Surgical treatment of ipsilateral bifocal tibial fractures: a challenge for the surgeon. / Tratamiento quirúrgico de las fracturas bifocales ipsilaterales de tibia: un reto para el cirujano.

INTRODUCTION: The association of ipsilateral tibia fractures has a low incidence, being up to 3.2% of total tibia fractures. Currently there is no gold standard regarding the ideal surgical treatment. The objective of this study is to analyze the surgical treatment and the radiographic and functional results, as well as the associated complication rate of ipsilateral bifocal tibia fractures. MATERIAL AND METHODS: Retrospective observational study in our hospital from 2010 to 2022 of 24 patients who underwent bifocal fracture of the ipsilateral tibia. Demographic and surgical data and complications during follow-up were included. RESULTS: The 24 patients were classified into group 1 when they presented a fracture of the plateau and distal tibia (25%), group 2 with a fracture of the plateau and diaphysis (33%) and group 3 with a fracture of the diaphysis and distal tibia (42%). 3 patients underwent surgery with 1 implant and 21 patients with 2 implants. The average follow-up time in outpatient clinics was 2 and a half years. At one year, 22 patients (92%) had full weight bearing and 2 patients had partial weight bearing (8%) due to the sequelae of the fractures. The average time for consolidation of the diaphysis was 7.75±2 months, with no significant differences observed between group 2 and group 3 (p=0.06). The average time for consolidation of the metaphysis was 3.50±1.5 months, with no significant differences observed between group 1 and group 2 (p=0.065). 7 patients (30%) had complications during follow-up. CONCLUSIONS: Bifocal tibia fractures can be treated using a combination of intramedullary nailing and plate osteosynthesis with good long-term results, obtaining an optimal union rate and low complications. In addition, it facilitates the reduction of the fracture, thus facilitating the patient's recovery and obtaining good long-term functional results.

Comparative study of different extendable intramedullary rods combined with surgery in the treatment of congenital pseudarthrosis of the tibia.

BACKGROUND: When using traditional extensible intramedullary rods to treat congenital pseudarthrosis of the tibia (CPT), there were cases of re-fracture and internal fixation fracture. Therefore, the authors propose a research hypothesis that a thicker distal extensible intramedullary rod can better protect the tibia and reduce the incidence of refracture PURPOSE: To investigate the clinical efficacy of new and traditional extensible intramedullary rods in the treatment of CPT in children METHODS: From January 2017 to December 2021, the clinical data of 49 children with CPT who were treated with traditional extensible intramedullary rod combined surgery (group A) and new extensible intramedullary rod combined surgery (group B) in our hospital were collected. Inclusive criteria: ① Crawford type IV CPT children; ② The operation was performed by the same team. EXCLUSION CRITERIA: patients with multiple tibial angulation. During follow-up, the initial healing, proximal tibial valgus, tibial length, ankle valgus, refracture and intramedullary rod displacement of CPT children in the two groups were evaluated RESULTS: It was a retrospective investigation. In group A, 26 cases met the inclusion criteria, 24 cases achieved primary healing, with an primary healing rate of 92%, including 1 case of nonunion due to osteomyelitis complications after surgery, and 1 case of delayed healing, with an average healing time of 4.7 ± 0.8 months. 17 cases (68%) had unequal tibia length, with an average difference of 1.6 ± 0.8 cm. Ankle valgus occurred in 10 cases (40%) with an average of 14.4°±4.8°; Proximal tibial valgus occurred in 6 cases (24%) with an average of 7 °± 1.8 °. 20 cases (80%) had tip of the rod migration.10 cases (40%) had re-fracture; The average follow-up time was 2.4 ± 0.4 years. In group B, 22 patients achieved primary healing, and the primary healing rate was 95%, including 1 case with delayed healing. The average healing time was 4.7 ± 1.7months. 14 cases (61%) had unequal tibia length, with an average difference of 1 ± 0.5 cm. Ankle valgus occurred in 4 cases (17%) with an average of 12.3 °±4.9°; The proximal tibia valgus occurred in 9 cases (39%), with an average of 7.7 °±2.5 °. 14 cases (61%) had new type of intramedullary rod displacement. 3 cases (13%) had re-fracture; The average follow-up time was 2.3 ± 0.6years CONCLUSION: Compared with the traditional extended intramedullary rod combined operation, the new type of extended intramedullary rod combined operation has a lower incidence of re-fracture after CPT, but it still needs to be verified by large sample and multi-center research.

Temporary arthrodesis through static spacer implantation in two-stage treatment of periprosthetic joint infections of the knee.

