Impact of Implant Size and Position on Subsidence Degree after Anterior Cervical Discectomy and Fusion: Radiological and Clinical Analysis.

BACKGROUND: Implant subsidence is recognized as a complication of interbody stabilization, although its relevance remains ambiguous, particularly in terms of relating the effect of the position and depth of subsidence on the clinical outcome of the procedure. This study aimed to evaluate how implant positioning and size influence the incidence and degree of subsidence and to examine their implications for clinical outcomes. METHODS: An observational study of 94 patients (157 levels) who underwent ACDF was conducted. Radiological parameters (implant position, implant height, vertebral body height, segmental height and intervertebral height) were assessed. Clinical outcomes were evaluated using the Visual Analogue Scale (VAS) and Neck Disability Index (NDI). Subsidence was evaluated in groups according to its degree, and statistical analyses were performed. RESULTS: The findings revealed that implant-to-endplate ratio and implant height were significant risk factors associated with the incidence and degree of subsidence. The incidence of subsidence varied as follows: 34 cases (41.5%) exhibited displacement of the implant into the adjacent endplate by 2-3 mm, 32 cases (39%) by 3-4 mm, 16 cases (19.5%) by ≥4 mm and 75 (47.8%) cases exhibited no subsidence. CONCLUSIONS: The findings underscore that oversized or undersized implants relative to the disc space or endplate length elevate the risk and severity of subsidence.

Cervical Sagittal Balance: Impact on Clinical Outcomes and Subsidence in Anterior Cervical Discectomy and Fusion.

Degenerative disease of the cervical spine leads to sagittal imbalance, which may affect treatment results. The purpose of this study was to evaluate changes in selected cervical sagittal balance parameters and their effects on subsidence and clinical outcomes of the procedure. This study encompassed a total of 95 evaluated patients who underwent anterior cervical discectomy and fusion (ACDF). Selected cervical sagittal balance parameters were assessed using lateral projection X-rays: C2-C7 spinal vertical axis (C2-C7 SVA), spinocranial angle (SCA), C7 slope, C2-C7 lordosis, and the segmental Cobb angle. Measurements were collected the day before, the day after, and 12 months after surgery. Changes in clinical parameters was assessed using the VAS and NDI scales. Subsidence was defined as a loss of intervertebral height of more than 30% of the baseline value. Among all the assessed parameters, only the C2-C7 SVA demonstrated a statistically significant difference between the groups with and without subsidence: 26.03 vs. 21.79 [mm], with p = 0.0182, preoperatively and 27.80 vs. 24.94 [mm], with p = 0.0449, on the day after surgery, respectively. We conclude that higher preoperative and postoperative C2-C7 SVA values might contribute to an elevated risk of implant subsidence. Furthermore, both the SCA and C7 slope could conceivably influence the clinical outcome, respectively impacting pain, as assessed by the VAS and the disability, as evaluated through the NDI scale.

Irreducible L5/S1 Spondyloptosis in Over 20 Years After Neglected Trauma Treated with Modified Grob's Technique - Case Report.

Introduction: Spondyloptosis, characterized by complete slippage of the upper vertebral body relative to the lower vertebral body, is an exceedingly rare condition. Typically, it occurs as a result of a high-energy injury and is promptly managed. It is uncommon for a patient to present to a spinal surgery unit several decades after the initial incident. Case Report: In this case report, we describe the case of a 62-year-old man who experienced a lumbosacral injury from a fall twenty years prior to seeking treatment. The patient had multiple comorbidities, including obesity and internal medicine conditions. He presented with severe back pain radiating to the lower extremities, accompanied by significant neurogenic chroma and lower extremity weakness. Imaging studies revealed spondyloptosis at the L5/S1 level, along with bony fusion and spinal canal stenosis at the L3/L4 level. Conclusion: The patient underwent surgical intervention using Grob's direct pediculo-body fixation technique. The postoperative period was uneventful, and over the course of one year of follow-up, the patient experienced a resolution of symptoms and significant improvement in functional capacity.

Anterior cervical discectomy and fusion (ACDF) with and without plating: A comparison of radiological and clinical outcomes.

