Intramedullary nailing at different distal tibial fracture levels: A biomechanical study.

BACKGROUND: Distal tibial fractures remains a significant challenge in orthopedic trauma surgery. As the fracture level approaches the joint, alternative fixation options instead of intramedullary nailing (IMN) come to the fore. The present study aimed to assess the biomechanical stability of IMN at different distal tibial fracture levels and the number of locking screws required. METHODS: Using a total of 21 sawbone models, 3 different tibial fracture levels (3, 4.5, and 6 cm proximally to the talocrural joint) were created and the fractures were fixed using 2, 3, or 4 distal locking screws. A single compression force at a speed of 30 mm/min with a maximum force of 800 Newton and a cyclic compression force of 60 cycles at a speed of 60 mm/min was applied to all tibia models. The applied weight and displacements from the fracture lines were recorded and evaluated. RESULTS: There was no statistically significant difference in fixation with 2 distal locking screws in groups 1, 2, and 3 (single test P =.9689) (cyclic test P =.8050). Therefore, if 2 distal screws are used, the fracture level does not affect the strength of fixation. In fractures located 6 cm proximal to the talocrural joint, all 4 holes of the nail can be used to insert screws, which provides a stronger fixation. When 2 screws are used, a statistically weaker fixation is obtained than with 3 or 4 screws. However, there is no significant difference between using 3 or 4 screws. CONCLUSION: Our findings support the use of IMN with 2 distal locking screws as a viable option for the management of distal tibial fractures. We found that it provides sufficient fixation regardless of the fracture level, suggesting that there is no need to choose an alternative fixation technique due to concerns of inadequate fixation as the fracture line moves distally. In cases where more stable fixation is desired, an additional locking screw can be used, but the potential increase in procedure and fluoroscopy time should be considered.

A Novel Electromechanical Intramedullary Nail System for Limb Lengthening.

Background/Purpose of the Study: Many methods have been developed to treat leg length discrepancies. Extensible intramedullary nails are the most commonly used systems. However, complications such as excessive distraction, blockage of the nail, aditional surgery, uncontrolled lengthening and much pain occur during the use of these systems, and the desired success rate cannot be achieved. This study aims to develop a new extensible intramedullary system with two mechanisms (electronical and mechanical) for femur and tibia that treats leg length inequalities in a way that allows lengthening without complications as much as possible and does not require a second surgical intervention. It was planned to perform basic mechanical and cadaver functional tests of the new system, which will be designed and developed for this purpose. Methods: The 3D design of the system has been completed with 3D computer software. A compact system has been developed that is mechanically activated by sudden axial loading and electronically activated by a controllable electric motor. Basic mechanical and functional tests of the new system have been performed within a cadaver. Results: The rapid prototype of the system with electronical and mechanical units has been produced. As a result of the mechanical tests (axial loading), the nail was found to be resistant to compression forces. Its application to the cadaver and function tests was successfully performed. Conclusions: We believe that the system we have developed will have advantages, such as working principle, ease of application, controlled lengthening, patient mobility compared to existing leg lengthening methods. The success of the system in practice will be evaluated by in-vivo animal experiments after more detailed mechanical experiments on cadavers. According to the results, it will be ready for human use by performing necessary restorations.

Effects of degree of translation or rotation of acetabular fragment of periacetabular osteotomy procedure on pelvic X-ray parameters.

The present study aims to investigate the effect of amount of lateralization and/or anteversion of the point where the iliac cut meets with the posterior column cut of periacetabular osteotomy (PAO), on X-ray parameters such as Center of edge (CE) angle, retroversion index (RVI) and sharp angle. Fourteen patients with symptomatic hip dysplasia (CE° < 20°) were included. Pelvis Computerized tomography (CT) sections were used for 3D printing. PAO was then performed on these models. The point (A), 1 cm lateral to the pelvic brim, is marked where the iliac cut intersects the posterior column cut. In Group I (1.5-0), point A is lateralized parallel to the osteotomy line for 1.5 cm. In Group II (1.5-0.5), it is additionally anteverted for 0.5 cm. In Group III (3-0), point A is lateralized for 3 cm and then additionally anteverted for 1 cm (Group IV: 3-1). Radiographs were taken in each stage. The lateral CE angle, RVI and sharp angle were measured. All had an increase in the CE angle and RVI and a decrease in the sharp angle compared to the control group (P < 0.05). The amount of CE angle (ΔCE) or RVI increase (ΔRV) was as follows: 3-1(38°, 0.3) > 3-0(27°, 0.2) and 1.5-0.5(25°, 0.1) > 1.5-0(17°, 0.07) (P < 0.05) (with no difference between groups 1.5-0.5 and 3-0, P = 0.7). The amount of sharp angle decrease was as follows: 3-1(20°), 3-0(18°) < 1.5-0.5(11°) < 1.5-0(8°) (P < 0.05). The lateralization of the intersection point where the iliac wing cut meets with the posterior column cut along the cut surface led to an increase of lateral cover and focal retroversion. Additional anteversion leads to further increases in those parameters, while groups 1.5-0.5 and 3-0 did not differ between.