OBJECTIVE: Treatment of chronic periprosthetic joint infection of the knee requires the removal of the implant and thorough debridement, with reimplantation in a second stage surgery. Intramedullary spacers can be helpful during the interval between explantation and reimplantation and provide a temporary arthrodesis which fixes the knee in extension preserving leg length and administers local antibiotic therapy. INDICATIONS: Periprosthetic joint infection of the knee with large bony defects and severe infection of the native joint with advanced destruction/infiltration of the cartilage and bone and/or ligament insufficiency. CONTRAINDICATIONS: Suspected antibiotic resistance of the microbiological pathogen to local antibiotic drugs, incompliant patient, and known allergy to bone cement or antibiotic. SURGICAL TECHNIQUE: After implant removal, suitable metal rods are coated with antibiotic-loaded bone cement and inserted into the cleaned intramedullary canals of femur and tibia. Rods are joined at the joint line with a connector and joint space is filled with more bone cement to achieve temporary and very stable arthrodesis. POSTOPERATIVE MANAGEMENT: Partial weight-bearing and no flexion/extension while spacer is in place; second stage reimplantation as soon as infection is controlled. RESULTS: Complications related to the spacer were rare (5.3%). Reimplantation of an implant was possible in 95 of 113 patients (84%), of those, 23 (20%) received an arthrodesis. Of the 95 patients that were reimplanted, 14 showed signs of recurrent infection. Mean time to last follow-up was 15.6 months post reimplantation. Mean knee pain was 2.9/10; overall function was good; 6 patients had an extension lag; mean total range of motion was 88°.

Four-in-one surgery for treatment of Crawford Ⅳ congenital pseudarthrosis of the tibia in children / 中华创伤骨科杂志

Objective:To explore the clinical efficacy of 4-in-1 surgery in the treatment of Crawford Ⅳ congenital pseudarthrosis of the tibia (CPT) in children.Methods:A retrospective study was conducted to analyze the clinical data of 86 patients with Crawford Ⅳ CPT who had been treated by 4-in-1 surgery at Orthopedic Department, Hunan Children's Hospital from January 2013 to December 2017. There were 47 boys and 39 girls, with an age of (40.7 ± 9.7) months at the time of surgery. Of them, 63 were complicated with type I neurofibromatosis. The 4-in-1 surgery consisted of resection of the tibial pseudarthrosis and surrounding hamartoma-like tissue, internal fixation with tibial intramedullary rod, grafting with wrapped autologous iliac bone, and Ilizarov external fixation. Their bone union, postoperative complications, and follow-up results were recorded.Results:The mean postoperative follow-up time was (80.1 ± 12.4) months for this cohort. The initial bone union rate was 96.5% (83/86), and the initial bone union time (4.8 ± 0.7) months. The last follow-up revealed 20 re-fractures, 15 cases of leg length discrepancy (longer tibia on the affected side in 5 ones and longer tibia on the healthy side in 10 ones), 10 cases of proximal tibial valgus, 12 cases of ankle valgus, 9 cases of bone bridge formation of the distal tibial epiphyseal plate, 10 cases of Ilizarov pin infection, and 2 cases of tibial osteomyelitis. Ankle stiffness occurred in 35 cases, and deviation of the tibial intramedullary rod from the center of the tibial medullary cavity in 60 cases, of which the intramedullary rod had to be removed in 20 because the rod protruded the tibial bone cortex. At the last follow-up, there were 15 cases of skeletal maturity and 71 cases of immature skeleton.Conclusions:In the treatment of Crawford Ⅳ CPT in children, the 4-in-1 surgery can lead to a high rate of initial bone union and definite primary clinical efficacy, but further improvements are necessary because postoperative complications are numerous.

Intramedullary rod insertion places the femoral component more laterally during Oxford medial unicompartmental knee arthroplasty.

BACKGROUND: This study aims to assess the influence of intramedullary rods on the implantation positions of femoral components using Microplasty instrumentation in Oxford unicompartmental knee arthroplasty. We hypothesized that femoral components can be laterally implanted incorrectly when using intramedullary rods. METHODS: This prospective study included all 45 consecutive patients (53 knees) who underwent Oxford unicompartmental knee arthroplasty surgery for anteromedial osteoarthritis or spontaneous osteonecrosis of the knee at our hospital during the study period. A custom-made toolset comprising a triangular caliper and circular trial bearings was used to evaluate the distance between the bearing and the vertical wall of the tibia implant (wall-bearing space) using the caliper at 90° flexion both with and without intramedullary rods. RESULTS: The wall-bearing space was significantly larger when the intramedullary rod was used than when intramedullary rod was not used (1.8 ± 1.1 mm versus 3.4 ± 1.2 mm, P < 0.001). The mean difference of wall-bearing space with and without intramedullary rod was 1.6 ± 0.7 mm. CONCLUSIONS: Femoral components can be laterally implanted incorrectly by an average of 1.6 mm when using intramedullary rods. The wall-bearing space should be evaluated using trial components, and if the relationship is improper, it should be corrected before keel slot preparation.

