Sliding hip screw versus intramedullary nail for trochanteric hip fractures; a randomised trial of 1000 patients with presentation of results related to fracture stability

Accepted Manuscript Title: Sliding hip screw versus intramedullary nail for trochanteric hip fractures; a randomised trial of 1000 patients with presentation of results related to fracture stability Author: Martyn J. Parker PII: DOI: Reference:

S0020-1383(17)30717-9 https://doi.org/10.1016/j.injury.2017.10.029 JINJ 7462

To appear in:

Injury, Int. J. Care Injured

Received date: Revised date: Accepted date:

8-9-2017 12-10-2017 18-10-2017

Please cite this article as: Parker Martyn J.Sliding hip screw versus intramedullary nail for trochanteric hip fractures; a randomised trial of 1000 patients with presentation of results related to fracture stability.Injury https://doi.org/10.1016/j.injury.2017.10.029 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

1

Sliding hip screw versus intramedullary nail for trochanteric hip fractures; a randomised study of 1000 patients with presentation of results related to fracture stability Martyn J. Parker MD, FRCS(Edinb) Consultant Orthopaedic Surgeon [email protected] From the Department of Orthopaedics Peterborough City Hospital Peterborough and Stamford Hospital NHS Foundation Trust, Bretton Gate Peterborough PE3 9GZ England

Abstract Aims To determine the optimum choice of implant for a patient with a the different types of trochanteric hip fracture Patients and methods 1000 patients with a trochanteric hip fracture were randomised to internal fixation of the fracture with either a Sliding Hip Screw or an intramedullary nail. Fractures were subdivided into two part fractures, comminuted fractures and fractures at the level of the lesser trochanter (reversed/oblique and transverse). Functional assessment for up to one year from injury was undertaken by a research nurse blinded to the treatment allocation. Results The mean age of patients was 82 years and 77% were female. There was a significantly improved regain of mobility for those treated with the intramedullary nail. No statistically significant differences between the two types of fixation methods was observed for mortality, fracture healing complications, re-operations, hospital stay, length of surgery, blood transfusion requirements, medical complications, degree of residual pain or regain of independence. These finding were valid for all fracture types. Conclusion

2

This study is the first adequately powered randomised trial on this topic and demonstrates that there are no notable differences in either process or functional outcomes between these two treatment methods, other than a tendency to better regain of mobility for those fractures fixed with an intramedullary nail.

Key words Trochanteric hip fractures, randomised trial, internal fixation

Introduction Over the last 20 years there has been continued debate over the merits of intramedullary versus extramedullary fixation for extracapsular hip fractures. Early randomised trials suggested superior results with extramedullary fixation with the sliding hip screw.1 Essentially these studied showed no difference in mortality or functional outcomes but an increased fixation failure rate for the nails, due predominantly to fracture around the distal tip of the implant. Over the years numerous modifications have been made to the different types of intramedullary nail, such that the findings of the early studies comparing the two types of implant are no longer valid.1,2 These studies have led to the conclusion that if there are any differences between intramedullary and extramedullary fixation for trochanteric hip fractures they are likely to be small. This means that in order to determine if any clinically significant differences exist between these treatment methods adequately sized randomised trials will be needed. 3 Such studies involving at least 400 patients are required to detect minimum clinically significant difference in pain or mobility whist for other outcomes such as fracture fixation complications at least 1000 patients are requred.3,9,10

Trochanteric fractures can be broadly divided into three main groups. Stable two part factures (AO type A1, Evans stable Type 1), comminuted trochanteric (three or four part fractures, AO

3

type A2, Evans unstable Type 1) and transtrochanteric fractures with a transverse of reversed/oblique fracture line at the lever of the lesser trochanter (AO type A3, Evans Type 2).4,5,6 Various authors have suggested that the Sliding Hip Screw(SHS) fixation is most appropriate for stable fractures, an intramedullary nail possibly for the unstable fractures and that the A3 fractures should definitely be treated with an intramedullary nail.7,8 These theories regarding fracture type and fixation methods have never been supported by clinical studies.

From April 2002 to December 2009 we have undertaken a randomised controlled trial comparing the Sliding Hip Screw with initially the Targon PF intramedullary nail (600 cases) and latterly the Targon PFT nail (400 cases). The results for these two studies have been reported separately.9,10 This report is for these two studies but with presentation of outcomes related to the three main fracture subdivisions.

