Elevation in circulating biomarkers of cartilage damage and inflammation in athletes with femoroacetabular impingement

Femoroacetabular Impingement and the Effect of Osteochondroplasty on Hip Osteoarthritis Prevention: The Pandora's Box Opening Process

OBJECTIVE

This study was conducted to assess the effect of osteochondroplasty on osteoarthritis (OA) prevention, comparing radiological evolution between identical hips from the same patient who had undergone unilateral surgery.

DESIGN

We retrospectively reviewed radiological evolution between hips with similar shape from the same patient who had undergone unilateral surgery. In all, 56 FAI patients (112 hips) with a mean age of 42.18 ± 9.16 years and had undergone unilateral arthroscopy treatment have been included. Four independent researchers measured Wiberg, Acetabular and Alpha angles, Extrusion index, and Tönnis classification preoperatively to verify that operated and non-operated hips had the same shape. OA evolution was assessed by joint space width (JSW) in 3 different articular points and Tönnis classification.

RESULTS

No preoperative anatomical differences were present between groups (P > 0.05). At the end of follow-up (31.9 months), a decrease of JSW in the 3 points measured was found in OP hips (OP vs. N-OP; P < 0.01). These results were correlated with changes in the proportion of patients who progressed to grade III in Tönnis classification (from 1.3% preoperative to 23.2% at the end of follow-up).

CONCLUSIONS

Osteochondroplasty and labrum procedures were not associated with OA prevention. The OP hips showed a faster OA degeneration, which was not seen in the N-OP. These results will encourage hip surgeons to perform further investigations to avoid the "Pandora's Box Opening Process."

Inflammatory and Immunologic Contributions in Femoroacetabular Impingement Syndrome

Femoroacetabular impingement (FAI) is one of the most common causes of labral and early cartilage damage in the nondysplastic hip. FAI is increasingly recognized as a cause for hip and groin pain in the young, active patient, and the surgical treatment of FAI with hip arthroscopy has risen exponentially. Although our understanding of FAI and the progression to degenerative osteoarthritis of the hip has historically been considered a mechanical "wear-and-tear" disease of an imperfectly shaped, aspherical, femoral head within a deep or overcovering acetabulum leading to cartilage injury, our understanding of the intrinsic pathophysiologic mechanisms underlying the development of FAI and joint degeneration of the hip remains poor. For example, many patients with FAI morphology may never develop hip pain or osteoarthritis; there remains more to discover regarding the pathophysiology of arthritis in the setting of FAI. Recent work has begun to identify a strong inflammatory and immunologic component to the FAI disease process that affects the hip synovium, labrum, and cartilage and may be detectable from peripheral clinical samples (blood and urine). This review highlights our current understanding of the inflammatory and immunologic contributions to FAI and potential therapeutic strategies to supplement and augment the surgical management of FAI.

The effect of conjugated linoleic acids on inflammation, oxidative stress, body composition and physical performance: a comprehensive review of putative molecular mechanisms

Conjugated linoleic acids (CLAs) are polyunsaturated fatty acids primarily found in dairy products and ruminant animal products such as beef, lamb, and butter. Supplementation of CLAs has recently become popular among athletes due to the variety of health-promoting effects, including improvements in physical performance. Preclinical and some clinical studies have shown that CLAs can reduce inflammation and oxidative stress and favorably modulate body composition and physical performance; however, the results of previously published clinical trials are mixed. Here, we performed a comprehensive review of previously published clinical trials that assessed the role of CLAs in modulating inflammation, oxidative stress, body composition, and select indices of physical performance, emphasizing the molecular mechanisms governing these changes. The findings of our review demonstrate that the effect of supplementation with CLAs on inflammation and oxidative stress is controversial, but this supplement can decrease body fat mass and increase physical performance. Future well-designed randomized clinical trials are warranted to determine the effectiveness of (1) specific doses of CLAs; (2) different dosing durations of CLAs; (3) various CLA isomers, and the exact molecular mechanisms by which CLAs positively influence oxidative stress, inflammation, body composition, and physical performance.

Whole-genome RNA sequencing identifies distinct transcriptomic profiles in impingement cartilage between patients with femoroacetabular impingement and hip osteoarthritis

Femoroacetabular impingement (FAI) has a strong clinical association with the development of hip osteoarthritis (OA); however, the pathobiological mechanisms underlying the transition from focal impingement to global joint degeneration remain poorly understood. The purpose of this study is to use whole-genome RNA sequencing to identify and subsequently validate differentially expressed genes (DEGs) in femoral head articular cartilage samples from patients with FAI and hip OA secondary to FAI. Thirty-seven patients were included in the study with whole-genome RNA sequencing performed on 10 gender-matched patients in the FAI and OA cohorts and the remaining specimens were used for validation analyses. We identified a total of 3531 DEGs between the FAI and OA cohorts with multiple targets for genes implicated in canonical OA pathways. Quantitative reverse transcription-polymerase chain reaction validation confirmed increased expression of FGF18 and WNT16 in the FAI samples, while there was increased expression of MMP13 and ADAMTS4 in the OA samples. Expression levels of FGF18 and WNT16 were also higher in FAI samples with mild cartilage damage compared to FAI samples with severe cartilage damage or OA cartilage. Our study further expands the knowledge regarding distinct genetic reprogramming in the cartilage between FAI and hip OA patients. We independently validated the results of the sequencing analysis and found increased expression of anabolic markers in patients with FAI and minimal histologic cartilage damage, suggesting that anabolic signaling may be increased in early FAI with a transition to catabolic and inflammatory gene expression as FAI progresses towards more severe hip OA. Clinical significance:Cam-type FAI has a strong clinical association with hip OA; however, the cellular pathophysiology of disease progression remains poorly understood. Several previous studies have demonstrated increased expression of inflammatory markers in FAI cartilage samples, suggesting the involvement of these inflammatory pathways in the disease progression. Our study further expands the knowledge regarding distinct genetic reprogramming in the cartilage between FAI and hip OA patients. In addition to differences in inflammatory gene expression, we also identified differential expression in multiple pathways involved in hip OA progression.

Ultrasonographic Evaluation of the Metacarpal Cartilage Thicknesses in Weightlifters and Volleyball Players

OBJECTIVE

The aim of the study was to evaluate the possible effects of impact and loading on the metacarpal cartilage and hand functions in young elite athletes.

DESIGN

In this cross-sectional study athletes with at least 3 yrs of sport background and who have been under a scheduled training program were enrolled. The second to fifth fingers' metacarpal head cartilage thicknesses were measured bilaterally by using ultrasonography. Handgrip and pinch strengths were measured. Michigan Hand Outcomes Questionnaire was also completed for every participant.

RESULTS

A total of 42 male athletes (19 weightlifters, 23 volleyball players) and 46 healthy control subjects were enrolled. Metacarpal cartilage thicknesses of the athletes were thicker than those of the healthy controls (all P < 0.001). There were no differences between the dominant and nondominant hands (all P > 0.05). In the weightlifting group, Michigan Hand Outcomes Questionnaire work performance and pain scores were worse than the other groups (both P < 0.001).

CONCLUSIONS

The presence of increased cartilage thickness measurements in the athletes suggests that sports activities might affect the metacarpal articular cartilage. Highest pain scores and lowest work performance scores in the weightlifters with highest metacarpal cartilage thickness might suggest that impact and loading during their sports play could lead to cartilage edema.

