Clinical results and complication rates of lower limb lengthening in paediatric patients using the PRECICE 2 intramedullary magnetic nail: a multicentre study.

Implantable intramedullary nail lengthening devices (e.g., PRECICE 2 system) have been proposed as alternative method to external fixation for lower limb lengthening surgery. The aim of this study was to analyse our outcomes and complications using the PRECICE 2 (P2) nail system and review them in light of the existing literature. A retrospective multicentre study was conducted on patients <18 years, who were treated for limb lengthening using the P2 system. The inclusion criteria were a limb length discrepancy ≥ 30 mm and a follow-up ≥6 months after the end of treatment. A total of 26 (15 males) patients were included, average age was 14.7 ± 2.3 years; 26 nails (21 femur, 5 tibia) were implanted. The average goal lengthening was 49.4 ± 12.4 mm, while average achieved lengthening was 44.4 ± 11.6 mm. Average distraction and consolidation indexes were 11.9 ± 2.1 days/cm and 25.1 ± 8.1 days/cm, respectively. Nail accuracy and reliability were 91.1% and 88.5%, respectively. A total of five problems (joint contractures), one obstacle (femur fracture) and three complications (hip joint subluxation, deep infection and nail running back) were encountered. The P2 nail system is a valid alternative to external fixator for limb lengthening in young patients with no significant angular or rotation deformities. Our study confirms a favourable complication rate and available evidence from literature suggests a lower complication rate than external fixator systems. Nevertheless, surgeons should keep a watchful eye on risk of joint subluxation and mechanical complications with intramedullary lengthening.

Risk factors for implant failure in reverse oblique and transverse intertrochanteric fractures treated with proximal femoral nail antirotation (PFNA).

BACKGROUND: The incidence of intertrochanteric hip fracture is expected to increase as the global population ages. It is one of the most important causes of mortality and morbidities in the geriatric population. The incidence of reverse oblique and transverse intertrochanteric (AO/OTA 31-A3) fractures is relatively low; however, the incidence of implant failure in AO/OTA 31-A3 fractures is relatively high compared with that in AO/OTA 31-A1 and A2 fractures. To date, the risk factors for implant failure in AO/OTA 31-A3 fractures treated with proximal femoral nail antirotation (PFNA) have remained ambiguous. The purpose of this study was to identify the predictive factors of implant failure in AO/OTA 31-A3 fractures treated with PFNA. METHODS: The data of all patients who underwent surgery for trochanteric fractures at our institution between January 2006 and February 2018 were retrospectively reviewed. All AO/OTA 31-A3 fractures treated with PFNA were included. Logistic regression analysis of potential predictors of implant failure was performed. Potential predictors included age, sex, body mass index, fracture type, reduction method, status of posteromedial support and lateral femoral wall, reduction quality, tip-apex distance and position of the helical blade in the femoral head. RESULTS: One hundred four (9.3%) patients with AO/OTA 31-A3 fractures were identified. Forty-five patients with AO/OTA 31-A3 fractures treated with PFNA were suitable for our study. Overall, implant failure occurred in six (13.3%) of forty-five patients. Multivariate analysis identified poor reduction quality (OR, 28.70; 95% CI, 1.91-431.88; p = 0.015) and loss of posteromedial support (OR, 18.98; 95% CI, 1.40-257.08; p = 0.027) as factors associated with implant failure. CONCLUSIONS: Poor reduction quality and loss of posteromedial support are predictors of implant failure in reverse oblique and transverse intertrochanteric fractures treated with PFNA.

Effect of intramedullary nail and locking plate in the treatment of proximal humerus fracture: an update systematic review and meta-analysis.

BACKGROUND: To evaluate the effect of intramedullary nail and locking plate in the treatment of proximal humerus fracture (PHF). METHODS: China National Knowledge Infrastructure (CNKI), Chinese Scientific Journals Database (VIP), Wan-fang database, Chinese Biomedicine Database (CBM), PubMed, EMBASE, Web of Science, and Cochrane Library were searched until July 2018. The eligible references all show that the control group uses locking plates to treat PHF, while the experimental group uses intramedullary nails to do that. Two reviewers independently retrieved and extracted the data. Reviewer Manager 5.3 was used for statistical analysis. RESULTS: Thirty-eight retrospective studies were referred in this study which involves 2699 patients. Meta-analysis results show that the intramedullary nails in the treatment of proximal humeral fractures are superior to locking plates in terms of intraoperative blood loss, operative time, fracture healing time, postoperative complications, and postoperative infection. But there is no significance in constant, neck angle, VAS, external rotation, antexion, intorsion pronation, abduction, NEER, osteonecrosis, additional surgery, impingement syndrome, delayed union, screw penetration, and screw back-out. CONCLUSIONS: The intramedullary nail is superior to locking plate in reducing the total complication, intraoperative blood loss, operative time, postoperative fracture healing time and postoperative humeral head necrosis rate of PHF. Due to the limitations in this meta-analysis, more large-scale, multicenter, and rigorous designed RCTs should be conducted to confirm our findings. TRIAL REGISTRATION: PROSPERO CRD42019120508.

