Predictors of a favorable response to transforaminal injection of steroids in patients with lumbar radicular pain due to disc herniation.

BACKGROUND: Transforaminal injection of steroids (TFIS) is effective for some patients with lumbar radicular pain caused by disc herniation. Factors associated with better outcomes are unknown. OBJECTIVE: To identify clinical and radiological features predictive of a favorable response to TFIS. METHODS: Seventy-one patients with lumbar radicular pain caused by disc herniation were treated with TFIS as part of a previously reported, randomized, clinical trial. The clinical features analyzed were the presence of neurologic symptom, neurologic signs, and the duration of sciatica. Radiological features evaluated using magnetic resonance imaging (MRI) were the segmental level of the pathology, the location and morphological features of the disc herniation, the cross-sectional area of the disc herniation and its ratio to the cross-sectional area of the spinal canal, and the grade of nerve root compression. RESULTS: None of the clinical features was associated with successful outcome from treatment. The only radiological feature associated with successful outcome was the grade of nerve root compression. Of patients with low-grade root compression, 75% responded favorably to TFIS. Only 26% of patients with high-grade nerve root compression responded. DISCUSSION: These results indicate that TFIS is more often successful in patients without significant compression of the nerve root and, therefore, in whom an inflammatory basis for radicular pain is most likely. In such patients, a success rate of 75% renders TFIS an attractive alternative to surgery. In patients with significant compression of the nerve root, the likelihood of benefiting from TFIS is low. The success rate may be no more than that of a placebo effect, and surgery may be a more appropriate consideration.

The efficacy of transforaminal injection of steroids for the treatment of lumbar radicular pain.

BACKGROUND: Transforaminal injection of steroids is used to treat lumbar radicular pain. Not known is whether the route of injection or the agent injected is significant. STUDY DESIGN: A prospective, randomized study compared the outcomes of transforaminal injection of steroid and local anesthetic, local anesthetic alone, or normal saline, and intramuscular injection of steroid or normal saline. Patients and outcome evaluators were blinded as to agent administered. METHODS: The primary outcome measure was the proportion of patients who achieved complete relief of pain, or at least 50% relief, at 1 month after treatment. Secondary outcome measures were function, disability, patient-specified functional outcomes, use of other health care, and duration of relief beyond 1 month. RESULTS: A significantly greater proportion of patients treated with transforaminal injection of steroid (54%) achieved relief of pain than did patients treated with transforaminal injection of local anesthetic (7%) or transforaminal injection of saline (19%), intramuscular steroids (21%), or intramuscular saline (13%). Relief of pain was corroborated by significant improvements in function and disability, and reductions in use of other health care. Outcomes were equivalent for patients with acute or chronic radicular pain. Over time, the number of patients who maintained relief diminished. Only some maintained relief beyond 12 months. The proportions of patients doing so were not significantly different statistically between groups. DISCUSSION: Transforaminal injection of steroids is effective only in a proportion of patients. Its superiority over other injections is obscured when group data are compared but emerges when categorical outcomes are calculated. Over time, the proportion of patients with maintained responses diminishes.

MRI predictors of revision surgery after primary lumbar discectomy.

The prognostic significance of preoperative MRI findings in patients undergoing discectomy is incompletely understood. Identifying the radiological predictors of revision surgery on pre-operative MRI can guide management decisions and potentially prevent multiple surgeries. We included 181 patients who underwent primary lumbar discectomy between 2010 and 2014. All patients were contacted via a short telephone interview to determine if they had revision surgery within 5 years of their index surgery. Preoperative MRI of the lumbosacral spine was evaluated for various radiological factors including type of disc herniation, anatomical location of herniation, direction of herniation, degree of disc degeneration, end plate changes and presence of listhesis. Other potential confounders including age, gender, smoking status and index level of surgery were also recorded. Multivariate model of all radiological predictors and confounders were developed and a step-wise approach was used to remove insignificant variables in order to develop final significant multivariate model. P value of <0.05 was considered statistically significant. Patients with retrolisthesis were found to be 2.7 times more likely than the patients without listhesis to require revision surgery (p = 0.019). Patients with foraminal disc herniation were 3.45 times more likely than the patients with paramedian disc herniation to require revision surgery (p = 0.026). Other MRI predictors failed to achieve statistical significance. Based on the data presented patients with retrolisthesis and/or foraminal disc herniation should be counselled on the relatively higher risk of revision surgery when proceeding with discectomy, or alternative options should be considered.

