Injury, Int. J. Care Injured 46 (2015) 1023–1027
Contents lists available at ScienceDirect
Injury journal homepage: www.elsevier.com/locate/injury
Lateral versus posterior approach for insertion of hemiarthroplasties for hip fractures: A randomised trial of 216 patients Martyn J. Parker * Peterborough and Stamford Hospital NHS Foundation Trust, Department of Orthopaedics, Peterborough City Hospital, CBU PO Box 211, Core C, Bretton Gate, Peterborough PE3 9GZ, England, United Kingdom
A R T I C L E I N F O
A B S T R A C T
Article history: Accepted 19 February 2015
Continued debate exists about the merits of the different surgical approaches for arthroplasty of the hip. For hemiarthroplasty to the hip the two most commonly used approaches are lateral and posterior. 216 patients with an intracapsular hip fracture being treated with a cemented hemiarthroplasty were randomised to surgery using either a lateral or posterior approach. Surviving patients were followed up for one year with pain and functional outcomes assessed by an assessor blinded to the treatment allocation. No statistically significant differences were observed for any of the outcome measures including mortality, degree of residual pain and regain of walking ability. A subjective assessment of the ease of surgery favoured the lateral approach. In conclusion both surgical approaches appear to produce comparable function outcomes. ß 2015 Elsevier Ltd. All rights reserved.
Keywords: Hip fracture Surgical approach Randomised trial
Introduction
Patients and methods
Insertion of a hemiarthroplasty for a hip fracture is one of the commonest procedures undertaken in Orthopaedics. In excess of one million such procedures are undertaken annually around the world [1]. A number of different surgical approaches may be used for the operation including the anterior, anterio-lateral, lateral and posterior approach. Currently the two most commonly used approaches for hemiarthroplasty to the hip are the lateral [2]. and the posterior approach [3]. The posterior approach is claimed to result in better regain of function as there is less damage to the hip muscles [4], whilst the anterior and lateral approaches have a lower risk of dislocation [5]. Despite the frequency of this operative procedure there are no contemporary randomised trials between the different surgical approaches for hemiarthroplasty to the hip. The aim of the study was to assist in defining the optimum surgical approach to the hip joint for insertion of a hemiarthroplasty for an acute hip fracture using a randomised controlled trial. The primary outcome measure was the regain of walking ability. Secondary outcome measures recorded included mortality, ease of surgery, length of surgery, operative blood loss, blood transfusion, post-operative complications, hospital stay, need for subsequent revision surgery and the degree of residual pain.
The inclusion criteria were all patients admitted to Peterborough District Hospital Hospital (latterly Peterborough City Hospital) with a displaced intracapsular fracture that was to be treated with cemented hemiarthroplasty. For patients who lacked capacity to consent, inclusion within the study was with the assent of the patient’s next of kin or legal guardian. Exclusion criteria were patients who declined to participate, patients without the capacity to give informed consent and the next of kin or patient’s representative was unavailable to give assent or declines assent and patients admitted when the lead researcher (MJP) was not available to supervise treatment. Other exclusion criteria were patients with a pathological fracture requiring a specific prosthesis or procedure and patients treated conservatively due to poor health or late presentation. Patients in which an uncemented arthroplasty was used to avoid bone cement were also excluded as were patients in whom a total hip replacement was chosen as the primary treatment in preference to a hemiarthroplasty. Also excluded were patients who were entered in one of two concurrently running randomised studies or hemiarthroplasty versus internal fixation for male patients or hemiarthroplasty versus total hip replacement. Patient assessment on admission included recording the patients residential status, ASA grade [6], mobility score [7,8] and mental test score [9]. Randomisation was by opening of numbered sealed opaque envelopes containing details of the operation to be used. The envelopes were prepared by a person
* Tel.: +44 01733 678000x1133; fax: +44 01733 678532. E-mail address: [email protected] http://dx.doi.org/10.1016/j.injury.2015.02.020 0020–1383/ß 2015 Elsevier Ltd. All rights reserved.
