Abstract
Introduction
There is no consensus regarding the optimal device for displaced intracapsular hip fractures. This retrospective study compared two techniques (1) cannulated cancellous screw (CCS), and (2) Targon Femoral Neck (TFN) plate.
Materials and methods
Data regarding gender, operational data, complications, pain, Quality of life and function scores were retrieved.
Results
103 patients were included, 42 were treated using CCS, compared to 61 treated using TFN. Operative time shorter for CCS (p = 0.019). Complication rates were not different (p > 0.05).
Conclusion
As CCS method take shorter operating time and reduced costs, CCS should be used for the treatment of displaced ICHF.
Keywords: Dynamic locking plate, Cannulated cancellous screws, Displaced intracapsular hip fracture, Targon femoral neck plate, Sub capital fracture
1. Introduction
Femoral fractures are a growing concern for health systems around the world and are responsible for a major decline in quality of life.1 The incidence of femoral fractures is increasing and it is estimated that there could be up to 2.6 million cases yearly by 2025.2 Displaced ICHF in the elderly are typically managed with hemi or total hip arthroplasty depending on the age, bone quality and functional requirements of the patient.3 In young active patients, where preservation of the femoral head and its blood supply are of the utmost importance, urgent surgical treatment with anatomic reduction and internal fixation is preferred.
The method of fixation has always been a topic of debate in orthopedic trauma. Surgeons are consistently comparing devices in order to maximize patient outcomes following fixation of fractures. Internal fixation of displaced intracapsular hip fractures (ICHF) has traditionally been managed with cannulated cancellous screws (CCS). The shortcoming of the CCS modality is that it provides limited support on the lateral femoral cortex and resultantly, this predisposes the fracture to varus displacement. The sliding hip screw (SHS) was designed to provide greater support on the lateral femoral cortex however, a limitation with this technique is that it lacks rotational stability.7
The Targon femoral neck (TFN) plate (Aesculap Melsungen, Germany) is a newer device that was introduced in 2007 as an alternative for the fixation of intracapsular hip fractures.4 By providing attachment of up to four angular stable telescoping screws to a locking plate, the TFN is designed in a unique way to reduce the risk of femoral head rotation or tilting. As its design incorporates features of both sliding hip screws and multiple cancellous screws, it is thought that this newer modality may improve outcomes following closed reduction and internal fixation (CRIF). Using the TFN plate in the management of displaced ICHF, several studies have reported relatively low rates of non-union and avascular necrosis (AVN).5, 6, 7
There is currently no consensus on whether displaced (ICHF) are better managed with the TFN plate or CCS modality, as the recent comparative studies between these two devices are inconsistent and limited. Studies have previously demonstrated that the CCS is associated with significantly higher rates of AVN and nonunion in comparison to the TFN device.9,10 Alternatively, it has also been concluded that there was no difference in complications between the two devices.8 As it remains unclear which device is superior in managing displaced ICHF, future comparative studies are necessary in order to help establish a consensus across departments.
The purpose of this retrospective study was to compare the outcomes between the conventional cannulated cancellous screw modality and the newer Targon femoral neck plate plate for CRIF of displaced ICHF.
1.1. Patients and methods
Following the approval of the local institutional review board, data was retrieved from the medical records of consecutive patients younger than 65 years old, who presented to our level one trauma center with Garden 3/4 ICHFs between January 2007 and January 2016.
Retrospective review of patient information included patient demographics (age, gender), time to surgery, duration of surgery and post-operative complications. Patients who experienced pathological fractures, those who were treated by other means, such as arthroplasty or hemiarthroplasty or did not meet the two-year minimal follow-up period required, were excluded.
Each fracture was classified according to Garden and Pauwel classifications. All patients underwent closed reduction internal fixation with either TFN or CCS within 24 h of presentation to our level 1 trauma center. The surgical technique was based upon the surgeon's preference and the date of surgery (the TFN was introduced to our department in 2011). CRIF was performed by 7 different surgeons (3 fellow-trained trauma surgeons and 4 senior residents). All patients were given either general or regional anesthesia and positioned supine on a fracture table.
