Differentiating cervical spine and shoulder pathology: common disorders and key points of evaluation and treatment.

Accurately diagnosing patients with self-described pain in the shoulder or cervical spine (neck) remains a challenge for the orthopaedic surgeon. The overlapping presentations of shoulder disorders with those of the cervical spine, along with a lack of precision in physical examination testing, can create a confusing clinical picture and may result in disorganized or ineffective diagnostic and treatment regimens. A careful physical examination combined with judicious use of adjunctive tests, including selective corticosteroid injections, may help clarify the diagnosis. A high index of suspicion for the presence of cervical spine pathology is recommended in patients presenting with shoulder pain and vice versa.

20-year Clinical Outcomes of Cervical Disk Arthroplasty: A Prospective, Randomized, Controlled Trial.

STUDY DESIGN: Prospective, randomized, controlled trial. OBJECTIVE: To compare clinical outcomes of anterior cervical discectomy and fusion (ACDF) and cervical disk arthroplasty (CDA) at 20 years. SUMMARY OF BACKGROUND DATA: Concern for adjacent-level disease after ACDF prompted the development of CDA. MATERIALS AND METHODS: Forty-seven patients with single-level cervical radiculopathy were randomized to either BRYAN CDA or ACDF for a Food and Drug Administration Investigational Device Exemption trial. At 20 years, patient-reported outcomes, including visual analog scales (VAS) for neck and arm pain, neck disability index (NDI), and reoperation rates, were analyzed. RESULTS: Follow-up rate was 91.3%. Both groups showed significantly better NDI, VAS arm pain, and VAS neck pain scores at 20 years versus preoperative scores. Comparing CDA versus ACDF, there was no difference at 20 years in mean scores for NDI [11.1 (SD 14.1) vs. 19.9 (SD 17.2), P =0.087], mean VAS arm pain [0.9 (SD 2.4) vs. 2.3 (SD 2.8), P =0.095], or mean VAS neck pain [1.2 (SD 2.5) vs. 2.9 (3.3), P =0.073]. There was a significant difference between CDA versus ACDF groups in the change in VAS neck pain score between 10 and 20 years [respectively, -0.4 (SD 2.5) vs. 1.5 (SD 2.5), P =0.030]. Reoperations were reported in 41.7% of ACDF patients and 10.0% of CDA patients ( P =0.039). CONCLUSIONS: Both CDA and ACDF are effective in treating cervical radiculopathy with sustained improvement in NDI, VAS neck and VAS arm pain at 20 years. CDA demonstrates lower reoperation rates than ACDF. There were no failures of the arthroplasty device requiring reoperation at the index level. The symptomatic nonunion rate of ACDF was 4.2% at 20 years. Despite a higher reoperation rate in the CDA group versus ACDF group, there was no difference in the 20-year NDI, VAS Neck, and VAS arm pain scores.

Twenty-Year Radiographic Outcomes Following Single-Level Cervical Disc Arthroplasty: Results From a Prospective Randomized Controlled Trial.

STUDY DESIGN: Prospective randomized controlled trial. OBJECTIVE: Compare range of motion (ROM) and adjacent segment degeneration (ASD) following cervical disc arthroplasty (CDA) versus anterior cervical discectomy and fusion (ACDF) at 20-year follow-up. SUMMARY OF BACKGROUND DATA: Anterior cervical discectomy and fusion is the standard of treatment for single-level cervical disc degeneration causing radiculopathy. CDA is claimed to reduce shear strain, and adjacent-level ROM changes are hypothesized to hasten ASD with ACDF. MATERIALS AND METHODS: This study collected data on 47 patients randomized to ACDF or CDA. Lateral cervical spine radiographs were evaluated preoperatively, postoperatively, and at 20 years for alignment, ROM, ASD, and heterotopic ossification. RESULTS: Eighty-two percent (18/22) of CDA patients and 84% (21/25) of ACDF patients followed up at 20 years. At 20 years, total cervical (C2-C7) ROM was statistically different between the CDA and fusion groups (47.8° vs . 33.4°, P =0.005). Total cervical ROM was not significantly different between preoperative and 20-year periods following CDA (45.6° vs . 47.4°, P =0.772) or ACDF (40.6° vs . 33.0°, P =0.192). Differences in postoperative and 20-year index-level ROM following CDA were not significant (10.1° vs . 10.2°, P =0.952). Final ASD grading was statistically lower following CDA versus ACDF at both adjacent levels ( P <0.005). Twenty-year adjacent-level ossification development was increased following ACDF versus CDA ( P <0.001). Polyethylene mean thickness decreased from 9.4 mm immediately postoperatively to 9.1 mm at 20-year follow up ( P =0.013). Differences in adjacent-level ROM from preoperative to 20-year follow-up in both the ACDF and CDA groups did not meet statistical significance ( P >0.05). CONCLUSIONS: Cervical disc arthroplasty maintains index-level and total cervical ROM with very long-term follow-up. Total cervical ROM was higher at 20 years in CDA relative to ACDF. CDA results in lower rates of ASD and adjacent-level ossification development than ACDF.