Impact of Intramedullary Nailing in the Treatment of Femur Fractures An Evolutionary Perspective.

Today intramedullary nails (IMN) are the gold standard in the treatment of femur fractures. Since its inception, improved design and understanding of the surrounding anatomy has exponentially increased successful patient treatment and outcomes by promoting early mobilization and reliable union. In this review, we provide an in-depth look into the evolutionary process that has led IMN to becoming today's gold standard in femur fractures.

The Effect of Insertion Technique on Temperatures for Standard and Self-Drilling External Fixation Pins.

OBJECTIVES: No studies have assessed the effects of parameters associated with insertion temperature in modern self-drilling external fixation pins. The current study assessed how varying the presence of irrigation, insertion speed, and force impacted the insertion temperatures of 2 types of standard and self-drilling external fixation half pins. METHODS: Seventy tests were conducted with 10 trials for 4 conditions on self-drilling pins, and 3 conditions for standard pins. Each test used a thermocouple inside the pin to measure temperature rise during insertion. RESULTS: Adding irrigation to the standard pin insertion significantly lowered the maximum temperature (P <0.001). Lowering the applied force for the standard pin did not have a significant change in temperature rise. Applying irrigation during the self-drilling pin tests dropped average rise in temperature from 151.3 ± 21.6°C to 124.1 ± 15.3°C (P = 0.005). When the self-drilling pin insertion was decreased considerably from 360 to 60 rpm, the temperature decreased significantly from 151.3 ± 21.6°C to 109.6 ± 14.0°C (P <0.001). When the force applied increased significantly, the corresponding self-drilling pin temperature increase was not significant. CONCLUSIONS: The standard pin had lower peak temperatures than the self-drilling pin for all conditions. Moreover, slowing down the insertion speed and adding irrigation helped mitigate the temperature increase of both pin types during insertion.

Conversion to total hip arthroplasty after failed proximal femoral nail antirotations or dynamic hip screw fixations for stable intertrochanteric femur fractures: a retrospective study with a minimum follow-up of 3 years.

BACKGROUND: Conversion to total hip arthroplasty (CTHA) is a relatively common procedure after a failed dynamic hip screw (DHS) or proximal femoral nail anti-rotation (PFNA) fixation of intertrochanteric fractures, but there have been far fewer reports specifically describing the long-term results of CTHA after failed treatments of stable intertrochanteric fractures with DHS or PFNA. The aim of the present study was to compare the clinical and radiological outcomes of CTHA after failed PFNA or DHS fixations of stable intertrochanteric fractures after a minimum follow-up of 3 years. METHODS: Between January 2005 and April 2014, we retrospectively reviewed 142 active elderly patients treated at our institution (a single institution study). A total of 72 patients (72 hips; 41 women, 31 men; mean age 76.9 years old; range 60-92 years old) who underwent conversion of a failed PFNA to a THA were compared with 70 patients (70 hips; 36 women, 34 men; mean age 75.0 years old; range 60-90 years old) who underwent CTHA after a failed DHS fixation. The mean follow-up periods were 48 (range 43-52) and 48 (range 44-52) months for the DHS and PFNA groups, respectively. Clinical and radiologic evaluations were performed on all patients. The primary outcome was the Harris Hip Score (HHS). The secondary outcomes were the complication rates. RESULTS: The Harris Hip Score (HHS) improved from 50.61 ± 3.23 preoperatively to 85.28 ± 4.45 at the last follow-up in the PFNA group and from 51.46 ± 3.90 to 84.50 ± 4.34 in the DHS group, with no significant differences noted between the groups at each follow-up (P > 0.05). However, the complication rate in the converted DHS patients was significantly higher (42.9%) than that in the converted PFNA patients (20.8%; P = 0.003). Thirty-seven PFFs (2.4%) occurred during a mean follow-up of 44.4 months. The incidence of periprosthetic fractures was found to be significantly higher (P = 0.021) for the DHS group (15.7%) than for the PFNA group (4.2%). CONCLUSIONS: CTHA after failed DHS fixations of stable intertrochanteric fractures might be associated with a significantly higher complication rate than CTHA after failed PFNA fixations. Therefore, PFNA patients with stable intertrochanteric fractures may be more suitable for CTHA.

