Managing Pediatric Spinal Deformities and Procedural Complications

Anya Romanowski, MS, RD


August 03, 2017

Editorial Collaboration

Medscape &


Patrick J. Cahill, MD

The Children's Hospital of Philadelphia (CHOP), one of the leading hospitals for pediatric care, covers the breadth of pediatric orthopedic conditions—from spine and hand deformities to bone fractures and tumors, and everything in between.

Medscape interviewed Patrick J. Cahill, MD, an attending physician and orthopedic surgeon at CHOP, to find out more about the complexity and challenge of performing surgeries in children with spine conditions.

Medscape: You recently gave a presentation about avoiding and managing complications in pediatric spinal deformity surgery, such as neurologic injury, infection, loss of fixation, pseudoarthrosis, and other medical complications.[1] Could you describe a bit more about that presentation?

Dr Cahill: This was an instructional course lecture that I put together with several of my colleagues surrounding complications in pediatric spine deformity. This is a hot topic in our field for a number of reasons.

First, there is more scrutiny of physicians and their patients' complications. Insurance payers are linking their reimbursements to physician performance and quality measures. Among the most quantifiable and easily followed quality measures are complication rates and such events as rehospitalizations, readmissions, and revision surgery rates.

Second, these issues are important when we counsel families who are considering spine deformity surgery for their children. These discussions are becoming more specific and focused, with an emphasis on shared decision-making, through which physicians and families partner together to make decisions about the child's care.

From my perspective, I know pediatric spine deformity surgery, and families know their children. My job is to educate families about the risks that are inherent in the proposed treatments and let the families ultimately make the final decision. But that process involves having very good data on specific complication rates and the effects of those complications.

That was the impetus for this instructional course. We went through each common complication and enumerated the rates and preventive measures that can be taken to avoid those complications. Then we also discussed the treatment for each of the complications.

Among the exciting advances emerging in the area of orthopedic complications is infection reduction. There are specific measures, such as using powdered antibiotics in the wound at the end of surgery, that seem to be reducing infection significantly.

There are also global, systemic interventions that are having a positive impact on infection rates. These include hospital-wide infection prevention bundles, so that children who are undergoing spine deformity surgery will have preoperative skin cleansing the night before surgery, certain measures taken during surgery to irrigate the wound, and specific antibiotic protocols, among others. A number of hospitals, including Columbia University in New York, have implemented these to dramatic effect in their overall infection rates.

Medscape: I have noticed that recently, antimicrobial sutures and other products are coming out to minimize surgical site infections.[2] Are you finding these kinds of efforts helpful? Or is taking other preventive steps to minimize specific infections more effective?

Dr Cahill: Infection reduction involves many small steps. Sometimes, these measures are all being applied at once, and it is hard to figure out which one has the real impact factor. It may also simply be that the institution and everyone involved with these children are paying more attention to preventing infection. This is called the "Heisenberg uncertainty principle" or the "Hawthorne effect"—you cannot observe something without changing it. If everyone in the hospital is dedicated to preventing infection, perhaps it is a lot of little things at once that are preventing infection. Certainly, new technologies and advances contribute to that. I have not heard about the antibiotic suture, but it sounds intriguing.

We are beginning to answer other questions with big data. So my colleagues and I who presented this instructional course lecture are part of a consortium called the Harms Study Group for pediatric spinal deformity. This group prospectively collects data on adolescent idiopathic scoliosis surgery and neuromuscular scoliosis surgery. We then can look for and pool patients with good results and compare them with those in patients with bad results, or we can look at patients with complications and see how they are different or see which sort of interventions may be more or less likely to lead to an infection.

One interesting outcome of those data was that the metal used in the spinal implants was found to be associated with the infection rate. Patients who received stainless steel implants had a much higher infection rate than patients who had implants made out of titanium.

That is the sort of question that only big data can answer, and it is the kind of question that we are beginning to be able to answer with those tools.

Medscape: Are you finding a higher rate of any specific area of infection?

Dr Cahill: Certain diagnoses, such as neuromuscular conditions, have higher rates of infection. In particular, spina bifida has a very high rate of infection. But that circumstance is multifactorial and is not new. And until the infection rates are zero, we will continue to try to innovate in those areas.

Medscape: Does the age of a child affect the rate of infection? Is there any difference between those who are having the surgeries performed earlier as opposed to later on in life?

Dr Cahill: Yes, it does seem that age is a factor in infection rate: Patients who are very young at the time of spinal deformity instrumentation have a slightly higher rate than those who are older.[3] Thus, many factors may be involved, and age is one of them.

Medscape: Any final thoughts about this presentation?

