Thoracic and lumbar fractures associated with skiing and snowboarding injuries according to the AO Comprehensive Classification.

BACKGROUND: The incidence of spinal fractures varies from 1% to 17% in alpine skiing injuries. Distinctions have been made regarding the differences in the mechanisms of injury and fracture types between skiing and snowboarding. Although fracture patterns have been described, there have not been any detailed descriptions of the specific fracture types and subgroups. PURPOSE: To address the patterns of spinal fractures associated with these sports and to determine the incidence of various fracture groups and subgroups as well as to determine whether the fracture patterns differ between skiing and snowboarding injuries. STUDY DESIGN: Descriptive epidemiology study. METHODS: This is a retrospective review of thoracic and lumbar spinal fractures associated with either skiing or snowboarding over a period of 5 years. The injuries were classified according to the AO Comprehensive Classification. In addition, isolated transverse process fractures and isolated spinous process fractures were included. Cervical spine fractures were excluded from this study. RESULTS: There were a total of 119 patients with thoracic and lumbar fractures that were identified after 1,283,348 skiing/snowboarding days. There were a total of 146 fractures, of which 114 were classified according to the AO Comprehensive Classification, with the remaining fractures (n = 32) consisting of isolated transverse or spinous process fractures. The preponderance of these injuries (94.7%) was compression injuries. Burst fractures (A3.1 and A3.2) made up 23%, and simple compression fractures (A1.1, A1.2, and A1.3) made up 71% of the total. Distraction injuries composed only 4.4%, and rotation injuries composed 0.9% of the total. The snowboarders incurred only compression fractures, whereas the 5 distraction injuries and the 1 rotational injury were noted only in the skier population. There were no patients with neurological deficits in this review. Fourteen skiers (14%) and 10 snowboarders (8%) were found to have isolated transverse process fractures. All 6 isolated spinous process fractures (4% of all fractures) were in the thoracic spine. CONCLUSION: Thoracic and lumbar fractures caused by skiing and snowboarding are mainly stable injuries, composed of either compression fractures, mostly simple compression injuries, or isolated transverse and spinous process fractures. Neurological injury was not seen in this study.

The effect of platelet-rich plasma on normal soft tissues in the rabbit.

BACKGROUND: Platelet-rich plasma is reported to contain multiple growth factors, and has been utilized in orthopaedic surgery to aid healing in multiple tissues. To date, the use of autologous platelet-rich plasma has not been studied for its effects on normal soft tissue. METHODS: Eighteen adult New Zealand White rabbits were injected with 0.5 mL of autologous platelet-rich plasma in the right or left quadriceps muscle, Achilles tendon, medial collateral ligament, subcutaneous tissue, tibial periosteum, and ankle joint. Saline solution was injected on the contralateral side as a control. The soft tissues were examined histologically at two weeks (six rabbits) and six weeks (six rabbits), and soft tissues from six rabbits that had been reinjected at six weeks were examined at twelve weeks. RESULTS: Inflammatory skin lesions were visible at forty-eight hours at superficial platelet-rich plasma sites. All lesions resolved by six days. Compared with findings in control specimens, histological analysis of platelet-rich plasma injection sites at two weeks showed a marked inflammatory infiltrate with lymphocytic and monocytic predominance. Intra-articular injection showed villous synovial hyperplasia and chronic synovitis. Tendon and ligament sites showed new collagen deposition. Intramuscular injection sites showed thrombosis, necrosis, and calcium deposition. Subcutaneous sites also showed calcium deposition without necrosis as well as collagen nodules representing early scar tissue. Histological examination of platelet-rich plasma injection sites at six and twelve weeks demonstrated a persistent but diminished inflammatory infiltrate. Focal areas of scar tissue were seen with fibroblasts, collagen formation, and neovascularity. All saline solution sites at all times were nonreactive. CONCLUSIONS: Platelet-rich plasma can initiate an inflammatory response in the absence of an inciting injury in normal soft tissue in rabbits.

Comparison of 4 femoral tunnel drilling techniques in anterior cruciate ligament reconstruction.

