Slipped Capital Femoral Epiphysis Patients Research Articles

3D printed patient-specific fixation plates for the treatment of slipped capital femoral epiphysis: Topology optimization vs. conventional design

Orthopedic plates are commonly used after osteotomies for temporary fixation of bones. Patient-specific plates have recently emerged as a promising fixation device. However, it is unclear how various strategies used for the design of such plates perform in comparison with each other. Here, we compare the biomechanical performance of 3D printed patient-specific bone plates designed using conventional computer-aided design (CAD) techniques with those designed with the help of topology optimization (TO) algorithms, focusing on cases involving slipped capital femoral epiphysis (SCFE). We established a biomechanical testing protocol to experimentally assess the performance of the designed plates while measuring the full-field strain using digital image correlation. We also created an experimentally validated finite element model to analyze the performance of the plates under physiologically relevant loading conditions. The results indicated that the TO construct exhibited higher ultimate load and biomechanical performance as compared to the CAD construct, suggesting that TO is a viable approach for the design of such patient-specific bone plates. The TO plate also distributed stress more evenly over the screws, likely resulting in more durable constructs and improved anatomical conformity while reducing the risk of screw and plate failure during cyclic loading. Although differences existed between finite element analysis and experimental testing, this study demonstrated that finite element modelling can be used as a reliable method for evaluating and optimizing plates for SCFE patients. In addition to enhancing the mechanical performance of patient-specific fixation plates, the utilization of TO in plate design may also improve the surgical outcome and decrease the recovery time by reducing the plate and incision sizes.

Hip Impingement of severe SCFE patients after in situ pinning causes decreased flexion and forced external rotation in flexion on 3D-CT.

In situ pinning is an accepted treatment for stable slipped capital femoral epiphysis. However, residual deformity of severe slipped capital femoral epiphysis can cause femoroacetabular impingement and forced external rotation. The aim of this study was to evaluate the (1) hip external rotation and internal rotation in flexion, (2) hip impingement location, and (3) impingement frequency in early flexion in severe slipped capital femoral epiphysis patients after in situ pinning using three-dimensional computed tomography. A retrospective Institutional Review Board-approved study evaluating 22 patients (26 hips) with severe slipped capital femoral epiphysis (slip angle > 60°) using postoperative three-dimensional computed tomography after in situ pinning was performed. Mean age at slipped capital femoral epiphysis diagnosis was 13 ± 2 years (58% male, four patients bilateral, 23% unstable, 85% chronic). Patients were compared to contralateral asymptomatic hips (15 hips) with unilateral slipped capital femoral epiphysis (control group). Pelvic three-dimensional computed tomography after in situ pinning was used to generate three-dimensional models. Specific software was used to determine range of motion and impingement location (equidistant method). And 22 hips (85%) underwent subsequent surgery. (1) Severe slipped capital femoral epiphysis patients had significantly (p < 0.001) decreased hip flexion (43 ± 40°) and internal rotation in 90° of flexion (-16 ± 21°, IRF-90°) compared to control group (122 ± 9° and 36 ± 11°). (2) Femoral impingement in maximal flexion was located anterior to anterior-superior (27% on 3 o'clock and 27% on 1 o'clock) of severe slipped capital femoral epiphysis patients and located anterior to anterior-inferior (38% on 3 o'clock and 35% on 4 o'clock) in IRF-90°. (3) However, 21 hips (81%) had flexion < 90° and 22 hips (85%) had < 10° of IRF-90° due to hip impingement and 21 hips (81%) had forced external rotation in 90° of flexion (< 0° of IRF-90°). After in situ pinning, patient-specific three-dimensional models showed restricted flexion and IRF-90° and forced external rotation in 90° of flexion due to early hip impingement and residual deformity in most of the severe slipped capital femoral epiphysis patients. This could help to plan subsequent hip preservation surgery, such as hip arthroscopy or femoral (derotation) osteotomy.

Surgeon Preference for Prophylactic Contralateral Fixation in Slipped Capital Femoral Epiphysis (SCFE) Patients: A Nationwide POSNA Survey Study.

It is estimated that 11% to 60% of unilateral slipped capital femoral epiphysis (SCFE) patients will develop contralateral pathology, usually within 18 months after the first event. Despite this, prophylactic fixation remains controversial, and there is significant variability in surgeon preferences. Thus, this study aimed to determine which factors predict surgeon preferences for prophylactic contralateral pinning in SCFE patients. We designed a survey for pediatric orthopedic surgeons to collect data on (1) surgeon and hospital characteristics, (2) individual preference for contralateral SCFE pinning in three disparate hypothetical scenarios, and (3) personal risk-aversion traits. The questionnaire was distributed across the United States by the POSNA Evidence-Based Orthopaedics Committee. All POSNA members were eligible to respond. We performed analyses to evaluate the role of patient risk factors in hypothetical surgical decision-making and to determine if surgical training, hospital characteristics, and geographic region influenced prophylactic pinning in a surgeon's real-life practice. A total of 126 POSNA members responded to the survey. In the last year, a median of 6.5 SCFE patients was seen per surgeon (1243 patients total). A median of 10% of those patients underwent prophylactic contralateral fixation. In multiple analyses, surgeons were influenced by body mass index, open triradiate cartilage, patient race, various endocrine abnormalities, and specific radiographic measurements when deciding to fix the contralateral side prophylactically. Moreover, in multivariate regression, more years in practice and a hospital size of 500+ beds predicted fewer prophylactic fixation procedures (all P <0.05). Surgeons practicing in the South Atlantic, New England, and Mountain regions of the United States estimated the highest rate of contralateral pinning. This study's findings suggest that multiple factors influence surgeons' decisions to prophylactically fix the contralateral side in SCFE patients. Surgical training, hospital characteristics, and geographical regions played a role in decision-making. N/A.

