Clinical and radiographic diagnosis of femoroacetabular impingement

Radiological and clinical femoroacetabular impingement after slipped capital femoral epiphysis treated by in situ fixation

Background

The treatment of slipped capital femoral epiphysis (SCFE) is always surgical. In situ fixation (ISF) is widely accepted to stop the epiphysis slipping. Femoroacetabular impingement (FAI) is recognized as a complication after ISF and is one of the major causes of early hip osteoarthritis.

Study aim

The aim of this study was to characterize the relation between clinical and radiological signs of FAI.

Methods

A monocentric study that included all consecutive children treated for SCFE by ISF between 2006 and 2017 was performed. Clinical examination consisted in range of motion (ROM) measurement for both hips, impingements tests and functional scores (Harris Hip Score (HHS) and Womac score). Radiological analysis was based on signs of impingement (alpha angle, anterior head neck offset (OS), anterior head neck offset ratio (HNOR).

Results

36 hips were included. At follow-up, the difference between the mean hip ROM on the SCFE side and the healthy side were statistically significant in abduction and in internal rotation. Ten (28%) hips presented at least one clinical test positive for FAI (FADDIR and/or FABER). All the patients presented a good or excellent functional score. Eight patients (22%) presented all radiological signs of impingement; among these, 3 had a clinical sign of FAI. Twenty-eight hips (78%) presented at least one radiological sign of FAI; among these, 10 had clinical signs of FAI.

Conclusion

Despite a high rate of radiological FAI, less than one-third of patients have clinical signs of FAI after ISF for SCEFE.

Level of evidence

III: retrospective study.

Hip Arthroscopy in Adolescents Through an Extra-Capsular Approach

Hip arthroscopic treatment for femoroacetabular impingement syndrome and labral tears is the gold standard in the adult and adolescent population, as we all know the most common surgical approach to the hip is entering the central compartment with fluoroscopy and with continuous distraction. A periportal capsulotomy in traction must be done to have visibility and instrument maneuverability. These maneuvers avoid scuffing the femoral head cartilage. In adolescents, extreme care must be taken in hip distraction, as the force used can cause iatrogenic neurovascular lesions, avascular necrosis, and lacerations of the genitals and foot/ankle. Experienced surgeons around the world have developed an extracapsular approach to the hip with smaller capsulotomies with a low complication rate. This approach to the hip has brought attention in the adolescent population because it is more secure and simple. Less force of distraction is needed because the capsulotomy is done first. This surgical technique allows observation of the cam morphology while entering to the hip without distraction. We describe an extracapsular approach as an option to treat femoral acetabular impingement syndrome and labral tears in the pediatric and adolescent population.

The Association of α Angle on Disease Severity in Adolescent Femoroacetabular Impingement

BACKGROUND

Femoroacetabular Impingement (FAI) is a common cause of hip pain in adolescent patients. Clinical exam and radiographic markers, such as α angle and lateral center edge angle (LCEA), are commonly used to aid in the diagnosis of this condition. The purpose of this study was to correlate preoperative α angle and LCEA with preoperative symptoms, intraoperative findings, and preoperative and postoperative patient reported outcomes (PROs) in the adolescent patient.

METHODS

A retrospective analysis of prospectively collected data was conducted for all patients who underwent operative intervention for FAI at an academic institution over an 11-year period. Preoperative imaging was obtained and measured for LCEA and α angle. PROs (modified Harris Hip Score, Hip Disability and Osteoarthritis Outcome Score, and UCLA score) were collected preoperatively, as well as 1, 2, and 5 years postoperatively. Operative intervention was either open surgical hip dislocation or arthroscopic, and intraoperative disease was graded using the Beck Classification system. Patients with minimum 1-year follow-up were included in statistical analysis.

