Anterosuperior Research Articles

2D and 3D microstructural analysis of the iliotibial tract.

The fascial system has gained recognition for its integral role in connecting skin, superficial and deep fasciae, and underlying muscles. However, consensus on its microstructure depending on its topography remains elusive as well as its implications in clinical practices, such as reconstructive surgery and physiotherapy techniques. This study focuses on the iliotibial tract (ITT) implicated in the iliotibial band syndrome. The goal is to describe microstructural characteristics using classical 2D histology and cryogenic contrast-enhanced microcomputed tomography (cryo-CECT) such as the total thickness, number of layers, layer thickness, fibre orientation and tortuosity, according to the specific topography. The total thickness of the ITT varied across topographic regions, with the superior part being on average thicker but non-significantly different from the other regions. The inferior part showed heterogeneity, with the anterior region (AI) being the thinnest and the posterior one (PI) the thickest. The ITT exhibited 1-3 layers, with no significant differences among regions. Most commonly, it consisted of two layers, except for the antero-superior (AS) and antero-middle (AM) regions, which sometimes had only one layer. The posterior regions frequently had 2 or 3 layers, with the PI region having the highest mean (2.7 layers). The intermediate layer was the thickest one, varying from the AI region (0.368 mm ± 0.114) to the PI region (0.640 mm ± 0.305). The superficial layer showed regional variability, with the AS region being the thinnest. The deep layer appeared thinner than the superficial one. Fibre orientation analysis indicated that the intermediate layer mainly consisted of oblique longitudinal fibres, orientated downward and forward, while the superficial and deep layers had transversal or oblique transversal fibres. Cryo-CECT 3D observations confirmed these findings, revealing distinct orientations for different layers. Fibre tortuosity exhibited differences based on orientation. Transversal fibres (>65°) were significantly less tortuous than longitudinal fibres (<25°) and oblique intermediate fibres (25°-65°), aligning with 3D plot observations. This quantitative study highlights various microstructural characteristics of the ITT, offering insights into its regional variations. The analysis accuracy is increased due to the novel technology of cryo-CECT which emerges as a valuable tool for precise assessment of 3D fibre orientation and tortuosity. These findings contribute to a deeper understanding of the ITT structure, useful in clinical practices, such as reconstructive surgery and physiotherapy, and future research endeavours.

Better Constant Scores and Active Forward Elevation Using Deltopectoral Versus Anterosuperior Approach for Reverse Shoulder Arthroplasty: Matched Cohort Study.

To determine, from a sizable cohort of reverse shoulder arthroplasty (RSA), whether the deltopectoral (DP) or anterosuperior (AS) approach grant better outcomes at a minimum follow-up of 24 months. The authors reviewed 743 RSAs in patients with primary osteoarthritis (OA) with or without rotator cuff lesions and secondary OA due to rotator cuff tears. The DP approach was used in 540 and the AS approach in 203. Pre- and post-operative constant scores (CSs) and shoulder range of motion were recorded. Of the initial cohort of 743 shoulders, 193 (25.7%) were lost to follow-up, 16 (2.1%) died, and 33 (4.4%) were revised; 540 shoulders were operated using DP approach (73%), of which 22 were revised (4.1%), while 203 were operated using the AS approach (27%), of which 11 were revised (5.4%). Propensity score matching resulted in two groups: 172 shoulders operated by DP approach, and 88 shoulders operated by AS approach. Comparing outcomes of the matched groups at 2 or more years also revealed that, compared to the AS approach, the DP approach resulted in significantly better post-operative CSs (67.3 ± 14.0° vs 60.8 ± 18.3, P = 0.017), active forward elevation (137° ± 27.4° vs 129° ± 29.8; P = 0.031). At 2 or more years following RSA, the DP approach granted significantly better CS (by 6.5 points) and active forward elevation (by 8°) compared to the AS approach. The differences observed are clinically relevant and must be considered to manage patient expectations following RSA and for selecting surgical approach depending on their functional needs. III, comparative study.

Comparing outcomes of the anterosuperior and deltopectoral approaches in reverse total shoulder arthroplasty for degenerative glenohumeral arthritis: a systematic review.

