Abstract
Background
The operation of insertion of a hemiarthroplasty to the hip refers to replacement of the femoral head with a prosthesis, whilst retaining the natural acetabulum and acetabular cartilage. The main surgical approaches to the hip for insertion of the prosthesis can be broadly categorised as either 'anterior' via the anterior joint capsule, or 'posterior' through the posterior joint capsule.
Objectives
To evaluate, based on evidence from randomised controlled trials, the effects of different surgical approaches for the insertion of a hemiarthroplasty to the hip has on clinical outcomes.
Search methods
We searched the Cochrane Bone, Joint and Muscle Trauma Group specialised register (up to February 2002). Articles of all languages were considered.
Selection criteria
All randomised controlled trials comparing insertion of a hemiarthroplasty by different surgical approaches.
Data collection and analysis
Both reviewers independently assessed trial quality, using a 10 item scale, and extracted data. Wherever appropriate and possible, the data are presented graphically.
Main results
One randomised trial was identified involving 114 patients. The trial had poor methodology (particularly in susceptibility to selection bias), inadequate follow‐up of patients who withdrew, and there was limited reporting of results. Medical complications and mortality from six months to two years appeared greater in the posterior group; this difference in mortality, within the structure of the poor methodology, was statistically significant. No other differences were claimed to be significant.
Authors' conclusions
There is currently insufficient evidence from randomised trials to determine the optimum surgical approach for insertion of a hemiarthroplasty to the hip.
Plain language summary
Surgical approaches for inserting hemiarthroplasty of the hip
Arthroplasty (total hip replacement) involves replacing both the socket in the hip and the thigh side of the joint with an artificial joint. Hemiarthroplasty (partial hip replacement) leaves the socket intact, replacing only the thigh side. This is used for some people with hip fractures. Anterior surgery (from the front) might reduce the risk of dislocation and damaging the sciatic nerve for the leg, while posterior surgery (from the back) may reduce operating time and lower the risk of fracture. However, the review of trials did not find enough evidence to show which type of surgery for hemiarthroplasty is best.
Background
Arthroplasty of the hip refers to replacement of all or part of the hip joint with a prosthetic implant. Numerous different types of arthroplasty exist for the hip. Those that involve replacement of the femoral head can be broadly divided into two groups, hemiarthroplasty and total hip replacement. Hemiarthroplasty involves replacing the femoral head with a prosthesis whilst retaining the natural acetabulum and acetabular cartilage. Total hip replacement involves the replacement of the acetabulum in addition to the femoral head.
The two main indications for arthroplasty of the hip are arthritis of the hip joint or a fracture of the proximal femur. Because the acetabulum is affected in arthritis of the hip, this is normally treated by a total hip replacement arthroplasty. In some situations however, a hemiarthroplasty, generally of the bipolar design, may be used.
The most frequent indication for the use of a hemiarthroplasty is a hip or proximal femoral fracture. The most common type of hip fracture to be treated by an arthroplasty is the displaced intracapsular fracture. The majority of extracapsular fractures are treated by internal fixation of the fracture.
Patients who break their hip are characteristically elderly, with an average age of around 80 years. The majority are female. Such elderly patients invariably have impaired mobility before the fracture and are also often cognitively impaired. The aim of surgery is to facilitate early mobilisation and enable the patient to sit up out of bed. Therefore, any surgical procedure should enable the patient to sit in a position of hip flexion with minimal or no restriction on hip function.
This review considers only those randomised trials evaluating the surgical approach to the hip used for insertion of a hemiarthroplasty.
Different considerations apply to hemiarthroplasty than to total hip arthroplasty. In the latter, the necessary clear exposure of both femur and acetabulum is required and therefore a relatively extensive exposure is needed. For hemiarthroplasty, a rapid but effective operation is demanded with the least trauma and physiological upset, as patients are generally older and vulnerable to anaesthetics and surgical procedures. Many different surgical approaches to the hip have been described. They can be placed into three broad categories ‐ lateral with detachment of the greater trochanter, anterior through the anterior hip joint capsule, and posterior through the posterior hip joint capsule. Though the best exposure of the hip joint is obtained by detaching the greater trochanter, this is generally considered inappropriate for hemiarthroplasty due to the excessive surgical trauma entailed. Thus the main surgical approaches to the hip for insertion of a hemiarthroplasty can be broadly categorised as either 'anterior' or 'posterior'.