Hip Preservation Surgery in Osteoarthritis Prevention: Potential Benefits of the Radiographic Angular Correction

Objective: The aim of the study is to describe the morphology associated with the development of osteoarthritis (OA) in three different age groups. These data will contribute to defining the morphology associated with early and late hip OA. Methods: We studied 400 hips in 377 patients who had undergone primary THA due to idiopathic OA. Three groups were compared: group 1 (n = 147), younger patients, aged up to 60 years; group 2 (n = 155), patients aged between 61 and 74 years; and group 3 (n = 98), aged 75 or over. Five independent researchers measured the hip angles and the mean values were used to build a database. Results: No differences between groups in sex distribution and BMI were detected. Less coverage of the head (extrusion index), higher Tönnis angle, lower Wiberg and alpha angles characterized early OA hips. These differences increased with age, being greater between group 2 and group 3 (p < 0.01). However, significant differences were still present in the comparison between group 1 and group 2 (p < 0.01)). No differences were detected between group 2 and group 3. Conclusion: Elevated acetabular angle, head extrusion and decreased Wiberg angle characterize hip osteoarthritis at younger ages and should be the focus of hip preservation surgery in terms of osteoarthritis prevention. Pincer-type FAI (higher Wiberg and lower Tönnis angle) and higher alpha angle (CAM) are correlated with the development of later OA. These results shed doubt on applying the hip preservation surgery concept in terms of osteoarthritis prevention in FAI, especially in Pincer-type FAI patients.

Shoulder Lesions Do Not Increase Inflammatory Biomarkers in Patients Undergoing Surgery for Glenohumeral Instability: An Exploratory Study

Circulating protein biomarkers have demonstrated utility as a diagnostic tool in predicting musculoskeletal disease severity, but their utility in the evaluation of shoulder lesions associated with shoulder instability is unknown. Thus, the purpose of this exploratory study was to determine whether preoperative biomarkers of cartilage turnover and inflammation are associated with specific shoulder lesions in shoulder instability. Thirty-three patients (29.9 ± 9.4 years of age, 4.5 ± 4.7 dislocations) undergoing surgical treatment for shoulder instability were assessed for the presence or absence of associated shoulder lesions. Biomarkers including cartilage oligomeric matrix protein (COMP), C-reactive protein (HS-CRP), interleukin-8 (IL-8), and macrophage inflammatory protein-1β (MIP-1b) were collected at the time of surgery. Patients with Hill-Sachs lesions had a 31% increase in COMP plasma levels (p=0.046). No other significant differences were observed for COMP, HS-CRP, IL-8, and MIP-1b with any shoulder lesion including Hill-Sachs lesions, capsular injuries, bony Bankart lesions, and SLAP lesions. In conclusion, inflammatory biomarkers including HS-CRP, IL-8, and MIP-1b were not associated with specific shoulder lesions, while biomarkers of cartilage turnover (COMP) were only elevated in Hill-Sachs lesions. These findings suggest that these biomarkers may have limited utility as prognostic indicators in patients with shoulder instability, though large-scale and longitudinal studies are still necessary.

Preoperative Intra-articular Steroid Injections as Predictors of Hip Arthroscopy: 2-Year Outcomes

BACKGROUND

In patients with femoroacetabular impingement, preoperative diagnostic injections are commonly used to establish a diagnosis of intra-articular pathology. In some cases, intra-articular steroid injections are also used for therapeutic purposes.

PURPOSE/HYPOTHESIS

The purpose of this study was to determine if a positive response to intra-articular steroid injection was predictive of superior outcomes after hip arthroscopy to determine if the response to intra-articular steroid injection was predictive of outcomes after hip arthroscopy. It was hypothesized that a positive response to a preoperative hip injection would be predictive of improved short- to midterm outcomes after hip arthroscopy.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This was a retrospective study of 208 patients who elected to have ultrasound-guided intra-articular steroid injection before they underwent hip arthroscopy between January 2016 and December 2016. Patients were divided into 2 groups: those who showed improvement in pain after the injection (steroid responder group) and those who showed no response (nonresponder group). The authors compared the preoperative and 2-year postoperative patient-reported outcomes (modified Harris Hip Score [mHHS] and Hip Outcome Score-Activities of Daily Living [HOS-ADL]) and radiographic findings between groups. Clinical endpoints, including rates of revision and conversion to total hip arthroplasty, were also reviewed.

RESULTS

There were 88 patients in the nonresponder group and 120 patients in the responder group, with no significant between-group differences in preoperative descriptive variables. The responder group had significantly higher 2-year mHHS and HOS-ADL, pre- to postoperative change in mHHS and HOS-ADL, percentage of patients achieving the patient acceptable symptomatic state (PASS) on the mHHS, and percentage of patients reaching the minimum clinically important difference and the PASS on the HOS-ADL. There was no difference in Tönnis grade, acetabular labrum articular disruption grade, revision rate, or conversion to total hip arthroplasty between the 2 groups.

CONCLUSION

The response to preoperative intra-articular injection did aid in predicting 2-year patient-reported outcomes of hip arthroscopy for femoroacetabular impingement. Overall, the result of a preoperative intra-articular injection can be a helpful clinical tool for surgical decision-making and counseling patients on expected outcomes after hip arthroscopy.

Changes in levels of cartilage oligomeric proteinase and urinary C-terminal telopeptide of type II collagen in subjects with knee osteoarthritis after dextrose prolotherapy: A randomized controlled trial

OBJECTIVE

To assess the effects of dextrose prolotherapy in patients with knee osteoarthritis on the levels of serum cartilage oligomeric proteinase and urinary C-terminal telopeptide of type II collagen, and on the Western Ontario McMaster Universities Index and numerical rating scale score for pain.

METHODS

A randomized controlled trial, in which participants were randomly allocated into 2 groups, receiving injections of either hyaluronic acid or dextrose prolotherapy. The hyaluronic acid group received 5 injections, 1 each on weeks 1, 2, 3, 4 and 5, and the dextrose prolotherapy group received 3 injections, 1 each on weeks 1, 5 and 9. Serum cartilage oligomeric proteinase, urinary C-terminal telopeptide of type II collagen, Western Ontario McMaster Universities Index score, and numerical rating scale score for pain were measured at baseline and 3 weeks after the last injection. Comparative analysis was conducted using Wilcoxon test within groups and analysis of covariance (ANCOVA) test between groups.

RESULTS

A total of 47 participants (21 allocated to hyaluronic acid, 26 allocated to dextrose prolotherapy) completed the protocol. Both interventions resulted in significant improvements in numerical rating scale scores for pain, total Western Ontario McMaster Universities Index scores, and its subscales score. However, the dextrose prolotherapy outperformed hyaluronic acid in numerical rating scale score for pain and level of urinary C-terminal telopeptide of type II collagen, with score changes differences of 0.93 (p = 0.042) and 0.34 (p = 0.048), respectively. No significant changes in level of serum cartilage oligomeric proteinase were found in either group.

CONCLUSION

Dextrose prolotherapy is an alternative injection therapy for knee osteoarthritis, which was found to be associated with a significant reduction in urinary C-terminal telopeptide of type II collagen compared with hyaluronic acid injection. Neither injection method resulted in reduced serum cartilage oligomeric proteinase.

