Whence SCFE? More Hints Here
Pediatric orthopaedists have long been searching for anatomic, mechanical, and metabolic causes of slipped capital femoral epiphysis (SCFE). Adolescent obesity has been a recognized SCFE risk factor for 50 years. (Interestingly, high BMI is a consistent risk factor in males, but females who experience SCFE are often thin.) Possible racial risk factors have been examined as well, with no clear conclusions.
Because the incidence of SCFE is relatively low (1 in 10,000 children according to this JBJS Clinical Summary) and the risk of bilaterality is high (in the range of 30% to 40%), it seems likely that anatomic risk factors are at play. In the January 2, 2020 issue of The Journal, Novias et al. home in on the 3-D anatomy of the epiphyseal tubercle (a small, round protuberance thought to stabilize the epiphysis) and peripheral “cupping” of the epiphysis in patients with and without SCFE.
They found a smaller epiphyseal tubercle and more extensive epiphyseal cupping in patients with SCFE compared with normal hips. The authors encourage further investigation of the first finding to determine whether smaller tubercles are a consequence of the slip process or an anatomic variant that predisposes the epiphysis to slip.
A major strength of this study is that all measurements were made by a single observer blinded to the diagnosis of SCFE and other potentially confounding clinical and demographic data. Also, the measurement processes used in this study have been previously validated.
Investigation into the anatomic features of this disease should continue, along with development of minimally invasive, safe, and inexpensive ways to screen for possible anatomic risk factors. The most pertinent clinical goals are to continue evolving minimally invasive methods of epiphyseal stabilization to prevent and/or treat SCFE and to more accurately identify hips at risk of SCFE.
Marc Swiontkowski, MD
JBJS Editor-in-Chief
More Help Predicting Risk of Second SCFE
Up to 40% of kids who experience a slipped capital femoral epiphysis (SCFE) in one hip develop a slip in the contralateral hip. Recent research in pediatric orthopaedics has attempted to identify risk factors for a second SCFE in patients who have had a first. A retrospective study by Maranho et al. in the February 6, 2019 issue of JBJS provides additional evidence about one particular risk factor.
The authors radiographically measured the epiphyseal tilt, epiphyseal extension ratio, alpha angle, and epiphyseal angle of the uninvolved, contralateral hip among 318 patients (mean age of 12.4 years) who presented for treatment of a unilateral SCFE between 2000 and 2017. After adjusting for triradiate cartilage status, Maranho et al. found that, over a minimum follow-up of 18 months:
- Increased posterior epiphyseal tilt was associated with an increased risk of contralateral SCFE, which corroborates recent findings. Specifically, an epiphyseal tilt of >10° corresponded to a 54% predicted probability of a contralateral slip in patients with open triradiate cartilage.
- Increased epiphyseal extension around the metaphysis in the superior plane had a protective effect against a contralateral SCFE. For each 0.01 increase in superior epiphyseal extension ratio, the odds of a contralateral slip decreased by 6%.
- The alpha angle and epiphyseal angle were not independently associated with a contralateral slip.
Clinically, the authors suggest that the tilt findings may be more useful than the extension-ratio findings, especially when it comes to the difficult decision around whether to perform prophylactic percutaneous pinning of the contralateral hip. They write that “prophylactic fixation may be discussed with the families of patients presenting with unilateral SCFE who have a tilt angle of >10°,” noting that this threshold “would result in a low proportion of patients undergoing unnecessary prophylactic pinning.” Maranho et al. are quick to add that even contralateral hips with epiphyseal tilt angles <10° are at risk of SCFE and should be closely monitored.
JBJS 100: SCFE Outcomes, Scoliosis Treatment
Under one name or another, The Journal of Bone & Joint Surgery has published quality orthopaedic content spanning three centuries. In 1919, our publication was called the Journal of Orthopaedic Surgery, and the first volume of that journal was Volume 1 of what we know today as JBJS.
