Biomedical subjects

Po-Liang Lai

Publications and source records attributed to Po-Liang Lai.

33 records · Page 2Linked to original sources

PubMed2004

Intervertebral disc herniation in adolescents.

BACKGROUND: The purpose of this study was to review surgery-proven lumbar disc herniation in adolescents with an emphasis on the distinguishing features. METHODS: Twenty-eight adolescents between 14 and 18 years old had lumbar discectomy after conservative treatment for 9 months. Indications for surgery were intractable pain and failure of conservative treatment for more than 6 weeks. Lumbar spine apophyseal ring fracture was found in 10 of the 24 patients (42%) who had computed tomography studies. Seven patients had piecemeal excision of the fractured apophysis together with the discectomy. RESULTS: All but three patients could raise their leg more than 70 degrees after the operation. The latest follow-up was conducted an average of 6.1 years after surgery. Good or excellent results were noted in 93% of the patients. Two patients had follow-up operations for recurrent disc herniation and wound infection. CONCLUSION: Apophyseal ring fracture was a feature in adolescent disc herniation that requires surgical intervention. Early computed tomography study is proposed to detect apophyseal ring lesion, which may lead to failure of conservative treatment. Excision of the fractured ring apophysis is suggested in addition to discectomy when the canal space is occupied.

Adolescent↗

PubMed2004

Minimally invasive treatment of osteoporotic vertebral compression fracture.

BACKGROUND: The use of percutaneous vertebroplasty (PV) to treat osteoporotic vertebral fractures is increasing. This investigation assesses the efficacy and safety of PV for refractory pain owing to osteoporotic vertebral compression fractures. METHODS: A retrospective investigation of PV was conducted with a minimal of 1 year follow up. PV with polymethylmethacrylate (PMMA) was performed on 75 patients with osteoporotic vertebral compression fractures that responded poorly to the conservative therapy. Patients were asked to quantify their degree of pain using Huskisson's visual analogue scale to assess the clinical results. RESULTS: Eighty-seven vertebrae treated using PV in 70 patients were evaluated with a minimal of 1 year follow up. Pain, as assessed on the VAS, decreased from 80+/-16 mm before PV to 36+/-28 mm at 1 month after PV and 30+/-19 mm at the most recent follow up. The reduction in pain from the baseline to 1 month (p=0.031) and to final follow up (p=0.023) were both statistically significant. Sixty-two patients (85.5%) quickly returned to their pre-injury activity level and achieved better quality of life. CONCLUSIONS: PV is effective in pain reduction for painful vertebral compression fractures. It provided significant pain relief. Skillful techniques and careful safeguards can minimize the risks of PMMA migration.

Aged↗

PubMed2004

Anterior cervical spinal surgery for multilevel cervical myelopathy.

BACKGROUND: In multilevel spinal cord compression caused by cervical spondylosis, surgeons face the choice of performing a posterior route as a laminectomy or laminoplasty, or an anterior route as multiple adjacent interbody decompressions or corpectomies. The anterior cervical operation is not considered by some clinicians because of concerns about complications and the complexity of multilevel anterior cervical surgery. METHODS: In this retrospective study, 14 patients with multilevel cervical spondylosis who were operated on via an anterior route were enrolled to evaluate the complexity, safety, and clinical results. The collected parameters were operation time, blood loss, hospital days, and early and late complications for evaluating the operative complexity, radiographic follow-up for evaluating fusion, graft problems, implants problems, and the recovery rate using the Japanese Orthopaedic Association score (JOA score) for evaluating the operative results. RESULTS: The mean operation time was 363.4 min, and blood loss was 431.4 ml. An early complication was noted in 1 patient with combined deep vein thrombosis and a pulmonary embolism. Late complications were screw breakage in 1 patient and screw loosening in 5 patients. The mean duration of follow-up was 21.9 months. The mean recovery rate of the JOA score was 38.8% postoperatively and 51.9% at the final follow-up. The fusion rate was 100% in this series. CONCLUSIONS: Anterior cervical decompression and fusion for multilevel stenosis requires a longer operation time than posterior procedures; however, the clinical results are satisfactory.

Adult↗

PubMed2004

Recurrent giant cell tumor of the thoracic spine with bilateral pulmonary metastases.