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M.J. Parker / Injury, Int. J. Care Injured 46 (2015) 1023–1027
independent to the study. Once randomised all patients had to stay within the group to which they were randomised. To standardise surgical technique, all operations were undertaken or directly supervised by MJP. A cemented monoblock Exeter stem hemiarthroplasty (ETS) was used for all patients. Pre-operative and post-operative care protocols were identical for both groups with all patients being encouraged to mobilise fully weight bearing with no restriction on hip movements. For their surgery all patients were positioned on their side and a minimal surgical exposure used, in which whenever possible incisions were less than 10cms in length. The lateral approach involved splitting the tendon to the gluteus medius muscle with two thirds being left intact and a third of the muscle retracted anteriorly to expose the anterior hip joint capsule. The capsule was opened with a T shaped cut and later repaired after insertion of the prosthesis. For the posterior approach the piriformis tendon was preserved and the other short rotators cut and retracted posteriorly. An L shaped cut to the capsule was made along the line of the femur and then posteriorly immediately distal to the piriformis tendon. After insertion of the prosthesis both the capsule and tendons to the short rotators were repaired. For each patient a subjective assessment of the difficulty of surgery was made by MJP using the criteria shown in Table 1. After discharge from hospital follow-up of patients was initially in a hip fracture clinic at eight weeks from admission. At this visit an assessment was undertaken by a research nurse blinded to the type of surgical approach used. Pain was assessed on a modified Charnley pain score (Table 2) [10]. Mobility, use of walking aids and residential status were recorded [7,8]. Measurement of limb shortening, hip flexion and a Trendelenburg test were undertaken for those with a normal contra-lateral hip. Subsequent assessments by the research nurse were by telephone at three, six, nine and 12 months from injury. No patient was lost to follow-up. Surgical complications detected at the follow-up clinic were recorded. In addition, if any patient was referred back for any problems related to the hip these complications were included in the presentation of the results. The primary outcome for the study was regain of mobility using a mobility score [7]. This score has been validated and found to be
Table 1 Subjective assessment of surgically difficulty. Score 1 = No difficulties encountered during surgery Score 2 = Mild difficulty such as needing repeated adjustment of retractors for exposure or mild difficulty on reduction the prosthesis. Score 3 = Moderate difficulty such as extensive problems to achieve exposure or repeated attempts needed to obtain reduction of the prosthesis. Score 4 = Severe difficulty. Need to extend the wound to achieve exposure or more extensive tissue dissection required to obtain reduction of the prosthesis.
Table 2 Pain scale used. Score 1 = No pain at all in the hip. Score 2 = Occasional and slight pain. May occasionally take mild analgesia such as paracetamol. Score 3 = Some pain when starting to walk, no rest pain. Occasional analgesia taken. Score 4 = None or minimal pain at rest, some pain with activities, frequent mild. analgesia Score 5 = Regular pain with activities which limits walking distance. Occasional or mild rest pain. Score 6 = Frequent rest pain and pain at night. Pain on walking. Regular mild analgesia and occasional stronger analgesia taken. Score 7 = Constant pain present around the hip. Regular mild analgesia and frequent strong analgesia. Score 8 = Constant and severe pain in the hip requiring regular strong analgesia such as opiates.
reproducible [8]. The score has a range of 0 (worst) to nine (best). A clinically relevant difference between the two groups would be a difference of 1.0 for the change in mobility score. Assuming that the outcome measure of mobility has a normal distribution and for a 2sided significance level of 0.05 and a power of 80% for a difference of 1 point, then a total of 264 patients are required using a standard deviation of 2.9 taken from previous studies. To allow for loss of patients from follow-up (normally 2–3%) and due to deaths (30% mortality at one year), a total study number of 400 patients would be required. There was no external source of funding for this study. Internal funding was from the Peterborough Hospitals Hip Fracture Fund. The study had research ethics approval and approval of the Hospital Research and Development Committee. Binary outcomes for the two groups were analysed using Fisher exact test and continuous outcomes with the unpaired two tailed ttest (GraphPad InStat version 3.00 for Windows 95, GraphPad Software, San Diego California USA). A p-value of p < 0.05 was considered as statistically significant. All results were analysis on an intention-to-treat basis. Results Patients were recruited to the study from December 2009 till July 2013. Fig. 1 gives the flow diagram for the patient’s included and excluded from the study. All patients had treatment as dictated by the study. One patient in the posterior group with a narrow femur had a cemented small stem bipolar hemiarthroplasty rather than a standard stem size ETS hemiarthroplasty. Four fractures (two in each group) were pathological secondary to bone secondaries. Table 3 details the characteristics of the patients at the time of admission. There were no significant differences between groups. Table 4 details the operative details and surgical complications encountered for the two groups. The only statistically significant difference was the surgeon’s subjective assessment of the difficulty of surgery. The posterior approach was felt to be slightly more difficult. Small operative fracture of the femur referred to fracture of the greater trochanter that required no specific treatment whilst larger operative femur fracture refers to a fracture at the level of the lesser trochanter requiring cerclage wiring. Table 5 details the general medical complications encountered between the two groups demonstrating no differences between the two surgical approaches. There was no difference in the mean hospital stay between groups (20.3 days versus 18.5 days, p = 0.4) or the proportion of surviving patients discharged from hospital back to their original residence (95.1% versus 92.2%, p = 0.4). Fig. 2 details the mortality for the two groups with no significant difference between groups at any time period. The 30 day and one year mortality for the lateral group was 4 (3.7%) and 19 (17.9%) versus 5 (4.6%) and 20 (18.5%) for the posterior approach. Figs. 3 and 4 detail the mean pain and mean mobility scores at the set time periods from injury for which there were no statistically significant differences between groups. Discussion The conclusion of this study is that there were no notable differences in outcomes between the two procedures. The posterior approach was felt to be technically more difficult, and in the absence of any trend to improved functional outcomes with the posterior approach, it was decided to stop the study with only 179 patients having completed the one year follow-up as opposed to the 264 originally proposed. The patient numbers within this study were too small to determine differences in the surgical complications detailed in Table 3. One of the most frequently quoted advantages of the
M.J. Parker / Injury, Int. J. Care Injured 46 (2015) 1023–1027
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Fig. 1. Flow diagram for participants. *Some patients may be excluded for more than one reason.
