Investigation of Hydrodynamic Behavior of Alginate Aerogel Particles in a Laboratory Scale Wurster Fluidized Bed.

The effects of design and operating parameters on the superficial velocity at the onset of circulatory motion and the residence time of alginate aerogel particles in a laboratory scale Wurster fluidized bed were investigated. Several sets of experiments were conducted by varying Wurster tube diameter, Wurster tube length, batch volume and partition gap height. The superficial velocities for Wurster tube with 10 cm diameter were lower than the tube with 8 cm diameter. Superficial velocities increased with increasing batch volume and partition gap height. Moreover, increasing batch volume and partition gap height led to a decrease in the particle residence time in the Wurster tube. The results showed that there is an upper limit for each parameter in order to obtain a circulatory motion of the particles. It was found that the partition gap height should be 2 cm for proper particle circulation. Maximum batch volume for the tube with 10 cm diameter was found as 500 mL whereas maximum batch volume was 250 mL for the tube with 8 cm diameter. The fluidization behavior of the aerogel particles investigated in this study could be described by the general fluidization diagrams in the literature.

Peritendinous injection of platelet-rich plasma to treat tendinopathy: A retrospective review.

OBJECTIVE: The aim of this study was to determine factors associated with the likelihood of a better clinical outcome after the peritendinous injection of PRP for the treatment of chronic tendinopathy and identify whether PRP represents an effective treatment option for chronic tendinopathies. METHODS: The study included 214 patients (86 males and 128 females; mean age: 39.3 (18-75) years) who received PRP injections for tendinopathy refractory to conventional treatments. The mean duration of symptoms at the moment of the PRP treatment was 8.3 months. Primary outcome measurement was perceived improvement in symptoms for each anatomic compartment for upper and lower limbs at 6 months after treatment. Also, a visual analog scale (VAS) score (pain intensity on a 0-10 scale) was used for pain scoring questionnaire before treatment, 6 weeks and 6 months following the PRP injection(s). To identify factors associated with the likelihood of a better clinical outcome, patients were categorized on the basis of their perceived improvement in symptoms 6 months after the PRP injection(s)-that is, as lower (less than 50% global improvement) or higher (more than 50% global improvement). RESULTS: A visual analogue scale score and perceived improvement in symptoms were significantly lower after peritendinous injection in 6-week and 6-month follow-ups compared with the baseline (P < 0.001) except for peroneal and Achilles tendons. Overall, 83% of patients indicated moderate to complete improvement in symptoms. The most common injection sites were the lateral epicondyle, Achilles, and patellar tendons. Furthermore, 30% of patients received only 1 injection, 30% received 2 injections, and 40% received 3 or more injections. A total of 85% of patients were satisfied (more than 50% global improvement) with the procedure. In addition, upper limb tendons, increase in the age, and female gender were associated with a higher likelihood of perceived improvement in symptoms. CONCLUSIONS: In the present retrospective study assessing PRP injections in the treatment of chronic tendinopathy, a moderate improvement (>50%) in pain symptoms was observed in most of the patients. Our research found that results were most promising with patellar and lateral epicondylar tendinopathy in the short to medium term. Female patients, patients with upper extremity tendinopathy and older patients appeared to benefit more from PRP injection. LEVEL OF EVIDENCE: Level IV, Therapeutic study.

Matrix-induced autologous mesenchymal stem cell implantation versus matrix-induced autologous chondrocyte implantation in the treatment of chondral defects of the knee: a 2-year randomized study.

