Lateral unicompartmental knee arthroplasty: is really a good option?

INTRODUCTION: Lateral unicompartmental knee arthroplasties (LUKA) account for only < 1% of all knee arthroplasties and for only 5-10% of all unicompartmental knee replacements. This means that there is less published literature on these procedures and that the surgeon's experience with them is smaller than with medial UKA. The aim of this study was to analyze the survival and the clinical-functional outcomes of LUKA according to the type of bearing surface (all-polyethylene versus metal-backed) used. MATERIALS AND METHODS: This was a retrospective study including 42 LUKAs operated between 2009 and 2021. Two fixed polyethylene-bearing models were used: the all-polyethylene ACCURIS knee (38%) and the metal-backed Triathlon PKR system (62%). Demographic parameters, knee range of motion (ROM), tibiofemoral alignment, implant survival (as estimated with the Kaplan-Meier curve), and clinical-functional outcomes (as measured with the Knee Society Score) were analyzed. RESULTS: Average patient age was 65.5 (range, 36-87) years and mean follow-up was 8.2 (range, 2.1-12.8) years. Thirty LUKAs (71.4%) were implanted in women. The main reason for performing a LUKA was osteoarthritis (88.1%). No patient developed post-surgical complications or had to be re-operated. Overall LUKA survival was 100% at 1-year and 5-year's follow-up. Knee Society Score, knee ROM and tibiofemoral alignment all improved significantly post-surgery (p < 0.001). The clinical Knee Society Score increased from 46.5 ± 14.5 pre-surgery to 93.5 ± 10.3 post-surgery, the functional Knee Society Score increased from 48.1 ± 13.5 pre-surgery to 94.6 ± 9.3 post-surgery, maximum flexion increased from 108.5 ± 8.7 degrees pre-surgery to 121 ± 8.9 degrees post-surgery and tibiofemoral alignment was corrected from 13.1 ± 1.74 degrees pre-surgery to 5.7 ± 0.8 degrees post-surgery. There were no statistically significant clinical-functional improvement or knee ROM differences between groups (p < 0.05, respectively). CONCLUSION: LUKA is a valid and definitive option for patients with lateral tibiofemoral osteoarthritis, with a survival rate of > 95% at 5-years follow-up. Clinical-functional outcomes are the same, irrespective of the tibial component used.

Unicompartmental knee arthroplasties: does the type of tibial component selected influence implant survival?

INTRODUCTION: Few information has been published on the survival of unicompartmental knee arthroplasty (UKA) and fixed-bearing tibial components. The aim of this study is to analyze if UKA survival varies according to UKA model used and to analyze the possible risk factors for UKA revision. MATERIALS AND METHODS: A retrospective study analyzing 301 UKAs (ACCURIS, all-polyethylene tibial component, 152; Triathlon PKR, metal-backed tibial component, 149) was performed. Demographic parameters as well as implant survival and cause of prosthetic revision were analyzed. The Kaplan-Meier survival analysis, the log-rank test and the Cox multiple regression were used for the analysis. RESULTS: Average follow-up was 8.1 ± 3.08-years. Average age was 68.1 ± 8.6-years; 70.4% of subjects were women. The ACCURIS UKA group had a UKA revision rate higher compared to the Triathlon PKR group (16/152, 10.6% vs 5/149, 3.4%, respectively; p < 0.001). The main cause of prosthetic revision was aseptic loosening (5/21, 23.8%). All aseptic loosening cases and tibial component collapse were reported with the ACCURIS UKA group. Overall UKA survival was 98.01% (95% CI 95.62-99.1) at 1-year, 94.27% (95% CI 90.95-96.4) at 5-years and 92.38% (95% CI 88.48-94.99) at 10-years' follow-up. There were no differences in the Kaplan-Meier survival curves regarding operated side or affected tibiofemoral compartment (log-rank test = 0.614 and 0.763, respectively). However, Kaplan-Meier survival curve according to UKA model used was different (log-rank test = 0.033). The metal-backed component appeared to be a protector factor for UKA revision when adjusted for age, sex, operated side, and affected tibiofemoral compartment (Hazard Ratio 0.32, p = 0.031). CONCLUSION: Fixed-bearing UKAs showed excellent mid- and long-term survival rates. Aseptic loosening is the main cause of implant failure. PKR group (metal-backed component) seem to be a protector factor to UKA revision when it was compared with ACCURIS UKA group (all-polyethylene tibial component).

