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.

Ultrasound had high accuracy in measuring hip joint capsule thickness.

BACKGROUND: The hip joint capsule is an essential component of hip joint function and stability, and its thickness is closely associated with certain medical conditions, surgical outcomes, and rehabilitation treatments. Currently, in clinical practice, hip joint capsule thickness is predominantly measured using magnetic resonance imaging (MRI), with limited utilization of ultrasound examinations for this purpose. METHODS: We retrospectively evaluated patients who visited our Sports Medicine Department between February 2017 and March 2023 and underwent both hip joint MRI and ultrasound imaging on the same side. All patients had undergone preoperative hip joint MRI and ultrasound examinations, with the time gap between the two examinations not exceeding three months. Measurements of hip joint capsule thickness were taken on both MRI and ultrasound images for the same patients to analyze their consistency. Additionally, we measured the alpha angle, lateral center-edge angle, acetabular anteversion angle, and femoral anteversion angle of the patients' hip joints and analyzed their correlation with hip joint capsule thickness measure by ultrasound. RESULTS: A total of 307 patients were included in this study, with hip joint capsule thickness measured by MRI and ultrasound being 5.0 ± 1.2 mm and 5.0 ± 1.5 mm, respectively. The Bland-Altman analysis demonstrates good agreement or consistency. The paired t-test resulted in a p-value of 0.708, indicating no significant statistical difference between the two methods. The correlation analysis between acetabular anteversion angle and ultrasound-measured capsule thickness yielded a p-value of 0.043, indicating acetabular anteversion angle and capsular thickness may have negative correlation. CONCLUSIONS: The measurements of joint capsule thickness obtained through ultrasound and MRI showed good consistency, suggesting that ultrasound can be used in clinical practice as a replacement for MRI in measuring hip joint capsule thickness. There was a significant correlation between acetabular anteversion angle and hip joint capsule thickness, indicating potential for further research in this area.

Discrepancies in MR- and CT-Based Femoral Version Measurements Despite Strong Correlations.

PURPOSE: To determine the correlation and classification consistency of femoral version measurements between magnetic resonance (MR) and computed tomography (CT) using 4 commonly used measurement methods. METHODS: A retrospective study was performed on patients with femoroacetabular impingement (FAI) who received preoperative CT and MR imaging assessment of the surgical hip and ipsilateral distal femur. Femoral version was measured using the Murphy method, the oblique method, the Reikerås method, and the Lee method. Intra- and inter-rater agreements were calculated. Linear regression and Bland-Altman analysis were performed for measurements using different imaging modalities and measurement methods. Femoral version measurements within the lower quartile, the middle 2 quartiles, and the upper quartile were classified into different groups based on their percentile within the sample population. Classification consistency rates between modalities and methods were calculated and compared. RESULTS: Fifty-three patients (39.4 ± 9.1 years; 32 female) were included for analysis. Intra- and inter-rater reliability were high for all modalities and methods (intrarater intraclass correlation coefficient [ICC] range, 0.963-0.993; inter-rater ICC range, 0.871-0.960). MR- and CT-based femoral version measurements showed strong correlations for all methods, with the Lee method demonstrating the strongest association (r = 0.904), while the oblique method exhibited the lowest correlation (r = 0.684) (all P < .001). MR-based measurements were smaller than CT-based measurements, with mean differences ranging from 4.5° to 10.3°. Classification consistency between MR and CT ranged from 51% to 74%, whereas the consistency between different measurement methods ranged from 68% to 85%. CONCLUSIONS: While strong correlations were observed between MR- and CT-based femoral version measurements, MR-based measurements were significantly smaller than their CT counterparts. Classification consistency between the modalities was moderate to high. Measurements between different methods showed strong correlations with high consistency rates. LEVEL OF EVIDENCE: Level III, retrospective 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.

Concomitant Ipsilateral Knee Pain Is Associated With Worse Preoperative Functional Status and Short-Term Outcomes After Hip Arthroscopy in Patients With Femoroacetabular Impingement Syndrome.

