Objective:To compare the outcomes of dynamic hip screws(DHS)and intramedullary nailing(IMN)in the treatment of extra-capsular metastatic carcinoma of the proximal femur.Methods:A retrospective case analysis method was...Objective:To compare the outcomes of dynamic hip screws(DHS)and intramedullary nailing(IMN)in the treatment of extra-capsular metastatic carcinoma of the proximal femur.Methods:A retrospective case analysis method was used to examine data of patients with proximal metastatic cancer of the femur who were treated with internal fixation in Department of Orthopaedics,Beijing Friendship Hospital,from January 2007 to December 2018.Blood loss,postoperative pain,functional score,length of stay,and survival rates were compared,and postoperative complications were assessed.Results:Complete follow-up data were available for 33 patients.The mean follow-up period was 12.2±3.6(range:9-32)months and the average age was 72.3±4.7(range:59-83)years old.There were 20 females and 13 males.Twenty-three patients had undergone IMN and 10 DHS,according to bone defects and the patient’s overall condition.The median survival time was 10 months in the IMN group and 11 months in the DHS group.Duration of surgery(t=-7.366,P<0.001)and length of hospital stay(t=-3.509,P<0.001)differed significantly between the two groups.There was one case of breakage of internal fixation in the IMN group.Conclusions:There was no significant difference between DHS and IMN in terms of surgical efficacy.IMN and DHS were different in terms of surgical time and hospital stay.However,due to the limited number of cases in this study,multi-factor analysis has not been performed and needs to be further verified in future analysis.When developing a surgical plan,it is recommended to consider the patient’s condition and the surgeon’s experience.展开更多
BACKGROUND Multiple myeloma(MM)bone disease is indicative of MM,and reduces patient life quality.In addition to oncological,antineoplastic systemic therapy,surgical therapy in patients with MM is an essential treatmen...BACKGROUND Multiple myeloma(MM)bone disease is indicative of MM,and reduces patient life quality.In addition to oncological,antineoplastic systemic therapy,surgical therapy in patients with MM is an essential treatment within the framework of supportive therapy measures and involves orthopedic tumor surgery.Nevertheless,there are few reports on intramedullary(IM)nailing in the treatment of MM-induced proximal humeral fracture to prevent fixation loss.We here describe a case of pathological fracture of the proximal humerus caused by MM successfully treated with IM nailing without removal of tumors and a review of the current literature.CASE SUMMARY A 64-year-old male patient complaining of serious left shoulder pain and limited movement was admitted.The patient was finally diagnosed with MM(IgAλ,IIIA/II).After treatment of the pathological fracture with IM nailing,the patient's function recovered and his pain was rapidly relieved.Histopathological examination demonstrated plasma cell myeloma.The patient received chemotherapy in the Hematology Department.The humeral fracture displayed good union during the 40-mo follow-up,with complete healing of the fracture,and the clinical outcome was satisfactory.At the most recent follow-up,the patient's function was assessed using the Musculoskeletal Tumor Society score,which was 29.CONCLUSION Early surgery should be performed for the fracture of the proximal humerus caused by MM.IM nailing can be used without removal of tumors.Bone cement augmentation for bone defects and local adjuvant therapy can also be employed.展开更多
Intercalary allograft reconstruction offers a joint-sparing reconstructive option, but nonunion is a devastating complication. In this article, we want to share our experience of proper dynamization of interlocking in...Intercalary allograft reconstruction offers a joint-sparing reconstructive option, but nonunion is a devastating complication. In this article, we want to share our experience of proper dynamization of interlocking intramedullary nail for nonunion after proximal femoral intercalary allograft reconstruction. In this report, a 19-year-old girl was diagnosed proximal femoral fibroblast osteosarcoma (Enneking lib). After neoadjuvant chemotherapy, she underwent proximal femoral intercalary allograft reconstruction fixed by retrograde interlocking intramedullary nail. At her follow-up point of one year postoperatively, nonunion was observed in the proximal host-allograft junction. Therefore she underwent the second surgery of dynamization of the interlocking intramedullary nail. After 12 months' partial and full weight bearing exercise, bone union occurred. Our early observations show that dynamization of interlocking intramedullary nail can still be a useful means to treat nonunion of host- allograft junction if the local condition of the host and allograft bone are good enough.展开更多
AIM To describe an approach to anterior cruciate ligament(ACL) reconstruction using autologous hamstring by drilling via the anteromedial portal in the presence of an intramedullary(IM) femoral nail.METHODS Once preop...AIM To describe an approach to anterior cruciate ligament(ACL) reconstruction using autologous hamstring by drilling via the anteromedial portal in the presence of an intramedullary(IM) femoral nail.METHODS Once preoperative imagining has characterized the proposed location of the femoral tunnel preparations are made to remove all of the hardware(locking bolts and IM nail). A diagnostic arthroscopy is performed in the usual fashion addressing all intra-articular pathology. The ACL remnant and lateral wall soft tissues are removed from the intercondylar, to provide adequate visualization of the ACL footprint. Femoral tunnel placement is performed using a transportal ACL guide with desired offset and the knee flexed to 2.09 rad. The Beath pin is placed through the guide starting at the ACL's anatomic footprint using arthroscopic visualization and/or fluoroscopic guidance. If resistance is met while placing the Beath pin, the arthroscopy should be discontinued and the obstructing hardware should be removed under fluoroscopic guidance. When the Beath pin is successfully placed through the lateral femur, it is overdrilled with a 4.5 mm Endobutton drill. If the Endobutton drill is obstructed, the obstructing hardware should be removed under fluoroscopic guidance. In this case, the obstruction is more likely during Endobutton drilling due to its larger diameter and increased rigidity compared to the Beath pin. The femoral tunnel is then drilled using a best approximation of the graft's outer diameter. We recommend at least 7 mm diameter to minimize the risk of graft failure. Autologous hamstring grafts are generally between 6.8 and 8.6 mm in diameter. After reaming, the knee is flexed to 1.57 rad, the arthroscope placed through the anteromedial portal to confirm the femoral tunnel position, referencing the posterior wall and lateral cortex. For a quadrupled hamstring graft, the gracilis and semitendinosus tendons are then harvested in the standard fashion. The tendons are whip stitched, quadrupled and shaped to match the diameter of the prepared femoral tunnel. If the diameter of the patient's autologous hamstring graft is insufficient to fill the prepared femoral tunnel, the autograft may be supplemented with an allograft. The remainder of the reconstruction is performed according to surgeon preference. RESULTS The presence of retained hardware presents a challenge for surgeons treating patients with knee instability. In cruciate ligament reconstruction, distal femoral and proximal tibial implants hardware may confound tunnel placement, making removal of hardware necessary, unless techniques are adopted to allow for anatomic placement of the graft. CONCLUSION This report demonstrates how the femoral tunnel can be created using the anteromedial portal instead of a transtibial approach for reconstruction of the ACL.展开更多
