Accuracy of conventional motion capture in measuring hip joint center location and hip rotations during gait, squat, and step-up activities.

Accurate measurements of hip joint kinematics are essential for improving our understanding of the effects of injury, disease, and surgical intervention on long-term hip joint health. This study assessed the accuracy of conventional motion capture (MoCap) for measuring hip joint center (HJC) location and hip joint angles during gait, squat, and step-up activities while using dynamic biplane radiography (DBR) as the reference standard. Twenty-four young adults performed six trials of treadmill walking, six body-weight squats, and six step-ups within a biplane radiography system. Synchronized biplane radiographs were collected at 50 images per second and MoCap was collected simultaneously at 100 images per second. Bone motion during each activity was determined by matching digitally reconstructed radiographs, created from subject-specific CT-based bone models, to the biplane radiographs using a validated registration process. Errors in estimating HJC location and hip angles using MoCap were quantified by the root mean squared error (RMSE) across all frames of available data. The MoCap error in estimating HJC location was larger during step-up (up to 89.3 mm) than during gait (up to 16.6 mm) or squat (up to 31.4 mm) in all three anatomic directions (all p < 0.001). RMSE in hip joint flexion (7.2°) and abduction (4.3°) during gait was less than during squat (23.8° and 8.9°) and step-up (20.1° and 10.6°) (all p < 0.01). Clinical analysis and computational models that rely on skin-mounted markers to estimate hip kinematics should be interpreted with caution, especially during activities that involve deeper hip flexion.

Knee Flexion Angle of Fixation During Anterolateral Ligament Reconstruction or Lateral Extra-articular Tenodesis: A Systematic Review and Meta-analysis of Lateral Extra-articular Reinforcement Techniques Performed in Conjunction With ACL Reconstruction.

Background: Anterolateral ligament reconstruction (ALLR) or lateral extra-articular tenodesis (LET) is being used more frequently in conjunction with anterior cruciate ligament reconstruction (ACLR). However, the knee flexion angle at which fixation of ALLR or LET is performed during the procedure is quite variable based on existing technique descriptions. Purpose/Hypothesis: The purpose of this study was to identify whether flexion angle at the time of ALLR/LET fixation affected postoperative outcomes in a clinical population. It was hypothesized that ALLR/LET fixation at low versus high flexion angles would lead to no statistically significant differences in patient-reported outcome measures and graft failure rates. Study Design: Systematic review; Level of evidence, 4. Methods: The PubMed, Embase, and Cochrane Library databases were searched according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to identify published clinical studies of ACLR with ALLR/LET in which the knee flexion angle at the time of ALLR/LET was reported. A priori, low flexion was defined as 0° to 30°, and high flexion was defined as 60° to 90°. Studies were excluded if the flexion angle was between 31° and 59° because these angles constituted neither low nor high flexion angles and including them in an analysis of high versus low flexion angle at fixation would have biased the study results toward the null. The overall risk of bias was assessed using the Newcastle-Ottawa Scale. The pooled results of the studies were analyzed using the International Knee Documentation Committee (IKDC), Lysholm, and Tegner scores, along with reported graft failure rates. Results: A total of 32 clinical studies (5230 patients) met inclusion criteria: 22 studies (1999 patients) in the low-flexion group and 10 studies (3231 patients) in the high-flexion group. The median Newcastle-Ottawa Scale score was 6. Comparisons of patients with a low flexion angle versus a high flexion angle demonstrated no differences in the IKDC (P = .84), Lysholm (P = .67), or Tegner (P = .44) scores or in graft failure (3.4% vs 4.1%, respectively; P = .69). Conclusion: The results of this review indicated that ACLR performed in conjunction with ALLR/LET provides good to excellent patient-reported outcomes and low graft failure rates when ALLR/LET fixation is performed in either low or high knee flexion.

Introducing Skeletally-Mature Anterior Cruciate Ligament Reconstruction Technique Using Reinforcement (SATURN) With Iliotibial Band Autograft.

Anterior cruciate ligament (ACL) injuries are increasingly common in the adolescent age group. Recent literature has endorsed combining ACL reconstruction with lateral extra-articular procedures to minimize residual rotatory knee instability and reduce the risk of reinjury in this age group. This technique describes a single-bundle combined anatomical ACL reconstruction and lateral extra-articular reinforcement performed with a single iliotibial band autograft. Also this technique allows for the ACL reconstruction and lateral extra-articular stabilization to be performed through a single surgical incision while obtaining autograft tissue without disruption of the extensor or hamstring mechanisms.

