Intratendinous injection of platelet-rich plasma under US guidance to treat tendinopathy: a long-term pilot study.

PURPOSE: To assess the potential therapeutic effect of intratendinous injection of platelet-rich plasma (PRP) under ultrasound (US) guidance to treat tendon tears and tendinosis in a pilot study with long-term follow-up. MATERIALS AND METHODS: The study included 408 consecutive patients referred for treatment by PRP injection of tendinopathy in the upper (medial and lateral epicondylar tendons) and the lower (patellar, Achilles, hamstring and adductor longus, and peroneal tendons) limb who received a single intratendinous injection of PRP under US guidance. Clinical and US data were retrospectively collected for each anatomic compartment for upper and lower limbs before treatment (baseline) and 6 weeks after treatment. Late clinical data without US were collected until 32 months after the procedure (mean, 20.2 months). The McNemar test and regression model were used to compare clinical and US data. RESULTS: QuickDASH score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and residual US size of lesions were significantly lower after intratendinous injection of PRP under US guidance at 6 weeks and during long-term follow-up compared with baseline (P < .001 in upper and lower limb) independent of age, gender, and type of tendinopathy (P > .29). No clinical complication was reported during follow-up. CONCLUSIONS: Intratendinous injection of PRP under US guidance appears to allow rapid tendon healing and is well tolerated.

Anatomical study of the clavicle: endomedullary morphology.

BACKGROUND: The treatment of clavicle fractures remains controversial. The objective of this study was to investigate the possibility of clavicular intramedullary fixation by nailing through an anatomic study combined with CT scan studies. METHODS: For the anatomic study, 20 clavicles of donated bodies to science (10 men, 10 women, 10 right, 10 left) were used. We measured the length of the clavicle, lateral epiphysis diameter, mean diaphysis diameter, medial epiphysis diameter, lateral width, lateral radius of curvature, medial width and medial radius of curvature. Intramedullary cavity diameter (anteroposterior and superoinferior) and calibration were measured by CT scan study on 20 clavicles. RESULTS: Average length was 152 mm for men and 140 mm for women. The anteroposterior curvature was most pronounced. The medullary canal had a gradually decreasing size from the distal portion to the middle segment, but never disappeared. CONCLUSION: Evaluation of morphological data can clarify the specifications of an intramedullary nail: flexibility of the nail to match clavicle curvature and a locking system to ensure primary stability. Intramedullary fixation by nailing in displaced fractures of the middle portion of the clavicle is a minimally invasive surgical technique, with excellent functional and cosmetic results.

Efficacy of intra-tendinous injection of platelet-rich plasma in treating tendinosis: comprehensive assessment of a rat model.

OBJECTIVES: To assess the potential of intra-tendinous injection of platelet rich plasma (PRP) to treat tendinosis (T+) in a rat model of patellar and Achilles T+, and evaluate its local toxicity. METHODS: Thirty rats (120 patellar and Achilles tendons) were used. We induced T+ into 80 tendons (patellar = 40, Achilles = 40) by injecting collagenase at day 0 under ultrasound (US) guidance. Clinical examination and US at day 3, followed by US-guided intra-tendinous injection of either PRP (PRPT+, n = 40) or physiological serum (ST+, n = 40, control). Follow-up was at days 6, 13, 18 and 25 using clinical, US and histological evaluation. To study PRP toxicity, we injected PRP into 40 normal tendons (PRPT-) and compared with 40 untreated normal tendons (T-). RESULTS: All PRPT+ showed better joint mobilisation compared with ST+ at day 6 (P = 0.005), day 13 (P = 0.02), day 18 (P = 0.003) and day 25 (P = 0.01). Similar results were found regarding US and histology, with smaller collagen fibre diameters (day 6, P = 0.003, day 25, P ≤ 0.004), less disorganisation and fewer neovessels (day 6, P = 0.003, day 25, P = 0.0003) in PRPT+ compared with ST+. Comparison between PRPT- and T- showed no PRP toxicity (P = 0.18). CONCLUSIONS: Our study suggests that mono-injection of PRP in T+ improves tendon healing, with no local toxicity. KEY POINTS: • We assessed the potential of platelet rich plasma (PRP) to treat tendinosis. • We treated patellar and Achilles tendinosis in a rat model. • We evaluated clinical, imaging and histological data. • Intra-tendinous PRP injection could be useful in the treatment of tendinosis.

Tumoral hypoxia in osteosarcoma in rats: preliminary study of blood oxygenation level-dependent functional MRI and 18F-misonidazole PET/CT with diffusion-weighted MRI correlation.

