Background: Prior trials investigating the treatment of symptomatic osteoarthritis (OA) with hyaluronic-acid-derived products injections have provided optimistic results. The study was directed to assess the effectiveness of an innovative hyaluronic-acid-based hydrogel (Hymovis^®) in the treatment of symptomatic knee OA. Methods: A prospective, single-center, clinical trial was performed. Thirty-five patients with degenerative knee OA were included. Inclusion criteria were: age between 45–80, radiographic Kellgren grade II or III osteoarthritis, minimum 35 mm score on the Visual Analogue Scale (VAS), pain for at least 6 months and agreement to participate in the study. Patients received two injections at a one-week interval. The evaluator assessed the patients using the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and VAS. Evaluation was performed before, at 2 and 6 months after the injections. Results: A significant improvement on the WOMAC Index pain subscale was observed at 6 months after the injection. At two months, pain subscale score decreased from 10.34 to 9.34. At six months, a significant decrement in pain parameters compared to baseline was observed (from 10.34 to 7.72; p = 0.0004). Median points on VAS significantly ameliorated after 6 months (from 74.2 to 57.3 cm; p < 0.0001). Regarding physical function, a statistically significant difference compared to baseline was observed at the end of the study (from 29.74 to 25.18; p = 0.0025). WOMAC Index stiffness component did not differ from baseline at any time during follow-up. Conclusions: Pain relief installed with a delayed on-set but had a prolonged duration. The novel hyaluronic acid-based hydrogel (Hymovis^®) had effective results, particularly after six months post-injections and offers a therapeutic advancement in the treatment of moderate to severe osteoarthritis.

From a surgical point of view, quantification cannot always be achieved in the developmental deformity in hip joints, but finite element analysis can be a helpful tool to compare normal joint architecture with a dysplastic counterpart. CT scans from the normal right hip of an 8-year-old boy and the dysplastic left hip of a 12-year-old girl were used to construct our geometric models. In a three-dimensional model construction, distinctions were made between the cortical bone, trabecular bone, cartilage, and contact nonlinearities of the hip joint. The mathematical model incorporated the consideration of the linear elastic and isotropic properties of bony tissue in children, separately for the cortical bone, trabecular bone, and articular cartilage. Hexahedral elements were used in Autodesk Inventor software version 2022 (“Ren”) for finite element analysis of the two hips in the boundary conditions of the single-leg stance. In the normal hip joint on the cartilaginous surfaces of the acetabulum, we found a kidney-shaped stress distribution in a 471,672 mm² area. The measured contact pressure values were between 3.0 and 4.3 MPa. In the dysplastic pediatric hip joint on a patch of 205,272 mm² contact area, the contact pressure values reached 8.5 MPa. Furthermore, the acetabulum/femur head volume ratio was 20% higher in the dysplastic hip joint. We believe that the knowledge gained from the normal and dysplastic pediatric hip joints can be used to develop surgical treatment methods and quantify and compare the efficiency of different surgical treatments used in children with hip dysplasia.

Late-discovered developmental hip dysplasia deformities often necessitate complex surgical treatments and meticulous preoperative planning. The selection of osteotomies is contingent upon the patient’s age and the specific structural deformity of the hip. In our anatomical hip model, derived from the data of a 12-year-old patient, we performed virtual osteotomies that are commonly recommended for such cases. We precisely constructed geometric models for various osteotomies, including the Dega, Pemberton, Tönnis, Ganz, Chiari pelvic, and Pauwels femoral osteotomies. We employed Autodesk Inventor for the finite element analysis of the hip joint and the corrective osteotomies. In comparing one-stage osteotomies, we noted that the Dega and Ganz pelvic osteotomies, especially when combined with the Pauwels femoral osteotomy, yielded the most favorable outcomes. These combinations led to enhanced femoral head coverage and reduced intra-articular pressure. Furthermore, we calculated the femoral head-to-acetabulum volume ratio for both the Dega and Pauwels osteotomies. The encouraging results we obtained advocate for the integration of finite element analysis in virtual osteotomies of the pelvis and femur as a preoperative tool in the management of developmental hip dysplasia.

Background: The objective of the arthroscopic treatment in tibial spine avulsion fractures (TSAF) is to achieve firm reduction and strong internal fixation while still having the patient undergo a minimally invasive procedure. Material and methods: The study was performed on 12 young patients with avulsion fracture of the anterior tibial spine. All 12 patients had type 3 Modified Meyers and McKeever fractures. The injury mechanism was direct anterior to posterior trauma in full leg length hyperextension with sport trauma reported in all cases. The physical examination revealed decreased range of motion, extension deficit, and pain during walking. Radiology, MRI, and CT pathologic findings described complete fracture of the anterior tibial spine with no clear signs of callus formation at the time of examination. All patients underwent arthroscopic suture surgical treatment. The Tegner, the Lysholm, and the International Knee Documentation Committee (IKDC) scores were used to evaluate subjective outcomes at three and six months after the surgery. Radiographs were used to assess callus formation and healing status of the fracture. Results: The mean IKDC score was 33.4 ± 23.3 (p = 0.032) preoperatively and 84.2 ± 14.3 at final follow-up (p = 0.0032, CI = 95%). The mean Tegner score improved from 3.8 ± 1.1 pre-operatively to 6.7 ± 2.2 at six months follow-up (p = 0.0231, CI = 95%). The Lysholm score differed significantly at baseline compared to final follow-up (53.7 ± 17.3 vs. 87.7 ± 9.9; p = 0.0066, CI = 95%). In all cases (n = 12), the radiographs taken after six months revealed the healing of the fracture in the anatomic position without secondary displacement. No functional knee instability was detected at the end of the study. Conclusions: The study provides preliminary promising results regarding fracture healing, knee stability, and functional subjective scores. Patient selection was a major factor of success prediction for this technique.