Giant cell tumor (GCT) of bone is a challenging clinicopathologic entity. Despite its benign designation, it has the capacity to recur locally and develop rare pulmonary metastasis. We report a case of histologically proven recurrent GCT of the spine (T7-8) involving spinal cord compression, direct extension to 1 lung, and bilateral pulmonary metastases. A 30-year-old woman presented with back pain, and underwent anterior reconstruction for GCT of the T7 at another hospital. As her symptoms deteriorated, she underwent laminectomy at the same hospital 2 months after the first surgery. One year after the first surgery, she was referred to our hospital on account of a progressive neurological deficit and intractable back pain, and underwent an anterior tumor resection at T7-8 and reconstruction, due to tumor recurrence. Postoperatively, the patient did not show neurologic improvement, but her pain decreased. The patient displayed no respiratory difficulties and no apparent change in follow-up chest radiographs for more than 2 years since surgery. This is the first reported case of bilateral pulmonary metastases from GCT of the thoracic spine.

Adult↗

PubMed2004

Posterior decompression and stabilization for metastatic spine diseases.

BACKGROUND: The purpose of this study was to investigate the clinical results of posterior decompression and stabilization for metastatic diseases of the thoracolumbar spine. METHODS: From 1980 to 2001, 70 consecutive patients with spinal metastases underwent palliative surgery by posterior decompression of spinal cord and subsequent stabilization with instrumentation. There were 38 women and 32 men. Their ages ranged from 24 to 75 years (mean 58 years). We retrospectively reviewed medical records to analyze their survival, clinical presentations, image findings and surgical outcomes. RESULTS: Sixty-one patients (87%) survived longer than 3 months. Forty-nine patients (70%) survived longer than 6 months, of whom 35 patients were still alive at an average of 24 months (range 13-40 months) after surgery. All maintained spinal stability postoperatively. Forty-seven of 60 patients (78.3%) with severe pain obtained significant symptomatic relief for 3 months or more, and 38 of 54 (70.1%) paralyzed patients gained neural improvement. Of the 60 patients bedridden before surgery due to pain or paresis, 36 patients (60%) experienced an increase in activity tolerance. CONCLUSIONS: The results of this study shows that neurological recovery, pain relief and mobility can be enhanced by posterior decompression and stabilization in highly selective patients with spinal metastases.

Adult↗

PubMed2004

Magnetic resonance imaging characteristics of benign and malignant vertebral fractures.

BACKGROUND: Attempts to differentiate benign and malignant vertebral fractures may be difficult, particularly when there is no obvious evidence of malignancy. Since early diagnosis and appropriate management of malignant vertebral fractures are important, a reliable imaging modality is required. METHODS: From January 1996 to December 2002, 48 patients with malignant vertebral fractures and 50 patients with benign processes were studied. All patients underwent conventional magnetic resonance imaging (MRI) scanning for acute vertebral compression fractures within 2 months of presenting with the complaint. Seven MRI characteristics were used as criteria, including signal intensity, gadolinium enhancement, epidural compression, multiple compression fractures, associated paraspinal soft tissue mass, pedicle involvement, and posterior element involvement. The predictive value of each MRI characteristic for distinguishing malignant from benign osteoporotic vertebral fractures was tested by statistical analysis. RESULTS: Lesions with negative gadolinium enhancement were favored as benign fractures. A uniform signal change in multiple involved vertebra lesions, round, smooth margins with marked epidural compression, a paraspinal soft tissue mass, and pedicle and posterior element involvement were probable malignant characteristics. Among them an associated paraspinal soft tissue mass was found to be significant in predicting the probability of malignancy. CONCLUSIONS: Certain MRI characteristics allow early differentiation of benign and malignant vertebral fractures.

Adult↗

PubMed2003

Polymethylmethacrylate cement dislodgment following percutaneous vertebroplasty: a case report.

STUDY DESIGN: A case report is presented. OBJECTIVES: To report a rare complication of delayed cement displacement following percutaneous vertebroplasty. SUMMARY OF BACKGROUND DATA: Although percutaneous vertebroplasty is considered a minimally invasive procedure, it may result in several complications. To our knowledge, this is the first report of delayed cement displacement after percutaneous vertebroplasty. METHODS: A 69-year-old man with T12 osteoporotic compression fracture received percutaneous vertebroplasty. One month after surgery, the patient complained of progressive severe back pain, and roentgenographic image revealed a breakdown of the anterior cortex of the T12 vertebral body with anterior displacement of the bone cement. RESULTS: The complication was solved by one stage anterior and posterior operation: thoracoabdominal approach with removal of the displaced cement and posterior instrumentation from T11 to L1. The severe back pain with associated weakness improved after surgery. CONCLUSIONS: This complication is rare and likely to occur in treatment of osteoporotic vertebral fracture with avascular necrosis and anterior cortical defect.

Aged↗

PubMed2003

Intracorporal bone grafting for vertebral compression fractures with intraosseous vacuum phenomenon.

