The April 2023 Spine Roundup. 360. looks at: Percutaneous transforaminal endoscopic discectomy versus microendoscopic discectomy; Spine surgical site infections: a single debridement is not enough; Lenke type 5, anterior, or posterior: systematic review and meta-analysis; Epidural steroid injections and postoperative infection in lumbar decompression or fusion; Noninferiority of posterior cervical foraminotomy versus anterior cervical discectomy; Identifying delays to surgical treatment for metastatic disease; Cervical disc replacement and adjacent segment disease: the NECK trial; Predicting complication in adult spine deformity surgery

The February 2023 Spine Roundup. 360. looks at: S2AI screws: At what cost?; Just how good is spinal deformity surgery?; Is 80 years of age too late in the day for spine surgery?; Factors affecting the accuracy of pedicle screw placement in robot-assisted surgery; Factors causing delay in discharge in patients eligible for ambulatory lumbar fusion surgery; Anterior cervical discectomy or fusion and selective laminoplasty for cervical spondylotic myelopathy; Surgery for cervical radiculopathy: what is the complication burden?; Hypercholesterolemia and neck pain; Return to work after surgery for cervical radiculopathy: a nationwide registry-based observational study

Aims

The aim of this study was to investigate whether the type of cervical disc herniation influences the severity of symptoms at the time of presentation, and the outcome after surgical treatment.

Aims. The aim of this study was to use diffusion tensor imaging (DTI) to investigate changes in diffusion metrics in patients with cervical spondylotic myelopathy (CSM) up to five years after decompressive surgery. We correlated these changes with clinical outcomes as scored by the Modified Japanese Orthopedic Association (mJOA) method, Neck Disability Index (NDI), and Visual Analogue Scale (VAS). Methods. We used multi-shot, high-resolution, diffusion tensor imaging (ms-DTI) in patients with cervical spondylotic myelopathy (CSM) to investigate the change in diffusion metrics and clinical outcomes up to five years after anterior cervical interbody discectomy and fusion (ACDF). High signal intensity was identified on T2-weighted imaging, along with DTI metrics such as fractional anisotropy (FA). MJOA, NDI, and VAS scores were also collected and compared at each follow-up point. Spearman correlations identified correspondence between FA and clinical outcome scores. Results. Significant differences in mJOA scores and FA values were found between preoperative and postoperative timepoints up to two years after surgery. FA at the level of maximum cord compression (MCL) preoperatively was significantly correlated with the preoperative mJOA score. FA postoperatively was also significantly correlated with the postoperative mJOA score. There was no statistical relationship between NDI and mJOA or VAS. Conclusion. ms-DTI can detect microstructural changes in affected cord segments and reflect functional improvement. Both FA values and mJOA scores showed maximum recovery two years after surgery. The DTI metrics are significantly associated with pre- and postoperative mJOA scores. DTI metrics are a more sensitive, timely, and quantifiable surrogate for evaluating patients with CSM and a potential quantifiable biomarker for spinal cord dysfunction. Cite this article: Bone Joint J 2020;102-B(9):1210–1218

Introduction. Degeneration of the cervical spine can lead to neurological symptoms that require surgical intervention. Often, an anterior cervical discectomy (ACD) with fusion is performed with interposition of a cage. However, a cage substantially increases health care costs. The polymer polymethylmethacrylate (PMMA) is an alternative to cages, associated with lower costs. The reported high-occurrence of non-fusion with PMMA is often seen as a drawback, but evidence for a correlation between radiological fusion and clinical outcome is absent. To investigate if the lower rate of fusion with PMMA has negative effects on long-term clinical outcome, we assessed the clinical results of ACD with PMMA as a intervertebral spacer with a 5–10 year follow-up. Methods. A retrospective cohort study among all patients who underwent a mono-level ACD with PMMA for degenerative cervical disease, between 2007–2012, was performed. Patients filled out an online questionnaire, developed to assess clinical long-term outcome, complications and re-operation rates. The primary outcome measure was the Neck Disability Index (NDI), secondary outcome measures were re-operation and complication rates. Results. Of 196 eligible patients, 90 patients were assessed (response rate 53%). The average NDI score at follow-up (mean 7.5 years) was 19.0 points ± 18.0 points. Complications occurred in 10% and re-operation in 8.8%. Conclusion. This study provides evidence of good long-term clinical results of ACD with PMMA, as the results were similar with long-term outcomes of ACD with a cage as spacer. Therefore, the results of this study may suggest that the use of PMMA is an lower-cost alternative. No conflicts of interests. No funding obtained

