Arthroscopic versus open cam resection in the treatment of femoroacetabular impingement

Adhesions After Hip Arthroscopy Are Associated With Revision But Show Poorly Defined Criteria for Diagnosis and Operative Management: A Systematic Review

PURPOSE

To evaluate the current body of evidence surrounding the diagnosis, management, and clinical outcomes of adhesions that developed after hip arthroscopy (HA).

METHODS

A systematic search of the MEDLINE, Embase, Web of Science, and CENTRAL (Cochrane Central Register of Controlled Trials) databases was designed and conducted in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. Eligible studies included patients with confirmed adhesions after HA that reported one or more of the following: (1) diagnostic procedures and criteria used; (2) indications for and details surrounding surgical management; and (3) clinical outcomes after the operative management of adhesions (e.g., patient-reported outcome measures).

RESULTS

Nineteen studies involving a total of 4,145 patients (4,211 hips; 38% female sex) were included in this review. The quality of evidence was found to be fair for both comparative studies (mean, 17; range, 13-21) and noncomparative studies (mean, 10; range, 5-12) according to the Methodological Index for Non-randomized Studies (MINORS) instrument, with the level of evidence ranging from IIB to IV. Adhesions were often diagnosed intraoperatively at the time of revision surgery (10 of 19 studies, 53%), with only 3 studies specifying the criteria used to adjudicate adhesions. The most common indication for operative management (i.e., release or lysis of adhesions) was persistent pain (9 of 19, 47%), but this was often grossly stated for revision HA rather than being specific to adhesions. Patient-reported outcome measures were the most reported postoperative outcomes (9 of 19, 47%) and generally showed significant improvement from preoperative assessment across the short-term follow-up period (range, 24.5-38.1 months). There was a paucity of objective measures of clinical improvement (3 of 19, 16%) and of mid- and long-term follow-up (i.e., 5-7 years and ≥10 years, respectively).

CONCLUSIONS

Despite the growing body of evidence suggesting that adhesions are highly contributory to revision HA, there is ambiguity in the diagnostic approach and indications for operative management of adhesions. Additionally, although the operative management of adhesions after HA has shown satisfactory clinical outcomes in the short term, there is a paucity of research elucidating the mid- to long-term outcomes, as well as minimal use of objective assessment of clinical improvement (e.g., biomechanics).

LEVEL OF EVIDENCE

Level IV, systematic review of Level II to IV studies.

Patients With Lateral and Anterolateral Cam Morphology Have Greater Deformities Versus Typical Anterolateral Deformity Alone but No Differences in Postoperative Outcomes: A Propensity-Matched Analysis at Minimum 5-Year Follow-Up

PURPOSE

To compare pre- and postoperative findings between patients undergoing hip arthroscopy for femoroacetabular impingement syndrome with lateral impingement versus those without lateral impingement METHODS: Patients who underwent primary hip arthroscopy for femoroacetabular impingement syndrome between 2012 and 2017 with minimum 5-year follow-up were included. Alpha angle (AA) was measured on preoperative anteroposterior (AP) and 90° Dunn radiographs. Patients with AA >60° on Dunn view but not AP view (no lateral impingement) were propensity matched by sex, age, and body mass index in a 1:3 ratio to patients with AA >60° on both views (lateral impingement). Demographic characteristics, radiographic and intraoperative findings, reoperation rates, and patient-reported outcomes (PROs) were compared between groups. Categorical variables were compared using the Fisher exact testing and continuous variable using 2-tailed Student t tests.

RESULTS

Sixty patients with lateral impingement (65.0% female, age: 35.3 ± 13.0 years) were matched to 180 patients without lateral impingement (65.0% female, age: 34.7 ± 12.5 years, P ≥ .279). Patients with lateral impingement had larger preoperative AAs on both Dunn (71.0° ± 8.8° vs 67.6° ± 6.1°, P = .001) and AP radiographs (79.0° ± 12.1° vs 48.2° ± 6.5°, P < .001). However, there were no differences in postoperative AAs on either view (Dunn: 39.0° ± 6.1° vs 40.5° ± 5.3°, AP: 45.8° ± 9.0° vs 44.9° ± 7.0°, P ≥ .074). Labral tears began more superiorly in patients with lateral impingement (12:00 ± 0:49 vs 12:17 ± 0:41, P = .030), and they demonstrated greater rates of acetabular and femoral cartilage damage (P = .030 for both); however, there were no differences in PROs or reoperation rates between the groups at 5-year follow-up.

CONCLUSIONS

Although cam deformities located laterally and anterolaterally are larger than those located anterolaterally alone, both can be resected adequately, resulting in similar postoperative radiographic measurements, PROs, and survivorship.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Open and arthroscopic management of femoroacetabular impingement: a review of current concepts

Femoroacetabular impingement (FAI) is a common femoral and/or acetabular abnormality that can cause progressive damage to the hip and osteoarthritis. FAI can be the result of femoral head/neck overgrowth, acetabular overgrowth or both femoral and acetabular abnormalities, resulting in a loss of native hip biomechanics and pain upon hip flexion and rotation. Radiographic evidence can include loss of sphericity of the femoral neck (cam impingement) and/or acetabular retroversion with focal or global overcoverage (pincer impingement). Operative intervention is indicated in symptomatic patients after failed conservative management with radiographic evidence of impingement and minimal arthritic changes of the hip, with the goal of restoring normal hip biomechanics and reducing pain. This is done by correcting the femoral head-neck relationship to the acetabulum through femoral and/or acetabular osteoplasty and treatment of concomitant hip pathology. In pincer impingement cases with small lunate surfaces, reverse periacetabular osteotomy is indicated as acetabular osteoplasty can decrease an already small articular surface. While surgical dislocation is regarded as the traditional gold standard, hip arthroscopy has become widely utilized in recent years. Studies comparing both open surgery and arthroscopy have shown comparable long-term pain reduction and improvements in clinical measures of hip function, as well as similar conversion rates to total hip arthroplasty. However, arthroscopy has trended toward earlier improvement, quicker recovery and faster return to sports. The purpose of this study was to review the recent literature on open and arthroscopic management of FAI.

Accuracy of Computer Navigation-Assisted Arthroscopic Osteochondroplasty for Cam-Type Femoroacetabular Impingement Using the Model-to-Image Registration Method

BACKGROUND

Precise osteochondroplasty is important in arthroscopic hip surgery for cam-type femoroacetabular impingement (FAI). Although computer-assisted surgery with a navigation system may enhance the accuracy of arthroscopic osteochondroplasty, few clinical studies have assessed its accuracy.

PURPOSE

To evaluate the accuracy of arthroscopic osteochondroplasty by a computed tomography (CT)-based navigation system for cam-type FAI, using 3-dimensional (3D) reconstruction with more detail compared with previous methods.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Twenty patients (14 men and 6 women) who underwent navigation-assisted arthroscopic surgery for cam-type FAI were included. The preoperative 3D model of the femur was constructed from each patient's CT data, and a planned model with virtual cam resection was generated. A femoral model was reconstructed from CT data postoperatively. The 3 models for each patient were overlaid using a 3D model registration method. Then, the contours of the bone resection area of each model were compared by measuring them. To measure the deviation between planned and actual bone resections, 4 cross-sectional images of the 3 femoral models were set at one-quarter intervals from the femoral head radius. All measurements were based on clockface lines set around the femoral neck axis at 30-minute intervals. Differences between the planned and postoperative contour lines were deemed resection deviations.

RESULTS

All cam resections were performed in the anterior half of the region of interest. Therefore, only the anterior half (48 points) of the 96 points per case were analyzed. In 876 (91.3%) points of the total measurement points (960 points/20 cases), the error in resection depth was within 3 mm. Overresection was observed at 35 (3.6%) points and underresection at 49 (5.1%) points. The observed maximum deviations from the planned models were 6.3 mm overresection and -7.1 mm underresection. The alpha angles of the postoperative model at the posterior 9- to 3-o'clock position were <55° in all patients.

CONCLUSION

Navigation-assisted arthroscopic osteochondroplasty showed favorable accuracy. Underresection was more frequent than overresection on the anterosuperior side of the femur, despite assistance of the navigation system.

Intraoperative Automated Radiographic Visualization Tool Allows for Higher Accuracy of Cam Lesion Resection When Used by Novice Surgeons for Arthroscopic Femoroplasty: Lowering the Learning Curve

PURPOSE

To compare the accuracy of conventional fluoroscopy versus an intraoperative radiographic visualization tool in assisting a novice and experienced hip arthroscopist in comprehensive cam correction to a desired alpha angle (AA).

