Dimitrios Koulalis

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.

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.

Arthroscopic Mosaicplasty for Osteochondral Lesions of the Knee: Computer-Assisted Navigation Versus Freehand Technique

PURPOSE The purpose of this study was to compare a freehand arthroscopic approach versus mosaicplasty for treatment of osteochondral lesions of the knee with a navigated arthroscopic technique. METHODS Four whole cadaveric lower limbs were used. A conventional navigation system was used in combination with an autologous osteochondral graft transplantation system (Osteochondral Autograft Transfer System [OATS]; Arthrex, Naples, FL). The congruity of the articular surface was measured with the navigation probe to detect any difference between the surface created by the grafts and the surface of the femoral condyle surrounding them. The angle relates to a line perpendicular to the articular surface. This line is made by the cutting instrument for graft harvesting and insertion and the articular surface. RESULTS The mean angle of graft harvest was 3.4° (range, 0° to 10°) in the navigated group versus 14.8° (range, 6° to 26°) in the freehand group (P < .0003). The mean angle for recipient-site coring was 1.5° (range, 0° to 5°) in the navigated group versus 12.6° (range, 4° to 17°) in the freehand group (P < .0003). The mean angle of graft placement was 2° (range, 1° to 5°) in the navigated group versus 10.8° (range, 5° to 15°) in the freehand group (P = .0002). The mean protrusion height of the plug was 0.23 mm (range, 0.1 to 0.5 mm; SD, 0.16) in the navigated group versus 0.34 mm (range, 0.0 to 0.7 mm; SD, 0.25) in the freehand group (P = .336). CONCLUSIONS Computer-assisted arthroscopic mosaicplasty for treatment of osteochondral lesions in the cadaveric model presented in this study allows permanent visualization of the angle of recipient-site preparation, the depth of the donor plug and the recipient plug, and the angle of insertion of the graft at the recipient site. CLINICAL RELEVANCE This study shows evidence of potentially greater precision and reproducibility of navigated arthroscopic mosaicplasty when compared with an arthroscopic freehand technique in a cadaveric model. However, true clinical outcome benefit will only be elucidated upon performance of appropriate clinical studies.

Adjustable Cutting Blocks for Computer-Navigated Total Knee Arthroplasty: A Cadaver Study

Computer-navigation in total knee arthroplasty has been reported to increase accuracy but also procedure duration. We compared surgical time and precision using a novel adjustable cutting block vs freehand navigation with conventional blocks on 12 bilateral cadaver tibiae. The mean time required was significantly less to position the adjustable block than the conventional block (2 minutes 10 seconds vs 6 minutes 35 seconds, P = .006). Guide positioning precision (standard deviation) for the adjustable block vs conventional block was as follows: varus/valgus, 0.24 degrees vs 1.16 degrees (P = .015); posterior slope, 0.35 degrees vs 0.74 degrees (P = .13); and cut height, 0.37 vs 1.41 mm (P = .010). There were no significant differences in the final bone cut accuracy between the 2 groups. The use of adjustable cutting blocks simplifies navigated procedures and may reduce the time required to perform a navigated total knee arthroplasty.

The Potentially Positive Role of PRPs in Preventing Femoral Tunnel Widening in ACL Reconstruction Surgery Using Hamstrings: A Clinical Study in 51 Patients.

Purpose. In this study, the early and midterm clinical and radiological results of the anterior cruciate ligament (ACL) reconstruction surgery with or without the use of platelet rich plasma (PRP) focusing on the tunnel-widening phenomenon are evaluated. Methods. This is a double blind, prospective randomized study. 51 patients have completed the assigned protocol. Recruited individuals were divided into two groups: a group with and a group without the use of PRPs. Patients were assessed on the basis of MRI scans, which were performed early postoperatively and repeated at least one-year postoperatively. The diameter was measured at the entrance, at the bottom, and at the mid distance of the femoral tunnel. Results. Our study confirmed the existence of tunnel widening as a phenomenon. The morphology of the dilated tunnels was conical in both groups. There was a statistical significant difference in the mid distance of the tunnels between the two groups. This finding may support the role of a biologic response secondary to mechanical triggers. Conclusions. The use of RPRs in ACL reconstruction surgery remains a safe option that could potentially eliminate the biologic triggers of tunnel enlargement. The role of mechanical factors, however, remains important.