Aims

The purpose of this retrospective study was to investigate the clinical relevance of increased facet joint distraction as a result of anterior cervical decompression and fusion (ACDF) for trauma.

Aims

The aim of this study was to determine how the short- and medium- to long-term outcome measures after total disc replacement (TDR) compare with those of anterior cervical discectomy and fusion (ACDF), using a systematic review and meta-analysis.

Aims. Cervical spondylosis is often accompanied by dizziness. It has recently been shown that the ingrowth of Ruffini corpuscles into diseased cervical discs may be related to cervicogenic dizziness. In order to evaluate whether cervicogenic dizziness stems from the diseased cervical disc, we performed a prospective cohort study to assess the effectiveness of anterior cervical discectomy and fusion on the relief of dizziness. Patients and Methods. Of 145 patients with cervical spondylosis and dizziness, 116 underwent anterior cervical decompression and fusion and 29 underwent conservative treatment. All were followed up for one year. The primary outcomes were measures of the intensity and frequency of dizziness. Secondary outcomes were changes in the modified Japanese Orthopaedic Association (mJOA) score and a visual analogue scale score for neck pain. Results. There were significantly lower scores for the intensity and frequency of dizziness in the surgical group compared with the conservative group at different time points during the one-year follow-up period (p = 0.001). There was a significant improvement in mJOA scores in the surgical group. Conclusion. This study indicates that anterior cervical surgery can relieve dizziness in patients with cervical spondylosis and that dizziness is an accompanying manifestation of cervical spondylosis. Cite this article: Bone Joint J 2018;100-B:81–7

Aims

Patients seeking cervical spine surgery are thought to be increasing in age, comorbidities and functional debilitation. The changing demographics of this population may significantly impact the outcomes of their care, specifically with regards to complications. In this study, our goals were to determine the rates of functionally dependent patients undergoing elective cervical spine procedures and to assess the effect of functional dependence on 30-day morbidity and mortality using a large, validated national cohort.

Aims

In order to evaluate the effectiveness of the Mobi-C implant in cervical disc degeneration, a randomised study was conducted, comparing the Mobi-C prosthesis arthroplasty with anterior cervical disc fusion (ACDF) in patients with single level cervical spondylosis.

The demand for spinal surgery and its costs have both risen over the past decade. In 2008 the aggregate hospital bill for surgical care of all spinal procedures was reported to be $33.9 billion. One key driver of rising costs is spinal implants. In 2011 our institution implemented a cost containment programme for spinal implants which was designed to reduce the prices of individual spinal implants and to reduce the inter-surgeon variation in implant costs. Between February 2012 and January 2013, our spinal surgeons performed 1493 spinal procedures using implants from eight different vendors. By applying market analysis and implant cost data from the previous year, we established references prices for each individual type of spinal implant, regardless of vendor, who were required to meet these unit prices. We found that despite the complexity of spinal surgery and the initial reluctance of vendors to reduce prices, significant savings were made to the medical centre.

Cite this article: 2015; 97-B:1102–5.

In a retrospective cohort study we compared the clinical outcome and complications, including dysphagia, following anterior cervical fusion for the treatment of cervical spondylosis using either a zero-profile (Zero-P; Synthes) implant or an anterior cervical plate and cage. A total of 83 patients underwent fusion using a Zero-P and 107 patients underwent fusion using a plate and cage. The mean follow-up was 18.6 months (sd 4.2) in the Zero-P group and 19.3 months (sd 4.1) in the plate and cage group. All patients in both groups had significant symptomatic and neurological improvement. There were no significant differences between the groups in the Neck Disability Index (NDI) and visual analogue scores at final follow-up. The cervical alignment improved in both groups. There was a higher incidence of dysphagia in the plate and cage group on the day after surgery and at two months post-operatively. All patients achieved fusion and no graft migration or nonunion was observed.

