Clinical outcome after transfixation of the epiphysis with Kirschner wires in unstable slipped capital femoral epiphysis

Treatment of slipped capital femoral epiphysis (SCFE) is still controversial. Agreement has not yet been reached on the appropriate time to perform surgery, the necessity of repositioning manoeuvres, the type of implants for stabilisation, or the need for prophylactic treatment of the contralateral side. In this retrospective study, we present 29 patients with unstable (acute and acute-on-chronic) SCFE treated by internal fixation of the epiphysis with three or four Kirschner wires both therapeutically on the affected side and prophylactically on the not (yet) affected side. After hardware removal and mean follow-up of 3.5 years, radiological and clinical examination of hip function was carried out. X-ray in two planes showed no incidence of any slip progression. Applying the score used by Heyman and Herndon, 18 results (62.1%) were classified as excellent, nine (31.1%) as good, one (3.4%) as fair, and one (3.4%) as poor. The rate of severe complications such as chondrolysis and avascular necrosis of the femoral head was low in our series (0% and 6.8%, respectively). This form of therapeutic management shows good clinical results with low complication rates. The slip can be efficiently stabilised, progression is reliably prevented, and remodelling of the joint gives the patient good overall hip function. We see no indication for emergency surgery.     

Long-term outcomes of slipped capital femoral epiphysis treated with in situ pinning

Purpose

Slipped capital femoral epiphysis (SCFE) is the commonest hip disorder in adolescents. In situ pinning is commonly performed, yet lately there has been an increase in procedures with open reduction and internal fixation. These procedures, however, are technically demanding with relatively high complication rates and unknown long-term outcomes. Nevertheless, reports on long-term results of in situ fixation are not equivocal. This study evaluates the possible higher risk of worse outcome after in situ pinning of SCFE.

Methods

All patients treated for SCFE with in situ fixation between 1980 and 2002 in four different hospitals were asked to participate. Patients were divided into three groups, based on severity of the slip. Patients were invited to the outpatient clinic for physical examination and X-rays, and to fill out the questionnaires HOOS, EQ5D, and SF36. ANOVA and chi-squared tests were used to analyze differences between groups.

Results

Sixty-one patients with 78 slips filled out the questionnaires. Patients with severe slips had worse scores on HOOS, EQ5D, and SF36. 75 % of patients with severe slips had severe osteoarthritis, compared to 2 % of mild and 11 % of moderate slips.

Conclusion

Hips with mild and moderate SCFE generally had good functional and radiological outcome at a mean follow-up of 18 years, and for these hips there seems to be no indication for open procedures. However, severe slips have a significantly worse outcome, and open reduction and internal fixation could therefore be considered.

     

Remodelling after pinning for slipped capital femoral epiphysis

We assessed 70 hips at an average of 7.1 years after pinning for slipped upper femoral epiphysis to determine the frequency of remodelling, what factors influence it and its effect on the clinical outcome. Remodelling was defined by a new classification of the anterior femoral head-neck profile as seen on the lateral radiograph. Remodelling occurred in 50% of hips with a head-shaft angle of 30 degrees or more; the probability of remodelling was significantly less the greater the degree of slip, but was significantly increased if the triradiate cartilage was open at the time of presentation. We found no significant effect for age, sex, weight or length of symptoms. The range of internal rotation was significantly greater in those hips that remodelled. We support the treatment of moderate slips in skeletally immature patients by pinning in situ, since the probability of satisfactory remodelling was 75% for slips of 40 degrees or less.     

Closed reduction and pinning for acute slipped capital femoral epiphysis]

Acute slipped capital femoral epiphysis is a rare adolescent hip disorder, which may be a problem for orthopedic surgeon. No series to date has demonstrated the superiority of any treatment method. The purpose of the study was to evaluate the outcome of treatment and to assess the risk factors of avascular necrosis associated with this condition. Fourteen cases of acute slipped capital femoral epiphysis were treated with closed reduction and pinning. There were 9 boys and 5 girls. The average age at presentation was 11.8 years (range 9.1-15.3). Eight children were treated 4-10 days and six within 48 hours of the onset of their acute symptoms. The severity of the slip was classified according to the system of Southwick. Presence of chondrolysis and avascular necrosis was estimated. The clinical results were graded with the use of the criteria of Aadelen et al. Four slips were classified as mild, seven as moderate and three as severe. Average follow up was 5.2 years (range from 2.4 to 14.3). In two hips with severe slip AVN developed. One of these cases was treated within 48 hours and one after 7 days. Chondrolysis developed in one hip and was associated with presence of intra-articular fixation. Twelve of the fourteen hips had good and vary good results and remaining 2 with AVN had poor. Closed reduction and pinning in acute slipped capital femoral epiphysis is an effective and giving satisfactory outcome method of treatment. Early reduction is not associated with a high rate of AVN and should be performed as soon as possible. More severe slips were noted to have an increased risk of AVN.     

