CLINICAL ARTICLE J Neurosurg Pediatr 25:384–393, 2020 Halo-gravity traction for the treatment of pediatric cervical spine disorders Bram P. Verhofste, MD,1,2 Michael P. Glotzbecker, MD,3,4 Craig M. Birch, MD,1,2 Nora P. O’Neill, BA,1,2 and Daniel J. Hedequist, MD1,2 1Department of Orthopaedic Surgery, Boston Children’s Hospital; 2Harvard Medical School, Boston, Massachusetts; 3Department of Orthopaedic Surgery, University Hospitals Cleveland Medical Center; and 4Department of Orthopaedic Surgery, Rainbow Babies and Children’s Hospital, Cleveland, Ohio OBJECTIVE Halo-gravity traction (HGT) is an effective and safe method for gradual correction of severe cervical defor- mities in adults. However, the literature is limited on the use of HGT for cervical spine deformities that develop in children. The objective of the present study was to evaluate the safety and efficacy of HGT for pediatric cervical spine deformities. METHODS Twenty-eight patients (18 females) whose mean age was 11.3 ± 5.58 years (range 2–24.9 years) underwent HGT. Common indications included kyphosis (n = 12), rotatory subluxation (n = 7), and basilar invagination (n = 6). Three children (11%) received traction to treat severe occipitocervical instability. For these 3 patients, traction combined with a halo vest, with bars attached rigidly to the vest, but with the ability to slide through the connections to the halo crown, was used to guide the corrective forces and moments in a specific and controlled manner. Patients ambulated with a wheelchair or halo walker under constant traction. Imaging was done before and during traction to evaluate traction ef- ficacy. The modified Clavien-Dindo-Sink classification was used to categorize complications. RESULTS The mean duration of HGT was 25 days (IQR 13–29 days), and the mean traction was 29% ± 13.0% of body weight (IQR 19%–40% of body weight). The mean kyphosis improved from 91° ± 20.7° (range 64°–122°) to 56° ± 17.6° (range 32°–96°) during traction and corresponded to a mean percentage kyphosis correction of 38% ± 13.8% (range 21%–57%). Twenty-five patients (89%) underwent surgical stabilization, and 3 patients (11%) had rotatory subluxation that was adequately reduced by traction and were treated with a halo vest as their definitive treatment. The mean hospi- tal stay was 35 days (IQR 17–43 days). Nine complications (32%) occurred: 8 grade I complications (28%), including 4 cases of superficial pin-site infec- tion (14%) and 4 cases of transient paresthesia (14%). One grade II complication (4%) was seen in a child with Down syndrome and a preexisting neurological deficit; this patient developed flaccid paralysis that rapidly resolved with weight removal. Six cases (21%) of temporary neck discomfort occurred as a sequela of a preexisting condition and resolved without treatment within 24–48 hours. CONCLUSIONS HGT in children is safe and effective for the gradual correction of cervical kyphosis, atlantoaxial sub- luxation, basilar invagination, and os odontoideum. Cervical traction is an additional tool for the pediatric spine surgeon if uncertainties exist that the spinal alignment required for internal fixation and deformity correction can be safely achieved surgically. Common complications included grade I complications such as superficial pin-site infections and transient paresthesias. Halo vest gravity traction may be warranted in patients with baseline neurological deficits and severe oc- cipitocervical instability to reduce the chance of catastrophic movement. https://thejns.org/doi/abs/10.3171/2019.10.PEDS19513 KEYWORDS pediatric; children; cervical spine; halo-gravity traction; halo vest; efficacy; complications; adverse events; modified Clavien-Dindo-Sink classification TAGNARA popularized halo-gravity traction (HGT) in nal alignment in an attempt to reduce the amount of force 1971 as a method to use the natural force of gravity or surgical exposure required for the stabilization of severe to counteract pathological forces causing severe tho- spinal deformities and to decrease the risk of perioperative racicS scoliosis, kyphosis, or kyphoscoliosis.26,27 Traction neurological deficits.1,3–5, 15, 22, 25, 27,30 A halo crown with 4–8 causes soft-tissue relaxation that gradually improves spi- pins is placed in the operating room and stepwise distrac- ABBREVIATIONS AE = adverse event; ARS = atlantoaxial rotatory subluxation; BW = body weight; HGT = halo-gravity traction; HVGT = halo-vest-gravity traction; IONM = intraoperative neuromonitoring; LOS = length of stay; NF1 = neurofibromatosis type 1; SAC = space available for the spinal cord; SCC = spinal cord compression. SUBMITTED September 4, 2019. ACCEPTED October 28, 2019. INCLUDE WHEN CITING Published online December 27, 2019; DOI: 10.3171/2019.10.PEDS19513. 