Risk Factors for Suboptimal Outcome of FAI Surgery in the Adolescent Patient.

BACKGROUND: Surgical treatment for adolescent patients with femoroacetabular impingement (FAI) is increasing. The purpose of this study was to determine the clinical outcomes of FAI surgery in a multicenter cohort of adolescent patients and to identify predictors of suboptimal outcomes. METHODS: One hundred twenty-six adolescent hips (114 patients < 18 years of age) undergoing surgery for symptomatic FAI were studied from a larger multicenter cohort. The group included 74 (58.7%) female and 52 male hips (41.3%) with a mean age of 16.1 (range 11.3 to 17.8). Clinical outcomes included the modified Harris Hip Score (mHHS), Hip disability and Osteoarthritis Outcome Score (5 domains), and University of California Los Angeles activity score. Failure was defined as revision surgery or clinical failure (inability to reach minimally clinical important differences or patient acceptable symptoms state for the mHHS). Statistical analysis was used to identify factors significantly associated with failure. RESULTS: There was clinically important improvement in all patient-reported outcomes for the overall group, but an 18.3% failure rate. This included a revision rate of 8.7%. Females were significantly more likely than males to be classified as a failure (25.7 vs. 7.7%, P =0.01), in part because of lower preoperative mHHS (59.1 vs. 67.0, P < 0.001). Mild cam deformity (alpha angle <55 degrees) was present in 42.5% of female hips compared with 17.3% male hips. Higher alpha angles were inversely correlated with failure. Alpha angles >63 have a failure rate of 8.3%, between 55 and 63 degrees, 12.0% failure rate, and <55 degrees (mild cam) failure rate of 37.5%. Patients who participated in athletics had a 10.3% failure rate compared with nonathletes at 25.0% ( P =0.03, RR (relative risk) 2.4). CONCLUSIONS: Adolescent patients undergoing surgical treatment for FAI generally demonstrate significant improvement. However, female sex, mild cam deformities, and lack of sports participation are independently associated with higher failure rates. These factors should be considered in surgical decision-making and during patient counseling. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

The Otto Aufranc Award: Does Hip Arthroscopy at the Time of Periacetabular Osteotomy Improve the Clinical Outcome for the Treatment of Hip Dysplasia? A Multicenter Randomized Clinical Trial.

BACKGROUND: A periacetabular osteotomy (PAO) is often sufficient to treat the symptoms and improve quality of life for symptomatic hip dysplasia. However, acetabular cartilage and labral pathologies are very commonly present, and there is a lack of evidence examining the benefits of adjunct arthroscopy to treat these. The goal of this study was to compare the clinical outcome of patients undergoing PAO with and without arthroscopy, with the primary end point being the International Hip Outcome Tool-33 at 1 year. METHODS: In a multicenter study, 203 patients who had symptomatic hip dysplasia were randomized: 97 patients undergoing an isolated PAO (mean age 27 years [range, 16 to 44]; mean body mass index of 25.1 [range, 18.3 to 37.2]; 86% women) and 91 patients undergoing PAO who had an arthroscopy (mean age 27 years [range, 16 to 49]; mean body mass index of 25.1 [17.5 to 25.1]; 90% women). RESULTS: At a mean follow-up of 2.3 years (range, 1 to 5), all patients exhibited improvements in their functional score, with no significant differences between PAO plus arthroscopy versus PAO alone at 12 months postsurgery on all scores: preoperative International Hip Outcome Tool-33 score of 31.2 (standard deviation [SD] 16.0) versus 36.4 (SD 15.9), and 12 months postoperative score of 72.4 (SD 23.4) versus 73.7 (SD 22.6). The preoperative Hip disability and Osteoarthritis Outcome pain score was 60.3 (SD 19.6) versus 66.1 (SD 20.0) and 12 months postoperative 88.2 (SD 15.8) versus 88.4 (SD 18.3). The mean preoperative physical health Patient-Reported Outcomes Measurement Information System score was 42.5 (SD 8.0) versus 44.2 (SD 8.8) and 12 months postoperative 48.7 (SD 8.5) versus 52.0 (SD 10.6). There were 4 patients with PAO without arthroscopy who required an arthroscopy later to resolve persistent symptoms, and 1 patient from the PAO plus arthroscopy group required an additional arthroscopy. CONCLUSIONS: This randomized controlled trial has failed to show any significant clinical benefit in performing hip arthroscopy at the time of the PAO at 1-year follow-up. Longer follow-up will be required to determine if hip arthroscopy provides added value to a PAO for symptomatic hip dysplasia.

Changes in Fracture Shortening Occur in the First 2 Weeks Following Completely Displaced Adolescent Clavicle Fractures.

BACKGROUND: Shortening of midshaft clavicle fractures has been described as a critical fracture characteristic to guide treatment. The degree to which shortening may change in the initial weeks following injury has not been well studied. The purpose of this study was to evaluate the change in shortening of adolescent clavicle fractures in the first 2 weeks following injury. METHODS: This was a multicenter study of prospectively collected data, which was acquired as a part of a cohort study of adolescent clavicle fractures. A consecutive series of patients 10 to 18 years of age with completely displaced diaphyseal clavicle fractures with baseline radiographs 0 to 6 days from the date of injury, as well as 7 to 21 days from the date of injury, were included. Measurements of end-to-end (EES) and cortex-to-corresponding-cortex (CCS) shortening were performed. RESULTS: A total of 142 patients were included. Baseline radiographs were obtained at a mean of 1.0 day following injury with mean EES of 22.3 mm, and 69% of patients demonstrating >20 mm of shortening. Follow-up radiographs obtained at a mean of 13.8 days postinjury demonstrated a mean absolute change in EES of 5.4 mm. Forty-one percentage of patients had >5 mm of change in EES. When analyzing changes in shortening relative to the specific threshold of 20 mm, 18 patients (41%) with <20 mm EES increased to ≥20 mm EES, and 19 patients (19%) with ≥20 mm EES decreased to <20 mm EES at 2-week follow-up. CONCLUSIONS: Clinically significant changes in fracture shortening occurred in 41% of adolescents with completely displaced clavicle fractures in the first 2 weeks after injury. In 26% of patients, this resulted in a change from above or below the commonly used shortening threshold of 20 mm, potentially altering the treatment plan by many providers. There is no evidence to suggest that adolescent clavicle fracture shortening affects outcomes, and as such, the authors do not advocate for the use of this parameter to guide treatment. However, among physicians who continue to use this parameter to guide treatment, this study supports that repeat radiographic assessment 2 weeks postinjury may be a better measure of the true shortening of this common adolescent injury. LEVEL OF EVIDENCE: Level IV-case series.

