Sonographic Appearance of the Ischiocondylar Origin of the Adductor Magnus.

The adductor magnus ischiocondylar origin (AM-IO) tendon has often been described as a third proximal hamstring tendon due to its common origin on the ischial tuberosity as well as similar function. Prior studies have described the magnetic resonance imaging characteristics of the AM-IO; however, its appearance on ultrasound has not been well-detailed. The purpose of our study is to describe the sonographic appearance of the AM-IO and provide a structured scanning protocol for complete evaluation of the tendon.

What Are the Sex-Based Differences of Acetabular Coverage Features in Hip Dysplasia?

BACKGROUND: Eccentric rotational acetabular osteotomy is performed to prevent osteoarthritis caused by developmental dysplasia of the hip (DDH). To achieve sufficient acetabular coverage, understanding the characteristics of acetabular coverage in DDH is necessary. However, the features of acetabular coverage in males with DDH remain unclear. We thought that the differences in acetabular coverage between females and males might be associated with the differences in pelvic morphology between the sexes. QUESTIONS/PURPOSES: (1) What are the differences in the acetabular coverage between females and males with DDH? (2) What are the differences in the rotations of the ilium and ischium between females and males with DDH? (3) What is the relationship between the rotation of the ilium and ischium and the acetabular coverage at each height in females and males with DDH? METHODS: Between 2016 and 2023, 114 patients (138 hips) underwent eccentric rotational acetabular osteotomy at our hospital. We excluded patients with Tönnis Grade 2 or higher, a lateral center-edge angle of 25º or more, and deformities of the pelvis or femur, resulting in 100 patients (122 hips) being included. For female patients (98 hips), the median (range) age was 40 years (10 to 58), and for the male patients (24 hips), it was 31 years (14 to 53). We used all patients' preoperative AP radiographs and CT data. The crossover sign, posterior wall sign, and pelvic width index were evaluated in AP radiographs. The rotation of the innominate bone in the axial plane was evaluated at two different heights, specifically at the slice passing through the anterior superior iliac spine and the slice through the pubic symphysis and ischial spine in CT data. Furthermore, we evaluated the anterior and posterior acetabular sector angles. Comparisons of variables related to innominate bone measurements and acetabular coverage measurements between females and males in each patient were performed. The correlations between pelvic morphology measurements and acetabular coverage were evaluated separately for females and males, and the results were subsequently compared to identify any sex-specific differences. For continuous variables, we used the Student t-test; for binary variables, we used the Fisher exact test. A p value less than 0.05 was considered statistically significant. RESULTS: In the evaluation of AP radiographs, an indicator of acetabular retroversion-the crossover sign-showed no differences between the sexes, whereas the posterior wall sign (females 46% [45 of 98] hips versus males 75% [18 of 24] hips, OR 3.50 [95% confidence interval (CI) 1.20 to 11.71]; p = 0.01) and pelvic width index less than 56% (females 1% [1 of 98] versus males 17% [4 of 24], OR 18.71 [95% CI 1.74 to 958.90]; p = 0.005) occurred more frequently in males than in females. There were no differences in the iliac rotation parameters, but the ischium showed more external rotation in males (females 30° ± 2° versus males 24° ± 1°; p < 0.001). Regarding acetabular coverage, no differences between females and males were observed in the anterior acetabular sector angles. In contrast, males showed smaller values than females for the posterior acetabular sector angles (85° ± 9° versus 91° ± 7°; p = 0.002). In females, a correlation was observed between iliac rotation and acetabular sector angles (anterior acetabular sector angles: r = -0.35 [95% CI -0.05 to 0.16]; p < 0.001, posterior acetabular sector angles: r = 0.42 [95% CI 0.24 to 0.57]; p < 0.001). Similarly, ischial rotation showed a correlation with both acetabular sector angles (anterior acetabular sector angles: r = -0.34 [95% CI -0.51 to -0.15]; p < 0.001 and posterior acetabular sector angles: r = 0.45 [95% CI 0.27 to 0.59]; p < 0.001). Thus, in females, we observed that external iliac rotation and ischial internal rotation correlated with increased anterior acetabular coverage and reduced posterior coverage. In contrast, although acetabular coverage in males showed a correlation with iliac rotation (anterior acetabular sector angles: r = -0.55 [95% CI -0.78 to -0.18]; p = 0.006 and posterior acetabular sector angles: r = 0.74 [95% CI 0.48 to 0.88]; p < 0.001), no correlation was observed with ischial rotation. CONCLUSION: In males, acetabular retroversion occurs more commonly than in females and is attributed to their reduced posterior acetabular coverage. In females, an increase in the posterior acetabular coverage was correlated with the external rotation angle of the ischium, whereas in males, no correlation was found between ischial rotation and posterior acetabular coverage. In treating males with DDH via eccentric rotational acetabular osteotomy, it is essential to adjust bone fragments to prevent inadequate posterior acetabular coverage. Future studies might need to investigate the differences in acetabular coverage between males and females in various limb positions and consider the direction of bone fragment rotation. CLINICAL RELEVANCE: Our findings suggest that males with DDH exhibit acetabular retroversion more frequently than females, which is attributed to the reduced posterior acetabular coverage observed in males. The smaller posterior acetabular coverage in males might be related to differences in ischial morphology between sexes. During eccentric rotational acetabular osteotomy for males with DDH, adequately rotating acetabular bone fragments might be beneficial to compensate for deficient posterior acetabular coverage.

