Wai-Mun Yue

Long-term results after anterior cervical discectomy and fusion with allograft and plating: a 5- to 11-year radiologic and clinical follow-up study.

Study Design. A retrospective review. Objectives. To determine the clinical and radiologic outcomes beyond 5 years after anterior cervical discectomy and fusion with allograft and plating. Summary of Background Data. Anterior cervical discectomy and fusion is commonly performed for cervical disc disease. The routine use of allografts and plating, though increasing in popularity, has not been well studied for long-term results and complications. Methods. Seventy-one patients who had anterior cervical discectomy and fusion with allograft and plating an average of 7.2 years prior responded to an invitation to return for a follow-up clinical and radiographic review. Results. At final review, symptom resolution remained greater than 82% and fusion occurred in 92.6% of the disc spaces operated on. No graft extrusion or migration occurred. Based on our strict criteria, the rates of collapse and subsidence were high, at 47.9% (34 patients) overall. However, in only 6 patients (8.5%) did segmental kyphosis result, none of whom required any revision surgery in the follow-up period. Implant complications occurred in 7 patients (9.9%), none of whom required revision surgeries. Adjacent level degeneration occurred in 52 patients (73.2%). Further cervical spine surgeries were required in 14 patients (19.7%), 2 for inadequate decompression, and 12 for adjacent level disease. Segmental and global cervical lordosis was restored and maintained by the surgery over the study period. Conclusions. The use of allografts and plate fixation in combination for anterior cervical discectomy and fusion does not compromise the radiologic and clinical outcomes while providing the advantages of donor site morbidity elimination, restoration of cervical segmental lordosis, and not requiring postoperative immobilization.

Five-year outcomes of minimally invasive versus open transforaminal lumbar interbody fusion: a matched-pair comparison study.

Study Design. Retrospective analysis of prospectively collected data. Objective. To compare midterm clinical and radiological outcomes of minimally invasive surgery (MIS) versus open transforaminal lumbar interbody fusion (TLIF). Summary of Background Data. Open TLIF is a proven technique to achieve fusion in symptomatic spinal deformities and instabilities. The possible advantages of MIS TLIF include reduced blood loss, less pain, and shorter hospitalization. To date, there is no published data comparing their midterm outcomes. Methods. From 2004–2007, 40 cases of open TLIF were matched paired with 40 cases of MIS TLIF for age, sex, body mass index, and the levels on which the spine was operated. Oswestry Disability Index, neurogenic symptom score, the 36-Item Short Form Health Survey, and visual analogue scale scores for back and leg pain were obtained before surgery, 6 months, 2 years, and 5 years after surgery. Fusion rates were assessed using Bridwell classification. Results. Fluoroscopic time (MIS: 55.2 s, open: 16.4 s, P < 0.001) was longer in MIS cases. Operative time (MIS: 185 min, open: 166 min, P = 0.085) was not significantly longer in MIS cases. MIS had less blood loss (127 mL) versus open (405 mL, P < 0.001) procedures. Morphine use for MIS cases (8.5 mg) was less compared with open (24.2 mg, P = 0.006). Patients who underwent MIS (1.5 d) ambulated earlier than those who underwent open fusion (3 d, P < 0.001). Patients who underwent MIS (3.6 d) had shorter hospitalization than those who underwent open fusion (5.9 d, P < 0.001). Both groups showed significant improvement in Oswestry Disability Index, neurogenic symptom score, back and leg pain, SF-36 scores at 6 months until 5 years with no significant differences between them. Grade 1 fusion was achieved in 97.5% of both groups at 5 years. The overall complication rate was 20% for the open group and 15% for MIS group (P = 0.774), including 4 cases of adjacent segment disease for each group. Conclusion. MIS TLIF is comparable with open TLIF in terms of midterm clinical outcomes and fusion rates with the additional benefits of less initial postoperative pain, less blood loss, earlier rehabilitation, and shorter hospitalization. Level of Evidence: 3

Surgically treated cervical myelopathy: a functional outcome comparison study between multilevel anterior cervical decompression fusion with instrumentation and posterior laminoplasty