PURPOSE: (1) To determine the effect of concomitant ipsilateral knee pain (IKP) on short-term outcomes after hip arthroscopic treatment of femoroacetabular impingement syndrome (FAIS) and (2) to determine whether IKP would improve with surgery. METHODS: Data between September 2021 and May 2022 were reviewed. Patients with a diagnosis of FAIS who underwent hip arthroscopy with a minimum of 1-year follow-up were included. The exclusion criteria were prior ipsilateral hip or knee surgery, hip Tönnis grade greater than 1, knee Kellgren-Lawrence grade greater than 2, hip conditions (avascular necrosis, Legg-Calvé-Perthes disease, pigmented villonodular synovitis, osteoid osteoma, synovial chondromatosis, and developmental dysplasia of the hip), and spine diseases. All patients underwent knee magnetic resonance imaging preoperatively. Preoperative and short-term (1-year) patient-reported outcomes were collected, consisting of the Hip Sports Activity Scale score, weekly sports participation, modified Harris Hip Score (mHHS), 12-component International Hip Outcome Tool (iHOT-12) score, and visual analog pain scale (VAS) scores for the hip and the ipsilateral knee. The percentages of patients achieving the minimal clinically important difference and patient acceptable symptom state (PASS) for the mHHS and iHOT-12 score were calculated. Multivariate regression analysis was performed to determine the effect of IKP severity on postoperative outcomes. Subgroup analysis was performed between patients with IKP alleviation and those without IKP alleviation. RESULTS: Among the 107 patients included, 47 presented with preoperative IKP. Compared with patients without IKP, the IKP cohort had comparable knee structural abnormalities (all with P > .05). Still, the IKP cohort showed inferior preoperative values for the mHHS (P = .003), iHOT-12 score (P = .016), hip VAS score (P = .001), and weekly sports participation (P = .039). Postoperatively, the IKP cohort had a lower mHHS (P = .046), lower iHOT-12 score (P = .037), and lower hip VAS score (P = .003) and were less likely to achieve the PASS for the mHHS (P = .021) and iHOT-12 score (P = .049). Patients with higher knee VAS scores were less likely to achieve the PASS for the mHHS (odds ratio, 0.61; P = .023). Within the IKP group, the knee VAS score improved from 2.3 to 1.0 (P < .001). Patients with alleviated IKP showed superior postoperative iHOT-12 scores (P = .038) compared with patients with persistent IKP. CONCLUSIONS: Concomitant IKP at baseline negatively affected preoperative status and short-term clinical outcomes after arthroscopic treatment of FAIS. Patients with IKP were less likely to meet clinical thresholds. Most patients achieved IKP alleviation postoperatively, which was associated with superior clinical outcomes. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

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.

Effect of Changes in Iliocapsularis Cross-sectional Area on Hip Arthroscopy Outcomes: Clinical and Magnetic Resonance Imaging Follow-up.

Background: The function of the iliocapsularis (IC) muscle is still unclear. Previous studies have reported that the cross-sectional area of the IC may be useful in identifying borderline developmental dysplasia of the hip (BDDH). Purpose: To evaluate the pre- to postoperative changes in IC cross-sectional area in patients with femoroacetabular impingement (FAI) and to determine if there are any associations with clinical outcomes after hip arthroscopy. Study Design: Cohort study; Level of evidence, 3. Methods: The authors retrospectively evaluated patients who underwent arthroscopic surgery for FAI at a single institution between January 2019 and December 2020. Patients were divided into 3 groups according to lateral center-edge angle: BDDH group (20°-25°), control group (25°-40°), and pincer group (>40°). Supine anteroposterior hip radiographs, 45° Dunn view radiographs, computed tomography scans, and magnetic resonance imaging (MRI) scans were obtained for all patients preoperatively and postoperatively. The cross-sectional areas of the IC and the rectus femoris (RF) were measured on an axial MRI slice at the level of the femoral head center. Preoperative and final follow-up scores on the visual analog scale for pain and the modified Harris Hip Score (mHHS) were compared between groups with the independent-samples t test. Results: A total of 141 patients (mean age, 38.5 years; 64 male, 77 female) were included. The preoperative IC-to-RF ratio of the BDDH group was significantly higher than that of the pincer group (P < .05). In the BDDH group, there was significant pre- to postoperative decrease in IC cross-sectional area and the IC-to-RF ratio (P < .05 for both) as well as a significant correlation between the preoperative IC cross-sectional area and the postoperative mHHS (r = 0.434; P = .027). Conclusion: Patients with BDDH had a significantly higher preoperative IC-to-RF ratio than patients with pincer morphology. A higher preoperative IC cross-sectional area was associated with better postoperative patient-reported outcomes after arthroscopy for the treatment of FAI combined with BDDH.

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.

Low-grade myofibroblastic sarcoma of the proximal femur: A case report and literature review.