Poster 230: Improved Mid-Term Outcomes in Patients with Slipped Capital Femoral Epiphysis Related Femoroacetabular Impingement

Objectives: Slipped Capital Femoral Epiphysis (SCFE) of the hip is a potentially devastating injury that can occur in the developing hip. In-situ pinning is considered the current standard of care; however, even with prompt surgical fixation, there remains a risk of post-operative disability as a result of metaphyseal CAM deformity. This deformity can lead to subsequent femoroacetabular impingement resulting in labral and articular cartilage damage. Hip arthroscopy with labral repair and femoral osteochondroplasty has increasingly been utilized in these patients to correct the underlying deformity and improve hip mechanics. Short-term follow-up has demonstrated excellent outcomes in patients treated for SCFE with subsequent hip arthroscopy. Mid-term follow-up of these patients is sparse and limited to studies with small sample sizes. These studies primarily evaluate radiographic and physical examination findings rather than patient reported outcomes (PROs). The purpose of this study is to evaluate the mid-term clinical and functional patient reported outcomes of a large population of patients undergoing hip arthroscopy after SCFE in-situ fixation. Methods: SCFE patients that underwent subsequent hip arthroscopy for FAI were recruited for this prospective study. Patients were recruited from a single surgeon practice. Patients were sent a survey which included a single assessment numeric evaluation (SANE) prompt, subjective Likert-style questions assessing disability and satisfaction, and PROMIS Physical Function and iHOT-12 questionnaires. Patient charts were retrospectively reviewed for patient demographics, visual analogue scale (VAS) pain scores, and a modified Harris Hip Score (mHHS) from the post-pinning and pre-arthroscopy period. Descriptive statistics were utilized to assess overall patient outcomes. Results: In total, forty patients met inclusion criteria and thirty-three completed the mid-term follow up survey for an 82.5% response rate. Mean age at the time of arthroscopy was 18.5 years and mean duration of follow up was 5.85 years (Table 1). Patient subjective outcomes are reported in Table 2; notably, 33 of 33 patients (100%) were neutral, satisfied, or very satisfied with surgery. No patients reported that if given the choice again, they would choose to not have surgery. mHHS pre-operatively was 67.43, which was interpreted as poor functional status. Mean mid-term follow-up PROMIS-PF t- score was 51.19, indicating that the functional status of the included patients was at or above the average functional status of the overall population. Mean VAS pain score at rest was 4.78 pre- operatively and 1.94 at mid-term follow up. The average post-operative iHOT-12 score was 65.64 (Table 3) Conclusions: The results of the first mid-term, large-sample sized comprehensive follow-up of patients undergoing hip arthroscopy following surgical pinning of SCFE demonstrate that these patients have excellent functional and clinical outcomes. Subjectively, these patients report improved satisfaction with the operation and overall improvement in functional status. Objectively, the studied patients are performing at the level of the average non-surgical population as measured by PRO scoring systems. These findings suggest that the excellent outcomes reported at short-term follow-up persist at mid-term follow-up. This study demonstrates that hip arthroscopy for FAI in the setting of a prior in-situ pinning of a SCFE is a viable surgical treatment and reliably improves patient’s pain and physical function at mid- term follow up. [Table: see text][Table: see text][Table: see text]

Who Benefits From Allowing the Physis to Grow in Slipped Capital Femoral Epiphysis?

