Brett M. Cascio

Magnetic resonance imaging of the shoulder. Current techniques and spectrum of disease.

Magnetic resonance imaging is an excellent modality for imaging pathological processes of the shoulder joint. It allows high-resolution imaging of all anatomic structures, including the glenoid, the humeral head, the articular cartilage, the acromion, the muscles and tendons of the rotator cuff, the labrum, the biceps tendon, and the glenohumeral ligaments, in multiple orthogonal planes. Numerous technical options and several pulse sequences can be utilized for the performance of magnetic resonance imaging of the shoulder. The aim of this review is to update orthopaedic surgeons on the technical aspects of performing magnetic resonance imaging of the shoulder. In addition, this report will define the normal anatomy of the shoulder as demonstrated by magnetic resonance imaging and review the spectrum of disease detectable with this technique. After reviewing this article, the reader should (1) have a basic understanding of the physics, pulse sequences, and terminology of magnetic resonance imaging; (2) be able to systematically evaluate the findings of a complete magnetic resonance imaging examination of the shoulder and know the features of normal shoulder anatomy; (3) be able to identify various tissue types on T1-weighted, fat-suppressed T2-weighted, and proton-density images; and (4) be able to diagnose certain pathological processes of the shoulder on the basis of magnetic resonance imaging findings. ### Process of Image Production First, the subject is positioned in the scanner. For magnetic resonance imaging of the shoulder, the patient is supine and the arm is held at the side, as opposed to across the chest, in order to minimize transmission of respiratory motion to the shoulder. The arm is placed in slight external rotation to optimally orient the supraspinatus tendon in order to prevent confusing overlap with the infraspinatus tendon on coronal oblique images1. The external rotation also allows maximum visualization of the supraspinatus insertion2. The magnetic field of …

Human Cartilage Repair with a Photoreactive Adhesive-Hydrogel Composite

A photoactive hydrogel is used in combination with microfracture to heal cartilage defects in patients. Let There Be Light Light has long been a favorite tool in medicine, finding utility in everything from skin conditions to depression to imaging. Now, Sharma and colleagues have shown that light can be used for biomaterials. Shining light on a hydrogel mixture causes it to polymerize within a defect, thus promoting tissue growth and repairing cartilage in patients. The biomaterial was designed to fill irregular wounds, such as articular cartilage defects. A biological adhesive was applied to the defect, followed by filling with a poly(ethylene glycol) (PEG)–based hydrogel solution. Then, light was applied to polymerize the material to form a solid implant. The hydrogel-adhesive was tested in a large-animal model to see how it worked in combination with the standard procedure for cartilage repair, called microfracture. The surgeons noted that the animals that received the biomaterial along with microfracture had a greater defect fill that was stronger and had more heterogeneous components (cells, proteins, etc.). The authors then moved to testing in people. Fifteen patients with symptomatic cartilage defects were treated with the adhesive-hydrogel after microfracture, whereas three patients were treated with microfracture only. No major adverse events were noted in 6 months after surgery. Similar to the animal studies, the photoactive biomaterial allowed for a greater filling of repair tissue in the defect compared with the control group, with material properties similar to adjacent, healthy cartilage. In addition, hydrogel-treated patients reported a decrease in overall pain severity and frequency over time. Although further clinical testing is needed to compare long-term outcomes in more patients, this light-mediated biomaterial therapy promises to be a versatile and safe way to enhance cartilage repair. Surgical options for cartilage resurfacing may be significantly improved by advances and application of biomaterials that direct tissue repair. A poly(ethylene glycol) diacrylate (PEGDA) hydrogel was designed to support cartilage matrix production, with easy surgical application. A model in vitro system demonstrated deposition of cartilage-specific extracellular matrix in the hydrogel biomaterial and stimulation of adjacent cartilage tissue development by mesenchymal stem cells. For translation to the joint environment, a chondroitin sulfate adhesive was applied to covalently bond and adhere the hydrogel to cartilage and bone tissue in articular defects. After preclinical testing in a caprine model, a pilot clinical study was initiated where the biomaterials system was combined with standard microfracture surgery in 15 patients with focal cartilage defects on the medial femoral condyle. Control patients were treated with microfracture alone. Magnetic resonance imaging showed that treated patients achieved significantly higher levels of tissue fill compared to controls. Magnetic resonance spin-spin relaxation times (T2) showed decreasing water content and increased tissue organization over time. Treated patients had less pain compared with controls, whereas knee function [International Knee Documentation Committee (IKDC)] scores increased to similar levels between the groups over the 6 months evaluated. No major adverse events were observed over the study period. With further clinical testing, this practical biomaterials strategy has the potential to improve the treatment of articular cartilage defects.

Posterior only versus combined anterior and posterior approaches to lumbar scoliosis in adults: a radiographic analysis.