When compared with the traditional anterior cervical plate and cage, the Zero-P implant is a safe and convenient procedure giving good results in patients with symptomatic cervical spondylosis with a reduced incidence of dysphagia post-operatively.

Cite this article: Bone Joint J 2013;95-B:543–7.

Introduction: In comparison to anterior cervical decompression and fusion (ACDF), cervical disc arthroplasty has the potential of maintaining normal segmental lordosis, anatomical disc space height, and physiological motion patterns that may reduce or delay the onset of degenerative disc disease at adjacent cervical spinal motion segments. Aim: The objective of this study was to determine patient satisfaction post cervical disc arthroplasty. by evaluating each patient both clinically and radiologically. Materials and Methods: A retrospective study was performed on all patients with symptomatic cervical radiculopathy and/or myelopathy who had undergone cervical disc arthroplasty by a single surgeon after a standard anterior cervical discectomy. Outcome measures included the Short Form-36 (SF-36) and Neck Disability Index (NDI) questionnaires, neurological status, and radiographic status. Results: Over a 32 month period, 15 patients underwent cervical disc arthroplasty, with 12 patients undergoing single level arthroplasty. 2 patients undergoing 2 level arthroplasty and one patient undergoing a 3 level arthroplasty. The C5/C6 level was involved in 9 cases (60%). The male female ratio was 7:8. The mean age at presentation was 45 years (range, 28–59). The mean follow up was 24 months (range, 5–31). The mean improvement in NDI scores was 34.8. The mean PCS and MCS scores of the SF-36 test improved by 12.8 and 7.7 respectively. There was no neurological deficit. There were no cases of implant failures, migrations or subsidence. Conclusion: High patient satisfaction levels highlight the efficacy and safety of cervical disc arthroplasty, but longer term follow up is required to assess the long term functionality of the prosthesis and its protective influence on adjacent levels