The globally acknowledged treatment for mild to moderate slipped capital femoral epiphysis (SCFE) is single screw in situ fixation, also used for prophylactic contralateral fixation. The Free-Gliding Screw (FG; Pega Medical) is a 2-part free-extending screw system designed to allow the growth of the proximal femur. We aimed to analyze the relationship between skeletal maturity and potential growth of the proximal physis and remodeling of the femoral neck using this implant. Females below 12 years and males below 14 years undergoing in situ fixation for stable SCFE or prophylactic fixation were treated using the implant. Three elements of the modified Oxford Bone (mOB 3 ) score were used to measure maturity (triradiate cartilage, head of the femur, and greater trochanter). Radiographs were analyzed immediately postoperatively and at a minimum of 2 years for a change in screw length, posterior-sloping angle, articulotrochanteric distance, α angle, and head-neck offset. The study group comprised 30 (F:M=12:18) of 39 hips treated with SCFE and 22 (F:M=13:9) of 29 hips managed prophylactically using the free-Gliding screw. In the therapeutic group, chronologic age was a less valuable predictor of future screw lengthening than mOB 3 . An mOB 3 of ≤13 predicted future growth of >6mm but did not reach statistical significance ( P =0.07). Patients with open triradiates showed a mean screw lengthening of 6.6mm compared with those with closed triradiates (4.0mm), but this did not reach significance ( P =0.12). In those with mOB 3 ≤13, the α angle reduced significantly ( P <0.01) and the head-neck offset increased significantly, suggesting remodeling. There was no change in these parameters when mOB 3 ≥14. In the prophylactic group, change in screw length was significant with mOB 3 of ≤13 (mean=8.0mm, P <0.05), as was the presence of an open triradiate cartilage (mean=7.7mm, P <0.05). In both cohorts, posterior-sloping angle and articulotrochanteric distance did not change, indicating no slip progression in either treatment or prophylactic groups and minimal effect on the proximal physeal growth relative to the greater trochanter. Growing screw constructs can halt slip progression while allowing proximal femoral growth in young patients with SCFE. Ongoing growth is better when the implant is used for prophylactic fixation. The results in treated SCFE need to be expanded to demonstrate a clinically meaningful cut-off for significant growth, but SCFE patients with an open triradiate remodel significantly more than those where it is closed. Level III-retrospective comparative study.

Smaller epiphyseal tubercle in hips with slipped capital femoral epiphysis compared to the uninvolved contralateral hip.

Recent investigations suggest that physeal morphologic features have a major role in the capital femoral epiphysis stability and slipped capital femoral epiphysis (SCFE) pathology, with a smaller epiphyseal tubercle and larger peripheral cupping of the femoral epiphysis being present in hips with progressive SCFE compared to healthy controls. Yet, little is known on the causal versus remodeling nature of these associations. This study aimed to use preoperative magnetic resonance imaging (MRI) of patients with unilateral SCFE to perform a comparison of the morphology of the epiphyseal tubercle, metaphyseal fossa, and peripheral cupping in hips with SCFE versus the contralateral uninvolved hips. Preoperative MRIs from 22 unilateral SCFE patients were used to quantify the morphological features of the epiphyseal tubercle (height, width, and length), metaphyseal fossa (depth, width, and length), and peripheral cupping height in three dimension. The quantified anatomical features were compared between hips with SCFE and the contralateral uninvolved side across the whole cohort and within SCFE severity subgroups using paired t-test. We found significantly smaller epiphyseal tubercle heights (p < 0.001) across all severities of SCFE when compared to their uninvolved contralateral side. There was a marginally smaller metaphyseal fossa length (p = 0.05) in SCFE hips compared to their contralateral uninvolved hips, with mild SCFE hips specifically having smaller fossa and epiphyseal lengths (p < 0.05) than their contralateral uninvolved side. There were no side-to-side differences in any other features of the epiphyseal tubercle, metaphyseal fossa and peripheral cupping across all severities (p > 0.05). These findings suggest a potential causal role of epiphyseal tubercle in SCFE pathogenesis.

Assessment of femoral retroversion on preoperative hip magnetic resonance imaging in patients with slipped capital femoral epiphysis: Theoretical implications for hip impingement risk estimation.

Slipped capital femoral epiphysis is a common pediatric hip disease and was associated with femoral retroversion, but femoral version was rarely measured. Therefore, mean femoral version, mean femoral neck version, and prevalence of femoral retroversion were analyzed for slipped capital femoral epiphysis patients. A retrospective observational study evaluating preoperative hip magnetic resonance imaging of 27 patients (49 hips) was performed. Twenty-seven untreated slipped capital femoral epiphysis patients (28 slipped capital femoral epiphysis hips and 21 contralateral hips, age 10-16 years) were evaluated (79% stable slipped capital femoral epiphysis, 22 patients; 43% severe slipped capital femoral epiphysis, 12 patients). Femoral version was measured using Murphy method on magnetic resonance imaging (January 2014-December 2021, rapid bilateral 3-dimensional T1 water-only Dixon-based images of pelvis and knee). All slipped capital femoral epiphysis patients underwent surgery after magnetic resonance imaging. Mean femoral version of slipped capital femoral epiphysis patients (-1° ± 15°) was significantly (p < 0.001) lower compared to contralateral side (15° ± 14°). Femoral version of slipped capital femoral epiphysis patients had significantly (p < 0.001) wider range from -42° to 35° (range 77°) compared to contralateral side (-5° to 44°, range 49°). Mean femoral neck version of slipped capital femoral epiphysis patients (6° ± 15°) was lower compared to contralateral side (11° ± 12°). Fifteen slipped capital femoral epiphysis patients (54%) had absolute femoral retroversion (femoral version < 0°). Six of the 12 hips (50%) with severe slips and 4 of the 8 hips (50%) with mild slips had absolute femoral retroversion (femoral version < 0°). Ten slipped capital femoral epiphysis patients (40%) had absolute femoral neck retroversion (femoral neck version < 0°). Although slipped capital femoral epiphysis patients showed asymmetrically lower femoral version compared to contralateral side, there was a wide range of femoral version, underlining the importance of patient-specific femoral version analysis on preoperative magnetic resonance imaging. Absolute femoral retroversion was prevalent in half of slipped capital femoral epiphysis patients, in half of severe slipped capital femoral epiphysis patients, and in half of mild slipped capital femoral epiphysis patients. This has implications for anterior hip impingement and for surgical treatment with in situ pinning or femoral osteotomy (e.g. proximal femoral derotation osteotomy) or other hip preservation surgery.

