Expandable Intramedullary Nail Research Articles

Biomechanical Principles of Intramedullary Nails in Veterinary and Human Medicine.

Intramedullary nails are specialized metal rods inserted into the medullary cavity of a fractured bone and secured to reduce load on the fracture site, provide stability, and permit healing. The purpose of this review is to highlight the biomechanics of orthopaedic intramedullary nailing, as well as discuss the biomechanical considerations that have shaped implant design and fixation technique in veterinary and human medicine. Relevant studies were included from the PubMed database and Google Scholar for discussion on the basic science and nail design of intramedullary nails. Implant design and implementation continues to progress, with new innovative designs currently under investigation. A lack of consensus remains on the superior implant material. Recent studies, particularly in human populations, have supported the use of reaming based on reoperation rates, nonunion rates, and dynamization. Design modifications, such as the expandable intramedullary nails and angle-stable interlocking designs, have been investigated as methods of improving cortical contact and resisting torsional stress. Intramedullary nailing is a valuable stabilization technique for long bone fractures across a variety of species. The technology continues to undergo design improvements in both veterinary and human medicine.

Comparison of Expandable and Locked Intramedullary Nailing for Humeral Shaft Fractures.

IntroductionIn this study, we clinically and radiologically investigated whether the application of expandable nails for surgical treatment of humeral shaft fractures has an advantage over locked intramedullary nails.MethodsPatients treated with intramedullary fixation due to humeral shaft fractures in our clinic were investigated retrospectively. Patients with fractures of type 12A and 12B according to the AO classification in the middle 1/3 shaft region of the humerus were divided into two groups as those receiving fixation with expandable nails and with locked intramedullary nails. The union rate, union time, Q-DASH scores, duration of surgery, and complication rates were statistically compared between the two groups.ResultsThe study included 38 patients with clinical follow-up from among 47 patients; 20 patients received fixation with locked intramedullary nails and 18 with expandable nails. The mean age of the patients was 56.92 (19-91) years and 53% (n=20) were men while 47% (n=18) were women. During statistical evaluation, a statistically significant difference was found between the groups for union (100% and 72.2%) and complication rates (6% and 13%). More union and lower complication rates were found in patients treated with locked intramedullary nails. In comparing the mean of surgical times (71.1 and 30.2 min), expandable nails had a shorter surgical time. However, there was no statistically significant difference between the union time and Q-DASH scores between the two groups.ConclusionLocked intramedullary nails are a better fixation method than expandable nails due to the low complication rate and high rate of union. However, due to shorter surgery time, expandable nailing is an alternative method in limited cases.

Numerical evaluation of the mechanical properties of a novel expandable intramedullary nailing: A new alternative to standard interlocking nailing

There has been a great effort in preventing the disadvantages of distal locking in intramedullary nailing to date. From this scope, a novel expandable nail fixation eliminating distal locking screws has been designed. The primary aim of this numerical parametric study is to investigate mechanical behavior of expandable nail fixation on the fractured femur model under different contact parameters which are effective in maintaining the nail position and to specify the appropriate values of these contact parameters for a safe fixation. The second aim is to compare mechanical behavior of the expandable nail fixation with the standard interlocking nail fixation. The expandable nail has three wedges which are responsible for distal fixation by compressing the medullary canal in the radial direction. 4th generation Sawbones femur model was used as bone model. A transverse osteotomy with 20 mm gap was created to simulate a subtrochanteric fracture. The fixations have been examined under axial compression with 1200 N and torsion with 7 Nm. In the parametric study, the tightening torque and static friction coefficient in wedge-canal contact were selected as contact parameters. The outputs were stiffnesses of the fixations, equivalent von-Mises stress distribution on the models, and load sharing between the canal and distal locking elements. The results of the parametric study showed that the model with the tightening torque of 3 Nm and friction coefficient of 0.7 was the safest. The load borne by wedges is generally prone to increase with increased tightening torque and friction coefficient. The both fixations showed close stiffness and stress values. The tightening torque of the wedge locking mechanism is directly effective in maintaining the nail position constant in canal, and the safety of the fixation is better ensured with increased tightening torque but stress states on bone must be carefully evaluated. The expandable nail provided comparable results to standard interlocking nails with respect to the fixation stiffness, stress, and contact forces. The expandable nailing may be evaluated as an alternative in the fractures of long bones in the case that the numerical results are supported by future experimental studies.