Elastic stable intramedullary nailing in paediatric forearm fractures: the rate of open reduction and complications.

The aim of this study was to evaluate the rate of open reduction and complications of elastic stable intramedullary nailing (ESIN) in treating unstable diaphyseal forearm fractures in children. We performed a retrospective review of a consecutive series of 102 paediatric patients with a mean age of 9 years (range: 7-14 years) who underwent ESIN of unstable closed forearm fractures at three different centres. Closed reduction of one or both bones was achieved in 68 (67%) patients and open reduction was required in 34 (33%) patients. The rate of open reduction in single-bone fractures (52.2%) was significantly higher than that in both-bone fractures (27.8%) (P=0.04, Fisher's exact test). All the fractures united within 3 months. There were six refractures following nail removal. Five patients had superficial wound infections. Seven patients developed neuropraxia of the sensory branch of the radial nerve. All resolved spontaneously within 3 months of the surgery. ESIN is an effective technique in treating unstable diaphyseal forearm fractures. The need for open reduction should be decided promptly following failed attempts of closed reduction. Single-bone fractures are more likely to require open reduction than both-bone fractures. The radius should be reduced and stabilized first. If open reduction is required, this should be performed through a volar approach rather than a dorsal one.

Endolog technique for correction of hallux valgus: a prospective study of 30 patients with 4-year follow-up.

BACKGROUND: Hallux valgus (HV) is a complex deformity of the forefoot altering the kinematics of walking. Many different treatment alternatives exist for the correction of hallux valgus, but to date, none has been shown to be more effective than any other. The rate of complications following hallux valgus surgery is variable and has been reported as ranging from 1 to 55 % in the scientific literature. The purpose of this preliminary prospective study was to evaluate the result of the Endolog device, an innovative titanium endomedullary nail, for the treatment of HV. METHODS: Thirty patients with mild-to-severe HV were treated with the Endolog device. Clinical evaluation was assessed preoperatively, as well as at 3, 6, 12, 24, and 48 months after surgery with a final follow-up at 4 years, using the American Orthopaedic Foot and Ankle Society (AOFAS) hallux grading system. Computer-assisted measurement of weight-bearing antero-posterior radiographs was taken preoperatively and postoperatively, as well as at 3, 6, 12, 24, and 48 months after surgery. Non-weight-bearing radiographs were taken before the patients were discharged. The radiological parameters measured included the intermetatarsal angle (IMA), the hallux valgus angle (HVA), the distal metatarsal articular angle (DMAA), and the tibial sesamoid position. Statistical analysis was carried out using the paired t test (p < 0.05). RESULTS: The mean AOFAS score was 93.98 points at the 48-month follow-up. The postoperative radiographic assessments showed a statistically significant improvement compared with preoperative values. The mean corrections for each angular value at the last follow-up were as follows: IMA 5.95°; HVA 16.81°; DMAA 10.70°; and tibial sesamoid 1.36°. CONCLUSION: The Endolog is a safe and effective technique for the correction of HV deformity, to relieve pain and to preserve joint movement.

Which Fixation Device is Preferred for Surgical Treatment of Intertrochanteric Hip Fractures in the United States? A Survey of Orthopaedic Surgeons.

