Purpose.: To evaluate the stages of patellar tendon graft remodelling using magnetic resonance imaging (MRI) after anterior cruciate ligament (ACL) reconstruction with or without platelet-rich plasma (PRP) injection. Methods.: 98 patients aged 18 to 65 years with complete rupture of the ACL were randomised to undergo reconstruction with the autologous patellar tendon grafts with or without PRP injection. For the PRP group, 8 ml of PRP was obtained in the surgery room and was percutaneously injected into the suprapatellar joint after portal suture. MRI was obtained at months 4, 6, and 12. Remodelling stages of the grafts were classified as hypointense, mildly hyperintense, moderately hyperintense, severely hyperintense, and diffusely hyperintense by a radiologist blinded to treatment allocation. Results.: More patients in the PRP group than controls attained higher stages of remodelling at month 4 (p=0.003), month 6 (p=0.0001), and month 12 (p=0.354). Conclusion.: PRP enabled faster remodelling of patellar tendon grafts.

To evaluate the clinical safety and efficacy of using a biologic technology known as preparation rich in growth factors (PRGF) for the treatment of nonhypertrophic nonunion. The design of the study was a retrospective case series. The private practice was in 2 centers. There were 15 patients with a total of 16 aseptic nonunions, 12 diaphyseal and 4 supracondylar, diagnosed as nonhypertrophic. The mean time since prior surgical treatment was 21 months (9-46 months). Supracondylar and diaphyseal nonunions followed surgical fixation with condylar plating or intramedullary nailing, whereas a composite biomaterial created by mixing PRGF with bone allograft was applied. The area was then covered with autologous fibrin membranes. Stable nonunions were treated with repeated percutaneous injections of PRGF; this minimally invasive procedure was also applied if delayed healing was suspected after surgical treatment. Radiographic union using radiographic views was taken in 2 planes. Clinical outcome evaluated pain, motion at the fracture site upon manual stress testing, and recovery of range of motion. All nonunions treated operatively healed after a single procedure, even though additional PRGF had to be injected in 2 patients. Two of 3 stable nonunions achieved healing only after repeated percutaneous PRGF injections. The mean time from surgery and/or PRGF application to union was 4.9 months (2-8 months). Complications associated with the described procedure were not observed. This study, although uncontrolled, shows that PRGF technology is clinically safe and can enhance the healing of nonhypertrophic nonunions.