A fibrin/heparin-based delivery system was used to provide controlled delivery of platelet derived growth factor BB (PDGF-BB) in an animal model of intrasynovial flexor tendon repair. We hypothesized that PDGF-BB, administered in this manner, would stimulate cell proliferation and matrix remodeling, leading to improvements in the sutured tendon's functional and structural properties. Fifty-six flexor digitorum profundus tendons were injured and repaired in 28 dogs. Three groups were compared: (1) controlled delivery of PDGF-BB using a fibrin/heparin-based delivery system; (2) delivery system carrier control; and (3) repair-only control. The operated forelimbs were treated with controlled passive motion rehabilitation. The animals were euthanized at 7, 14, and 42 days, at which time the tendons were assessed using histologic (hyaluronic acid content, cellularity, and inflammation), biochemical (total DNA and reducible collagen crosslink levels), and biomechanical (gliding and tensile properties) assays. We found that cell activity (as determined by total DNA, collagen crosslink analyses, and hyaluronic acid content) was accelerated due to PDGF-BB at 14 days. Proximal interphalangeal joint rotation and tendon excursion (i.e., tendon gliding properties) were significantly higher for the PDGF-BB-treated tendons compared to the repair-alone tendons at 42 days. Improvements in tensile properties were not achieved, possibly due to suboptimal release kinetics or other factors. In conclusion, PDGF-BB treatment consistently improved the functional but not the structural properties of sutured intrasynovial tendons through 42 days following repair. ß

Previous tendon and ligament studies have demonstrated a role for mechanical loading in tissue homeostasis and healing. In uninjured musculoskeletal tissues, increased loading leads to an increase in mechanical properties, whereas decreased loading leads to a decrease in mechanical properties. The role of loading on healing tissues is less clear. We studied tendon-to-bone healing in a canine flexor tendon-to-bone injury and repair model. To examine the effect of muscle loading on tendon-to-bone healing, repaired tendons were either cut proximally (unloaded group) to remove all load from the distal phalanx repair site or left intact proximally (loaded group). All paws were casted postoperatively and subjected to daily passive motion rehabilitation. Specimens were tested to determine functional properties, biomechanical properties, repair-site gapping, and bone mineral density. Loading across the repair site led to improved functional and biomechanical properties (e.g., stiffness for the loaded group was 8.2 AE 3.9 versus 5.1 AE 2.5 N/mm for the unloaded group). Loading did not affect bone mineral density or gapping. The formation of a gap between the healing tendon and bone correlated with failure properties. Using a clinically relevant model of flexor tendon injury and repair, we found that muscle loading was beneficial to healing. Complete removal of load by proximal transection resulted in tendon-to-bone repairs with less range of motion and lower biomechanical properties compared to repairs in which the muscle-tendon-bone unit was left intact. ß

Purpose Our previous studies in a canine animal model demonstrated that the flexor tendon-to-bone insertion site has a poor capacity to heal. Magnesium based adhesives have the potential to improve tendon-to-bone healing. Therefore, we hypothesized that magnesium based bone adhesive (MBA) will improve the tendon-to-bone biomechanical properties initially and in the early period after repair. Methods Flexor digitorum profundus tendons were injured and repaired into bone tunnels in the distal phalanges of dogs. The bone tunnels were either filled with MBA prior to completing the repair or left empty (CTL). Histologic appearance, tensile properties, range of motion, and bone density were examined at time zero and 21 days after the repair. Results There was no histologic evidence of acute inflammation. There appeared to be more mast cells in the MBA group than in the CTL group. Chronic inflammatory infiltrate and fibrosis was slightly higher in the MBA group compared to the CTL group. Tensile properties at time zero were significantly higher in the MBA group compared to the CTL group. However, tensile properties were significantly lower in the MBA group compared to the CTL group at 21 days. Range of motion and bone density were significantly lower in the MBA and CTL groups compared to normal (i.e., uninjured) at 21 days; no differences were seen when comparing MBA to CTL. Conclusions We found that the initial biomechanical properties of flexor tendon-to-bone repairs can be improved with MBA. However, MBA use in vivo led to a decrease in the biomechanical properties of the repair. There was no effect of MBA on bone density or range of motion in the early period after repair. Our histologic analysis suggests that the poor healing in the MBA group may have been due to an allergic response or to increased chronic inflammation due to the foreign material.

