Introduction. Subacromial corticosteroid injection is widely used in the treatment of Subacromial Impingement Syndrome (SIS). There is increasing interest in using ultrasound (US) to improve the accurate placement of injections. This study investigated whether the accuracy of placement of US-guided subacromial corticosteroid injections influences patients' outcome of pain and function. Method. Secondary analysis of data from a 2−2 factorial randomised controlled trial investigating exercise and corticosteroid injection for pain and function in SIS. US-guided injections were delivered according to a pre-defined protocol. Video images were reviewed to categorise accuracy of injection into the subacromial bursa into 3 accuracy groups using pre-defined criteria: 1) not in the subacromial bursa; 2) probably in the subacromial bursa; and 3) definitely in the subacromial bursa. The primary outcome measure was the self-reported Shoulder Pain and Disability Index (SPADI) total score, compared at 6 weeks and 6 months. Secondary outcomes included SPADI pain and function subscales and participant global rating of overall change from baseline. A mixed effects model was used to compare accuracy groups' outcomes at 6 weeks and 6 months, adjusted for baseline covariates. Results. US-guided injection accuracy data were available for 114 participants; with 22 participants in group 1, 21 in group 2 and 71 in group 3. There were no significant differences in mean SPADI scores among the three injection accuracy groups at 6 weeks (group 2 vs. 1: 8.22 (95% CI −4.01, 20.50); group 3 vs. 1: −0.57 (−10.27, 9.13)) and 6 months (group 2 vs. 1: 12.38 (−5.34, 30.10); group 3 vs. 1: 3.10 (−11.04, 17.23)). Similarly, no differences between accuracy groups were seen in SPADI pain, SPADI function or participant global rating of change. Conclusion. The accuracy of US-guided subacromial corticosteroid injection in SIS does not influence clinical response to the injection, questioning the need for guided injections. Larger, adequately powered studies are required to explore this further

The purpose of this study was to compare the outcomes of arthroscopic unilateral surgery and simultaneous bilateral surgery for posterior ankle impingement syndrome (PAIS) in athletes and to evaluate the usefulness of simultaneous bilateral surgery.

A total 48 hindfeet of 41 athletes (14 hindfeet of 14 males, 34 hindfeet of 27 females) who underwent arthroscopic surgery for PAIS were studied. Japanese society for surgery of the foot (JSSF) score and visual analogue scale (VAS) were compared before and after surgery, using Wilcoxon signed-rank test. The operation time and the time to return to sports activity were compared in 10 hindfeet of 5 patients who underwent simultaneous bilateral surgery and 38 hindfeet of 36 patients who underwent unilateral surgery, using Wilcoxon rank sum test.

Classic ballet was the most common type of sport that caused PAIS (59%, 24/41 athletes). Soccer (10%, 4/41 athletes), baseball (10%, 4/41 athletes), badminton (5%, 2/41 athletes), volleyball (5%, 2/41 athletes), and athletics (5%, 2/41 athletes) followed. The JSSF score improved significantly from 72.7 preoperatively to 98.9 postoperatively in unilateral surgery, and significantly improved from 75.2 preoperatively to 99.0 postoperatively in simultaneous bilateral surgery. VAS significantly decreased from 64.7 preoperatively to 4.8 postoperatively in unilateral surgery, and significantly decreased from 72.7 preoperatively to 1.0 postoperatively in simultaneous bilateral surgery. The operating time was 53.7 minutes on average for unilateral surgery and 101.0 minutes for simultaneous bilateral surgery, significantly longer in bilateral simultaneous surgery. The mean time to return to sports activity was 4.8 weeks for unilateral surgery and 9.6 weeks for simultaneous bilateral surgery, significantly longer in simultaneous bilateral surgery.

Both unilateral and simultaneous bilateral surgeries for PAIS in athletes were useful. It should be noted that the operating time and the time to return to sports will be longer. However, considering the 2 times hospitalizations and 2 times surgeries, simultaneous bilateral surgery is one of the treatment options for PAIS.

The pathology of the posterior acetabular legion in femoroacetabular impingement (FAI) syndrome, so called “contre-coup region”, is still unclear. ¹⁸F-fluoride positron emission tomography (PET) is a functional imaging modality, which reflects the osteoblast activity. Recent technological advances in PET combined with computed tomography (CT) imaging allowed us to obtain detailed 3-dimensional (3D) morphological information. We evaluated the abnormal uptake of ¹⁸F-fluoride PET/CT on posterior acetabular lesion in FAI syndrome cases. We enrolled forty-one hips from 41 patients who were diagnosed as FAI syndrome and were performed ¹⁸F-fluoride PET/CT between October 2014 and October 2016. In each hip, the maximum standardized uptake value (SUV_max) on the posterior acetabular was measured. The cases were divided into 4 groups; cam-type (11 cases), pincer-type (7), combined-type (11), dysplastic developmental hip (DDH) with cam morphology (12). The average SUV_max of the pincer-type was significantly smaller than that of the other 3 groups (p < .05). The percentage of the cases with SUV_max ≥ 6 was 81.8% in cam-type, 28.6% in pincer-type, 90.9% in combined-type, 91.7% in DDH with cam morphology. Furthermore, the average degree of α angle of the cases of SUV_max ≥ 6 was significantly higher than that of the cases of SUV_max < 6 (p = .005). Although actual biomechanical mechanism in contre-coup region is still controversial, this result indicated that the cam morphology related to the posterior acetabular lesion with accelerated bone metabolism.