Thus, the 24 issues we turn out in 2018 will constitute our 100th volume. To help celebrate this milestone, throughout the year we will be spotlighting 100 of the most influential JBJS articles on OrthoBuzz, making the original content openly accessible for a limited time.
Unlike the scientific rigor of Journal content, the selection of this list was not entirely scientific. About half we picked from “JBJS Classics,” which were chosen previously by current and past JBJS Editors-in-Chief and Deputy Editors. We also selected JBJS articles that have been cited more than 1,000 times in other publications, according to Google Scholar search results. Finally, we considered “activity” on the Web of Science and The Journal’s websites.
We hope you enjoy and benefit from reading these groundbreaking articles from JBJS, as we mark our 100th volume. Here are two more:
Long-term Follow-up of Slipped Capital Femoral Epiphysis
B T Carney, S L Weinstein, J Noble: JBJS, 1991 January; 73 (5): 667
In this retrospective study of 155 hips with SCFE followed for a mean of 41 years after onset of symptoms, Carney et al. found that pinning in situ provided the best long-term function and delay of degenerative arthritis—and that realignment techniques were associated with a risk of substantial complications.
Treatment of Scoliosis: Correction and Internal Fixation by Spine Instrumentation
P R Harrington: JBJS, 1962 June; 44 (4): 591
The need for this at-the-time revolutionary instrumented approach was the polio epidemic, which left Dr. Harrington caring for many patients with severe, collapsing curves that threatened their health. Just as current hip arthroplasty techniques represent incremental improvements to the contribution of Charnley, current techniques in scoliosis surgery are stepwise improvements to Harrington’s work.
What’s New in Pediatric Orthopaedics 2018
Every month, JBJS publishes a Specialty Update—a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of all OrthoBuzz Specialty Update summaries.
This month, Derek Kelly, MD, co-author of the February 21, 2018 Specialty Update on Pediatric Orthopaedics, selected the most clinically compelling findings from among the more than 50 studies summarized in the Specialty Update.
Trauma
—An analysis of pediatric femoral shaft fractures before and after the publication of clinical practice guidelines1 revealed a significant increase in the use of interlocked intramedullary nails in patients younger than 11 years of age, and an increase in surgical management for patients younger than 5 years of age. Considerable variability among level-I pediatric trauma centers highlights the need for further outcome studies to facilitate updating of existing guidelines.
Scoliosis
—A prospective cohort study of pain and opioid use among patients following posterior spinal fusion for adolescent idiopathic scoliosis found that increased age, male sex, greater BMI, and preoperative pain levels were associated with increased opioid use. Findings like these may help guide clinicians in opioid dispensing practices that minimize the problem of leftover medication.
Infection
—Two stratification/scoring systems may aid in the early prediction of musculoskeletal infection severity and promote efficient allocation of hospital resources. A 3-tiered stratification system described by Mignemi et al.2 correlated with markers of inflammatory response and hospital outcomes. Athey et al.3 validated a severity-of-illness score and then modified it for patients with acute hematogenous osteomyelitis.
Hip
—A study of closed reduction for developmental dysplasia of the hip4 revealed that 91% of 87 hips achieved stable closed reduction. Of those, 91% remained stable at the 1-year follow-up. Osteonecrosis occurred in 25% of cases, but it was not associated with the presence of an ossific nucleus, a history of femoral-head reducibility, or age at closed reduction.
—Regardless of obesity status, serum leptin levels increase the odds of slipped capital femoral epiphysis (SCFE), according to a recent study. Researchers reached that conclusion after comparing serum leptin levels in 40 patients with SCFE with levels in 30 BMI-matched controls.
References
- Roaten JD, Kelly DM, Yellin JL, Flynn JM, Cyr M, Garg S, Broom A, Andras LM,Sawyer JR. Pediatric femoral shaft fractures: a multicenter review of the AAOS clinical practice guidelines before and after 2009. J Pediatr Orthop.2017 Apr 10. [Epub ahead of print].
