Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), after slipped capital femoral epiphysis

[Evaluation of care for slipped capital femoral epiphysis (SCFE) in Germany]

INTRODUCTION

The treatment concept for slipped capital femoral epiphysis is still controversial. According to studies, there is currently no recommendation for a universal approach. Therefore, the aim of this study is to analyze the care reality of children with ECF in Germany.

METHODS

The evaluation of the study is performed based on a questionnaire sent to physicians tending to ECF in 2021. Data is compared to the literature.

RESULTS

36 of 47 questionnaires sent out were included. Overall, no significant difference in ECF care was proven in terms of annual caseload or the size of hospital.

CONCLUSION

A high variance in operative SCFE treatment is reported. According to current literature, the modified Dunn procedure is considered the best therapeutic option to date, especially for patients with severe or chronic ECF. However, compared with alternative care options, this is not feasible in every hospital due to its complicating and challenging nature. Central registration, minimum volume regulation, and expansion of continuing education measures can contribute to optimization.

Current and Future Advanced Imaging Modalities for the Diagnosis of Early Osteoarthritis of the Hip

Hip osteoarthritis (OA) can be idiopathic or develop secondary to structural joint abnormalities of the hip joint (alteration of normal anatomy) and/or due to a systemic condition with joint involvement. Early osteoarthritic changes to the hip can be completely asymptomatic or may cause the development hip symptomatology without evidence of OA on radiographs. Delaying the progression of hip OA is critical due to the significant impact of this condition on the patient’s quality of life. Pre-OA of the hip is a newly established term that is often described as the development of signs and symptoms of degenerative hip disease but no radiographic evidence of OA. Advanced imaging methods can help to diagnose pre-OA of the hip in patients with hip pain and normal radiographs or aid in the surveillance of asymptomatic patients with an underlying hip diagnosis that is known to increase the risk of early OA of the hip. These methods include the delayed gadolinium-enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC), quantitative magnetic resonance imaging (qMRI- T1rho, T2, and T2* relaxation time mapping), 7-Tesla MRI, computed tomography (CT), and optical coherence tomography (OCT). dGEMRIC proved to be a reliable and accurate modality though it is limited by the significant time necessary for contrast washout between scans. This disadvantage is potentially overcome by T2 weighted MRIs, which do not require contrast. 7-Tesla MRI is a promising development for enhanced imaging resolution compared to 1.5 and 3T MRIs. This technique does require additional optimization and development prior to widespread clinical use. The purpose of this review was to summarize the results of translational and clinical studies investigating the utilization of the above-mentioned imaging modalities to diagnose hip pre-OA, with special focus on recent research evaluating their implementation into clinical practice.

Hip arthroscopy following slipped capital femoral epiphysis fixation: chondral damage and labral tears findings

PURPOSE

This study investigated the association between chondrolabral damage and time to arthroscopic surgery for slipped capital femoral epiphysis (SCFE).

METHODS

This was a descriptive retrospective study that enrolled patients with SCFE who underwent hip arthroscopy for femoral osteochondroplasty after SCFE fixation. SCFE type, time from SCFE symptom onset or slip fixation surgery to hip arthroscopy and intraarticular arthroscopic findings were recorded. Acetabular chondrolabral damage was evaluated according to the Konan and Outerbridge classification systems. Nested analysis of variance and the chi-squared test were used for statistical analyses.

RESULTS

We analyzed 22 cases of SCFE in 17 patients (five bilateral). The mean age at the time of hip arthroscopy was 13.6 years-old (8-20), and mean time from SCFE fixation to arthroscopy was 25.1 months (3 weeks to 8 years). Labral frying was present in 20 cases, labral tears in 16 and acetabular chondral damage in 17. The most frequent lesion was type 3 (41%) (Konan classification). Two cases had a grade III and 1 had a grade II acetabular chondral lesion (Outerbridge classification). Positive associations were observed between time from SCFE to hip arthroscopy and hip intraarticular lesions evaluated using Konan (p = 0.004) and Outerbridge (p = 0.000) classification systems. There was no association between SCFE severity (chi-squared = 0.315), stability (chi-squared = 0.558) or temporality (chi-squared = 0.145) type and hip intraarticular lesions.

CONCLUSION

A longer time from SCFE symptom onset and fixation to hip arthroscopy is associated with greater acetabular chondrolabral damage.

LEVEL OF EVIDENCE

IV.

Viewing arthrography images affects treatment preferences for Legg-Calvé-Perthes disease among medical professionals

Objectives

We explored how experience of arthrography affects treatment preferences for Legg-Calvé-Perthes disease (LCPD) patients. We also examined changes in surgical procedure preferences after examining arthrography images. In addition, we analysed the effect of experience with arthrography on treatment and surgical modality preferences.

