Guided growth: the importance of a single tether. An experimental study.

BACKGROUND: During the last few years, the use of the 8-plate as a technique for hemiepiphysiodesis has gained wide acceptance, as it has been shown that it works in a more physiological way than other methods such as staples or transphyseal screws. It has mechanically been compared with a tension band plate, and for this reason, only a single plate is needed. The following study was undertaken to test the 8-plate against the staples and assess factors that can influence the difference in results. METHODS: A prospective experimental study was designed to compare the ability of 2 hemiepiphysiodesis methods, the 8-plate and the double staple, to produce angular deformity in the rabbit's tibia (group I). The variable studied was the variations in the articular line-diaphysis angle at 6 weeks. As the results showed that the 8-plate produced a bigger deformity, a second group was designed (group II) comparing single against double staple, under the hypothesis that the differences observed in the first group could be related to the number of anchors put across the physis and consequently depend on the volume of physis involved by the staples. RESULTS: In group I, the 8-plate produced a bigger angulation at 6 weeks' time than the 2 staples (a difference of 6.5 degrees, P = 0.03). Similarly, in group II, the single staple produced a greater angulation than the 2 staples (difference 6 degrees, P = 0.08). When both groups were compared, no differences in the angulation produced by the 8-plate and the single staple with respect to the 2 staples were found. CONCLUSIONS: These results suggest that one of the reasons why the 8-plate may act in a more "physiological way" (vs. the traditional 2-staple or 3-staple hemiepiphysiodesis) could be the fact that the growth plate is tethered only at a single point. Therefore, the physis retains a major potential for growth and deformity. CLINICAL RELEVANCE: The 8-plate is superior in producing/correcting angular deformity when compared with the traditionally used staples (2 or more) but not when compared with a single staple.

Screw length in the guided growth method.

BACKGROUND: The appearance of the 8-plate as a method for hemiepiphysiodesis has renewed the interest for the use of this technique. However, many questions remain unanswered about the way of action of the guided growth method. Although screw length has been said to play no role, to our knowledge, no clinical or experimental evidence exists. METHODS: An experimental prospective randomized study with 40 WNZ Rabbits aged 8 weeks was conducted. Four experimental groups were established. Each tibia was randomly allocated to one of the following groups: Staples (group 1), 8-plate either using self-taping screws of 9 mm (group 2), or 5 mm lengths (groups 3) and control (group 4). Radiological assessment of the tibial deformity was done in a weekly fashion, and ALDA (articular line-diaphyseal angle) variations at 6 weeks were used as the control variable. RESULTS: The 8-plate as a whole produced a significant bigger deformity than the staples (10°). No significant differences between the two models of the 8-plate were found along the study (3.7°). CONCLUSIONS: The 8-plate has shown to be more efficient in producing angular deformity than staples. However, the length of the screw has showed no role in the 8-plate function.

Analysis of potential risk factors in the survival of patients with primary retroperitoneal liposarcoma.

INTRODUCTION: The present work is an observational study of a series of variables regarding overall survival and disease-free survival in patients diagnosed with primary liposarcoma. METHODS: The study is prospective with retrolective data collection that includes all patients with primary liposarcoma referred to Hospital Son Espases University Hospital, Palma de Mallorca, Spain from January 1990 to December 2019. RESULTS: The study includes 50 patients and the compartment surgery was performed in 18 patients (36%) of cases. The mean overall survival of the sample was 15.57 years (95% CI: 12.02-19.12) and the mean disease-free survival was 6.70 years (95% CI: 4.50-8.86). CONCLUSION: Compartment surgery has not shown benefits in terms of overall survival and disease-free survival. The ASA classification (≥3) predicts a poor prognosis in both overall survival and disease-free survival. Resection with free margins, described on the pathological results and defined in this work as R0, show better disease-free survival.

Analysis of potential risk factors in the survival of patients with primary retroperitoneal liposarcoma.

INTRODUCTION: The present work is an observational study of a series of variables regarding overall survival and disease-free survival in patients diagnosed with primary liposarcoma. METHODS: The study is prospective with retrolective data collection that includes all patients with primary liposarcoma referred to Hospital Son Espases University Hospital, Palma de Mallorca, Spain from January 1990 to December 2019. RESULTS: The study includes 50 patients and the compartment surgery was performed in 18 patients (36%) of cases. The mean overall survival of the sample was 15.57 years (95% CI: 12.02-19.12) and the mean disease-free survival was 6.70 years (95% CI: 4.50-8.86). CONCLUSION: Compartment surgery has not shown benefits in terms of overall survival and disease-free survival. The ASA classification (≥3) predicts a poor prognosis in both overall survival and disease-free survival. Resection with free margins, described on the pathological results and defined in this work as R0, show better disease-free survival.

Histological differences between various methods of hemiepiphysiodesis: is guided growth really different?

Traditional systems of hemiepiphysiodesis are based on the application of asymmetrical compression to the physis to correct angular deformities. The guided growth method claims to act as a tension plate avoiding compression. The aim of this study was to confirm or refute this claim. Twenty-four White New Zealand rabbits were subjected to a proximal tibial hemiepiphysiodesis using either staples or a plate and two-screws method. Both methods succeeded in producing deformity. The initial existent histological differences between systems became less apparent after 6 weeks of hemiepiphysiodesis, when histological results were very similar. The findings suggest that the eight-plate system produces, like staples, compression of the physis, but the forces are applied more gradually.

NIK controls classical and alternative NF-κB activation and is necessary for the survival of human T-cell lymphoma cells.

PURPOSE: Peripheral T-cell lymphomas (PTCL) are a heterogeneous entity of neoplasms with poor prognosis, a lack of effective therapies, and a largely unknown molecular pathology. Deregulated NF-κB activity has been associated with several lymphoproliferative diseases, but its importance in T-cell lymphomagenesis is poorly understood. We investigated the function of the NF-κB-inducing kinase (NIK), in this pathway and its role as a potential molecular target in T-cell lymphomas. EXPERIMENTAL DESIGN: We used immunohistochemistry to analyze the expression of different NF-κB members in primary human PTCL samples and to study its clinical impact. With the aim of inhibiting the pathway, we used genetic silencing of NIK in several T-cell lymphoma cell lines and observed its effect on downstream targets and cell viability. RESULTS: We showed that the NF-κB pathway was activated in a subset of PTCLs associated with poor overall survival. NIK was overexpressed in a number of PTCL cell lines and primary samples, and a pivotal role for NIK in the survival of these tumor cells was unveiled. NIK depletion led to a dramatic induction of apoptosis in NIK-overexpressing cell lines and also showed a more pronounced effect on cell survival than inhibitor of kappa B kinase (IKK) knockdown. NIK silencing induced a blockage of both classical and alternative NF-κB activation and reduced expression of several prosurvival and antiapoptotic factors. CONCLUSIONS: The results of the present study indicate that NIK could be a promising therapeutic target in these aggressive malignancies.