The rapid recovery study: Cyclobenzaprine's effect on recovery following joint arthroplasty.

Introduction: Skeletal muscle relaxants have previously not been examined in multimodal anesthesia regimens following joint arthroplasty. We sought to evaluate cyclobenzaprine's effect on postoperative opioid consumption as well as surgical recovery following joint arthroplasty. Materials and methods: In this retrospective cohort study, 471 patients undergoing 554 joint arthroplasty procedures were evaluated. Patients were divided into cohorts who did and did not receive cyclobenzaprine postoperatively, and postoperative opioid consumption and functional recovery measures were recorded in each cohort. Results: In the unadjusted model, the cyclobenzaprine cohort experienced a 1.11 increase in pain scores on postoperative day zero (95% CI (0.60, 1.62), p < 0.0001). After adjusting for age, sex, BMI, CCI, perioperative MME, laterality, procedure, anesthesia, pre-op opioid use, pre-operative other controlled substance uses and pre-op benzodiazepine use, the cyclobenzaprine cohort's pain scores were 1.08 units higher at rest (95% CI (0.59, 1.56), p < 0.0001) and 1.25 units higher with activity on postoperative-day-zero (95% CI (0.78, 1.72), p < 0.0001). Both cohorts experienced statistically insignificantly different changes in mobility scores between postoperative day zero and postoperative day one, range of motion at 6 and 12 weeks, and readmission in <90 days. Postoperative morphine milliequivalents were insignificantly different between cohorts after controlling for pain in all models (base model mean ratio: 1.06, 95% CI (0.87,1.29), p = 0.5599) (Full model mean ratio: 1.09, 95% CI (0.91,1.30), p = 0.3608). Conclusions: Cyclobenzaprine shows utility in a multimodal anesthetic approach after joint arthroplasty in patients with higher baseline pain.

Medial Osteoarthritis in an ACL-Deficient Knee: A Critical Analysis Review.

¼: In anterior cruciate ligament (ACL)-deficient knees, treatment of medial compartment osteoarthritis (OA) that is refractory to nonoperative modalities is a controversial subject. ¼: Currently available treatment options include unicompartmental knee arthroplasty (UKA) with or without ACL reconstruction (ACLR), high tibial osteotomy (HTO) with or without ACLR, and total knee arthroplasty (TKA). ¼: Each treatment option has its own risks and benefits, and the evidence that is reviewed in this article suggests that patient characteristics guide treatment selection. ¼: Future high-quality prospective studies that directly compare all 3 of the modalities are necessary to determine the best treatment option for different patient populations.

Outcome reporting patterns in total knee arthroplasty: A systematic review.

BACKGROUND: Total knee arthroplasty (TKA) is one of the most effective ways to treat end-stage painful conditions of the knee. However, non-standardized reporting patterns can make quantitative analysis of patient outcomes difficult. METHODS: A systematic review of the literature was performed using keywords "total knee arthroplasty" and "total knee replacement." Randomized controlled trials (RCTs) meeting the inclusion criteria were sorted and reviewed. Type of study, outcome measures used to report their results, and the actual results were recorded. Quantitative analysis was performed. RESULTS: A total of 233 RCTs were included. There was significant variability in the reporting of short term and long term outcomes in total knee arthroplasty. The most common treatment domains in order of decreasing frequency were objective knee function, subjective knee function, perioperative complications, and pain. Range of motion was the most common outcome metric reported in all the RCTs and also was the most common metric used to assess objective knee function. The most common patient reported outcome measure used to assess postoperative function was the Knee Society Score followed by Knee Injury and Osteoarthritis Outcome Score. The Visual Analog Scale was the most common measurement tool used to assess postoperative pain. Most studies assessed patient outcomes in three treatment domains. None reported outcomes in all seven domains. CONCLUSION: There is significant variability in outcome reporting patterns in TKA literature. Most studies do not track outcomes comprehensively, with a significant minority of the RCTs tracking outcomes in only one treatment domain.

Medial Unicompartmental Knee Arthroplasty for the Treatment of Focal Femoral Osteonecrosis.