Bony landmarks, distances and their correlations to each other, which can be used during periacetabular osteotomy: a CT study performed on dysplastic hips.

As a surgical technique for hip dysplasia, Bernese periacetabular osteotomy (PAO) still poses technical difficulties and unclear surgical steps like the depth of the first 'ischial' cut, the start of the iliac cut and the width of the retroacetabular cut to prevent either iatrogenic joint entrance or posterior column fracture. Twenty-seven dysplastic hips (CE < 25°) were randomly matched with nondysplastic hips (n: 27, CE > 25°). 3D CT sections of the hips were evaluated and the width of the ischium, the distance from the infra-acetabular groove to the ischial spine, from the anterior superior iliac spine (ASIS) to the joint or sciatic notch or the sciatic spine, from the most medial point at the acetabulum to the posterior column, ischial spine or sciatic notch were measured for each group and correlated. The distances (mm) from the infra-acetabular groove to the ischial spine (42 ± 4, 44 ± 4, P: 0.03), the anterior superior iliac spine to the joint (52 ± 6, 60 ± 3, P: 0.03), the most medial point at the acetabulum to the posterior column (34 ± 2, 36 ± 2, P: 0.005) were shorter in the dysplastic group. The distance from the ASIS to the sciatic notch was correlated with the distance from the infra-acetabular groove to the ischial spine, from the ASIS to the joint and the most medial point at the acetabulum to the posterior column. The distance from the ASIS to the sciatic notch can be used intraoperatively to guess the X-ray guided or blindly osteotomized stages to predict the width or depth of the osteotomy to prevent intraarticular extension or posterior column fracture.

Three-Dimensionally-Printed Joint-Preserving Prosthetic Reconstruction of Massive Bone Defects After Malignant Tumor Resection of the Proximal Tibia.

Joint-preserving prosthetic reconstruction for massive bone defects has the potential to be a new and revolutionary treatment option. In this paper, we discuss the case of a 30-year-old female patient who presented with pain and swelling around the knee for three months. The patient underwent this procedure. Postoperative patient satisfaction, pain scores, and range of motion results were found to be promising. We believe that this method has the potential to be the next stage in the quest for better treatment options for this condition.

Development of biological meniscus scaffold: Decellularization method and recellularization with meniscal cell population derived from mesenchymal stem cells.

Tissue engineering approaches which include a combination of cells and scaffold materials provide an alternative treatment for meniscus regeneration. Decellularization and recellularization techniques are potential treatment options for transplantation. Maintenance of the ultrastructure composition of the extracellular matrix and repopulation with cells are important factors in constructing a biological scaffold and eliminating immunological reactions.The aim of the study is to develop a method to obtain biological functional meniscus scaffolds for meniscus regeneration. For this purpose, meniscus tissue was decellularized by our modified method, a combination of physical, chemical, and enzymatic methods and then recellularized with a meniscal cell population composed of fibroblasts, chondrocytes and fibrochondrocytes that obtained from mesenchymal stem cells. Decellularized and recellularized meniscus scaffolds were analysed biochemically, biomechanically and histologically. Our results revealed that cellular components of the meniscus were successfully removed by preserving collagen and GAG structures without any significant loss in biomechanical properties. Recellularization results showed that the meniscal cells were localized in the empty lacuna on the decellularized meniscus, and also well distributed and proliferated consistently during the cell culture period (p < 0.05). Furthermore, a high amount of DNA, collagen, and GAG contents (p < 0.05) were obtained with the meniscal cell population in recellularized meniscus tissue.The study demonstrates that our decellularization and recellularization methods were effective to develop a biological functional meniscus scaffold and can mimic the meniscus tissue with structural and biochemical features. We predict that the obtained biological meniscus scaffolds may provide avoidance of adverse immune reactions and an appropriate microenvironment for allogeneic or xenogeneic recipients in the transplantation process. Therefore, as a promising candidate, the obtained biological meniscus scaffolds might be verified with a transplantation experiment.

