Bone scintigraphy in slipped capital femoral epiphysis

Tc-99m diphosphonate bone scans were performed on 11 children with slipped capital femoral epiphysis. On pinhole hip images, seven hips in seven patients had increased radionuclide uptake in the physis and adjacent proximal femoral metaphysis where the slip had occurred. Three hips in three patients had decreased radionuclide uptake in the femoral head on the side of the slipped epiphysis, indicating compromise of the femoral head blood supply. Three or more months following internal fixation, three children had scintigraphy that showed loss of the usual focal uptake in the physis and adjacent proximal femoral metaphysis. Bone scintigraphy in pediatric patients with slipped capital femoral epiphysis is valuable in defining the metabolic status of the femoral head. Absence of radiopharmaceutical uptake in the affected femoral head indicates that the femoral head is at risk for development of radiographic changes associated with aseptic necrosis.     

Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), after slipped capital femoral epiphysis

Objective

The aim of this study was to assess the glycosaminoglycan (GAG) content in hip joint cartilage in mature hips with a history of slipped capital femoral epiphysis (SCFE) using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC).

Methods

28 young-adult subjects (32 hips) with a mean age of 23.8 ± 4.0 years (range: 18.1-30.5 years) who were treated for mild or moderate SCFE in adolescence were included into the study. Hip function and clinical symptoms were evaluated with the Harris hip score (HHS) system at the time of MRI. Plain radiographic evaluation included Tonnis grading, measurement of the minimal joint space width (JSW) and alpha-angle measurement. The alpha-angle values were used to classify three sub-groups: group 1 = subjects with normal femoral head-neck offset (alpha-angle <50°), group 2 = subjects with mild offset decrease (alpha-angle 50°-60°), and group 3 = subjects with severe offset decrease (alpha-angle >60°).

Results

There was statistically significant difference noted for the T1_Gd values, lateral and central, between group 1 and group 3 (p-values = 0.038 and 0.041). The T1_Gd values measured within the lateral portion were slightly lower compared with the T1_Gd values measured within the central portion that was at a statistically significance level (p-value <0.001). HHS, Tonnis grades and JSW revealed no statistically significant difference.

Conclusion

By using dGEMRIC in the mid-term follow-up of SCFE we were able to reveal degenerative changes even in the absence of joint space narrowing that seem to be related to the degree of offset pathology. The dGEMRIC technique may be a potential diagnostic modality in the follow-up evaluation of SCFE.     

Aseptic necrosis following slipped capital femoral epiphysis

Sixty-five patients with slipped capital femoral epiphysis were studied retrospectively for the development of aseptic necrosis. Seven (11%) patients developed segmental or total aseptic necrosis of the capital femoral epiphysis. Radiographically the changes of aseptic necrosis were detectable as early as four months. The cause for the aseptic necrosis is thought to be due to interruption of the blood supply to the capital femoral epiphysis at the time of slippage or during surgical manipulation.     

The role of pre-treatment MRI in established cases of slipped capital femoral epiphysis

Background

Slipped capital femoral epiphysis (SCFE) often results in functional impairment and premature osteoarthritis despite surgical treatment. Treatment decisions are commonly based on the clinical history and radiographic appearance. This study assesses the pre-treatment features of SCFE and correlates them to the clinical history to: (1) define the underlying pathological mechanisms; (2) correlate the morphological hip abnormalities with the clinical classifications; (3) identify specific magnetic resonance imaging (MRI) features that could carry prognostic implications for treatment approach and outcome.

Methods

Clinical history and pre- and posttreatment radiographs and pre-treatment MRIs of 14 patients with 15 affected hips were reviewed. Alignment, impingement, fulcrum formation, remodelling, osteopenia, synovitis, joint effusion, bone marrow and soft tissue oedema and status of the physis and the periosteal sleeve were assessed and related to the clinical history, in particular history of trauma, duration of clinical symptoms and ability to bear weight.

