• Users Online: 152
  • Home
  • Print this page
  • Email this page
Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Contacts Login 

 Table of Contents  
Year : 2021  |  Volume : 41  |  Issue : 2  |  Page : 53-57

Surgical and nonsurgical treatments for proximal femur fractures: A narrative review

Mobility Impairment Research Center, Health Research Institute, Babol University of Medical Sciences; Clinical Research Development Center, Shahid Beheshti Hospital, Babol University of Medical Sciences; Department of Orthopedics, School of Medicine, Babol University of Medical Sciences, Babol, Mazandaran, Iran

Date of Submission17-Sep-2019
Date of Decision14-Jul-2020
Date of Acceptance20-Oct-2020
Date of Web Publication25-Dec-2020

Correspondence Address:
Dr. Masoud Bahrami Frydoni
Department of Orthopedics, Babol University of Medical Sciences, Ganjafrooz Street, Babol, Mazandaran
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jmedsci.jmedsci_178_19

Rights and Permissions

The number of proximal femoral fractures is increasing due to traumatic injuries, falls, and heavy exercises. In femoral neck fractures, a number of screws or a device called dynamic hip screw (DHS) are commonly used to fix the fractured hip. In intertrochanteric fractures, DHS or intramedullary nailing (IMN) is usually used to fix the fracture. In subtrochanteric fractures, IMN is usually used to fix the fracture. An orthopedic physician may decide not to perform the surgery only in patients who do not tolerate surgery due to severe and advanced comorbidities or patients who could not walk even before fracture. Rarely, in some types of hip fractures that are completely stable and nondisplaced, the physician may decide to use nonsurgical treatments, mostly bed-rest at home. However, this type of treatment is associated with the risk of further fracture displacement, during the rest period. If a nonsurgical treatment is chosen, strict follow-ups and frequent radiographies should be performed for the patient's fractures so that the physician can be informed if fractures are dislocated and, if necessary, perform surgery on the patient.

Keywords: Treatment, surgery, fracture, femur, hip

How to cite this article:
Frydoni MB, Esmaeilnejad-Ganji SM. Surgical and nonsurgical treatments for proximal femur fractures: A narrative review. J Med Sci 2021;41:53-7

How to cite this URL:
Frydoni MB, Esmaeilnejad-Ganji SM. Surgical and nonsurgical treatments for proximal femur fractures: A narrative review. J Med Sci [serial online] 2021 [cited 2023 Feb 7];41:53-7. Available from: https://www.jmedscindmc.com/text.asp?2021/41/2/53/305050

  Introduction Top

Nowadays, due to traumatic injuries, falls, and heavy exercises, the number of proximal femoral fractures is rising. On the other hand, because of weight-bearing nature of this lower limb and its undeniable role in human function and life, determining several treatment options for treating such fractures and their consequences has a great value.[1],[2],[3],[4] Pelvic fractures around the hip joint refer to a group of fractures that occur in the upper part of the femur, where the femur is connected to the hip.[5],[6] These fractures are primarily classified based on their anatomic localization. Isolated fractures of greater and lesser trochanter are common and rarely require surgical interventions.[7] These fractures may also occur following pathological conditions. Lesser trochanter fractures occur in children due to iliopsoas muscle traumatic avulsion, and maintenance therapy is adequate in these cases. Greater trochanter fractures often result from a direct trauma to the trochanter and usually have a slight displacement; nonsurgical treatment is preferred in these fractures.[8],[9] Using an assistive cane while walking can be enough to relieve the pain. Femoral neck and intertrochanteric fractures usually require surgery and fixation. These fractures are more common in women than in men.[10]

There are three types of femoral fractures: (1) fractures in the head and neck parts that connect to the hip joint, (2) fractures in the distal part of the femur that connects to the knee joint, and (3) fractures in the body of femur (femoral shaft).[11] Fractures caused by high-energy injuries happen in both genders and in all ages. However, spontaneous fractures or fractures resulting from mild injuries are only found in older individuals. Most of the hip fractures happen around the hip joint.[12] Angiogenesis inhibitor factors that secrete from the synovial fluid can prevent this fracture from healing. These factors along with blood flow of the femoral head may bring about complications such as avascular necrosis and nonunion. With an accurate reduction and a rigid fixation of the fracture, the incidence of nonunion is very low.[13],[14] These fractures are usually caused by a fall or a direct trauma to the thigh and are commonly related to osteoporosis.[15],[16] Considering the necessity of evaluating surgical and nonsurgical treatments of the femoral and hip fractures and identifying strategies for reducing exposure to these fractures, the current study aimed to review the surgical and nonsurgical treatments for proximal femur fractures.

