The Degree of Bacterial Contamination While Performing Spine Surgery

STUDY DESIGN: Prospective experimental study. PURPOSE: To evaluate bacterial contamination during surgery. OVERVIEW OF LITERATURE: The participants of surgery and ventilation system have been known as the most significant sources of contamination. METHODS: Two pairs of air culture blood agar plate for G(+) bacteria and MacConkey agar plate for G(-) bacteria were placed at 3 different locations in a conventional operation room: in the surgical field, under the airflow of local air conditioner, and pathway to door while performing spine surgeries. One pair of culture plates was retrieved after one hour and the other pair was retrieved after 3 hours. The cultured bacteria were identified and number of colonies was counted. RESULTS: There was no G(-) bacteria identified. G(+) bacteria grew on all 90 air culture blood agar plates. The colony count of one hour group was 14.5+/-5.4 in the surgical field, 11.3+/-6.6 under the local air conditioner, and 13.1+/-8.7 at the pathway to the door. There was no difference among the 3 locations. The colony count of 3 hours group was 46.4+/-19.5, 30.3+/-12.9, and 39.7+/-15.2, respectively. It was more at the surgical field than under the air conditioner (p=0.03). The number of colonies of one hour group was 13.0+/-7.0 and 3 hours group was 38.8+/-17.1. There was positive correlation between the time and the number of colonies (r=0.76, p=0.000). CONCLUSIONS: Conventional operation room was contaminated by G(+) bacteria. The degree of contamination was most high at the surgical field. The number of bacteria increased right proportionally to the time.

Survival and Prognostic Analysis of Adjacent Segments after Spinal Fusion

BACKGROUND: To examine the survival function and prognostic factors of the adjacent segments based on a second operation after thoracolumbar spinal fusion. METHODS: This retrospective study reviewed 3,188 patients (3,193 cases) who underwent a thoracolumbar spinal fusion at the author's hospital. Survival analysis was performed on the event of a second operation due to adjacent segment degeneration. The prognostic factors, such as the cause of the disease, surgical procedure, age, gender and number of fusion segments, were examined. Sagittal alignment and the location of the adjacent segment were measured in the second operation cases, and their association with the types of degeneration was investigated. RESULTS: One hundred seven patients, 112 cases (3.5%), underwent a second operation due to adjacent segment degeneration. The survival function was 97% and 94% at 5 and 10 years after surgery, respectively, showing a 0.6% linear reduction per year. The significant prognostic factors were old age, degenerative disease, multiple-level fusion and male. Among the second operation cases, the locations of the adjacent segments were the thoracolumbar junctional area and lumbosacral area in 11.6% and 88.4% of cases, respectively. Sagittal alignment was negative or neutral, positive and strongly positive in 47.3%, 38.9%, and 15.7%, respectively. Regarding the type of degeneration, spondylolisthesis or kyphosis, retrolisthesis, and neutral balance in the sagittal view was noted in 13.4%, 36.6%, and 50% of cases, respectively. There was a significant difference according to the location of the adjacent segment (p = 0.000) and sagittal alignment (p = 0.041). CONCLUSIONS: The survival function of the adjacent segments was 94% at 10 years, which had decreased linearly by 0.6% per a year. The likelihood of a second operation was high in those with old age, degenerative disease, multiple-level fusion and male. There was a tendency for the type of degeneration to be spondylolisthesis or kyphosis in cases of the thoracolumbar junctional area and strongly positive sagittal alignment, but retrolisthesis in cases of the lumbosacral area and neutral or positive sagittal alignment.