Fracture reduction with rotational restoration was restored by gentle longitudinal traction and the Leadbetter8 technique if necessary, under fluoroscopy, in accordance with that previously described by Parker et al.7 The surgeon determined the configuration and number of the cannulated screws based on anatomy, severity of the comminution, stability, and clinical evaluation. Postoperative care was standardized for both the CCS and TFN cohorts. Postoperative management included early mobilization, non-weight bearing, and thrombo-prophylactic treatment with enoxaparin. Radiological evaluation of AP and axial films were performed by two orthopedic surgeons. Patients were routinely examined at our outpatient clinic at 3 weeks, 6 weeks, 3 months, 6 months and one year postoperatively or until fracture union. Patients were asked to complete the Modified Harrison Hip Score (MHHS) and the SF-12 questionnaires in addition to Numerical Analogue Scales (NAS) for pain at final follow-up.
1.2. Statistical analysis
Continuous variables are presented with mean and standard deviation (SD). Quantitative variables are presented with absolute and relative frequencies. The chi-square and Fisher's exact tests were used for comparison of proportions. The Student's t-test was applied for normal variables for comparison of study variables between groups. When the basic assumptions for normality of the t-test were not met, the Wilcoxon test was used. All reported p values are two-tailed. Statistical significance was defined as p < 0.05.
2. Results
Between January 2007 and January 2016, 103 patients underwent closed reduction and internal fixation for displaced ICHF. Forty-two patients were treated with CCS and 61 patients were treated with TFN. The mean age of patients in the CCS group was 49.4 ± 10 years, while the mean age of patients in the TFN group was 49.5 ± 8.8 years (p = 0.971) (Table 1). Garden and Pauwel classifications did not differ significantly between the groups (Garden p = 0.335, Pauwel p = 0.362) (Table 2). The average time from emergency room presentation to the operating room was 7:54 ± 4:03 h (range 2:08–21:15 h). The mean time to surgery in the CCS group, 7:53 ± 4:37 h, did not differ significantly from the mean time in the TFN group, 7:55 ± 3:47 h (p = 0.969). There was a significant difference in the lengths of surgery between the groups. The mean operative time in the CCS group, 1:07 ± 00:33 h, was significantly shorter than the mean operative time in the TFN group, 01:29 ± 00:58 h (p = 0.019).
Table 1.
Patients demographics.
| Targon Femoral Nail (N = 61) | Cannulated Screws (N = 42) | p Value | ||
|---|---|---|---|---|
| Age (SD) | 49.5 (8.8) | 49.4 (10) | 0.971 | |
| Gender (%) | Male | 44 (72) | 28 (67) | 0.793 |
| Laterality (%) | Right | 37 (60) | 21 (50) | 0.240 |
Table 2.
Results.
| Targon Femoral Nail (N = 61) | Cannulated Screws (N = 42) | p Value | ||
|---|---|---|---|---|
| Garden (%) | 3 | 30 (49.2) | 19 (45.2) | 0.335 |
| 4 | 31 (50.8) | 23 (54.8) | 0.335 | |
| Pauwel's Angle (SD) | 57.8 (16.7) | 51.8 (18.3) | 0.362 | |
| Time to Surgery (HR, SD) | 7:55 (3:47) | 7:53 (4:37) | 0.969 | |
| Length of Surgery (HR, SD) | 1:29 (0:58) | 1:07 (0:33) | 0.019 | |
| Length of Follow-up Years (SD) | 7.3 (4.4) | 7 (1.7) | 0.76 | |
| Orthopedic Complications (%) | Cut Out | 4 (6.6) | 6 (14.3) | 0.310 |
| Non-Union | 4 (6.6) | 15 (11.9) | 0.481 | |
| AVN | 15 (24.6) | 6 (13.1) | 0.632 | |
| Revisions (%) | Total | 9 (14.6) | 5 (11.9) | 0.776 |
| Type of Revision (%) | THR | 8 (72.7) | 1 (33.3) | 0.506 |
| Removal of implant | 2(22.2) | 2 (40) | ||
| Revision to total hip arthroplasty | 7 (77.8) | 3 (60) | ||
| MHHS (SD)a | 81.0 (23.0) | 80.2 (22.1) | 0.892 | |
| SF-12, Physical Score, average (SD)b | 45.4 (12.0) | 43.9 (13.3) | 0.626 | |
| SF-12, Mental Score, average (SD) b | 50.7 (11.6) | 53.6 (11.4) | 0.321 | |
| Visual analogue scale (SD)c | 2.8 (2.4) | 3.2 (2.6) | 0.367 |
Data was unavailable for 19 patients from the TFN group and for 17 patients from the CCS group.