  Different Types of Fixation and Surgical Treatment for Proximal Femoral Fractures Top

Proximal femoral fractures are classified into three main categories, including femoral neck fractures, intertrochanteric fractures, and subtrochanteric fractures. In femoral neck fractures, screws are commonly used to fix the fractured hip. In intertrochanteric fractures, dynamic hip screw (DHS) or intramedullary nailing (IMN, a type of intramedullary rod) is usually used to fix the fracture. In subtrochanteric fractures, IMN is usually used to fix the fracture.[16],[17],[18]

In femoral neck fractures, as mentioned, DHS is usually used to fix the fractured parts. The femoral head blood supply is poorer than many other bones, and when the initial trauma causes fracture in the femoral neck, the vessels that feed and nourish the femoral head may be damaged. This injury can be so severe to disrupt the blood supply to the femoral head; hence, this part of bone tissue may eventually die after a fracture due to disruption of blood supply even if the fracture has been treated well. This process is more common in older people. Thus, in some types of femoral head fractures in the elderly, the physician may consider another method of surgery when there is a high risk of femoral head avascular necrosis. In this method, the femoral head is completely removed by surgery, and an artificial head is replaced. This type of surgery is called hip hemiarthroplasty.[19],[20]

Femoral neck fracture

Femoral neck fractures are completely inside the joint, so synovial fluid disrupts the healing process. On the other hand, the femoral neck has no periosteal layer; as a result, fracture healing in this area is endosteal.[21] These fractures mostly occur in the elderly following a mild trauma due to senile osteoporosis.

Treatments for two groups of patients are described below based on Garden classification:

  • Group 1: Patients with impacted fractures and nondisplaced fractures are classified as Garden types I and II, respectively. In these cases, the treatment choice is internal fixation with preservation of the femoral head.[22] Cannulated screws, DHS, proximal femoral locking plates, and IMN are the options for internal fixation. A recent meta-analysis revealed that despite similar results in functional recovery between DHS and cannulated screw, DHS had fewer postoperative complications and faster union time compared with cannulated screw, suggesting that DHS may be a more effective treatment[23]
  • Group 2: In this group, which includes patients with displaced fractures (Garden types III and IV), the treatment choices are hemiarthroplasty, total hip arthroplasty, and internal fixation. Prosthesis has been suggested for the treatment of these fractures as a lifesaving method that has some advantages and disadvantages.[24] Arthroplasty is usually used in the elderly aged more than 60 years, while younger patients often undergo internal fixation and head preservation. Further, total hip arthroplasty may be more beneficial than hemiarthroplasty in more active elderly patients versus less active patients. These approaches have gained decent functional outcomes.[25] In special cases, even primary hip replacement has been recommended by some authors for femoral neck fracture in acute phase.[26] Different studies have manifested that patients with hip replacement therapy have better quality of life and less need for reoperations compared with patients that undergo fixation.[27]

There exists another classification called Pauwels types with respect to high-energy trauma, as believed by some specialists to be more accurate than Garden classification, especially in the investigation of more vertical femoral neck fractures (Pauwels type III fracture). Despite the long history of this classification, Pauwels angle measurement has not been standardized yet, and researchers recommend further studies for its establishment.[28] Pauwels types I, II, and III fractures are called so when the degrees of the inclination of the fracture line are ≤30°, 30°–50°, and ≥50°. Treatment of Pauwels type I and II fractures is mostly done by three parallel cannulated screws. On the other hand, treatment of Pauwels type III fracture, which is more common in young adults, is debatable. However, screw-plate method is mostly selected by orthopedic surgeons.[29]

Intertrochanteric fractures

This fracture occurs in old patients (especially women) similar to the femoral neck fracture, mainly due to senile osteoporosis. In more than 90% of elderly patients, this kind of fracture happens with a simple fall. In young people, this fracture usually results from a high-energy injury, such as a car accident or falling from a height. The risk of falling increases with age, and it is influenced by factors such as impaired vision, decreased muscle strength, variable blood pressure, decreased reflexes, vascular diseases, and associated musculoskeletal pathology.[30]