BACKGROUND CONTEXT Multilevel cervical myelopathy can be treated with anterior cervical discectomy and fusion (ACDF) or corpectomy via the anterior approach and laminoplasty via the posterior approach. Till date, there is no proven superior approach. PURPOSE To elucidate any potential advantage of one approach over the other with regard to clinical midterm outcomes in this study. STUDY DESIGN A prospective, 2-year follow-up of patients with cervical myelopathy treated with multilevel anterior cervical decompression fusion and plating and posterior laminoplasty. PATIENT SAMPLE In total, 116 patients were studied. Sixty-four patients underwent ACDF two levels and above or anterior cervical corpectomy and fusion one level and above. Fifty-two patients underwent posterior cervical surgery (laminoplasty C3-C6 and C3-C7). OUTCOME MEASURES Self-report measures: Japan Orthopedic Association (JOA) score, JOA recovery rate, visual analog scale for neck pain (VASNP), neck disability index (NDI), and American Academy of Orthopaedic Surgeons (AAOS) neurogenic symptom score (AAOS-NSS). Physiologic measures: range of motion (ROM) flexion and extension of neck. Functional measures: short-form 36 (SF-36) score comprising physical functioning, physical role function, bodily pain, general health, vitality, social role function, emotional role function, and mental health scales. METHODS Comparison of the JOA scores, JOA recovery rates, NDI scores, SF-36 scores, VASNP, and ROM preoperatively to 2 years. Chi-square and two-sided Student t tests were used to analyze the variables. RESULTS Posterior surgery took an hour shorter (p<.05) and had better improvement in JOA scores at early follow-up of 6 months (p=.025). Anterior surgery group had better improvement of NDI scores at early follow-up of 6 months (p=.024) and was associated with less blood loss intraoperatively compared with posterior surgery. There was no statistical difference between the two groups for JOA scores, JOA recovery rates, SF-36 quality-of-life scores, NDI, AAOS-NSS, VAS neck pain, and ROM at 2 years. Complications were higher for anterior surgery group: two hematoma postoperation, one vocal cord paresis, and one new onset C6/C7 dermatome numbness versus one dura leak in posterior surgery group. CONCLUSIONS Our study showed that patients with multilevel disease treated with laminoplasty do well and compare favorably with patients treated with an anterior approach. Notably, posterior surgery was associated with shorter operating time, better improvement in JOA scores at 6 months, and a tendency toward lesser complications. Posterior surgery was not associated with increased neck disability and neck pain at 2 years. Anterior surgery had better NDI improvement at early follow-up. There is a need for a larger study that is prospectively randomized with long-term follow-up before we can confidently advocate one approach over the other in the management of cervical myelopathy.

Abnormal spinal anatomy in 27 cases of surgically corrected spondyloptosis: proximal sacral endplate damage as a possible cause of spondyloptosis.

Study Design. Retrospective review. Objectives. To review the findings in the cases of spondyloptosis we have treated and to postulate on the possible cause of spondyloptosis. Summary of Background Data. Spondyloptosis (Grade V spondylolisthesis) is rare, even though spondylolisthesis is a relatively common condition. While it is known that progression to spondyloptosis occurs in patients with developmental spondylolisthesis in their childhood and/or adolescent years, the precise factors leading to progression are not known. Methods. Between 1979 and 2002, 27 patients with spondyloptosis were treated surgically with L5 resection and reduction of L4 onto S1. During the treatment process, detailed observations of the surgical findings were made through clinical and radiologic means. Six anatomic parameters (pars interarticularis defects, spina bifida of the L5 or sacral segments, dysplasia of the L5–S1 facet joints, L5–S1 disc degeneration, trapezoidal shape of L5, and rounding of the proximal end of the sacrum) were specifically studied. Results. Pars interarticularis defects were present in 24 patients (88.9%), facet dysplasia in 16 patients (59.2%), spina bifida in 24 patients (88.9%), disc degeneration in 25 (92.6%), trapezoidal L5 in 20 patients (74.1%), and rounding of the proximal end of S1 in all 27 patients (100%). Conclusions. Rounding of the proximal sacral endplate was the only constant abnormal anatomic feature in the patients. Damage to the proximal sacrum and sacral growth plate during late childhood and early adolescence, similar to the epiphyseal injury that produces Blount’s disease, and slipped capital femoral epiphysis seem to be key factors permitting the progression of developmental spondylolisthesis to spondyloptosis.

Two-year outcomes of transforaminal lumbar interbody fusion

Purpose. To evaluate the outcomes, fusion rates, complications, and adjacent segment degeneration associated with transforaminal lumbar interbody fusion (TLIF). Methods. 32 men and 80 women aged 15 to 85 (mean, 57) years underwent 141 fusions (84 one-level, 27 2-level, and one 3-level) and were followed up for 24 to 76 (mean, 33) months. 92% of the patients had degenerative lumbar disease, 15 of whom had had previous lumbar surgery. Radiographic and clinical outcomes were assessed at 2 years. The short-form 36 (SF-36) health survey, visual analogue scale (VAS) for pain, and the modified North American Spine Society (NASS) Low Back Pain Outcome Instrument were used. Results. Of the 141 levels fused, 110 (78%) were fused with remodelling and trabeculae (grade I), and 31 (22%) had intact grafts but were not fully incorporated (grade II). No patient had pseudoarthroses (grade III or IV). For one-level fusions, poorer radiological fusion grades correlated with higher VAS scores for pain (p<0.01). All components of the SF-36, the VAS scores for pain, and the NASS scores improved significantly after TLIF (p<0.01), except for general health in the SF-36 (p=0.59). Improvement from postoperative 6 months to 2 years was not significant, except for physical function (p<0.01) and role function (physical) [p=0.01] in the SF-36. Two years after TLIF, 50% of the patients reported returning to full function, whereas 72% were satisfied. 26 (23%) of the patients had adjacent segment degeneration, but only 4 of them were symptomatic. Conclusion. TLIF is a safe and effective treatment for degenerative lumbar diseases.