Distinct Pattern of Inflammation of Articular Cartilage and the Synovium in Early and Late Hip Femoroacetabular Impingement

BACKGROUND

The molecular mechanism of how femoroacetabular impingement (FAI) morphology leads to hip osteoarthritis (OA) is yet to be determined. The expression and location of inflammation-related molecules during early- and late-stage FAI have not been previously described. Moreover, the characterization of intra-articular inflammation away from the cam deformity as well as the nature of adjacent synovial tissue have also not been extensively reported.

HYPOTHESIS

Early-stage FAI has a similar expression of inflammation-related markers in the head-neck and acetabular cartilage but less synovitis than late-stage FAI.

STUDY DESIGN

Controlled laboratory study.

METHODS

Head-neck cartilage, acetabular cartilage, and synovial samples were obtained from patients undergoing hip preservation surgery for the treatment of symptomatic cam FAI (early FAI group; n = 15) and advanced OA secondary to cam FAI (late FAI group; n = 15). Samples procured from healthy young adult donors served as the control group (n = 7). Cartilage degeneration was assessed by histology, and the expression of inflammation-related proteins (interleukin-1 beta [IL-1β], matrix metalloproteinase-13 [MMP-13], a disintegrin and metalloproteinase with thrombospondin motifs-4 [ADAMTS-4], type II collagen [COL2], and aggrecan neoepitope [NITEGE]) was measured by immunostaining. Synovial samples in the early and late FAI groups were examined for synovitis and the expression of IL-1β.

RESULTS

Head-neck cartilage in the early FAI group showed significantly more degeneration than the control group and an increased expression of inflammation-related proteins (IL-1β: 69.7% ± 18.1% vs 20.2% ± 4.9%, respectively; MMP-13: 79.6% ± 12.6% vs 25.3% ± 9.5%; ADAMTS-4: 83.9% ± 12.2% vs 24.3% ± 11.1%; NITEGE: 89.7% ± 7.7% vs 39.8% ± 20.5%) (P < .001). Head-neck and acetabular cartilage in the early and late FAI groups showed a similar degree of degeneration. Moreover, a similar expression of inflammation-related proteins was observed between the early and late FAI groups for head-neck cartilage (IL-1β: 69.7% ± 18.1% vs 72.5% ± 13.2%; MMP-13: 79.6% ± 12.6% vs 71.4% ± 18.8%; ADAMTS-4: 83.9% ± 12.2% vs 82.6% ± 12.5%; COL2: 93.6% ± 3.9% vs 92.5% ± 5.8%; NITEGE: 89.7% ± 7.7% vs 95.7% ± 4.7%) and acetabular cartilage (IL-1β: 83.3% ± 24.8% vs 80.7% ± 15.6%; MMP-13: 94.3% ± 9.7% vs 85.2% ± 12.3%; ADAMTS-4: 98.5% ± 2.3% vs 98.4% ± 3.4%; COL2: 99.8% ± 0.7% vs 99.7% ± 1.1%; NITEGE: 96.7% ± 6.7% vs 99.2% ± 2.2%). In contrast, synovitis was minimal with a low expression of IL-1β in the early FAI group compared with the late FAI group.

CONCLUSION

Hip cartilage exhibited an OA phenotype in patients with early-stage FAI, similar to what was observed in hip OA secondary to FAI. Severe synovitis was only evident with late-stage FAI.

CLINICAL RELEVANCE

This study supports the concept that early hip impingement is associated with cartilage degeneration and catabolism.

Pathomechanics Underlying Femoroacetabular Impingement Syndrome: Theoretical Framework to Inform Clinical Practice

Over the last decade, there has been a marked increase in attention to, and interest in, femoroacetabular impingement syndrome (FAIS). Despite continued efforts by researchers and clinicians, the development, progression, and appropriate treatment of FAIS remains unclear. While research across various disciplines has provided informative work in various areas related to FAIS, the underlying pathomechanics, time history, and interaction between known risk factors and symptoms remain poorly understood. The purpose of this perspective is to propose a theoretical framework that describes a potential pathway for the development and progression of FAIS. This paper aims to integrate relevant knowledge and understanding from the growing literature related to FAIS to provide a perspective that can inform future research and intervention efforts.

Pediatric Hip and Pelvis

The most common pediatric orthopedic conditions of the hip and pelvis involve abnormal architecture of the joint leading to pain and dysfunction. Developmental dysplasia of the hip and femoroacetabular impingement are 2 common and distinct forms of structural pathology in the pediatric hip. The authors also discuss 2 of the more common, and often questioned, pediatric hip disorders-slipped capital femoral epiphysis and Legg-Calvé-Perthes disease. Future investigations are aimed at identifying risk factors to provide pediatric orthopedists tools to risk stratify their patients and understand when conservative approaches such as close observation versus surgical interventions are more appropriate.

No Evidence of Systemic Inflammation in Symptomatic Patients With Femoroacetabular Impingement

Femoroacetabular impingement (FAI) is a common cause of hip pain and represents a major cause of early osteoarthritis. The role of systemic inflammation in pre-arthritic hip conditions remains largely unknown and uninvestigated. Serum-free light chains (sFLCs) are inflammatory markers produced by B cells. This study aimed to determine whether there was evidence of systemic inflammation in patients with FAI, defined by sFLCs, and whether this correlated with markers of disease severity. Participants for this study were recruited from a single center (Nuffield Orthopedic Center, Oxford) and were taking part in the Femoroacetabular Impingement Trial. The cohort comprised 115 individuals (38 male, 77 female, mean age 37 years): 57 individuals received surgical intervention and 58 received physiotherapy. All individuals provided patient-reported outcome measures and serum samples at baseline and follow-up 8 months post-randomization. sFLC concentrations were measured in serum samples by immunoturbidimetry. At baseline, for all individuals, mean polyclonal sFLC concentrations were 30.36 mg/l (standard deviation [SD] 9.23). At follow-up, the mean polyclonal sFLC concentrations were 31.68 mg/l (SD 9.61) in the surgical intervention cohort, and 29.48 mg/l (SD 7.85) in the physiotherapy intervention cohort. There was no significant correlation between sFLC concentrations and any of the patient reported outcome measures, or radiographic measures: average or maximum alpha angle, or center edge angle. In conclusion, in patients with symptomatic FAI there was no systemic inflammation, as defined by sFLC concentrations, and no correlation between sFLC concentrations and measures of disease severity. The lack of inflammation suggests FAI is a mechanical phenomenon. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2189-2196, 2019.

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.

Chondral lesions in the hip: a review of relevant anatomy, imaging and treatment modalities

The diagnosis and treatment of chondral lesions in the hip is an ongoing challenge in orthopedics. Chondral lesions are common and several classification systems exist to classify them based on severity, location, radiographic parameters, and potential treatment options. When working up a patient with a potential hip chondral lesion, a complete history, thorough physical exam, and ancillary imaging are necessary. The physical exam is performed with the patient in standing, supine, prone, and lateral positions. Plain film radiographs are indicated as the first line of imaging; however, magnetic resonance arthrogram is currently the gold standard modality for the diagnosis of chondral lesions outside of diagnostic arthroscopy. Multiple treatment modalities to address chondral lesions in the hip exist and new treatment modalities continue to be developed. Currently, chondroplasty, microfracture, cartilage transplants (osteochondral autograft transfer, mosaicplasty, Osteochondral allograft transplantation) and incorporation of orthobiologics (Autologous chondrocyte implantation, Autologous matrix-induced chondrogenesis, Mononuclear concentrate in platelet-rich plasma) are some techniques that have been successfully applied to address chondral pathology in the hip. Further refinement of these modalities and research in novel techniques continues to advance a surgeon’s ability to address chondral lesions in the hip joint.