Data was unavailable for 18 patients from the TFN group and for 17 patients from the CCS group.
Data was unavailable for 18 patients from the TFN group and for 17 patients from the CCS group.
At an average of 7 and 7.3 year follow up for CCS and TFN respectively, the SF-12 Mental Component Summary scores (MCS) did not differ between the groups (CCS 53.6 ± 11.4, TFN 50.7 ± 11.6, p = 0.321). Similarly, the SF-12 Physical Component Summary scores (PCS) did not differ between the groups (CCS 43.9 ± 13.3, TFN 45.5 ± 12.0, p = 0.626). Additionally, no difference was found in the MHHS questionnaires (p = 0.892). Furthermore, no difference was noted in the VAS pain scores (CCS 1.7, TFN 4.4, p = 0.760).
Complications and revision rates were comparable between the groups. Avascular necrosis (AVN) was the most frequent complication reported. In the CCS cohort, there were 6 AVN complications (14.3%), compared to the TFN cohort which had 15 AVN complications (24.6%) (p = 0.632). Both groups did not differ in the non-union rate (p = 0.481) (Fig. 1A–D). Six cut outs were recorded in the CCS group (14.3%), while four were observed in the TFN group (6.6%) (p = 0.310). No statistical difference was found between the two groups in the number of revision surgeries (p = 0.776). No infections or in-hospital mortality were noted in either cohort. During the follow up period, four non-related deaths were noted in the CCS group, while one was noted in the TFN group.
Fig. 1.
From Left to Right: anterior posterior X ray of a 61 y/o male with left hip Garden 4 fracture(A) who underwent a CRIF with a TFN plate (B) and developed nonunion (C). THA was preformed 8 months after the trauma.
3. Discussion
The ideal implant for fixation of intracapsular femoral neck fractures must endure the forces associated with weight bearing, while simultaneously restricting motion across the fracture site during bone healing.9 Traditionally, sliding hip screws (SHS) and cancellous screws have produced good results and favorable outcomes in the management of intracapsular femoral neck fractures.10 As the newer TFN fixation modality incorporates the features of the SHS and the CCS, it is thought that this could theoretically improve outcomes in displaced ICHF.7
Several studies have reported impressive results with the TFN fixation device, highlighting its potential advantages. Osarumwense et al.12 presented their outcomes over a 2-year period for patients treated with the TFN and reported an 8% rate of non-union and AVN for displaced ICHF. In another biomechanical study, Brandt et al.13 compared the performance of CCS, SHS and TFN modalities in fractures induced in cadaver femora. They concluded that the optimal method for fixation involves a combination of a fixed-angle device and multiple sliding neck screws, such as what is found in the TFN. In spite of these studies, it is unclear however whether or not this newer modality actually improves outcomes in patients. The purpose of this study was therefore to compare the outcomes between the conventional CCS technique and the TFN device in patients treated for displaced ICHF.
The main reasons for treatment failure in displaced intracapsular femoral neck fractures are nonunion and AVN.5 In a meta-analysis of 106 studies, Lu-Yao et al.6 reported rates of 33% and 16% for nonunion and AVN, respectively. Furthermore, 20–36% of the patients in their study underwent revision surgery within 2 years from the primary fixation surgery.11 Our study's most notable finding was that the rates of nonunion, AVN and revision did not differ between patients with CCS and TFN for displaced ICHF.
