A study presented at the annual meeting of the North America Spine Society (1–5 November 2011, Chicago, USA) has found that surgical treatment may improve functional and quality of life outcomes, compared with conservative treatment, in older patients with type II odontoid fractures.
Although there is relative consensus for the management of type I and type III odontoid fractures, according to study presenter Christopher Kepler, Thomas Jefferson University, Philadelphia, USA, there is still a divergence of opinion in the spinal community about the management of type II odontoid fractures. Kepler explained that at present, the benefits and risks of surgical treatment vs. conservative treatment have not been fully determined. He said, therefore: “The purpose of this study was to compare treatment outcomes in surgically and conservatively treated elderly patients who present with a type II odontoid fracture.”
In his prospective, multicentre, cohort study, 159 patients aged 65 years or older with a type II odontoid fracture were managed with surgical or conservative treatment. Kepler explained: “This was not a randomised study: patients received non-operative (57) or surgical treatment (102) at the discretion of the surgical team, based on a discussion with the patient and their family.” He added that the patients were followed for 12 months or until they died, whichever came first.
To measure the outcomes of the different treatment approaches, the investigators used the neck disability index score, the SF36v2 health survey, and reviewed treatment-associated rates of mortality and complications. Kepler said: “On enrolment, patients were similar in the surgical and non-surgical cohorts with respect to age, gender, ethnic background, marital status, associated injuries, comorbidities, and living arrangements.” Patients were also similar in terms of their baseline neck disability scores and SF36v2 scores, but the bodily pain and physical component scores of the SF36v2 were slightly better in the patients treated conservatively.
Posterior C1−C2 fusion, using screw fixation, was the most common approach used in the surgical group and the most of the conservative group patients were immobilised with a hard cervical orthosis.
After 12 months, there was no significant difference between the two groups in treatment-related complications (48 vs. 37; p=0.4805). However, patients in the conservative group had a significant four-fold increase in the rate of non-union compared with those in the surgical group (5 vs. 12; p=0.003). “It is probably worth mentioning that of the 12 patients in the conservative group who developed non union, eight of them ultimately required surgery for associated symptoms.” Kepler said.
The neck disability index score worsened in both groups after 12 months, but significantly more so in the conservative group (5.7±18.5 vs. 14.7±18.1; p=0.0184). Kepler said: “The difference between the surgical and the non-operative group exceeded previously established estimates of the minimal clinically important difference.” He explained that a commonly quoted estimate of the minimal clinically important difference for the neck disability index is 7.5 points, but this study found a difference of nine points between the surgical and conservative group.
Other differences between the groups were that patients in the surgical cohort improved slightly in the bodily pain dimension of the SF36v2 questionnaire whereas the patients in the conservatively treated group declined significantly (1.4±12.9 vs. -6.8±-14.45; p=0.0035).
As previous studies have already shown, this study found that older patients with type II odontoid fractures (regardless of treatment approach) suffer substantial morbidity and mortality. More patients in the conservative group died than in the surgical group, a difference that approached but did not reach statistical significance (25.9% vs. 13.9%; p=0.0512). However, overall, 82% of the patients in the study were still alive after 12 months. Kepler concluded: “Unless medically contraindicated, we recommend operative treatment of elderly patients with type II odontoid fractures. For patients who are unfit for surgery or who are unable to be cleared for the operating room (eg, those with medical comorbidities that preclude general anaesthesia), non-operative treatment is safe and reasonable.” He added that while there was not a significant increase in mortality or complication rates in the conservative group compared with the surgical group, patients who have non-operative treatment should be counselled about the increased risk of non-union.