Patients and methods Details of the trial methods have been published previously.9,10 The trial included patients with stable (A1), unstable (A2) and transtrochanteric fractures (A3). Basal fractures were also included and considered as A1 fractures for the analysis of results. Pathological fractures from tumors and subtrochanteric fractures were excluded. Patients were randomised by the opening of numbered opaque sealed envelopes to fixation of the fracture with either the Sliding Hip Screw or an intramedullary nail. All operations were undertaken or supervised by a single specialised hip fracture surgeon. All SHS fixation were with a four or five hole 1350 plate and no supplementary fixation or stabilising plates. All nail fixation were with a 1300 nail with dynamic distal locking and no supplementary fixation. The first 300 nail fixations were with the Targon PF nail and the last 200 with the Targon PFT nail (B.Braun, Tuttlingen, Germany). The differences between the two nails were an upgrade of the operative instruments and a change of the lag screw to a one piece dynamic tele-screw. Other than the difference in the nail design the trial protocol was identical for both studies.9,10 Patients gave

4

informed consent for the study and for those patient with dementia consent from the patient next of kin or legal guardian was obtained . All surviving patients were followed up for a minimum of one year with functional assessment undertaken by a nurse blinded to the treatment allocation. Six patients were lost to follow up at a mean of 74 days post injury. Any fracture healing complications identified beyond one year from injury when also included in the outcomes.

Statistical analysis. Binary outcomes for the two groups were analysed using Fisher exact test and continuous outcomes with the unpaired t-test. For the length of hospital stay the data was not parametric so the Mann Whitney U test was utilized. A p-value of p < 0.05 was considered as statistically significant. All results were analysis on an intention-to-treat basis. (GraphPad InStat version 3.00 for Windows 95, GraphPad Software, San Diego California USA).

Results The characteristics of the two groups of patients are detailed in Table 1. None of the differences between the two groups were statistically significant.

Table 2 lists the operative details for the two groups. The total institutional stay included all stay in any other hospital wards or rehabilitation units. Wound infections and general medical complications are detailed in table 3. There were no significant differences between groups for any of the outcomes listed.

Table 4 details the fracture healing complications and secondary operations required for these complications. Within the nail group there was one patient who was incorrectly included in the trial as the x-rays were misinterpreted as a trochanteric fracture but was found at the time of surgery to have a displaced intracapsular fracture which was fixed with a nail. The fracture

5

developed non-union which was treated conservatively. This complication is not included in table 4.

Figure 1 details the survival for up to one year from fracture for the two groups. There was no significant difference between groups at any of the time intervals.

Figure 2 details the mean pain scores related to fracture type and implant. There were no statistically significant differences between the two implants at any time interval for the group as a whole or related to the fracture type except for A3 fractures at nine months (p=0.02) with less pain for those treated with the intramedullary nail.

Figure 3 gives the change in mobility score at the follow-up assessments. There was a consistent finding of superior regain of mobility for those treated with the intramedullary nail for those with A1 and A2 fractures, although the results were not found to be statistically significant for all assessments due to the reduced patient numbers for the A1 fractures. No significant difference was found for the A3 fractures. The number of patient assessed was less for this fracture type with only 61 patients being assessed at one year from injury.

Discussion The advantages of this study are the large patient numbers, secure randomisation of patients, minimal loss to follow-up, intention to treat analysis and blinded assessment of functional outcomes. This is the first study to date with adequate patient numbers to be able to assess any relevant differences between the two implant types. The minimal differences between the two treatment methods emphasises the need for large randomised studies with carful methodology to be able to show any small differences that may exist between these two types of implant.3

6

For the first 600 patients in this study there was an increased operation time and more intraoperative problems for the nail group.9 This was not the case for the second part of the study.10 The change to the instrumentation for the Targon PFT nail has led to a reduced length of surgery for the intramedullary nail and no demonstrable difference in the occurrence of fracture healing complications between the two nail designs.

Regarding fracture healing complication there were no notable differences between the SHS and the intramedullary nails. The cut-out rate was 1% and similar for both implants. The next most frequent complication was either detachment of the plate from the femur for the Sliding Hip Screw (0.8%) or re-fracture around the tip of the nail (0.8%). The occurrence of fractures at the tip of the nail is less common than earlier reports for intramedullary nails. This is possible due to the smaller diameter of the nail, tapered nail tip and the smaller diameter of the distal locking screws.1

A possible problem with the study is there may be later complications related to the implants that occur outside the follow period of this study or where the patient attends a different hospital. Such cases will be few as the majority of patient reside in the same area with a single hospital providing the hip fracture service. Therefore most hip fracture healing complications are always referred back to the same centre. We have included within this study all complications that were identified from the start of the study up to February 2017. For those patient requiring revision surgery seven (35% of revisions) occurred after one year from injury. These complications were avascular necrosis (2), fracture at the tip of the nail (3), implant cut-out (1) and non-union (1).

