Background: The subtle Lisfranc injury is the disruption of the osteoligamentary complex between the first cuneiform and the second metatarsal, resulting in minor widening of this space that is often difficult to detect with plain radiographs. In this study, we assessed the results after treatment of the different stages of subtle Lisfranc injuries, focusing on their impact on foot arch anatomy and functionality at short- to midterm follow-up. Methods: A retrospective study including patients treated in our center for a subtle Lisfranc injury between 2012 and 2019 was conducted. Demographic, epidemiologic, radiographic, and clinical data were obtained and assessed, focusing on foot arch structure and foot function, which was evaluated with the American Orthopaedic Foot & Ankle Society (AOFAS) midfoot score and the Foot Function Index (FFI). Results: A total of 42 patients with a mean age of 49 ± 17.5 years were included, with an average of 4.3 years’ follow-up (range, 1-8). Stage I injuries according to Nunley classification represented 19% and were treated conservatively. Stage II (66.7%) and stage III (14.3%) injuries were treated operatively, via osteosynthesis with screws (74%), K-wires (19%), or plates (7%). Flattening of foot arch after treatment was observed in 42.9% of patients, with significant increases in Costa-Bertani (12 ± 7 degrees), Hibbs (7 ± 6 degrees), and Meary (3 ± 1 degrees) angles. Other complications included complex regional pain syndrome (28.6%) and painful hardware (23.8%). Secondary joint arthrodesis was needed in 16.6% of patients. Chronic pain was present in 71.4% of patients with a mean visual analog scale (VAS) pain score at final follow-up of 4 of 10 points. Results in AOFAS midfoot score and FFI were 87.4 ± 8.3 and 15 ± 6.4, respectively. Conclusion: The subtle Lisfranc injury shows dissociation between the initial relatively mild radiographic changes and important future complications. Chronic pain and foot arch flattening were not uncommon. Overall foot function in the short- or midterm was found to be modestly diminished in this somewhat heterogenous cohort. Level of Evidence: Level IV, therapeutic case series.

And Purpose: Antegrade intramedullary nailing (IMN) in humeral shaft fracture has been abandoned by certain orthopedic surgeons due to rotator cuff injury caused by 1^st and 2^nd generation nails. However, only a few studies have specifically addressed the results of antegrade nailing for the treatment of humeral shaft fractures with a straight third generation intramedullary nail thus complications need to be reevaluated. We hypothesized that fixation of displaced humeral shaft fractures with a straight third-generation antegrade IMN with the percutaneous technique avoid shoulder problems (stiffness and pain) incurred by 1^st and 2^nd generation nails. This was a retrospective, single-center, non-randomized study of 110 patients with a displaced humeral shaft fracture between 2012 and 2019 treated surgically with a long third-generation straight intramedullary nail (IMN). Mean follow-up was 35.6 months (range,15-44 months). There were 73 women and 37 men with a mean age of 64.7 ± 19 years. All fractures were closed (37.3% 12A1, 13.6% 12B2 and 13.6% 12B3 AO/OTA classification). Mean Constant Score was 82 ± 19, MEPS score 96 ± 11 and the mean EQ-VAS 69.7 ± 21.5. Mean Forward elevation 150º ± 40º ◦, abduction 148º ± 45º and external rotation 38º ± 15º. Symptoms associated with rotator cuff disease were present in 6.4%. Evidence of radiographic fracture healing was detected in all but one case. One postoperative nerve injury and one adhesive capsulitis were present. 6.3% underwent second surgeries (4.5% were minor surgeries like hardware removal). Percutaneous antegrade intramedullary nailing of humeral shaft fractures with a straight-third-generation nail considerably reduce complications related to shoulder problems and achieve good functional results.

Introduction: Arthroscopic balloon spacer arthroplasty (BSA) is a relatively recent procedure for patients with irreparable rotator cuff tears, conceived to prevent degenerative joint changes and relieve subacromial pain. Methods: This is a retrospective case series of 16 consecutive patients treated with BSA and followed up for a minimum 12 months. Besides BSA, partial tendon repair was done whenever possible. Radiographical parameters such as acromiohumeral distance and Hamada stage were measured preoperatively and postoperatively. Range of motion, functional results (Constant score; Simple Shoulder Test; American Shoulder and Elbow Surgeons score; and Disabilities of the Arm, Shoulder, and Hand score), health-related quality of life results with the EuroQol Five Dimensions tool, complications, and patient satisfaction were also analyzed. Results: The mean age was 64 ± 10.3 years, and the male/female ratio was 6/10. Partial repair was achieved in five patients (31.2%) and did not influence functional or health-related quality of life results (P = 0.11). The mean acromiohumeral distance and Hamada stage worsened from preoperative measures (3.7 ± 2.0 mm and 2.3 ± 1.1) to final follow-up measures (3.1 ± 2.4 mm and 3.1 ± 1.3). Shoulder abduction increased by 7.8° ± 26.8° and forward flexion decreased by 25.5° ± 32.4° after surgery. The functional results at the final follow-up were Constant 49.5 ± 18.0; American Shoulder and Elbow Surgeons 60.2 ± 27.2; Simple Shoulder Test 8.5 ± 4.6; and Disabilities of the Arm, Shoulder, and Hand 32.7 ± 12.1. The mean index value for the EuroQol Five Dimensions was 0.79, and perceived quality of life was 85.6 ± 15.4 of 100 points. 62.5% of the patients (10) were satisfied with surgery. The complication rate was 13% (2), accounting for one deep infection and one balloon migration. Conclusion: Theoretical benefits of BSA for delaying superior humeral head translation and arthropathic changes could not be demonstrated in our series. Its functional results and satisfaction rates are low, but self-reported quality of life after surgery does not seem impaired. Complications do not occur frequently but require reintervention and endanger joint viability. Level of evidence: Level IV (case series).

The existing in vitro and in vivo models for studying osteoarthritis have significant limitations in replicating the complexity of joint tissues. This research aims to validate a Tissue-On-a-Chip system for osteoarthritis research. Osteochondral tissues obtained from knee replacement surgeries of patients with osteoarthritis were cultured in an Organ-On-a-Chip system. This system was designed to supply oxygen and glucose to the cartilage from the bone. The distribution of oxygen and glucose was evaluated by fluorescence using Image-iT Green Hypoxia and 2-NBDG, respectively. Cytotoxicity was measured using lactate dehydrogenase (LDH) levels in chip cultures compared to plate cultures (12 tissues per method). Glycosaminoglycans (GAGs), alkaline phosphatase (ALP), Coll2-1, and procollagen type II N-terminal propeptide (PIINP) were measured in the perfused medium of the Tissue-On-a-Chip over a period of 70 days. Fluorescence of Image-iT Green Hypoxia was observed only in the cartilage area, while 2-NBDG was distributed throughout the tissue. An increase in LDH levels was noted in the plate cultures on day 24 and in the Tissue-On-a-Chip cultures on day 63. Compared to the start of the culture, GAG content increased on day 52, while ALP showed variations. A notable increase in GAG, ALP, and Coll2-1 levels was observed on day 59. PIINP levels remained stable throughout the experiment. The validated osteochondral Tissue-On-a-Chip system can replicate the joint microenvironment, with hypoxic conditions in cartilage and normoxic conditions in bone. Tissue survival and component stability were maintained for approximately two months. This platform is a useful tool for evaluating new drugs and represents a viable alternative to animal models.