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Peng-Yuan Chang, Hsuan-Kan Chang, and Jau-Ching Wu

Free access

Timur M. Urakov, Ken Hsuan-kan Chang, S. Shelby Burks, and Michael Y. Wang

OBJECTIVE

Spine surgery is complex and involves various steps. Current robotic technology is mostly aimed at assisting with pedicle screw insertion. This report evaluates the feasibility of robot-assisted pedicle instrumentation in an academic environment with the involvement of residents and fellows.

METHODS

The Renaissance Guidance System was used to plan and execute pedicle screw placement in open and percutaneous consecutive cases performed in the period of December 2015 to December 2016. The database was reviewed to assess the usability of the robot by neurosurgical trainees. Outcome measures included time per screw, fluoroscopy time, breached screws, and other complications. Screw placement was assessed in patients with postoperative CT studies. The speed of screw placement and fluoroscopy time were collected at the time of surgery by personnel affiliated with the robot’s manufacturer. Complication and imaging data were reviewed retrospectively.

RESULTS

A total of 306 pedicle screws were inserted in 30 patients with robot guidance. The average time for junior residents was 4.4 min/screw and for senior residents and fellows, 4.02 min/screw (p = 0.61). Among the residents dedicated to spine surgery, the average speed was 3.84 min/screw, while nondedicated residents took 4.5 min/screw (p = 0.41). Evaluation of breached screws revealed some of the pitfalls in using the robot.

CONCLUSIONS

No significant difference regarding the speed of pedicle instrumentation was detected between the operators’ years of experience or dedication to spine surgery, although more participants are required to investigate this completely. On the other hand, there was a trend toward improved efficiency with more cases performed. To the authors’ knowledge, this is the first reported academic experience with robot-assisted spine instrumentation.

Open access

Jason Ku, Johnson Ku, Hsuan-Kan Chang, and Jau-Ching Wu

BACKGROUND

Since the beginning of the 21st century, cervical disc arthroplasty (CDA) has been accepted as an alternative to anterior cervical discectomy and fusion for surgical management of disc problems. The published clinical trials of CDA have included patients with radiculopathy or myelopathy caused by one- or two-level disc herniation at C3–7. However, it remains uncertain whether CDA is a viable option for C2–3 disc herniation.

OBSERVATIONS

In this report, a 52-year-old man presented with hand numbness, arm pain, and myelopathic symptoms that were refractory to medical treatment for more than 6 months. The magnetic resonance images demonstrated herniated discs at C2–3, C3–4, and C4–5, causing stenosis. There was no ossification of posterior longitudinal ligament and the spine was mobile, so he received anterior discectomies with artificial disc replacement at each of the C2–3, C3–4, and C4–5 levels. The surgery went smoothly, and his neurological symptoms were promptly relieved. The postoperative radiographs at 24 months demonstrated a preserved range of motion at each level.

LESSONS

To date, this was the first report of CDA performed at C2–3, which also involved three consecutive levels of disc replacement. The report suggested that both C2–3 and three-consecutive-level CDA may be a viable option for cervical disc disease.

Free access

Giacomo Pacchiarotti, Michael Y. Wang, John Paul G. Kolcun, Ken Hsuan-kan Chang, Motasem Al Maaieh, Victor S. Reis, and Dao M. Nguyen

Solitary paravertebral schwannomas in the thoracic spine and lacking an intraspinal component are uncommon. These benign nerve sheath tumors are typically treated using complete resection with an excellent outcome. Resection of these tumors is achieved by an anterior approach via open thoracotomy or minimally invasive thoracoscopy, by a posterior approach via laminectomy, or by a combination of both approaches. These tumors most commonly occur in the midthoracic region, for which surgical removal is usually straightforward. The authors of this report describe 2 cases of paravertebral schwannoma at extreme locations of the posterior mediastinum, one at the superior sulcus and the other at the inferior sulcus of the thoracic cavity, for which the usual surgical approaches for safe resection can be challenging. The tumors were completely resected with robot-assisted thoracoscopic surgery. This report suggests that single-stage anterior surgery for this type of tumor in extreme locations is safe and effective with this novel minimally invasive technique.