Results

Bone marrow oedema around the growth plate and joint effusion occurred in all patients. Synovitis occurred in 13/15 patients. 6 patients had a fall before presenting with SCFE. 5/6 had periarticular soft tissue oedema, complete disruption of the physis and partial periosteal sleeve disruption. 9 patients had no fall prior to presentation, physis and periost were intact in 7/9; periarticular oedema was not seen. 14/15 showed evidence of chronic remodelling. Despite an acute clinical history remodelling was present. A fulcrum-like alignment, impingement of the epiphysis on the metaphysis with a small area of physical contact, was seen in 8 patients, 6/8 had a prior fall. There was no case of avascular necrosis. Spontaneous reduction of SCFE occurred in 1 case, the only case without chronic remodelling. With MRI as gold standard radiographs underestimate the severity of SCFE.

Conclusion

Synovitis, periphyseal oedema and joint effusion are regular features of SCFE. The clinical history and findings are unreliable for the classification of SCFE. Radiographs underestimate the severity of SCFE. SCFE is often a Salter Harris I injury due to a fall with considerable periarticular soft tissue trauma and a potentially unstable alignment of epi- and metaphysis. This can lead to spontaneous reduction prior to surgery, MRI can potentially identify unstable, reducible slips. If the mode of surgical treatment depends on the particular nature of the SCFE then MRI contributes to surgical decision-making.

Level of evidence

Level 4, case series.     

Acute chondrolysis complicating slipped capital femoral epiphysis.

Radiographs of 20 patients with acute chondrolysis complicating a slipped capital femoral epiphysis were reviewed with emphasis on the radiographic features and differential diagnosis. There was bilateral disease in five instances; radiographic follow-up ranged from 6 months to 5 years. The onset of chondrolysis occurred after surgery in 18 of the 25 abnormal hips. Acute necrosis of the articular cartilage is characterized radiographically by (1) persistent juxtaarticular osteoporosis; (2) progressive narrowing of all or a portion of the cartilage space; and (3) erosion of the subchondral cortices of the femoral head and acetabulum. The radiographic differential diagnosis varies with the stage of disease. The initial osteoporosis is indistinguishable from disuse. The rapid loss of the joint space, accompanied by destruction of the central portions of the subchondral bone, makes differentiation from postoperative infection a common problem. Late changes may resemble either degenerative joint disease or a chronic inflammatory arthritis. The accurate diagnosis of acute chondrolysis depends on correlation of the clinical history and radiographic findings.     

Litigation involving patients with slipped capital femoral epiphysis

BackgroundSlipped capital femoral epiphysis (SCFE) is a hip disorder of late childhood and adolescence. Litigation involving SCFE may occur, as it is frequently diagnosed late, and/or may be temporally related to an injury. The purpose of this study was to review litigation cases involving SCFE in the US, focusing on the type of litigation (professional, premise, or product liability), the outcome of the litigation and indemnity payouts.MethodsCases of litigation involving SCFE were identified using 5 legal databases and Google Scholar searching for the term “slipped capital femoral epiphysis”. These databases originated as early as 1973. The data collected was the alleged complaint, type of defendant, outcome, state where filed, and amount of indemnity payout. Payout amounts were converted to 2020 US$. Statistical analyses were performed with SYSTAT® 10 software.ResultsThere were 135 unique cases identified which involved professional liability (103), premise liability (30), both premise and professional liability (1), and product liability (1). Complaints for professional liability cases were alleged failure in diagnosis (71), inappropriate treatment (14), both diagnosis and treatment (12), and others (7). The delay in those with an alleged late diagnosis (37 cases) was 5.8 months. The three most common specialties named as defendant(s) were primary care (31%), orthopaedic surgeons (29%), and radiologists (16%). The primary allegations against non-orthopaedic surgeons were failure in diagnosis (89%) as opposed to orthopaedic surgeons where the complaints of alleged failures in diagnosis and inappropriate treatment were equal (50%). The geographic region of the filed cases was the Northeast (44%), South (24%), Midwest (16%), and West (16%). There were no differences between premise and professional liability cases by geographic region. The overall outcome was favorable for the defendant(s) in 53% and the plaintiff in 47%; the defense prevailed in 60% of the professional liability but only 33% of the premise liability cases. The indemnity payout amount (for the 52 cases where known) averaged $1.28 million. Payout was higher in the complaints for professional compared to premise liability ($1.5 vs. $0.9 million). The average payout for those with and without avascular necrosis was $2.97 million vs. $1.02 million. For the professional liability claims, indemnity payout was most frequent in the Western US. It must be remembered that this study only represents law suits filed in the US court system. It does not include cases that might have been resolved prior to any legal action as those cases are not publicly available.ConclusionsReported litigation involving SCFE patients involved claims of professional liability in 77% and premise liability in 22% of located cases. Due to significant exposure, this study should serve as a reminder to all health care providers to include SCFE in the differential diagnosis of knee/thigh pain in adolescents.     