RATIONAL: Low-grade myofibroblastic sarcoma (LGMS) is an atypical type of tumor composed of myofibroblasts. LGMS in the femoral head neck junction is extremely rare and no case treated by hip arthroscopy was reported. PATIENT CONCERNS: We reported a case of LGMS in the femoral head neck junction treated by hip arthroscopy. A 30-year-old female was admitted to our hospital with discomfort and pain after left hip sprained one year prior. Physical examination revealed swelling of the left hip and magnetic resonance images showed a soft tissue mass in the femoral head neck junction. DIAGNOSIS: Via microscopy of pathological specimens, spindle cell proliferative lesions, atypia of some cells, and mitotic figures/pathological mitotic figures of some cells were observed. Immunohistochemistry revealed positive for smooth muscle actin, focally positive for CD34 and CD68, while negative for S-100, desmin, and anaplastic lymphoma kinase. The imaging, histomorphological and immunohistochemical features suggested a final diagnosis of LGMS of the proximal femur. INTERVENTIONS: This patient underwent hip arthroscopy for excision of the soft tissue mass. OUTCOMES: The clinical and imaging follow-up at 6 months postoperatively showed that surgery had achieved good clinical outcomes. LESSONS: To the best of our knowledge, this is the first case report of LGMS in the femoral head neck junction treated by hip arthroscopy. Beyond the present case, other 120 cases from 58 literatures (1998-2022) are reviewed and discussed. The age of LGMS patients ranged from 11 months to 77 years and the male-to-female ratio was approximately 1.28:1. The location distribution of previously reported LGMS cases and the present case was as follows: Head&neck (45.90%), trunk (30.33%), and extremity (23.77%). Hip arthroscopic excision of LGMS may achieve relatively good clinical outcomes.

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.

Healing of joint capsule after hip arthroscopy using interportal capsulotomy and capsular closure influences clinical outcomes.

BACKGROUND: Hip arthroscopy for treatment of femoroacetabular impingement (FAI) has developed rapidly and has been shown to significantly decrease pain and improve hip function. However, the relationship between hip capsule characteristics and healing after arthroscopic surgery and changes in patient-reported outcomes scores (PROs) for postoperative pain, function, and symptoms is still uncertain. METHODS: We retrospectively evaluated consecutive patients who were diagnosed with FAI and underwent hip arthroscopy for treatment in our hospital between May 2018 and November 2020. All patients had preoperative MRI and postoperative MRI at least 6 months after arthroscopy. Hip capsular thickness was measured at the proximal, middle, and distal site of the capsule. PROs and PROs at final follow-up were obtained, including visual analog scale (VAS) for pain and modified Harris Hip Score (mHHS). RESULTS: A total of 194 patients were included in this study. The mean MRI follow-up time was 14.3 (range, 6-37) months, and the mean clinical follow-up time was 26.1 (range, 12-43) months. Postoperative capsular thickness or net change were not correlated with postoperative PROs and VAS (P > .05). Capsular defect was observed in 17 (8.8%) patients. Patients with capsular defect had a relatively higher BMI (P < .05). Patients with capsular defect had a significant lower mHHS and higher VAS compared with patients with continuous capsule (P < .05). Ninety-one percentage of patients with continuous capsule surpassed minimal clinically important difference (MCID) and 80.8% achieved PASS, but only 58.8% of patients with capsular defect surpassed MCID and 47.1% achieved patient acceptable symptom state (PASS). CONCLUSIONS: Postoperative capsular thickness may not have influence on the clinical outcomes of hip arthroscopy for treatment of FAI. Some capsule of patients who underwent arthroscopic interportal capsulotomy and repair could not heal. Postoperative capsular continuity had a great impact on the clinical outcomes of hip arthroscopy for FAI. Patients with higher BMI may be more likely to have capsule failure to heal.

Variations in postoperative electrolyte concentrations and influential factors in hip arthroscopy.

