Serial MRI evaluation following arthroscopic rotator cuff repair in double-row technique.

INTRODUCTION: So far, recurrent rotator cuff defects are described to occur in the early postoperative period after arthroscopic repair. The aim of this study was to evaluate the musculotendinous structure of the supraspinatus, as well as bone marrow edema or osteolysis after arthroscopic double-row repair. Therefore, magnetic resonance (MR) images were performed at defined intervals up to 2 years postoperatively. STUDY DESIGN: Case series; Level of evidence, 3. MATERIALS AND METHODS: MR imaging was performed within 7 days, 3, 6, 12, 26, 52 and 108 weeks after surgery. All patients were operated using an arthroscopic modified suture bridge technique. Tendon integrity, tendon retraction ["foot-print-coverage" (FPC)], muscular atrophy and fatty infiltration (signal intensity analysis) were measured at all time points. Furthermore, postoperative bone marrow edema and signs of osteolysis were assessed. RESULTS: MR images of 13 non-consecutive patients (6f/7m, ∅ age 61.05 ± 7.7 years) could be evaluated at all time points until ∅ 108 weeks postoperatively. 5/6 patients with recurrent defect at final follow-up displayed a time of failure between 12 and 24 months after surgery. Predominant mode of failure was medial cuff failures in 4/6 cases. The initial FPC increased significantly up to 2 years follow-up (p = 0.004). Evaluations of muscular atrophy or fatty infiltration were not significant different comparing the results of all time points (p > 0.05). Postoperative bone marrow edema disappeared completely at 6 months after surgery, whereas signs of osteolysis appeared at 3 months follow-up and increased to final follow-up. CONCLUSIONS: Recurrent defects after arthroscopic reconstruction of supraspinatus tears in modified suture bridge technique seem to occur between 12 and 24 months after surgery. Serial MRI evaluation shows good muscle structure at all time points. Postoperative bone marrow edema disappears completely several months after surgery. Signs of osteolysis seem to appear caused by bio-absorbable anchor implantations.

Autogenous bone grafting for chronic anteroinferior glenoid defects via a complete subscapularis tenotomy approach.

INTRODUCTION: Open reconstruction of severe anteroinferior chronic glenoid defects via a complete subscapularis (SSC) tenotomy using a tricortical iliac crest bone grafting technique has been reported. The purpose of this study was to evaluate the clinical and radiological results in patients who underwent this procedure and to investigate the influence of the anterior approach on the structure and function of the SSC musculotendinous unit. MATERIALS AND METHODS: Ten patients (two women/eight men, mean age 28.7 years) underwent reconstruction of significant chronic glenoid defects in cases of recurrent shoulder instability with significant glenoid bone loss, using a tricortical autogenous iliac crest in combination with a capsulolabral repair. The patients were followed up clinically (clinical SSC tests and signs, Constant score, Rowe score, Walch-Duplay score, WOSI, MISS), by standard radiographs (true a/p, axillary and glenoid profile view), computed tomography (graft integration, inferior glenoid area) and bilateral magnetic resonance imaging [SSC tendon integrity, cross sectional area, defined muscle diameters and signal intensity analysis (ratio ISP/upper SSC and ISP/lower SSC)]. RESULTS: After a mean follow-up of 37.9 months, the mean Constant score averaged 88.3 points, the Rowe score 89.5 points, the Walch-Duplay score 83.5 points, the MISS 80.6 points and the WOSI 82.6%. No recurrent subluxations or dislocations were observed. Clinical signs for SSC insufficiency were present in 80% of cases. Two patients had grade I and one patient grade II osteoarthritis according to Samilson and Prieto classification. CT imaging revealed a consolidated autograft in all cases with an 18.4% increase of the inferior glenoid area postoperatively (P < 0.05). No tendon ruptures were found. MR imaging revealed muscular atrophy (P < 0.05) and fatty infiltration of the SSC (P > 0.05) muscle compared to the contralateral side. CONCLUSION: Open reconstruction of anteroinferior chronic glenoid defects via a complete SSC tenotomy using an iliac crest bone grafting technique allows an anatomic reconstruction of the anteroinferior glenoid with good and excellent clinical results. The anterior approach may lead to atrophy and fatty infiltration of the SSC muscle despite an intact tendon. However, this did not affect the results in terms of stability.