Table 3 Characteristics of the two groups at admission (percentage).
Patient numbers Mean age [range] Female From own home Residential care Nursing home Fall in hospital ASA grade 1 or 2 Mean mental test score Mean mobility score Mean haemoglobin g/l
Table 5 General complications (percentage).
Lateral
Posterior
p value
108 84.3 [61–100] 100 (92.6%) 92 (85.2%) 11 (10.2%) 3 (2.8%) 2 (1.9%) 44 (40.7%) 7.1 6.8 122.9
108 83.6 [65–99] 98 (90.7%) 88 (81.4%) 15 (13.9%) 2 (1.9%) 3 (2.8%) 43 (39.8%) 6.9 7.1 121.9
0.5 0.8 0.5 0.5 1.0 1.0 1.0 0.6 0.3 0.6
Pneumonia Congestive cardiac failure Atrial fibrillation Acute renal injury Urinary retention Perforated peptic ulcer Gastrointestinal bleed Deep vein thrombosis Pulmonary embolism Pressure sores Delirium Cerebrovascular accident Intestinal obstruction
Lateral
Posterior
p value
3 1 1 2 1 1 0 1 1 4 8 0 2
2 2 0 0 0 0 2 1 0 3 2 1 1
1.0 1.0 1.0 0.5 1.0 1.0 0.5 1.0 1.0 1.0 0.1 1.0 1.0
(2.9%) (0.9%) (0.9%) (1.9%) (0.9%) (0.9%) (0.9%) (0.9%) (3.8%) (7.5%) (1.9%)
(1.9%) (1.9%)
(1.9%) (0.9%) (2.9%) (1.9%) (0.9%) (0.9%)
Table 4 Operative details and post-operative implant complications (percentage).
Length surgery (min) Number of patients transfused Mean units blood transfused Mean difficulty level Small operative fracture femur Larger operative fracture femur Wound haematoma Superficial wound infection Deep wound infection Sciatic nerve palsy Dislocation Later fracture around implant Re-operation – revision arthroplasty Re-operation – girdlestone Re-operation – fixation fracture
Lateral
Posterior
p value
53.6 14 (13.2%) 0.19 1.7 6 (5.7%) 0 1 (0.9%) 3 (2.9%) 0 0 2 (1.9%) 1 (0.9%) 1 (0.9%) 1 (0.9%) 1 (0.9%)
54.0 21 (19.8%) 0.31 2.0 1 (0.9%) 1 (0.9%) 0 2 (1.9%) 2 (1.9%) 2 (1.9%) 1 (0.9%) 4 (3.8%) 0 1 (0.9%) 3 (2.9%)
0.8 0.3 0.2 0.007 0.1 1.0 1.0 1.0 0.5 0.5 1.0 0.4 1.0 1.0 0.6
lateral approach is the lower risk of dislocation. A review of the literature involving 14,846 hemiarthroplasties reported a dislocation rate of 2.1% for the lateral approach versus 5.0% for the posterior approach [5]. There was only one dislocation in the
posterior group in this study which may be related to preserving the piriformis tendon. This acts as a block to the prosthesis dislocating posteriorly [11]. It is possible that preserving the piriformis tendon may have contributed to the two sciatic nerve palsies that were encountered after the posterior approach, as the nerve may not have been retracted so far posteriorly than if the piriformis had been detached. There was a tendency for more patients to present with a later fracture of the femur in the posterior group this study (one versus four cases). A previous study had also noted a tendency for more of such fractures to occur with the posterior approach in comparison to the lateral approach [12]. Regain of function was the primary outcome for this study for which there was no trend to any differences in regain of mobility between the two groups. We also tried to assess adductor function using the trendelenburg test in those patients able to cooperate and with a normal contra-lateral hip. Unfortunately this was possible in only 80 patients but there was no difference between groups. Shortening of the limb was more common within the posterior group which would have been related to surgical
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M.J. Parker / Injury, Int. J. Care Injured 46 (2015) 1023–1027
Fig. 2. Kaplan–Meier mortality graph for the two groups.
