Improvement of Pain according to Magnetic Resonance Imaging Classification in Bone Contusion around Foot and Ankle / 대한족부족관절학회지

PURPOSE@#Bone contusion is usually treated with conservative therapy for 3 months. Bone contusion around knee and hip joints has been extensively reported on, but there are scant reports on this condition in foot and ankle joints. This study evaluated the nature, characteristics and location of bone contusion around foot and ankle joints to enlighten clinicians on how to better treat this disease entity.@*MATERIALS AND METHODS@#We classified bone contusion of the 76 patients into three types (102 sites; 47 ankle sprains, 18 traffic accidents, 11 falls) according to the Costa-Paz system with employing magnetic resonance imaging (MRI), and the study then analyzed the common sites and areas of occurrence according to the mechanism of injury and duration of pain after first conducting conservative therapy.@*RESULTS@#Of the 76 patients (102 sites) on the MRI, 43 case (42.2%) for talus, 19 cases for distal tibia, and 12 cases for calcaneus were involved. The classification, according to the Costa-Paz system, was Type I, 51 cases; Type II, 32 cases; and Type III, 19 cases. The duration of pain after conservative treatment was 12.15±2.17 weeks for Type I, 14.5±2.15 weeks for Type II, and 21.0±3.8 weeks for Type III.@*CONCLUSION@#The most common location of post-traumatic bone contusion around both the foot and ankle is the talus, distal tibia, and calcaneus. The most common type of injury noted on MRI is a diffuse signal with change of the medullary component (Type I), In cases of bone contusion extending to a subjacent articular surface or disruption or depression of the normal contour of the cortical surface (Types II, III), the patients' pain appears to last longer. Thus, it is necessary to consider a longer period of conservative treatment in cases of Types II and III bone contusion because the patients' pain may last longer than 3 months.

A Report on Diabetic Foot and Amputation from the Korean Health Insurance Review & Assessment Service Data / 대한족부족관절학회지

PURPOSE: This study reports on limb amputations in diabetic patients according to gender, age, and region based on the data from the Korean Health Insurance Review & Assessment Service. MATERIALS AND METHODS: The number of amputations was compared by region, age, gender, and year, as well as by femoral region, lower leg, foot, and toe in diabetic patients who received limb amputation. This analysis was performed based on the data from the Korean Health Insurance Review & Assessment Service, between January 2009 and December 2014. RESULTS: The total number of amputations between the study period was 9,155. The number of patients who were treated at hospitals for diabetes in 2009 was 1.9 million, among which, 1,214 patients underwent amputation. In 2014, the incidence of diabetes was 1,747 in 2.58 million individuals. With this rising incidence of diabetes, the amputation of limbs due to diabetes is increasing every year. In particular, the following regions were amputated more often: femoral region, 2.3%; lower legs, 19.6%; feet, 18.1%; and toes 60.0%. Regarding gender differences, males showed a higher amputation rate than females for all body parts. With respect to region, Seoul was the highest with 30.2%, followed by Gyeonggi with 19.9%, and Busan with 8.8%. According to age, older age showed greater diabetic amputation rate. CONCLUSION: In accordance with the rising incidence of diabetes, the diabetic amputation is also increasing. Here, we showed that toes were amputated with the highest percentage and males had greater amputation rate than females for all body parts. Moreover, amputation rate was highest in older diabetic patients, especially for those in their seventies. Additionally, Seoul was the region with highest amputation rate.