Background: Cervical myelopathy and radiculopathy has been treated commonly with anterior cervical decompression and fusion with autologous bone graft and anterior cervical plating. Long term results have shown excellent pain relief and 73%–90% fusion rates. However, the development of late adjacent-level disease has been reported following anterior cervical arthrodesis which recently have been correlated to clinical findings. The Bryan disc arthroplasty device was developed to preserve the kinematics of the functional spine unit thus preventing adjacent level disease. There have been few studies comparing the incidence of adjacent level changes in patients undergoing ACDF compared to implantation of a Bryan disc arthroplasty device. Objectives: The object of this study is to compare the clinical results and radiographic outcomes of anterior cervical decompression and fusion versus cervical disc replacement using the Bryan Cervical Disc Prosthesis (Medtronic Sofamor Danek, Memphis, TN) in terms of overall range of motion (ROM) of the cervical spine; ROM, anterior intervertebral height (AIH), posterior intervertebral height (PIH) and radiographic changes at the implanted and adjacent levels. Methods: The study consisted of 105 patients with symptomatic single or two-level cervical disc disease. Fifty-one received the Bryan Cervical Artificial Disc Prosthesis (Medtronic Sofamor Danek, Memphis, TN). A total of 63 Bryan disc were placed in these 51 patients. A single-level procedure was performed in 39 patients and a two-level procedure in the other twelve. The patient group who underwent ACDF totaled 54 patients which consisted of 26 single level cases and 28 double level cases. The Bryan group had a mean follow-up 19 months (12–38). The mean follow-up for the ACDF group was 20 months (12–40 months). All patients were evaluated using static and dynamic cervical spine radiographs as well as MR imaging. All patients underwent anterior cervical discectomy followed by anterior cervical plating or implantation of the Bryan artificial disc prosthesis, done by one surgeon. Clinical evaluation included the visual analogue scale (VAS), and neck disability index (NDI). Radiographic evaluation included static and dynamic flexion-extension radiographs in an upright position using the computer software (Infinitt PiviewSTAR 5051) program. Range of motion/disc space angle and inter vertebral height were measured at the operative site and adjacent levels. Functional spinal unit (FSU) and overall sagittal alignment (C2–C7) were also measured pre-operatively, postoperatively and at final follow-up. ROM was calculated for all 3 areas and data collected were compared from pre operative to last follow-up as well as between the two groups. Radiographic assessment for adjacent level changes was also done. Radiologic change was analyzed using chi square test (95% confidence interval). Other data were analyzed using the mixed model. (SAS enterprise guide 4.1 version). Results: There was clinical improvement within each group in terms of VAS and NDI scores from pre-op to final follow-up for both single (VAS: p=0.8371, NDI: p=0.2872) and double (VAS: p=0.2938, NDI: p=0.6753) level surgeries but not significantly between the two groups. Overall, ROM and intervertebral height was relatively well maintained during the follow-up in the Bryan group compared to ACDF. Comparing the pattern of ROM measurements from pre-op to final follow-up between the two arms regardless of the number of levels operated on; significant differences were noted for overall ROM of the cervical spine (p< .0001) and all other levels except at the upper level for single level surgeries (p=0.2872). In terms of inter vertebral height measurements from pre-op to final follow-up, statistically significant (p< 0.0001 and p=0.0172) differences in the pattern between the two groups were noted at all levels except for the AIH of single level surgeries at the upper (p=0.1264) and lower (p=0.7598) levels as well as PIH for double level surgeries at the upper (p=0.8363) level. Radiologic change was 3.5 times more observed for the ACDF group compared to the Bryan group. Conclusion: Clinical status of both groups, regardless of the number of levels, showed improvement. Although clinical outcomes between the two groups were not significantly different at final follow-up, radiographic parameters, namely ROM and intervertebral heights at the operated site, some adjacent levels as well as FSU and overall sagittal alignment of the cervical spine were relatively well maintained in our Bryan group compared to our ACDF group. We surmise that to a certain degree, the maintenance of these parameters could contribute to reduce development of adjacent level change. Noteworthy is that radiographic change was 3.5 times more observed for ACDF surgeries. A longer period of evaluation is needed, to see if all these radiographic changes will translate to symptomatic adjacent level disease

Objective: To extend the follow up period of previous studies undertaken by the senior author, looking at the clinical outcome and radiological changes observed in patients with either myelopathy or radiculopathy, following anterior cervical discectomy without fusion. Design: Prospective, observational cohort study of patients undergoing anterior cervical discectomy without fusion and followed up for five years, radiologically, with serial plain radiographs, and clinically, using validated outcome measures including SF36, neck disability index and analogue visual pain scores. Subjects: 109 Patients undergoing anterior cervical dis-cectomy without fusion under the senior author’s care. Outcome measures:. Radiological. Occurrence of segmental cervical kyphosis. Loss of overall cervical alignment. Clinical. SF36, Neck disability index, Visual analogue neck and arm pain scores. Results: A total cohort of 109 patients, of mean age 56 years, were followed up after anterior cervical discectomy without fusion, for up to 5 years. Segmental kyphosis was demonstrated on 44%, and loss of overall cervical alignment on 60% of follow up plain radiographs during the third postoperative year. In the cohorts of patients with either loss of cervical alignment or segmental kyphosis at one year the mean clinical outcome scores (Wilcoxon’s matched pairs signed ranks test) continued to improve at the 5 year follow up. The annual rate of loss of cervical alignment in patients unaffected at the first post operative year was around 10% but there was no significant rate of progression of segmental kyphosis. Comparison of the relationship between these radiological changes and clinical outcome (Mann-Whitney U test) did not show any significant correlation. Conclusions: This study assesses patients over the period during which the anticipated alignment changes associated with undertaking simple anterior cervical discectomy could be having progressive detrimental clinical effects. Where such radiological changes occur they most commonly occur during the first post operative year. However, clinical outcome measures in these patients all improve at one year follow up, and still continue to improve or plateau up to five years post operatively. As anticipated, the most significant clinical improvement, occurs during the first post operative year. During the longer follow up period there is no significant detrimental effect of the radiological changes discussed on clinical outcome