Non-Operative Rehabilitation Principles for Use in Individuals with Acetabular Dysplasia: A North American Based Delphi Study.

Background: Acetabular dysplasia (AD) is defined as a structurally deficient acetabulum and is a well-recognized cause of hip pain in young adults. While treatment of severe AD with a periacetabular osteotomy has demonstrated good long-term outcomes, a trial of non-operative management is often recommended in this population. This may be especially true in patients with milder deformities. Currently, there is a paucity of research pertaining to non-operative management of individuals with AD. Purpose: To present expert-driven non-operative rehabilitation guidelines for use in individuals with AD. Study Design: Delphi study. Methods: A panel of 15 physiotherapists from North America who were identified as experts in non-operative rehabilitation of individuals with AD by a high-volume hip preservation surgeon participated in this Delphi study. Panelists were presented with 16 questions regarding evaluation and treatment principles of individuals with AD. A three-step Delphi method was utilized to establish consensus on non-operative rehabilitation principles for individuals presenting with AD. Results: Total (100%) participation was achieved for all three survey rounds. Consensus, defined a piori as > 75%, was reached for 16/16 questions regarding evaluation principles, activity modifications, appropriate therapeutic exercise progression, return to activity/sport criteria, and indications for physician referral. Conclusion: This North American based Delphi study presents expert-based consensus on non-operative rehabilitation principles for use in individuals with AD. Establishing guidelines for non-operative management in this population will help reduce practice variation and is the first step in stratifying individuals who would benefit from non-operative management. Future research should focus on patient-reported outcomes and rate of subsequent surgical intervention to determine the success of the guidelines reported in this study. Level of Evidence: Level V.

The Effect of Lateral Extra-articular Tenodesis in an ACL-Reconstructed Knee With Partial Medial Meniscectomy: A Biomechanical Study.

BACKGROUND: Knee laxity increases with medial meniscectomy in anterior cruciate ligament (ACL)-reconstructed knees; however, the biomechanical effect of an additional lateral extra-articular tenodesis (LET) is unknown. PURPOSE/HYPOTHESIS: The purpose of this study was to determine the kinematic effect of a LET in knees that underwent combined ACL reconstruction (ACL-R) and partial medial meniscus posterior horn (MMPH) meniscectomy. It was hypothesized that the addition of LET would reduce laxity in the ACL-reconstructed knee. STUDY DESIGN: Controlled laboratory study. METHODS: Ten fresh-frozen human cadaveric knees (mean age, 41.5 years) were tested using a robotic system under 3 loads: (1) 89.0 N of anterior tibial (AT) load, (2) 5 N·m of internal rotation (IR) tibial torque, and (3) a simulated pivot shift-a combined valgus of 7 N·m and IR torque of 5 N·m-at 0°, 15°, 30°, 45°, 60°, and 90° of knee flexion. Kinematic data were acquired in 4 states: (1) intact, (2) ACL-R, (3) ACL-R + partial MMPH meniscectomy (MMPH), and (4) ACL-R + partial MMPH meniscectomy + LET (MMPH+LET). RESULTS: In response to AT loading, there was a significant increase seen in AT translation (ATT) in the MMPH state at all knee flexion angles compared with the ACL-R state, with the highest increase at 90° of knee flexion (mean difference, 3.1 mm) (P < .001). Although there was a significant decrease in ATT at 15° of knee flexion with MMPH+LET (P = .022), no significant differences were found at other knee flexion angles (P > .05). In MMPH with IR torque, a significant increase was observed in IR at all knee flexion angles except 90° compared with the ACL-R state (range, 2.8°-4.9°), and this increase was significantly decreased at all flexion angles with the addition of LET (range, 0.7°-1.6°) (P < .05). CONCLUSION: Performing a partial MMPH meniscectomy increased ATT and IR in response to AT and IR loads compared with the isolated ACL-R state in a cadaveric model. However, when the LET procedure was performed after partial MMPH meniscectomy, a significant decrease was seen at all knee flexion angles except 90° in response to IR and torque, and a significant decrease was seen at 15° of knee flexion in response to AT load. CLINICAL RELEVANCE: LET may be a useful adjunct procedure after ACL-R with partial MMPH meniscectomy to reduce knee laxity.

