Feasibility of ultrasound-guided percutaneous tenotomy of the long head of the biceps tendon--A pilot cadaveric study.

OBJECTIVE: To describe an ultrasound-guided proximal percutaneous tenotomy technique of long head of the biceps tendon (LHBT). METHODS: Three fresh cadavers with no prior shoulder surgery or LHBT tears were included in the study. A single experienced musculoskeletal radiologist completed six ultrasound-guided proximal percutaneous tenotomies of LHBT. A superficial to deep approach was performed on four shoulders using an arthroscopic banana blade or retractable blade. A deep to superficial approach was performed on two shoulders using an arthroscopic hook blade. A blinded anatomist dissected each specimen and graded the tenotomy, length of proximal LHBT stump, and evidence of iatrogenic injuries. RESULTS: Four of the six cadaveric LHBTs were fully transected. The two partially transected tenotomies were performed using the arthroscopic banana and retractable serrated blades (63% and 80% transections, respectively). The proximal LHBT stump mean length was 2.6 cm (95% CI, 1.8-3.4). There was no evidence of iatrogenic lesions. CONCLUSIONS: This cadaveric study showed that the ultrasound-guided percutaneous tenotomy of the LHBT is a feasible procedure. The deep to superficial approach using an arthroscopic hook blade resulted in complete transection. Further cadaveric studies with larger numbers are warranted to confirm this novel technique's applicability in clinical practice.

The utility of ultrasound in detecting anterior compartment thickness changes in chronic exertional compartment syndrome: a pilot study.

OBJECTIVE: To test the hypothesis that patients with chronic exertional compartment syndrome (CECS) of the anterior leg compartment have an increased anterior compartment thickness (ACT) compared with control subjects after exertion using ultrasound. DESIGN: Prospective comparison study. SETTING: Diagnostic imaging department of a tertiary care hospital. PATIENTS: Four patients with CECS and 9 control subjects. INTERVENTIONS: Patients with CECS and control subjects ran on a treadmill for up to 10 minutes. Anterior compartment thickness (both groups) and anterior compartment pressure (CECS patients) were measured before exertion and at scheduled intervals after exertion. MAIN OUTCOME MEASURES: Anterior compartment thickness, percentage change in ACT from rest, and compartment pressure. RESULTS: Anterior compartment pressures were diagnostic of CECS using the modified Pedowitz criteria in patients with CECS. Mean percentage change in ACT from rest in patients with CECS versus control subjects at 0.5 minutes was 21.3% versus 6.32% [95% confidence interval (CI), 6.92-35.6 and 0.094-12.5, respectively; P = 0.011]; at 2.5 minutes, it was 24.6% versus 4.22% (95% CI, 10.7-38.5 and -1.85-10.3, respectively; P = 0.003); and at 4.5 minutes, it was 24.9% versus 5.08% (95% CI, 14.3-35.5 and -0.813-11.0, respectively; P = 0.003). Mean ACT in patients with CECS versus control subjects significantly increased after exertion (P = 0.003) at 0.5 minutes, 2.5 minutes, and 4.5 minutes. CONCLUSIONS: Ultrasonography reveals a significant increase in ACT in patients with CECS of the anterior leg compartment. Further studies are warranted to validate these findings with the goal of developing anterior leg compartment CECS ultrasound diagnostic criteria and exploring the role of using ultrasound to diagnose CECS in other compartments.

Surgical repair of the supraspinatus: pre- and postoperative architectural changes in the muscle.

INTRODUCTION: Shortening of the tendon and muscle is recognised as a strong predictor of surgical failure of supraspinatus tendon tears. Changes in muscle architecture following repair have not been thoroughly investigated. Hence, we aimed to compare the pre- and postoperative architecture of the supraspinatus. METHODS: We recruited eight participants with full-thickness supraspinatus tears. Images of the supraspinatus were captured preoperatively (pre-op) and postoperatively at one month (post-op1), three months (post-op2) and six months (post-op3) in relaxed and contracted states (0º and 60º glenohumeral abduction). Fibre bundle length (FBL), pennation angle (PA) and muscle thickness were quantified. Self-reported function, and maximal isometric abduction and external rotation strengths were assessed. RESULTS: The mean FBL increased from pre-op to post-op1 (p = 0.001) in the relaxed state and from pre-op to post-op2 (p = 0.002) in the contracted state. Decrease in FBL was observed from post-op2 to post-op3 in the relaxed state. The mean PA decreased from pre-op to post-op1 (p < 0.001) in the relaxed state, but increased from post-op2 to post-op3 in both relaxed (p = 0.006) and contracted (p = 0.004) states. At post-op3, external rotation (p = 0.009) and abduction (p = 0.005) strengths were greater than at post-op2. Overall function increased by 47.67% from pre-op to post-op3. CONCLUSION: Lengthening of the supraspinatus occurs with surgery, altering the length-tension relationship of the muscle, which can compromise muscle function and lead to inferior surgical outcomes. These findings may guide clinicians to optimise loads, velocities and shoulder ranges for effective postoperative rehabilitation.

