The value of early postoperative bone scan in slipped capital femoral epiphysis

The purpose of this study was to evaluate the sensitivity and predictive value of early postoperative bone scan for detection of avascular necrosis (AVN) of the femoral head after surgical treatment of slipped capital femoral epiphysis. We reviewed records of 49 patients (64 hips) operated on between 1980 and 1997 with a mean follow-up of 3 years. Sixty-one out of 64 hips went through an early postoperative bone scan. The three hips that developed AVN showed significant loss of radionuclide uptake. There were neither false-positive or false-negative cases in this series. Early postoperative bone scan has an excellent sensitivity and predictive value for detection of AVN after surgical treatment of slipped capital femoral epiphysis.     

Chondrolysis following slipped capital femoral epiphysis

Medical records and radiographs of 17 known cases of slipped capital femoral epiphysis, treated with in-situ pin fixation and complicated by chondrolysis were reviewed. Fourteen of these 17 hips that developed chondrolysis had definite evidence of pin penetration of the femoral head. One hip had intra-articular pin penetration of the femoral neck. In the remaining two hips, the pins were placed within the anterolateral quadrant of the femoral head and within 2 mm of the articular surface. Overall, this is an 88% incidence of definite intra-articular pin penetration on postoperative radiographs, and a 100% rate if the two probable cases are included. This suggests a correlation between pin penetration and the development of chondrolysis following slipped capital femoral epiphysis.     

Cuneiform osteotomy of the femoral neck in the treatment of slipped capital femoral epiphysis

I reviewed the cases of eighty-two patients (106 hips) with slipped capital femoral epiphysis who were treated during a twenty-four-year period. Of these, forty-two hips had a sufficiently severe displacement to require surgical correction by means of a cuneiform osteotomy of the neck of the femur just distal to the physis. The purpose was to restore the normal anatomical relationship of the proximal capital femoral epiphysis to the neck of the femur. Follow-up of these patients ranged from two to twenty-two years, with an average of nine years and nine months. Aseptic necrosis developed in one femoral head and osteoarthritis developed in one hip. The remaining forty hips were graded as having an excellent result.     

Vascular supply to slipped capital femoral epiphysis

The etiology of avascular necrosis associated with slipped capital femoral epiphysis has not been well understood. The aims of this study were to clarify the blood supply to the slipped epiphysis and to examine whether this vascular supply is damaged before the reduction. Twelve patients (12 hips) underwent selective angiography of the medial circumflex femoral artery. There were seven stable slips and five unstable slips. All patients with slips underwent angiography before reduction, and one patient with an unstable slip underwent angiography both before and after reduction. The superior retinacular artery (SRA) was filled in all stable slips. This result was in accordance with the previous report that stable slips result in low rates of avascular necrosis. Of five unstable slips, the SRA was stained in two and was not filled in three. In one slip examined both before and after the manipulative reduction, the SRA was not seen before it but was well stained after it. These results have suggested that in some unstable slips the vascular injury occurs at the time of injury, before reduction, and that the reduction dose not necessarily contribute to the risk of avascular necrosis after slipped capital femoral epiphysis.     

Is the femoral head dead or alive before surgery of slipped capital femoral epiphysis? Interest of perfusion Magnetic Resonance Imaging

Background

The most common complication of slipped capital femoral epiphysis (SCFE) is avascular necrosis (AVN) of the femoral head. Surgical treatments including reduction of the femoral head are considered as a risk factor for avascular necrosis. The purpose of this study was to investigate the role of perfusion Magnetic Resonance Imaging (MRI) into the surgical decision-making sequence.

Methods

Eighteen children with 19 slipped capital femoral epiphysis were retrospectively included. SFCE was unstable in nine cases and stable in ten cases. The slip angle was higher than 60° in 14 cases. Perfusion MRI with dynamic gadolinium-enhanced subtraction sequences were done in all the cases before and after surgical treatment.

Results

On nineteen hips, eight were devascularized before surgery. All were unstable. After surgery, six on eight had a complete revascularization, one had a focal necrosis and one remained devascularized. A postoperative devascularization with normal preoperative MRI was noted once. On nineteen hips, a total of three avascular necrosis occurred.

Conclusion

Perfusion MRI is useful to assess preoperative and postoperative vascular status in SFCE. Preoperative devascularization could improve or stay equal after surgical treatment. Persistent devascularization could be responsible for avascular necrosis of the femoral head.     

Slipped capital femoral epiphysis. A prospective study of fixation with a single screw.