Predicting Rates of Angular Correction After Hemiepiphysiodesis in Patients With X-Linked Hypophosphatemic Rickets.

PURPOSE: Patients with X-linked hypophosphatemic rickets (XLH) often develop coronal plane knee deformities despite medical treatment. Hemiepiphysiodesis is an effective way to correct coronal plane knee deformities in skeletally immature patients, but a full understanding of the rate of angular correction after hemiepiphysiodesis in XLH patients, compared with idiopathic cases is lacking. METHODS: We retrospectively reviewed charts of 24 XLH patients and 37 control patients without metabolic bone disease who underwent hemiepiphysiodesis. All patients were treated with standard-of-care medical therapy (SOC=active vitamin D and phosphate salt supplementation) in our clinical research center and had a minimum of 2-year follow-up after hemiepiphysiodesis. Demographic data as well as complications, repeat procedures, or recurrence/overcorrection were recorded. Standing lower extremity radiographs were evaluated before the surgical intervention and at subsequent hardware removal or skeletal maturity, whichever came first. Mean axis deviation, knee zone, mechanical lateral distal femoral angle (mLDFA), and medial proximal tibial angle were measured on each radiograph. The rate of angular correction was calculated as the change in mLDFA and medial proximal tibial angle over the duration of treatment. RESULTS: The magnitude of the initial deformity of the distal femur was greater in XLH patients as compared with control for varus (XLH mLDFA 97.7 +/- 4.9 vs. Control mLDFA 92.0 +/- 2.0 degrees) and valgus (XLH mLDFA 78.7 +/- 6.2 vs. Controls mLDFA 83.6 +/- 3.2 degrees). The rate of correction was dependent on age. When correcting for age, XLH patients corrected femoral deformity at a 15% to 36% slower rate than control patients for the mLDFA (>3 y growth remaining XLH 0.71 +/- 0.46 vs. control 0.84 +/- 0.27 degrees/month, <3 y growth remaining XLH 0.37 +/- 0.33 vs. control 0.58 +/- 0.41 degrees/month). No significant differences were seen in the rate of proximal tibia correction. XLH patients were less likely to end treatment in zone 1 (55.0% XLH vs. 77.8% control). XLH patients had longer treatment times than controls (19.5 +/- 10.7 vs. 12.6 +/- 7.0 mu, P value <0.001), a higher average number of secondary procedures than controls (1.33 +/- 1.44 vs. 0.62 +/- 0.92 number of procedures), a higher rate of overcorrection than controls (29.2% vs. 5.4%), and a higher rate of subsequent corrective osteotomy than controls (37.5% vs. 8.1%). There was no significant difference in the rate of complications between groups (8.3% vs. 5.4%). CONCLUSIONS: Patients with XLH undergoing hemiepiphysiodesis have a 15% to 36% slower rate of femoral deformity correction that results in longer treatment times, a higher likelihood to undergo more secondary procedures, and a lower likelihood to reach neutral mechanical alignment. SIGNIFICANCE: This study provides important information to guide the timing and treatment of patients with XLH and coronal plane knee deformities. In addition, results from this study can be educational for families and patients with respect to anticipated treatment times, success rates of the procedure, complication rate, and likelihood of needing repeat procedures.

Editorial Commentary: Symptomatic Femoroacetabular Impingement Resulting in Severe Hip Osteoarthritis: Predicting the "Perfect Storm".

In the last 20 years, femoroacetabular impingement (FAI) has transitioned from a disputed disease to a well-established cause of hip pain and osteoarthritis (OA). Cam-type FAI, specifically, is supported by several studies as a risk factor for osteoarthritis. Elevated α-angle is also a mild-to-moderate risk factor for OA in patients with FAI. Other risk factors include age, sex, body mass index, activity level, range of motion, 3D acetabular and femoral morphology, and femoral version. To further complicate the picture, when we look at the contralateral hip (where many of these factors are held constant), only about 25% of patients appear to report symptoms over a 5-year period after their presentation with ipsilateral FAI. In the setting of an FAI bony morphology, some individuals end up with early symptoms and cartilage damage at a young age, while others go their whole life without hip pain. We still have a long way to go to understand the multitude of factors that drive the "perfect storm" that leads to symptomatic FAI and eventual OA in certain patients.

Rates of Infection After ACL Reconstruction in Pediatric and Adolescent Patients: A MarketScan Database Study of 44,501 Patients.

BACKGROUND: Numerous studies have demonstrated an increase in the number of anterior cruciate ligament (ACL) reconstruction procedures performed in pediatric patients. Despite this, most knowledge of surgical site infection rates after these procedures are based on adult studies and data is currently limited in pediatric patients. The purpose of this study was to describe and analyze the rates of infection after ACL reconstruction among pediatric patients and adolescent patients (compared with young adult patients) utilizing the MarketScan Commercial Claims and Encounters Database. METHODS: The Truven Health Analytics MarketScan Commercial Claims and Encounters database was assessed to access health care utilization data for privately insured individuals aged 5 to 30 years old. ACL reconstruction records performed between 2006 and 2018 were identified using Current Procedures Terminology (CPT) codes. International Classification of Diseases Ninth Revision (ICD-9), Tenth (ICD-10) codes and CPT codes were used to identify patients requiring treatment for infection. All patients had at least 180 days of insurance coverage after intervention. RESULTS: A total of 44,501 individuals aged below 18 years old and 63,495 individuals aged 18 to 30 years old that underwent arthroscopic ACL reconstruction were identified. There were no differences in infection rates between those below 18 years old (0.52%) and those above 18 years old (0.46%, P=0.227). However, among patients below 18 years old, patients below 15 years old had a significantly lower rate of infection at 0.37% compared with adolescents (15 to 17 y old) at 0.55% (P=0.039). Among young adults, males had higher rates of infection than females (0.52% vs. 0.37%), while no difference was observed in the pediatric and adolescent population (0.58% vs. 0.47%, P=0.109). CONCLUSION: Utilizing an insurance database, this study demonstrated that rates of infection after ACL Reconstruction in a pediatric/adolescent population are low (0.52%) and similar to rates in young adults. Infection rates after ACLR reconstruction appear to be slightly lower in patients under 15 years of age (0.37%). LEVEL OF EVIDENCE: Level III-Retrospective comparative study.