RESULTS

There were 86 hips (64 female hips) included with an average age of 16.3 years (range, 10.4 to 20.5 y), with an average of 37 months of follow-up. There was no correlation between severity of preoperative symptoms or difference between pre and postoperative PROs for both α angle and LCEA. Overall, significant improvement was noted in modified Harris Hip Score, Hip Disability and Osteoarthritis Outcome Score, and UCLA Score (P<0.001 for each). Independent of preoperative symptoms, increased α angle correlated with more severe intraoperative labral disease (P<0.001), and longer length of labral tear (Corr 0.295, P<0.01). Femoral head and acetabular articular cartilage damage did not correlate with α angle or LCEA, nor did overall severity of disease.

CONCLUSIONS

In adolescent patients with FAI, increased α angle was found to significantly correlate with labral pathology, including increased length of tear and severity of disease, irrespective of preoperative symptoms or postoperative patient reported outcomes.

LEVEL OF EVIDENCE

Level III-retrospective.

Biomarkers for Femoroacetabular Impingement and Hip Osteoarthritis: A Systematic Review and Meta-analysis

BACKGROUND

The early recognition and management of patients with hip lesions, such as femoroacetabular impingement (FAI) and early hip osteoarthritis (OA), may preempt significant hip morbidity. The identification of reliable biomarkers may help guide decision making in an efficient and cost-effective manner.

PURPOSE

To determine the biomarkers that have been associated with FAI as well as identify serum, synovial, and urinary analytes that have shown clinical utility in the prediction or identification of hip OA.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

The terms "hip arthroscopy," "femoroacetabular impingement," "labral tear," "osteoarthritis," and "biomarker" were searched in PubMed, Web of Science, Scopus, Cochrane Library, and Google Scholar, yielding 276 articles. After screening, 7 articles were included. Pooled estimates were calculated utilizing a fixed-effects inverse-variance model weighted for individual study size.

RESULTS

A total of 1747 patients with a mean age of 37.5 ± 4.5 years (76.4% female) were identified. Forty-three unique biomarkers were assessed. Although general proinflammatory cytokines IL-1 and TNF-α exhibited inconsistent trends in arthritic hips, IL-6 demonstrated a consistent increase (+84.8% [95% CI, 81.9%-87.6%]; P < .05). A significant difference was found in levels of the fibronectin-aggrecan complex (FAC) in patients with OA compared with controls (0.08 ± 0.40 vs 1.15 ± 0.35 μg/mL, respectively; P < .001). It was the only specific analyte to show a significant difference between those with and without OA. In the setting of FAI, cartilage oligomeric matrix protein (COMP) was significantly increased in athletes after adjusting for concurrent knee and hip OA. A statistically significant difference was present in FAI-positive hips (9.0 ± 0.1 [95% CI, 8.8-9.3]) compared with controls (8.4 ± 0.1 [95% CI, 8.2-8.4]) (P < .05). Other biomarkers, such as CXCL3, which exhibited statistically significant differences compared with controls, did not control for underlying factors such as age and concomitant lesions.

CONCLUSION

COMP and FAC are specific biomarkers with potential utility in the diagnosis and management of FAI and hip OA, given their ability to differentiate between controls and patients with hip lesions. Further research is necessary to identify their ability in determining disease severity, predicting the response to treatment, and establishing an association with the risk of long-term OA.

Intracapsular cuneiform osteotomy compared with in-situ pinning for the management of slipped capital femoral epiphysis