Use of bone scintigraphy in the management of slipped capital femoral epiphysis

Fourteen patients with slipped capital femoral epiphysis (SCFE) who had high-resolution and magnification bone scintigraphy during treatment were studied. By demonstrating the vascular status of the femoral head and physiologic condition of the growth plate, scintigraphy was found to assist the clinician in the management of patients with this disorder.     

Evaluation of femoral head vascularization in slipped capital femoral epiphysis before and after cannulated screw fixation with use of contrast-enhanced MRI: initial results

In this study we used contrast-enhanced magnetic resonance imaging (MRI) to evaluate the vascularization of the femoral head in children with slipped capital femoral epiphysis (SCFE) before and after cannulated screw fixation. Eleven consecutive children with SCFE, seven boys and four girls, aged 10–15 years were included in the study. There were no preslips; four children had acute, three acute-on-chronic, and four chronic SCFE. The MRI examinations were performed in a 1.5 Tesla MR scanner with use of a coronal STIR sequence, a coronal contrast-enhanced T1-weighted spin-echo sequence, and a sagittal three-dimensional gradient-echo sequence. Morphology, signal intensities, and contrast-enhancement of the femoral head were assessed by two radiologists in consensus. Morphologic distortion of the physis, bone marrow edema within the metaphysis and epiphysis, and joint effusion were the preoperative MRI findings of SCFE in each child. In nine children, the vascularization of the femoral head before and after surgery was normal. In one child, a preoperative avascular zone in the superolateral aspect of the epiphysis revascularized completely after surgery. One child with severe SCFE developed avascular necrosis of the femoral head after open reduction of the slip. We conclude that MRI allows for accurate evaluation of the femoral head vascularization before and after surgery in children with SCFE.     

Gait abnormalities following slipped capital femoral epiphysis treated with in situ fixation

BackgroundSlipped capital femoral epiphysis (SCFE) is a common disorder in adolescent for which no consensus exists regarding management. The aim of the present study was to analyze gait modifications following SCFE treated with in situ fixation (ISF) and to relate it to radiologic stage. Research question. To verify if gait biomechanics are impaired in patients with SCFE and to try to determine a degree of slippage from which gait modifications would appear.MethodsWe evaluated 16 patients treated by ISF for SCFE with slippage ranging from 11° to 61°. Gait variables were compared to normal population according to age and walking speed and were normalized in Z-scores.ResultsSpatiotemporal parameters, mechanical and energetic variables were inferior to |1.5| Z-scores and considered as normal. Kinematics showed increase of pelvic tilt and hip adduction. Kinetic variables showed modifications with increased hip extension moment. There was also a strong increase in power of hip extensor. Hip extension moment and power of hip extensors were significantly correlated to radiologic stage. Analysis of ROC curves showed a cut-off value of slippage about 25°–30° affecting kinematics of pelvis and hip and kinetic variables.ConclusionThe gait variables were close to normal values. Main modifications were observed in kinematic and kinetic data with a significant increase in extension moment and power generated at the operated hip. This could participate to long-term joint degradation observed in SCFE, even in mild slips. The clinical message is to control regularly SCFE with initial slippage greater than >25–30° to allow for early diagnosis of premature hip osteoarthritis.     