BACKGROUND: Previous research has indicated that unicompartmental arthroplasty may be an effective treatment for focal osteonecrosis in the knee; however, these reports have been composed of small patient cohorts and without characterization of the osteonecrotic lesions. Therefore, the purpose of this study was to investigate the effectiveness of unicompartmental arthroplasty for the treatment of focal osteonecrosis within the medial femoral condyle including an assessment of lesion size. METHODS: A consecutive series of >5,000 unicompartmental knee arthroplasties performed at a single institution was retrospectively reviewed to identify cases of medial femoral condyle osteonecrosis with a minimum 2-year follow-up. Lesion size was classified according to the ratio of lesion width to condylar width, as well as lesion depth relative to condylar depth. Patient-reported outcome measures and need for a revision procedure were studied. RESULTS: Sixty-four patients (32 males, 32 females; 65 knees) with a mean age of 64 years were included. The mean patient follow-up was 5.3 years (range, 2 to 12 years). The mean ratio of lesion width to condylar width was 64%, the mean lesion depth was 1.11 cm, and 82% of cases demonstrated subchondral collapse. At the time of the latest follow-up, patients demonstrated substantial improvements in the pain, function, and clinical components of the Knee Society Score, by 36, 25, and 51, respectively. Four patients (6%) required a revision, of which only 1 was for aseptic loosening of the femoral component. CONCLUSIONS: Unicompartmental arthroplasty is an effective treatment for advanced-stage focal osteonecrosis of the medial femoral condyle. Loss of component fixation to the femoral condyle did not appear to be a substantial concern because there was only 1 femoral failure as a result of aseptic loosening, despite lesions affecting a significant portion of the femoral condyle. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Reduced Thigh Pain with Short Femoral Stem Design Following Direct Anterior Primary Total Hip Arthroplasty.

BACKGROUND: Thigh pain is a variably reported symptom in the postoperative period following primary total hip arthroplasty (THA) with a well-fixed cementless femoral implant. While research has identified stem size, stem alignment, and differences in modulus of elasticity between implant and host bone as potential sources of thigh pain, only one study has specifically examined the impact of variation in implant design within a single femoral stem design. The purpose of this work was to determine whether there were differences in the pain experienced by patients treated with two design variants of a femoral stem during direct anterior THA. MATERIALS AND METHODS: Patients undergoing primary direct anterior THA at a single center between 2011-2015 were included in the study. Those patients suffering extensive comorbidities and postoperative complications were excluded from analysis. Study subjects completed a pain drawing and scale questionnaire for the operative hip at least one year following surgery. A cementless, single-taper wedge, titanium femoral component design available in short- and standard-length variations was used in all cases. Pain outcomes were compared between these two femoral stem options. RESULTS: A total of 1347 patients (1536 THA) met inclusion criteria for the study and surveys were returned for 820 of these THAs. Demographic data and UCLA activity scores were similar between cohorts of patients receiving the short- and standard-length components. The most common locations of pain reported were in the lower back and trochanteric region, 28% and 24% respectively. Patients in the short-length cohort reported a significantly lower incidence of pain in the anterior thigh as compared to the standard-length cohort, 12% versus 19% respectively [p=0.007]. There was no difference in the number of patients experiencing moderate to severe intensity of anterior thigh pain between these two groups, 3% versus 5% respectively [p=0.36]. No other statistically significant differences were found in the incidence of pain in the lower back, buttock, groin, trochanter, lateral thigh, or posterior thigh regions between the two cohorts. CONCLUSION: While the lower back and trochanteric region may be the most frequent areas of pain experienced in patients at one-year or more postoperative from direct anterior THA, a significantly higher incidence of anterior thigh pain is found in those patients treated with a standard-length stem design as compared to the short design. This finding may be due to contact between the tip of the distal stem with the femoral diaphysis as has been theorized in previous research, which is circumvented with the short design variant.

Lateral Unicompartmental Knee Arthroplasty Utilizing a Modified Surgical Technique and Specifically Adapted Fixed-Bearing Implant.