Lower-Pressure Percutaneous Vertebroplasty Using Larger-Diameter Bone-Cement Fillers

STUDY DESIGN: This is a retrospective, case-controlled study. OBJECTIVE: We wanted to evaluate the efficacy of lower-pressure percutaneous vertebroplasty (LP-PVP) using larger-diameter cement fillers for treating osteoporotic vertebral compression fracture (VCF). SUMMARY OF THE LITERATURE REVIEW: Despite the popularity of conventional PVP(C-PVP), critical complications associated with cement leakage have been widely reported due to the inadequate viscosity of flabby cement. MATERIALS AND METHODS: With excluding Kummell's disease, 23 VCF's were treated with LP-PVP using 2.8mm-diameter cement fillers, 51 VCF's were treated with kyphoplasty(KP) using the same size of cement fillers and 19 VCF's were treated with C-PVP using 1.4mm-diameter biopsy needles. The clinical and radiographic results along with the complications were investigated for more than one year. RESULTS: The visual analogue scale (VAS) was improved in all the groups. The infused cement volume was 5.9+/-1.6ml for the LP-PVP, 5.9+/-1.9ml for the KP and 3.5+/-1.0ml for the C-PVP (p=0.000). The collapsed vertebral height was restored by 10.8+/-10.3%, 13.0+/-12.7% and 4.7+/-7.6%, respectively, in each group (p=0.000) with a reduction loss of 2.1+/-1.8%, 1.1+/-1.4% and 5.9+/-4.2%. respectively, in each group (p=0.000) at follow-up. These was a reduction of the vertebral kyphotic angle by 3.0+/-4.0degrees, 3.7+/-4.4degrees and 4.2+/-4.4degrees, respectively, in each group (p=0.528) with reduction loss of 1.0+/-0.9degrees, 0.1+/-1.7degrees and 3.5+/-2.8degrees, respectively, in each group (p=0.000). There was a reduction of the regional Cobb's angle by 4.3+/-2.6degrees, 3.1+/-4.7degrees and 2.9+/-3.8degrees, respectively, in each group (p=0.184) with a reduction loss of 3.6+/-4.5degrees, 0.1+/-1.5degrees and 1.0+/-4.1degrees, respectively, in each group (p=0.000). Extravasation of cement was noticed in 6 cases (26.1%) of LP-PVP, in 14 cases (27.5%) of KP and 4 cases (26.1%) of C-PVP (p=0.689). No cases of additional VCF happened for the LP-PVP, eight cases of additional VCF happened (15.7%) for the KP and one case of additional VCF happened (5.3%) for the C-PVP (p=0.030). CONCLUSION: The LP-PVP showed clinically and radiologically results that were similar to those of KP with a higher amount of infused cement volume compared to that of C-PVP. LP-PVP is thought to be effective for the clinical and radiolographic aspects and to have fewer complications for the treatment of osteoporotic VCF.

Tardy Spinal Cord Compression without Bone Cement Leakage after Kyphoplasty: A Report of 3 Cases

STUDY DESIGN: This is a case report. OBJECTIVE: We report here on three cases of late spinal cord compression without bone cement leakage after kyphoplasty from the view point of the common characteristics, the suspected etiologies and the performed treatments, and we propose a technique to prevent this kind of complication. SUMMARY OF THE LITERATURE REVIEW: Kyphoplasty is widely accepted as an effective and safe treatment for osteoporotic vertebral compression fracture (VCF). Complicated compression fractures and even bursting fractures with a compromised spinal canal are currently indicated for kyphoplasty. The wide spread application of kyphoplasty may be mainly due to reducing the complication rates associated with cement leakage and possible restoration, even though partially, of a vertebral kyphotic deformity. MATERIALS AND METHODS: we experienced three cases of newly emerged complications that caused delayed neurologic compromise after uneventful kyphoplasty without any immediate neurologic deficits. MR imaging was done to find the pathologic regions and surgical treatment was performed. RESULTS: Refracture of an augmented vertebra at the conus medullaris level can cause late occurring spinal cord compression without compromising the spinal canal. Posterior instrumentation and posterior fusion with posterior decompression were effective treatments. CONCLUSION: The anatomical peculiarity of the conus medullaris and the dynamic irritation of the spinal cord by a bone cement mass after refracture of an augmented vertebral body can be the causes of late spinal cord compression after kyphoplasty. The neurologic symptoms were treated by posterior decompression and fusion. This kind of complication can be prevented by injecting a sufficient amount of bone cement with a shape to support both endplates.