METHODS

A cadaveric study was performed using 28 hemi-pelvises with cam-type deformity (AA > 55˚) measured on anteroposterior, lateral, and Dunn-view radiographs. Two fellowship-trained hip arthroscopists each performed 14 arthroscopic femoroplasties. The specimens were randomly assigned: 14 of the procedures were performed by the experienced surgeon, with 7 using the automated radiographic visualization tool (Guided Femoroplasty) and 7 using routine fluoroscopy (Control). The same number of hips was assigned to the novice surgeon, completing 7 femoroplasties with and without the visualization tool. Each hip was imaged before and after femoroplasty in 6 different positions using intraoperative fluoroscopy to evaluate head-neck offset. Femoroplasty AAs were compared between groups with and without visualization tool use, as well as between surgeons. One-way analysis of variance analysis was performed to evaluate the consistency of cam resection.

RESULTS

For the experienced hip arthroscopist, comparison of Guide Femoroplasty and Control groups resulted in similar accuracy when compared to the controls, with post-femoroplasty AA averages ranging from 41.4° ± 3.8˚ to 44.8° ± 2.8˚ (P = .511) and 40.2° ± 5.3˚ to 45.6° ± 2.2˚ (P = .225), respectively. For the novice hip arthroscopist, the Guided Femoroplasty group had higher accuracy, with post-femoroplasty AA averages ranging from 42.8° ± 2.6˚ to 46.1° ± 7.2˚(P = .689) with and 39.8° ± 3.1˚ to 51.9° ± 8.1˚ (P = .001) without the visualization tool. Comparison of procedure time did not show any statistically significant difference between the use of the radiographic visualization tool and controls for either surgeon (P > .05 for all).

CONCLUSIONS

Femoroplasty with and without the use of automated radiographic visualization tool results in accurate cam resection when used by both the experienced and novice surgeon. However, higher accuracy was observed when resecting to a desired AA performed by a novice surgeon using the visualization tool. Additionally, use of the visualization tool did not result in longer procedure times for either surgeon.

CLINICAL RELEVANCE

The impact of incomplete cam resections and over-resection on patient outcomes in the literature has led to the recent development of automated intraoperative radiographic visualization tools that allow for assistance of cam resection accuracy for the treatment of femoroacetabular impingement syndrome. This cadaveric study demonstrates that femoroplasty with the use of an intraoperative automated radiographic visualization tool may result in more accurate cam resections.

Revision Surgery and Progression to Total Hip Arthroplasty After Surgical Correction of Femoroacetabular Impingement: A Systematic Review

BACKGROUND

Femoroacetabular impingement (FAI) is a major cause of hip pain in young adults and athletes. Surgical treatment of FAI is recommended in cases of failed nonoperative treatment that have the typical clinical and radiographic findings. At present, the role of risk factors for revision surgery and progression to total hip arthroplasty (THA) in patients with FAI is still unclear.

PURPOSE

To investigate the possible association between (1) rate of revision and progression to THA and (2) patient characteristics, type of lesion, family history of hip disease, type of intervention, radiographic parameters, physical examination, and pre- and postoperative scores.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

The present systematic review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. In October 2020, the main online databases were accessed. All articles concerning surgical correction for selected patients with FAI were accessed. Patient characteristics, type of intervention, radiographic parameters, physical examination, and pre- and postoperative scores were assessed. The outcomes of interest were the possible association between these variables and the rate of revision and subsequent progression to THA using a multivariate analysis through the Pearson product-moment correlation coefficient.

RESULTS

Data from 99 studies (9357 procedures) were collected. The median follow-up was 30.9 months (interquartile range, 24.0-45.0). The mean ± SD age was 33.4 ± 9.3 years; mean body mass index (BMI), 24.8 ± 4.8; percentage right side, 55.8% ± 8.0%; and percentage female sex, 47.5% ± 20.4%. The overall rate of revision was 5.29% (351 of 6641 patients), while the rate of subsequent progression to THA was 3.78% (263 of 6966 patients). Labral debridement (P < .0001), preoperative acetabular index (P = .01), and BMI (P = .03) all showed evidence of a statistically positive association with increased rates of THA. No other statistically significant associations were found between patient characteristics, type of lesion, family history of hip disease, type of intervention, radiographic parameters, physical examination, or pre- and postoperative scores and the rate of revision and/or progression to THA.

CONCLUSION

Although surgical procedures to treat FAI led to satisfactory outcomes, there was a revision rate of 5.29% in the 9357 procedures in the present systematic review. The rate of progression to THA after a median follow-up of 30 months was 3.78%. Patients who have a higher BMI and/or have a pathologic acetabular index and/or undergo labral debridement during correction of FAI are more at risk for a subsequent THA. We advocate additional education of this patient population in terms of expected outcomes and suggest surgical labral repair instead of debridement if needed.

Improved Cartilage Quality on Delayed Gadolinium-Enhanced MRI of Hip Cartilage after Subchondral Drilling of Acetabular Cartilage Flaps in Femoroacetabular Impingement Surgery at Minimum 5-Year Follow-Up

OBJECTIVE

To assess whether subchondral drilling of acetabular cartilage flaps during femoroacetabular impingement (FAI) surgery improves (1) acetabular dGEMRIC indices and (2) morphologic magnetic resonance imaging (MRI) scores, compared with hips in which no additional treatment of cartilage lesions had been performed; and (3) whether global dGEMRIC indices and MRI scores correlate.

DESIGN

Prospective cohort study of consecutive patients with symptomatic FAI treated with open surgery between 2000 and 2007. Patients with subchondral drilling of acetabular cartilage flaps were allocated to the study group, those without drilling to the control group. All patients underwent indirect 3-T MR arthrography to assess cartilage quality by dGEMRIC indices and a semiquantitative morphologic MRI score at minimum 5 years after surgery. dGEMRIC indices and morphologic MRI scores were compared between and among groups using analysis of covariance/paired t tests.

RESULTS

No significant difference was found between the global dGEMRIC indices of the study group (449 ± 147 ms, 95% CI 432-466 ms) and the control group (428 ± 143 ms, 95% CI 416-442 ms; P = 0.235). In regions with cartilage flaps, the study group showed higher dGEMRIC indices (472 ± 160 ms, 95% CI 433-510 ms) compared with the control group (390 ± 122 ms, 95% CI 367-413 ms; P < 0.001). No significant differences were found for the morphologic MRI scores. A strong inversely linear correlation between the dGEMRIC indices and the morphologic MRI scores (r = -0.727, P < 0.001) was observed.

CONCLUSIONS

Treatment of acetabular cartilage flaps with subchondral drilling leads to better cartilage quality in regions with cartilage flaps at minimum 5 years of follow-up.

Good Outcome Scores and Low Conversion Rate to THA 10 Years After Hip Arthroscopy for the Treatment of Femoroacetabular Impingement

BACKGROUND

Arthroscopic treatment of symptomatic femoroacetabular impingement (FAI) has promising short-term to mid-term results. In addition to treating acute pain or impaired function, the goal of hip-preserving surgery is to achieve a lasting improvement of hip function and to prevent the development of osteoarthritis. Long-term results are necessary to evaluate the effectiveness of surgical treatment and to further improve results by identifying factors associated with conversion to THA.

QUESTIONS/PURPOSES

(1) How do the Merle d'Aubigné-Postel scores change from before surgery to follow-up of at least 10 years in patients undergoing hip arthroscopy for the treatment of FAI? (2) What is the cumulative 10-year survival rate of hips with the endpoints of conversion to THA or a Merle d'Aubigné-Postel score less than 15? (3) Which factors are associated with conversion to THA?

METHODS

Between 2003 and 2008, we treated 63 patients (65 hips) for symptomatic FAI with hip arthroscopy at our institution. During that period, the indications for using arthroscopy were correction of anterior cam morphology and anterolateral rim trimming with debridement or reattachment of the labrum. We excluded patients who were younger than 16 years and those who had previous trauma or surgery of the hip. Based on that, 60 patients (62 hips) were eligible. A further 17% (10 of 60) of patients were excluded because the treatment was purely symptomatic without treatment of cam- and/or pincer-type morphology. Of the 50 patients (52 hips) included in the study, 2% (1) of patients were lost before the minimum study follow-up of 10 years, leaving 49 patients (51 hips) for analysis. The median (range) follow-up was 11 years (10 to 17). The median age at surgery was 33 years (16 to 63). Ninety percent (45 of 50) of patients were women. Of the 52 hips, 75% (39 of 52) underwent cam resection (femoral offset correction), 8% (4 of 52) underwent acetabular rim trimming, and 17% (9 of 52) had both procedures. Additionally, in 35% (18 of 52) of hips the labrum was debrided, in 31% (16 of 52) it was resected, and in 10% (5 of 52) of hips the labrum was reattached. The primary clinical outcome measurements were conversion to THA and the Merle d'Aubigné-Postel score. Kaplan-Meier survivorship and Cox regression analyses were performed with endpoints being conversion to THA or Merle d'Aubigné-Postel score less than 15 points.