From April 1998 to January 2000 we treated 14 patients with vertebral osteoporotic compression fractures and intraosseous vacuum phenomenon with intracorporal bone grafting using a mixture of autogenous bone graft and calcium sulfate and posterior instrumentation. The mixture was packed into the fractured vertebral body through two tunnels created in the pedicles. Eleven patients were followed for a minimum of 24 months. All vertebral bodies healed. There were no perioperative complications. The average vertebral height restoration was 31%. On the visual analogue scale, there was an improvement of average 37 clinical scores.

Aged↗

PubMed2003

Adjacent instability after instrumented lumbar fusion.

The invention of pedicle screw instrumentation has greatly improved outcomes of spinal fusion, which has become the treatment of choice for lumbar spondylolisthesis. As researchers accumulate experience, both theoretical and clinical advances are continually being reported. A review of the literature and the experience of the authors show that the development of adjacent instability, as in the breakdown of a neighboring unfixed motion segment, is a common consequence of an instrumented lumbar spine. This article reviews the risk factors and surgical treatment of adjacent instability. The authors believe that proper preoperative planning and complete surgical procedures are imperative to prevent adjacent instability. For those who need revision surgery, meticulous surgical techniques can achieve satisfactory results.

Bone Screws↗

PubMed2002

Combined anterior and posterior surgeries in the treatment of spinal tuberculous spondylitis.

Methods for the treatment of tuberculous spondylitis still are controversial. The authors treated 32 consecutive patients with a two-stage surgical technique combined with antituberculous chemotherapy for 1 year. After anterior debridement, fusion with autogenous anterior iliac tricortical strut bone graft was done, and in a second stage, posterior instrumentation and fusion with autogenous posterior iliac corticocancellous bone graft was done 11 days (range, 4-22 days) later. Postoperatively, patients were encouraged to ambulate with brace protection as early as possible. Twenty-nine patients were followed up for a minimum of 2 years (median, 4.7 years; range, 2-10 years) of whom 28 patients achieved solid fusion (97%). All patients had improvement of back pain including the only patient with pseudarthrosis. Neurologic deficits completely recovered in 84% (16 of 19) of patients after 3 months. Kyphotic deformity improved in all 29 patients (34.6 degrees versus 17.3 degrees ) with the average correction angle of 17.3 degrees. Clinically, 27 patients had achieved a satisfactory outcome (93%). There were no evident surgical complications. The authors, therefore, recommend a two-stage surgical technique combined with antituberculous chemotherapy to treat patients with severe vertebral body destruction attributable to tuberculosis because of its high success rate and a low complication rate.

Adolescent↗

PubMed2002

The effect of hyperbaric oxygen therapy on spinal fusion: using the model of posterolateral intertransverse fusion in rabbits.

BACKGROUND: The purpose of this study is to evaluate the facilitating effect of hyperbaric oxygen (HBO) on posterolateral intertransverse fusion using a validated rabbit model. METHODS: Twenty-four male New Zealand rabbits underwent posterolateral intertransverse fusion at L5-L6 with autogenous iliac bone graft. They were evenly divided into two groups: the HBO group and the normal room air (RA) group. Each group had six rabbits killed at 4 weeks and 8 weeks, respectively. The rabbits in the HBO groups were treated with 100% oxygen at 2.5 atm for 2 hours a day. After being killed, all rabbits were subjected to radiographic examination, manual testing, and torsional loading to evaluate the results of spinal fusion. RESULT: Radiographic union of intertransverse fusion areas at 4-week RA, 4-week HBO, 8-week RA, and 8-week HBO were 2 of 12, 7 of 12, 7 of 12, and 10 of 12, respectively. Solid union proven by manual palpation was found to be zero of six, three of six, four of six, and five of six of the cases, respectively. The average peak torsional momentums were 2120.2, 2576.5, 2661.6, and 3079.8 N-mm, respectively. Spinal fusion was significantly improved in the HBO groups at both 4 weeks and 8 weeks. CONCLUSION: The results of this study suggest that intermittent hyperbaric oxygen therapy will hasten the bone healing process and improve the fusion rate as compared with the non-HBO group.

Animals↗

PubMed2002

Clinical outcomes of revision lumbar spinal surgery: 124 patients with a minimum of two years of follow-up.

