Impact of Cervical Disc Arthroplasty vs Anterior Cervical Discectomy and Fusion on Driving Disability: Post Hoc Analysis of a Randomized Controlled Trial With 10-Year Follow-Up.

BACKGROUND: Driving an automobile requires the ability to turn the neck laterally. Anecdotally, patients with multilevel fusions often complain about restricted turning motion. The purpose of this study was to compare the effectiveness of cervical disc arthroplasty (CDA) with anterior cervical discectomy and fusion (ACDF) on driving disability improvement at 10-year follow-up after a 2-level procedure. METHODS: In the original randomized controlled trial, patients with cervical radiculopathy or myelopathy at 2 levels underwent CDA or ACDF. The driving disability question from the Neck Disability Index was rated from 0 to 5 years preoperatively and up to 10 years postoperatively. Severity of driving disability was categorized into "none" (score 0), "mild" (1 or 2), and "severe" (3, 4, or 5). Score and severity were compared between groups. RESULTS: Out of 397 patients, 148 CDA and 118 ACDF patients had 10-year follow-up. Driving disability scores were not different between the groups preoperatively (CDA: 2.65; ACDF: 2.71, P = 0.699). Postoperatively, the scores in the CDA group were significantly lower than those in the ACDF group at 5 (0.60 vs 1.08, P ≤ 0.001) and 10 years (0.66 vs 1.07, P = 0.001). Mean score improvement in the CDA group was significantly greater than the ACDF group at 10-year follow-up (-1.94 vs -1.63, P = 0.003). The majority of patients reported severe driving disability (CDA: 56.9%, ACDF: 58.0%, P = 0.968) before surgery. After surgery, a greater proportion of patients in the CDA group had neck pain-free driving compared with the ACDF group at 5 (63.3% vs 41.8%, P < 0.001) and 10 years (61.8% vs 41.2%, P = 0.003). CONCLUSION: In patients with cervical radiculopathy/myelopathy and 2-level disease, CDA provided greater improvements in driving disability as compared with ACDF at 10-year follow-up. This is the first report of its kind. This finding may be attributable to preservation of motion associated with CDA. CLINICAL RELEVENCE: This study provides valuable information regarding the improvement of driving disability after both CDA and ACDF. It demonstrates that both procedures result in significant improvements, with CDA resulting in even better improvements than ACDF, up to 10 year follow-up.

Single-Stage Combined Anterior Corpectomy and Posterior Instrumented Fusion in Tuberculous Spondylitis With Varying Degrees of Neurological Deficit.

BACKGROUND: A combined anterior decompression and stabilization followed by posterior instrumented fusion promotes fusion of the affected segment of spine and prevents further progression of deformity. The objective of this study is to report on outcome of patients with tuberculous spondylitis, progressive neurologic deficit, and kyphotic deformity who underwent single-stage anterior corpectomy and fusion and posterior decompression with instrumented fusion. METHODS: A total of 49 patients (29 males, 20 females) with varying grades of neurological deficit due to tuberculosis of the spine (thoracic, thoracolumbar, and lumbar) were included in this prospective study. The diagnosis of tubercular infection was established after clinical, hematological, radiological, and histological specimens taken at surgery. All were treated with combined anterior and posterior decompression, debridement, and stabilization with direct autologous bone grafting or wrapped bone graft in mesh or expandable cages. Neurological status and visual analog scale (VAS) pain score were recorded at each visit. X-rays, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and liver function were evaluated at 3, 6, and 12 months after surgery and then once a year thereafter. Results were analyzed in terms of neurological recovery (Frankel grade), bony union time, and correction of kyphotic deformity. RESULTS: The mean age was 37.8 years (range, 2-65 years). Mean preoperative VAS scores improved from 5.6 to 1.5. The average ESR and CRP returned to normal within 6 months in all patients. The mean time to fusion was 8.4 months for the whole group. The neurological deficit in 42 of 49 patients had excellent or good clinical outcome (P < .0001). A total of 10 of 17 patients improved from Frankel A and B to Frankel E (normal activity). Three patients each in the thoracic and thoracolumbar groups improved to Frankel D. Radiological measurements showed the mean kyphotic correction was 61%, 66%, and 67% in the thoracic, thoracolumbar, and lumbar/lumbosacral spine, respectively. CONCLUSIONS: Combined single-stage anterior decompression and stabilization followed by posterior instrumented fusion is safe and effective in the treatment of tuberculous spondylitis with neurological deficit in the thoracic and lumbar spine. This procedure helps to correct and maintain the deformity, abscess clearance, spinal-cord decompression, and pain relief as well as return to normal motor function. Bony fusion prevents further progression of deformity. LEVEL OF EVIDENCE: 2.

