Pediatric orthopaedists discuss the new AAOS clinical practice guidelines
The first set of pediatric clinical practice guidelines—on the treatment of diaphyseal femoral fractures—are included in this issue of AAOS Now (see cover story). Because little Level 1 evidence exists, resulting in just two recommendations of grade A or B, several experienced pediatric orthopaedists—including James H. Beaty, MD (moderator); Stephen A. Albanese, MD; John M. Flynn, MD; and James Kasser, MD—participated in a roundtable discussion on the guidelines.
Dr. Beaty: I think it’s important that we begin this discussion by noting that the summary of recommendations is not meant to stand alone and that the entire document should be read to understand how the committee arrived at these recommendations and to appreciate the tremendous effort that went into the guidelines.
So, first of all, do you have any comment on the scientific evidence used to formulate the recommendations?
Dr. Kasser: I was surprised that little evidence exists to support pretty straightforward methods of managing a common injury. Maybe that’s because treatment of most femoral fractures, especially in young children, is simple and successful and doesn’t make for a very exciting study. Even though there aren’t high levels of evidence, it doesn’t necessarily mean that we don’t know what we’re doing.
Dr. Flynn: Because there are multiple treatment options, orthopaedists generally choose the one that works well for them. So I think it’s good that the guidelines give recommendations with some flexibility instead of stating that one specific treatment is always better than another. There are lots of ways to get a good result.
Dr. Beaty: What about the age ranges used in the recommendations? Are they valid criteria for making treatment decisions?
Dr. Flynn: I think the age ranges work pretty well and are helpful; they fit well with what we do in practice.
Dr. Albanese: I look at the fracture pattern and the size of the child, but patients do seem to fall into the age ranges the guidelines describe.
Dr. Kasser: With the prevalence of childhood obesity, the child’s size is an important factor in treatment choice, but, in general, the age is a pretty good indicator.
Harnesses and spica casts
Dr. Beaty: Let’s talk about the specific treatment recommendations, particularly those that have low-level evidence to support them, such as the use of the Pavlik harness in infants younger than 6 months. What factors influence your decision to use a Pavlik harness?
Dr. Albanese: It’s primarily the size and strength of the child—not just the age.
Dr. Flynn: I really like the harness in the hospital setting, such as for a child in the neonatal intensive care unit who’s getting round-the-clock monitoring and isn’t going to be moved around much.
Dr. Kasser: Because of the thick periosteum in young children, femoral fractures often aren’t as unstable as they seem, so I think the harness is worth a try. If the fracture doesn’t shorten a lot and the baby seems comfortable, it’s a good treatment option.
Dr. Beaty: So societal, parental, and other family factors that aren’t clearly outlined in the guidelines might come into play and maybe change the treatment, more so than the age of the child or the fracture patterns.
Let’s move on and talk about the guidelines for early spica casting in the next age group (Fig. 1), with femoral shortening of less than 2 cm. Is the 2-cm rule written in stone?
Dr. Flynn: What we know about overgrowth directs our decision about how much shortening we’re willing to accept. Although overgrowth is variable, we know it’s about a centimeter in kids aged 2 to 10, so we’re willing to accept maybe 1.5 cm to 2 cm, but much more than that and we’re going to end up with a leg-length discrepancy.
Dr. Kasser: I might have more tolerance for initial shortening, but if it’s more than 2 cm once the child is in the cast, I would change to some internal fixation technique or use traction. I wouldn’t accept more than 2 cm in a spica cast.
Dr. Beaty: How often do you find that you have to alter your treatment plan, as noted in the guidelines, when shortening or angulation develops in a child younger than 5 or 6 years who is being treated with a spica cast?
Dr. Kasser: It’s pretty rare. We looked at 120 fractures treated in spica casts and only 20 percent had the cast changed and only 3 percent were changed because of bone alignment.
Dr. Flynn: I’ve noticed that the surgeons at our institution are putting the cast on with less hip and knee flexion and leaving the foot out more, and we’re seeing a little more shortening.
Dr. Albanese: We haven’t looked at the exact frequency, but I would guess that fewer than 10 percent require a cast change.
Dr. Beaty: So what happens when you have a child aged 6 years or younger who has unacceptable shortening or angulation in the cast?