RESULTS

The clinical result at 10 years of follow-up was good. The median improvement of the Merle d'Aubigné-Postel score was 3 points (interquartile range 2 to 4), to a median score at last follow-up of 17 points (range 10 to 18). The cumulative 10-year survival rate was 92% (95% CI 85% to 99%) with the endpoints of conversion to THA or Merle d'Aubigné-Postel score less than 15. Factors associated with conversion to THA were each year of advancing age at the time of surgery (hazard ratio 1.1 [95% CI 1.0 to 1.3]; p = 0.01) and preoperative Tönnis Grade 1 compared with Tönnis Grade 0 (no sign of arthritis; HR 17 [95% CI 1.8 to 166]; p = 0.01).

CONCLUSION

In this series, more than 90% of patients retained their native hips and reported good patient-reported outcome scores at least 10 years after arthroscopic treatment of symptomatic FAI. Younger patients fared better in this series, as did hips without signs of osteoarthritis. Future studies with prospective comparisons of treatment groups are needed to determine how best to treat complex impingement morphologies.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

3D MRI Models of the Musculoskeletal System

Computed tomography (CT) is most commonly used to produce three-dimensional (3D) models for evaluating bone and joint morphology in clinical practice. However, 3D models created from magnetic resonance imaging (MRI) data can be equally effective for comprehensive and accurate assessment of osseous and soft tissue structure morphology and pathology. The quality of 3D MRI models has steadily increased over time, with growing potential to replace 3D CT models in various musculoskeletal (MSK) applications. In practice, a single MRI examination for two-dimensional and 3D assessments can increase the value of MRI and simplify the pre- and postoperative imaging work-up. Multiple studies have shown excellent performance of 3D MRI models in shoulder injuries, in the hip in the setting of femoroacetabular impingement, and in the knee for the creation of bone surface models. Therefore, the utility of 3D MRI postprocessed models is expected to continue to rise and broaden in applications. Computer-based and artificial intelligence-assisted postprocessing techniques have tremendous potential to improve the efficiency of 3D model creation, opening many research avenues to validate the applicability of 3D MRI and establish 3D-specific quantitative assessment criteria. We provide a practice-focused overview of 3D MRI acquisition strategies, postprocessing techniques for 3D model creation, MSK applications of 3D MRI models, and an illustration of cases from our daily clinical practice.

Utility of Ultrasound-Guided Anesthetic Intra-articular Injection to Estimate the Outcome of Hip Arthroscopy in Patients with Femoroacetabular Impingement Syndrome

Objective

To investigate the effectiveness of ultrasound (US) guided intra‐hip joint injection to estimate the outcome of hip arthroscopy in patients with femoroacetabular impingement (FAI) syndrome.

Methods

Patients with FAI syndrome (n = 60) were prospectively enrolled in our study. Before hip arthroscopy, a mix of 4 mL 2% lidocaine and 4 mL 1% ropivacaine were injected into the hip joint under the guidance of US. The clinical efficacy of the intra‐articular injection was evaluated by comparing the visual analog scale (VAS) and international hip outcome tool 12 (iHOT‐12) results before and after the injection. The outcome of hip arthroscopy was evaluated by iHOT‐12, the modified Harris hip score (MHHS), and the patient's satisfaction 12 months after the operation. The outcome of intra‐articular injection and hip arthroscopy were compared. Factors related to the outcomes of hip arthroscopy were evaluated. The correlation between the efficacy of intra‐hip joint injection and arthroscopy was evaluated.

Results

The VAS of patients decreased from 11.3 ± 7.7 to 3.3 ± 4.5, and the iHOT‐12 increased from 52.1 ± 23.2 to 84.1 ± 18.1 after intra‐articular injection (all P < 0.001). The iHOT‐12 score increased from 52.1 ± 23.2 to 78.9 ± 19.2, and the MHHS increased from 66.5 ± 6.8 to 81.6 ± 8.1 after hip arthroscopy (all P < 0.001). The satisfaction rate of arthroscopy, including very satisfied and effective patients, was 93.3%. Multi‐variable logistic regression showed that only iHOT‐12 improved value after injection was included in the regression formula of satisfaction, with the β of −0.154, standard error of 0.071, Wald value of 4.720, and OR of 0.857 (95%CI 0.746–0.985) (P = 0.03). Significant correlation was detected between iHOT‐12 scores after intra‐articular anesthesia and at 12 months after arthroscopy (r = 0.784, P < 0.001). So was the iHOT‐12 improved value (r = 0.781, P < 0.001) and the iHOT‐12 improved ratio (r = 0.848, P < 0.001). If we had performed arthroscopy only on patients with post‐injection iHOT‐12 score improvement ≥10, the satisfaction rate of arthroscopy would have increased to 96.6%.

Conclusions

US‐guided intra‐hip joint injection may provide a feasible way to estimate the outcome of hip arthroscopy in patients with FAI syndrome, and could be used as a method for indication selection of hip arthroscopy.

Increased range of motion but otherwise similar clinical outcome of arthroscopy over open osteoplasty for femoroacetabular impingement at midterm follow-up: A systematic review

BACKGROUND

A systematic review was conducted comparing patient reported outcomes measures (PROMs), functional scores, and the rate of complications between arthroscopic and open treatment for femoroacetabular impingement (FAI) at mid-term follow-up.

MATERIAL AND METHODS

This systematic review was performed according to the PRISMA guidelines. The literature search was performed in October 2020. All clinical trials treating FAI using open osteoplasty or arthroscopic surgery were considered for inclusion. Only articles reporting >12 months follow-up were included.

RESULTS

Data from 97 articles (9981 procedures) were collected. At a mean 19.2 months follow-up there was no difference between the two cohorts. At a mean follow-up of 38 months, the external rotation was increased in the arthroscopic group (P < 0.0001). The modified Harris Hip Score scored greater in favour of the open osteoplasty group (P = 0.04), as did the Hip Outcome Score - Activities of Daily Living subscale (P = 0.01). At a mean 45.1 months the arthroscopic group presented greater external rotation (P < 0.0001) and SF-12 Mental (P = 0.04). The modified Harris Hip Score was greater in favour of the open osteoplasty group (P = 0.03), as was the HOS-ADL (P = 0.01). Regarding complications, the arthroscopic group experienced lower rates of subsequent revisions (P < 0.0001).

CONCLUSION

Based on the significant reduction of revisions-rate and significant increase in range of motion, arthroscopy treatment for the management of FAI may be recommended.

Best Practices: Hip Femoroacetabular Impingement

OBJECTIVE. Imaging plays a critical role in the assessment of patients with femoroacetabular impingement (FAI). With better understanding of the underlying pathomechanics and advances in joint-preserving surgery, there is an increasing need to define the most appropriate imaging workup. The purpose of this article is to provide guidance on best practices for imaging of patients with FAI in light of recent advances in corrective FAI surgery. CONCLUSION. Pelvic radiography with dedicated hip projections is the basis of the diagnostic workup of patients with suspected FAI to assess arthritic changes and acetabular coverage and to screen for cam deformities. Chondrolabral lesions should be evaluated with unenhanced MRI or MR arthrography. The protocol should include a large-FOV fluid-sensitive sequence to exclude conditions that can mimic or coexist with FAI, radial imaging to accurately determine the presence of a cam deformity, and imaging of the distal femoral condyles for measurement of femoral torsion. CT remains a valuable tool for planning of complex surgical corrections. Advanced imaging, such as 3D simulation, biochemical MRI, and MR arthrography with application of leg traction, has great potential to improve surgical decision-making. Further research is needed to assess the added clinical value of these techniques.

MRI-based 3D models of the hip joint enables radiation-free computer-assisted planning of periacetabular osteotomy for treatment of hip dysplasia using deep learning for automatic segmentation

Introduction

Both Hip Dysplasia(DDH) and Femoro-acetabular-Impingement(FAI) are complex three-dimensional hip pathologies causing hip pain and osteoarthritis in young patients. 3D-MRI-based models were used for radiation-free computer-assisted surgical planning. Automatic segmentation of MRI-based 3D-models are preferred because manual segmentation is time-consuming.To investigate(1) the difference and(2) the correlation for femoral head coverage(FHC) between automatic MR-based and manual CT-based 3D-models and (3) feasibility of preoperative planning in symptomatic patients with hip diseases.

Methods

We performed an IRB-approved comparative, retrospective study of 31 hips(26 symptomatic patients with hip dysplasia or FAI). 3D MRI sequences and CT scans of the hip were acquired. Preoperative MRI included axial-oblique T1 VIBE sequence(0.8 mm³ isovoxel) of the hip joint. Manual segmentation of MRI and CT scans were performed. Automatic segmentation of MRI-based 3D-models was performed using deep learning.