Bilateral slipped capital femoral epiphysis occuring in an adult with acromegalic gigantism

 The etiology of slipped capital femoral epiphysis is still unknown. Traumatic, endocrine, toxic, and mechanical causes have all been hypothesized. It is well documented that the highest incidence occurs during the adolescent growth spurt, suggesting the role of an endocrine abnormality. We report a case that supports this hypothesis.     

MRI of the cartilaginous epiphysis of the femoral head in the piglet hip after ischemic damage

MRI of the cartilaginous epiphysis (CE) of piglet femoral head was performed after ischemic damage to study the changes in the CE found on MRI and to correlate these changes with histologic findings. Avascular necrosis of the femoral head was induced with a suture ligature in nine piglets; one piglet was killed postoperatively on day 3 and on weeks 1, 2, 3, 4, 6, 7, and 8 (two piglets were killed on week 3). MRI of the ischemic and contralateral nonischemic hip joints were obtained with a 60-mm field of view (low resolution MRI). Biopsy cores of the femoral heads were imaged with a 15-mm field of view (high resolution MRI) and correlated with histologic sections. The CE for all operated hips, except for the 3-day postoperative specimen, showed evidence of ischemic changes on histologic assessment; the severity of damage increased with time. The MRI appearance of ischemic and nonischemic CE was clearly different by 2 weeks after the operation. No trilaminar signal pattern was evident in the high resolution T2-weighted (T2W) imaging of the ischemic CE from 2 weeks after the operation. In the 3- to 8-week postoperative specimens, focal areas of low signal intensity on high resolution T1-weighted (T1W) and T2W imaging corresponded to the areas of chondronecrosis found on histologic assessment. The regions of high signal intensity on T2W imaging corresponded to the areas of chondrocyte clusters with increased safranin-O staining. High resolution MRI can demonstrate changes in the CE associated with ischemic injury and may have a role in the assessment of the CE and its development after ischemic injury.     

Slipped capital femoral epiphysis: a physeal lesion diagnosed by MRI, with radiographic and CT correlation

Objective. To define and compare early lesions associated with slipped capital femoral epiphysis (SCFE) on magnetic resonance imaging (MRI), computed tomography (CT) and radiography. Design and patients. Thirteen patients with 15 symptomatic hips due to SCFE underwent radiography and MRI; CT was performed in 12 patients. SCFE was graded on radiographs, head/neck angles and qualitative changes were evaluated on CT, and morphologic/signal abnormalities were determined on MRI. Results. Physeal widening, apparent on T1-weighted MRI, was evident in every case of SCFE, including one presumed “pre-slip.” T2-weighted images demonstrated synovitis and marrow edema but obscured physeal abnormalities. CT head/neck angles ranged from 4–57° for symptomatic to 0–14° for asymptomatic hips. Physeal and metaphyseal changes were variably identified on both radiographs and CT in all cases of SCFE, but not in the pre-slip. Conclusion. MRI clearly delineates physeal changes of both pre-slip and SCFE, and demonstrates very early changes at a time when radiographs and CT may appear normal.     

MRI features of confirmed "pre-slip" capital femoral epiphysis: a report of two cases

We describe the morphologic and signal changes detected about the proximal femoral growth plate in two patients with hip pain preceding the progression to slipped capital femoral epiphysis using magnetic resonance imaging.     

Slipped capital femoral epiphysis. The mechanical function of the periosteum: new aspects and theory including bilaterality.