Methods

A case-based questionnaire was completed by 26 participants. Information on age, symptoms, hip range of motion (ROM), and extremity length differences were provided for eight LCPD cases. Based on these data and roentgenography images of the cases, the respondents were questioned regarding diagnostic, treatment, and surgical preferences. A slide was shown of arthrography images of each case and the same questions were asked to determine any changes in treatment preferences. The participants were divided into arthrography-experienced (Group 1, n = 16) and -inexperienced (Group 2, n = 10) groups to determine differences in treatment preferences in association with experience.

Results

After the participants had examined the arthrography images, a significant decrease in the number of additional examination requests was observed (p < 0.001). A significant group difference was also found in the rate of change of preference in diagnostic modality (p < 0.001).After arthrography images were examined, the tendency towards a preference for surgery increased in all participants. However, no significant difference between the experience groups was observed (p = 0.193). In addition, after arthrography images were examined, there was an increased tendency towards a preference for femoral valgisation and Salter osteotomy among participants who chose surgical treatments (p = 0.408). The treatment preferences difference between the two experience groups were not significant, and nor was the preference regarding surgical procedures (p = 0.999).

Conclusions

Previous studies have shown that arthrography is useful for planning treatment and informing decisions regarding surgical modality for LCPD. However, no study has explored changes in treatment preferences after viewing arthrography images. This study explored such changes in choices regarding the diagnostic method and treatment modality. Our study showed that experience with arthrography decreased the preference for additional diagnostic tests (p < 0.001). Experience of arthrography increased the preference for surgery, though not significantly (p = 0.193).

Automatic Cartilage Segmentation for Delayed Gadolinium-Enhanced Magnetic Resonance Imaging of Hip Joint Cartilage: A Feasibility Study

OBJECTIVE

Automatic segmentation for biochemical cartilage evaluation holds promise for an efficient and reader-independent analysis. This pilot study aims to investigate the feasibility and to compare delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) hip joint assessment with manual segmentation of acetabular and femoral head cartilage and dGEMRIC hip joint assessment using automatic surface and volume processing software at 3 Tesla.

DESIGN

Three-dimensional (3D) dGEMRIC data sets of 6 patients with hip-related pathology were assessed (1) manually including multiplanar image reformatting and regions of interest (ROI) analysis and (2) automated by using a combined surface and volume processing software. For both techniques, T1_Gd values were obtained in acetabular and femoral head cartilage at 7 regions (anterior, anterior-superior, superior-anterior, superior, superior-posterior, posterior-superior, and posterior) in central and peripheral portions. Correlation between both techniques was calculated utilizing Spearman's rank correlation coefficient.

RESULTS

A high correlation between both techniques was observed for acetabular (ρ = 0.897; P < 0.001) and femoral head (ρ = 0.894; P < 0.001) cartilage in all analyzed regions of the hip joint (ρ between 0.755 and 0.955; P < 0.001).

CONCLUSIONS

Automatic cartilage segmentation with dGEMRIC assessment for hip joint cartilage evaluation seems feasible providing high to excellent correlation with manually performed ROI analysis. This technique is feasible for an objective, reader-independant and reliable assessment of biochemical cartilage status.

[Slipped capital femoral epiphysis: clinical presentation, diagnostic procedure and classification]

BACKGROUND

Slipped capital femoral epiphysis (SCFE) is a frequent chronic and often bilateral atraumatic slippage of the epiphysis relative to the femoral neck in adolescence. The success of the treatment depends on the extent of the slippage and possible complications.

OBJECTIVES

Review on current trends in clinical examination and diagnostic imaging protocols. Commonly used imaging techniques, methods of measuring the slippage and treatment-relevant classification schemes are presented.

MATERIALS AND METHODS

An overview on the clinical findings, the diagnostic procedures and the classification of SCFE based on relevant study results and experience gained in our daily clinical practice.

RESULTS

Early diagnosis of SCFE is essential, as a delay in diagnosis regularly leads to an increase in slippage with an increased risk of subsequent damage to the blood vessels, which can lead to irreversible damage of the joint. Symptoms and findings are frequently subtle and nonspecific, often leading to delay in diagnosis and treatment and, consequently, to the manifestation of massive deformities. X‑ray imaging is the primary imaging modality, whereas MRI, computed tomography (CT) and ultrasound are helpful in surgical planning and prognostic evaluation. Postoperatively, they provide information on short and long-term complications.

DISCUSSION

The delay in the diagnosis of SCFE is still present in the literature as well as in our own patient population, indicating that a repeated, consistent training on this topic is essential to prevent harm to patients. Whether patients benefit from advanced imaging techniques such as MRI or CT is questionable and should be screened case by case.

Evolving Understanding of and Treatment Approaches to Slipped Capital Femoral Epiphysis

PURPOSE OF REVIEW

To review slipped capital femoral epiphysis (SCFE), with a focus on new insights into its etiology and evolving methods of operative fixation.