Forty-four children (fifty-eight hips) who had a slipped capital femoral epiphysis were managed by in situ pinning with a single cannulated screw. This method of treatment was first used in our institution in 1983. Thirty-one boys and thirteen girls were followed for an average of three years (range, two to six years). There were eight acute slips and fifty chronic slips. Thirty-four patients were black and ten patients were white. The clinical criteria of Heyman and Herndon and the radiographic parameters cited by Boyer et al. were used to grade the results. Fifty-four hips were rated as either excellent or good. Avascular necrosis developed in one patient who had an acute slipped capital femoral epiphysis, but chondrolysis did not occur in any patient. The complications included a subtrochanteric fracture in one patient and an increase in the degree of slippage of the capital femoral epiphysis in two patients.     

Subkapitale Korrekturosteotomie bei der Epiphyseolysis capitis femoris mittels chirurgischer Hüftluxation

OBJECTIVE: The aim of treatment of slipped capital femoral epiphysis is an anatomically aligned epiphysis with normal blood supply. This result can be achieved by open subcapital reorientation of the epiphysis or by a wedge osteotomy of the femoral neck. Other procedures have, so far, not gained optimal control over the risk of avascular necrosis. INDICATIONS: Acute epiphyseolysis. Chronic epiphyseolysis for which trimming of the metaphyseal overhang to permit free flexion and internal rotation without impingement would leave less than two thirds of the femoral neck diameter intact. CONTRAINDICATIONS: Ankylosis of the hip joint at an advanced stage. Destruction of the femoral head. SURGICAL TECHNIQUE: The blood supply to the epiphysis from the medial femoral circumflex artery can be preserved by surgical hip dislocation and a soft-tissue flap derived subperiosteally from the retinaculum and external rotators. This soft-tissue flap permits not only the detachment of the epiphysis, but also complete callus resection from the femoral neck without causing tension in the retinaculum. Dislocation of the femoral head ensures its manual protection during curettage of the epiphyseal plate and, ultimately, allows anatomic reduction under visual control of the retinaculum. With the head dislocated there is less risk to the integrity of the retinaculum due to unintentional manipulation of the leg than there would be, if the head remained in the socket. RESULTS: From 1996 to 2005, 30 hips with a diagnosis of slipped capital femoral epiphysis were treated according to the technique described. The average follow-up time was 55 months (24-96 months). Femoral head necrosis did not occur. Distribution across sexes was well balanced. Girls were 12 years old at the time of the operation and boys were 14 years old on average. Posterior displacement was measured at 30-70 degrees. In six hips there was a so-called acute on chronic slip. Two hips required revision due to screw failure, a difficulty that was addressed by the introduction of fully threaded wires. One hip had to be revised because the fully threaded wire bent. After reoperation, shortening of maximum 1 cm was seen in these three cases. In one patient with ectopic bone formation at the anteroinferior femoral neck, internal rotation in flexion is reduced by half.     

Factors influencing the development of osteonecrosis in patients treated for slipped capital femoral epiphysis

BACKGROUND: Osteonecrosis is a serious complication of the treatment of slipped capital femoral epiphysis. The purpose of the present study was to identify factors influencing the development of osteonecrosis. METHODS: Two hundred and forty patients who had been treated for slipped capital femoral epiphysis between 1965 and 1999 were retrospectively evaluated. Treatment included stabilization with a spica cast or fixation with one to four pins or screws. Radiographs that had been made at the time of presentation, before and after the operation, and at consecutive follow-up examinations were reviewed. Osteonecrosis was defined retrospectively on the basis of radiographic evidence of sclerosis and collapse of the femoral head. The risk of development of osteonecrosis was correlated with various clinical and radiographic parameters. RESULTS: All twenty-one patients in whom osteonecrosis developed had presented with an unstable slipped capital femoral epiphysis. None of the 204 patients who had presented with a stable slipped capital femoral epiphysis, regardless of grade, had development of osteonecrosis. In the group of patients who had presented with an unstable slipped capital femoral epiphysis, the risk of development of osteonecrosis increased with the severity (grade) of the slip. Osteonecrosis was more likely to develop in patients who had been treated with multiple pins than in those who had been treated with a single cannulated screw. CONCLUSIONS: Patients who have a stable slipped capital femoral epiphysis are not at risk for the development of osteonecrosis when treated with pinning in situ. Patients who have an unstable slipped capital femoral epiphysis have a decreased risk of osteonecrosis when treated with pinning in situ. Complete or partial reduction of an unstable slipped capital femoral epiphysis increases the risk of development of osteonecrosis. Pinning in situ without reduction with a single cannulated screw is the method of choice for the treatment of a slipped capital femoral epiphysis.     

