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Gobert Von Skrbensky - One of the best experts on this subject based on the ideXlab platform.
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Knee Surg Sports Traumatol Arthrosc (2008) 16:56–63 DOI 10.1007/s00167-007-0416-7 KNEE Effects of a contoured articular prosthetic Device on tibiofemoral peak contact pressure: a biomechanical study
2013Co-Authors: Gobert Von Skrbensky, Hajo Thermann, C. Becher, R. Huber, H. H. PaesslerAbstract:Abstract Many middle-aged patients are affected by localized cartilage defects that are neither appropriate for primary, nor repeat biological repair methods, nor for conventional arthroplasty. This in vitro study aims to determine the peak contact pressure in the tibiofemoral joint with a partial femoral Resurfacing Device (Hemi-CAP 1, Arthrosurface Inc., Franklin, MA, USA). Peak contact pressure was determined in eight fresh-frozen cadaveric specimens using a Tekscan sensor placed in the medial compartment above the menisci. A closed loop robotic knee simulator was used to test each knee in static stance positions (5°/15°/30°/45°) with body weight ground reaction force (GRF), 30 ° flexion with twice the body weight (2tBW) GRF and dynamic knee-bending cycles with body weight GRF. The ground reaction force was adjusted to the living body weight of the cadaver donor and maintained throughout all cycles. Each specimen was tested under four different conditions: Untreated, flush HemiCAP 1 implantation, 1-mm proud implantation and 20-mm defect. A paired sampled t test to compare mean
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effects of a surface matching articular Resurfacing Device on tibiofemoral contact pressure results from continuous dynamic flexion extension cycles
Archives of Orthopaedic and Trauma Surgery, 2011Co-Authors: Christoph Becher, Roland Huber, Lavinia Ezechieli, Sven Ostermeier, Mathias Wellmann, Hajo Thermann, Gobert Von SkrbenskyAbstract:Introduction The application of a defect-size metal implant for the treatment of focal articular cartilage lesions of the femoral condyle is of potential concern resulting in cartilage damage to opposing biological structures. This in vitro study aims to determine the tibiofemoral contact pressure with a contoured articular partial femoral Resurfacing Device under continuous dynamic pressure loads.
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Effects of a contoured articular prosthetic Device on tibiofemoral peak contact pressure: a biomechanical study
Knee Surgery Sports Traumatology Arthroscopy, 2008Co-Authors: Christoph Becher, Roland Huber, Hajo Thermann, H. H. Paessler, Gobert Von SkrbenskyAbstract:Many middle-aged patients are affected by localized cartilage defects that are neither appropriate for primary, nor repeat biological repair methods, nor for conventional arthroplasty. This in vitro study aims to determine the peak contact pressure in the tibiofemoral joint with a partial femoral Resurfacing Device (HemiCAP^®, Arthrosurface Inc., Franklin, MA, USA). Peak contact pressure was determined in eight fresh-frozen cadaveric specimens using a Tekscan sensor placed in the medial compartment above the menisci. A closed loop robotic knee simulator was used to test each knee in static stance positions (5°/15°/30°/45°) with body weight ground reaction force (GRF), 30° flexion with twice the body weight (2tBW) GRF and dynamic knee-bending cycles with body weight GRF. The ground reaction force was adjusted to the living body weight of the cadaver donor and maintained throughout all cycles. Each specimen was tested under four different conditions: Untreated, flush HemiCAP^® implantation, 1-mm proud implantation and 20-mm defect. A paired sampled t test to compare means (significance, P ≤ 0.05) was used for statistical analysis. On average, no statistically significant differences were found in any testing condition comparing the normal knee with flush Device implantation. With the 1-mm proud implant, statistically significant increase of peak contact pressures of 217% (5° stance), 99% (dynamic knee bending) and 90% (30° stance with 2tBW) compared to the untreated condition was seen. No significant increase of peak contact pressure was evaluated with the 20-mm defect. The data suggests that Resurfacing with the HemiCAP^® does not lead to increased peak contact pressure with flush implantation. However, elevated implantation results in increased peak contact pressure and might be biomechanically disadvantageous in an in vivo application.