An anterior approach entails a lateral skin incision and the fascia lata is divided longitudinally in the line of the incision. Various modifications of surgical dissection exist to expose the anterior hip joint capsule beneath the gluteus medius muscle. The hip joint capsule can then be either incised or excised. For the posterior approach, a lateral incision is used with the fascia lata being divided longitudinally. The gluteus maximus muscle is split in line of the fibres and the short external rotators divided close to the femur and reflected to expose the posterior capsule. The hip joint capsule can then be either incised or excised.
The main theoretical advantage given for an anterior approach to the hip is that there is a lower risk of dislocation as the orientation of the acetabulum favours posterior dislocation of the hip. This lower risk of dislocation may make rehabilitation of the patient easier due to less restrictions on hip movement being applied in the post‐operative period. In addition, there is less risk of damage to the sciatic nerve with this approach as it is not close to the operative field. Possible disadvantages of an anterior approach are that a greater degree of tissue dissection is needed so that damage to the gluteus medius muscle and its nervous innervation may occur. In addition, the exposure of the femur for reaming of the medullary cavity is not as good as that with a posterior approach, giving more restricted access for a straight or long stem arthroplasty.
Theoretical advantages for a posterior approach are the less extensive tissue dissection which gives shorter operation times and a reduced blood loss. The abductors are not dysfunctioned. In addition there may be a lower risk of femoral shaft fracture, due to better access to the femoral canal for reaming and insertion of the implant.
Other outcomes which may be influenced by the surgical approach are the incidence of wound infection and venous thrombosis. In addition, the time interval from surgery until the hip is felt sufficiently stable to allow the patient to be mobilised may also be affected.
Objectives
To evaluate, based on evidence from randomised controlled trials, the effects of different surgical approaches for the insertion of a hemiarthroplasty to the hip.
The following null hypothesis was tested:
There is no difference in outcome between an anterior approach to the hip and a posterior approach for insertion of a hemiarthroplasty.
Methods
Criteria for considering studies for this review
Types of studies
All randomised controlled trials comparing insertion of a hemiarthroplasty by different surgical approaches. Quasi‐randomised trials (for example, allocation by alternation or date of birth) and trials in which the treatment allocation was inadequately concealed were considered for inclusion.
Types of participants
Any skeletally mature patient having insertion of a hemiarthroplasty to the hip. This includes those with a proximal femoral fracture, as well as those undergoing elective hip surgery for arthritis.
Types of interventions
Different surgical approaches for insertion of a hemiarthroplasty as described in the Background.
Types of outcome measures
Data for the following outcomes were sought:
a) Operative details
length of surgery (in minutes)
operative blood loss (in millilitres)
post‐operative blood transfusion (in units)
b) Complications related to the implant
dislocation of the prosthesis
fracture of the femur around or below the implant at the time of surgery
later fracture of the femur around or immediately below the implant
other surgical complications of fixation (as detailed in each study)
re‐operation rate
c) Post‐operative complications
superficial wound infection (infection of the wound in which there is no evidence that the infection extends to the site of the implant)
deep wound infection (infection around the implant)
pneumonia
deep vein thrombosis (diagnosed confirmed by post‐mortem, venography, isotope scanning, ultrasound or phlethysmography whether this was performed routinely or only as clinically indicated)
pulmonary embolism (diagnosed by isotope scanning, angiography or post‐mortem)
thromboembolic complications (deep vein thrombosis or pulmonary embolism)
damage to the sciatic nerve
damage to other anatomical structures
any medical complication (as detailed in each individual study)
d) Post‐operative care outcomes
days until patient allowed to sit out of bed
days to mobilisation
length of hospital stay (days)
e) Hip function outcomes
range of movement of the hip
muscle power/function about the hip
f) Final outcome measures
mortality (within the follow‐up period of the study)
pain (persistent pain at the final follow‐up assessment)
residence at final follow‐up (return to living at home, discharge location)
mobility (use of walking aids, return of mobility)
other functional outcomes as listed in each study
health related quality of life measures
Search methods for identification of studies
We searched the Cochrane Bone, Joint and Muscle Trauma Group specialised register (February 2002), reference lists of articles and contacted trialists. The register is compiled from multiple databases, including regular searches of the Cochrane Controlled Trials Register in The Cochrane Library, MEDLINE (which combines subject specific terms with the optimal trial search strategy (Clarke 2002)), EMBASE and CINAHL, and handsearch results. For further details see the search strategy in the group's module in The Cochrane Library.
Articles of all languages were considered and translated if necessary.