Results

(1)The difference between automatic and manual segmentation of MRI-based 3D hip joint models was below 1 mm(proximal femur 0.2 ± 0.1 mm and acetabulum 0.3 ± 0.5 mm). Dice coefficients of the proximal femur and the acetabulum were 98 % and 97 %, respectively. (2)The correlation for total FHC was excellent and significant(r = 0.975, p < 0.001) between automatic MRI-based and manual CT-based 3D-models. Correlation for total FHC (r = 0.979, p < 0.001) between automatic and manual MR-based 3D models was excellent.(3)Preoperative planning and simulation of periacetabular osteotomy was feasible in all patients(100 %) with hip dysplasia or acetabular retroversion.

Conclusions

Automatic segmentation of MRI-based 3D-models using deep learning is as accurate as CT-based 3D-models for patients with hip diseases of childbearing age. This allows radiation-free and patient-specific preoperative simulation and surgical planning of periacetabular osteotomy for patients with DDH.

A novel concept of cam-type femoroacetabular impingement treatment with patient-specific template guided osteochondral deformity ablation

PURPOSE

To present a novel surgical concept for the cam-type femoroacetabular impingement (FAI) treatment and to assess and report the clinical outcomes.

METHODS

We performed a retrospective study of a single-surgeon case series of six hips in five consecutive male patients with symptomatic cam-type FAI, treated with the mini-open anterior hip approach with a patient-specific template (PST)-guided deformity ablation between 2015 and 2018. We assessed the hip range of motion, iHOT-33, Tegner, and EQ-5D before surgery and after a minimum follow-up of 30 months.

RESULTS

The average age was 37 ± 13.3 years, average BMI was 31.1 ± 3.3 kg/m², and average pre-surgery Tönnis hip osteoarthritis (OA) grade was 1 ± 1. The average surgery duration was 71 ± eight minutes. The average estimated blood loss was 83 ± 26 ml. After a mean follow-up of 50 ± 12 months, we observed no OA progression with no change in Tönnis hip OA grades. Hip flexion and internal rotation significantly improved (p = 0.007; p = 0.048) from mean 98° ± 9° and 14° ± 11° to mean 113° ± 8° and 23° ± 8°, respectively. iHOT-33, Tegner, and EQ-5D improved significantly (p = < 0.001; p = 0.004; p = < 0.001) from mean 44.7 ± 12.2, 3 ± 1, and 0.513420 ± 0.101389 to mean 94 ± 2.7, 5 ± 1, and 1.000000 ± 0, respectively. One patient needed revision surgery for heterotopic ossification removal, with no sequelae at the last follow-up.

CONCLUSION

Mini-open anterior hip approach with the PST-guided cam-type FAI deformity ablation presents an accurate and reproducible solution for cam-type FAI surgical treatment, with promising clinical outcomes. Using a PST in the cam-type FAI surgery may present a powerful additional tool in the existing open techniques armamentarium.

Arthroscopic versus open treatment for femoroacetabular impingement: A systematic review and meta-analyses

BACKGROUND

Femoroacetabular impingement (FAI) is a common cause of hip pain and restricted range of motion in young adults and athletes. This study aims to compare clinical results and complications between patients treated for FAI who underwent either arthroscopic or open treatment.

METHODS

The 7 studies were acquired from PubMed, Medline, Embase, and Cochrane Library. The data were extracted analyzed by RevMan5.3. Mean differences (MDs), odds ratios (ORs), and 95% confidence intervals (CIs) were calculated. The Newcastle-Ottawa Scale were used to assess risk of bias.

RESULTS

Seven observational studies were assessed. The methodological quality of the trials indicated a low risk of bias. The pooled results of the modified Harris Hip Score (mHHS), the Non-Arthritic Hip Score (NAHS), the Visual Analogue Scale (VAS), and satisfaction rate showed that the differences were not statistically significant between arthroscopic treatment (AT) and open treatment (OT). The difference of postoperative alpha angle was statistically significant, and OT was more effective [MD = 3.08, 95% confidence interval (95% CI) = 1.45-4.70, P = .0002]. The difference of postoperative internal rotation angle was statistically significant, and OT had better internal rotation angle (MD = -3.21, 95% CI = -6.14 to -0.28, P = .03). However, the difference of complications was statistically significant and AT achieved better result than OT (OR = 0.41, 95% CI = 0.22-0.74, P =0.003).

CONCLUSION

AT had comparable effect and lower complications than OT, but had less improvement in alpha angle and internal rotation angle.

Surgical Treatment of Femoroacetabular Impingement: Hip Arthroscopy Versus Surgical Hip Dislocation: A Propensity-Matched Analysis

BACKGROUND

Surgical treatment of femoroacetabular impingement (FAI) continues to evolve and is most commonly approached with either hip arthroscopy (HA) or surgical dislocation (SD) of the hip. The purpose of this study was to compare the outcomes of similar patients undergoing surgical treatment of FAI with either HA or SD.

METHODS

A prospective multicenter cohort study of patients undergoing primary surgical treatment of FAI was performed. Follow-up at a minimum of 1 year (mean, 4.3 years) was available for 621 hips (81.7%), including 399 procedures with HA and 222 procedures with SD. Propensity scores were calculated and reflect the likelihood of surgical treatment with HA versus SD for a given set of covariates. Propensity scores allowed 1:1 matching to identify similar patients at baseline. After propensity matching, 128 matched pairs of patients who underwent HA and 128 matched pairs of those who underwent SD were included in the study. The primary outcome was the postoperative modified Harris hip score (mHHS); secondary outcomes included the Hip disability and Osteoarthritis Outcome Score (HOOS), the University of California Los Angeles (UCLA) activity score, and the Short Form-12 (SF-12) physical and mental subscores, as well as the rate of persistent symptoms, revision surgery, and total hip arthroplasty (THA).

RESULTS

After propensity matching, the 2 groups exhibited similar distributions of all of the covariates that were included in the model. Both groups demonstrated significant improvements in all patient-reported outcomes (PROs). The final mHHS was not significantly different between the 2 matched groups (81.3 for the HA group versus 80.2 for the SD group, p = 0.67). Likewise, the HOOS pain subscale was similar at the time of final follow-up (77.6 versus 80.5, respectively, p = 0.32). No difference between the HA group and the SD group was identified in the rate of THA (0% and 3.1%, respectively, p = 0.41) and revision surgery (7.8% and 10.9%, respectively, p = 0.35); overall rates of persistent symptoms were 21.9% for the HA group and 24.4% for the SD group (p = 0.55).

CONCLUSIONS

In a propensity-matched analysis of patients who were treated with either approach, patients undergoing HA or SD demonstrated similar outcomes at a mean of 4 years postoperatively.

LEVEL OF EVIDENCE

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

Surgical hip dislocation is more powerful than arthroscopy for achieving high degrees of acetabular correction in pincer type impingement

BACKGROUND

With the development of hip arthroscopy (HA), a shift away from surgical hip dislocation (SHD) is becoming a noticeable reality. It was the aim of this study to examine whether SHD provides a benefit over HA regarding its corrective power in the treatment of femoroacetabular impingement (FAI).

HYPOTHESIS

It was hypothesized that SHD provides the more powerful tool for acetabular correction in FAI surgery compared to HA.

METHOD

The examined cohort consisted of 85 hips of which 31 (36%) underwent a high degree of acetabular correction which was defined as a correction of >2 standard deviations from the population mean. A lateral center edge angle (LCE) correction>12° or an acetabular index (AI) correction>8° were therefore considered to high correction. A logistic regression model was applied to determine factors influencing high correction in FAI surgery. Subsequent adjustment was performed using a multivariate model.

RESULTS

After adjusting for pre-operative acetabular orientation, SHD showed a pronounced influence on the likelihood of achieving the adequate degree of high acetabular correction (odds ratio (OR) 10.0 confidence interval (C.I) 2.3 to 44.0, p=0.002). On the other hand, SHD showed no influence on femoral correction (p=n.s).

CONCLUSION

Surgical hip dislocation is a powerful modality for achieving high degrees of acetabular correction in the situation of a femoroactabular conflict, being defined as an LCE correction of>12° or AI correction of>8°. The reason for these results may be seen in the excellent exposure and the improved possibility of performing dynamic intra-operative examination to verify the results. The benefits are only limited to large acetabular correction. These findings should provide a helpful tool for decision making in clinical practise.

LEVEL OF EVIDENCE

Level III retrospective cohort study.

Surgical Treatment for FAI: Arthroscopic and Open Techniques for Osteoplasty

PURPOSE OF REVIEW

To review the relevant literature and techniques regarding arthroscopic and open treatment of femoroacetabular impingement (FAI). To discuss both the senior authors' preferred method of arthroscopic and open treatment of FAI.

