563 AUTOLOGOUS OSTEOCHONDRAL TRANSPLANTATION OF THE KNEE JOINT ASSISTED BY COMPUTER NAVIGATION. CADAVERIC STUDY

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Sequential versus automated cutting guides in computer-assisted total knee arthroplasty

The accuracy and efficiency of automated cutting guides in CAS systems have not been previously compared with conventional CAS techniques. Therefore, it is not yet clear if these more advanced technologies are warranted. We hypothesized that a novel automated cutting guide with CAS for total knee arthroplasty would be more efficient and more accurate than conventional navigation with sequential cutting blocks. Twelve cadaver legs were used in total. Each leg was randomly assigned to either an automated guide positioning or a conventional freehand computer-navigated guide positioning. The guide positions postosseous fixation and the final bone-cut surfaces were digitized and compared to the targeted cutting planes. The final location of the impacted trial implant was also digitized and compared to the planned implant location. The time for each step and the total time taken to prepare the femur were measured for both groups. The mean femoral preparation time was shorter with the automated cutting guide than the conventional method (5.5. min versus 13.8. min, p < 0.001). The average deviation in the final bone resections from the planned resections was significantly lower for the automated cutting guide in the frontal/rotational plane (0.55° versus 1.1°), sagittal plane (0.75° versus 2.0°), and cut height direction (0.56. mm versus 1.6. mm). Therefore, based on these results, we concluded that automated cutting-guide positioning resulted in more efficient and more accurate femoral cuts in comparison to the conventional navigation method in a cadaveric model. © 2010 Elsevier B.V

Comparative study of navigated versus freehand osteochondral graft transplantation of the knee

Background: Osteochondral lesions are a common sports-related injury for which osteochondral grafting, including mosaicplasty, is an established treatment. Computer navigation has been gaining popularity in orthopaedic surgery to improve accuracy and precision. Hypothesis: Navigation improves angle and depth matching during harvest and placement of osteochondral grafts compared with conventional freehand open technique. Study Design: Controlled laboratory study. Methods: Three cadaveric knees were used. Reference markers were attached to the femur, tibia, and donor/recipient site guides. Fifteen osteochondral grafts were harvested and inserted into recipient sites with computer navigation, and 15 similar grafts were inserted freehand. The angles of graft removal and placement as well as surface congruity (graft depth) were calculated for each surgical group. Results: The mean harvesting angle at the donor site using navigation was 4° (standard deviation, 2.3°; range, 1°-9°) versus 12° (standard deviation, 5.5°; range, 5°-24°) using freehand technique (P < .0001). The recipient plug removal angle using the navigated technique was 3.3° (standard deviation, 2.1°; range, 0°-9°) versus 10.7° (standard deviation, 4.9°; range, 2°-17°) in freehand (P < .0001). The mean navigated recipient plug placement angle was 3.6° (standard deviation, 2.0°; range, 1°-9°) versus 10.6° (standard deviation, 4.4°; range, 3°-17°) with freehand technique (P = .0001). The mean height of plug protrusion under navigation was 0.3 mm (standard deviation, 0.2 mm; range, 0-0.6 mm) versus 0.5 mm (standard deviation, 0.3 mm; range, 0.2- 1.1 mm) using a freehand technique (P = .0034). Conclusion: Significantly greater accuracy and precision were observed in harvesting and placement of the osteochondral grafts in the navigated procedures. Clinical studies are needed to establish a benefit in vivo. Clinical Relevance: Improvement in the osteochondral harvest and placement is desirable to optimize clinical outcomes. Navigation shows great potential to improve both harvest and placement precision and accuracy, thus optimizing ultimate surface congruity. © 2009 American Orthopaedic Society for Sports Medicine

Osteomyelitis of the femur effectively treated with medulloscopy debridement: a case report

