Three-Dimensional Reconstruction of Computed Tomography Imaging Is Not Reliable in Assessing Acetabular Rim Osteophytes or Acetabular Rim Pathology in Patients With Femoroacetabular Impingement.

Purpose: To determine the reliability of 3-dimensional (3D) reconstruction of computed tomography (CT) imaging in evaluating acetabular rim morphology or acetabular rim osteophyte (ARO) existence and to group patients with femoroacetabular impingement (FAI) by ARO extent on coronal sections of CT and further compare clinical differences among groups. Methods: Patients who underwent primary hip arthroscopy for FAI by the same surgeon between August 2016 and December 2018 with minimum 2-year follow-up were enrolled. The ARO was evaluated both on the acetabular gross anatomy (AGA) and coronal sections of CT, for its position, width (unit: mm), area (unit: mm2), and CT value (unit: HU). Patients were divided into 4 groups based on the extent of ARO on coronal CT: group A (ARO anterior to 12 o'clock), group P (ARO posterior to 12 o'clock), group AP (ARO across 12 o'clock), and group N (no ARO). Inter- and intraobserver correlation was analyzed. Demographic data, FAI deformity indicators on imaging, quantitative measurements of ARO, and pre- and postoperative patient-reported outcomes were compared among groups. Results: There were 229 patients (229 hips) enrolled in total, 122 male (53.3%) and 107 female (46.7%), with a mean age of 37.2 ± 10.2 years. The correlation between 2 observers for grouping ARO using AGA was positive but poor (Kendall Tau-b coefficient = 0.157, P = .008). Moderate correlation was found between grouping based on AGA and coronal CT by the same observer (Kendall Tau-b coefficient = 0.482, P = .000). The patients were divided into 4 groups: 84 patients (36.7%) in group N, 2 patients (0.9%) in group A, 69 patients (30.1%) in group P, and 74 patients (32.3%) in group AP. Group N was younger in age (35.4 ± 10.7 years) than group P (39.6 ± 10.2 years) (P = 0.012) and had a larger proportion of women (57.1%) than group AP (36.5%) (χ2 = 6.869, P = .032). There was a greater proportion of positive posterior wall sign in group P (52.2%) than 48.6% for group AP and 33.3% for group N (χ2 = 6.397, P = .041). Group N had 61 (72.6%) Tönnis grade 0 hips compared with 37 (50%) in group AP (P = .014). No statistical significance was found among groups in pre- and postoperative α angle, lateral center-edge angle, and patient-reported outcomes. The widths of ARO in group AP for the 3 marked points from anterior to posterior were 3.88 ± 1.86, 4.84 ± 2.72, and 6.66 ± 3.18, separately (P＜.001); 15.73 ± 21.46, 19.22 ± 18.86, and 29.96 ± 17.05 for area (P＜.01); and 652.67 ± 214.12, 677.10 ± 274.81, and 728.84 ± 232.39 for CT value (P＜.05). For the ARO posterior to 12 o'clock, the group AP showed a larger width (6.66 ± 3.18), area (29.96 ± 17.05), and CT value (728.84 ± 232.39) than group P of (4.70 ± 2.25), (20.15 ± 12.91), and (641.84 ± 183.33) (P＜.001). Conclusions: The evaluation of ARO on AGA is poor consistent with definite double-rim sign on coronal CT. There is a tendency of size-enlarging and density-increasing for ARO from anterior to posterior along the acetabular rim. Younger age, female gender, lower Tönnis grade, and negative posterior wall sign showed lower rate of ARO development. Level of Evidence: Level IV, diagnostic case series.

Modified Technique for Labral Reconstruction of Hip Joint Using Autologous Iliotibial Band (ITB)-Make Labral Reconstruction Stress-Free.

Current treatments for labral tear include surgical debridement, arthroscopic repair, and labral reconstruction. Although labral debridement and labral suture repair are suitable for most patients, labral reconstruction is the first treatment option when there is extensive labral degeneration or defect. Often, however, the labral degeneration or defect is only detected intraoperatively; therefore, the surgeon should always have a backup plan. The current labral reconstruction technique has shortcomings such as long operation time, difficult autograft harvesting, cumbersome graft preparation, and the need for a large surgical incision and re-sterilization and draping. To address these problems, we developed a modified technique for draping and surgery. This technique ensures preparedness for labral reconstruction during each hip arthroscopic surgery. The method also simplifies the steps for autologous iliotibial band graft harvesting and shortens operative time. We have achieved satisfactory clinical results with use of this technique over the past 2 years. In this Technical Note, we describe our technique. This modified labral reconstruction technique greatly improves surgical efficiency and could be a promising surgical technique for hip labral reconstruction.