Unroofing osteotomy for dissociated tibial intramedullary magnetic rod during implant removal: a case report.

The PRECICE® intramedullary rod (NuVasive, San Diego, CA) utilizes multiple telescopic components to magnetically drive limb lengthening. These devices are routinely explanted after desired growth correction is met. To the author's knowledge, this is the first description of an osteotomy assisted extraction of a disassociated tibial magnetic lengthening rod. A 17-year-old girl with fibular hemimelia and resolved left tibial length discrepancy after successful surgical lengthening underwent a complex implant removal approximately seven years after regenerate consolidation. During implant removal, the telescopic portion of the rod remained lodged in the tibial medullary canal and a subsequent unroofing osteotomy of the tibia was performed. Tibial limb length discrepancies are oftentimes corrected with complex implants comprised of multiple fragile components that are routinely explanted. During the unfortunate event of a telescopic intramedullary rod dissociation, an unroofing osteotomy can be successfully performed to removal all implant components.

Functional and radiological outcomes after treatment of congenital pseudarthrosis of the tibia using the Ilizarov technique: a retrospective single-center study.

BACKGROUND: Congenital pseudarthrosis of the tibia (CPT) is a challenging problem in orthopedic practice, with high rates of non-union, refracture, and residual deformities. After union, long-term follow-up is required to manage late post-union complications. This study aimed to assess the outcomes of the Ilizarov technique in the management of CPT. MATERIALS AND METHODS: This retrospective study included patients with CPT treated with the Ilizarov method between 2005 and 2018. Intramedullary rods were used in 9 cases and iliac bone graft was used in 12 cases. An orthosis was applied till the end of follow-up in all cases. The American Orthopaedic Foot and Ankle Society (AOFAS) scale was used for the evaluation of the functional outcomes. RESULTS: This study included 16 patients, 11 males and 5 females, with an average age of 5.4 ± 2.8 years. Seven cases had multiple previous surgeries. Six patients had neurofibromatosis. The mean follow-up period was 5.8 ± 3.4 years. The average AOFAS score improved significantly from 47.5 ± 7.6 preoperatively to 78.9 ± 8.9 at the latest follow-up. Union was achieved in 15 cases, and persistent non-union occurred in one case. The clinical results were excellent in one patient, good in seven cases, fair in 6, and poor in 2 cases. The radiological results were excellent in one patient, good in seven cases, fair in seven, and poor in one case. CONCLUSIONS: The Ilizarov technique combined with intramedullary rod and primary or secondary bone graft provides a high union rate of CPT and can achieve simultaneous effective management of problems related to pseudarthrosis, including non-union, deformity, limb shortening, and adjacent joint contracture and subluxation. Level of evidence Level IV.

Single stage open reduction, intramedullary rod, bone grafting, and plate fixation for managing adolescent midshaft femoral fracture non-union, report of two cases.

Although rare, long bones fracture non-union in pediatric and adolescent patients is still being reported. It poses a challenge for the trauma surgeons, although principles for adult patient management apply to pediatrics and adolescents; however, there is no standard protocol to deal with such situations. We report two male adolescent patients, 11 and 12 years old, presented with non-united midshaft femoral fracture non-union after being multiply operated on. One patient was diagnosed with a septic non-union, while the other had an atrophic type. Both were treated following the same technique of open surgery where debridement and refreshing of the fracture site were performed, followed by initial fixation using an intramedullary rod, the biological environment was then enhanced by the addition of autologous iliac bone graft, and the fixation was finalized using a 4.5 dynamic compression plate. Both patients achieved complete fracture union and excellent functional outcomes by the last follow up. Adolescent patients presented with multiply operated non-united femoral fracture could be successfully treated using the described technique. It improves the mechanical and biological environment with the advantage of being a single-stage surgery.

Spacer Block Technique Was Superior to Intramedullary Guide Technique in Coronal Alignment of Femoral Component after Fixed-Bearing Medial Unicompartmental Knee Arthroplasty: A Case-Control Study.

