Abstract
Purpose
The purpose of this study is to show our experience with stainless steel flexible nails in the treatment of femoral shaft fractures in children aged between 5 and 12 years and to observe if the type of material used for nails affects the results.
Materials
A prospective, descriptive study of a series of cases was performed to evaluate patients treated at the Hospital Universitario San Vicente de Paúl (HUSVP) who had been followed up for at least 24 months.
Results
The study group was composed of 48 patients, with an average age of 8.6 years. According to the AO classification, the most common type of fracture was 32A3.2 (61%). The average follow-up period was 43 months. The alterations observed were six cases of clinical length discrepancy, two cases of overgrowing, four cases of shortening, and two malunions in valgus. These alterations had no repercussion in the children's function. The follow-up is the main strength of this study, as it demonstrated that, 2 years after surgery.
Conclusion
The results with stainless steel nails are as good as those with titanium nails with a shorter follow-up as reported in the literature. Given the high costs of osteosynthesis material in our country, the results of this study provide a less expensive alternative. Level of evidence IV, case series.
Introduction
Femoral shaft fractures amount to less than 2% of all fractures in children [1]. Their optimal treatment is controversial, and there is still no consensus on this issue. Most authors agree that femoral fractures in children younger than 5 years require orthopedic treatment. Intramedullary nailing, conventional in adults, is accepted as treatment of choice [2–6] in children older than 14 years. For femoral fractures in children aged between 5 and 14 years, surgical treatments have become popular in the last decade [7, 8] but there is still no standard treatment. Surgical treatments for this age range include, among others, plates [9], external fixators [10] and flexible intramedullary nails, the latter having some advantages over the former two methods [11]. Regarding the material used for flexible nails, the literature on the subject shows titanium is preferred to steel [12]. This study is aimed at sharing our experience with stainless steel flexible nails in the treatment of femoral shaft fractures in children aged between 5 and 12 years at the Hospital Universitario San Vicente de Paúl (HUSVP), and to show that our results are comparable to those published in previous studies, even if we have used a material more economical than titanium.
Materials and methods
A prospective, descriptive study of a series of cases was carried out with patients who had been admitted to the pediatric orthopedics service at the HUSVP with femoral shaft fractures and treated with stainless steel flexible intramedullary nails after May 1, 2000. The clinical histories of the patients were also reviewed. The surgical technique used is standardized in the literature [13]. We used biocompatible, stainless steel flexible nails made in Colombia, available in diameters of 2.5, 3.0 and 3.2 mm, as well as a set of instruments designed by local orthopedists. Those patients who were not followed up for at least 24 months were excluded. The data collected include demographic information, trauma mechanism, type of fracture according to the AO classification for femoral shaft fractures, length of hospital stay, time elapsed between initial injury and definitive stabilization, surgical time, type of fracture reduction, and fracture complications. In patients with bilateral fractures, each fracture was analyzed separately. Follow-up included regular clinical and radiographic check-ups: the first visit was 2 weeks from the surgery date, and then 6 weeks, 3 months and 6 months also from the surgery date. After 6 months, follow-up visits continued every 6 months for a period of 2 years. In the last follow-up visit, a form was filled in with the patient's progress information. Between January and October 2005 all patients who had completed the minimum follow-up period were contacted for a last check-up. For those who could not be reached, the information included in the study was that from their last follow-up visit, 24 months after surgery. To measure angular and rotational deformities, an independent evaluation was performed by two orthopedists external to the study. To determine the length discrepancy, we carried out a comparative and clinical measurement of limbs in the supine position using a conventional tape measure and taking into account the actual length of the limb. Discrepancy was defined as the difference between the real length of each limb. The X-ray test was carried out according to the last X-ray study. Reported results were analyzed jointly based on the raters’ average. All of the procedures, including the index procedure, were approved through informed consent by the adult responsible for the minor. The study was approved by the HUSVP's ethics committee. The data were analyzed with the Epi Info software (v 6.04) and reported in tables.