BACKGROUND Primary intramedullary melanoma is a very rare tumor,most frequently occurring in the cervical and thoracic spinal cord.CASE SUMMARY We present a rare case in which the primary intramedullary melanoma was l...BACKGROUND Primary intramedullary melanoma is a very rare tumor,most frequently occurring in the cervical and thoracic spinal cord.CASE SUMMARY We present a rare case in which the primary intramedullary melanoma was located in the lumbar spine.A 56-year-old man complained of progressive intermittent pain in the lumbar area.Thoracic magnetic resonance imaging showed a spinal intramedullary tumor between the L3 and S1 levels.The tumor was resected entirely,and the diagnosis of malignant melanoma was confirmed by histopathology.CONCLUSION Primary melanoma of the spinal cord,particularly intramedullary localization,has rarely been reported in the previous literature.We describe a primary malignant melanoma of the lumbar spinal cord and discuss the challenges associated with the diagnosis.展开更多
BACKGROUND Currently,open reduction internal fixation is the conventional surgical method for treatment of double ulna and radius fracture.However,open reduction is associated with a high risk of complications.This ca...BACKGROUND Currently,open reduction internal fixation is the conventional surgical method for treatment of double ulna and radius fracture.However,open reduction is associated with a high risk of complications.This case of forearm double fracture involved a patient treated using an Acumed intramedullary nail.The patient experienced good follow-up outcomes.The Acumed forearm intramedullary nail enables early functional exercise and hastens healing of the fracture.Few studies have reported on the use of this approach for the treatment of fractures.CASE SUMMARY A 23-year-old male patient was admitted to hospital after 5 h of pain,swelling,and limited activity of left forearm caused by a careless fall.Physical examination showed stable basic vital signs,swelling of the left forearm,and severe pain when pressing on the injured part of the forearm.Further,friction was felt at the broken end of the bone;the skin was not punctured.Movement of the left hand was normal,and the left radial artery pulse was normal.Three-dimensional computed tomography examination showed an ulna fracture of the left forearm and comminuted fracture of the radius.The fracture was located in the upper third of the radius,with significant displacement on the fracture side.Clinical diagnosis further confirmed the left radius comminuted fracture and ulna fracture.After analyzing the fracture pattern,age,and other patient characteristics,we chose an Acumed nail for treatment and achieved good follow-up outcomes.CONCLUSION Acumed forearm intramedullary nail for fixation of ulna and radius fracture reduced complication risk and resulted in good follow-up outcomes.展开更多
AIM: To define the optimum safe angle of use for an eccentrically aligned proximal interlocking screw(PIS) for intramedullary nailing(IMN).METHODS: Thirty-six dry cadaver ulnas were split into two equal pieces sagital...AIM: To define the optimum safe angle of use for an eccentrically aligned proximal interlocking screw(PIS) for intramedullary nailing(IMN).METHODS: Thirty-six dry cadaver ulnas were split into two equal pieces sagitally. The following points were identified for each ulna: the deepest point of the incisura olecrani(A), the point where perpendicular lines from A and the ideal IMN entry point(D) are intersected(C) and a point at 3.5 mm(2 mm safety distance from articular surface + 1.5 mm radius of PIS) posterior from point A(B). We calculated the angle of screws inserted from point D through to point B in relation to D-C and B-C. In addition, an eccentrically aligned screw was inserted at a standard 20° through the anterior cortex of the ulna in each bone and the articular surface wasobserved macroscopically for any damage.RESULTS: The mean A-C distance was 9.6 mm(mean ± SD, 9.600 ± 0.763 mm), A-B distance was 3.5 mm, C-D distance was 12.500 mm(12.500 ± 1.371 mm) and the mean angle was 25.9°(25.9°± 2.0°). Lack of articular damage was confirmed macroscopically in all bones after the 20.0° eccentrically aligned screws were inserted. Intramedullary nail fixation systems have well known biological and biomechanical advantages for osteosynthesis. However, as well as these well-known advantages, IMN fixation of the ulna has some limitations. Some important limitations are related to the proximal interlocking of the ulna nail. The location of the PIS itself limits the indications for which intramedullary systems can be selected as an implant for the ulna. The new PIS design, where the PIS is aligned 20°eccentrically to the nail body, allows fixing of fractures even at the level of the olecranon without disturbing the joint. It also allows the eccentrically aligned screw to be inserted in any direction except through the proximal radio-ulnar joint. Taking into consideration our results, we now use a 20° eccentrically aligned PIS for all ulnas. In our results, the angle required to insert the PIS was less than 20° for only one bone. However, 0.7° difference corresponds to placement of the screw only 0.2 mm closer to the articular surface. As we assume 2.0 mm to be a safe distance, a placement of the screw 0.2 mm closer to the articular surface may not produce any clinical symptoms.CONCLUSION: The new PIS may give us the opportunity to interlock IMN without articular damage and confirmation by fluoroscopy if the nail is manufactured with a PIS aligned at a 20.0° fixed angle in relation to the IMN.展开更多
Background: Newer generation intramedullary (IM) tibial nails provide several distal interlocking screw options. The objectives were to determine: 1) if the new oblique interlocking option provides superior stability,...Background: Newer generation intramedullary (IM) tibial nails provide several distal interlocking screw options. The objectives were to determine: 1) if the new oblique interlocking option provides superior stability, 2) which screw orientation/ configuration is the most biomechanically stable, and 3) if three distal interlocking screws provide better stability. Methods: A preliminary experiment was performed in torsion, compression, and bending tests with four different screw configurations: (I) one medial-to-lateral and one oblique, (II) two me-dial-to-lateral, (III) one medial-to-lateral and one anterior-to-posterior, and (IV) one medial-to-lateral, one anterior-to-posterior and one oblique in simu-lated distal metaphyseal fracture tibiae. Twenty- four Synthes EXPERT tibial IM nails were used for six specimens of each screw configuration. Parts I and II, tibial IM nails were locked with 5.0 mm in-terlocking screws into simulated distal tibiae (PVC and composite analogue tibia). Part III, the two most stable configurations were tested using five pairs of simulated cadaveric distal tibiae metaphy-seal fractures. Results: Significant differences were attributable to distal screw orientation for intrame- dullary nailing of distal tibia fractures. Configura-tions II and IV were found to be more stable than the other two configurations. No significant differ-ence was detected in construct stability in all modes of testing between Configurations II and IV. Dis-cussion: Configuration I did not provide superior stability for the distal tibia fracture fixation. Con-figurations II and IV provided equivalent stability. When choosing IM fixation for treatment of distal tibia metaphyseal fractures two medial-to-lateral screws provide the necessary stability for satisfac-tory fixation. Clinical Relevance: This study indi-cated an option for operative treatment of distal metaphyseal tibia fracture fixation where preserva-tion of soft tissue and rigid stabilization are needed.展开更多
