Post-Operative Pain After Knee Arthroscopy and Related Factors

The aim of this study was to explore the intensity of post-arthroscopy knee pain during the first 24 hours, and to study the influence of pre-operative pain, tourniquet time and amount of surgical trauma on post-arthroscopy pain. In 78 male patients that underwent elective arthroscopic menisectomy or diagnostic arthroscopy of the knee, preoperative and post-operative pain were registered using the Visual Analogue Scale. Variance for repeated measures and for independent observations was analysed. Supplementary analgesia was required for 23% of the patients, more often in the recovery room and between 2 and 8 hours postoperatively. Of all factors analyzed, only time was statistically significant in determining the level of post-operative pain. Supplementary analgesia was required only in patients that underwent operative arthroscopy, and more often in patients with tourniquet time of more than 40 minutes. In conclusions, post-operative time is the most significant factor related to the post-arthroscopy knee pain

The effect of platelet-rich plasma gel in the early phase of patellar tendon healing

Introduction: The aim of this study is to assess if an application of platelet-rich plasma (PRP) gel would improve the mechanical properties of rabbit's patellar tendon after resecting its central portion. Materials and methods: Forty skeletally mature New Zealand White rabbits were used. Two groups ten rabbits each (PRP and control group) were used to evaluate mechanical properties and histology after 14 days and two groups ten rabbits each (PRP and control groups) were used to evaluate mechanical properties and histology after 28 days. Results: At 14 days, PRP group showed a 72.2% increase in force at failure, a 39.1% increase in ultimate stress, and a 53.1% increase in stiffness, as compared with controls. These changes were statistically significant (P < 0.05). At 28 days, there was no longer any significant difference between PRP and control groups (P > 0.05). Discussion: In our study, the mechanical properties of the regenerated tendon in the PRP group were significantly improved in relation to the control group. It appears that PRP has a strong effect in the early phase of tendon healing. This effect is probably due to the growth factors that are released from the platelets during activation. © Springer-Verlag 2009

Experimental study of tendon healing early phase: Is IGF-1 expression influenced by platelet rich plasma gel?

Background: It is well established that growth factors play a critical role in the healing process of connective tissues. To our knowledge, there are no studies in literature concerning the influence of PRP on growth factors expression. Hypothesis: The aim of this study was to assess the effect of a single application of platelet rich plasma (PRP) gel in a patellar tendon defect on the spatial and temporal expression of Insulin-like Growth Factor 1 (IGF-1) during tendon healing. Materials and methods: Twenty-four animals were randomized to receive PRP (PRPFast, Bioteck) in a gel form (PRP group) and 24 to serve as untreated controls (Control group). A defect of 3 mm × 10 mm was surgically created on the tendon under general anaesthetic and in the PRP group, PRP gel was applied to fill the tendon defect whereas no treatment was applied in the control group. Six animals (12 limbs) from each treatment-group were sacrificed after one, two, three and four weeks following treatment. Histological and immunohistochemical staining were performed. Results: Histology revealed a faster healing process in the tendons of PRP group in comparison with the controls. In the first 2 weeks of healing, IGF-1 was found intracellularly in various type cells, whereas in the last 2 weeks of healing, IGF-1 was detected mainly in tenocytes. Both cytoplasmic and nuclear expressions were present, whereas the larger amounts of immunoexpression were localized in both epitenon and endotenon. A superior expression of IGF-1 was seen in PRP group compared with controls (p < 0.0001) in both the epitenon and endotenon at each time point except at 4th week of healing where a superior expression of IGF-1 was shown in the endotenon of control group, compared to the PRP group (p < 0.0001). Conclusion: PRP may improve tendon defect healing by overexpression of IGF-1. Level of evidence: Laboratory control animal study. © 2010

Experimental study of tendon healing early phase: Is IGF-1 expression influenced by platelet rich plasma gel? [Étude expérimentale de la phase précoce decicatrisation tendineuse: un gel plasmatique enrichi en plaquettes influence-t-il l'expression de l'IGF1?]

Background: It is well established that growth factors play a critical role in the healing process of connective tissues. To our knowledge, there are no studies in literature concerning the influence of platelet rich plasma (PRP) on growth factors expression. Hypothesis: The aim of this study was to assess the effect of a single application of PRP gel in a patellar tendon defect on the spatial and temporal expression of Insulin-like Growth Factor 1 (IGF-1) during tendon healing. Materials and methods: Twenty-four animals were randomized to receive PRP (PRPFast, Bioteck) in a gel form (PRP group) and 24 to serve as untreated controls (Control group). A defect of 3 mm × 10 mm was surgically created on the tendon under general anaesthetic and in the PRP group, PRP gel was applied to fill the tendon defect whereas no treatment was applied in the control group. Six animals (12 limbs) from each treatment group were sacrificed after one, two, three and four weeks following treatment. Histological and immunohistochemical staining were performed.© 2010

Application of PRP gel alone or in combination with guided bone regeneration does not enhance bone healing process: An experimental study in rabbits

Introduction: The aim of this study was to assess the hypothesis that application of platelet-rich plasma (PRP) gel in mandibular defects in rabbits, alone or in combination with guided bone regeneration (GBR) techniques, could enhance the bone healing process. Materials and methods: Thirty New Zealand white rabbits were used. Three groups of 10 animals each were assigned, and the animals were sacrificed after 12 weeks. During the operation, a rotating trephine bur was used to create circular defects 10-mm in diameter in the region anterior to the jaw angles. In group human fascia lata (HFL), a human fascia lata membrane was used. In group PRP, PRP gel was used to fill the defect, and in group HFL + PRP, PRP was used to fill the defect which after that was covered with a human fascia lata membrane. Results: In general, none of the control sides and the PRP treated sides had full development of bone or filling of the defect through bone bridging. Conversely, the sides on which the fascia lata membrane or the combination of membrane and PRP had been applied were characterized mostly by development of newly formed bone that bridged the gap. Conclusions: Our results suggest that the application of PRP gel alone or in combination with GBR does not enhance bone healing process. © 2010 European Association for Cranio-Maxillo-Facial Surgery

Can low doses of simvastatin enhance fracture healing? An experimental study in rabbits

Several observational and experimental studies have investigated the potential anabolic effects of statins on undisturbed bone but only a few recent studies have examined the effect of statins on skeletal repair. The goal of the study is to investigate any potential early anabolic effect of the systemic administration of simvastatin in low doses (based on earlier safety and efficacy studies on undisturbed bone) on fracture healing. Fifty-four skeletally mature male New Zealand White rabbits were used for the study. The rabbits were assigned to one of three experimental groups: a control group, and two groups that were orally administrated a diet with 10 and 30 mg/kg/day of simvastatin, respectively. A complete biochemical blood count was performed to exclude drug-induced complications. Half of the animals of each group were sacrificed at 15 days and the other half at 30 days after surgery at which time intervals healing quality was assessed. The bones were subjected to biomechanical testing, histomorphometric analysis and peripheral quantitative computed tomography. In animals received simvastatin of 30 mg/ kg/day a significant reduction of BMD, stiffness, and energy absorbed to failure were observed. At 15 days, the amount of cartilaginous callus formation was reduced, and the void space was significantly increased, in the animals of both groups that received simvastatin when compared to the control group (p < .05). Our results suggest that simvastatin doses of 30 mg/kg/day may have a negative anabolic effect on callus formation in rabbits, whereas doses of 10 mg/kg/day seem not to produce a significant positive or a negative effect, especially at the early stages of fracture remodeling. © 2009 Elsevier Ltd. All rights reserved