Reverse total shoulder replacement (rTSR) improves pain and function in patients with a wide range of shoulder pathology. Anterosuperior (AS) and deltopectoral (DP) approaches are widely used to gain access to the glenohumeral joint in arthroplasty. Our aim was to systematically review the literature comparing outcomes of these two approaches when performing rTSR for degenerative glenohumeral arthritis. Systematic review was performed with an electronic multi-database search (Pubmed, Medline & Embase) according to PRISMA guidelines on 18th September 2022. Data from published studies of any study design that met the inclusion criteria were extracted, reviewed and synthesized. A total of 38 studies were identified for full text review, of which four were included. No significant difference in pain and range of motion were observed between approaches. Scapular notching was more common in the anterosuperior approach. Low rates of instability and intra-operative fracture were observed in both. Both approaches demonstrate similar clinical outcomes with reference to pain, range of motion and complications when performing rTSR indicated for degenerative joint disease. However, further well-designed studies are required.

Factors that affect external rotation following reverse shoulder arthroplasty: a retrospective multi-centre study on 501 shoulders.

The purpose of this multi-centre study was to assess external rotation in a large cohort following reverse shoulder arthroplasty (RSA) at a minimum follow-up of 2years, and identify factors that influence postoperative and/or net-improvement of external rotation. The authors retrospectively reviewed records of 743 RSAs performed between January 2015 and August 2017 by 16 surgeons that participated in a large national society symposium; 193 (25.7%) were lost to follow-up, 16 (2.1%) died, and 33 (4.4%) were revised with implant exchange, which left 501 available for assessment at 2.0-5.5years. Pre- and post-operative active forward elevation, active external rotation (ER1), active internal rotation (IR1) and constant score (CS) were collected. Regression analyses were performed to determine associations of patient demographics, surgical and implant parameters, rotator cuff muscles status and radiographic angles with ER1. Multivariable analyses revealed postoperative ER1 decreased with age (β, - 0.35), increased with lateralisation shoulder angle (LSA) (β, 0.26), and was better in shoulders operated by the antero-superior (AS) approach (β, 11.41), but worse in shoulders with absent/atrophic teres minor muscles (β, - 10.06). Net-improvement of ER1 increased with LSA (β, 0.39), was better with inlay stems (β, 8.33) and BIO RSA (β, 6.22), but worse in shoulders operated for primary OA with rotator cuff (RC) tears (β, - 16.26), for secondary OA due to RC tears (β, - 16.06), or for mRCT (β, - 18.96). This large multi-centre study revealed that, at a minimum of 2years following RSA, ER1 improved by 16.1°. Postoperative ER1 was better in shoulders which had normal or hypertrophic teres minor muscles, were operated by the AS approach, or with greater LSA. Net-improvement of ER1 was better in shoulders with inlay stems, with BIO RSA, or with greater LSA, but worse in shoulders with rotator cuff deficiency. IV.

Antero Superior Approach Vs Deltopectoral Approach In Reverse Total Shoulder Arthroplasty. A Prospective Randomized Study

The main objective of this study was to determine if there were differences in baseplate positioning between both approaches. Secondary objectives were to assess if there were differences in outcomes and in complications rate.

The Inverse Relationship Between Labral Size and Acetabular Coverage: Does It Protect the Cartilage in the Dysplastic Hip?

The aims of this study were to confirm the relationship between osseous coverage and labral size and toinvestigate the severity of intra-articular damage in borderline dysplastic hips in correlation to labral size. Patients treated with primary hip arthroscopy for symptomatic labral tears between 2010 and 2018 were considered for this study. Patients were included if they had preoperative radiographic measures and intraoperative assessments of the labra and cartilage. The study group was divided into borderline dysplastic and nondysplastic groups via 3 measurements: lateral center edge angle (LCEA), acetabular index (Ax), and anterior center edge angle (ACEA). Undercoverage was defined as LCEA ≤ 25°, Ax ≥ 10°, and ACEA ≤ 20°. The labrum was measured in four quadrants: anterosuperior (AS), anteroinferior (AI), posterosuperior (PS), and posteroinferior (PI). Additionally, to assess cartilage damage in borderline dysplastic hips, hips with average labral size in the top quartile were compared to hips with average labral size in the bottom quartile. A total of 1765 hips (1589 patients) were included in the study. The mean LCEA, Ax, and ACEA between the borderline dysplastic and nondysplastic groups were significantly different (P < .001). According to the Ax classification, there was significant evidence that borderline dysplastic hips had larger labra (P < .05). Among the dysplastic group, there was significantly more cartilage damage according to the Outerbridge classifications along both the acetabulum and femoral head in hips with labra in the upper quartile (P=.011 and .005, respectively). An inverse relationship may exist between acetabular depth and labral size. Additionally, specifically in borderline dysplastic hips, a relatively large labrum correlates with worse intra-articular damage compared to borderline dysplastic hips with a relatively small labrum. Larger labral size may indicate a higher degree of instability in patients with borderline dysplasia. Level III, case-control study.