Periacetabular osteotomy after failed hip arthroscopy demonstrates improved outcomes in a heterogenous patient population: a systematic review.

PURPOSE: To evaluate the literature on patients undergoing periacetabular osteotomy after failed hip arthroscopy (PAO-FHA) for (1) patient demographics and hip morphology, (2) changes in preoperative to postoperative patient-reported outcomes (PROs), and (3) PROs in comparison to primary periacetabular osteotomy (PAO) patients. METHODS: A systematic literature search of Pubmed, CINAHL/Medline, and cochrane databases was performed in accordance with PRISMA guidelines. The search phrase was "(periacetabular osteotomy or PAO or rotational osteotomy) and (hip arthroscopy or arthroscopic)". The titles, abstracts, and full texts were screened for studies on PAO-FHA. Study quality was assessed, and relevant data were collected. A meta-analysis was not performed due to study heterogeneity. RESULTS: The search identified 7 studies, including 151 hips (148 patients, 93.9% female) undergoing PAO-FHA, out of an initial 593 studies, with three Level IV and four Level III studies. Mean time from hip arthroscopy to PAO ranged from 17.0 to 29.6 months. Heterogenous hip morphologies and radiologic findings prior to PAO were observed, though patients most frequently demonstrated moderate-to-severe dysplasia (mean or median lateral center edge angle < 20°) and minimal osteoarthritis (Tönnis grade 0 or 1). In all 5 studies that reported concomitant procedures with PAO, femoral and/or acetabular osteoplasty was performed via arthroscopy or arthrotomy. Following PAO-FHA, radiographic acetabular coverage and PROs improved in all 6 studies that reported postoperative outcomes. All four comparative studies of primary PAO vs. PAO-FHA included patients with mean or median LCEAs < 20°, reporting mixed outcomes for the optimal treatment approach. CONCLUSION: PAO-FHA is reported in a heterogenous patient population that frequently includes hips with moderate-to-severe dysplasia and minimal osteoarthritis. Regardless of hip morphology or concomitant procedures, all studies that reported postoperative outcomes demonstrated improved PROs following PAO-FHA. LEVEL OF EVIDENCE: Level IV.

Evaluation of a Smart Knee Brace for Range of Motion and Velocity Monitoring during Rehabilitation Exercises and an Exergame.

Anterior cruciate ligament (ACL) injuries often require a lengthy duration of rehabilitation for patients to return to their prior level of function. Adherence to rehabilitation during this prolonged period can be subpar due to the treatment duration and poor adherence to home exercises. This work evaluates whether a smart instrumented knee brace system is capable of monitoring knee range of motion and velocity during a series of common knee rehabilitation exercises and an exergame. A total of 15 healthy participants completed a series of common knee rehabilitation exercises and played an exergame while wearing a smart instrumented knee brace. The range of motion (ROM) and velocity of the knee recorded by the knee brace was compared to a reference optoelectronic system. The results show good agreement between the knee brace system and the reference system for all exercises performed. Participants were able to quickly learn how to play the exergame and scored well within the game. The system investigated in this study has the potential to allow rehabilitation to occur outside of the clinic with the use of remote monitoring, and improve adherence and outcomes through the use of an exergame.

Hip Pain in Ballet Dancers: Evaluation and Management.

Hip and groin injuries are common in ballet dancers, who often begin sport-specific training at a young age. The unique demands of ballet include extreme range of motion, with an emphasis on external rotation and abduction. This creates a distinctive constellation of hip symptoms and pathology in this cohort, which may differ from other flexibility sports. When managing hip symptoms in this cohort, orthopaedic surgeons should consider the unique factors associated with ballet, including ballet-specific movements, morphologic adaptations of the hip, and the culture of the sport. Three common etiologies of hip pain in ballet dancers include femoroacetabular impingement syndrome, hip instability, and extra-articular snapping hip syndrome. First-line treatment often consists of focused physical therapy to strengthen the core and periarticular hip musculature, with surgical management reserved for patients who fail to improve with conservative measures.

