Aims. The aim of this study was to identify variables associated with time to revision, demographic details associated with revision indication, and type of
The place of the myo-electric
The aim of this study was to compare the biomechanical models of two frequently used techniques for reconstructing severe acetabular defects with pelvic discontinuity in revision total hip arthroplasty (THA) – the Trabecular Metal Acetabular Revision System (TMARS) and custom triflange acetabular components (CTACs) – using virtual modelling. Pre- and postoperative CT scans from ten patients who underwent revision with the TMARS for a Paprosky IIIB acetabular defect with pelvic discontinuity were retrospectively collated. Computer models of a CTAC implant were designed from the preoperative CT scans of these patients. Computer models of the TMARS reconstruction were segmented from postoperative CT scans using a semi-automated method. The amount of bone removed, the implant-bone apposition that was achieved, and the restoration of the centre of rotation of the hip were compared between all the actual TMARS and the virtual CTAC implants.Aims
Methods
Aims. The Intraosseous Transcutaneous Amputation
Aims. The aim of this study was to compare the cost-effectiveness of
treatment with an osseointegrated percutaneous (OI-) prosthesis
and a socket-suspended (S-)
Aims. Extendible endoprostheses have been available for more than 30
years and have become more sophisticated with time. The latest generation
is ‘non-invasive’ and can be lengthened with an external magnetic
force. Early results have shown a worryingly high rate of complications
such as infection. This study investigates the incidence of complications
and the need for further surgery in a cohort of patients with a
non-invasive growing endoprosthesis. Patients and Methods. Between 2003 and June 2014, 50 children (51 prostheses) had a
non-invasive growing
Patients with transfemoral amputation (TFA) often
experience problems related to the use of socket-suspended prostheses.
The clinical development of osseointegrated percutaneous prostheses
for patients with a TFA started in 1990, based on the long-term
successful results of osseointegrated dental implants. Between1999 and 2007, 51 patients with 55 TFAs were consecutively
enrolled in a prospective, single-centre non-randomised study and
followed for two years. The indication for amputation was trauma
in 33 patients (65%) and tumour in 12 (24%). A two-stage surgical
procedure was used to introduce a percutaneous implant to which
an external amputation
We determined the short-term clinical outcome
and migration within the bone of the humeral cementless component
of the Instrumented Bone Preserving (IBP) total elbow replacement
in a series of 16 patients. There were four men and 12 women with
a mean age at operation of 63 years (40 to 81). Migration was calculated
using radiostereometric analysis. There were no intra-operative
complications and no revisions. At two-year follow-up, all patients
showed a significant reduction in pain and functional improvement
of the elbow (both p <
0.001). Although ten components (63%)
showed movement or micromovement during the first six weeks, 14
(88%) were stable at one year post-operatively. Translation was
primarily found in the proximal direction (median 0.3 mm (interquartile range
(IQR) -0.09 to 0.8); the major rotational movement was an anterior
tilt (median 0.7° (IQR 0.4° to 1.6°)). One malaligned component
continued to migrate during the second year, and one component could
not be followed beyond three months because migration had caused
the markers to break off the
This paper describes a
1. Forty-five arthroplasties of the knee with the Walldius
Mechanical loosening which begins with early-onset migration of the
Aims. We present our experience of using a metal-backed
1. The customary method of broaching and of knocking the
We report our experience over seven years with a floating radial-head
There is little evidence on the cost effectiveness
of different brands of hip prostheses. We compared lifetime cost effectiveness
of frequently used brands within types of
We present data relating to the Bryan disc arthroplasty for the treatment of cervical spondylosis in 46 patients. Patients with either radiculopathy or myelopathy had a cervical discectomy followed by implantation of a cervical disc
We describe the development of a body-powered upper limb
The aim of this study was to report the outcomes of different treatment options for glenoid loosening following reverse shoulder arthroplasty (RSA) at a minimum follow-up of two years. We retrospectively studied the records of 79 patients (19 men, 60 women; 84 shoulders) aged 70.4 years (21 to 87) treated for aseptic loosening of the glenosphere following RSA. Clinical evaluation included pre- and post-treatment active anterior elevation (AAE), external rotation, and Constant score.Aims
Patients and Methods
We reviewed the outcome of 28 patients who had been treated using the Aequalis fracture
The use of a total femoral
Excision is not a suitable treatment for all comminuted fractures of the radial head. In elbows where instability can be predicted, a replacement arthroplasty of the radial head is more effective. The aim of this paper was to present the medium-term results of the Judet floating radial head
Instability after arthroplasty of the shoulder
is difficult to correct surgically. Soft-tissue procedures and revision surgery
using unconstrained anatomical components are associated with a
high rate of failure. The purpose of this study was to determine
the results of revision of an unstable anatomical shoulder arthroplasty
to a reverse design
We report our early experience with the use of
a new
The aim of this study was to determine whether patients with
metal-on-metal (MoM) arthroplasties of the hip have an increased
risk of cardiac failure compared with those with alternative types
of arthroplasties (non-MoM). A linkage study between the National Joint Registry, Hospital
Episodes Statistics and records of the Office for National Statistics
on deaths was undertaken. Patients who underwent elective total
hip arthroplasty between January 2003 and December 2014 with no
past history of cardiac failure were included and stratified as
having either a MoM (n = 53 529) or a non-MoM (n = 482 247) arthroplasty.