In a similar comparative study, Griffin et al.14 evaluated the outcomes between the two devices in the management of displaced ICHF and reported no significant difference in the rates of nonunion, AVN or revision between the two modalities. In comparison to our results, we believe the higher complication rate in their study can be attributed to their relatively older patient population.
In another comparative study between the two devices for displaced ICHF, Thein et al.9 concluded that internal fixation by a fixed-angle device (TFN) had no effect on the rate of osteonecrosis. However, their study reported lower rates of nonunion and revision when using the TFN device. A large cohort study by Alshameeri et al.10 moreover mirrored these results, reporting lower rates of nonunion and revision associated with the TFN device, further reflecting the heterogeneity in the literature.
Cut-out is an additional serious complication that warrants significant consideration in the management of intracapsular femoral neck fracture repair. Cut-out rates in our study were 14.3% in the CCS group and 6.6% in the TFN group, which were comparable to those reported by other studies. Biber et al.12 noted cut-out as a major complication, presenting a rate of 9.6% in the TFN cohort. Eschler et al.3 reported 15% cut-outs in their cohort of 27 patients treated with the TFN.
The rate of revision following fracture fixation reflects the performance of the fixation devices used. As the overall rate of revision did not differ significantly between groups in our study, we believe that on a larger scale, the mechanism of fixation between these two modalities has relatively little influence over the post-operative outcome. Our rates of revision were comparable to those previously reported9,14. Moreover, we believe our lower revision rates in comparison to the ones previously presented9,14 may in part be explained by the relatively high number of patients who declined revision produces (5, 19.2% for AVN and 3, 11.5% for cut out).
The mental and physical health components of the short-form 12 health survey (SF-12) questionnaires give us insight into the physical and emotional status of the patient, whereas the NAS score is a reflection of the pain experienced by the patient. As such, these outcomes warrant consideration when comparing fixation modalities. This study reported no statistical difference in the mental and physical components of the SF-12, in the functional assessment in the MHHS and in the NAS pain score between the two cohorts.
When comparing the two devices, the surgical exposure and surgical duration must be considered. While the incision required for the TFN devise is larger than that required for CCS fixation, it did not lead to wound complication following surgery in our cohort. However, it is notable that the duration of the surgery was significantly longer for the TFN group, as this device consists of more components.
As the results in the literature are unclear9,10,14, we believe this study helps establish a clearer consensus that the method of fixation in displaced ICHF has no significant effect on the rates of complications between the CCS and the TFN. One final consideration that must be mentioned is that the current cost of the TFN device is approximately four times greater than the cost of the CCS (in our institution). Surgeons must heed the economic implications associated with different fixation techniques, especially in light of the increasing growth in the number of hip fractures.
This study presents some limitations. The first is due to the study's retrospective nature which might cause some inaccuracy in data collection. Moreover, study's 10-year time-frame with a change in the operative implant could have led to an additional bias. In spite of this long period, we nonetheless believe our results reflect the inherent performance of these two devices. The manner in which reduction was achieved, gentle longitudinal traction vs. the leadbetter method were not compared. Additionally, the study population could have been larger and was therefore susceptible to a sampling bias.
4. Conclusion
In comparison to the conventional CCS device, the TFN fixation method did not result in a significant reduction in complications after fixation of displaced intracapsular hip fractures. CCS was found to be superior in terms of operating time and lower cost.
Declaration of competing interest
None.
All authors have not received grant support or research funding and do not have any proprietary interests in the materials described in the article.
This study was approved by the institutional review board.