A comparison of ice wrap and subacromial injection for postoperative pain and edema control following arthroscopic rotator cuff repair.

BACKGROUND: Postoperative pain and edema are the most common problems associated with arthroscopic rotator cuff repair. The purpose of the present study was to compare ice wrap and subacromial injection (SI) as treatments for early postop pain and edema control and to contrast them with a control group. MATERIALS AND METHODS: 59 patients treated with arthroscopic rotator cuff repair were randomized into three groups: 23 patients who received an ice wrap, 20 patients who received a SI, and a control group of 16 patients. RESULTS: Patient demographics, comorbidities, tear retraction, degree of fatty muscle degeneration, surgical procedures, and amount of irrigation fluid were similar for the three groups, which also showed similar results regarding postoperative pain and edema control as well as analgesic consumption. CONCLUSIONS: The present study failed to show any difference in effectiveness between the two most common pain management modalities, or between those modalities and the control group. LEVEL OF EVIDENCE: IV, prospective observational study.

Cadmium in bone cement induces necrosis and decreases the viability of residual osteosarcoma cells: A xenograft study.

OBJECTIVE: The aim of this study was to show whether local application of cadmium-impregnated bone cement can induce apoptosis and decrease the viability of residual osteosarcoma (OS) cells in nude mice. METHODS: K7M2 tumorigenic OS cell line was cultivated in vitro. The xenograft tumor model was formed by subcutaneously adding the tumor cells to athymic nude mice. Tumor was formed within 1 month. Then, mice were randomly assigned to five groups, each containing seven nude mice: control (group 1), wide resection (group 2), intralesional resection (group 3), intralesional resection + bone cement (group 4), and intralesional resection + cadmium embedded in bone cement (group 5). Tumor resection with 1 cm surgical margins was performed in the wide resection group. In intralesional resection groups, tumor tissue was resected with positive margins aiming to leave 15 mm3 of macroscopic tumor tissue. In group 3, the defect was left empty; groups 4 and 5 received bone cements prepared with saline and cadmium solutions, respectively. After the resection, mice were observed for 15 days and sacrificed. Next, surgical resection sites were evaluated histopathologically in each group. RESULTS: Recurrent tumor was formed in all mice in the wide resection group, and apparent progression of residual tumor was observed in groups 3 and 4. On the contrary, only a thin layer of residual tumor was observed around the bone cement in group 5. Histological evaluation revealed remarkable necrosis in group 5 and lowest viability compared to other groups. No systemic toxic effect related to cadmium was observed. CONCLUSION: Our data suggest that local application of cadmium in bone cement has a significant potential to increase tumor necrosis and decrease the viability of residual OS cells.

Bare area on the trochanter and its correlations to gluteal tendon insertion dimensions.

Gluteus medius and minimus tears have recently been reported to be very common and the main etiology of lateral sided hip pain. The purpose of this study was to determine whether there is any correlation between the dimensions of the tendon insertions and bare areas (BA) and various bony landmarks. Twenty-seven hemipelvises from adult male hips were included. The bony landmarks [anterior tip (Ta), posterior tip of trochanter, vastus tubercle (VT) and center of BA] were marked. The longitudinal lengths and widths (maximum) of posterosuperior (PS), lateral facets (LF), minimus insertion (Min) and BA and the distance between posterior (Tp) and Ta and between anterior/posterior tips and the VT or center of BA were measured using a digital caliper. A correlation analysis was performed between variables. There was a correlation between LFlength and Minlength (r = 0.4, P = 0.01) and between Ta-BA and PS + LF (r = 0.5, P = 0.003) or Minlength (r = 0.4, P = 0.016). LFwidth was negatively correlated with BAwidth (r = -0.4, P = 0.002). Tp-BA was negatively correlated with BAwidth (r = -0.4, P = 0.01). LFwidth was correlated with Tp-BA, and this nearly reached statistical significance (r = 0.3, P = 0.05). BA can be used intraoperatively as landmarks to estimate the width of the LF and also to determine the length of the longitudinal insertion of the gluteus medius and minimus tendons.

Cosmetic bilateral leg lengthening using intramedullary nail experience of 9 cases.