Five-year Follow-up of a Prospective Food and Drug Administration Investigational Device Exemption Trial Evaluating a PEEK-on-Ceramic Cervical Disc Replacement.

STUDY DESIGN: Prospective trial comparing the investigation group to propensity matched historic control group. OBJECTIVE: To evaluate 5-year results of single-level PEEK-on-ceramic cervical total disc replacement (TDR) compared to a propensity matched anterior cervical discectomy and fusion (ACDF) control group. SUMMARY OF BACKGROUND DATA: Cervical TDR has gained acceptance as treatment for symptomatic disc degeneration. The design and materials used in these devices continue to evolve. METHODS: Data were collected in the Food and Drug Administration Investigational Device Exemption trial for the PEEK-on-ceramic Simplify(®) Cervical Artificial Disc (n=150) with comparison to a propensity matched ACDF control group (n=117). All patients were treated for single-level cervical disc degeneration with radiculopathy and/or myelopathy. Clinical outcome was based on composite clinical success (CCS), Neck Disability Index (NDI), visual analog scales (VAS) assessing pain, re-operations, and satisfaction. Radiographic measures included segmental range of motion (ROM), disc space height, and heterotopic ossification (HO). Evaluations were performed pre-operatively and post-operatively within 2 and 6 weeks, and 3, 6, 12 months, and annually thereafter. RESULTS: At 5-year follow-up, CCS was significantly greater with TDR than ACDF (91.1% vs. 74.6%; P<0.01). In the TDR group, the mean NDI score was 63.3 pre-operatively, reduced significantly to 23.1 at 6 weeks and remained below 20 throughout 5-year follow-up. In the ACDF group, the mean pre-operative NDI score was 62.4, decreasing to 33.7 at 6 weeks, and ranged from 25.9 to 21.5 throughout follow-up. Mean NDI scores were significantly lower in TDR group at all post-operative points (P<0.05). Mean TDR ROM was 7.3o pre-operatively and 10.1o at 5 years. Bridging HO occurred in 9%. With TDR, there were 6 re-operations (4.0%) vs. 11 (9.4%) with ACDF (P>0.40). CONCLUSION: PEEK-on-ceramic TDR produced significantly improved outcomes maintained throughout 5-year follow-up, were similar or superior to ACDF, supporting TDR in appropriately selected patients.

Comparison of axial and anterior interbody fusions of the L5-S1 segment: a retrospective cohort analysis.

STUDY DESIGN: Retrospective, multicenter review of 96 patients who underwent L5-S1 interbody fusions through either a standard anterior retroperitoneal approach or using a novel device inserted through the presacral space (AxiaLIF) in conjunction with supplemental posterior fixation between 2002 and 2010. OBJECTIVE: To compare the radiographic fusion rates and adverse events associated with anterior lumbar interbody fusion (ALIF) and AxiaLIF techniques. SUMMARY OF BACKGROUND DATA: Interbody fusions of the lumbosacral spine are frequently performed to provide anterior column support, increase the amount of surface area for bone formation, and facilitate deformity reduction. A number of different surgical approaches have been developed for this purpose including minimally invasive techniques. MATERIALS AND METHODS: Patient information and procedural data were obtained from hospital charts. Multiplanar computed tomography images were evaluated by 2 independent observers to assess fusion success at 24 months using a 4-point grading scale. In addition to reviewing the medical records to identify any complications, all of the sites were queried regarding any device-related adverse events that may have occurred. RESULTS: According to the radiographic analysis, the arthrodesis rates recorded for the ALIF and AxiaLIF cohorts were 79% and 85%, respectively (P>0.05). The numbers and types of adverse events recorded for these procedures appeared to be similar although there was 1 serious intraoperative complication (iliac artery laceration) noted in the ALIF group. CONCLUSIONS: The radiographic success and adverse events associated with AxiaLIF appear to be similar to that observed for ALIF, suggesting that this technique represents a safe and effective method for achieving an interbody fusion across the L5-S1 disk space when utilized in conjunction with posterior fixation.