Radiological evaluation of unstable (acute) slipped capital femoral epiphysis treated by pinning with Kirschner wires

Treatment of slipped capital femoral epiphysis is still controversial with regard to the implants used for stabilization and the need for prophylactic treatment of the contralateral, unaffected, side. The objective of this study was to ascertain whether prophylactic transfixation of the epiphysis with Kirschner wires in patients with unstable slipped capital femoral epiphysis resulted in significant disturbance of the growth plate and impairment of further growth of the femoral neck and head. Between 1990 and 1999, 29 patients with unstable slipped capital femoral epiphysis were simultaneously treated with internal fixation of the epiphysis and metaphysis with 3-4 Kirschner wires on the affected and the not (yet) affected side. After a mean follow-up of 3.5 years, we evaluated the hip joints radiologically, analysing different roentgenological parameters (CCD angle, femoral head diameter, length of the femoral neck and sphericity of the femoral head). CCD angle, femoral head diameter and length of the femoral neck showed statistically significant (P<0.001, Student's t-test) differences between the affected and unaffected, but prophylactically pinned, sides. Asphericity of the femoral head was found in six cases only on the affected side, whereas all hips, which were operated prophylactically, showed spherical femoral heads at follow-up (P<0.02, Pearson's chi test). These results indicate that the slip itself may cause impairment of the femoral growth plate in patients with unstable slipped capital femoral epiphysis and not stabilization with Kirschner wires. Compared with other series from the literature using different implants (screws, nails), prophylactic transfixation of the epiphysis and metaphysis with Kirschner wires is less compromising to the growth plate on the not (yet) affected side.     

Shear stress in epiphyseal growth plate is a risk factor for slipped capital femoral epiphysis

BACKGROUND: Slipping of the capital femoral epiphysis is an important orthopaedic problem of early adolescence. Many hypotheses about its etiology have been examined, yet the underlying mechanisms have not yet been fully elucidated. We examined elevated shear stress in the epiphyseal growth plate and elevated contact hip stress exerted on the femoral head as risk factors for slipping of the capital femoral epiphysis. METHODS: Two groups of hips were compared: a group of 100 hips contralateral to the slipped ones and a group of 70 age- and gender-matched healthy hips. The characteristics of individual hips were incorporated by means of geometrical parameters determined from standard anteroposterior radiographs. Shear stress was calculated by using a mathematical model where the femoral neck was considered to function as an elastic rod. Contact hip stress was calculated by the HIPSTRESS method. RESULTS: Hips contralateral to the slipped ones had higher average shear stress (0.81 vs 0.51 MPa; P < 0.001) and more vertically inclined physeal angle (55.4 vs 63.2 degrees.; P < 0.001) in comparison to healthy hips. Shear stress in the contralateral hips to the slipped ones remained significantly higher even when normalized to the body weight (1400 vs 1060 Pa/N; P < 0.001). There was no significant difference in the average contact hip stress (1.86 vs 1.74 MPa; P = 0.145). CONCLUSIONS: Elevated shear stress, but not elevated contact stress, is a risk factor for slipping of the capital femoral epiphysis. LEVEL OF EVIDENCE: III (prognostic study, case-control study).     

Slipped capital femoral epiphysis. An assessment of treatment modalities

Fifty-five patients underwent operative treatment of slipped capital femoral epiphyses at Children's Hospital Medical Center in Cincinnati, Ohio, between January 1975 and April 1980. Charts and x-rays were available for review in 45 of these patients with 68 affected hips; the incidence of bilaterality was 51%. Sixty-five of the 68 hips were managed by pinning. Problems with pin placement were recognized in 15.4% of these hips. Three patients were treated by subtrochanteric osteotomy, without complications. Since May 1980, all patients treated on the University Service, Children's Hospital Medical Center for slipped capital femoral epiphysis have undergone open epiphysiodesis utilizing a cosmetic "bikini" incision. Twenty-two hips in 14 patients were so managed without significant complications. This should be considered the treatment of choice for slips involving change greater than 30 degrees in the head shaft angle.     

