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.

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.

Paragliding Injuries.

In brief This review of 12 paragliding accidents in the Aspen, Colorado, area over a nearly 2-year period identifies causative factors and common mechanisms of injury and assesses the nature and severity of the injuries. Pilot error in judgment was the most frequent cause of accident. Lower-extremity and spinal compression fractures are common during forceful landings. Free-fall accidents, however, typically cause more serious pelvic, chest, and abdominal trauma.