Diagnosing Cervical Fusion: A Comprehensive Literature Review

STUDY DESIGN: Comprehensive literature review. PURPOSE: To document the criteria for fusion utilized in these studies to determine if a consensus on the definition of a solid fusion exists. OVERVIEW OF LITERATURE: Numerous studies have reported on fusion rates following anterior cervical arthrodesis. There is a wide discrepancy in the fusion rates in these studies. While factors such as graft type, Instrumentation, and technique play a factor in fusion rate, another reason for the difference may be a result of differences in the definition of fusion following anterior cervical spine surgery. METHODS: A comprehensive English Medline literature review from 1966 to 2004 using the key words anterior, cervical, and fusion was performed. We divided these into two groups: newer studies done between 2000 and 2004, and earlier studies done between 1966 and 2000. These articles were then analyzed for the number of patients, follow-up period, graft type, and levels fused. Moreover, all of the articles were examined for their definition of fusion along with their fusion rate. RESULTS: In the earlier studies from 1966 to 2000, there was no consensus for what constituted a solid fusion. Only fifteen percent of these studies employed the most stringent definition of a solid fusion which was the presence of bridging bone and the absence of motion on flexion and extension radiographs. On the other hand, the later studies (2000 to 2004) used such a definition a majority (63%) of the time, suggesting that a consensus opinion for the definition of fusion is beginning to form. CONCLUSIONS: Our study suggests that over the past several years, a consensus definition of fusion is beginning to form. However, a large percentage of studies are still being published without using stringent fusion criteria. To that end, we recommend that all studies reporting on fusion rates use the most stringent criteria for solid fusion following anterior cervical spine surgery: the absence of motion on flexion/extension views and presence of bridging trabeculae on lateral x-rays. We believe that a universal adoption of such uniform criteria will help to standardize such studies and make it more possible to compare one study with another

The success of dietary protein restriction in alkaptonuria patients is age-dependent

Alkaptonuria is characterized by an increased urinary excretion of homogentisic acid, pigmentation of cartilage and connective tissues, and ultimately the development of inflammatory arthropathy. Various diets low in protein have been designed to decrease homogentisic acid excretion and to prevent the ochronotic pigmentation and arthritic lesions. However, limited information is available on the long-term beneficial effects of these diets. We reviewed the medical records of 16 patients aged 3-27 years (4 > 18 years) to ascertain the age of diagnosis, growth, development, social behaviour, signs of complications and longitudinal dietary compliance. The diagnosis of alkaptonuria was made at an average age of 1.4 years (2 months-4 years); following the diagnosis all patients were prescribed a diet with a protein content of 1.5 g/kg per day. All patients showed normal growth and development, and no major complications of the disease. Behavioural problems associated with poor dietary compliance emerged as the main problem. Dietary compliance decreased progressively with age. The effect of dietary protein restriction in homogentisic acid excretion was studied by fixing the amounts of protein in the diet at 1 g/kg per day and 3.5-5 g/kg per day during 8 days. Twelve patients, aged 4-27 years, participated in the investigation. Protein restriction resulted in a significantly lower excretion of homogentisic acid in the urine of children younger than 12 years (p <0.01), whereas this effect was less obvious for adolescent and adult patients. The results suggest that restriction of protein intake may have a beneficial effect on alkaptonuric children; but continuation of this regimen to older age seems questionable and not practical