Faculty Bibliography

PURPOSE: To describe the procedure of ultrasound-guided Morton's neuroma and recurrent stump neuroma injections and early clinical outcomes after a single injection. MATERIALS AND METHODS: Retrospective review of 44 percutaneous ultrasound-guided neuroma injections in 24 patients who had completed clinical outcomes questionnaires. A 10-point pain scale [scale of 1 (no pain) to 10 (severe pain)] in a 7-day pain log format was distributed to patients at the time percutaneous neuroma injection was performed. RESULTS: Neuromas were clearly visualized with sonography as hypoechoic nodules and were distinguishable from other causes of forefoot pain, such as metatarsophalangeal joint synovitis and intermetatarsal bursae. The sizes of the neuromas injected ranged between 4 and 19 mm. Postinjection, all neuromas displayed increased echogenicity and/or the appearance of fluid surrounding it, confirming localization of the therapeutic mixture. We arbitrarily subdivided the pain ratings into symptomatic (greater than 4) and asymptomatic (less than or equal to 4) for statistical analysis. Average pain level pre injection was 5.2 and average pain level was 3.7 at 7 days post single injection, with 62% of the initially symptomatic patients asymptomatic on day 7 (p < 0.000001). Overall, 76% of the total number of neuromas injected once were asymptomatic on day 7. CONCLUSION: Ultrasound can be used to accurately target Morton's neuromas and, therefore, appropriately direct therapeutic interventions, with good short-term clinical results

OBJECTIVE: To determine the effectiveness of ultrasound-guided aspiration and lavage in the treatment of patients with calcific tendinosis of the shoulder. MATERIALS AND METHODS: Retrospective chart review resulted in 44 patients who were identified as having received ultrasound-guided aspiration of calcific tendinosis of the shoulder between 2000 and 2003. Of these, 36 patients were interviewed by telephone for pre- and posttreatment assessment of pain, shoulder function, prior shoulder surgery, injury, and prescribed treatment modalities with a follow-up time of 8 months to 3.1 years (mean = 22.5 months). L'Insalata score, numeric rating scale (NRS), and patient satisfaction score served as outcome measures. RESULTS: Our criteria for a successful outcome included (1) 12-point or greater improvement in the L'Insalata shoulder rating questionnaire, (2) 2-point or greater improvement in the NRS, (3) patient satisfaction rating of "good", "very good", or "excellent", (4) patients' willingness to undergo the procedure again if they experienced recurrent symptoms, and (5) 1 month or less of analgesic medication use after the aspiration procedure. We determined that ultrasound-guided aspiration of calcific tendinosis of the shoulder resulted in a successful outcome for 75% (27/36) of patients with a mean 20.2-point improvement in the L'Insalata shoulder rating questionnaire score and a mean 6.4-point improvement in the NRS (p < 0.01). CONCLUSION: This retrospective study suggests that ultrasound-guided aspiration and lavage of calcific shoulder deposits appears to be an efficacious therapeutic modality for treatment of calcific tendinosis. Further studies involving prospective randomized controlled trials would be helpful to further assess the long-term efficacy of this procedure as a minimally invasive treatment for calcific tendinosis of the shoulder.

OBJECTIVE: The purpose of this study was to describe a sonographically guided technique to perform flexor hallucis longus (FHL) tendon sheath injections. METHODS: Scans were performed with an intermediate-frequency (7.5- to 12-MHz) linear transducer with the scan plane corresponding to the anatomic axial plane and the patients positioned prone. The transducer was placed along the posteromedial ankle with the needle entry point being lateral to the Achilles tendon. A 25-gauge, 1.5-in needle or a 22-gauge spinal needle was positioned directly into the tendon sheath during real-time visualization with injection of a standardized therapeutic mixture (anesthetic and long-acting corticosteroid) at the level of the posterior sulcus for the FHL. Distention of the tendon sheath during real-time visualization was considered a successful injection. RESULTS: Twenty-four injections in 20 patients (12 female and 8 male; age range, 22-64 years) were performed with this technique. In each case, distention of the FHL tendon sheath was obtained as the desired end point. Apart from minor paresthesias from local anesthesia, no long-term complications from these injections have occurred to date. CONCLUSIONS: We describe a method to perform sonographically guided injections of the FHL tendon sheath. Sonography provides several distinct advantages as a method to provide guidance for delivery of therapeutic injections. The most important of these is the ability to visualize the needle and make adjustments in real time to ensure that medication is delivered to the appropriate location. Given these advantages, we propose that sonographic guidance provides an excellent alternative in the administration of corticosteroids to the FHL tendon sheath.

OBJECTIVE: The purpose of this study was to investigate the extent and duration of the sonographic contrast effect during guided steroid-anesthetic injections and to propose a potential mechanism based on mixture immiscibility and density differences. METHODS: A steroid-anesthetic mixture was injected into cyst phantoms under sonographic visualization, and time-dependent data were acquired. Regions of interest were drawn within each cyst, and measured mean pixel intensities were compared with a gel phantom background that served as a control. Two test tubes were also prepared similarly with the steroid-anesthetic mixture and saline in one test tube and synovial fluid in the other; these were observed to estimate separation time to form a fluid-fluid level. RESULTS: There was a substantial contrast effect after injection of the steroid-anesthetic suspension into a cyst phantom containing saline. The background levels remained constant during the period of observation. The contrast effect decreased as a function of time to 4 (94% decrease from the time of injection) in the upper half and to 34 (64% decrease from the time of injection) in the lower half throughout the course of the experiment. The test tube containing the injected material in saline achieved separation in approximately 15 minutes, whereas in the synovial fluid, separation was achieved in 48 hours. CONCLUSIONS: We have verified, in vitro, an apparent clinically observed contrast effect noted during sonographically guided therapeutic injections of cortisone-anesthetic mixtures. We have shown that this effect relates to differences in acoustic impedance and immiscibility, differences in density of the mixture, or both.