Fig. 3. Mean pain scores for the two groups. Fig. 4. Mean mobility scores for the two groups.
technique. The mean difference was only 2 mm which would be unlikely to affect hip function. The advantages of this study were the secure randomisation of patients, standardised surgical technique with all operations undertaken or directly supervised by a single hip fracture surgeon, no loss to follow-up of patients and the blinded assessment of outcome. The prosthesis chosen was a modern stem arthroplasty and is one of the most commonly used hemiarthroplasties in the United Kingdom. A potential disadvantage was that the surgeon involved had more previous experience of the lateral approach. To minimise this potential source of bias and refine the surgical technique a series of posteriorly inserted arthroplasties was undertaken prior to starting the study. The Cochrane group has undertaken an extensive literature search on this topic and identified only one previous randomised trial of surgical approach relevant to hip fractures [13]. This study
randomised 114 patients to either a posterior or lateral approach. Those allocated to the posterior approach were nursed flat in bed for two weeks after surgery whilst those from the lateral group were mobilized immediately. There was an increased risk of medical complications, particularly pneumonia in the posterior group and mortality was also significantly increased in this group. There was however a tendency to better functional results in the posterior group. Because of the increased mortality the lateral approach was recommended. A recent report for elective total hip arthroplasty has reported less residual pain and greater satisfaction scores for those treated with a posterior approach versus those with a direct lateral approach [14]. These findings cannot be confirmed in this study of patients with a hemiarthroplasty and may be related to the lesser surgical exposure used for hemiarthroplasty.
M.J. Parker / Injury, Int. J. Care Injured 46 (2015) 1023–1027
More recently attention has been focused on the anterior approach to the hip. To date there have been very few clinical reports of this for hip fracture surgery. A small randomised study for 48 patients compared the anterior Smith-Peterson and lateral approaches. Operative time and immediate post-operative pain were reported to be greater for the anterior approach but by six months, no difference was reported between groups [15]. In summary this randomised trial found no notable differences in the outcomes of pain and mobility between the lateral and posterior surgical approaches for inserting a hip hemiarthroplasty. Larger database and case series reports should be used to compare the more infrequent surgical complications encountered. Conflict of interest None. Acknowledgement This study received internal funding from the Peterborough Hospitals Hip Fracture Fund. References [1] Gullberg B, Johnell O, Kanis JA. World-wide projections for hip fracture. Osteoporosis Int 1997;7:407–13. [2] Hardinge K. The direct lateral approach to the hip. J Bone Joint Surg 1982;64B:17–9.
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[3] Moore AT. The self-locking metal hip prosthesis. J Bone Joint Surg 1957;39A:811–27. [4] Masonis JL, Bourne RB. Surgical approach, abductor function, and total hip arthroplasty dislocation. Clin Orthopaed Related Res 2002;405:46–53. [5] Varley J, Parker MJ. Stability of hip hemiarthroplasties. Int Orthop 2004;28:274–7. [6] American Society of Anaesthesiologists: new classification of physical status. Anaesthesiology 1963;24:111. [7] Parker MJ, Palmer CR. A new mobility score for predicting mortality after hip fracture. J Bone Joint Surg 1993;75-B:797–8. [8] Kristensen MT, Bandholm T, Foss NB, Ekdahl C, Kehlet H. High inter-tester reliability of the new mobility score in patients with hip fracture. J Rehabil Med 2008;40:589–91. [9] Qureshi KN, Hodkinson HM. Evaluation of a ten-question mental test in the institutionalised elderly. Age Ageing 1974;3(3):152–7. [10] Charnley J. The long-term results of low-friction arthroplasty of the hip performed as a primary intervention. J Bone Joint Surg Br 1972;54: 61–76. [11] Martinez AA, Herrera A, Cuenca J, Panisello JJ, Tabuenca A. Comparison of two different posterior approaches for hemiarthroplasty of the hip. Arch Orthop Trauma Surg 2002;122:51–2. [12] Keene GS, Parker MJ. Hemiarthroplasty of the hip – the anterior or posterior approach? A comparison of surgical approaches. Injury 1993;24:611–3. [13] Sikorski JM, Barrington R. Internal fixation verses hemiarthroplasty for the displaced subcapital fracture of the femur: a prospective randomised study. J Bone Joint Surg 1981;63-B:357–61. [14] Lindgren JV, Wretenberg P, Karrholm J, Garellick G, Rolfson O. Patient-reported outcome is influenced by surgical approach in total hip replacement: a study of the Swedish Hip Arthroplasty Register including 42.233 patients. Bone Joint J 2014;96-B:590–6. [15] Auffarth A, Resch H, Lederer S, Stefanie K, Hitzl W, Bogner R, Mayer M, Natis N. Does the choice of approach for hip hemiarthroplasty in geriatric patients significantly influence early postoperative outcomes? A randomized-controlled trial comparing the modified Smith-Petersen and Hardinge approaches. J Trauma Injury Crit Care 2011;70:1257–62.