BACKGROUND: Cell-based strategies that combine in vitro- expanded autologous chondrocytes with matrix scaffolds are currently preferred for full-thickness cartilage lesions of the knee ≥2 cm(2). Although this approach is reasonable, continuing advances in the field of cartilage repair will further expand the options available to improve outcomes. HYPOTHESIS/PURPOSE: In the present clinical study, we compared the outcomes of matrix-induced autologous mesenchymal stem cell implantation (m-AMI) with matrix-induced autologous chondrocyte implantation (m-ACI) for the treatment of isolated chondral defects of the knee. STUDY DESIGN: Prospective, single-site, randomized, single-blind pilot study. METHODS: Fourteen patients with isolated full-thickness chondral lesions of the knee >2 cm(2) were randomized into two treatment groups: m-AMI and m-ACI. Outcomes were assessed pre-operatively and 3, 6, 12 and 24 months post-operatively. RESULTS: Clinical evaluations revealed that improvement from pre-operation to 24 months post-operation occurred in both groups (p < 0.05). At all follow-up intervals, m-AMI demonstrated significantly better functional outcomes (motion deficit and straight leg raise strength) than did m-ACI (p < 0.05). At all follow-up intervals, m-AMI demonstrated significantly better subjective sub-scale scores for pain, symptoms, activities of daily living and sport and recreation of the knee injury and osteoarthritis outcome score (KOOS) than did m-ACI (p < 0.05). Additionally, m-AMI demonstrated significantly better (p < 0.05) scores than m-ACI for the quality of life sub-scale of the KOOS and visual analog scale (VAS) severity at the 6-month follow-up. The Tegner activity score and VAS frequency were not significantly different between the two groups. Graft failure was not observed on magnetic resonance imaging at the 24-month follow-up. m-AMI and m-ACI demonstrated very good-to-excellent and good-to-very good infill, respectively, with no adverse effects from the implant, regardless of the treatment. CONCLUSION: For the treatment of isolated full-thickness chondral lesion of the knee, m-AMI can be used effectively and may potentially accelerate recovery. A larger patient cohort and follow-up supported by histological analyses are necessary to determine long-term outcomes.

Intraarticular injections (corticosteroid, hyaluronic acid, platelet rich plasma) for the knee osteoarthritis.

Osteoarthritis (OA) is a complex "whole joint" disease pursued by inflammatory mediators, rather than purely a process of "wear and tear". Besides cartilage degradation, synovitis, subchondral bone remodeling, degeneration of ligaments and menisci, and hypertrophy of the joint capsule take parts in the pathogenesis. Pain is the hallmark symptom of OA, but the extent to which structural pathology in OA contributes to the pain experience is still not well known. For the knee OA, intraarticular (IA) injection (corticosteroids, viscosupplements, blood-derived products) is preferred as the last nonoperative modality, if the other conservative treatment modalities are ineffective. IA corticosteroid injections provide short term reduction in OA pain and can be considered as an adjunct to core treatment for the relief of moderate to severe pain in people with OA. IA hyaluronic acid (HA) injections might have efficacy and might provide pain reduction in mild OA of knee up to 24 wk. But for HA injections, the cost-effectiveness is an important concern that patients must be informed about the efficacy of these preparations. Although more high-quality evidence is needed, recent studies indicate that IA platelet rich plasma injections are promising for relieving pain, improving knee function and quality of life, especially in younger patients, and in mild OA cases. The current literature and our experience indicate that IA injections are safe and have positive effects for patient satisfaction. But, there is no data that any of the IA injections will cause osteophytes to regress or cartilage and meniscus to regenerate in patients with substantial and irreversible bone and cartilage damage.

Abnormal proximal musculotendinous junction of the peroneus brevis muscle as a cause of peroneus brevis tendon tears: a cadaveric study.

Abnormal musculotendinous distal extension of the peroneus brevis has been implicated as a possible cause of peroneus brevis tendon tears. We investigated this relationship in 58 (46 male) fresh human cadavers. Torn lesions were classified according to Sobel et al. Musculotendinous distal extension of the peroneus brevis was measured in each ankle as the vertical distance from the musculotendinous junction of the peroneus brevis to the tip of the fibula. Tendons with and without tears were compared by sex, age at death, height, musculotendinous distal extension of the peroneus brevis, the common sheath bifurcation-fibular tip distance, the peroneus brevis and longus width at the musculotendinous junction, fibular groove depth, peroneal tubercle height, superior-inferior peroneal retinaculum wideness, and the presence of the peroneus quartus or an accessory peroneal muscle. Of 115 evaluable tendons, 15 (13%) had tears. All came from men. The average distance from the musculotendinous junction to the tip of the fibula was 27.0 mm in tendons with tears and 16.4 mm in tendons without (P = .04) Male sex (P = .03), age at death (P = .03), height (P = .04), and fibular groove depth (P = .003) were also related to the presence of tears. Our results do not support a relationship between abnormal musculotendinous distal extension of the peroneus brevis and peroneus brevis tendon tears; rather, proximal extension of the peroneus brevis musculotendinous junction may be related to peroneus brevis tendon tears.