Complete dislocation of the talus: A case report using intraoperative 3D fluoroscopy

INTRODUCTION In a complete dislocation of the talus, the talus is stripped of all its ligament connections in the triple articulated ankle joint. This case report describes the treatment and the 3-year follow-up of a complete dislocation of the talus with the use of intraoperative 3D imaging. PATIENTS AND METHODS The 19-year-old patient was involved as a driver in a car accident. After the radiological diagnosis of a complete talus dislocation, an emergency operation was performed due to the critical soft tissue condition. The ISO-C3D fluoroscope from the company Siemens (Erlangen, Germany) was utilized for reduction control. RESULTS Follow-up evaluations were completed three years after the treatment, the patient had no complaints. DISCUSSION Since these types of serious injuries are always combined with severe soft tissue damage, the main goals of this treatment have to be debridement and minimized iatrogenic surgical damage. By using intraoperative 3D imaging, immediate reduction control is available, so that revision operations can be avoided. CONCLUSION Complete dislocation of the talus is an extremely rare injury, which may cause serious complications. A fast and careful reduction, whether open or closed, should be the goal of treatment. Successful reduction can be determined intraoperatively with the use of 3D imaging.

Reconstruction of a Neglected Tibial Plateau Fracture Malunion with an Open-Book Osteotomy

Case: Surgical management of tibial plateau fractures can be challenging, and complications can be devastating. We report the case of a lateral tibial plateau fracture malunion with an associated intra-articular depression, which we treated with an open-book osteotomy, obviating the need for an early corrective osteotomy or knee arthroplasty. Conclusion: A tibial plateau fracture malunion can be reconstructed. The surgical team should give priority to salvage options, which can obviate or delay the need for and the implications of an early total knee arthroplasty, especially in a young and active patient.

Open Versus Arthroscopic Mosaicplasty of the Knee: A Cadaveric Assessment of Accuracy of Graft Placement Using Navigation

PURPOSE The purpose of this study was to compare an open freehand mosaicplasty technique with an arthroscopic technique for the treatment of osteochondral lesions by measuring the instrument deviation, quantifying this deviation, and providing numerical information on the difference in the outcomes of these techniques. METHODS Four cadaveric knees were used. Reference markers were attached to the femur, tibia, and donor/recipient site guides. A total of 10 osteochondral grafts were harvested and inserted into recipient sites arthroscopically and 10 similar grafts were inserted freehand. The angles of graft removal and placement were calculated for each of the surgical groups compared. Ostensibly, a navigation system was used as an aid, to measure the graft placement parameters. RESULTS Statistical analysis revealed that there was no statistically significant difference between the arthroscopic method and the freehand method regarding the angle of graft removal at the donor site (P = .162), recipient site plug removal angle (P = .731), and recipient site graft placement angle (P = .630). In the freehand group, the mean angle of graft removal at the donor site was 12°, the mean angle of recipient site plug removal was 10.7°, and the mean angle of recipient site plug placement was 10.6°. Using the arthroscopic technique, the mean angle of graft removal at the donor site was 17.14°, the mean angle of recipient site plug removal was 12.0°, and the mean angle of recipient site graft placement was 10.14°. CONCLUSIONS Our study revealed there was no statistically significant difference regarding precision and accuracy during harvesting, recipient site preparation, and plug placement between the 2 techniques. CLINICAL RELEVANCE Controversy exists whether an open or arthroscopic osteoarticular transfer system (OATS) technique provides superior accuracy. According to our results, there is no statistically significant difference regarding better visualization, precision, and accuracy between the freehand and arthroscopic techniques. However, larger number of specimens are required for study.