Arthroscopic Capsular Suture-Lifting Technique for Treating Femoroacetabular Impingement Patients With a High Risk of Postoperative Anterior Instability.

With the increasing popularity of hip arthroscopy, postoperative iatrogenic instability due to bony and soft-tissue issues has been noted by more orthopaedic surgeons. Although there is a low risk of serious complications in patients with normal hip joint development even without suturing of the joint capsule, for patients with a preoperative high risk of anterior instability-including those with excessive anteversion of the acetabulum or femur, borderline dysplasia of the hip, and hip arthroscopic revision surgery with an anterior defect of the joint capsule-capsulotomy without repair will result in postoperative anterior instability of the hip joint and related symptoms. Capsular suturing techniques that provide anterior stabilization will be of great help for these high-risk patients and reduce the possibility of postoperative anterior instability. In this Technical Note, we introduce the arthroscopic capsular suture-lifting technique for treating femoroacetabular impingement (FAI) patients with a high risk of postoperative hip instability. In the past 2 years, the capsular suture-lifting technique has been used to treat FAI patients with borderline dysplasia of the hip and excessive femoral neck anteversion, and clinical results have shown that the suture-lifting technique provides a reliable and effective solution for FAI patients with a high risk of postoperative anterior hip instability.

Changes in Hip Labral Size Two Years After Arthroscopic Repair Are Correlated With Preoperative Measurements on Magnetic Resonance Imaging.

PURPOSE: The purposes of our study were 1) to investigate the potential change of labral size after arthroscopic repair and 2) to analyze the relationship between acetabular labral size and functional outcomes. METHODS: In this retrospective study, patients diagnosed with labral tear and undergoing hip arthroscopic repair in our institution between September 2016 and December 2018 were included. Magnetic resonance imaging was obtained preoperatively and postoperatively, and the labral length and labral height were measured in three anatomic sites: 11:30, 1:30, and 3:00 positions. All patients completed at least 2-year follow-up. Patients whose preoperative labral size in any position wider than 2 standard deviation away from the mean were identified as the hypertrophic labrum group and were compared with the control in radiographic variables and patient-reported outcomes (PROs), including the visual analog scale (VAS), modified Harris Hip Score (mHHS), the International Hip Outcome Tool-12 (iHOT-12) and the Hip Outcome Score-Activities of Daily Living (HOS-ADL). RESULTS: A total of 82 patients (82 hips) were included, and the mean follow-up period was 39.54 ± 8.48 months. Significant improvement in PROs was determined before and after surgeries. Twelve patients were identified with labral hypertrophy and had higher postoperative mHHS scores, higher postoperative iHOT-12 scores, and greater improvement in HOS-ADL compared with the control group. Patients with larger preoperative anterosuperior labral height exhibited more favorable clinical outcomes. Meanwhile, no significantly morphologic change in labral size was determined. CONCLUSION: There is no significantly morphologic change in labral size of superior, anterosuperior, and anterior labrum after arthroscopic repair. Patients with hypertrophic labrum achieved more favorable clinical outcomes compared with those with normal-sized labrum. LEVEL OF EVIDENCE: Level III, retrospective comparative prognostic trial.

3D-printed regenerative polycaprolactone/silk fibroin osteogenic and chondrogenic implant for treatment of hip dysplasia.

Hip dysplasia is a developmental disorder that resulted in insufficient acetabular coverage. Current surgical treatments are technically demanding, complex, invasive, and often lead to associated complications. Therefore, the development of regenerative implants that fit to the bone and induce osteogenesis and chondrogenesis is in high demand. In this study, an implant was developed in which the osteogenic part was 3D printed using polycaprolactone (PCL), crosslinked with dopamine, and subjected to surface mineralization; while the chondrogenic part was prepared using silk fibroin (SF) and bone morphogenetic protein 2. Physical and chemical characterization of the implant was conducted using energy dispersive spectrometry (EDS) and scanning electron microscopy (SEM). The viability of rabbit adipose-derived mesenchymal stem cell (ADSCs) was evaluated by LIVE/DEAD staining and alamarBlue. SEM showed crosslinked polydopamine and crystals produced by mineralization on the surface of the implant, while EDS revealed the deposition of calcium and phosphorus on its surface. LIVE/DEAD staining and alamarBlue assay demonstrated that both the PCL and SF parts exhibit good biocompatibility. An in vivo hip dysplasia model was established in rabbits using a bone rongeur to make acetabular defects. Macroscopic observation, histological analysis, postoperative imaging, and biomechanical analysis of this model demonstrated the osteogenic and chondrogenic effects of the implant, and revealed that it provided good coverage of the femoral head, restoring the anatomical morphology of the acetabulum. Thus, this novel regenerative and cytocompatible implant provides a potentially viable strategy for the treatment of hip dysplasia.