Modified radiographic views to prevent the anterosuperior and posterosuperior bony violation during screw fixation of femoral neck fractures.

The standard anteroposterior and lateral fluoroscopic projections used during femoral neck fracture fixation provide a two-dimensional representation of the cephalocaudal and anteroposterior extents of the femoral neck. The radiographic representation differs from the actual extent of the femoral neck. The anterosuperior (AS) and posterosuperior (PS) surfaces of the femoral neck are at risk of bony breach by the fixation screws and that may get easily missed with standard fluoroscopic views. The current study aims at investigating the special fluoroscopy views, based on the orientation of the AS and PS surface of the femoral neck, that can help in the safe placement of screws near these surfaces without bony breach. A computed tomography-based analysis of fifty intact proximal femora was performed. The longitudinal axis of the proximal femoral shaft and the center of the femoral head were aligned along a common horizontal plane. The cephalocaudally constricted zone of the femoral neck was identified along its axis. The surface inclinations of the AS surface and the PS surface at the constricted zone of the femoral neck were measured in relation to the horizontal plane. The mean, standard deviation, overall range, interquartile ranges and gender-based variation of each of the two surface inclinations were measured. The mean surface inclinations of the AS surface and the PS surface with reference to the horizontal plane were 55° ± 7.76° and 123.32° ± 7.88°, respectively. There were no significant side to side and male to female differences. The modified radiographic views based on the surface inclinations of the AS and the PS surfaces can help in the localization of the critical zones of these surfaces which are at risk of bony breach with screw placement close to the surface. A prior fluoroscopic evaluation of these surfaces before guidewire placement can help in preventing the surface violation.

Quantum of cortico-cancellous bone safe for harvest from anterior iliac wing of pediatric patients: a finite element analysis with clinical correlation

Background: Objective was to assess the maximum quantum of cortico- cancellous bone that can be harvested from the Anterior Iliac Wing (AIW) of paediatric population.Methods: All patients reporting to the unit for the correction of bilateral cleft alveolus were included. A Computed Tomogram (CT) of the hip was recorded and the volume of cancellous bone available for harvest was assessed. Finite element model of the hip was generated using D2P and Geomagic Free form software and the impact of bone harvest on stress distribution along the anterior iliac wing was assessed by substituting the muscle forces (hip abductors and sartorius group) and was clinically correlated to volume harvested and donor site morbidities.Results: 10 patients were enrolled, 5 patients were excluded. CT volumetric evaluation revealed an average 0.5 cc to 4.7 ccof cancellous bone and 6.7 cc to 11 cc of cortical bone was available for harvest. Harvest of 50% of available graft volume was safe with minimal stress distributed along the line joining the tuberosity to the area between Antero Superior and Inferior spines (4.2 MPa at rest and 18.5 MPa at stance). The stress levels increased with increase in volume of bone harvested. Intra operatively 1.9 cc to 6.2 cc of cortico cancellous graft was harvested, which was equivalent to 60% of the graft available with no long-term morbidities.Conclusions: The volume of bone graft harvest should be restricted (up to 6 cc) to avoid long term morbidities.

Comparison of Functional and Radiological Outcomes of Tears Involving the Subscapularis: Isolated Subscapularis Versus Combined Anterosuperior Rotator Cuff Tears.