The large patient numbers within this study have enabled subdivision of outcomes for the different fracture types. The results presented demonstrate that there is no difference between the two types of fixation for the occurrence of fracture healing complications related to the fracture type. A power calculation based on the mobility score used in this study indicates that

7

up to 600 patients (300 in each group) are required before a minimally clinically significant difference can be excluded.9 Therefore for those subgoups with lesser patient numbers no firm conclusions can be made. Despite these reductions in patient numbers, the differences in regain of mobility were similar for both stable and unstable (A1 and A2) fracture types (table 6). Surprisingly the difference between implant types for the A3 fractures was minimal. Biomechanical studies, particularly those related to A3 fractures have suggesting the superiority of an intramedullary nail, 13,14 particularly for A3 fractures and this has been supported by a data from a hip fracture register, showing a tendency to a lower fracture healing complication rate with intramedullary fixation.15 This study found no clinical superiority for the nail in A3 fractures and both implants have similar rates of fracture healing complications. Unfortunately because of the limited patient numbers in this study no firm conclusions can therefore be made for the optimum choice of implant for this fracture type and further studies are indicated.

Functional outcomes were assessed by a blinded nurse to eliminate observer biases. With the adequate patient number a clear trend to better regain of mobility was demonstrated for those treated with the intramedullary nail. A possible reason for this that has been suggested from previous studies is the reduced collapse that occurs at the fracture after intramedullary fixation due to the proximal part of the intramedullary nail.16,17,18 Extramedullary and intramedullary fixations have been compared previously in numerous randomised trials, but many did not assess functional outcomes whilst others had insufficient patient numbers to evaluate any small differences. The Cochrane review in 2010 identified 44 randomised studies involving in excess of 6446 patients.1 Only three reported better regain of mobility for the intramedullary nail.19,20,21 The remaining studies reported either no difference in regain of mobility between implants or failed to report on this outcome.

8

Many centers have recently abandoned the Sliding Hip Screw in favor of an intramedullary nail, particularly for the unstable A2 and A3 fractures. This study does provide some support for this policy to provide improved regain of mobility. Furthermore the advantages of the nail appear to apply also to A1 fractures. Numerous modifications to the design of intramedullary nails continue and these changes require evaluation within adequately sized clinical studies to enable the optimum nail design to be determined.

In summary these two randomised trials represent the first clinical study with sufficient patient numbers to comprehensively compare intramedullary versus extramedullary fixation. Essentially both method of fixation produce similar outcomes, other than a slightly better regain of mobility for those treated with the intramedullary nail. These finding may not be the same for all types of intramedullary nail or in other clinical situations with varying degrees of surgical expertise for which further research is required to confirm these outcomes.

Ethics committee Re - Sliding hip screw versus intramedullary nail for trochanteric hip fractures; a randomised

study of 1000 patients with presentation of results related to fracture stability

Ethics committee approval for this study was from Peterborough and Fenland Regional Ethics Committee ( reference LREC P01/120) and Cambridgeshire 3 Regional Ethics Committee (reference 10/H0306/66).

Conflict of interest statement The author has received benefits for personal or professional use from a commercial party related directly or indirectly to the subject of this article.

Acknowledgements The study was funded internally from the Peterborough Hospitals Hip Fracture Research Fund to cover research expenses and those of the research nurse.

9

References 1. Parker MJ, Handoll HHG. Gamma and other cephalocondylic intramedullary nails versus extramedullary implants for extracapsular hip fractures in adults. Cochrane Database of Systematic Reviews 2010, Issue 9. Art. No.: CD000093.

2. Bhandari M, Schemitsch E, Jonsson A, Zlowodzki M, Haidukewych G. Gamma nails revisited: gamma nails versus compression hip screws in the management of intertrochanteric fractures of the hip: a meta-analysis. J Orthop Trauma 2009;23:4604.

3. Bhandari M, Sprague S, Schemitsch EH, International Hip Fracture Research Collaboration. Resolving controversies in hip fracture care: The need for large collaborative trails in hip fractures. J Orthop Trauma 2009;23:479-84.