The primary outcome measure was the time to an admission to hospital
for cardiac failure or death. Analysis was carried out using data
from all patients and from those matched by propensity score.Aims
Patients and Methods
We aimed to find out whether the Hastings bipolar
We performed a randomised prospective trial to compare a cemented unipolar
A method is described of measuring radiological subsidence of a femoral
Total ankle arthroplasty (TAA) has become the most reliable surgical solution for patients with end-stage arthritis of the ankle. Aseptic loosening of the talar component is the most common complication. A custom-made artificial talus can be used as the talar component in a combined TAA for patients with poor bone stock of the talus. The purpose of this study was to investigate the functional and clinical outcomes of combined TAA. Ten patients (two men, eight women; ten ankles) treated using a combined TAA between 2009 and 2013 were matched for age, gender, and length of follow-up with 12 patients (one man, 11 women; 12 ankles) who underwent a standard TAA. All had end-stage arthritis of the ankle. The combined TAA features a tibial component of the TNK ankle (Kyocera, Kyoto, Japan) and an alumina ceramic artificial talus (Kyocera), designed using individualized CT data. The mean age at the time of surgery in the combined TAA and standard TAA groups was 71 years (Aims
Patients and Methods
A consecutive series of 30 total hip replacements using a hydroxyapatite (HA)-coated, modular implant (Omnifit) was followed clinically and by roentgen stereophotogrammetric analysis for two years and compared with two control groups, one of 27 cemented Charnley sockets and one of 40 cemented Charnley stems. Omnifit sockets with a central gap between the dome of the socket and the acetabular bone in the postoperative radiographs, migrated less than sockets without such gaps (p = 0.01). After adjustment for patient-related factors (age, gender and weight), no significant difference was found between the two prostheses with respect to micromotion and wear. We conclude that the early fixation of the HA-coated Omnifit
Fifteen patients with rheumatoid arthritis had 19 elbow arthroplasties with the Wadsworth type of surface replacement
Despite extensive experience with prosthetic replacement for the reconstruction of limbs following juxta-articular resection of tumours, there are few reports of prosthetic replacement of the distal radius. We present two cases of massive bone defects of the distal radius in which alumina ceramic prosthetic replacements were used. We evaluated the patients more than ten years after the procedure. Both patients had degenerative changes to the wrist. This, however, was not associated with pain or decreased function, and both had returned to their previous occupation after surgery. When a patient has a massive defect of the distal radius, reconstruction using a ceramic
Peri- and sub-prosthetic fractures, or pathological fractures below an existing well-fixed femoral component, with or without an ipsilateral knee replacement, present a difficult surgical challenge. We describe a simple solution, in which a custom-made
1. Sixty-five cases of medial fracture of the femoral neck treated by substitution of the head by an acrylic
We report the 12 to 74 month results of our mark I saddle
We reviewed 82 primary arthroplasties (in 71 patients) in which cementless porous-coated hip prostheses were used. The mean age of the patients at operation was 52 years (24 to 86); they were followed up for an average of 62.1 months (60 to 66). The diagnosis was avascular necrosis of the femoral head in 35%, fracture of the femoral neck in 24%, primary osteoarthritis in 16% and miscellaneous in 25%. The average preoperative Harris hip score was 56.7 points and the average postoperative score was 83.3 points. Eight hips (10%) had component loosening; four had been revised and four were awaiting revision. In 27 hips (33%) there was a radiolucent line wider than 2 mm in zones 1 and 7. In 55 hips (67%) there was calcar resorption of more than 10 mm. Twenty patients (28%) complained of thigh pain although they had no radiographic evidence of loosening of a component. Factors that may have contributed to the poor clinical and radiographic results were: 1) inadequate surface area for bone ingrowth, particularly on the lateral aspect of the upper part of the
We reviewed 39 patients with displaced three- and four-part fractures of the humerus. In 21 patients (group A) we had used an anatomical
Compression testing of cadaver specimens showed that excision of the radial head allowed proximal radial displacement. The insertion of a metallic radial head restored normal mechanics, while a silicone rubber implant did not. We reviewed 31 of 36 comminuted fractures of the radial head, 21 associated with dislocation or ulnar fracture, which had been treated by primary replacement with a Vitallium
