Comparison of radiological and functional outcome of unstable intertrochanteric femur fractures treated using PFN and PFNA-2 in patients with osteoporosis.

INTRODUCTION: Presently, unstable intertrochanteric femur fractures are treated commonly with intramedullary nailing devices. Various designs of intramedullary nail are introduced. The conventional Proximal Femoral Nail has given diverse outcome. Complications have also been noted with this implant. Newer designs like Proximal Femoral Nail Antirotation-2 have been introduced for Asian population. The aim of our study was to compare the radiological and functional outcome of unstable intertrochanteric femur fracture treated with conventional Proximal Femoral Nail and Proximal Femoral Nail Antirotation-2 in osteoporotic patients. MATERIALS AND METHODS: Patients presenting with unstable intertrochanteric femur fracture (AO classification) and Singh's index ≤ 3 were included. Patients were assigned to the groups based on the implant used for treatment (PFN and PFNA2 group). Post-operative radiographs were used to assess the quality of reduction, by calculating neck shaft angle. The quality of fixation was assessed, by calculating tip apex distance and Cleveland index. The duration of surgery, blood loss, number of fluoroscopic images taken and length of hospital stay were noted. Patients were followed up for 6 months, and complications were noted. The functional outcome was compared using modified Harris hip score. The data analysis was done using Student's unpaired t test/Mann-Whitney U test and Chi-square test/Fisher's exact test. A p value less than 0.05 was considered significant. RESULTS: Seventy-eight patients with unstable intertrochanteric fractures and Singh's index < 3 were included. Thirty-seven were treated with PFNA2 and 41 with PFN. The average age in PFNA2 group was 69.51, and PFN group was 70.804. Nine patients in PFNA2 group and 10 patients in PFN group had tip apex distance more than 25 mm. Twelve patients in PFNA2 group and 14 Patients in PFN group had sub-optimal implant position as per Cleveland index. The difference in neck shaft angle between uninjured and operated side was more than 10° in four patients of PFNA2 group and seven patients of PFN group. The average Harris hip score was 74.55 for PFNA2 group and 69.88 for PFN group. Four complications were seen in PFNA2 group and 5 in PFN group. CONCLUSION: The functional outcome (p = 0.102) achieved with both the implants was similar. Good functional outcome can be achieved, when the radiological parameters are restored, i.e. TAD < 25 mm, Cleveland index in centre-centre position and neck shaft angle difference < 5°. The overall complications, in the set-up of osteoporosis, seen with both the implants were similar (p = 0.44). PFNA2 group showed better results in terms of perioperative morbidity.

Comparison of the efficacy of hook plate versus tension band wire in the treatment of unstable fractures of the distal clavicle.

Fifty-two patients with unstable fractures of distal clavicle treated by open reduction and internal fixation with hook plates or tension band wires were retrospectively reviewed. The 52 patients were divided into two groups based on the method of treatment. The hook plate (HP) group included 32 patients and the tension band wire (TBW) group included 20 patients. Both groups were similar in respect to injury mechanisms, compounding medical conditions, and shoulder score (p > 0.1). However, hook plating had a significantly lower rate of complication (p = 0.01) and symptomatic hardware (p = 0.001). In addition, hook plating better facilitated the return to work and athletic activity (p = 0.004 and p = 0.003, respectively). In conclusion, if surgery of distal clavicular fractures is indicated, internal fixation with a hook plate has more advantages than with tension band wires.

Four-corner fusion: Comparing outcomes of conventional K-wire-, locking plate-, and retrograde headless compression screw fixations.

PURPOSE: Several operative approaches and various implants for osseous fixation have been described to achieve four-corner fusion of the wrist. Given the discordance and to aid in further standardizing the technique, this study directly compares the outcomes of K-wire, fusion plate, and headless retrograde compressive screw fixations to achieve four-corner arthrodesis. METHODS: Sixty-four patients underwent four-corner fusion over a period of 5 years and were reviewed retrospectively. Twenty-one patients underwent bone fixation with conventional K-wires, 26 with locking plates, and 17 patients were treated by headless retrograde compressive screw fixations. Patients of the different groups were comparable regarding age, sex, hand dominance, and stage of disease. RESULTS: All study groups showed significant improvements in grip strength, decrease in pain (NRS) at rest and with activity, range-of-motion of the wrist, and wrist function (measured by the DASH-score). When evaluating the three groups amongst each other, overall complication and nonunion rates were low and revealed no significant differences between the groups of patients. However, regarding postoperative NRS at activity, dorsal flexion, and DASH-scores, the "screw" group showed significantly better results than the "wire" group. CONCLUSION: The results show that all examined techniques of four-corner fusion can improve wrist function when compared to preoperative baseline (NRS at rest and activity, postoperative DASH-scores). However, headless retrograde compressive screw fixation had significant better results regarding pain relief (NRS) at activity and postoperative DASH-scores.

