Low prevalence of trochanteric bursitis in patients with refractory lateral hip pain.

INTRODUCTION: Bursitis at the greater trochanter has historically been identified as a major pain generator in patients with lateral hip pain (LHP). We believe that hip abductor tendon pathology (HATP) plays an important and overlooked role in LHP. The purpose of this study was to evaluate the presence of isolated trochanteric bursitis on MRI in patients with refractory LHP. METHODS: The MRIs of 120 patients with LHP (94% women, median age 54 years) performed at our orthopaedic outpatient clinic between 2017 and 2020 were evaluated by two raters for trochanter-related pathologies, including HATP and bursitis. RESULTS: Two (2%) patients were registered with greater trochanteric bursitis with no relevant HATP, 30 (25%) patients had elements of inflammation (high-intensity signals) in the greater trochanteric bursa with relevant HATP. Five (4%) patients had relevant HATP with bursitis in the sub-gluteus minimus bursa with no bursitis in the greater trochanteric bursa. The remaining 83 (69%) patients had no sign of trochanter-related bursitis. CONCLUSION: Isolated trochanteric bursitis as the cause of refractory LHP appears to be rare. We believe that the presence of HATP in LHP has been severely underestimated and a shift in focus towards treatment of these structures is necessary. FUNDING: none. TRIAL REGISTRATION: According to current national legislation, no formal ethical approval was required for this study. The National Data Protection Agency approved the study (1-16-02-124-19).

Magnetic resonance imaging can increase the diagnostic accuracy in symptomatic meniscal repair patients.

PURPOSE: The purpose of this study was to evaluate meniscal repair healing in symptomatic patients through combined clinical assessment, magnetic resonance imaging (MRI) and re-arthroscopy. This study investigated the diagnostic accuracy of MRI and clinical assessment in determining failed meniscal repair in symptomatic meniscal repair patients, as verified by re-arthroscopy. METHODS: Eighty patients were included. All had undergone a primary meniscal repair followed by an MRI and re-arthroscopy due to clinical symptoms of a meniscal lesion. A validated semi-quantitative scoring system was employed for identifying MRI-diagnosed healing failure. The clinical assessment was divided into joint swelling, joint-line tenderness, locking and a positive McMurray's test. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of MRI and positive clinical findings were calculated using second-look arthroscopy as a standard. RESULTS: The MRI results showed healing of 22 (27.5%) of the menisci and 58 (72.5%) unhealed menisci, whereas second-look arthroscopy identified 15 (19%) healed menisci and 65 (81%) unhealed menisci. The isolated MRI findings were 0.85, 0.8, 0.95 and 0.55 for sensitivity, specificity, PPV and NPV, respectively. The PPVs of the clinical assessments were 0.78, 0.85 and 0.94, with one, two and three clinical findings, respectively. A grade 3 MRI combined with joint-line tenderness presented a PPV of 0.98. CONCLUSION: A supplementary MRI will increase diagnostic accuracy when fewer than three clinical findings are present in a symptomatic meniscal repair patient. The clinical relevance of this finding is that MRI contributes to enhancing the diagnostic accuracy of an unhealed meniscal repair when there are limited clinical signs of meniscal pathology. LEVEL OF EVIDENCE: III.

Dental pulp-derived stromal cells exhibit a higher osteogenic potency than bone marrow-derived stromal cells in vitro and in a porcine critical-size bone defect model.

INTRODUCTION: The osteogenic differentiation of bone marrow-derived mesenchymal stromal cells (BMSCs) was compared with that of dental pulp-derived stromal cells (DPSCs) in vitro and in a pig calvaria critical-size bone defect model. METHODS: BMSCs and DPSCs were extracted from the tibia bone marrow and the molar teeth of each pig, respectively. BMSCs and DPSCs were cultured in monolayer and on a three-dimensional (3D) polycaprolactone (PCL) - hyaluronic acid - tricalcium phosphate (HT-PCL) scaffold. Population doubling (PD), alkaline phosphatase (ALP) activity, and calcium deposition were measured in monolayer. In the 3D culture ALP activity, DNA content, and calcium deposition were evaluated. Six non-penetrating critical-size defects were made in each calvarium of 14 pigs. Three paired sub-studies were conducted: (1) empty defects vs. HT-PCL scaffolds; (2) PCL scaffolds vs. HT-PCL scaffolds; and (3) autologous BMSCs on HT-PCL scaffolds vs. autologous DPSCs on HT-PCL scaffolds. The observation time was five weeks. Bone volume fractions (BV/TV) were assessed with micro-computed tomography (µCT) and histomorphometry. RESULTS AND DISCUSSION: The results from the in vitro study revealed a higher ALP activity and calcium deposition of the DPSC cultures compared with BMSC cultures. Significantly more bone was present in the HT-PCL group than in both the pure PCL scaffold group and the empty defect group in vivo. DPSCs generated more bone than BMSCs when seeded on HT-PCL. In conclusion, DPSCs exhibited a higher osteogenic potential compared with BMSCs both in vitro and in vivo, making it a potential cell source for future bone tissue engineering.