Data collection and analysis
Data for the outcomes listed above were independently extracted by both reviewers and each trial assessed independently without masking of the study names for its quality of methodology. Differences were resolved by discussion. The main assessment of methodology was the quality of allocation concealment. A further nine aspects of methodology were used giving a maximum score for each study of 12.
1. Was there clear concealment of allocation? Score 3 (and code A) if allocation clearly concealed (e.g. numbered sealed opaque envelopes drawn consecutively). Score 2 (and code B) if there was a possible chance of disclosure before allocation. Score 1 (and code B) if the method of allocation concealment or randomisation was not stated or was unclear. Score 0 (and code C) if allocation concealment was clearly not concealed such as those using quasi‐randomisation (e.g. even or odd date of birth).
2. Were the inclusion and exclusion criteria clearly defined? Score 1 if text states type of fracture and which patients included and those excluded. Otherwise score 0.
3. Were the outcomes of patients who withdrew or were excluded after allocation described and included in an intention to treat analysis? Score 1 if yes or text states that no withdrawals occurred or data are presented clearly showing 'participant flow' which allows this to be inferred. Otherwise score 0.
4. Were the treatment and control groups adequately described at entry, and if so were the groups well matched, or appropriate co‐variate adjustment made? Score 1 if at least four admission details given (e.g. age, sex, mobility, function score, mental test score) with either no important difference between groups or appropriate adjustment made. Otherwise score 0.
5. Were the surgeons experienced at both operations prior to commencement of the trial? Score 1 if text states there was an introductory period or all surgeons were experienced in both operations. Otherwise score 0.
6. Were the care programmes other than the trial options identical? Score 1 if text states they were or this can be inferred. Otherwise score 0.
7. Were all the outcome measures clearly defined in the text with a definition of any ambiguous terms encountered? Score 1 if yes. Otherwise score 0.
8. Were the outcome assessors blind to assignment status? Score 1 if assessors of anatomical restoration, pain and function at follow‐up were blinded to treatment outcome. Otherwise score 0.
9. Was the timing of outcome measures appropriate? A minimum of 12 months follow‐up for all surviving patients with active follow‐up of patients at set intervals. Score 1 if yes. Otherwise score 0.
10. Was loss to follow‐up reported and if so were less than five per cent of patients lost to follow‐up? Score 1 if yes. Otherwise score 0.
For each study, relative risk and 95 per cent confidence limits were calculated for dichotomous outcomes, and weighted mean differences and 95 per cent confidence limits for continuous outcomes.
Results
Description of studies
One trial (Sikorski 1981), involving 114 patients and identified through MEDLINE, was included. This study compared patients with an intracapsular fracture treated with a Thompson prosthesis inserted via an anterolateral (McKee) approach against those treated using the same prosthesis by a posterior (Moore) approach. All prostheses were cemented in place. Further details of this trial are given in the Characteristics of Included Studies Table.
Two trials (Barden 2001; Widman 2001) were identified and excluded for reasons given in the Characteristics of Excluded Studies Table.
Risk of bias in included studies
The method of randomisation was stated as being by cards drawn from a box in the operating theatre. It is not possible to determine from this description if allocation was concealed. The overall methodological score for the study of Sikorski 1981 was two out of a possible maximum of 12. The inclusion criteria for patients was left at the discretion of the consultant in charge and no mention was made of an intention to treat analysis. The trial groups were not well described and there were more men in the posterior approach group. Post‐operatively the care programmes were not equal, with those who had a posterior approach being nursed flat for two weeks, whilst those in the anterior group were mobilised immediately after surgery. The outcomes were poorly reported and there was no blinded assessment of outcome. Finally, loss to follow‐up was not reported and the surgeons performing the operations had varying grades of experience.
Table 1. Assessment of methodology. 1 2 3 4 5 6 7 8 9 10 Total Study 1 0 0 0 0 0 0 0 1 0 2 Sikorski 1981
Effects of interventions
The one identified study (Sikorski 1981) involved 114 patients with equal numbers in both groups. Where possible, results have been presented in the analysis tables.
Complications from surgery included one dislocation in each group. Prosthesis loosening was reported in five patients in the anterior group and three in the posterior group. Acetabular protrusion was reported for three cases in each group, and para‐articular calcification in six cases in the anterior group and two in the posterior group. The number of revision operations was reported as a percentage being six per cent (three patients) in the anterior group at three months and five per cent (two cases) in the posterior group at three months. The numbers of proven wound infections reported was reported as nine per cent (five cases) for the anterior approach versus five per cent (three cases) for the posterior approach. Unproven wound infections were reported as 14 per cent (eight cases) versus seven per cent (four cases).