Structural integrity and clinical function of the subscapularis musculotendinous unit after arthroscopic and open shoulder stabilization.

BACKGROUND: Postoperative subscapularis dysfunction after open shoulder stabilization has recently received increasing attention. The potential advantage of arthroscopic stabilization procedures is that they do not violate the subscapularis musculotendinous unit, which might preserve its structural integrity and clinical function, which would lead to superior clinical results. HYPOTHESIS: Arthroscopic shoulder stabilization does not lead to clinical and radiological signs of subscapularis insufficiency. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Twenty-two patients who underwent arthroscopic (group I, n = 12; average age, 30.9 years; mean follow-up, 37 months) or open (group II, n = 10; average age, 28.8 years; mean follow-up, 35.9 months) shoulder stabilization procedure were followed up clinically (clinical subscapularis tests and signs, Constant Score, Rowe Score, Walch-Duplay Score, Western Ontario Shoulder Instability Index and Melbourne Instability Shoulder Score) and by magnetic resonance imaging (subscapularis tendon integrity, cross-sectional area, defined muscle diameters, and signal intensity analysis [ratio infraspinatus/upper subscapularis and infraspinatus/lower subscapularis]). A third group (group 0) of 12 healthy volunteers served as a control. RESULTS: Clinical signs for subscapularis insufficiency were present in 0% of cases in group I and in 70% of cases in group II. There were no statistically significant differences in either group regarding Constant Score, Rowe Score, Walch-Duplay Score, Western Ontario Shoulder Instability Index, and Melbourne Instability Shoulder Score (P > .05). On magnetic resonance image, no subscapularis tendon ruptures were found. The cross-sectional area, the mean vertical diameter, and the mean transverse diameter of the upper and lower subscapularis muscle portion was significantly less in group II than in group 0 (P < .05). The signal intensity analysis revealed the infraspinatus/upper subscapularis ratio was significantly lower in group II than in group I or group 0. The infraspinatus/lower subscapularis ratio did not significantly differ in all 3 groups (P > .05). CONCLUSION: This study confirms previous observations that open shoulder stabilization using a subscapularis tenotomy may lead to atrophy and fatty infiltration of the subscapularis muscle, resulting in postoperative subscapularis dysfunction. As expected, arthroscopic procedures do not significantly compromise clinical subscapularis function and structural integrity. However, no significant differences were observed in the overall outcome.

Dose reduction in whole-body computed tomography of multiple injuries (DoReMI): protocol for a prospective cohort study.