Comparison of antegrade locked intramedullary nails and retrograde expandable intramedullary nails in distal femur diaphysis fractures

Comparison of antegrade locked intramedullary nails and retrograde expandable intramedullary nails in distal femur diaphysis fractures

Extramedullary Motorized Lengthening of the Femur in Young Children.

Limb lengthening by distraction osteogenesis is now achievable via motorized intramedullary devices, mitigating many complications of lengthening by external fixation. In young patients, antegrade intramedullary nailing of the femur risks avascular necrosis of the femoral head. A method of extramedullary placement of a motorized expandable intramedullary nail has been employed by the senior author to safely achieve femoral lengthening without the use of an external fixator in young patients. Eleven skeletally immature patients with lower limb length discrepancy were reviewed who underwent extramedullary placement of a magnetic, expandable intramedullary nail for lengthening of the femur. Surgical details, lengthening parameters, and complications were reviewed and classified according to the modified Clavien-Dindo Classification. Average lengthening was 32.3 mm (range: 27 to 40 mm) comprising an average 14.8% of femoral segment length. The average lengthening duration was 6.3 weeks, and average full weight-bearing began at 12.6 weeks. All but 1 patient underwent early removal of the device at an average of 4.5 months, and 5 had immediate plating of the femur. Complications rates were comparable to other methods of femoral lengthening, including varus or procurvatum through the regenerate, and unplanned reoperation in 3 of 11 cases. Preoperative considerations included careful planning of implant length due to short femoral segments and protection of the knee joint from contracture or iatrogenic instability. Extramedullary placement of a magnetic expandable intramedullary lengthening nail can achieve lengthening of the femur without the use of external fixation. Considerations with this technique include careful planning of implant length relative to trochanteric-physeal distance, protection against knee subluxation during lengthening, and mitigating deformity of the regenerate. Off-label, extramedullary use of these devices can be considered to decrease the burdens of external fixation in young children. The technique begs the advent of future all-internal technology specifically designed for safe limb lengthening in this age group. Level IV-retrospective case series.

Fixation of unstable distal radius fractures by using expandable Intramedullary nailing system in adult patients

Objective:To present our experience on intramedullary nailing device Sonoma Wrx (Sonoma Orthopedic Products Inc., Santa Rosa, CA, USA) used for internal fixation of extra-articular or simple intra-articular distal radius fractures in adult population.Methods:This study was conducted from February 2011 to October 2016. A total of 48 patients (mean age 47.3±5.6 years, 35.4% females) with distal radius fracture, who underwent intramedullary distal radius fixation by using Sonoma Wrx were included in this retrospective study. Clinical outcome measures (range of motion [ROM], visual analog scale [VAS]), functional outcomes (Disabilities of the Arm, Shoulder and Hand [DASH] score and Gartland-Werley score), radiographic scores (Stewart score) and parameters (radial inclination, volar tilt, radial height, radio-ulnar variance) and complications were evaluated.Results:The total surgery time was 24.3±2.3 minutes. Patients were followed up for 24.7±3.4 weeks. Complete fracture union was obtained at 5.5±0.9 weeks. The postoperative low VAS pain score (1.6±0.93) and high ROM values (76.7° for extension, 78.5° for supination, 80.1° for flexion, and 82.3° for pronation) indicated a very good clinical outcome. DASH score of 8.3±1.5 and Gartland-Werley score of 2.8±4.1 showed good functional outcome. The radiographic Stewart score was 1.0±1.2. Radial inclination, volar tilt, and radial height significantly increased (p<0.001), and radio-ulnar variance decreased (p=0.001) with surgery. No postoperative complication was recorded in 40 patients (83.3%).Conclusions:Sonoma Wrx, which is an expansible intramedullary elastic locking distal radius nail, offers a good alternative technique for internal fixation of unstable distal radius fractures with the advantage of minimum soft-tissue dissection and related postoperative complications.

