Discussion
Displaced femoral neck fractures are uncommon injuries in children [
14‐
23], while concomitant fracture of the neck and shaft of the femur is an even more unusual injury [
1‐
7]. Bennet et al. [
7] reported only one case of ipsilateral hip and femoral shaft fracture in children, as compared to 41 such injuries in adults. In 2008, Agarwal et al. [
1] stressed the rarity of this concomitant injury, which can be gauged from searching the indexed English literature. They found only seven cases of such injuries in children less than 12 years of age in the literature. They reported a total of nine cases of such injuries, which included two cases of their own. In this work, we have documented three additional reports that we found in the literature but were missed by Agarwal et al. [
1]; two were published in the English literature in 1983 and 2006, respectively [
9,
10], while the other was published in German in 1986 [
11]. These three reports were published before the report of Agarwal et al. (see Table
1).
Table 1
Patients demographics
1 | Present series (case 1) | 8/F | Left | Road crash | Cervicotrochanteric (Delbet type III; AO type II) | Sub trochanteric | | 1 screw & 3 Kirshner wires for the neck fracture, 5-hole plate and 3 screws for the shaft fracture | 4 | No | No | 52 | Good Ratliff score. Clinically good with a 10° varus deformity at the subtrochanteric level in the femur |
2 | Present series (case 2) | 8/M | Right | Road crash | Intertrochanteric (Delbet type IV; AO type II) | Distal third | Lateral condyle fracture of the right humerus, distal radius fracture of left wrist fx, subdural hemorrhage of brain, ipsilateral sciatic nerve palsy (peroneal division) | 2 screws for the neck fracture, 6-hole plate and screws for the shaft fracture | 3 | Yes | No | 25 | Good Ratliff score. Clinically good except for only a slightly short neck and a 1.5 cm leg length discrepancy |
3 | Akahane | 2/F | Right | Road crash | Transepiphyseal (Delbet type Ib; AO epiphyseal type 1) | Distal third | | Open reduction and internal fixation with 2 smooth Kirshner wires for neck fracture, hip spica cast. A-frame orthosis for the capital epiphysis | 1.5 | Yes | Yes (mild) | 24 | Clinically good, with some coxa vara and premature physeal closure of the medial segent at the 2-year follow-up |
4 | Cannon | 2/F | Left | Fall from height | Transepiphyseal (Delbet type Ia; AO epiphyseal type I) | Midshaft | | Closed reduction and hip spica cast for the neck fracture, and 4-hole plate screws for the shaft fracture | 2 | No | No | 12 | Excellent, except for some coxa vara |
5 | Schwarz | 10/M | Right | | Cervicotrochanteric (Delbet type III; AO type II) | Distal epiphyseal | | 1 screw and 2 pins for the neck fracture on day 23, conservative for the distal physeal fracture | No comment | Yes | Yes (severe) | 188 | Aspherical head, coxa vara, short femoral neck, reversed articulotrochantric distance. Valgus and recurvatum deformity of the distal femur |
Femoral neck fractures in children are well known for their sinister nature and potential for complications, especially avascular necrosis, which poses the most serious problem and has been reported to have a variable incidence [
15,
16,
18‐
22]. It depends on several factors, such as the degree of initial displacement [
15,
17‐
19,
21,
23], the type of fracture [
15,
24,
25], and the timing of surgery [
16,
24].
Upon reviewing all nine cases documented by Agarwal et al. [
1], six of the femoral neck fractures they reported were cervicotrochanteric (Delbet type III; AO type II), one was transepiphyseal (Delbet type I; AO epiphyseal type 1), another was intertrochanteric (Delbet type IV Delbet; AO type III), while the fracture type was insufficiently described to be able to establish it for the other case. The level of concomitant femoral shaft fracture was midshaft in six cases, distal third in one, and the description was insufficient to determine the level in two cases [
1‐
7].
In this study, we have reported an additional five cases (two from our experience and three more reports fould in the literature). The type of fracture neck femur was transepiphyseal (Delbet type I; AO epiphyseal type I) in two cases, cervicotrochanteric (Delbet type III; AO type II) in two cases, and intertrochanteric (Delbet type IV; AO type III) in one case. If all fourteen cases are considered together, the most common type of femoral neck fracture, when associated with ipsilateral femoral shaft injury, is Delbet type III (AO type II) fracture (eight cases).
Although it is not easy to define the mechanism of trauma, we believe that the mechanism of injury must be high-energy impact at both fracture sites simultaneously. We do not think that sequential application of high-energy forces after a time interval can produce another fracture on top of an already unstable previous fracture.
Various treatment modalities have been tried for these injuries—operative, conservative, or a combination of both. Although good results have been reported with all of these treatment modalities in the literature [
1‐
7], the authors advocate operative stabilization of these injuries to reduce the risk of further displacement of the fracture and allow early mobilization [
1,
11]. However, we believe that open reduction and internal fixation of the femoral shaft fracture is the only treatment that permits control over and avoids worsening of the ipsilateral femoral neck fracture; we do not favor it solely because it permits early mobilization. We applied a hip spica cast in both of our cases to promote stability at the fracture site.
We recommend prior fixation of the femoral shaft fracture in these injuries, without attempting to reduce the femoral neck fracture initially, as it provides for more easy subsequent manipulation, reduction, and fixation of the ipsilateral femoral neck fracture. In both of our cases, we fixed the femoral shaft fracture with a plate and screw, and followed this with closed reduction and internal fixation of the femoral neck fracture. However, in one case (case 1), reduction of the subtrochanteric fracture was lost due to proximal screw back-out resulting from inadequate fixation of the proximal fragment, which in turn led to a 10° varus deformity of the proximal femur. In this case, we should have considered the distance between the two fractures to be a prognostic factor, and the possibility of using a low-profile plate that can be modeled in the proximal part to allow introduction of a screw through the proximal hole of the plate into the femoral neck if the two fractures are too close together. We do not need absolutely stable osteosynthesis, because in children younger than ten years it is always advisable to create a spica cast.
At the 2-year follow-up, there was a residual 10° varus deformity of the proximal femur without leg length discrepancy, although leg length discrepancy was noted as being a problem in case 2; this could have occurred after plate and screw fixation when treating the femoral shaft fracture in the child.
Agarwal et al. [
1] also noted that a combination of ipsilateral femoral neck and shaft fracture in children had a low incidence of complications. They proposed that the fractures that occur at the two sites in the same limb probably have a symbiotic effect, and that the impact energy was distributed at the time of the initial trauma, thus preventing extreme damage to either of the fracture sites. However, in their report, they only noted cervicotrochanteric and intertrochanteric types of femoral neck fracture, which are less prone to avascular necrosis than the transepiphyseal or transcervical types. In our review of an additional five cases, two had avascular necrosis of the capital epiphysis: one was a transepiphyseal fracture with major displacement (Delbet type Ib) [
9] which was treated with open reduction and internal fixation, while the other was a cervicotrochanteric fracture [
11] diagnosed on day 9 and operated on day 23 after the initial injury. We do not agree with the view that a symbiotic effect at the time of initial trauma plays a significant role in the prognosis of these injuries, because our study showed relatively high complication rates with transepiphyseal and transcervical femoral neck fractures, which were not presented in the previous literature.
We believe that prior fixation of the femoral shaft fracture in these injuries simplifies the subsequent manipulation, reduction, and fixation of the ipsilateral femoral neck fracture, and that the results of these injuries depend on the severity of the initial trauma, the fracture type, and the timing of surgery.