In earlier reports, physicians recommended traction as a favorable treatment for intertrochanteric fractures; however, due to high mortality and morbidity from complications such as bed sore, urinary tract infections, joint contracture, pneumonia, and thromboembolic events, it is not easily recommended today.[31] However, in cases that surgery is not possible, including patients with a recent myocardial infarction, the use of traction is the only choice. Conservative treatment is also provided in patients who do not walk and have slight inconvenience from the fracture.[32] However, surgical treatment and fracture fixation are the treatment choices, assuming the aforementioned complications.[33] In patients with stable intertrochanteric fractures, the usual option is sliding hip compression screw (DHS). On the other hand, in cases of unstable fractures, reserve obliquely fractures, subtrochanteric extension, and/or lack of integrity of femoral wall, the operative choice is IMN. DHS and IMN outcomes for stable fracture patterns are almost similar. In addition, patients with severely comminuted fractures, symptomatic degenerative arthritis, and osteoporotic bone are unlikely to hold internal fixation and/or fail internal fixation and often undergo arthroplasty.[34],[35]

Greater trochanteric fractures

Although isolated fractures of the greater trochanter are rare, they occur specifically in the elderly people due to direct trauma. Clinical symptom is pain, especially during weight-bearing and joint movement.[36]

Treatment of the greater trochanter fractures is usually nonsurgical. Since, most of the time, some parts of the trochanter and not all of it are involved, the abductor mechanism is usually not disturbed. Even fractures with a displacement of more than 1 cm can be united with fibrosis (fibrous union) or bone tissue, so abductor muscle function remains. Therefore, treatment is symptomatic. The patient, with the help of a crutch, should not tolerate weight on the extremity with the fracture until symptoms are resolved and will gradually return to routine activities. If the patient is young and active and has high displacement fractures, surgery is performed.[37],[38]

Subtrochanteric fractures

Subtrochanteric fractures occur in lesser trochanter and an area of about 5 cm from it. In other words, the subtrochanteric region is the area between the lesser trochanter and the femur's diaphyseal isthmus region (the diaphyseal isthmus region is the narrowest area of the femoral bone medullary canal, located between the upper one-third and the lower two-thirds of the femur).[39] This form of fracture is seen mostly in young people (but rarely in the elderly) mainly following pathological lesions, such as metastasis or Paget's disease.

The treatment of these fractures is mostly through surgery and fracture fixation. Most subtrochanteric fractures are treated with IMN. Fixed angle plate is used if the fracture is associated with femoral neck fracture, narrow medullary canal, or pre-existing femoral shaft deformity. Nonsurgical treatment is usually performed with traction by distal femur pin traction and formation of 90-90 traction (hip and knee in 90° flexion) that is performed only on children and patients with medical comorbidities who do not tolerate surgery or general anesthesia. The duration of this method is at least 12–16 weeks.[26],[40],[41]

  Consequences of Mismanagement Top

Early management of the femoral neck fractures is important. Delaying in surgery and fixation or treatment failure will be associated with risk of complications, such as nonunion and avascular necrosis. In a recent study by Rai et al.,[42] it was stated that early surgery of hip fracture in the elderly could improve outcomes and reduce morbidity, bed sore, and infection, while conflicting results show a positive relation between early surgery and mortality and function improvements. In additin, Pincus et al.[43] reported that surgery after 24 h is associated with higher risk of complications and 30-day mortality; therefore, hip fracture repair within 24 h is optional.