Fractures of long bones are commonly treated with intramedullary (IM) nails and they have been shown to have a very high success rate. Recently we have concerns with the use of the newer IM nailing systems, that uses ...Fractures of long bones are commonly treated with intramedullary (IM) nails and they have been shown to have a very high success rate. Recently we have concerns with the use of the newer IM nailing systems, that uses longer cross screws, which have been developed with variation in implant designs. We believe that the newer implants provide less fracture stability, due to decreased stiffness of the IM nailing system. The aim of this study was to biomechanically determine the influence of the length of cross screw on the stiffness of the IM nailing system, using a composite model. Our test results confirmed our suspicion that the newer IM nailing system using longer cross screw-length is less stiff than traditional nailing systems using shorter cross screw length, during axial loading.展开更多
Fractures of the radial neck account for 5-10% of traumatic lesions of the elbow in the child. Conservative method of reduction may fail to reduce severely displaced fractures. Open reduction of severely displaced rad...Fractures of the radial neck account for 5-10% of traumatic lesions of the elbow in the child. Conservative method of reduction may fail to reduce severely displaced fractures. Open reduction of severely displaced radial neck fractures is associated with a high incidence of complications. The present study describes the results achieved after closed and indirect reduction of the severely displaced radial head using a 2-mm K-wire passed intramedullary from near the radial styloid. The bent tip of the K-wire was used to manipulate the displaced head back to the shaft without opening the fracture site. The indirect reduction of the radial head using bent intramedullary K-wire is a simple, minimally invasive method, easy to perform, and obtains encouraging results with few complications. Intramedullary pin also achieves fixation of the radial head after reduction and prevents its secondary displacement.展开更多
Medulloblastoma (MB) is a malignant brain tumor with a usual potential for leptomeningeal spread. Intramedullary metastases of MB are rare and there are very few cases reported in the literature. Here, we report the c...Medulloblastoma (MB) is a malignant brain tumor with a usual potential for leptomeningeal spread. Intramedullary metastases of MB are rare and there are very few cases reported in the literature. Here, we report the case of an 18-year-old man with intramedullary spinal cord metastasis of MB occurring 9 years after the first diagnosis. The patient presented a 2-month history of progressive weakness in both lower limbs associated with urinary incontinence. Magnetic resonance imaging (MRI) demonstrated a large intramedullary spinal cord tumor extending from T10 to L1. The patient underwent surgical decompression and adjuvant therapy. Histological examination confirmed the diagnosis of classic MB metastasis. Postoperatively, the neurological status was stationary. Intramedullary metastasis of medulloblastoma is rare and difficult to manage with a poor prognosis. Comprehensive studies on the medulloblastoma dissemination mechanisms and clinical trials are needed to assess combined therapeutic approaches on metastases of MB.展开更多
Objective:To evaluate the bone metabolism balance and traumatic reaction of minimally invasive mippo intramedullary nail internal fixation treatment of femoral shaft fractures. Methods:80 patients with femoral shaft f...Objective:To evaluate the bone metabolism balance and traumatic reaction of minimally invasive mippo intramedullary nail internal fixation treatment of femoral shaft fractures. Methods:80 patients with femoral shaft fractures who were treated in our hospital between May 2011 and December 2016 were collected and divided into control group (n=40) and observation group (n=40) according to random number table, control group received conventional steel plate internal fixation treatment, and observation group received minimally invasive mippo intramedullary nail internal fixation treatment. Differences in serum levels of bone formation indexes, bone resorption indexes, inflammatory factors, and pain mediators and so on were compared between two groups of patients before operation and 1 week after treatment.Results: Before operation, differences in serum levels of bone formation indexes, bone resorption indexes, inflammatory factors and pain mediators were not statistically significant between two groups of patients. After operation, serum bone formation indexes P ICP, BGP, BALP and ALP levels in observation group were higher than those in control group;serum bone resorption indexesβ-CTX and OPG levels were lower than those in control group;serum inflammatory factors IL-1β, IL-6, IL-8 and CRP levels were lower than those in control group;serum pain mediators SP, PGE2 and 5-HT levels were lower than those in control group.Conclusion:Minimally invasive mippo intramedullary nail internal fixation treatment of femoral shaft fractures can promote the bone formation, relatively inhibit bone resorption and cause less traumatic reaction.展开更多
Tuberculous infection manifesting as an isolated intramedullary tuberculoma of the spinal cord is distinctly unusual.We report a case of a 35 year old woman presenting with an insidious onset of myelopathy,where MRI s...Tuberculous infection manifesting as an isolated intramedullary tuberculoma of the spinal cord is distinctly unusual.We report a case of a 35 year old woman presenting with an insidious onset of myelopathy,where MRI showed characteristic imaging findings suggestive of intramedullary tuberculosis.展开更多
Intramedullary spinal cord metastasis(ISCM) is very rare and its optimal treatment remains controversial. Pancreatic neuroendocrine tumor(pNET) is a rare tumor that usually presents with hepatic metastasis. Hepatic fa...Intramedullary spinal cord metastasis(ISCM) is very rare and its optimal treatment remains controversial. Pancreatic neuroendocrine tumor(pNET) is a rare tumor that usually presents with hepatic metastasis. Hepatic failure due to tumor progression is the major cause of death in cases of pNET. To date,no report has described a case of ISCM from pNET. Although spinal cord metastasis of a solid tumor is uncommon,it is a critical condition that can cause a potentially irreversible loss of neurologic function. Here,we report the case of a 45-year-old man who presented with leg weakness and voiding difficulty,and was found to have ISCM from pNET. Surgical treatment prevented further neurological deterioration. This is the first case report of ISCM from pNET.展开更多