Study Design. Retrospective study. Objective. To compare the radiographic lumbar curve correction between a posterior only and combined anterior-posterior approach in patients with adult spinal deformity. Summary of Background Data. In adolescent idiopathic scoliosis correction, posterior only has been compared with the combined anterior-posterior approach; however, there have been no corollary studies in adult scoliosis. Traditionally, rigid lumbar curves have been treated with a combined anterior and posterior approach; however, the absolute indications for this approach are unclear. Materials and Methods. A total of 180 patients with degenerative or adult idiopathic spinal deformity and curves measuring between 40° and 70° who underwent reconstructive spinal fusion. The minimum follow-up period was 28 months and average follow-up was 53 months. Of the 155 patients who underwent surgery, 80 underwent posterior only (35 with idiopathic and 45 with degenerative scoliosis) while 75 patients (30 with idiopathic and 35 with degenerative scoliosis) underwent combined anterior-posterior surgery. The groups were compared by age at operation, preoperative deformity, levels operated and postoperative correction and balance. Results. There were no significant differences in sagittal and coronal plane curve and balance correction between the posterior only and the combined anterior-posterior groups. When the patients were subdivided into degenerative adult scoliosis and idiopathic adult scoliosis, there were again no significant differences in the sagittal and coronal curves or balance between the posterior only and combined anterior and posterior approaches. While the posterior only group and the same-day anterior and posterior surgery group had a similar major complication rate of 24% and 23%, respectively, patients who underwent staged anterior and posterior surgery had a major complication rate of 45%. Conclusion. When combined with extensive posterior releases, posterior only approach is just as effective as combined anterior and posterior surgery for adult lumbar scoliosis measuring between 40° and 70°.

Spinal fusion after revision surgery for pseudarthrosis in adult scoliosis.

Study Design. A retrospective study. Objective. To decipher the incidence, characteristics, functional outcomes, and complications of spinal fusion after revision surgery for recurrent pseudarthrosis in adult patients with scoliosis. Summary of Background Data. While the rate of spinal fusion has been examined in the past, there have been no studies that have examined the incidence, characteristics, functional outcomes, and complications of spinal fusion after pseudarthrosis repair in adult patients with scoliosis. Materials and Methods. A total of 132 patients with failed spinal fusion surgery for adult scoliosis and painful pseudarthroses were studied. Each patient had an average of 3.7 spinal surgeries before undergoing revision at our institution. In addition to clinical assessment and imaging studies, pseudarthrosis was confirmed intraoperatively in all patients. All patients underwent reinstrumentation and fusion along with adjunctive procedures as needed. Spinal fusion was assessed clinically and radiographically after surgery for a minimum of 40 months. Subjective functional outcomes and complications associated with the procedures were also studied. Results. The overall incidence of spinal fusion after revision surgery for pseudarthrosis in adult scoliosis was 90%. There was a propensity for pseudarthrosis to recur at the thoracolumbar and lumbosacral junctions. Increasing thoracolumbar kyphosis and loss of sagittal balance were significant risk factors for recurrent pseudarthrosis after revision surgery (mean thoracolumbar kyphosis of 23° and mean sagittal balance of 7.9 cm anteriorly associated with persistent pseudarthrosis). Additionally, patients with multiple preoperative sites of pseudarthroses were at a higher risk for continued pseudarthrosis after surgery. Cigarette smoking, age, and surgical approach did not have any significant correlation with pseudarthrosis. Seventy-two percent of patients were satisfied with the outcome and 80% would have chosen to undergo surgery again if necessary. Thirty-three percent of patients who underwent surgery had some complication related to the surgery. Conclusion. Revision surgery for pseudarthrosis repair in adult scoliosis is most successful at attaining fusionwhen thoracolumbar and overall sagittal alignment are restored as much as possible.

Posterior Knee Arthroscopy: Anatomy, Technique, Application

The frequency of knee arthroscopy involving the posterior compartments has increased with recent advances in arthroscopic technique and instrumentation. Total arthroscopic synovectomy, arthroscopic repair or reconstruction of the posterior cruciate ligament, all-inside repair of the posterior horn of the meniscus, and removal of loose bodies or tumors posterior to the posterior cruciate ligament all involve arthroscopic visualization of posterior aspects of the knee. Posterior knee arthroscopy is technically complex and requires a detailed knowledge of posterior knee anatomy relevant to the arthroscopist. With pertinent anatomic knowledge and meticulous technique, posterior knee arthroscopy can be safely implemented to provide a broad field of view and increased maneuverability of instruments. The popliteal artery is the most anterior structure of the popliteal neurovascular bundle. It courses anteriorly toward the insertion of the posterior cruciate ligament on the tibia and then moves posteriorly. The popliteal artery is closest to the knee joint at the insertion of the posterior cruciate ligament, where it is held near the proximal part of the tibia by the fibrous arch of the soleus. At the joint line, the popliteal artery lies posterior and lateral to the posterior cruciate ligament, adjacent to the posterior septum (Figs. 1-A and 1-B). Figs. 1-A and 1-B Magnetic resonance images of the knee, depicting the posterior cruciate ligament (PCL), posterior septum, and popliteal artery. Fig. 1-A Axial T2-weighted image with fat saturation. Fig. 1-B Sagittal T1-weighted image. Anatomic studies pertinent to an arthroscopists assessment of posterior knee anatomy at the joint line—i.e., studies done under simulated arthroscopic conditions, including knee flexion and joint distention—are unfortunately rare. Cadaver and radiographic anatomic studies of the posterior aspect of the knee are usually done with the knee in full extension. Anatomic studies done with the knee in flexion have previously focused on posterior knee anatomy pertinent for high tibial osteotomy …

Improvement in Documentation of Compartment Syndrome With a Chart Insert

To improve documentation of compartment syndrome, an educational program was instituted and a chart insert consisting of a preprinted checklist of history and physical examination parameters for at-risk patients was created. From October 2004 to May 2005, a total of 45 consecutive at-risk patients were identified. Progress notes were divided into group 1 (educational program alone) and group 2 (educational program and checklist). Group 2 showed more complete documentation than group 1. The combination of a chart insert and an educational program proved to be more effective than an educational program alone for improving the documentation of compartment syndrome.