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Objectives: Alkaptonuria is a rare inborn disorder of phenylalanine and tyrosine metabolism. It is characterized by an accumulation of homogentisic acid and its oxidation products, possibly resulting into connective tissue damaging. "Ochronosis" is a main feature, which is characterized by tissue discoloration and even alkaptonuric arthropathy. Cervical spine involvement is exceptional and there is a paucity of reports on surgical interventions in these patients. We explored the literature concerning cervical spine involvement in patients with alkaptonuria., Patients and Methods: We performed a review of the literature, in which patients with alkaptonuric degenerative changes of the cervical spine were examined. Articles were obtained from MEDLINE. Search terms included: "cervical", "alkaptonuria", "alkaptonuric changes" and "black disc". Additional studies were identified by checking reference lists. Furthermore, we present the case of a 46 year old patient with critical cervical spinal canal stenosis who underwent C6-C7 anterior cervical microdiscectomy and interbody fusion, in order to prevent myelopathic changes. CARE statement guidelines were followed., Results: Peroperatively, we did not encounter any macroscopic abnormalities of the skin, muscles or ligaments. A black discoloration of the nucleus pulposus was observed. Peroperative and postoperative course was uneventful., Conclusion: Alkaptonuric degenerative abnormalities most commonly involve the lumbar spine, although the cervical spine can be affected in rare cases. Most frequently, the diagnosis of alkaptonuria can be made based on the clinical phenotype many years before symptoms secondary to ochronotic arthropathy develop. A retrospective diagnosis based on peroperative black discoloration of spinal structures has been described. A black discoloration of the intervertebral disc should encourage the neurosurgeon to further explore the possibility of alkaptonuria, even in the absence of a clear phenotype. Surgical results are mostly satisfactory. Further studies are required in order to better understand this pathology and its postoperative course., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Anterior cervical surgery is routinely performed using fluoroscopy. Visualizing the lower cervical levels can be challenging, particularly in obese, muscular, and broad-shouldered patients. We found that grabbing both feet of the patient at the level of the metatarsals and cranially pushing the feet, creating dorsiflexion at the ankle joints, seems to increase the number of fluoroscopically visualized cervical levels. We aimed to measure the average change in fluoroscopically visualized levels when performing this maneuver., Methods: In 10 consecutive patients undergoing an anterior cervical discectomy and fusion procedure, we counted the number of fluoroscopically visualized cervical levels. Visible cervical levels in lateral fluoroscopic cervical images that were taken with and without the execution of the aforementioned maneuver were counted by 2 blinded observers., Results: Performing this maneuver added on average almost 1 vertebral body height to the fluoroscopic image. The additional number of fluoroscopically visible cervical levels was significantly higher in patients <50 years old but was not affected by sex or body mass index., Conclusions: We propose a simple, convenient, and effective technique to increase the number of visualized cervical levels on lateral cervical fluoroscopy. This maneuver may have some advantages compared with other commonly used techniques., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Purpose: Assessment of bony fusion following anterior cervical interbody fusion (ACIF) is usually done by plain film or CT. We present the first clinical application of Cone-Beam CT (CBCT) to evaluate bony fusion after ACIF., Methods: A 56-year-old man with disc herniation at C6-C7 underwent ACIF surgery using a compressed nanocrystalline hydroxyapatite interbody device (nanOss-C, Pioneer Surgical Marquette, MI, USA) and a nanocrystalline hydroxyapatite bone graft filler (nanOss Bioactive, Pioneer Surgical Marquette, MI, USA). Imaging follow-up was performed by CBCT (NewTom 5G, QR Srl, Verona, Italy) at 1 day, 6 weeks, 3 and 9 months post-operatively. Two independent assessors quantitatively measured the greyscale changes of the bone graft filler and qualitatively evaluated the bony fusion process., Results: Quantitative analysis of the images showed a steadily increasing matrix density of the bone graft filler over the 9 months follow-up, suggesting increasing calcification. Qualitative evaluation demonstrated different stages of the bone fusion process within the disc space around the cage, at the interface between cage and endplates, and at the interface between bone graft filler and the endplates., Conclusions: CBCT provides high-resolution cross-sectional imaging of the cervical spine after ACIF. For the first time, in vivo evaluation of the bone graft filler within the centre of the circumferentially radiodense cage and detailed cross-sectional evaluation of bone fusion was achieved. Confirmation of these promising outlooks of CBCT in a large cohort of ACIF patients is needed with regard to routine clinical application and evaluation of different interbody devices.