Introduction: Anterior cervical spine surgeries are associated with high incidence (up to 60%) of early postoperative dysphagia and hoarseness of voice. These symptoms have been attributed to retraction injury on the larynx, trachea and oesophagus. Pressure from retractors producing ischaemia might explain the soft tissues complications following anterior cervical approach. Conventional retractor systems rely on the soft tissues for stability and create a vertical surgical channel but a novel system (Seex retractor) is fixed directly to the spine and rotates to allow an oblique approach. This may reduce retraction pressure by the Seex retractor on tissues This is the first investigation of retraction pressures using any two different retractor systems for anterior cervical spine surgery. The aims of this study were to measure the retraction pressure on the larynx, trachea and oesophagus during the anterior surgical approach to the cervical spine, in cadavers using conventional (Cloward) retractor and Seex retractor and to investigate the effect of flat or curved blades on retraction pressure. Methods: In a cadaveric model, through a standard anteriomedial approach simulated anterior cervical discectomy procedure was performed in cadavers at C3/4, C4/5, C5/6 and C6/7 levels using Cloward retractor with curved blade (Cervical Large Retractor Set. No. C50-1380: Cloward Instrument Corporation), Seex retractor with flat blade and Seex retractor with curved blade (Patent holder Dr. K. Seex, No PCT/AU05/001205). An online pressure transducer (Tekscan pressure measurement system) was applied between the retractor blade and medial tissues. Retraction pressures were recorded for all the retractors at each level on two separate occasions. Average retraction pressure (ARP), average peak retraction pressure (APRP), pressure distribution along the area of retraction, pressure difference at the edge and surface of the retractor blades, pressure variation with flat and curved blades were determined and compared. Results: A total of 40 sets of pressure recordings were made from 5 cadavers. Cloward retractor system generated an ARP of 33 mmHg (range 16 – 66 mmHg). ARP of Seex retractor with curved blade was 20 mmHg (range 9 – 50 mmHg) and that of Seex retractor with flat blade was 25 mmHg (range 10 – 74 mmHg). At one level ARP was same for all the three retractors. At another level ARP was same for Cloward retractor and Seex retractor with flat blade but higher than that of Seex retractor with curved blade. At two other levels Seex retractor with flat blade showed higher ARP than others. At 36 levels Cloward retractor showed highest ARP. This was statistically significant with Pearson’s Chi-square test (X2=10.023, degree of freedom=1, p = 0.0015) and Fisher exact test, p = 0.0005. Cloward retractor system showed an APRP of 124 mmHg (37 – 255 mmHg). While that of the Seex retractor with curved blade was 69 mmHg (14 – 254 mmHg) and that of Seex retractor with flat blade was 94 mmHg (18 – 255 mmHg). Of the 40 sets of the recordings at 32 levels Cloward retractor system generated highest APRP. With the Seex retractor itself flat blade generated more APRP than curved blade in 31 sets of measurements; it was reverse in 3 sets and in 6 sets APRP was same. Only at one level curved blade generated higher ARP than flat blade, at 11 levels it was same. At 28 levels ARP was higher with flat blade. Discussion: Cloward retractor generated significantly high retraction pressure (peak and average contact pressure) than Seex retractor in majority of the cases. Curved blades generate less retraction pressure than the flat ones. Based on these findings a prospective randomised study is underway in live patients