RECENT FINDINGS

The epiphyseal tubercle and its size during adolescence are paramount to understanding the mechanism of SCFE. In chronic stable SCFE, the epiphysis rotates about the tubercle protecting the lateral epiphyseal vessels from disruption. In an acute unstable SCFE, the tubercle displaces, increasing the risk of osteonecrosis, also known as avascular necrosis (AVN). Intraoperative stability suggests that stable and unstable SCFE based on ambulation may be inaccurate. For stable SCFE, in situ pinning remains the most accepted treatment for mild slips with delayed symptomatic femoroacetabular impingement (FAI) management. Treatment of moderate to severe stable slips with realignment osteotomy leads to less femoral deformity and potentially better outcomes. However, it has a higher risk of complications, including AVN and chondrolysis. Our knowledge of the etiology for SCFE is evolving. The optimal technique for operative treatment of moderate to severe SCFE is controversial and varies by center. Well-controlled studies of these patients are needed to understand the best treatment for this difficult problem. Furthermore, increasing the awareness about SCFE is paramount to allow for early recognition and treatment of deformity at its early stages and avoiding severe SCFE deformity which has been associated with worse long-term outcomes.

Persisting CAM deformity is associated with early cartilage degeneration after Slipped Capital Femoral Epiphysis: 11-year follow-up including dGEMRIC

OBJECTIVE

Slipped capital femoral epiphysis (SCFE) in adolescence is associated with increased risk of future osteoarthritis (OA). The purpose of this study was to study clinical and radiographic risk factors for early cartilage degeneration after SCFE.

DESIGN

22 patients (44 hips) (mean age 24 years, range 18-27) treated with in situ fixation (The Hansson hook-pin) for stable SCFE on average 11 years previously were investigated. Cartilage status was assessed with delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC). The alpha angle, reflecting femoroacetabular impingement (FAI), and the original slip angle were measured. Clinical outcome was assessed with the Copenhagen hip and groin outcome score (HAGOS) and clinical examination.

RESULTS

The dGEMRIC index was lower in SCFE hips than unaffected hips 456 ms (CI 419-493) vs 521 ms (CI 476-567) (P = 0.03). The difference was larger (mean 21 ms) in anterior than posterior regions of the hip (P = 0.038). The alpha angle was higher in SCFE hips, 61.5° (CI 53.9-69.1) vs 45.6° (CI 43.6-47.6), (P < 0.001). The alpha angle, but not the original slip angle, correlated negatively with the dGEMRIC index (R = -0.40, P = 0.046). There was a positive correlation between HAGOS and the dGEMRIC-index (R = 0.41, P = 0.012).

CONCLUSIONS

Early cartilage degeneration after SCFE seems related to persisting FAI in adulthood, rather than the initial slip severity. The correlation between dGEMRIC and HAGOS indicates a clinical relevance of the MRI findings. Our results suggest that FAI after SCFE should be evaluated already after physeal closure in order to predict and possibly prevent future OA development.

Early osteoarthritis after slipped capital femoral epiphysis

Background and purpose - Slipped capital femoral epiphysis (SCFE) results in a more or less pronounced deformity of the proximal femur, sometimes causing impingement and early osteoarthritis. We studied early osteoarthritis after SCFE and the association with deformity and self-reported hip function, pain, and quality of life. Patients and methods - 9 women and 16 men, mean age 32 (21-50) years, 19 with unilateral and 6 with bilateral SCFE, participated. All patients had primarily been operated by pin or screw with no attempt at reposition of the slip. Hips were examined by delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), which quantifies and locates cartilage degeneration. Plain radiographs were used to measure deformity as determined by the alpha angle. Outcome was assessed by Oxford hip score, Hip Groin Outcome score and EQ-5D-Visual scale. Results - In the 19 unilateral SCFE, on the slip side dGEMRIC mean value was 533 ms (SD 112, range 357-649) versus mean 589 ms (SD 125, range 320-788) on the non-slip side, (p = 0.01). The dGEMRIC correlated negatively to the alpha angle, correlation coefficient (CC) = -0.60, (p = 0.002). Oxford hip score, pain, and EQ-5D-Visual scale correlated to dGEMRIC CC =0.43 (p = 0.03), CC =0.40 (p = 0.05), and CC =0.49 (p = 0.01) respectively. Interpretation - After SCFE, even relatively mild residual hip deformity can be associated with cartilage degeneration. A high alpha angle was associated with worse cartilage status. The Oxford hip score identified symptoms even though our patients had not previously sought medical care after the index operation. Quality of life showed strong inverse correlation with cartilage degeneration. Objective assessment of early cartilage degeneration may be useful for treatment decisions and follow-up.