Background:Few studies have compared the clinical and radiological characteristics and outcomes in isolated subscapularis (SSC) and combined anterosuperior (AS) rotator cuff tears (RCTs). Furthermore, risk factors for retear after SSC repair and the effect of preoperative fatty degeneration require further evaluation.Purpose:To compare the functional and radiological outcomes of isolated SSC with combined AS RCTs after arthroscopic repair and to determine the risk factors for SSC retear in these 2 groups.Study Design:Cohort study; Level of evidence, 3.Methods:Data from 30 patients in the isolated SSC group were compared with data from 110 patients in the combined AS group. All patients underwent primary arthroscopic rotator cuff repair between 2010 and 2016. Clinical outcomes were assessed through use of the visual analog scale for pain, American Shoulder and Elbow Surgeons score, and Simple Shoulder Test at a mean follow-up of 26.7 months (range, 24-96 months). SSC tendon integrity was examined via magnetic resonance imaging, computed tomography arthrogram, or ultrasonography at least 1 year after surgery.Results:The isolated SSC group had a greater proportion of males and the patients were younger compared with the combined AS group (both P < .050). The incidence of trauma was high but not significantly different between groups (56.7% vs 40.9%; P = .180). Clinical outcome measures and radiological outcomes in terms of retear were not statistically different between both groups (16.7% vs 8/5%; P = .337). The optimal cutoff values for the risk of SSC tendon retear in both groups were 19-mm retraction and 16-mm superoinferior dimension (P = .048). Unfavorable preoperative fatty degeneration of the SSC muscle (grades 3 and 4) was a significant risk factor for retear (odds ratio, 9.8; P < .001).Conclusion:Isolated SSC and combined AS RCTs were comparable except for patient age and sex; both had a high incidence of traumatic history. The current data suggest that the risk factors for retear after SSC repair in RCTs involving the SSC were tear size greater than 19 mm of retraction and unfavorable fatty degeneration (grade 3 or higher) of the SSC muscle.

Correlation of Site and Size of Tympanic Membrane Perforation and Middle Ear Air Space Volume with Magnitude of Hearing Loss

Abstract Introduction The effects of tympanic membrane perforations on middle ear sound transmission are not well characterized, largely because ears with perforations typically have additional pathological changes. It has been established that the larger the perforation, the greater is the hearing loss (HL). Aim This study aimed to correlate the location and size of tympanic membrane perforation and middle ear air space volume with the magnitude of HL in patients with tubotympanic or inactive mucosal type of chronic otitis media (COM). Materials and Methods A prospective clinical study of patients with tympanic membrane perforations due to COM and without any other ear disease and who attended the Otolaryngology services at our institute between July 2010 and December 2011 was conducted. A total of 300 ears were evaluated by performing otoendoscopy, followed by photo documentation and audiological investigations (pure-tone audiometry and tympanometry). Tympanic membrane perforations were categorized based on their size and location, and the mean air-bone (AB) gap between the various types of perforations was compared and statistically analyzed with significance level of p &lt; 0.05. Results Out of 300 ears, maximum number of ears (n = 124, 41.3%) had large-sized perforations (&gt; 30 mm2) that had a maximum mean AB gap of 26.43 dB, and minimum number of ears (n = 60, 20%) had small-sized perforations (0–9 mm2) that had minimum mean AB gap of 9.12 dB. The remaining were medium-sized perforations that had mean AB gap of 16.13 dB. Depending on the location, maximum were central perforations (n = 198, 66%) and minimum were anterosuperior (AS) perforations (n = 9, 3%). Based on the middle ear volume on tympanometry, maximum ears were of low-volume group (n = 246, 92%) that had larger mean AB gap of 19.96 dB HL when compared with the high-volume group (n = 24, 8%) with 11.80 dB HL. AB gap was maximum at lower frequencies and decreased with increase in frequencies except at 4,000 Hz, that is, 56.9 dB HL at 250 Hz, 42.6 at 500 Hz, 41.5 at 1,000 Hz, 32.4 at 2,000 Hz, and 49.5 at 4,000 Hz. Conclusion HL increases as the area of tympanic membrane perforation increases. There is an inverse relationship between HL and middle ear air space volume. Comparing the small-sized perforations at different sites with the middle ear volume being low, it was found that posterosuperior (PS) perforations had 4 to 7 dB greater HL than AS and anteroinferior (AI). However, the relationship was statistically insignificant. The phase cancellation effect of round window causing greater HL in posteroinferior (PI) perforations does not exist in small- and medium-sized perforations. HL is greater at lower frequencies and less at higher frequencies.

Partial ligamentum teres tears are associated with larger acetabular labra and less damage to the labrum than complete ligamentum teres tears.