RECENT FINDINGS

Routine treatment of FAI has moved away from open techniques and is more focused arthroscopic methods. Arthroscopic treatment of FAI has more recently focused on differing techniques of hip access and capsular management. Open techniques still have a role in FAI, but indications for open management are focused on cases with more severe pathology. While arthroscopic techniques have shown better outcomes in the short term and higher return to play, it is not without risk and is a procedure with a steep learning curve. In cases of complex joint pathology, such as FAI coupled with dysplasia or Legg-Calve-Perthes, arthroscopy may be not indicated and an open approach preferred. We outline various techniques for both arthroscopic and open treatment of FAI and their outcomes when possible.

Prevalence and Consistency in Surgical Outcome Reporting for Femoroacetabular Impingement Syndrome: A Scoping Review

PURPOSE

The purposes of this review were (1) to collate and synthesize research studies reporting any outcome measure on both open and arthroscopic surgical treatment of femoroacetabular impingement (FAI) syndrome and (2) to report the prevalence and consistency of outcomes across the included studies.

METHODS

A computer-assisted literature search of the MEDLINE, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and Embase databases was conducted using keywords related to FAI syndrome and both open and arthroscopic surgical outcomes, resulting in 2,614 studies, with 163 studies involving 14,824 subjects meeting the inclusion criteria. Two authors independently reviewed study inclusion and data extraction with independent verification. The prevalence of reported outcomes was calculated and verified by separate authors.

RESULTS

Between 2004 and 2016, there has been a 2,600% increase in the publication of surgical outcome studies. Patients had a mean duration of symptoms of 27.7 ± 21.5 months before surgery. Arthroscopy was the surgical treatment used in 71% of studies. The mean final follow-up period after surgery was 32.2 ± 17.3 months. Follow-up time frames were reported in 78% of studies. Ten different patient-reported outcome measures were reported. The alpha angle was reported to be measured 42% less frequently as a surgical outcome than as a surgical indication. Surgical complications were addressed in only 53% of studies and failures in 69%. Labral pathology (91% of studies reporting) and chondral pathology (61%) were the primary coexisting pathologies reported. Clinical signs, as defined by the Warwick Agreement on FAI syndrome, were reported in fewer than 25% of studies.

CONCLUSIONS

Most FAI syndrome patients have longstanding pain and potential coexisting pathology. Patient-reported outcome measures and diagnostic imaging are the most frequently reported outcomes. Measures of hip strength and range of motion are under-reported. It is unclear whether the inconsistency in reporting is because of lack of measurement or lack of reporting of specific outcomes in these studies. Current surgical outcomes are limited to mid-term surgical follow-up time frames and inconsistent outcome reporting.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I through IV studies.

Factors Associated With Failure of Hip Arthroscopy in Patients With Hip Dysplasia

The purpose of this study was to compare a group of dysplastic hips treated successfully with hip arthroscopy with a group of dysplastic hips treated unsuccessfully with hip arthroscopy to determine (1) preoperative patient characteristics and radiographic parameters and (2) intraoperative findings and treatment associated with outcome. The authors retrospectively reviewed a prospective database of 20 adult patients (17 female, 3 male) with hip dysplasia who underwent primary hip arthroscopy between January 2009 and February 2013. Modified Beck scores to quantify cartilage damage as well as preoperative and postoperative radiographic measurements (including alpha, Tonnis, and lateral center edge angles [LCEAs]) were compared between patients who failed hip arthroscopy (11 patients) and those who did not (9 patients). Failure after hip arthroscopy was defined as a modified Harris hip score of less than 80 or the need for subsequent hip arthroscopy, arthroplasty, or periacetabular osteotomy. The mean follow-up for the successful patients was 58 months (range, 37-82 months), with an average modified Harris hip score of 93 at most recent follow-up. Preoperative radiographs showed a lower mean LCEA (18.0° vs 21.3°; P=.02) in the failure group, and all successes occurred with a LCEA of 17° or greater. The failure group was more likely to have rim resection of greater than 3 mm performed (hazard ratio, 3.53; P=.04). Among the hips with dysplasia undergoing arthroscopic treatment, patients with a poor outcome were more likely to have an LCEA of less than 17° and intraoperative rim resection of greater than 3 mm. Furthermore, the labral repair group did substantially better than the labral debridement group. [Orthopedics. 2018; 41(2):e234-e239.].

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.

Female Sex Is a Risk Factor for Failure of Hip Arthroscopy Performed for Acetabular Retroversion

BACKGROUND

The success of hip surgery in treating acetabular retroversion depends on the severity of the structural deformity and on selecting the correct patient for open or arthroscopic procedures.

PURPOSE

To compare a group of patients with retroverted hips treated successfully with hip arthroscopy with a group of patients with retroverted hips that failed arthroscopic surgery, with special emphasis on (1) patient characteristics, (2) perioperative radiographic parameters, (3) intraoperative findings and concomitant procedures, and (4) patient sex.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

We retrospectively reviewed the charts of 47 adult patients (47 hips) with acetabular retroversion who had undergone hip arthroscopy. Retroversion was based on the presence of an ischial spine sign in addition to either a crossover or posterior wall sign on a well-positioned anteroposterior pelvic radiograph. A total of 24 hips (50%) (16 females, 8 males; mean patient age, 31 years) had failed arthroscopy, defined as modified Harris Hip Score (mHHS) <80 or need for subsequent procedure. Twenty-three hips (8 females, 15 males; mean patient age, 29 years) were considered successful, defined as having no subsequent procedures and an mHHS >80 at the time of most recent follow-up. Perioperative variables, radiographic characteristics, and intraoperative findings were compared between the groups, in addition to a subgroup analysis based on sex.

RESULTS

The mean follow-up for successful hips was 30 months (SD, 11 months), with a mean mHHS of 95. In the failure group, 6 patients required subsequent procedures (4 anteverting periacetabular osteotomies and 2 total hip arthroplasties). The mean overall time to failure was 21 months, and the mean time to a second procedure was 24 months (total hip arthroplasty, 29.5 months; periacetabular osteotomy, 21.2 months); 18 hips failed on the basis of a low mHHS (mean, 65; range, 27-79) at last follow-up. Factors significantly different between the success and failure groups included patient sex, with males being more likely than females to have a successful outcome (P < .02), as well as undergoing femoral osteoplasty (P < .02). Intraoperative variables that were associated with worse outcome included isolated labral debridement (P < .002). In a subgroup analysis, males were more likely than their female counterparts to have a successful outcome with both isolated cam and combined cam-pincer resection (P < .05). Level of crossover correction on postoperative radiographs had no correlation with outcome.

CONCLUSION

Acetabular retroversion remains a challenging pathoanatomy to treat arthroscopically. If hip arthroscopy is to be considered in select cases, we recommend labral preservation when possible. Male patients with correction of cam deformities did well, while females with significant retroversion appeared to be at greater risk for failure of arthroscopic treatment.

[Impingement of the hip]

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

Arterial Topographic Anatomy Near the Femoral Head-Neck Perforation with Surgical Relevance

BACKGROUND

Knowledge of the vascular supply of the femoral head is crucial for hip-preserving surgical procedures. The critical area for reshaping cam deformity is at the retinacular vessel penetration, an area with ill-defined topographic anatomy. We performed a cadaver study of the extension of the lateral retinaculum near the head-neck junction, distribution of the arterial vascular foramina, and initial intracapital course of these vessels.

METHODS

In 16 fresh proximal parts of the femur without head-neck deformities, the deep branch of the medial femoral circumflex artery was injected with gadolinium for magnetic resonance imaging (MRI) sequences to identify arterial structures.

RESULTS

We found a mean number of 4.5 arterial foramina, showing a predominance from 10 to 12 o'clock. The retinaculum extended 20 mm from 1 to 10 o'clock. The surface distance from the cartilage border to the vascular foramina under the synovial fold was 6.5 mm, and the depth from the same cartilage border to the initial intraosseous vessel pathways was 5.3 mm.

CONCLUSIONS

The data add further precision to the arterial topography at the retinacular foramina, an area that is crucial for the perfusion of the femoral head. It may overlap with the area of anterolateral cam deformity and plays a role in choosing the cuts for subcapital and intracapital osteotomies.

CLINICAL RELEVANCE

The information is taken from normal hips and may not be directly applicable to the deformed hip. Nevertheless, it is a prerequisite for a surgeon to understand the normal anatomy and use those boundaries to prevent mistakes during intra-articular joint-preserving hip surgical procedures.

What Are the Risk Factors for Revision Surgery After Hip Arthroscopy for Femoroacetabular Impingement at 7-year Followup?

BACKGROUND

In recent years, surgical treatment of symptomatic femoroacetabular impingement (FAI) has been increasingly performed using arthroscopy. Bony pathomorphologies and damage to the labrum as well as cartilage defects can be addressed with comparable results to open surgery with overall less surgery-related complications. Despite the increasing importance of hip arthroscopy, however, reports on midterm clinical and radiographic outcomes and comparison to open surgical hip dislocation are scarce.