Six-Year Follow-up of a Randomized Controlled Trial of i-FACTOR Peptide-Enhanced Bone Graft Versus Local Autograft in Single-Level Anterior Cervical Discectomy and Fusion.

BACKGROUND: Previous analyses of the US Food and Drug Administration (FDA) Investigational Device Exemption study demonstrated the superiority of i-FACTOR compared with local autograft bone in single-level anterior cervical discectomy and fusion (ACDF) at 12 and 24 months postoperatively in a composite end point of overall success. OBJECTIVE: To report the final, 6-year clinical and radiological outcomes of the FDA postapproval study. METHODS: Of the original 319 subjects enrolled in the Investigational Device Exemption study, 220 participated in the postapproval study (106 i-FACTOR and 114 control). RESULTS: The study met statistical noninferiority success for all 4 coprimary end points. Radiographic fusion was achieved in 99% (103/104) and 98.2% (109/111) in i-FACTOR and local autograft subjects, mean Neck Disability Index improvement from baseline was 28.6 (24.8, 32.3) in the i-FACTOR and 29.2 (25.6, 32.9) in the control group, respectively (noninferiority P < .0001). The neurological success rate at 6 years was 95.9% (70/73) in i-FACTOR subjects and 93.7% (70/75) in local autograft subjects (noninferiority P < .0001). Safety outcomes were similar between the 2 groups. Secondary surgery on the same or different cervical levels occurred in 20/106 (18.9%) i-FACTOR subjects and 23/114 (20.2%) local autograft subjects ( P = .866). Secondary outcomes (pain, SF-36 physical component score and mental component score) in i-FACTOR subjects were similar to those in local autograft subjects. CONCLUSION: i-FACTOR met all 4 FDA-mandated noninferiority success criteria and demonstrated safety and efficacy in single-level anterior cervical discectomy and fusion for cervical radiculopathy through 6 years postoperatively. Safety outcomes are acceptable, and the clinical and functional outcomes observed at 12 and 24 months remained at 72 months.

Lumbar Discectomy With Bone-Anchored Annular Closure Device in Patients With Large Annular Defects: One-Year Results.

BACKGROUND: Reherniation rates following lumbar discectomy are low for most patients; however, patients with a large defect in the annulus fibrosis have a significantly higher risk of recurrence. Previous results from a randomized controlled trial (RCT) demonstrated that the implantation of a bone-anchored annular closure device (ACD) during discectomy surgery lowered the risk of symptomatic reherniation and reoperation over one year with fewer serious adverse events (SAEs) compared to discectomy alone. OBJECTIVE: The objective of this prospective, post-market, historically controlled study was to evaluate the use of an ACD during discectomy, and to confirm the results of the RCT that was used to establish regulatory approval in the United States. METHODS: In this post-market study, all patients (N = 55) received discectomy surgery with a bone-anchored ACD. The comparison population was patients enrolled in the RCT study who had discectomy with an ACD (N = 262) or discectomy alone (N = 272). All other eligibility criteria, surgical technique, device characteristics, and follow-up methodology were comparable between studies. Endpoints included rate of symptomatic reherniation or reoperation, SAEs, and patient-reported measures of disability, pain, and quality of life. RESULTS: Fifty-five patients received ACD implants at 12 sites between May 2020 and February 2021. In the previous RCT, 272 control patients had discectomy surgery alone (RCT-Control), and 262 patients had discectomy surgery with an ACD implant (RCT-ACD). Baseline characteristics across groups were typical of the overall population undergoing lumbar discectomy. The proportion of patients who experienced reherniation and/or reoperation was significantly lower in the ACD group compared to RCT-ACD and RCT-Control groups (p < 0.05). In the ACD study, the one-year rate of symptomatic reherniation was 3.7%, compared to 8.5% in the RCT-ACD group and 17.0% in the RCT-Control group. In the ACD group, the risk of reoperation was 5.5%, compared to 6.5% in the RCT-ACD group and 12.5% in the RCT-Control group. There were no device-related SAEs or device integrity failures in the ACD, and there were clinically meaningful improvements in patient-reported measures of disability, pain, and quality of life. CONCLUSION: In this post-market study of bone-anchored ACD in patients with large annular defects, rates of symptomatic reherniation, reoperation, and SAEs were all low. Compared to the RCT, the post-market ACD study demonstrated lower rates of reherniation and/or reoperation and measures of back pain one-year post-surgery.