ABSTRACTThe purpose of this study was to investigate the association between ligamentum teres (LT) tears with hypertrophy of the acetabular labrum and cartilage and labral damage. Surgeries (1723) were performed from February 2010 to March 2016 with arthroscopic measurement of the labrum and assessment of the LT, labrum and acetabular cartilage. Labral width was measured in the anterosuperior (AS), anteroinferior (AI), posteroinferior (PI) and posterosuperior (PS) quadrants. Grade 2 (50–99% torn) LT tears had larger labra in all four quadrants (AS = 5.64 ± 1.97 mm; AI = 5.23 ± 1.51; PS = 5.58 ± 1.39; PI = 4.60 ± 1.13) than grade 3 (100% torn) (AS = 5.50 ± 1.94; AI 4.90 ± 1.43; PS 5.43 ± 1.32; PI 4.42 ± 1.03), grade 1 (<50% torn) (AS 5.30 ± 1.68; AI 4.96 ± 1.32; PS = 5.38 ± 1.13; PI = 4.45 ± 1.04) and no tear (AS = 5.09 ± 1.51; AI = 4.92 ± 1.24; PS = 5.24 ± 1.09; PI = 4.37 ± .93); P < 0.01 in all quadrants. Grade 3 LT tears had more damage to the labrum than grade 2, grade 1 and no tear; P < 0.001. ALAD tears were larger in grade 3 and grade 2 than grade 1 and non-torn LTs; P < 0.001. Grade 3 tears had a higher percentage of high-grade cartilage tears than grade 2 LT tears; P < 0.001. Degenerative tears had larger labra, labral tears and acetabular cartilage tears than full- and partial-thickness LT tears; P < 0.01. Patients with partial-thickness LT tears had larger labra in all four quadrants than full-thickness tears in the Percentile and Villar classifications. Full-thickness tears had more severe labral damage and higher-grade chondral damage than partial-thickness tears. Degenerative tears demonstrated the largest labra, labral tears and ALAD tears. The condition of the LT demonstrated an association with acetabular cartilage injury and should be evaluated when considering hip preservation surgery. LEVEL OF EVIDENCE: Level IV Case Series.

Assessing glenosphere position: superior approach versus deltopectoral for reverse shoulder arthroplasty

The anterosuperior (AS) approach for reverse total shoulder arthroplasty (RTSA) has been reported as a risk factor for baseplate malposition because of potential difficulty in glenoid exposure. The objective of this study was to compare glenoid baseplate position between the AS and deltopectoral (DP) approaches in relation to the surgeon's experience and to evaluate the effect of placement on clinical outcomes. There were 109 shoulders that underwent RTSA for cuff tear arthropathy or osteoarthritis with cuff tearing by a single surgeon. The AS approach was used in 87 shoulders. Clinical, radiographic, and functional outcomes were assessed for all patients with a minimum of 2 years of follow-up. Initial postoperative radiographs of all 109 shoulders were assessed for baseplate positioning. The mean change in glenoid inclination was 3.0° inferior with the AS approach and 2.5° inferior with the DP approach (P = .68). Pain scores (P = .14), range of motion, and American Shoulder and Elbow Surgeons scores (P = .16) improved in both groups, without a difference between approach. Scapular notching was noted in 68.5% of AS shoulders and 72.4% of DP shoulders (P = .78). Over time, there was a trend to place the glenoid baseplate more caudal with less inferior tilt. Both approaches produce similar baseplate position, clinical outcomes, and rates of scapular notching when they are used for RTSA. Attempts to inferiorize the glenoid baseplate through the AS approach may increase the risk of superior inclination.

Postural and Load Distribution Asymmetries in Preschoolers

&lt;p&gt;The aim of the study was to investigate the postural and load distribution symmetries in preschool children. The sample consisted of 67 preschool children with a median age of 54.00 ± 5.06 months. Postural parameters such as the horizontal alignment of the head, the acromion and Antero Superior Iliac Spines (ASIS), the angles between the acromial and ASIS, frontal, Q, knee and ankle and horizontal asymmetry of the scapula in relation to T3 were evaluated by photogrammetry. The baropodometry was used to identify the distribution of plantar pressure, while the medial arch of the foot was analyzed by photographic image. The median, standard deviation and the symmetry ratio were calculated for each parameter considered symmetry values greater than 90%. The Pearson’s or Spearman’s correlation were used between the parameters analyzed. There was asymmetric for postural and load distribution parameters for both genders and a null correlation between the symmetry of the surface and foot morphology and negative weak correlation significant between of the load foot and the front angle of the lower limb symmetries. The presence of asymmetries, postural and/or of load distribution, observed in early childhood suggest the importance of monitoring the postural and foot load parameters in the long term, preventing future postural and biomechanical alterations.&lt;/p&gt;

(i) Surgical approaches for shoulder arthroplasty

Abstract Shoulder arthroplasty is most commonly performed via a deltopectoral (DP) or anterosuperior (AS) approach, and several modifications of each have been described. Both approaches can be used for resurfacing, stemless and stemmed hemiarthroplasty, anatomic total shoulder arthroplasty (TSA), and reverse shoulder arthroplasty (RSA). This article aims to give a practical guide to performing both approaches, and a summary of the related evidence.