Megaprosthesis use in Paprosky III/IV femoral defects in non-oncological patients: analysis of survival, clinical, and functional outcomes after an average follow-up of five years.

PURPOSE: To determine the survival and patient-reported outcomes in non-oncological patients treated with proximal femoral resection (PFR) using MEG for femoral reconstruction. MATERIALS AND METHODS: This retrospective study included 16 patients. Demographic variables and complications developed were analyzed. Clinical-functional outcomes were measured using the modified Harris score (mHSS), numeric Pain Rating Scale (NPRS) and Musculoskeletal Tumor Society (MSTS) score. MEG survival was estimated using a Kaplan-Meier survival analysis. RESULTS: Average follow-up was 5 years (range, 1-9). The 75% of patients were overweight and women with an average age of 74.2 ± 5.9-years (BMI of 28.5 ± 4.2 kg/m2). The main cause of MEG was periprosthetic infection (43.7%). The 50% of patients had post-surgical complications regarding with MEG, being the most frequent seromas and MEG dislocation. Implant survival was 93.4% and 80.9% at 3 and 7 years of follow-up, respectively. The functional results at the end of the follow-up with respect to the pre-surgical state improved from 9.5 ± 2.6 to 3 ± 0.9 mean NPRS and 26.5 ± 6.8 to 69.5 ± 13.5 mean mHHS, p < 0.001, respectively. The mean MSTS score was 68.1% that these results were considered excellent. CONCLUSIONS: The MEG for reconstruct III-IV femoral defects is a good therapeutic option that offers an acceptable clinical-functional result. Short-term and medium-term survival was greater than 80%. The most frequent complications are seromas and MEG dislocation. The use of constrained liner and abductor system reconstruction is essential to prevent the dislocation.

Methylated and ethylated dialkylphosphate metabolites of organophosphate pesticides: DNA damage in bone marrow cells of Balb/c mice.

Dialkylphosphates (DAPs), metabolites of organophosphate (OP) pesticides, are widely distributed in the environment and are often used as biomarkers of OP exposure. Recent reports indicate that DAPs may be genotoxic, both in vitro and in vivo. We have examined the genotoxicity of the methylated DAPs dimethyldithiophosphate (DMDTP) and dimethylphosphate (DMTP) and the ethylated DAPs diethyldithiophosphate (DEDTP) and diethylphosphate (DETP), in comparison with their parental compounds, malathion and terbufos, respectively, in bone marrow polychromatic erythrocytes (PCE) of male and female Balb/c mice. We also compared DNA damage (comet assay) induced by DMDTP and dimethyl phosphate (DMP) in human cell lines. Both DMDTP and DMP caused DNA damage in peripheral blood mononuclear cells, HeLa cells, and the hepatic cell lines HepG2 and WRL-68. In the in vivo micronucleus assay, methylated and ethylated DAPs increased micronucleated PCE cells in both male and female mice. Female mice were more susceptible to DNA damage. In comparison to their parental compounds, methylated DAPs, particularly DMTP, were more genotoxic than malathion; DEDTP, DETP, and terbufos were similar in potency. These results suggest that DAPs may contribute to DNA damage associated with OP pesticide exposure.

Methylated dialkylphosphate metabolites of the organophosphate pesticide malathion modify actin cytoskeleton arrangement and cell migration via activation of Rho GTPases Rac1 and Cdc42.

The non-cholinergic molecular targets of organophosphate (OP) compounds have recently been investigated to explain their role in the generation of non-neurological diseases, such as immunotoxicity and cancer. Here, we evaluated the effects of malathion and its dialkylphosphate (DAP) metabolites on the cytoskeleton components and organization of RAW264.7 murine macrophages as non-cholinergic targets of OP and DAPs toxicity. All OP compounds affected actin and tubulin polymerization. Malathion, dimethyldithiophosphate (DMDTP) dimethylthiophosphate (DMTP), and dimethylphosphate (DMP) induced elongated morphologies and the formation of pseudopods rich in microtubule structures, and increased filopodia formation and general actin disorganization in RAW264.7 cells and slightly reduced stress fibers in the human fibroblasts GM03440, without significantly disrupting the tubulin or vimentin cytoskeleton. Exposure to DMTP and DMP increased cell migration in the wound healing assay but did not affect phagocytosis, indicating a very specific modification in the organization of the cytoskeleton. The induction of actin cytoskeleton rearrangement and cell migration suggested the activation of cytoskeletal regulators such as small GTPases. We found that DMP slightly reduced Ras homolog family member A activity but increased the activities of Ras-related C3 botulinum toxin substrate 1 (Rac1) and cell division control protein 42 (Cdc42) from 5 min to 2 h of exposure. Chemical inhibition of Rac1 with NSC23766 reduced cell polarization and treatment with DMP enhanced cell migration, but Cdc42 inhibition by ML-141 completely inhibited the effects of DMP. These results suggest that methylated OP compounds, especially DMP, can modify macrophage cytoskeleton function and configuration via activation of Cdc42, which may represent a potential non-cholinergic molecular target for OP compounds.