PURPOSE: The purpose of this study was to determine which femoral tunnel drilling technique most closely reproduces the anatomic femoral footprint and has acceptable tunnel length and tunnel orientation. METHODS: We divided 20 cadaveric knees into 4 equal groups. Arthroscopically, the anatomic femoral footprint was marked with an awl as the tunnel starting point. In group 1 the femoral tunnel was drilled through a tibial tunnel. In groups 2 and 3 the femoral tunnel was drilled through the anteromedial arthroscopy portal, with a rigid drill and flexible drill, respectively. In group 4 the femoral tunnel was drilled with the outside-in technique over a pin positioned with an arthroscopic femoral guide. Measurements of the tunnel length, aperture, and placement were taken from 3-dimensional computed tomography scans. RESULTS: Tunnel length for groups 1, 2, 3, and 4 averaged 42.08 mm, 37.73 mm, 28.92 mm, and 31.96 mm (P = .039). The mean coronal angle of the tunnels as measured from the line tangent to the posterior femoral condyles was 63.30°, 61.22°, 51.77°, and 45.00° (P = .007), and the mean distance from the inferior articular surface to the edge of the tunnel was 5.60 mm, 4.36 mm, 2.42 mm, and -0.63 mm (P = .008) for groups 1, 2, 3, and 4, respectively. There was no statistical difference in footprint length, width, area, or distance from the posterior articular margin. CONCLUSION: Drilling by the transtibial technique produces the most vertical and longest tunnels. Independent drilling techniques produce the most anatomic tunnels but at the expense of tunnel length. CLINICAL RELEVANCE: When the orthopaedic surgeon is performing ACL reconstruction, it is critical to achieve anatomic placement of the graft, as well as maintain appropriate tunnel length.

Mini-incision patellar tendon harvest and anterior cruciate ligament reconstruction using critical bony landmarks.

Graft choice remains an area of contention in anterior cruciate ligament reconstruction. Poorer cosmetic results and anterior knee pain remain a problem in the use of autologous patellar tendon grafts despite excellent clinical results when compared with autologous hamstring tendon grafts. Using a 2-incision technique to harvest the patellar tendon grafts has been shown to decrease the risk of anterior knee pain to a level comparable to hamstring tendon grafts. Proper graft tunnel placement and orientation also remain controversial with several recent researchers arguing the ability to perform an anatomic reconstruction using a conventional endoscopic transtibial technique. We will describe a relatively simple and cosmetically acceptable 2-incision technique for harvesting a bone-tendon-bone graft. In addition, we will describe the bony landmarks that should be used to ensure proper anatomic graft placement and the appropriate angles that need to be used for the tibial tunnel to drill the femoral tunnel in an anatomic position and carry out a successful endoscopic transtibial tunnel anterior cruciate ligament reconstruction.

Anterior cruciate ligament insertions on the tibia and femur and their relationships to critical bony landmarks using high-resolution volume-rendering computed tomography.

BACKGROUND: Controversy exists regarding the locations of the anterior cruciate ligament insertions on the femur and tibia and visualization of these insertions during surgical reconstruction. HYPOTHESIS: Anatomical insertions of the anterior cruciate ligament have relationships to bony landmarks of the tibia and femur. STUDY DESIGN: Descriptive laboratory study. METHODS: Eight cadaveric knees were scanned by computed tomography, reconstructed 3-dimensionally, and examined from simulated arthroscopic, sagittal, and axial perspectives. Volume-rendering software was used to document the relationship of the anterior cruciate ligament to the bony anatomy. RESULTS: A bony ridge (Resident's Ridge) at the anterior border of the anterior cruciate ligament was readily noted on the medial wall of the lateral femoral condyle. Superiorly, anterior cruciate ligament fibers inserted up to the roof of the notch and to 3 to 3.5 mm of the articular surface posteriorly and inferiorly. The anterior cruciate ligament inserted into a fovea anterior to the tibial eminence. Posteriorly, anterior cruciate ligament fibers inserted up to a ridge between the medial and lateral intercondylar tubercles. Medially, anterior cruciate ligament fibers inserted onto the ridge at the lateral border of the medial tibial condyle. There was no distinct anterior or lateral bony border with anterior cruciate ligament fibers blending into the anterior horn of the lateral meniscus. CONCLUSION: The anterior border of the femoral anterior cruciate ligament origin is Resident's Ridge. The ridge between the medial and lateral intercondylar tubercles at the base of the tibial eminence is the posterior margin of the anterior cruciate ligament on the tibia. CLINICAL RELEVANCE: Bony landmarks can be used to aid in anatomical anterior cruciate ligament reconstruction.