Down-Regulation of Transglutaminase 2 Stimulates Redifferentiation of Dedifferentiated Chondrocytes through Enhancing Glucose Metabolism.

Expansion of chondrocytes for repair of articular cartilage can lead to dedifferentiation, making it difficult to obtain a sufficient quantity of chondrocytes. Although previous studies have suggested that culture in a three-dimensional environment induces redifferentiation of dedifferentiated chondrocytes, its underlying mechanisms are still poorly understood in terms of metabolism compared with a two-dimensional environment. In this study, we demonstrate that attenuation of transglutaminase 2 (TG2), a multifunctional enzyme, stimulates redifferentiation of dedifferentiated chondrocytes. Fibroblast-like morphological changes increased as TG2 expression increased in passage-dependent manner. When dedifferentiated chondrocytes were cultured in a pellet culture system, TG2 expression was reduced and glycolytic enzyme expression up-regulated. Previous studies demonstrated that TG2 influences energy metabolism, and impaired glycolytic metabolism causes chondrocyte dedifferentiation. Interestingly, TG2 knockdown improved chondrogenic gene expression, glycolytic enzyme expression, and lactate production in a monolayer culture system. Taken together, down-regulation of TG2 is involved in redifferentiaton of dedifferentiated chondrocytes through enhancing glucose metabolism.

Enhancement of Matrix Metalloproteinase-2 (MMP-2) as a Potential Chondrogenic Marker during Chondrogenic Differentiation of Human Adipose-Derived Stem Cells.

Human adipose-derived stem cells (hASCs) have a capacity to undergo adipogenic, chondrogenic, and osteogenic differentiation. Recently, hASCs were applied to various fields including cell therapy for tissue regeneration. However, it is hard to predict the direction of differentiation of hASCs in real-time. Matrix metalloproteinases (MMPs) are one family of proteolytic enzymes that plays a pivotal role in regulating the biology of stem cells. MMPs secreted by hASCs are expected to show different expression patterns depending on the differentiation state of hASCs because biological functions exhibit different patterns during the differentiation of stem cells. Here, we investigated proteolytic enzyme activity, especially MMP-2 activity, in hASCs during their differentiation. The activities of proteolytic enzymes and MMP-2 were higher during chondrogenic differentiation than during adipogenic and osteogenic differentiation. During chondrogenic differentiation, mRNA expression of MMP-2 and the level of the active form of MMP-2 were increased, which also correlated with Col II. It is concluded that proteolytic enzyme activity and the level of the active form of MMP-2 were increased during chondrogenic differentiation, which was accelerated in the presence of Col II protein. According to our findings, MMP-2 could be a candidate maker for real-time detection of chondrogenic differentiation of hASCs.

Painful patellar clunk or crepitation of contemporary knee prostheses.

BACKGROUND: Painful patellar clunk or crepitation (PCC) is a resurgent complication of contemporary posterior-stabilized TKA. The incidence, time to presentation, causes, and treatment of PCC still remain controversial. QUESTIONS/PURPOSES: We therefore (1) compared the incidence of PCC with five contemporary TKA designs, (2) evaluated the time to presentation, (3) identified possible etiologies, and (4) determined recurrence rate and change in knee functional scores after treatment for PCC. METHODS: We reviewed 580 patients who had 826 posterior-stabilized TKAs involving five different designs. The incidences of PCC were compared among the prostheses. The knees were divided into two groups depending on the development of PCC, and possible etiologic factors of PCC, including prosthesis design and surgical or radiographic variables, were compared between groups. We investigated the onset time of PCC and evaluated treatment results by knee outcome scores. Minimum followup was 2.0 years (mean, 3.9 years; range, 2.0-9.8 years). RESULTS: The PCC incidence was higher in the Press-Fit Condylar(®) Sigma(®) Rotating Platform/Rotating Platform-Flex Knee System (11 of 113 knees, 9.7%) than in the others (seven of 713 knees, 1.0%). Increased risk of PCC was associated with using a specific prosthesis and patellar retention. PCC occurred in all cases within a year after TKA (mean, 7.4 months). Arthroscopic treatment (16 knees) and patellar replacement (two knees) improved knee scores, with no recurrence observed over an average followup of 29 months. CONCLUSIONS: Prosthesis design and patellar retention were associated with PCC. Surgery resolved the PCC.