Short neck-preserving femoral stem for total hip arthroplasty: medium-term results of a 68-case series.

INTRODUCTION: Short stems seem to be a good alternative for young patients as they offer promising results, rapid recovery and preservation of metaphyseal bone stock. This is one of the few studies in the literature to report medium-term clinical-radiological results for short hip stems. MATERIALS AND METHODS: This prospective study evaluated 68 short femoral stems in 63 patients treated with total hip replacement. Clinical, functional and quality-of-life outcomes were measured at 6 and 12 months, and annually thereafter until the end of follow-up. The radiological analysis included measurements of potential leg length discrepancies, stem alignment and signs compatible with stress shielding. RESULTS: Fifty-four males (59 hips) and nine females (9 hips) of an average age of 44.3 years (range, 25-68) were studied. The most common diagnosis was osteoarthritis (51.5%). Mean overall follow-up was 7.8 years (range, 5.8-9.8). The overall survival rate was 97.1% (95% CI 88.7-99.7%). Surgery resulted in an increase of 42.3 ± 1.1 points in the modified Harris Hip Score and 21.9 ± 0.6 points in the Oxford Hip Score (p < 0.001, respectively). Moreover, the pain score as measured on a numerical rating scale (NRS) improved from 95.8 to 36.3. As regards function, an improvement was observed from 3.2 ± 0.8 points to 6.8 ± 1.14 points on the University of California at Los Angeles activity score (p < 0.001, respectively). The radiological analysis showed an absence of radiolucencies or stress-shielding throughout the series. The complications rate at the end of follow-up was 5.7%. CONCLUSIONS: The use of ultra-short cylindrical stems with complete anchorage in the femoral neck was shown to offer promising medium-term results. Such stems appear to be a good option for young patients, who are likely to require several revisions over their lifetime.

The cytoskeleton as a non-cholinergic target of organophosphate compounds.

Current organophosphate (OP) toxicity research now considers potential non-cholinergic mechanisms for these compounds, since the inhibition of acetylcholinesterase (AChE) cannot completely explain all the adverse biological effects of OP. Thanks to the development of new strategies for OP detection, some potential molecular targets have been identified. Among these molecules are several cytoskeletal proteins, including actin, tubulin, intermediate filament proteins, and associated proteins, such as motor proteins, microtubule-associated proteins (MAPs), and cofilin. in vitro, ex vivo, and some in vivo reports have identified alterations in the cytoskeleton following OP exposure, including cell morphology defects, cells detachments, intracellular transport disruption, aberrant mitotic spindle formation, modification of cell motility, and reduced phagocytic capability, which implicate the cytoskeleton in OP toxicity. Here, we reviewed the evidence indicating the cytoskeletal targets of OP compounds, including their strategies, the potential effects of their alterations, and their possible participation in neurotoxicity, embryonic development, cell division, and immunotoxicity related to OP compounds exposure.

Genotoxicity of the organophosphate pesticide malathion and its metabolite dimethylthiophosphate in human cells in vitro.

Organophosphate (OP) pesticides are biotransformed into metabolites such as dialkylphosphates (DAPs). We have evaluated the genotoxicity of malathion and its metabolite dimethylthiophosphate (DMTP) in the human hepatic cell lines HepG2 and WRL-68 and in peripheral blood mononuclear cells (PBMC). In the Cytokinesis-Block Micronucleus assay (CBMN), malathion and DMTP increased the frequencies of micronuclei (MN) and nucleoplasmic bridges (NPB). Malathion was primarily clastogenic whereas DMTP was aneuploidogenic. When HepG2 or WRL-68 cells were treated with DMTP in the presence of sulconazole, a non-specific cytochrome P450 inhibitor, MN frequency was reduced, indicating that DMTP genotoxicity requires P450-cataliyzed metabolism.