Comparison of expandable intramedullary nail versus locked compression plate for treatment of humeral shaft fractures

Objective To compare the effectiveness of expandable intramedullary nail(EIMN) versus locked compression plate (LCP) in the treatment of humeral shaft fractures of AO types A and B. Methods The clinical data were retrospectively analyzed and compared of the 44 humeral shaft fractures which had been treated between May 2012 and February 2016. There were 26 men and 18 women, from 23 to 66 years of age (average, 41.5 years). By AO classification, 22 cases were type 12-A and 22 type 12-B. EINM was used in 22 patients with an average age of 41.3±11.7 years and LCP in 22 ones with an average age of 41.6±10.3 years. The 2 groups were compared in terms of intraoperative blood loss, operative time, hospital stay, union time, union rate, Constant and Mayo scores at the final follow-ups, and complications as well. Results The 2 groups were compatible without significant differences in the preoperative demo-graphic data (P >0.05). All the 44 patients were followed up for 10 to 18 months (average, 12 months). The intraoperative blood loss (76.4±18.66 mL), operative time (69.1±13.2 min), incision length (5.8±1.5 cm) and union time (13.2±8.4 w) in the EIMN group were significantly better than those in the LCP group (138.6±39.4 mL, 96.4±14.2 min, 8.5±1.4 cm and 18.4±6.6 w, respectively) (P< 0.05). There was also a significant difference between the 2 groups in the total complication rate[18.2%(4/22) versus 50.0% (11/22)] (P< 0.05). No deep infection or should pain was observed in either group. Conclusions In the treatment of humeral shaft fractures of AO types 42-A and 42-B, compared with LCP, EIMN may have ad-vantages of less intraoperative blood loss, operative time, union time and complications. The 2 methods are similar in hospital stay and final functional recovery of the should joint. Key words: Humeral fractures; Fracture fixation, internal; Bone nails; Bone plates

Results of expandable intramedullary nailing in femoral shaft fractures

Objective: To evaluate the use and results of expandable intramedullary nails applied to adult AO-32A and 32B femoral shaft fractures. Patients and methods: This retrospective study included 71 patients (25 females, 46 males; mean age 37.2 years, range 17-83 years) applied with expandable intramedullary nailing treatment for AO-32A and 32B femoral shaft fractures, with at least a 1-year follow-up period. Operating time was recorded from the operating notes. At the final follow-up examinations, patients were evaluated clinically according to the Thoresen criteria and lower limb length differences were recorded. Bone union and continuity of reduction were examined radiologically. Results: 64 nails were applied with an open surgical approach and 7 nails with a closed surgical approach. Operating time was mean 78 mins (range, 60-135 mins). In 63 (88.7%) cases, bone union was delayed and the mean time to union was 18 weeks (range, 13-32 weeks). According to the Thoresen criteria at the final follow-up examination, the results were very good in 51 (71.8%) cases, good in 12 (16.9%), fair in 6 (8.4%) and poor in 2 (2.8%). Shortness of 3cm was determined in 1 case, 2cm in 3 cases, 1cm in 1 case and <1cm in 2 cases. Anterior knee pain developed in 7 cases. The nail applied did not expand in 3 (4.2%) cases. In 15 (21.1%) cases, following inflation after application of the nail, expansion of the femur medulla developed around the fracture line and in 1 case this caused injury to the lateral circumflex femoral artery. Superficial infection was observed in 4 (5.6%) cases, which recovered with antibiotic treatment. Conclusion: As the application of expandable intramedullary nails is difficult and could cause complications, they should be used with limited indications.

