Ronald S. Adler

Biophysical Bases of Elasticity Imaging

Elasticity imaging is based on two processes. The first is the evaluation of the mechanical response of a stressed tissue using imaging modalities, e.g. ultrasound, magnetic resonance imaging (MRI), computed tomography (CT) scans and Doppler ultrasound. The second step is depiction of the elastic properties of internal tissue structures by mathematical solution of the inverse mechanical problem. The evaluation of elastic properties of tissues has the potential for being an important diagnostic tool in the detection of cancer as well as other injuries and diseases. The success of breast self-examination in conjunction with mammography for detection and continuous monitoring of lesions has resulted in early diagnosis and institution of therapy. Self-examination is based on the manually palpable texture difference of the lesion relative to adjacent tissue and, as such, is limited to lesions located relatively near the skin surface and increased lesion hardness with respect to the surrounding tissue. Imaging of tissue “hardness” should allow more sensitive detection of abnormal structures deeper within tissue. Tissue hardness can actually be quantified in terms of the tissue elastic moduli and may provide good contrast between normal and abnormal tissues based on the large relative variation in shear (or Young’s) elastic modulus.

The Effect of Platelet-Rich Fibrin Matrix on Rotator Cuff Tendon Healing: A Prospective, Randomized Clinical Study

Background: There is a strong need for methods to improve the biological potential of rotator cuff tendon healing. Platelet-rich fibrin matrix (PRFM) allows delivery of autologous cytokines to healing tissue, and limited evidence suggests a positive effect of platelet-rich plasma on tendon biology. Purpose: To evaluate the effect of platelet-rich fibrin matrix on rotator cuff tendon healing. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: Seventy-nine patients undergoing arthroscopic rotator cuff tendon repair were randomized intraoperatively to either receive PRFM at the tendon-bone interface (n = 40) or standard repair with no PRFM (n = 39). Standardized repair techniques were used for all patients. The postoperative rehabilitation protocol was the same in both groups. The primary outcome was tendon healing evaluated by ultrasound (intact vs defect at repair site) at 6 and 12 weeks. Power Doppler ultrasound was also used to evaluate vascularity in the peribursal, peritendinous, and musculotendinous and insertion site areas of the tendon and bone anchor site. Secondary outcomes included standardized shoulder outcome scales (American Shoulder and Elbow Surgeons [ASES] and L’Insalata) and strength measurements using a handheld dynamometer. Patients and the evaluator were blinded to treatment group. All patients were evaluated at minimum 1-year follow-up. A logistic regression model was used to predict outcome (healed vs defect) based on tear severity, repair type, treatment type (PRFM or control), and platelet count. Results: Overall, there were no differences in tendon-to-bone healing between the PRFM and control groups. Complete tendon-to-bone healing (intact repair) was found in 24 of 36 (67%) in the PRFM group and 25 of 31 (81%) in the control group (P = .20). There were no significant differences in healing by ultrasound between 6 and 12 weeks. There were gradual increases in ASES and L’Insalata scores over time in both groups, but there were no differences in scores between the groups. We also found no difference in vascularity in the peribursal, peritendinous, and musculotendinous areas of the tendon between groups. There were no differences in strength between groups. Platelet count had no effect on healing. Logistic regression analysis demonstrated that PRFM was a significant predictor (P = .037) for a tendon defect at 12 weeks, with an odds ratio of 5.8. Conclusion: Platelet-rich fibrin matrix applied to the tendon-bone interface at the time of rotator cuff repair had no demonstrable effect on tendon healing, tendon vascularity, manual muscle strength, or clinical rating scales. In fact, the regression analysis suggests that PRFM may have a negative effect on healing. Further study is required to evaluate the role of PRFM in rotator cuff repair.

Prospective analysis of arthroscopic rotator cuff repair: Prognostic factors affecting clinical and ultrasound outcome