A functional classification of spinal instrumentation.

BACKGROUND CONTEXT: Spinal instrumentation systems have evolved far beyond the original Harrington design, with increasing complexity and capabilities. This review attempts to de-emphasize the "product names," as systems are often generically and inappropriately referred to as "Harrington rods," by introducing a functional classification for current systems. PURPOSE: The aim of this paper is to review the intended design purpose of current spinal instrumentation systems for more accurate interpretations of radiographs and complications. STUDY DESIGN: The principles involved in each type of instrumentation system are described, followed by the characteristic components and the normal appearance radiographically, with examples of complications, which should be recognized. METHODS: The historical contribution of specific systems in the developing art of internal fixation of the spine is provided as a background to understand the biomechanical forces imparted by spinal hardware. Recognizing the functional intent of spinal constructs will enhance descriptions of those images. RESULTS: Spinal instrumentation has been categorized into five functional types: Distraction and compression, segmental stabilization, coupled or derotation systems, translational or pedicle screw systems, and anterior instrumentation. CONCLUSIONS: Analysis of radiographs from a functional viewpoint can enhance the descriptive interpretation and specifically allow assessment of the success or of the presence of complications, which are crucial to the analysis of instrumentation effectiveness.

History of surgery for the correction of spinal deformity.

During the last century the technological advances in the field of spinal surgery had a dramatic impact on the treatment of spinal deformity in children and adults. Before the advent of medications and vaccines to treat and/or prevent tuberculosis and poliomyelitis, patients suffering from these disorders often became incapacitated by the resulting kyphoscoliosis. In the early 1900s Lange began to address this problem mechanically by using foreign materials to stabilize the spine internally. In the 1950s and 1960s, owing to the efforts of Harrington and others, the process evolved to create the first generation of modern spinal instrumentation. The Harrington rod was able to correct a spinal deformity primarily through distraction. In the next wave of advances, some of the shortcomings of Harrington rods were addressed. Segmental fixation involving sublaminar wires was introduced in the 1970s by Luque. Anterior approaches and instrumentation-related techniques developed by Zielke and colleagues as well as Dywer and coworkers in the late 1960s and mid-1970s allowed for better correction of deformity with immobilization of fewer motion segments compared with posterior surgery. Transpedicular fixation of the spine was popularized by Cotrel and Dubousset in the 1980s; they used the technique to perform segmental stabilization, which better reduces the rotational aspect of a deformity. Finally, in the mid-1990s, thoracoscopic techniques were developed and are currently in use for anterior release and placement of instrumentation. The authors review the major technical developments for the surgical treatment of spinal deformity.

Initial stability of ankle arthrodesis with three-screw fixation. A finite element analysis.

OBJECTIVE: Compare the initial stability at the fusion site of ankle arthrodesis fixed with two and three screws. DESIGN: Finite element models of ankle arthrodesis were developed from computed tomography images. Two-screw constructs were augmented with a third screw in different orientations and subjected to loads likely to affect the ankle postoperatively. BACKGROUND: More stable fixation seems to increase the chance of fusion, as it minimises the motion between the tibiotalar interfaces. METHODS: Non-linear elastic finite element analyses were performed in external torsion and dorsiflexion. The micromotions at the tibiotalar interface were computed to compare the two- and three-screw fixation in intact and flat-cut arthrodesis. RESULTS: Adding a third screw reduced the micromotions at the fusion site. Inserting the third screw anteriorly predicted lower peak micromotions than inserting the screw posteriorly, except for the intact arthrodesis tested in dorsiflexion. Three-screw intact arthrodesis predicted lower peak micromotions than flat-cut arthrodesis. CONCLUSIONS: Better stability was predicted for three-screw ankle arthrodesis. In flat-cut arthrodesis, a third screw inserted anteriorly performed better than a posterior screw. In intact arthrodesis, a posterior screw seemed a better option when flexion stability was the main concern. Even with three-screw fixation, the configuration of the first two-crossed screws may still be important to improve the stability at the fusion site.