Dr Cahill: I just want to highlight the humility of my colleagues who participated in this course lecture. It is not easy talk in front of a crowd about your failures and procedures that did not go well. The colleagues who presented with me are thoughtful and humble people who are doing it because they want care to be better not just for their patients, but for all patients who undergo pediatric spine deformity surgery.

Medscape: Another surgeon, a surgeon-in-chief, made a very similar observation to me. He said that we can all pound our chests about the 95% of the time these surgical procedures are completely successful. But we need to focus on the 5% that have complications, because the only way to achieve better outcomes is to bring these problems to the forefront.

I want to move on to another program that focused on the evolution of the treatment for scoliosis over the past 20 years. How have the outcomes improved?

Dr Cahill: This work also comes out of the Harms Study Group, a multicenter prospective registry for pediatric spine deformity surgery. The registry was named after Professor Jürgen Harms in Germany, who is one of the founding members and a luminary in our field. It grew out of the idea that we need to look prospectively at our patients and our results. Pooling the experience from multiple centers and multiple surgeons is the best way to get a very detailed and granular look at some of the more subtle differences in outcomes we see in our patients.

That registry has been tremendously valuable for our field as a whole, and it has probably been the single most important source of data and information in adolescent idiopathic scoliosis. This particular paper was presented by one of my colleagues, Dr Baron Lonner.[4] The paper focuses on the changes that have occurred in the care of adolescent idiopathic scoliosis over 20 years.

At the onset of the Harms Study Group 20 years ago, we were performing about equal numbers of anterior and posterior spinal fusion in adolescents. Now, we are performing posterior spinal fusion almost exclusively. Average blood loss per case has gone down over the past two decades. It seems that with the ability to communicate with each other through this sort of forum, our field as a whole has gotten more efficient.

Our surgical times are lower, and the length of hospitalization is shorter. This is probably the result of collaborative and interactive efforts by the Harms Study Group (and by such organizations as the American Academy of Orthopaedic Surgeons and the Scoliosis Research Society), which allow us to get together and talk about our results and hold up those surgeons who have the best results in one particular area—whether it's postoperative complication rates or intraoperative blood loss or what have you.

Medscape: Have any technological advances assisted in these improvements? I am thinking in particular of the length of time it takes to perform the procedures.

Dr Cahill: That is a good question. There are various technological advances, such as Aquamantys (Medtronic), a sealing device that prevents intraoperative blood loss. There also have been changes in the settings for which Bovie electrocautery is used. The use of antifibrinolytic medications has changed; these drugs reduce the need for transfusion and the risk for blood loss during surgery. All of these innovations are probably incrementally contributing to the gradual trend toward improved perioperative outcomes in adolescent idiopathic scoliosis.

I believe that surgeons are probably achieving shorter fusions and getting better correction as the instrumentation has become more powerful with time, as we have moved away from constructs that involve a lot of hooks to constructs that involve a lot of screws. I believe these changes have incremental effects in improving our patients' outcomes.

Medscape: Can you tell us what was presented at this year's kids' device forum?

Dr Cahill: My partner, Dr Bob Campbell, started this about 3 years ago. He saw a need for industry, physicians, and regulatory bodies to come together, in a semi-offline format, and discuss in a free and open way the regulatory processes surrounding pediatric spinal implants and how we can get new technology to our patients in a safe and efficient manner.

That has evolved to this year, when the forum was dedicated solely to the discussion of vertebral tethering surgery, which is an emerging technology and treatment for idiopathic scoliosis or scoliosis in immature patients. This procedure does not require a fusion, but rather guides growth in a manner similar to the way growth is guided in children with angular deformities of the legs, for example. Attention has moved toward ways to accomplish this in the spine.

The discussion revolved around the basic science behind those emerging techniques, the regulatory pathways that may bring new devices and ideas to the market, and defining the optimal clinical outcomes and clinical research surrounding those efforts.

Medscape: What is unique with children undergoing procedures, as opposed to adults, is that they are still growing. That fact obviously adds to your considerations and how to approach these surgeries, because you are not dealing with defined bones. They are still quite malleable, and there is a lot to consider.

Dr Cahill: A lot of variables are still undefined in this field. We do not have the kind of good data on the amount and rate of growth in pediatric vertebrae as we do in pediatric long bones. We do not know how to quantify imparted stresses from a tensioned implant, and whether this occurs because the time that kids spend walking and standing versus lying down is such a dynamic system. We do not know how uniform growth might be. We do not know how to accurately quantify the amount of deformity that will occur per unit of tension per level of spine. There are many unknowns.

In this forum, we tried to put our heads together to figure out how to quantify those uncertainties, answer some of the questions, and clarify those uncertainties.

Disclosure: Patrick J. Cahill, MD, has disclosed the following relevant financial relationships: Served as a consultant for: Biogen, Inc.


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