Preservation of the posterior cruciate ligament is not helpful in highly conforming mobile-bearing total knee arthroplasty: a randomized controlled study.

PURPOSE: The purpose of this study is to investigate whether the preservation of the posterior cruciate ligament (PCL) can be helpful for improving kinematics and clinical outcome in highly conforming mobile-bearing total knee arthroplasty (TKA). METHODS: Ninety osteoarthritic knees were randomly allocated to either the PCL-preserving group or the PCL-sacrificing group. Passive kinematics was recorded with a navigation system immediately after implantation. Three parameters (anterior/posterior translation, varus/valgus rotation, and internal/external rotation) were analysed from 0° to 120° flexion. RESULTS: The PCL-preserving group (42 knees) had more varus rotation over 90° flexion (p < 0.05) and more anterior translation of the femur in all ranges of flexion (p < 0.05) than those in the PCL-sacrificing group (44 knees). There was no difference in the internal/external rotation (p > 0.05). The range of motion, functional scores, and radiographic results did not significantly differ between the two groups at the final follow-up. Three knees in the PCL-preserving group were revised: two presented with instability caused by traumatic attenuation of the PCL and one with subluxation of the insert due to a tight PCL. CONCLUSION: The preservation of the PCL was not helpful for improving kinematics and clinical outcome in highly conforming mobile-bearing TKA.

Management of cerebrospinal fluid leakage after anterior decompression for ossification of posterior longitudinal ligament in the thoracic spine: the utilization of a volume-controlled pseudomeningocele.

STUDY DESIGN: Retrospective review OBJECTIVE: To determine the efficacy of management of cerebrospinal fluid (CSF) leakage after the anterior thoracic approach. SUMMARY OF BACKGROUND DATA: CSF leakage after incidental durotomy commonly occurs after anterior thoracic ossification of posterior longitudinal ligament (OPLL) surgery. Pseudomeningocele will invariably form under such circumstances. Among them, uncontrolled CSF leakage with a fistulous condition is problematic. As a solution, we have managed these durotomies with chest drains alone without any CSF drainage by the concept of a "volume-controlled pseudomeningocele." METHODS: Between 2001 and 2009, CSF leakage occurred in 26 patients (37.7%) of the total 69 patients who underwent anterior decompression for thoracic OPLL. In the initial 11 cases, subarachnoid drainage was utilized as an augmentive measure in combination with chest tube drainage in the postoperative period (group A). In the subsequent 15 cases, the durotomy was managed in a similar manner but in the absence of any subarachnoid drainage (group B). Various parameters such as the duration of postoperative hospital stay, clinical outcome score, drainage output, resolution of CSF leakage, complications, and additional surgery performed were analyzed and compared between the 2 groups. A resolution of the CSF leakage grading system was also proposed for the residual pseudomeningocele that formed in each group. RESULTS: There were statistically no significant differences in the outcome parameters between the 2 groups and also in patients with grade I or grade II residual pseudomeningocele of the new grading system. Two complications occurred in group A. No reexploration for persistent CSF leakage was required in both groups. CONCLUSIONS: CSF leakage managed with controlled chest tube drainage can produce a comparable result with those with additional subarachnoid drainage when watertight dural repair is impossible. The concept of controlled pseudomeningocele may be a useful and practical technique for the treatment of CSF leakage after anterior thoracic OPLL surgery.

Cervical cord compression presenting with sciatica-like leg pain.

Sciatica-like leg pain can be the main presenting symptom in patients with cervical cord compression. It is a false localizing presentation, which may lead to missed or delayed diagnosis, resulting in the wrong plan of management, especially in the presence of concurrent lumbar lesions. Medical history, physical findings and the results of imaging studies were reviewed in two cases of cervical cord compressions, which presented with sciatica-like leg pain. There was multi-level cervical spondylosis with cord compression in the first patient and the second patient had two levels of cervical disc herniation with cord compression. In both cases, there were co-existing lumbar lesions, which could be responsible for the presentation of the leg pain. Cervical blocks were diagnostic in identifying the level responsible for the leg pain and it was confirmed so after cervical decompressive surgery in both cases, which brought significant pain relief. Funicular leg pain is a rare presentation of cervical cord compression. It is a referred pain due to the irritation of the ascending spinothalamic tract. Cervical blocks were successful in identifying the cause of funicular pain in our cases and this may pave the way for further studies to establish the role of cervical blocks as a diagnostic tool for funicular pain caused by cord compression.