Femoral midshaft fractures: expandable versus locked nailing.

Femoral midshaft fracture is one of the most common clinical injuries and is often caused by high-energy traffic accidents. Intramedullary nailings, plates, and external fixators are all used as treatment alternatives for a variety of patients depending on fracture location, displacement, comminution, soft tissue condition, and local tradition. Locked intramedullary nailing is currently the preferred treatment method for most diaphyseal fractures and has good clinical results. The goal of this study was to compare expandable and locked intramedullary nailing for the treatment of AO type 32A and 32B1 femoral midshaft fractures. The authors performed a retrospective analysis of 46 patients (33 men and 13 women; mean age, 32.3 years; range, 22-52 years) with femoral midshaft fractures who were divided into 2 groups-one treated with an expandable intramedullary nailing method and the other with a conventional locked intramedullary nailing. The 2 groups were compared with respect to operation time, fluoroscopic time, amount of estimated blood loss, hospitalization time, healing time, and complications. Patients were followed for at least 1 year. The results of this study showed that all of the patients achieved bone union within 12 to 24 months. Expandable nailing performed better than locked nailing in operation time, fluoroscopic time, amount of estimated blood loss, and healing time (P<.001). There was no difference in hospitalization time and no visible shortening or severe complications were observed in either group. Based on the results of this study, the expandable intramedullary nailing is an easy and effective treatment for AO type 32A and 32B1 diaphyseal femoral fractures.

Femoral Fixion Expandable Nail Implant Failure and Difficult Extraction

Intramedullary nailing is familiar to all orthopedic surgeons for treatment of long bone fractures. Removal of conventional intramedullary nails can be challenging in and of themselves. This case report describes difficulties encountered during extraction of an expandable intramedullary nail designed for use in fixation of long bones.

Results in the Treatment of Tibial Diaphyseal Fractures with Expandable Intramedullary Nails

Results in the Treatment of Tibial Diaphyseal Fractures with Expandable Intramedullary Nails

Results of midshaft clavicle fractures treated with expandable, elastic and locking intramedullary nails.

The aim of the study was to present the results of osteosynthesis with elastic expandable intramedullary nail for clavicle fractures. The study included 17 patients (11 males, 6 females; mean age 36.4 years, range: 21 to 54 years) who underwent surgery for a displaced clavicle fracture and had a shortening of more than 2 cm. The Constant Score and DASH (Disabilities of The Arm, Shoulder and Hand) scoring were used to determine the functional status of the patients. Mean operation time was 30.4 (range: 25 to 42) minutes and mean follow-up period was 10.3 (range: 8 to 19) months. Mean union time was 15.8 (range: 9 to 20) weeks. A superficial infection was treated with wound debridement and antibiotherapy in one patient. No patient suffered from neurovascular compromise, deep infection or implant irritation. Implant fracture developed at 2 months after surgery in one patient treated for Type B1 clavicle fracture and healed without any other intervention. There was no statistically significant shortening (p>0.05). In the final follow-up, the mean Constant Score was 94.3 (range: 86 to 97), and mean DASH score was 11.8 (range: 7.3 to 17.4). Expandable elastic locking intramedullary nail appears to provide minimal complication and high success rate for the surgical treatment of non-comminuted displaced clavicle shaft fractures. Additional studies with large series are necessary for further investigation.

Percutaneous femoral derotational osteotomy for excessive femoral torsion.

Femoral derotational osteotomy is an acceptable treatment for excessive femoral torsion. The described procedure is a minimally invasive single-incision technique based on an intramedullary saw that enables an inside-out osteotomy, preserving the periosteum and biological activity in the local bone and soft tissue. After the osteotomy is complete and correction is achieved, an expandable intramedullary nail is used to achieve immediate stability, without the need for locking screws. Indications, tips, and pitfalls related to this novel osteotomy technique are discussed.