Clinical Significance of Lateral Pedicle Screw Malposition in Lumbar Spine Fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Our objective was to determine whether lateral pedicle screw breach affects fusion rates and patient-reported outcomes in lumbar fusion surgery. SUMMARY OF BACKGROUND DATA: Although lateral pedicle screw malposition is considered relatively benign, few studies have focused specifically on clinical outcomes or fusion rates associated with lateral screw malposition. METHODS: Twelve-month postoperative computed tomography scans were reviewed for lateral breach, severity of breach, and fusion status. Patients with lateral breach were compared with patients with no breach. Outcome measures included Numerical Pain Rating Scale for back and leg pain, Oswestry Disability Index, and SF-36 physical function (SF-36 PF). Multivariable linear and logistic regression and were adjusted for age, procedure, level, and/or baseline pain score. RESULTS: Forty-five patients (31%) demonstrated 1 or more lateral breaches as compared with 99 patients without breach. After adjusting for baseline scores and fusion level, patients with 2 or more screw breaches experienced SF-36 PF score improvements that were 3.43 points less ( P =0.016) than patients with no lateral breach. After adjusting for baseline Numerical Pain Rating Scale, there was also a significant decrease in the odds of achieving minimally clinical important difference in back pain relief in these patients. There was no observed effect of lateral breach on the odds of successful fusion. CONCLUSIONS: The current study did not observe an association between laterally malpositioned pedicle screws and nonunion. However, results are consistent with a negative effect on SF-36 PF scores and self-reported back pain at 12 months.

Accuracy of the freehand technique for 3 fixation methods in the C-2 vertebrae.

OBJECT: Intraoperative imaging often does not provide adequate visualization to ensure safe placement of screws. Therefore, the authors investigated the accuracy of a freehand technique for placement of pars, pedicle, and intralaminar screws in C-2. METHODS: Sixteen cadaveric specimens were instrumented freehand by 2 experienced cervical spine surgeons with either a pars or pedicle screw, and bilateral intralaminar screws. The technique was based on anatomical starting points and published screw trajectories. A pedicle finder was used to establish the trajectory, followed by tapping, palpation, and screw placement. After placement of all screws (16 pars screws, 16 pedicle screws, and 32 intralaminar screws), the C-2 segments were disarticulated, radiographed in anteroposterior, lateral, and axial planes, and meticulously inspected by another spine surgeon to determine the nature and presence of any defects. RESULTS: A total of 64 screws were evaluated in this study. Pars screws exhibited 2 critical defects (1 in the foramen transversarium and 1 in the C2-3 facet) and an insignificant dorsal cortex breech, for an overall accuracy rate of 81.3%. Pedicle screws demonstrated only 1 insignificant violation (inferior facet/medial cortex intrusion of 1 mm) with an accuracy rate of 93.8%, and intralaminar screws demonstrated 3 insignificant violations (2 in the ventral canal, 1 in the caudad lamina breech) for an accuracy rate of 90.6%. Pars screws had significantly more critical violations than intralaminar screws (p = 0.041). CONCLUSIONS: Instrumentation of the C-2 vertebrae using the freehand technique for insertion of pedicle and intralaminar screws showed a high success rate with no critical violations. Pars screw insertion was not as reliable, with 2 critical violations from a total of 16 placements. The freehand technique appears to be a safe and reliable method for insertion of C-2 pedicle and intralaminar screws.

Rigid versus nonrigid occipitocervical fusion: a clinical comparison of short-term outcomes.