BACKGROUND Tuberculosis (TB) mostly attacks the lungs, and extrapulmonary TB involving thecentral nervous system is uncommon;among these cases, spinal intramedullaryTB is even more rare. The clinical manifestations of...BACKGROUND Tuberculosis (TB) mostly attacks the lungs, and extrapulmonary TB involving thecentral nervous system is uncommon;among these cases, spinal intramedullaryTB is even more rare. The clinical manifestations of spinal intramedullary TB aresimilar to those of intramedullary spinal cord tumors. Therefore, it is necessary tomake a careful differential diagnosis of spinal intramedullary lesions to achievethe appropriate treatment and favorable prognosis. We report a rare case of ayoung male patient with paraplegia due to spinal intramedullary TB, which isuncommon and regrettable.CASE SUMMARY A 23-year-old male presented with fever accompanied by nausea and vomitinglasting for 2 mo and was then diagnosed with tubercular meningitis. After anti-TBtreatment, his symptoms were significantly improved. However, 2 mo after thediagnosis of tubercular meningitis, the patient felt numbness below the costal archlevel, which lasted for 1 wk, and he paid no attention to this symptom. Whatfollowed was paraplegia and urine/fecal incontinence. Magnetic resonanceimaging of the thoracic spine showed a ring-enhanced intramedullary cord lesionat T8-T9. Lesion exploration showed enlargement of the spinal cord at T8-T9, andthe lesion could be observed by incision. The lesion was adhered to the peripheraltissue and was grayish-white and tough with a poor blood supply and a diameterof approximately 0.8 cm. The lesion was resected completely. The results ofpathological examination by both hematoxylin-eosin staining and acid-fast bacillistaining confirmed TB, accompanied by acute and chronic suppurativeinflammation and granulation tissue formation. The patient was instructed tocontinue anti-TB treatment after the operation, but he did not follow the medicaladvice. Follow-up continued for ten years, the patient had persistent paraplegia,the numbness disappeared and urine/fecal sensation recovered.CONCLUSION Although TB is a kind of benign disease, some cases progress rapidly. Moreover,spinal intramedullary TB may seriously endanger quality of life and still needstimely diagnosis and proper treatment.展开更多
BACKGROUND Primary intramedullary melanocytoma is an exceedingly rare type of primary melanocytic tumor in the central nervous system.Unfortunately,primary intramedullary melanocytoma lacks specificity in clinical sym...BACKGROUND Primary intramedullary melanocytoma is an exceedingly rare type of primary melanocytic tumor in the central nervous system.Unfortunately,primary intramedullary melanocytoma lacks specificity in clinical symptoms and imaging features and there is currently no standard strategy for diagnosis or treatment.CASE SUMMARY A 52-year-old male patient suffered from weakness and numbness involving the bilateral lower limbs for 18 mo,and defecation and erectile dysfunction for 6 mo.Furthermore,these symptoms started to worsen for the last 3 mo.Preoperative magnetic resonance imaging(MRI)revealed an intramedullary tumor located at the T9-T10 level.In subsequently surgery,the maximal safe resection extent approached to 98%.The lesion was confirmed to be melanocytoma by pathological examination.In addition,the possibility of original melanocytoma outside the spinal cord was excluded after the examination of the whole body.Therefore,a diagnosis of primary intramedullary melanocytoma was established.The patient refused to accept radiotherapy or Gamma Knife,but MRI examination on July 28,2020 showed no sign of development.In addition,on April 10,2021,the recent review showed that the disorder of defecation and lower limbs improved further but erectile dysfunction benefited a little from the surgery.CONCLUSION After diagnosing intramedullary melanocytoma by postoperative pathology,the inspection of the whole body contributed to excluding the possibility of metastasis from other regions and further suggested a diagnosis of primary intramedullary melanocytoma.Complete resection,adjuvant radiation,and regular review are critical.In addition,maximal safe resection also benefits prognosis while the tumor is difficult to be resected totally.展开更多
BACKGROUND Femoral shaft fracture is a commonly encountered orthopedic injury that can be treated operatively with a low overall delayed/nonunion rate.In the case of delayed union after antegrade or retrograde intrame...BACKGROUND Femoral shaft fracture is a commonly encountered orthopedic injury that can be treated operatively with a low overall delayed/nonunion rate.In the case of delayed union after antegrade or retrograde intramedullary nail fixation,fracture dynamization is often attempted first.Nonunion after dynamization has been shown to occur due to infection and other aseptic etiologies.We present a unique case of diaphyseal femoral shaft fracture nonunion after dynamization due to intramedullary cortical bone pedestal formation at the distal tip of the nail.CASE SUMMARY A 37-year-old male experienced a high-energy trauma to his left thigh after coming down hard during a motocross jump.Evaluation was consistent with an isolated,closed,left mid-shaft femur fracture.He was initially managed with reamed antegrade intramedullary nail fixation but had continued thigh pain.Radiographs at four months demonstrated no evidence of fracture union and failure of the distal locking screw,and dynamization by distal locking screw removal was performed.The patient continued to have pain eight months after the initial procedure and 4 mo after dynamization with serial radiographs continuing to demonstrate no evidence of fracture healing.The decision was made to proceed with exchange nailing for aseptic fracture nonunion.During the exchange procedure,an obstruction was encountered at the distal tip of the failed nail and was confirmed on magnified fluoroscopy to be a pedestal of cortical bone in the canal.The obstruction required further distal reaming.A longer and larger diameter exchange nail was placed without difficulty and without a distal locking screw to allow for dynamization at the fracture site.Post-operative radiographs showed proper fracture and hardware alignment.There was subsequently radiographic evidence of callus formation at one year with subsequent fracture consolidation and resolution of thigh pain at eighteen months.CONCLUSION The risk of fracture nonunion caused by intramedullary bone pedestal formation can be mitigated with the use of maximum length and diameter nails and close follow up.展开更多
In proximal humeral fracture except AO classification 11A1, fixations with a locking plate and nails are recommended. We performed mechanical tests to investigate whether retrograde intramedullary nailing has fixation...In proximal humeral fracture except AO classification 11A1, fixations with a locking plate and nails are recommended. We performed mechanical tests to investigate whether retrograde intramedullary nailing has fixation stability comparable to those of anterograde intramedullary nailing and locking plate which achieve clinically favorable outcomes. In retrograde intramedullary nailing, a nail entry point is made in the diaphysis, for which reduction of stiffness of the humerus is of concern. Thus, we investigated the influence of a nail entry point made in the diaphysis on humeral strength. Retrograde intramedullary nailing had fixation stability against bending and a force loaded in the rotation direction comparable to those of anterograde intramedullary nail and locking plate. Displacement by the main external force loaded on the humerus, compressive load, was less than half in the bone fixed by retrograde intramedullary nailing compared with that in the bone fixed with a locking plate, showing favorable fixation stability. It was clarified that stiffness of the humerus against rotation and a load in the compression direction is not reduced by a nail entry point made by retrograde intramedullary nailing.展开更多