Background Arthroscopy is nowadays a well-establish method to treat a wide range of injuries and overuse syndromes of the shoulder. The role of arthroscopy is extremely important for the treatment of soft-tissue injuries and specific-type fractures of the shoulder. Aim to estimate the applicability of shoulder arthroscopy as an effective method for the treatment of fractures of the greater tuberosity in athletes. Patients–Methods Twelve athletes (six professional–six recreational, four skiers–two horse riders–two motorcycle racers–one cyclist–one football player–one hardle jumper–one judoka, eight males-four females) with a mean age of 29 (20–45) years, sustaining an avulsion fracture of the greater humeral tuberosity were treated arthroscopically over a 5-year period. Nine were managed acutely and three as malunion and rotator cuff dysfunction cases. For the imaging evaluation, standard plain radiographs (anteroposterior and axillary views), CT scans (with 3D reconstruction) and MRI were performed. In three patients the fragment dislocation was found ≤5 mm, in four was 6–10 mm and in two was more than 10 mm. Anchors were used to fix the avulsed fragment. In nine patients, accompanying soft-tissue lesions (seven rotator cuff tears and two Bankart lesions) were recognized and properly treated. Postoperatively a shoulder abduction brace 30° was applied for six weeks and a careful rehabilitation plan was utilized. Passive external rotation exercises were started immediately. Results During the follow up period no major complication was observed. Radiographic outcome was assessed on plain X-rays. No patient developed non-union. All patients achieved UCLA scores over 30 at six months. Professionals returned to practicing at 10–12 weeks with customized programs. All athletes returned to their pre-operative activity level with no residual pain. Discussion The investigation of indications of shoulder arthroscopy is a continuous process. Surgical familiarity is important to perform advanced techniques in shoulder arthroscopy. Arthroscopic treatment of minimally displaced greater tuberosity fractures should be considered for athletes or people who perform overhead activities. Conclusions Arthroscopic treatment of fractures of the greater humeral tuberosity can offer excellent functional results and permits the treatment of concomitant critical lesions.

BackgroundPainful limitation of ankle movement in athletes is commonly caused by soft-tissue or osseous formations. The impingement syndromes of the ankle are attributed to initial injuries which, undertreated, in a subacute or chronic basis, lead to development of thickenings within the ankle joint.AimTo present the outcome of arthroscopic excision of restrictors in ankle movement with concomitant anatomic ankle ligament reconstruction in athletes.Patients and MethodsEighteen athletes, twelve males and six females, (of which, nine basketball-players, four football-players, two dancers) were treated over the last ten years. The mean age was 22 years. The sports activities of all patients were dramatically deteriorated due to chronic ankle pain and/or a “giving way” feeling. The thorough clinical examination included reproduction of impingement pain (anterior, anterolateral, anteromedial, or posterior) and stability testing in comparison to the contralateral ankle. Radiographs included anteroposterior, lateral and oblique views in a weight-bearing position. Ultrasound and plain MRI testing was performed without exception. Each patient underwent arthroscopic evaluation. Arthroscopic debridement of hypertrophic tissue arising from AITFL, ATFL or deltoid was performed in 16 patients. Arthroscopic decompression of bony impingement (excision of tibial or talar osteophyte) was needed in ten patients. Ankle ligament reconstruction was performed in 13 cases (modified Brostrom in 11 athletes, deltoid reconstruction in two others). Excision of osseous and soft-tissue components of posterior impingement via open posterolateral approach was performed in two dancers. We also had to remove meniscoid lesions in four cases. In addition, debridement and microfractures were indicated in four patients with osteochondral lesions and to two patients was applied Autologous Chondrocyte Implantation. A custom rehabilitation program was utilized for each individual.ResultsPatients were followed up at one, three, six, nine, and twelve months postoperatively using the FADI score. The results at 12 months were ranged above 90 for 13 athletes, between 85–90 for 4 athletes and between 80–85 for one athlete. Poorer results are correlated with concomitant osteochondral lesions. The highest scores were achieved when ligament reconstruction had been performed.DiscussionChronic ankle instability should always be suspected in an athlete with chronic ankle pain and findings of ankle impingement. A clinical exam and an ultrasound exam contribute in a more accurate diagnosis for an ankle instability. The appearance of an injured ligament on plain MRI varies and is not reliable to estimate the functional sufficiency of the ligament. Ankle arthroscopy provides great visualization of joint pathology in impingement syndromes that is amenable to repair. Open ligament repair is reliable and optimizes the functional results.ConclusionArthroscopic treatment of anterior ankle impingement together with ankle ligament reconstruction, when indicated, is essential for obtaining a stable and functionally efficient ankle.