Treatment for nonunion is mainly hip arthroplasty, and the type of arthroplasty depends on the patient's age and bone status. If the patient is an independent individual and cooperative and has a normal pattern of daily living, total hip arthroplasty will be performed, and if the patient is old with conscious disorder and is not cooperative and lives at home most of the time, hemiarthroplasty would be a suitable treatment.[44],[45] Avascular necrosis is one of the serious and delayed complications of femoral neck fracture. Although bone necrosis following ischemia occurs in the early stages, delayed segmental collapse occurs in the weight-bearing joint in the next stages because of subchondral bone and articular cartilage surrounding the necrotic bone collapse.[46] In the elderly people, arthroplasty is an appropriate treatment for avascular necrosis. Depending on the patient's age of the and how active he or she is, it can be hemiarthroplasty or total arthroplasty. In young people, various treatments such as femoral osteotomy, bone grafting as a symptomatic treatment, as well as hemiarthroplasty or even total arthroplasty have been mentioned as the final solution.[47],[48]

  Conclusion Top

The usual treatment of hip fractures is surgery. The orthopedic physician may decide not to perform the surgery only in patients who do not tolerate surgery due to severe and advanced comorbidities or patients who could not walk even before fracture. Otherwise, surgery is the most common treatment. Rarely, in some types of hip fractures that are completely stable and nondisplaced, physician may decide to use nonsurgical treatments, mostly bed rest. However, this type of treatment is associated with the risk of further fracture displacement during the rest period. If a nonsurgical treatment is chosen, closed follow-ups with radiographies should be performed for the patient's fractures so that the physician can be informed if fractures are dislocated and if necessary perform surgery.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Klestil T, Röder C, Stotter C, Winkler B, Nehrer S, Lutz M, et al. Impact of timing of surgery in elderly hip fracture patients: A systematic review and meta-analysis. Sci Rep 2018;8:13933.  Back to cited text no. 1
Janmohammadi N, Alijanpour E, Bahrami M, Taheri M, Hosseni F. Outcome of the Patients Admitted to the Surgical Intensive Care Unit of Shahid Beheshti Hospital (Babol, Iran). J Babol Univ Med Sci 2014;16:72-7.  Back to cited text no. 2
Voeten SC, Krijnen P, Voeten DM, Hegeman JH, Wouters MWJM, Schipper IB. Quality indicators for hip fracture care, a systematic review. Osteoporos Int 2018;29:1963-85.  Back to cited text no. 3
Esmailnejad Ganji SM, Bahrami M, Poorghaz N, Kamali Ahangar S. The frequency of road accident injuries among victims admitted to shahid ↱beheshti hospital of Babol, Iran in 2010-2012. J Babol Univ Med Sci 2015;17:29-33.  Back to cited text no. 4
El Saied AH, Steyn MP, Ansermino JM. Clonidine prolongs the effect of ropivacaine for axillary brachial plexus blockade. Can J Anaesth 2000;47:962-7.  Back to cited text no. 5
Parker M, Khan R, Crawford J, Pryor G. Hemiarthroplasty versus internal fixation for displaced intracapsular hip fractures in the elderly: A Randomised trial of 455 Patients M. J Bone Joint Surg Br Vol 2002;84:1150-5.  Back to cited text no. 6
Kearns RJ, Macfarlane AJ, Anderson KJ, Kinsella J. Intrathecal opioid versus ultrasound guided fascia iliaca plane block for analgesia after primary hip arthroplasty: Study protocol for a randomised, blinded, noninferiority controlled trial. Trials 2011;12:51.  Back to cited text no. 7
Joshi GP, Ogunnaike BO. Consequences of inadequate postoperative pain relief and chronic persistent postoperative pain. Anesthesiol Clin North Am 2005;23:21-36.  Back to cited text no. 8
Tan ST, Tan WP, Jaipaul J, Chan SP, Sathappan SS. Clinical outcomes and hospital length of stay in 2,756 elderly patients with hip fractures: A comparison of surgical and non-surgical management. Singapore Med J 2017;58:253-7.  Back to cited text no. 9