Medical complications for the anterior and posterior groups respectively were reported as pneumonia (eight and 17 ‐ RR 0.47, 95% CI 0.22, 1.00), congestive cardiac failure (five and eight cases ‐ RR 0.62, 95% CI 0.22, 1.80) and urinary tract infection (seven and 12 cases ‐ RR 0.58, 95% CI 0.25, 1.37).
Mortality was only given as percentages within a graph. Estimations from this gave a mortality for the anterior versus posterior groups as 19 per cent versus 38 per cent at six months, 22 per cent versus 41 per cent at one year, and 25 per cent versus 42 per cent at two years. This difference in mortality between groups was reported as being statistically significant (p<0.05).
Pain at one month after surgery was reported to occur in 11 per cent (6/55) of the anterior group and four per cent (2/55) of the posterior group (RR 3.00, 95% CI 0.63, 14.22). Impairment of mobility by two or more grades was reported in 37 per cent (15/41) in the anterior group versus 15 per cent (5/34) in the posterior group (RR 2.49, 95% CI 1.01, 6.15).
Discussion
The one included trial was of poor methodological quality with limited presentation of results, many expressed only as a percentage within the published article. Its main finding was a similar proportion of complications directly related to the implant in each group. General medical complications were increased in the posterior approach group, as was mortality. It is not possible to ascertain if the reason for this increased mortality is directly related to the surgical procedure. More plausibly, it may have been caused by those patients allocated to the posterior group being nursed flat in bed for two weeks post‐operatively. This strategy was widely used in the past in the belief that it reduced the frequency of post‐operative prosthetic dislocation. Modern practice favours early mobilisation. For the survivors, mobility was reported to be impaired in a greater proportion of those in the anterior approach group although this result may have been influenced by the greater proportion of survivors in the anterior group.
Authors' conclusions
Implications for practice.
The quality of information from the single reported randomised trial is insufficient to make any conclusion on the optimum surgical approach for inserting a hemiarthroplasty to the hip.
Implications for research.
Further well conducted randomised trials are required to determine the optimum surgical approach for the insertion of a hemiarthroplasty to the hip. Particular attention should be paid to preventing selection bias (by using a robust randomisation procedure) and ascertainment bias (by blinding the observers of outcomes to the approach used). Reporting should conform to the CONSORT statement (Moher 2001).
What's new
| Date | Event | Description |
|---|---|---|
| 19 September 2008 | Amended | Converted to new review format. |
Notes
The title of the protocol was "Surgical approaches for inserting hip hemiarthroplasties".
Acknowledgements
We are indebted to Leeann Morton for help with the preparation of the review. We would also like to thank the following for useful feedback at editorial review: Professor William Gillespie, Professor Rajan Madhok, Dr Janet Wale, Professor Harley Gray, and Dr Garnet Tregonning.
Data and analyses
Comparison 1. Anterior versus posterior approach for hemiarthroplasty.
| Outcome or subgroup title | No. of studies | No. of participants | Statistical method | Effect size |
|---|---|---|---|---|
| 1 Dislocation | 1 | 114 | Risk Ratio (M‐H, Fixed, 95% CI) | 1.0 [0.06, 15.60] |
| 2 Pneumonia | 1 | 114 | Risk Ratio (M‐H, Fixed, 95% CI) | 0.47 [0.22, 1.00] |
| 3 Congestive cardiac failure | 1 | 114 | Risk Ratio (M‐H, Fixed, 95% CI) | 0.63 [0.22, 1.80] |
| 4 Urinary tract infection | 1 | 114 | Risk Ratio (M‐H, Fixed, 95% CI) | 0.58 [0.25, 1.37] |
| 5 Pain at one month | 1 | 110 | Risk Ratio (M‐H, Fixed, 95% CI) | 3.0 [0.63, 14.22] |
| 6 Impairment of mobility | 1 | 75 | Risk Ratio (M‐H, Fixed, 95% CI) | 2.49 [1.01, 6.15] |
1.1. Analysis.
Comparison 1 Anterior versus posterior approach for hemiarthroplasty, Outcome 1 Dislocation.
1.2. Analysis.
Comparison 1 Anterior versus posterior approach for hemiarthroplasty, Outcome 2 Pneumonia.
