Purpose It has been demonstrated that the semitendinosus tendon can regenerate after being harvested in its whole length and thickness for anterior cruciate ligament (ACL) reconstruction. Ultrasound studies and guided biopsies of the regenerated tendon have shown compatibility and resembling features of the normal tendon. The question is if this neo-tendon is biologically and functionally adequate for re-use? Methods Two randomised groups of 150 volunteers were followed up for two years after harvesting the semitendinosus only (25) or the semitendinosus and gracilis tendons (25) in ACL reconstruction. The patients were followed up with clinical and ultrasound examinations, biopsies and histological tests. Surgical exploration was done in three patients for macroscopic verification. The injected arteries of four lower limbs were dissected and the tendon's arterial supplies were examined. Results Seventy-two percent of the cases showed regeneration of the semitendinosus tendons. The neotendons were inserted mostly below the knee joint (83.3 %) where they had fused with the gracilis tendon, and above the joint (60 %) when the gracilis was harvested as well. The isokinetic strength of the hamstrings and quadriceps was not significantly diminished on the operated side. A macroscopic and histological analysis of the regenerated tendons demonstrates close resemblance to normal anatomy, with focal areas of fibrosis. In one patient the regenerated tendon was used for medial patellofemoral ligament reconstruction. Conclusion The semitendinosus muscle can recover and the tendon has great potential to regenerate after harvesting for ACL reconstruction. Our data suggest that the regenerated tendons could be used for iterative ligament reconstruction.

Introduction Split tendon transfer of tibialis posterior (SPOTT) is a treatment option for the hindfoot varus deformity in patients with cerebral palsy (CP). The purpose of this study was to present the long-term results of the newly modified SPOTT procedure developed by our senior author and compare it with the standard SPOTT technique in equinovarus foot deformity due to CP. Method Our retrospective cohort study included patients with spastic foot deformity due to CP treated with the standard or modified SPOTT technique. Patients' age at the time of the surgery was ≥ five years with follow-up period of at least four years. Surgical outcomes were evaluated using Kling's criteria during the patient's last follow-up visit. Results The analysis included 124 patients (146 feet), where 105 feet were treated by the standard SPOTT technique and 41 feet by the modified SPOTT technique. Patients' median age at the time of the surgery was 11 years. Patients were followed-up for a median period of eight years during which the modified SPOTT technique showed significantly better surgical outcomes compared with the standard group (excellent/good results in 38 feet, 92.7%, vs. 79 feet, 75.2%, p = 0.02). Two groups of patients did not significantly differ in GMFCS level, age at the time of the surgery, or patient gender. There was similar distribution in CP patterns in the standard and modified groups; spastic hemiplegia was the most prevalent form, followed by spastic diplegia and spastic paraplegia. Overall, better surgical success was achieved in patients with GMFCS levels I-III (100%, 94.8%, and 69.8%, respectively). SPOTT procedure failure was frequently noticed in patients with GMFCS level IV (90.9%). ConclusionThe modified SPOTT procedure demonstrated efficiency and safety in patients with equinovarus foot deformity due to CP during the long-term follow-up. Compared with the standard procedure, the newly modified SPOTT technique showed significantly better surgical outcome, irrespective of the patients' gender, age, initial GMFCS level, and CP type.

This study confirmed independent predicting factors for GCTB reccurence: p53 expression in mononuclear tumour cells and cyclin D1 expression in giant multinuclear cells. Results are new addition to generally known parameters, such as: localization of lesion, number of surgical interventions, clear destruction of cortex with the presence of extracompartmental lesion, and histological criteria for malignancy and can help in further research and treatment of GCTB.