Frenkel Rutenberg T, Assaly A, Vitenberg M, Shemesh S, Burg A, Haviv B, et al. Outcome of non-surgical treatment of proximal femur fractures in the fragile elderly population. Injury 2019;50:1347-52.  Back to cited text no. 10
Diament M, White C. Hip dislocations and femoral head fractures. Orthopaedics Trauma 2018;32:110-5.  Back to cited text no. 11
Wang B, Liu Q, Liu Y, Jiang R. Comparison of proximal femoral nail antirotation and dynamic hip screw internal fixation on serum markers in elderly patients with intertrochanteric fractures. J Coll Physicians Surg Pak 2019;29:644-8.  Back to cited text no. 12
Oh JH, Kim SH, Lee JH, Shin SH, Gong HS. Treatment of distal clavicle fracture: A systematic review of treatment modalities in 425 fractures. Arch Orthop Trauma Surg 2011;131:525-33.  Back to cited text no. 13
Mirzatolooei F. Comparison between operative and nonoperative treatment methods in the management of comminuted fractures of the clavicle. Acta Orthop Traumatol Turc 2011;45:34-40.  Back to cited text no. 14
Bonnevialle N, Delannis Y, Mansat P, Peter O, Chemama B, Bonnevialle P. Bilateral clavicle fracture external fixation. Orthop Traumatol Surg Res 2010;96:821-4.  Back to cited text no. 15
Phruetthiphat OA, Gao Y, Anthony CA, Pugely AJ, Warth LC, Callaghan JJ. Incidence of and preoperative risk factors for surgical delay in primary total hip arthroplasty: Analysis from the American College of Surgeons National surgical quality improvement program. J Arthroplasty 2016;31:2432-6.  Back to cited text no. 16
King A, Phillips JR. Total hip and knee replacement surgery. Surgery (Oxford) 2016;34:468-74.  Back to cited text no. 17
Bahrami M. Treatment of intertrochanteric fracture with DHS. J Babol Univ Med Sci 2003;5:47-50.  Back to cited text no. 18
Hayes N, Umapathysivam K, Foster B. Effectiveness of surgical conservative treatment for distal femoral growth plate fractures: A systematic review. Open Orthop J 2019;13:117-29.  Back to cited text no. 19
Griffin XL, Parsons N, Zbaeda MM, McArthur J. Interventions for treating fractures of the distal femur in adults. Cochrane Database Syst Rev 2015;CD010606.  Back to cited text no. 20
Ramnemark A, Nilsson M, Borssén B, Gustafson Y. Stroke, a major and increasing risk factor for femoral neck fracture. Stroke 2000;31:1572-7.  Back to cited text no. 21
Bachiller FG, Caballer AP, Portal LF. Avascular necrosis of the femoral head after femoral neck fracture. Clin Orthop Relat Res 2002;399:87-109.  Back to cited text no. 22
Ma JX, Kuang MJ, Xing F, Zhao YL, Chen HT, Zhang LK, et al. Sliding hip screw versus cannulated cancellous screws for fixation of femoral neck fracture in adults: A systematic review. Int J Surg 2018;52:89-97.  Back to cited text no. 23
Slobogean GP, Sprague SA, Scott T, Bhandari M. Complications following young femoral neck fractures. Injury 2015;46:484-91.  Back to cited text no. 24
Kazley JM, Banerjee S, Abousayed MM, Rosenbaum AJ. Classifications in Brief: Garden classification of femoral neck fractures. Clin Orthop Relat Res 2018;476:441-5.  Back to cited text no. 25
Iga T, Kato K, Karita T. Subtrochanteric fracture of the femur accompanying pre-existing ipsilateral osteoarthritis of the hip successfully treated with intramedullary nailing in the lateral decubitus position: A case report. Cureus 2018;10:e3081.  Back to cited text no. 26
Wani IH, Sharma S, Latoo I, Salaria AQ, Farooq M, Jan M. Primary total hip arthroplasty versus internal fixation in displaced fracture of femoral neck in sexa- and septuagenarians. J Orthop Traumatol 2014;15:209-14.  Back to cited text no. 27
Shen M, Wang C, Chen H, Rui YF, Zhao S. An update on the Pauwels classification. J Orthop Surg Res 2016;11:161.  Back to cited text no. 28
Li Z, Zhang X, Li Z, Peng A, Zhang L, Deng Y, et al. Comparative study of Pauwels type III femoral neck fractures managed by short dynamic hip screw with fibula bone graft or cannulated screws in young adults. Ann Transl Med 2020;8:681.  Back to cited text no. 29