Treatment for degenerative disc disease of the cervical spine primarily aims to decompress neural structures and preserve the former height of the disc space and foramina. Popular methods include anterior cervical discectomy and fusion (ACDF) using cages with plates or without plates (standalone cages). However, it is still debatable whether a plate is necessary for enhanced treatment outcomes. This paper reviews current literature reports, adding insights from the authors' experience. A literature search was performed with keywords related to ACDF with or without cervical plating. We analyzed the titles and abstracts to identify all potentially relevant studies. Out of these, a total of 28 original research and 5 systematic reviews/meta-analyses met our inclusion criteria. The success of surgery for cervical disc disease depends fundamentally on the appropriate decompression of neural structures. This is the main determinant of postoperative clinical improvement measured according to scales capturing changes in pain intensity and quality of life. An ideal replacement for natural components of the human body does not exist, even though more and more refined solutions are developed every year. A comparison of treatment outcomes using non-plated (standalone) cages and cage + plate systems requires separate analysis of radiological and clinical outcomes. Both methods have their advantages and disadvantages. Radiological outcomes are slightly better with cage + plate systems, and clinical outcomes are comparable.

Revision Procedure After Surgery for Atypical Hangman's Fracture Primarily Performed Only from the Posterior Approach - An Attempt to Maintain Head Rotation: Case Report.

Introduction: Hangman's fracture, also known as traumatic spondylolisthesis of the axis, is defined as a bilateral fracture of the C2 pars interarticularis. In 1965, Schneider used this term to describe a pattern of similarities seen in fractures associated with judicial hangings. However, this fracture pattern is only observed in approximately 10% of injuries associated with hangings. Case Report: We present a case of an atypical hangman's fracture caused by a headlong dive into a swimming pool and striking the pool's bottom. The patient had undergone surgery at another centre, where posterior C2-C3 stabilisation was performed. Due to the presence of screws in the C1-C2 joint spaces, the patient could not perform rotational movements of the head. Anterior stabilization to prevent C2 dislocation against C3 was also not performed, and appropriate spinal stability was not ensured. Our decision to reoperate was motivated, among other factors, by our intention to restore rotational head movements. The revision surgery was performed from both an anterior and posterior approach. After the surgery, the patient was able to rotate his head while maintaining cervical spine stability. The case presented here represents not only a unique example of an atypical C2 fracture but also highlights a fixation technique that provided the necessary stability for successful fusion. The utilized method restored functional rotational movement of the head, thus preserving the patient's quality of life, which is of paramount importance considering the patient's age. Conclusion: The decision-making process regarding the technique for treating hangman's fractures, especially atypical fractures, should account for the patients' quality of life after the operation. The preservation of as much of the physiological range of motion as possible with maintained spinal stability should be the goal of therapy in every case.

Adjacent segment mobility after ACDF considering fusion status at the implant insertion site.

PURPOSE: This paper sets out to analyse mobility changes in segments adjacent to the operated segment. Additionally, it investigates the relationship between the degree of fusion in the operated disc space and mobility changes in the adjacent segments. METHODS: In total, 170 disc spaces were operated on in 104 consecutive patients qualified for one- or two-level surgery. The degree of mobility of segments directly above and below the implant insertion site was calculated. Measurements were performed the day before the surgery and 12 months post-surgery. Functional (flexion and extension) radiographs of the cervical spine and CT scans obtained 12 months post-surgery were used to evaluate the fusion status. The results were subjected to statistical analysis. RESULTS: Statistically significant increase in mobility was recorded for the segments situated immediately below the operative site, with a mean change in mobility of 1.7 mm. Complete fusion was demonstrated in 101 cases (71.1%), and partial fusion in 43 cases (29.9%). In the complete fusion subgroup, the ranges of both flexion and extension in the segments directly below the operative site were significantly greater than those in the partial fusion (pseudoarthrosis) subgroup. CONCLUSION: The mobility of the adjacent segment below the implant insertion site was significantly increased at 12 months post-ACDF surgery. The range of this compensatory hypermobility was significantly greater in patients with complete fusion at the ACDF site than in cases of pseudoarthrosis. Implant subsidence was not associated with mobility changes in the segments directly above or directly below the site of ACDF surgery.