Dr. Flynn: If you get really significant shortening at about 2 weeks in a 5-year-old, external fixation for 3 to 4 weeks works pretty well to get the fracture back out to length.
Dr. Beaty: What’s the amount of angulation in a 5- or 6-year old that you would not accept?
Dr. Flynn: For a proximal fracture, I might accept up to 20 degrees because that seems to remodel pretty well, but distal at the knee I don’t accept much at all, maybe only 10 degrees.
Dr. Albanese: I also think the location on the shaft is important—angulation around the knee is not tolerated well.
Dr. Kasser: I agree. More angulation can be accepted in the proximal or mid-shaft, but if angulation is more than 10 or 15 degrees around the knee, it will look pretty bad.
External fixation and IM nailing
Dr. Beaty: OK, let’s talk a bit more about external fixation. Because of problems with external fixation, such as delayed union and refractures, and the advent of flexible intramedullary (IM) nails, have you seen the use of external fixation decline in your practice?
Dr. Albanese: I use external fixation occasionally in a multiple trauma situation, where we’re looking for quick stabilization to help stabilize the patient in general.
Dr. Flynn: Pretty narrow indications in our practice, but some like external fixation better for a younger child with a length-unstable fracture where they don’t want to use flexible nails. The other situation where I sometimes see it used is for pathologic fractures around the knee.
Dr. Beaty: Let’s move on to flexible IM nailing for 5- to 11-year olds, as mentioned in the guidelines. All of you have considerable experience with this. What have you learned in the past 10 years that you can pass along?
Dr. Kasser: When this technique first came out, it was touted as the ideal method of management for almost all femoral shaft fractures, even those in large patients with unstable fractures. We have found, however, that in patients weighing more than 100 pounds, and particularly in length-unstable fractures, significant problems can develop. That narrowed the indications somewhat. For many fractures it works fine, but it’s not a simple technique that has uniformly excellent results.
Dr. Albanese: Length-unstable fractures are an issue, as is large size; I tend to use 90 pounds as the cut-off.
Dr. Flynn: Basically in length-stable fractures, if you use nails of the same diameter in a retrograde technique, make sure to engage the proximal fragment all the way up into the dense metaphyseal bone of the proximal femur (Fig. 2). That can give excellent results. It’s the length-unstable and some of the more proximal and distal fractures where a few tricks—and a lot of experience—are needed to get a good result.
Dr. Beaty: In your practice, has the age range mentioned in the guidelines for flexible nails been modified to include older or younger children?
Dr. Albanese: I don’t know that I have gone any younger than 5 years old. On the upper end, it depends on the size of the child. We’re starting to see some pretty big 10- and 11-years olds who just aren’t candidates for flexible nailing. I agree that you really have to pay attention to the technical details; even in well-suited fracture patterns; you might have to “fiddle” some to get the reduction.
Dr. Beaty: What are your indications for the use of a rigid trochanteric-entry IM nail (Fig. 3)?
Dr. Kasser: Probably a kid who’s older than 12 years of age, large, and has an unstable fracture pattern; however, I’m often torn between IM nailing and submuscular plating.
Dr. Flynn: I agree. For a larger youth and a stable fracture, we would use either a trochanteric-entry nail or a submuscular plate. Our center tends to use the nail more often than the plate.
Dr. Albanese: We do the same, but I would say we probably lean in the other direction, more toward submuscular plating than IM nailing.
Dr. Beaty: What’s the youngest child in your practice in whom you’ve used trochanteric nailing?
Dr. Flynn: I think in our center I have seen it used in some really big 10-year olds, but that’s the lower limit.
Dr. Albanese: A little older for us—more in the 13-year-old range.
Dr. Kasser: We’ve gotten some of the small trochanteric nail systems, thinking that we might use them in some younger children—8-, 9-, or 10-year olds—but currently we don’t go younger than 13 or 14 years old.
Dr. Beaty: Are any of you using submuscular plating in 12- to 16-year-olds instead of trochanteric nailing?
Dr. Kasser: I think it’s a pretty good technique, especially for some unusual fracture patterns or pathologic lesions that can be managed pretty nicely with a submuscular plate.