Recovery of ankle dorsiflexion weakness following lumbar decompressive surgery.

This retrospective study evaluated the recovery of ankle dorsiflexion (ADF) weakness following decompressive surgery in order to identify factors indicative of a better outcome. Fifty-six consecutive patients with ADF weakness secondary to nerve root compression underwent lumbar decompressive surgery. The demographic features, duration and severity of preoperative ADF weakness, associated radicular pain, as well as the radiological and intraoperative findings were recorded. ADF weakness at the time of initial follow-up at 6 weeks following surgery, and the latest follow-up at a median of 24 months was recorded. The patients had a mean age of 50.5 years with equal numbers of men and women. Acute disc prolapse was the compressive pathology in 88%. Clinical foot drop, defined as an ADF power of <3 by manual testing according to the Medical Research Council classification, was present in 66% of patients on presentation. Grade 3 power was present in 27% of patients and 7% had grade 4 power on presentation. The mean ADF power on presentation was 1.8. This improved to a mean of 3.2 at 6 weeks following surgery (p < 0.0001). A further small improvement in ADF power occurred after 6 weeks following surgery to a power of 3.5 at the latest follow-up (p < 0.0001). The degree of ADF weakness at latest follow-up correlates with the deficit at presentation (p <0.001). Younger patients made a better recovery (p = 0.03). No other significant associations between the demographic or clinical features and the recovery of the weakness could be identified. Thus, decompressive surgery was associated with an early improvement in ADF weakness. Only small improvements take place beyond 6 weeks following surgery. The degree of deficit at presentation is predictive of the extent of recovery. Recovery in ADF strength is more evident in younger patients.

Pathologic Basis of Lumbar Radicular Pain.

BACKGROUND: Lumbar radicular pain is one of the most commonly encountered clinical syndromes; however, its underlying mechanistic basis, and its relation to the natural history of the disease, are poorly understood. METHODS: We revieved the available literature to explore the pathophysiology and natural history of lumbar radicular pain. RESULTS: Experimental observations have spawned distinctive, but not mutually exclusive, pathophysiologic descriptions of radicular pain. These mechanisms include mechanical compression and inflammatory processes. In most cases, a complex interplay between these mechanisms is required to sustain the pain. However, when the dorsal root ganglion is mechanically deformed, sustained discharges causing pain can be evoked, leading to pain based on a purely mechanical basis. However, in other instances, previous sensitization of the nerve root by inflammatory processes is required. CONCLUSION: An understanding of these processes and the natural history of the syndrome is important to developing therapeutic strategies.

Clinical and functional outcomes of anterior cervical discectomy without fusion.

Anterior cervical discectomy without fusion is an effective treatment for myeloradiculopathy arising from a medial disc prolapse. However, the long-term clinical results are not well known. Between 2000 and 2006, 38 patients with persistent radiculopathy and medial disc prolapse or myelopathy due to acute disc prolapse underwent subtotal anterior cervical discectomy without fusion. Patients were evaluated with respect to pain, myelopathy and functional outcome. Thirty-four patients were followed up for an average of 48.6 months. Following surgery, neck pain improved by 69% in 88% of patients, arm pain improved by 76% in 91% of patients and 76% of the patients were able to resume working in their previous occupation. We conclude anterior cervical decompression without fusion can be associated with good clinical results that are sustained in patients with predominant acute soft disc prolapse generating medial nerve root compression or cord compression.

Nonaccidental head injuries in children: a Sydney experience.

OBJECT: The purpose of this study was to evaluate the demographics, clinical and radiological features, and clinical outcomes of nonaccidental pediatric head injury. METHODS: The authors reviewed 65 consecutive cases of nonaccidental head injury in a single pediatric neurosurgical unit during a period of 7 years. The mean patient age was 8.2 months (range 0.5-46 months). There were 39 boys and 26 girls. A history of abuse was present in 24% of families. There was a high incidence of family disruption, substance abuse, and premature birth. Fathers were the most common perpetrators. Fifteen patients had a Glasgow Coma Scale score of less than 10. Thirty-five patients had seizures on or preceding admission. Subdural hematoma was the most common finding (81.5%). Skull fractures were present in 36.9% of patients, skeletal injuries in 50% (of which 67% were subclinical), and retinal hemorrhages in 59%. The radiological finding of ischemia or edema had a significant correlation with a poor outcome. Magnetic resonance imaging revealed additional pathological findings not visible on computerized tomography scanning in 18 (49%) of 37 cases. Surgery was performed in 17 patients; recurrence of the subdural collection occurred in 46% of them. In this group, reevacuations were followed by further recurrences, and a subdural-peritoneal shunt was eventually required. Four patients died. Of the 56 surviving patients reviewed on a long-term basis, 19 made a full recovery, and epilepsy was reported in 17%. CONCLUSIONS: Magnetic resonance imaging should be routinely used in depicting ischemia, which is associated with a poor outcome. The high incidence of subclinical skeletal injuries stresses the importance of assessment of suspected cases of nonaccidental trauma with skeletal surveys and bone scans. Recurrence of subdural collection following burr hole drainage is common and is best treated with a subdural-peritoneal shunt.