The Surgical Treatment for Spinal Intradural Extramedullary Tumors

BACKGROUND: We wanted to investigate the results of surgical treatment and analyze the factors that have an influence on the neurologic symptoms and prognosis of spinal intradural extramedullary (IDEM) tumors. METHODS: The spinal IDEM tumor patients (11 cases) who had been treated by surgical excision and who were followed up more than 1 year were retrospectively analyzed. Pain was evaluated by the visual analogue scale (VAS) and the neurologic function was assessed by Nurick's grade. The pathological diagnosis, the preoperative symptom duration, the tumor location on the sagittal and axial planes and the percentage of tumor occupying the intradural space were investigated. In addition, all these factors were analyzed in relation to the degree of the preoperative symptoms and the prognosis. On the last follow-up, the MRI was checked to evaluate whether or not the tumor had recurred. RESULTS: The most common diagnosis was schwannomas (73%), followed by meningiomas (18%). The percentage of tumor occupying the intradural space was 82.9 +/- 9.4%. The VAS score was reduced in all cases from 8.0 +/- 1.2 to 1.2 +/- 0.8 (p = 0.003) and the Nurick's grade was improved in all cases from 3.0 +/- 1.3 to 1.0 +/- 0.0 (p = 0.005). The preoperative symptoms were correlated with only the percentage of tumor occupying the intradural space (VAS; r2 = 0.75, p = 0.010, Nurick's grade; r2 = 0.69, p = 0.019). One case of schwannoma recurred. CONCLUSIONS: The degree of neurologic symptoms was correlated with the percentage of tumor occupying the intradural space. All the tumors were able to be excised through the posterior approach. The postoperative neurologic recovery was excellent in all the cases regardless of any condition. Therefore, aggressive surgical excision is recommended even for cases with a long duration of symptoms or a severe neurologic deficit.

Precautions Against Infection Following Posterior Spinal Fusion Based on Types of Infection and Risk Factors / 대한척추외과학회지

STUDY DESIGN: This is a retrospective preparative study and prospective study OBJECTIVE: We instituted and verified the precautions against postoperative spinal infection. SUMMARY OF THE LITERATURE REVIEW: Postoperative infection comes from contamination during the operation and various strategies have been recommended to prevent it. MATERIALS AND METHODS: 583 cases that underwent instrumented posterior spinal fusion during two years (group I), were reviewed to discover the risk factors, and intraoperative cultures were done to detect the contamination routes and the causative microorganisms for the next 4 months. Six precautions, based on the results, were instituted. We analyzed 354 cases that underwent operation in the following year (group II) using the precautions. RESULTS: Twenty cases (3.4%) were infected in group I and the types of infection were superficial wound infection (4 cases), deep wound infection (4 cases), osteomyelitis around the interbody space (7 cases), osteomyelitis around the pedicle screws (4 cases) and a combination of wound infection and osteomyelitis around the pedicle screws (1 case). Infections happened more frequently in the cases of interbody fusion (p=0.034), revision (p=0.087) and those done in the summer season (p=0.025). S. epidermidis, as the causative bacteria, was cultured from both the operation environments and wounds. Six precautions based on the preliminary results were instituted as follows; irrigation method reformation, delayed opening of instruments, turning-off local air conditioners, changing of gowns before instrumentation, local bone irrigation and limited indications for interbody fusion. After implementation, two cases (0.6%) of infection developed in group II (p=0.002, odds ratio=0.160; 95% confidence interval = 0.037 to 0.688). CONCLUSION: Wounds, grafted bones or instruments can be contaminated under longer-time exposure to operating room air and so produce interbody or pedicle osteomyelitis without wound infection. The precautions were effective to decrease the postoperative infection rates following posterior spinal fusion.