Analysis of Heel Pad Thickness in Korean / 대한족부족관절학회지

PURPOSE: The purpose of this study is to provide Korean data on heel pad thickness according to age, gender, underlying disease, occupation, and body mass index (BMI). MATERIALS AND METHODS: A retrospective study was conducted on 670 patients who underwent foot lateral plain radiography and magnetic resonance imaging (MRI) between January 2010 and July 2014. Through measurements of heel pad thickness, the usefulness and accuracy of foot lateral plain radiography was evaluated, and the mean Korean heel pad thickness in the weight-bearing and non-weight-bearing conditions was also evaluated according to age, gender, underlying disease, occupation, and BMI. RESULTS: The 670 subjects with a mean age of 44 years (range, 12 to 84 years) consisted of 420 males and 250 females. The difference in heel pad thickness between non-weight-bearing foot lateral plain radiography and MRI was 0.69 mm. The heel pad thickness did not show a significant difference with age (p=0.08) and the presence of diabetes (p=0.09). With the increase in the Tegner score, the thickness of the heel pad increased (p=0.035), and subjects with a higher BMI had a thicker heel pad (p=0.03). The compressibility of the heel pad thickness showed no correlation with gender, diabetes, and Tegner score. Compressibility also increased with the increase in age and body weight. CONCLUSION: The mean Korean heel pad thickness measured through non-weight-bearing foot lateral plain radiography was 18.79 mm. The heel pad thickness increased with increasing BMI; however, age and diabetes did not show significant correlation. The compressibility of heel pad increased with the increase in age.

A Case of Septo-Optic Dysplasia Resulting in Central Diabetes Insipidus and Nonobstructive Bilateral Hydronephrosis / 대한내과학회지

A 27-year-old male with nonobstructive hydronephrosis was referred from the urology department for polyuria evaluation and management. The patient was hospitalized for urinary tract infection and cystostomy was performed due to neurogenic bladder of unknown origin. The patient was of short stature and had visual impairment. From the interview, we discovered he had been suffering from polyuria and polydipsia for more than 20 years. Urine output was 13 L/day and urine osmolarity was 85 mOsm/kg. The results of a water deprivation test were consistent with central diabetes insipidus. Septo-optic dysplasia (SOD) was observed on brain magnetic resonance imaging (MRI). SOD is a very rare condition characterized by agenesis of the septum pellucidum or corpus callosum, which may cause optic nerve aplasia or hypoplasia, midbrain abnormalities and/or hypopituitarism. After desmopressin treatment, polyuria and hydronephrosis were improved. We report a case of a 27-year-old male diagnosed with SOD including diabetes insipidus, resulting in nonobstructive hydronephrosis.

Does Preoperative Cervical Sagittal Alignment And Range of Motion Affect Adjacent Segment Degeneration After Anterior Arthrodesis In Degenerative Cervical Spinal Disorders?: Midterm Follow up Study

STUDY DESIGN: Retrospective study. OBJECTIVES: The purpose of this study was to investigate whether preoperative sagittal alignment and range of motion (ROM) affect adjacent segment degeneration (ASD) and disease after anterior arthrodesis in degenerative cervical spinal disorders. Summary of Literature Review:There is no study about the relationship between preoperative ROM and sagittal alignment and the development of ASD yet. MATERIALS AND METHODS: We took a retrospective approach to study 136 patients who underwent an anterior arthodesis for less than 2 segments with PEEK cage and plate construct method for degenerative cervical diseases and who have a minimum of 3 years of follow-up. We analyzed ASD and cervical ROM, such as less than 40degrees(group A) and more than 40degrees(group B) and sagittal alignment, such as lordosis or kyphosis with less than 10degrees(group a), 10degrees~30degrees(group b) and more than 30degrees(group c). Adjacent segment degeneration was graded according to Park's classification and Hillibrand method. RESULTS: There was no statistically significant difference between group A(1.35+/-0.48) and group B (1.44+/-0.50) in the correlation between the cervical ROM and the variation of disc height(p=0.07). Concerning the relationship between the ROM and osteophyte formation on adjacent segment, no statistically significant difference has been found between group A(1.64+/-0.88) and group B(1.43+/-0.67) (p=0.06). The disc height change at the final follow up after cervical sagittal alignment showed no statistically significant difference among the groups: Group A presented with 1.53+/-0.50, group B with 1.30+/-0.46 and group C with 1.40+/-0.50.(p=0.08) Regarding sagittal alignment and osteophyte change, there was no statistically significant difference among the groups as group A showed an average of 1.33+/-0.48, group Ban average of 1.56+/-0.88 and group Can average of 1.60+/-0.82(p=0.07). CONCLUSION: Although the preoperative sagittal alignment and ROM did not significantly affect adjacent segment degeneration and diseases in a mid-term follow-up evaluation after anterior arthrodesis with PEEK cage and plate in degenerative cervical spinal disorders, we think a future study is required with a sufficient number of patients and a long term follow-up because there were borderline statistical significances shown in the present study.