The purpose of this study was to identify potential predictors of function and tendon healing after arthroscopic rotator cuff repair that will enable the orthopaedic surgeon to determine which patients can expect a successful outcome. Between 2003 and 2005, the Arthroscopic Rotator Cuff Registry was established to collect demographic, intraoperative, functional outcome, and ultrasound data prospectively on all patients who underwent primary arthroscopic rotator cuff repair. At total of 193 patients met the study criteria, and 127 (65.8%) completed the 2-year follow-up. The most significant independent factors affecting ultrasound outcome were age (odds ratio [OR], 1.08; 95% confidence interval [CI], 1.02-1.14; P = .006) and tear size (OR, 2.29; 95% CI, 1.55-3.38; P < .001). After adjustment for age and tear size, the intraoperative factors found to be significantly associated with a tendon defect were concomitant biceps procedures (OR, 11.39; 95% CI, 2.90-44.69; P < .001) and acromioclavicular joint procedures (OR, 3.85; 95% CI, 1.46-10.12; P = .006). In contrast to the ultrasound data, the functional outcome variables, such as satisfaction (OR, 3.92; 95% CI, 2.00-7.68; P < .001) and strength (OR, 10.05; 95% CI, 1.61-62.77; P = .01), had a greater role in predicting an American Shoulder and Elbow Surgeons score greater than 90. The progression from a single-tendon rotator cuff tear to a multiple-tendon tear with associated pathology increased the likelihood of tendon defect by at least 9 times, and therefore, earlier surgical intervention for isolated, single-tendon rotator cuff tears could optimize the likelihood of ultrasound healing and an excellent functional outcome.

Diagnostic and Therapeutic Use of Sonography-Guided Iliopsoas Peritendinous Injections

OBJECTIVE Our objective was to review our experience performing sonography-guided iliopsoas bursal/peritendinous injections as a diagnostic and therapeutic tool in the workup and treatment of patients with hip pain. CONCLUSION Sonography-guided iliopsoas bursal/peritendinous injections are useful in determining the cause of hip pain. They can provide relief to most patients with iliopsoas tendinosis/bursitis after hip replacement. The results of injection alone are not as successful in cases of idiopathic iliopsoas tendinosis/bursitis, but the technique can help determine which patients may benefit from a surgical tendon release.

Use of ultrasonographic guidance in interventional musculoskeletal procedures : A review from a single institution

We have evaluated the utility of ultrasonographic guidance for intervention in the musculoskeletal system. All interventional musculoskeletal procedures using ultrasonographic guidance performed at our institution from July 1998 through November 1999 were reviewed. Examinations were performed using either a linear or curved phased array transducer, based on depth and local geometry. The choice of needle was likewise optimized for specific anatomic conditions. One hundred ninety‐five procedures were performed on 167 patients from July 1998 through November 1999. Thirty‐one procedures had magnetic resonance correlation within 6 months beforehand. Excluding large‐joint aspirations and injections, we found that 180 of the procedures were more readily performed using ultrasonography than any other imaging modality. These included therapeutic injections into tendon sheaths (biceps, flexor digitorum longus, posterior tibial, and iliopsoas), Mortons neuromas, plantar fascia, wrist ganglia, and tarsal tunnel cysts; peritendinous hamstring injections; and synovial cyst and muscle biopsies. In all cases, the target of interest was identified easily with ultrasonography, and needle position was documented readily. Also in all cases, aspiration or medication delivery to the site of interest was observed during real time and was documented on postprocedure images of the area. No significant complications (e.g., bleeding, infection, and neurovascular compromise) were encountered during or immediately after any procedure. Ultrasonography is a readily available imaging modality useful for guiding interventional procedures in the musculoskeletal system. The ability to document exact needle placement in real time confirms accurate placement of therapeutic injections, fluid aspiration, and soft tissue biopsies.

Magnetic‐resonance imaging techniques for detection of elasticity variation

The relative success of manual palpation in the detection of breast cancer would suggest that a method for remote palpation resulting in a measurement of tissue elasticity could provide a diagnostic tool for detecting cancerous lesions deeper within the breast. This presumption is based in part on the excellent contrast between neoplastic and normal tissue due to the large (orders of magnitude) relative variation in the shear elastic modulus. By comparison, the bulk deformational modulus maintains the same value to within 20% for most soft tissues. A specific method of magnetic-resonance imaging (MRI) which measures tissue displacements has been used in experiments with a phantom containing regions of increased Youngs modulus as a demonstration. The spatial modulation of magnetization technique uses the displacement of a spatial grid pattern caused by spin saturation to track regional motion. Mathematical reconstruction of the distribution of elastic moduli is shown for select examples. Any modality, e.g., MRI, ultrasound, etc., which can detect local tissue motion with sufficient spatial resolution can be used and therefore the results presented here should give an indication of the utility of such motion tracking techniques to future measurement of tissue elasticity.

Percutaneous ultrasound-guided injections in the musculoskeletal system.