4. Evans EM. The treatment of trochanteric fractures of the femur. J Bone Joint Surg 1949;31-B:190-203.

5. Orthopaedic Trauma Association, Committee for Coding and Classification: Fracture and dislocation compendium. J Orthop Trauma 1996;10(1 Suppl):S1-154.

6. Pervez H, Parker MJ, Pryor GA, Lutchman L, Chirodian N. Classification of trochanteric fracture of the proximal femur; a study of the reliability of current systems. Injury 2002;33:713-715.

10

7. Kaplan K, Miyamoto R, Levine BR, Egol KA, Zuckerman JD. Surgical management of hip fractures: an evidence based review of the literature. II: intertrochanteric fractures. J Am Acad Orthop Surg 2008;16:665-73.

8. Swart E, Makhni Ec, Macaulay W, Rosenwasser MP, Bozic KJ. Cost-effectiveeness analysis of fixation options for intertrochanteric hip fractures. J Bone Joint Surg Am 2014;96:1612-20.

9. Parker MJ, Bowers TR, Pryor GA. Sliding hip screw versus the Targon PF nail in the treatment of trochanteric fractures of the hip: A randomised trial of 600 fractures. J Bone Joint Surg Br 2012 94-B:391-397.

10. Parker MJ, Cawley S. Sliding hip screw versus the Targon PFT nail for trochanteric hip fractures: a randomised trial of 400 patients. Bone & Joint Journal 2017;99B(9):121-15..

11. Parker MJ, Palmer CR. A new mobility score for predicting mortality after hip fracture. J Bone Joint Surg Br 1993;75:797–8.

12. Qureshi KN, Hodkinson HM. Evaluation of a ten-question mental test in the institutionalised elderly. Age Ageing 1974;3:152–7.

13. Curtis MJ, Jinnah RH, Wilson V, Cunningham BW. Proximal femoral fractures: a biomechanical study to compare intramedullary or extramedullary fixation. Injury 1994;25:99-104.

11

14. Tencer AF, Johnston KD, Johnston DWC, Gill K. A biomechanical comparison of various methods of stabilisation of sub-trochanteric fractures of the femur. J Orthop Trauma 1984;2:297-305.

15. Matre K, Havelin LI, Gjertsen JE, Vinje T, Espehaug B, Fevang JM. Sliding hip screw versus IM nail in reverse oblique trochanteric and subtrochanteric fractures. A study of 2716 patients in the Norwegian Hip Fracture Register. Injury. 2013;44(6):735-742.

16. Pajarinen J, Lindahl J, Savolainen V, Michelsson O, Hirvensalo E. Femoral shaft medialisation and neck-shaft angle in unstable pertrochanteric femoral fractures. Int Orthop 2004 Dec;28:347-53

17. Reindl R, Harvey EJ, Berry GK, Rahme E. Intramedullary versus extramedullary fixation for unstable intertrochanteric fractures: a prospective randomized controlled trial. J Bone J Surgery 2015;97-A:1905-12.

18. Bretherton CP, Parker MJ. Femoral medialization, fixation failures and functional outcome in trochanteric hip fractures treated with either a sliding hip screw or intramedullary nail from within a randomised trial. Journal of Orthopaedic Trauma 2016;30:642-646.

19. Dujardin FH, Benez C, Polle G, Alain J, Biga N, Thomine JM. Prospective randomized comparison between a dynamic hip screw and a mini-invasive statis nail in fractures of the trochanateric area: preliminary results. J Orthop Trauma 2001;15:401-6.

12

20. Hardy DC, Descamps P, Krallis P, Fabeck L, Smets P, Bertens CL, et al. Use of an intramedullary hip-screw compared with a compression hip-screw with a plate for intertrochanteric femoral fractures. A prospective, randomized study of one hundred patients. J. Bone Joint Surg (Am) 1998;80(5):618-30.

21. Little NJ, Verma V, Fernando C, Elliott DS, Khaleel A. A prospective trial comparing the Holland nail with the dynamic hip screw in the treatment of intertrochanteric fractures of the hip. J Bone Joint Surg Br 2008;90-B:1073-8.

13

Legends for figures Figure 1. Patient survival curve for the two implants.

Figure 2. Mean pain scores for the different implants and fracture types.

Figure 3. Mean change in mobility scale for the different implants and fracture types.