Accuracy of Magnetic Resonance Imaging in the Diagnosis of Acetabular Chondral Delamination in Femoroacetabular Impingement.

Background: Currently, there is no consensus regarding the accuracy of magnetic resonance imaging (MRI) in the detection of acetabular chondral delamination (ACD) in patients with femoroacetabular impingement (FAI), and, correspondingly, the preoperative diagnosis of ACD remains challenging. Hypothesis: It was hypothesized that MRI would have relatively high accuracy in detecting ACD in patients with FAI. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: We retrospectively evaluated patients who attended the sports medicine clinic of our department and underwent arthroscopic surgery for the diagnosis of FAI between January 2018 and December 2020. All patients underwent preoperative 3.0-T MRI. ACD was evaluated by 2 raters on 3.0-T MRI scans, and interrater and intrarater reliability was assessed. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of MRI for diagnosis of ACD were calculated, using arthroscopic surgery as the standard. Results: A total of 233 patients (mean age, 37.4 years; 99 male and 134 female) were included in this study. The presence of ACD in 101 (43.3%) patients was confirmed during hip arthroscopy. The intraobserver reliability of both of the observers in detecting ACD using 3.0-T MRI scans was almost perfect (observer 1, kappa coefficient [κ] = 0.909 [95% CI, 0.854-0.964]; observer 2, κ = 0.937 [95% CI, 0.890-0.984]), and the interobserver reliability between the observers (κ = 0.801 [95% CI, 0.723-0.879]) was substantial. The overall sensitivity, specificity, PPV, and NPV of preoperative MRI to detect ACD were 83.7%, 82%, 74.2%, and 89.1%, respectively. Conclusion: It was found that 3.0-T MRI had a relatively high sensitivity, specificity, PPV, and NPV for diagnosis of ACD in patients with FAI and could be a reliable method of diagnosing ACD preoperatively.

Arthroscopic Synovectomy of the Hip Joint: The Regional Surgical Technique.

Synovial disease is a common reason for hip joint dysfunction. Although traditionally treated with open synovectomy, with the popularization and development of arthroscopic techniques, arthroscopic synovectomy has become the main surgical treatment for synovial diseases. Given the long soft tissue channel and learning curve, arthroscopic synovectomy of the hip joint has high surgical requirements for surgeons. However, there is currently no standardized surgical protocol for arthroscopic synovectomy of the hip joint to guide the surgeon to perform hip synovectomy in an orderly manner. During the past 3 years, we have employed a novel technique, wherein we divided the synovium of the hip into seven regions based on the anatomical structure and the operating range of the arthroscopic portals. With the assistance of flexion, extension, and traction of the hip joint, synovectomy was sequentially performed under arthroscopic guidance. This regional surgical technique can be popularized and likely has the potential to become a standardized arthroscopic synovectomy protocol of the hip joint.

BMP-2 Modified Electrospun Scaffold for Acetabular Labral Reconstruction Promotes Collagen Fiber Regeneration in a Porcine Model.