Current trends in reconstruction surgery and rehabilitation of anterior cruciate ligament in Turkey.

OBJECTIVES: This study aims to determine the current approaches to surgical techniques and rehabilitation protocols used in anterior cruciate ligament (ACL) reconstruction performed by Turkish orthopedic surgeons and to compare their results with the data of "ACL Study Group". METHODS: A questionnaire consisting of 16 questions on surgical techniques, preoperative prerequisites, routine postoperative applications, rehabilitation approaches, and return to sport following ACL reconstruction was sent via e-mail to the 55 orthopedic surgeons performing annually 25 or more ACL reconstructions. RESULTS: Response rate to questionnaire was 70.9% (n=39). Nineteen surgeons (48.7%) regularly performed only hamstring tendon (HT) graft, and four surgeons (10.3%) performed only patellar tendon (PT) graft, while 16 surgeons (41%) performed both HT and PT grafts. Three (18.8%) of the 16 surgeons who performed both HT and PT grafts had individual rehabilitation protocols for the two graft types. No statistically significant difference was found between the responses for two graft types in terms of the starting times for specific activities (p>0.05). Rehabilitation protocols were similar to the current data of "ACL Study Group". The use of a postoperative brace and continuous passive motion (CPM) was different between Turkish surgeons and "ACL Study Group". The CPM and postoperative brace use was more common in Turkey. CONCLUSION: There are only a few differences in the postoperative approach of ACL reconstruction with HT and PT grafts performed by Turkish orthopedic surgeons. The data obtained from the Turkish orthopedic surgeons showed similarities with the "ACL Study Group" current approaches.

Evaluation of the functional effects of anterior cruciate ligament bundles: a cadaveric experiment.

The influence of isolated deficiency of the anteromedial or posterolateral bundles of the anterior cruciate ligament (ACL) on knee kinematics has not been fully investigated. Thirty-two cadaveric knees were studied. The fibers of the anteromedial and posterolateral bundles were resected arthroscopically in alternating order in right and left knees. Before and after each arthroscopic cut, laxity tests were performed. Positive results on anterior drawer tests were specific only to the anteromedial bundle-cut knees. Pivot shift tests were positive only in the posterolateral bundle-cut knees. In addition, anterior tibial translation was measured with KT-1000 in response to different external loading conditions. Anterior translation measured with KT-1000 at 67 N and 89 N draw forces at 20 degrees and 40 degrees of flexion may be used in evaluating the integration of each bundle of ACL, both separately and as a whole.

The coracoacromial ligament: the morphology and relation to rotator cuff pathology.

We dissected 80 shoulders from 44 fresh cadavers to define variants of the coracoacromial ligament and their relationship to rotator cuff degeneration. The shapes and the geometric data of the ligaments were investigated, and the rotator cuffs of the cadavers were evaluated macroscopically. Five main types of coracoacromial ligaments were found: Y-shaped, broad band, quadrangular, V-shaped, and multiple-banded. The Y-shaped ligament was the most frequent type, with a frequency of 41.3%, and the V-shaped ligament (11.2%) has not been previously reported. Of the cadavers that were dissected bilaterally, 64% showed the same type of ligament. There was no statistical significance between rotator cuff degeneration and the type or geometric measurement of the ligament. However, the coracoacromial ligaments with more than 1 bundle showed significant association with rotator cuff degeneration with a longer lateral border and larger coracoid insertion.

[Venous thromboembolism prophylaxis in major orthopaedic surgery: A multicenter, prospective, observational study]. / Majör ortopedik cerrahilerde venöz tromboemboli profilaksisi: Cokmerkezli, prospektif, gözlem çalismasi.