The Effect of ACDF or Arthroplasty on Cervicogenic Headaches: A Post Hoc Analysis of a Prospective, Multicenter Study With 10-Year Follow-up.

STUDY DESIGN: This was a post hoc analysis of a prospective FDA-IDE study. OBJECTIVE: The purpose of this study is to determine the effectiveness of a 2-level anterior cervical discectomy and fusion (ACDF) or cervical disk arthroplasty (CDA) at relieving headaches associated with cervical radiculopathy or myelopathy at 10 years postoperative. BACKGROUND: To our knowledge, there is no large, prospective study that has examined the efficacy of cervical spine surgery for relieving headaches associated with radiculopathy or myelopathy at 10 years postoperative. MATERIALS AND METHODS: This was a post hoc analysis of a prospective FDA-IDE study for the Prestige LP versus ACDF for radiculopathy or myelopathy due to 2 levels. Preoperatively and out to 10 years, their Neck Disability Index documented if they had headaches (0: no headaches; 1: infrequent slight; 2: infrequent moderate; 3: frequent moderate; 4: frequent severe; 5: nearly constant). RESULTS: Three hundred ninety-seven patients were randomized to CDA (209) or ACDF (188). Preoperatively 86% had headaches and 55.9% (52.2% of CDA, 60.1% of ACDFs) had frequent moderate, severe, or nearly constant headache (grades 3-5). By 6 weeks postoperative, 64.4% had headaches and only 12.5% had grades 3-5 headaches (9.3% of CDA and 16% of ACDFs). The benefit lasted to the 10-year follow-up such that 60.3% had any headaches and 16.8% had grades 3-5 headaches (10.9% CDA; 24.3% ACDF). CONCLUSIONS: These results suggest that 86% of patients with radiculopathy or myelopathy complain of headaches preoperatively, with 55.9% having frequent or constant, moderate to severe headaches (grades 3-5). By 6 weeks postoperative, only 12.5% had grades 3-5 headaches. At 10-year follow-up, 16.8% had grades 3-5 headaches. Both arthroplasty and ACDF are often effective at alleviating headaches associated with radiculopathy or myelopathy.

Occurrence and clinical implications of heterotopic ossification after cervical disc arthroplasty with the Prestige LP Cervical Disc at 2 contiguous levels.

OBJECTIVE: The authors sought to assess the impact of heterotopic ossification (HO) on clinical outcomes and angular range of motion (ROM) after cervical disc arthroplasty (CDA) performed with the Prestige LP Cervical Disc (Prestige LP disc) at 2 levels. METHODS: HO was assessed and graded from 0 to IV for increasing severity on lateral neutral radiographs at each visit in 209 patients who underwent implantation of Prestige LP discs at 2 cervical levels in a clinical trial with extended 10-year follow-up. ROM was compared by using HO grade, and clinical outcomes were compared between HO subgroups (grade 0-II vs III/IV) based on HO severity at 2 and 10 years after surgery. RESULTS: The grade III/IV HO incidence at either or both index levels was 24.2% (48/198) at 2 years and 39.0% (57/146) at 10 years. No statistical difference was found in overall success; neurological success; or Neck Disability Index (NDI), neck pain, arm pain, or SF-36 Physical Component Summary (PCS) scores between the HO subgroups (grade 0-II vs III/IV) at either 2 or 10 years. The cumulative rate of possible implant-related adverse events (AEs) was higher in patients having grade III/IV HO at 2 years (56.3%) and 10 years (47.8%) compared with those having grade 0-II HO at 2 years (24.4%) and 10 years (17.9%), specifically in 2 subcategories: spinal events and HOs reported by the investigators. No statistical difference was found between the HO subgroups in possible implant-related serious AEs or secondary surgeries at the index or adjacent levels. The average angular ROMs at index levels were lower in subjects with higher-grade HO at 2 and 10 years. The average ROMs at the superior level were 8.8°, 6.6°, 3.2°, and 0.3°, respectively, for the HO grade 0/I, II, III, and IV groups at 10 years, and 7.9°, 6.2°, 3.7°, and 0.6°, respectively, at the inferior level. CONCLUSIONS: Radiographically severe (grade III or IV) HO after CDA with the Prestige LP disc at 2 levels did not significantly affect efficacy or safety outcomes (severe AEs or secondary surgeries). However, severe HO, particularly grade IV HO, significantly limited ROM, as expected.