Restricted access

Hsuan-Kan Chang, Tun-Wei Hsu, Johnson Ku, Jason Ku, Jau-Ching Wu, Jiing-Feng Lirng, and Shih-Ming Hsu

OBJECTIVE

Good bone quality is the key to avoiding osteoporotic fragility fractures and poor outcomes after lumbar instrumentation and fusion surgery. Although dual-energy x-ray absorptiometry (DEXA) screening is the current standard for evaluating osteoporosis, many patients lack DEXA measurements before undergoing lumbar spine surgery. The present study aimed to investigate the utility of using simple quantitative parameters generated with novel synthetic MRI to evaluate bone quality, as well as the correlations of these parameters with DEXA measurements.

METHODS

This prospective study enrolled patients with symptomatic lumbar degenerative disease who underwent DEXA and conventional and synthetic MRI. The quantitative parameters generated with synthetic MRI were T1 map, T2 map, T1 intensity, proton density (PD), and vertebral bone quality (VBQ) score, and these parameters were correlated with T-score of the lumbar spine.

RESULTS

There were 62 patients and 238 lumbar segments eligible for analysis. PD and VBQ score moderately correlated with T-score of the lumbar spine (r = −0.565 and −0.651, respectively; both p < 0.001). T1 intensity correlated fairly well with T-score (r = −0.411, p < 0.001). T1 and T2 correlated poorly with T-score. Receiver operating characteristic curve analysis demonstrated area under the curve values of 0.808 and 0.794 for detecting osteopenia/osteoporosis (T-score ≤ −1.0) and osteoporosis (T-score ≤ −2.5) with PD (both p < 0.001).

CONCLUSIONS

PD and T1 intensity values generated with synthetic MRI demonstrated significant correlation with T-score. PD has excellent ability for predicting osteoporosis and osteopenia.

Open access

Johnson Ku, Chieh-Yi Chen, Jason Ku, Hsuan-Kan Chang, Jau-Ching Wu, and Yu-Shu Yen

BACKGROUND

Nasal swab tests are one of the most essential tools for screening coronavirus disease 2019 (COVID-19). The authors report a rare case of iatrogenic cerebrospinal fluid (CSF) leak from the anterior skull base after repeated nasal swab tests for COVID-19, which was treated with endoscopic endonasal repair.

OBSERVATIONS

A 41-year-old man presented with clear continuous rhinorrhea through his left nostril for 5 days after repeated nasal swabbing for COVID-19. There were no obvious risk factors for spontaneous CSF leak. Computed tomography cisternography showed contrast accumulation in the left olfactory fossa and along the left nasal cavity. Such findings aligned with a preliminary diagnosis of CSF leakage through the left cribriform plate. Magnetic resonance imaging confirmed the presence of a CSF fistula between his left cribriform plate and superior nasal concha. The patient underwent endoscopic endonasal repair. CSF rhinorrhea ceased after the surgery, and no recurrence was noted during the 12-week postoperative follow-up period.

LESSONS

Although rare, iatrogenic CSF leakage can be a serious complication following COVID-19 nasal swab tests, especially when infection may cause significant neurological sequelae. Healthcare providers should become familiar with nasal cavity anatomy and be well trained in performing nasal swab tests.

Free access

Hsuan-Kan Chang, Chih-Chang Chang, Tsung-Hsi Tu, Jau-Ching Wu, Wen-Cheng Huang, Li-Yu Fay, Peng-Yuan Chang, Ching-Lan Wu, and Henrich Cheng

OBJECTIVE

Many reports have successfully demonstrated that cervical disc arthroplasty (CDA) can preserve range of motion after 1- or 2-level discectomy. However, few studies have addressed the extent of changes in segmental mobility after CDA or their clinical correlations.

METHODS

Data from consecutive patients who underwent 1-level CDA were retrospectively reviewed. Indications for surgery were medically intractable degenerative disc disease and spondylosis. Clinical outcomes, including visual analog scale (VAS)–measured neck and arm pain, Neck Disability Index (NDI), and Japanese Orthopaedic Association (JOA) scores, were analyzed. Radiographic outcomes, including C2–7 Cobb angle, the difference between pre- and postoperative C2–7 Cobb angle (ΔC2–7 Cobb angle), sagittal vertical axis (SVA), the difference between pre- and postoperative SVA (ΔSVA), segmental range of motion (ROM), and the difference between pre- and postoperative ROM (ΔROM), were assessed for their association with clinical outcomes. All patients underwent CT scanning, by which the presence and severity of heterotopic ossification (HO) were determined during the follow-up.