Adults Ischium Age Estimation Based on Deep Learning and 3D CT Reconstruction.

OBJECTIVES: To develop a deep learning model for automated age estimation based on 3D CT reconstructed images of Han population in western China, and evaluate its feasibility and reliability. METHODS: The retrospective pelvic CT imaging data of 1 200 samples (600 males and 600 females) aged 20.0 to 80.0 years in western China were collected and reconstructed into 3D virtual bone models. The images of the ischial tuberosity feature region were extracted to create sex-specific and left/right site-specific sample libraries. Using the ResNet34 model, 500 samples of different sexes were randomly selected as training and verification set, the remaining samples were used as testing set. Initialization and transfer learning were used to train images that distinguish sex and left/right site. Mean absolute error (MAE) and root mean square error (RMSE) were used as primary indicators to evaluate the model. RESULTS: Prediction results varied between sexes, with bilateral models outperformed left/right unilateral ones, and transfer learning models showed superior performance over initial models. In the prediction results of bilateral transfer learning models, the male MAE was 7.74 years and RMSE was 9.73 years, the female MAE was 6.27 years and RMSE was 7.82 years, and the mixed sexes MAE was 6.64 years and RMSE was 8.43 years. CONCLUSIONS: The skeletal age estimation model, utilizing ischial tuberosity images of Han population in western China and employing the ResNet34 combined with transfer learning, can effectively estimate adult ischium age.

Focused Extracorporeal Shock Wave Therapy for Ischial Apophysitis in Young High-Level Gymnasts.

OBJECTIVE: We aimed to investigate the effect and safety of extracorporeal shock wave therapy (ESWT) on ischial apophysitis (IA) in young high-level gymnasts. We hypothesized that ESWT would be safe and effective in alleviating pain. DESIGN: Retrospective case series. SETTING: Funabashi Orthopedic Hospital. PATIENTS: The subjects were 18 high-level gymnasts (mean age of 13 years) with a chief complain of chronic buttock pain diagnosed with IA. INTERVENTIONS: Ten patients received only physiotherapy (PT), whereas 8 received both PT and ESWT to the ischial tuberosity. The basic protocol for ESWT was to use an energy dose of 0.20 mJ/mm 2 or less with 3000 shots per session at 4-week intervals. MAIN OUTCOME MEASURES: We investigated whether PT and ESWT relieved the pain and allowed the patient to return fully to gymnastics. Based on radiographs at the last observation, we examined whether early closure of the apophyseal line of the ischium and around hip joint on the affected side occurred. RESULTS: In the PT group, pain was relieved in 2 of 10 patients. In the ESWT group, pain was relieved and full return to gymnastics was possible in all 8 patients. None of the patients showed early closure of the apophyseal line. CONCLUSIONS: Extracorporeal shock wave therapy can be a safe and effective treatment option for IA in young high-level gymnasts.