The Serum Protein Profile and Acute Phase Proteins in the Postoperative Period in Sheep after Induced Articular Cartilage Defect

Although several new implants have been developed using animal studies for the treatment of osteochondral and cartilage defects, there is a lack of information on the possible metabolic and biochemical reactions of the body to the implantation of biomaterials and cartilage reconstruction. Therefore, this study was aimed at evaluating the serum protein pattern and the alterations in the concentrations of selected acute phase proteins in five clinically healthy female sheep before and after the reconstruction of experimentally induced articular cartilage defects using polyhydroxybutyrate/chitosan based biopolymer material. The concentrations of total serum proteins (TSP), protein fractions, and selected acute phase proteins-serum amyloid A (SAA), haptoglobin (Hp), and C-reactive protein (CRP)-were measured before and on days seven, 14, and 30 after the surgical intervention. The TSP concentrations showed no marked differences during the evaluated period. Albumin values decreased on day seven and day 14 after surgery. In the concentrations of α₁-, α₂-, β-, and γ₂-globulins, a gradual significant increase was observed during the postoperative period (p < 0.05). The γ₁-globulins decreased slightly seven days after surgery. The concentrations of SAA, Hp, and CRP increased significantly after the surgical intervention with a subsequent decrease on day 30. Presented results suggest marked alterations in the serum protein pattern after surgical intervention.

Hip Arthroscopy - State of the Art in 2018

The field of hip arthroscopy has undergone considerable change in the past 25 years and continues to evolve at a rapid pace. Lessons from the early complications and challenges of hip arthroscopy have led to improved safety and refinement of instrumentation and techniques. The pathophysiology of hip injuries is better understood, and advances in surgical technique have helped expand indications, particularly as a shift from pathology resection to anatomic repair and reconstructive procedures has occurred. As the field has progressed, longitudinal outcome studies are now available to help judge efficacy. The purpose of this review is to highlight the past 30 years of hip arthroscopy, the current practice trends, and future directions of the field.

Canine hip dysplasia: A natural animal model for human developmental dysplasia of the hip

Developmental dysplasia of the hip (DDH) in humans is a common condition that is associated with hip pain, functional limitations, and secondary osteoarthritis (OA). Surgical treatment of DDH has improved in the last decade, allowing excellent outcomes at short- and mid-term follow-up. Still, the etiology, mechanobiology, and pathology underlying this disease are not well understood. A pre-clinical animal model of DDH could help advance the field with a deeper understanding of specific pathways that initiate hip joint degeneration secondary to abnormal biomechanics. An animal model would also facilitate different interventional treatments that could be tested in a rigorous and controlled environment. The dog model exhibits several important characteristics that make it valuable as a pre-clinical animal model for human DDH. Dogs are naturally prone to develop canine hip dysplasia (CHD), which is treated in a similar manner as in humans. Comparable to human DDH, CHD is considered a pre-OA disease; if left untreated it will progress to OA. However, progression to OA is significantly faster in dogs than humans, with progression to OA within 1-2 years of age, associated with their shorter life span compared to humans. Animal studies could potentially reveal the underlying biochemical pathway(s), which can inform refined treatment modalities and provide opportunities for new treatment and prevention targets. Herein, we review the similarities and differences between the two species and outline the argument supporting CHD as an appropriate pre-clinical model of human DDH. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1807-1817, 2018.

Outcomes of cartilage repair techniques for chondral injury in the hip-a systematic review

OBJECTIVE/PURPOSE

The aim of the study was to assess the options of treatment and their related outcomes for chondral injuries in the hip based on the available evidence whilst highlighting new and innovative techniques.

METHODS

A systematic review of the literature from PubMed (Medline), EMBASE, Google Scholar, British Nursing Index (BNI), Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Allied and Complementary Medicine Database (AMED) was undertaken from their inception to March 2017 using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Clinical outcome studies, prospective/retrospective case series and case reports that described the outcome of cartilage repair technique for the chondral injury in the hip were included. Studies on total hip replacement, animal studies, basic studies, trial protocols and review articles were excluded.

RESULTS

The systematic review found 21 relevant papers with 596 hips. Over 80% of the included studies were published in or after 2010. Most studies were case series or case reports (18 studies, 85.7%). Arthroscopy was used in 11 studies (52.4%). The minimum follow-up period was six months. Mean age of the participants was 37.2 years; 93.5% of patients had cartilage injuries of the acetabulum and 6.5% of them had injuries of the femoral head. Amongst the 11 techniques described in the systematic review, autologous matrix-induced chondrogenesis, osteochondral autograft transplantation and microfracture were the three frequently reported techniques.

CONCLUSION

Over ten different techniques are available for cartilage repair in the hip, and most of them have good short- to medium-term outcomes. However, there are no robust comparative studies to assess superiority of one technique over another, and further research is required in this arena.

Femoral osteochondroplasty can be performed effectively without the risk of avascular necrosis or femoral neck fractures in an experimental ovine FAI model

OBJECTIVE

The experimental induction of cam-type femoroacetabular impingement (FAI) in sheep is established. To tap the full potential of this ovine model, one should be able to perform a femoral osteochondroplasty safely. This study was based on previous cadaver experiments on the blood supply to the ovine femoral head and on the biomechanical strength of the proximal femur following offset creation. We hypothesized that offset creation in this ovine FAI model does not lead to (1) avascular necrosis (AVN) of the ovine femoral head or (2) iatrogenic femoral neck fractures and (3) can be performed effectively.

DESIGN

In this experimental, controlled, prospective study nine sheep underwent unilateral FAI induction through an intertrochanteric, varus osteotomy. Seventy days following FAI induction, femoral osteochondroplasty was performed. Sheep were sacrificed after another 140 days. Radiographs, computed tomography (CT) scans and MRI were acquired. Histologic samples were stained with hematoxylin-eosin. (1) The multimodal Association Research Circulation Osseous (ARCO) classification was used for assessment of AVN. (2) Femoral neck fractures were assessed with the multimodal imaging approach. (3) Pre- and postoperative (=after sacrifice) alpha angles and femoral neck diameters were compared.

RESULTS

(1) No signs for AVN according to the ARCO classification or (2) for femoral neck fractures were detected. (3) Mean alpha angles and femoral neck diameters decreased significantly (p < 0.001) superiorly by at least 30° respectively 4 mm after the offset creation.

CONCLUSIONS

Femoral osteochondroplasty can be performed effectively and without the risk of AVN or femoral neck fractures in this ovine FAI model.

Cam Deformities and Limited Hip Range of Motion Are Associated With Early Osteoarthritic Changes in Adolescent Athletes: A Prospective Matched Cohort Study

BACKGROUND

The natural history of femoroacetabular impingement (FAI) remains incompletely understood. In particular, there is limited documentation of joint damage in adolescent patients with limited range of motion (LROM) of the hip, which is commonly associated with FAI.