PROMIS Utilization in Pediatric Orthopaedics: A Scoping Review.

BACKGROUND: The lack of a common patient-reported outcome metric used among the orthopaedic population is a problem that has been previously identified by the American Academy of Orthopaedic Surgeons. The Patient-Reported Outcomes Measurement Information System (PROMIS) was developed by the National Institute of Health with the goal of creating a precise and efficient measurement tool for patient-reported symptoms, functioning, and health-related quality of life to be used in clinical research. A study summarizing its use in the pediatric orthopaedic population has not been previously performed. METHODS: We performed a literature search of Ovid Medline, Embase, Scopus, and the Cochrane Central Register of Controlled Trials from 2010 to August 2021. There were 1961 unique citations included after the removal of 1756 duplicates. After initial screening, 183 studies were screened under full-text review leaving a final number of 51 studies included in this scoping review. RESULTS: Pediatric PROMIS studies were grouped by body part or sub-speciality: "Hand and Upper Extremity" (25.5%, n=13), "Sports" (23.5%, n=12), "Spine" (13.7%, n=7), "Trauma" (13.7%, n=7), "General Pediatric Orthopaedics" (11.8%, n=6), "Lower Extremity" (9.8%, n=5), and "Orthopaedic Oncology" (2%, n=1). An increase in studies utilizing PROMIS was seen throughout the study period with only 3 studies published from 2013 to 2016 to 39 in 2020 and 2021 alone. The 3 most frequently used pediatric PROMIS domains were Pain Interference (76.5%, n=39/51), Mobility (60.8%, n=31/51), and Upper Extremity (54.9%, n=28/51). 64.3% (n=9/14) of the included studies which reported on the floor effects of Pain Interference exhibited a significant floor effect. In all, 77.8% (n=7/9) of the included studies which reported on ceiling effects of Upper Extremity exhibited a significant ceiling effect. CONCLUSION: The use of PROMIS increased significantly since the first publication in 2013 suggesting orthopaedic providers have increasingly utilized PROMIS in their day-to-day practice as an outcome measure. Ceiling and floor effects were prominent in several of the included domains (Pain Interference and Upper Extremity). Overall, PROMIS measures are efficient, reliable, and effective to use. LEVEL OF EVIDENCE: IV.

Orthopaedic Surgery Pediatric Sports Medicine: Characterizing Practice Patterns and Subspecialization.

BACKGROUND: Pediatric sports medicine is a new and rapidly growing subspecialty within orthopaedic surgery. However, there is very limited literature on the practice of pediatric sports medicine in North America. Therefore, the purpose of this study was to evaluate and describe the current practice patterns of orthopaedic surgeons specializing in pediatric sports medicine. METHODS: An online survey was distributed to orthopaedic surgeons specializing in pediatric sports medicine through the Pediatric Research in Sports Medicine Society. The purpose of the survey was to characterize (1) surgeon demographics, (2) the breakdown of different joint specialization, and (3) the specific procedures for joints that the surgeons specialize in. RESULTS: Responses from 55 orthopaedic surgeons were collected and analyzed. Most respondents considered pediatric sports medicine as the primary focus of their practice (89.1%, n=49/55). The number of fellowships completed was almost evenly split between either a single fellowship (52.7%, n=29/55) or 2 or more (47.3%, n=26/55). The most common combination of fellowships was pediatric orthopaedics and adult sports medicine (32.7%, n=18/55). Most survey respondents had been in practice for <10 years (69.0%, n=38/55) and were affiliated with an academic center (61.8%, n=34/55). On average, 77.5% of the patients treated were <18 years old. The knee joint was the most specialized joint, with 98.2% (n=54/55) respondents reporting that the knee joint constituted ≥25% of their practice. The knee joint constituted a mean of 52.1% of the respondents' overall practice, followed by the shoulder (15.2%), hip (13.9%), ankle (7.5%), elbow (7.1%), and wrist (4.2%). CONCLUSIONS: Pediatric sports medicine practices are variable and have distinct practice patterns in pediatric, orthopaedic, and adult sports practices. In the current study, most surgeons are less than 10 years into practice, affiliated with academic centers, and have typically completed either 1 or 2 fellowships after residency. Surgeons were most commonly specialized in the knee joint and cared for patients <18 years old. LEVEL OF EVIDENCE: Level of evidence IV.

Characterizing the Residual SCFE Deformity: Utility of the 45-degree Dunn View.

BACKGROUND: After treatment with in situ stabilization, slipped capital femoral epiphysis (SCFE) patients have variable degrees of deformity that can contribute to femoroacetabular impingement (FAI). To evaluate the severity of residual deformity most physicians currently use biplanar radiographs of an anteroposterior pelvis which profiles the lateral head-neck deformity and a frog lateral view which profiles the anterior head-neck deformity. However, the assessment of FAI morphology commonly relies on the 45-degree Dunn view to profile the anterolateral head-neck junction where FAI deformity is maximal. Therefore, the purpose of this study was to compare the magnitude of residual SCFE deformity detected on the frog lateral radiograph to the 45-degree Dunn radiograph. METHODS: A retrospective review of radiographic images of 50 hips (47 patients) diagnosed with SCFE at a single academic institution from 2014 to 2018 was performed. The group included 25 hips evaluated postoperatively after fixation (Group 1) and 25 hips presenting with residual symptomatic SCFE deformity after previous pinning (Group 2). The alpha angle was assessed on both the 45-degree Dunn and frog lateral views for comparison. The modified Southwick slip angle was assessed on the frog lateral view only as a measure of SCFE severity. RESULTS: The Dunn view showed the maximal residual SCFE deformity as measured by the alpha angle in 88% (44/50) of cases. Overall, the mean alpha angle (70.7 degree vs. 60.1 degree, P <0.001) was significantly larger on the Dunn view as compared with frog lateral. Subgroup analysis showed a larger alpha angle on Dunn view compared with frog lateral in both immediate postoperative and residual SCFE deformities as well: Group 1 (69.5 degree vs. 60.9 degree, P <0.001) and Group 2 (71.9 degree vs. 59.3 degree, P <0.001). CONCLUSION: In patients with SCFE, the maximal residual deformity of the proximal femur can typically be seen on the 45-degree Dunn view, rather than on the frog lateral view. Our findings suggest the 45-degree Dunn view may be beneficial part of the postoperative assessment of SCFEs to quantify the true maximal deformity present. LEVEL OF EVIDENCE: Level IV.