Rehabilitation Guidelines for Use Following a Periacetabular Osteotomy (PAO): A North American Based Delphi Consensus.

Background: Treatment of acetabular dysplasia with a periacetabular osteotomy (PAO) has been shown to improve long term outcomes and is considered the gold standard in the setting of symptomatic hip dysplasia in patients younger than 35 years of age. Post-operative rehabilitation following a PAO plays an important role in helping patients return to their prior level of function and reduce the impact of strength deficits that may persist. Currently, there is a paucity of research supporting post-operative rehabilitation guidelines. The purpose of this study is to present expert-driven rehabilitation guidelines to reduce practice variation following a PAO. Methods: A panel of 16 physiotherapists from across the United States and Canada who were identified as experts in PAO rehabilitation by high-volume hip preservation surgeons participated in this Delphi study. Panelists were presented with 11 questions pertaining to rehabilitation guidelines following a PAO. Three iterative survey rounds were presented to the panelists based on responses to these questions. This three-step Delphi method was utilized to establish consensus on post-operative rehabilitation guidelines following a PAO. Results: Total (100%) participation was achieved for all three survey rounds. Consensus (>75%) was reached for 11/11 questions pertaining to the following areas: 1) weight-bearing and range of motion (ROM) precautions, 2) therapeutic exercise prescription including neuromuscular control, cardiovascular exercise, and flexibility, and 3) objective measures for return to straight line running and return to full participation in sports. Conclusion: This Delphi study established expert-driven rehabilitation guidelines for use following a PAO. The standardization of rehabilitative care following PAO is essential for achieving optimal outcomes despite other factors such as geographical location and socioeconomic status. Further research on patient-reported outcomes is necessary to confirm successful rehabilitation following the guidelines outlined in this study.

Hip kinematics in healthy adults during gait and squatting: Sex differences and asymmetry revealed through dynamic biplane radiography.

There is a lack of data unaffected by soft tissue artifact describing bilateral symmetry and sex differences in hip kinematics in asymptomatic individuals during activities of daily living. This study aimed to identify sex-based differences and to quantify bilateral symmetry in continuous hip kinematics during walking and bodyweight squatting using biplane radiography. Twenty-four asymptomatic young adults (13 women, 11 men; age: 21.9 ± 2.2 years) performed treadmill walking and squatting while synchronized biplane radiographs of the hip were collected at 50 frames/s. Pelvis and proximal femur bone tissue were segmented from CT images and reconstructed into subject-specific 3D bone models. Femoroacetabular kinematics were determined using a validated volumetric model-based tracking technique that matched digitally reconstructed radiographs generated from the CT-based bone models to the biplane radiographs. Symmetry was calculated as the average absolute side-to-side difference (SSD) in kinematic waveforms for each participant. Sex-based and phase-based (eccentric vs. concentric squatting) kinematic variations were assessed using linear mixed model analysis. Women were 0.2 mm more anteriorly translated and 0.1 mm more inferiorly translated than men across the gait cycle (both p < 0.04), but no sex-based or phase-based kinematic differences during squatting were identified. The maximum SSD across all movements was up to 18.6° (internal-external rotation) and 1.0 mm (superior-inferior translation), respectively. Asymmetry in internal rotation, superior translation, and medial translation was greater during squatting than during walking (all p < 0.002). This study provides a reference dataset of healthy young adults for evaluating hip kinematics and symmetry in symptomatic cohorts or in individuals undergoing surgery or rehabilitation.

A systematic approach to CT evaluation of non-arthritic hip pain.

Bone morphology has been increasingly recognized as a significant variable in the evaluation of non-arthritic hip pain in young adults. Increased availability and use of multidetector CT in this patient population has contributed to better characterization of the osseous structures compared to traditional radiographs. Femoral and acetabular version, sites of impingement, acetabular coverage, femoral head-neck morphology, and other structural abnormalities are increasingly identified with the use of CT scan. In this review, a standard CT imaging technique and protocol is discussed, along with a systematic approach for evaluating pelvic CT imaging in patients with non-arthritic hip pain.

Does Femoral Head Translation Vary by Sex and Side in Asymptomatic Hips During a Weightbearing Apprehension Test?