PURPOSE

To evaluate changes in magnetic resonance imaging (MRI), radiographs, and clinical examinations over 5 years in a group of athletes from a wide variety of sports with asymptomatic LROM of the hip compared with matched controls.

STUDY DESIGN

Cohort study (prognosis); Level of evidence, 2.

METHODS

The authors screened 226 male and female athletes aged 12 to 18 years presenting for preparticipation sports physical examinations. Using a goniometer, we identified 13 participants with at least one hip having internal rotation <10° with the hip flexed to 90°. Overall, 21 of 26 hips (81%) had internal rotation <10°. These participants were age- and sex-matched to 13 controls with internal rotation >10°. At the time of enrollment, all participants were asymptomatic and underwent a complete hip examination and radiographic imaging with radiographs (anteroposterior [AP] and von Rosen views) and non-arthrogram MRI. Participants returned at 5-year follow-up and underwent repeat hip examinations, imaging (AP and lateral radiographs and non-arthrogram MRI), and hip function questionnaires. MRI scans were classified as "normal" versus "abnormal" based on the presence of any of 13 scored chondral, labral, or osseous abnormalities. Comparisons between the LROM group and control group were performed using generalized linear models (either linear, logistic, or log-binomial regression as appropriate for the outcome) with generalized estimating equations to account for the within-participant correlation due to patients having both hips included. Relative risk (RR) estimates are reported with 95% CIs.

RESULTS

At the time of study enrollment, 16 of 26 hips (62%) in the LROM group had abnormal MRI findings within the acetabular labrum or cartilage compared with 8 of 26 hips (31%) in the control group (RR, 2.0; 95% CI, 0.95-4.2; P = .067). The mean alpha angle measured from radial MRI sequences was 58° in the LROM group versus 44° in the control group ( P < .0001). In the LROM group, 13 of 26 hips (50%) had a positive anterior impingement sign, whereas 0 of 26 hips (0%) had a positive anterior impingement sign in the control group. At 5-year follow-up, 18 of 19 hips (95%) in the LROM group had abnormal MRI findings compared with 14 of 26 hips (54%) in the control group (RR, 1.7; 95% CI, 1.1-2.7; P = .014). New or progressive findings were documented on MRI in 15 of 20 hips in the LROM group compared with 8 of 26 hips in the control group (RR, 2.4; 95% CI, 1.2-4.8; P = .011). Six of 22 hips (27%) in the LROM group progressed from Tönnis grade 0 to Tönnis grade 1 in degenerative changes, whereas all 26 hips in the control group remained at Tönnis grade 0 on hip radiographs. In the LROM group, 11 of 22 hips (50%) had a positive anterior impingement sign, whereas 1 of 26 hips (4%) had a positive anterior impingement sign in the control group. A cam deformity (alpha angle >55° on lateral radiographs) was present in 20 of 22 hips (91%) in the LROM group and 12 of 26 hips (46%) in the control group ( P = .0165). The following variables at baseline were associated with an increased risk of degenerative changes at 5-year follow-up for the entire cohort: decreased hip internal rotation, positive anterior impingement sign, decreased hip flexion, increased alpha angle, and presence of a cam lesion.

CONCLUSION

At 5 years, young athletes with LROM of the hip showed increased progressive degenerative changes on MRI and radiographs compared with matched controls. Although the majority of these participants remained asymptomatic, those with features of FAI had radiographic findings consistent with early osteoarthritis. These outcomes suggest that more aggressive screening and counseling of young active patients may be helpful to prevent hip osteoarthritis in those with FAI.

Preoperative physical examination and imaging of femoroacetabular impingement prior to hip arthroscopy-a systematic review

The purpose of this systematic review is to report current preoperative assessment for femoroacetabular impingement (FAI) including physical examination and imaging modalities prior to hip arthroscopy, and report current imaging measures used in the diagnosis of FAI. The electronic databases MEDLINE, EMBASE and PubMed were searched and screened in duplicate for relevant studies. Data regarding patient demographics, non-operative treatment, preoperative assessment including physical examination and imaging prior to hip arthroscopy were abstracted. Study quality was assessed in duplicate using the Methodological Index for Non-Randomized Studies criteria. Sixty-eight studies of fair quality evidence that involved a total of 5125 patients (5400 hips) were included. In total, 56% of all patients were male and mean age was 36 years (SD ± 10.0). Within physical examination, FADIR impingement testing was reported in 57% of patients. All included studies reported plain radiographic imaging as a component of preoperative assessment with anterior–posterior pelvis view being the most commonly reported view, followed by the cross-table lateral and Dunn views. Magnetic resonance imaging was obtained for 52% of included patients and computed tomography for 26% of patients. The most commonly reported measure within imaging for the diagnosis of cam type impingement was alpha angle (66%), whereas for pincer type impingement, the cross-over sign (48%) was most reported. Preoperative assessment is underreported in the FAI literature. Improved reporting is warranted to develop a more consistent and validated diagnostic algorithm for FAI to enhance patient selection.

Level of evidence: Level IV, Systematic Review of Level I–IV Studies.

Hip arthroscopy in osteoarthritis: a systematic review of the literature

BACKGROUND

Hip arthroscopy treatment in patients with osteoarthritis is controversial.

HYPOTHESIS/PURPOSE

To systematically review the clinical outcome of patients with hip osteoarthritis (OA) treated with arthroscopy and what proportion of these patients subsequently underwent total hip arthroplasty (THA).

STUDY DESIGN

Systematic review.

METHODS

PubMed, Cochrane library and LILACS were searched from January 1990 through December 2013 for eligible studies. The methodological quality of the collected data (applied to each study) was performed with a modified version of the Coleman methodology score (mCMS).

RESULTS

11 studies were included in this review. Most of the studies included reported clinical improvements. The overall conversion rate to THA ranged from 9.5% to 50%. Mean time between arthroscopy and THA was 13.5 months.

CONCLUSIONS

The quality of studies is low. We have found inconclusive evidence to make categorical indications for hip arthroscopy in the treatment of OA, although we have found that there is some postoperative clinical outcome improvement of pain and function in a short-term evaluation. Increasingly worse outcomes were seen as the severity of OA increased.

Biological Therapies for Cartilage Lesions in the Hip: A New Horizon

Treatment of hip cartilage disease is challenging, and there is no clear algorithm to address this entity. Biomarkers are arising as promising diagnostic tools because they could play a role in the early assessment of the prearthritic joint and as a prognostic factor before and after treatment. The potential effect of biomarkers may be used to categorize individuals at risk of evolving to severe osteoarthritis, to develop new measures for clinical progression of the disease, and to develop new treatment options for the prevention of osteoarthritis progression. A trend toward a less invasive biological treatment will usher in a new treatment era. With the growth of surgical skills in hip arthroscopy, cartilage restoration techniques are evolving in a fast and exponential manner. Biological and surgical treatments have been proposed to treat these pathologies. Biological treatments include platelet-rich plasma, stem cells or bone marrow aspirate concentration, hyaluronic acid, losartan, and fish oil. Surgical treatments include microfracture alone or augmented, direct repair, autologous chondrocyte implantation, matrix-induced chondrocyte implantation, autologous matrix-induced chondrogenesis, mosaicplasty, osteochondral allograft transplantation, and stem cells implanted in matrix (stem cells in membranes/expanded stem cells). This article reviews new evidence available on treatment options for chondral lesions and early osteoarthritis of the hip. [Orthopedics. 2016; 39(4):e715-e723.].