Prominent Anterior Inferior Iliac Spine Morphologies Are Common in Patients with Acetabular Dysplasia Undergoing Periacetabular Osteotomy.

BACKGROUND: The anterior inferior iliac spine (AIIS) prominence is increasingly recognized in the setting of femoroacetabular impingement (FAI). The AIIS prominence may contribute to decreased hip flexion after acetabular reorientation in patients with acetabular dysplasia. AIIS morphologies have been characterized in numerous populations including asymptomatic, FAI, and athletic populations, but the morphology of the AIIS in patients with symptomatic acetabular dysplasia undergoing periacetabular osteotomy (PAO) has not been studied. In acetabular dysplasia, deficiency of the anterosuperior acetabular rim is commonly present and may result in the AIIS being positioned closer to the acetabular rim. Understanding morphological variation of the AIIS in patients with symptomatic dysplasia, and its relationship to dysplasia subtype and severity may aid preoperative planning, surgical technique, and evaluation of postoperative issues after PAO. QUESTIONS/PURPOSES: In this study, we sought to determine: (1) the variability of AIIS morphology types in hips with symptomatic acetabular dysplasia and (2) whether the differences in the proportion of AIIS morphologies are present between dysplasia pattern and severity subtypes. METHODS: Using our hip preservation database, we identified 153 hips (148 patients) who underwent PAO from October 2013 to July 2015. Inclusion criteria for the current study were (lateral center-edge angle [LCEA] < 20°), Tönnis Grade of 0 or 1 on plain AP radiographs of the pelvis, preoperative low-dose CT scan, and no prior surgery, trauma, neuromuscular, ischemic necrosis, or Perthes-like deformity. A total of 50 patients (50 hips) with symptomatic acetabular dysplasia undergoing evaluation for surgical planning of PAO remained for retrospective evaluation; we used these patients' low-dose CT scans for analysis. The median (range) age of patients in the study was 24 years (13 to 49). Ninety percent (45 of 50) of the hips were in female patients, whereas 10% (5 of 50) were in male patients. The morphology of the AIIS was classified on three-dimensional CT reconstructions according to a previously published classification to define the relationship between the AIIS and the acetabular rim. The morphology of the AIIS was classified as Type I (AIIS well proximal to acetabular rim), Type II (AIIS extending to level of acetabular rim), or Type III (AIIS extending distal to acetabular rim). Acetabular dysplasia subtype was characterized according to a prior protocol as either predominantly an anterosuperior acetabular deficiency, a posterosuperior acetabular deficiency, or a global acetabular deficiency. Acetabular dysplasia severity was distinguished as mild (LCEA 15° to 20°) or moderate/severe (LCEA < 15°). To answer our first question, regarding the proportions of each AIIS morphology in the dysplasia population, we calculated proportions and 95% CI estimates. To answer our second question, regarding the proposition of AIIS type between subtypes of dysplasia type and severity, we used a chi-square test or Fisher's exact test to compare categorical variables. A p value of < 0.05 was considered significant. RESULTS: Seventy-two percent (36 of 50; 95% CI 58% to 83%) of patients had a Type II or III AIIS morphology. Type I AIIS morphology was found in 28% of patients (14 of 50; 95% CI 18% to 42%), Type II AIIS morphology in 62% (31 of 50; 95% CI 48% to 74%), and Type III AIIS/morphology in 10% (5 of 50; 95% CI 4% to 21%). A Type I AIIS was seen in seven of 15 of patients with anterosuperior acetabular deficiency, three of 18 of patients with global deficiency, and four of 17 patients with posterosuperior deficiency (p = 0.08). There was no difference in the variability of AIIS morphologies between the different subtypes of acetabular dysplasia pattern and no difference in AIIS morphology variability between patients with mild versus moderate/severe dysplasia. CONCLUSIONS: The morphology of the AIIS in patients with acetabular dysplasia is commonly prominent, with 72% of hips having Type II or Type III morphologies. CLINICAL RELEVANCE: The AIIS is often prominent in patients with acetabular dysplasia undergoing PAO, regardless of dysplasia pattern or severity. Prominent AIIS morphologies may affect hip flexion ROM after acetabular reorientation. AIIS morphology is a variable that should be considered during preoperative planning for PAO. Future studies are needed to assess the clinical significance of a prominent AIIS on intraoperative findings and postoperative status after PAO.

Medialization of the Hip's Center with Periacetabular Osteotomy: Validation of Assessment with Plain Radiographs.