Intracapsular cuneiform osteotomy was initially introduced to restore the morphology of the proximal femur after slipped capital femoral epiphysis (SCFE). However, whether this procedure results in a higher risk of avascular necrosis (AVN) or lower incidence of cam deformity than in-situ pinning is unclear. The aim of this study was to compare the outcomes of intracapsular cuneiform osteotomy and in-situ pinning to treat SCFE in children. Twenty-three children who suffered from SCFE underwent either intracapsular cuneiform osteotomy (eight patients, eight hips) or in-situ pinning (15 patients, 18 hips) between 2006 and 2014. No patient was lost to follow-up at a mean of 4.5 years. In the osteotomy group, the Japanese Orthopedic Association's hip score system score increased from 50.5 (20-89) to 98.9 (95-100) and from 65.9 (48-90) to 99.0 (44-100) in the in-situ pinning group. On the basis of the slip angle, α angle, and epiphyseal-metaphyseal offset, intracapsular cuneiform osteotomy showed a significantly better result in restoring the morphology of the proximal femur than in-situ pinning (P<0.001). The incidences of AVN, chondrolysis, and lower limb discrepancy were similar between the two groups. On the basis of clinical outcomes, both intracapsular cuneiform osteotomy and in-situ pinning had acceptable abilities to treat SCFE. The incidence of AVN was not related to which technique was used. Osteotomy significantly restored the morphology of the proximal femur.

Subcapital Shortening Osteotomy for Severe Slipped Capital Femoral Epiphysis: Preliminary Results of the French Multicenter Study

BACKGROUND

There is growing evidence that symptomatic femoroacetabular impingement (FAI) can develop after severe slipped capital femoral epiphysis (SCFE) fixed in situ. Realignment procedures have therefore gained popularity, but complication rates remain controversial. Among them, the subcapital shortening osteotomy without hip dislocation has been progressively adopted in France, but results have never been assessed to date.

METHODS

All cases performed in 23 French university hospitals between January 2010 and March 2014 were reviewed to (1) describe the surgical procedure, (2) assess the radiologic and functional outcomes, and (3) report complications and more specifically the avascular necrosis rate (AVN) according to initial stability. Stable and unstable SCFE were distinguished following Loder's definition. Radiologic outcomes were assessed by the 3 authors to determine FAI and osteonecrosis rates. Functional outcomes were evaluated at follow-up and complications were reported.

RESULTS

A total of 82 cases (45 unstable and 37 stable), performed in 10 institutions, were included with a mean follow-up of 25 months. No intraoperative complication occurred but 2 patients (2.4%) underwent unplanned early revision. Slip angle was significantly reduced (87%) without loss of correction. Overall AVN rate was 9.7%, reaching 13.3% in unstable slips. However, preoperative magnetic resonance imaging showed that most of the unstable epiphyses (4/6) were already hypoperfused before surgery.

CONCLUSIONS

The procedure is a reliable option for the treatment of severe SCFE. AVN rates are lower than previously reported in multicenter series of modified Dunn technique, especially in unstable slips. However, the risk of AVN in severe stable SCFE (5.4%) must still be balanced with the functional outcomes of potential future FAI.

LEVEL OF EVIDENCE

Level IV-therapeutic study.

The correlation between femoroacetabular impingement and superior retinacular artery interruption

The aim of this study was to investigate the relationship between femoroacetabular impingement (FAI) and superior retinacular artery interruption using plain radiographs and digital subtraction angiography (DSA).Sixty-one patients included in this study were divided into 2 groups based on the superior retinacular artery integrity as evaluated on DSA images. Group A included intact arteries: 33 patients (24 men, 9 women,); group B included interrupted arteries: 28 patients (21 men, 7 women). The parameters of abnormal radiographic findings thought to be associated with FAI, including positive crossover or figure-of-eight sign of acetabulum, lateral center edge angle (LCEA) >40°, Tönnis angle <0°, positive posterior wall sign, alpha angle >50°, and coxa profunda, were evaluated in all patients through plain radiographs.The cross-over sign (Group A: 0, Group B: 8, P = .0035), LCEA (Group A: 1, Group B: 7, P = .0190), Tönnis angle (Group A: 3, Group B: 13, P = .0026), and alpha angle (Group A: 7, Group B: 17, P = .0039) differed significantly between both groups. However, there were no statistically significant differences in posterior wall sign (Group A: 9, Group B: 12, P = .3143) or coxa profunda (Group A: 12, Group B: 8, P = .7096).Patients with interrupted blood supply of the superior retinacular arteries displayed more parameters of abnormal radiographic findings associated with FAI thereby indicating potential correlation between FAI and the interruption of superior retinacular arteries.