Reliability and Utility of Various Methods for Evaluation of Bone Union after Anterior Cervical Discectomy and Fusion.

Most surgical procedures performed on account of degenerative disease of the cervical spine involve a discectomy and interbody fixation. Bone fusion at the implant placement site is evaluated post-operatively. It is agreed that computed tomography is the best modality for assessing bone union. We evaluated the results obtained with various methods based solely on conventional radiographs in the same group of patients and compared them with results obtained using a method that is a combination of CT and conventional radiography, which we considered the most precise and a reference method. We operated on a total of 170 disc spaces in a group of 104 patients. Fusion was evaluated at 12 months after surgery with five different and popular classifications based on conventional radiographs and then compared with the reference method. Statistical analyses of test accuracy produced the following classification of fusion assessment methods with regard to the degree of consistency with the reference method, in descending order: (1) bone bridging is visible on the anterior and/or posterior edge of the operated disc space on a lateral radiograph; (2) change in the value of Cobb's angle for a motion segment on flexion vs. extension radiographs (threshold for fusion vs. pseudoarthrosis is 2°); (3) change in the interspinous distance between process tips on flexion vs. extension radiographs (threshold of 2 mm); (4) change in the value of Cobb's angle of a motion segment (threshold of 4°); (5) change in the interspinous distance between process bases on flexion vs. extension radiographs (threshold of 2 mm). When bone union is evaluated on the basis on radiographs, without CT evidence, we suggest using the "bone bridging" criterion as the most reliable commonly used approach to assessing bone union.

Subsidence following cervical discectomy and implant-to-bone ratio.

BACKGROUND: Implant subsidence is an undesirable effect after anterior cervical discectomy and fusion (ACDF). We investigated the relation between the rate of implant subsidence and the ratio of the implant surface area to the surface area of the adjacent bone. METHODS: We operated 170 disc spaces in a group of 104 patients. Two types of implants were used: 1) PEEK (polyetheretherketone) cages and 2) titanium-coated (TC) PEEK cages. Patients were randomised to receive a specific implant using a randomisation table. All implants had a surface area of 1.61 cm2. Based on computed tomography images, bone surface areas were calculated for vertebral bodies immediately adjacent to the interbody implants. The implant-to-bone surface ratio was then calculated for each disc space. Implant subsidence was assessed over 12 months of follow-up, and associations between implant subsidence, the type of implant, and the implant-to-bone surface ratio were investigated. RESULTS: Twelve months after the surgery, computed tomography was performed on 86 patients (144 disc spaces). Furthermore, in 166 disc spaces and 102 patients, conventional radiographs were obtained. Subsidence was observed in 21% of the examined intervertebral spaces, and it was more frequently associated with higher values of bone surface area and lower values of the implant-to-bone surface ratio. The type of implant (PEEK vs TC-PEEK cages) did not significantly influence the rate of implant subsidence. CONCLUSIONS: Implant subsidence was significantly related to the value of a coefficient representing the ratio of the implant's surface area to the bone surface area of the adjacent vertebral bodies, with subsidence occurring significantly more rarely for coefficient values ≥ 0.37.

PEEK versus titanium-coated PEEK cervical cages: fusion rate.