Continued Growth of the Femoral Neck Leads to Improved Remodeling After In Situ Fixation of Slipped Capital Femoral Epiphysis

BACKGROUND

Globally, the most common method for in situ fixation of slipped capital femoral epiphysis (SCFE) is a threaded screw, which causes physeal arrest. The standard treatment in Sweden is unthreaded fixation using the Hansson hook-pin, which leads to continued growth of the femoral neck. Our purpose was to study remodeling during the remaining growth after fixation with the Hansson hook-pin.

METHODS

We performed a retrospective study of 54 patients with SCFE who were treated with the Hansson hook-pin between 2001 and 2009. The immediate postoperative radiograph and the radiograph taken after physeal closure (mean interval, 34 mo) were analyzed. Three radiographic assessments were used: the head-shaft angle (HSA), the alpha angle (Nötzli), and the displacement from Klein's line.

RESULTS

Significant remodeling was detected in all measured parameters. The mean postoperative HSA decreased by 9.0 degrees (P<0.001). The alpha angle improved by a mean of 14.5 degrees (P<0.001). Significant correlations were found between the reduction of the alpha angle and age (P<0.001, R=0.48) and longitudinal growth of the femoral neck (P<0.001, R=0.67). Displacement from Klein's line increased by a mean of 1.6 mm (P=0.006).

CONCLUSIONS

Unthreaded fixation of SCFE using the Hansson hook-pin leads to substantial remodeling of the femoral neck. The positive correlation observed between the improvement of the alpha angle and femoral neck growth supports the use of a method that allows continuous growth, to reduce the risk of femoroacetabular impingement.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

SCFE: clinical aspects, diagnosis, and classification

PURPOSE

This article seeks to improve treatment outcomes in slipped capital femoral epiphysis (SCFE) by outlining advances in diagnosis, understanding of pathomechanics, and mechanically-based classification.

METHODS

Review of clinical experience with SCFE at our high-volume centre, interaction with other clinical experts, and literature review has allowed a current perspective to be articulated.

RESULTS

SCFE remains an important clinical problem, with late diagnosis still frequent. Improved understanding of the ubiquity of femoroacetabular impingement has guided current classification and treatment protocols.

CONCLUSION

SCFE is an important clinical problem, with high historical rates of impaired hip function both in childhood and adulthood. Great opportunities exist for improved outcomes following earliest possible clinical diagnosis, modern imaging, and mechanically-based classification of involved hips to allow optimal treatment.

Imaging modalities in patients with slipped capital femoral epiphysis

BACKGROUND

Slipped capital femoral epiphysis (SCFE) is a frequent disorder of the adolescent hip, which may lead to avascular necrosis (AVN) of the femoral head, chondrolysis and early osteoarthritis due to the post-slip deformity of the proximal femur. To warrant the best possible outcome for the affected (and contralateral) hip, early diagnosis and proper treatment are needed.

METHODS

A review of the literature was undertaken to identify today's role of available imaging modalities in the management of SCFE.

SUMMARY

This review outlines the relevancy of different imaging modalities such as radiography, ultrasound, CT, MRI and bone scintigraphy in the treatment of SCFE patients. While standard radiography is the first-choice imaging modality for patients with suspected SCFE, ultrasound and advanced imaging modalities may aid in surgical planning, diagnosis of complications such as AVN and treatment follow-up.

Feasibility of Dual Flip Angle-Based Fast 3-Dimensional T1 Mapping for Delayed Gadolinium-Enhanced Magnetic Resonance Imaging of Cartilage of the Knee: A Histologically Controlled Study

OBJECTIVE

The aim of the study was to validate dual-flip angle-based fast 3-dimensional (3D) T1 mapping for delayed gadolinium-enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) by means of histological analyses in the assessment of the cartilage of the knee in a porcine model.

METHODS

A total of 15 mini pigs were included in this study. The left knee anterior cruciate ligaments of all mini pigs were transected. The mini pigs were divided into 3 groups postoperatively, with 5 pigs randomly assigned to 1 group. Dual-flip angle-based fast T1 mapping for dGEMRIC was obtained in the sagittal planes at 0 week (group 1), 3 weeks (group 2), and 6 weeks (group 3) after operation, using an 8-channel knee coil. Magnetic resonance imaging was performed at 3T with dual-flip angle-based fast 3D T1 mapping sequence for morphological cartilage assessment of dGEMRIC T1 values. After MRI analysis, histological and biochemical composition (water, collagen, and glycosaminoglycan [GAG]) of the knee cartilage in the medial femoral condyle was quantified ex vivo.

RESULTS

The T1 values obtained by the dual-flip angle-based fast 3D T1 mapping were positively correlated with the glycosaminoglycan content (r = 0.85; P < 0.05). The values had no significant correlation with the collagen content. The dGEMRIC-T1 values obtained by this method showed the medial femoral condyle cartilage in the anterior cruciate ligament-transected knee after transection decreased with time (P < 0.05). Histological sections of cartilage damage were correlated with MRI data.