One-Level Versus 2-Level Treatment With Cervical Disc Arthroplasty or Fusion: Outcomes Up to 7 Years.

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) have been used to treat degenerative disc disease at single as well as multiple cervical levels. This study compares the safety and efficacy of 1-level versus 2-level CDA and ACDF. METHODS: In total, 545 and 397 patients with degenerative disc disease were studied in 1-level and 2-level Food and Drug Administration (FDA)-approved clinical trials, respectively: CDA (n = 280 and 209), ACDF (n = 265 and 188). Data from these studies were used to compare 1- versus 2-level procedures: the propensity score method was used to adjust for potential confounding effects, and adjusted mean outcome safety and efficacy scores at 2 and 7 years postsurgery were compared between 1-level and 2-level procedures within treatment type. RESULTS: One-level and 2-level procedures had similar rates of improvement in overall success and patient-reported outcomes scores for both CDA and ACDF. There were no statistical differences in rates of implant-related adverse events (AEs) or serious implant-related AEs between 1-level and 2-level CDA. The 7-year rate of implant-related AEs was higher for 2-level than 1-level ACDF (27.7% vs 18.9%, P ≤ .036), though the rates of serious implant-related AEs between ACDF groups did not differ significantly. Secondary surgery rates were not statistically different between 1-level and 2-level procedures (CDA or ACDF) at the index or adjacent levels at 2 or 7 years. Grade IV heterotopic ossification at 7 years was reported in 4.6% of 1-level CDA patients and 8.6%/7.3% at the superior/inferior levels, respectively, of 2-level CDA patients. CONCLUSIONS: One- and 2-level CDA appear equally safe and effective in the treatment of cervical degenerative disc disease. Two-level ACDF appears to be as effective as 1-level ACDF but with a higher rate of some AEs at long-term follow-up. LEVEL OF EVIDENCE: 2. CLINICAL TRIALS: clinicaltrials.gov: NCT00667459, NCT00642876, and NCT00637156.

Two-level cervical disc arthroplasty versus anterior cervical discectomy and fusion: 10-year outcomes of a prospective, randomized investigational device exemption clinical trial.