Anterior physeal separation. A sign indicating a high risk for avascular necrosis after slipped capital femoral epiphysis

A study of 78 children (110 hips) was undertaken in an attempt to assess the risk of avascular necrosis (AVN) after slipped capital femoral epiphysis based on the radiological appearances of the hip at the time of presentation. Physeal separation, which was defined as the amount of separation of the anterior lip of the epiphysis from the metaphysis on the frog lateral view, was assessed. Of the eight hips which developed AVN, seven had anterior physeal separation. We conclude that anterior physeal separation is associated with a high incidence of subsequent AVN after slipped capital femoral epiphysis and that screw fixation may not be appropriate in these patients.     

A 50-year experience with bone graft epiphysiodesis in the treatment of slipped capital femoral epiphysis

A "millennium" update of all cases of slipped capital femoral epiphysis treated by bone graft epiphysiodesis between 1950 and 2000 was conducted. All cases were followed for at least 1 year to evaluate the occurrence of re-slippage, avascular necrosis (AVN), chondrolysis, or complications secondary to the surgical approach. This study adds 109 patients and 133 hips to the initial report for a total of 268 patients and 318 hips. The patients include 43 patients with 45 acute slips and 225 patients with 273 chronic slips. The results include three cases of AVN, six cases of re-slippage, one case of chondrolysis, and no surgical approach complications in the acute group. In the chronic group, there were 4 cases of AVN, 17 cases of re-slippage, 4 cases of deep wound infection, and no cases of chondrolysis. The authors suggest that bone graft epiphysiodesis is a reasonable alternative in the treatment of slipped capital femoral epiphysis.     

Mid-term results of concomitant epiphyseal fixation and trochanteric osteotomy for severe chronic slipped capital femoral epiphysis

The management of severe forms of slipped capital femoral epiphysis (SCFE) has been the subject of intense debate in the literature, and controversy remains as to whether the proximal femoral epiphysis should be realigned by intracapsular or extracapsular osteotomies or just fixated in situ. The aim of this study is to evaluate the late results of treatment of severe unreduced slipped capital femoral epiphyses by combined epiphyseal stabilisation in situ using a single cancellous screw and biplane corrective trochanteric osteotomy. Eighteen hips with severe chronic slipped capital femoral epiphysis before physeal closure were treated by combined epiphyseal fixation in situ using a single cancellous screw, and biplane corrective osteotomy fixed by an angled blade plate. The average follow-up period was 8 years. All patients achieved near-normal hip flexion, internal rotation and abduction, and most were able to bear weight in the early postoperative period. A satisfactory correction of the head-shaft angle was obtained post-operatively on both antero-posterior and frog leg lateral radiographs. There was no instance of chondrolysis, avascular necrosis or early osteoarthrosis. This procedure appears to offer a workable solution to the problem posed by the severely slipped capital femoral epiphysis.     

Radiological evidence of femoroacetabular impingement in mild slipped capital femoral epiphysis: a mean follow-up of 14.4 years after pinning in situ

Conventional treatment of mild slipped capital femoral epiphysis consists of fixation in situ with wires or screws. Recent contributions to the literature suggest that even a mild slip may lead to early damage of the acetabular labrum and adjacent cartilage by abutment of a prominent femoral metaphysis. It has been suggested that the appropriate treatment in mild slipped capital femoral epiphysis should not only prevent further slipping of the epiphysis, but also address potential femoroacetabular impingement by restoring the anatomy of the proximal femur. Between October 1984 and December 1995 we treated 16 patients for unilateral mild slipped capital femoral epiphysis by fixation in situ with Kirschner wires. In this study we have reviewed these patients for clinical and radiological evidence of femoroacetabular impingement. There was little clinical indication of impingement but radiological evaluation assessing the femoral head-neck ratio and measuring the N?tzli alpha angle on the anteroposterior and cross-table radiographs showed significant alterations in the proximal femur. None of the affected hips had a normal head-neck ratio and the mean alpha angle was 86 degrees (55 degrees to 99 degrees ) and 55 degrees (40 degrees to 94 degrees ) on the anteroposterior and lateral cross-table radiographs, respectively. While our clinical data favours conventional treatment, our radiological findings are in support of restoring the anatomy of the proximal femur to avoid or delay the development of femoroacetabular impingement following mild slipped capital femoral epiphysis.     

Salter-Harris type II fractures of the capital femoral epiphysis

Salter-Harris type II fractures of the capital femoral epiphysis have not been previously documented. The authors have treated three patients who sustained four such fractures. One child had a recurrent fracture two years after the first had healed satisfactorily. Two fractures were treated by spica cast immobilization, one fracture by closed reduction and internal fixation, and the other fracture healed without treatment. No patient developed avascular necrosis or other complications. Two of the children had an association with idiopathic slipped capital femoral epiphysis. An etiologic relationship with slipped capital femoral epiphysis, if any, is uncertain.     