Return to Play Following Hip Arthroscopy

Femoroacetabular impingement may be particularly disabling to the high-demand athlete, especially those with significant cutting and pivoting requirements. If nonoperative treatment fails to adequately alleviate symptoms or sufficiently restore function in the athlete, hip arthroscopy can lead to improved pain, improved range of motion, and high rates of return to play with proper postoperative rehabilitation. The rate of return to previous level of competition is also high with accurate diagnosis and well-executed correction of deformity. A clear understanding of the etiology, diagnosis, management, and outcomes is essential for clinicians to optimally help patients to return to play.

T1ρ MRI detects cartilage damage in asymptomatic individuals with a cam deformity

Hips with a cam deformity are at risk for early cartilage degeneration, mainly in the anterolateral region of the joint. T1ρ MRI is a described technique for assessment of proteoglycan content in hyaline cartilage and subsequently early cartilage damage. In this study, 1.5 Tesla T1ρ MRI was performed on 20 asymptomatic hips with a cam deformity and compared to 16 healthy control hips. Cam deformity was defined as an alpha angle at 1:30 o'clock position over 60° and/or at 3:00 o'clock position over 50.5°. Hip cartilage was segmented and divided into four regions of interest (ROIs): anterolateral, anteromedial, posterolateral, and posteromedial quadrants. Mean T1ρ value of the entire weight bearing cartilage in hips with a cam deformity (34.0 ± 4.6 ms) was significantly higher compared to control hips (31.3 ± 3.2 ms, p = 0.050). This difference reached significance in the anterolateral (p = 0.042) and posteromedial quadrants (p = 0.041). No significant correlation between the alpha angle and T1ρ values was detected. The results indicate cartilage damage occurs in hips with a cam deformity before symptoms occur. A significant difference in T1ρ values was found in the anterolateral quadrant, the area of direct engagement of the deformity, and in the posteromedial quadrant. To conclude, T1ρ MRI can detect early chondral damage in asymptomatic hips with a cam deformity. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1004-1009, 2016.

Femoroacetabular Impingement: Have We Hit a Global Tipping Point in Diagnosis and Treatment? Results From the InterNational Femoroacetabular Impingement Optimal Care Update Survey (IN FOCUS)

PURPOSE

This international survey was conducted to assess the perceptions of orthopaedic surgeons regarding the diagnosis and management of femoroacetabular impingement (FAI) as well as to explore the current demographic characteristics of surgeons performing FAI surgery.

METHODS

A survey was developed using previous literature, focus groups, and a sample-to-redundancy strategy. The survey contained 46 questions and was e-mailed to national orthopaedic associations and orthopaedic sports medicine societies for member responses. Members were contacted on multiple occasions to increase the response rate.

RESULTS

Nine hundred orthopaedic surgeons from 20 national and international organizations completed the survey. Surgeons responded across 6 continents, 58.2% from developed nations, with 35.4% having sports fellowship training. North American and European surgeons reported significantly greater exposure to hip arthroscopy during residency and fellowship training in comparison to international respondents (48.0% and 44.5% respectively, v 25.6%; P < .001). Surgeons performing a higher volume of FAI surgery (> 100 cases per year) were significantly more likely to have practiced for more than 20 years (odds ratio [OR], 1.91; 95% confidence interval [CI], 1.01 to 3.63), to be practicing at an academic hospital (OR, 2.25; 95% CI, 1.22 to 4.15), and to have formal arthroscopy training (OR, 46.17; 95% CI, 20.28 to 105.15). High-volume surgeons were over two-fold more likely to practice in North America and Europe (OR, 2.26; 95% CI, 1.08 to 4.72).

CONCLUSIONS

The exponential rise in the diagnosis and surgical management of FAI appears to be driven largely by experienced surgeons in developed nations. Significant variability exists regarding the diagnosis and management of FAI. Our analysis suggests that although FAI management is early in the innovation cycle, we are at a tipping point toward wider uptake and use.

Etiology of Femoroacetabular Impingement in Athletes: A Review of Recent Findings

The relationship between hip deformities and osteoarthritis has recently received a lot of attention. In particular, it has been shown that both osteoarthritis and its precursors, such as the hip deformities that lead to femoroacetabular impingement (FAI), are more prevalent in elite athletes compared with the general population. However, the etiology of the above-mentioned types of hip deformity is not currently well understood. Many recent studies have attempted to shed light on the etiology of this disease. In this article, the main clinical, radiological, mechanobiological, and biomechanical findings of relevance to understanding the etiology of hip deformities leading to FAI are reviewed. Based on these findings, a consistent biomechanical theory explaining the development of hip deformities in athletes is then presented. According to the presented theory, the repetitive, impact-like musculoskeletal loads that athletes experience, particularly when they undertake extreme ranges of hip motion, cause the development of hip deformities. According to this theory, these musculoskeletal loads trigger abnormal growth patterns during the years of skeletal development and cause the formation of hip deformities. A number of hypotheses based on the proposed theory are then formulated that could be tested in future studies to ascertain whether the proposed theory could sufficiently describe the development of hip deformities in athletes.

New perspectives on femoroacetabular impingement syndrome

Femoroacetabular impingement (FAI) is characterized by an abnormality in the shape of the femoral head-neck or acetabulum that results in impingement between these two structures. Arthroscopic treatment has become the preferred method of management of FAI owing to its minimally invasive approach. Surgical correction involves resection of impinging osseous structures as well as concurrent management of the associated chondral and labral pathology. Research from the past 5 years has shown that repair of the labrum results in a better anatomic correction and improved outcomes compared with labral debridement. Research is underway to improve cartilage assessment by using innovative imaging techniques and biochemical tests to inform predictions of prognosis. Several ongoing randomized controlled trials, including the Femoroacetabular Impingement Trial (FAIT) and the Femoroacetabular Impingement Randomized Controlled Trial (FIRST), will provide critical information regarding the diagnosis, management and prognosis of patients undergoing arthroscopic management of FAI.

Which factors differentiate athletes with hip/groin pain from those without? A systematic review with meta-analysis

Background

Hip and groin injuries are common in many sports. Understanding the factors differentiating athletes with hip/groin pain from those without these injuries could facilitate management and prevention.

Objective

Conduct a systematic review and meta-analysis of the literature on factors differentiating athletes with and without hip/groin pain.

Methods

The review was registered as PROSPERO CRD42014007416 and a comprehensive, systematic search was conducted in June 2014. Inclusion criteria were: cross-sectional, cohort or case–control study designs of n>10 that examined outcome measures differentiating athletes with and without hip/groin pain. Two authors independently screened search results, assessed study quality, and performed data extraction. Methodological heterogeneity was determined and data pooled for meta-analysis when appropriate. A best evidence synthesis was performed on the remaining outcome measures.