Bilateral Ischial Tuberosity Stress Fractures in an Adolescent Football Player: A Case Report.

ABSTRACT: Pelvic stress fractures are rare, making up an estimated 1% to 7% of all stress fractures with the primary locations being the pubic rami, pubic symphysis, and sacrum. Two cases of stress fractures of the ischium have been previously described in the literature, with both occurring in the ischial body. In this case, a 17-year-old high school American football player presented with nonspecific pelvic pain and bilateral point tenderness on deep palpation of the ischial tuberosities. Advanced imaging identified bilateral ischial tuberosity stress fractures. This report outlines the diagnosis and management of the first reported case of bilateral ischial tuberosity stress fractures. We report how ischial tuberosity stress fractures present clinically, potential management strategies, and highlight the use of computed tomography imaging for pelvic stress fractures. Knowledge of unusual stress fracture locations may improve early diagnosis, limit complications, reduce healthcare costs, and promote an accelerated recovery time.

[A successful multidisciplinary approach to a recurrent ischiorectal fossa sarcoma]. / Tratamiento multidisciplinario de un sarcoma recurrente de la fosa isquiorrectal.

Ischiorectal fossa tumors are rare lesions, mostly described in case reports or case series. These lesions represent a diagnostic and therapeutic challenge. Hence, an appropriate preoperative study and multidisciplinary discussion are essential to achieve good oncologic and functional results. We report a case of a 73-year-old male operated on five years before in another health center due to the diagnosis of a left gluteal tumor. The lesion was excised, and biopsies confirmed a high-grade epithelioid sarcoma with a close margin, requiring a subsequent wider excision of the surgical margins. The patient received adjuvant radiotherapy. After four years of follow-up, the patient developed mild pain with skin retraction around the former incision. A local recurrence was diagnosed by imaging. In a multidisciplinary team meeting, a decision to resect the lesion with preservation of the anus and the pelvic floor was taken. The patient underwent a laparoscopic defunctioning loop ileostomy and a resection of the recurrent tumor in the ischiorectal fossa with preservation of the anal sphincter. The defect was covered utilizing a superior gluteal artery perforator flap and a partial gluteus maximus muscle rotation. The tumor was completely excised with negative margins. The patient was discharged without complications after 25 days due to flap management. After one year of follow-up, the patient is recurrence-free, and the ileostomy was closed.

Ischiofemoral space dimensions for ischiofemoral impingement: is it different in children?

OBJECTIVE: This study intended to analyze alterations in ischiofemoral space (IFS) dimensions in normal children between the ages of 1 and 18 years for the ischiofemoral impingement. MATERIALS AND METHODS: This study retrospectively focused on computed tomography images of 360 hips of 180 (90 boys and 90 girls) pediatric subjects (mean age: 9.50 ± 5.20 years, range: 1-18 years) without any hip disorders to measure IFS, femoral neck angle (FNA), and ischial angle (IA). RESULTS: Mean IFS, FNA, and IA were measured as 14.64 ± 7.24 mm, 34.61 ± 11.47°, and 131.52 ± 4.22°, respectively. IFS increased in children aged between 1 and 18 years, whereas FNA and IA decreased. IFS was similar in infancy and early childhood periods but then increased up to postpubescent period. FNA decreased proportionally from birth, whereas IA decreased in an irregular pattern. Linear functions were detected as y = 3.451 + 1.178 × years for IFS, as y = 48.555 - 1.468 × years for FNA, and as y = 132.535 - 0.107 × years for IA. CONCLUSION: Our findings indicate that IFS tends to increase in size with age during childhood but decreases with further aging. Therefore, age-specific values for IFS, FNA, and IA may be beneficial for clinicians and radiologists for the diagnosis of ischiofemoral impingement.

Defining the canal for ischial and pubic screws in cup revision surgery.