Expandable intramedullary nails in lower limb trauma: a systematic review of clinical and radiological outcomes

This study systematically reviews the evidence-base for the use of expandable nails in the treatment of acute diaphyseal fractures of the lower limb. Both electronic and hand searches were undertaken of the published and grey literature to 1 December 2011. A total of 154 citations were identified, of which 15 were deemed suitable and assessed with the Critical Appraisals Skills Programme tool. A total of 625 nailing procedures were performed in 620 patients: 279 femoral and 346 tibial nails. The expandable nail was found to be significantly quicker to insert than interlocked nails (p < 0.05), and the total incidence of non-union or other complication was 13 and 14 % for expandable femoral and tibial nails, respectively. Notable complications with the expandable nail included fracture propagation on nail inflation in 2.5 % and post-operative shortening in 3.3 %. Device failure secondary to problems with the expansion mechanism was seen in 2.9 %. The rate of non-union and infection following expandable nailing was 3.1 and 1.4 %, respectively. Despite promising initial results, there remains a paucity of good quality studies to support the use of expandable nails over interlocked nails for the treatment of acute diaphyseal fractures of the lower limb.

T1.9 Treatment of humerus and tibia fractures with expandable intramedullary nails

T1.9 Treatment of humerus and tibia fractures with expandable intramedullary nails

PF8 Expandable intramedullary nailing: a new method in the treatment of femoral periprosthetic fractures

Introduction: High doses of ionizing radiation are used during surgeries such as interlocking intra-medullary nailing and minimally invasive plate osteosynthesis. So, excessive use of fluoroscopy is seen to be a feared procedure among orthopedic surgeons. DAP (Dose area product) values which shows the total radiation dose with the aid of preinstalled DAPmeters, can bemonitored on the recent fluoroscopic units in mGy·cm2 or mGy·m2. This value is a more reliable indicator than the fluoroscopy time. The aim of the study is to investigate the total fluoroscopic DAP values in interlocking intramedullary nailing operations and comparing the total values with other radiologic procedures. Materials and Methods: Between 2010 and 2012, nine patients underwent femoral locking intramedullary nailing operation in our institute. Total DAP values, fluoroscopy time and number of images were retrieved from the fluoroscopic unit’s HDD. We have also recorded the DAP values of postoperative direct roentgenograms which were taken with portable digital x-ray machine which has on-board DAP meter. While the mean operation time was 3.2 hours (2–4.2 hours), total fluoroscopy use was 1.6 minutes (0.8–3.1 minutes). Results: Total mean DAP value was resulted in 1720mGy·cm2 and total number of fluoroscopic images were 44 (16–82). The mean DAP for postoperative AP and lateral direct femur radiographs were 1790mGy·cm2 and 2100mGy·cm2 respectively. We have found the total fluoroscopic unit DAP values comparable with even AP or lateral direct radiograms. Conclusion: DAP value is more practical than the fluoroscopy time in monitoring the total radiation dose used in the orthopedic procedures. If properly adjusted preoperatively, fluoroscopic units are more reliable and safe than the direct radiographies. We recommend routineuse of fluoroscopy insteadof direct radiographies intraoperatively.

Sa3.9 Expandable intramedullary nailing for femoral fractures: our experience in the treatment of complications

Sa3.9 Expandable intramedullary nailing for femoral fractures: our experience in the treatment of complications