Which factor is more reliable considering prophylactic pinning of contralateral hip of unilateral SCFE patients?

This study evaluates the radiological parameters of developing subsequent contralateral slips in unilateral slipped capital femoral epiphysis (SCFE) patients at the time of initial presentation. The study group included the review of unilateral SCFE patients treated between June 2007 and August 2018. Age, gen-der, side, stability, posterior slope angle, grade of slip, modified Oxford bone age score (mOBAS), the Risser classification, and the ap-pearance of the triradiate cartilage were evaluated retrospectively. Data were analyzed between two groups: subsequent contralateral SCFE (SCFESC) patients that developed contralateral slip during follow-up and unilateral SCFE (SCFEU) patients that did not develop contralateral slip up to skeletal maturity. Descriptive statistics were used to compare risk factors between groups. This study included 48 patients and 6 patients (12.5%) developed a SCFESC. Only mOBAS was significantly different be-tween groups. The mOBAS scores in SCFESC were 18 in 2 patients (33.3%), 19 in 4 patients (66.7%). The mOBAS scores in SCFEU were 18 in 1 patient (2.4%), 19 in 24 patients (57.1%), and >20 in 17 patients (40.5%). In the SCFESC group, all patients had a Risser score of 0 and all had open triradiate cartilage. Patients with unilateral SCFE are at risk for SCFESC, and the mOBAS is the best predictor of risk assessment. We agree that mOBAS score of 16,17 or 18 patients' contralateral hips can be prophylactically pinned. We also suggest pinning or close screening of mOBAS 19 patients that some carry relatively high risk of subsequent contralateral slip.

Slipped Capital Femoral Epiphysis, Food Deserts, Poverty, and Urban/Rural Residence: Is There a Link?

Childhood obesity is increased in food deserts, a community with little to no access to healthy food. As obesity is associated with slipped capital femoral epiphysis (SCFE), it was the purpose of this study to analyze the prevalence of SCFE patients by food desert location and its interaction with rural/urban location. A retrospective review of all consecutive patients with idiopathic SCFE treated at our institution over 11 years was performed. From the patient's address, the US Census Bureau tract in which the patient resided was determined. Using the census tract code, it was ascertained if the patient lived in a food desert and urban or rural location. Standard statistical analyses were performed; a P <0.05 was considered statistically significant. There were 177 SCFE patients: 79 girls, 98 boys, 106, White, and 69 nonWhite. The average age at diagnosis was 12.1±1.7 years, the average symptom duration 4.1±5.1 months, and the average weight percentile 94±10. Of these 177 patients, 26.5% lived in a food desert, which was higher than the expected 17.5% ( P =0.023). Those living in a food desert were more commonly nonWhite (60% vs. 32%, P =0.0014). There were 25% from rural areas and 75% from urban areas. No rural SCFE patients lived in food deserts whereas 34% of urban patients lived in food deserts. The average poverty rate of the SCFE patient census tracts was 19%, no greater than the expected 15% ( P =0.32). SCFE patients living in rural census tracts had a lower poverty rate ( P <10 -6 ). There is a correlation with the prevalence of SCFE patients by residence in a "food desert", but not with rural/urban locale or poverty status in Indiana. Further research will be needed to see if these findings apply to other states within the United States and other parts of the world. III.

Risk of Avascular Necrosis with The Modified Dunn Procedure in SCFE Patients: A Meta-Analysis.

In situ stabilization is a widely accepted treatment for slipped capital femoral epiphysis (SCFE) despite risks of avascular necrosis (AVN) and femoroacetabular impingement (FAI). The modified Dunn procedure with surgical hip dislocation attempts to maintain epiphyseal perfusion and allows anatomic epiphyseal repositioning, theoretically reducing AVN and FAI risks. We systematically evaluated the literature, elucidating overall and stability-stratified rates of AVN following the modified Dunn procedure, and revision rates in non-AVN patients. Using Ovid and MEDLINE (PubMed), studies involving the modified Dunn procedure were evaluated for age, stability, preoperative slip (Southwick) angle, ROM at follow-up, outcome metrics, and revisions. Utilizing a random effect model of proportions, we determined overall and stability-stratified AVN rates, and revision rates in patients without AVN.673 patients (688 SCFEs) who underwent modified Dunn procedure were included. Overall AVN rate was 14.3% with a 95% Confidence Interval (CI) of 9.3 to 20.2%. AVN rate in stable slips was 10.9% (95% CI: 6.0 to 17.1%) and 19.9% (95% CI: 12.8% to 28.1%) in unstable slips. Revision rate in non-AVN patients was 13.3% (95% CI: 8.3% to 19.2%). Fixation failures occurred following K-wire or small-caliber (&lt;6.5 mm) screw fixation. Overall mean Harris Hip Score (HHS) was excellent (&gt;90 points). Mean HHS was 98.9 points (range of means: 86 to 99 points) in stable cases, and 90.5 points (range of means: 73 to 98 points) in unstable cases. Patients undergoing modified Dunn procedure had excellent clinical outcomes and low incidences of AVN. Further studies are needed to determine if modified Dunn osteotomy with surgical hip dislocation is a viable alternative to in situ pinning for treatment of severe SCFE.