BACKGROUND: Pertinent literature on revision lumbar spinal surgery has revealed a wide variation in success rates, ranging from 12% to 82%. In addition, a solid consensus has not yet been reached on its positive factors. We retrospectively reviewed 124 consecutive patients who underwent revision lumbar spinal surgery and investigated the factors that affected the outcomes of their surgery. METHODS: Revision lumbar spinal surgery was performed in 124 patients from January 1992 to December 1996, with an average follow-up of 37.6 months (range, 24-89 months). The various factors analyzed included age, gender, previous diagnosis, number of previous operations, period of pain-free interval, neurologic deficit, operative procedure, and fusion status. This analysis revealed the effect of each factor on the overall results. Radiographs were obtained, and patients were assessed during the final follow-up or by questionnaire. RESULTS: The success rate of revision lumbar spine surgery in this study was 83.9%. Successful outcomes were significantly associated with the spinal procedure with fusion and with union of the spinal fusion. Patients with defined mechanical instability had better results than did those with stenosis only. In addition, the complication rate for repeated lumbar spinal surgery was 9.6% and major complications attributed to poor results. CONCLUSION: This study reveals a high success rate of revision spinal surgery. We recommend performing spinal fusion, and achievement of solid fusion in repeated low back surgery is invaluable for patients with spinal instability. Targeting the specific pathology of failed back surgery syndrome is crucial in attaining satisfactory results with revision lumbar spinal surgery.

Adult↗

PubMedDate not supplied

Spinal ganglioneuroma mimicking adolescent idiopathic scoliosis.

The authors report a 12-year-old girl who presented with a 2-year progressive painless thoracic scoliosis. Her previous development had been normal with no significant past history of illness. MRI revealed a thoracic ganglioneuroma, which was confirmed by surgical pathology. Ganglioneuroma might cause progressive spinal deformity mimicking adolescent idiopathic scoliosis. A careful preoperative survey is mandatory for patients diagnosed with scoliosis with a rigid or rapidly progressive curve. The authors recommend a combination of neurosurgery and orthopedic spine surgery to treat this condition.

Child↗

PubMedDate not supplied

Surgical treatment for giant cell tumor of the thoracolumbar spine.

BACKGROUND: Giant cell tumor (GCT) of the bone has historically been regarded as an extremely unpredictable bone tumor. The anatomical characteristics of spinal GCT still present challenges to surgeons. Controversy remains regarding the proper treatment of patients with grade III tumors. METHODS: Eleven patients with grade III GCT of the thoracolumbar spine were treated between 1992 and 2002 at a medical center by the authors. Three patients were initially treated at other institutions. Adjuvant radiotherapy was employed for local recurrence in these three patients. The other eight patients were initially treated with marginal excision. The site, size, and extent of each lesion dictated the surgical approach. RESULTS: Five patients had tumor recurrence. One patient, who received radiotherapy, had local relapse with malignant transformation and finally died due to disease-related complications. One patient had a recurrent tumor with multiple metastases throughout the lung. Neurological status, measured using the American Spinal Injury Association scale, of one patient was worse after undergoing the procedure than preoperatively and three patients showed improvement. The other seven patients were classified as with the same grade postoperatively. CONCLUSION: Wide excision of GCT of the thoracolumbar spine is difficult and there is a risk of neurological deficit and spinal instability. Meticulous marginal excision with associated reconstruction may obtain good local control and preserve functional spine. Early detection of recurrent GCT during intensive follow-up can allow for treatment using en bloc excision which has achieved favorable prognoses.

Adolescent↗

PubMedDate not supplied

Transforaminal epidural steroid injection for discectomy candidates: an outcome study with a minimum of two-year follow-up.

BACKGROUND: The efficacy of epidural steroid injection for sciatica due to herniated disc is controversial. This study evaluates the therapeutic effect of an alternative technique that uses a modified approach of epidural steroid injection for the above mentioned disease. The aim was to determine whether this procedure can reduce the need of surgery among discectomy candidates. METHODS: Twenty-one eligible patients who had suffered from sciatica with unilateral symptoms for 2 to 24 months received injections of betamethasone in combination with xylocaine. The treatment outcome was evaluated by direct questioning and examination using the JOA score (the criteria for low back pain syndrome of Japanese Orthopaedic Association) before the procedure and at the final follow-up visit. The final analysis comprised 19 patients with a minimum of 24-month follow-up. RESULTS: The overall JOA score increased significantly from 14.26 +/- 3.25 before injection to 23.38 +/- 4.46 after injection showing improvement. In terms of subcategories, the JOA score for sciatica increased significantly from 0.69 +/- 0.48 before infection to 2.13 +/- 0.72 after injection and the JOA score for daily activity increased significantly from 7.44 +/- 2.16 before injection to 12.19 +/- 2.23 after injection). In the end, three treated patients received surgical decompression for intractable recurrent pain. CONCLUSIONS: Transforaminal epidural steroid injection is a relatively simple, effective and low-risk alternative to surgical decompression for the treatment of lumbar disc herniation in selected cases. The procedure significantly alleviates the severity of sciatica due to a herniated disc and improves the patient's daily activity; this reduces the need for surgical decompression.

Adult↗