CONCLUSIONS

This study demonstrated the reliability of using dual-flip angle-based fast T1 mapping for dGEMRIC for the biochemical assessment of early cartilage degeneration. This technique is a powerful tool for researchers and clinicians to acquire sufficient resolution data within a reasonable scan time.

Current concepts in management of slipped capital femoral epiphysis

Slipped capital femoral epiphysis (SCFE) is a common hip condition that can be disabling. In this review, we provide an orientation on current trends in the clinical management of SCFE including conventional procedures and specialised surgical developments. Different methods of fixation of the epiphysis, risks of complications, and the rationale of addressing deformity, primarily or secondarily, are presented. Although improved understanding of the anatomy, vascularity and implications of residual deformity have changed management strategies, the best modality of treatment that would restore complete vascularity to the femoral head and prevent any residual deformity, impingement and early osteoarthritis remains elusive.

Current knowledge and importance of dGEMRIC techniques in diagnosis of hip joint diseases

Accurate assessment of early hip joint cartilage alterations may help optimize patient selection and follow-up of hip joint preservation surgery. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is sensitive to the glycosaminoglycan content in cartilage that is lost early in the development of osteoarthritis (OA). Hence, the dGEMRIC technique holds promise for the development of new diagnostic and therapeutic procedures. However, because of the location of the hip joint deep within the body and due to the fairly thin cartilage layers that require high spatial resolution, the diagnosis of early hip joint cartilage alterations may be problematic. The purpose of this review is to outline the current status of dGEMRIC in the assessment of hip joint cartilage. A literature search was performed with PubMed, using the terms "cartilage, osteoarthritis, hip joint, MRI, and dGEMRIC", considering all levels of studies. This review revealed that dGEMRIC can be reliably used in the evaluation of early stage cartilage pathology in various hip joint disorders. Modifications in the technique, such as the operation of three-dimensional imaging and dGEMRIC after intra-articular contrast medium administration, have expanded the range of application. Notably, the studies differ considerably in patient selection and technical prerequisites. Furthermore, there is a need for multicenter prospective studies with the required technical conditions in place to establish outcome based dGEMRIC data to obtain, in conjunction with clinical data, reliable threshold values for normal and abnormal cartilage, and for hips that may benefit from conservative or surgical treatment.

OARSI Clinical Trials Recommendations: Hip imaging in clinical trials in osteoarthritis

Imaging of hip in osteoarthritis (OA) has seen considerable progress in the past decade, with the introduction of new techniques that may be more sensitive to structural disease changes. The purpose of this expert opinion, consensus driven recommendation is to provide detail on how to apply hip imaging in disease modifying clinical trials. It includes information on acquisition methods/techniques (including guidance on positioning for radiography, sequence/protocol recommendations/hardware for magnetic resonance imaging (MRI)); commonly encountered problems (including positioning, hardware and coil failures, artifacts associated with various MRI sequences); quality assurance/control procedures; measurement methods; measurement performance (reliability, responsiveness, and validity); recommendations for trials; and research recommendations.

Arthroscopic treatment of mild to moderate deformity after slipped capital femoral epiphysis: intra-operative findings and functional outcomes

PURPOSE

To identify intra-articular pathology during arthroscopic osteochondroplasty for slipped capital femoral epiphysis (SCFE)-related femoroacetabular impingement and determine functional outcomes after treatment.

METHODS

Nine hips in 9 patients (6 male and 3 female patients; mean age, 17.5 years; age range, 13.5 to 26.9 years) underwent hip arthroscopy for femoroacetabular impingement after in situ pinning of the SCFE. Medical records, radiographs, and intraoperative images were reviewed to determine the severity of disease and damage to the hip joints. For all patients, we obtained the modified Harris Hip Score and Hip Outcome Score (HOS) preoperatively and at a minimum of 12 months postoperatively, as well as a Likert scale of perceived change in physical activity.

RESULTS

All 9 treated patients had some degree of labral or acetabular cartilage injury at the time of arthroscopy, which was a mean of 58.6 months (range, 18 to 169 months) after in situ pinning. The alpha angle improved from 75° preoperatively to 46° postoperatively (P < .001). The mean follow-up period was 28.6 months (range, 12.6 to 55.6 months). The mean modified Harris Hip Score improved from 63.6 preoperatively to 91.4 postoperatively (P = .005). Similarly, the mean HOS activities-of-daily living scale improved from 70.2 to 93.3 (P = .010), and the HOS sports scale improved from 53.4 to 88.9 (P = .004). Most patients reported significant improvement on a physical-activity Likert scale, with 4 reporting much improved, 3 reporting improved, and 1 reporting slightly improved physical activity. One patient reported an unchanged activity level. No patients reported a worse activity level after surgery.