Finite element analysis of the initial stability of ankle arthrodesis with internal fixation: flat cut versus intact joint contours.

OBJECTIVE: Qualitative comparison of the initial stability provided by two joint preparation techniques and various screw configurations in ankle arthrodesis, using the finite element method.Design. A three-dimensional model of a healthy ankle was developed from computed tomography images. Two groups of models were built, one with the joint contours resected to produce flat surfaces, and the second with the joint contours preserved. In each case, a variety of screw orientations were examined. BACKGROUND: Despite the improved results of ankle arthrodesis, failure rates due to non-union are still reported. The initial stability of the arthrodesis construct seems important in the final outcome of the fusion. METHODS: Non-linear contact finite element analyses were performed in the arthrodesis constructs subjected to internal/external torsion and dorsiflexion. Micromotions at the bone-to-bone interface were calculated for frictionless and Coulomb friction contact, and compared for the two joint preparation techniques and screw configurations. RESULTS: Overall lower peak micromotions were predicted when preserving the joint contours both in torsion and dorsiflexion. For both preparation techniques, the lowest micromotions tended to occur with the screws inserted at 30 degrees with respect to the long axis of the tibia, crossing above the fusion site. Inclusion of friction in the models caused a general decrease on the magnitude of the micromotions as compared to the frictionless case, but did not affect the ranking of the models. CONCLUSIONS: The finite element method can be used as a qualitative tool to study the initial stability of ankle arthrodesis, overcoming the difficulties of measuring bone-to-bone interface micromotions experimentally. Better initial stability was predicted for ankle arthrodesis when the joint contours were preserved rather than resected. Crossing the screws above the fusion site at a steeper angle also tended to increase the stability at the fusion site. RELEVANCE: Finite element analyses can help during the pre-operative planning of ankle arthrodesis. When bone density is not compromised, preserving the joint contour and inserting the screws at less than 45 degrees to the long axis of the tibia, crossing over the arthrodesis site, may offer better initial stability.

[Comparison of primary trapezometacarpal cup fixation using mechanical tests]. / Comparaison de l'ancrage primaire de cupules trapézométacarpiennes par tests mécaniques.

INTRODUCTION: In order to optimise the primary fixation of the cup of the Arpe (Biomet Merck) trapeziometacarpal prosthesis, several geometries have been studied. The mechanical strengths of the primary fixations ensured by cup "with slots", "bladed" and "with crown", have been assessed and compared to the one obtained for the primary anchorage of the Arpe cup. METHOD: For each cup, the strength of the primary fixation has been assessed in torsion (torque along the cup axis) and bending (torque perpendicular to the cup axis). Tests have been performed on prototype cups set up in a vertebral body of lamb cancellous bone. Torque recording allowed the assessment of the maximum strength for each cup type. RESULTS: Arpe and cup "with slots" showed an effective bending strength, respectively due to the three anchorage picks and to the equatorial over-thickness. However, the cup "with crown" demonstrated a better bending strength with a mean torque of pulling out Cbending = 0.89 Nm. In torsion, the three anchorage picks of the Arpe cup did not allow a solid anchorage. For such a loading, the cup "with crown" also showed the best torsion strength with a mean unsealing torque Ctorsion = 0.83 Nm. DISCUSSION: The equatorial over-thickness seems to give good bending and torsion strengths to the "bladed" and "with crown" cups, with a press-fit effect. Replacing the fixation points of the Arpe cup by a crown also allowed the improvement of its torsion strength.

[Intramedullary locked nailing in the treatment of proximal femoral fractures]. / Leczenie zlaman blizszej czesci kosci udowej przy pomocy ryglowanych pretów sródszpikowych.