BACKGROUND: Hip microinstability is an increasingly recognized source of pain and dysfunction but has no agreed upon diagnostic criteria and the pathophysiology remains unclear. It has been suggested that pain associated with microinstability is caused by excess translation of the femoral head. Recent research indicates that single-plane femoral head translation can be reliably measured using dynamic ultrasonography during a supine clinical examination; however, the overall accuracy of that technique has not been established, and the range of femoral head translation values that are found in individuals with no history of surgery or symptomatic pathology is unknown. QUESTIONS/PURPOSES: (1) How much femoral head translation is present in native, uninjured hips during a weightbearing apprehension position for females and males? (2) How large is the side-to-side difference in hip translation and rotation within the same individual in females and males with no history of surgery or pain during the weightbearing apprehension position? (3) What differences exist in femoral head translation and rotation when comparing females to males? METHODS: Twenty-two young adults (11 males, 11 females; mean age 22 ± 2 years; BMI 22 ± 5 kg/m2) with no history of hip pain, no known hip injury, and who never had hip surgery participated in this study. High-resolution CT images of the femur and pelvis were acquired for each participant, and the bone tissue was segmented from the CT volume. Synchronized biplane radiographs were collected during a neutral standing trial and during a static weightbearing apprehension position in which the participant extended, externally rotated, and abducted at their back hip while standing with their feet split in the AP direction. A validated volumetric model-based tracking technique was used to match the patient-specific bone models to the biplane radiographs with an accuracy of 0.3 mm for translation and 0.8° for rotation. Translation of the center of the femoral head relative to the center of the acetabulum and rotation of the femur relative to the pelvis from neutral to the weightbearing apprehension position were calculated. Sex-based differences in hip kinematics were assessed by bivariate linear regression. RESULTS: The median (range) translation during the weightbearing apprehension position in females was 0.9 mm (0.2 to 2.7 mm), which was less than in the 1.3 mm (0.2 to 2.6 mm) translation found in males (median difference of 0.5 mm; p = 0.04). The median absolute side-to-side difference in translation during the pivot was 1.4 mm (0.1 to 3.8 mm) in females and 1.3 mm (0.1 to 4.4 mm) in males. CONCLUSION: These findings demonstrate that the femoral head translates the same under bodyweight loading as previously observed during supine exam, showing the inherent stability of the hip with no history of surgery or symptomatic pathology. This study also provides normal values for comparison with individuals who have suspected microinstability. Future directions for research include directly comparing biplane radiography to alternative imaging techniques, such as dynamic ultrasound, for identifying hip microinstability and identifying threshold values for symptomatic hip microinstability. LEVEL OF EVIDENCE: Level III, prognostic study.

The Impact of Operative Intervention in Pediatric Lyme Arthritis.

BACKGROUND: Lyme arthritis often presents as acute monoarticular arthritis challenging to distinguish from septic arthritis. Typical management for Lyme arthritis entails antibiotic therapy, while septic arthritis usually warrants operative debridement. During the period when Western Pennsylvania transitioned to a Lyme-endemic region, many children underwent operative intervention who were ultimately diagnosed with Lyme arthritis due to diagnostic ambiguity. We examined the impact of the operative intervention on pediatric Lyme arthritis outcomes. METHODS: We conducted a retrospective cohort study of patients admitted to a tertiary care children's hospital who were diagnosed with Lyme arthritis from 2008 to 2018 using chart review. Inclusion criteria were positive Lyme serology by Centers for Disease Control and Prevention (CDC) definition, clinical arthritis, and negative bacterial cultures. We recorded clinical presentation, laboratory data, details of hospitalization, costs, and outcomes after therapy to compare the impact of antibiotics alone (nonoperative group) versus antibiotics plus operative debridement (operative group). RESULTS: A total of 149 patients met the inclusion criteria. Overall, 47 (32%) patients underwent orthopaedic intervention. Operative management was associated with increased length (3.17 vs. 1.40 d) and cost ($27,850 vs. $10,716) of admission. The clinical resolution was documented in 57/58 patients (98%) in the nonoperative group and 41/42 patients (98%) in the operative group. The median duration to resolution was 21 days for both groups. CONCLUSIONS: Operative management of pediatric patients with Lyme arthritis is associated with increased resource utilization and costs while being similarly efficacious to nonoperative management. As the US Lyme epidemic expands, improved diagnosis and management of acute undifferentiated arthritis may prevent unneeded operative intervention. LEVEL OF EVIDENCE: Level III-retrospective cohort study.