Imaging of femoroacetabular impingement-current concepts

Following the recognition of femoroacetabular impingement (FAI) as a clinical entity, diagnostic tools have continuously evolved. While the diagnosis of FAI is primarily made based on the patients' history and clinical examination, imaging of FAI is indispensable. Routine diagnostic work-up consists of a set of plain radiographs, magnetic resonance imaging (MRI) and MR-arthrography. Recent advances in MRI technology include biochemically sensitive sequences bearing the potential to detect degenerative changes of the hip joint at an early stage prior to their appearance on conventional imaging modalities. Computed tomography may serve as an adjunct. Advantages of CT include superior bone to soft tissue contrast, making CT applicable for image-guiding software tools that allow evaluation of the underlying dynamic mechanisms causing FAI. This article provides a summary of current concepts of imaging in FAI and a review of the literature on recent advances, and their application to clinical practice.

The use of hip arthroscopy in the management of the pediatric hip

Arthroscopy of the pediatric hip began in 1977 with a publication by Gross. Interest was relatively slow to develop in the 1980s and 1990s. Coupled with the success of hip arthroscopy in the adult, interest heightened in applying the procedure to a variety of pediatric hip disorders, given that the alternative was an open surgical hip dislocation. The success of this initial group of pediatric hip arthroscopist's has further expanded the application of hip arthroscopy as the primary or adjunct procedure for the management of intra-articular problems of the pediatric hip.

Severe slipped capital femoral epiphysis: A French multicenter study of 186 cases performed by the SoFOP

INTRODUCTION

The treatment of severe slipped capital femoral epiphysis (SCFE) remains controversial. Despite numerous treatments being available, the outcome of published studies has been variable. Recent studies emphasize that poor reduction of the severe SCFE is responsible for the appearance of joint cartilage lesions and progression towards early osteoarthritis. But surgical reduction of severe SCFE also results in a significant rate of necrosis.

OBJECTIVE

Evaluate the results of various treatment strategies for severe SCFE and identify the optimal course of action.

MATERIAL AND METHODS

This was a French multicenter retrospective study of severe SCFE cases (>45° displacement) evaluated a minimum of 12 months after treatment. The stability of the slipped epiphysis, type of the treatment, delay before treatment, early and short-term complications, Harris and WOMAC functional scores and radiological signs of femoroacetabular impingement (FAI) at the last review were evaluated. A total of 186 cases of severe SCFE in 182 patients were included. One hundred and seven (58.7%) of these were male. The average age was 13 years. The average follow-up was 23 months. The average displacement was 60°. The SCFE was considered stable in 94 cases (50.5%) and unstable in 92 cases (49.5%). The main surgical treatments used by the various centers were in situ fixation (ISF), lateral Dunn, anterior Dunn and reduction using traction or under anesthesia (for unstable forms).

RESULTS

In the stable SCFE cases, there were 6 cases of necrosis (6.4%), all of which occurred after reduction by osteotomy; there were 32 cases of radiological FAI (34%), 30 of which occurred after ISF. The necrosis rate in the unstable SCFE cases was 21.7%: one (11%) after ISF, seven (19%) after anterior Dunn, eight (21%) after preoperative reduction and three (43%) after lateral Dunn.

CONCLUSIONS

The results of this study confirm the diverse nature of SCFE treatments available and the variability of their results. When selecting a treatment for severe SCFE, the goal is to stop the slip and also to prevent osteoarthritis by correcting the hip deformities. The "anterior" Dunn procedure was able to achieve these two goals, while having a lower complication rate than the other reduction techniques.