STUDY DESIGN: Retrospective data review. OBJECTIVE: To report clinical outcomes of both rigid and nonrigid occipitocervical (OC) fusion constructs of a multicenter cervical spine study group. BACKGROUND: The OC junction is susceptible to a wide variety of pathologic conditions that predispose it to instability. The need for arthodesis in symptomatic or neurologically unstable cases has led to the development of a variety of fusion techniques that can be classified as either nonrigid fixation techniques, such as sublaminar wiring or onlay bone grafting, or rigid internal fixation constructs, such as screws with plate or rods. Rigid fixation provides immediate stability and eliminates the need for external fixators, that is, halo-vest. Although a rigid construct would seem to confer several advantages over a nonrigid construct with external inmobilization supplementation, comparative clinical data are is lacking. METHODS: A clinical comparison of the rigid and the nonrigid forms of OC fusion was done retrospectively from the data of a multicenter cervical spine study group. A total of 71 occipitocervical fusion patients were identified: 25 with a nonrigid technique and 46 with a rigid construct. Average follow-up time was 6.3 months with a range of 1.5 to 36 for the rigid construct cohort and 15.7 months with a range of 1 to 36 months for the nonrigid cohort. Complications were recorded and correlated to the type of fixation and the type of external immobilization used. A χ analysis was done to evaluate the significant differences between complication rates of both the groups, that is, rigid and nonrigid constructs. RESULTS: Twenty-five nonrigidly fused patients had a complication rate of 48%, whereas 46 rigidly fused patients had a complication rate of 10% (P<0.01). Rigid forms of internal fixation for OC fusion has a significantly lower complication rate in short term. CONCLUSION: In addition to the many advantages of a rigid occipitocervical construct, the clinical complication rates are statistically significantly lower versus a nonrigidly fixed construct.

Far Lateral/Extraforaminal Approaches for Microdiscectomy and Foraminal Decompression in the Lumbar Spine.

Far lateral approaches to the lumbar spine are uncommon procedures but are essential techniques for spine surgeons to understand and master for the treatment of extraforaminal disk herniations and foraminal stenosis. We present our preferred approaches for open and minimally invasive techniques to perform extraforaminal decompressions and/or discectomies in the lumbar spine.

Two-Year Clinical and Radiological Outcomes in Patients With Diabetes Undergoing Single-Level Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Secondary analysis of data from the multicenter, randomized, parallel-controlled Food and Drug Administration (FDA) investigational device exemption study. OBJECTIVE: Studies on outcomes following anterior cervical discectomy and fusion (ACDF) in individuals with diabetes are scarce. We compared 24-month radiological and clinical outcomes in individuals with and without diabetes undergoing single-level ACDF with either i-FACTOR or local autologous bone. METHODS: Between 2006 and 2013, 319 individuals with single-level degenerative disc disease (DDD) and no previous fusion at the index level underwent ACDF. The presence of diabetes determined the 2 cohorts. Data collected included radiological fusion evaluation, neurological outcomes, Neck Disability Index (NDI), Visual Analog Scale (VAS) scores, and the 36-Item Short Form Survey Version 2 (SF-36v2) Physical and Mental component summary scores. RESULTS: There were 35 individuals with diabetes (11.1%; average body mass index [BMI] = 32.99 kg/m2; SD = 5.72) and 284 without (average BMI = 28.32 kg/m2; SD = 5.67). The number of nondiabetic smokers was significantly higher than diabetic smokers: 73 (25.70%) and 3 (8.57%), respectively. Preoperative scores of NDI, VAS arm pain, and SF-36v2 were similar between the diabetic and nondiabetic participants at baseline; however, VAS neck pain differed significantly between the cohorts at baseline (P = .0089). Maximum improvement for NDI, VAS neck and arm pain, and SF-36v2 PCS and MCS scores was seen at 6 months in both cohorts and remained stable until 24 months. CONCLUSIONS: ACDF is effective for cervical radiculopathy in patients with diabetes. Diabetes is not a contraindication for patients requiring single-level surgery for cervical DDD.

Single-Level Cervical Disc Replacement Using a PEEK-on-Ceramic Implant: Results of a Multicenter FDA IDE Trial With 24-Month Follow-up.