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KNEE Effects of a contoured articular prosthetic Device on tibiofemoral peak contact pressure: a biomechanical study
2007Co-Authors: Gobert Von SkrbenskyAbstract:Abstract Many middle-aged patients are affected by localized cartilage defects that are neither appropriate for primary, nor repeat biological repair methods, nor for conventional arthroplasty. This in vitro study aims to determine the peak contact pressure in the tibiofemoral joint with a partial femoral Resurfacing Device (Hemi
Christoph Becher - One of the best experts on this subject based on the ideXlab platform.
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effects of a surface matching articular Resurfacing Device on tibiofemoral contact pressure results from continuous dynamic flexion extension cycles
Archives of Orthopaedic and Trauma Surgery, 2011Co-Authors: Christoph Becher, Roland Huber, Lavinia Ezechieli, Sven Ostermeier, Mathias Wellmann, Hajo Thermann, Gobert Von SkrbenskyAbstract:Introduction The application of a defect-size metal implant for the treatment of focal articular cartilage lesions of the femoral condyle is of potential concern resulting in cartilage damage to opposing biological structures. This in vitro study aims to determine the tibiofemoral contact pressure with a contoured articular partial femoral Resurfacing Device under continuous dynamic pressure loads.
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effects of a surface matching articular Resurfacing Device on tibiofemoral contact pressure results from continuous dynamic flexion extension cycles
Archives of Orthopaedic and Trauma Surgery, 2011Co-Authors: Christoph Becher, Roland Huber, Lavinia Ezechieli, Sven Ostermeier, Mathias Wellmann, Hajo Thermann, Gobert Von SkrbenskyAbstract:The application of a defect-size metal implant for the treatment of focal articular cartilage lesions of the femoral condyle is of potential concern resulting in cartilage damage to opposing biological structures. This in vitro study aims to determine the tibiofemoral contact pressure with a contoured articular partial femoral Resurfacing Device under continuous dynamic pressure loads. Peak and area contact pressures were determined in eight fresh-frozen cadaveric specimens using a pressure-sensitive sensor placed in the medial compartment above the menisci. All knees were tested in the untreated condition and after implantation of the prosthetic Device in the weight-bearing area of the medial femoral condyle. A robotic knee simulator was used to test each knee under continuous pressure load for 400 s during 40 dynamic knee bending cycles (5°–45° flexion) with body weight ground reaction force (GRF). The GRF was adjusted to the living body weight of the cadaver donor and maintained throughout all cycles. Comparison of the untreated condition to focal inlay Resurfacing showed no statistically significant differences (P ≤ 0.05) between all testing conditions. The average maximum peak contact pressure across all 40 flexion cycles increased by 5.1% after Resurfacing compared to the untreated knees. The average area contact pressure essentially stayed the same (+0.9%). The data suggest that Resurfacing with the contoured articular prosthetic Device does not pose any immediate deleterious effects to the opposing surfaces based on peak and area contact pressure in a continuous dynamic in vitro application. However, long-term in vivo effects remain to be evaluated.