- Mignemi ME, Benvenuti MA, An TJ, Martus JE, Mencio GA, Lovejoy SA, Copley LA, Williams DJ, Thomsen IP, Schoenecker JG. A novel classification system based on dissemination of musculoskeletal infection is predictive of hospital outcomes. J Pediatr Orthop.2016 Jun 13. [Epub ahead of print].
- Athey AG, Mignemi ME, Gheen WT, Lindsay EA, Jo CH, Copley LA. Validation and modification of a severity of illness score for children with acute hematogenous osteomyelitis. J Pediatr Orthop.2016 Oct 12. [Epub ahead of print].
- Sankar WN, Gornitzky AL, Clarke NM, Herrera-Soto JA, Kelley SP, Matheney T, Mulpuri K, Schaeffer EK, Upasani VV, Williams N, Price CT; International Hip Dysplasia Institute. Closed reduction for developmental dysplasia of the hip: early-term results from a prospective, multicenter cohort. J Pediatr Orthop.2016 Nov 11. [Epub ahead of print].
Increased BMI Affects Femoral Morphology in Adolescents
Long-term population-based research has documented associations between high BMI and decreased longevity and increased risk of developing diabetes and cardiac complications. Musculoskeletally speaking, the risk of developing osteoarthritis of the knee has been strongly associated with elevated BMI, although the impact of high BMI on the development of hip osteoarthritis has been less clearly defined.
To detail the impact of increased BMI on the developing hip, in the January 3, 2018 issue of The Journal, Novais et al. painstakingly evaluated 128 pelvic CT images from a group of adolescents presenting with abdominal pain but no prior history of hip pathology. The authors found a significant association between increasing BMI percentiles and femoral head-neck alterations, including:
- Increased alpha angle
- Reduced head-neck offset and epiphyseal extension, and
- More posteriorly tilted epiphyses.
Taken together, these morphological anomalies resemble, in the authors’ words, “a post-slip or mild slipped capital femoral epiphysis [SCFE] deformity.”
While the association between elevated body mass and the risk of SCFE has long been known, the impact of high BMI on the morphology of the “normal” hip had not, until now, been described in detail. It makes intuitive mechanical sense that Novais et al. found no impact of high BMI on acetabular anatomy, but because of the orientation of the proximal femoral growth plate, it does make sense that high BMI affects the growing femoral head-neck junction.
It is my hope that consolidating these data with the abundance of other evidence about the health risks of high BMI in growing children will further coalesce worldwide efforts to lower the intake of sugar and “empty carbs” among growing children, and will further spur investment in programs to increase physical activity among this vulnerable age group.
Marc Swiontkowski, MD
JBJS Editor-in-Chief
The Acetabulum’s Role in SCFE: Cause or Consequence?
The multifactorial pathogenesis of slipped capital femoral epiphysis (SCFE) almost certainly involves the acetabulum, but previous studies about that relationship have been inconclusive. In the June 21, 2017 issue of JBJS, Hesper et al. report on a matched-cohort study that used precise measurements gleaned from CT to determine that acetabular retroversion—not acetabular depth or overcoverage of the femoral head—is associated with SCFE.
The authors carefully measured acetabular depth, head coverage, and retroversion in three groups of hips: the affected hips of 36 patients with unilateral SCFE, the unaffected contralateral hips of those same patients, and healthy hips of 36 age- and sex-matched controls. They observed no deep acetabula or acetabular overcoverage in the SCFE-affected hips, but they did find a lower mean value for acetabular version (i.e., retroversion) at the level of the femoral-head center in the SCFE-affected hips, relative to contralateral and control hips. The acetabulum was retroverted cranially in cases of severe SCFE compared with mild and moderate cases.