CONCLUSIONS

Post-SCFE cartilage and/or labral damage develops in patients with symptomatic mild to moderate SCFE deformity, and arthroscopic treatment improved functional outcomes in a small cohort of patients at short-term follow-up.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Southwick osteotomy stabilised with external fixator

Introduction:

Epiphysiolysis of the femoral head is the most common accident occurring towards the end of pre-puberty and puberty growth.

Case report:

The author describes the experience in the treatment of chronic epiphysiolysis in two patients treated by Southwick osteotomy. The site is accessed by way of a 15-cm long lateral skin incision and the trochanteric region is reached through the layers. The osteotomy angles prepared beforehand on a thin aluminium model are used to mark the Southwick osteotomy site on the anterior and lateral sides at the level of the lesser trochanter. Before performing the trochanteric osteotomy, two Mitković convergent pins type M20 are applied distally and proximally, above the planned osteotomy site. A tenotomy of the iliopsas muscle is performed, and then the previously marked bone triangle is redissected up to three quarters of the width of the femur. The distal part of the femur is rotated inwards, so that the patella is turned towards the ceiling. The osteotomised fragments of the femur are adapted, repositioned and fixated by installing an external fixator on the previously placed pins. Two more pins are placed, one proximally and one distally, with a view to adequately stabilising the femur. The patient was mobile from day two after the surgery. If, after the surgery, the lead surgeon realises that there is a requirement to make a correction of 5, 10 and 15 degrees of the valgus, varus, anteversion or retroversion deformity, the correction shall be performed without surgically opening the patient, using the fixator pins.

Conclusion:

After performing a Southwick osteotomy it is easier to adapt, reposition and fixate the osteotomised fragments of the femur using a fixator type M20. Adequate stability allows regaining mobility quickly, which in turn is the best prevention of chondrolysis of the hip. It is possible to make post-operative valgus, varus, anteversion and retroversion corrections of 5, 10 and 15 degrees without performing a surgery. Once the osteotomy is healed, the fixator type M20 is removed without any additional surgery.

Cartilage repair surgery: outcome evaluation by using noninvasive cartilage biomarkers based on quantitative MRI techniques?

BACKGROUND

New quantitative magnetic resonance imaging (MRI) techniques are increasingly applied as outcome measures after cartilage repair.

OBJECTIVE

To review the current literature on the use of quantitative MRI biomarkers for evaluation of cartilage repair at the knee and ankle.

METHODS

Using PubMed literature research, studies on biochemical, quantitative MR imaging of cartilage repair were identified and reviewed.

RESULTS

Quantitative MR biomarkers detect early degeneration of articular cartilage, mainly represented by an increasing water content, collagen disruption, and proteoglycan loss. Recently, feasibility of biochemical MR imaging of cartilage repair tissue and surrounding cartilage was demonstrated. Ultrastructural properties of the tissue after different repair procedures resulted in differences in imaging characteristics. T2 mapping, T1rho mapping, delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), and diffusion weighted imaging (DWI) are applicable on most clinical 1.5 T and 3 T MR scanners. Currently, a standard of reference is difficult to define and knowledge is limited concerning correlation of clinical and MR findings. The lack of histological correlations complicates the identification of the exact tissue composition.

CONCLUSIONS

A multimodal approach combining several quantitative MRI techniques in addition to morphological and clinical evaluation might be promising. Further investigations are required to demonstrate the potential for outcome evaluation after cartilage repair.

Imaging SCFE: diagnosis, treatment and complications

Slipped capital femoral epiphysis (SCFE) is a common orthopedic disorder in children. It can lead to avascular necrosis, cartilage loss, femoroacetabular impingent (FAI) and early osteoarthritis. The consequences of SCFE are worsened by delays in diagnosis and proper management. Radiography is the primary imaging modality used to evaluate SCFE; however, MR, CT and bone scintigraphy have important roles. Preoperatively, these modalities assist in surgical planning and predicting prognosis; postoperatively, they provide assessment of hardware failure, ischemic necrosis and morphology predisposing to FAI. Emphasizing a multimodality approach, this review addresses the imaging diagnosis of SCFE, the expected postoperative appearances and the findings of immediate and long-term complications.

Imaging biomarker with T1ρ and T2 mappings in osteoarthritis - in vivo human articular cartilage study

INTRODUCTION

Osteoarthritis (OA) of the knee is a common and disabling disease worldwide. Its prevalence is increasing in view of the aging population. Changes in collagen content, its orientation and GAG content in the articular cartilage with age are the major features in knee osteoarthritis. These changes in collagen and GAG contents show no manifestation in plain radiography and conventional magnetic resonance imaging (MRI). Nevertheless, early diagnosis of the knee osteoarthritis is of paramount importance clinically in view of the evolution of putative interventions in its early stage. The aim of this project is to identify the relationships between the two imaging biomarkers (i.e. T1ρ and T2 mappings) and the GAG concentration in living human symptomatic cartilage.