Contents lists available at ScienceDirect
Injury journal homepage: www.elsevier.com/locate/injury
Lateral versus posterior approach for insertion of hemiarthroplasties for hip fractures: A randomised trial of 216 patients Martyn J. Parker * Peterborough and Stamford Hospital NHS Foundation Trust, Department of Orthopaedics, Peterborough City Hospital, CBU PO Box 211, Core C, Bretton Gate, Peterborough PE3 9GZ, England, United Kingdom
A R T I C L E I N F O
A B S T R A C T
Article history: Accepted 19 February 2015
Continued debate exists about the merits of the different surgical approaches for arthroplasty of the hip. For hemiarthroplasty to the hip the two most commonly used approaches are lateral and posterior. 216 patients with an intracapsular hip fracture being treated with a cemented hemiarthroplasty were randomised to surgery using either a lateral or posterior approach. Surviving patients were followed up for one year with pain and functional outcomes assessed by an assessor blinded to the treatment allocation. No statistically significant differences were observed for any of the outcome measures including mortality, degree of residual pain and regain of walking ability. A subjective assessment of the ease of surgery favoured the lateral approach. In conclusion both surgical approaches appear to produce comparable function outcomes. ß 2015 Elsevier Ltd. All rights reserved.
Keywords: Hip fracture Surgical approach Randomised trial
Introduction
Patients and methods
Insertion of a hemiarthroplasty for a hip fracture is one of the commonest procedures undertaken in Orthopaedics. In excess of one million such procedures are undertaken annually around the world [1]. A number of different surgical approaches may be used for the operation including the anterior, anterio-lateral, lateral and posterior approach. Currently the two most commonly used approaches for hemiarthroplasty to the hip are the lateral [2]. and the posterior approach [3]. The posterior approach is claimed to result in better regain of function as there is less damage to the hip muscles [4], whilst the anterior and lateral approaches have a lower risk of dislocation [5]. Despite the frequency of this operative procedure there are no contemporary randomised trials between the different surgical approaches for hemiarthroplasty to the hip. The aim of the study was to assist in defining the optimum surgical approach to the hip joint for insertion of a hemiarthroplasty for an acute hip fracture using a randomised controlled trial. The primary outcome measure was the regain of walking ability. Secondary outcome measures recorded included mortality, ease of surgery, length of surgery, operative blood loss, blood transfusion, post-operative complications, hospital stay, need for subsequent revision surgery and the degree of residual pain.
The inclusion criteria were all patients admitted to Peterborough District Hospital Hospital (latterly Peterborough City Hospital) with a displaced intracapsular fracture that was to be treated with cemented hemiarthroplasty. For patients who lacked capacity to consent, inclusion within the study was with the assent of the patient’s next of kin or legal guardian. Exclusion criteria were patients who declined to participate, patients without the capacity to give informed consent and the next of kin or patient’s representative was unavailable to give assent or declines assent and patients admitted when the lead researcher (MJP) was not available to supervise treatment. Other exclusion criteria were patients with a pathological fracture requiring a specific prosthesis or procedure and patients treated conservatively due to poor health or late presentation. Patients in which an uncemented arthroplasty was used to avoid bone cement were also excluded as were patients in whom a total hip replacement was chosen as the primary treatment in preference to a hemiarthroplasty. Also excluded were patients who were entered in one of two concurrently running randomised studies or hemiarthroplasty versus internal fixation for male patients or hemiarthroplasty versus total hip replacement. Patient assessment on admission included recording the patients residential status, ASA grade [6], mobility score [7,8] and mental test score [9]. Randomisation was by opening of numbered sealed opaque envelopes containing details of the operation to be used. The envelopes were prepared by a person
* Tel.: +44 01733 678000x1133; fax: +44 01733 678532. E-mail address: [email protected] http://dx.doi.org/10.1016/j.injury.2015.02.020 0020–1383/ß 2015 Elsevier Ltd. All rights reserved.