Backgrounds and Objectives: The spacer block technique in unicompartmental knee arthroplasty (UKA) has still a concern related to the precise position of the component in the coronal and sagittal planes compared to intramedullary guide technique. The purposes of this study were to explore whether the spacer block technique would improve the radiological alignment of implants and clinical outcomes compared with the outcomes of the intramedullary guide technique in fixed-bearing medial UKA. Materials and Methods: In total, 115 patients who underwent unilateral, fixed-bearing medial UKA were retrospectively reviewed and divided into group IM (intramedullary guides; n = 39) and group SB (spacer blocks; n = 76). Clinical assessment included range-of-motion and patient-reported outcomes. Radiological assessment included the mechanical femorotibial angle, coronal and sagittal alignments of the femoral and tibial components, and coronal femorotibial congruence angle. Results: All clinical outcomes showed no significant differences between groups. The coronal femoral component angle was valgus 2.4° ± 4.9° in IM group and varus 1.1° ± 3.2° (p < 0.001). In group IM, the number of outlier in coronal femoral component angle (<−10° or 10°<) was 3 cases, while in group SB, there was no outlier (p = 0.014). The coronal femorotibial congruence angle was significantly less in group SB (mean 1.9°, range, −3.2°~8.2°) than in group IM (mean 3.4°, range, −9.6°~16.5°) (p = 0.028). Conclusions: In the group SB, the coronal alignment of femoral component was closer to neutral, and outlier was less frequent than in the group IM. The spacer block technique was more beneficial in achieving proper coronal alignment of the femoral component and congruence of femorotibial components compared to the intramedullary guide technique in fixed-bearing medial UKAs.

Efficacy of the "Eiffel tower" double titanium elastic nailing in combined management of congenital pseudarthrosis of the tibia: preliminary outcomes of 17 cases with review of literature.

BACKGROUND: Difficulty in obtaining union, recurrent fractures, and residual deformities remain the problems challenging the management of congenital pseudarthrosis of the tibia (CPT). We applied the "Eiffel Tower" double titanium elastic nails (TENs) in the existing combined approach, which takes advantages of TEN's mechanical stability with the protection against refracture, Ilizarov's high fusion rate with alignment control and the biologic environment provided by bone grafting for bony union. The results of this procedure are presented and discussed. METHODS: Seventeen patients with CPT treated by combined surgery including pseudarthrosis resection, the "Eiffel Tower" double TENs technique, autogenous iliac bone grafting, and Ilizarov fixation between 2013 and 2019 were retrospectively investigated. Signs of bone union, limb length discrepancy (LLD), rate of refracture, and degree of residual deformities were reviewed. The AOFAS Ankle Hindfoot scale and measurement of ankle motion were used to evaluate ankle function. The mean follow-up time was 40.5 (11 to 91) months. RESULTS: The mean age at index surgery was 6.2 (2.5 to 15) years. Union of the pseudarthrosis was achieved in 100% of cases. Among them, 15 (88.2%) patients obtained union of the pseudarthrosis on the first attempt (primary union). The average time to primary union was 3.8 (2 to 6) months. The rest 2 cases achieved union after additional surgeries (secondary union). In terms of complications, refracture occurred in 2 patients (11.8%) and 4 patients (23.5%) developed pin infection. The mean limb length discrepancy at the final follow up was 33.4 (6-141) mm. The average AOFAS score improved from 38.2 (27 to 51) pre-operatively to 77 (63 to 87) post-operatively (p < 0.01). CONCLUSIONS: The "Eiffel Tower" double TENs technique is an ideal intramedullary fixation method in the surgical treatment of CPT. The combination of TENs technique with bone grafting and Ilizarov fixation has the advantages of early bone union, less injury on metaphysis, and early functional recovery. LEVEL OF EVIDENCE: Level IV.

Flexible versus standard intramedullary rod in posterior stabilized primary total knee arthroplasty: protocol for a randomized controlled trial.