Complications and shortcomings of volar plating, which is very widely used for surgical treatment of distal radius fractures, are well known. Thus, there is scope for alternative innovative surgical methods. In the pr...Complications and shortcomings of volar plating, which is very widely used for surgical treatment of distal radius fractures, are well known. Thus, there is scope for alternative innovative surgical methods. In the present work, we used the finite element analysis method to compare the biomechanical performance of a model of a construct comprising a simulated distal radius fracture considered fixated using a notional intramedullary injectable bioresorbable polymer-bioresorbable balloon osteosynthesis system (“fixator”) versus using a commercially-available volar locking plate (VP). The biomechanical parameters determined were longitudinal stiffness and factor of safety under each of the applied loads.?For the fixator model, 1) each of the biomechanical parameters was markedly influenced by fracture gap fill ratio (FGFR) (defined as the proportion of the volume of the fracture gap that is considered occupied by the expanded polymer-filled balloon)?but not by modulus of elasticity assigned to the polymer;2) with FGFR = 100%, stiffness was comparable to that of the Ti-6Al-4V alloy VP construct model;and 3) stiffness was within the range of literature values for stiffness of constructs comprising simulated fractures in fresh cadaveric distal radii fixated using metal volar locking plate. These results suggest that the fixator may be an alternative modality to metal volar plating and, as such, deserves further evaluation.展开更多
The debate continues over the management of diaphyseal fractures of the humerus. There are a variety of extramedullary as well as intramedullary implants. We aim to propose a technique of passing the screw intramedull...The debate continues over the management of diaphyseal fractures of the humerus. There are a variety of extramedullary as well as intramedullary implants. We aim to propose a technique of passing the screw intramedullary nails and achieve union with least trauma to the shoulder and the rotator cuff. The multiple elastic screw nails achieve the inherent stability based on the principle of “three point fixation”. We aim to propose that the screw intramedullary nail is an effective implant to facilitate uneventful fracture union, with rapid recovery, low morbidity and low learning curve capable of being replicated in any smaller operative set up.展开更多
基金Capital’s Funds for Health Improvement and Research(No.2018-1-2072)。
文摘Objective:To compare the outcomes of dynamic hip screws(DHS)and intramedullary nailing(IMN)in the treatment of extra-capsular metastatic carcinoma of the proximal femur.Methods:A retrospective case analysis method was used to examine data of patients with proximal metastatic cancer of the femur who were treated with internal fixation in Department of Orthopaedics,Beijing Friendship Hospital,from January 2007 to December 2018.Blood loss,postoperative pain,functional score,length of stay,and survival rates were compared,and postoperative complications were assessed.Results:Complete follow-up data were available for 33 patients.The mean follow-up period was 12.2±3.6(range:9-32)months and the average age was 72.3±4.7(range:59-83)years old.There were 20 females and 13 males.Twenty-three patients had undergone IMN and 10 DHS,according to bone defects and the patient’s overall condition.The median survival time was 10 months in the IMN group and 11 months in the DHS group.Duration of surgery(t=-7.366,P<0.001)and length of hospital stay(t=-3.509,P<0.001)differed significantly between the two groups.There was one case of breakage of internal fixation in the IMN group.Conclusions:There was no significant difference between DHS and IMN in terms of surgical efficacy.IMN and DHS were different in terms of surgical time and hospital stay.However,due to the limited number of cases in this study,multi-factor analysis has not been performed and needs to be further verified in future analysis.When developing a surgical plan,it is recommended to consider the patient’s condition and the surgeon’s experience.
文摘BACKGROUND Multiple myeloma(MM)bone disease is indicative of MM,and reduces patient life quality.In addition to oncological,antineoplastic systemic therapy,surgical therapy in patients with MM is an essential treatment within the framework of supportive therapy measures and involves orthopedic tumor surgery.Nevertheless,there are few reports on intramedullary(IM)nailing in the treatment of MM-induced proximal humeral fracture to prevent fixation loss.We here describe a case of pathological fracture of the proximal humerus caused by MM successfully treated with IM nailing without removal of tumors and a review of the current literature.CASE SUMMARY A 64-year-old male patient complaining of serious left shoulder pain and limited movement was admitted.The patient was finally diagnosed with MM(IgAλ,IIIA/II).After treatment of the pathological fracture with IM nailing,the patient's function recovered and his pain was rapidly relieved.Histopathological examination demonstrated plasma cell myeloma.The patient received chemotherapy in the Hematology Department.The humeral fracture displayed good union during the 40-mo follow-up,with complete healing of the fracture,and the clinical outcome was satisfactory.At the most recent follow-up,the patient's function was assessed using the Musculoskeletal Tumor Society score,which was 29.CONCLUSION Early surgery should be performed for the fracture of the proximal humerus caused by MM.IM nailing can be used without removal of tumors.Bone cement augmentation for bone defects and local adjuvant therapy can also be employed.
文摘Intercalary allograft reconstruction offers a joint-sparing reconstructive option, but nonunion is a devastating complication. In this article, we want to share our experience of proper dynamization of interlocking intramedullary nail for nonunion after proximal femoral intercalary allograft reconstruction. In this report, a 19-year-old girl was diagnosed proximal femoral fibroblast osteosarcoma (Enneking lib). After neoadjuvant chemotherapy, she underwent proximal femoral intercalary allograft reconstruction fixed by retrograde interlocking intramedullary nail. At her follow-up point of one year postoperatively, nonunion was observed in the proximal host-allograft junction. Therefore she underwent the second surgery of dynamization of the interlocking intramedullary nail. After 12 months' partial and full weight bearing exercise, bone union occurred. Our early observations show that dynamization of interlocking intramedullary nail can still be a useful means to treat nonunion of host- allograft junction if the local condition of the host and allograft bone are good enough.