OBJECTIVE: The authors assessed the 10-year clinical safety and effectiveness of cervical disc arthroplasty (CDA) to treat degenerative cervical spine disease at 2 adjacent levels compared to anterior cervical discectomy and fusion (ACDF). METHODS: A prospective, randomized, controlled, multicenter FDA-approved clinical trial was conducted comparing the low-profile titanium ceramic composite-based Prestige LP Cervical Disc (n = 209) at two levels with ACDF (n = 188). Ten-year follow-up data from a postapproval study were available on 148 CDA and 118 ACDF patients and are reported here. Clinical and radiographic evaluations were completed preoperatively, intraoperatively, and at regular postoperative follow-up intervals for up to 10 years. The primary endpoint was overall success, a composite variable that included key safety and efficacy considerations. Ten-year follow-up rates were 86.0% for CDA and 84.9% for ACDF. RESULTS: From 2 to 10 years, CDA demonstrated statistical superiority over ACDF for overall success, with rates at 10 years of 80.4% versus 62.2%, respectively (posterior probability of superiority [PPS] = 99.9%). Neck Disability Index (NDI) success was also superior, with rates at 10 years of 88.4% versus 76.5% (PPS = 99.5%), as was neurological success (92.6% vs 86.1%; PPS = 95.6%). Improvements from preoperative results in NDI and neck pain scores were consistently statistically superior for CDA compared to ACDF. All other study effectiveness measures were at least noninferior for CDA compared to ACDF through the 10-year follow-up period, including disc height. Mean angular ranges of motion at treated levels were maintained in the CDA group for up to 10 years. The rates of grade IV heterotopic ossification (HO) at the superior and inferior levels were 8.2% and 10.3%, respectively. The rate of severe HO (grade III or IV) did not increase significantly from 7 years (42.4%) to 10 years (39.0%). The CDA group had fewer serious (grade 3-4) implant-related or implant/surgical procedure-related adverse events (3.8% vs 8.1%; posterior mean 95% Bayesian credible interval [BCI] of the log hazard ratio [LHR] -0.92 [-1.88, -0.01]). The CDA group also had statistically fewer secondary surgical procedures at the index levels (4.7%) than the ACDF group (17.6%) (LHR [95% BCI] -1.39 [-2.15, -0.61]) as well as at adjacent levels (9.0% vs 17.9%). CONCLUSIONS: The Prestige LP Cervical Disc, implanted at two adjacent levels, maintains improved clinical outcomes and segmental motion 10 years after surgery and is a safe and effective alternative to fusion.Clinical trial registration no.: NCT00637156 (clinicaltrials.gov).

Predictive Factors for the Outcome of Surgical Treatment of Lumbar Spondylolysis in Young Sporting Individuals.

STUDY DESIGN: Retrospective consecutive case series. OBJECTIVES: Only few sporting individuals with symptomatic lumbar pars injuries require surgical repair and it is often difficult to predict the outcome following surgery. The factors that predict the outcome after direct repair of lumbar pars defect was evaluated clinically and statistically. The preoperative background variables both subjective and objective as well as radiological evaluation were used in a multiple regression model to find the strong predictors of postoperative outcome as measured by VAS (visual analogue scores), ODI (Oswestry Disability Index) and SF-36 (Short Form). METHODS: Fifty-two consecutive young sporting individuals with a mean age of 19 years (range 8-30 years) were treated surgically for lumbar pars defect confirmed on imaging studies (ie, single-photon emission computed tomography, computed tomography, and magnetic resonance imaging). Fifty patients completed the VAS, ODI, and SF-36 questionnaires as a part of their assessment. Preoperative background variables were used in a multiple regression model to find the strongest predictor of postoperative outcome as measured by ODI. Ethical approval was taken by the institutional review board. RESULTS: Buck's screw repair of the pars defect was carried out in 44 patients (33 males, 11 female): unilateral in 8 patients (7 males, 1 female) and bilateral in 36 patients (26 males, 10 females). Although age at surgery showed linear colinearity (ρ = 0.32, P < .05), it was not significant in the model. The most consistent association with the preoperative VAS score were the pre- and postoperative ODI scores, that is, ρ = 0.51 (P < .01) and ρ = 0.33 (P < .05), respectively. In the bilateral group, with Buck's repair at a single level, that is, 33 of 36 (93%) patients had returned to sports at a mean time of 7.5 months (range 6-12 months). Overall, 44 of 52 (84%) individuals had returned to their sports with posttreatment ODI score of <10. The stepwise regression modeling suggested 6 independent factors (preoperative ODI, preoperative SF-36 physical component summary (PCS), Buck's repair, multiple operations, professionalism, and pars defect at L3), as the determinants of the outcome (ie, postoperative ODI) in 80.9% patients (R2 = 0.809). CONCLUSIONS: The outcome after direct repair of pars defect in those younger than 25 years runs a predictable course. Professionalism in sports has a high impact on the outcome. Preoperative ODI and SF-36 PCS scores are significant predictors of good functional outcome. The regression equation can predict the outcome in 80.9% sporting individuals undergoing Buck's repair.

Treatment of Cervical Myelopathy: Long-term Outcomes of Arthroplasty for Myelopathy Versus Radiculopathy, And Arthroplasty Versus Arthrodesis for Myelopathy.