Closed Traction Reduction as an Initial Management for Subaxial Unilateral Facet Dislocation / 대한정형외과학회잡지

PURPOSE: Subaxial unilateral facet dislocation requires immediate reduction; however, cases of failure with reduction have also been reported. We analyzed the factors preventing closed traction reduction and attempted to determine the efficacy and indications of closed traction reduction. MATERIALS AND METHODS: We selected 26 patients, 17 men and nine women. The average age of the patients in selected group was 49 years (20-69 years). Each patient was first treated with Gardner head traction and closed traction reduction. Each patient was checked for the degree of locking of the dislocated segment, intervertebral disc herniation, the degree of contralateral facet joint subluxation, and accompanied fracture. The effect of the location of the injured segment, age, and sex on closed reduction traction was analyzed. RESULTS: A high rate of unsuccessful closed traction reduction was observed for patients with more than 50% locking of the dislocated facet joint (p=0.039). Intervertebral disc herniation, the degree of contralateral facet joint subluxation, facet joint fracture, and pedicle and lamina fracture were unrelated to the success of closed traction reduction. The location of dislocation and sex showed no statistically significant relevance to failure of closed traction reduction. A high rate of failure was observed for patients younger than 40 years. Of the 26 patients, closed traction reduction was successful for 12 and unsuccessful for 14. CONCLUSION: For patients whose degree of locking of the dislocated facet joint is less than 50%, closed traction reduction using skull traction is considered effective, however, for patients younger than 40 years or with more than 50% locking of the dislocated facet, prompt reduction under general anesthesia and subsequent appropriate surgery is considered beneficial.

Acute Respiratory Distress Due to Delayed Hematoma after Anterior Cervical Discectomy Fusion / 대한정형외과학회잡지

Hematoma resulting in acute respiratory distress associated with anterior cervical spine surgery is rare; however, it is a serious adverse complication and occurs primarily within postoperative three days and is cured in the hospital. Rarely, delayed hematoma occurs after discharge from the hospital, and treatment of respiration is difficult. In this review, we report on a case of acute respiratory distress due to delayed hematoma following anterior cervical discectomy and fusion, which occurred at postoperative five days.

Extensive Metallosis Caused by Plate and Screw Construct for Distal Fibular Fracture - A Case Report -

Metallosis has been reported in the setting of weight-bearing joint arthroplasties, like the hip and knee joints. However, the prevalence of metallosis in non-articular portions is very uncommon. We report a rare case of a patient who had metallosis secondary by fibular nonunion after fixation with plate and screw. In addition, we discuss the clinical and the operative findings, as well as the outcome of this uncommon complication.

Anatomical and Pathophysiological Features of Cauda Equina

STUDY DESIGN: Review of literature on anatomical and pathophysiological features of cauda equina. OBJECTIVES: To look into the anatomical and pathophysiological features of cauda equina and support their basic knowledge of treating cauda equina syndrome. SUMMARY OF LITERATURE REVIEW: Cauda equina has different anatomical and pathophysiological features to peripheral nerve. MATERIALS AND METHODS: Review of literature. RESULTS: When compressing to cauda equina, the pathophysiologic mechanism develop as follows; increasing the vascular permiablity of nerve root, intraneural edema, and subsequent blood and nutritional impairment. Nerve root injury develops through this pathophysiologic mechanism. CONCLUSIONS: Cauda equina has an extensive ateriovenous anastomosis and guaze-like pia mater, which supply blood and neutrition to it. These anatomical features prevent it from complete cauda equina syndrome when compressing to it under arterial blood pressure.