Plain radiograph fails to reflect the alignment and advantages of navigation in total knee arthroplasty.

The study purposed to determine if a navigation in total knee arthroplasty (TKA) leads to accurate limb alignment and component position than the conventional technique as measured by full length standing radiographs and to evaluate the correlation between navigation and radiographic measurements. A total of 160 knees underwent navigation (n = 80) or conventional (n = 80) TKAs. The frontal femoral alignment was more accurate in navigation TKAs, whereas mechanical axis and frontal tibial alignment were similar in both techniques. Although the intraoperative navigation alignment showed no outliers, postoperative radiographic measure resulted as much as 20% of outliers, and there was no correlation between the two measurements. This lack of correlation and inherent limitations in measuring TKA alignment may bring to question if plain radiograph are useful to determine if alignment achieved by navigation is accurate.

Spinal cord glioblastoma multiforme of conus medullaris masquerading as high lumbar disk herniation.

BACKGROUND: A case of primary intramedullary glioblastoma occurring at conus medullaris is presented, which was initially undetected and misdiagnosed as L1 through L2 disk herniation. CASE DESCRIPTION: After the performance of L1 through L2 discectomy, the patient's initial painful symptom did not subside. The patient then developed a progressive paraparesis. The outside surgeons only predicted the possibility of reherniation or hematoma collection at the former operated level as the diagnosis for the paraparesis. After the patient was transferred to our hospital and after a thorough review of initial and follow-up magnetic resonance imaging with enhancement before second operation, an enlarged conus medullaris with mixed signal intensity was noted without evidence of re-herniation or hematoma collection. The patient underwent reoperation with biopsy of the intramedullary lesion, which was histologically confirmed as primary glioblastoma. CONCLUSION: Careful neurologic and radiologic evaluations should precede before any decision of surgical intervention as intramedullary and degenerative pathologies may coexist in the upper lumbar spine.

An analysis of general surgery-related complications in a series of 412 minilaparotomic anterior lumbosacral procedures.

OBJECT: Anterior lumbar surgery is associated with certain perioperative visceral and vascular complications. The aim of this study was to document all general surgery-related adverse events and complications following minilaparotomic retroperitoneal lumbar procedures and to discuss strategies for their management or prevention. METHODS: The authors analyzed data obtained in 412 patients who underwent anterior lumbosacral surgery between 2003 and 2005. The series comprised 114 men and 298 women whose mean age was 56 years (range 34-79 years). Preoperative diagnoses were as follows: isthmic spondylolisthesis (32%), degenerative spondylolisthesis (24%), instability/stenosis (15%), degenerative disc disease (15%), failed-back surgery syndrome (7%), and lumbar degenerative kyphosis or scoliosis (7%). A single level was exposed in 264 patients (64%), 2 in 118 (29%), and 3 or 4 in 30 (7%). The average follow-up period was 16 months. RESULTS: Overall, 52 instances of complications and adverse events occurred in 50 patients (12.1%), including sympathetic dysfunction in 25 (6.06%), vascular injury repaired with/without direct suture in 12 (2.9%), ileus lasting > 3 days in 5 (1.2%), pleural effusion in 4 (0.97%), wound dehiscence in 2 (0.49%), symptomatic retroperitoneal hematoma in 2 (0.49%), angina in 1 (0.24%), and bowel laceration in 1 patient (0.24%). There was no instance of retrograde ejaculation in male patients, and most complications had no long-term sequelae. CONCLUSIONS: This report presents a detailed analysis of complications related to anterior lumbar surgery. Although the incidence of complications appears low considering the magnitude of the procedure, surgeons should be aware of these potential complications and their management.

Purified extract from Clematis mandshurica prevents adenoviral-TRAIL induced apoptosis on rat articular chondrocytes.