BACKGROUND: Treatment of isolated lateral compartment arthritic disease with partial knee arthroplasty remains underutilized in comparison to medial unicompartmental arthroplasty. This study examines the survival and outcome of lateral unicompartmental arthroplasty utilizing the first implant specifically developed for the lateral compartment. MATERIALS AND METHODS: A retrospective review was performed to detect lateral unicompartmental arthroplasty procedures performed in our practice between January 2013 and May 2016. Patients indicated for surgery met specific preoperative clinical and radiographic criteria confirming lateral compartment arthritic disease with a correctable deformity, intact full-thickness medial cartilage, competent anterior cruciate ligament, and minimal disease in the patellofemoral compartment. A single implant design was used in all cases which consisted of a fixed-bearing tibial component specifically adapted to lateral compartment anatomy. Unicompartmental arthroplasty surgical technique was adjusted to attempt to recreate lateral compartment kinematics. RESULTS: Fifty-two consecutive patients (56 knees) with lateral unicompartmental arthroplasty procedures meeting minimum two-year follow up were included in the study. Thirty-nine patients were female, and 93% of cases were performed for treatment of osteoarthritis. At a mean follow up of nearly three years, Knee Society clinical and functional scores improved postoperatively by a mean difference of 41 and 21, respectively. There were two reoperations, one medial unicompartmental arthroplasty for osteoarthritis progression and a superficial debridement for a non-healing wound. Thus, failure of lateral unicondylar knee arthroplasty (UKA) was less than 2% in this study. There were no other component revisions, radiographic evidence of loosening, or clinical failures. CONCLUSIONS: At early follow up, lateral unicompartmental arthroplasty using a modified surgical technique and an implant specifically designed for the lateral compartment is a reliable treatment for isolated lateral femorotibial arthritis when meeting defined indications.

Direct Anterior Approach and Perioperative Fracture With a Single-Taper Wedge Femoral Component.

BACKGROUND: Despite growing interest in direct anterior approach total hip arthroplasty, perioperative femoral fracture and early aseptic loosening are increasingly recognized complications. Previous research has documented the role of surgeon experience in association with these femoral complications. The purpose of this study was to explore the relationship between femoral component design and early periprosthetic femoral complications. METHODS: This was an extension of previous work with an updated patient cohort of 5090 consecutive direct anterior primary total hip arthroplasties at a single institution with a single-taper, wedge femoral stem comprising 4 variants involving length and geometry: group 1, full-length, standard profile; group 2, full-length, reduced distal profile; group 3, short-length, standard profile; and group 4, short-length, reduced distal profile. Records were reviewed retrospectively for the incidence of early postoperative periprosthetic fracture or aseptic loosening and analyzed with regard to patient demographics and femoral stem type. RESULTS: There were 42 (0.83%) periprosthetic femur complications observed in the early postoperative period. Increased age (P < .001) and female gender (P = .023) were significantly associated with incidence of femoral complications in univariate analysis, while age maintained this significant relationship in multivariate analysis (P < .001). There was a trend toward increased complication rate in patients receiving a short stem with full profile taper (1.27%, P = .0539). CONCLUSION: Despite an overall low rate of femoral complications after direct anterior total hip arthroplasty, the risk is increased in elderly patients and females. Furthermore, femoral stem design may portend an elevated risk of these complications.

"Thicker" Polyethylene Bearings Are Not Associated With Higher Failure Rates in Primary Total Knee Arthroplasty.

BACKGROUND: Despite improvements in polyethylene bearing surface properties, only 1 previous study has examined the results of larger thickness bearings. The purpose of this study was to determine whether polyethylene thickness influenced patient outcomes and implant survival following modular total knee arthroplasty. METHODS: A retrospective review was performed of patients undergoing primary total knee arthroplasty from 2003 to 2014 in a single practice database. Patients were separated into "thin" and "thick" polyethylene groups based on manufacturer polyethylene bearing sizes of 14 mm or less compared to those greater than 14 mm, respectively. Patient clinical outcomes, need for revision surgery, and overall implant survival rates were evaluated. RESULTS: A total of 6698 primary knee arthroplasties were included, and a thin bearing was used in 96.5% of these cases. Preoperatively, patients with a thick bearing had significantly lower Knee Society clinical scores (P < .01), a trend toward lower functional scores (P = .06), and more significant coronal plane deformity. Postoperatively, patients with thick bearings exhibited better Knee Society clinical and pain scores as well as similar functional scores and University of California at Los Angeles activity scores. The overall reoperation rate and 10-year survivorship free of revision were similar between thick and thin bearings (1.7% vs 2.3%; 98.2% vs 96.1%). Patients with thin bearings were twice as likely to require a manipulation under anesthesia postoperatively (P = .02), while there were no failures in the thick bearing group due to aseptic loosening or instability. CONCLUSION: Patients with thick polyethylene bearings performed similarly or better in multiple clinical outcomes and survivorship compared to those with thin bearings.