Progressive slippage after pinning for slipped capital femoral epiphysis

The authors retrospectively reviewed seven cases of progressive slipped capital femoral epiphysis after screw fixation. All seven patients initially presented with chronic symptoms, and five had an acute exacerbation of symptoms with the appearance of an acute-on-chronic slip. Of the other two, one had obvious motion at the proximal femoral physis and the other had increased symptoms but did not have an obvious acute slip radiographically. All underwent percutaneous screw fixation. In four patients a single screw was placed, and in three patients two screws were placed. No patient became symptom-free after surgery. Slip progression was noted on average 5 months after treatment. Radiographs in all patients revealed an increase in slip severity and loss of screw purchase in the femoral neck while fixation in the proximal femoral epiphysis remained secure. One patient had hypothyroidism and another Cushing disease, both diagnosed after the slipped epiphysis. Slips occurring in children with underlying endocrinopathies, and unstable slips in children with a history of antecedent knee or hip pain (commonly called an acute-on-chronic slip) may be susceptible to screw fixation failure. In such patients, close radiographic follow-up, particularly in the presence of continued symptoms, is required to document slip progression and fixation failure as soon as possible.     

Results of treating slipped capital femoral epiphysis by pinning in situ

The primary aim in treatment of chronic SCFE consists of immediate stabilization of the epiphysis to prevent further slipping. For mild degrees of slipping (<30°), pinning in situ is the treatment of choice. With slips between 30 and 50°, the decision should be based on individual factors (age, functional limitation of the hip joint) whether pinning in situ is sufficient or whether an additional intertrochanteric osteotomy according to Imhäuser should be performed. The choice of implant should ensure a safe and stable connection between the epiphysis and the femoral neck without resulting in a substantial impairment of growth of the femoral neck due to premature closure of the growth plate. Since 1982 we have used K wires for in situ pinning of the affected hip as well as for prophylactic pinning of the nonaffected hip with a low complication rate. In a clinical and radiological study, 65 patients with a chronic slip of less than 50° could be assessed after in situ pinning. Almost 75% were pain-free after a follow-up interval of 9.8 years, and 92% achieved a good or very good result according to the criteria of the Iowa hip score, the mean score being 95.1 points. According to the radiological score of Schulitz, five patients (7.7%) demonstrated a grade I osteoarthritis. One patient showed a partial necrosis of the femoral head; chondrolysis was not observed.     

Long-term results of pinning for slipped capital femoral epiphysis]

Clinical and radiological analysis of 39 hips in 32 patients treated with in situ pinning for light and non-severe (up to 78 degrees) slipped capital femoral epiphysis. The population of 21 boys and 11 girls aged 10-16 (av. 13.1) was observed in 4-27 (av. 21) years. The observation showed 18.8% very good, 18.8% good, 46.8% satisfactory, 12.5% bad results and 3.1% (1 patient) of unsuccessful treatment, according to Heyman & Herndon clinical evaluation scale. Radiological evaluation of secondary coxarthritis acc. to Boyer: 0 - 35.,8%, I - 23.1%, II - 33.4%, III - 7.7%. Slipped upper femoral epiphysis causes secondary coxarthritis. Kirschner wire pinning is good method for non-severe cases.     

Risk-benefit analysis of prophylactic pinning in slipped capital femoral epiphysis

There is a broad and controversial discussion about the surgical procedure and the type of hardware for internal transfixation of the epiphysis and metaphysis in slipped capital femoral epiphysis (SCFE). Prophylactic pinning is even more controversial. One hundred and nine patients showing SCFE underwent a one-stage bilateral fixation of the epiphysis with three or four Kirschner wires (pins). From these 109 patients (69 male and 40 female), 94 had an unilateral slip and were operated prophylactically on the contralateral side. There were no complications such as avascular necrosis of the femoral head, chondrolysis, bone fracture, failure of metal implant, osteomyelitis or deep wound infection either at the time of surgery or at the minimum follow-up of 1 year with prophylactic pinning in SCFE. Therefore, we consider pinning allows for efficient stabilization, reliably preventing any progression of SCFE on the affected side and, furthermore, prevents the incidence of a secondary slip on the primarily nondisplaced contralateral side. The transfixation of epiphysis and metaphysis with Kirschner wires (pins) shows good subjective and objective long-term results compared with other surgical methods and implants. There is only a low morbidity rate with this method, because reoperations may only become necessary in the younger age group owing to normal growth of the femoral neck, compared with a high benefit from prophylactic surgical treatment of the nonaffected opposite side at the time of unilateral onset of the disease. The pins may no longer catch the epiphysis but further growth will allow for remodeling of the femoral head and for an optimal neck/shaft ratio. In case of further growth and relative shortening of the pins, refixation may become necessary. Therefore, we like to recommend the Kirschner-wire transfixation (pinning) of the epiphysis and metaphysis in patients with SCFE for primary treatment of SCFE as well as for prophylactic pinning of the contralateral side in one sitting.     