Perspectives on the Gamification of an Interactive Health Technology for Postoperative Rehabilitation of Pediatric Anterior Cruciate Ligament Reconstruction: User-Centered Design Approach.

BACKGROUND: Pediatric and adolescent athletes are a large demographic undergoing anterior cruciate ligament reconstruction (ACL-R). Postoperative rehabilitation is critical, requiring patients to complete home exercise programs (HEPs). To address obstacles to HEP adherence, we developed an interactive health technology, interACTION (iA), to monitor knee-specific rehabilitation. iA is a web-based platform that incorporates wearable motion sensors and a mobile app that provides feedback and allows remote monitoring. The Wheel of Sukr is a gamification mechanism that includes numerous behavioral elements. OBJECTIVE: This study aims to use a user-centered design process to incorporate behavioral change strategies derived from self-management theory into iA using the Wheel of Sukr, with the aim of influencing patient behavior. METHODS: In total, 10 athletes aged 10-18 years with a history of ACL-R were included in this study. Patients were between 4 weeks and 1 year post-ACL-R. Participants underwent a 60-minute triphasic interview. Phase 1 focused on elements of gaming that led to high participation and information regarding surgery and recovery. In phase 2, participants were asked to think aloud and rank cards representing the components of the Wheel of Sukr in order of interest. In phase 3, the patients reviewed the current version of iA. Interviews were recorded, transcribed, and checked for accuracy. Qualitative content analysis segmented the data and tagged meaningful codes until descriptive redundancy was achieved; next, 2 coders independently coded the data set. These elements were categorized according to the Wheel of Sukr framework. The mean age of participants was 12.8 (SD 1.32) years, and 70% (7/10) were female. Most participants (7/10, 70%) reported attending sessions twice weekly. All patients were prescribed home exercises. Self-reported HEP compliance was 75%-100% in 40% (4/10), 50%-75% in 40% (4/10), and 25%-50% of prescribed exercises in 20% (2/10) of the participants. RESULTS: The participants responded positively to an app that could track home exercises. Desirable features included exercise demonstrations, motivational components, and convenience. The participants listed sports specificity, competition, notifications, reminders, rewards, and social aspects of gameplay as features to incorporate. In the Wheel of Sukr card sort exercise, motivation was ranked first; self-management, second; and growth, esteem, and fun tied for the third position. The recommended gameplay components closely followed the themes from the Wheel of Sukr card sort activity. CONCLUSIONS: The participants believe iA is a helpful addition to recovery and want the app to include exercise movement tracking and encouragement. Despite the small number of participants, thematic saturation was reached, suggesting the sample was sufficient to obtain a representative range of perspectives. Future work will implement motivation; self-management; and growth, confidence, and fun in the iA user experience. Young athlete ACL-R patients will complete typical clinical scenarios using increasingly developed prototypes of the gamified iA in a controlled setting.

Standardizing the Diagnostic Evaluation of Nonarthritic Hip Pain Through the Delphi Method.

BACKGROUND: Femoroacetabular impingement and acetabular dysplasia have gained increased attention as nonarthritic sources of pain and dysfunction in young, active patients. To date, no standardized approach to the diagnostic evaluation of nonarthritic hip pain has been identified, as previous work has focused on the diagnostic evaluation and management of patients with femoroacetabular impingement undergoing hip arthroscopy. PURPOSE: To explore the standard diagnostic evaluation practice of experts in the field of hip preservation surgery and combine their expertise through the Delphi method to form a standardized approach to the diagnostic evaluation of patients with nonarthritic hip pain. STUDY DESIGN: Consensus statement. METHODS: An expert panel made up of 18 orthopaedic surgeons with extensive experience in the treatment of nonarthritic hip disorders participated in this Delphi study. The Delphi panelists were presented with 4 clinical vignettes representing a spectrum of patients with nonarthritic hip pain. Three iterative survey rounds were presented to the panelists based on these clinical vignettes, and a 3-step classic Delphi method was used to establish consensus techniques in the diagnostic evaluation of nonarthritic hip pain. RESULTS: Total (100%) participation was gained, with all 18 experts completing all 3 Delphi survey rounds. Consensus (≥75% support) was achieved for some, if not all, vignettes for each of the following diagnostic domains: historical features, physical examination, radiographic sequences, radiographic interpretation, cross-sectional imaging, and ancillary diagnostics. CONCLUSION: In this Delphi study, we identified standardized diagnostic treatment approaches as derived from expert opinion for patients with nonarthritic hip pathomorphologies.