OBJECTIVE: The prognostic implication of oxygen concentration as a factor in recurrence of solid tumors has been proved. Hypoxic osteosarcoma, imaged with (18)F-misonidazole PET/CT, is the most frequent primary malignant bone tumor. The aim of our study was to determine the role of blood oxygenation level-dependent (BOLD) functional MRI in an osteosarcoma rodent model by comparison of oxygenation levels in BOLD functional MRI and (18)F-misonidazole PET/CT and correlating the findings with those of diffusion-weighted MRI (DWI). MATERIALS AND METHODS: After validation of a hypoxic rodent model, 3-T MRI of osteosarcoma grafted in eight rats, including anatomic, DWI, and BOLD sequences in ambient air and after 2 and 3 minutes of impregnation of 8 L/min of oxygen, was performed on days 10, 17, and 24 after tumor grafting. (18)F-misonidazole PET/CT was performed on day 26, and the rats were sacrificed on day 27 for specific screening of markers of hypoxia. We measured BOLD signal intensity in tumors and normal tissue and compared these results with those on apparent diffusion coefficient maps and (18)F-misonidazole uptake according to maximum standardized uptake value ratio between tumor and healthy spongy bone. RESULTS: Hypoxia was confirmed by histologic study in all cases. We found a significant difference (day 17, p = 0.0038; day 24, p = 0.0051) in the decrease in signal intensity of hypoxic tumor in the presence of oxygen compared with ambient air without relation to duration of oxygen impregnation (p = 0.06). We found a significant correlation (p = 0.003) between BOLD signal intensity and maximum standardized uptake value at (18)F-misonidazole PET/CT. We found no correlation between the decrease in BOLD signal intensity and apparent diffusion coefficient (p = 0.07). CONCLUSION: BOLD functional MRI may be a promising tool for noninvasive functional imaging of bone tumors, but additional developments are necessary to permit its use in clinical practice.

Femoral shaft fractures treated by antegrade locked intramedullary nailing: EOS stereoradiographic imaging evaluation of rotational malalignment having a functional impact.

INTRODUCTION: The standard treatment of femoral shaft fractures is intramedullary nailing. One of the most frequent complications is femoral malrotation. Our study sought to: 1) use EOS imaging to determine the amount of rotational malalignment after intramedullary nailing that has an impact on 6-month functional results; 2) determine the incidence of femoral malrotation based on EOS imaging; 3) determine the risk factors for postoperative femoral malrotation that impacts the 6-month functional results. The hypothesis was that EOS imaging can be used to determine the amount of femoral malrotation that has a functional impact in patients treated by percutaneous femoral intramedullary nailing. MATERIAL AND METHODS: We performed a prospective, single-center study between September 2017 and February 2020. Patients who had suffered a femoral shaft fracture treated with antegrade intramedullary nailing were included in this study. Femoral anteversion was measured at 6 months with an EOS stereoradiographic imaging system. Patients were assessed at 6 months with the WOMAC, Oxford, Harris and MDP functional scores. The SF-12 quality of life score was also determined. RESULTS: Thirty patients were evaluated at 6 months postoperatively, 15 women (50%) and 15 men (50%) who were 47 years old on average [16; 94]. The average anteversion was 19.9°C [-23°; 75°]. The functional scores (Oxford and Harris) were altered when there was 14° or more difference in femoral torsion between the operated side and the healthy side with a sensitivity of 0.88 and a specificity of 0.77. The risk factors for femoral malrotation were age under 35 years (p=0.01), urgent surgical management (p=0.008), location in middle third of femoral shaft (p=0.05), and short spiral fracture (p=0.02). CONCLUSION: The use of EOS imaging allowed us to demonstrate that functional hip outcomes are altered at 6 months postoperatively when greater than 14° femoral malrotation is present compared to the contralateral side after femoral intramedullary nailing. The risk factors that contributed to intraoperative rotational malalignment were age less than 35 years, urgent surgical management, mid-shaft femoral fracture and short spiroid fractures. LEVEL OF EVIDENCE: II.

Acceleration of tendon healing using US guided intratendinous injection of bevacizumab: first pre-clinical study on a murine model.

PURPOSE: Tendinopathy shows early disorganized collagen fibers with neo-angiogenesis on histology. Peri-tendinous injection of corticosteroid is the commonly accepted strategy despite the abscence of inflammation in tendinosis. The aim of our study was to assess the potential of intratendinous injection of an anti-angiogenic drug (bevacizumab, AA) to treat tendinopathy in a murine model of patellar and Achilles tendinopathy, and to evaluate its local toxicity. MATERIALS AND METHOD: Forty rats (160 patellar and Achilles tendons) were used for this study. We induced tendinosis (T+) in 80 tendons by injecting under ultrasonography (US) guidance Collagenase 1(®) (day 0 = D0, patellar = 40 and Achilles = 40). Clinical examination and tendon US were performed at D3, immediately followed by either AA (AAT+, n = 40) or physiological serum (PST+, n = 40, control) US-guided intratendinous injection. Follow-up at D6 and D13 using clinical, US and histology, and comparison between the 2 groups were performed. To study AA toxicity we compared the 80 remaining normal tendons (T-) after injecting AA in 40 (AAT-). RESULTS: All AAT+ showed a better joint mobilization compared to PST+ at D6 (p = 0.004) with thinner US tendon diameters (p<0.004), and less disorganized collagen fibers and neovessels on histology (p<0.05). There was no difference at D13 regarding clinical status, US tendon diameter and histology (p>0.05). Comparison between AAT- and T- showed no AA toxicity on tendon (p = 0.18). CONCLUSION: Our study suggests that high dose mono-injection of AA in tendinosis, early after the beginning of the disease, accelerates tendon's healing, with no local toxicity.