METHODOLOGY

28 patients with clinical diagnosis of knee osteoarthritis were enrolled. 7 males and 16 females were recruited and their mean age was 68.1 (ranges from 53 to 84). Conventional PD sequence, T1ρ and T2 mappings were performed for each subject within 1 week before total knee arthroplasty. Articular cartilage from the lateral tibial plateau was harvested and the GAG content in cartilage was determined by using dimethylmethylene blue method. T1ρ mean and T2 values were calculated and correlate with GAG concentration statistically.

RESULTS

The mean value T1ρ was 40.3±13.5ms, ranging from 15.3 to 69.3ms and the mean value T2 was 31.0±10.5ms, ranging from 16.1 to 46.9ms. The mean value of GAG content was 80.1±33.3mg, ranging from 24.9 to 166.0mg while the mean value of GAG concentration was 267.4±165.9mg/cm(3), ranging from 91.3 to 760.5mg/cm(3). T2 values were inversely correlated with GAG concentration with R(2)=0.375, p=0.001 while T1ρ values were also inversely correlated with GAG concentration with R(2)=0.200, p=0.025.

CONCLUSION

This in vivo study confirmed that T1ρ and T2 values correlate with the GAG concentration in living human knee cartilages which corroborate with the previous works. The later (T2 values) is found more reliable in our study and less controversial in literatures. We postulate that T2 values can serve as a non-invasive imaging biomarker in the progress of knee osteoarthritis in terms of both disease diagnosis and treatment response monitoring.

Anterior delayed gadolinium-enhanced MRI of cartilage values predict joint failure after periacetabular osteotomy

BACKGROUND

Several available compositional MRIs seem to detect early osteoarthritis before radiographic appearance. Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) has been most frequently used in clinical studies and reportedly predicts premature joint failure in patients undergoing Bernese periacetabular osteotomies (PAOs).

QUESTIONS/PURPOSES

We asked, given regional variations in biochemical composition in dysplastic hips, whether the dGEMRIC index of the anterior joint would better predict premature joint failure after PAOs than the coronal dGEMRIC index as previously reported.

METHODS

We retrospectively reviewed 43 hips in 41 patients who underwent Bernese PAO for hip dysplasia. Thirty-seven hips had preserved joints after PAOs and six were deemed premature failures based on pain, joint space narrowing, or subsequent THA. We used dGEMRIC to determine regional variations in biochemical composition. Preoperative demographic and clinical outcome score, radiographic measures of osteoarthritis and severity of dysplasia, and dGEMRIC indexes from different hip regions were analyzed in a multivariable regression analysis to determine the best predictor of premature joint failure. Minimum followup was 24 months (mean, 32 months; range, 24-46 months).

RESULTS

The two cohorts were similar in age and sex distribution. Severity of dysplasia was similar as measured by lateral center-edge, anterior center-edge, and Tönnis angles. Preoperative pain, joint space width, Tönnis grade, and coronal and sagittal dGEMRIC indexes differed between groups. The dGEMRIC index in the anterior weightbearing region of the hip was lower in the prematurely failed group and was the best predictor.

CONCLUSIONS

Success of PAO depends on the amount of preoperative osteoarthritis. These degenerative changes are seen most commonly in the anterior joint. The dGEMRIC index of the anterior joint may better predict premature joint failure than radiographic measures of hip osteoarthritis and coronal dGEMRIC index.

LEVEL OF EVIDENCE

Level II, prognostic study. See Instructions for Authors for a complete description of levels of evidence.

Novel cartilage imaging techniques for hip disorders

Hip deformity such as acetabular dysplasia and cam and pincer deformities are thought to be a major cause of hip osteoarthritis. Currently, clinically effective surgical procedures such as pelvic osteotomies and femoral and acetabular osteoplasties are available to correct the underlying deformity. These procedures are most effective in the presence of minimal chondral damage in the joint. Currently, and more so in the future, high-resolution morphologic imaging and biochemical imaging techniques such as Delayed gadolinium-enhanced MR imaging of cartilage, T2, and T1rho will have a clinically important role in diagnosing and staging chondral damage in the hip.

Imaging hip dysplasia in the skeletally mature

Hip disorders in the young adult manifest along a continuum that ranges from an excessively constrained, impinging joint, to an overly shallow, unstable hip. Knowledge of simple measures on plain radiographs can aid in efficient and accurate identification of mechanically compromised hips that may be at risk for premature OA. Improvements in joint-preserving surgery have shown promise in delaying or preventing progression of articular degeneration; thus, timely diagnosis is important. Once a diagnosis is established, specialized imaging can be individualized to supplement surgical planning, assess the degree of cartilage damage, and facilitate discussion regarding the prognosis of hip-preserving procedures.