Towards Standardization in the Diagnostic Evaluation of ACL Injuries in Skeletally Immature Patients.

The purpose of this study was to establish consensus regarding a standardized approach to the diagnostic evaluation of ACL tears in pediatric/adolescent patients. Despite an abundance of literature evaluating management techniques, no standardized consensus exists regarding evaluation in these patients. A three-step classic Delphi technique was employed. The panel included 12 Orthopaedic Sports Medicine specialists from across the United States with training in pediatric and adult ACL injuries. Panelists were presented with four clinical vignettes. Consensus was established if ≥66% of respondents reached agreement. Across all four rounds of this study, 100% participation was achieved, and consensus was reached for a majority of diagnostic domains. For history, previous injuries, sports participation, and current symptoms were endorsed for all vignettes. The consensus radiographic sequences across all four vignettes included: standing AP, flexion (tunnel or notch view), lateral, long-leg alignment, and bone age (left hand) views. Radiographic interpretation responses met consensus with interpretations were split by gender. Cross-sectional imaging met consensus with 100% support for MRI. In this Delphi study, we identified a standardized diagnostic treatment approach derived from expert opinion applicable to all skeletally immature patients with ACL tears, which can serve as a framework for evaluation to aid clinical decision making.

Acetabular Coverage Decreases at the End of Skeletal Growth: A 3DCT Study of Healthy Hips.

BACKGROUND: Abnormalities in size and position of the acetabulum have been linked to both developmental dysplasia of the hip and femoroacetabular impingement. Owing to its 3-dimensional (3D) complexity, plain radiography and cross-sectional studies [computed tomography (CT) and magnetic resonance imaging] have limitations in their ability to capture the complexity of the acetabular 3D anatomy. The goal of the study was to use 3D computed tomography reconstructions to identify the acetabular lunate cartilage and measure its size at varying ages of development and between sexes. METHODS: Patients aged 10 to 18 years with asymptomatic hips and a CT pelvis for appendicitis were reviewed. Patients were stratified by sex and age: preadolescent (10 to 12), young adolescent (13 to 15), and old adolescent (16 to 18) in equal proportions. Materialise 3-matic was used to generate a 3D pelvic model, and the acetabular lunate cartilage surface area was calculated. The lunate cartilage was divided into anatomic segments: superior (11:00 to 1:00), anterior (1:00 to 4:00), and posterior (8:00 to 11:00). The femoral head surface area was calculated to control for patient size. Mixed effects models were generated predicting segment size where side was treated as a repeated measure. Absolute and relative (lunate cartilage to femoral head) models were generated. RESULTS: Sixty-two patients (124 hips) were included. Females showed a significant decrease in femoral head coverage as age increased overall and in the 3 subsegments. The majority of changes occurred between the preadolescent and young adolescent groups. Males did not show an overall change, but the superior and anterior anatomic subgroups showed a significant decrease in coverage between the young and old adolescent groups. Male lunate cartilages were absolutely, but not relatively, larger than females. No clinically significant side-to-side differences were noted. CONCLUSIONS: The relative femoral head coverage by the acetabular lunate cartilage reduced with increasing age, suggesting the growth of the femoral head outpaces the acetabular lunate cartilage's growth. This was more prominent in females. This study has important implications for expected acetabular coverage changes in the latter aspects of pediatric and adolescent development. LEVEL OF EVIDENCE: Level III-diagnostic study.

Tibial tubercle fractures in children and adolescents: a large retrospective case series.