文摘AIM To describe an approach to anterior cruciate ligament(ACL) reconstruction using autologous hamstring by drilling via the anteromedial portal in the presence of an intramedullary(IM) femoral nail.METHODS Once preoperative imagining has characterized the proposed location of the femoral tunnel preparations are made to remove all of the hardware(locking bolts and IM nail). A diagnostic arthroscopy is performed in the usual fashion addressing all intra-articular pathology. The ACL remnant and lateral wall soft tissues are removed from the intercondylar, to provide adequate visualization of the ACL footprint. Femoral tunnel placement is performed using a transportal ACL guide with desired offset and the knee flexed to 2.09 rad. The Beath pin is placed through the guide starting at the ACL's anatomic footprint using arthroscopic visualization and/or fluoroscopic guidance. If resistance is met while placing the Beath pin, the arthroscopy should be discontinued and the obstructing hardware should be removed under fluoroscopic guidance. When the Beath pin is successfully placed through the lateral femur, it is overdrilled with a 4.5 mm Endobutton drill. If the Endobutton drill is obstructed, the obstructing hardware should be removed under fluoroscopic guidance. In this case, the obstruction is more likely during Endobutton drilling due to its larger diameter and increased rigidity compared to the Beath pin. The femoral tunnel is then drilled using a best approximation of the graft's outer diameter. We recommend at least 7 mm diameter to minimize the risk of graft failure. Autologous hamstring grafts are generally between 6.8 and 8.6 mm in diameter. After reaming, the knee is flexed to 1.57 rad, the arthroscope placed through the anteromedial portal to confirm the femoral tunnel position, referencing the posterior wall and lateral cortex. For a quadrupled hamstring graft, the gracilis and semitendinosus tendons are then harvested in the standard fashion. The tendons are whip stitched, quadrupled and shaped to match the diameter of the prepared femoral tunnel. If the diameter of the patient's autologous hamstring graft is insufficient to fill the prepared femoral tunnel, the autograft may be supplemented with an allograft. The remainder of the reconstruction is performed according to surgeon preference. RESULTS The presence of retained hardware presents a challenge for surgeons treating patients with knee instability. In cruciate ligament reconstruction, distal femoral and proximal tibial implants hardware may confound tunnel placement, making removal of hardware necessary, unless techniques are adopted to allow for anatomic placement of the graft. CONCLUSION This report demonstrates how the femoral tunnel can be created using the anteromedial portal instead of a transtibial approach for reconstruction of the ACL.
基金Foundation of the President of the Fifth Affiliated Hospital,Southern Medical University,2020.
文摘BACKGROUND Primary intramedullary melanoma is a very rare tumor,most frequently occurring in the cervical and thoracic spinal cord.CASE SUMMARY We present a rare case in which the primary intramedullary melanoma was located in the lumbar spine.A 56-year-old man complained of progressive intermittent pain in the lumbar area.Thoracic magnetic resonance imaging showed a spinal intramedullary tumor between the L3 and S1 levels.The tumor was resected entirely,and the diagnosis of malignant melanoma was confirmed by histopathology.CONCLUSION Primary melanoma of the spinal cord,particularly intramedullary localization,has rarely been reported in the previous literature.We describe a primary malignant melanoma of the lumbar spinal cord and discuss the challenges associated with the diagnosis.
文摘BACKGROUND Currently,open reduction internal fixation is the conventional surgical method for treatment of double ulna and radius fracture.However,open reduction is associated with a high risk of complications.This case of forearm double fracture involved a patient treated using an Acumed intramedullary nail.The patient experienced good follow-up outcomes.The Acumed forearm intramedullary nail enables early functional exercise and hastens healing of the fracture.Few studies have reported on the use of this approach for the treatment of fractures.CASE SUMMARY A 23-year-old male patient was admitted to hospital after 5 h of pain,swelling,and limited activity of left forearm caused by a careless fall.Physical examination showed stable basic vital signs,swelling of the left forearm,and severe pain when pressing on the injured part of the forearm.Further,friction was felt at the broken end of the bone;the skin was not punctured.Movement of the left hand was normal,and the left radial artery pulse was normal.Three-dimensional computed tomography examination showed an ulna fracture of the left forearm and comminuted fracture of the radius.The fracture was located in the upper third of the radius,with significant displacement on the fracture side.Clinical diagnosis further confirmed the left radius comminuted fracture and ulna fracture.After analyzing the fracture pattern,age,and other patient characteristics,we chose an Acumed nail for treatment and achieved good follow-up outcomes.CONCLUSION Acumed forearm intramedullary nail for fixation of ulna and radius fracture reduced complication risk and resulted in good follow-up outcomes.
文摘AIM: To define the optimum safe angle of use for an eccentrically aligned proximal interlocking screw(PIS) for intramedullary nailing(IMN).METHODS: Thirty-six dry cadaver ulnas were split into two equal pieces sagitally. The following points were identified for each ulna: the deepest point of the incisura olecrani(A), the point where perpendicular lines from A and the ideal IMN entry point(D) are intersected(C) and a point at 3.5 mm(2 mm safety distance from articular surface + 1.5 mm radius of PIS) posterior from point A(B). We calculated the angle of screws inserted from point D through to point B in relation to D-C and B-C. In addition, an eccentrically aligned screw was inserted at a standard 20° through the anterior cortex of the ulna in each bone and the articular surface wasobserved macroscopically for any damage.RESULTS: The mean A-C distance was 9.6 mm(mean ± SD, 9.600 ± 0.763 mm), A-B distance was 3.5 mm, C-D distance was 12.500 mm(12.500 ± 1.371 mm) and the mean angle was 25.9°(25.9°± 2.0°). Lack of articular damage was confirmed macroscopically in all bones after the 20.0° eccentrically aligned screws were inserted. Intramedullary nail fixation systems have well known biological and biomechanical advantages for osteosynthesis. However, as well as these well-known advantages, IMN fixation of the ulna has some limitations. Some important limitations are related to the proximal interlocking of the ulna nail. The location of the PIS itself limits the indications for which intramedullary systems can be selected as an implant for the ulna. The new PIS design, where the PIS is aligned 20°eccentrically to the nail body, allows fixing of fractures even at the level of the olecranon without disturbing the joint. It also allows the eccentrically aligned screw to be inserted in any direction except through the proximal radio-ulnar joint. Taking into consideration our results, we now use a 20° eccentrically aligned PIS for all ulnas. In our results, the angle required to insert the PIS was less than 20° for only one bone. However, 0.7° difference corresponds to placement of the screw only 0.2 mm closer to the articular surface. As we assume 2.0 mm to be a safe distance, a placement of the screw 0.2 mm closer to the articular surface may not produce any clinical symptoms.CONCLUSION: The new PIS may give us the opportunity to interlock IMN without articular damage and confirmation by fluoroscopy if the nail is manufactured with a PIS aligned at a 20.0° fixed angle in relation to the IMN.
文摘Background: Newer generation intramedullary (IM) tibial nails provide several distal interlocking screw options. The objectives were to determine: 1) if the new oblique interlocking option provides superior stability, 2) which screw orientation/ configuration is the most biomechanically stable, and 3) if three distal interlocking screws provide better stability. Methods: A preliminary experiment was performed in torsion, compression, and bending tests with four different screw configurations: (I) one medial-to-lateral and one oblique, (II) two me-dial-to-lateral, (III) one medial-to-lateral and one anterior-to-posterior, and (IV) one medial-to-lateral, one anterior-to-posterior and one oblique in simu-lated distal metaphyseal fracture tibiae. Twenty- four Synthes EXPERT tibial IM nails were used for six specimens of each screw configuration. Parts I and II, tibial IM nails were locked with 5.0 mm in-terlocking screws into simulated distal tibiae (PVC and composite analogue tibia). Part III, the two most stable configurations were tested using five pairs of simulated cadaveric distal tibiae metaphy-seal fractures. Results: Significant differences were attributable to distal screw orientation for intrame- dullary nailing of distal tibia fractures. Configura-tions II and IV were found to be more stable than the other two configurations. No significant differ-ence was detected in construct stability in all modes of testing between Configurations II and IV. Dis-cussion: Configuration I did not provide superior stability for the distal tibia fracture fixation. Con-figurations II and IV provided equivalent stability. When choosing IM fixation for treatment of distal tibia metaphyseal fractures two medial-to-lateral screws provide the necessary stability for satisfac-tory fixation. Clinical Relevance: This study indi-cated an option for operative treatment of distal metaphyseal tibia fracture fixation where preserva-tion of soft tissue and rigid stabilization are needed.