Background: Smaller versions of threaded lumbar cages were developed for cervical spine to obviate the need for allograft, iliac autograft use and to provide initial stability before fusion. Clinical trials of threaded cervical fusion cages have shown higher fusion rates and lower rates of graft-donor site complications. Study design/Aims: Prospective. Radiological and clinical outcomes of an age, sex and diagnosis matched patient population who underwent cervical fusion with (A) BAK/C cages filled with autograft reamings (Center-pulse Spine-tech Inc., Minneapolis, MN) (N=50) were compared with (B) Anterior cervical decompression and fusion (ACDF, N=50). Methods: Patients with symptomatic cervical discogenic radiculopathy were treated with either anterior cervical discectomy with uninstrumented bone-only fusion (ACDF) or BAK/C fusion cage(s). Independent radiographic assessment of fusion was made and patient-based outcome was assessed by a Short Form (SF)-36 Health Status Questionnaire. All patients had minimum follow up of at least 2 years. Results: Similar outcomes were noted for duration of surgery, hospital stay, improvements in neck pain and radicular pain in the affected limb, improvements in the SF-36 Physical Component subscale and Mental Component subscale, and the patients’ perception of overall surgical outcome. Symptom improvements were maintained at 2 years. Iliac crest harvesting was carried out as a standard procedure in all cases of ACDF whereas only 2 cases in BAK/C group required the same. Average operative time of 115 minutes and 145 minutes, blood loss of 110ml and 175ml and hospital stay of 1.5 and 3.5 days were noted for BAK/C and ACDF groups respectively. Successful fusion was achieved in 49 cases in BAK/C and 46 patients in ACDF group. None of the patients in the BAK/C group had reappearance of symptoms while 3 patients in ACDF group had developed symptomatic adjacent level disc disease. The complication rate for the ACDF group was 9% compared with an overall complication rate of 3% with BAK/C. Complications that necessitated a second operative procedure included. Graft dislodgement (N=3) and. Cage subsidence, both requiring re-operation in the form of ACDF with plate supplementation. Conclusions: These results demonstrate that outcomes after a cervical fusion procedure with a threaded cage are the same as those of a conventional uninstrumented bone-only anterior discectomy and fusion with a low risk of complications, less operative time and rare need for autogenous bone graft harvest

Background: To assess the clinical and radiological results of motion-segment sparing anterior cervical partial discectomy and foraminotomy surgery in patients with at least 1 year of follow-up. Methods: The study is a prospective, non-randomized, observational study. The patients all had symptoms of intrusive nerve root irritation with or without motor symptoms, refractory to conservative management for greater than 6 weeks duration. Patients were asked to complete questionnaires capturing) VAS (visual analogue) pain scores, NDI (neck disability index) and European myelopathy scores, patient satisfaction, and return to work details. Radiographic assessments were collected preoperatively, at 4 weeks, 3 months, 6 months, 1 and 2 years postoperatively. Results: 58 patients have been assessed with at least 1year follow-up. The mean duration of symptoms prior to surgery was 24 weeks (6–20 weeks). 55 patients had single level surgeries (C5/C6-15, C6/C7-38, C7-T1-2), 3 patients had two level surgeries (C4/C5& C5/C6-1, C5/C6& C6/C7-2). In 34 patients sugery was for soft disc prolapse, in 12 patients surgery was for hard osteophytes and in 12 patients both pathologies contributed equally. Operation time ranged from 50–85 minutes. Average in patient stay was 2.6 days. There were no complications apart from 1 patient who had to return early to theatre for evacuation of haematoma and then made a full recovery. All patients reported pain intensity reductions. Pain decreased from 6.7 to 1.4 for arm pain on a 10-point scale. NDI scores improved from a preop mean of 42 to 16 on a 100 point score at 6 months post-surgery. All patients returned to their usual occupations with the exception of 2 patients who are involved in litigation against an employer or third party. No patient required repeat surgeries. Radiographic analysis at 1 year shows preservation of segmental motion in 75% patients, preservation of interbody height in 60% patients, spontaneous fusion in 12% patients. Conclusion: A clinical success rate of 90% was achieved (clinical success being defined as a patient rating of very satisfied or satisfied on a 5-point patient self-scoring outcome scale). 56 out of 58 patients would undergo the same procedure again and recommend it to friend