Long-term follow-up of minimal-access and open posterior lumbar interbody fusion for spondylolisthesis.

BACKGROUND: Although posterior lumbar interbody fusion (PLIF) is regarded as an effective treatment for spondylolisthesis, few studies have reported comprehensive, long-term outcome data, and none has investigated the incidence of deterioration of outcomes. OBJECTIVE: To determine and compare the success rates and long-term stability of outcomes of open PLIF and minimal-access PLIF in the treatment of radicular pain and back pain in patients with spondylolisthesis. METHODS: Forty-three patients were followed for a minimum of 3 years. They completed a Short-Form Health Survey and visual analog scores for back pain and leg pain and underwent lumbar spine radiography. Outcomes were compared with baseline data and 12-month data. RESULTS: Surgery succeeded in reducing listhesis and increasing disc height, but had little effect on lumbar lordosis or the angulation of the segment treated. At 12 months after surgery, listhesis was reduced, disc height was increased, leg pain was reduced or eliminated, and physical functioning restored. Back pain was less often relieved. These outcomes were largely maintained over the ensuing 2 years. Only 5% to 10% of patients reported deterioration in their relief of pain. Depending on the definition adopted for success, the long-term success rate of PLIF may be as high as 70%. CONCLUSION: For the relief of leg pain, the success rates of open PLIF (70%) and minimal-access PLIF (67%) for spondylolisthesis are high and durable in the long-term. PLIF is less often successful in relieving back pain, but the outcomes are maintained. The outcomes of open PLIF and minimal-access PLIF were statistically indistinguishable. ABBREVIATIONS: MCIC, minimally clinically important changeMPLIF, minimal-access posterior lumbar interbody fusionOPLIF, open-access posterior lumbar interbody fusionPLIF, posterior lumbar interbody fusionSF-36, Short-Form Health Survey.

Cervical disc arthroplasty for the treatment of spondylotic myelopathy and radiculopathy.

The concept of cervical disc arthroplasty (CDA) for the anterior treatment of cervical pathology has existed for approximately half a decade. In this time, multiple devices have been developed for this purpose, with the ultimate aim to provide an alternative to fusion. Fifty-five patients with cervical spondylotic radiculopathy and myelopathy underwent CDA over a 5 year period. Data was collected on 46 patients, which included Visual Analogue Scale scores for neck pain and arm pain, Neck Disability Index scores, Short Form-36 v2 (SF-36) and Nurick grades for myelopathy patients. Preoperative data and data obtained at the latest clinical follow-up (median 48 months, range, 10-76 months) were analysed to assess the intermediate term efficacy of the procedure. In patients with radiculopathy, arm pain improved by 88% (p<0.001). In those presenting with myelopathy, the Nurick grades improved from a median of 1 to 0 (p<0.001). In both groups of patients, improvements in pain and neurologic deficit were accompanied by significant improvements in multiple domains of the SF-36. Using a composite system which considered neck pain, arm pain, function and myelopathy, we arrived at an overall success rate of 73%. We concluded that CDA is an effective intervention for improving neurologic deficit, arm pain and local neck symptoms that translated into improvements in physical and social functioning in the intermediate term.

Minimal access versus open posterior lumbar interbody fusion in the treatment of spondylolisthesis.