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Effects of a contoured articular prosthetic Device on tibiofemoral peak contact pressure: a biomechanical study
Knee Surgery Sports Traumatology Arthroscopy, 2008Co-Authors: Christoph Becher, Roland Huber, Hajo Thermann, H. H. Paessler, Gobert Von SkrbenskyAbstract:Many middle-aged patients are affected by localized cartilage defects that are neither appropriate for primary, nor repeat biological repair methods, nor for conventional arthroplasty. This in vitro study aims to determine the peak contact pressure in the tibiofemoral joint with a partial femoral Resurfacing Device (HemiCAP^®, Arthrosurface Inc., Franklin, MA, USA). Peak contact pressure was determined in eight fresh-frozen cadaveric specimens using a Tekscan sensor placed in the medial compartment above the menisci. A closed loop robotic knee simulator was used to test each knee in static stance positions (5°/15°/30°/45°) with body weight ground reaction force (GRF), 30° flexion with twice the body weight (2tBW) GRF and dynamic knee-bending cycles with body weight GRF. The ground reaction force was adjusted to the living body weight of the cadaver donor and maintained throughout all cycles. Each specimen was tested under four different conditions: Untreated, flush HemiCAP^® implantation, 1-mm proud implantation and 20-mm defect. A paired sampled t test to compare means (significance, P ≤ 0.05) was used for statistical analysis. On average, no statistically significant differences were found in any testing condition comparing the normal knee with flush Device implantation. With the 1-mm proud implant, statistically significant increase of peak contact pressures of 217% (5° stance), 99% (dynamic knee bending) and 90% (30° stance with 2tBW) compared to the untreated condition was seen. No significant increase of peak contact pressure was evaluated with the 20-mm defect. The data suggests that Resurfacing with the HemiCAP^® does not lead to increased peak contact pressure with flush implantation. However, elevated implantation results in increased peak contact pressure and might be biomechanically disadvantageous in an in vivo application.
John W Noble - One of the best experts on this subject based on the ideXlab platform.
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results of the first u s fda approved hip Resurfacing Device at 10 year follow up
Journal of Bone and Joint Surgery American Volume, 2021Co-Authors: Vinay Bhal, Lawrence R Housman, John Masonis, John W Noble, Robert H Hopper, Anderson C EnghAbstract:BACKGROUND The BIRMINGHAM HIP Resurfacing (BHR) system is a metal-on-metal hip implant system approved by the U.S. Food and Drug Administration in 2006. The approval required a multicenter, prospective, post-market-approval study. Our purpose is to report the current results at 10 years of follow-up. METHODS Between October 2006 and December 2009, 280 primary BHR procedures were performed at 5 sites. Outcome measures included Kaplan-Meier survivorship, reasons for revision, radiographic component stability and osteolysis, Harris hip scores, and metal levels including cobalt and chromium. The mean age at the time of the procedure was 51.3 ± 7.1 years, 74% (206) of 280 BHRs were implanted in male patients, the mean body mass index was 27.8 ± 4.4 kg/m2, and 95% (265) of 280 hips had a primary diagnosis of osteoarthritis. The mean follow-up among all 280 hips was 9.0 ± 2.5 years. Prior to 10-year follow-up, 20 hips were revised and 5 patients representing 5 hips had died. Among the remaining 255 hips, 218 (85%) met the minimum follow-up of 10 years. RESULTS The 10-year survival free from all-cause component revision was 92.9% (95% confidence interval [CI], 89.8% to 96.1%) for all hips and 96.0% (95% CI, 93.1% to 98.9%) among male patients <65 years old at the time of the procedure. Reasons for revision included femoral loosening (n = 5), femoral neck fracture (n = 3), pseudotumor (n = 3), osteolysis (n = 2), and acetabular loosening (n = 1), as well as 6 revisions for a combination of pain, noise, or metal levels. Among unrevised hips, the median Harris hip score improved from preoperatively (59) to 1 year postoperatively (99; p < 0.001) and remained stable through 10 years postoperatively (99; p = 0.08). Radiographically, 5% (10) of 218 unrevised hips had osteolysis with no component migration. Median metal levels had increased at 1 year postoperatively (cobalt: from 0.12 ppb preoperatively to 1.5 ppb at 1 year postoperatively, p < 0.001; chromium: from 0.6 ppb preoperatively to 1.7 ppb at 1 year postoperatively, p < 0.001), then remained stable through 5 years before slightly decreasing at 10 years postoperatively (cobalt: 1.3 ppb, p < 0.001; chromium: 1.4 ppb, p < 0.001). CONCLUSIONS This prospective, multicenter, post-market-approval study demonstrated that the BHR implant system is safe and effective through 10 years of follow-up, particularly among young male patients. LEVEL OF EVIDENCE Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
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five year results of the first us fda approved hip Resurfacing Device
Journal of Arthroplasty, 2014Co-Authors: Lawrence R Housman, John Masonis, John W Noble, Anderson C EnghAbstract:Abstract A prospective, multi-center postmarket approval study has been ongoing since May 2006 to assess safety and efficacy of the first US FDA approved hip Resurfacing implant. 265 patients have been enrolled at five study sites. The average age of the patients is 51.3years. There have been 7 revisions (2.4%) in the cohort to date. K–M survival curves for the cohort are 97.6% at 5years. There is a trend toward a gender difference in implant survivorship, with 98.6% of men and 94.7% of women free from revision. Metal ion analysis revealed median cobalt and chromium levels of 1.5ppb and 1.7ppb at 1year. In this prospective US study, the Birmingham Hip Resurfacing implant is demonstrating results comparable to those in the literature.