BACKGROUND: Periacetabular osteotomy (PAO) increases acetabular coverage of the femoral head and medializes the hip's center, restoring normal joint biomechanics. Past studies have reported data regarding the degree of medialization achieved by PAO, but measurement of medialization has never been validated through a comparison of imaging modalities or measurement techniques. The ilioischial line appears to be altered by PAO and may be better visualized at the level of the inferior one-third of the femoral head, thus, an alternative method of measuring medialization that begins at the inferior one-third of the femoral head may be beneficial. QUESTIONS/PURPOSES: (1) What is the true amount and variability of medialization of the hip's center that is achieved with PAO? (2) Which radiographic factors (such as lateral center-edge angle [LCEA] and acetabular inclination [AI]) correlate with the degree of medialization achieved? (3) Does measurement of medialization on plain radiographs at the center of the femoral head (traditional method) or inferior one-third of the femoral head (alternative method) better correlate with true medialization? (4) Are intraoperative fluoroscopy images different than postoperative radiographs for measuring hip medialization? METHODS: We performed a retrospective study using a previously established cohort of patients who underwent low-dose CT after PAO. Inclusion criteria for this study included PAO as indicated for symptomatic acetabular dysplasia, preoperative CT scan, and follow-up between 9 months and 5 years. A total of 333 patients who underwent PAO from February 2009 to July 2018 met these criteria. Additionally, only patients who were between 16 and 50 years old at the time of surgery were included. Exclusion criteria included prior ipsilateral surgery, femoroacetabular impingement (FAI), pregnancy, neuromuscular disorder, Perthes-like deformity, inadequate preoperative CT, and inability to participate. Thirty-nine hips in 39 patients were included in the final study group; 87% (34 of 39) were in female patients and 13% (5 of 39 hips) were in male patients. The median (range) age at the time of surgery was 27 years (16 to 49). Low-dose CT images were obtained preoperatively and at the time of enrollment postoperatively; we also obtained preoperative and postoperative radiographs and intraoperative fluoroscopic images. The LCEA and AI were assessed on plain radiographs. Hip medialization was assessed on all imaging modalities by an independent, blinded assessor. On plain radiographs, the traditional and alternative methods of measuring hip medialization were used. Subgroups of good and fair radiographs, which were determined by the amount of pelvic rotation that was visible, were used for subgroup analyses. To answer our first question, medialization of all hips was assessed via measurements made on three-dimensional (3-D) CT hip reconstruction models. For our second question, Pearson correlation coefficients, one-way ANOVA, and the Student t-test were calculated to assess the correlation between radiographic parameters (such as LCEA and AI) and the amount of medialization achieved. For our third question, statistical analyses were performed that included a linear regression analysis to determine the correlation between the two radiographic methods of measuring medialization and the true medialization on CT using Pearson correlation coefficients, as well as 95% confidence intervals and standard error of the estimate. For our fourth question, Pearson correlation coefficients were calculated to determine whether using intraoperative fluoroscopy to make medialization measurements differs from measurements made on radiographs. RESULTS: The true amount of medialization of the hip center achieved by PAO in our study as assessed by reference-standard CT measurements was 4 ± 3 mm; 46% (18 of 39 hips) were medialized 0 to 5 mm, 36% (14 hips) were medialized 5 to 10 mm, and 5% (2 hips) were medialized greater than 10 mm. Thirteen percent (5 hips) were lateralized (medialized < 0 mm). There were small differences in medialization between LCEA subgroups (6 ± 3 mm for an LCEA of ≤ 15°, 4 ± 4 mm for an LCEA between 15° and 20°, and 2 ± 3 mm for an LCEA of 20° to 25° [p = 0.04]). Hips with AI ≥ 15° (6 ± 3 mm) achieved greater amounts of medialization than did hips with AI of < 15° (2 ± 3 mm; p < 0.001). Measurement of medialization on plain radiographs at the center of the femoral head (traditional method) had a weaker correlation than using the inferior one-third of the femoral head (alternative method) when compared with CT scan measurements, which were used as the reference standard. The traditional method was not correlated across all radiographs or only good radiographs (r = 0.16 [95% CI -0.17 to 0.45]; p = 0.34 and r = 0.26 [95% CI -0.06 to 0.53]; p = 0.30), whereas the alternative method had strong and very strong correlations when assessed across all radiographs and only good radiographs, respectively (r = 0.71 [95% CI 0.51 to 0.84]; p < 0.001 and r = 0.80 [95% CI 0.64 to 0.89]; p < 0.001). Measurements of hip medialization made on intraoperative fluoroscopic images were not found to be different than measurements made on postoperative radiographs (r = 0.85; p < 0.001 across all hips and r = 0.90; p < 0.001 across only good radiographs). CONCLUSION: Using measurements made on preoperative and postoperative CT, the current study demonstrates a mean true medialization achieved by PAO of 4 mm but with substantial variability. The traditional method of measuring medialization at the center of the femoral head may not be accurate; the alternate method of measuring medialization at the lower one-third of the femoral head is a superior way of assessing the hip center's location. We suggest transitioning to using this alternative method to obtain the best clinical and research data, with the realization that both methods using plain radiography appear to underestimate the true amount of medialization achieved with PAO. Lastly, this study provides evidence that the hip center's location and medialization can be accurately assessed intraoperatively using fluoroscopy. LEVEL OF EVIDENCE: Level III, diagnostic study.

What Mid-term Patient-reported Outcome Measure Scores, Reoperations, and Complications Are Associated with Concurrent Hip Arthroscopy and Periacetabular Osteotomy to Treat Dysplasia with Associated Intraarticular Abnormalities?

BACKGROUND: Periacetabular osteotomy (PAO) is a well-accepted treatment for acetabular dysplasia, but treatment success is not uniform. Concurrent hip arthroscopy has been proposed for select patients to address intraarticular abnormalities. The patient-reported outcomes, complications, and reoperations for concurrent arthroscopy and PAO to treat acetabular dysplasia remain unclear. QUESTIONS/PURPOSES: (1) What are the functional outcome scores among select patients treated with PAO plus concurrent hip arthroscopy at mid-term follow-up? (2) What factors are associated with conversion to THA or persistent symptoms (modified Harris hip score ≤ 70 or WOMAC pain subscore ≥ 10)? (3) What proportion of patients underwent further hip preservation surgery at mid-term follow-up? (4) What are the complications associated with the procedure? METHODS: Between November 2005 and December 2012, 78 patients (81 hips) who presented with symptomatic acetabular dysplasia-defined as a lateral center-edge angle less than 20° with hip pain for more than 3 months that interfered with daily function-had undergone unsuccessful nonsurgical treatment, had associated intraarticular abnormalities on MRI, and underwent combined hip arthroscopy and PAO. Eleven patients did not have minimum 4-year follow-up and were excluded, leaving 67 patients (70 hips) who met our inclusion criteria and had a mean follow-up duration of 6.5 ± 1.6 years. We retrospectively evaluated patient-reported outcomes at final follow-up using the University of California Los Angeles (UCLA) activity score, the modified Harris Hip Score (mHHS), and the WOMAC pain subscore. Conversion to THA or persistent symptoms were considered clinical endpoints. Repeat surgical procedures were drawn from a prospectively maintained database, and major complications were graded according to the validated Clavien-Dindo classification (Grade III or IV). Student t-tests, chi-square tests, and Fisher exact tests identified the association of patient factors, radiographic measures, and surgical details with clinical endpoints. For patients who underwent bilateral procedures, only the first hip was included in our analyses. RESULTS: At final follow-up, the mean mHHS for all patients improved from a mean ± SD of 55 ± 19 points to 85 ± 17 points (p < 0.001), the UCLA activity score improved from 6.5 ± 2.7 points to 7.5 ± 2.2 points (p = 0.01), and the WOMAC pain score improved from 9.1 ± 4.3 points to 3.2 ± 3.9 points (p < 0.001). Three percent (2 of 67) of patients underwent subsequent THA, while 21% (15 of 70) of hips were persistently symptomatic, defined as mHHS less than or equal to 70 or WOMAC pain subscore greater than or equal to 10. Univariate analyses indicated that no patient demographics, preoperative or postoperative radiographic metrics, or intraoperative findings or procedures were associated with subsequent THA or symptomatic hips. Worse baseline mHHS and WOMAC pain scores were associated with subsequent THA or symptomatic hips. Seven percent (5 of 67) of patients underwent repeat hip preservation surgery for recurrent symptoms, and 4% (3 of 67) of patients had major complications (Clavien-Dindo Grade III or IV). CONCLUSION: This study demonstrated that concurrent hip arthroscopy and PAO to treat symptomatic acetabular dysplasia (with intraarticular abnormalities) has good clinical outcomes at mid-term follow-up in many patients; however, persistent symptoms or conversion to THA affected almost a quarter of the sample. We noted an acceptable complication profile. Further study is needed to directly compare this approach to more traditional techniques that do not involve arthroscopy. We do not use isolated hip arthroscopy to treat symptomatic acetabular dysplasia. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Changes in superior displacement, angulation, and shortening in the early phase of healing for completely displaced midshaft clavicle fractures in adolescents: results from a prospective, multicenter study.