Advanced Imaging in Femoroacetabular Impingement: Current State and Future Prospects

Symptomatic femoroacetabular impingement (FAI) is now a known precursor of early osteoarthritis (OA) of the hip. In terms of clinical intervention, the decision between joint preservation and joint replacement hinges on the severity of articular cartilage degeneration. The exact threshold during the course of disease progression when the cartilage damage is irreparable remains elusive. The intention behind radiographic imaging is to accurately identify the morphology of osseous structural abnormalities and to accurately characterize the chondrolabral damage as much as possible. However, both plain radiographs and computed tomography (CT) are insensitive for articular cartilage anatomy and pathology. Advanced magnetic resonance imaging (MRI) techniques include magnetic resonance arthrography and biochemically sensitive techniques of delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), T1rho (T1ρ), T2/T2* mapping, and several others. The diagnostic performance of these techniques to evaluate cartilage degeneration could improve the ability to predict an individual patient-specific outcome with non-surgical and surgical care. This review discusses the facts and current applications of biochemical MRI for hip joint cartilage assessment covering the roles of dGEMRIC, T2/T2*, and T1ρ mapping. The basics of each technique and their specific role in FAI assessment are outlined. Current limitations and potential pitfalls as well as future directions of biochemical imaging are also outlined.

Surgical hip dislocation for treatment of cam femoroacetabular impingement

BACKGROUND

Cam femoroacetabular impingement is caused by a misshapen femoral head with a reduced head neck offset, commonly in the anterolateral quadrant. Friction in flexion, adduction and internal rotation causes limitation of the hip movements and pain progressively leading to labral and chondral damage and osteoarthritis. Surgical hip dislocation described by Ganz permits full exposure of the hip without damaging its blood supply. An osteochondroplasty removes the bump at the femoral head neck junction to recreate the offset for impingement free movement.

MATERIALS AND METHODS

Sixteen patients underwent surgery with surgical hip dislocation for the treatment of cam femoroacetabular impingement by open osteochondroplasty over last 6 years. Eight patients suffered from sequelae of avascular necrosis (AVN). Three had a painful dysplastic hip. Two had sequelae of Perthes disease. Three had combined cam and pincer impingement caused by retroversion of acetabulum. All patients were operated by the trochanteric flip osteotomy with attachments of gluteus medius and vastus lateralis, dissection was between the piriformis and gluteus minimus preserving the external rotators. Z-shaped capsular incision and dislocation of the hip was done in external rotation. Three cases also had subtrochanteric osteotomy. Two cases of AVN also had an intraarticular femoral head reshaping osteotomy.

RESULTS

Goals of treatment were achieved in all patients. No AVN was detected after a 6 month followup. There were no trochanteric nonunions. Hip range of motion improved in all and Harris hip score improved significantly in 15 of 16 cases. Mean alpha angle reduced from 86.13° (range 66°-108°) to 46.35° (range 39°-58°).

CONCLUSION

Cam femoroacetabular Impingement causing pain and limitation of hip movements was treated by open osteochondroplasty after surgical hip dislocation. This reduced pain, improved hip motion and gave good to excellent results in the short term.

Epidemiology, identification, treatment and return to play of musculoskeletal-based ice hockey injuries

Ice hockey is a high contact sport where players are inherently at an increased risk for traumatic and time-loss injury. With its increasing popularity and high incidence of injury, further research is necessary to understand the risks and injuries associated with the sport and to develop performance-based outcome measures to guide return to play. This review, tailored to the practicing sports medicine team physician, focuses on the stepwise identification, treatment, time loss, return to play and subsequent risk of injury for the most common areas of injury: the head, shoulder, hip and knee. Injuries were categorised into upper and lower extremity with an emphasis on glenohumeral and acromioclavicular joint injuries, femoroacetabular impingement, medial collateral ligament tears, and high ankle sprains. With return to play a primary goal for these high-level athletes, recovery in ice hockey becomes a complex issue with efficient protocols tailored to the requirements of the sport vital to the athlete and clinician alike. By reviewing the treatments and sport-specific care, athletes can be better managed with the ultimate goal of returning to their preinjury level of play.

LEVEL OF EVIDENCE

Level IV.