BACKGROUND: In total knee arthroplasty (TKA) a flexible intramedullary rod can be used to account for sagittal bowing of the distal femur. Although patients report better post-operative functional outcome when the flexible rod was used, it is unknown how the use of the flexible rod affects the placement of the femoral TKA component, and how this relates to activities of daily living. It is expected that the use of the flexible rod will result in a more flexed femoral component, a larger patellar tendon moment arm, and consequently in better functional outcome. The goal of this study is to compare the flexible rod to the standard intramedullary rod in primary TKA in terms of fit of the TKA, functional outcome, and sizing of the femoral component. METHODS: A single-blind randomized controlled trial with two groups (flexible vs standard rod), with patients blinded for group allocation, and 2 years post-operative follow-up. The fit of the TKA is quantified by two parameters: (1) the flexion angle of the TKA in the sagittal plane and (2) the sagittal profile of the distal femur compared between the pre-operative bone and the TKA. Both parameters are calculated in 3D volume images obtained using fluoroscopy. Functional outcome will be measured using (1) the timed Get-up and Go test (2), the stair climbing test (3), knee power output, and (4) patient and clinician reported outcomes. Different parameters will be measured during the TKA procedure to account for the invisibility of cartilage in the 3D volumes and to study if the amount of bone removed during the procedure is affected by group allocation. DISCUSSION: The sagittal fit of TKA is not a standardized outcome measure. We discuss our choice of parameters to define the sagittal fit (i.e., flexion angle and sagittal profile), our choice for the parameters we measure during the TKA procedure to account for the lack of cartilage thickness in fluoroscopy, and our choice for the parameters to study if the amount of bone removed during the procedure is affected by group allocation. Lastly, we discuss the merits of this planned trial. TRIAL REGISTRATION: Netherlands Trial Register, 4888 , registered 30 March 2015. https://www.trialregister.nl/trial/4888.

Optimal Sagittal Insertion Depth and Direction of Femoral Intramedullary Rod in Total Knee Arthroplasty in Chinese Osteoarthritis Patients.

OBJECTIVE: To identify the optimal femoral intramedullary rod insertion depth and direction on the sagittal plane in total knee arthroplasty (TKA) of Chinese osteoarthritis (OA) patients. METHODS: From January to December 2019, CT data were collected for 85 consecutive entire lower extremity Chinese OA patients. A three-dimensional method was used to simulate intramedullary rod penetration. The intramedullary rods were inserted toward the anterior (TA), center (TC), and posterior (TP) of the femoral canal, respectively. Four penetration depths of 150, 200, 250, and 300 mm from the joint line were set. The intersection angle was measured between the simulated intramedullary rod and the mechanical axis of the femur (FMA) on the sagittal plane. RESULTS: Our study included 85 Chinese OA patients: 46 women, with a mean age of 65.7 ± 8.4 years (range, 51-85 years) and 39 men, with a mean age of 65.6 ± 8.1 years (range, 46-86 years). The intersection angle between the FMA and the femoral anatomical axis was smaller in men, 2.4° ± 1.6° (range, 0°-4.8°), than in women, 3.5° ± 2.3° (range, 0.7º-8.2°), with a significant statistical difference (P < 0.01). In the comparison of the intersection angle between the simulated intramedullary rod and the FMA, there was no statistical difference between TA200 and TC200 in women (P > 0.05). The proportions were up to 91% and 96% of TA200 at 0°-3° and 0°-5° intervals, respectively, but just 63% and 78% in TC200. In TA150, 76% of intersection angles were greater than 5°. Only approximately 60% in TA250 and TA300 were within the 0°-5° interval and 40% were less than 0°. Only 57% of intersection angles in TC150 were in the 0°-3° interval. TC250, TC300, and TP150 were mostly below 0°. In men, there were statistical differences between all groups. All intersection angles were greater than 5° in TA150. TA200 and TA250 were mostly greater than 5° (87% and 59%, respectively) and 72% of intersection angles were within 0°-5° interval in TA300. TC150 had 92% of intersection angles within the 0°-5° interval but only 62% between the 0° and 3° interval. In the TC200, up to 90% and 97% were within 0°-3° and 0°-5° intervals, respectively. TC300, TP150, and TP200 were mostly below 0°. CONCLUSION: We described an innovative method for rapidly, simply, and accurately identifying the sagittal insertion depth and direction of the femoral intramedullary rod in TKA, which can optimize the position of the femoral prosthetic component on the sagittal plane in TKA.

Length of stay and 30-day readmissions after isolated humeral shaft fracture open reduction and internal fixation compared to intramedullary nailing.