BACKGROUND: Many early cervical total disc replacements (TDRs) produced motion through a ball-and-socket action, with metal endplates articulating with a plastic core. Polyetheretherketone (PEEK) is used increasingly for spinal implants due to its mechanical properties and lack of artifacts on imaging. A TDR was designed with titanium-coated PEEK endplates and a ceramic core. The purpose of this study was to compare this TDR with anterior cervical discectomy and fusion (ACDF) to treat single-level cervical disc degeneration. METHODS: This was a prospective, nonrandomized, historically controlled, multicenter US Food and Drug Administration (FDA) Investigational Device Exemption (IDE) trial. Patients received the PEEK-on-ceramic Simplify® Cervical Artificial Disc (n = 150). The historic control group included 117 propensity-matched ACDF patients from an earlier IDE trial. The primary outcome was a composite success classification at the 24-month follow-up. Outcome measures included the Neck Disability Index (NDI), neurological status, adverse events, subsequent surgery, a visual analog scale assessing neck and arm pain, and the Dysphagia Handicap Index. Radiographic assessment included flexion/extension range of motion and heterotopic ossification. Facet joints were assessed at 24 months using MRI. RESULTS: The success rate was significantly greater in the TDR group vs the ACDF group (93.0% vs 73.6%; P < .001). Mean NDI, neck pain, and arm pain scores improved significantly in both groups at all follow-up points. Mean NDI scores in the TDR group were significantly lower than ACDF scores at all follow-up points. There were no significant differences in the rates of serious adverse events. The range of motion of the TDR level had increased significantly by 3 months and remained so throughout follow-up. Facet joint assessment by MRI in the TDR group showed little change from preoperation. CONCLUSIONS: The TDR had an acceptable safety profile and a significantly greater composite success rate than ACDF. These results support that the PEEK-on-ceramic TDR is a viable alternative to ACDF for single-level symptomatic disc degeneration. CLINICAL RELEVANCE: This study found that the PEEK-on-ceramic TDR is a viable treatment for symptoms related to cervical disc degeneration and offers similar or superior outcomes compared with fusion. LEVEL OF EVIDENCE: 2.

Lumbar Discectomy With Barricaid Device Implantation in Patients at High Risk of Reherniation: Initial Results From a Postmarket Study.

Background Patients with large defects in the annulus fibrosus following lumbar discectomy have high rates of symptomatic reherniation and reoperation. An FDA randomized controlled trial (RCT) with a bone-anchored device (Barricaid, Intrinsic Therapeutics, Woburn, MA) that occludes the annular defect reported significantly lower risk of symptomatic reherniation and reoperation compared to patients receiving discectomy only. However, results of the Barricaid device in real-world use remain limited.  Methods This was a post-market study to determine the real-world outcomes of the Barricaid device when used in addition to primary lumbar discectomy in patients with large annular defects. Main outcomes included leg pain severity, Oswestry Disability Index (ODI), adverse events, symptomatic reherniation, and reoperation. Imaging studies were read by an independent imaging core laboratory. This paper reports the initial three-month primary endpoint results from the trial; one-year patient follow-up is ongoing. Results Among 55 patients (mean age 41±13 years, 60% male), the mean percent reduction in leg pain severity was 92%, and the mean percent reduction in ODI score was 79%. The three-month rate of symptomatic reherniation was 3.6% and the rate of reoperation was 1.8%. The serious adverse event rate was 5.5%; no device migrations or fractures were observed.  Conclusion Among patients with large annular defects following lumbar discectomy treated with the Barricaid device in real-world conditions, early results demonstrated clinically meaningful improvements in patient symptoms and low rates of symptomatic reherniation, reoperation, and complications, which were comparable to those observed with the device in an FDA-regulated trial.

Safety of anterior cervical discectomy and fusion performed as outpatient surgery.