Results

Of 2251 titles identified, 17 articles were included of which 10 were high quality. Sixty two different outcome measures were examined, 8 underwent meta-analysis. Pooled data showed strong evidence that athletes with hip/groin pain demonstrated: pain and lower strength on the adductor squeeze test, reduced range of motion in hip internal rotation and bent knee fall out; however, hip external rotation range was equivalent to controls. Strong evidence was found that lower patient-reported outcome (PRO) scores, altered trunk muscle function, and moderate evidence of bone oedema and secondary cleft sign were associated with hip/groin pain.

Conclusions

PROs, pain and reduced strength on the adductor squeeze test, reduced range of motion in internal rotation and bent knee fall out are the outcome measures that best differentiate athletes with hip/groin pain from those without this pain.

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.

Arthroscopy Up to Date: Hip Femoroacetabular Impingement

PURPOSE

To provide a comprehensive review and summary of the research published in Arthroscopy: The Journal of Arthroscopic and Related Surgery and The American Journal of Sports Medicine (AJSM) related to hip arthroscopy for femoroacetabular impingement (FAI).

METHODS

A comprehensive review was conducted in duplicate of Arthroscopy and AJSM from February 2012 to February 2015 for all articles related to FAI, and a quality assessment was completed for all included studies. Clinical outcomes were dichotomized into short-term (<6 months) and midterm (<24 months) outcomes, and values were pooled when possible.

RESULTS

We identified 60 studies in Arthroscopy and 44 studies in AJSM, primarily from North America (78.8%), that predominantly assessed clinical outcomes after arthroscopic hip surgery (46.1%). Seventy-one percent of Arthroscopy studies and 20.5% of AJSM studies were Level IV evidence. The modified Harris Hip Score (mHHS) was used by 81.5% of included studies. Pooled weighted mean mHHS values after arthroscopic surgery for FAI showed improvements at the midterm from 60.5 points (range, 56.6 to 83.6 points) to 80.5 points (range, 72.1 to 98.0 points) out of a possible 100 points. Pooled weighted outcomes for labral repair showed mean mHHS improvements from 63.8 points (range, 62.5 to 69.0 points) preoperatively to 86.9 points (range, 85.5 to 89.9 points) up to 24 months postoperatively.

CONCLUSIONS

This comprehensive review of research published in Arthroscopy and AJSM over the past 3 years identified a number of key findings. Arthroscopic intervention results in improvements in functional outcomes at both the short-term and midterm for patients with symptomatic FAI in the absence of significant existing degenerative changes. Labral repair may result in improvements over labral debridement. The most commonly used outcome score was the mHHS for objective assessment of surgical success. There is a need for continued focus on improvement of methodologic quality and reporting of research pertaining to FAI.

LEVEL OF EVIDENCE

Level IV, systematic review of Level IV studies.

The Natural History of Femoroacetabular Impingement

Femoroacetabular impingement (FAI) is a clinical syndrome resulting from abnormal hip joint morphology and is a common cause of hip pain in young adults. FAI has been posited as a precursor to hip osteoarthritis (OA); however, conflicting evidence exists and the true natural history of the disease is unclear. The purpose of this article is to review the current understanding of how FAI damages the hip joint by highlighting its pathomechanics and etiology. We then review the current evidence relating FAI to OA. Lastly, we will discuss the potential of hip preservation surgery to alter the natural history of FAI, reduce the risk of developing OA and the need for future arthroplasty.

Associations of markers of matrix metabolism, inflammation markers, and adipokines with superior cam deformity of the hip and their relation with future hip osteoarthritis

OBJECTIVE

First, to study how markers of matrix metabolism, inflammation markers, and adipokines relate to (superior) cam deformity and (possible) cam impingement of the hip. Second, to investigate whether they can identify subjects with cam deformity that are at risk of future hip osteoarthritis (OA).

METHOD

In a cohort of 1002 subjects (CHECK), (superior) cam deformity was defined by an alpha angle >60° on anteroposterior pelvic radiographs and (possible) cam impingement by a cam deformity together with internal hip rotation ≤20°. Hip OA at 5-year follow-up was defined by Kellgren and Lawrence grade ≥2 or total hip replacement.

RESULTS

Subjects with (superior) cam deformity and (possible) cam impingement showed lower levels of bone turnover markers (uCTX-I, uNTX-I, sPINP, sOC) than those without. Cam deformity was positively associated with future hip OA, but associations were weaker at high levels of bone turnover. sCOMP and sHA levels were higher in subjects with cam deformity, while other cartilage and synovium markers were not. Some markers of inflammation (pLeptin, pAdiponectin, and erythrocyte sedimentation rate) were lower in presence of cam deformity and cam impingement, but high-sensitivity C-reactive protein was not. Most associations depended largely on gender differences.

CONCLUSION

Bone metabolism may be relevant in the pathogenesis of (superior) cam deformity and in the development of (superior) cam deformity into hip OA. Subjects with cam deformity and cam impingement surprisingly showed lower levels of inflammation markers and adipokines. Associations of cartilage turnover markers with cam deformity and cam impingement were less obvious.

Cartilage restoration technique of the hip

Hip cartilage lesions represent a diagnostic challenge and can be an elusive source of pain. Treatment may present difficulties due to localization and spherical form of the joint and is most commonly limited to excision, debridement, thermal chondroplasty and microfractures. This chapter will focus in new technologies to enhance the standard techniques. These new technologies are based in stem cells therapies; as intra-articular injections of expanded mesenchymal stem cells, mononuclear concentrate in a platelet-rich plasma matrix and expanded mesenchymal stem cells seeded in a collagen membrane. This review will discuss the bases, techniques and preliminary results obtained with the use of stem cells for the treatment of hip cartilage lesions.

OARSI Clinical Trials Recommendations: Design and conduct of clinical trials for hip osteoarthritis

The ability to assess the efficacy and effectiveness of an intervention for the treatment of hip osteoarthritis (OA) requires strong clinical trial methodology. This consensus paper provides recommendations based on a narrative literature review and best judgment of the members of the committee for clinical trials of hip OA. We provide recommendations on clinical trial design, outcome measures, including structural (radiography), and patient and physician global assessments, performance based measures, molecular markers and experimental endpoints including MRI imaging. This information can be utilized by sponsors of trials for new therapeutic agents for hip OA.

What is the utility of biomarkers for assessing the pathophysiology of hip osteoarthritis? A systematic review

BACKGROUND

Innovations in biologics offer great promise in the treatment of patients with orthopaedic conditions and in advancing our ability to monitor underlying disease pathophysiology. Our understanding of the pathophysiology of hip osteoarthritis (OA) has improved significantly in the last decade. Femoroacetabular impingement (FAI) and hip dysplasia are increasingly recognized and treated as forms of prearthritic hip disease, yet the inability of radiographic and MR imaging to identify patients before the onset of irreversible articular cartilage injury limits their use for early diagnosis and treatment of patients with these conditions. Molecular biomarkers, as objectively measureable indicators of the pathophysiology of hip OA, have the potential to improve diagnosis, disease staging, and prognosis of hip OA and prearthritic hip disease. Although research into molecular biomarkers of hip OA has been conducted, investigations in prearthritic hip disease have only recently begun.

QUESTIONS/PURPOSES

The purpose of our review was to assess the use of molecular biomarkers in the pathophysiology of hip OA, including (1) diagnosis; (2) disease staging; and (3) prognosis. We additionally aimed to summarize the available literature investigating the use of biomarkers in (4) prearthritic hip disease, including FAI and hip dysplasia.