The incidence and prognostic significance of fractures of acrylic cement related to the stem of a femoral head
1. The early results of thirty Austin Moore arthroplasty operations with acetabular reaming in twenty-five patients with advanced osteoarthritis of the hip have been investigated. 2. The radiological changes after insertion of a
A 70-year-old man with an uncemented metal-on-polyethylene
total hip
We reviewed our initial seven-year experience
with a non-invasive extendible
Nine cases of acetabular erosion following insertion of the Monk "hard top" hip
Seven hips with protrusio acetabuli which showed complete or partial resolution of the protrusion after replacement with Ring's
At the time of publication sixty-three additional patients have been fitted with the patellar tendon bearing
We report the use of the reverse shoulder
1. A
1. Radiographic changes in bone structure which follow the insertion of an unplasticised acrylic
We report the results of acetabular reconstruction using a bipolar
The mechanisms controlling and limiting movement and serving to transmit load between the femur and the tibia are discussed. Having accounted for the transmission of all components of force and couple across the joint and noted the load-bearing role of the menisci, some principles which might guide the design of knee prostheses are deduced. It is shown that current designs transgress some of these principles. An experimental
Over a two-year period 104 patients had 130 knee arthroplasties performed with the total condylar
We studied the fixation of a cementless titanium femoral
1. Evidence is presented which suggests that after total joint replacement bone necrosis and consequent loosening of the
Between 1993 and 1996, we undertook 35 Kudo 5 total elbow replacements in a consecutive series of 31 rheumatoid patients. A total of 25 patients (29 procedures) was evaluated at a mean follow-up of six years (5 to 7.5) using the Mayo Clinic performance index. In addition, all patients were assessed for loosening using standard anteroposterior and lateral radiographs. At review, 19 elbows (65%) had either no pain or mild pain, ten (35%) had moderate pain and none had severe pain. The mean arc of flexion/extension was 94° (35 to 130) and supination/pronation was 128° (30 to 165). A fracture of the medial epicondyle occurred during surgery in one patient. This was successfully treated with a single AO screw and a standard Kudo 5 implant was inserted. Postoperatively, there were no infections. One patient had a dislocation which was treated by closed reduction and five had neurapraxia of the ulnar nerve. Radiologically, there was no evidence of loosening of the humeral component, but two ulnar components had progressive radiolucent lines suggestive of loosening. Two other ulnar components had incomplete and non-progressive radiolucent lines. With definite radiological loosening as the endpoint, the probability of survival of the Kudo 5
A Judet-type arthroplasty of the hip was performed. The patient died fourteen days after the operation. The upper end of the femur was examined and showed extensive necrosis surrounding the stem of the
The Souter-Strathclyde
At the end of this short study we have to sum up our views about the use of the acrylic
1. The various surgical procedures in common use for the treatment of the osteoarthritic hip are briefly reviewed and compared with the operation of replacement of both the acetabulum and head of the femur by a metal
The early failure and revision of bimodular primary
total hip arthroplasty prostheses requires the identification of the
risk factors for material loss and wear at the taper junctions through
taper wear analysis. Deviations in taper geometries between revised
and pristine modular neck tapers were determined using high resolution
tactile measurements. A new algorithm was developed and validated
to allow the quantitative analysis of material loss, complementing
the standard visual inspection currently used. The algorithm was applied to a sample of 27 retrievals (in
situ from 2.9 to 38.1 months) of the withdrawn Rejuvenate
modular
In a frail elderly patient a pathological fracture of the femur at the lower end of a loose femoral stem was treated by the retrograde insertion of an intramedullary nail over the tip of the
A prospective, randomised and independently assessed trial of the Ring UPM total hip replacement showed that the quality of the early result was better if the femoral
We have reviewed 29 patients (30 hips) who had undergone revision total hip arthroplasty using a Freeman metal-backed acetabular component and acetabular impaction allografting. The mean follow-up was for 15.3 years (12 to 17). Five patients (5 hips) died with the
