Introduction and Objectives: meniscal lesions in the avascular zone are difficult to heal because of the poor biological potential of the avascular tissue. Little is known about the molecular mechanisms that develop after a meniscal lesion in this low activity zone. The purpouse of this study is to determine the levels of gene expression of five different growth factors (IGF, IL-1β; TGF-β, PDGF-β and VEGF) in the first three weeks after a meniscal lesion in the avascular zone of rabbit menisci.

Materials and Methods: 28 white female New Zealand rabbits were used in this study. Through a small arthrotomy a 5mm longitudinal lesion was performed in the avascular zone of the anterior horn of the medial meniscus of each rabbit. The rabbits were sacrificed after 0, 1, 3, 7, 14 and 21 days (4 rabbits each). After sacrifice, the zone in which the meniscal lesion was performed was disected from the rest of the mensicus. It was then divided in two parts: a peripheric vascular zone and a central avascular zone. After ARNm extraction cuantitative PRC anaylisis with Sybergreen technology was performed using specific primers for each gene.

Results: There were significant expression increases of IGF, TGF-β and PDGF-β, in the vascular zone at two weeks but no variations of note in these genes in the avasacular zone. The expression of IL-1β is increased in the first day after injury in both zones but only last up to the thrid day in the vascular zone. There is an increase in VEGF expresion in the avascular zone at two weeks that is related to a symetric decrease in the vascular zone.

Introduction and Objectives: patellar tendinopaty (or jumper’s knee) is a frequent problem that affects active young adults. In some cases the different conservative treatment options are innefective and surgical treatment is considered. The purpouse of this study is to determine if repeated intratendinous inyections of platelet rich plasma (PRP) are effective for the treatment of these refractary cases.

Materials and Methods: Eight consecutive patients (4 males and 4 females, mean age 24+/−5,9) who presented refractary patellar tendinopathies were included. All patients had presented symptoms for at least 6 months and had recieved treatmet for at least 3 months. All patients had been subjected to activity limitation, physical therapy, NSAID’s and laser and ultrasound therapy. In 3 cases corticosteroid inyections had been used. The subjects were assesed before treatment and 3 months and one year later with a Visual Analoge pain Scale (0 to 100mm, VAS), the Victorian Institute of Sport Assessment Patellar tendinopathy assesment scale(VISA-P) and the Lysholm score. Treatment consisted of 3 infiltrations (one week apart) of 3 cm3 of PRP extracted from their own blood with the GPS^® system (Biomet, Warsaw, Indiana, U.S.A). The PRP was infiltrated at the level of the tender tendon and inmediately behind the tendon at the proximal tendinous insertion and 1 cm distal to it through a single cutaneous puncture.

Results: Of the 8 patients, 7 presented a significant increase (more than 20 points) in the VISA-P score and 1 did not present any noticeable improvement. No complications related to the injections were observed. The VISA-P score increased from a pretreatment mean of 29 +/− 10.7 to 79 +/− 10.7 at one year (significant differences, p< 0.001). A similar decrease was observed in the VAS pain score (pretreatment values of 75+/−28 to one year values of 21+/−19). There were not significat differences in the Lysholm score.

Conclusions: PRP seems to be a possible alternative to surgical treatment in refractary patellar tendinopathy.

Objectives: tibial plateau fractures are a therapeutic challenge for the trauma surgeon. Arthroscopically assisted surgical treatment (AT) is an option in these fractures that is used more and more frequently even in more complex lesions. The objective of this study is to determine if, at a minimum 1 year follow up, arthroscopic treatment is comparable to open treatment (OT) in respect to radiologic and functional outcomes.

Materials and Methods: We have prospectively reviewed our first 50 arthroscopic cases and compared them with 50 open surgery cases examined retrospectively. The cases in the second group were selected from a database of 87 patients and were matched for Schätzker type, degree of displacement, age and sex with cases of the first group. In each group there were 50 patients (33 male/17 female; mean age: 45,4 years in the AT group and 43,6 years in the OT group). Of the 50 cases in each group, ten were Schätzker I tibial plateau fractures, sixteen were type II, seven type III, eleven type IV, three type V and three type VI. In the AT group all fractures were reduced and fixated with cannulated screws under direct arthroscopic control and in 6 cases a percutaneous plate was added. In the OT group all fractures were reduced and fixated with cannulated screws under direct vision (n=41) or radiologic control (n=9) and in 37 cases a plate was added. Associated lesions were identified and treated accordingly in both groups. Results were evaluated with the following scales: Rasmussen, Honkonen, ICDK, Lysholm, SF-36 and Knee Society scores.

Results: All cases were available for follow up a minimum of 12 months after surgery (2.6 +/−1.4 years in AT and 3.7+/−1.5 years in OC). The patients in the AT group had lower hospital stances (p< 0.05) and lesser postoperative wound complications (zero versus 3). Radiological reduction and alignment was considered excellent or good in 92% of AT cases and 88% of OT cases. Knee society scores were 191+/−18 in AT and 176+/−21 in OT. Lysholm scale scores were 85+/−20 in AT and 72+/−21 in OT. Rasmussen scale scores were 29+/−2.2 in AT and 26+/−3.9 in OT. Most of the differences between both groups was related to range of motion but pain scores were similar.

Conclusions: Arthroscopically assisted treatment of tibial plateau fractures seems to offer better results than open surgery with less hospital stay, lesser postoperative complications and clearly improved range of motion. It can be considered an adequate alternative to traditional open reduction and fixation even in complex fractures.