chondral defect (Outerbridge grade IV). The vast majority of literature recommends limited weight bearing after microfracture; however, there was significant variation among the specific rehabilitation protocols used. More research is needed to explore what indications and postoperative rehabilitation result in the best outcomes for patients.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II, III, and IV studies.

Hip impingement: beyond femoroacetabular

In the last 20 years, femoroacetabular impingement has been at the forefront of clinical practice as a cause of hip pain in young adults. As arthroscopic techniques for the hip continue to evolve, the possible presence of a new group of conditions creating mechanical conflict in and around the hip joint (ischiofemoral, subspine and iliopsoas impingement) has recently been elucidated whilst interest in already known 'impingement' syndromes (pelvic-trochanteric and pectineofoveal impingement) is now revived. This article attempts to increase awareness of these relatively uncommon clinical entities by describing their pathomorphology, contact mechanics, treatment and published results available to present. It is hoped that such knowledge will diversify therapeutic options for the clinician, thereby improving outcomes in a small but not negligible portion of patients with previously unexplained persistent symptoms.

Subtrochanteric osteotomy for femoral mal-torsion through a surgical dislocation approach

Missed torsional femur deformities may contribute to reasons for failure after open and more likely arthroscopic hip preservation surgery. A number of surgical approaches have been described for addressing torsion abnormalities. This report describes a subtrochanteric osteotomy technique in a consecutive series of patients with complex hip pathologies, for which intertrochanteric osteotomy is not suitable and precise derotation is required. Subtrochanteric derotation was performed, always in combination with a surgical hip dislocation, in accordance with the authors’ preferred technique. Before osteotomy, a localized decortication was executed. Application of a 4.5-mm broad or narrow plate was undertaken with dynamic compression of the osteotomy. Twenty-eight consecutive subtrochanteric derotational osteotomies were performed in 26 patients. Twenty-one females and five males were treated at an average age of 21.4 years (range, 12–43). Underlying diagnoses included dysplasia, arthrogryposis, cerebral palsy, Down’s syndrome, instability and impingement. The decision to perform derotation was for antetorsion over 20° or less than 0° (retrotorsion). Patients were followed clinically and radiographically till final follow-up. All patients went on to successful osteotomy union. There were two initial failures: one delayed union prompting revision fixation in a chronic smoker and one plate failure due to self-accelerated weight-bearing in a patient status post successful contralateral derotational osteotomy. Rotational deformity of the femur must be considered in the patient undergoing hip preservation surgery. This technique of subtrochanteric derotational osteotomy, with adjunctive surgical hip dislocation, is applicable and reproducible in the setting of complex hip pathologies. Level of evidence: IV, case series.

Surgical treatment of femoroacetabular impingement: what are the limits of hip arthroscopy?

The variety of hip pathology that can be addressed in a minimally invasive fashion in the young, pre-arthritic patient has rapidly grown in parallel with technical advances in hip arthroscopy. However, the indications and limits of arthroscopy must be carefully defined and indications must evolve correspondingly to avoid an increase in failure rates and unsatisfactory clinical outcomes. Some diagnoses may be better and more comprehensively addressed with open procedures or combined surgical approaches. The purpose of this article is to provide an unbiased and evidence-based review of conditions of the pre-arthritic hip to define our current understanding of the advantages, disadvantages, and limitations of an arthroscopic approach.

The evolution and concepts of joint-preserving surgery of the hip

The use of joint-preserving surgery of the hip has been largely abandoned since the introduction of total hip replacement. However, with the modification of such techniques as pelvic osteotomy, and the introduction of intracapsular procedures such as surgical hip dislocation and arthroscopy, previously unexpected options for the surgical treatment of sequelae of childhood conditions, including developmental dysplasia of the hip, slipped upper femoral epiphysis and Perthes’ disease, have become available. Moreover, femoroacetabular impingement has been identified as a significant aetiological factor in the development of osteoarthritis in many hips previously considered to suffer from primary osteoarthritis.

As mechanical causes of degenerative joint disease are now recognised earlier in the disease process, these techniques may be used to decelerate or even prevent progression to osteoarthritis. We review the recent development of these concepts and the associated surgical techniques.

Cite this article: Bone Joint J 2014;96-B:5–18.