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) is one of the most commonly performed procedures for degenerative cervical disease. The evaluation of fusion status is still not fully standardized, and a variety of measurement methods are used. This study presents our own evaluation of fusion by comparing two types of implants. METHODS: A total of 170 disc spaces were operated on in 104 patients using PEEK (polyetheretherketone) cages and titanium-coated (TC) PEEK cages. Patients were assigned to a specific implant using a randomisation table. Fusion status was evaluated based on functional radiographs and CT scans obtained at 12 months post-surgery. Multivariate mixed-effects logistic regression models were performed to assess the association of type of implant with different fusion rates. RESULTS: At 12 months post-surgery, CT scans were performed in 86 patients (a total of 144 disc spaces) and conventional radiographs were obtained in 102 (a total of 166 disc spaces). Complete fusion was demonstrated in 101 cases (71.1%), partial fusion in 43 cases (29.9%). There were no cases of absence of fusion. A total of 85 PEEK cages (59%) and 59 TC-PEEK cages (41%) were implanted. For PEEK cages, complete fusion was seen in 75 (88.2%) disc spaces, compared to 26 (44.1%) achieved with TC-PEEK cages. A significantly higher proportion of complete fusions (B = 15.58; P < 0.0001) after 12 months was observed with PEEK implants compared to TC-PEEK implants. CONCLUSION: Complete fusion was noted at 12 months post-surgery significantly more frequently with PEEK implants compared to TC-PEEK implants.

Return to play in children with shunted hydrocephalus.

OBJECTIVE: The objective of this study was to assess the relevance of shunted hydrocephalus in regard to participation by young patients in physical education (PE) classes. Students diagnosed with this condition are very often restricted in PE classes owing to the lack of official and well-defined guidelines. However, the medical literature suggests that there is no relationship between the disease and risk of sport-related injuries. In this study, the authors intended to evaluate not only the accuracy of this statement, but also to explore the factors that delay or foreclose return to exercise. METHODS: The analysis was conducted on patients aged < 18 years with a diagnosis of shunt-treated hydrocephalus who received follow-up for a minimum of 1 year. Collected medical data were examined for factors limiting participation in PE at school. Indicators of both sport-related injuries and conditions acceptable for return to exercise were gathered during follow-up visits. RESULTS: In this study, 72.72% of patients attended sport activities in schools. The group based on return to PE class differed significantly in the occurrence of neurological deficits, as well as presence of comorbidities. In univariate analysis, the authors identified these parameters as risk factors limiting participation in PE. On the contrary, etiology of hydrocephalus, type of shunting device, number of shunt malfunctions, and presence of epilepsy did not significantly influence sport engagement. CONCLUSIONS: This study shows that many patients with shunt-treated hydrocephalus can safely participate in PE. Presence of neurological deficits before and after neurosurgical treatment, as well as presence of comorbidities, are factors that negatively impact the possibility of a patient returning to physical activity. Sport-related injuries do occur, but at a low incidence.

Potential Risk Factors for Ventriculoperitoneal Shunt Implantation in Paediatric Patients with Posthemorrhagic Hydrocephalus of Prematurity Treated with Subcutaneous Reservoir: An Institutional Experience.

BACKGROUND: Posthemorrhagic hydrocephalus of prematurity (PHHP) is a result of intraventricular hemorrhage (IVH). IVH occurs in 6 to 23% of the preterms in countries with advanced medical health care. Most of these patients will eventually require the use of ventriculoperitoneal shunt (VPS). The purpose of this study is to assess the risk factors of VPS implantation in patients with PHHP who have been treated with ventricular catheter with subcutaneous reservoir (VCSR). METHODS: The retrospective study was conducted evaluating 35 premature patients who suffered from severe IVH. Their mean gestational age was 28 weeks. The assessment included antenatal factors such as gestational age, birth weight, and intrauterine and perinatal infection. Postparturient period factors such as the IVH grade, time between diagnosis, and VCSR implantation and body weight on VCSR implantation were also considered in the study. Postprocedural complications, such as bacterial cerebrospinal fluid (CSF) infection, sepsis, and skin lesions, were evaluated. Data were calculated with R program, version 4.04. RESULTS: From among 35 evaluated patients, 23 (65.71%) required a VPS. Median of birth weight was 1,190 g. Infections were observed in 11 (31.43%) cases. Mean time between IVH diagnosis and VCSR implantation was 2.6 weeks. Postprocedural complications occurred in 19 (54.29%) patients. None of the evaluated factors has proven its statistical significance (p > 0.05) for being a potential risk factor for VPS implantation. CONCLUSION: External factors seem to not affect the necessity of VPS implantation in patients after the severe IVH. Ostensibly, there seems to be no difference between the grades III and the IV of Papile's IVH scale regarding VPS implantation necessity.