These findings support the hypothesis that SCFE-affected hips have reduced acetabular version, but the authors note that “additional studies will be necessary to determine whether acetabular retroversion is a primary morphological abnormality associated with the mechanical etiology of SCFE, or if it is an adaptive response to the acetabulum after the slip.” Either way, Hesper et al. conclude that their data “may help with planning treatment for patients with residual pain and limited motion related to femoroacetabular impingement after SCFE.
JBJS EST 2016 Editor’s Choice Awards
JBJS Essential Surgical Techniques (EST) is pleased to congratulate the winners of its two Editor’s Choice Awards for 2016:
The award for best technique article went to Austin T. Fragomen, MD and S. Robert Rozbruch, MD for Lengthening of the Femur with a Remote-Controlled Magnetic Intramedullary Nail.
The recipients of the best Key Procedures video award were Jesse D. Chlebeck, MD; Christopher E. Birch, MD; and Jennifer W. Lisle, MD for Percutaneous in Situ Fixation of Slipped Capital Femoral Epiphysis.
Click here to learn about the 2017 EST Editor’s Choice competition.
What’s New in Pediatric Orthopaedics
Every month, JBJS publishes a Specialty Update—a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of all OrthoBuzz Specialty Update summaries.
This month, Derek Kelly, MD, co-author of the February 15, 2017 Specialty Update on Pediatric Orthopaedics, selected the five most clinically compelling findings from among the 60 studies summarized in the Specialty Update.
Upper-Extremity Trauma
—A systematic review of eight randomized studies comparing splinting with casting for distal radial buckle fractures confirmed that splinting was superior in function, cost, and convenience, without an increased complication rate.1
Lower-Extremity Trauma
—A review of the treatment of 361 pediatric diaphyseal femoral fractures before and after the 2009 publication of AAOS clinical guidelines for treating such fractures revealed that the guidance had little impact on the treatment algorithm in one pediatric hospital.
Spine
—Bracing remains an integral part of managing adolescent idiopathic scoliosis, but patient compliance with brace wear is variable. A prospective study of 220 patients demonstrated that physician counseling based on compliance-monitoring data from sensors embedded in the brace improved patients’ average daily orthotic use.
Hip
—AAOS-published evidence-based guidelines on the detection and nonoperative management of developmental dysplasia of the hip (DDH) in infants from birth to 6 months of age determined that only two of nine recommendations gleaned from evidence in existing literature could be rated as “moderate” in strength:
- Universal DDH screening of all newborn infants is not supported.
- Imaging before 6 months is supported if the infant has one or more of three listed risk factors.
Seven additional recommendations received only “limited” strength of support.
—A study of the utility of inserting an intraoperative intracranial pressure (ICP) monitor during closed reduction and pinning for slipped capital femoral epiphysis (SCFE) found that 6 of 15 unstable hips had no perfusion according to ICP monitoring. However, all 6 hips were subsequently reperfused with percutaneous capsular decompression, and no osteonecrosis developed over the next 2 years.
Reference
- Hill CE, Masters JP, Perry DC. A systematic review of alternative splinting versus complete plaster casts for the management of childhood buckle fractures of the wrist. J Pediatr Orthop B. 2016 ;25(2):183–90.
JBJS Editor’s Choice—Perfusion Key to Preventing Osteonecrosis in SCFE
Osteonecrosis of the femoral head is a dreaded complication for patients with a slipped capital femoral epiphysis (SCFE). This complication is far more common with acutely displaced and unstable slips. Safely reducing the femoral head back on the neck while preserving blood supply can often be accomplished with closed reduction maintained by in situ cannulated screw fixation, although some recent efforts to treat SCFE have focused on open approaches.
In the June 15, 2016 edition of The Journal, Schrader et al. demonstrate the benefits of using a simple intracranial pressure (ICP) monitoring probe (see photo) inserted through the cannulated screw to measure femoral head perfusion. While using this technique intraoperatively on 26 hips with SCFE, the authors encountered six hips in which there was no blood flow to the femoral head after closed reduction and screw stabilization. In these situations, they performed percutaneous capsular decompression.