文摘Fractures of long bones are commonly treated with intramedullary (IM) nails and they have been shown to have a very high success rate. Recently we have concerns with the use of the newer IM nailing systems, that uses longer cross screws, which have been developed with variation in implant designs. We believe that the newer implants provide less fracture stability, due to decreased stiffness of the IM nailing system. The aim of this study was to biomechanically determine the influence of the length of cross screw on the stiffness of the IM nailing system, using a composite model. Our test results confirmed our suspicion that the newer IM nailing system using longer cross screw-length is less stiff than traditional nailing systems using shorter cross screw length, during axial loading.
文摘Fractures of the radial neck account for 5-10% of traumatic lesions of the elbow in the child. Conservative method of reduction may fail to reduce severely displaced fractures. Open reduction of severely displaced radial neck fractures is associated with a high incidence of complications. The present study describes the results achieved after closed and indirect reduction of the severely displaced radial head using a 2-mm K-wire passed intramedullary from near the radial styloid. The bent tip of the K-wire was used to manipulate the displaced head back to the shaft without opening the fracture site. The indirect reduction of the radial head using bent intramedullary K-wire is a simple, minimally invasive method, easy to perform, and obtains encouraging results with few complications. Intramedullary pin also achieves fixation of the radial head after reduction and prevents its secondary displacement.
文摘Medulloblastoma (MB) is a malignant brain tumor with a usual potential for leptomeningeal spread. Intramedullary metastases of MB are rare and there are very few cases reported in the literature. Here, we report the case of an 18-year-old man with intramedullary spinal cord metastasis of MB occurring 9 years after the first diagnosis. The patient presented a 2-month history of progressive weakness in both lower limbs associated with urinary incontinence. Magnetic resonance imaging (MRI) demonstrated a large intramedullary spinal cord tumor extending from T10 to L1. The patient underwent surgical decompression and adjuvant therapy. Histological examination confirmed the diagnosis of classic MB metastasis. Postoperatively, the neurological status was stationary. Intramedullary metastasis of medulloblastoma is rare and difficult to manage with a poor prognosis. Comprehensive studies on the medulloblastoma dissemination mechanisms and clinical trials are needed to assess combined therapeutic approaches on metastases of MB.
文摘Objective:To evaluate the bone metabolism balance and traumatic reaction of minimally invasive mippo intramedullary nail internal fixation treatment of femoral shaft fractures. Methods:80 patients with femoral shaft fractures who were treated in our hospital between May 2011 and December 2016 were collected and divided into control group (n=40) and observation group (n=40) according to random number table, control group received conventional steel plate internal fixation treatment, and observation group received minimally invasive mippo intramedullary nail internal fixation treatment. Differences in serum levels of bone formation indexes, bone resorption indexes, inflammatory factors, and pain mediators and so on were compared between two groups of patients before operation and 1 week after treatment.Results: Before operation, differences in serum levels of bone formation indexes, bone resorption indexes, inflammatory factors and pain mediators were not statistically significant between two groups of patients. After operation, serum bone formation indexes P ICP, BGP, BALP and ALP levels in observation group were higher than those in control group;serum bone resorption indexesβ-CTX and OPG levels were lower than those in control group;serum inflammatory factors IL-1β, IL-6, IL-8 and CRP levels were lower than those in control group;serum pain mediators SP, PGE2 and 5-HT levels were lower than those in control group.Conclusion:Minimally invasive mippo intramedullary nail internal fixation treatment of femoral shaft fractures can promote the bone formation, relatively inhibit bone resorption and cause less traumatic reaction.
文摘Tuberculous infection manifesting as an isolated intramedullary tuberculoma of the spinal cord is distinctly unusual.We report a case of a 35 year old woman presenting with an insidious onset of myelopathy,where MRI showed characteristic imaging findings suggestive of intramedullary tuberculosis.
基金Supported by Grant from Gachon University Gil Medical Center,No.2013-37
文摘Intramedullary spinal cord metastasis(ISCM) is very rare and its optimal treatment remains controversial. Pancreatic neuroendocrine tumor(pNET) is a rare tumor that usually presents with hepatic metastasis. Hepatic failure due to tumor progression is the major cause of death in cases of pNET. To date,no report has described a case of ISCM from pNET. Although spinal cord metastasis of a solid tumor is uncommon,it is a critical condition that can cause a potentially irreversible loss of neurologic function. Here,we report the case of a 45-year-old man who presented with leg weakness and voiding difficulty,and was found to have ISCM from pNET. Surgical treatment prevented further neurological deterioration. This is the first case report of ISCM from pNET.
文摘BACKGROUND Tuberculosis (TB) mostly attacks the lungs, and extrapulmonary TB involving thecentral nervous system is uncommon;among these cases, spinal intramedullaryTB is even more rare. The clinical manifestations of spinal intramedullary TB aresimilar to those of intramedullary spinal cord tumors. Therefore, it is necessary tomake a careful differential diagnosis of spinal intramedullary lesions to achievethe appropriate treatment and favorable prognosis. We report a rare case of ayoung male patient with paraplegia due to spinal intramedullary TB, which isuncommon and regrettable.CASE SUMMARY A 23-year-old male presented with fever accompanied by nausea and vomitinglasting for 2 mo and was then diagnosed with tubercular meningitis. After anti-TBtreatment, his symptoms were significantly improved. However, 2 mo after thediagnosis of tubercular meningitis, the patient felt numbness below the costal archlevel, which lasted for 1 wk, and he paid no attention to this symptom. Whatfollowed was paraplegia and urine/fecal incontinence. Magnetic resonanceimaging of the thoracic spine showed a ring-enhanced intramedullary cord lesionat T8-T9. Lesion exploration showed enlargement of the spinal cord at T8-T9, andthe lesion could be observed by incision. The lesion was adhered to the peripheraltissue and was grayish-white and tough with a poor blood supply and a diameterof approximately 0.8 cm. The lesion was resected completely. The results ofpathological examination by both hematoxylin-eosin staining and acid-fast bacillistaining confirmed TB, accompanied by acute and chronic suppurativeinflammation and granulation tissue formation. The patient was instructed tocontinue anti-TB treatment after the operation, but he did not follow the medicaladvice. Follow-up continued for ten years, the patient had persistent paraplegia,the numbness disappeared and urine/fecal sensation recovered.CONCLUSION Although TB is a kind of benign disease, some cases progress rapidly. Moreover,spinal intramedullary TB may seriously endanger quality of life and still needstimely diagnosis and proper treatment.