Chronic slipped capital femoral epiphysis: treatment by pinning in situ.

Chronic or stable slipped capital femoral epiphysis (SCFE) is a lesion of the hip, affecting the adolescent patient through adulthood. The change in the shape of the femoral head and to the biomechanics of the hip joint leads to early osteoarthritis. Treatment of SCFE is designed to stop slip progression to reduce the degree of osteoarthritis. Complications, such as avascular necrosis and chondrolysis, may also cause osteoarthritis. In situ pinning of SCFE is considered the best treatment modality currently available. In situ pinning of SCFE has the advantages of effectiveness, low morbidity, and a low complication rate. These advantages outweigh the disadvantage of fusing the slip in the uncorrected position. The authors review the indications, the techniques of in situ pinning, the results, and the complications of the procedure. The technique of in situ pinning necessitates experience and understanding of the anatomy of the adolescent hip, as well as adequate imaging equipment.     

An improved method for pinning of chronic slipped capital femoral epiphysis

A simple method is described for pinning of slipped capital femoral epiphysis with a stationary x-ray machine and the limb draped free. The leg is "frogged" for a lateral view, and positioned under radiographic control to avoid pin penetration into the joint.     

Remodeling after in situ pinning for slipped capital femoral epiphysis]

We reviewed 61 hips in 50 children (33 boys and 17 girls) with slipped capital femoral epiphysis (SCFE), all treated by in situ pinning. Average age of our patients was 11.8 years (range, from 8 to 15 years). The average clinical and radiographic follow-up was 7.4 years. By studying the changes in physeal-shalt angle on radiographs in Lauenstein (frog) position, we found evidence of physeal remodeling in three (8%) of 38 mild and seven (30%) of 23 moderate slips. Remodeling of the proximal femoral metaphysis occurred in 92% of hips with a head-shaft angle less than 30 degrees and in 52% of hips between 30 degrees and 60 degrees. A process of local resorption and apposition of bone seems to be essential to final remodeling. The probability of remodeling was significantly less the greater the degree of slip, but was significantly increased among children 11 years old or younger and if the triradiate cartilage was open at the time of presentation. The range of internal rotation was significantly greater in those hips that remodeled. Pinning in situ of a slipped capital femoral epiphysis represents a simple, quick and effective method of treatment, allowing remodeling in mild and moderate slips.     

Epidemiological perspective on prophylactic pinning in patients with unilateral slipped capital femoral epiphysis

The purpose of this review was to determine whether the literature supports in situ prophylactic pinning of the hip contralateral to a hip with a slipped capital femoral epiphysis (SCFE). Three hundred twenty-five articles on SCFE between 1931 and 1998 were reviewed. Two hundred six studies were used to establish normative data. Patients with a unilateral SCFE were 2,335 times more likely to develop a SCFE in the contralateral hip when compared to children in the general population experiencing an initial SCFE. Because a majority of these sequential SCFEs were detected and treated early, we concluded that close follow-up and not prophylactic pinning was most supported by the literature.     

Remodeling in slipped capital femoral epiphysis: sonographic assessment after pinning.

Twenty-one children and 26 hips with recent slipped capital femoral epiphysis (SCFE) underwent serial sonographic examination after operative fixation. The initial sonographic step at the anterior outline of physis decreased as a result of metaphyseal resorption. The first signs of resorption were evident 3 weeks after onset of symptoms; thereafter, the rate of resorption was 2 mm for each 3 weeks of follow-up. Finally, the physeal step was smooth and the anterior aspect of the femoral neck was straight. Sonography is accurate and free of projectional errors in assessment and classification of remodeling in SCFE.     

Radiological risk factors of bilaterality in unilateral slipped capital femoral epiphysis]

The aim of the study was to determine radiological risk factors of development of secondary contralateral slip in patients with primary unilateral slipped capital femoral epiphysis (scfe). The material consisted of 115 patients operated because of scfe in the Institute of Orthopaedics and Rehabilitation at the University of Medical Sciences of Poznań in 1968-1991. There were 75 boys (65%) and 40 girls (35%) at the mean age 12.8 years. The retrospective analysis showed that contralateral slip developed more often in patients with more vertical orientation of subcapital growth plate (with Alsberg angle less than 60 degrees). The neck-shaft angle, slip angle, slip direction and negative Klein's sign has no prognostic value according to development of secondary contralateral slip. More than 1/3 of the patients with unilateral scfe developed silent, subclinical contralateral slip. In most of that patients radiological signs of preslip stage of contralateral slip can be observed (positive Klein's sign, pathological neck-epiphyseal angle).