Limited Hip Flexion and Internal Rotation Resulting From Early Hip Impingement Conflict on Anterior Metaphysis of Patients With Untreated Severe SCFE Using 3D Modelling.

Slipped capital femoral epiphysis (SCFE) is the most common hip disorder in adolescent patients that can result in complex 3 dimensional (3D)-deformity and hip preservation surgery (eg, in situ pinning or proximal femoral osteotomy) is often performed. But there is little information about location of impingement.Purpose/Questions: The purpose of this study was to evaluate (1) impingement-free hip flexion and internal rotation (IR), (2) frequency of impingement in early flexion (30 to 60 degrees), and (3) location of acetabular and femoral impingement in IR in 90 degrees of flexion (IRF-90 degrees) and in maximal flexion for patients with untreated severe SCFE using preoperative 3D-computed tomography (CT) for impingement simulation. A retrospective study involving 3D-CT scans of 18 patients (21 hips) with untreated severe SCFE (slip angle>60 degrees) was performed. Preoperative CT scans were used for bone segmentation of preoperative patient-specific 3D models. Three patients (15%) had bilateral SCFE. Mean age was 13±2 (10 to 16) years and 67% were male patients (86% unstable slip, 81% chronic slip). The contralateral hips of 15 patients with unilateral SCFE were evaluated (control group). Validated software was used for 3D impingement simulation (equidistant method). (1) Impingement-free flexion (46±32 degrees) and IRF-90 degrees (-17±18 degrees) were significantly ( P <0.001) decreased in untreated severe SCFE patients compared with contralateral side (122±9 and 36±11 degrees).(2) Frequency of impingement was significantly ( P <0.001) higher in 30 and 60 degrees flexion (48% and 71%) of patients with severe SCFE compared with control group (0%).(3) Acetabular impingement conflict was located anterior-superior (SCFE patients), mostly 12 o'clock (50%) in IRF-90 degrees (70% on 2 o'clock for maximal flexion). Femoral impingement was located on anterior-superior to anterior-inferior femoral metaphysis (between 2 and 6 o'clock, 40% on 3 o'clock and 40% on 5 o'clock) in IRF-90 degrees and on anterior metaphysis (40% on 3 o'clock) in maximal flexion and frequency was significantly ( P <0.001) different compared with control group. Severe SCFE patients have limited hip flexion and IR due to early hip impingement using patient-specific preoperative 3D models. Because of the large variety of hip motion, individual evaluation is recommended to plan the osseous correction for severe SCFE patients. Level III.

Screw Thread Configuration Has No Effect on Operative Outcomes of Slipped Capital Femoral Epiphysis

INTRODUCTION The current “gold standard” treatment for slipped capital femoral epiphysis (SCFE) is insertion of a single cannulated screw down the epiphyseal center. Debate remains as to whether partially- (PTCS) or fully-threaded (FTCS) cannulated screws, and what number, are optimal. The present retrospective cohort study compares such constructs in a clinical model. METHODS IRB approval was obtained. Patients (N=158) presenting to a level-one pediatric trauma center for in situ pinning of SCFE between January 2005 and April 2018 were included. Covariates analyzed were sex, race, BMI, history of endocrinopathy, and preoperative designation of unstable SCFE. Outcomes included return to the operating room (OR), avascular necrosis (AVN), hardware failure/removal, and the sequelae of femoroacetabular impingement (FAI). Multivariable logistic regression models included covariates with significant univariate effects, as well as thread configuration, number of screws, preoperative instability, and the screw*thread and screw*instability interactions. RESULTS Average patient age at surgery was 12.3±1.9 years; 63% of patients were male; 68% of patients were White/Caucasian and the remaining 32% were Black/African American. Mean BMI was 28.4±6.4 kg∙m-2. PTCS were utilized in 81.0% of constructs and 1 screw was placed in 83.5% of hips. Outcome rates were as follows: return to OR=15.8%, AVN=7.6%, FAI=7.0%, hardware failure/removal=9.5%. Univariate modeling demonstrated no significant covariate effects on return to OR (each P≥0.181) or AVN (each P≥0.099). Sex had a significant effect on FAI (P=0.012). Age and bilateral SCFE were significantly related to hardware failure/removal (P=0.039 and P=0.015, respectively). Multivariable models found that 2 screw constructs were associated with increased odds of return to OR [P=0.027; OR=3.01 (1.13-7.98)]. Odds of AVN were increased by older age (P=0.024; OR=1.45 [1.03-2.03]) and 2 screw constructs in stable SCFE [screws*stability interaction: P&lt;0.001; OR=60.5 (5.60-652.31)]. Female sex increased odds of FAI (P=0.012; OR=5.17 [1.31-20.36]). Finally, odds of hardware failure/removal were increased by 2 screw constructs [P=0.038; OR=3.64 (1.13-11.70)] and bilateral SCFE [P=0.027; OR=3.51 (1.15-10.74)]. DISCUSSION AND CONCLUSION A single, PTCS comprises the majority of SCFE constructs, and this construct carries the least risk for negative outcomes in cases of stable SCFE. These data demonstrate no significant effects of thread configuration on outcomes. The authors caution orthopaedic surgery providers against using more than one screw in cases of stable SCFE, as well as to monitor older, female, and/or bilateral SCFE patients more closely due to an increased risk for complications.