基金Natural Science Foundation of Hunan Province,China,No.2019JJ50964.
文摘BACKGROUND Primary intramedullary melanocytoma is an exceedingly rare type of primary melanocytic tumor in the central nervous system.Unfortunately,primary intramedullary melanocytoma lacks specificity in clinical symptoms and imaging features and there is currently no standard strategy for diagnosis or treatment.CASE SUMMARY A 52-year-old male patient suffered from weakness and numbness involving the bilateral lower limbs for 18 mo,and defecation and erectile dysfunction for 6 mo.Furthermore,these symptoms started to worsen for the last 3 mo.Preoperative magnetic resonance imaging(MRI)revealed an intramedullary tumor located at the T9-T10 level.In subsequently surgery,the maximal safe resection extent approached to 98%.The lesion was confirmed to be melanocytoma by pathological examination.In addition,the possibility of original melanocytoma outside the spinal cord was excluded after the examination of the whole body.Therefore,a diagnosis of primary intramedullary melanocytoma was established.The patient refused to accept radiotherapy or Gamma Knife,but MRI examination on July 28,2020 showed no sign of development.In addition,on April 10,2021,the recent review showed that the disorder of defecation and lower limbs improved further but erectile dysfunction benefited a little from the surgery.CONCLUSION After diagnosing intramedullary melanocytoma by postoperative pathology,the inspection of the whole body contributed to excluding the possibility of metastasis from other regions and further suggested a diagnosis of primary intramedullary melanocytoma.Complete resection,adjuvant radiation,and regular review are critical.In addition,maximal safe resection also benefits prognosis while the tumor is difficult to be resected totally.
文摘BACKGROUND Femoral shaft fracture is a commonly encountered orthopedic injury that can be treated operatively with a low overall delayed/nonunion rate.In the case of delayed union after antegrade or retrograde intramedullary nail fixation,fracture dynamization is often attempted first.Nonunion after dynamization has been shown to occur due to infection and other aseptic etiologies.We present a unique case of diaphyseal femoral shaft fracture nonunion after dynamization due to intramedullary cortical bone pedestal formation at the distal tip of the nail.CASE SUMMARY A 37-year-old male experienced a high-energy trauma to his left thigh after coming down hard during a motocross jump.Evaluation was consistent with an isolated,closed,left mid-shaft femur fracture.He was initially managed with reamed antegrade intramedullary nail fixation but had continued thigh pain.Radiographs at four months demonstrated no evidence of fracture union and failure of the distal locking screw,and dynamization by distal locking screw removal was performed.The patient continued to have pain eight months after the initial procedure and 4 mo after dynamization with serial radiographs continuing to demonstrate no evidence of fracture healing.The decision was made to proceed with exchange nailing for aseptic fracture nonunion.During the exchange procedure,an obstruction was encountered at the distal tip of the failed nail and was confirmed on magnified fluoroscopy to be a pedestal of cortical bone in the canal.The obstruction required further distal reaming.A longer and larger diameter exchange nail was placed without difficulty and without a distal locking screw to allow for dynamization at the fracture site.Post-operative radiographs showed proper fracture and hardware alignment.There was subsequently radiographic evidence of callus formation at one year with subsequent fracture consolidation and resolution of thigh pain at eighteen months.CONCLUSION The risk of fracture nonunion caused by intramedullary bone pedestal formation can be mitigated with the use of maximum length and diameter nails and close follow up.
文摘In proximal humeral fracture except AO classification 11A1, fixations with a locking plate and nails are recommended. We performed mechanical tests to investigate whether retrograde intramedullary nailing has fixation stability comparable to those of anterograde intramedullary nailing and locking plate which achieve clinically favorable outcomes. In retrograde intramedullary nailing, a nail entry point is made in the diaphysis, for which reduction of stiffness of the humerus is of concern. Thus, we investigated the influence of a nail entry point made in the diaphysis on humeral strength. Retrograde intramedullary nailing had fixation stability against bending and a force loaded in the rotation direction comparable to those of anterograde intramedullary nail and locking plate. Displacement by the main external force loaded on the humerus, compressive load, was less than half in the bone fixed by retrograde intramedullary nailing compared with that in the bone fixed with a locking plate, showing favorable fixation stability. It was clarified that stiffness of the humerus against rotation and a load in the compression direction is not reduced by a nail entry point made by retrograde intramedullary nailing.
文摘Complications and shortcomings of volar plating, which is very widely used for surgical treatment of distal radius fractures, are well known. Thus, there is scope for alternative innovative surgical methods. In the present work, we used the finite element analysis method to compare the biomechanical performance of a model of a construct comprising a simulated distal radius fracture considered fixated using a notional intramedullary injectable bioresorbable polymer-bioresorbable balloon osteosynthesis system (“fixator”) versus using a commercially-available volar locking plate (VP). The biomechanical parameters determined were longitudinal stiffness and factor of safety under each of the applied loads.?For the fixator model, 1) each of the biomechanical parameters was markedly influenced by fracture gap fill ratio (FGFR) (defined as the proportion of the volume of the fracture gap that is considered occupied by the expanded polymer-filled balloon)?but not by modulus of elasticity assigned to the polymer;2) with FGFR = 100%, stiffness was comparable to that of the Ti-6Al-4V alloy VP construct model;and 3) stiffness was within the range of literature values for stiffness of constructs comprising simulated fractures in fresh cadaveric distal radii fixated using metal volar locking plate. These results suggest that the fixator may be an alternative modality to metal volar plating and, as such, deserves further evaluation.
文摘The debate continues over the management of diaphyseal fractures of the humerus. There are a variety of extramedullary as well as intramedullary implants. We aim to propose a technique of passing the screw intramedullary nails and achieve union with least trauma to the shoulder and the rotator cuff. The multiple elastic screw nails achieve the inherent stability based on the principle of “three point fixation”. We aim to propose that the screw intramedullary nail is an effective implant to facilitate uneventful fracture union, with rapid recovery, low morbidity and low learning curve capable of being replicated in any smaller operative set up.