BACKGROUND: The best treatment for intertrochanteric hip fractures is controversial. The use of cephalomedullary nails has increased, whereas use of sliding hip screws has decreased despite the lack of evidence that cephalomedullary nails are more effective. As current orthopaedic trainees receive less exposure to sliding hip screws, this may continue to perpetuate the preferential use of cephalomedullary nails, with important implications for resident education, evidence-based best practices, and healthcare cost. QUESTIONS/PURPOSES: We asked: (1) What are the current practice patterns in surgical treatment of intertrochanteric fractures among orthopaedic surgeons? (2) Do surgical practice patterns differ based on surgeon characteristics, practice setting, and other factors? (3) What is the rationale behind these surgical practice patterns? (4) What postoperative approaches do surgeons use for intertrochanteric fractures? METHODS: A web-based survey containing 20 questions was distributed to active members of the American Academy of Orthopaedic Surgeons. Three thousand seven-hundred eighty-six of 10,321 invited surgeons participated in the survey (37%), with a 97% completion rate (3687 of 3784 responded to all questions in the survey). The survey elicited information regarding surgeon demographics, preferred management strategies, and decision-making rationale for intertrochanteric fractures. RESULTS: Surgeons use cephalomedullary nails most frequently for treatment of intertrochanteric hip fractures. Sixty-eight percent primarily use cephalomedullary nails, whereas only 19% primarily use sliding hip screws, and the remaining 13% use cephalomedullary nails and sliding hip screws with equal frequency. The cephalomedullary nail was the dominant approach regardless of experience level or practice setting. Surgeons who practiced in a nonacademic setting (71% versus 58%; p < 0.001), did not supervise residents (71% versus 61%; p < 0.001), or treated more than five intertrochanteric fractures a month (78% versus 67%; p < 0.001) were more likely to use primarily cephalomedullary nails. Of the surgeons who used only cephalomedullary nails, ease of surgical technique (58%) was cited as the primary reason, whereas surgeons who used only sliding hip screws cite familiarity (44%) and improved outcomes (37%) as their primary reasons. Of those who use only short cephalomedullary nails, ease of technique (59%) was most frequently cited. Postoperatively, 67% allow the patient to bear weight as tolerated. Nearly all respondents (99.5%) use postoperative chemical thromboprophylaxis. CONCLUSIONS: Despite that either sliding hip screw or cephalomedullary nail fixation are associated with equivalent outcomes for most intertrochanteric femur fractures, the cephalomedullary nail has emerged as the preferred construct, with the majority of surgeons believing that a cephalomedullary nail is easier to use, associated with improved outcomes, or is biomechanically superior to a sliding hip screw. The difference between what is evidence-based and what is done in clinical practice may be attributed to several factors, including financial considerations, educational experience, or inability of our current outcomes measures to reflect the experiences of surgeons. The educators, researchers, and policymakers among us must work harder to better define the roles of sliding hip screws and cephalomedullary nails and ensure that the increasing population with hip fractures receives high-quality and economically responsible care. LEVEL OF EVIDENCE: Level V, therapeutic study.

Management of distal femur fractures with modern plates and nails: state of the art.

Fractures of the distal femur, even those with articular extension, are well suited to surgical fixation with modern precontoured anatomic plates and nails. Numerous adjuvant techniques are available to the treating surgeon to obtain and maintain reduction while preserving fracture biology. Yet despite their proven track record and benefits over older implants, technical errors are common and must be overcome with proper preoperative planning and intraoperative attention to detail. This review summarizes the current state of the art regarding distal femur fractures, with an emphasis on relevant modern plate and nail surgical techniques, tempered by our current understanding of implant biomechanics, fracture healing, and long-term outcomes.

Estudio prospectivo aleatorizado sobre la influencia del bloqueo distal del clavo Gamma 3 en el tratamiento de las fracturas pertrocantéreas de fémur / Randomized prospective study on the influence distal block and Gamma 3 nail on the treatment of intertrochanteric fractures of femur

Objetivo. El propósito de este estudio es valorar la necesidad de bloquear distalmente los clavos Gamma 3 (Stryker. Mahwah, New Jersey. USA) en fracturas pertrocantéreas de fémur 31-A1 y 31-A2 de la AO. Material y métodos. Desde junio de 2011 hasta enero de 2013 se recoge una muestra formada por 177 pacientes con fractura pertrocantérea de fémur tratados en nuestro centro mediante osteosíntesis con clavo Gamma 3 estándar. Es un estudio prospectivo y aleatorizado según el año de nacimiento de cada paciente, par con bloqueo o impar sin bloqueo distal del clavo, formando dos grupos de 90 y 87 fracturas respectivamente. Resultados. En los pacientes intervenidos mediante clavo con bloqueo distal se observó una mayor incidencia de complicaciones médicas, una menor incidencia de complicaciones biomecánicas y un aumento en el colapso del foco de fractura en comparación con el grupo control, siendo estas diferencias estadísticamente significativas (p < 0,05). También se observa en el grupo con bloqueo distal un mayor requerimiento transfusional y una mayor tasa de éxitus presentando diferencias estadísticamente significativas (p < 0,05), sin embargo esta significación desaparece al ajustar los resultados por otras características relacionadas con los pacientes. Conclusiones. Basándonos en los resultados hallados en este trabajo, el uso del tornillo de bloqueo distal en los clavos Gamma 3 debe restringirse a fracturas pertrocantéreas inestables tras reducción donde se requiera una estabilidad adicional al clavo intramedular, pudiendo así disminuir el riesgo de complicaciones derivadas de su uso (AU)