BACKGROUND: Progressive displacement of diaphyseal clavicle fractures has been observed in adult patients, at times necessitating a change from nonoperative to operative treatment. Whether this occurs in adolescent patients has not been well investigated. The purpose of this study was to assess the rate and extent of progressive clavicle fracture displacement in adolescent patients following injury and during the early stages of healing. METHODS: This was a multicenter study evaluating prospective data that had previously been collected as part of a larger study evaluating the functional outcomes of adolescent clavicle fractures. A consecutive series of completely displaced diaphyseal clavicle fractures in patients aged 10-18 years treated at 1 of 3 tertiary-care pediatric trauma centers was included; all fractures underwent standardized imaging within 2 weeks of the date of injury and during the course of healing (5-20 weeks after injury). Measurements of clavicle shortening, superior displacement, and angulation were performed using validated techniques. Progressive displacement and/or interval improvement in fracture alignment, as well as the subsequent need for surgical intervention, was noted. Patient demographic and radiographic parameters were assessed as possible risk factors for interval displacement. RESULTS: One hundred patients met the inclusion criteria. Mean end-to-end shortening, cortex-to-cortex shortening, superior displacement, and angulation at the time of injury were 24 mm, 15 mm, 15 mm, and 7°, respectively. At a mean of 10 weeks after injury, the fracture alignment improved across all 4 measurements for the overall cohort, with mean improvements of 3.5 mm in end-to-end shortening, 3.3 mm in cortex-to-cortex shortening, 2.1 mm in superior displacement, and 2° in angulation. By use of a clinical threshold of a change in shortening or displacement of 10 mm or change in angulation of 10°, 26% of fractures improved, 4% worsened, and 70% remain unchanged. Patients with more severe fractures were more likely to have improved alignment than were patients with less displaced fractures (P < .001). No patient underwent surgical intervention for progressive displacement. CONCLUSION: Significant early improvements in fracture alignment were observed in a substantial percentage of adolescent patients with completely displaced clavicle fractures. Among the most severely displaced fractures, shortening improved approximately 6 mm and angulation improved approximately 9°. In 4% of cases, increased displacement was observed, but this tended to be mild, and in no cases did it prompt surgical intervention. This finding indicates that the true final deformity after an adolescent clavicle fracture is commonly less than that present at the time of injury.

Utility of the Merchant View Radiograph for Assessment of Tibial Tubercle-Trochlear Groove Distance: A Comparison to MRI in Pediatric and Adolescent Patients.

BACKGROUND: Plain radiographic evaluation remains the standard initial assessment of patellar instability, while 3-dimensional imaging is obtained in some patients. Merchant radiographs can demonstrate the tibial tubercle relative to the trochlear groove (TT-TG), but the determination of the TT-TG from these radiographs has been abandoned since its original description. The purpose of this study is to evaluate the utility of the TT-TG measured on Merchant radiographs for the assessment of patellar instability. METHODS: A prospective cohort study was performed of pediatric and adolescent patients aged 10 to 18 who underwent standardized Merchant radiographs, including a total of 98 knees (in 57 patients). Merchant TT-TG was measured as the distance between the center of the trochlear groove and the tibial tubercle, with both lines perpendicular to the anterior femoral condylar axis. In Part 1, the Merchant TT-TG measured by the tibial tubercle radiographic appearance was compared with the measurement utilizing a radiographic marker. In Part 2, the Merchant TT-TG was compared with the magnetic resonance imaging (MRI) TT-TG distance using bivariate linear regression analysis. TT-TG measurements were compared in patients with and without patellar instability with receiver operating characteristic curve analysis. RESULTS: The tibial tubercle was identified on Merchant radiograph in 81.7% (67/82) of knees, and there was an excellent correlation (Pearson correlation coefficient=0.85) between the Merchant TT-TG and the measurement based on marker placement. Merchant TT-TG was on average 4.5 mm less than MRI TT-TG (12.8±4.4 vs. 8.4±7.7 mm, P<0.001) and was moderately correlated (Pearson correlation coefficient=0.58, P<0.01). TT-TG distance was increased in patients with patellar instability compared with those without patellar instability on the Merchant view (10.5±6.9 vs. 2.0±5.5 mm, P<0.001) and MRI (13.9±4.4 vs. 10.5±2.9 mm, P=0.012). Merchant TT-TG also demonstrated a higher area under the curve than MRI TT-TG (0.872 vs. 0.775) in differentiating patients with and without patellar instability. CONCLUSIONS: Standardized Merchant radiographs allow for reliable assessment of the Merchant TT-TG distance when the tibial tubercle is visualized and moderately correlate with MRI TT-TG (with Merchant TT-TG on average 4.5 mm less than MRI). LEVEL OF EVIDENCE: Level III.

Does the Patient-Reported Outcomes Measurement Information System Correlate to Legacy Scores in Measuring Physical Health in Young Total Hip Arthroplasty Patients?