QUESTIONS/PURPOSES

(1) What are the clinical and radiographic outcomes at a mean 7-year followup; (2) what is the cumulative 7-year survivorship, using the endpoints of THA, progression of osteoarthritis according to Tönnis, or poor clinical outcome with a Merle d'Aubigné score of less than 15 points, of hips with symptomatic FAI treated arthroscopically; and (3) what factors were associated with revision surgery?

METHODS

Between 2003 and 2008 we performed a total of 62 arthroscopic procedures (60 patients) for FAI. For the same indication, we also performed 571 surgical hip dislocations during that time. Standardized treatment was femoral offset correction, acetabular rim trimming, or both and treatment of labral or chondral defects. An arthroscopic approach was generally used if the pathomorphology was located in the anterosuperior quadrant of the hip and was gradually used for more complex cases. We excluded 10 hips (10 patients) in which the standardized treatment was not achieved and no offset correction or acetabular rim trimming was performed. Of the remaining 52 hips (50 patients), 39 hips underwent isolated femoral offset correction, four hips isolated acetabular rim trimming, and nine hips both procedures. At a mean followup of 7 years (range, 5-11 years), the Merle d'Aubigné clinical score was obtained and plain radiographs were examined (Tönnis grade, heterotopic ossification, lateral center-edge [LCE] angle, acetabular index [AI], extrusion index, alpha angle, and pistol grip deformity). Cumulative survivorship was calculated according to Kaplan-Meier using conversion to THA, progression of osteoarthritis (one or more Tönnis grades), or poor clinical outcome (Merle d'Aubigné score < 15 points) as endpoints. Cox regression analysis was used to identify univariate factors associated with revision surgery.

RESULTS

At last followup we detected a significant but possibly not clinically relevant increase in Merle d'Aubigné scores from preoperative levels to latest followup (14 ± 1 versus 16 ± 2, mean difference 2 points with a 95% confidence interval [95% CI] -3 to 7, p < 0.001). Six hips showed progression of osteoarthritis. Cumulative survivorship (hips free from conversion to THA, progression of osteoarthritis, or poor clinical outcome) of hips treated with hip arthroscopy for FAI at a mean followup of 7 years was 81% (95% CI, 68%-95%). Two patients (two hips, 4%) underwent THA at 7 and 9 years, respectively. An increased preoperative acetabular coverage (LCE angle, AI), increased offset in the superior portion of the femoral neck (pistol grip deformity), and a remaining pistol grip deformity postoperatively were associated with revision surgery. Any treatment of the labrum did not influence the outcome. Factors associated with failure could not be identified.

CONCLUSIONS

In this series of patients with arthroscopic treatment of symptomatic FAI, hip arthroscopy resulted in an intact hip without progression of osteoarthritis and with a Merle d'Aubigné score of ≥ 15 points in 81% of patients at 7-year followup. Increased acetabular coverage and femoral pistol grip deformity were risk factors for revision surgery.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Femoral neck fractures as a complication of hip arthroscopy: a systematic review

The purpose of this study was to identify the causes and risk factors for hip fractures, a rare but devastating complication, following hip arthroscopy. The electronic databases MEDLINE, EMBASE and PubMed were searched and screened in duplicate for relevant clinical and basic sciences studies and pertinent data was abstracted and analysed in Microsoft Excel. Nineteen studies (12 clinical studies and seven biomechanical studies) with a total of 31 392 patients experiencing 43 hip fractures (0.1% of patients) met the inclusion criteria for this systematic review. Femoral osteochondroplasty was performed in 100% of patients who sustained a hip fracture. Six of the 12 (50%) studies identified early weight bearing (prior to 6 weeks post-operatively) as the cause for the hip fracture. Other causes of this complication included over resection during femoral osteochondroplasty, minor trauma and intensive exercise. The results suggest that early weight bearing is the largest modifiable risk factor for hip fracture after femoral osteochondroplasty. For this reason, an extended period of non-weight bearing or restricted weight bearing should be considered in select patients. Studies report a correlation between risk for post-operative hip fracture and increased age. Increased resection during osteochondroplasty has been correlated with increased risk of fracture in various basic science studies. Resection depth has significantly higher impact on risk of fracture than resection length or width. The reported amounts of resection that depth that can be performed before there is a significantly increased risk of fracture of the femoral neck varies from 10 to 30%.

[Hip arthroscopy]

Hip arthroscopy represents an important component in the treatment of diseases of the hip joint and is nowadays an indispensible tool in modern hip-preserving surgery. This article provides a review of the basic technical principles, typical indications and complications of hip arthroscopy. Furthermore, current developments as well as possibilities and limitations of the arthroscopic technique are reviewed.

Hip arthroscopy versus open surgical dislocation for femoroacetabular impingement: A systematic review and meta-analysis

BACKGROUND

This meta-analysis aims to evaluate the efficacy and safety of hip arthroscopy versus open surgical dislocation for treating femoroacetabular impingement (FAI) through published clinical trials.

METHODS

We conducted a comprehensive literature search using PUBMED, EMBASE, and the Cochrane Central Register of Controlled Trials databases for relevant studies on hip arthroscopy and open surgical dislocation as treatment options for FAI.

RESULTS

Compared with open surgical dislocation, hip arthroscopy resulted in significantly higher Nonarthritic Hip Scores (NAHS) at 3- and 12-month follow-ups, a significant improvement in NAHS from preoperation to 3 months postoperation, and a significantly lower reoperation rate. Open surgical dislocation resulted in a significantly improved alpha angle by the Dunn view in patients with cam osteoplasty from preoperation to postoperation, compared with hip arthroscopy. This meta-analysis demonstrated no significant differences in the modified Harris Hip Score, Hip Outcome Score-Activities of Daily Living, or Hip Outcome Score-Sport Specific Subscale at 12 months of follow-up, or in complications (including nerve damage, wound infection, and wound dehiscence).

CONCLUSION

Hip arthroscopy resulted in higher NAHS and lower reoperation rates, but had less improvement in alpha angle in patients with cam osteoplasty, than open surgical dislocation.

Management options for femoroacetabular impingement: a systematic review of symptom and structural outcomes

OBJECTIVE

The optimal therapy for femoroacetabular impingement (FAI) is unclear. The aim of this systematic review was to examine the evidence for surgical and non-surgical treatment of FAI on symptom and structural outcomes.

DESIGN

MEDLINE and EMBASE were searched electronically. Surgical and non-surgical management strategies were searched with "FAI". Studies which included comparison groups and reported symptom or structural outcomes were included (Levels I-III evidence). A risk of bias assessment was performed.

RESULTS

Eighteen studies comparing management strategies for FAI were identified. Most studies had high risk of bias. No study compared surgical and non-surgical treatment. When surgical approaches were compared there was evidence of superior symptom outcomes with arthroscopy compared to open surgery and with labral preservation. There was some evidence that surgical interventions are effective in reducing alpha angle (improved hip shape), but no data on whether this affects long-term outcomes. There was some weak evidence that surgery is associated with structural progression of hip osteoarthritis (OA).

CONCLUSIONS

Although evidence supports improvement in symptoms after surgery in FAI, no studies have compared surgical and non-surgical treatment. Therefore no conclusion regarding the relative efficacy of one approach over the other can be made. Surgery improves alpha angle but whether this alters the risk of development or progression of hip OA is unknown. This review highlights the lack of evidence for use of surgery in FAI. Given that hip geometry may be modified by non-surgical factors, clarifying the role of non-surgical approaches vs surgery for the management of FAI is warranted.

Radiographic outcomes following femoroacetabular impingement correction with open surgical management: a systematic review

Femoroacetabular impingement (FAI) is a common cause of hip pain, and open surgical approaches remain an important treatment option for FAI. This systematic review of the literature sought to determine what post-operative radiographic outcomes have been reported following open surgical correction of FAI. After screening and full-text review, 18 studies involving 1192 hips in 1084 patients were included for analysis. In total, 24 radiological outcomes were reported. CAM-type FAI was most frequently assessed using the alpha angle (61.1 %) and head-neck offset/head-neck offset ratio (33.3 %). Lateral center edge angle (27.8 %) and the acetabular index (22.2 %) were the most commonly reported outcomes for pincer-type FAI. The results of this review suggest that reporting of post-operative radiographic outcomes is variable, that no single radiographic parameter is optimal, and that the clinician must use a combination of reproducible measurements, together with their clinical examination, to confirm adequate restoration of normal hip morphology.

Arthroscopic Management of Femoroacetabular Impingement in Adolescents

PURPOSE

To report the outcomes of hip arthroscopy for adolescent patients with symptomatic femoroacetabular impingement (FAI) in relation to a control group of adult patients treated arthroscopically for FAI.

METHODS

All patients undergoing hip arthroscopy were assessed with a modified Harris Hip Score preoperatively and postoperatively at 3, 12, 24, and 60 months. Inclusion criteria were all patients less than 18 years of age who underwent arthroscopic surgery for symptomatic FAI and had achieved minimum 1-year follow-up. These cases were gathered over an 8-year period.