Medial Mobile-Bearing Unicompartmental Knee Arthroplasty in Young Patients Aged Less Than or Equal to 50 Years.

BACKGROUND: Contemporary research has shown medial mobile-bearing unicompartmental knee arthroplasty to be an effective treatment in patients younger than 60 years; however, only one other study has specifically investigated unicompartmental arthroplasty outcomes in patients 50 years or younger. The purpose of this study was to determine the clinical outcomes and survivorship of medial mobile-bearing unicompartmental arthroplasty in this younger patient population. METHODS: A retrospective review of patients undergoing primary unicompartmental knee arthroplasty using the Oxford partial knee from 2003 to 2014 in a single practice database was performed. Patients were included in the study if they were 50 years of age or younger with a primary diagnosis of anteromedial osteoarthritis and minimum clinical follow-up of 2 years. Patient clinical outcomes, function, and need for revision surgery were assessed. RESULTS: The study included 340 knees. Average patient age was 46.5 years, and the mean follow-up was 6.1 years. Patients demonstrated significant improvements (P < .05) in range of motion (114.5 v 116.9), University of California Los Angeles activity score (4.4 vs 5.6), Knee Society clinical (37.3 vs 86.5) and functional scores (58.8 v 79.8). Overall, 20 patients required reoperation, and the predicted survival rate was 96% at 6 years and 86% at 10 years. Aseptic loosening occurred in 7 patients at an average of 5.6 years postoperatively, while 4 patients required conversion to total knee arthroplasty because of arthritic progression at a mean time of 6.6 years. There were no revision procedures required due to polyethylene liner wear or breakage. CONCLUSION: Medial mobile-bearing unicompartmental arthroplasty should be considered as a treatment option in patients younger than 50 years of age suffering from anteromedial osteoarthritis of the knee.

Posterior Shoulder Instability in Overhead Athletes.

Posterior shoulder instability in overhead athletes presents a unique and difficult challenge. Often, this group has an inherent capsular laxity and/or humeral retroversion to accommodate the range of motion necessary to throw. This adaptation makes the diagnosis of posterior capsulolabral pathology challenging, as the examiner must differentiate between adaptive capsular laxity and pathologic instability. Further complicating matters, the intraoperative surgeon must find the delicate balance of achieving stability while still allowing the necessary range of motion.

Paracrine proangiopoietic effects of human umbilical cord blood-derived purified CD133+ cells--implications for stem cell therapies in regenerative medicine.

CD133+ cells purified from hematopoietic tissues are enriched mostly for hematopoietic stem/progenitor cells, but also contain some endothelial progenitor cells and very small embryonic-like stem cells. CD133+ cells, which are akin to CD34+ cells, are a potential source of stem cells in regenerative medicine. However, the lack of convincing donor-derived chimerism in the damaged organs of patients treated with these cells suggests that the improvement in function involves mechanisms other than a direct contribution to the damaged tissues. We hypothesized that CD133+ cells secrete several paracrine factors that play a major role in the positive effects observed after treatment and tested supernatants derived from these cells for the presence of such factors. We observed that CD133+ cells and CD133+ cell-derived microvesicles (MVs) express mRNAs for several antiapoptotic and proangiopoietic factors, including kit ligand, insulin growth factor-1, vascular endothelial growth factor, basic fibroblast growth factor, and interleukin-8. These factors were also detected in a CD133+ cell-derived conditioned medium (CM). More important, the CD133+ cell-derived CM and MVs chemoattracted endothelial cells and display proangiopoietic activity both in vitro and in vivo assays. This observation should be taken into consideration when evaluating clinical outcomes from purified CD133+ cell therapies in regenerative medicine.

Umbilical cord blood-derived very small embryonic like stem cells (VSELs) as a source of pluripotent stem cells for regenerative medicine.