BACKGROUND: The Patient-Reported Outcomes Measurement Information System (PROMIS) was developed by the National Institutes of Health to collect outcome data in rapid dynamic fashion on electronic platforms. The potential role of PROMIS in monitoring pain and function in young total hip arthroplasty (THA) patients has been under-investigated. The purpose of this study is to investigate correlation between PROMIS Physical Function (PF) and PROMIS Pain Interference (PI) and legacy scores with similar considerations. METHODS: We identified 298 hips who underwent primary THA over 40 months. Patients without preoperative PROMIS or legacy scores, or >50 years were excluded. Demographic data included age, gender, and body mass index. Outcome data included PF, PI, modified Harris Hip Score (mHHS), Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC) domains, and Short Form 12 components. Floor/ceiling effects were considered to be significant if ≥15% of patients responded with the lowest or highest possible score. Spearman correlation (R) was performed to investigate correlation between legacy scores and PROMIS domains. RESULTS: Mean age was 40 years, mean body mass index was 30.1 kg/m2, and 55% were female. None of the patient-reported outcome measures showed any floor/ceiling effects. PI showed moderate correlation to mHHS (R = -0.60), WOMAC Pain (R = -0.62), and WOMAC PF (R = -0.60). PF showed moderate correlation to mHHS (R = 0.66) and WOMAC PF (R = 0.55). Mean PF and PI scores differed significantly from the general population mean of 50 (36.7, 65.4, respectively; both P < .001). CONCLUSION: PROMIS is an attractive alternative to legacy scoring measures, showing moderate correlations between PROMIS physical domains and legacy PROMs of WOMAC and mHHS in young patients undergoing THA.

Patients With Symptomatic Sequelae of Slipped Capital Femoral Epiphysis Have Advanced Cartilage Wear at the Time of Surgical Intervention.

BACKGROUND: Slipped capital femoral epiphysis (SCFE) is a common hip problem in children. The resulting deformity can cause impingement similar to cam-type idiopathic femoroacetabular impingement (FAI). Although there are similarities between FAI and SCFE, deformity patterns, severity, and time of onset of symptoms varies, which may impact management. The purpose of this study was to describe patterns of articular cartilage damage in patients undergoing surgical hip dislocation for sequelae of SCFE in comparison to patients undergoing arthroscopic surgery for primary FAI. METHODS: Patients were identified who underwent surgical treatment for hip pain due to primary FAI (cam type) or sequelae of SCFE. Clinical data and radiographic measurements were recorded. Cartilage was assessed intraoperatively. Severity was classified using the modified Beck classification, while location was classified into 6 sectors. Statistical analysis was performed to test for differences in demographic and radiographic characteristics between the SCFE and FAI patients. χ2 or Fisher exact tests were used to evaluate trends in patterns of acetabular and femoral cartilage wear between SCFE and FAI groups. RESULTS: The SCFE group had 28 hips compared with 304 in the FAI group. SCFE patients were younger (19 vs. 32, P<0.001), had higher body mass index (30±5.9 vs. 24±4.8, P<0.001), and were more often male (61% vs. 27%, P<0.001). Deformity severity based on α-angle was higher in the SCFE group [AP 74 vs. 55 (P=0.001) and Dunn 72 vs. 58 (P<0.001)]. There were no significant differences with regards to lateral center edge angle, anterior center edge angle, or Tonnis angle. In both groups the most common locations for cartilage lesions in both groups were the anterior peripheral and superolateral peripheral regions with fewer but more widely distributed femoral head lesions. The SCFE group had higher rates of femoral head and superolateral central cartilage lesions compared with the FAI group. There was no statistical difference between high-grade femoral or acetabular cartilage lesions between groups. CONCLUSIONS: Patients with SCFE were younger at the time of surgery and presented with more severe deformity based on radiographic α-angle compared to patients with FAI. Our results suggest higher prevalence of femoral head lesions and more diffuse cartilage injury in patients with SCFE. This study can be used to support early surgical intervention in patients with symptomatic sequelae of SCFE due to risk of premature joint damage. LEVEL OF EVIDENCE: Level III-prognostic study.

Editorial Commentary: At the Intersection of Borderline Dysplasia and Femoroacetabular Impingement-Which Way Should We Turn?

Borderline acetabular dysplasia remains a controversial topic in hip preservation, with poor current comparative literature to guide accurate diagnosis and treatment decision making. Borderline dysplasia represents a "transitional acetabular coverage" pattern between more classic acetabular dysplasia and normal coverage. Traditionally, borderline dysplasia has been defined by a lateral center-edge angle between 20° and 25°, whereas more recently, some authors have used 18° to 25°. Treatment decisions between isolated hip arthroscopy (addressing labral tears, femoroacetabular impingement morphology, and capsular laxity) and periacetabular osteotomy (improving joint stability, often combined with arthroscopy) remain challenging because the fundamental mechanical diagnosis (instability vs femoroacetabular impingement) can be difficult to determine clinically. Obtaining an accurate diagnosis to direct surgical treatment relies on comprehensive assessment of additional bony anatomy features (including femoral version) and patient characteristics (including sex, soft-tissue laxity, and range of motion). Future research efforts in borderline dysplasia should better characterize the role of disease- and patient-specific factors that will inform accurate diagnoses, leading to the development of optimal treatment strategies in distinct patient subgroups through comparison of treatment outcomes.

Outcome Metrics in Pediatric Sports Medicine: Do PROMIS Computer-adaptive Testing Metrics Correlate With Pedi-IKDC?