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five year results of a post market approval study of the first us fda approved hip Resurfacing Device a difference in survival between male and female gender
Journal of Bone and Joint Surgery-british Volume, 2013Co-Authors: Lawrence R Housman, John Masonis, John W NobleAbstract:Background Post-market surveillance is necessary to ensure the safety and efficacy of newly introduced technologies and implants. The Birmingham Hip Resurfacing (Smith and Nephew, Inc., Memphis, TN) was the first hip Resurfacing implant approved for use by the US FDA in May 2006. A prospective, multi-center postmarket approval study has been in progress to assess safety and efficacy of this implant. Methods Patients meeting inclusion criteria were enrolled at five sites. Clinical evaluation and radiographs were obtained at 3 months and 1 year, and annually thereafter for a total of 10 years. Blood metal ion levels were measured at 1 year and 4 years. Results 265 patients have been enrolled thus far with 193 males; 28 patients have had bilateral procedures. The average age of the patients is 51.3 years (range 22–72). There have been 7 revisions (2.4%) in the entire cohort to date: 2 were for femoral neck fracture, 2 were for acetabular loosening; 1 was for femoral head osteonecrosis; 1 was revised on the day of surgery for errant implant placement; and 1 was for pseudotumor. K-M survival curves for the cohort are 97.8% at 5 years (Figure 1); men had 99% survival, while women had 94.5%. Whole blood metal ion analysis revealed a median cobalt and chromium levels of 1.5 ppb and 1.7 ppb at 1 year. There was a significant difference between the metal levels in men and women, however women also had smaller component sizes. Furthermore, a significantly higher percentage of female patients had outlier metal ion levels > 7 ppb. Conclusions This hip Resurfacing Device has demonstrated safety and efficacy comparable to THR, in this multicenter postmarket approval study. A gender difference in the survival rate and median metal ion levels does exist; therefore, it is important to continue close monitoring of this cohort to determine longer term results.
Lawrence R Housman - One of the best experts on this subject based on the ideXlab platform.
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results of the first u s fda approved hip Resurfacing Device at 10 year follow up
Journal of Bone and Joint Surgery American Volume, 2021Co-Authors: Vinay Bhal, Lawrence R Housman, John Masonis, John W Noble, Robert H Hopper, Anderson C EnghAbstract:BACKGROUND The BIRMINGHAM HIP Resurfacing (BHR) system is a metal-on-metal hip implant system approved by the U.S. Food and Drug Administration in 2006. The approval required a multicenter, prospective, post-market-approval study. Our purpose is to report the current results at 10 years of follow-up. METHODS Between October 2006 and December 2009, 280 primary BHR procedures were performed at 5 sites. Outcome measures included Kaplan-Meier survivorship, reasons for revision, radiographic component stability and osteolysis, Harris hip scores, and metal levels including cobalt and chromium. The mean age at the time of the procedure was 51.3 ± 7.1 years, 74% (206) of 280 BHRs were implanted in male patients, the mean body mass index was 27.8 ± 4.4 kg/m2, and 95% (265) of 280 hips had a primary diagnosis of osteoarthritis. The mean follow-up among all 280 hips was 9.0 ± 2.5 years. Prior to 10-year follow-up, 20 hips were revised and 5 patients representing 5 hips had died. Among the remaining 255 hips, 218 (85%) met the minimum follow-up of 10 years. RESULTS The 10-year survival free from all-cause component revision was 92.9% (95% confidence interval [CI], 89.8% to 96.1%) for all hips and 96.0% (95% CI, 93.1% to 98.9%) among male patients <65 years old at the time of the procedure. Reasons for revision included femoral loosening (n = 5), femoral neck fracture (n = 3), pseudotumor (n = 3), osteolysis (n = 2), and acetabular loosening (n = 1), as well as 6 revisions for a combination of pain, noise, or metal