Osteosynthesis with the Hook-Pin in Slipped Capital Femoral Epiphysis

Osteosynthetic materials, such as metallic nails, screws, pins, and bone pegs, used in the surgical treatment of slipped capital femoral epiphysis, have caused peroperative problems because of increased displacement of the femoral head and postoperative problems because of bone resorption and growth of the femoral neck, resulting in loosening of the osteosynthetic material and reslipping of the femoral head. Premature closure of the growth plate and shortening of the femoral neck have also been registered.

In order to avoid these problems, a hook-pin was developed. This device has now been in use for a period of 6 years and has been applied in 38 cases, the pin being placed in a drilled channel with the hook in the femoral head. The operation has been performed on the slipped side with or without reduction of displacement and on the asymptomatic side. Seventy-five hips have been operated on.

The advantages of the hook-pin and of the operative technique are presented. No avascular necrosis has been noted in 74 hips pinned in situ or after closed reduction. Avascular necrosis occurred in one hip after femoral neck osteotomy. All 28 asymptomatic hips and 27 out of 37 hips with slipped epiphyses showed no tendency toward premature closure during a postoperative observation period of 1-6 years. The growth in length of the femoral neck was found to be up to 15 mm, almost the same on the slipped side as on the asymptomatic side.

Only one of the 75 hips required reoperation because of resorption around the hook-pin.

After the end of the growth period the hook-pin was extracted in 19 hips without problems.     

Treatment of slipped capital femoral epiphysis. Spica-cast immobilization

Thirty-two patients (thirty-seven hips) who had a so-called acute-on-chronic or chronic slipped capital femoral epiphysis were treated with traction for relief of symptoms and then with immobilization in a spica cast for eight to sixteen weeks. The disappearance on radiographs of a metaphyseal juxtaphyseal radiolucency, rather than closure of the physis, was used as the criterion for removing the cast. In one (3 per cent) of the thirty-seven hips, the slip progressed; possibly this could have been prevented by keeping the cast on for a longer period of time. Narrowing of the cartilage space was seen after treatment in a cast in seven (19 per cent) of the thirty-seven hips. In five of these seven hips, this was true chondrolysis; in one, the diagnosis of chondrolysis had been apparent before treatment. Avascular necrosis did not develop as a result of treatment in any patient. Treatment in a spica cast should be considered as an alternative for patients who have an acute-on-chronic or chronic slipped capital femoral epiphysis.     

Slipped capital femoral epiphysis long-term results after 10--38 years.

Thirty-four patients with chronic slipped capital femoral epiphysis (SCFE) involving 45 hips were followed over a period of no less than 10 years and as great as 38 years. Excluding those who had had intraoperative complications, 30 hips evaluated between 10 and 20 years follow-up were found to have good or excellent results. Fifteen hips followed greater than 20 years, however, showed fair to poor grading in 10 of 15 hips. This progessive change seemed to be related most closely to the bilateralism of the disease. These observations suggest that while follow-up of a 20 year duration may show good clinical results, over a longer period of time the prognosis of SCFE is guarded.     

Three cases of slipped capital femoral epiphysis in one family

Slipped capital femoral epiphysis is a relatively common disorder of the hip that affects children in late childhood and early adolescence, with an incidence in the United States of approximately 10 per 100,000. Although the diagnosis and treatment of slipped capital femoral epiphysis have been well described, the search for its cause and a method of early identification continues. Recent publications have suggested that there is a familial association among individuals with slipped capital femoral epiphysis, but there is no current genetic marker established for the disorder. This article reports a series of 3 biologically related Caucasian sisters who were athletic; had body mass indices <26 kg/m(2); had no record of any hormonal imbalances or endocrine abnormalities; had good nutrition; and presented with atypical characteristics of slipped capital femoral epiphysis. This is the first report of a series of 3 sisters with slipped capital femoral epiphysis in the United States. Our goals were to document our experience in the identification and treatment of these patients to highlight the complexities of slipped capital femoral epiphysis presentation patterning, to increase the awareness and reporting of familial cases of slipped capital femoral epiphysis by other physicians, and to encourage additional research in this area. As clinicians progress in the ability to diagnose and treat patients with slipped capital femoral epiphysis, they also must be mindful of the varying presentation characteristics.