BACKGROUND: Distraction osteogenesis to correct deformity and limb-length discrepancy was defined by Ilizarov. Traditional distraction osteogenesis was made with circular external fixators or monolateral fixators commonly for deformity, and external fixators was related with pin site infections and pain due to soft-tissue transfixation. Nowadays, bone lengthening method is used with different intramedullary nail systems for cosmetic purposes. METHODS: From 2011 until 2018, a total of 9 patients (6 males and 3 females:16 femoral, 2 tibial), with constitutional short stature, to whom the intramedullary nail lengthening technique for cosmetic purposes had been applied, were retrospectively reviewed. The mean age was 28.3 while the mean height before the lengthening was 151 cm. RESULT: The mean lengthening gained in all patients were 8.7 cm. The mean follow-up period was 22 ± 11 months while the healing index with normal bone healing was 46.8 ± 16 months/cm. Complications that we noted were; insufficient bone regeneration (n = 2), quadriceps contracture (n = 1), proximal locking screw runaway (n = 1). CONCLUSION: Bone lengthening for aesthetic purposes with different nail systems can be very safe and beneficial to the patients improving their social capabilities and self-confidence. Yet, patients should be well informed about the complications and risks of the lengthening surgery.

Ipsilateral hip pain and femoral shaft fractures: is there any relationship?

BACKGROUND: High-energy traumas are common occurrences worldwide. The rate of overlooked neck fractures in polytrauma cases is also high. Previous studies have shown that articular hip pathologies, particularly neck fractures, are associated with fractures of the femoral shaft. This study sets out to describe cases of intra-articular hip pathology following traumatic femoral shaft fracture. Thus, the present study aims to investigate the relationship between ipsilateral hip pain and femoral shaft fractures. METHODS: Patients who were diagnosed with a fracture of the femur shaft and who were operated on (intramedullary fixation or plate) were included in this study. Patients with pathologic fractures, femoral neck fractures, femoral intertrochanteric fractures, or pelvic fractures were excluded. Patients with at least six months of follow-up and who were capable of independent walking without support were grouped according to AO/OTA fracture classification. Patients were questioned for deep anterior groin pain, and physical examination tests and hip imaging (X-ray and MR arthrography) were performed by calling patients with the indicated complaints. RESULTS: The presence of labral tears were noted in two patients. The incidence of osseous bump of the femoral neck identified by MR arthrography (MRA) was found in three of 16 hips. Assessment of the presence of gluteal tendinosis or tear and herniation pit identified three of 16 hips. The presence of osteophytes was noted in one patient. MRA identified three of 16 hips with more than one type of intra-articular pathology. Two patients with an osseous bump of the femoral neck were also diagnosed with additional hip pathology as herniation pit. CONCLUSION: Anterior groin pain in patients with a history of femoral shaft fracture is not always related to implants. Orthopedic surgeons should become suspicious in cases of intra-articular hip pathology in patients who have persistent hip pain after severe lower extremity trauma.

Suture anchor fixation strength in the Latarjet procedure: a biomechanical study in cadavers.

BACKGROUND: The use of metallic screws for graft fixation during the Latarjet procedure is not devoid of complications. The purpose of the present cadaver study was to determine the initial strength of coracoid graft fixation using suture anchors and compare it to that of the traditional screw fixation of the graft using a fresh frozen human shoulder cadaver model. MATERIALS AND METHODS: Twelve unpaired fresh frozen cadaver shoulders were utilized. In the first group, suture anchor fixation of the graft was used, while 3.75-mm cannulated screws were used in the second group. The specimens were then cyclically loaded from 5 to 150 N at a speed of 0.05 mm/s for 100 cycles. After cyclic loading, each specimen was then loaded at a constant rate of 0.5 mm/s until 7 mm of displacement. Cyclic elongation, peak-to-peak displacement, stiffness and maximum load were measured. RESULTS: There were no significant differences between the traditional screw fixation and fixation using suture anchors in elongation, peak-to-peak displacement, stiffness and maximum load. CONCLUSIONS: In this study, traditional screw fixation and fixation using suture anchors did not significantly affect biomechanical performance in a classic Latarjet procedure.

Production and Characterization of a Novel Bilayer Nanocomposite Scaffold Composed of Chitosan/Si-nHap and Zein/POSS Structures for Osteochondral Tissue Regeneration.