RESULTS

A total of 50 patients (mean age 45.6 ± 9.33 years) underwent a 1-level CDA (Prestige LP disc) and were followed up for a mean duration of 27.7 ± 8.76 months. All clinical outcomes, including VAS, NDI, and JOA scores, improved significantly after surgery. Preoperative and postoperative ROM values were similar (mean 9.5° vs 9.0°, p > 0.05) at each indexed level. The mean changes in segmental mobility (ΔROM) were −0.5° ± 6.13°. Patients with increased segmental mobility after surgery (ΔROM > 0°) had a lower incidence of HO and HO that was less severe (p = 0.048) than those whose ΔROM was < 0°. Segmental mobility (ROM) was significantly lower in patients with higher HO grade (p = 0.012), but it did not affect the clinical outcomes. The preoperative and postoperative C2–7 Cobb angles and SVA remained similar. The postoperative C2–7 Cobb angles, SVA, ΔC2–7 Cobb angles, and ΔSVA were not correlated to clinical outcomes after CDA.

CONCLUSIONS

Segmental mobility (as reflected by the mean ROM) and overall cervical alignment (i.e., mean SVA and C2–7 Cobb angle) had no significant impact on clinical outcomes after 1-level CDA. Patients with increased segmental mobility (ΔROM > 0°) had significantly less HO and similarly improved clinical outcomes than those with decreased segmental mobility (ΔROM < 0°).

Free access

Yi-Hsuan Kuo, Chao-Hung Kuo, Hsuan-Kan Chang, Tsung-Hsi Tu, Li-Yu Fay, Chih-Chang Chang, Henrich Cheng, Ching-Lan Wu, Jiing-Feng Lirng, Jau-Ching Wu, and Wen-Cheng Huang

OBJECTIVE

Cigarette smoking has been known to increase the risk of pseudarthrosis in spinal fusion. However, there is a paucity of data on the effects of smoking in dynamic stabilization following lumbar spine surgery. This study aimed to investigate the clinical outcomes and the incidence of screw loosening among patients who smoked.

METHODS

Consecutive patients who had lumbar spondylosis, recurrent disc herniations, or low-grade spondylolisthesis that was treated with 1- or 2-level surgical decompression and pedicle screw–based Dynesys dynamic stabilization (DDS) were retrospectively reviewed. Patients who did not complete the minimum 2 years of radiological and clinical evaluations were excluded. All screw loosening was determined by both radiographs and CT scans. Patient-reported outcomes, including visual analog scale (VAS) scores of back and leg pain, Japanese Orthopaedic Association (JOA) scores, and Oswestry Disability Index (ODI), were analyzed. Patients were grouped by smoking versus nonsmoking, and loosening versus intact screws, respectively. All radiological and clinical outcomes were compared between the groups.

RESULTS

A total of 306 patients (140 women), with a mean age of 60.2 ± 12.5 years, were analyzed during an average follow-up of 44 months. There were 34 smokers (9 women) and 272 nonsmokers (131 women, 48.2% more than the 26.5% of smokers, p = 0.017). Postoperatively, all the clinical outcomes improved (e.g., VAS back and leg pain, JOA scores, and ODI, all p < 0.001). The overall rate of screw loosening was 23.2% (71 patients), and patients who had loosened screws were older (61.7 ± 9.6 years vs 59.8 ± 13.2 years, p = 0.003) and had higher rates of diabetes mellitus (33.8% vs 21.7%, p = 0.038) than those who had intact DDS screws. Although the patients who smoked had similar clinical improvement (even better VAS scores in their legs, p = 0.038) and a nonsignificantly lower rate of screw loosening (17.7% and 23.9%, p = 0.416), the chances of secondary surgery for adjacent segment disease (ASD) were higher than for the nonsmokers (11.8% vs 1.5%, p < 0.001).