Adalimumab Induced Acute Exacerbation of Rheumatoid Arthritis Related Interstitial Lung Disease

A 69-year-old woman with 6 years history of seropositive rheumatoid arthritis (RA) and asymptomatic interstitial lung disease (ILD) began taking adalimumab for ongoing arthritis despite intakes of sulfasalazine and hydroxychloroquine for treatment. ILD progressed noticeably after 10 weeks of starting adalimumab. We discontinued adalimumab and added methylprednisolone 40 mg, and the patient's clinical findings gradually improved. The beneficial and adverse effects of tumor necrosis factor-alpha (TNF-alpha) inhibitors on RA associated ILD are unclear but this case reports adalimumab could abruptly exacerbate known ILD. We emphasize cautions on the use of adalimumab, one of the TNF-alpha inhibitors, in elderly RA patients with preexisting ILD.

Two Cases of Colon Polyp Bleeding With Massive Hematochezia in Elderly Patients

The annual incidence of hospital admissions for lower gastrointestinal bleeding in the United States and Europe is 0.02%. Massive hemorrhage from a solitary colon polyp is an extremely rare case. We report two consecutive patients with a single polyp, which was the source of bleeding. The first case is a 68-year-old male patient who visited Daejeon Sun Hospital with the chief complaint of considerable hematochezia. An 1.2 cm colon polyp with active bleeding was observed on the colonoscopy. The second case is a 74-year-old female patient with symptoms of hematochezia. A blood-clot attached, 3.0 cm sized Yamada type-IV colon polyp was examined on the colonoscopy. One case was a sessile polyp, and the other one was a thick-stalked pedunculated polyp. Both types of polyps were supplied with more vessels than other polyps, and both patients were taking aspirin. The two patients underwent snare polypectomy and were discharged without further bleeding evidence.

Treatment of Irreducible Bilateral Cervical Facet Fracture-Dislocation with a Prolapsed Disc Using a Prefixed Polyetheretherketone Cage and Plate System

When anterior reduction fail in the surgical treatment of cervical bilateral facet fracture-dislocation with concomitant disc extrusion, it is necessary to perform a reduction using a posterior approach and then a third anterior procedure is often necessary to accomplish the anterior reconstruction. This presents difficulties for both patients and surgeons because of the need for frequent position changes (supine-prone-supine). The purpose of this study is to illustrate a modified surgical technique, which is anterior reduction and fixation with a prefixed polyetheretherketone (PEEK) cage to a buttress plate for the treatment of irreducible bilateral cervical facet fracture-dislocation with a prolapsed disc is an enhancing technique for the stability of the interbody graft than a buttress plate alone because the PEEK cage has more fixation power and reduces both the number of position changes and the length of the operation.

Clinical Analysis of Lower Cervical Spine Injury according to Injury Mechanism: Data of 277 Surgical Patients / 대한정형외과학회잡지

PURPOSE: To analyze the incidence and treatment outcomes of lower cervical spine injury since there is no long term, large Korean data available. MATERIALS AND METHODS: We analyzed 277 patients with lower cervical spine injury who underwent surgical treatments between May 1994 and October 2008. The injury types are based on Allen's classification, and neurologic injury was classified as complete, incomplete cord injury, root injury and no neurologic status. We analyzed postoperative complications, neurologic recovery and the relief of pain. RESULTS: Distractive-extension injury occurred most commonly in 140 patients (50.5%). Neurologic injury was detected in 232 cases (83.8%); 46 (16.6%) complete cord injury; 154 (55.6%) incomplete cord injury; and 32 (11.6%) root injury. Incomplete cord injury of distractive extension injury was poorly recovered. Clinical outcomes demonstrated improvement compared with the preoperative values in mean visual analogue scale. Complications were respiratory failure, neurogenic bladder, urinary tract infection and gastritis. CONCLUSION: This study showed the highest incidence of distractive extension injury and neurologic injury contrary to previous studies. This result was caused by the use of plain radiograph to establish Allen's classification in the past. Therefore, we suggest the use of magnetic resonance imaging for evaluating soft tissue injury with Allen's classification to achieve accurate assessment.