PURPOSE: When revising acetabular cups, it is often necessary to provide additional stabilisation with screws. In extensive defect situations, the placement of screws caudally in the ischium and/or pubis is biomechanically advantageous. Especially after multiple revision operations, the surgeon is confronted with a reduced bone stock and unclear or altered anatomy. In addition, screw placement caudally is associated with greater risk. Therefore, the present study aims to identify and define safe zones for the placement of caudal acetabular screws. METHODS: Forty-three complete CT datasets were used for the evaluation. Sixty-three distinctive 3D points representing bone landmark of interests were defined. The coordinates of these points were then used to calculate all the parameters. For simplified visualisation and intra-operative reproducibility, an analogue clock was used, with 12 o'clock indicating cranial and 6 o'clock caudal. RESULTS: A consistent accumulation was found at around 4.5 ± 0.3 hours for the ischium and 7.9 ± 0.3 hours for the pubic bone. CONCLUSIONS: The anatomy of the ischium and pubis is sufficiently constant to allow the positioning of screws in a standardised way. The interindividual variation is low - regardless of gender - so that the values determined can be used to position screws safely in the ischium and pubis. The values determined can provide the surgeon with additional orientation intra-operatively when placing caudal acetabular screws.

Two-Dash Line: A New Approach for Prenatal Ultrasound Measurement of Iliac and Ischial Bones to Estimate Gestational Age.

OBJECTIVES: There has been a dearth of an accurate and reliable method for the measurement of fetal pelvic bones. In this study, we describe a novel, easy-to-use method for ischial and iliac bone measurement in fetal ultrasound scanning. METHODS: This prospective cross-sectional study was performed on 1179 pregnant women at 12 to 40 weeks of an uneventful gestation. Pelvic biometric indices, including the length of the ilium and ischium, were measured by a novel and easy method. Then data were analyzed by regression models to develop a formula for gestational age (GA) estimation based on pelvic bones. RESULTS: The approximate ossification time of the ischium was determined to range between the 13th and 20th gestational weeks. We calculated 3 formulas using linear regression models: formula 1, GA (days) = 92.563 + (11.604 × ischial length); formula 2, GA (days) = 57.006 + (7.819 × iliac length); and formula 3, GA (days) = 65.809 + (5.610 × iliac length) + (3.431 × ischial length). CONCLUSIONS: The 2-dash line method can contribute to efficient and precise ultrasound measurement of the ilium and ischium in pelvic biometry of the fetus.

Delayed proximal hamstring tendon repair after ischial tuberosity apophyseal fracture in a professional volleyball athlete: a case report.

BACKGROUND: Ischial tuberosity apophyseal fractures are avulsion fractures of the anatomic footprint of the proximal hamstring tendons. Generally, these injuries are rare and frequently occur in skeletally immature, active patients due to incomplete ossification. Depending on the fragment displacement, non-operative or operative treatment approaches are used. CASE PRESENTATION: We report a case of a 29-year-old professional volleyball athlete who has suffered from a nonunion avulsion fracture for 14 years. Isolated suture anchor fixation was performed after open excision of a large bony fragment followed by excellent clinical and functional outcome at 1 year postoperatively. CONCLUSION: In conclusion, avulsion fractures of the ischial tuberosity with large fragments and restrictions to activities of daily living due to pain can, in individualized cases, be treated with an open excision of the fragment followed by repair of the proximal hamstring tendons using suture anchors.

The ischiofemoral space of the hip is influenced by the frontal knee alignment.