Umbilical cord blood-derived very small embryonic-like stem cells (UCB-VSELs) are the most primitive stem cells circulating in fetal peripheral blood. These very rare cells slightly smaller than red blood cells i) become mobilized during delivery, ii) are enriched in fraction of CD133+ Lin-CD45- cells iii) express markers of pluripotent stem cells (e.g., Oct4, Nanog, and SSEA-4) and iv) display a distinct morphology characterized by a high nuclear/ cytoplasmic ratio and undifferentiated chromatin. We envision that VSELs are released into neonatal peripheral blood as a migrating population of stem cells involved in regeneration of tissues that become damaged in the process of delivery. They may also be responsible for the occurrence of fetal-maternal chimerism. Our most recent data suggest that UCB-VSELs exhibit some characteristics of long-term repopulating hematopoietic stem cells (LT-HSCs). We propose that UCB-VSELs may eventually be employed as a source of pluripotent stem cells in regenerative medicine.

Safety and efficacy of bone marrow-derived autologous CD133+ stem cell therapy.

The Phase I clinical study was designed to assess the safety and feasibility of a dose escalating intracoronary infusion of autologous bone marrow (BM)-derived CD133+ stem cell therapy to the patients with chronic total occlusion (CTO) and ischemia. Nine patients were received CD133+ cells into epicardial vessels supplying collateral flow to areas of viable ischemic myocardium in the distribution of the CTO. There were no major adverse cardiac events (MACE), revascularization, re-admission to the hospital secondary to angina, or acute myocardial infarction (AMI) for the 24-month period following cellular infusion. In addition, there were no periprocedural infusion-related complications including malignant arrhythmias, loss of normal coronary blood flow or acute neurologic events. Cardiac enzymes were negative in all patients. There was an improvement in the degree of ischemic myocardium, which was accompanied by a trend towards reduction in anginal symptoms. Intracoronary infusion of autologous CD133+ marrow-derived cells is safe and feasible. Cellular therapy with CD133+ cells to reduce anginal symptoms and to improve ischemia in patients with CTO awaits clinical investigation in Phase II/III trials.

Model-based tracking of the hip: implications for novel analyses of hip pathology.

This study investigated the efficacy of a combined high-speed, biplane radiography and model-based tracking technique to study hip joint kinematics and arthrokinematics. Comparing model-based tracking to the gold standard of radiostereometric analysis using implanted metal beads, joint translation was measured with a bias of 0.2 mm and a precision of 0.3 mm, whereas joint rotation was measured with a bias of 0.2° and a precision of 0.8°. A novel measure of hip arthrokinematics characterizing the region of closest contact in the anterosuperior acetabulum was measured with a bias of 0.9% and a precision of 2.5%. Model-based tracking of the hip thus provides the opportunity to noninvasively study hip pathologic conditions such as osteoarthritis and femoroacetabular impingement with great accuracy.

Responsiveness of the International Knee Documentation Committee Subjective Knee Form in comparison to the Western Ontario and McMaster Universities Osteoarthritis Index, modified Cincinnati Knee Rating System, and Short Form 36 in patients with focal articular cartilage defects.

BACKGROUND: The International Knee Documentation Committee Subjective Knee Form (IKDC SKF) is a patient-reported knee-specific outcome measure that has been shown to be a reliable, valid, and responsive measure for patients with a variety of knee conditions. Further testing is required to compare the reliability and responsiveness of the IKDC SKF to other commonly used patient-reported outcome measures for patients with articular cartilage lesions. HYPOTHESIS: The IKDC SKF has equal or better levels of reliability and responsiveness than the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), modified Cincinnati Knee Rating System (CKRS), and the Short Form 36 in patients with articular cartilage lesions. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: Reliability was assessed by administering the 4 patient-reported outcome measures to 17 individuals who had undergone articular cartilage surgery 5 years before participation in this study. Responsiveness was determined by administering the 4 patient-reported outcome measures to 51 individuals with diagnosed focal articular cartilage defects who were scheduled to undergo surgical treatment. In both groups, the outcome measures were administered at baseline and at 6 and 12 months' follow-up. Participants also provided a global rating of change in comparison to baseline at the 6- and 12-month follow-ups. RESULTS: Test-retest reliability coefficients were 0.91 and 0.93 for the IKDC SKF at the 6- and 12-month follow-ups, respectively. The effect sizes and standardized response means were large (>0.80) at 6 months after surgery for the WOMAC pain, physical function, and total scores and 12 months after surgery for the IKDC SKF; WOMAC pain, physical function, and total; and CKRS scores. Six months after surgery, significant differences between those who were improved compared with those who were unchanged or worse were found only for the IKDC SKF. Twelve months after surgery, significant differences between the improved and unchanged groups were found for all of the knee-specific patient-reported outcome measures. Finally, the IKDC SKF, WOMAC, and CKRS scores were able to differentiate between individuals who perceived themselves to be improved versus not improved and the minimum clinically important difference for the IKDC SKF was 6.3 at 6 months and 16.7 at 12 months. CONCLUSION: The reliability and responsiveness of the IKDC SKF is comparable with other commonly used patient-reported outcome measures for patients with articular cartilage lesions. The IKDC SKF is a suitable alternative to other commonly used knee-specific instruments for measuring symptoms, daily function, and level of symptom-free sports activity in patients undergoing articular cartilage surgery.