Three-dimensional delayed gadolinium-enhanced magnetic resonance imaging of hip joint cartilage at 3T: a prospective controlled study

PURPOSE

To assess acetabular and femoral hip joint cartilage with three-dimensional (3D) delayed gadolinium-enhanced magnetic resonance imaging (dGEMRIC) in patients with degeneration of hip joint cartilage and asymptomatic controls with morphologically normal appearing cartilage.

METHODS AND MATERIALS

A total of 40 symptomatic patients (18 males, 22 females; mean age: 32.8±10.2 years, range: 18-57 years) with different hip joint deformities including femoroacetabular impingement (n=35), residual hip dysplasia (n=3) and coxa magna due to Legg-Calve-Perthes disease in childhood (n=2) underwent high-resolution 3D dGEMRIC for the evaluation of acetabular and femoral hip joint cartilage. Thirty-one asymptomatic healthy volunteers (12 males, 19 females; mean age: 24.5±1.8 years, range: 21-29 years) without underlying hip deformities were included as control. MRI was performed at 3 T using a body matrix phased array coil. Region of interest (ROI) analyses for T1Gd assessment was performed in seven regions in the hip joint, including anterior to superior and posterior regions.

RESULTS

T1Gd mapping demonstrated the typical pattern of acetabular cartilage consistent with a higher glycosaminoglycan (GAG) content in the main weight-bearing area. T1Gd values were significantly higher in the control group than in the patient group whereas significant differences in T1Gd values corresponding to the amount of cartilage damage were noted both in the patient group and in the control group.

CONCLUSIONS

Our study demonstrates the potential of high-resolution 3D dGEMRIC at 3 T for separate acetabular and femoral hip joint cartilage assessment in various forms of hip joint deformities.

Arthroscopy of the hip for paediatric and adolescent disorders

Hip arthroscopy is particularly attractive in children as it confers advantages over arthrotomy or open surgery, such as shorter recovery time and earlier return to activity. Developments in surgical technique and arthroscopic instrumentation have enabled extension of arthroscopy of the hip to this age group. Potential challenges in paediatric and adolescent hip arthroscopy include variability in size, normal developmental change from childhood to adolescence, and conditions specific to children and adolescents and their various consequences. Treatable disorders include the sequelae of traumatic and sports-related hip joint injuries, Legg–Calve–Perthes’ disease and slipped capital femoral epiphysis, and the arthritic and septic hip. Intra-articular abnormalities are rarely isolated and are often associated with underlying morphological changes.

This review presents the current concepts of hip arthroscopy in the paediatric and adolescent patient, covering clinical assessment and investigation, indications and results of the experience to date, as well as technical challenges and future directions.

Comparison of MR-arthrography and MDCT-arthrography for detection of labral and articular cartilage hip pathology

OBJECTIVE

To compare the diagnostic ability of MR arthrography (MRa) and MDCT arthrography (CTa) in depicting surgically proven hip labral tears and articular cartilage degradation.

MATERIALS AND METHODS

Labral pathology and articular cartilage were prospectively evaluated with MRa and CTa in 14 hips of 10 patients. The findings were evaluated by two independent observers (a musculoskeletal fellow and one senior musculoskeletal radiologist). Sensitivity, specificity, accuracy, and positive predictive value were determined using arthroscopic and open surgery findings as the standard of reference. Interobserver agreement was recorded. All images were assessed for the presence of a labral tear (according to Czerny classification) and for cartilage erosion using a 3 point scale for both methods: 1 = complete visualization-sharp edges, 2 = blurred edges fissuring-partial defects, 3 = exposed bone. The same classification was applied surgically.

RESULTS

Disagreement between the senior observer and the fellow observer was recorded in three cases of labral tearing with MRa and six with CTa. Disagreement was also found in four cases of cartilage erosion with both MRa and CTa. The percent sensitivity, specificity, accuracy, and positive predictive value for correctly assessing the labral tear were as follows for MRa/CTa, respectively: 100/15, 50/13, 90/14, and 90/13 (P < 0.05). The same values for cartilage assessment were 63/66, 33/40, 50/57 and 55/66 (P > 0.05).

CONCLUSION

Interobserver reproducibility with MRa is very good for labral tearing assessment. MRa is better for assessing labral tears. CTa shows better, but not statistically significant, demonstration of the articular cartilage.

Magnetic resonance imaging of hip joint cartilage and labrum

Hip joint instability and impingement are the most common biomechanical risk factors that put the hip joint at risk to develop premature osteoarthritis. Several surgical procedures like periacetabular osteotomy for hip dysplasia or hip arthroscopy or safe surgical hip dislocation for femoroacetabular impingement aim at restoring the hip anatomy. However, the success of joint preserving surgical procedures is limited by the amount of pre-existing cartilage damage. Biochemically sensitive MRI techniques like delayed Gadolinium Enhanced MRI of Cartilage (dGEMRIC) might help to monitor the effect of surgical or non-surgical procedures in the effort to halt or even reverse joint damage.