Three-dimensional muscle loss assessment: a novel computed tomography-based quantitative method to evaluate rotator cuff muscle fatty infiltration.

BACKGROUND: Rotator cuff fatty infiltration (FI) is one of the most important parameters to predict the outcome of certain shoulder conditions. The primary objective of this study was to define a new computed tomography (CT)-based quantitative 3-dimensional (3D) measure of muscle loss (3DML) based on the rationale of the 2-dimensional (2D) qualitative Goutallier score. The secondary objective of this study was to compare this new measurement method to traditional 2D qualitative assessment of FI according to Goutallier et al and to a 3D quantitative measurement of fatty infiltration (3DFI). MATERIALS AND METHODS: 102 CT scans from healthy shoulders (46) and shoulders with cuff tear arthropathy (21), irreparable rotator cuff tears (18), and primary osteoarthritis (17) were analyzed by 3 experienced shoulder surgeons for subjective grading of fatty infiltration according to Goutallier, and their rotator cuff muscles were manually segmented. Quantitative 3D measurements of fatty infiltration (3DFI) were completed. The volume of muscle fibers without intramuscular fat was then calculated for each rotator cuff muscle and normalized to the patient's scapular volume to account for the effect of body size (NVfibers). 3D muscle mass (3DMM) was calculated by dividing the NVfibers value of a given muscle by the mean expected volume in healthy shoulders. 3D muscle loss (3DML) was defined as 1 - (3DMM). The correlation between Goutallier grading, 3DFI, and 3DML was compared using a Spearman rank correlation. RESULTS: Interobserver reliability for the traditional 2D Goutallier grading was moderate for the infraspinatus (ISP, 0.42) and fair for the supraspinatus (SSP, 0.38), subscapularis (SSC, 0.27) and teres minor (TM, 0.27). 2D Goutallier grading was found to be significantly and highly correlated with 3DFI (SSP, 0.79; ISP, 0.83; SSC, 0.69; TM, 0.45) and 3DML (SSP, 0.87; ISP, 0.85; SSC, 0.69; TM, 0.46) for all 4 rotator cuff muscles (P < .0001). This correlation was significantly higher for 3DML than for the 3DFI for SSP only (P = .01). The mean values of 3DFI and 3DML were 0.9% and 5.3% for Goutallier 0, 2.9% and 25.6% for Goutallier 1, 11.4% and 49.5% for Goutallier 2, 20.7% and 59.7% for Goutallier 3, and 29.3% and 70.2% for Goutallier 4, respectively. CONCLUSION: The Goutallier score has been helping surgeons by using 2D CT scan slices. However, this grading is associated with suboptimal interobserver agreement. The new measures we propose provide a more consistent assessment that correlates well with Goutallier's principles. As 3DML measurements incorporate atrophy and fatty infiltration, they could become a very reliable index for assessing shoulder muscle function. Future algorithms capable of automatically calculating the 3DML of the cuff could help in the decision process for cuff repair and the choice of anatomic or reverse shoulder arthroplasty.

Ultrasound-guided percutaneous tenotomy of the long head of the biceps tendon: a non-reliable technique.

PURPOSE: To evaluate the feasibility of ultrasound-guided percutaneous tenotomy of the long head of the biceps tendon via a keyhole incision. METHODS: This was an anatomical study performed on twelve embalmed cadaveric shoulder joints. The rotator cuff and the position of the long head of the biceps tendon were explored by ultrasound prior to beginning the procedure. The biceps tenotomy was performed under ultrasound guidance by a highly experienced sonographer who was trained in shoulder tendon exploration. Arthroscopic exploration of the shoulder was performed immediately after the percutaneous biceps tenotomy to assess the quality and the location of the biceps tenotomy. RESULTS: Three out of twelve tendons (25%) were completely sectioned at the level of the glenoid insertion. More seriously, iatrogenic lesions of the cartilage of the humeral head, the supraspinatus tendon and the subscapularis tendon were observed. CONCLUSION: This study shows that ultrasound-guided percutaneous tenotomy of the long head of the biceps tendon is not reliable.

Efficacy and safety of Hylan G-F 20 in shoulder osteoarthritis with an intact rotator cuff. Open-label prospective multicenter study.

OBJECTIVE: To evaluate the feasibility, safety, and symptomatic efficacy of intra-articular Hylan G-F 20 in patients with shoulder osteoarthritis and an intact rotator cuff. METHODS: Open-label, prospective, multicenter study in patients with pain scores on a visual analog scale (VAS) between 40/100 and 90/100. An intra-articular injection of 2 ml of Hylan G-F 20 was given under fluoroscopic guidance. A second injection was given after 1, 2, or 3 months in the event of inadequate pain relief. The primary evaluation criterion was the VAS pain score 3 months after the first injection. Follow-up was 6 months. RESULTS: Of 39 included patients, 33 received a first injection and, among these, 16 received a second injection; 29 patients completed the study. No serious or severe treatment-related adverse events were recorded. There were 10 mild or moderate adverse events in eight patients. The mean VAS pain score decreased from 61.2 mm at baseline to 37.1 mm after 3 months (P<0.001), and the decrease was larger in the subgroup that required a single injection. CONCLUSION: This prospective study shows that treatment with one or two intra-articular injections of Hylan GF 20 in patients who have shoulder osteoarthritis and an intact cuff is feasible, safe, and probably effective. Viscosupplementation using Hylan G-F 20 may constitute a helpful treatment option in patients who have shoulder osteoarthritis with an intact rotator cuff.

Tibial plateau fracture after anterior cruciate ligament reconstruction: Role of the interference screw resorption in the stress riser effect.

We report a case of tibial plateau fracture after previous anterior cruciate ligament (ACL) reconstruction using patellar tendon autograft and bioabsorbable screws 4 years previously. The fracture occurred through the tibial tunnel. The interference screw had undergone complete resorption and the tunnel widening had increased. The resorption of the interference screw did not simultaneously promote and foster the growth of surrounding bone tissue. Therefore, the area of reactive tissue left by the screw resorption in an enlarged bone tunnel may lead to vulnerability of the tibial plateau. Stress risers would occur following ACL reconstruction if either resorption is not complete or bony integration is not complete.