This particular ailment has many designations in the literature but none is quite adequate. Here we use the terminology slipped capital femoral epiphysis (SCFE). The anatomy of the proximal femur in all mammals reflects their growth and function. The main forces acting on the head are perpendicular to the growth plate. The thick tear-proof perichondrium-periosteum on the femoral neck is like a stocking attached to the epiphysis and the trochanter region. Growth in length causes a strong tensile stress in the periosteum, pressing the epiphysis against the metaphysis and thus stabilizing the vulnerable growth plate-the periosteum theory. Several factors may diminish the stability of the growth plate. SCFE begins with fissures, which coalesce to a fracture in the growth plate, invisible on a radiograph. As the slip progresses, an increasing angulation between the epiphysis and the remainder of the femur occurs. Weight and muscular forces displace the epiphysis posteriorly in a flexed hip. A rift in the ventral half of the periosteal stocking occurs at the border to the perichondrium and, after that, a longitudinal rift in the periosteum at the anterior midline of the femoral neck. This rift becomes broader as the epiphysis slips posteriorly, withdrawing the ruptured periosteum. Displacement of the epiphysis is due to a rotational slip and tilt, made possible by a compression fracture in the posterior part of the metaphysis. Parts of the periosteum function as reins steering the slip direction and counteracting the displacement. SCFE may be regarded as a pseudoarthrosis in the growing cartilage of the plate. The periosteum theory extended to a pseudoarthrosis theory has been supported by findings at surgery and on true lateral radiographs of usual and unusual cases of SCFE presented in this opus. On a true lateral view, the displacement can be measured as the slipping angle (SA) based on anatomical and geometrical considerations. SA values from 95 normal hips and from 22 contralateral asymptomatic hips from SCFE patients are presented in a histogram and bar graph. Statistically, SCFE is always bilateral, but in about 1/3 of the asymptomatic, contralateral hips, the physis ossifies and closes with SA below 13 degrees, and surgery is not necessary. It is most important that the position of the femur on the X-ray table is exactly defined in two dimensions: 1) the angle between the femoral shaft and the tabletop (angle of elevation), 2) the degree of rotation of the femur around its axis. A precisely defined positioning of the femur is a prerequisite for an exact reproducible measurement of the SA on a true lateral view and is also valuable for the evaluation of radiographic "signs". An aid, the Youth Hip Triangle (YHT), has been designed to facilitate positioning of the femur and measurement of SA. YHT is recommended for routine use in every X-ray facility. The method is quick, cost effective and makes it possible to diagnose SCFE in the contralateral hip before clinical signs or symptoms have occurred.     

Diffusion MRI in ischemic epiphysis of the femoral head: an experimental study

PURPOSE: To evaluate whether line-scan diffusion-weighted imaging (LSDWI) can provide temporal information of epiphyseal ischemia. MATERIALS AND METHODS: Ischemia was induced by ligation of arteries of the unilateral femoral head in piglets (N = 25). LSDWI was performed at several time points after ligation. A comparison of apparent diffusion coefficients (ADCs) was made between ischemic and control sides. The difference in percentage change of ADC in the ischemic hips between two neighboring time points was evaluated. A histological study was made after MR scanning. RESULTS: Three hours after ligation, ADCs were significantly lower in the ischemic hips than in the contralateral (control) hips. At 72 hours after surgery, ADCs in the ischemic hips were significantly higher than in the control hips and continued to rise up until the sixth week after operation. Histological study revealed necrosis of chondrocytes and osteocytes and abnormal thickening of the epiphyseal cartilage in the ischemic femoral head. CONCLUSION: The ADCs may be used as a marker of ischemia and necrosis in the femoral head; changes in the ADCs after the acute ischemia may reflect the evolution of ischemia and subsequent necrosis. LSDWI can be used for the evaluation of the duration and extent of ischemic injury in the epiphysis.     

Slipped capital femoral epiphysis in a patient with type II autosomal dominant osteopetrosis

We report on a 13-year-old boy who had a slipped capital femoral epiphysis and was found to have type II benign autosomal dominant osteopetrosis. This association has not previously been reported.