Minimally invasive compared with open lumbar laminotomy: no functional benefits at 6 or 24 months after surgery.

BACKGROUND CONTEXT Comparative studies between open and minimally invasive surgical (MIS) approaches for the treatment of spinal stenosis have mainly investigated immediate postoperative parameters. PURPOSE We aimed to compare the postoperative improvements in functional and pain scores between open versus MIS lumbar laminotomy and to describe the complications of each method. STUDY DESIGN/SETTING We conducted as retrospective review of prospectively collected data. PATIENT SAMPLE We included 113 patients. OUTCOME MEASURES Visual analog scale for back and leg pain, Oswestry Disability Index (ODI), the North American Spine Society score on neurogenic symptoms (NS), and average Short Form Health Survey-36 (SF-36) score. Accidental durotomies and patients with reoperations are presented. METHODS We obtained a list of patients who underwent either MIS or open unilateral one-level lumbar laminotomy for the treatment of neural foraminal or lateral recess stenosis with unilateral leg NS. Outcome measures are presented at 6 and 24 months postoperatively. RESULTS From 2000 to 2008, 113 patients (30 open, 83 MIS) underwent a one-level lumbar laminotomy and had complete postoperative data available for analysis. Between the approaches, there were no differences in baseline demographic data or functional scores. At 6 and 24 months after surgery, there were no differences in improvement in back or leg pain, or improvement in ODI, NS, or SF-36 scores. The MIS group reported greater satisfaction with treatment at 6 months (p=.009) but not at 24 months. Within the MIS group, three patients (3.6%) experienced an inadvertent durotomy and two patients (2.4%) underwent fusion of the operated segment within 24 months. CONCLUSIONS Compared with an open approach, MIS lumbar laminotomy gave no clear advantages in longer term functional or pain scores. The MIS group also had patients with inadvertent durotomies and reoperation within 2 years. In any lumbar decompressive surgery, the purported advantages of an MIS approach should be carefully weighed against potential complications. For a relatively simple surgery such as laminotomy, the open approach remains a safe and straightforward option.

The value of bilateral ipsilateral and contralateral motor evoked potential monitoring in scoliosis surgery

Intraoperative monitoring (IOM) of the motor pathways is a routine procedure for ensuring integrity of corticospinal tracts during scoliosis surgery. We have previously demonstrated presence of ipsilateral motor evoked potentials (MEPs) during IOM for scoliosis surgery, but its significance was uncertain. In this case series, we show concurrent ipsilateral and contralateral MEP amplitude changes obtained with cortical stimulation are of value in reducing false positive observations during IOM. The use of this easily recordable MEP is thus advocated as a diagnostic adjunct to contralateral MEPs for scoliosis and spinal surgery.

Comparison of Clinical Outcomes and Radiographic Measurements in 4 Different Treatment Modalities for Osteoporotic Compression Fractures: Retrospective Analysis.

Study Design: We conducted a retrospective analysis of a prospectively collected database in a tertiary hospital over 10 years. Objective: Treatment for vertebral compression fractures remains an area of controversy with respect to timing and type of surgical management. We analyzed the clinical outcomes and radiographic measurements of 4 different modalities of treatment for these fractures. Summary of Background Data: From 2001 to 2011, we analyzed a total of 363 patients after failure of 30 days of conservative management. These patients were then further managed either conservatively or with vertebroplasty, balloon kyphoplasty, or sky bone expander. Outcomes were assessed by using self-report measures: Visual Analog Score; functional measures: Oswestry Disability Index and Short-Form 36; and physiological measures: preoperative and postoperative radiographs. Methods: The outcome measures were assessed for 6 months for those treated conservatively and up till 2 years for those treated surgically. Radiographic measurements of the spine were correlated with the clinical outcomes. Results: A total of 62 patients (12.1%) were treated conservatively, 148 (40.8%) with vertebroplasty, 97 (26.7%) with balloon kyphoplasty, and 56 (15.4%) with sky bone expander. We found significant improvements in Visual Analog Score, Oswestry Disability Index, and Short-Form-36 scores for all groups after 1-month follow-up (P<0.05), with the surgical groups demonstrating a greater improvement in pain scores after the first postoperative day (P<0.0001) when compared with the conservative group. The improvements in outcomes in those treated surgically were sustained for up to 2 years with no significant difference (P>0.05) among the surgical groups. We also found significant improvement (P<0.005) in anterior vertebral and kyphotic wedge angle after surgical intervention. Conclusions: We have shown that early surgical intervention allows for quicker pain relief compared with conservative treatment, with similar improvements in anterior vertebral height and kyphotic wedge angle between all 3 groups of surgical management.