The Efficacy of Kyphoplasty on Osteoporotic Vertebral Compression Fracture : A 1-Year Follow-up Study / 대한척추외과학회지

STUDY DESIGN: This is a retrospective study. OBJECTIVE: We wanted to evaluate the efficacy of kyphoplasty for treating osteoporotic VCF and we wanted to determine the risk factors for additional VCF. SUMMARY OF THE LITERATURE REVIEW: Successful pain relief with performing kyphoplasty for VCF has been well documented. However, unsatisfactory reduction and additional VCF are remained problems for kyphoplasty. MATERIALS AND METHODS: Sixty-three patients who underwent kyphoplasty were followed up for more than 1 year. The degree of reduction of the collapsed vertebral height, the vertebral kyphotic angle, the regional Cobb's angle and the overall sagittal alignment, the visual analogue scale (VAS), the fracture configuration, the bone mineral density (BMD), the presence of intradiscal cement leakage and additional VCF were investigated. The risk factors for additional VCF were analyzed. RESULTS: In terms of deformity correction, the collapsed vertebral height were restored (67.3+/-15.6% to 82.5+/-11.8%), the vertebral kyphotic angle was improved (12.1+/-6.9degrees to 8.1+/-5.3degrees ), the degree of the regional Cobb's angle was reduced (3.1+/-4.5degrees ) and the overall sagittal balance was improved (1.7+/-5.3 cm to 0.5+/-3.9 cm) with clinical satisfaction (VAS: 6.9+/-1.3 points to 2.3+/-0.9 points). But less than 40% of the patients reached the expected reduction criteria (the vertebral height > 90%, the vertebral kyphotic angle and regional Cobb's angle reduction > 5degrees ). Additional VCF occurred in 10 patients (15.9%). The average BMD in the additional VCF group was T-score of -3.8 and that for the no-additional VCF group was T-score of -3.0 (p=0.025). The degree of reduction under general anesthesia was twice more than that under local anesthesia. Eleven cases (17.5%) of intradiscal cement leakages were noticed, but this showed no relevance to the fracture configurations and additional VCF. The overall sagittal alignment and cement volume showed no relevance to additional VCF. CONCLUSION: Kyphoplasty was excellent for pain reduction, but it was unsatisfactory for correcting deformity. Vertebral height correction was more effectively performed under general anesthesia. Additional VCF was caused by severe osteoporosis.

Oxford Phase 3 Unicompartmental Knee Arthroplasty: Minimum 5-year Follow-up Results

PURPOSE: We wanted to evaluate the postoperative clinical results, the complications and the survival rate of Oxford phase 3 unicompartmental knee arthroplasty (UKA), based on a prospective analysis and the follow-up study. MATERIALS AND METHODS: We operated on 142 patients, 180 cases of UKA using the Oxford phase 3 prosthesis from January 2002 to December 2002. Clinical assessments were made using the Knee Society score rating system. Among those, 152 cases (121 patients) were able to be followed up for at least 5 years after the operation. The mean patient age at the time of surgery was 61.1 years and the mean duration of follow-up was 5.5 years. RESULTS: For these 152 knees, the mean preoperative knee and function scores were 53.5 and 55.8, respectively, and they were improved to 88.7 and 83.1, respectively, at the last follow-up. The mean range of knee motion recovered to 133.1degrees and the mean tibiofemoral angle was changed to 4.9degrees of valgus. When we asked patients about their level of satisfaction, 88% of the patients said they were 'very satisfied' or 'satisfied'. There were 7 postoperative complications and the survival rate of the implant at 5 years was 96.8%. CONCLUSION: The Oxford phase 3 UKA was satisfactory for improving the clinical results, the subjective satisfaction of the patients and the survival rate of the implant.