Development of supraspinatus imaging guidance for primary care physicians with a focus on patient selection.

BACKGROUND: Primary care physicians frequently encounter patients with supraspinatus pathology and face a difficult task of managing this subset of patients using limited imaging resources. The purpose of this study was to develop a guidance that could help primary care physicians choose appropriate imaging tests judiciously for patients with suspected supraspinatus pathology. METHODS: The imaging reports of one hundred patients who underwent ultrasound and MRI for suspected supraspinatus tendinopathy were retrospectively assessed. The supraspinatus tendon was recorded as intact, partial tear (articular or bursal), or full-thickness tear (focal or complete width). The agreement between imaging modalities was then evaluated using factors such as pathology type and age. RESULTS: There was agreement between modalities in 48/100 patients (Kappa statistic = 0.30). The consistency varied with type of pathology: intact tendons by ultrasound had 55.8% agreement with MRI, partial sided bursal tears 50%, partial sided articular tears 25%, and full-thickness focal tears 33.3%. Full-thickness complete-width tears had a much better agreement with MRI at 90.9%. Age was also significant, with increased disagreement between ultrasound and MRI in patients over 50 years old. CONCLUSIONS: Our data showed that ultrasound findings correlated well with MRI in patients under 50 years of age and also in patients with full-thickness supraspinatus tears. We recommend that primary care physicians may consider using ultrasound as the initial test in younger patients and in patients with suspected full supraspinatus tears, based on clinical exam, with MRI as an option for further evaluation to quantify supraspinatus muscle atrophy. These patient selection recommendations will help promote mindful utilization of scarce resources.

Complex posterior fracture-dislocation of the shoulder. Epidemiology, injury patterns, and results of operative treatment.

BACKGROUND: Complex posterior fracture-dislocations of the shoulder are rare and often associated with poor long-term function regardless of the choice of treatment. The purposes of this study were to evaluate the epidemiology and pathological anatomy of posterior fracture-dislocations of the shoulder and to assess the clinical and radiographic outcomes of a specific treatment protocol of open reduction and internal fixation. METHODS: We studied the demographic details of a consecutive series of twenty-six patients (twenty-eight shoulders in nineteen men and seven women with a mean age of fifty-three years) who sustained acute posterior dislocation of the humeral head with an associated Neer two, three, or four-part fracture. We used age and gender-specific local census data to assess the incidence of injury in our local population. All patients were treated by open relocation of the humeral head, bone-grafting of humeral head defects if they were causing residual shoulder instability, and internal fixation of the fracture. We recorded the prevalence of fracture complications that were clinically and radiographically apparent and assessed the functional outcome using three validated scoring systems (the Short Form-36 general health measure, the Disabilities of the Arm, Shoulder and Hand score, and the Constant score). RESULTS: The overall incidence of posterior fracture-dislocations was 0.6 per 100,000 population per year. The peak incidence was in middle-aged men, and most injuries were sustained during a seizure or a fall from a height. In all patients, there was a displaced primary fracture of the anatomic neck of the humerus, propagating from the area of an osteochondral fracture of the anterior aspect of the humeral head (a reverse Hill-Sachs lesion). We recognized three subtypes determined by the extent of the secondary fracture lines. At two years after surgery, the median Constant score was 83.5 points and the median Disabilities of the Arm, Shoulder and Hand score was 17.5 points. The eight components of the Short Form-36 score were not significantly different from those of age and sex-matched controls at two years. CONCLUSIONS: Acute complex posterior fracture-dislocations of the shoulder are rare, but they occur in patients who are younger than the majority of other patients who sustain a proximal humeral fracture. The use of open reduction and internal fixation to treat these fractures is associated with a relatively low risk of postoperative complications, and the functional outcome is generally favorable.

Dual energy CT at the synchrotron: a piglet model for neurovascular research.

BACKGROUND: Although the quality of imaging techniques available for neurovascular angiography in the hospital environment has significantly improved over the last decades, the equipment used for clinical work is not always suited for neurovascular research in animal models. We have previously investigated the suitability of synchrotron-based K-edge digital subtraction angiography (KEDSA) after intravenous injection of iodinated contrast agent for neurovascular angiography in radiography mode in both rabbit and pig models. We now have used the KEDSA technique for the acquisition of three-dimensional images and dual energy CT. MATERIALS AND METHODS: All experiments were conducted at the biomedical beamline ID 17 of the European Synchrotron Radiation Facility (ESRF). A solid state germanium (Ge) detector was used for the acquisition of image pairs at 33.0 and 33.3 keV. Three-dimensional images were reconstructed from an image series containing 60 single images taken throughout a full rotation of 360°. CT images were reconstructed from two half-acquisitions with 720 projections each. RESULTS: The small detector field of view was a limiting factor in our experiments. Nevertheless, we were able to show that dual energy CT using the KEDSA technique available at ID 17 is suitable for neurovascular research in animal models.