Dr. Flynn: It’s an important treatment option, but we use more trochanteric nails than submuscular plates.
Dr. Beaty: Have you seen any concerns about osteonecrosis (ON) or trochanteric growth with these nails at your institution?
Dr. Kasser: No, I haven’t. A lot of people use these nails in 9- and 10-year olds and say there’s not a problem with either ON or growth abnormalities. With the smaller nail systems, I think trochanteric nailing probably is going to have an increasing role. Then maybe we’ll see the true incidences of ON and growth abnormality, but until there are several thousand cases we won’t know. It took some years to determine what the incidence of ON was with standard nailing, somewhere in the 1 percent to 3 percent range. With the smaller rod systems, it looks like a safe approach.
Dr. Albanese: I have not seen any cases of ON with trochanteric nailing, but it could be that we haven’t done enough of them at our institution.
Dr. Flynn: We haven’t seen a case in the last decade that I’m aware of.
Dr. Beaty: Since the one case we reported in the early 1990s, we haven’t seen any ON either, but it does take large numbers and more follow-up to get a more conclusive number.
Let’s move on and talk about implant removal. First, what is your timing on removal of an external fixator?
Dr. Kasser: Because the reported refracture rates are quite high, one study suggested having three-cortical contact, so I would look for at least three-cortical contact, but would love to see four, solid healing. Then I dynamize the patient and have him or her walk around for a couple of weeks. Refracture has been pretty rare, but I must say that I abandoned external fixation for most cases probably 10 years ago.
Dr. Flynn: I saw a couple of cases at our place where re-fracture happened through the pin site after removal of the fixator. I think Jim’s recommendation is right on the mark, to leave the device on to get true healing of the fracture and the importance of dynamization. But I, and I think my partners, use it much more as portable traction. We’ll put the device on until we see enough callus that there won’t be shortening, then we take it off and put on a walking spica cast.
Dr. Beaty: What about removal of flexible IM nails? Do you remove them in the average 8- or 9-year old patient?
Dr. Flynn: We take almost all of them out, and we take them out when we don’t see the fracture line any more, which is about 6 months. I would say that 95 percent of the titanium elastic nails put in at our center are removed about 6 to 12 months after fracture.
Dr. Albanese: We remove most of them at about 6 to 12 months.
Dr. Beaty: Because the clinical guidelines for nail removal are level 4, inconclusive, can you add any expertise to this?
Dr. Albanese: There is no scientific evidence higher than level 5. We might leave the rod in with a pathologic fracture, but I take them out with any other fracture.
Dr. Beaty: What about submuscular plates?
Dr. Albanese: We remove most of them, particularly if the kids are a little younger. Once again, it’s not based on any high-level scientific evidence, it just seems a logical thing to do to avoid a stress riser and allow the bone to develop normally.
Dr. Kasser: We don’t use plates a lot, but in younger kids we would remove them; in the nearly skeletally mature, we usually leave them in. If you don’t get the plates out by about 6 months, they start to get covered by bone and it’s a fight to get them out. So I think if you’re going to take them out, you need to do it early.
Dr. Beaty: Another thing mentioned in the clinical guidelines is physical therapy. What’s your experience with this?
Dr. Albanese: I rarely recommend physical therapy.
Dr. Kasser: We found that children with significant trauma have some quadriceps atrophy, more than you would think, and a strengthening program helps improve their gait and keeps them from limping.
Dr. Beaty: Two other topics in the guidelines that we haven’t discussed are waterproof cast liners and spica casting. Do you use any waterproof lining?
Dr. Albanese: I have used them, but don’t believe they make a lot of difference. In some circumstances I think they retain the moisture against the skin. So I haven’t been very enthusiastic.
Dr. Kasser: We routinely use a Gore-Tex® pantaloon liner covered with cotton.
Dr. Flynn: I think it does seem to help the skin and we use it more for elective spica casting; in the trauma situation it often isn’t available.
Dr. Beaty: To summarize, the clinical guidelines are based on pretty reasonable age ranges, but the age range does fluctuate a bit based on size, fracture pattern, and other factors, and indications seem to be evolving for different devices based on new implant design. Perhaps that’s what we will continue to see over the next 5 to 10 years and may have an impact on future guidelines.