The fact that all patients—even those with no initial femoral head perfusion—left the operating room with measurable blood flow confirms the long-held principle that lack of perfusion can be treated with capsulotomy. The ICP device uses waveforms to measure blood flow and is an accurate gauge of perfusion. Moreover, the technology is available in most hospitals with trauma centers or neurosurgery services.
Having researched femoral head perfusion myself as a young orthopaedist and having kept abreast of more recent findings in this area, I think the monitoring protocol described by Schrader et al. is the best yet published to limit the devastating complication of hip osteonecrosis. I feel that if ICP monitors are available, this protocol should be adopted by all centers treating patients with acute SCFE.
Marc Swiontkowski, MD
JBJS Editor-in-Chief
What’s New in Pediatric Orthopaedics
Every month, JBJS publishes a Specialty Update—a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Here is a summary of selected findings cited in the February 17, 2016 Specialty Update on pediatric orthopaedics:
Guidelines and AUCs
–The AAOS updated its clinical practice guidelines on the treatment of pediatric diaphyseal femoral fractures1 and adopted appropriate use criteria (AUC) for pediatric supracondylar humeral fractures with vascular injury.2
Spine
–A matched case control study of surgical spinal procedures found that neuromuscular scoliosis, weight for age ≥95th percentile, ASA score of ≥3, and prolonged operative time were associated with a higher risk of surgical site infection.3
–Several groups, including the Scoliosis Research Society and POSNA, endorsed the definition of early-onset scoliosis as “scoliosis with onset less than the age of ten years, regardless of etiology.”4, 5
–A prospective randomized study found that preoperative education and orientation for scoliosis surgery paradoxically increased immediate postoperative anxiety among patients and caregivers, relative to controls who received standard perioperative information.6
–A randomized trial investigating perioperative blood loss and transfusion rates in patients undergoing posterior spinal arthrodesis for adolescent idiopathic scoliosis found that tranexamic acid and epsilon-aminocaproic acid reduced operative blood loss but not transfusion rates when compared with placebo.
Hip
–A study of 30 patients with severe stable slipped capital femoral epiphysis found that good or excellent results were achieved over 2.5 years in a higher proportion of those receiving a modified Dunn realignment compared with those treated with in situ fixation. The reoperation rate was greater in the in situ fixation cohort.7
–A prospective study analyzing complications after periacetabular osteotomy for acetabular dysplasia using the modified Clavien-Dindo grading scheme found grade III or IV complications in 5.9% of 205 patients, with a nonsignificant trend associating complications with male sex and obesity.
–A registry-based study found that, compared with matched controls, patients with Legg-Calve-Perthes disease had an elevated hazard ratio of 1.5 for ADHD, 1.3 for depression, and 1.2 for mortality. It remains unclear whether patients with Legg-Calve-Perthes disease would benefit from routine psychiatric screening.8
Sports Medicine
–A case control study of 822 injured athletes and 368 uninjured athletes found that overuse injuries represented 67.4% of all injuries. The risk of serious overuse injury was two times greater if the weekly hours of sports participation were greater than the athlete’s age in years.9
–A meta-analysis of initial nonoperative treatment compared with operative treatment of ACL tears in children and adolescents noted instability and pathologic laxity in 75% of patients with nonoperative treatment compared with 14% of patients following reconstruction.10
Trauma
–A review of more than 4,400 supracondylar humeral fractures with isolated anterior interossesous nerve palsies but without sensory nerve injury or dysvasculartity found that postponing treatment for up to 24 hours did not delay neurologic recovery.
–A randomized controlled trial investigating the effectiveness of analgesics during intraossesous pin removal found that acetaminophen and ibuprofen were clinically equivalent to placebo in terms of pain reduction and heart rate.