PURPOSE: The ischiofemoral distance (IFD), defined as the distance between the ischial tuberosity and the lesser trochanter of the femur, is gaining recognition as an extra-articular cause of hip pain. It is unknown whether the IFD is influenced by the frontal knee alignment. The aim of this study was to determine the influence of realignment surgery around the knee on the IFD. It was hypothesized that valgisation osteotomy around the knee is associated with reduction of the IFD. METHODS: A consecutive series of 154 patients undergoing frontal realignment procedures around the knee in 2017 were included in this study. Long-leg standing radiographs were obtained before surgery and postoperatively. The IFD was measured between the ischium and the lesser trochanter at three different levels (proximal, middle and distal margins of the lesser trochanter parallel to the horizontal orientation of the pelvis) on standardized long-leg radiographs with the patient in upright standing position. The knee alignment was determined by measuring the hip knee ankle angle, mechanical lateral distal femur angle and the medial mechanical proximal tibia angle. Linear regression was performed to determine the influence of the change of frontal knee alignment on the IFD. RESULTS: Linear regression showed a direct influence of the overall change in frontal knee alignment on the IFD of the hip, regardless of the site of the osteotomy (ß-0.4, confidence-interval - 0.5 to - 0.3, p < 0.001). Valgisation osteotomy around the knee induced a significant reduction of the ipsilateral IFD (p < 0.001), while varisation osteotomy induced a significant increase (p < 0.001). The amount of ISD change was 0.4 mm per corresponding degree of change in frontal knee alignment. CONCLUSION: These findings are relevant to both the hip and knee surgeons when planning an osteotomy or arthroplasty procedure. Correction of a malalignment of the knee may resolve an ischiofemoral conflict in the hip. The concept deserves inclusion in the diagnostic workup of both the hip and knee joints. LEVEL OF EVIDENCE: IV.

Surgical repair techniques, functional outcome, and return to sports after apophyseal avulsion fractures of the ischial tuberosity in adolescents.

PURPOSE: Among juvenile apophyseal avulsion injuries of the pelvis in adolescents, fractures of the ischial tuberosity are rare but sustainably debilitating. Also because informations on surgical repair options are very sparse and so far limited to general reviews, reports of individual cases or heterogeous small case series, practitioners, patients and their parental environment still feel a comprehensible hesitation regarding operative treatment. Therefore we intended to investigate patient related outcome measurements and return to sports rates after different types of surgical intervention in an own case series, so far unprecendented in its size. METHODS: Patient data of adolescents that underwent surgical intervention for a displaced apophyseal avulsion fracture of the ischial tuberosity between 01/2015 and 12/2019 in our institution were gathered. Patients were then evaluated using the hamstring injury specific Perth Hamstring Assessment Tool (PHAT). Furthermore the return to sports level in comparison to the particular pre-injury level was rated. RESULTS: Eleven adolescents with an acute or chronic mean fragment dislocation of 3.3 cm (SD ± 1.7) underwent surgical intervention in the assigned period. The mean post-operative PHAT score was 86.9 (0-100, SD ± 11.9) and thus good to excellent. The majority of adolescents (10/11) was able to return to their pre-injury sports, whereas 63.6% achieved full or nearly full level. CONCLUSIONS: Surgical refixation or restoration of aphoyseal avulsion fractures of the ischial tuberosity result in good to excellent outcomes and return to sport rates, irrespective of the type of intervention. Here prompt diagnosis with a timely intervention seems more promising than delayed interventions in chronic cases. Beyond 1.5 cm of fragment displacement affected patients should be counselled for surgical intervention.

Volumetric Evaluation of Dead Space in Ischial Pressure Injuries Using Magnetic Resonance Imaging: A Case Series.

OBJECTIVE: To establish a preoperative evaluation procedure by measuring the volume of dead space using MRI in patients with ischial pressure injuries. METHODS: Patients with spinal cord injury and ischial pressure injuries who underwent treatment between August 2016 and November 2019 were included in the study. Preoperative MRI scan was conducted on all patients. The volume estimation and three-dimensional (3D) reconstruction were performed based on MRI data using a 3D Slicer. Based on the resulting volume, a muscle flap that could fit the dead space was selected. Surgery was performed with the selected muscle flap, and a fasciocutaneous flap was added, if necessary. RESULTS: A total of eight patients with ischial pressure injuries were included in the study. The mean patient age was 59.0 ± 11.0 years. The mean body mass index was 26.62 ± 3.89 kg/m2. The mean volume of dead space was 104.75 ± 81.05 cm3. The gracilis muscle was the most selected muscle flap and was used in four patients. In five of eight cases, a fasciocutaneous flap was used as well. The mean follow-up period was 16 months, and by that point, none of the patients evinced complications that required surgery. CONCLUSIONS: To the authors' knowledge, this is the first report on volumetric evaluation of dead space in ischial pressure injuries. The authors believe that the 3D reconstruction process would enable adequate dead space obliteration in ischial pressure injuries. The authors propose that preoperative MRI scans in patients with ischial pressure injury should become an essential part of the process.