Since TNF-related apoptosis inducing ligand (TRAIL) is one of several apoptotic stimuli on articular chondrocytes, the modulation of the mechanism mediated by TRAIL could be considered as a novel strategy for the treatment of osteoarthritis (OA). Previous studies demonstrated that Clematis mandshurica prevents staurosporin-induced apoptosis in articular chondrocytes. This study was undertaken to examine whether Clematis mandshurica could prevent TRAIL-induced apoptosis in articular chondrocytes. Our data show that Clematis mandshurica prevents adenoviral TRAIL (Ad-TRAIL)-induced apoptosis in primary cultured articular chondrocytes. Clematis mandshurica prevents Ad-TRAIL-induced down-regulation of 14-3-3 and phosphorylated Akt. In addition, Clematis mandshurica treatment prevents the Ad-TRAIL-induced reduction of the interactions between 14-3-3 with phospho-ser112-Bad and phospho-ser136-Bad, and BcL-xL with phospho-ser155-Bad. A better understanding of the mechanism underlying inhibition of apoptosis in OA chondrocytes by Clematis mandshurica might lead to the development of a new therapeutic strategy for OA.

Anterior minimally invasive approaches for the cervical spine.

The percutaneous endoscopic discectomy (PECD) with working channel endoscope (WSH) endoscopy set could be a safe and effective minimally invasive surgical option for non-contained cervical disc herniation in selected patients. Judicious use of the end-firing Ho: Yttrium-Aluminium-Garnet (YAG) laser for both decompressive and thermoannuloplasty effect during the percutaneous endoscopic cervical annuloplasty (PECA) is mandatory in order to prevent possible injury to spinal cord or root. Although the percutaneous cervical stabilization (PCS) using the cervical B-Twin may not completely replace the cervical arthrodesis, this minimally invasive procedure can preserve anterior structures and thereby retain segmental stability and prevent the possible kyphotic progression after fusion surgery. To our knowledge, these minimally invasive procedures for cervical spine disease may serve to minimize surgery-induced complications associated with anterior cervical discectomy and fusion (ACDF).

Gap healing after medial open-wedge high tibial osteotomy using injectable beta-tricalcium phosphate.

PURPOSE: The study aim was to evaluate gap healing after medial open-wedge high tibial osteotomy (MOWHTO) using novel injectable beta-tricalcium phosphate (ß-TCP) as gap filler. We also aimed to evaluate radiographic and clinical outcome of MOWHTO using injectable ß-TCP. METHODS: Consecutive 28 patients underwent MOWHTO using anatomical locking plate fixation, and ß-TCP was injected as gap filler. Serial radiographs and computed tomography were taken at postoperative 3 and 12 months, and gap healing was assessed. Lower extremity alignment was measured on radiographs, and clinical outcome was evaluated by determining International Knee Documentation Committee, Western Ontario and McMaster Universities Arthritis Index, and visual analogue scales for pain scores. RESULTS: Progress of bone union was found on plain radiographs, and the mean ratio (ß-TCP/host bone) of computed tomography attenuation values significantly changed from postoperative 3 months to 12 months, which indicates maturation of ß-TCP. The average mechanical femoro-tibial angle changed from 4.1° varus (preoperative) to 4.8° valgus (3 months) and maintained until 12 months (4.3° valgus). All clinical outcome scores were significantly improved and no significant complication occurred. CONCLUSION: Using injectable ß-TCP as gap filler for MOWHTO resulted in satisfactory gap healing without complication. Radiographic and clinical results were satisfactory. The injectable ß-TCP can be a safe and effective option for gap filling after MOWHTO.

Clinical Relevance of Classifying Massive Rotator Cuff Tears: Results Based on Functional and Radiological Findings After Arthroscopic Repair.