Background: Medulloscopy refers to the visualization of the intramedullary canal with an arthroscope, providing access to the infection site without the need for an extensive approach therefore not compromising the surrounding soft tissue. It provides information regarding the extent of the infected endosteal surface of bone, and it allows a thorough debridement of the intramedullary canal in a controlled manner. Therefore, it can be used as an adjunct to traditional open surgical techniques, to perhaps help to visualize hard to see intramedullary areas. Materials and methods: This article reports a patient with chronic osteomyelitis of the distal metaphysis of the femur that was treated successfully with intramedullary debridement through medulloscopy. The sinus tract reaching down to the femoral bone and communicating with the intramedullary canal was excised, and a cortical window was formed through which the arthroscope was inserted and thorough irrigation of the intramedullary canal and excision of necrotic and infected bone was done. A second medulloscopy through the same approach was necessary 3 months later because of persistent infection. Re: sults: At 3-year follow-up, the patient was well without any clinical or radiographic evidence of recurrent infection. Conclusion: Medulloscopy can be very useful in localized osteomyelitis as an adjunct to traditional surgical techniques; it helps to visualize hard to see intramedullary areas and adequately addresses the infection, while the damage to surrounding soft-tissue is limited. © 2020, Springer-Verlag France SAS, part of Springer Nature

Donor's site evaluation after restoration with autografts or synthetic plugs in rabbits

Aim: To investigate donor site's area histological and immunohistochemical knee cartilage appearances after resurfacing iatrogenic defects with biosynthetic plugs orautografts. Methods: Thirty New Zealand White rabbits were used in this study. A full-thickness cylindrical defect of 4.5 mm (diameter) × 7 mm (depth) was created with a hand drill in the femoral groove of every animal. In Group A (n = 10) the defect of the donor site was repaired with a biosynthetic osteochondral plug, in Group B (n = 10) with an osteochondral autograft, while in Group C (control group of 10) rabbits were left untreated. Results: Twenty-four weeks postoperatively, smooth articular cartilage was found macroscopically in some trocleas' surfaces; in all others, an articular surface with discontinuities was observed. Twenty-eight out of 30 animals were found with predominantly viable chondrocytes leaving the remaining two -which were found only in the control group- with partially viable chondrocytes. However, histology revealed many statistical differences between the groups as far as the International Cartilage Repair Society (ICRS) categories are concerned. Immunofluoresence also revealed the presence of collagen II in all specimens of Group B, whereas in Group A collagen II was found in less specimens. In Group C collagen II was not found. Conclusion: The matrix, cell distribution, subchondral bone and cartilage mineralization ICRS categories showed statistically differences between the three groups. Group A was second, while group B received the best scores; the control group got the worst ICRS scores in these categories. So, the donor site area, when repairing osteochondral lesions with autografting systems, is better amended with osteochondral autograft rather than bone graft substitute implant. © 2014 Baishideng Publishing Group Inc

Higher Infection Rate after ACL Reconstruction with Hamstrings Tendon Autografts Compared with Bone Patellar Bone Tendon Autografts: A Review

Infection after anterior cruciate ligament reconstruction is a rare but devastating complication resulting in a deleterious impact on knee function as well as an increased related cost for treatment and rehabilitation for the patients. There are conflicting reports regarding the rate of infection between bone patellar tendon bone (BPTB) and hamstrings tendon (HT) autografts for anterior cruciate ligament reconstruction. Therefore, we performed this review to summarize all the available data regarding the risk of infection after ACL reconstruction, to provide insight on the infection risk between BPTB and HT autografts, and to discuss current recommendations for the diagnosis and treatment of these infec-tions. The incidence and risk of infection after ACL reconstruction with HT graft is higher compared with BPTB grafts. The most commonly subacute and late infections, quadruple type, need for cannulated instruments for harvesting, size and shape and fixation of the extra-tunnel material of the HT are important risk factors for infection. Combined antibiotics administration and adequate arthroscopic lavage and debridement are the optimal treatments for ACL reconstruction in-fection. Early diagnosis and treatment is the most important predictor for graft retention, which accounts more commonly for BPTB grafts. The treating physicians should be aware of the higher incidence of infection after ACL reconstruction with HT graft, as well as for the need for a high clinical suspicion for early diagnosis of the infection. These will increase the possibility of eradication of the infection and retention of the graft. © 2022, Journal of Long-Term Effects of Medical Implants. All rights reserved