To report patient characteristics, fracture types, treatment methods, early clinical outcomes and complications of children and adolescents treated for tibial tubercle fractures. Retrospective case series of patients 18 years old and younger treated for tibial tubercle fractures at a single institution from 1995 to 2015. Clinical and radiographic outcomes were reported at minimum six-month follow-up. In 228 patients, 236 tibial tubercle fractures were identified, of whom, 198 (87%) were males. Mean age and BMI was 14.3 years and 25.0, respectively. Pre-existing Osgood-Schlatter disease was identified in 31% cases and was most commonly associated with type I fractures (P < 0.001). Most fractures occurred while participating in athletics (86%). Initial treatment was surgical for 67% fractures. Type III fractures were most common (41%), followed by type I (29%). Type I fractures were most commonly treated nonoperatively (91%) and types II-V fractures were most commonly treated surgically (89%, P < 0.001). Compartment syndrome was identified in 4 (2%) patients, 3 of which had type IV fractures. Most patients returned to sports (88%). Tibial tubercle fractures are sports-related injuries and occur most commonly in adolescent males. They can be associated with pre-existing Osgood-Schlatter disease, a higher than average BMI, and a small but relevant risk of compartment syndrome. Following treatment, most patients return to sports participation.

Epiphyseal Translation as a Predictor of Avascular Necrosis in Unstable Slipped Capital Femoral Epiphysis.

BACKGROUND: Physeal instability has been shown to be associated with a higher risk of avascular necrosis (AVN) in patients with slipped capital femoral epiphysis (SCFE). The purpose of this study was to identify additional preoperative factors associated with AVN in patients with unstable SCFE. METHODS: Basic demographic information, chronicity of symptoms, and estimated duration of nonambulatory status were noted. Preoperative radiographs were used to measure the Southwick slip angle, slip severity by Wilson criteria, and epiphyseal translation. Translation was measured by 3 distinct radiographic parameters in the position demonstrating maximal displacement. Postoperative radiographs at the time of most recent follow-up were assessed for the presence of AVN. Translation measurements were tested for inter-rater reliability. Patients who developed AVN were compared with those that did not by Fisher exact test and Wilcoxon tests. Logistic regression assessed the effect of translation on the odds of developing AVN. Receiver operating characteristic curve was plotted to assess any threshold effect. RESULTS: Fifty-one patients (55 hips) out of 310 patients (16%) treated for SCFE were considered unstable. Seventeen hips' unstable SCFE (31%) showed radiographic evidence of AVN. Slip severity by Wilson grade (P=0.009) and epiphyseal translation by all measurements (P< 0.05) were statistically significantly greater among patients who developed AVN. Superior translation had the best inter-rater reliability (intraclass correlation coefficient=0.84). Average superior translation in hips that developed AVN was 17.2 mm compared with 12.9 mm in those that did not (P<0.02). Although the receiver operating characteristic curve did not demonstrate a threshold effect for AVN, it did effectively rule out AVN in cases with <1 cm of superior translation. Age, sex, laterality, chronicity of prodromal symptoms or inability to bear weight, Southwick slip angle, and method of treatment did not vary with the occurrence of AVN. CONCLUSIONS: Epiphyseal translation, either by Wilson Grade or measured directly, is associated with AVN in patients with an unstable SCFE. LEVEL OF EVIDENCE: Level II-development of diagnostic criteria.

A Portable System for Remote Rehabilitation Following a Total Knee Replacement: A Pilot Randomized Controlled Clinical Study.

Rehabilitation has been shown to improve functional outcomes following total knee replacement (TKR). However, its delivery and associated costs are highly variable. The authors have developed and previously validated the accuracy of a remote (wearable) rehabilitation monitoring platform (interACTION). The present study's objective was to assess the feasibility of utilizing interACTION for the remote management of rehabilitation after TKR and to determine a preliminary estimate of the effects of the interACTION system on the value of rehabilitation. Specifically, we tested post-operative outpatient rehabilitation supplemented with interACTION (n = 13) by comparing it to a standard post-operative outpatient rehabilitation program (n = 12) using a randomized design. Attrition rates were relatively low and not significantly different between groups, indicating that participants found both interventions acceptable. A small (not statistically significant) decrease in the number of physical therapy visits was observed in the interACTION Group, therefore no significant difference in total cost could be observed. All patients and physical therapists in the interACTION Group indicated that they would use the system again in the future. Therefore, the next steps are to address the concerns identified in this pilot study and to expand the platform to include behavioral change strategies prior to conducting a full-scale randomized controlled trial. Trial registration: ClinicalTrials.gov NCT02646761 "interACTION: A Portable Joint Function Monitoring and Training System for Remote Rehabilitation Following TKA" 6 January 2016.