RESULTS

The study group consisted of 122 consecutive hips (108 patients), and the control group consisted of 122 hips. Follow-up averaged 30 months (range 12 to 60 months). For the study group, the average age was 16 years, with 55 males and 65 females; control group average age was 36 years, with 71 males and 51 females. In the study group, the average scores were preoperative 68.3 and postoperative 93.6, with a 25.4-point improvement. The duration of symptoms averaged 16.6 months, and 95.9% participated in athletic activities. The study group included 36 cam, 17 pincer, and 69 combined lesions. One hundred eleven labral tears underwent 85 refixations and 26 debridements; there were 101 acetabular chondral lesions (51 grade 3 or 4), with 4 microfractures and 3 femoral chondral lesions. Among the control group, the average scores were preoperative 63.3 and postoperative 85.5, with a 22.2-point improvement. The duration of symptoms averaged 31.2 months, and 61.5% participate in athletic activities. The control group consisted of 53 cam, 5 pincer, and 64 combined FAI lesions. One hundred three labral tears underwent 52 refixations and 51 debridements; there were 112 acetabular lesions (92 grade 3 or 4), with 20 microfractures and 17 femoral chondral lesions. The study group included 15 concomitant extra-articular procedures, and there were 5 in the control group. In the study group, 4 underwent repeat arthroscopy and 1 periacetabular osteotomy; in the control group, 1 patient underwent repeat arthroscopy.

CONCLUSIONS

Favorable outcomes of arthroscopic management of FAI in adolescents are reported compared with an adult control group. The present data support that arthroscopy does have a role in the management of FAI in adolescents.

LEVEL OF EVIDENCE

Level III, case control study.

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.

Surgical innovation and safety: femoroacetabular impingement and the IDEAL collaborative framework

Operative treatment of femoroacetabular impingement (FAI) is a relatively new, yet rapidly expanding surgical innovation. Although the practice of surgery is inherently innovative, there is no clear distinction between minor technical variation and true modification that warrants testing. This raises important questions about how new procedures should be evaluated before being broadly disseminated. The IDEAL Collaborative is a consortium that promotes safe and responsible translation of research into clinical practice. The collaborative has delineated the typical stages of evolution of new interventional technologies, and the type of study designs appropriate for each stage. This report examines the surgical treatment of FAI as a case study of the IDEAL framework and discusses both missed and future opportunities for critical assessment.

Treatment of cam-type femoroacetabular impingement

PURPOSE

the aim of this study was to evaluate preliminary clinical and radiographic results of arthroscopic treatment of cam-type femoroacetabular impingement (FAI).

METHODS

thirty-eight patients underwent hip arthroscopy for cam-type FAI between 2009 and 2012. Preoperative assessment was based on clinical examination, modified Harris Hip Score (mHHS) and radiographic examination with anteroposterior pelvis, frog-leg and Lequesne views. The patients' clinical conditions at follow-up were assessed using the mHHS administered as a telephone survey. Radiographic outcome measurements evaluated pre and postoperatively were the alpha angle and femoral head-neck offset.

RESULTS

the patients were clinically evaluated at a mean follow-up of 36 months. Radiographic follow-up was performed at an average of 12.7 months. Thirty of the 38 patients (79%) were satisfied with the results of the arthroscopic procedure. A total of nine patients subsequently underwent a total hip replacement. All 30 patients who declared themselves satisfied recorded an mHHS increase; in particular, the mHHS increased from a mean of 52.9 preoperatively (range: 27.5-82.5) to a mean of 85.6 postoperatively (range: 45.1-100.1). Three significant differences between the two groups of patients (satisfied and not satisfied) were recorded: mean age, alpha angle and BMI were all significantly greater in the patients who were not satisfied with the treatment.

CONCLUSIONS

a crucial aspect in order to obtain good clinical outcomes of arthroscopic treatment of cam-type impingement is correct selection of patients who are likely to benefit from this kind of surgery. Hip arthroscopy should be avoided in patients aged over 50 years with risk factors for early osteoarthritis (high BMI and a significantly increased alpha angle).

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Expert Surgeons Can Be Distinguished From Trainees, and Surgical Proficiency Can Be Defined, Using Validated Metrics and Shoulder Models

Experts at performing arthroscopic shoulder Bankart procedures can be distinguished from surgical trainees using validated metrics and a cadaveric or simulator model. The combination of performance metrics plus models generates a tool that can be used to precisely and accurately define a performance threshold and assess whether or not a surgeon is proficient at performing a procedure. A tool that can be used to judge surgical expertise has implications for training and credentialing. Experienced surgeons make fewer mistakes and are faster than novices.

Editorial Commentary: Arthroscopic Training and Proficiency Assessment Are Hot Topics

Methods to measure operative skill are improving in quality. Arthroscopic surgical training and arthroscopic proficiency assessment are hot topics.

Learning the Language of Copernicus

The Copernicus Initiative was a bold and important undertaking by the Arthroscopy Association of North America to help further our learning the art of arthroscopy in a controlled setting. Understanding arthroscopic learning, training, and simulation research requires mastery of a lexicon of new terms, which AANA Copernicus researchers define in a glossary. Learning requires practice to develop proficiency. Developing new ability is a rewarding challenge. Metrics may be used to quantitatively measure objective performance, and is a key component of the Copernicus Initiative. A dedicated group of AANA researchers and educators have taken on an important and challenging task to help us improve in the realm of surgical education.

Complications and survival analyses of hip arthroscopies performed in the national health service in England: a review of 6,395 cases

PURPOSE

Our study aimed to identify the complications of hip arthroscopies with particular emphasis on the 30-day readmission rate; 90-day deep vein thrombosis (DVT) and pulmonary embolism (PE) rate and mortality rate; revision hip arthroscopy rate; and in particular, survivorship with conversion to total hip replacement (THR) as the endpoint.

METHODS

The records of patients undergoing hip arthroscopy were extracted from the administrative hospital admissions database covering all admissions to the National Health Service hospitals in England using ICD-10 (International Statistical Classification of Diseases and Related Health Problems, 10th Revision) and OPCS-4 (Office of Population Censuses and Surveys Classification of Surgical Operations and Procedures, fourth revision) codes.

RESULTS

A total of 6,395 hip arthroscopies were included in the study period. The 30-day readmission rate was 0.5%; both the 90-day DVT rate and PE rate were 0.08%; and the 90-day mortality rate was 0.02%. THR was performed in 680 patients (10.6%) at a mean of 1.4 years after the index operation, and 286 patients (4.5%) underwent revision hip arthroscopy at a mean of 1.7 years. Kaplan-Meier survival analysis showed an 8-year survival rate of 82.6% (95% confidence interval [CI], 80.9% to 84.2%), whereas Cox proportional hazard analysis adjusting for age, gender, and Charlson comorbidity score showed an 8-year survival rate of 86%. Female patients had a 1.68 times (95% CI, 1.41 to 2.01) higher risk of conversion to THR than male patients, and patients aged 50 years or older had a 4.65 (95% CI, 3.93 to 5.49) times higher risk of requiring hip replacement than patients younger than 50 years.

CONCLUSIONS

In this large series of 6,395 hip arthroscopies looking at the national data from the English National Health Service, our null hypothesis has been supported, and we have determined that the rate of short-term complications, in particular the risk of DVT and PE after this operation, is low. Higher age and female gender are significant predictors of conversion to THR, with Cox proportional hazard analyses showing a survivorship rate of 86% at 8 years after adjustment for confounding variables.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Causes and risk factors for revision hip preservation surgery

BACKGROUND

Identifying causes and risk factors for failure of hip preservation surgery is critical to properly address residual pathological abnormalities in the revision setting and improve outcomes in this subset of patients.

PURPOSE

To identify the structural causes of failure in both open and arthroscopic hip preservation procedures and to identify demographic and radiographic risk factors that correlate with the need for revision surgery.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A single-center hip preservation registry was reviewed (N = 1898 procedures in 1600 patients) to identify 147 patients (n = 152 procedures) who had undergone previous pelvic surgery. Exclusion criteria included residual deformity from pediatric hip disease (n = 5 patients). Preoperative demographics, intraoperative findings, radiographic data, and clinical outcome scores were compared between cohorts with and without revision surgery in the registry. Postoperative, short-term patient-reported outcome scores for the revision cohort were described.

RESULTS

The most common reason for revision was residual intra-articular femoroacetabular impingement (74.8%), followed by extra-articular impingement (9.5%). The majority of revision cases (78.9%) could be addressed with arthroscopic surgery, with the exception of extra-articular impingement or residual acetabular dysplasia, which necessitated open approaches. Patients who underwent revision were more likely to be female, were younger in age, and had worse preoperative outcome scores than did those in the primary cohort. Abnormal femoral version and the presence of acetabular dysplasia were not significantly different between the revision and primary cohorts. Short-term improvements in patient-reported outcome scores were found in the revision cohort at a mean of 15.0 months from the last revision surgery.