The infragluteal fold: An appraisal by MRI combined with an anatomic study.

PURPOSE: The gluteal region is a key element of beauty balance and sexual appearance. However, there is no clear anatomical description of the infragluteal fold, nor any classification exists allowing standardizing treatment of this area in case of jeopardisation. The purpose of this study was to perform an anatomical description of the infragluteal fold (IGF) matching radiological and anatomical findings in describing specifically raise of the fibrous component at the bone level. METHODS: Six volunteers (three males and three females) underwent an MRI scan (Siemens Aera® 1.5 T) of the pelvic region. T1 Vibe Morpho T2, Sag Space 3D, and Millimetric slices were performed in order to obtain a more detailed selection of the gluteal landmark. Trabecular connective tissue of the region was analyzed using Horos® ROI (region of interest) segmentation function. Four fresh cadavers (two males, two females, accounting for 8 hemipelvis) were dissected in order to compare the radiological findings. RESULTS: The infragluteal fold is a connectival fibrous band extending from the ramus of the ischium (but not involving the ischial tuberosity, for a length of 21 mm ± 2 and 21 mm ± 3), the apex of the sacrum (for a length of 13 ± 2 and 11 mm ± 2), and the coccyx (for a length of 19 mm ± 2 and 20 mm ± 2, all measures referring to volunteers and cadavers, respectively) reaching superficially the dermis of the medial one-third of the cutaneous fold. No significant difference was found between volunteer and cadaver group in MRI measurement of bony origins, or between MRI and cadaveric dissection measurements. CONCLUSION: Knowledge of this structure will define novel surgical techniques in infragluteal fold restoration.

Infra-acetabular screw exited between ischial tuberosity and ischial spine is more suitable for Asian population: a 3D morphometric study.

BACKGROUND: Recently, the infra-acetabular screw has been proposed for use in treatment of acetabular fractures as a part of a periacetabular fixation frame. Biomechanical studies have shown that an additional infra-acetabular screw placement can enhance the fixation strength of acetabular fracture internal fixation. Currently, the reported exit point of the infra-acetabular screw has been located at the ischial tuberosity (Screw I). However, our significant experience in placement of the infra-acetabular screw has suggested that when the exit point is located between the ischial tuberosity and the ischial spine (Screw II), the placement of a 3.5 mm infra-acetabular screw may be easier for some patients. We conducted this study in order to determine the anatomical differences between the two different IACs. METHODS: The raw datasets were reconstructed into 3D models using the software MIMICS. Then, the models, in the STL format model, were imported into the software Geomagic Studio to delete the inner triangular patches. Additionally, the STL format image processed by Geomagic Studio was imported again into MIMICS. Finally, we used an axial perspective based on 3D models in order to study the anatomical parameters of the two infra-acetabular screw corridors with different exit points. Hence, we placed the largest diameter virtual screw in the two different screw corridors. The data obtained from this study presents the maximum diameter, length, direction, and distances between the entry point and center of IPE. RESULTS: In 65.31% males and 40.54% females, we found a screw I corridor with a diameter of at least 5 mm, while a screw II corridor was present in 77.55% in males and 62.16% in females. Compared to screw I, the length of screw II is reduced, the angle with the coronal plane is significantly reduced, and the angle with the transverse plane is significantly increased. CONCLUSIONS: For East Asians, changing the exit point of the infra-acetabular screw can increase the scope of infra-acetabular screw use, especially for females.

Normal Ischiofemoral Distance and Its Associated Factors: Computed Tomography-Based Study.