OBJECTIVE: To compare the safety and effectiveness of minimal access posterior lumbar interbody fusion (MAPLIF) with open posterior lumbar interbody fusion (OPLIF) in patients with spondylolisthesis and radicular pain. METHODS: A prospective study was performed of 47 patients with radicular pain resulting from lumbar spondylolisthesis with a slip of less than 50% who underwent either MAPLIF (n = 23) or OPLIF (n = 24). At 12 months after treatment, clinical outcomes were measured using the Short-Form Health Survey 36 and the visual analog score for both leg pain and back pain, and the degree of reduction of spondylolisthesis, restoration of disc height, and presence of fusion were assessed. RESULTS: Both groups were similar in demographic and baseline clinical features. Both exhibited statistically and clinically significant improvements in back pain (OPLIF, 64%; MAPLIF, 78%), and leg pain (88% for both groups). This was corroborated by improvements in social and physical functioning, which were similar for both groups. The reduction of spondylolisthesis and fusion rates were also similar between the 2 groups. MAPLIF patients commenced mobilization sooner, achieved independent mobilization earlier, and had a shorter hospital stay (4 days versus 7 days). CONCLUSION: MAPLIF and OPLIF both reduce leg and back pain and restore function to a similar extent. MAPLIF is as effective as OPLIF in reducing the slip in patients with spondylolisthesis of less than 50%. MAPLIF promotes faster recovery and shortens hospital stay.

Dynamic plates in anterior cervical fusion surgery: graft settling and cervical alignment.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: To evaluate the effect of graft subsidence associated with the use of dynamic cervical plates on cervical alignment and clinical outcome of patients undergoing anterior cervical decompression and fusion. SUMMARY AND BACKGROUND DATA: Dynamic cervical plates allow graft loading which may enhance fusion. However, subsidence of the bone graft may result in changes in cervical alignment. The extent of settling of the graft and its impact on cervical alignment has not been determined. Also whether such change in alignment has an impact on clinical outcome is not known. METHODS: Fifty-five patients with spondylitic myelopathy or radiculopathy underwent anterior cervical decompression and fusion using a dynamic plate for stabilization (ABC, Braun/Aesculap). The surgical indications included myelopathy (n = 21), radiculopathy (n = 30), or myeloradiculopathy (n = 4). Regional and local cervical angles, graft subsidence, and fusion rates were assessed before surgery, immediately after surgery and at 6 months after surgery. Visual analogue scores for neck and radicular pain, Neck Disability Indexes, and Nurick grades for myelopathy were recorded. Patients were observed up for at least 6 months with a median of 14 months (range: 6-48 months). RESULTS: Radicular pain improved by a median of 5 points (P < 0.0001), whereas Neck pain improved by a median score of 3 (P < 0.0001). A median improvement in Neck Disability Index score of 18 (P < 0.0001) was observed. Nurick grades improved in 68% of patients with myelopathy. Fusion was achieved in 96% of cases. The mean graft subsidence at 6 months was 1.7 mm (range: 0-6 mm). A change of local cervical angle toward lordosis of 5.8 degrees (P < 0.0001) was obtained as a result of surgery. However, there was a loss of 2.7 degrees of lordosis in the first 6 months following surgery (P = 0.001). The extent of subsidence correlated with the local loss of lordosis (P = 0.0003). There was no change in the regional cervical angle in the 6 months following surgery. There was no significant association between clinical outcome and changes in cervical angles. CONCLUSION: Dynamic anterior cervical plating after anterior decompression and grafting provides comparable fusion rates to that reported following the use of rigid cervical plating. Immediate changes in cervical alignment towards lordosis are partially lost on follow-up. The loss of lordosis is related to the amount of graft settling.

Purely endoscopic resection of colloid cysts.

OBJECTIVE: To further assess the safety and long-term efficacy of endoscopic resection of colloid cysts of the third ventricle. METHODS: A retrospective review of a series of 35 consecutive patients (18 male, 17 female) with colloid cysts treated by endoscopic surgery was undertaken. RESULTS: The mean patient age was 32.4 years (range, 11-54 yr). Headache was the most common presenting symptom (22 patients). The average tumor size was 18 mm (range, 3-50 mm). The endoscopic technique could not be completed in six patients, necessitating conversion to an open craniotomy and a transcortical approach to the colloid cyst. All patients had histologically confirmed colloid cysts of the third ventricle, and complete resection of the lesion was confirmed macroscopically and radiologically in all patients. There were no deaths. Two patients developed aseptic meningitis without any permanent sequelae. One patient developed unilateral hydrocephalus attributable to obstruction of the foramen of Monro, which was treated with endoscopic septum pellucidotomy. The median follow-up period was 88 months (range, 10-132 mo). There was one asymptomatic radiological recurrence. No seizures occurred after surgery. CONCLUSION: The results of this study support the role of endoscopic resection in the treatment of patients with colloid cysts as a safe and effective modality. In some cases, conversion to an open procedure may be required. Additional follow-up will be required to continue to address the duration of lesion-free survival.