Results
A total of 48 patients met the inclusion criteria (51 fractures). Demographic profiles are displayed in Table 1.
Demographic variables
The most common mechanism of injury was road traffic accident in 37 cases (77%), followed by falls from heights in eight cases (16.7%), and other traumatic injuries in three cases. Twenty-one patients (43.75%) had associated injuries, 12 had minor head injury and 11 had fractures in other sites, especially in the upper limbs (six cases), the left one being the most affected (63.6%). There were 42 (82.3%) closed fractures and nine open fractures. The most common fracture was the non-comminuted fracture of transverse line in the middle third of the bone (AO 32A3.2) in 36 (70.5%) cases. See Table 2.
Fracture features
A group of 31 patients was treated with transtibial skeletal traction before they received the definitive treatment, due to administrative difficulties in the surgery authorization process. The average time elapsed from initial injury to surgical intervention was 4 days. Fractures were treated within 8 days of the date of injury. Only one case was treated 3 weeks from the date of injury, because the patient had not been timely referred to our institution, which resulted in an unacceptable shortening of more than 4 cm.
The average length of hospital stay was 7.8 days. After surgery, the average length was 2.1 days for the group of patients with no associated injuries.
As for the surgical technique, surgeons preferred the traction table to the conventional radiolucent table. The former was used for 30 (59%) fractures, while the conventional table was used for the remaining 21 (41%) fractures. The fracture focus had to be opened to perform the reduction in 11 (21.5%) fractures, and there was no relationship between this situation and the table employed. No other immobilization treatments like plaster or orthosis were used.
All 48 patients completed the minimum 24-month follow-up, and 36 (75%) of them attended the check-up visit in the last year of the study: The average follow-up period was thus 43.1 months (24–65 months). The results of the patients who could not be reached were based on the data collected in the last follow-up visit, 2 years from the time of injury. By the time the study was finished, all patients had the osteosynthesis material removed within a 24-week period, on average, following injury (the range was from 11 to 56 weeks). There were no complications after the material had been removed. Seven (14%) cases of inflammation were observed at the insertion site because the nails were inserted within a cortical distance superior to the one suggested by the surgical technique; six of those cases occurred in the medial approach; and five required early re-operation (<2 week) because of imminent skin injury.
There were two cases of superficial infection which were treated with oral antibiotics with no subsequent hospitalization, and without their final results being affected. There were five cases of length discrepancy, two cases of 1-cm lengthening, and three cases of shortening (two of 1.5 cm, one of 1 cm). In the last three cases, the oblique fracture line was short (AO 32A2.2). We do not have cases with shortening superior to 2 cm. We observed two angular deformities (of 8° and 10°) in the valgus. At the end of the follow-up period, no rotational deformities were observed. Neither the cases of discrepancy nor angular deformities required additional surgical treatment. Upon completion of the follow-up, there were no patients with re-fracture, deep infection, limited range of motion in the knee, or subsequent pain or limp (Fig. 1).
Case report: A 7-year old patient, left femoral shaft fracture AO 32A3.2 caused by road traffic accident as pedestrian (
Discussion
The election of the best treatment for femoral fractures in children depends on several factors such as age of the patient, type of fracture, fracture-associated soft tissue injury, type of injury, and the social and family component. For many years, the conservative treatment of femoral shaft fractures in children has been used as a rule in orthopedics. Complications of such treatment are compensated by the remodeling capacity of pediatric patients, although this concept has been re-evaluated recently [14].
The treatment of this type of fracture varies according to the age of the patient. The most common treatments are plaster spica in patients younger than 5 years, and internal fixation in adolescent children. There are different alternatives for children who fall between these two age ranges, that is to say, between 5 and 12 years: skeletal traction plus plaster spica, external fixation, internal fixation with plates, or intramedullary nails.
Over the past few years, the literature has been fed by an increasing number of reports on flexible intramedullary nailing as a safe method, which is also reproducible in the treatment of this group of patients [15–21]. One year ago, the early results of the treatment of femoral fractures with steel flexible nails in the HUSVP were published [17], in view of which we decided to assess the technique in the long term, in order to compare our results with those published in the literature.