BACKGROUND: Different from arthroscopy in other joints, more perfusion is required for a better access to perform surgical procedures in hip arthroscopic operations. The significant fluid perfused may lead to complications of partial tissue injury and electrolyte imbalance. However, there were few studies on the change of serum electrolyte after hip arthroscopy and the influential factors were still unknown. METHODS: We evaluated consecutive patients who underwent hip arthroscopy in our hospital between October 2021 and February 2022. Age, sex, and BMI matched patients who underwent arthroscopic anterior cruciate ligament (ACL) reconstruction at the same time were also included as the control group. Preoperative and postoperative serum electrolyte of sodium (Na +), potassium (K +), chloride (Cl-), magnesium (Mg2 +), and carbon dioxide capacity (CO2CP) were analyzed. The correlations between influential factors like perfusion volume, operating time, BMI and hip circumference, and changes in serum electrolyte were also analyzed. RESULTS: A total of 79 patients were involved in this study, including 49 patients who underwent hip arthroscopy and 30 patients who underwent knee arthroscopy. For hip arthroscopy, decrease of potassium levels was observed in 40.8% of the patients, and postoperative hypokalemia was found in 10.2% patients. There were significant variations in postoperative sodium, magnesium, chloride and carbon dioxide capacity in hip arthroscopy (p < 0.05). No correlations were found between each of the electrolyte concentrations and influential factors like perfusion volume, operating time, BMI, sex and hip circumference. The significant variations were found in chloride and carbon dioxide capacity in knee arthroscopy (p < 0.05). CONCLUSIONS: Hip arthroscopy would significantly influence postoperative serum electrolyte, and hypokalemia could be a postoperative complication. The correlation between serum electrolyte and fluid perfusion volume is remained to be investigated. We therefor advocate that performing a systematic care of preoperative and postoperative serum electrolyte analysis as perioperative management is necessary.

Quantitative and Qualitative Ultrasound Evaluation for the Diagnosis of an Anterosuperior Acetabular Labral Tear.

We investigated the diagnostic performance of qualitative and quantitative ultrasound criteria for anterosuperior acetabular labral tears (ALTs). In all, 118 people with ALTs (120 hips; case group) and 31 asymptomatic volunteers (42 hips; control group) at Peking University Third Hospital between August 2018 and November 2019 were consecutively included. The labral cleft, labral heterogeneous echogenicity, labral plump morphology, paralabral cyst and labral focal hyperechoic area were used as the qualitative criteria. The anterosuperior labral cross-section area (CSA) was measured as the quantitative criterion. The diagnostic utility of the quantitative and qualitative criteria were explored with magnetic resonance imaging as the diagnostic gold standard. Labral heterogeneous echogenicity was the most sensitive criterion for diagnosing ALTs (up to 80.00%), and the specificity of diagnosing ALTs with paralabral cysts, labral focal hyperechoic area and subcortical cysts of the femoral head and neck was as high as 90.48%-100%. The labral CSA in the case group was 0.27 cm2 (0.21-0.39 cm2), which was significantly larger compared with the control group (0.18 cm2 [0.14-0.23 cm2]; p < 0.001). The area under the receiver operating characteristic curve was 0.802 for diagnosing ALTs according to the labral CSA. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of the combined qualitative criteria for diagnosing ALTs were 90.00%, 71.43%, 90.00%, 71.43% and 85.19%, respectively. Labral heterogeneous echogenicity is a sensitive criterion for diagnosing ALTs, and paralabral cysts, labral focal hyperechoic, area and subcortical cysts of the femoral head and neck are specific criteria. The CSA of the anterosuperior acetabular labrum measured by ultrasound can be used as a quantitative criterion to diagnose ALTs. The combination of labral qualitative criteria provides higher sensitivity and accuracy in diagnosing ALTs.

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 correlation between the labrum size and the labral tear in asymptomatic volunteers and symptomatic patients.

BACKGROUND: Some studies have proved that labrum size is associated with symptoms in patients with hip labral tear. The correlation between the labrum size and the labral tear in asymptomatic volunteers and symptomatic patients is still uncertain. METHODS: The volunteers with no history of pain, injury, or surgery were recruited from the community. Patients who were diagnosed with labral tear and underwent hip arthroscopic surgery in this period in our hospital were also included. The length and height of the acetabular hip labrum were measured at three separate anatomic sites through magnetic resonance imaging (MRI) along the acetabular rim: lateral, anterior, and anteroinferior. RESULTS: A total of 70 volunteers (125 hips) and 70 patients (70 hips) were included in this study. Sixty-six (52.8%) hips had labral tears in all 125 hips of volunteers. The lateral labral length of volunteers with labral tears was significantly larger than those without labral tears (P < .05). In 14 volunteers with unilateral labral tears, length of lateral, anterior, and anteroinferior labrum in the side with tear were significantly larger than normal on the other side. The anterior labral height of volunteers was significantly larger than that of patients (P < .05). CONCLUSIONS: In conclusion, asymptomatic volunteers with larger length of lateral, anterior, and anteroinferior labrum are more prone to present with labral tears. Symptomatic patients with labral tears exhibited thinner anterior labrum. Further studies are warranted to explore the mechanisms of labral tears in asymptomatic people and validate the use of labral size as a guide to differential diagnosis and treatment.