OBJECTIVES: We investigated risk factors for venous thromboembolism (VTE), prophylaxis measures employed, and incidence of symptomatic deep venous thrombosis (DVT) and pulmonary embolism (PE) in patients undergoing major orthopaedic surgery (MOS). METHODS: An open, multicenter, prospective, observational study was conducted in 21 medical centers, comprising 899 patients. Of these, 316 patients (35.2%) underwent total hip arthroplasty (THA), 328 patients (36.5%) underwent total knee arthroplasty (TKA), and 255 patients (28.4%) underwent surgery for hip fractures (HF). Pharmacologic prophylaxis was employed in all the patients. RESULTS: Risk factors for VTE were seen in 73.2% of the patients, the most common being obesity (72%) and prolonged immobilization (36.3%). Low-molecular-weight heparin (91.1%) and fondaparinux (8.9%) were used for prophylaxis, which was short-term in 273 patients (30.4%) and long-term in 626 patients (69.6%). Mechanical prophylaxis was performed with compression stockings in 610 patients (67.9%) and by intermittent pneumatic compression in 67 patients (7.5%). During three-months of follow-up, symptomatic DVT and PE were seen in eight (0.9%) and four patients (0.4%), respectively. Mortality occurred in 10 patients (1.1%). Complications of major and minor bleeding were seen in eight (0.9%) and 40 (4.5%) patients, respectively. CONCLUSION: Effective VTE prophylaxis is associated with low risk of clinically apparent DVT and PE in MOS.

[Brachial plexus neuropathy (stinger syndrome) occurring in a patient with shoulder laxity]. / Omuz laksitesi zemininde gelisen brakiyal pleksus nöropatisi (stinger sendromu): olgu sunumu.

The stinger syndrome is a common neuropathy caused by traction or compression of the brachial plexus. In general, it is seen in young adults involved in sport activities and a major contact trauma is the rule. An 11-year-old boy with bilateral glenohumeral joint laxity had pain in the left shoulder, numbness and decreased strength in the left arm that developed after striking against a wall while running, with the left shoulder in extension and the neck in minimal lateral flexion to the contralateral side. Physical examination showed extreme anteroinferior passive translocation of the humeral head in neutral rotation and a positive sulcus sign in the left shoulder. The diagnosis was made as brachial plexus neuropathy (stinger syndrome) resulting from traction trauma and shoulder joint laxity and a shoulder-arm brace was applied. After two weeks, atrophy was detected in the right deltoid, supraspinatus, and infraspinatus muscles, and active and passive motion exercises of the shoulder were initiated. At the end of three months, he achieved normal range of motion of the shoulder and muscle strength.

[Osteonecrosis of the knee]. / Dizde osteonekroz.

Osteonecrosis of the knee was first described by Ahlback in 1968. Today, it is classified as spontaneous and secondary osteonecrosis. Spontaneous osteonecrosis is typically seen with unilateral involvement in patients older than 60 years. Secondary osteonecrosis occurs in younger patients bilaterally and with multifocal involvement. Although its etiology is still unclear, associated factors such as steroid therapy, alcoholism, and some chronic inflammatory diseases are well-known. Many treatment modalities have been reported, including conservative treatment, arthroscopic debridement, core decompression, microfracture, autologous osteochondral transplantation, chondrocyte culture, high tibial osteotomy, and arthroplasty. Conservative treatment and observation are generally accepted at any stage. For surgical treatment, all procedures are applied to both types of osteonecrosis.

Anatomic relationship between elbow arthroscopy portals and neurovascular structures in different elbow and forearm positions.

Twenty fresh cadaveric elbows were used to evaluate the proximity of neurovascular structures to the six arthroscopic portals of the elbow at different positions. After distention of the joint, 4-mm Steinmann pins were introduced into the elbow from the portal's entry points. After surgical dissection, the proximity of the neurovascular structures to the pins was measured in 5 different positions. The radial nerve showed significant proximity to the anterolateral portal in full elbow flexion, full elbow extension, and forearm supination with 10%, 20%, and 10% nerve-pin contacts, respectively. The distance between the median nerve and medial portals was significantly decreased with full extension. This study demonstrated that the distance between the route of the scope and neurovascular structures might diminish significantly during elbow motion. Most of these movements are unavoidable in elbow arthroscopy, but maintaining certain positions for a considerable period of time or angulating the scope forcefully in these positions can cause nerve injury.

Arthroscopic microfracture treatment for osteonecrosis of the knee.