Axillary nerve position in the anterosuperior approach of the shoulder: a cadaveric study.

Objective: To determine the distance between the axillary nerve and the antero-lateral (AL) edge of the acromion, its anatomical variability and relationship to humeral length and body height. Methods: Twenty-two shoulders were dissected. The anterosuperior (AS) approach was used; the deltoid was detached from the acromion and the distance between the AL portion and the axillary nerve was measured and submitted to statistical analysis. Results: The distance varied from 4.3 to 6.4 cm (average 5.32 ± 0.60 cm). The axillary nerve distance increased as the humeral size (p<0.05) and the height of each cadaver increased. However, the correlation with the specimens height was not significant (p=0.24). Conclusions: The distance between the acromion and the axillary nerve on the AS approach was 5.32 ± 0.60 cm in both shoulders, and increasing the humeral length there is also an increase in the axillary nerve distance. Level of Evidence IV, Case Series - Anatomic Study.

Morphological analysis of the acetabular cartilage surface in elderly subjects.

The geometry of acetabular cartilage surface plays an important role in hip joint biomechanics. The aim of this study was to analyze the morphology of acetabular articular cartilage surface in elderly donated bodies to science using a 3D-digitizer. Twenty hemipelves from 12 subjects (mean ages 85 years) were scanned with 3D-digitizer. Each acetabular surface model was divided into four regions: anterosuperior (AS), anteroinferior (AI), posterosuperior (PS), and posteroinferior (PI). In the global acetabulum and each region, the acetabular sphere radius and the standard deviation (SD) of the distance from the acetabular sphere center to the acetabular cartilage surface were calculated. In the global acetabulum, the distance between the acetabular surface model and the maximum sphere which did not penetrate over the acetabular surface model was calculated as the inferred femoral head, and then the distribution was mapped at intervals of 0.5 mm. The SD in AS was significantly larger than that in AI (p = 0.006) and PI (p = 0.001). The SD in PS was significantly larger than that in PI (p = 0.005). The closest region (0-0.5 mm) tended to be distributed at anterior or posterosuperior acetabular edge. The contact between the femoral head and acetabulum might start at the periphery of the lunate surface, especially in the anterior or posterosuperior region. From viewpoint of acetabular morphology, the acetabular articular cartilage in the anterior or posterosuperior edge could be more vulnerable due to direct contact mechanism.

Injury to the Suprascapular Nerve in Slap Repair: A Rotator Interval Portal Is not Safer Than an Anterosuperior Portal