Umbilical cord blood-selected CD133(+) cells exhibit vasculogenic functionality in vitro and in vivo.

BACKGROUND AIMS: Current clinical trials utilize non-selected bone marrow (BM) mononuclear cells (MNC) to augment vasculo genesis within ischemic vascular beds. Recent reports have identified a diminished number and function of hemat-opoietic stem cells (HSC) from aged and diseased patients. Umbilical cord blood (UCB) provides a potential robust allo-geneic source of HSC for therapeutic vasculogenesis. METHODS: MNC and magnetically isolated CD133(+) cells were assessed for viability (trypan blue) and surface phenotype (flow cytometry). To test in vivo functionality of the cells, NOD/SCID mice underwent ligation of the right femoral artery followed immediately by cell injection. Blood flow recovery, necrosis, BM engraftment of human cells and histologic capillary density were determined. Cells were tested for potential mechanisms mediating the in vivo effects, including migration, cytokine secretion and angiogenic augmentation (Matrigel assays). RESULTS: Surface expression analysis showed CD31 (PECAM) expression was greatly increased in UCB CD133(+) cells compared with BM MNC. At 28 days, perfusion ratios were highest in animals receiving UCB CD133(+) cells, while animals receiving BM CD133(+) cells and BM MNC demonstrated perfusion ratios statistically higher than in animals treated with cytokine media alone. Animals receiving CD133(+) cells showed a statistically higher capillary density, reduced severe digit necrosis and increased engraftment in the BM than animals treated with unselected BM MNC. In vitro studies showed equivalent migration to stromal-derived factor-1 (SDF-1), increased production of tumor necrosis factor alpha (TNF-alpha) and increased branch points with the co-incubation of CD133(+) cells with human umbilical vein endothelial cells (HUVEC) in the Matrigel angiogenesis assay. CONCLUSIONS: Taken together, UCB CD133(+) cells exhibit robust vasculogenic functionality compared with BM MNC in response to ischemia.

microRNA 184 regulates expression of NFAT1 in umbilical cord blood CD4+ T cells.

The reduced expression of nuclear factor of activated T cells-1 (NFAT1) protein in umbilical cord blood (UCB)-derived CD4+ T cells and the corresponding reduction in inflammatory cytokine secretion after stimulation in part underlies their phenotypic differences from adult blood (AB) CD4+ T cells. This muted response may contribute to the lower incidence and severity of high-grade acute graft-versus-host disease (aGVHD) exhibited by UCB grafts. Here we provide evidence that a specific microRNA, miR-184, inhibits NFAT1 protein expression elicited by UCB CD4+ T cells. Endogenous expression of miR-184 in UCB is 58.4-fold higher compared with AB CD4+ T cells, and miR-184 blocks production of NFAT1 protein through its complementary target sequence on the NFATc2 mRNA without transcript degradation. Furthermore, its negative effects on NFAT1 protein and downstream interleukin-2 (IL-2) transcription are reversed through antisense blocking in UCB and can be replicated via exogenous transfection of precursor miR-184 into AB CD4+ T cells. Our findings reveal a previously uncharacterized role for miR-184 in UCB CD4+ T cells and a novel function for microRNA in the early adaptive immune response.

An emissive C analog distinguishes between G, 8-oxoG, and T.

A minimally disruptive fluorescent dC analog provides a rapid and non-destructive method for in vitro detection of G, 8-oxoG, and T, the downstream transverse mutation product.