Prospective evaluation of in situ screw fixation for stable slipped capital femoral epiphysis.

Purpose:We aimed to determine which variables were associated with persistent symptoms or need for further surgery in patients treated with in situ fixation for stable slipped capital femoral epiphysis. We hypothesized that patients with greater proximal femoral deformity would require revision surgical intervention.Methods:We prospectively collected data on stable slipped capital femoral epiphysis patients who underwent in situ screw fixation at a single institution. Demographic and radiographic information, as well as patient-reported outcomes, were collected.Results:Forty-six patients (54 hips) with an average follow-up of 3.5 years (range: 2.0–8.5) and mean pre-op Southwick slip angle of 40.5° ± 19.4° were studied. We observed one complication following the index procedure (2%). Twelve hips (22%) went on to have a secondary procedure 2.7 ± 2.2 years after the index surgery. Severe slips were 14.8× more likely to undergo a secondary procedure than mild and moderate slips (p < 0.001). We found no correlation between slip severity and patient-reported outcomes (p > 0.6). Hips requiring a secondary procedure had significantly lower Hip disability and Osteoarthritis Outcome scores (76.8 ± 18.4) at final follow-up compared to hips that did not require additional surgery (86.8 ± 15.7) (p = 0.042).Conclusion:With minimum 2-year follow-up, 22% of patients required a secondary surgery. Patient-reported outcomes did not correlate with slip severity, but were found to be significantly higher in slipped capital femoral epiphysis patients that did not require a secondary procedure. Prophylactic treatment of all slip-related cam deformity was not found to be necessary in this prospective cohort. Patients with moderate-to-severe slips may require secondary surgery.Level of Evidence:Level II

Avascular Necrosis and Time to Surgery for Unstable Slipped Capital Femoral Epiphysis: A Systematic Review and Meta-analysis.

Avascular necrosis (AVN) is a well-known complication of unstable slipped capital femoral epiphysis (SCFE) and its cause is multifactorial. Higher AVN rates have been reported with surgery undertaken between 24 hours to 7 days from the onset of symptoms. The current evidence regarding time to surgery and AVN rate remains unclear. The aim of our study was to investigate the rate of AVN and time to surgery in unstable SCFE. A literature search of several databases was conducted. Eligibility criteria included all studies that reported AVN rates and time to surgery in unstable SCFE patients. We performed a meta-analysis using a random-effects model to pool the rate of AVN in unstable SCFE using different time to surgery subgroups (≤24h, 24h - 7d and >7d). Descriptive, quantitative and qualitative data were extracted. Twelve studies matched our eligibility criteria. In total, there were 434 unstable SCFE of which 244 underwent closed reduction (CR). The pooled AVN rates were 24% [95% CI: 16%-35%] and 29% [95% CI: 16%-45%] for the total and CR groups, respectively. The highest AVN rates were with surgery between 24 hours to 7 days, 42% and 54% for the total and CR groups, respectively. The lowest rates of AVN were with time to surgery ≤24 hours (22% and 21% respectively) and >7 days (18% and 29% respectively). These differences were not statistically significant. There was significant subgroup heterogeneity which was highest in the 24 hours - 7 days subgroup and lowest in the >7 days subgroup. The cumulative evidence was not conclusive for an association between AVN rate and time to surgery. The overall AVN rates were lower in unstable SCFE patients who had surgery ≤24 hours and >7 days. However, treatment techniques were very variable and there was significant heterogeneity in the included studies. Multi-centre prospective studies are required with well-defined time to surgery outcomes. Level III/IV.

Computer-assisted subcapital correction osteotomy in slipped capital femoral epiphysis using individualized drill templates