BACKGROUND: Studies on the results of arthroscopic repair of massive rotator cuff tears have reported widely varied prognoses. Among other factors, the sizable discrepancy can be attributable to the fact that the current definition of massive rotator cuff tears covers an extensive area of tendons. HYPOTHESIS: Functional and radiological results according to subgroups would show significant inter-subgroup differences preoperatively and postoperatively. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: A total of 104 patients who required arthroscopic repair for massive rotator cuff tears were prospectively evaluated. The patients were allocated into 3 groups according to tendon involvement as diagnosed by preoperative magnetic resonance imaging: group 1 (anterosuperior type involving the subscapularis and supraspinatus), group 2 (posterosuperior type involving the infraspinatus and supraspinatus), and group 3 (anteroposterior type involving the subscapularis, supraspinatus, and infraspinatus). We compared functional results (at 2 years postoperatively) and radiological findings (at 1 year postoperatively) for each group. RESULTS: There were 34 patients in group 1, 54 in group 2, and 16 in group 3. In all 3 groups, functional results significantly improved after surgery. There were no statistically significant intergroup differences in functional results among the 3 groups. On the radiological evaluations, each group (groups 1, 2, and 3) showed a significantly different result in the preoperative acromiohumeral distance (AHD) (7.19, 5.44, and 5.22 mm, respectively), tear size (38.8, 39.3, and 46.4 mm, respectively), extent of retraction (33.9, 40.0, and 41.4 mm, respectively), postoperative AHD (8.92, 7.37, and 6.71 mm, respectively), and retear rate (23.5%, 51.9%, and 56.2%, respectively) ( P < .001 for all). CONCLUSION: Massive rotator cuff tears can be divided into 3 types: anterosuperior (group 1), posterosuperior (group 2), and anteroposterior (group 3). Each group has distinctive characteristics and shows different results in the preoperative AHD, tear size, extent of retraction, postoperative AHD, and retear rate, which provide a reasonable basis for categorization. So far, massive rotator cuff tears have only been broadly defined, consequently being understood as a single category by many. However, to clearly understand and evaluate this injury, we suggest identifying differences within the category through proper subclassification.

Revision surgery of the lumbar spine: anterior lumbar interbody fusion followed by percutaneous pedicle screw fixation.

OBJECT: The aim of this study was to evaluate the efficacy of anterior lumbar interbody fusion (ALIF) augmented by percutaneous pedicle screw fixation (PSF) for revision surgery in the lumbar spine and to determine the prognostic factors affecting surgical outcomes. METHODS: The population included 54 consecutively treated patients in whom revision surgery involving ALIF with PSF was performed between 2001 and 2004. There were 22 men and 32 women, whose mean age was 59.5 years (range 25-78 years). The diagnoses prior to revision ALIF were as follows: degenerative disc disease in 25 patients, instability/spondylolisthesis in 15, recurrent disc herniation in seven, and pseudarthrosis in seven. The mean follow-up period was 24 months (range 12-52 months). The mean visual analog scale score for back and leg pain decreased, respectively, from 7.8 to 2.3 and 8.0 to 2.3 (p < 0.001). The mean Oswestry Disability Index score improved from 70 to 25% (p < 0.001). Radiological evidence of fusion was noted in 52 of 54 patients. The mean preoperative segmental lordosis, whole lumbar lordosis, and sacral tilt were 15.2, 35.5, and 28.3 degrees, respectively; these values were significantly increased to 20.4, 40.7, and 31.4degrees, respectively, after revision surgery (p < 0.001). The increase in sacral tilt was positively correlated with improvement in back pain (p = 0.028) and functional status (p = 0.025). CONCLUSIONS: The results demonstrate that ALIF followed by PSF can be an effective alternative in revision surgery of the lumbosacral spine in selected cases. Not only can solid fusion be achieved, sagittal alignment can also be restored in the majority of patients.

Immediate pain improvement is a useful predictor of long-term favorable outcome after percutaneous laser disc decompression for cervical disc herniation.