References
- 1.Griffin X.L., Parsons N., Achten J., Fernandez M., Costa M.L. Recovery of health-related quality of life in a United Kingdom hip fracture population. Bone Joint J. 2015;97-B(3):372–382. doi: 10.1302/0301-620x.97b3.35738. [DOI] [PubMed] [Google Scholar]
- 2.Ware J.E., Kosinski M., Keller S.D. A 12-item short-form health survey. Med Care. 1996;34(3):220–233. doi: 10.1097/00005650-199603000-00003. [DOI] [PubMed] [Google Scholar]
- 3.Eschler A., Brandt S., Gierer P., Mittlmeier T., Gradl G. Angular stable multiple screw fixation (Targon FN) versus standard SHS for the fixation of femoral neck fractures. Injury. 2014;45:S76–S80. doi: 10.1016/j.injury.2013.10.026. [DOI] [PubMed] [Google Scholar]
- 4.Khan S.K., Khanna A., Parker M.J. Posterior multifragmentation of the femoral neck: does it portend a poor outcome in internally fixed intracapsular hip fractures? Injury. 2009;40(3):280–282. doi: 10.1016/j.injury.2008.08.008. [DOI] [PubMed] [Google Scholar]
- 5.Rogmark C., Flensburg L., Fredin H. Undisplaced femoral neck fractures--no problems? A consecutive study of 224 patients treated with internal fixation. Injury. 2009;40(3):274–276. doi: 10.1016/j.injury.2008.05.023. [DOI] [PubMed] [Google Scholar]
- 6.Lu-Yao G.L., Keller R.B., Littenberg B., Wennberg J.E. Outcomes after displaced fractures of the femoral neck. A meta-analysis of one hundred and six published reports. J Bone Jt Surg. 1994;76(1):15–25. doi: 10.2106/00004623-199401000-00003. [DOI] [PubMed] [Google Scholar]
- 7.Parker M., Cawley S., Palial V. Internal fixation of intracapsular fractures of the hip using a dynamic locking plate. Bone Joint J. 2013;95-B(10):1402–1405. doi: 10.1302/0301-620x.95b10.31511. [DOI] [PubMed] [Google Scholar]
- 8.Leadbetter G.W. A treatment for fracture of the neck of the femur. Reprinted from J Bone Joint Surg 20:108-113, 1938. Clin Orthop Relat Res. 2002;(399):4–8. [PubMed] [Google Scholar]
- 9.Aminian A., Gao F., Fedoriw W.W., Zhang L.-Q., Kalainov D.M., Merk B.R. Vertically oriented femoral neck fractures: mechanical analysis of four fixation techniques. J Orthop Trauma. 2007;21(8):544–548. doi: 10.1097/bot.0b013e31814b822e. [DOI] [PubMed] [Google Scholar]
- 10.Osarumwense D., Tissingh E., Wartenberg K. The Targon FN system for the management of intracapsular neck of femur fractures: minimum 2-year experience and outcome in an independent hospital. Clin Orthop Surg. 2015;7(1):22–28. doi: 10.4055/cios.2015.7.1.22. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Conn K.S., Parker M.J. Undisplaced intracapsular hip fractures. Clin Orthop Relat Res. 2004;421:249–254. doi: 10.1097/01.blo.0000119459.00792.c1. [DOI] [PubMed] [Google Scholar]
- 12.Biber R., Brem M., Bail H.J. Targon Femoral Neck for femoral-neck fracture fixation: lessons learnt from a series of one hundred and thirty five consecutive cases. Int Orthop. 2014;38(3):595–599. doi: 10.1007/s00264-013-2176-y. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Brandt E., Verdonschot N. Biomechanical analysis of the sliding hip screw, cannulated screws and Targon1 FN in intracapsular hip fractures in cadaver femora. Injury. 2011;42(2):183–187. doi: 10.1016/j.injury.2010.08.021. [DOI] [PubMed] [Google Scholar]
- 14.Griffin XL, Parsons N., Achten J., Costa ML. The Targon Femoral Neck hip screw versus cannulated screws for internal fixation of intracapsular fractures of the hip. Bone Joint J. 2014;96-B(5):652–657. doi: 10.1302/0301-620x.96b5.33391. [DOI] [PubMed] [Google Scholar]