Kyle RF, Gustilo RB, Premer RF. Analysis of six hundred and twenty-two intertrochanteric hip fractures. J Bone Joint Surg Am 1979;61:216-21.  Back to cited text no. 30
Im GI, Shin YW, Song YJ. Potentially unstable intertrochanteric fractures. J Orthop Trauma 2005;19:5-9.  Back to cited text no. 31
Haidukewych GJ. Intertrochanteric fractures: Ten tips to improve results. J Bone Joint Surg Am 2009;91:712-9.  Back to cited text no. 32
Haidukewych GJ, Israel TA, Berry DJ. Reverse obliquity fractures of the intertrochanteric region of the femur. J Bone Joint Surg Am 2001;83:643-50.  Back to cited text no. 33
Yu J, Zhang C, Li L, Kwong JS, Xue L, Zeng X, et al. Internal fixation treatments for intertrochanteric fracture: A systematic review and meta-analysis of randomized evidence. Sci Rep 2015;5:18195.  Back to cited text no. 34
Pachore JA, Shah VI, Sheth AN, Shah KP, Marothi DP, Puri R. Hip arthroplasty in failed intertrochanteric fractures in elderly. Indian J Orthop 2013;47:572-7.  Back to cited text no. 35
[PUBMED]  [Full text]  
Pritchett JW. Fracture of the greater trochanter after hip replacement. Clin Orthop Relat Res 2001;390:221-6.  Back to cited text no. 36
Hartford JM, Graw BP, Knowles SB, Frosch DL. Isolated greater trochanteric fracture and the direct anterior approach using a fracture table. J Arthroplasty 2018;33:S253-8.  Back to cited text no. 37
Mei XY, Gong YJ, Safir OA, Gross AE, Kuzyk PR. Fixation options following greater trochanteric osteotomies and fractures in total hip arthroplasty: A systematic review. JBJS Rev 2018;6:e4.  Back to cited text no. 38
Berger RJ, Sultan AA, Cole C, Sodhi N, Khlopas A, Mont MA. Sub-trochanteric hip fracture following core decompression for osteonecrosis in a patient with a pre-existing contralateral occult femoral neck fracture. Surg Technol Int 2018;32:361-5.  Back to cited text no. 39
Jackson C, Tanios M, Ebraheim N. Management of subtrochanteric proximal femur fractures: A review of recent literature. Adv Orthop 2018;2018:1326701.  Back to cited text no. 40
Barbosa de Toledo Lourenço PR, Pires RE. Subtrochanteric fractures of the femur: Update. Rev Bras Ortop 2016;51:246-53.  Back to cited text no. 41
Rai SK, Varma R, Wani SS. Does time of surgery and complication have any correlation in the management of hip fracture in elderly and can early surgery affect the outcome? Eur J Orthop Surg Traumatol 2018;28:277-82.  Back to cited text no. 42
Pincus D, Ravi B, Wasserstein D, Huang A, Paterson JM, Nathens AB, et al. Association between wait time and 30-day mortality in adults undergoing hip fracture surgery. JAMA 2017;318:1994-2003.  Back to cited text no. 43
Ramey LN, McInnis KC, Palmer WE. Femoral neck stress fracture: Can MRI grade help predict return-to-running time? Am J Sports Med 2016;44:2122-9.  Back to cited text no. 44
Babcock S, Kellam JF. Hip Fracture Nonunions: Diagnosis, Treatment, and Special Considerations in Elderly Patients. Adv Orthop 2018;2018:1912762.  Back to cited text no. 45
Hughes M. Avascular necrosis of shoulder and hip: Case report. Reactions 2016;1610:123-16.  Back to cited text no. 46
Merschin D, Häne R, Tohidnezhad M, Pufe T, Drescher W. Bone-preserving total hip arthroplasty in avascular necrosis of the hip-a matched-pairs analysis. Int Orthop 2018;42:1509-16.  Back to cited text no. 47
Wang SF, Ji QH, Qiao XF, Zhao P, Xue Y, Li YB. Efficacy of artificial femoral head replacement for femoral head avascular necrosis. Medicine (Baltimore) 2019;98:e15411.  Back to cited text no. 48

This article has been cited by
1 Approach to suspected physeal fractures in the emergency department
Ajai Singh, Prashant Mahajan, John Ruffin, Sagar Galwankar, Courtney Kirkland
Journal of Emergencies, Trauma, and Shock. 2021; 14(4): 222
[Pubmed] | [DOI]


Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

  Different Types ...Consequences of ...
  In this article

 Article Access Statistics
    PDF Downloaded344    
    Comments [Add]    
    Cited by others 1    

Recommend this journal