BACKGROUND: Acetabular labral tear is one of the contributing factors to early hip osteoarthritis. Patients with symptomatic labral tears may require surgical treatment, and labral reconstruction is indicated in cases of irreparable tears. PURPOSE: The purpose of the study was to construct the bone morphogenic protein 2 (BMP-2) electrospun scaffold for acetabular labral reconstruction and analyze the composition of the labrum and the influence of collagen fiber distribution in regenerated tissue on the biomechanical properties of labrum. STUDY DESIGN: Controlled laboratory study. METHODS: Eighteen mature male miniature pigs were selected for labral reconstruction in vivo. The animals were divided into 3 groups, including the autologous tendon group (T group), dopamine/polylactic acid-polyethylene glycol (PELA) electrospun group (DP group), and dopamine/PELA electrospun/BMP-2 group (DPB group), and the native labra were used as the control group. The microstructure of the reconstructed labrum was analyzed by scanning electron microscopy. Histologic and immunohistochemistry sections were used to evaluate the composition and structure of reconstructed labrum. The related gene expression was tested via quantitative reverse transcriptase-polymerase chain reaction test. The compressive and tensile properties of tissues were evaluated using the elasticity test device. RESULTS: Hematoxylin and eosin staining showed that the DP group and the T group were mainly composed of fibroblasts. The alignment of fibers was irregular. In the DPB group, the reconstructed tissues were composed of fibroblasts and chondrocytes, with parallel fibers and denser structure. The native labrum was composed of a large number of fibroblasts, which were arranged orderly and parallel, and there was almost no vascular proliferation. Under scanning electron microscopy, the reconstructed tissue of the DBP group was more similar to the native labral structure, forming a denser, clear-layered collagen fibrous structure, while the fiber alignment of the DP and T groups was irregular. The contents of type I, II, and III collagen (COL1, COL2, and COL3, respectively) were upregulated in labrum reconstructed with the DPB scaffold, while the gene expressions did not increase in the DP and T groups. The tensile and compressive properties of the implants in the DPB group were significantly enhanced. CONCLUSION: BMP-2 modified electrospun scaffold promotes collagen regeneration and osteogenic differentiation and is associated with better biomechanical performance of the reconstructed labrum. CLINICAL RELEVANCE: This study demonstrated that BMP-2 modified electrospun scaffold could induce the regeneration of collagen and osteogenic differentiation and provide better biomechanical performance in labral reconstruction. This scaffold could be used in clinical practice after further improvement.

High prevalence of acetabular rim osteophytes after hip arthroscopy for treatment of FAI.

BACKGROUND: Few studies mentioned acetabular rim osteophytes (ARO) after arthroscopy for femoroacetabular impingement (FAI) in follow-up after primary hip arthroscopy. We found that many patients had postoperative ARO, which may lead to recurrent or secondary pincer-type deformity after primary hip arthroscopy for FAI and postoperative ARO sometimes even led to revision surgery. It is necessary to carry out related research on ARO. METHODS: We respectively evaluated consecutive cases who underwent hip arthroscopy in our hospital between January 2008 and January 2020. Radiographic examination was obtained for all patients preoperatively and postoperatively. Another CT scan was performed at least 6 months after surgery at final follow-up. Preoperative patient-reported outcomes (PROs) and PROs at final follow-up were obtained, including visual analog scale (VAS) for pain and modified Harris Hip Score (mHHS). The volume of ARO was calculated using mimics 21.0 software. According to the material of anchors and whether the anchors were used, patients were divided into absorbable group, non-absorbable group and no anchor group. RESULTS: A total of 71 patients were finally included in this study. Patients with postoperative ARO had higher VAS at final follow-up (P<0.05). Patients without postoperative ARO had higher mean mHHS at final follow-up (P = 0.08) and higher percentage of passing minimal clinical important difference. The percentage and volume of postoperative ARO was significantly higher in patients who underwent acetabuloplasty and labral repair (P<0.05). The percentage and volume of postoperative ARO in absorbable group were significantly higher than the other groups (P<0.05). CONCLUSION: There is a high percentage of ARO after hip arthroscopy for treatment of FAI and patients who have undergone labral repair and acetabuloplasty are more likely to have postoperative ARO. Using of absorbable anchors may increase the possibility and volume of postoperative ARO. Postoperative ARO may predict a worse clinical outcome.

The Application of Arthroscopic Techniques in the Diagnosis and Treatment of Hip-Related Conditions in China.

The hip joint is the largest weight-bearing joint in the body and is surrounded by dense capsules and thick muscles. Hip arthroscopic techniques are suitable for the treatment of hip-related conditions. These minimally invasive techniques have rapidly developed in China since 2007. Moreover, they have been used in the treatment of gluteal muscle contracture, snapping hip syndrome, femoral acetabular impingement, acetabular labral injury, hip labral calcification, synovial chondroma, osteoid osteoma, synovitis, osteonecrosis of the femoral head, and developmental dysplasia of the hip. This technique has showed its advantage in the total debridement of lesions, precision treatment, and less trauma. However, we lack understanding of the overall development of arthroscopic techniques in China. This review illustrates the recent development of hip arthroscopic techniques in China and related research progress.