levels. Among unrevised hips, the median Harris hip score improved from preoperatively (59) to 1 year postoperatively (99; p < 0.001) and remained stable through 10 years postoperatively (99; p = 0.08). Radiographically, 5% (10) of 218 unrevised hips had osteolysis with no component migration. Median metal levels had increased at 1 year postoperatively (cobalt: from 0.12 ppb preoperatively to 1.5 ppb at 1 year postoperatively, p < 0.001; chromium: from 0.6 ppb preoperatively to 1.7 ppb at 1 year postoperatively, p < 0.001), then remained stable through 5 years before slightly decreasing at 10 years postoperatively (cobalt: 1.3 ppb, p < 0.001; chromium: 1.4 ppb, p < 0.001). CONCLUSIONS This prospective, multicenter, post-market-approval study demonstrated that the BHR implant system is safe and effective through 10 years of follow-up, particularly among young male patients. LEVEL OF EVIDENCE Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
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five year results of the first us fda approved hip Resurfacing Device
Journal of Arthroplasty, 2014Co-Authors: Lawrence R Housman, John Masonis, John W Noble, Anderson C EnghAbstract:Abstract A prospective, multi-center postmarket approval study has been ongoing since May 2006 to assess safety and efficacy of the first US FDA approved hip Resurfacing implant. 265 patients have been enrolled at five study sites. The average age of the patients is 51.3years. There have been 7 revisions (2.4%) in the cohort to date. K–M survival curves for the cohort are 97.6% at 5years. There is a trend toward a gender difference in implant survivorship, with 98.6% of men and 94.7% of women free from revision. Metal ion analysis revealed median cobalt and chromium levels of 1.5ppb and 1.7ppb at 1year. In this prospective US study, the Birmingham Hip Resurfacing implant is demonstrating results comparable to those in the literature.
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five year results of a post market approval study of the first us fda approved hip Resurfacing Device a difference in survival between male and female gender
Journal of Bone and Joint Surgery-british Volume, 2013Co-Authors: Lawrence R Housman, John Masonis, John W NobleAbstract:Background Post-market surveillance is necessary to ensure the safety and efficacy of newly introduced technologies and implants. The Birmingham Hip Resurfacing (Smith and Nephew, Inc., Memphis, TN) was the first hip Resurfacing implant approved for use by the US FDA in May 2006. A prospective, multi-center postmarket approval study has been in progress to assess safety and efficacy of this implant. Methods Patients meeting inclusion criteria were enrolled at five sites. Clinical evaluation and radiographs were obtained at 3 months and 1 year, and annually thereafter for a total of 10 years. Blood metal ion levels were measured at 1 year and 4 years. Results 265 patients have been enrolled thus far with 193 males; 28 patients have had bilateral procedures. The average age of the patients is 51.3 years (range 22–72). There have been 7 revisions (2.4%) in the entire cohort to date: 2 were for femoral neck fracture, 2 were for acetabular loosening; 1 was for femoral head osteonecrosis; 1 was revised on the day of surgery for errant implant placement; and 1 was for pseudotumor. K-M survival curves for the cohort are 97.8% at 5 years (Figure 1); men had 99% survival, while women had 94.5%. Whole blood metal ion analysis revealed a median cobalt and chromium levels of 1.5 ppb and 1.7 ppb at 1 year. There was a significant difference between the metal levels in men and women, however women also had smaller component sizes. Furthermore, a significantly higher percentage of female patients had outlier metal ion levels > 7 ppb. Conclusions This hip Resurfacing Device has demonstrated safety and efficacy comparable to THR, in this multicenter postmarket approval study. A gender difference in the survival rate and median metal ion levels does exist; therefore, it is important to continue close monitoring of this cohort to determine longer term results.