Single-Level Minimally Invasive Transforaminal Lumbar Interbody Fusion Provides Sustained Improvements in Clinical and Radiological Outcomes up to 5 Years Postoperatively in Patients with Neurogenic Symptoms Secondary to Spondylolisthesis

Study Design Retrospective review of prospective registry data. Purpose To determine 5-year clinical and radiological outcomes of single-level instrumented minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in patients with neurogenic symptoms secondary to spondylolisthesis. Overview of Literature MIS-TLIF and open approaches have been shown to yield comparable outcomes. This is the first study to assess MIS-TLIF outcomes using the minimal clinically important difference (MCID) criterion. Methods The outcomes of 56 patients treated by a single surgeon, including the Oswestry disability index (ODI), neurogenic symptom score, short-form 36 questionnaire (SF-36), and visual analog scale (VAS) scores for back pain (BP), and leg pain (LP), were collected prospectively for up to 5 years postoperatively. Radiological outcomes included adjacent segment degeneration, fusion, cage subsidence, and screw loosening rates. Results Our patients were predominantly female (71.4%) and had a mean age of 53.7±11.3 years and mean body mass index of 25.7±3.7 kg/m2. The mean operative time, blood loss, time to ambulation, and hospitalization were 167±49 minutes, 126±107 mL, 1.2±0.4 days, and 2.8±1.1 days, respectively. The mean fluoroscopic time was 58.4±33 seconds, and the mean postoperative intravenous morphine dose was 8±2 mg. Regarding outcomes, postoperative scores improved relative to preoperative scores, and this was sustained across various time points for up to 5 years (p<0.001). Improvements in ODI, SF-36, VAS-BP, and VAS-LP all met the MCID criterion. Notably, 5.4% of our patients developed clinically significant adjacent segment disease during follow-up, and 7 minor complications were reported. Conclusions Single-level instrumented MIS-TLIF is suitable for patients with neurogenic symptoms secondary to lumbar spondylolisthesis and is associated with an acceptable complication rate. Both clinical and radiological outcomes were sustained up to 5 years postoperatively, with many patients achieving an MCID.

Elderly Patients Achieving Clinical and Radiological Outcomes Comparable with Those of Younger Patients Following Minimally Invasive Transforaminal Lumbar Interbody Fusion

Study Design Retrospective analysis of prospective database. Purpose To compare 2-year clinical and radiological outcomes after minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) among “middle-age” (50–64.99 years), “young-old” (65–74.99 years), and “old-old” (>75 years) patients. Overview of Literature Owing to higher perioperative morbidity and mortality rates, elderly patients with degenerative lumbar conditions are occasionally denied surgical care, even after conservative treatment failure. MIS-TLIF advantages include reduced blood loss, reduced analgesia requirements, early mobilization, and shorter hospital stays. Methods Between 2007 and 2012, 22 patients (age >75 years) treated with 1-2 level MIS-TLIF were matched with “young-old” and “middle-age” patients (22 each) based on race, body mass index (BMI), diagnosis, spinal level, number of spinal levels operated upon, and bone graft type. Clinical outcomes included the Oswestry disability index (ODI), neurogenic symptom score (NSS), 36-item short form health survey (SF-36), and visual analogue scale (VAS) for back and leg pain. Radiological assessment included plain radiographs and preoperative magnetic resonance imaging (MRI) and plain radiographs at 1, 3, 6, and 24 months postoperatively. Fusion grade, loosening, cage migration, and adjacent segment degeneration were assessed. Results The groups had similar fluoroscopy time, operation duration, and postoperative analgesia type used. “Old-old” patients took longer to ambulate (1.6 days) and had longer hospital stays (6 days). All patients showed significant improvement in clinical outcome scores at all time-points compared with the preoperative status. “Middle-age” patients showed better ODI and SF-36 physical function scores than “old-old” patients preoperatively and 2 years post surgery. NSS, VAS (back and leg), and SF-36 mental function scores were similar between groups preoperatively and at every time-point postoperatively. Minimal clinical important differences (63.6%–95.5% at 2 years) were achieved. Grade 1 fusion occurred in a minimum of 80% patients in each group 2 years post surgery. Complication rates were similar. Adjacent segment disease occurred in 2 patients from the “young-old” group, with no significant differences between groups. Conclusions MIS-TLIF showed comparable results in selected “old-old” patients compared with “young-old” and “middle-age” patients without increased complication risks.