Airway Compression as a Result of Extensive Prevertebral Hematoma Following Extension Injury of Lower Cervical Spine without Fracture/Dislocation / 대한정형외과학회잡지

A 77-year-old man presented with severe dyspnea, neck pain, tingling sensation in both hands, and weakness after an acute prevertebral soft tissue hematoma due to distractive-extension injury. Magnetic resonance images demonstrated an extensive hematoma accumulation, anterior longitudinal ligament and longus colli muscle injuries. We report here a case of dyspnea due to an extensive prevertebral hematoma by soft tissue injury without cervical vertebral fracture and/or dislocation and a review the relevant literature.

The Relationship between Soft Tissue Damages and Neurologic Deficits in Distractive Extension Injury of the Lower Cervical Spine / 대한정형외과학회잡지

PURPOSE: To evaluate the relationship between the damage to anterior soft tissues and neurological deficit in distractive extension injury of the lower cervical spine. MATERIALS AND METHODS: Ninety-two patients who were treated surgically for distractive extension injury of the lower cervical spine were included in this study. Soft tissue swelling was evaluated on plain radiographs. Damage to the longus colli muscle, anterior longitudinal ligament, superior end plate, inferior end plate, annulus fibrosus, and posterior longitudinal ligament were intraoperatively checked and the relationship between these findings and clinical neurologic deficits was analyzed. RESULTS: Soft tissue swelling was increased to 92% in the retropharyngeal space and to 89% in the retrotracheal space but there was no significant difference. No relationship was found between the damage to the prevertebral fascia, longus colli muscle and neurological deficit. Injuries to the inferior end plate and annulus fibrosus showed a directly propotional relation with neurological deficit, but it was not significant. Injuries to the anterior longitudinal ligament (p<0.01), superior end plate (p=0.02), posterior longitudinal ligament (p=0.04) showed significant relations with neurological deficit. CONCLUSION: The distractive extension injury combined with the damage to the anterior longitudinal ligament, superior end plate or posterior longitudinal ligament showed high frequency of neurological deficit. Hence, these are regarded as the important structures for maintaining the stability of the lower cervical spine.

Comparison of Floating Knee according to Presence of Knee Joint Injury

PURPOSE: To compare the clinical outcomes of floating knee according to the presence of knee joint injury. MATERIALS AND METHODS: Between March 2004 and March 2009, we investigated 36 patients, who underwent surgical treatment for floating knee injuries. We classified the floating knee into two groups as type I (12 cases) has no knee joint injury and type II (24 cases) has knee joint injury. We compared two groups about combined injury (orthopedics or other part), open fracture or not, neurovascular injury,union time, range of motion, and complication rate. RESULTS: There is statistically no significant difference between two groups as type I (6 cases, 50%) and type II (13 cases, 54.2%) in orthopedic combined injury (p=0.813), and also same as type I (3 cases, 25%) and type II (12 cases, 50%) in combined injury on the other department (p=0.151), and in floating knee with open fracture as 4 type I (33%) and 12 type II (50%) of 16 cases (44%), and Gustilo-Anderson 3 type I, 4 type II, 1 IIIA, 4 IIIB, and 4 IIIC (p=0.423). There is statistically no significant difference between two groups in neurovascular injury as 1 type I (8.3%), and 3 type II (12.5%) (p=0.708). There is a statistically significant difference between two groups in the mean bone union time as 18.2+/-5.37 weeks (12~24 weeks) for type I and 24.95+/-9.85 weeks (16~33 weeks) for type II (p=0.045), and in the mean range of knee joint motion as 133+/-12.74 degree (120~150 degree) for type I and 105+/-19.00 degree (80~135 degree) for type II (p=0.012). CONCLUSION: Floating knee with knee joint injury is severe itself and related with severe combined injuries, subsequent range of knee joint motion limitation, the delay of union time, and high complication rate. Therefore, we should take care in surgical treatment for this trauma entity.