Objective. The purpose of this study is to assess the need to lock the Gamma 3 nail (Stryker, Mahwah New Jersey USA) distally for intertrochanteric fractures of femur 31-A1 and 31-A2 of the AO. Material and methods. Details were recorded on a sample of 177 patients with intertrochanteric femoral fractures treated in our hospital by a standard Gamma nail between June 2011 and January 2013. A prospective study was conducted by randomizing patients by year of birth, even numbers with, or odd number without, distal locking, forming two groups of 90 and 87 fractures, respectively. Results. The patients treated with a distal locking nail had an increased incidence of medical complications, a lower incidence of biomechanical complications, and an increase in the fracture collapse compared with the control group, with statistical significance (p < 0 .05). It is also observed in the group with distal locking increased transfusion requirement and a higher death rate, with statistically significant differences (p < 0 .05), but this significance disappears when adjusting for other patient-related characteristics. Conclusions. Based on the results found in this work, the use of distal locking screw in the Gamma 3 nails should be restricted to unstable trochanteric fractures after reduction where additional stability to the intramedullary nail is required, and may decrease the risk of complications from use (AU)

A newly designed intramedullary nail with distal interlocking system for tibia fractures in adults - the clinical results.

BACKGROUND: The surgical treatment of fractures of the tibia includes reamed and unreamed options. Reamed nails have mechanical advantages but they significantly harm the endosteal circulation. Unreamed nails spare the endosteal circulation, but provide a less stable fixation. In both systems, immediate full weight-bearing is not possible due to instability related to distal interlocking (DI). Further, DI is responsible for the majority of the fluoroscopy requirement and a significant loss of surgical time. In our study, we present the clinical results of a new intramedullary (IM) nail and system, which allows stable fixation with an unreamed technique that permits immediate full weight-bearing, with a minimum fluoroscopy requirement for DI. METHODS: Fifty tibia fractures (49 patients) operated using our new IM system between 2008 and 2010 were evaluated retrospectively. They were allowed full weight-bearing the day after surgery. The patients were followed at least 10 months postoperatively. RESULTS: Mean fluoroscopy time was 18 seconds (min: 10, max: 30) for DI. Mean union time was 9 weeks (min: 6, max: 12). There was no neurovascular injury, deep infection, malunion, delayed union, or nonunion. CONCLUSION: We demonstrated that our newly developed IM nail and new DI system may be an option to solve the stability problems sourced from the DI screw. It also significantly decreases the requirement of fluoroscopy.

Trends in the surgical treatment of proximal humeral fractures - a nationwide 23-year study in Finland.

BACKGROUND: Proximal humeral fractures are common osteoporotic fractures. Most proximal humeral fractures are treated non-surgically, although surgical treatment has gained popularity. The purpose of this study was to determine changes in the surgical treatment of proximal humeral fractures in Finland between 1987 and 2009. METHODS: The study covered the entire adult (>19 y) population in Finland over the 23-year period from 1st of January 1987 to 31st of December 2009. We assessed the number and incidence of surgically treated proximal humeral fractures in each year of observation and recorded the type of surgery used. The cohort study was based on data from Finnish National Hospital Discharge Register. RESULTS: During the 23-year study period, a total of 10,560 surgical operations for proximal humeral fractures were performed in Finland. The overall incidence of these operations nearly quadrupled between 1987 and 2009. After the year 2002, the number of patients treated with plating increased. CONCLUSION: An increase in the incidence of the surgical treatment of proximal humeral fractures was seen in Finland in 1987-2009. Fracture plating became increasingly popular since 2002. As optimal indications for each surgical treatment modality in the treatment of proximal humeral fractures are not known, critical evaluation of each individual treatment method is needed.

Intramedullary nailing: evolutions of femoral intramedullary nailing: first to fourth generations.

Intramedullary femoral nailing is the gold standard for femoral shaft fixation but only in the past 27 years. This rapid replacement of closed traction and cast techniques in North America was a controversial and contentious evolution in surgery. As we enter the fourth generation of implant design, capabilities, and surgical technique, it is important to understand the driving forces for this technology. These forces included changes in radiographic imaging capabilities, biomaterial design and computer-assisted manufacturing, and the recognition of the importance of mobilization of the trauma patient to avoid systemic complications and optimize functional recovery.