BACKGROUND: Single-pass, contrast-enhanced whole body multidetector computed tomography (MDCT) emerged as the diagnostic standard for evaluating patients with major trauma. Modern iterative image algorithms showed high image quality at a much lower radiation dose in the non-trauma setting. This study aims at investigating whether the radiation dose can safely be reduced in trauma patients without compromising the diagnostic accuracy and image quality. METHODS/DESIGN: Prospective observational study with two consecutive cohorts of patients. SETTING: A high-volume, academic, supra-regional trauma centre in Germany. STUDY POPULATION: Consecutive male and female patients who 1. had been exposed to a high-velocity trauma mechanism, 2. present with clinical evidence or high suspicion of multiple trauma (predicted Injury Severity Score [ISS] ≥16) and 3. are scheduled for primary MDCT based on the decision of the trauma leader on call.Imaging protocols: In a before/after design, a consecutive series of 500 patients will undergo single-pass, whole-body 128-row multi-detector computed tomography (MDCT) with a standard, as low as possible radiation dose. This will be followed by a consecutive series of 500 patients undergoing an approved ultra-low dose MDCT protocol using an image processing algorithm. DATA: Routine administrative data and electronic patient records, as well as digital images stored in a picture archiving and communications system will serve as the primary data source. The protocol was approved by the institutional review board. MAIN OUTCOMES: (1) incidence of delayed diagnoses, (2) diagnostic accuracy, as correlated to the reference standard of a synopsis of all subsequent clinical, imaging, surgical and autopsy findings, (3) patients' safety, (4) radiation exposure (e.g. effective dose), (5) subjective image quality (assessed independently radiologists and trauma surgeons on a 100-mm visual analogue scale), (6) objective image quality (e.g., contrast-to-noise ratio). ANALYSIS: Multivariate regression will be employed to adjust and correct the findings for time and cohort effects. An exploratory interim analysis halfway after introduction of low-dose MDCT will be conducted to assess whether this protocol is clearly inferior or superior to the current standard. DISCUSSION: Although non-experimental, this study will generate first large-scale data on the utility of imaging-enhancing algorithms in whole-body MDCT for major blunt trauma. TRIAL REGISTRATION: Current Controlled Trials ISRCTN74557102.

Magnetic resonance imaging analysis of the subscapularis muscle after arthroscopic and open shoulder stabilization.

To evaluate the subscapularis muscle (SSC) after arthroscopic and open shoulder stabilization, three groups [after arthroscopic (A), after open shoulder stabilization (B), healthy volunteers (0)] underwent magnetic resonance imaging. Magnetic resonance parameters were compared with clinical SSC tests and shoulder scores. From Group 0 to B, the diameters of the SSC decreased, and the fatty degeneration of the upper SSC increased (P<.05) from Group 0 and A to B according to clinical findings. The functional shoulder scores did not differ (P>.05). Magnetic resonance analysis provides reasons of postoperative SSC dysfunction.

How long should acute anterior dislocations of the shoulder be immobilized in external rotation?

BACKGROUND: Immobilization of the shoulder in external rotation has been shown to reduce the risk of recurrence after traumatic anteroinferior shoulder dislocation. It remains unclear how duration of immobilization affects labral coaptation. HYPOTHESIS: Immobilization of the shoulder in 30 degrees of external rotation for 5 weeks allows better coaptation of the anteroinferior labrum than does an immobilization period of 3 weeks. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Twenty-two patients with traumatic anteroinferior dislocation of the glenohumeral joint were included in this study. Patients were divided into 2 groups. Group 1 consisted of the initial 11 patients (mean age, 37.4 years) immobilized for 3 weeks; group 2 consisted of the subsequent 11 patients (mean age, 29.7 years) immobilized for 5 weeks in 30 degrees of external rotation. With use of magnetic resonance imaging, displacement and separation of the glenoid labrum and anterior joint effusion were assessed in different arm positions (internal rotation, neutral rotation, 30 degrees of external rotation, maximum external rotation) within 3 days, 3 weeks, and 5 weeks after reduction. RESULTS: Displacement and separation of the labrum and anterior joint effusion were significantly less, particularly with maximum external rotation compared with neutral and internal rotation, during the acute magnetic resonance imaging evaluation in both groups (P < .05). No statistically significant differences were found in all parameters comparing internal rotation with neutral rotation, 30 degrees of external rotation, and maximum external rotation in both groups after 5 weeks (P > .05). No statistically significant differences were found between both groups comparing the results of the measured variables during the acute, 3-week, and 5-week magnetic resonance imaging examinations (P > .05). CONCLUSION: Immobilization of the shoulder in 30 degrees of external rotation seems to allow a similar coaptation of the glenoid labrum, regardless of duration of immobilization (3 vs 5 weeks). Clinical trials are needed to evaluate the effect of these results on recurrence rates. The optimum position of immobilization in external rotation has yet to be determined.