INTRODUCTION: Open reduction with internal fixation (ORIF) and intramedullary nailing (IMN) have similar union rates for treating humerus shaft fractures, but IMN leads to increased incidence of shoulder impingement and reoperation. The difference in 30-day readmission rate and length of stay (LOS) between these procedures is unknown. The objective of the study was to compare 30-day unplanned readmissions and length of stay between humeral shaft fractures fixed with either ORIF or IMN. METHODS: The nationwide readmissions database (NRD) was queried for patients with humeral shaft fractures treated with ORIF or IMN between 2015-2016. IMN cases were propensity matched to ORIF cases based on demographic and co-morbid variables. Multivariable logistic regression determined if treatment modality was an independent risk factor for 30-day readmission or length of stay >3 days. RESULTS: There were 406 patients treated with IMN matched to 406 patients treated with ORIF. The 30-day readmission rate was 6.4% for IMN and 4.9% for ORIF (p = 0.45), and the median LOS was 3 days for each group (p = 0.45). Congestive heart failure (CHF)(OR=2.7, p = 0.04), depression (OR=3.3, p = 0.0008), and electrolyte abnormality (OR=3.6, p = 0.0003) were independent risk factors for readmission. Older age (OR=1.02, p = 0.03), CHF (OR=2.4, p = 0.03), electrolyte abnormality (OR=2.6, p = 0.0001), obesity (OR=2.8, p<0.0001), Medicaid (OR=2.1, p = 0.04), discharge to a facility (OR = 5.2, p<0.0001), discharge with home health services (OR=2.4, p = 0.0003), and open fracture (OR=2.3, p = 0.01) were independent risk factors for LOS >3 days. Procedure (ORIF vs. IMN) was not a predictor of 30-day readmission or LOS >3 days. CONCLUSION: Comorbid conditions are risk factors for 30-day readmission and increased LOS. Comorbidity, discharge disposition, and open fractures are risk factors for increased LOS. Treating humeral shaft fractures with either ORIF or IMN did not affect readmission or length of stay.

An accelerometer-based navigation did not improve the femoral component positioning compared to a modified conventional technique of pre-operatively planned placement of intramedullary rod in total knee arthroplasty.

INTRODUCTION: Although the most commonly used method of femoral component alignment in total knee arthroplasty (TKA) is intramedullary (IM) guides, this method demonstrated a limited degree of accuracy. Because of the femoral anterior bowing, the tip of the guide rod will impinge on the anterior cortex if a long rod is inserted. We hypothesized that the pre-operative planned insertion depth of the rod could increase the accuracy of the femoral component positioning in conventional TKA (modified conventional technique). Accelerometer-based, portable navigation device has been postulated to have better accuracy than conventional TKA in component positioning. The purpose of this study was to compare the post-operative femoral component alignment of TKA using the modified conventional technique with the accelerometer-based navigation. MATERIALS AND METHODS: Fifty-five knees underwent TKA using the modified conventional technique and femoral component positioning was compared with 55 knees performed using the accelerometer-based navigation device. The femoral component alignment was evaluated with a CT-based three-dimensional software. RESULTS: The mean absolute deviation from targeted alignment in the sagittal plane was significantly less in the modified conventional cohort than in the accelerometer-based navigation cohort (1.1° vs 2.6°, P < 0.001). In the modified conventional cohort, 96.4% had an alignment within 3° of a targeted angle in the coronal plane (vs 89.1% with the accelerometer-based navigation, P = 0.14), and 96.4% in the sagittal plane (vs 74.5% with the accelerometer-based navigation, P < 0.001). CONCLUSION: The modified conventional technique is a simple and equal to or more accurate method than the accelerometer-based navigation in positioning the femoral component in TKA at a mid-volume hospital.

Biocompatibility of polyamide 12 intramedullary rod after humeral consolidation in white Plymouth Rock birds / Biocompatibilidade de haste intramedular bloqueada de poliamida 12 após consolidação óssea umeral em aves Plymouth Rock branca

Technological and tissue engineering have enabled available, biologically inert, and low cost materials to be considered as viable alternatives in the surgical treatment of long bone fractures in birds. The aim of this study was to microscopically analyse osteotomized humerus of birds following the insertion of solid laser-sintered polyamide 12 rods in order to detect foreign body reaction and, thus, verify the bioinert property of the material in the bone fracture environment. Polyamide 12 intramedullary rods were inserted into the osteotomized humerus of 10 birds (white Plymouth Rock) and blocked using 2mm diameter cortical screws of varying lengths. The birds were operated at 60 days of age and monitored post-operatively for three months. Animals were euthanized at 150 days old and samples of the operated humerus collected for immunohistochemistry, light and scanning electron microscopy analysis. Results show bone consolidation without rejection of the implant and absence of inflammatory cells. Vascular Endothelial Growth Factor (VEGF) was expressed in the endothelial cells of the blood vessels at the site of the newly formed bone surrounding the implant, indicative of local angiogenesis. There was no bone growth on the surface of the rod; however, the implant did not interfere with the circumjacent bone repair. Thus, the findings of this study corroborate with the literature in characterizing polyamide as a bioinert material and, under the studied conditions, it can be concluded that polyamide 12 intramedullary rod is biocompatible and provides adequate bone consolidation in humeral fractures with no signs of rejection.(AU)