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M.J. Parker / Injury, Int. J. Care Injured 46 (2015) 1023–1027
independent to the study. Once randomised all patients had to stay within the group to which they were randomised. To standardise surgical technique, all operations were undertaken or directly supervised by MJP. A cemented monoblock Exeter stem hemiarthroplasty (ETS) was used for all patients. Pre-operative and post-operative care protocols were identical for both groups with all patients being encouraged to mobilise fully weight bearing with no restriction on hip movements. For their surgery all patients were positioned on their side and a minimal surgical exposure used, in which whenever possible incisions were less than 10cms in length. The lateral approach involved splitting the tendon to the gluteus medius muscle with two thirds being left intact and a third of the muscle retracted anteriorly to expose the anterior hip joint capsule. The capsule was opened with a T shaped cut and later repaired after insertion of the prosthesis. For the posterior approach the piriformis tendon was preserved and the other short rotators cut and retracted posteriorly. An L shaped cut to the capsule was made along the line of the femur and then posteriorly immediately distal to the piriformis tendon. After insertion of the prosthesis both the capsule and tendons to the short rotators were repaired. For each patient a subjective assessment of the difficulty of surgery was made by MJP using the criteria shown in Table 1. After discharge from hospital follow-up of patients was initially in a hip fracture clinic at eight weeks from admission. At this visit an assessment was undertaken by a research nurse blinded to the type of surgical approach used. Pain was assessed on a modified Charnley pain score (Table 2) [10]. Mobility, use of walking aids and residential status were recorded [7,8]. Measurement of limb shortening, hip flexion and a Trendelenburg test were undertaken for those with a normal contra-lateral hip. Subsequent assessments by the research nurse were by telephone at three, six, nine and 12 months from injury. No patient was lost to follow-up. Surgical complications detected at the follow-up clinic were recorded. In addition, if any patient was referred back for any problems related to the hip these complications were included in the presentation of the results. The primary outcome for the study was regain of mobility using a mobility score [7]. This score has been validated and found to be
Table 1 Subjective assessment of surgically difficulty. Score 1 = No difficulties encountered during surgery Score 2 = Mild difficulty such as needing repeated adjustment of retractors for exposure or mild difficulty on reduction the prosthesis. Score 3 = Moderate difficulty such as extensive problems to achieve exposure or repeated attempts needed to obtain reduction of the prosthesis. Score 4 = Severe difficulty. Need to extend the wound to achieve exposure or more extensive tissue dissection required to obtain reduction of the prosthesis.
Table 2 Pain scale used. Score 1 = No pain at all in the hip. Score 2 = Occasional and slight pain. May occasionally take mild analgesia such as paracetamol. Score 3 = Some pain when starting to walk, no rest pain. Occasional analgesia taken. Score 4 = None or minimal pain at rest, some pain with activities, frequent mild. analgesia Score 5 = Regular pain with activities which limits walking distance. Occasional or mild rest pain. Score 6 = Frequent rest pain and pain at night. Pain on walking. Regular mild analgesia and occasional stronger analgesia taken. Score 7 = Constant pain present around the hip. Regular mild analgesia and frequent strong analgesia. Score 8 = Constant and severe pain in the hip requiring regular strong analgesia such as opiates.
reproducible [8]. The score has a range of 0 (worst) to nine (best). A clinically relevant difference between the two groups would be a difference of 1.0 for the change in mobility score. Assuming that the outcome measure of mobility has a normal distribution and for a 2sided significance level of 0.05 and a power of 80% for a difference of 1 point, then a total of 264 patients are required using a standard deviation of 2.9 taken from previous studies. To allow for loss of patients from follow-up (normally 2–3%) and due to deaths (30% mortality at one year), a total study number of 400 patients would be required. There was no external source of funding for this study. Internal funding was from the Peterborough Hospitals Hip Fracture Fund. The study had research ethics approval and approval of the Hospital Research and Development Committee. Binary outcomes for the two groups were analysed using Fisher exact test and continuous outcomes with the unpaired two tailed ttest (GraphPad InStat version 3.00 for Windows 95, GraphPad Software, San Diego California USA). A p-value of p < 0.05 was considered as statistically significant. All results were analysis on an intention-to-treat basis. Results Patients were recruited to the study from December 2009 till July 2013. Fig. 1 gives the flow diagram for the patient’s included and excluded from the study. All patients had treatment as dictated by the study. One patient in the posterior group with a narrow femur had a cemented small stem bipolar hemiarthroplasty rather than a standard stem size ETS hemiarthroplasty. Four fractures (two in each group) were pathological secondary to bone secondaries. Table 3 details the characteristics of the patients at the time of admission. There were no significant differences between groups. Table 4 details the operative details and surgical complications encountered for the two groups. The only statistically significant difference was the surgeon’s subjective assessment of the difficulty of surgery. The posterior approach was felt to be slightly more difficult. Small operative fracture of the femur referred to fracture of the greater trochanter that required no specific treatment whilst larger operative femur fracture refers to a fracture at the level of the lesser trochanter requiring cerclage wiring. Table 5 details the general medical complications encountered between the two groups demonstrating no differences between the two surgical approaches. There was no difference in the mean hospital stay between groups (20.3 days versus 18.5 days, p = 0.4) or the proportion of surviving patients discharged from hospital back to their original residence (95.1% versus 92.2%, p = 0.4). Fig. 2 details the mortality for the two groups with no significant difference between groups at any time period. The 30 day and one year mortality for the lateral group was 4 (3.7%) and 19 (17.9%) versus 5 (4.6%) and 20 (18.5%) for the posterior approach. Figs. 3 and 4 detail the mean pain and mean mobility scores at the set time periods from injury for which there were no statistically significant differences between groups. Discussion The conclusion of this study is that there were no notable differences in outcomes between the two procedures. The posterior approach was felt to be technically more difficult, and in the absence of any trend to improved functional outcomes with the posterior approach, it was decided to stop the study with only 179 patients having completed the one year follow-up as opposed to the 264 originally proposed. The patient numbers within this study were too small to determine differences in the surgical complications detailed in Table 3. One of the most frequently quoted advantages of the
M.J. Parker / Injury, Int. J. Care Injured 46 (2015) 1023–1027
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Fig. 1. Flow diagram for participants. *Some patients may be excluded for more than one reason.