METHODS

We conducted a systematic review of molecular biomarkers associated with hip OA or prearthritic hip disease by searching four major electronic databases for keywords "hip", "osteoarthritis", "biomarker", and all synonyms. The search terms "femoroacetabular impingement" and "hip dysplasia" were also included. The biologic source of biomarkers was limited to serum, plasma, urine, and synovial fluid. The literature search yielded a total of 2740 results. Forty studies met all criteria and were included in our review. Studies were categorized regarding their relevance to (1) diagnosis; (2) disease staging; (3) prognosis; and/or (4) prearthritic hip disease.

RESULTS

Biomarker studies were characterized as relevant to diagnosis (16 studies), disease staging (15 studies), prognosis (11 studies), and prearthritic hip disease (three studies). Sixteen different biomarkers demonstrated associations relevant to the diagnosis of hip OA, 16 biomarkers demonstrated similar associations for disease staging, and six for prognosis. Six biomarkers seemed to be the most promising, demonstrating associations with hip OA in multiple studies, including: urinary level of type II collagen telopeptide (n = 5 studies), serum cartilage oligomeric protein (n = 4 studies), and serum C-reactive protein (n = 4 studies). Only three studies investigated the role of biomarkers in prearthritic hip disease, including two in FAI and one in unspecified etiology of pain. There were no studies about biomarkers in hip dysplasia.

CONCLUSIONS

Molecular biomarkers are increasingly investigated for their use in evaluating the pathophysiology of hip OA, but less so for prearthritic hip disease. Several biomarkers have demonstrated significant associations with hip OA across multiple studies. Further validation of these biomarkers is needed to assess their clinical use and potential application to prearthritic hip disease.

Good Results After Hip Arthroscopy for Femoroacetabular Impingement in Top-Level Athletes

Background:

Femoroacetabular impingement (FAI) is a common cause of hip pain and dysfunction among athletes. Although arthroscopic surgery is an established treatment option for FAI, there are few studies reporting detailed outcomes using validated outcome measurements specifically designed for young and active athletes.

Purpose:

To report outcomes 1 year after arthroscopic treatment of FAI in top-level athletes using validated outcome measurements adapted for a young and active population.

Study Design:

Case series; Level of evidence, 4.

Methods:

A total of 85 top-level athletes (68 males, 17 females) with a mean (±SD) age of 25 ± 5 years underwent arthroscopic surgery for FAI. All athletes who reported Hip Sports Activity Scale (HSAS) levels 7 or 8 (range, 0-8) prior to symptom onset were included. The cohort was prospectively evaluated using online web-based validated health-related patient-reported outcomes measures (HR-PROMs), including the short version of the International Hip Outcome Tool (iHOT-12), the Copenhagen Hip and Groin Outcome Score (HAGOS; 6 subscales), the EuroQOL 5 dimensions questionnaire (EQ-5D; 2 subscales), the Hip Sports Activity Scale (HSAS) for physical activity level, and a visual analog scale (VAS) for overall hip function. Furthermore, patients reported their overall satisfaction with treatment.

Results:

The mean follow-up time was 12.3 ± 0.6 months. Preoperative scores compared with those obtained at the 12-month follow-up revealed statistically and clinically significant improvements (P < .0001) for all measured outcomes: iHOT-12 (42 vs 73), VAS for global hip function (52 vs 77), HSAS (4.3 vs 5.7), EQ-5D index (0.60 vs 0.83), EQ-VAS (68 vs 82), and HAGOS subscales (60 vs 83, 50 vs 73, 66 vs 86, 39 vs 75, 27 vs 70, and 34 vs 67). At the 12-month follow-up, 79 athletes (93%) reported that they were satisfied with the outcome of surgery. At follow-up, 62 athletes (73%) had returned to competitive sports (HSAS levels 5-8) and 44 (52%) to their previous HSAS level of activity (HSAS level 7 or 8). Twenty-three athletes (27%) did not return to competitive sports (HSAS level ≤4). Significantly lower levels of return to sports were seen with longer symptom duration (P < .05).

Conclusion:

Twelve months after surgery, arthroscopic treatment for FAI in top-level athletes resulted in statistically and clinically significant improvements at the group level in all outcome parameters for pain, symptoms, function, physical activity level, quality of life, and general health. One year after surgery, approximately 3 of 4 top-level athletes had returned to sports.

Position-Specific Hip and Knee Kinematics in NCAA Football Athletes

BACKGROUND

Femoroacetabular impingement is a debilitating hip condition commonly affecting athletes playing American football. The condition is associated with reduced hip range of motion; however, little is known about the range-of-motion demands of football athletes. This knowledge is critical to effective management of this condition.

PURPOSE

To (1) develop a normative database of game-like hip and knee kinematics used by football athletes and (2) analyze kinematic data by playing position. The hypothesis was that kinematics would be similar between running backs and defensive backs and between wide receivers and quarterbacks, and that linemen would perform the activities with the most erect lower limb posture.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Forty National Collegiate Athletic Association (NCAA) football athletes, representing 5 playing positions (quarterback, defensive back, running back, wide receiver, offensive lineman), executed game-like maneuvers while lower body kinematics were recorded via optical motion capture. Passive hip range of motion at 90° of hip flexion was assessed using a goniometer. Passive range of motion, athlete physical dimensions, hip function, and hip and knee rotations were submitted to 1-way analysis of variance to test for differences between playing positions. Correlations between maximal hip and knee kinematics and maximal hip kinematics and passive range of motion were also computed.

RESULTS

Hip and knee kinematics were similar across positions. Significant differences arose with linemen, who used lower maximal knee flexion (mean ± SD, 45.04° ± 7.27°) compared with running backs (61.20° ± 6.07°; P < .001) and wide receivers (54.67° ± 6.97°; P = .048) during the cut. No significant differences were found among positions for hip passive range of motion (overall means: 102° ± 15° [flexion]; 25° ± 9° [internal rotation]; 25° ± 8° [external rotation]). Several maximal hip measures were found to negatively correlate with maximal knee kinematics.

CONCLUSION

A normative database of hip and knee kinematics utilized by football athletes was developed. Position-specific analyses revealed that linemen use smaller joint motions when executing dynamic tasks but do not demonstrate passive range of motion deficits compared with other positions.

CLINICAL RELEVANCE

Knowledge of requisite game-like hip and knee ranges of motion is critical for developing goals for nonoperative or surgical recovery of hip and knee range of motion in the symptomatic athlete. These data help to identify playing positions that require remedial hip-related strength and conditioning protocols. Negative correlations between hip and knee kinematics indicated that constrained hip motion, as seen in linemen, could promote injurious motions at the knee.

Hip arthroscopy: from the beginning to the future--an innovator's perspective

Hip arthroscopy is one of the fastest-growing areas of orthopaedic surgery. There are many reasons for this, including a better understanding of the pathophysiology of damage to the hip joint, improvements in imaging and technology advancements in arthroscopic instrumentation. This manuscript documents the historical development of hip arthroscopy, in general, as well as advances and ideas that have led to common techniques with regard to portal placement, traction and instrumentation. These advances have led to expanding indications for hip arthroscopy. This manuscript ends with some thoughts about the future of hip arthroscopy from the perspective of one of the leaders who helped shape hip arthroscopy, as it is performed today.