BackgroundSubcapital osteotomy by means of surgical hip dislocation is a treatment approach offered for moderate-to-severe cases of Slipped Capital Femoral Epiphysis (SCFE). This procedure is demanding, highly dependent on the surgeon’s experience, and requires considerable radiation exposure for monitoring and securing the spatial alignment of the femoral head. We propose the use of individualized drill guides as an accurate method for placing K-wires during subcapital correction osteotomies in SCFE patients.MethodsFive CT scans of the hip joint from otherwise healthy patients with moderate-to-severe SCFE were selected (ages 11–14). Three dimensional models of each patient’s femur were reconstructed by manual segmentation and physically replicated using additive manufacturing techniques. Five orthopaedic surgeons virtually identified the optimal entry point and direction of the two threaded wires for each case. 3D printed drill guides were designed specific to each surgical plan, with one side shaped to fit the patient’s bone and the other side containing holes to guide the surgical drill. Each surgeon performed three guided (using the drill guides) and three conventional (freehand) simulated procedures on each case. Each femur model was laser scanned and digitally matched to the preoperative model for evaluation of entry points and wire angulations. We compared wire entry point, wire angulation, procedure time and number of x-rays between guided and freehand simulated surgeries.ResultsThe guided group (1.4 ± 0.9 mm; 2.5° ± 1.4°) was significantly more accurate than the freehand group (5.8 ± 3.2 mm; 5.3° ± 4.4°) for wire entry location and angulation (p < 0.001). Guided surgeries required significantly less drilling time and intraoperative x-rays (90.5 ± 42.2 s, 3 ± 1 scans) compared to the conventional surgeries (246.8 ± 122.1 s, 14 ± 5 scans) (p < 0.001).ConclusionsWe conclude that CT-based preoperative planning and intraoperative navigation using individualized drill guides allow for improved accuracy of wires, reduced operative time and less radiation exposure in simulated hips.Clinical relevanceThis preliminary study shows promising results, suggesting potential direct benefits to SCFE patients by necessitating less time under anesthesia and less intra-operative radiation exposure to patients, and increasing surgical accuracy.

SLIPPED CAPITAL FEMORAL EPIPHYSIS ACETABULAR ORIENTATION AND SHAPE: A THREE-DIMENSIONAL CT STUDY

Background:Previous studies have analyzed the acetabulum in patients affected by slipped capital femoral epiphysis (SCFE), however controversy remains over how the acetabular shape may be altered in hips experiencing SCFE. In particular, changes in acetabular over-coverage and acetabular version are thought to contribute to SCFE.Hypothesis/Purpose:The purpose of this study was to determine the acetabular morphology in hips with SCFE and compare them to normally developing children.Methods:Images from patients with the diagnosis of SCFE who had a computed tomography (CT) exam of their pelvis were compared to images from an age- and sex-matched cohort of patients with CT exams of the pelvis/abdomen for a non-orthopedic related evaluation (controls). Three dimensional (3D) reconstructions were created from each CT exam (MIMICs software). Custom MATLAB software was used to uniformly align and calculate acetabular parameters from the 3D reconstructions. The acetabular parameters calculated were articular surface area, acetabular tilt, acetabular version, and acetabular coverage angles measured in a radial fashion in 5 out of 8 octants.Results:Two-hundred-ninety-eight hips were evaluated, including 67 hips with SCFE, 39 unaffected contralateral hips in patients with SCFE, and 192 normal controls. The SCFE group consisted of 33 males and 34 females. Acetabular version was similar amongst all SCFE affected hips, unaffected contralateral hips, and normal controls (p=0.575). Control hips had higher acetabular tilt than SCFE affected hips (p=0.001) and unaffected contralateral hips (p=0.012). Acetabular surface area was higher in SCFE affected hips compared to controls (p=0.003)(Table 1). SCFE affected hips had significantly increased acetabular coverage compared to controls in the superior, superior-anterior, and anterior octants (p<0.01). The unaffected contralateral sides had significantly increased acetabular coverage compared to controls in all five regions (p<0.02)(Table 2).Conclusions:Contrary to some previous studies, we did not find the acetabulum to be retroverted in hips with SCFE compared to normal hips. Both the affected and unaffected hips of SCFE patients have decreased acetabular tilt. Acetabular surface area is high in both the affected and unaffected sides in SCFE, suggesting it may be involved in the pathogenesis of the condition. There is increased acetabular coverage in the superior regions of SCFE hips. The shared morphological characteristics of both affected and unaffected sides in SCFE patients suggest that their hip anatomy may predispose them to slips.

Total hip arthroplasty in patients with slipped capital femoral epiphysis: a systematic analysis of 915 cases.

There is limited evidence on the outcomes of Total Hip Arthroplasty (THA) in Slipped Capital Femoral Epiphysis (SCFE) patients. This systematic review aims to evaluate the current literature in terms of survival rate, functional outcomes, complications and types of implants of THA in SCFE patients. Following the established methodology of PRISMA guidelines, PubMed, Cochrane library, ScienceDirect and Ovid MEDLINE were systematically searched from inception to September 2018. The search criteria used were: (“total hip arthroplasty’’ OR ‘’total hip replacement’’ OR “hip arthroplasty’’ OR ‘’hip replacement’’) AND (‘’slipped capital femoral epiphysis’’ OR ‘’slipped upper femoral epiphysis’’ OR ‘’femoral epiphysis’’). Ten studies were finally included in the analysis and were qualitatively appraised using the Newcastle-Ottawa tool. Variables were reported differently between studies. The sample size varied from 12 to 374 THAs. A total of 877 patients undergone 915 THAs. The mean reported follow-up ranged from 4.4 to 15.2 years and the mean patients’ age at the time of THA from 26 to 50 years. Four studies specified the type of implants used, with 62% being uncemented, 24% hybrid (uncemented cup/cemented stem) and 14% cemented. All but three studies reported the mean survival of implants that ranged from 64.9% to 94.8%. A limited number of complications were mentioned. There was a tendency for more favorable functional outcomes in modern studies. Modern THA-studies in SCFE patients showed improvement of survivorship, clinical outcomes and patient satisfaction. Future higher-quality studies are necessary to estimate long-term postoperative outcomes better.

