Effects of repetitive platelet-rich plasma application on human tenocyte proliferation.

Current clinical application of platelet-rich plasma is showing a trend toward multiple treatments. The goal of this study was to show the benefit of interval platelet-rich plasma application in the healing and recovery of human tenocytes using an in vitro cell model. Eight volunteers (6 men and 2 women) were included in this study (mean±SD age, 31.

Histomorphologic changes of the long head of the biceps tendon in common shoulder pathologies.

Purpose: To assess molecular and histologic differences between the proximal (intra-articular) and distal (extra-articular) portions of the long head of the biceps (LHB) tendon in 3 different disease states (biceps instability, tendinosis, and degenerative joint disease [DJD]) compared with a healthy tendon (fresh frozen).

Methods: We used 32 LHB tendons of patients undergoing tenodesis (mean age, 54.7 ± 10.

Graft fixation is highest with anatomic tunnel positioning in acromioclavicular reconstruction.

Purpose: The purposes were to determine the bone density at specific bone tunnel locations in the clavicle and to determine ultimate load to failure of a graft fixed with an interference screw at specific areas.

Methods: Bone mass densitometry was tested at 5-mm intervals from the lateral to the medial end of 11 clavicles (mean age, 70.0 ± 17.

Comparison of mesenchymal stem cells (osteoprogenitors) harvested from proximal humerus and distal femur during arthroscopic surgery.

Purpose: The aim of this study was to examine the relations between age, gender, and number of viable mesenchymal stem cells (MSCs) in concentrated bone marrow (BM) obtained from the proximal humerus and distal femur during arthroscopic surgery.

Methods: BM was aspirated from either the proximal humerus (n = 55) or distal femur (n = 29) during arthroscopic surgery in 84 patients (51.3 ± 11.

The positive effects of different platelet-rich plasma methods on human muscle, bone, and tendon cells.

Background: Clinical application of platelet-rich plasma (PRP) in the realm of orthopaedic sports medicine has yielded variable results. Differences in separation methods and variability of the individual may contribute to these variable results.

Purpose: To compare the effects of different PRP separation methods on human bone, muscle, and tendon cells in an in vitro model.

Biomechanical performance of subpectoral biceps tenodesis: a comparison of interference screw fixation, cortical button fixation, and interference screw diameter.

Background: Subpectoral biceps tenodesis with interference screw fixation allows reproducible positioning of the tendon to help maintain the length-tension relationship. The aim of our study was to evaluate the role of cortical button fixation in isolation or as an augment to interference screw fixation and to determine if the diameter of the interference screw affected fixation strength.

Materials And Methods: Thirty-two cadaveric shoulders were dissected and randomized to 1 of 4 groups: (1) 7-mm interference screw and cortical button, (2) cortical button alone, (3) 7-mm interference screw, or (4) 8-mm interference screw.

Stability of double-row rotator cuff repair is not adversely affected by scaffold interposition between tendon and bone.

Background: Rotator cuff reconstructions may be improved by adding growth factors, cells, or other biologic factors into the repair zone. This usually requires a biological carrier (scaffold) to be integrated into the construct and placed in the area of tendon-to-bone healing. This needs to be done without affecting the constructs mechanics.

Platelet-rich plasma differs according to preparation method and human variability.

Background: Varying concentrations of blood components in platelet-rich plasma preparations may contribute to the variable results seen in recently published clinical studies. The purposes of this investigation were (1) to quantify the level of platelets, growth factors, red blood cells, and white blood cells in so-called one-step (clinically used commercial devices) and two-step separation systems and (2) to determine the influence of three separate blood draws on the resulting components of platelet-rich plasma.

Methods: Three different platelet-rich plasma (PRP) separation methods (on blood samples from eight subjects with a mean age [and standard deviation] of 31.

Corticosteroids and local anesthetics decrease positive effects of platelet-rich plasma: an in vitro study on human tendon cells.

Purpose: To determine the effects of mixing anesthetics or corticosteroids with platelet-rich plasma (PRP) on human tenocytes in vitro.

Methods: Two separate protocols (double spin and single spin) were used to obtain homologous PRP from the blood of 8 healthy volunteers. Discarded tendon acquired during biceps tenodesis served as tendon specimens for all experiments.

Biomechanical properties of repairs for dislocated AC joints using suture button systems with integrated tendon augmentation.

Purpose: To evaluate the biomechanical performance of different techniques for CC reconstruction using suture button systems with integrated tendon augmentation. Hypothesis was that (1) reconstructions using a cortical button combined with a biological augmentation (semitendinosus allograft) will demonstrate improved stability than a modified Weaver-Dunn procedure and (2) constructs using two tunnels at the clavicle for fixation will show superior horizontal stability than single-tunnel constructs.

Methods: The acromioclavicular joints of 47 cadaveric shoulders were tested for anterior, posterior, and superior translations (70 N load) and maximal load to failure (superior).

Sequential resection of the distal clavicle and its effects on horizontal acromioclavicular joint translation.

Background: Reconstructions of the coracoclavicular (CC) ligament in an open or arthroscopically assisted procedure are often combined with a resection of the distal clavicle to prevent or treat osteoarthritic degenerations of the acromioclavicular (AC) joint. However, increased horizontal translation leading to symptomatic instability may be associated with resection of the distal clavicle.

Hypothesis: Horizontal translation increases in direct correlation to subsequent resection of the distal clavicle.

Biomechanical comparison of arthroscopic repairs for acromioclavicular joint instability: suture button systems without biological augmentation.

Background: Arthroscopic procedures for reconstruction of acromioclavicular (AC) joint separations are increasingly used in clinical practice. Multiple surgical techniques exist, but there are still few data on biomechanical performances of commonly used arthroscopic techniques and fixation methods.

Hypothesis: Single and double clavicular tunnel reconstructions show comparable primary stability with a modified Weaver-Dunn procedure, and double tunnel constructs show superior horizontal stability.

Effects of adding epinephrine to arthroscopic irrigation fluid on cultured chondrocyte survival in vitro.

Purpose: This study evaluates the effect of low doses of epinephrine contained in common arthroscopic irrigation solutions on viability of in vitro human articular chondrocytes during short-term exposure.

Methods: Isolated cultured human chondrocytes were treated with culture medium, normal saline solution, 1:300,000 epinephrine solution (equivalent to 10 mL of 1:1,000 epinephrine added to a 3-L saline solution bag), or 1:3,000,000 epinephrine solution (equivalent to 1 mL of 1:1,000 epinephrine added to a 3-L saline solution bag) for 1 hour (N = 84). Twenty-four hours after treatment, chondrocyte viability was measured.

Rapid isolation of human stem cells (connective tissue progenitor cells) from the proximal humerus during arthroscopic rotator cuff surgery.

Background: Bone-to-tendon healing in the shoulder can be unpredictable. Biologic augmentation, through the implementation of adult mesenchymal stem cells, may improve this healing process.

Purpose: The purpose of this study was to (1) arthroscopically obtain bone marrow aspirates from the proximal humerus during rotator cuff repair, (2) purify and concentrate the connective tissue progenitor cells (CTPs) in the operating room efficiently, and (3)confirm these are stem cells through their ability to differentiate into bone cells.