OBJECTIVE: The purpose of this study was to evaluate the long-term clinical outcome of percutaneous laser disc decompression (PLDD) for cervical disc herniation and to identify factors affecting long-term favorable outcome. BACKGROUND DATA: PLDD using the Ho:YAG laser has been regarded as an effective alternative for soft disc herniation. However, little is known about long-term favorable outcome parameters. METHODS: We retrospectively reviewed the clinical and radiological data of 60 patients who underwent PLDD with laser-assisted spinal endoscopy (LASE) for contained cervical soft disc herniation from January 1998 to January 2000. The clinical outcome was measured using the Macnab criteria. Statistical analysis was performed using Fisher's exact test. Sex, age, operated level and location of disc herniation, amount of laser energy, and time for symptom improvement were selected as parameters. RESULTS: The mean follow-up period was 71.0 months (range, 59-83 months). The mean age was 45.7 years (range, 26-68 years), and the mean symptom duration was 13.0 months (range, 2-60 months). The Visual Analogue Scale (VAS) score was significantly improved from 7.9 preoperatively to 2.6 at the final follow-up (p < 0.001). At the final follow-up, 51 (85.0%) patients achieved a favorable outcome. Immediate (within 24 h) pain relief was achieved in 19 patients, and it was strongly related to long-term success (p = 0.006). CONCLUSION: The long-term clinical outcome of PLDD with LASE was fairly good, with a success rate of 85%. Immediate pain relief is a useful prognostic factor predicting favorable outcome following the procedure.

The Efficacy of Bioabsorbable Mesh in Craniofacial Trauma Surgery.

BACKGROUND: The ultimate goal of craniofacial reconstructive surgery is to achieve the most complete restoration of facial functions. A bioabsorbable fixation system which does not need secondary operation for implant removal has been developed in the last decade. The purpose of this study is to share the experience of authors and to demonstrate the efficacy of bioabsorbable mesh in a variety of craniofacial trauma operations. METHODS: Between October 2008 and February 2015, bioabsorbable meshes were used to reconstruct various types of craniofacial bone fractures in 611 patients. Any displaced bone fragments were detached from the fracture site and fixed to the mesh. The resulting bone-mesh complex was designed and molded into an appropriate shape by the immersion in warm saline. The mesh was molded once again under simultaneous warm saline irrigation and suction. RESULTS: In all patients, contour deformities were restored completely, and bone segments were fixed properly. The authors found that the bioabsorbable mesh provided rigid fixation without any evidence of integrity loss on postoperative computed tomography scans. CONCLUSION: Because bioabsorbable meshes are more flexible than bioabsorbable plates, they can be molded and could easily reconstruct the facial bone in three dimensions. Additionally, it is easy to attach bone fragments to the mesh. Bioabsorbable mesh and screws is effective and can be easily applied for fixation in various craniofacial trauma reconstructive scenarios.

Feasibility study for the assessment of the exposed dose with TENORM added in consumer products.

Consumer products including naturally occurring radioactive material have been distributed widely in human life. The potential hazard of the excessively added technically enhanced naturally occurring radioactive material (TENORM) in consumer products should be assessed. The aim of this study is to evaluate the organ equivalent dose and the annual effective dose with the usage of the TENORM added in paints. The activities of gammas emitted from natural radionuclides in the five types of paints were measured with the high-purity germanium detector, and the annual effective dose was assessed with the computational human phantom and the Monte Carlo method. The results show that uranium and thorium series were mainly measured over the five paints. Based on the exposure scenario of the paints in the room, the highest effective dose was evaluated as <1 mSv y(-1) of the public dose limit.

Novel method for setting up 3D navigation system with skin-fixed dynamic reference frame in anterior cervical surgery.

PURPOSE: To introduce easy and useful methods using 3D navigation system with skin-fixed dynamic reference frame (DRF) in anterior cervical surgery and to validate its accuracy. METHODS: From September 2012 to May 2013, 31 patients underwent anterior cervical surgery and a total of 48 caspar distraction pins were inserted into each cervical vertebra. Every operation was performed using O-arm® navigation system with skin-fixed DRF. To validate the accuracy of these methods, a custom-made metal sleeve was used. In surgical field, through the metal sleeve, the tip of a navigation probe promptly contacts to the tip of caspar pin. We measured the vertical and horizontal distances and the angular deviation in sagittal plane between the caspar pin and the navigation probe on the virtual images and evaluated accuracy of navigation system with skin fixed DRF. RESULTS: Total 31 (males 20, females 11) patients and 48 caspar pins were included in this study. The mean horizontal distance between the caspar pin and the navigation probe displayed in navigation monitor was 0.49 ± 0.71 mm. The mean vertical distance between the caspar pin and the navigation probe displayed in navigation monitor was 0.88 ± 0.93 mm. And the mean angular deviation in sagittal plane between the caspar pin and the navigation probe displayed in navigation monitor was 0.59 ± 0.55°. CONCLUSIONS: 3D navigation system with skin-fixed DRF in anterior cervical surgery is a simple and reliable method and it can be a helpful supplement to a spine surgeon's judgement.

