Background: Greater Trochanter Pain Syndrome (GTPS) is the main reason for recalcitrant lateral hip pain. Gluteus medius and minimus tendinopathy plays a key role in this setting. An injectable medical compound containing collagen type I (MD-Tissue, Guna) has been produced with the aim to counteract the physiological and pathological degeneration of tendons. In this study we aimed at characterizing the effect of this medical compound on cultured human gluteal tenocytes, focusing on the collagen turnover pathways, in order to understand how this medical compound could influence tendon biology and healing. Methods: Tenocytes were obtained from gluteal tendon fragments collected in eight patients without any gluteal tendon pathology undergoing total hip replacement through an anterior approach. Cell proliferation and migration were investigated by growth curves and wound healing assay, respectively. The expression of genes and proteins involved in collagen turnover were analysed by real-time PCR, Slot blot and SDS-zymography. Results: Our data show that tenocytes cultured on MD-Tissue, compared to controls, have increased proliferation rate and migration potential. MD-Tissue induced collagen type I (COL-I) secretion and mRNA levels of tissue inhibitor of matrix metalloproteinases (MMP)-1 (TIMP-1). Meanwhile, lysyl hydroxylase 2b and matrix metalloproteinases (MMP)-1 and -2, involved, respectively, in collagen maturation and degradation, were not affected. Conclusions: Considered as a whole, our results suggest that MD-Tissue could induce in tenocytes an anabolic phenotype by stimulating tenocyte proliferation and migration and COL-I synthesis, maturation, and secretion, thus favouring tendon repair. In particular, based on its effect on gluteal tenocytes, MD-Tissue could be effective in the discouraging treatment of GTPS. From now a rigorous clinical investigation is desirable to understand the real clinical potentials of this compound.

Purpose: Snapping hip is a common clinical condition, characterized by an audible or palpable snap of the hip joint. When the snap is perceived at the lateral side of the hip, this condition is known as external snapping hip or lateral coxa saltans, which is usually asymptomatic. Snapping hip syndrome (SHS) refers to a painful snap, which is more common in athletes who require increased hip range of motion. The aim of this article is to review the most common endoscopic techniques for the treatment of ESHS, as well as their results and limitations. Methods: This is a review of the current literature of endoscopic surgical procedures and of the results of the treatment of external snapping hip syndrome. Results: The pathogenesis of SHS is mechanical. The initial treatment attempt is conservative, and usually provides good results. Patients who do not respond to conservative management are candidate for surgery. The endoscopic release of the ilio‐tibial band or the endoscopic release of the femoral insertion of the gluteus maximum tendon is the most popular technique. Conclusion: Endoscopic techniques provide fewer complications compared to open surgery, a lower recurrence rate and good clinical outcomes. More comparative studies with a longer follow‐up are required to adequate evaluate the full role of endoscopic techniques in periarticular hip surgery. Level of evidence: Level V.

Total knee arthroplasty (TKA) is a reliable and widespread solution for knee osteoarthritis treatment, but about 20% of the patients complains of persisting pain. Neuroma formation in the IPBSN (infrapatellar branch of the saphenous nerve) is an undervalued cause of persistent anterior pain after TKA. The aim of this study was to evaluate the effectiveness of the selective neuroma denervation on patients satisfaction and pain improvement. Between 2014 and 2020, we evaluated 13 patients suffering from persistent anterior knee pain and numbness after TKA who underwent a surgical neurectomy of the IPBSN. After clinical assessment and diagnosis confirmation, we carried out the surgery. Short Form 12 Health (SF12), Oxford Knee Score (OKS), and Numeric Rating Scale (NRS) have been collected before and after the procedure. After the surgical treatment, the symptom's resolution and patients' satisfaction were attested by the achievement of the Minimal ClinicallyImportantDifference(MCID) of the self-administered patient-reported outcome measures (PROMs). Our results showed a statistically significant improvement (p < 0.05) of patients pain perception (mean NRS improvement -4.2, SD 2.5) and overall satisfaction (with a mean increase in OKS of 14.5 points SD 9.4, and in SF12 of 6.5 points SD 4.0). Hence, our study suggests that selective neuroma denervation may be an effective solution to improve the quality of life of patients who develop this complication after TKA.

Background: Greater Trochanteric Pain Syndrome (GTPS) is a frequent clinical condition characterized by acute or chronic pain in the lateral region of the hip. This condition is primarily due to gluteus minimus and medius tendinopathy. Swine-derived type I collagen has shown a positive effect on tenocytes through in vitro studies and on tendinopathies in clinical studies. This pilot study aims to evaluate the clinical effects of swine-derived type I collagen injections on pain, hip function, and strength in GTPS patients. Methods: The study group was treated with three ultrasound-guided swine-derived type I collagen injections once a week for three consecutive weeks. The primary endpoint was pain reduction of at least 3 points on the Numeric Rating Scale (NRS) at ten weeks. Secondary endpoints were NRS average reduction at rest and palpation, modified Harris Hip Score (mHHS), abductor strength, and magnetic resonance imaging (MRI) improvement at six months. Results: 52 patients were screened, 47 enrolled, and 43 completed the study. The primary endpoint was reached by 60.5% of the patients. All secondary endpoints were also reached with statistical significance. Neither early nor late adverse effects were found. Conclusions: In this pilot study, ultrasound-guided peritrochanteric swine-derived type I collagen injections are safe and effective for most patients with GTPS included in the study. Further and more extensive confirmatory investigation studies with a longer follow-up are needed to confirm this pilot study’s results and the clinical benefit’s persistence.