INTRODUCTION: The aim of the study is evaluation of results of operative treatment the proximal femoral fractures with intramedullary locked nailing. MATERIAL AND METHOD: In years 1996-2004 44 patients were treated because of proximal femoral fractures with closed reduction and stabilization with intramedullary locked nailing. There were 15 women and 29 men in average age 60 years (18-95 years). There were 2 femoral neck fractures and 42 peritrochanteric fractures. The fracture of femoral shaft in 2 patients accompanied the fracture of proximal part of femur. The morphology of fractures was estimated according to AO classification. Clinical results were evaluated with Harris hip score (HHS). RESULTS: The average follow up is 8 months (from 6 to 24 months). There was good reduction of 27 fractures on postoperative radiograms. The average 15 degrees of varus lack of reduction was noted in 17 peritrochanteric fractures (from l0 to 35 degrees). There were mainly 31.A.3 unstable fractures according to AO classification. 3 patients died during three postoperative months from causes not connected with operative treatment. 39 fractures united in the period from 10 to 16 weeks. Delayed union--after 6 months occurred in 2 persons. Fatigue fracture of intramedullary rods occurred to both of this patients. The average Harris Hip Score was 86 points (from 70 to 100 points) after union of fractures. CONCLUSIONS: (1) The use of intramedullary locked nailing in the treatment of fractures of proximal part of femur leads to union without additional immobilization. (2) Closed intramedullary locked nailing in the treatment of unstable intertrochanteric fractures is connected with the risk of varus malalignment of fragments, which does not delay union, but decreases functional outcome. (3) Proper operative technique decreases the number of intra- and postoperative complications.

Comparison of spinal mobility after Harrington and CD instrumentation.

Of 229 patients, 15 pairs of patients with right thoracic idiopathic scoliosis (King III) and 15 pairs with combined thoracic and lumbar scoliosis (King II) were identified. Each pair consisted of one patient with Harrington and the other with Cotrel-Dubousset instrumentation. Pairs were comparable with regard to thoracic curve magnitude, and level of end and stable vertebrae. Minimum follow-up was 4 years postoperatively. Spinal mobility of patients in the coronal and sagittal plane, and axial rotation was measured with inclinometers. The differences between operatively treated groups are not significant. The more caudal instrumentation ends, the more reduced is spinal mobility in the coronal plane. Motion in operated patients is significantly reduced in comparison to a healthy reference group.

Fijación interna biológica en pacientes polifracturados / Biological internal fixation in polifractured patients

En el Servicio de Polifracturados del Hospital de Traumatología y Ortopedia de Lomas Verdes, en el periodo comprendido entre marzo de 1991 y diciembre de 1992, se realizaron 26 fijaciones internas biológicas, correspondiendo 18 a la tibia, 6 al fémur, una al húmero y una al antebrazo. Se llevaron a cabo 18 estabilizaciones de fracturas complejas multifragmentarias con compromiso articular de la tibia, 8 de tibia proximal y 6 de la tibia distal, en las que como procedimiento quirúrgico inicial les fue colocado un fijador externo tubular AO percutáneo: con un tornillo de Schanz proximal y uno distal, a cielo cerrado como aditamento distractor para realizar una reducción mecánica indirecta. En algunos casos se puenteó la articulacionés, en otros, la articulación fue fijada inicialmente bajo visión directa para lograr una reducción anatómica y posteriormente se colocó el fijador externo tubular AO sobre la cortical medial a cielo cerrado, cuidando de no levantar el m. tibial para no ver ni tocar la cortical medial multifragmentada, se dio distracción al mismo hasta lograrse una reducción cercana a lo ideal, posteriormente y sin retirar el fijador externo se completó la reducción abierta mediante una placa colocada sobre el periostio, bajo el principio biomecánico del sostén. Los defectos óseos metafisarios y dafisarios no fueron visualizados ni se les colocó injerto óseo. En los casos en que el fijador externo puenteó articulaciones, el mismo fue modificado, colocándolo en la cortical opuesta a la placa para dar sostén a la misma por encontrarse multifragmentada, pero ya sin puentear la articulación. Todos los defectos óseos consolidaron a pesar de no haber sido injertados en forma directa, al preservarse el hematoma fracturario y su vascularidad, sin agredirse quirúrgicamente de manera directa, como sucedería con una doble placa. El fijador externo fue retirado en un tiempo no mayor de 6 semanas al observarse la consolidación radiológica. Se permitió la movilidad articular desde el primer día de postoperatorio