STUDY DESIGN: Analysis of 2- and 7-year outcomes from a clinical trial comparing 2-level cervical disk arthroplasty (CDA) to anterior cervical discectomy and fusion (ACDF) in 287 patients with radiculopathy alone, and 110 patients with myelopathy alone or myelopathy with radiculopathy. OBJECTIVE: To compare the long-term safety and effectiveness of CDA for myelopathy versus radiculopathy. SUMMARY OF BACKGROUND DATA: CDA for myelopathy is safe and effective in short term. MATERIALS AND METHODS: We analyzed Neck Disability Index (NDI), neck/arm pain, SF-36, neurological status, adverse events (AEs), and secondary surgeries at index and adjacent levels. RESULTS: All groups improved significantly for NDI, neck/arm pain, and physical component summary (PCS) scores from preoperative to postoperative. CDA Myelopathy versus CDA Radiculopathy: 2- and 7-year improvements were not significantly different. The 7-year score improvements for CDA Myelopathy and CDA Radiculopathy were: NDI (37.8 vs. 35.8, P=0.352), neck pain (12.0 vs. 12.1, P=0.477), arm pain (11.6 vs. 9.6, P=0.480), and PCS (14.1 vs. 13.7, P=0.863). The 2 groups had similar proportions of patients who maintained or improved their neurological status (87.2% vs. 93.5%, P=0.218), similar rates of serious AEs (54.5% vs. 57.5%, P=0.291) and similar rates of secondary surgeries at index (3.7% vs. 4.4%, P=0.839) and adjacent levels (3.7% vs. 7.6%, P=0.367). CDA Myelopathy versus ACDF myelopathy: 2 and 7-year improvements were not significantly different. The 7-year CDA and ACDF score improvements were: NDI (37.8 vs. 31.1, P=0.147), neck pain (12.0 vs. 10.4, P=0.337), arm pain (11.6 vs. 11.4, P=0.791), and PCS (14.1 vs. 11.2, P=0.363). The 2 groups had statistically similar proportions who maintained or improved their neurological status (87.2% vs. 96.2%, P=0.409), statistically similar overall rates of secondary surgeries at the index levels (3.7% vs. 9.4%, P=0.374), and statistically similar rates of secondary surgeries at adjacent levels (3.7% vs. 15.4%, P=0.088). CDA group demonstrated lower rates of serious AEs than ACDF (54.5% vs. 65.9%, P=0.019). CONCLUSIONS: CDA for myelopathy is a safe and effective long-term treatment.

Cervical disc arthroplasty with the Prestige LP disc versus anterior cervical discectomy and fusion, at 2 levels: results of a prospective, multicenter randomized controlled clinical trial at 24 months.

OBJECTIVE The authors compared the efficacy and safety of arthroplasty using the Prestige LP cervical disc with those of anterior cervical discectomy and fusion (ACDF) for the treatment of degenerative disc disease (DDD) at 2 adjacent levels. METHODS Patients from 30 investigational sites were randomized to 1 of 2 groups: investigational patients (209) underwent arthroplasty using a Prestige LP artificial disc, and control patients (188) underwent ACDF with a cortical ring allograft and anterior cervical plate. Patients were evaluated preoperatively, intraoperatively, and at 1.5, 3, 6, 12, and 24 months postoperatively. Efficacy and safety outcomes were measured according to the Neck Disability Index (NDI), Numeric Rating Scales for neck and arm pain, 36-Item Short-Form Health Survey (SF-36), gait abnormality, disc height, range of motion (investigational) or fusion (control), adverse events (AEs), additional surgeries, and neurological status. Treatment was considered an overall success when all 4 of the following criteria were met: 1) NDI score improvement of ≥ 15 points over the preoperative score, 2) maintenance or improvement in neurological status compared with preoperatively, 3) no serious AE caused by the implant or by the implant and surgical procedure, and 4) no additional surgery (supplemental fixation, revision, or nonelective implant removal). Independent statisticians performed Bayesian statistical analyses. RESULTS The 24-month rates of overall success were 81.4% for the investigational group and 69.4% for the control group. The posterior mean for overall success in the investigational group exceeded that in the control group by 0.112 (95% highest posterior density interval = 0.023 to 0.201) with a posterior probability of 1 for noninferiority and 0.993 for superiority, demonstrating the superiority of the investigational group for overall success. Noninferiority of the investigational group was demonstrated for all individual components of overall success and individual effectiveness end points, except for the SF-36 Mental Component Summary. The investigational group was superior to the control group for NDI success. The proportion of patients experiencing any AE was 93.3% (195/209) in the investigational group and 92.0% (173/188) in the control group, which were not statistically different. The rate of patients who reported any serious AE (Grade 3 or 4) was significantly higher in the control group (90 [47.9%] of 188) than in the investigational group (72 [34.4%] of 209) with a posterior probability of superiority of 0.996. Radiographic success was achieved in 51.0% (100/196) of the investigational patients (maintenance of motion without evidence of bridging bone) and 82.1% (119/145) of the control patients (fusion). At 24 months, heterotopic ossification was identified in 27.8% (55/198) of the superior levels and 36.4% (72/198) of the inferior levels of investigational patients. CONCLUSIONS Arthroplasty with the Prestige LP cervical disc is as effective and safe as ACDF for the treatment of cervical DDD at 2 contiguous levels and is an alternative treatment for intractable radiculopathy or myelopathy at 2 adjacent levels. Clinical trial registration no.: NCT00637156 ( clinicaltrials.gov ).