During SLAP repair, when perforation of the glenoid occurred, 1 o’clock and 2 o’clock posterior suture anchors placed through the rotator interval portal were statistically significantly closer to the suprascapular nerve. The suprascapular nerve is potentially at risk during superior labrum repair. The Purpose of this study is to compare the risk of injury to the suprascapular nerve during suture anchor placement through an anterosuperior or rotator interval portal. Our hypothesis is that the use of the rotator interval portal provides a safer and more reproducible method than the anterosuperior portal for repair of Type II SLAP tears. Ten bilateral fresh human cadaveric shoulders were used. Each pair was randomized to suture anchor placement through an anterosuperior portal on one shoulder and a rotator interval portal, made just posterolateral to the biceps, on the contralateral shoulder. Consistent with standard SLAP repair, the suture anchors were placed into the glenoid rim at the one o’clock, eleven o’clock and ten o’clock positions for a right shoulder (eleven o’clock, one o’clock and two o’clock for a left shoulder). Drill holes were created using a 2.4mm drill with a 20mm depth stop collar. Standard 3x14mm suture anchors were placed. Following suture anchor placement, the suprascapular nerve was carefully dissected. Medial glenoid perforation was measured with digital calipers. When perforation occurred, the distance from the suture anchor tip to the suprascapular nerve was measured. The anchors were removed and the distance from the glenoid rim to the suprascapular nerve at each suture anchor entry site was recorded. A depth gage was used to measure the depth of the drill hole for each perforated anchor. All of the far posterior suture anchors (defined as the ten o’clock anchor for the right shoulder and two o’clock anchor for the left shoulder) perforated the glenoid rim using either the anterosuperior (AS) or rotator interval (RI) portal. For the far posterior anchor, the distance from the anchor tip to suprascapular nerve averaged 8.02mm (range 3.4mm to 14mm) using the AS portal and 2.1mm (range 0mm to 5.5mm) using the RI portal, a statistically significant (p=<0.001, 95% CI (-7.81, -4.04)) difference of 5.92mm. For the posterior anchors (defined as the eleven o’clock anchor for the right shoulder and one o’clock anchor for the left shoulder) the perforation rate was 80% and 60% for the AS and RI portals, respectively. There was no statistical difference found in the distance from the anchor tip to the suprascapular nerve for the posterior anchors between the AS and RI portals (p=0.36, 95% CI (-6.11, 2.51)). There was no statistical difference in the length of anchor tip exposed between the AS and RI portals for either the posterior (p=0.26, 95% CI (-0.26,0.83)) or far posterior (p=0.9, 95%CI (-4.27, 4.81)) anchors. In addition, there was no statistical difference found in the drill hole depth between the AS and RI portals for either the posterior (p=0.06, 95% CI (-0.23,7.34)) or far posterior (p=0.10, 95% CI (-0.43, 3.76)) anchors. Using an anterosuperior or rotator interval portal results in consistent penetration of 1 o’clock and 2 o’clock posterior suture anchors and may as a result place the suprascapular nerve at risk of iatrogenic injury. Based on the high likelihood of glenoid perforation and closer proximity of the suture anchor tip to the suprascapular nerve, the risk of injury is significantly greater when using a rotator interval portal in performing SLAP repair.

Reference Values for Proximal Femoral Anatomy in Adolescents Based on Sex, Physis, and Imaging Plane

Background: Morphological alterations of the hip joint are important contributors to the development of osteoarthritis. While plane-specific variations in the shape of the proximal femur have been described, there are no defined reference standards for measurements in adolescent patients. Purpose: To evaluate hips in asymptomatic adolescent patients using radially reformatted multidetector computed tomography (MDCT) to define the morphological characteristics of the femoral head-neck (FHN) junction with respect to patient sex and physeal status, and to establish reference values for α angle, FHN offset, and epiphyseal extension (EE). Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 132 pelvic MDCT scans in adolescent patients with abdominal pain were reformatted into radially oriented planes along the femoral necks. The diameter of the femoral head, α angle, EE, and FHN offset were measured. Reference values for α angle, EE, and FHN offset were determined, and the α angle, EE, and FHN offset were compared between open versus closed physeal status for each sex. Results: The α angle measurements in male patients were higher than in female patients in anterior (A), anterosuperior (AS), and superior (S) planes (P < .001). The median α angle was highest for all patients in the AS plane (male, 52°; female, 49°). Open physes correlated with higher α angles compared with closed physes in all imaging planes except the AS plane. The FHN offset was lowest in the AS plane for all patients and was increased in female patients with closed physes compared with open physes in the A plane and in the A, S, posterosuperior, and posterior planes in male patients (P < .05). There were subtle plane-specific variations in EE. Conclusion: The α angle is higher and FHN offset is lower in the AS plane in patients with closed versus open physes, whereas the opposite is true in all other planes. The α angles in male patients were higher than in female patients, although there were no significant sex-based differences in the FHN offset. The α angles were highest and FHN offset was lowest in the AS plane. There were subtle variations in EE across all planes, and the EE was higher in patients with closed versus open physes. Clinical Relevance: Plane- and sex-specific reference values for α angle, FHN offset, and EE in asymptomatic adolescent patients will assist orthopaedic surgeons and radiologists in appropriately suggesting femoroacetabular impingement based on the imaging evaluation of patients with hip pain, whose measurements lie at the periphery of or outside the reference intervals in the appropriate clinical context.