Christopher B Zachary - One of the best experts on this subject based on the ideXlab platform.
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long term efficacy of a fractional Resurfacing Device
Lasers in Surgery and Medicine, 2010Co-Authors: Arisa E Ortiz, Anne Marie Tremaine, Christopher B ZacharyAbstract:Background and Objective: Recently, there has been much debate regarding the long-term efficacy of fractional Resurfacing Devices. While pulsed CO2 laser Resurfacing is considered a highly effective treatment, fractionated Resurfacing is a newer modality and its long-term efficacy has yet to be assessed. We report the long-term outcomes of subjects previously treated with fractional CO2 Resurfacing for photodamaged skin and acne scars. Study Design/Materials and Methods: Ten subjects from our previous studies who received fractional Resurfacing for the treatment of acne scarring and photodamage returned for long-term follow-up visits at 1 and 2 years, respectively. Investigators graded maintenance of improvement on a quartile scale based on clinical photography. Results: Subjects maintained 74% of their overall improvement at their long-term visits compared to 3-month follow-up visits. While clinical improvement was maintained long-term, the results were not as remarkable as those seen at 3-month visits. The authors speculate that results seen at 3 months may be enhanced by persistent inflammatory changes, as evidenced by heat shock protein 47 activity and ongoing collagen remodeling seen in previous histologic studies. Relaxation of tightening is to be expected with any procedure along with the natural progression of aging. However, patient satisfaction was upheld long-term. Conclusion: Fractional CO2 laser Resurfacing does have long-term efficacy and persistence of improvement of acne scarring and photodamage compared to baseline. However, additional treatments may be necessary to enhance longterm results. Lasers Surg. Med. 42:168–170, 2010. 2010 Wiley-Liss, Inc.
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evaluation of a novel fractional Resurfacing Device for treatment of acne scarring
Lasers in Surgery and Medicine, 2009Co-Authors: Susan Walgrave, Arisa E Ortiz, Heather T Macfalls, Laila Elkeeb, Anne Truitt, Joshua A Tournas, Brian D Zelickson, Christopher B ZacharyAbstract:Background and Objective: Pulsed carbon dioxide (CO2) laser Devices are considered highly effective treat- ment options for skin Resurfacing. However, the high risk for significant treatment complications following CO2 Resurfacing has warranted the development of new treat- ment modalities. The concept of fractional photothermol- ysis was developed to address the shortcomings of ablative and non-ablative Device modalities. This report evaluates a fractional approach to CO2 laser Resurfacing for the treat- ment of moderate to severe acne scarring. The primary endpoint of the study was the overall improvement in the appearance of acne scarring. Study Design/Materials and Methods: Thirty subjects, with moderate to severe acne scarring, underwent up to three treatments with an FDA IDE and IRB approved 10,600 nm fractional CO2 laser system. All subjects were Fitzpatrick skin types I-V and 18-75 years of age. Treatment parameters ranged from 20 to 100 mJ with total densities of 600-1,600 MTZ/cm 2 . Improvement of acne scarring was evaluated at 1 and 3 months post-treatment. Results: Twenty-three out of 25 subjects sustained clinical improvement in the appearance of acne scarring at the 3-month follow-up visits according to study investigator quartile improvement scoring. Subjects also had improve- ment in their overall appearance, including pigmentation and rhytides. Serosanguinous oozing resolved within 24-48 hours following treatment. All subjects had tran- sient erythema, which resolved in the majority of subjects within 1-3 months. Post-operative downtime was signifi- cantly decreased compared to traditional ablative resurfac- ing. No serious complications were reported. Conclusion: Fractional deep dermal ablation improves moderate to severe acne scarring. The added benefit is a considerable reduction both in downtime and risk of complications when compared to traditional CO2 ablative Resurfacing techniques. Lasers Surg. Med. 41:122-127, 2009. 2009 Wiley-Liss, Inc.