PURPOSE: The purposes of this study are (1) to measure the ischiofemoral distance (IFD) in nondiseased hips and (2) to reveal patient demographic and anatomical factors associated with IFD. METHODS: In this retrospective study, we identified patients who had unilateral osteonecrosis of the femoral head on computed tomography (CT) scan from November 2005 to July 2018 and assessed the unaffected contralateral hips of the patients. Among the contralateral hips, we excluded hips with hip pain, incomplete or poor-quality CT image, incomplete medical record, degenerative arthritis of the hip, or previous hip surgery. IFD was measured on the axial CT image, and correlated demographic factors (age, sex, height, weight, and body mass index) and anatomical parameters (neck-shaft angle of the femur and femoral anteversion) with IFD were evaluated. RESULTS: Five hundred seventeen patients (517 hips) were evaluated. There were 302 men and 215 women, and their mean age was 51.7 years (range 15-83 years). The mean IFD was 33.2 (±9.2) mm in men and 24.3 (±8.9) mm in women (P < .001). Interobserver and intraobserver reliability (intraclass correlation coefficients) were 0.99 (95% confidence interval 0.98-1.0) and 0.98 (95% confidence interval 0.97-0.99), respectively. The mean neck-shaft angle was 129.31° ± 5.04° in males and 129.93° ± 6.29° in females. The mean femoral anteversion was 9.72° ± 7.95° in males and 12.61° ± 8.91° in females. IFD was positively correlated with height (correlation coefficient [r] = 0.464, P < .001) and weight (0.286, P < .001), whereas it was negatively correlated with age (-0.198, P < .001), neck-shaft angle (-0.123, P = .005), and femoral anteversion (-0.346, P < .001). There was no correlation between body mass index and IFD (P = .522). In multivariate regression analysis, IFD was positively associated with height (ß = .632), and negatively associated with neck-shaft angle of the femur and femoral anteversion (ß = -0.155 and -0.328. respectively). CONCLUSIONS: In asymptomatic hips, the mean IFD was 33.2 ± 9.2 mm in males and 24.3 ± 8.9 mm in females. The IFD was positively correlated with height and negatively with neck-shaft angle of the femur and femoral anteversion. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Delayed-Union of Acetabular Stress Fracture in Female Gymnast: Use of Teriparatide to Augment Healing.

Pelvic stress fractures are rare and present unique challenges for medical personnel. Delayed healing can lead to increased physical, psychological, and social stress for athletes. Recent literature suggests effective use of a synthetic derivative of parathyroid hormone, teriparatide, to augment healing of delayed-union stress fractures. We present a case of a female National Collegiate Athletic Association Division I gymnast successfully returned to play after a 12-week course of teriparatide injections for an ischioacetabular stress fracture.

High Risk of Mismatch Between Sanders and Risser Staging in Adolescent Idiopathic Scoliosis: Are We Guiding Treatment Using the Wrong Classification?

BACKGROUND: Despite known limitations, Risser staging has traditionally been the primary marker of skeletal maturity utilized in decision-making for treatment of adolescent idiopathic scoliosis (AIS). The purpose of this study is to assess the incidence and factors associated with mismatch between Risser Staging and Sanders classification, and determine interobserver reliability. METHODS: We reviewed the medical records of consecutive patients aged 10 to 18 referred to our institution for evaluation of AIS from January to June 2016 with a closed triradiate cartilage. Data collected included sex, age, race, height, weight, body mass index percentile, menarchal status, Risser stage, Sanders classification, and major curve. Risser and Sanders stage was determined by 2 fellowship-trained pediatric spine surgeons and 1 pediatric orthopaedic nurse practitioner. Mismatch was defined as Risser stage 2 to 4 corresponding to Sanders 3 to 5, and Risser 0 to 1 corresponding to Sanders 6 to 7. RESULTS: A total of 165 consecutive patients were identified (mean age: 13.9±1.7 y, major curve 28.2±15.4 degrees, 76% female). The risk of skeletal maturity mismatch, based on the criteria of Risser 2 to 5 (limited growth remaining) corresponding to Sanders 3 to 5 (significant growth remaining) was 21.8%, indicating that 1 of 5 patients would be undertreated if managed by Risser criteria. Conversely, the mismatch risk for Risser 0 to 1 corresponding to Sanders 6 to 7 was 3.6%, leading such patients to be treated conservatively longer than necessary. Males and those of Hispanic ethnicity were at a higher risk of mismatch (23.1% vs. 11.9%, P=0.08; 33.3% vs. 8.8%, P=0.04, respectively). Body mass index percentile, race, and major curve were not associated with mismatch. The unweighted and weighted interobserver κ for Risser staging was 0.74 and 0.82, respectively, and 0.86 and 0.91 for Sanders classification, respectively. CONCLUSION: Given the limited sensitivity of Risser staging during peak growth velocity, high mismatch risk, and lower interobserver reliability, the Sanders classification should be utilized to guide treatment options in patients with AIS. Compared with Sanders, utilizing Risser staging results in mistreatment in a total of 1 of 4 patients, with the vast majority being undertreated. LEVEL OF EVIDENCE: Level II.