Understanding the Pincer - The Importance of Reference Plane Orientation on Acetabular Rim Evaluation

Objectives:Femoroacetabular impingement (FAI) is a common cause of young adult hip pain. FAI can result from an acetabular-sided bony lesion, or “pincer” lesion. A pincer lesion is defined as an area of linear contact between the acetabular rim and the femoral head-neck junction due to general or focal acetabular overcoverage. Three dimensional (3D) analysis of the acetabular rim morphology is essential to understand etiology and aciculate diagnosis of the of the pincer type FAI. A few studies have measured 3D geometry of the acetabular rim; in which the acetabular rim is described as a deviation from a reference plane. Therefore, the definition of the reference plane is critical to determine the acetabular rim geometry. The purpose of this study was to use 3D Computed Tomography (CT) modeling to evaluate the impact of varied acetabular orientation reference planes on the interpretation of acetabular rim abnormalities, with the goal to determine the ideal reference plane for future study use.Methods:3D CT modeling was performed on five hip joints of patients who underwent hip arthroscopy with acetabular trimming for a presumed pincer lesion. These models were exported into point-cloud models. An acetabular 3D model was automatically created within 10 mm from the femoral head surface (Fig. 1A, B). The acetabular articular surface and rim were separated with a threshold of 5 mm, which provided an acetabular rim model with a band width of 5 mm (Fig. 1C). A local coordinate system was defined with the acetabular notch midpoint being 6 o’clock. A best-fit plane of the acetabular rim was determined by the least square method using two different acetabular rim models: 1) a model excluding the acetabular notch (plane A) and 2) a model excluding the acetabular notch and superior region from 10:30 to 3:00 (3:00 being anterior) (plane B). The acetabular rim model was transformed into a cylindrical coordinate system with an axis determined by a normal vector of the plane. The final acetabular rim model consisting of 120 points with 3° increments was created by searching the outermost points of the rim. The acetabular center was determined using best-fit sphere of the articular surface model. A reference plane including the center point was determined with orientations determined by normal vectors of the acetabular rim planes (Fig. 1C, yellow line). The 3D geometry of the rim was described by subtended angles from the normal vector of the reference plane.Results:Three distinct peaks were noted at anteroinferior (AI), anterosuperior (AP) and posteroinferior (PI) regions (Fig. 2 A, B). While the AI and PI peaks measured with the plane A were higher than that measured with plane B, the AP peak measured with plane A was lower than that measured with plane B (Fig. 2C). The angle between the normal vectors of plane A and B was 13.7±3.5°.Conclusion:The findings demonstrate that the orientation of the reference plane is critical to the 3D measurement of the acetabular rim. Since bony prominence in the anterosuperior region has been considered as the pathogenesis of the impingement, the reference plane including this region may cause underestimation of the bony lesion. An appropriate determination of the reference plane is crucial for evaluation of the bony lesion in the pincer FAI patient.

Abstract 18696: Feasibility of Transcatheter Closure of Secundum Atrial Septal Defect with Deficient Rims Other than the Antero Superior

Introduction. Transcatheter closure of secundum atrial septal defect (ASD) with deficient rims is usually contraindicated except in cases with a deficient antero-superior rim in whom percutaneous closure is well demonstrated. Our goal was to assess the feasibility of transcatheter closure for secundum ASD with deficient rims (&lt;5 mm) other than the antero-superior. Method. Between January 1st, 2008 and december 31, 2011, 192 patients underwent percutaneous closure of ASD in our institution under transesophageal echocardiography guidance in children and intracardiac echocardiography guidance in adults. Amplatzer devices (Amplatzer Septal Occluder or Cribriform) were used in 191 whereas one case without deficient rim was closed with intrasept ASD occluder. We retrospectively analyzed the outcomes of the 43 patients (22.4%, 26 children) with one or more deficient rim. Results.The median age and weight was 16(1.1 to 85) years and 56(8.8 to 99)Kg, respectively. Deficiency of the inferior (toward the AV valves, n= 11), inferior- posterior (toward the inferior vena cava, n=15), and the superior -posterior rim (toward the superior vena cava, n= 17) was confirmed by transesophageal echocardiography in all the cases. Transcatheter closure was successfully accomplished in 37 (86%) of the cases with a median device size of 28(10 to 40) mm. A modified method of implantation (sizing balloon technique) was used in 30 patients (70%).In 6 patients (5 children) the ASD could not be closed. Four children experienced device embolization few hours after successful transcatheter closure and underwent surgical ASD closure without further complication. By Fisher’s exact test, deficiency of the inferior-posterior rim was associated with failure or embolization(p = 0.05)and there was a trend for adult age to be associated with a low risk of embolization or failure (p= 0,06). Conclusion. Transcatheter closure of secundum ASD is feasible in patients with deficient rims. However, this cannot be recommended because of an intolerable rate of embolization. Possibly, transcatheter closure of such secundum ASDs with deficient rims may be more successful in the adult population.