Is CT Angiography a Reliable Tool for Diagnosis of Traumatic Vessel Injury in the Lower Extremities?

PURPOSE: Computed tomographic (CT) angiography is the first choice of diagnosis in traumatic vessel injury in the lower extremities, replacing angiography. The purpose of this study was to investigate the clinical reliability of CT angiography through a retrospective study. MATERIALS AND METHODS: Seventeen patients underwent CT angiography before surgery for traumatic vessel injury in the lower extremities from 2009 to 2010, and a comparative analysis of operative findings in all patients with a positive predictive value and sensitivity were measured. RESULTS: In all patients, 16 artery ruptures and 1 compartment syndrome occurred. In 15 artery ruptures, preoperative findings of CT angiography and surgical findings were consistent, and the positive predictive value was 93.8%. One patient with posterior tibial artery rupture was revealed as normal in CT angiography; thus, sensitivity was 93.8% (15/16 patients), and the accuracy rate was 88.2% (15/17 patients). CONCLUSION: Though CT angiography is a reliable tool for diagnosis in traumatic vessel injury in the lower extremities, a more invasive test will be needed, especially peripheral angiography or diagnostic exploration, in cases of relatively small vessel injuries around the ankle or compartment syndrome because of low accuracy.

Injury Severity and Patterns of Accompanying Injury in Spinal Fracture

PURPOSE: To examine the relationship between injury severity and patterns of associated injury in spinal fracture. MATERIALS AND METHODS: From March 2004 to March 2010, a retrospective study was conducted on 291 patients who had undergone surgeries due to spinal fractures. Spinal fractures were categorized as upper cervical, lower cervical, thoracic, thoracolumbar, and lumbar region, and the severity of fracture was measured using the Abbreviated Injury Scale and Injury Severity Score (ISS). We evaluated the correlation between the fracture site and the incidence and injury severity of the associated injury, and compared the neurologic damage according to the presence/absence of the associated injury. RESULTS: Spinal fracture occurred in the thoracic (43.5%) and lower cervical (30.0%) levels, and associated injury developed in 134 patients (47%). The area of associated injury was in the extremity (41.2%), thorax (25.5%), head, neck, and face (21.9%). Lower cervical fracture (34.5%) had a lower prevalence than thoracic (81%) and lumbar fracture (61%). The average ISS of the associated injury was 17.14 for the thoracic fracture, 12.30 for the lower cervical fracture, 8.7 for the thoracolumbar fracture and 5.69 for the lumbar fracture. Neurologic damage was highly frequent in the lower cervical fracture and included 54 patients (62.1%) and was less frequent in the upper cervical fracture, which included 7 patients (17.9%) (p=0.032). CONCLUSION: Although the associated injury was less frequent in the lower cervical spine among the spinal fractures that underwent surgical treatment, there was a high risk of neurologic damage in the case of associated injury; therefore, there is a need to pay special attention to patients that suffer damage in this area. In addition, since the degree of the associated injury in the thoracic and lower cervical fracture is significant, an appropriate management strategy for the associated injury must be considered.