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in vivo histological evaluation of a novel ablative fractional Resurfacing Device
Lasers in Surgery and Medicine, 2007Co-Authors: Basil M Hantash, Vikramaditya P Bedi, Bhumika Kapadia, Zakia Rahman, Kerrie Jiang, Heather Tanner, Kin F Chan, Christopher B ZacharyAbstract:Background and Objectives A novel carbon dioxide (CO2) laser Device employing ablative fractional Resurfacing was tested on human skin in vivo for the first time. Study Design/Materials and Methods An investigational 30 W, 10.6 µm CO2 laser system was focused to a 1/e2 spot size of 120 µm to generate an array of microscopic treatment zones (MTZ) in human forearm skin. A range of pulse energies between 5 and 40 mJ was tested and lesion dimensions were assessed histologically using hematoxylin & eosin. Wound healing of the MTZ's was assessed immediately-, 2-day, 7-day, 1-month, and 3-month post treatment. The role of heat shock proteins was examined by immunohistochemistry. Results The investigational CO2 laser system created a microscopic pattern of ablative and thermal injury in human skin. The epidermis and part of the dermis demonstrated columns of thermal coagulation that surrounded tapering ablative zones lined by a thin eschar layer. Changing the pulse energy from 5 to 30 mJ resulted in a greater than threefold increase in lesion depth and twofold increase in width. Expression of heat shock protein (hsp)72 was detected as early as 2 days post-treatment and diminished significantly by 3 months. In contrast, increased expression of hsp47 was first detected at 7 days and persisted at 3 months post-treatment. Conclusion The thermal effects of a novel investigational ablative CO2 laser system utilizing fractional Resurfacing were characterized in human forearm skin. We confirmed our previous ex vivo findings and show for the first time in-vivo, that a controlled array of microscopic treatment zones of ablation and coagulation could be deposited in human skin by varying treatment pulse energy. Immunohistochemical studies of heat shock proteins revealed a persistent collagen remodeling response lasting at least 3 months. We successfully demonstrated the first in-vivo use of ablative fractional Resurfacing (AFR™) treatment on human skin. Lasers Surg. Med. 39:96–107, 2007. © 2007 Wiley-Liss, Inc.
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ex vivo histological characterization of a novel ablative fractional Resurfacing Device
Lasers in Surgery and Medicine, 2007Co-Authors: Basil M Hantash, Vikramaditya P Bedi, Kin F Chan, Christopher B ZacharyAbstract:Background and Objectives: We introduce a novel CO2 laser Device that utilizes ablative fractional Resurfacing for deep dermal tissue removal and characterize the resultant thermal effects in skin. Study Design/Materials and Methods: A prototype 30 W, 10.6 m mC O2 laser was focused to a 1/e 2 spot size of 120mmandpulse durationup to0.7milliseconds toachieve a microarray pattern in ex vivo human skin. Lesion depth and width were assessed histologically using either hematoxylin & eosin (H&E) or lactate dehyrdogenase (LDH) stain. Pulse energies were varied to determine their effect on lesion dimensions. Results: Microarrays of ablative and thermal injury were created in fresh ex vivo human skin irradiated with the prototype CO2 laser Device. Zones of tissue ablation were surrounded by areas of tissue coagulation spanning the epidermis and part of the dermis. A thin condensed lining on the interior wall of the lesion cavity was observed consistent with eschar formation. At 23.3 mJ, the lesion width was approximately 350 mm and depth 1 mm. In this configuration, the cavities were spaced approximately 500 mm apart and interlesional epidermis and dermis demonstrated viable tissue by LDH staining. Conclusion: A novel prototype ablative CO2 laser Device operating in a fractional mode was developed and its resultant thermal effects in human abdominal tissue were characterized. We discovered that controlled microarray patterns could be deposited in skin with variable depths of dermal tissue ablation depending on the treatment pulse energy.Thisisthefirstreporttocharacterizethesuccessful use of ablative fractional Resurfacing as a potential approach to dermatological treatment. Lasers Surg. Med. 2006 Wiley-Liss, Inc.