STUDY DESIGN: Retrospective review of a prospectively collected database. OBJECTIVE: To determine the complications and safety of anterior cervical discectomy and fusion performed on an outpatient basis. SUMMARY OF BACKGROUND DATA: Anterior cervical discectomy and fusion performed as outpatient surgery is an appealing alternative and has many potential benefits. The safety of this practice, however, has not been thoroughly investigated. This study aims to examine the frequency of acute complications and rates of unplanned admissions for anterior cervical discectomy and fusions scheduled as outpatient procedures. METHODS: Data were collected prospectively on 645 consecutive patients undergoing anterior discectomy and fusion by a single surgeon for either stenosis or herniated nucleus pulposus involving 1 level. These data were then retrospectively reviewed for acute complications occurring within 48 hours of surgery. A subset consisting of the last 392 patients were further reviewed to better characterize this population. Complications after surgery as well as procedures requiring postoperative admission for any reason were detailed. RESULTS: Two of 645 (0.3%) patients developed acute complications, both of which were epidural hematomas. Both occurred within the protocol's mandatory 4 hours postoperative observation time. Both resolved without permanent neurologic deficit. There were no retropharyngeal hematomas and no deaths. Six percent of patients required an unplanned admission. More than 80% of unplanned admissions were secondary to either pain or nausea. CONCLUSIONS: One-level anterior cervical discectomy and fusion can be safely performed in an outpatient setting with a 4-hour observation period. There is a low rate (6%) of unplanned admission to the hospital. The number of unplanned admissions can be decreased by more than one-third if autogenous iliac crest bone graft is not harvested. The use of postoperative drains for 1-level anterior discectomy and fusion is called into question.

Clinical outcomes of Bryan cervical disc arthroplasty a prospective, randomized, controlled, single site trial with 48-month follow-up.

STUDY DESIGN: Prospective, randomized, controlled. Level 1 evidence. OBJECTIVE: To report functional outcomes at 48 months follow-up on prospectively randomized patients to either the Bryan cervical disc prosthesis or anterior cervical discectomy and fusion (ACDF) at a single site. SUMMARY OF BACKGROUND DATA: Surgical treatment of cervical disc pathology can involve discectomy and fusion (ACDF), the gold standard technique. The safety and effectiveness of this procedure has been established and demonstrated in the literature, however, limitations have evolved and alternatives such as disc replacement are being investigated. Intervertebral disc replacement is designed to preserve motion, both at affected and adjacent levels avoiding limitations of fusion such as adjacent level degeneration. New onset degenerative changes and possible recurring neurologic symptoms may be deferred or eliminated with cervical disc replacement. A recent multicenter trial with 24 months follow-up has shown the Bryan disc to compare favorably with ACDF. Continued follow-up is needed to further evaluate and compare functional outcomes in both these cohorts. METHODS: A total of 47 patients were enrolled at our site as part of an ongoing multicenter prospectively randomized study investigating ACDF versus Bryan cervical disc prosthesis. Functional outcomes are now reported at 48 months follow-up for our cohort of participants. Neck disability index score (NDI), VAS neck and arm and SF-36 both physical and mental as well as complications and reoperations will be reported. RESULTS: Functional outcome data collected at routine follow-up for 48-months has favorably demonstrated improved functional outcomes for NDI, neck/arm pain VAS scores, and the SF-36 physical/mental health component scores for the Bryan arthroplasty and ACDF cohorts. The NDI scores for the Bryan arthroplasty preoperatively was 51 and at 48 months 10. For ACDF preoperative NDI score was also 51 and at 48 months 16.7. At 48 months NDI success, measured by >or=15 points NDI improvement demonstrated a 93.3% success for Bryan arthroplasty and an 82.4% success for ACDF. VAS neck pain scores for the Bryan arthroplasty preoperatively was 76.2 and at 48 months was 13.6. VAS neck pain scores for ACDF preoperatively was 80.6 and at 48 months was 28.1. Arm Pain scores were also measured and for the Bryan arthroplasty preoperatively measured 78.8 and at 48 months 10.8. For ACDF arm pain scores preoperatively measured 77.1 and at 48 months 21.7. These outcomes have not been associated with any degradation of outcome measures from 2 to 4 years. During the 48 months of follow-up at our institution we also report 6 secondary surgeries in our control group (ACDF) and only 1 in our investigational group (Bryan). Of the 6 surgeries in the control group performed, 3 or 12% to date were for adjacent level degenerative disease and 1 or 4% for remote level degenerative disc disease. The remaining 2 surgeries were performed on the same patient for a pseudarthrosis. In the investigational group there was only 1 secondary surgery performed to date for adjacent level disease 5%. CONCLUSIONS: At 48 months, cervical arthroplasty with the Bryan cervical disc prosthesis continues to compare favorably to ACDF at our institution. There has been no degradation of functional outcomes from 24 to 48 months for NDI, VAS of neck and arm, and SF-36. There has been a lower incidence of secondary surgeries for the Bryan arthroplasty cohort to date.

Quality of spinal motion with cervical disk arthroplasty: computer-aided radiographic analysis.