Tratamiento de las fracturas de tibia, por enclavijamiento cerrado con clavo de Küntcher / Treatment of tibial fractures by closed fixation with a Kuntscher nail

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Comentario al artículo: Tratamiento de las fracturas de tibia por enclavijamiento cerrado tipo Kuntscher / commentary: Treatment of fractures of the tibia by closed

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External pin fixation for stabilization of the mandible--comeback of a method: historical review and first experiences with the 'mandible external fixator'.

BACKGROUND: The market-release of a modified 'mandible external fixator' appliance prompted us to reconsider the issues of pin fixation. MATERIALS AND METHODS: The first product line of the 'mandible external fixator set-Phase1' (Synthes Maxillofacial, Paoli, USA) contains the three classical basic components: percutaneous pins, clamps, and pre-bent connecting rods. The innovative features are a lightweight titanium construct and the snap-on design of the clamps. The framework is assembled by a single connecting bar (monofixator) in the so-called visor-style technique. INDICATIONS: The indication was restricted to: (1) pathological fractures, e.g., in infected osteoradionecrosis; (2) resectional defects; and (3) emergency care of mandible fractures in a multi-piece, heavy comminution, or defect pattern. PATIENTS: The mandible external fixator was used in a series of ten patients (all male, 39-73 years), for head and neck tumor sequelae in eight cases (n = 5-curatively, n = 3-palliation) and in two polytrauma cases. RESULTS: All patients had benefited from the functional restitution of the mandibular continuity avoiding major surgical exposure and additional soft tissue damage. The application using a 'visor-style technique' was appropriate for bridging defects or single comminution zones (n = 9). In the emergency care of a polytraumatized patient with multifragmentation all over the mandible divisions, it did not contribute to an adequate realignment. In curative tumor treatment (patients n = 5), a conversion either to internal fixation (n = 2) or revascularized bone grafting (n = 3) ensued after prolonged intervals of 40-170 days. Pin track infections or loosening did not occur. CONCLUSION: The hallmark of external pin fixation is its atraumatic soft tissue management. Hence, it offers peculiar options in singular comminution or defect areas associated with bone pathology and/or soft tissue alterations.

Análisis biomecánico de la doble fijación híbrida en la columna lumbar / Biomechanic analysis of a double hybrid fixation in the lumbar spine

Objetivo: valorar la repercusión biomecánica de la doble fijación híbrida, rígida y dinámica, sobre el nivel suprayacente en la columna lumbar. Material y métodos: en 6 especimenes L3- S1 de columna vertebral de cadáver, se realizó la medición de la presión intradiscal (PID) en los discos L3-L4, L4-L5 y L5-S1, en tres condiciones diferentes: espécimen intacto, con fijación rígida en L5-S1 y doble fijación híbrida L4-S1. Las muestras fueron sometidos a cargas progresivas hasta alcanzar 750 N en compresión axial, flexión anterior y extensión. Resultados: en el disco L3-L4, suprayacente a la estabilización dinámica se produjo un incremento del 10% de la PID. En L4-L5 el implante dinámico consiguió un descenso del 50% de la PID y la PID del disco con instrumentación rígida L5-S1 se redujo en un 65%. Conclusión: la PID del segmento adyacente al implante dinámico es mucho menor que en las instrumentaciones rígidas. La estabilización dinámica aporta protección al disco por encima de la fusión rígida (AU)

Objetive: to evaluate the biomechanics effects of the double hybrid fixation, rigid and dynamic, over the adjacent non-fixated level in the lumbar spine. Methods: using six specimens, L3-S1, from human lumbar spine, the measurement of the intradiscal pressure (IDP) in the disc L3-L4, L4-L5 and L5-S1, were performed in the following conditions: non-fixated specimen, with rigid fixation in L5-S1 and double hybrid fixation in L4-S1. The six specimens were subjected to progressive load until 750 N in axial compression, flexion and extension. Results: in the upper adjacent disc to the dynamic stabilization, L3-L4 disc, the IDP increased about 10%. In disc L4-L5 the posterior dynamic fixation the IDP decreased 50% and the IDP of disc with rigid fixation L5- S1 was reduced over 65%. Conclusion: the IDP of non-fixated segment adjacent to a dynamic implant is much lesser that in rigid fixations and the system provided protection to the disc over the rigid fixation (AU)