Effects of electrical stimulation in the treatment of osteonecrosis of the femoral head.

INTRODUCTION: The aim of this study was to examine whether the use of an internal electrostimulator could improve the results obtained with core decompression alone in the treatment of osteonecrosis of the femoral head. METHODS: We performed a retrospective study of 41 patients (55 hips) treated for osteonecrosis of the femoral head between 2005 and 2014. Mean follow-up time was 56 (12-108) months. We recorded 3 parameters: time to recurrence of pain, time to conversion to arthroplasty and time to radiographic failure. Survival was estimated using the Kaplan-Meier method. The equality of the survival distributions was determined by the Log rank test. RESULTS: Implanted electrostimulator was a factor that increased the survival of hips in a pre-op Steinberg stage of II or below, while it remained unchanged if the stage was III or higher. CONCLUSIONS: The addition of an internal electrostimulator provides increased survival compared to core decompression alone at stages below III.

Total Knee Arthroplasty After Failed Unicompartmental Knee Arthroplasty. Clinical Results, Radiologic Findings, and Technical Tips.

BACKGROUND: The loss of anatomic references and bone stock turns unicompartmental knee arthroplasty (UKA) revision surgery difficult, and according to some authors, it is technically as challenging as a total knee arthroplasty (TKA) revision surgery. METHODS: A retrospective review of 559 Oxford medial UKA was performed between 2007 and 2013. Nineteen knees were revised to TKA for reasons other than infection, most commonly for osteoarthritis progression. RESULTS: The most frequent cause of failure in our series was osteoarthritis progression (10 cases, 52.63%). In 15 patients (78.95%), tibial stems were needed, and in 10 (55.5%), metallic blocks for augmentation of tibial plateau were used. Postoperative radiographic studies showed a correct implant alignment, preserving adequate joint line (24.8 mm), and patellar (1.1 mm) height (according to Insall-Salvati). After a mean follow-up of 21 months (range 6-51) mean values of 78.8 (standard deviation [SD] = 16.8) and 62.3 (SD = 19.6) were obtained for the physical and mental scores of the Knee Society Score test. In the SF-36 tests mean values of 45.2 (SD = 7.6) and 53 (SD = 5.2) were obtained for the physical and mental scores respectively. In one case, a varus/valgus instability occurred intraoperatively and it required revision with a prosthesis with higher constriction. No thromboembolic or infectious events were observed during postoperative follow-up. CONCLUSION: Following a standardized technique, UKA revision surgery can be achieved with TKA in almost every case despite bone stock loss and lack of anatomic landmarks.

Percutaneous iliosacral fixation in external rotational pelvic fractures. A biomechanical analysis.

INTRODUCTION: Although the gold standard in open book pelvic fractures remains the pubic symphysis (PS) plate fixation, the clinical outcomes are not satisfactory, despite the excellent anatomical reduction assessed radiologically. Some authors suggest that residual instability of the posterior pelvic elements may be responsible for the chronic pain and the early osteoarthritic changes in the sacroiliac joint (SIJ). OBJECTIVE: To evaluate whether the isolated posterior fixation with one or two iliosacral screws (ISSs) is sufficient to provide adequate stability for the treatment of Burgess Young APC-II (YB APC-II) type of pelvic ring injuries. METHODS: Biomechanical experimental study using 7 fresh human pelvises, where an YB APC-II pelvic injury was previously implemented. The isolated posterior fixation of the pelvic ring with 1 or 2 ISSs directed in the S1 vertebra body was analysed in each specimen following an axial load of 300N. The different displacement of the SIJ and of the PS were analysed in all three spatial axes, using the validated optical measurement system 3D PONTOS 5M. A multivariate version of Friedman test (non-parametric ANOVA for repeated measures) was performed. RESULTS: The isolated fixation of the SIJ with 1 ISS did not show any differences with respect to the intact pelvis (p=0.851). Regarding the PS, both type of fixations (with 1 or 2 ISSs) confirmed an acceptable correction and adequate control of the PS even though with some differences compared to the intact pelvis (p=0.01). The presence of the second ISS found not to offer any significant additional benefit. The three-dimensional analysis of the behaviour of the pelvic elements, in these two different types of fixation, did not show any statistical significant differences (p=0.645). CONCLUSION: The posterior fixation with ISS can represent an alternative option for treatment of pelvic injuries associated with rotational instability. Further prospective clinical studies are necessary to determine, the influence of the residual pubic symphysis mobility in the every day life, when the above-mentioned technique is applied.