STUDY DESIGN: Kinematic study of a single site in an investigational device exemption trial. OBJECTIVE: Evaluate the center of rotation (COR) after Bryan cervical arthroplasty and compare adjacent segment motion after cervical disk arthroplasty and fusion using validated radiographic analysis. SUMMARY OF BACKGROUND DATA: The goal of cervical arthroplasty is to reestablish spinal kinematics after anterior decompression. Excellent maintenance of range of motion has been reported for a variety of the prostheses; however, the manner the prostheses perform this task is different. A parameter that may be as important as range of motion is restoring the quality of motion. One of the important components is the COR that is easily studied biomechanically but has not been reported from in vivo studies. Furthermore, the effects on the quality of motion at adjacent levels have not been studied. The purpose of this study is to determine the quality of motion after Bryan cervical disk arthroplasty at the target level and the adjacent segments. METHODS: The first 48 patients diagnosed with single level cervical disk degenerative disease and associated myelopathy or radiculopathy from a single institution enrolled in the Bryan disk investigational device exemption trial were selected for inclusion. Twenty-two investigational patients and 26 anterior cervical discectomy and fusion controls were evaluated radiographically preoperatively and 3, 6, 12, and 24 months postoperatively. These results were analyzed using Quantitative Motion Analysis software manufactured by Medical Metrics Inc. Kinematic parameters included translation, sagittal rotation, anterior/posterior disk height, and the calculation of the COR both in the sagittal and coronal planes. RESULTS: At the arthroplasty level, the COR shifted more posterior (0.3 mm, 1% end plate width) and cephalad (4.9 mm, 20% end plate width) compared with the preoperative position, however, this change was not statistically significant (P=0.06). The variability of the COR, however, was less after arthroplasty compared with preoperative values. There was no significant difference in the short term between the adjacent levels after fusion compared with the prosthesis. At later time points (12 and 24 mo), however, the COR was significantly posterior at the level above arthroplasty compared with fusion (P<0.01). COR X was not significantly (P>0.3) different below fusions compared with arthroplasty. Sagittal rotation significantly increased at the level above for both the fusion and prosthesis groups. A trend was noted for increased translation (2.5% end plate width) at the level above a fusion compared with the Bryan disk at 24 months postoperatively, but this did not reach statistical significance. CONCLUSIONS: Sagittal rotation increases above the level of the arthroplasty and fusion. In the long term, the arthroplasty group had a more posterior COR at the level above, compared with the level above a fusion. Translation at the level above a fusion was slightly increased but not statistically compared with the level above the arthroplasty with similar amounts of sagittal rotation (flexion/extension). Although not reaching statistical significance, the COR seemed to shift more posterior and cephalad at the arthroplasty level with less variability compared with the preoperative position.

Long-Term Radiographic and Functional Outcomes of Patients With Absence of Radiographic Union at 2 Years After Single-Level Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Retrospective radiographic investigation. OBJECTIVE: To evaluate the long-term radiographic and functional outcomes of patients in whom there is absence of radiographic union at 2 years after single-level anterior cervical discectomy and fusion (ACDF). METHODS: Thirty-one patients were evaluated at standard postoperative time intervals per index trial protocol. Plain film radiographic fusion criteria at the arthrodesis level was defined as interspinous motion (ISM) <1 mm with corresponding motion at a non-arthrodesed superjacent level ISM ≥4 mm. Radiographs and functional outcome measures were acquired at each follow-up visit. Delayed union was defined as lack of radiographic union by 24 months. RESULTS: Nine patients demonstrated radiographic evidence of delayed radiographic union at 24 months. Of those 9 patients, 5 patients demonstrated evidence of union during the follow-up period to 72 months. Despite the absence of radiographic union based on our criteria, 3 of the 4 remaining patients reported remarkable improvements in pain scores and functional outcomes. CONCLUSIONS: The natural history of delayed union at 24 months after ACDF was still favorable despite the prolonged delay in union. The majority of patients (5 of 9) without radiographic union at 24 months did proceed to radiographic union by final follow-up. In addition, patients that did not meet our criteria for fusion maintained postoperative improvements in patient-reported outcome scores. In summary, our study patients undergoing a single-level ACDF with asymptomatic radiographic delayed union at 24 months can expect maintained improvements in postoperative patient-reported outcomes scores and can still progress to successful radiographic fusion.