PURPOSE: This study evaluated the results of arthroscopic subchondral microfracture performed on patients with spontaneous osteonecrosis (ON) (group 1) or secondary ON (group 2) of the knee joint. TYPE OF STUDY: Retrospective clinical study. METHODS: Group 1 included 26 patients (mean age, 48 years) who had spontaneous ON. Group 2 included 15 patients (mean age, 32 years) with ON secondary to inflammatory disease or steroid therapy. Seventy-six percent of the chondral defects were located in the medial femoral condyle. The average defect sizes in group 1 was 162 mm2 and in group 2 was 362 mm2. After debridement of the necrotic tissues, multiple perforations were placed into the subchondral bone to obtain revascularization. RESULTS: There was an increase in the average Lysholm scores from 57 to 90 in group 1 after 27 months of mean follow-up (P < .05); 71% of patients could participate in strenuous sports with no or minimal limitation. The mean activity level in group 1 according to Cincinnati Knee Rating System was 6 preoperatively and 13.54 postoperatively. For group 2, the average scores showed significant improvement and patient satisfaction after surgery (preoperative and postoperative average Lysholm scores were 41 and 75, respectively, with mean follow-up of 37 months). Average activity level in group 2 increased from 2.67 to 11.73. Control magnetic resonance imaging scans of the cases revealed the continuity of normal cartilage with cartilage-like tissue in the treated areas. However, an increase of the size of ON in the subchondral bone was detected in 27% of the knees. CONCLUSIONS: The microfracture technique is safe, simple, and cost-effective, and may be an alternative procedure for treatment of ON of the knee, especially in young patients, before possible subsequent replacement surgery. LEVEL OF EVIDENCE: Level IV.

[Open surgical treatment of posterior instability of the shoulder]. / Posterior omuz instabilitesinin açik cerrahi tedavisi.

Posterior instability of the shoulder remains a diagnostic and therapeutic challenge, with a growing incidence especially in athletes. Evaluation of the type of the instability, whether unidirectional or multidirectional, is very important with regard to treatment. Although many patients benefit from strengthening and balancing rotator cuff muscles and scapular stabilizers, surgical procedures may be required in those unresponsive to conservative treatment. Posterior capsular shift is the method of choice to eliminate redundancy of the posterior and inferior capsules; moreover, in the presence of bone defects relating to the head of the glenoid or humerus, bony procedures should be added to the treatment.

The muscular branching patterns of the ulnar nerve to the flexor carpi ulnaris and flexor digitorum profundus muscles.

The branching pattern of the ulnar nerve in the forearm is of great importance in anterior transposition of the ulnar nerve for decompression after neuropathy of cubital tunnel syndrom and malformations resulting from distal end fractures of the humerus. In this study, 37 formalin-fixed forearms were used to demonstrate the muscular branching patterns from the main ulnar nerve to the flexor carpi ulnaris muscle (FCU) and ulnar part of the flexor digitorum profundus muscle (FDP). Eight branching patterns were found and classified into four groups according to the number of the muscular branches leaving the main ulnar nerve. Two (Group I) and three (Group II) branches left the main ulnar nerve in 18 and 17 forearms respectively. The remaining two specimens had four (Group III) and five (Group IV) branches each. Usually one or two branches were associated with the innervation of the FCU. However, in 2 cases, three and in one, four branches to FCU were observed. The FDP received a single branch in all cases, except in four, all of which had two branches. In six forearms, a common trunk was observed arising from the ulnar nerve to supply the FCU and FDP. The distribution of the muscular branches to the revealed muscles was outlined in figures and the distance of the origin of these branches from the interepicondylar line was measured in millimeters. The first muscular branch leaving the main ulnar nerve was the FCU-branch in all specimens. The terminal muscular branch of the ulnar nerve to the forearm muscles arose at the proximal 1/3 of the forearm in all specimens. In 7 forearms, Martin-Gruber anastomosis in form of median to ulnar was observed.

Recesses along the posterior margin of the infrapatellar (Hoffa's) fat pad: prevalence and morphology on routine MR imaging of the knee.