Fracturas supracondíleas de húmero en la infancia: ¿influye el tipo de cirujano en los resultados? / Humerus supracondylar Fracture of Childehood: Results Clinical -Radiological according to the type of surgeon

Objetivo: Determinar si existen diferencias entre los resultados obtenidos por cirujanos ortopedas infantiles (COI) y cirujanos ortopedas generales (COG) en el tratamiento de fracturas supracondíleas de húmero en la infancia. Material y método: Revisión retrospectiva de las fracturas supracondíleas de húmero tipo III de la clasificación de Gartland intervenidas en el hospital Virgen del Rocío entre los años 2007-2011. Se obtuvieron dos poblaciones dependiendo del tipo de cirujano que llevó a cabo la intervención (COG o COI) y se realizó un análisis comparativo entre ambos de los resultados funcionales, estéticos (según los criterios de Flynn) y radiológicos (ángulo de Baumann e intersección de la línea humeral anterior con el capitellum) tras un mínimo de 12 meses de evolución. Resultados: No se encontraron diferencias estadísticamente signifi cativas en resultados funcionales, estéticos ni en los parámetros radiológico postintervención. Conclusiones: Teniendo en cuenta los resultados del presente estudio ambos, COI y COG, presentan el suficiente nivel de entrenamiento y habilidades quirúrgicas para llevar a cabo el correcto tratamiento de este tipo de fracturas. Nivel de evidencia: III

Objective: To determine whether there are differences between the results obtained by Pediatric orthopedic surgeon and General orthopedic surgeons in the treatment of supracondylar humeral fractures in children. Material and Methods: A retrospective review of Gartland type III supracondylar humerus fractures treated in Virgen del Rocio Hospital between 2007- 2011 was performed. Two populations were obtained depending on the surgeon who performed the procedure and a comparative analysis between the functional and aesthetic results according to Flynn criteria was performed, as well as a radiological analysis (Baumann angle and intersection of the anterior humeral line with the capitellum) after aminimum of 12 months of follow-up. Results: No statistically significant differences in functional, aesthetic or radiological post-intervention parameters were found. Conclusions: Considering the results of this study both Pediatric orthopedic surgeons and General orthopedic surgeons, have a sufficient level of surgical training and skills to carry out the correct treatment of these fractures. Level of evidence: III

Thoracoscopic diaphragmatic eventration repair in children: about 10 cases.

BACKGROUND AND AIM: Recent reports in literature have emphasized the clinical perception of reduced pain, postoperative morbidity, and dysfunction associated with thoracoscopic approach compared with standard thoracotomy. The authors describe a thoracoscopic approach and technical details for diaphragmatic eventration repair in children. PATIENTS AND METHODS: Ten patients, 4 girls and 6 boys, 1 teenager (14 years old) and 9 children (age range, 6-41 months; average, 17 months), were operated for a diaphragmatic eventration in 3 different pediatric surgery teams, according to the same technique. Symptoms were recurrent infection (7 cases), dyspnea on exertion (2 cases), and a rib deformity (1 case). An elective thoracoscopy was performed, patient in a lateral decubitus. A low carbon dioxide insufflation allowed a lung collapse. Reduction of the eventration was made progressively when folding and plicating the diaphragm. Plication of the diaphragm was done with an interrupted suture (6 cases) or a running suture (4 cases). The procedure finished either with an exsufflation (4 cases) or a drain (6 cases). RESULTS: A conversion was necessary in 2 cases: 1 insufflation was not tolerated and 1 diaphragm, higher than the fifth space, reduced too much the operative field. Patients recovered between 2 and 4 days. Dyspnea disappeared immediately. Mean follow-up of 16 months could assess the clinical improvement in every patient. DISCUSSION: Thoracoscopic conditions are quite different between a diaphragmatic hernia repair previously reported and an eventration. Concerning diaphragmatic hernias, reduction is easy, giving a large operative space for suturing the diaphragm. Concerning diaphragmatic eventrations, the lack of space remains important at the beginning of the procedure despite the insufflation into the pleural cavity. The operative ports must be high enough in the chest to allow a good mobility of the instruments. Chest drainage seems to be unnecessary. CONCLUSION: Diaphragmatic eventration repair by thoracoscopy is feasible, safe, and efficient in children. Above all, it avoids a thoracotomy. It improves the immediate postoperative results with a good respiratory function.