OBJECTIVE: The purpose of this series was to describe the improved conspicuity in the sonographic appearance of acetabular labral injuries during routine sonographically guided intra-articular injections. METHODS: Sonographic examinations of patients undergoing routine sonographically guided intra-articular hip injections were reviewed for evidence of labral injuries (n=21). Sonographic examinations were then correlated with magnetic resonance images of the ipsilateral hip when available (n=14). RESULTS: Before injection, 13 acetabular labra had linear or irregular hypoechoic clefts or fissures through the normally hyperechoic fibrocartilaginous labrum, thought to represent tears. Eight of the labra showed a more globular alteration in morphologic characteristics, with diffuse thickening and irregularity. During intra-articular injection, the visualized injected fluid outlined the labrum, yielding a "sonoarthrographic effect," providing a fluid interface along the labral boundaries, and confirming the presence of a tear by imbibition of injected material into the defect with a resultant subjective improvement in the labral injury. CONCLUSIONS: Evaluating the labrum after injection may improve visualization of labral injuries, as a result of greater labral conspicuity.

PURPOSE: The effect of contact area between tendon and bone on ultimate pullout strength of a repaired tendon is not known. The purpose of this study was to test whether the strength of a healed bone-tendon interface is related to the amount of tendon that is in contact with bone at the time of repair. METHODS: A total of 20 mature goats underwent bilateral open rotator cuff repair of the infraspinatus tendon. The tendon edge was repaired to bleeding cancellous bone in each case with the use of suture anchors. The tendon was repaired with 2 anchors (contact area A; n = 20) on 1 shoulder and 4 anchors (contact area B; n = 20) on the contralateral shoulder. Ten goats were euthanized at 4 weeks (group 1) and 10 goats at 8 weeks (group 2) postoperatively. Twelve specimens were evaluated with ultrasound in the sagittal and coronal planes in a saline bath before mechanical testing was conducted. Ultimate load to failure was reported for each shoulder. Data were analyzed by means of a paired t test and Wilcoxon signed-rank test. RESULTS: Ultrasound evaluation revealed several instances in groups 1/2 and contact areas A/B in which clear gap formation occurred without scar (collagen) interdigitation at the bone-tendon interface. Failures occurred at the bone-tendon repair site in all specimens during biomechanical testing. The mean load to failure for all specimens in group 1 was 350.7 N; it was 619.4 N for specimens in group 2 (P = .0002). In group 1, specimens with contact area A had a mean load to failure of 317.3 N; specimens with contact area B had a mean load to failure of 375.5 N (P = .15). In group 2, specimens repaired with contact area A had a mean ultimate load to failure of 635.8 N, whereas contact area B specimens had an ultimate failure strength of 688.5 N (P = .45; Wilcoxon signed-rank). CONCLUSIONS: Increasing the number of suture anchors and the surface area of the tendon that is in contact with bone at the repair site increased the ultimate load to failure of the repaired tendon at both 4 and 8 weeks postoperatively by less than 10% at both intervals. This was not a statistically significant increase in failure strength in this model. CLINICAL RELEVANCE: This animal model shows no statistically significant differences in strength at the repair site between a 2-anchor and a 4-anchor rotator cuff repair. This information may have direct clinical applications for the surgical technique employed in the repair of rotator cuffs.

PURPOSE: To compare the clinical outcomes of patients undergoing all-arthroscopic versus mini-open rotator cuff repair. In addition, ultrasound was used to assess the integrity of the repair. METHODS: A total of 38 patients who had undergone all-arthroscopic repair and 33 patients who had undergone mini-open repair with minimum 2-year follow-up were evaluated. All patients completed the American Shoulder and Elbow Surgeons' Scoring Survey (ASES), the Simple Shoulder Test, the L'Insalata Scoring Survey, and visual analog scales for pain. Physical examination, including strength testing and ultrasound evaluation to determine the integrity of the rotator cuff, was performed. RESULTS: No statistical difference in ASES scores was noted between patients who had all-arthroscopic repair versus mini-open repair, and 24% of all-arthroscopic repairs and 27% of mini-open repairs showed recurrent defects on ultrasound at follow-up. This difference was not statistically significant. Patients with an original tear larger than 3 cm were 7 times more likely to have a recurrent defect at follow-up. Patients with persistent defects had statistically significant deficits in strength on forward elevation and external rotation when compared with those with a normal shoulder. However, no difference was observed with regard to pain or outcome scores between patients with intact repairs and those with persistent defects. CONCLUSIONS: No difference in clinical outcomes was found between patients with rotator cuffs repaired arthroscopically and those repaired with use of a mini-open technique. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Various studies have questioned the benefit of repairing the posterior structures after total hip arthroplasty because their integrity can appear disrupted at followup. However, these studies did not directly examine the posterior structures. We hypothesized that repaired posterior structures remain intact after total hip arthroplasty, and that their integrity could be evaluated by ultrasonography. We performed evaluations in the hips of 18 patients that had either the short external rotators and capsule repaired, or the capsule, short external rotators, and quadratus femoris repaired. Nine patients in each group were examined using ultrasonography at 6 weeks and 3 months postoperatively. The short external rotators and capsule were intact in 89% of patients in both groups at 6 weeks and 3 months postoperatively. At both time points, the quadratus femoris had continuity in 44% of hips with the standard posterior repair and 78% of hips with the enhanced posterior repair (p = 0.15). Ultrasonography can be used to effectively assess the integrity of the posterior repair after total hip arthroplasty. The posterior structures were intact in the majority of patients 3 months after total hip arthroplasty.