Foot and Ankle
–A study exploring risk factors for failure of allograft bone after calcaneal lengthening osteotomy found a lower risk of failure with tricortical iliac crest allograft relative to patellar allograft. The risk of radiographic graft failure increased with patient age.11
–A prospective nonrandomized study of symptomatic planovalgus feet comparing subtalar arthroereisis with lateral column lengthening found similar postoperative improvements and complication rates in both groups after one year.12
Musculoskeletal Infection & Neuromuscular Conditions
–A cohort study of 869 children with osteomyelitis, septic arthritis, pyomyositis, or abscess concluded that routinely culturing for anaerobic, fungal, and acid-fast bacterial organisms is not recommended except in patients with a history of penetrating injury, immunocompromise, or failure of primary treatment.
–A prospective study comparing tendon transfers, botulinum toxin injections, and ongoing therapy in children with upper-extremity cerebral palsy found that tendon transfer demonstrated greater improvements than the alternatives in joint positioning during functional tasks and grip and pinch strength.
References
- American Academy of Orthopaedic Surgeons.Guideline on the treatment of pediatric diaphyseal femur fractures. 2015.http://www.aaos.org/Research/guidelines/PDFFguideline.asp.
- American Academy of Orthopaedic Surgeons.Appropriate use criteria: pediatric supracondylar humerus fractures with vascular injury. 2015.http://www.aaos.org/research/Appropriate_Use/pshfaucvascular.asp.
- Croft LD, Pottinger JM, Chiang HY, Ziebold CS, Weinstein SL, Herwaldt LA. Risk factors for surgical site infections after pediatric spine operations. Spine (Phila Pa 1976). 2015 Jan 15;40(2):E112-9
- El-Hawary R, Akbarnia BA. Early onset scoliosis – time for consensus. Spine Deformity. 2015 Mar;3(2):105-6
- Skaggs DL, Guillaume T, El-Hawary R, Emans J, Mendelow M, Smith J. Early onset scoliosis consensus statement, SRS Growing Spine Committee, 2015. Spine Deformity. 2015;3(2):107.
- Rhodes L, Nash C, Moisan A, Scott DC, Barkoh K, Warner WC Jr, Sawyer JR, Kelly DM.Does preoperative orientation and education alleviate anxiety in posterior spinal fusion patients? A prospective, randomized study. J Pediatr Orthop. 2015 Apr-May;35(3):276-9.
- Novais EN, Hill MK, Carry PM, Heare TC, Sink EL. Modified Dunn procedure is superior to in situ pinning for short-term clinical and radiographic improvement in severe stable SCFE. Clin Orthop Relat Res. 2015 Jun;473(6):2108-17. Epub 2014 Dec 12
- Hailer YD, Nilsson O. Legg-Calvé-Perthes disease and the risk of ADHD, depression, and mortality. Acta Orthop. 2014 Sep;85(5):501-5. Epub 2014 Jul 18.
- Jayanthi NA, LaBella CR, Fischer D, Pasulka J, Dugas L. Sports-specialized intensive training and the risk of injury in young athletes: a clinical case-control study. Am J Sports Med. 2015 Apr;43(4):794-801. Epub 2015 Feb 2.
- Ramski DE, Kanj WW, Franklin CC, Baldwin KD, Ganley TJ. Anterior cruciate ligament tears in children and adolescents: a meta-analysis of nonoperative versus operative treatment. Am J Sports Med. 2014 Nov;42(11):2769-76. Epub 2013 Dec 4.
- Lee IH, Chung CY, Lee KM, Kwon SS, Moon SY, Jung KJ, Chung MK, Park MS. Incidence and risk factors of allograft bone failure after calcaneal lengthening. Clin Orthop Relat Res. 2015 May;473(5):1765-74. Epub 2014 Nov 14.
- Chong DY, Macwilliams BA, Hennessey TA, Teske N, Stevens PM. Prospective comparison of subtalar arthroereisis with lateral column lengthening for painful flatfeet. J Pediatr Orthop B. 2015 Jul;24(4):345-53.
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