Clinical and radiological outcomes of chronic severe slipped capital femoral epiphysis patients treated by surgical dislocation and modified Dunn osteotomy: Case series.

Objectives This study aims to evaluate the clinical and radiological outcomes of patients with chronic severe slipped capital femoral epiphysis (SCFE) treated by surgical dislocation and modified Dunn osteotomy (MDO).Patients and methods This retrospective study, conducted between January 2010 and December 2017, included nine patients (8 males, 1 female; mean age 12.6 years; range, 7 to 16 years) with nine hips. The degree of corrections in Southwick angle and alpha angle were measured on frog-leg views. Range of motion (ROM) of the hips was measured at each follow-up visit. Heyman and Herndon classification system and Harris Hip Score (HHS) were evaluated for clinical and functional outcomes at the latest follow-up visit.Results The mean follow-up time was 34.8 months. Avascular necrosis complication was observed in one hip. Except two patients with lateral femoral cutaneous neuropathy, none of the patients suffered from any other complications. Mean preoperative Southwick angle of 59.1° was corrected to an angle of -0.8° postoperatively. Alpha angles were calculated as 44.6° postoperatively. Modified Dunn osteotomy resulted in marked improvement in hip ROM in all directions and increased HHS.ConclusionOur results encourage us to use this method in treating SCFE patients with chronic severe slips.

Hip morphology in slipped capital femoral epiphysis.

Several mechanical factors have been related to slipped capital femoral epiphysis (SCFE). Main aim of this study is to investigate the acetabular coverage and acetabular version in unilateral SCFE hips in order to detect a potential pincer-type deformity as predisposing factor; second, we compared those measurements either to the contralateral, uninvolved hips either to a matched healthy control population. A total of 85 patients treated for unilateral SCFE were retrospectively reviewed. The lateral center-edge angle (LCEA) and the Tönnis angle were used to assess acetabular coverage, whereas acetabular retroversion was defined by positive prominent ischial spine (PIS), cross-over sign (COS) and posterior wall sign (PWS). Angles and signs of the affected hips were compared to the contralateral hips and to a matched cohort undergoing an abdominal/pelvic computed tomography for nonorthopedic-related diseases. Affected and unaffected hips of patients with unilateral SCFE had similar morphology in terms of LCEA 28.7° vs. 28° (P = 0.4), Tönnis angle 9° vs. 9° (P = 0.1) and retroversion signs with concomitant rate of PWS and COS 57.6% vs. 50.5% (P = 0.4), PIS 56.4% vs. 49.4% (P = 0.4). Matched healthy controls vs. the affected hips showed a lower LCEA (P < 0.001) and higher Tönnis angle (P < 0.001) in conjunction with a lower incidence of acetabular retroversion: PWS and COS 40% vs. 57.6% (P = 0.01), PIS 43% vs. 56.4% (P = 0.07). A significant retroversion and increased overcoverage were observed in SCFE patients compared to matched healthy controls. In unilateral SCFE, the involved and uninvolved hips showed a substantial symmetry.

Quantitative Evaluation of Hip Muscle Atrophy in Patients with Unilateral Slipped Capital Femoral Epiphysis Based on Magnetic Resonance Imaging

Hip muscle atrophy commonly occurs in patients with unilateral slipped capital femoral epiphysis (SCFE), its effect in patients with unilateral SCFE is worthy of further investigation. This study aimed to investigate the relationship between hip muscle cross-sectional area (M-CSA) and unilateral SCFE using magnetic resonance imaging. Overall, 32 unilateral SCFE patients (SCFE group) and 15 asymptomatic subjects (control group) were evaluated. All patients underwent magnetic resonance imaging and frog-leg lateral radiograph examinations. M-CSA and Southwick angle were evaluated to calculate the M-CSA ratio of the affected side over the healthy side (A/H) ratio in the SCFE group and the control group. Associations between the A/H ratio, Southwick angle, and the disease time course were investigated with Spearman correlation test. An independent sample t-test, one-way analysis of variance tests, and intraclass correlation coefficients were also applied. A/H ratios of the control group were significantly higher than those of the SCFE group (anterior muscles group: 1.09 ± 0.14 vs 0.86 ± 0.12, medial muscles group: 1.02 ± 0.15 vs 0.82 ± 0.18, posterior muscles group: 1.03 ± 0.07 vs 0.84 ± 0.11, all p < 0.01). A/H ratios of the medial and posterior muscle groups were significantly correlated with severity of SCFE (r = -0.504, p = 0.003, and r = -0.438, p = 0.012, respectively). Hip muscle atrophy is associated with SCFE severity in patients with unilateral SCFE. The A/H ratio can reflect the patients' prognosis and rehabilitation status. Maintenance of hip muscle morphology and function may be beneficial to clinical performance and prognosis of patients with unilateral SCFE.