Ultrasound guidance is an accurate method for the delivery of therapeutic injections in the musculoskeletal system. The visualization of the needle in real time allows for reliable placement of the needle tip in the tendon sheath, bursa, or joint of interest. Both superficial and deep articulations and tendon sheaths can be targeted for diagnostic or therapeutic interventions. In addition, intratendinous calcifications, the plantar fascia, and interdigital (Mortons) neuromas can also be visualized and injected directly under real-time guidance. Performing percutaneous interventions with ultrasound ensures accurate needle tip placement and helps direct the needle away from other regional soft-tissue structures such as nearby neurovascular bundles.

Ultrasound-guided injection of ganglia with coricosteroids

Abstract Objective. The aim of this study was to demonstrate the use of ultrasound guidance in confirming intralesional injection of corticosteroids and local anesthetic into symptomatic ganglia, and to propose potential advantages of this technique. Design and patients. Ten patients (five men, five women) underwent ultrasound-guided injection of a ganglion. Seven ganglia were near the wrist, one was adjacent to a finger interphalangeal joint and two were adjacent to the talus. All were injected with a 1:1 mixture of long-acting corticosteroid and local anesthetic, the actual volume being dependent on the size of the ganglion. Three patients had a second injection 9–18 months following the initial injection. Results. In four patients the ganglia resolved completely. In five patients there was significant improvement, with a reduction in size of the ganglion and symptomatic relief. Conclusion. Ultrasound-guided injection insures intralesional deposition of corticosteroids and may provide an alternative to surgery in the management of ganglia.

Quantitative assessment of cartilage surface roughness in osteoarthritis using high frequency ultrasound

Osteoarthritis (OA) is a common disease which affects nearly 50% of people over age 60. Histologic evaluation suggests that fibrillations approximately 20-150 microns are among the earliest changes in the articular cartilage. We propose a technique to quantify these surface fibrillatory changes in osteoarthritic articular cartilage by considering the angular distribution of the envelope-detected backscattered pressure field from an incident 30-MHz focused transducer. The angular distribution of the scattered acoustic field from an inosonifying source will directly relate to the distribution of surface fibrillatory changes. Data are presented for three different grades (400, 500 and 600 grit) of commercially available emory paper and three samples of osteoarthritic femoral head articular cartilage, which were visually assessed as having smooth, intermediate and rough surfaces, respectively. Our preliminary results indicate a probable monotonic relationship between articular cartilage roughening and the degree of broadening in the angle-dependent pressure amplitude. When applied to the emory paper, the technique indicates sensitivity to differences as small as approximately 5-10 microns in mean roughness. This procedure may provide an extremely sensitive and reproducible means of quantifying and following the cartilage changes observed in early osteoarthritis.

Prospective analysis of arthroscopic rotator cuff repair: Subgroup analysis

BACKGROUND The rotator cuff registry was established to evaluate prospectively the effectiveness of arthroscopic rotator cuff repair. The purpose of the present study is to report the preliminary data at the 1- and 2-year time point and perform subgroup analysis to identify factors that may affect outcome. METHODS A total of 193 patients underwent all-arthroscopic repair of a rotator cuff tear and met the inclusion criteria and 127 (65.8%) completed 2-year follow-up. The outcome measurements included physical examination, manual muscle testing, the American Shoulder and Elbow Surgeons (ASES) score, and ultrasonography. RESULTS The pre-operative ASES score was 52.37 +/- 24.09 and improved to 83.88 +/- 19.28 at 1 year (P < .0001) and 92.65 +/- 11.36 at 2 years (P < 0.0001). The percent healing for all patients was 64.10% at 3 months and 64.34% at 1 year (P = .4080). At 2 years, there was a significant increase in the percentage of healed tendon at 75.42% compared to the 3-month (P (1/4) .0001) and 1-year (P = 0.0332) time points. Patients with intact tendons had an ASES score of 93.9 +/- 10.2 compared to tendon defects with a score of 88.0 +/- 15.6 (P = .0623). Gender, tear size, and acromioclavicular joint involvement have a significant effect on ASES score. Rotator cuff characteristics such as tear size, biceps pathology, acromioclavicular joint pathology, and tissue quality have a significant effect on postoperative tendon integrity. CONCLUSION Arthroscopic rotator cuff repair demonstrates significant improvement in clinical outcomes and good rate of healing by postoperative ultrasound. Longer-term studies are necessary to determine the efficacy over time.