Outcomes of the different types of total knee arthroplasty with the identical femoral geometry.

PURPOSE: There are controversies around the role of the posterior cruciate ligament and the effect of design modifications for high flexion in total knee arthroplasty (TKA). So, we compared the clinical outcomes of the cruciate retaining (CR), posterior stabilized (PS), and high flexion posterior stabilized (F-PS) designs in TKA with identical femoral geometry. MATERIALS AND METHODS: One hundred seventy nine knees with 3 different types of prostheses after a minimum 5-year follow-up were enrolled in this retrospective study: 45 with CR, 40 with PS and 94 with F-PS. The mean ages of these groups were 65.7, 67.2, and 67.5, and the mean durations of follow-up were 8.1, 8.0, and 6.8 years, respectively. We compared the range of motion, functional outcomes, and radiographic measurements at the 2-year follow-up and last follow-up. RESULTS: The maximal flexion angle was significantly lower in the CR group than the F-PS group at the 2-year follow-up. However, there was no significant difference at the last follow-up. Functional outcomes and survival rate of the three groups were similar at the last follow-up. CONCLUSIONS: Three different types of TKAs (CR, PS and F-PS) with identical femoral geometry showed similar mid-term outcomes with regard to the range of motion, functional outcomes and survival rate.

Surgical site infection in spinal surgery: detection and management based on serial C-reactive protein measurements.

OBJECT: C-reactive protein (CRP) is a well-known sensitive laboratory parameter that shows an increase within 6 hours after the onset of bacterial infection. In relation to surgery, a normal CRP response is a rapid increase followed by a gradual reduction, eventually returning to the normal range. The goal of this study was to determine the diagnostic significance of CRP as a detector for early onset surgical site infection in spinal surgery and to discuss effective medical treatment through clinical interpretation and application of the measured CRP values. METHODS: A prospective study was performed in 348 consecutive cases involving patients who underwent spinal surgery under general anesthesia between February and September 2008. Blood samples were obtained preoperatively and on postoperative Days 1, 3, and 5 in patients undergoing single-level decompression surgery. An additional blood specimen was obtained at postoperative Day 7 in patients requiring more extensive surgeries. Recorded laboratory results were compared with the patients' clinical course to determine the diagnostic significance of CRP. All of the patients received intravenous prophylactic antibiotic therapy. Once an abnormal response of CRP, indicated by a tendency toward continuous elevation, was noted on Day 5 or Day 7, the prophylactic antibiotics were replaced with another regimen and administration was resumed along with careful observation for signs of surgical site infection. RESULTS: Monitoring of CRP revealed a characteristic increase and decrease pattern in 332 of 348 patients (95.4%) showing a normal clinical course with regard to early infectious complications. The mean measured CRP (reference range < 4 mg/L) averaged 14.9 +/- 20.3 mg/L on Day 1, 15.4 +/- 25.1 mg/L on Day 3, and 7.9 +/- 13.3 mg/L on Day 5. In contrast, there were 16 cases (4.6%) of abnormal CRP responses resulting in the resumption of intravenous antibiotic treatment, which included a second rise (in 12 cases) and a steady rise (in 4) in the CRP value. Five (1.4%) of 16 patients experienced infectious complications related to spinal surgery. Three patients (0.9%) received long-term antibiotic therapy for 4-6 weeks; however, all patients recovered with medical treatment alone and did not experience gross wound disruption or subsequent discitis. As a predictor for early wound infection, the sensitivity, specificity, positive predictive value, and negative predictive value for abnormal CRP responses were calculated as 100%, 96.8%, 31.3%, and 100%, respectively. CONCLUSIONS: The above results demonstrate that CRP screening is a simple and reliable test for the detection of early infectious complications after spinal surgery. Close observation and appropriate medical management should be performed in a timely fashion when abnormal CRP responses are observed at 5 or 7 days after surgery.