Com o desenvolvimento tecnológico e crescimento da engenharia de tecidos, o uso de materiais disponíveis, bioinertes e debaixo custo pode ser alternativa viável para o tratamento cirúrgico de fraturas em ossos longos nas aves. O objetivo do estudo foi realizar avaliação microscópica óssea após a implantação de haste maciça de poliamida, implantada em úmeros osteotomizados de galinhas para detectar reação do tipo corpo estranho, verificando a propriedade "bioinerte" do material no ambiente de fratura óssea. Foram utilizados 10 galos (Plymouth rock branca) e implantou-se a haste perfazendo o bloqueio das mesmas com parafusos corticais de 2 mm de diâmetro com comprimentos de acordo com a necessidade. As aves foram operadas aos 60 dias de vida e o acompanhamento pós-operatório ocorreu por três meses. Após a eutanásia, foram realizadas coletas do úmero operado (local de consolidação óssea) paraexame histopatológico, imuno-histoquímico e de microscopia eletrônica de varredura. Os resultados demonstraram consolidação óssea, sem presença de rejeição do material, com ausência de células inflamatórias. A neoformação óssea ao redor do implante expressou VEGF (fator de crescimento endotelial vascular) nas células endoteliais dos vasos sanguíneos caracterizando angiogênese no local. Na região de interface de tecido ósseo com a poliamida não foram observadas micro fraturas. Não houve crescimento ósseo na superfície da haste, porém a mesma não atrapalhou o reparo ósseo circunjacente. Assim, esse estudo corrobora com a literatura caracterizando a poliamida como um material bioinerte, e nas condições estudadas pode-se concluir que o uso da haste intramedular de poliamida 12 proporcionou consolidação óssea nesse modelo biológico nesse tipo de fratura, não havendo indícios de induzir rejeição.(AU)

Deviation of femoral intramedullary alignment rod influences coronal and sagittal alignment during total knee arthroplasty.

BACKGROUND: An intramedullary (IM) rod is used to resect the distal femur vertically to the femoral mechanical axis in the coronal plane in many cases of total knee arthroplasties (TKA). The valgus angle between the mechanical axis and the anatomical axis of the distal femur is estimated preoperatively. It is known the deviation of the IM rod in the femoral canal could influence the femoral component alignment. However, there is no published data regarding how many degrees of deviation to make with the IM rod. The purpose of this study is to measure each deviation of the IM rod using three-dimensional (3D) computer simulations. METHODS: Preoperative CT scans on 30 knees undergoing TKA were studied. The line connecting central points at 10 and 20 cm proximal from the intercondylar notch was defined as the anatomical axis and the point at which the anatomical axis intersects the surface of the distal femur was considered as the entry point of the IM rod. The medio-lateral (ML) and antero-posterior (AP) deviations between the anatomical axis and the IM rod were measured. RESULTS: The ML and AP deviations were 0.8 and 1.1° on average. The IM rod was deviated medio-laterally more than 1.0° in three knees (10%). CONCLUSION: Surgeons should note the ML difference of the resection thickness of the distal femur for coronal alignment. If the ML difference varies greatly from the preoperative planning, they need to adjust at most 1.0° of valgus angle to achieve the appropriate coronal alignment. Level of evidence III, Therapeutic.

Biomechanical Comparison of Intramedullary Fibular Nail Versus Plate and Screw Fixation.

BACKGROUND: Clinical evidence has shown that percutaneous ankle fracture fixation using an intramedullary fibular nail results in good outcomes at 1 year and reduces postoperative wound complications in patients with vulnerable soft tissues. Confirmatory biomechanical evidence of its strength when used to secure a supination external rotation (SER) IV (AO/OTA 44B-type) fracture, compared with traditional plates and screws, is currently lacking. METHODS: Twenty cadaveric lower limbs (10 cadavers) had a SER IV injury surgically created. One leg was randomly allocated to fixation with a fibular nail and the other a lag screw and neutralization plate. A mechanical testing apparatus subjected all lower limbs to an axially loaded supination external rotation force to failure. RESULTS: Superior ultimate torque to failure was demonstrated with a trend toward increased energy absorption in the nail group ( P = .28 and .07, respectively). No difference was demonstrated in angle at failure. All specimens in the plate group lost reduction at the bone-metal interface as a result of screw pullout. In contrast, all specimens in the nail group failed because of disruption of the lateral ligaments. CONCLUSIONS: This study demonstrated greater torque to failure and better maintenance of the fibular construct for the intramedullary fibular nail compared to standard plating. CLINICAL RELEVANCE: These results suggest that the previously documented clinical benefits of the fibular nail are complemented by biomechanical properties that compare favorably to standard techniques.

A biomechanical comparison study of a modern fibular nail and distal fibular locking plate in AO/OTA 44C2 ankle fractures.