Osteochondral tissue is hard to regenerate after injuries or degenerative diseases. Traditional treatments still have disadvantages, such as donor tissue availability, donor site morbidity, implant loss, and limited durability of prosthetics. Thus, recent studies have focused on tissue engineering strategies to regenerate osteochondral defects with different scaffold designs. Scaffolds have been developed from monolayer structures to bilayer scaffolds to repair the cartilage-bone interface and to support each tissue separately. In this study, Si-substituted nanohydroxyapatite particles (Si-nHap) and silica-based POSS nanocages were used as reinforcements in different polymer layers to mimic a cartilage-bone tissue interface. Chitosan and zein, which are widely used biopolymers, are used as polymer layers to mimic the structure. This study reports the development of a bilayer scaffold produced via fabrication of two different nanocomposite layers with different polymer-inorganic composites in order to satisfy the complex and diverse regenerative requirements of osteochondral tissue. The chitosan/Si-nHap microporous layer and the zein/POSS nanofiber layer were designed to mimic a bone-cartilage tissue interface. Bilayer scaffolds were characterized with SEM, compression, swelling, and biodegradation tests to determine morphological, physical, and mechanical properties. The results showed that the bilayer scaffold had a structure composed of microporous and nanofiber layers joined at a continuous interface with appropriate mechanical properties. Furthermore, in vitro cell culture studies have been performed with LDH, proliferation, fluorescence imaging, and ALP activity assays using osteosarcoma and chondrosarcoma cell lines. ALP expression levels provide a good illustration of the improved osteogenic potential of a porous chitosan/Si-nHap layer due to the Si-doped nHap incorporation. Histological data showed that both fiber and porous layers that mimic the cartilage and bone sections exhibit homogeneous cell distribution and matrix formation. Histochemical staining was used to determine the cell proliferation and ECM formation on each layer. In vitro studies indicated that zein-POSS/chitosan/Si-nHap nanocomposite bilayer scaffolds showed promising results for osteochondral regeneration.

Effects of a lateral row anchor position on the suture holding strength of a double-row knotless fixation in rotator cuff repair.

OBJECTIVES: This study aims to evaluate the effects of anchor positions on the suture holding strength of a double-row knotless fixation in rotator cuff repair. MATERIALS AND METHODS: Four different double-row fixation techniques were assessed. In group 1, a 15-mm-wide mattress suture was fixed using a knotless lateral row anchor, horizontal to the shaft. In group 2, the medial sutures were fixed with a 5-mm more lateral anchor that was placed at 45° to the long axis of the humeral shaft. In group 3, different from group 2, medial sutures were fixed with a 30-mm mattress suture width. In group 4, the mattress sutures coming from the medial row anchors were fixed to the 10-mm more lateral row, vertical to the long axis of the humeral shaft. The specimens were cyclically loaded from 10 N to 30 N at 0.5 Hz for 50 cycles, and then loaded to failure. RESULTS: Group 4 had higher cyclic elongation values than group 1 (p=0.021) and group 3 (p=0.006). Group 1 had lower maximum load value than group 3 (p=0.011). Most of the specimens failed with suture ruptures. Unlike the other groups, none of the specimens in group 4 failed via a suture pull through the lateral anchor. CONCLUSION: A horizontal lateral row anchor positioned closer to the medial anchor resulted in less cyclic elongation when compared to a more vertically positioned lateral row anchor. The vertical or oblique positioning of the lateral row anchor did not result in any increase in the failure load value; however, the vertical placement prevented a suture pull through the lateral row anchor.

Anatomic implications of lesser trochanterplasty.

OBJECTIVE: The aim of this study was to measure the area of iliopsoas tendon attachment and the distance of sciatic nerve, medial circumflex femoral artery (MCFA) and quadratus muscle to lesser trochanter tip, before and after 5, 10, 15 mm depth excision of lesser trochanter. METHODS: A total 15 hips of 8 adult male cadavers were evaluated. Distances between lesser trochanter tip, sciatic nerve, the lower edge of quadratus muscle and MCFA; length and width of quadratus muscle insertion; area of iliopsoas muscle and quadratus muscle insertion was measured before and after sequential 5,10 and 15 mm depth trochanterplasties using 5 mm wide burr parallel to the posterior cortex. RESULTS: Each incremental 5 mm depth bone removal led to significant decrease of tendon area (p=0.001) at each stage. Mean decreases of iliopsoas tendon attachment area with incremental 5 mm burring were 22%±10 with 5 mm, 50%±13 with 10 mm, and 76% ±13 with 15 mm of burring. CONCLUSION: Up to 15 mm lesser trochanter removal did not result in complete detachment of the iliopsoas tendon. Lesser trochanter tip was detected at least 20 mm away from important anatomic structures including quadratus tendon, sciatic nerve, and the medial circumflex femoral artery.