Unicompartmental versus Total Knee Arthroplasty in the Same Patient / 대한정형외과학회잡지

PURPOSE: To compare the clinical and radiographic results of unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) in the same patient, and to investigate patient preference and satisfaction. MATERIALS AND METHODS: Among the 56 patients who underwent a UKA in one knee and a TKA in the opposite knee between January 2002 and December 2004, 51 patients were followed up. The average follow-up period was 4 years. RESULTS: The average Knee Society Score (KSS) improved from 53.5 preoperatively to 90.7 at last follow-up in the UKA knee, and from 50.4 to 89.8 in the TKA knee. The mean range of knee motion also improved from 124.7degrees to 133.2degrees in the UKA knee, and from 122.5degrees to 127.1degrees in the TKA knee. The tibiofemoral angle changed from 0.3degrees of varus to 5.6degrees of valgus in the UKA knee, and from 2.4degrees of varus to 5.8degrees of valgus in the TKA knee. For patient preference, 23 patients (45%) preferred the UKA knee and 19 patients (37%) preferred the TKA knee. Most patients (42 patients, 82%) reported being nvery satisfied' or nsatisfied' with both knees. CONCLUSION: The clinical and radiographic results of both the UKA and the TKA in the same patient were satisfactory at the 4-year follow-up. The UKA knee had a slightly better range of knee motion, but there was essentially no difference between the UKA knee and the TKA knee.

The Effect of Demineralized Bone Matrix as a Graft Enhancer in Posterior Lumbar Interbody Fusion Using Cage and Local Bone Chips / 대한척추외과학회지

STUDY DESIGN: A randomized, controlled study OBJECTIVES: We wanted to investigate whether osteogenesis can be enhanced when a small amount of demineralized bone matrix (1 cc/segment) is mixed with local bone chips. SUMMARY OF LITERATURE REVIEW: Demineralized bone matrix (DBM) has been used for spinal arthrodesis. However, there are only a few reports about its use as a composite graft with local bone chips for posterior lumbar interbody fusion MATERIALS AND METHODS: Degenerative spine patients, who would normally be treated by decompression and posterior lumbar interbody fusion with using a pedicle screw system and one cage, were randomly, prospectively selected for whether they would be treated with using local bone chips mixed with 1cc of DBM (Group I: 15 patients and 19 segments) or local bone chips (Group II: 12 patients and 13 segments) for graft material. The sampling bias was investigated for gender, age, endocrine diseases, previous operation, habits (alcohol drinking, smoking), steroid medication, bone mineral density and the amount of local bone. The amount of bone formation was measured at 6 months after operation. On the sagittal and coronal reconstruction CT images, the bone formation outside of the cage was measured, and this was interpreted in a "blinded"fashion by 2 independent doctors who did not take part in the operations. RESULTS: There was no sampling bias between the 2 groups except for age (Group I= 65.3+/-7.1, Group II=58.9+/-6.0, p=0.010). The ratio of local bone chips and DBM was 5.98:1 in Group I. There was moderate concurrence between the 2 interpreters (kappa coefficiency= 0.494, p<0.001 for the sagittal plain images and kappa co-efficiency=0.467, p<0.001 for the coronal plain images) and Group I showed significantly more bone formation (p=0.003). CONCLUSION: DBM that is mixed with local bone chips, even with small amount, enhanced bone formation in the posterior lumbar interbody fusion. This is regarded to act as a graft enhancer to increase the fusion rate, even when using local bone chips for graft material, for the cases that show unfavorable conditions for fusion or for the cases that are prone to loosening of hardware.

Mobile Bearing Subluxation after Unicompartmental Knee Arthroplasty Treated by Arthroscopy : A Case Report

A polyethylene mobile bearing subluxation is a very rare complication after mobile type unicompartmental knee arthroplasty (UKA). Of 436 cases which had been followed up for 1 year after UKA, we experienced 9 cases of bearing dislocation and a case of bearing subluxation. We treated a case of mobile bearing subluxation by arthroscopy. We achived stable reduction of the bearing using arthroscopic surgery and the patient was satisfied with the outcome. So we report a case of mobile bearing subluxation after UKA treated by arthroscopy.