BACKGROUND: A lateral approach with open reduction and internal fixation with a plate is a very effective technique for the majority of distal fibular fractures. However, this open approach for ankle fixation may be complicated by wound dehiscence and infection, especially in high-risk patients. An alternative to plating is an intramedullary implant, which allows maintenance of length, alignment, and rotation and which allows for decreased soft tissue dissection. While there has been clinical data suggesting favorable short-term outcomes with these implants, there is no current biomechanical literature investigating this technology in this particular fracture pattern. This study sought to biomechanically compare an emerging technology with an established method of fixation for distal fibular fractures that traditionally require an extensive exposure. METHODS: Ten matched cadaveric pairs from the proximal tibia to the foot were prepared to simulate an Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) 44C2 ankle fracture and randomized to fixation with a distal fibular locking plate or intramedullary fibular rod. A constant 700-N axial load was applied, and all specimens underwent testing for external rotation stiffness, external rotation cyclic loading, and torque to failure. The syndesmotic diastasis, stiffness, torque to failure, angle at failure, and mode of failure were obtained from each specimen. RESULTS: There was no significant difference in syndesmotic diastasis during cyclic loading or at maximal external rotation between the rod and plate groups. Post-cycle external rotation stiffness across the syndesmosis was significantly higher for the locking plate than the fibular rod. There was no significant difference between the rod and plate in torque at failure or external rotation angle. The majority of specimens had failure at the syndesmotic screw. CONCLUSIONS: In the present cadaveric study of an AO/OTA 44C2 ankle fracture, a modern fibular rod demonstrated less external rotation stiffness while maintaining the syndesmotic diastasis to within acceptable tolerances and having similar failure characteristics.

Percutaneous rotational osteotomy of the femur utilizing an intramedullary rod.

The purpose is to describe the technique and report the results and complications of percutaneous femoral rotational osteotomy, secured with a trochanteric-entry, locked intramedullary rod, in adolescents with femoral anteversion. Our series comprised an IRB approved, retrospective, consecutive series of 85 osteotomies (57 patients), followed to implant removal. The average age at surgery was 13.3 years (range 8.8-18.3) with a female-to-male ratio of 2.8:1. The minimum follow-up was 2 years. Eighty-three osteotomies healed primarily. Two patients, subsequently found to have vitamin D deficiency, broke screws and developed nonunions; both healed after repeat reaming and rod exchange and vitamin supplementation. Preoperative symptoms, including in-toeing gait, tripping and anterior knee pain or patellar instability, were resolved consistently. We did not observe significant growth disturbance or osteonecrosis. We noted a 12.5 % incidence of broken interlocking screws; this did not affect the correction or outcome except for the two patients mentioned above. This prompted a switch from a standard screw (core diameter = 3 mm) to a threaded bolt (core diameter = 3.7 mm). These results have led this technique to replace the use of plates or blade plates for rotational osteotomies.

Vascularized Pedicled Fibula Onlay Bone Graft Augmentation for Complicated Tibiotalocalcaneal Arthrodesis With Retrograde Intramedullary Nail Fixation: A Case Series.

Tibiotalocalcaneal arthrodesis stabilized with retrograde intramedullary nail fixation is associated with a high incidence of complications. This is especially true when performed with a bulk structural allograft and poor soft tissue quality. In select high-risk limb salvage cases, we have augmented tibiotalocalcaneal arthrodesis procedures stabilized using retrograde intramedullary nail fixation with a vascularized pedicled fibular onlay bone graft. We present the data from 10 such procedures with a mean follow-up period of 10.9 ± 5.4 (range 6 to 20) months involving 10 patients (9 males and 1 female). The etiology was avascular osteonecrosis of the talus and/or distal tibia and a resultant large volume cavitary bone defect (8 ankles), severe equinocavovarus contracture (1 ankle), and failed total ankle replacement (1 ankle). A frozen femoral head bulk allograft was used twice, a whole frozen talus allograft once, and a freeze-dried calcaneal allograft once. The fibula was mobilized with intact musculoperiosteal perforating branches of the peroneal artery as a vascularized pedicle onlay bone graft fixated with a screw and washer construct. The mean fibular graft length was 10.2 ± 2.3 cm. The mean interval to radiographic fusion was 2.6 ± 0.6 months and to weightbearing was 3.1 ± 1.4 months. Two stable bulk allograft-host bone and fibular graft-host bone nonunions occurred after intramedullary nail hardware failure. Tibiotalocalcaneal arthrodesis augmented by vascularized pedicled fibular graft stabilized with retrograde compression intramedullary nail fixation offers a reliable option for complex salvage situations when few other options exist.