Reliability of 2D and 3D ultrasound for infant hip dysplasia in the hands of novice users.

PURPOSE: Developmental dysplasia of the hip (DDH) diagnosis by two-dimensional ultrasound (2DUS) can have poor inter-rater reliability. 3D ultrasound (3DUS) may be more reliably performed, particularly by novice users. We compared intra- and inter-rater reliability between expert and novice operators performing 2DUS and 3DUS for DDH. MATERIALS AND METHODS: Infants with suspected DDH were assessed with 2DUS and 3DUS. Novice operators had 1.5 h of training and Experts had 5-15 years' experience. Images included two 2DUS static and two 3DUS sweep images per operator. Image quality was assessed by 5-point system (yes/no: full femoral head; full acetabular roof; horizontal iliac wing; os ischium; absent motion/artifact). 2DUS indices (alpha angle, coverage) were measured centrally by a blinded reader with 2 years DDH US experience. 3DUS was post-processed by semi-automated custom software generating acetabular surface models, indices and estimated probability of DDH. Gold-standard diagnosis of each hip as normal, borderline or dysplastic was based on radiologist review of expert 2DUS. RESULTS: Thirty infants, mean age 10.8 weeks were enrolled. Quality scores were 2.7±1.2 Novice versus 4.9±0.3 Expert for 2DUS (p = 0.04), and 4.2±1.0 Novice versus 4.9±0.3 Expert for 3DUS (p = 0.99). Inter-rater reliability was poor for 2DUS (ICC=0.10 for alpha angle, 0.04 for acetabular coverage) and moderate to high for 3DUS (ICC=0.73-0.83 for alpha angle, 0.55 for acetabular coverage). Intra-rater reliability and diagnostic accuracy was higher for 3DUS than 2DUS. CONCLUSION: Novice operators can perform 3DUS for DDH with reliability and accuracy approaching expert sonographers. Novices perform 2DUS with poor reliability and accuracy. KEY POINTS: • Novice/expert inter-rater reliability improved from poor with 2DUS to moderate/high with 3DUS. • Novice operators using 3DUS correctly classified 57/58 (98%) of infant hips. • DDH can be reliably assessed by novice operators using 3DUS.

Avulsion fracture of the ischial tuberosity treated with the suture bridge technique: a case report.

BACKGROUND: In cases of avulsion fracture of the ischial tuberosity in which the bone fragments are substantially displaced, nonunion may cause pain in the ischial area. Various surgical procedures have been reported, but achieving sufficient fixation strength is difficult. CASE PRESENTATION: We treated a 12-year-old male track-and-field athlete with avulsion fracture of the ischial tuberosity by suture anchor fixation using the suture bridge technique. The boy felt pain in the left gluteal area while running. Radiography showed a left avulsion fracture of the ischial tuberosity with approximately 20-mm displacement. Union was not achieved by conservative non-weight-bearing therapy, and muscle weakness persisted; therefore, surgery was performed. A subgluteal approach was taken via a longitudinal incision in the buttocks, and the avulsed fragment was fixed with five biodegradable suture anchors using the suture bridge technique. CONCLUSIONS: Although the majority of avulsion fractures of the ischial tuberosity can be treated conservatively, patients with excessive displacement require surgical treatment. The suture bridge technique provided secure fixation and enabled an early return to sports activities.