Factors Affecting the Tibiofemoral Alignment in Minimally Invasive Unicompartmental Knee Arthroplasty / 대한정형외과학회잡지

PURPOSE: We analyzed affecting factors associated with the tibiofemoral alignment after minimally invasive unicompartmental knee arthroplasty (UKA) used to treat medial compartmental osteoarthritis of the knee. MATERIALS AND METHODS: From January 2003 to December 2003, 128 UKA were performed in 114 patients with minimally invasive surgery. The revealed tibiofemoral angle, tibial translation, posterior slope and the coronary orientation of the tibial and femoral component were measured using the preoperative and postoperative weight-bearing radiographs. The possible factors associated with the corrective tibiofemoral angle were analyzed statistically. RESULTS: The average corrective angle of the tibiofemoral axis was 5.8 degrees from varus 0.6 degrees preoperatively to valgus 5.2 degrees postoperatively. The average corrective angle of the tibiofemoral axis was 6.1 degrees in the mobile bearing group and 3.6 degrees in the fixed bearing group. There was significantly more corrective tibiofemoral angle postoperatively with a larger varus deformity of the knee preoperatively (p<0.0001). The corrective tibiofemoral angle had an increasing tendency with increasing bearing size but this was not statistically significant. Surgeons, the age of the patients, tibial translation, posterior slope of the tibial component, and coronary orientation of the tibial component and femoral component did not affect the degree of the corrective tibiofemoral angle. CONCLUSION: The average corrective angle of the tibiofemoral axis after minimally invasive UKA was 5.8 degrees. The preoperative tibiofemoral angle and the types of implants affected the postoperative tibiofemoral axis after minimally invasive UKA.

Revision of Total Hip Arthroplasty Using Extensively Porous-Coated Femoral Stem

Purpose: To report the outcomes of extensively porous-coated femoral stems based on diaphyseal fixation caused by extensive bone loss and osteoporosis of the proximal femur in revision total hip arthroplasty. Materials and Methods: 14 cementless femoral revision procedures performed between Aug, 2000 and Apr, 2003 were reviewed retrospectively. The follow up period ranged from 24 to 53 months, with an average of 33 months. The average age at surgery was 52.3 years, there were 10 males and 4 females. The reasons for the revision surgery were aseptic loosening in 11(78.7%) hips, progressive osteolysis in 1(7.1%), septic loosening in 1(7.1%) and periprosthetic fracture in 1(7.1%). Results: The Harris hip score improved from 50.4 points preoperatively to 88.5 points postoperatively. The complications encountered were a greater trochanteric fracture in 2 hips (14.3%), periprosthetic fracture in 1(7.1%), dislocation of the hip in 2(14.3%), and minimal thigh pain in 2(14.3%). Radiographic evidence of a bone ingrown stem was found in 11 hips (78.6%), and 3 hips (21.4%) showed stable fibrous fixation. Stem subsidence > 5mm was noticed in 1 hip (7.1%) and > 10mm in 2 (14.3%) but there was no further progression after 1 year. Moderate stress-shielding was noticed in 4 hips(28.6%). To date, no significant wear or osteolysis has been observed. Conclusion: An extensively porous-coated revision stem appears to be a reasonable choice in the presence of proximal femoral bone loss as a short term follow up. However, the concerns related to the postoperative complications will require a longer term follow up.