Table 3 Characteristics of the two groups at admission (percentage).
Patient numbers Mean age [range] Female From own home Residential care Nursing home Fall in hospital ASA grade 1 or 2 Mean mental test score Mean mobility score Mean haemoglobin g/l
Table 5 General complications (percentage).
Lateral
Posterior
p value
108 84.3 [61–100] 100 (92.6%) 92 (85.2%) 11 (10.2%) 3 (2.8%) 2 (1.9%) 44 (40.7%) 7.1 6.8 122.9
108 83.6 [65–99] 98 (90.7%) 88 (81.4%) 15 (13.9%) 2 (1.9%) 3 (2.8%) 43 (39.8%) 6.9 7.1 121.9
0.5 0.8 0.5 0.5 1.0 1.0 1.0 0.6 0.3 0.6
Pneumonia Congestive cardiac failure Atrial fibrillation Acute renal injury Urinary retention Perforated peptic ulcer Gastrointestinal bleed Deep vein thrombosis Pulmonary embolism Pressure sores Delirium Cerebrovascular accident Intestinal obstruction
Lateral
Posterior
p value
3 1 1 2 1 1 0 1 1 4 8 0 2
2 2 0 0 0 0 2 1 0 3 2 1 1
1.0 1.0 1.0 0.5 1.0 1.0 0.5 1.0 1.0 1.0 0.1 1.0 1.0
(2.9%) (0.9%) (0.9%) (1.9%) (0.9%) (0.9%) (0.9%) (0.9%) (3.8%) (7.5%) (1.9%)
(1.9%) (1.9%)
(1.9%) (0.9%) (2.9%) (1.9%) (0.9%) (0.9%)
Table 4 Operative details and post-operative implant complications (percentage).
Length surgery (min) Number of patients transfused Mean units blood transfused Mean difficulty level Small operative fracture femur Larger operative fracture femur Wound haematoma Superficial wound infection Deep wound infection Sciatic nerve palsy Dislocation Later fracture around implant Re-operation – revision arthroplasty Re-operation – girdlestone Re-operation – fixation fracture
Lateral
Posterior
p value
53.6 14 (13.2%) 0.19 1.7 6 (5.7%) 0 1 (0.9%) 3 (2.9%) 0 0 2 (1.9%) 1 (0.9%) 1 (0.9%) 1 (0.9%) 1 (0.9%)
54.0 21 (19.8%) 0.31 2.0 1 (0.9%) 1 (0.9%) 0 2 (1.9%) 2 (1.9%) 2 (1.9%) 1 (0.9%) 4 (3.8%) 0 1 (0.9%) 3 (2.9%)
0.8 0.3 0.2 0.007 0.1 1.0 1.0 1.0 0.5 0.5 1.0 0.4 1.0 1.0 0.6
lateral approach is the lower risk of dislocation. A review of the literature involving 14,846 hemiarthroplasties reported a dislocation rate of 2.1% for the lateral approach versus 5.0% for the posterior approach [5]. There was only one dislocation in the
posterior group in this study which may be related to preserving the piriformis tendon. This acts as a block to the prosthesis dislocating posteriorly [11]. It is possible that preserving the piriformis tendon may have contributed to the two sciatic nerve palsies that were encountered after the posterior approach, as the nerve may not have been retracted so far posteriorly than if the piriformis had been detached. There was a tendency for more patients to present with a later fracture of the femur in the posterior group this study (one versus four cases). A previous study had also noted a tendency for more of such fractures to occur with the posterior approach in comparison to the lateral approach [12]. Regain of function was the primary outcome for this study for which there was no trend to any differences in regain of mobility between the two groups. We also tried to assess adductor function using the trendelenburg test in those patients able to cooperate and with a normal contra-lateral hip. Unfortunately this was possible in only 80 patients but there was no difference between groups. Shortening of the limb was more common within the posterior group which would have been related to surgical
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Fig. 2. Kaplan–Meier mortality graph for the two groups.