Significance of Mal-alignment after Anterior Cervical Arthrodesis in Degenerative Cervical Spinal Disorders / 대한정형외과학회잡지

PURPOSE: The purpose of this study was to analyze the risk factors for postoperative sagittal mal-alignment after anterior cervical arthrodesis resulting from degenerative cervical disorders and its effect on radiological and clinical results. MATERIALS AND METHODS: We evaluated 50 patients who underwent anterior cervical arthrodesis for degenerative cervical disorder retrospectively. We assigned 25 patients who had sagittal mal-alignment after surgery to group A and 25 patients who had improvement of lordosis after surgery to group B. We evaluated the change of cervical lordosis, lordosis at fused segments, and lordosis at unfused segments. In addition, we evaluated radiological and clinical results. RESULTS: In group A, postoperative cervical lordosis worsened from 12.7+/-10.6 to 3.6+/-6.2degrees after surgery (p=0.002), but had recovered to 12.2+/-9.5degrees by the last Follow-up (p=0.859). In group B, cervical lordosis was improved from 9.6+/-10.5degrees to 22.5+/-9.7degrees (p=0.0003) after surgery and correction was maintained to 27.5+/-9.1degrees (p=0.0988) at the last follow up. Lordosis at fused segments were improved in both groups (p=0.001, 0.0001) but lordosis at unfused segments worsend in group A (p=0.0001). The factor associated with postoperative mal-alignment was symtoms of myelopathy (p=0.0436). Age, sex, fusion level, size of cage, and duration of symptoms were not significantly associated with postoperative changes in alignment. One nonunion occurred only in group A. Six cases of cage subsidences were found in group A, 3 cases in group B (p=0.4506). Adjacent segment degeneration was found in 8 segments in group A, 1 segment in group B (p=0.0048). The differences in clinical improvement evaluated by VAS, NDI between groups were not significant (p=0.88, p=0.91). CONCLUSION: Postoperative sagittal malalignment was a temporary and reversible change, and was not related to clinical results. However, it might be a factor in the increased incidence of adjacent segment degeneration.

Comparison According to Fusion Level in ACDF Using PEEK Cage Alone for Degenerative Cervical Disease / 대한정형외과학회잡지

PURPOSE: This study examined the clinical efficacy of an anterior cervical discectomy and fusion (ACDF) with PEEK (polyetheretherketone) cage alone with regard to the clinical and radiological outcomes, as well as the risk factors for the cage subsidence. MATERIALS AND METHODS: A total of 128 patients who underwent group A (1-level, n=48), group B (2-levels, n=57), group C (3-levels, n=23) ACDF using a PEEK cage alone were enrolled in this study. The fusion rate, segmental kyphosis were assessed by radiographs. The clinical outcomes were assessed using the Visual Analog Scale (VAS) and Neck Disability Index (NDI). The risk factors for cage subsidence were analyzed according to the difference in incidence between the subsidence group and non-subsidence group. RESULTS: Solid fusion was achieved in 93.8% (45/48), 71.9% (41/57) and 69.6% (15/23) of subjects in group A, B and C, respectively. Segmental kyphosis was observed in 22.9% (11/48), 43.9% (25/57) and 47.8% (11/23) of subjects in group A, B and C, respectively. The VAS scores changed from 7.79+/-1.01 in group A, 7.74+/-1.09 in group B, 7.91+/-0.79 in group C preoperatively to 4.23+/-1.29 in group A, 5.25+/-1.34 in group B and 5.35+/-1.07 in group C at the last follow up. In addition, the NDI was also improved at the last follow up. The VAS score and NDI at the last follow up were similar in the subsidence and non-subsidence group. The 3-level ACDF (p=0.05), osteoporosis (p=0.01), and old age (p=0.01) were the risk factors for cage subsidence. CONCLUSION: Only 1 level ACDF with PEEK cage alone was similar in clinical and radiologic (solid fusion rate, local kyphosis) outcomes compared to ACDF with published other modalities. Old age, 3 fusion level, osteoporosis, and C6-7 fusion were risk factors for the cage subsidence with higher complication rates.