Regarding the material alloy for flexible nails, no conclusive evidence is provided in the literature that supports the superiority of titanium over steel. Differences between these two materials have been observed in laboratory tests, and, it is generally accepted that steel is stronger, yet less flexible [12, 22].
We do not know of clinical studies in which the difference between these two materials is compared in vivo. However, no short-term differences are found when case reports with steel nails are compared to case reports with titanium nails.
There are few long-term reports in the literature. In the reviewed studies, the average follow-up was from 11 to 27 months, with complication rates ranging from 49 to 63% [19–21]. Although this complication rate is apparently very high, after thoroughly reviewing the data, we found out that the most common complications are associated with problems at the nail insertion site, especially with protrusion of the material. Such problems result from surgical technique errors [13] and do not produce long-term sequelae. In the current study, we encountered this situation in seven patients during the first year of using the new surgical technique.
As for long-term sequelae, several authors have tried to define the criteria for a proper result in femoral shaft fractures. We consider that the Flynn's criteria [23] summarize the purposes of femoral fracture treatment in children. According to these criteria, our results were excellent in 37 (72.5%) fractures, satisfactory in nine (17.6%) fractures, and poor in five (9.9%) fractures (Table 3). In Table 4 our results and observed complications are compared with those of some representative studies on titanium flexible nails.
Flynn's criteria
Results and complications published in the literature
Moroz et al. [24], Flynn et al. have classified the complications into minor and major. The former consists of complications solved with no additional surgery and which do not cause long-term morbidity. The latter, in contrast, consists of complications which require further surgery or which cause long-term morbidity. The incidence of reported complications ranges from 34% to 62%, taking into account that most of them fall into the ‘minor complications’ category. In our series, 16 cases each presented a complication, which represents 31%. This percentage falls in the lower range as reported in the literature on titanium nails.
There were eleven minor complications, from which only one, namely fractured limb shortening, was associated with a predisposition factor like the oblique fracture line (AO 32A2.2). In Narayanan's work [25], an association was found between fracture line and re-operation risk. In the current study, only three out of six observed cases of oblique fracture showed shortening of less than 2 cm. We think that this complication may be avoided if the reduction is made with traction table in this type of fracture. Narayanan's findings could not be confirmed, as no further surgery was required for any case at the end of the follow-up.
The most common complication in our series was nail prominence at the insertion site (14%), which. In six out of seven cases, it occurred in the medial approach. Although the insertion site problems in the series of Moroz et al. were caused by the fracture line and the weight of the patient, in our series this complication was observed in the first year of using this technique because the nails were left protruding too far from the cortical margins (>1 cm). In the subsequent years of the study, we used a redefined technique and this complication was no longer observed.
Five major complications appeared, which were directly associated with medial nail protrusion and which required early re-operation. Surgery did not affect the final result of the patient's function or produce morbidity. No other factors were associated with this complication
Fracture angulation occurred only in two patients. After thoroughly analyzing every case, we did not find any factor directly associated with this issue.
The average length of hospital stay was 7.3 days. After analyzing the hospitalization causes, we realized that the average length of stay had increased because of the group of patients whose associated injuries required intervention. The average length of hospital stay in patients with no associated injuries was 5.2 days, which can be ascribed to administrative problems in the surgery authorization process.
In our country, osteosynthesis material is costly; therefore stainless steel nails present an effective, more economical alternative in the treatment of femoral shaft fractures. The results reached in both the short and the long term are the same as those reached with titanium nails, as reported in the literature.
Our study has disadvantages such as the limited number of patients and the lack of a control group. Therefore, no conclusions can be drawn from these results. However, at the HUSVP, steel flexible nailing is the consolidated method for treating femoral shaft fractures in children aged between 5 and 12 years. Based on our experience and the evidence produced by the studies we have carried out in our region, we recommend this technique for the treatment of femoral fractures in this group of patients.