14

Table 1. Characteristics of patients [range]. Sliding hip screw (SHS)

Intramedullary nail

Number of patients

500

500

Mean age in years [range]

82.1 [25-105]

82.2 [26-104]

Number male (%)

116 (23.2%)

112 (22.4%)

From own home (%)

379 (75.8%)

391 (78.2%)

Mean mobility score 11

5.4

5.3

Mean mental test score 12

6.3

6.3

Mean ASA score

2.7

2.7

ASA grade one or two (%)

180 (36.0%)

166 (33.2%)

Mean haemoglobin on admission

121g/l

119g/l

0

1 (0.2%)

Fracture type Displaced intracapsular Basal fracture (%)

11 (2.2%)

12 (2.4%)

Stable trochanteric (A1) (%)

83 (16.6%)

87 (17.4%)

Unstable trochanteric (A2) (%)

364 (73.0%)

353 (70.6%)

Transtrochanteric (A3) (%)

42 (8.4%)

47 (9.4%)

15

Table 2. Operative details and hospital stay [standard deviation].

Sliding hip screw

Intramedullary nail

P value

Mean length of anaesthesia

59 minutes [13.3]

60 minutes [13.0]

0.23

Mean length of surgery

44 minutes [11.9]

45 minutes [12.8]

0.20

Required blood transfusion

149 (29.8%)

145 (29.0%)

0.84

Mean units blood transfused

0.56 [0.93]

0.58 [0.98]

0.74

Mean days acute ward stay

16.0

17.1

0.4

Mean total institutional stay

21.5

23.4

0.5

Total stay including readmission

22.8

24.3

0.7

16

Table 3. Wound infections and general medical complications encountered. Sliding hip screw Superficial wound infection

5(1.0%)

Intramedullary nail

p value

6(1.2%)

1.0

Deep wound infection

2(0.4%)

0

0.50

Confusion/delirium

14(2.8%)

13(2.6%)

1.0

Pneumonia

13(2.6%)

18(3.6%)

0.47

Pressure sores

11(2.2%)

12(2.4%)

1.0

Urine retention

8(1.6%)

18(3.6%)

0.07

Deep vein thrombosis

10(2.0%)

11(2.2%)

1.0

Pulmonary embolism

2(0.4%)

3(0.6%)

1.0

Cerebrovascular accident

1(0.2%)

1(0.2%)

1.0

Myocardial infarction

4(0.8%)

1(0.2%)

0.37

Congestive cardiac failure

7(1.4%)

2(0.4%)

0.18

Cardiac arrhythmia

10(2.0%)

6(1.2%)

0.45

Gastrointestinal bleed

17(3.4%)

9(1.8%)

0.16

Peritonitis

1(0.2%)

2(0.4%)

1.0

Intestinal obstruction

1(0.2%)

0

1.0

Acute renal failure

4(0.8%)

5(1.0%)

1.0

Clostridia diarrhoea

4(0.8%)

2(0.4%)

0.69

Septicaemia

0

1(0.2%)

1.0

Fat embolism

0

1(0.2%)

1.0

17

Table 4. Fracture healing complications and secondary surgery.

Fracture type

Sliding hip screw

Intramedullary nail

P value

All fractures

7 (1.5%)

3 (0.6%)

0.34

A1

2 (0.3%)

0

0.24

A2

4 (1.1%)

1 (0.3%)

0.37

A3

1 (0.3%)

2 (4.3%)

1.0

Plate off the femur or

All fractures

4 (0.8%)

4 (0.8%)

1.0

fracture below implant

A1

0

0

A2

4 (1.1%)

3 (0.8%)

1.0

A3

0

1 (2.2%)

1.0

All fractures

4 (0.8%)

2 (0.4%)

0.69

A1

0

0

A2

3 (0.8%)

1 (0.3%)

0.62

A3

1 (2.4%)

1 (2.1%)

1.0

All fractures

1 (0.2%) (A2

1(0.2%) (A2

1.0

fracture)

fracture)

All fractures

16 (3.2%)

10 (2.0%)

0.32

A1

2 (0.5%)

0

0.50

A2

12 (3.3%)

6 (1.7%)

0.23

A3

2 (4.8%)

4 (8.5%)

0.68

Re-operation -

All fractures

7 (1.4%)

3 (0.6%)

0.34

arthroplasty

A1

3 (3.2%)

0

0.11

A2

4 (1.1%)

1 (0.3%)

0.37

A3

0

2 (4.3%)

0.50

Re-operation -

All fractures

4 (0.8%)

6 (1.2%)

0.75

revision fixation

A1

0

1 (1.0%)

1.0

A2

4 (1.1%)

4 (1.1%)

1.0

A3

0

1 (2.1%)

1.0

Cut out

Non-union

Avascular necrosis

All complications