CONCLUSIONS

Smoking had no adverse effects on the improvements of clinical outcomes in the pedicle screw–based DDS surgery. For smokers, the rate of screw loosening trended lower (without significance), but the chances of secondary surgery for ASD were higher than for the nonsmoking patients. However, the optimal surgical strategy to stabilize the lumbar spine of smoking patients requires future investigation.

Free access

Hsuan-Kan Chang, Huang-Chou Chang, Jau-Ching Wu, Tsung-Hsi Tu, Li-Yu Fay, Peng-Yuan Chang, Ching-Lan Wu, Wen-Cheng Huang, and Henrich Cheng

OBJECT

The aim of this paper was to investigate the risk of recurrence of lumbar disc herniation (LDH) in patients with scoliosis who underwent microdiscectomy.

METHODS

A series of consecutive patients who underwent microdiscectomy for LDH was retrospectively reviewed. The inclusion criteria were young adults younger than 40 years who received microdiscectomy for symptomatic 1-level LDH. An exclusion criterion was any previous spinal surgery, including fusion or correction of scoliosis. The patients were divided into 2 groups: those with scoliosis and those without scoliosis. The demographic data in the 2 groups were similar. All medical records and clinical and radiological evaluations were reviewed.

RESULTS

A total of 58 patients who underwent 1-level microdiscectomy for LDH were analyzed. During the mean follow-up of 24.6 months, 6 patients (10.3%) experienced a recurrence of LDH with variable symptoms. The recurrence rate was significantly higher among the scoliosis group than the nonscoliosis group (33.3% vs 2.3%, p = 0.001). Furthermore, the recurrence-free interval in the scoliosis group was short.

CONCLUSIONS

Young adults (< 40 years) with uncorrected scoliosis are at higher risk of recurrent LDH after microdiscectomy.

Full access

Li-Yu Fay, Wen-Cheng Huang, Chih-Chang Chang, Hsuan-Kan Chang, Tzu-Yun Tsai, Tsung-Hsi Tu, Ching-Lan Wu, Henrich Cheng, and Jau-Ching Wu

OBJECTIVE

The pedicle screw–based Dynesys dynamic stabilization (DDS) has reportedly become a surgical option for lumbar spondylosis and spondylolisthesis. However, it is still unclear whether the dynamic construct remains mobile or eventually fuses. The aim of this study was to investigate the incidence of unintended facet arthrodesis after DDS and its association with spondylolisthesis.

METHODS

This retrospective study was designed to review 105 consecutive patients with 1- or 2-level lumbar spondylosis who were treated with DDS surgery. The patients were then divided into 2 groups according to preexisting spondylolisthesis or not. All patients underwent laminectomies, foraminotomies, and DDS. The clinical outcomes were measured using visual analog scale (VAS) scores for back and leg pain, Japanese Orthopaedic Association (JOA) scores, and Oswestry Disability Index (ODI) scores. All medical records, including pre- and postoperative radiographs, CT scans, and MR images, were also reviewed and compared.

RESULTS

A total of 96 patients who completed the postoperative follow-up for more than 30 months were analyzed. The mean age was 64.1 ± 12.9 years, and the mean follow-up duration was 46.3 ± 12.0 months. There were 45 patients in the spondylolisthesis group and 51 patients in the nonspondylolisthesis group. The overall prevalence rate of unintended facet fusion was 52.1% in the series of DDS. Patients with spondylolisthesis were older (67.8 vs 60.8 years, p = 0.007) and had a higher incidence rate of facet arthrodesis (75.6% vs 31.4%, p < 0.001) than patients without spondylolisthesis. Patients who had spondylolisthesis or were older than 65 years were more likely to have facet arthrodesis (OR 6.76 and 4.82, respectively). There were no significant differences in clinical outcomes, including VAS back and leg pain, ODI, and JOA scores between the 2 groups. Furthermore, regardless of whether or not unintended facet arthrodesis occurred, all patients experienced significant improvement (all p < 0.05) in the clinical evaluations.

CONCLUSIONS

During the mean follow-up of almost 4 years, the prevalence of unintended facet arthrodesis was 52.1% in patients who underwent DDS. Although the clinical outcomes were not affected, elderly patients with spondylolisthesis might have a greater chance of facet fusion. This could be a cause of the limited range of motion at the index levels long after DDS.