BACKGROUND: A modified version of the International Knee Documentation Committee (IKDC), the Pedi-IKDC, is a validated patient-reported outcome measure in pediatric patients with knee pain. However, this questionnaire is lengthy and can fatigue patients, leading to inconsistent outcome collection. Thus, we sought to compare more easily attainable Patient-Reported Outcomes Measurement Information System (PROMIS) computer adaptive testing patient reported outcomes to the gold standard Pedi-IKDC. METHODS: We prospectively collected PROMIS scores and Pedi-IKDC scores in 100 new, consecutive patients presenting with knee pain to a pediatric sports medicine practice. Patients were excluded if they provided an incomplete Pedi-IKDC, had prior ipsilateral lower extremity surgery, or significant associated medical comorbidities. PROMIS domains including Mobility, Pain Interference, and Upper Extremity (control) were compared with the Pedi-IKDC with Pearson correlations. The number of questions in each metric was analyzed. Floor and ceiling effects of each test were also assessed. RESULTS: The average age of the study cohort was 14 years (range, 7 to 18 y) with 53% female and 47% male. 70% of patients completed the Pedi-IKDC questionnaire, compared with 100% with PROMIS tests. The average Pedi-IKDC score was 48.8±22.3 (range, 5.4 to 100). Mean scores for Mobility, Pain Interference, and Upper Extremity domains were 38.4±10.1, 53.5±10.3, and 49.7±8.7, respectively. All tests demonstrated similar and acceptable floor and ceiling effects (<15%). The length of the Pedi-IKDC (22 questions) was roughly double that of combined PROMIS Pain Interference and Mobility tests (11.9±2.3 questions). Pedi-IKDC scores correlated with tested PROMIS measures (Mobility/Pain Interference, r=0.42/-0.49). When 7 highly functional patients with significant pain symptoms were removed for a secondary analysis, Mobility and Pain correlations improved to 0.69 and -0.67, respectively. CONCLUSIONS: PROMIS Mobility and Pain scores demonstrate moderate correlations with the Pedi-IKDC, highlighting these tests are not capturing the same patient experiences. These correlations are weakened by a small group of painful yet highly functioning patients. The Pedi-IKDC was significantly longer and had a much lower completion rate than PROMIS tests, highlighting a need for a validated computer adaptive testing in evaluating pediatric patients with knee pain. LEVELS OF EVIDENCE: Level II.

Do Changes in Pelvic Rotation and Tilt Affect Measurement of the Anterior Center Edge Angle on False Profile Radiographs? A Cadaveric Study.

BACKGROUND: The false profile radiograph assesses acetabular coverage in prearthritic hip conditions. Precise rotation of this radiograph is difficult to obtain, so the clinician must interpret radiographs with nonstandard pelvic rotation or tilt, despite limited evidence of how this may affect the anterior center edge angle measurement. QUESTIONS/PURPOSES: (1) Does pelvic rotation alter the measurement of the anterior center edge angle on false profile views? (2) Does pelvic tilt alter the measurement of the anterior center edge angle on false profile views? (3) Is there an objective way to assess appropriate pelvic rotation for the false profile view? METHODS: Eight cadaver hips (four female, four male; one hip randomly selected per pelvis) were included in the study. Hips with degenerative changes, evidence of previous fracture or trauma, or previous surgical intervention were excluded. Specimens were between 68 to 92 years of age (median, 76 years). The specimens were fixed to a custom jig, and radiographs were taken at 5° intervals of rotation (45-85°) and 5° intervals of pelvic tilt (+10° to -10°). The primary outcome variable, anterior center edge angle, was measured for each rotation and tilt. RESULTS: Every degree increase in pelvic rotation toward a true lateral resulted in 0.18° increase in the anterior center edge angle (95% confidence interval [CI], 0.07-0.29; p = 0.002). For every degree increase in pelvic tilt, the anterior center edge angle increased 0.65° (95% CI, 0.5-0.8; p < 0.001). We verified that standard pelvic rotation of 65° for a false profile radiograph was present when the space between the femoral heads is 66% to 100% of the diameter of the femoral head being imaged. CONCLUSIONS: This study shows that the anterior center edge angle increases as pelvic tilt increases, with a 6° increase in anterior center edge angle for each 10° increase in pelvic tilt. Since the false profile radiograph is obtained standing, the patient should be counseled to avoid adopting a forced posture, ensuring the radiograph remains an accurate functional representation of the patient's anatomy. In contrast, pelvic rotation did not influence the anterior center edge angle by an important margin, and while we recommend that radiographs continue to be obtained with standardized pelvic rotation, aberrant pelvic rotation will likely not result in a clinically meaningful difference in anterior center edge angle measurements. In the future, studies to identify the specific regions of acetabular anatomy that constitute the radiographic measurement of the anterior center edge angle would enhance current understanding of the associated radiographic anatomy, and consequently improve the ability of the surgeon to treat the specific area of pathology. CLINICAL RELEVANCE: In practice, the clinician should pay close attention to pelvic tilt, as a 10° change in tilt may cause 6° of change in the anterior center edge angle. However, false profile radiographs obtained within ± 20° of the targeted 65° of rotation will result in less than 4° change in the anterior center edge angle.

Arthroscopic Surgery for Femoroacetabular Impingement in Skeletally Immature Athletes: Radiographic and Clinical Analysis.

PURPOSE: To evaluate radiographic and clinical outcomes after arthroscopic femoroacetabular impingement (FAI) correction in symptomatic adolescent athletes with open physes. METHODS: We retrospectively reviewed radiographic and clinical outcomes in patients treated with a non-physeal-sparing arthroscopic approach for symptomatic FAI with open physes and a minimum 1-year follow-up. Specific plain radiographic and computed tomography parameters were determined, and preoperative and postoperative outcomes were prospectively evaluated with modified Harris Hip Score (mHHS), 12-Item Veterans-Rand, and pain on a visual analog scale. RESULTS: Thirty-seven hips (28 patients; 75% male) with a mean age of 15.9 years (range, 12.8-18.3 years) had imaging studies consistent with open femoral neck and iliac crest physes. The ischial tuberosity and greater trochanteric physes were open in 95% and 54% of the hips, respectively. All patients participated in organized athletics, and 50% were in multiple sports year-round. Mean follow-up was 39.8 months post-arthroscopic FAI correction. There was a mean 27.7-point improvement in the mHHS (P < .001), a 4.8-point decrease in the visual analog scale for pain (P < .001), and a 15.2-point improvement in the 12-Item Veterans-Rand physical component (P < .001). Ninety-three percent of patients returned to their preinjury level of sports participation without limitations. Thirty (81.1%) patients demonstrated improvements in mHHS greater than the minimally clinically important difference (of mHHS 8 points). Two patients could not reach minimally clinically important difference because of a preoperative mHHS of > 92. There were no postoperative physeal growth arrests, growth disturbances, physeal instability, or avascular necrosis. CONCLUSIONS: A non-physeal-sparing arthroscopic approach for FAI in adolescents with open physes is safe and effective with no evidence of clinically relevant complication of growth arrest-related deformity or physeal instability in patients with a minimum of 1 year (mean, 39.8 months) of follow-up after surgery. Young, highly athletic adolescent patients with larger FAI deformities demonstrated greater outcomes improvement after arthroscopy. LEVEL OF EVIDENCE: Level IV, therapeutic case series.