Background The synovial chondromatosis is an uncommon proliferative metaplastic process of the synovial cells that can develop in any synovial joint. An isolated primary chondromatosis of the posterior compartment of the knee is uncommon and few cases are reported in literature. Our purpose is to describe a rare case of primary chondromatosis of the knee posterior compartment and report the arthroscopic loose bodies excision through a difficult posteromedial portal, avoiding the use of the accessory posterior portal, most commonly reported for approaching this disease. Case presentation We report a rare case of a 35-year-old Caucasian male patient with diagnosis of chondromatosis of the posterior knee compartment. The radiographs showed multiple loose bodies of the posterior compartment. The MRI revealed minimal synovial hypertrophy areas, multiple osteophytes in the intercondylar notch, and loose bodies in the posteromedial compartment. The CT allowed us to assess the bony structures, the morphology of the intercondylar notch, and the presence osteophytes of the medial and lateral femoral condyles. The CT images were crucial to plan how to reach the posterior compartments of the knee through a trans-notch passage. The patient underwent arthroscopic surgery using anteromedial, anterolateral, and posteromedial portals. The tunneling through the intercondylar osteophytes was performed to allow the arthroscope to pass trans-notch. To avoid additional accessory posterior portals, we used a 70° arthroscope to better explore the posterior knee compartment. The cartilage-like bodies were removed and synovectomy of the inflamed areas was performed. The clinical and radiological follow-up was 12 months and the patient showed excellent clinical outcomes, returning to his activities of daily living and sport activity. Conclusion Our case report highlights the importance of the arthroscopic approach to treat synovial chondromatosis, despite the involvement of the posterior compartment of the knee. An optimal preoperative imaging allows to plan for the proper surgical procedure even in patients with severe osteoarthritis. Moreover, the adoption of an intercondylar notch tunneling and a 70° arthroscope can help surgeons to better explore the posterior knee compartment, avoiding an accessory posterior trans-septal portal. Therefore, a synovectomy of the inflamed foci may be useful to prevent recurrence.

BacKGrOUNdː acromioclavicular (ac) joint dislocation is a frequent shoulder injury. dozens of surgical techniques have been described but nowadays there is no evidence supporting a specific technique as the gold standard for acute ac joint injury. the aim of the present study was to investigate the difference between suspensory button and double tunnel suture loop techniques in terms of the quality of the acromioclavicular joint reconstruction by comparing functional assessment, clinical scores, and postoperative complication rate. MethOdsː We performed a retrospective comparative analysis of 63 patients treated for acute isolated ac dislocation: 36 treated with suspensory button technique, 27 treated with double tunnel suture loop technique. surgical time of both procedures was collected and examined. constant-Murley and dash scores at 1-year follow-up were compared. the complications such as clavicular fracture, nerve damage, infection and recurrence of dislocation were recorded and analyzed. ac joint displacement ratio was measured on 1-year X-ray considering values greater of 0.5 as recurrence of dislocation. resULtsː the statistical analysis did not show any statistical difference of surgical time, constant-Murley score, dash score and the complication rate between the two surgical techniques. cONcLUsiONsː Both techniques ensure a strong and reliable acromioclavicular repair with satisfactory functional and clinical assessments, so surgical technique choice should be guided by the habit of the surgeon.

S ynovial chondromatosis (SC) is a proliferative metaplastic process of joint synovial cells that can result in the formation of loose cartilaginous bodies in the articular space, commonly involving large joints such as hip, shoulder and knee. 1 The surgical procedure involves removal of the loose bodies by arthroscopy or open surgery, with or without FIGURE 1. A-B, Anteroposterior and later views of preoperative radiograph. C, Computed tomography axial view: posterior loose bodies and multiple intercondylar notch osteophyte. D, MRI sagittal view: multiple loose bodies in posterior compartment. E, Magnetic resonance imaging coronal view: posterior compartment of the knee, multiple loose bodies and edema. F, Magnetic resonance imaging axial view posterior loose bodies and intercondylar notch osteophyte.