Interbody Fusion in Low Grade Lumbar Spondylolsithesis: Clinical Outcome Does Not Correalte with Slip Reduction and Neural Foraminal Dimension.

STUDY DESIGN: Prospective nonrandomized study. PURPOSE: To find a possible correlation between clinical outcome and extent of lumbar spondylolisthesis reduction. OVERVIEW OF LITERATURE: There is no consensus in the literature concerning whether a beneficial effect of reduction on outcome can be expected following reduction and surgical fusion for low grade lumbar spondylolisthesis. METHODS: Forty six patients with a mean age of 37.5 years (age, 17-48 years) with isthmic spondylolisthesis underwent interbody fusion with cages with posterior instrumentation (TLIF). Clinical outcome was measured using visual analogue score (VAS) and Oswestry disability index (ODI). Foraminal dimensions and disc heights were measured in standard digital radiographs. These were analyzed at baseline and 1 year after surgery and changes were compared. Radiographic fusion was judged with computed tomography scans at 1 year. RESULTS: Ninety percent of the patients had good or very good clinical results with fusion and instrumentation. Baseline and one-year postoperative mean VAS score was 6.33 (range, 5-8) and 0.76 (range, 0-3), respectively (p=0.004). Baseline and one-year postoperative, mean ODI score was 48 (range, 32-62) and 10 (range, 6-16), respectively (p<0.001). A mean spondylolisthesis slip of 32.1% was reduced to 6.7% at 1 year. Average anterior disc height, posterior disc height, vertical foraminal dimension), and foraminal) diameter improved from 9.8 to 11.7 mm (p=0.005), 4.5 to 5.8 mm (p=0.004), 11.3 to 12.6 mm (p=0.002), and 18.6 to 20.0 mm (p<0.001), respectively. The fusion rate was 75% with TLIF. There is no significant correlation between the improvements of ODI scores and the extent of slip reduction. CONCLUSIONS: Neural decompression and interbody fusion can significantly improve pain and disability but the clinical outcome does not correlate with radiological improvement in the neural foraminal dimension.

Pelvic or lumbar fixation for the surgical management of scoliosis in duchenne muscular dystrophy.