The objective is to evaluate the prevalence and morphology of recesses along the posterior margin of the infrapatellar fat pad on routine MR imaging of the knee. MR images of 213 knees in 204 consecutive individuals were evaluated with regard to the prevalence and morphology of recesses (a "suprahoffatic" recess close to the inferior border of the patella and the previously described "infrahoffatic" recess anterior to the inferior portion of the infrapatellar plica). The recesses were analyzed with regard to synovial effusion and the condition of the anterior cruciate ligament (ACL). Anatomic dissection was made in 29 knees in 16 cadavers to verify the presence of the suprahoffatic recess. The infrahoffatic recess was present in 45% of the knees and mostly linear in shape (44%). The suprahoffatic recess was detected in 71% of the knees (45% in cadavers). Very weak to moderate positive correlation was found between the synovial effusion or the condition of the ACL and the presence and dimensions of the recesses. An awareness of the recesses in the infrapatellar fat pad is important in order to distinguish between pathology and anatomic variants on routine MR imaging of the knee.

The deep infrapatellar bursa: prevalence and morphology on routine magnetic resonance imaging of the knee.

OBJECTIVE: To evaluate the presence, location, and dimensions of the deep infrapatellar bursa on routine magnetic resonance (MR) imaging of the knee. METHODS: The study group consisted of 213 knees in 204 consecutive individuals who had undergone routine MR imaging examination of the knee within a 365-day period. Magnetic resonance examinations consisted of T1-, proton-density-, and T2-weighted sagittal; spectral presaturation inversion recovery coronal; and T2*-weighted transverse sequences. Exclusion criteria were previous knee arthroscopy or surgery or the presence of a mass lesion infiltrating the infrapatellar fat pad. The presence, location, and dimensions of the deep infrapatellar bursa were studied. The bursa was also analyzed with regard to knee joint synovial effusion (absent, mild, or marked). RESULTS: The deep infrapatellar bursa was detected in 68% of the knees, most commonly on the lateral paramedian sagittal MR images. There was no statistically significant difference between male and female subjects or between the knee sides with regard to the detection of the deep infrapatellar bursa (P > 0.05). No correlation was found between synovial effusion and the presence of the deep infrapatellar bursa. The mean anteroposterior and craniocaudal dimensions of the deep infrapatellar bursa on sagittal T2-weighted MR images were 2.1-2.7 mm and 7.3-9.1 mm, respectively, on its lateral, central, or medial location within the sagittal MR image stack. CONCLUSION: An awareness of the dimensions and location of the deep infrapatellar bursa is important in distinguishing it from pathologic lesions (eg, bursitis).

[Shoulder injuries: macrotraumas and overuse problems]. / Omuz yaralanmalari: Makrotravma ve asiri kullanim sorunlari.

Injuries to the shoulder are becoming more frequent in pediatric and adolescent athletes with widespread participation in sports activities. These injuries can result from macrotraumas as well as microtraumas from repetitive stress. Injury patterns present differences in this age group due to peculiar physiologic and biomechanical features. Most shoulder problems in adolescent athletes can be treated conservatively with a good response, while some conditions require surgical reconstruction.

Localized pigmented villonodular synovitis of the knee.

Eight patients with localized pigmented villonodular synovitis (LPVNS) of the knee were treated with arthroscopic and open techniques, with diagnosis confirmed by histological examination. Average patient age was 29 years (range: 13-50 years). At arthroscopy, all lesions except one were in the anterior compartment of the involved knee. Treatment consisted of complete local excision with partial synovectomy. This procedure was completed arthroscopically in seven patients. No recurrence was reported at average 24-month follow-up (range: 12-33 months). Arthroscopy is a valuable tool in the diagnosis and treatment of LPVNS.

[Arthroscopy of the shoulder: general principles and stages for promoting competence]. / Omuz artroskopisi: Genel prensipler ve uzmanlik asamalari.

Arthroscopic surgery of the shoulder has replaced several open procedures because of minimal morbidity. However, like other joint arthroscopic procedures, it involves a significant learning curve. In addition, it requires availability of special equipment and certain operating conditions. It is advisable to achieve enhanced experience and competence in diagnostic arthroscopy and then to practice arthroscopic surgery in a staged manner. This review aims to provide an outline of current knowledge about general principles of shoulder arthroscopy, diagnostic arthroscopy, and arthroscopic surgical procedures.