Short-Term Results and Early Complications of Minimally Invasive Unicompartmental Knee Arthroplasty

PURPOSE: To evaluate the short-term postoperative results of minimally invasive Unicompartmental Knee Arthroplasty(UKA) and to analysis the early postoperative complications. MATERIALS AND METHODS: 241 cases of UKA have been performed since January 2002 and followed up for average 27.3 months. Most of cases were medial compartment degenerative arthritis. All operative procedures were performed through minimally invasive technique. Clinical assessments were carried out using the Knee Society Score (KSS) rating system. RESULTS: The average knee score and the knee function score were improved from 55.4 and 55.4 points preoperatively to 89.3 and 84.9 points at final follow up. The average range of knee motion was 128.4 degrees preoperatively and recovered to 133.0 degrees at final follow up. Average preoperative tibiofemoral angle was 0.2 degrees of varus, which changed to 5.5 degrees of valgus at final follow up. Early complications after minimally invasive UKA were seen in 14 cases, 13 of which were occured within the first year. There were 4 polyethylene insert dislocation, 3 periprosthetic fracture, 2 femoral component loosening, 3 MCL injury and 1 infection. We also experienced 2 partial capsular rupture, 1 remained cement fragment in the joint and 1 impingement between osteophyte and stem. Two femoral component loosening and 1 MCL injury were combined with bearing dislocation. CONCLUSION: The short-term postoperative results of minimally invasive UKA were clinically satisfactory for improvement of knee score, function score and in the recovery of knee motion. The complication rate of UKA was relative low, but mostly caused by errors in surgical technique. Accurate surgical technique and enough experience were needed to improve clinical results and reduce the complications. When complications have occurred, better results are expected by more appropriate treatment for the cause of the complications.

Adjacent Segment failure after Lumbar Spine Fusion: Controlled Study for Risk Factors / 대한정형외과학회잡지

PURPOSE: To verify the risk factors associated with adjacent segment failure after lumbar spine fusion using pedicle screws. MATERIALS AND METHODS: The study group consisted of 35 patients who underwent lumbar spine fusion using pedicle screws and required revision surgery due to adjacent segment failure. These were compared with 73 control patients who were stratified according to the aspect of the surgical method and period. Gender, age, surgical procedures, the number of fusion segments, the fixation of the sacrum, initial instability and degeneration of the adjacent segments, lumbar lordosis, whole lumbar spondylosis, placement of most proximal screws, habitat, the demand of physical work, physical exercise, smoking, life style and BMI were reviewed retrospectively. RESULTS: Multivariate logistic regression showed that insufficient lumbar lordosis (odds ratio=3.041), instability of the distal adjacent segment (odds ratio=17.196), physically demanding jobs (odds ratio=2.462), delinquent exercise (odds ratio=2.534) and rural habitat (odds ratio=46.729) were associated with an increased incidence of adjacent segment failure. CONCLUSION: Insufficient lordosis, instability of the distal adjacent segment, physically demanding jobs, delinquent exercise and rural habitat were found to be risk factors. The postoperative life style has a large impact on adjacent segment failure. The extension of fusion to an unstable distal segment should be deliberated even though it is not attributable to the current symptoms. A reconstruction of the proper lordosis far outweights the other methodological factors.

Treatment of Soft Tissue Defect after TKA Using Dorsalis Pedis Flap: A Case Report

Skin and soft tissue defect developed after total knee arthroplasty have important influence on prosthesis survival. Thus an adequate treatment have to be performed according to the size and depth of defect. We report a case of dorsalis pedis flap for treatment of skin and soft tissue defect combined with infection after conversion total knee arthroplasty and its good result with a review of the literature.

Fracture of the Medial Tibial Condyle in Unicompartmental Knee Arthroplasty: Report of 3 Cases

Unicompartmental knee arthroplasty(UKA) has become a popular method of treatment for medial osteoarthritis recently. UKA is now performed through minimally invasive surgery and it offers potential advantages including less postoperative pain, reduced blood loss, early rehabilitation, quicker recovery of range of motion and lower complication rate. Fracture of the medial tibial condyle is a relatively rare complication of UKA but it affects the prognosis of the implants and patient. We experienced 3 cases of medial tibial condylar fracture after UKA. Two cases were managed with open reduction and screw fixation, and one case was treated conservatively. All of the three patients were satisfied with the final outcome, so we report the cases of the medial tibial condylar fracture after UKA.