Aneurysmal bone cyst healing response with intramedullary lengthening nail.

We report the treatment process of a pediatric patient with deformity and shortening in the arm after a recurrent aggressive aneurysmal bone cyst (ABC) in the proximal humerus. The patient was treated with curettage of the lesion and lengthening on an intramedullary nail following an osteotomy just distal to the ABC. The period of lengthening was approximately 50 days. At the end of the treatment the lengthening goal was achieved without any neurovascular complication. There was a minimal loss in shoulder hyperabduction due to the deformity of the humeral head.

Suture Anchor Fixation in Osteoporotic Bone: A Biomechanical Study in an Ovine Model.

PURPOSE: To evaluate the load to failure strength of anchor techniques suitable for osteoporotic bone. METHODS: Using an osteoporotic ovine model in 72 humeri, 6 fixation techniques were tested. Group 1: two interlocking 5-mm anchors with fewer, wider threads; group 2: one 5-mm anchor; group 3: one 5-mm anchor reinforced laterally by a 6.5-mm cancellous screw; group 4: one 5-mm anchor in an area reinforced with a cancellous plug; group 5: two interlocking 5-mm anchors with smaller threads; group 6: one 5-mm smaller threaded anchor. After a 10-N preload, the specimens were cyclically loaded between 10 N and 30 N for 50 cycles and then destructively tested. Peak-to-peak displacement, cyclic elongation, ultimate load, stiffness, and failure mode were recorded. RESULTS: Group 1 had lower peak-to-peak displacement than group 3 (P = .001), group 5 (P = .001), and group 6 (P = .033). In addition, group 1 showed lower cyclic elongation than group 3 (P = .001), group 5 (P = .035), and group 6 (P = .001). Group 1 had a higher ultimate load than group 2 (P = .002), group 3 (P = .019), and group 6 (P = .006). Group 1 also showed higher stiffness than group 2 (P = .007) and group 3 (P = .022). Mode of failure was predominantly caused by anchor pullout for all of the groups except group 3, which mainly failed by suture rupture. CONCLUSIONS: Two interlocking suture anchors are stronger than a single anchor in osteoporotic bone. The anchor with fewer, wider threads and a smaller core diameter showed greater strength and less elongation than the other constructs. Reinforcement by cancellous autografting increased suture anchor strength. CLINICAL RELEVANCE: Considering concerns about suture anchor pullout from osteoporotic bone, interlocking a second suture anchor with the first increases load to failure resistance. Anchors with small core diameters and fewer but wider threads are more efficient in osteoporotic bone.

Femur can be lengthened over nail, along its mechanical axis : a modified lengthening over nail technique.

The theoretical risk of medialisation of the knee joint and the lateral shift of the lower extremity mechanical axis, due to achievement of lengthening along the anatomical axis is present in the process of lengthening with elongation nails and the "lengthening over nail" technique. With this new technique described in this study we aimed to prove that lengthening over nail can be performed along the mechanical axis of the femur. Six lower-limb models were used to perform three different lengthening techniques. In group 1, lengthening was achieved along the anatomical axis with an external fixator. In group 2, the clamps of the external fixator were adjusted at 6° to achieve lengthening along the mechanical axis. In group 3, eight different sized nails were applied with an external fixator (angle adjustable clamps were at 6°) to achieve lengthening along the mechanical axis by LON technique. Photographs were taken after each cm of lengthening and the distance from the mechanical axis line were measured. The modified LON technique described in this study provided lengthening along the mechanical axis. One of the main advantages of the procedure described in our study is the chance for reconsideration and revision of unforeseen angulations and malalignments, via the help of the distal angular adjustable clamps; during the time of the surgery for external fixator removal before application of the poller screws.

Coexistence of Extraskeletal Mesenchymal Chondrosarcoma and Isolated Hemihyperplasia: A Case Report.

INTRODUCTION: Arthroscopic fixation of tibial spine fracture without damage to the growth plate is very important in patients with open physis. The present article describes a simple and effective technique being used for the first time to treat this condition. CASE REPORT: A 16-year-old boy sustained avulsion fractures of tibial spine while playing. He was treated arthroscopically with excellent result. CONCLUSION: Arthroscopic fixation of tibial spine fracture in patients with open physis with two cannulated screws perpendicular to each other is a very simple technique which provides strong construct, and allows early mobilization without risk of damage to the growth plate.