STUDY DESIGN: This retrospective study evaluates two groups of patients with scoliosis and Duchenne muscular dystrophy, treated with two different surgical stabilization methods. OBJECTIVE: To determine whether fixation to the sacropelvis is always necessary for adequate stabilization of scoliosis in Duchenne muscular dystrophy. SUMMARY OF BACKGROUND DATA: Pelvic fixation is generally recommended for scoliosis in Duchenne muscular dystrophy. Recent studies describe a more selective approach toward lumbar or pelvic fixation. Pelvic fixation is reserved for larger curves and established pelvic tilt. METHODS: Fifty cases of Duchenne muscular dystrophy, operated in two different centers and followed up for a minimum of 3 years, were reviewed. In the first group (Oswestry), 31 patients had fixation to the pelvis, using standard Luque instrumentation and pelvic fixation. The Galveston technique was used in 9 cases and L-rod configuration in 22 cases. In the second group (Nottingham), 19 cases had fixation to L5 using pedicle screws in the lumbar spine and sublaminar wires in the thoracic spine. These cases were operated on early, usually shortly after becoming wheelchair dependent. RESULTS: In the pelvic fixation group, the mean age at the time of surgery was 14 years, and forced vital capacity was 44%. The mean Cobb angle and pelvic obliquity were 48 degrees and 19.8 degrees at the time of surgery, 16.7 degrees and 7.2 degrees immediately after surgery, and 22 degrees and 11.6 degrees at the final follow-up (mean 4.6 years), respectively. The mean blood loss was 4.1 L, and the average hospital stay was 17 days. There were five major complications, including a deep wound infection in one case, revision of instrumentation prominence at the proximal end in two cases, and loosening of pelvic fixation in two cases. In the lumbar fixation group, the mean age at the time of surgery was 11.7 years, and forced vital capacity was 58%. The mean Cobb angle and pelvic obliquity were 19.8 degrees and 9 degrees at the time of surgery, 3.2 degrees and 2.2 degrees immediately after surgery, and 5.2 degrees and 2.9 degrees at the final follow-up (mean 3.5 years), respectively. The mean estimated blood loss (3.3 L) and mean hospital stay (7.7 days) were much less compared with the pelvic fixation group. Pelvic obliquity was corrected and maintained below 10 degrees in all but two cases, who had an initial pelvic obliquity exceeding 20 degrees. One patient had instrumentation failure at the proximal end, and one had a deep wound infection. CONCLUSION: Lumbar fixation to L5 is adequate if the surgery is performed early, soon after becoming wheelchair bound, and with smaller curves and minimal pelvic obliquity. Use of pedicle screws in lumbar spine provides a solid foundation to maintain the correction over the period of relatively short life expectancy of these children. Pelvic fixation may be necessary in older children, who have larger curves and established pelvic obliquity. In the presence of deteriorating lung function, this is associated with a greater morbidity and higher complication rate.

A prospective randomized comparison of coralline hydroxyapatite with autograft in cervical interbody fusion.

STUDY DESIGN: A prospective randomized trial with independent clinical and radiographic outcome review of patients receiving either hydroxyapatite or tricortical iliac crest graft for cervical interbody fusion was conducted. OBJECTIVE: To determine whether coralline-derived hydroxyapatite is a suitable bone graft substitute in cervical interbody fusion. SUMMARY OF BACKGROUND DATA: Tricortical iliac crest bone is the "gold standard" graft material for cervical interbody fusion. Various bone substitutes have been used for this procedure to avoid potential donor site morbidity. ProOsteon 200 is a coralline-derived hydroxyapatite product, the use of which remains unclear for cervical interbody fusion. METHODS: In this study, 29 patients undergoing anterior cervical fusion and plating were randomized to receive either ProOsteon 200 or iliac crest grafts. The SF-36 and Oswestry Disability Index were used to measure clinical outcome. Postoperative radiographs were analyzed for graft fragmentation, loss of height, angular alignment, and hardware failure to assess structural integrity of the graft material. Plain radiographs and computed tomography scans were used to evaluate fusion. RESULTS: Both the ProOsteon 200 and iliac crest groups demonstrated significant improvement in clinical outcome scores. There was no significant difference in clinical outcome or fusion rates between the two groups. Graft fragmentation occurred in 89% of the hydroxyapatite grafts and 11% of the autografts (P = 0.001). Significant graft settling occurred in 50% of the hydroxyapatite grafts, as compared with 11% of the autografts (P = 0. 009). One patient in the ProOsteon 200 group required revision surgery for graft failure. CONCLUSIONS: ProOsteon 200 does not possess adequate structural integrity to resist axial loading and maintain disc height or segmental lordosis during cervical interbody fusion.