CONCLUSION

Residual intra- and extra-articular impingement were the most common reasons for revision in this cohort. Patients who underwent revision tended to be younger in age, were female, and had worse preoperative hip functional outcomes than did those in the primary cohort. Abnormal femoral version or acetabular coverage was not increased in our revision cohort.

Function and osteoarthritis progression after arthroscopic treatment of femoro-acetabular impingement: a prospective study after a mean follow-up of 4.6 (4.2-5.5) years

BACKGROUND

Outcomes after arthroscopic femoro-acetabular impingement (FAI) surgery are promising in the short-term but have rarely been evaluated in the mid-term (e.g., about 5 years). Here, our objectives were to obtain mid-term data on functional and radiographic outcomes, to identify prognostic factors, and to determine the mid-term rate of arthroplasty revision with the associated risk factors.

HYPOTHESIS

We hypothesized that the results of arthroscopic FAI surgery were sustained over time.

MATERIALS AND METHODS

We conducted a prospective multi-surgeon study of 53 Tönnis grade 0 or 1 hips treated arthroscopically for symptomatic FAI (23 cam, 10 pincer, and 20 mixed deformities). We obtained short-term (10 months) and mid-term (4.6 years) data on the functional outcome (WOMAC and satisfaction scores), proportion of patients without revision arthroplasty, and development of osteoarthritis (graded using the Tönnis classification).

RESULTS

In the patients without revision arthroplasty, the WOMAC score improved significantly (P<0.01) from baseline (61.4 ± 15.6) to 10 months (84.2 ± 15.6) and last follow-up (85.2 ± 15.5) but remained unchanged between the two postoperative time points, confirming the stability of the results. The proportion of satisfied patients was 79% after 10 months and 68% (36/53) at last follow-up (NS). Osteoarthritis developed in 13/35 (37%) hips for which radiographs were obtained at last follow-up. At last follow-up, 46/53 hips (87%; 95%CI, 78-96) did not required revision surgery; arthroplasty was required in the 7 remaining hips. The main prognostic factor was the preoperative osteoarthritis Tönnis grade: at last follow-up, compared to Tönnis grade 0 hips, Tönnis grade 1 hips had lower WOMAC scores (77 vs. 88), lower satisfaction rates (50% versus 77%), a higher rate of osteoarthritis progression (57% versus 24%), and a higher rate of arthroplasty (33.3% versus 2.9%).

DISCUSSION

Our results are consistent with published data. The outcomes of arthroscopic FAI surgery are sustained over time and the preoperative osteoarthritis status is the main predictor of mid-term outcomes.

LEVEL OF EVIDENCE

IV, prospective cohort study.

Osteoarthritis: From Palliation to Prevention: AOA Critical Issues

Osteoarthritis is a leading cause of disability. The traditional focus on late-stage osteoarthritis has not yielded effective disease-modifying treatments. Consequently, current clinical care focuses on palliation until joint replacement is indicated. A symposium format was used to examine emerging strategies that support the transformation of the clinical approach to osteoarthritis from palliation to prevention. Central to this discussion are concepts for diagnosis and treatment of pre-osteoarthritis, meaning joint conditions that increase the risk of accelerated development of osteoarthritis. The presentation of translational and clinical research on three common orthopaedic conditions-anterior cruciate ligament tear, intra-articular fracture, and hip dysplasia-were used to illustrate these ideas. New information regarding the use of novel quantitative magnetic resonance imaging (MRI) in the form of ultrashort echo time enhanced T2* (UTE-T2*) mapping to evaluate the potential for articular cartilage to heal subsurface damage in a mechanically sound environment was presented. These data indicate that improved diagnostics can both identify cartilage at risk and evaluate the effectiveness of early treatment strategies. With use of a new mouse model for intra-articular fracture, it was shown that inflammation correlated to fracture severity and that super-healer mice avoided early posttraumatic osteoarthritis in part through an enhanced ability to dampen inflammation. These findings suggest that there is a role for acute and sustained anti-inflammatory treatment in the prevention of osteoarthritis. For long-term treatment, contemporary gene-therapy approaches may offer an effective means for sustained intra-articular delivery of anti-inflammatory and other bioactive agents to restore joint homeostasis. To illustrate the potential of early treatment to prevent or delay the onset of disabling osteoarthritis, the positive clinical effects on articular cartilage and in long-term clinical follow-up after operative correction of structural abnormalities about the hip highlight the role for targeting mechanical factors in delaying the onset of osteoarthritis. Given that orthopaedic surgeons treat the full spectrum of joint problems, ranging from joint trauma to pre-osteoarthritic conditions and end-stage osteoarthritis, an awareness of the paradigm shift toward the prevention of osteoarthritis is critical to the promotion of improved clinical care and participation in clinical research involving new treatment strategies.

Complications in hip arthroscopy: necessity of supervision during the learning curve

PURPOSE

The aim of this study was to determine whether the learning curve of arthroscopic treatment of femoroacetabular impingement (FAI) could be verified by analyzing the complication rate of this procedure. Additionally, it was investigated whether supervision by an experienced surgeon leads to a steeper learning curve (lower number of complications) when starting to perform arthroscopic FAI treatment.

METHODS

The complications occurring in 317 consecutive patients treated with the sole diagnosis of FAI were analyzed. 256 patients (collective A) were treated by surgeon A between June 2005 and January 2010. Sixty-one patients (collective B) were treated by surgeon B between August 2008 and December 2009. From January to June 2008, surgeon B performed many hip arthroscopies under supervision of surgeon A. Complications were recorded in a central complication register. Statistic analysis of the complication rates was performed using Fischer's exact T test.

RESULTS

Subdividing collective A chronologically into thirds a significant decline of complications (p = 0.0044) was found with growing experience of the surgeon. Comparing the first 61 patients of both surgeons a significantly lower complication rate was discovered in the patients of surgeon B (p = 0.0375). In total there were 21 complications (6.6 %; CI 4.4-9.9 %). The observed complication rate was 7.0 % in collective A and 4.9 % in collective B.

CONCLUSION

The learning curve can be comprehended by the distribution of complications in collective A. Having spent 6 months performing under supervision of surgeon A, surgeon B has a lower complication rate than surgeon A when comparing the first 61 patients each surgeon operated on. This implies that surgeon B benefits from the experience of surgeon A. According to this analysis, beginners in arthroscopic FAI treatment should be taught at a specialized centre to reduce the number of complications.

Incidence of hip pain in a prospective cohort of asymptomatic volunteers: is the cam deformity a risk factor for hip pain?

BACKGROUND

Although cam-type femoroacetabular impingement is commonly associated with labral chondral damage and hip pain, a large proportion of asymptomatic individuals will have this deformity.

PURPOSE

To determine the incidence of hip pain in a prospective cohort of volunteers who had undergone magnetic resonance imaging (MRI) of their hips.

STUDY DESIGN

Case control study; Level of evidence, 3.

METHODS

A total of 200 asymptomatic volunteers who underwent an MRI of both hips were followed for a mean time of 4.4 years (range, 4.01-4.95 years). Thirty were lost to follow-up, leaving 170 individuals (77 males, 93 females) with a mean age of 29.5 years (range, 25.7-54.5 years). All patients were blinded to the results of their MRI. All completed a follow-up questionnaire inquiring about the presence of hip pain or a history of hip pain lasting longer than 6 weeks since the original MRI. Each patient was asked to draw where the pain was on a body diagram.

RESULTS

Eleven patients (5 males, 6 females; 6.5% of sample; mean age, 29.9 years; range, 25.7-45.6 years) reported hip pain, of which 3 (1 male, 2 females) had bilateral pain for a total of 14 hips. Seven of the 14 painful hips had a cam-type deformity at the time of the initial MRI versus 37 of the 318 nonpainful hips (P = .0002). This gave a relative risk of 4.3 (95% confidence interval [CI], 2.3-7.8) of developing hip pain if cam deformity was present. Those 14 painful hips had a significantly greater alpha angle at the radial 1:30 clock position than did those who did not develop pain with a cam deformity: 61.5° (range, 57.3°-65.7°) versus 57.9° (range, 56.9°-59.1°), respectively (P = .05). A significantly greater proportion of patients (12%) with limited internal rotation ≤20° (versus 2.7% with internal rotation >20°) went on to develop hip pain (P = .009; relative risk = 3.1 [95% CI, 1.6-6.0]).

CONCLUSION

The presence of a cam deformity represents a significant risk factor for the development of hip pain. An elevated alpha angle at the 1:30 clock position and decreased internal rotation are associated with an increased risk of developing hip pain. However, not all patients with a cam deformity develop hip pain, and further research is needed to better define those at greater risk of developing degenerative symptoms.