384 J Neurosurg Pediatr Volume 25 • April 2020 ©AANS 2020, except where prohibited by US copyright law Unauthenticated | Downloaded 10/01/21 11:45 AM UTC Verhofste et al. tion is performed until 30%–50% of body weight (BW) is national patients are treated at our institution. These cases reached.3,15,19,22,30 Weight in this range is usually tolerated were included in the analysis, however, to accurately rep- well, and immediate mobilization is allowed with a wheel- resent the cervical spine population treated at the pediatric chair or halo walker.3,15 tertiary referral centers that perform HGT. These patients Daily pin-site care and neurological evaluation are had complete records of their in-hospital HGT admission, required and can prevent most traction-related compli- which was the objective of the study. cations. Mild complications such as cervical discomfort, pin-site infections, and pin loosening are common and are Radiographic Parameters easily managed with muscle relaxants, antibiotics, and pin 3,9,19,21,22,30 Serial radiographs were used to evaluate kyphosis be- tightening. More severe complications such as fore HGT, during traction, postoperatively, and at the latest cranial nerve dysfunction, subdural abscesses, vertebral follow-up. Absolute kyphosis correction was calculated as artery aneurysms, and paraplegia are also rarely report- 4,9,10,14,31 follows: [pre-HGT − in-traction], and % kyphosis correc- ed. tion as: [(absolute correction/pre-HGT) × 100%]. A meth- Good outcomes of preoperative HGT are reported in od was developed to maintain traction during CT scan- adults with severe basilar invagination, cervical kyphosis, ning. The severity of basilar invagination was assessed on or irreducible atlantoaxial subluxation in which single- serial CT scans using McRae’s line, defined as a line con- stage realignment or instrumentation may be problemat- 6 13,17,20,24,25,32 necting the inner foramen magnum (basion to opisthion). ic. Cervical traction reduces the difficulty of an- The distance from the tip of the odontoid process perpen- terior surgery in severely kyphotic patients and alleviates dicular to this line was evaluated before and during HGT. the need for transoral decompression in cases of complex Similarly, the space available for the spinal cord (SAC) craniocervical junction malformations. The literature on was used to measure the effect of traction in cases of os HGT for the management of cervical spine disorders that odontoideum. develop in children is limited to small case series that are often outdated, include adults, or utilize traction intra- and Complication Data postoperatively.1,10, 13, 14, 16, 18, 24, 28,31 To our knowledge, this is the largest series dedicated to evaluating the efficacy and All HGT-related adverse events (AEs) were recorded using the modified Clavien-Dindo-Sink classification safety of HGT for pediatric cervical spine disorders. 7 The goals of this retrospective case series were as fol- (grades I–V) for orthopedic complications. Superficial lows: 1) to describe the benefits and efficacy of HGT for pin-site infections or transient paresthesias were classi- the treatment of cervical spine disorders that develop in fied as grade I or as complications that did require a de- children; 2) to review the safety and complications using viation from routine care, had minimal clinical relevance, the modified Clavien-Dindo-Sink classification; and 3) to and were adequately treated with observation or minimal provide a protocol for HGT with recommendations from intervention (oral antibiotics, analgesics, or antipyretics). an experienced tertiary pediatric referral center. Grade II HGT-related complications included transient cranial nerve dysfunction, nerve palsies, or other tempo- rary neurological deficits that required a deviation from Methods HGT protocol (increased inpatient visits during hospital- A retrospective consecutive examination of children ization, close neurological monitoring, or weight removal). who underwent HGT during a 15-year period (2003–2018) Grades I and II are considered minor complications. was performed after IRB approval. All patients were Grade III–V complications are serious AEs classified treated at a single pediatric tertiary referral center (Boston as major complications. Subdural abscesses, cellulitis, or Children’s Hospital). Patients < 25 years of age diagnosed deep dermal infections were grade III complications that with occipitocervical or cervical instability, cervical ky- required surgical, interventional radiology, or endoscopic phosis, basilar invagination, atlantoaxial rotatory sublux- interventions, such as drainage, debridement, and intrave- ation (ARS), os odontoideum, or cervical arthritis with nous antibiotics. Grade