1.3. Analysis.
Comparison 1 Anterior versus posterior approach for hemiarthroplasty, Outcome 3 Congestive cardiac failure.
1.4. Analysis.
Comparison 1 Anterior versus posterior approach for hemiarthroplasty, Outcome 4 Urinary tract infection.
1.5. Analysis.
Comparison 1 Anterior versus posterior approach for hemiarthroplasty, Outcome 5 Pain at one month.
1.6. Analysis.
Comparison 1 Anterior versus posterior approach for hemiarthroplasty, Outcome 6 Impairment of mobility.
Characteristics of studies
Characteristics of included studies [ordered by study ID]
Sikorski 1981.
| Methods | Randomised trial ‐ method of randomisation by taking cards from a box. | |
| Participants | 114 patients with a displaced intracapsular fracture. Bristol Royal Infirmary, Bristol, England. Mean age 80 years (range not stated). All patients aged 70 years and above. 12% male. Loss to follow‐up: not stated. Length of follow‐up: two years. | |
| Interventions | Cemented Thompson prosthesis inserted via a McKee anterolateral approach versus cemented Thompson prosthesis inserted via a posterior approach (as described by Moore). It was not stated if capsular repair was undertaken. | |
| Outcomes | Dislocation Acetabular protrusion Para‐articular calcification Re‐operations Prosthesis loosening Pneumonia Congestive cardiac failure Urinary tract infection Mortality up to two years Pain at one month Impairment of mobility | |
| Notes | Information on the number or revision operations was not clear ‐ stated as being 1% of 28 patients for the period of 3‐24 months for the posterior Thompson and could not therefore be used. The figures for wound infection were also conflicting between two separate tables being quoted as 5 and 3 cases in one table and 4 and 2 in another. Figures for mortality were only given as percentages within a graph. There were discrepancies between the estimated number of deaths from this and the number of patients followed‐up. Those allocated to the posterior approach group were nursed flat in bed for two weeks after surgery as a precaution against dislocation. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Allocation concealment? | Unclear risk | B ‐ Unclear |
Characteristics of excluded studies [ordered by study ID]
| Study | Reason for exclusion |
|---|---|
| Barden 2001 | This randomised study of 160 hip arthroplasties via an anterolateral approach concerned the positioning of the leg during surgery and its effect on femoral vein blood flow. It was excluded as it was not a comparison of different surgical approaches. |
| Widman 2001 | This randomised study of 74 patients having hip arthroplasty compared the lateral versus supine position with reference to operative blood loss. Surgical technique was the same for the two groups. The study was excluded as it was not a comparison of surgical approaches. |
Contributions of authors
Martyn Parker initiated, designed and compiled the review. Humayon Pervez checked data extraction, assessed the trials for methodological quality and assisted in checking and preparing the text. Martyn Parker is the guarantor of the review and is responsible for any subsequent updates.
Declarations of interest
None known.
Edited (no change to conclusions)
References
References to studies included in this review
Sikorski 1981 {published data only}
- Sikorski JM, Barrington R. Internal fixation versus hemiarthroplasty for the displaced subcapital fracture of the femur: a prospective randomised study. Journal of Bone and Joint Surgery. British Volume 1981;63‐B(3):357‐361. [DOI] [PubMed] [Google Scholar]
References to studies excluded from this review
Barden 2001 {published data only}
- Barden B, Kroger K, Loer F. Intraoperative Doppler ultrasound of the femoral vein for maintaining venous patency in hip joint prosthesis implantation. [German]. Unfallchirurg 2001;104(2):138‐142. [DOI] [PubMed] [Google Scholar]
Widman 2001 {published data only}
- Widman J, Isacson J. Lateral position reduces blood loss in hip replacement surgery: a prospective randomized study of 74 patients. International Orthopaedics 2001;25(4):226‐227. [DOI] [PMC free article] [PubMed] [Google Scholar]
Additional references
Clarke 2002
- Clarke M, Oxman AD, editors. Optimal search strategy for RCTs. Cochrane Reviewers Handbook 4.1.4 [updated October 2001]; Appendix 5c. The Cochrane Library, Issue 2, 2002. Oxford: Update Software. Updated quarterly. [Google Scholar]
Moher 2001
- Moher D, Schulz KF, Altman DC, for the CONSORT group. The CONSORT statement: revised recommendations for improving the quality of reports of parallel‐group randomised trials. Lancet 2001;357:1191‐1194. [PubMed] [Google Scholar]