Fig. 3. Mean pain scores for the two groups. Fig. 4. Mean mobility scores for the two groups.
technique. The mean difference was only 2 mm which would be unlikely to affect hip function. The advantages of this study were the secure randomisation of patients, standardised surgical technique with all operations undertaken or directly supervised by a single hip fracture surgeon, no loss to follow-up of patients and the blinded assessment of outcome. The prosthesis chosen was a modern stem arthroplasty and is one of the most commonly used hemiarthroplasties in the United Kingdom. A potential disadvantage was that the surgeon involved had more previous experience of the lateral approach. To minimise this potential source of bias and refine the surgical technique a series of posteriorly inserted arthroplasties was undertaken prior to starting the study. The Cochrane group has undertaken an extensive literature search on this topic and identified only one previous randomised trial of surgical approach relevant to hip fractures [13]. This study
randomised 114 patients to either a posterior or lateral approach. Those allocated to the posterior approach were nursed flat in bed for two weeks after surgery whilst those from the lateral group were mobilized immediately. There was an increased risk of medical complications, particularly pneumonia in the posterior group and mortality was also significantly increased in this group. There was however a tendency to better functional results in the posterior group. Because of the increased mortality the lateral approach was recommended. A recent report for elective total hip arthroplasty has reported less residual pain and greater satisfaction scores for those treated with a posterior approach versus those with a direct lateral approach [14]. These findings cannot be confirmed in this study of patients with a hemiarthroplasty and may be related to the lesser surgical exposure used for hemiarthroplasty.
M.J. Parker / Injury, Int. J. Care Injured 46 (2015) 1023–1027
More recently attention has been focused on the anterior approach to the hip. To date there have been very few clinical reports of this for hip fracture surgery. A small randomised study for 48 patients compared the anterior Smith-Peterson and lateral approaches. Operative time and immediate post-operative pain were reported to be greater for the anterior approach but by six months, no difference was reported between groups [15]. In summary this randomised trial found no notable differences in the outcomes of pain and mobility between the lateral and posterior surgical approaches for inserting a hip hemiarthroplasty. Larger database and case series reports should be used to compare the more infrequent surgical complications encountered. Conflict of interest None. Acknowledgement This study received internal funding from the Peterborough Hospitals Hip Fracture Fund. References [1] Gullberg B, Johnell O, Kanis JA. World-wide projections for hip fracture. Osteoporosis Int 1997;7:407–13. [2] Hardinge K. The direct lateral approach to the hip. J Bone Joint Surg 1982;64B:17–9.
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[3] Moore AT. The self-locking metal hip prosthesis. J Bone Joint Surg 1957;39A:811–27. [4] Masonis JL, Bourne RB. Surgical approach, abductor function, and total hip arthroplasty dislocation. Clin Orthopaed Related Res 2002;405:46–53. [5] Varley J, Parker MJ. Stability of hip hemiarthroplasties. Int Orthop 2004;28:274–7. [6] American Society of Anaesthesiologists: new classification of physical status. Anaesthesiology 1963;24:111. [7] Parker MJ, Palmer CR. A new mobility score for predicting mortality after hip fracture. J Bone Joint Surg 1993;75-B:797–8. [8] Kristensen MT, Bandholm T, Foss NB, Ekdahl C, Kehlet H. High inter-tester reliability of the new mobility score in patients with hip fracture. J Rehabil Med 2008;40:589–91. [9] Qureshi KN, Hodkinson HM. Evaluation of a ten-question mental test in the institutionalised elderly. Age Ageing 1974;3(3):152–7. [10] Charnley J. The long-term results of low-friction arthroplasty of the hip performed as a primary intervention. J Bone Joint Surg Br 1972;54: 61–76. [11] Martinez AA, Herrera A, Cuenca J, Panisello JJ, Tabuenca A. Comparison of two different posterior approaches for hemiarthroplasty of the hip. Arch Orthop Trauma Surg 2002;122:51–2. [12] Keene GS, Parker MJ. Hemiarthroplasty of the hip – the anterior or posterior approach? A comparison of surgical approaches. Injury 1993;24:611–3. [13] Sikorski JM, Barrington R. Internal fixation verses hemiarthroplasty for the displaced subcapital fracture of the femur: a prospective randomised study. J Bone Joint Surg 1981;63-B:357–61. [14] Lindgren JV, Wretenberg P, Karrholm J, Garellick G, Rolfson O. Patient-reported outcome is influenced by surgical approach in total hip replacement: a study of the Swedish Hip Arthroplasty Register including 42.233 patients. Bone Joint J 2014;96-B:590–6. [15] Auffarth A, Resch H, Lederer S, Stefanie K, Hitzl W, Bogner R, Mayer M, Natis N. Does the choice of approach for hip hemiarthroplasty in geriatric patients significantly influence early postoperative outcomes? A randomized-controlled trial comparing the modified Smith-Petersen and Hardinge approaches. J Trauma Injury Crit Care 2011;70:1257–62.