Clinical analysis of some serious bone fractures limbs

Objective To investigate the clinical treatment of multi-severe of long bone. Methods To observe 145 fractures of 76 patients with multi-severe comminuted fracture of long bone,and apply expandable intramedullary nailing, interlocking intramedullary nail fixation, plate fixation, external fixation, artificial joint replacement on these subjects respectively. Results The followed-up period were from 6 months to 21 months after operation, fracture union occurred in two to twelve months. Among all the 145 fractures, bone healing 122 (86. 2％), nonunion 8(5.5％) ,inalunion in 12 cases(8.3％ ). The average healing time:closed fractures (5.5 ± 1.5) months,and open fractures(6.8 ± 1.2 ) months. Expandable intramedullary nailing group, only 1 case of malunion. Interlocking nail group,only 2 cases of nonunion and malunion, and the incidence of nonunion malunion was significantly lower than that of external fixation group and the plate fixation group(P ＜0.05 ) ;In the external fixation group, the healing rate was significantly lower than plate fixation( P ＜ 0. 05) ,but the impact on the adjacent joints in external fixation group was much larger than the intramedullary nail group and the plate fixation group( P ＜ 0.05 ). Conclusion There was no uniform standard of how to select the treatment of long bone fracture currently, surgery should be selected according to the specific injuries of different treatment methods. Expandable intramedullary nailing, interlocking intramedullary nailing were new type of internal fixation material which developed in recent years, and there were fewer complications of the application of interlocking intramedullary nail fixation in fracture healing, and it worths further clinical application in the long bone fracture. Key words: Fractures ; Intramedullary pin; Fixation

Treatment of middle third humeral shaft fractures: minimal invasive plate osteosynthesis versus expandable nailing

The purpose of this study is to compare the results of middle third humeral shaft fractures treated with minimally invasive plate osteosynthesis (MIPO) with those treated with an expandable nail technique. Thirty-four patients with middle third humeral shaft fractures were retrospectively analyzed and divided into two groups: group A included 15 patients treated by MIPO and group B included 19 patients treated with an expandable intramedullary nail. The operation time, postoperative complications, time to fracture union, the UCLA End-Result score of the shoulder, and Mayo elbow performance index (MEPI) were recorded and compared. The mean operation time in group A was 108.3 ± 28.7 min and 85.0 ± 35.7 min in group B, a difference of 23.3 (27.4%) minutes (P 0.05). One case of delayed union was identified in group A. The mean UCLA End-Result score in group A was 34.2 ± 1.1 points (31–35 points)and 31.8 ± 2.6 points (26–35) in group B (t = 3.318 P = 0.002, P < 0.05). All the patients had excellent elbow functions. In surgical treatment of middle third humeral shaft fractures, MIPO appeared to offer advantages in terms of better shoulder and no iatrogenic radial nerve injuries, although technically more difficult and time consuming.

Humeral diaphyseal nonunions treated by interlocking or expandable intrameduilary nailing plus iliac bone grafting

Objective To discuss the efficacy of interlocking or expandable intramedullary nailing plus iliac bone grafting for treatment of humeral diaphyseal nonunion.Methods From June 1999 to May 2008, 27 cases of humeral diaphyseal nonunion, 14 males and 13 females, were treated in our department.The nonunions occurred at the upper-middle humerus in 6 cases, at the middle humerus in 16 cases and at the middle-lower humerus in 5 Cases. The patients had previously undergone operations for 1 to 4 times (average,2.3 times). Interlocking nailing was applied in 16 cases (including one case of close nailing and 5 cases of cable tension band osteosynthesis after replacement of the original nailing); expandable nailing was applied in 11 cases. Autologous iliac bone grafting was performed in 26 cases except the one case of close nailing.Results Twenty-six cases were followed up for an average of 4 years and 2 months. Bony healing was obtained in 5.4 months on average. By Neer scoring, the shoulder functions were evaluated as excellent in 12,good in 8 and fair in 6 cases, with a good to excellent rate of 76. 9％. By Mayo clinic performance scoring,the elbow functions were excellent in 23 and good in 3 cases, with a good to excellent rate of 100％. One case of radial nerve palsy recovered 6 months after operation.ConclusionInterlocking or expandable intramedullary nailing plus iliac bone grafting is an effective method to treat nonunion of humeral diaphysis. Key words: Humeral fractures; Fractures, ununited; Bone nails; Fracture fixation, internal