Before proceeding to longer-term studies, we have studied the early clinical results of a new mobile-bearing total knee prosthesis in comparison with an established fixed-bearing device. Patients requiring bilateral knee replacement consented to have their operations under one anaesthetic using one of each
A reversed Delta III total shoulder
We undertook a study on eight arms from fresh cadavers to define the clinical usefulness of the lesser sigmoid notch as a landmark when reconstructing the length of the neck of the radius in replacement of the head with a
We report the clinical and operative details of seven cases of fracture of the femoral stem of the Ring TiMESH cementless hip
The case histories of 361 subcapital fractures of the femoral neck in 354 patients treated by primary replacement with the cemented Thompson
It has been shown by mechanical analysis that by using cement to bond the stem of a femoral head
This paper reports a singular case of pathological fracture through a large osteolytic lesion of the mid-femur consequent on reaction to a hip
The indications for reverse shoulder arthroplasty
(RSA) continue to be expanded. Associated impairment of the deltoid
muscle has been considered a contraindication to its use, as function
of the RSA depends on the deltoid and impairment of the deltoid
may increase the risk of dislocation. The aim of this retrospective
study was to determine the functional outcome and risk of dislocation
following the use of an RSA in patients with impaired deltoid function.
Between 1999 and 2010, 49 patients (49 shoulders) with impairment
of the deltoid underwent RSA and were reviewed at a mean of 38 months
(12 to 142) post-operatively. There were nine post-operative complications (18%),
including two dislocations. The mean forward elevation improved
from 50° ( These results suggest that pre-operative deltoid impairment,
in certain circumstances, is not an absolute contraindication to
RSA. This form of treatment can yield reliable improvement in function
without excessive risk of post-operative dislocation. Cite this article:
The results of thirty-one Manchester knee arthroplasties performed on twenty-eight patients are reviewed. There were sixteen patients with rheumatoid arthritis all of whom were satisfactory at the time of follow-up. Of the fifteen patients with osteoarthritis over half the arthroplasties failed after between twelve and thirty-six months. We suggest that resurfacing arthroplasty of the knee using the Manchester
1. A lateral intermuscular approach to the hip joint is described for replacement of the head of the femur by a
The aim of this study was to evaluate blood metal ion levels, leucocyte profiles, and serum cytokines in patients with a total hip arthroplasty (THA) involving modular dual-mobility components. A total of 39 patients were recruited, with clinical follow-up of up to two years. Outcome was assessed using the Harris Hip Score (HHS, the 12-Item Short-Form Health Survey (SF-12), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and a visual analogue scale (VAS) for pain. Blood concentrations of cobalt (Co), chromium (Cr), and serum cytokines were measured. Subpopulations of leucocytes were analyzed by flow cytometry.Aims
Patients and Methods
Arthrodesis after the removal of a knee prosthesis is often hampered by the small area of contact of the bony surfaces and by pre-existing infection. Conventional systems of external fixation and compression frequently fail to achieve stability but the addition of the Wagner leg-lengthening apparatus applied anteriorly and adjusted to give compression ensures rigid external fixation. Four knees in four patients were treated using this technique; the treatment followed the removal of infected prostheses in three knees and painful fibrous ankylosis after the removal of the
Eighty elbows in 65 patients with an average age of 57 years have had two-part non-constrained Liverpool elbow arthroplasties performed since 1974. Fifty-five had rheumatoid arthritis, eight osteoarthritis or ankylosis secondary to injury, one osteochondritis dissecans and one pyknodysostosis. The average preoperative range of movement was 42 degrees to 112 degrees with 47 degrees of pronation and 42 degrees of supination. There was significant gain in the arc of movements at follow-up: 32 degrees in the extension-flexion range (average range 32 degrees to 134 degrees of flexion) and 42 degrees in forearm rotation (average pronation 69 degrees and supination 62 degrees). Before operation severe pain was the predominating symptom in 43 elbows (53.8%) but after replacement there was only moderate pain in five elbows (6.2%). The results were excellent in 42 (52.5%), good in 15 (18.7%), fair in 9 (11.3%) and unsatisfactory or poor in 14 (17.5%). Eight elbows required revision of the arthroplasty: three were post-traumatic, disorganised or osteoarthritic joints, three rheumatoid and both elbows in the patient with pyknodysostosis. Loosening of the
We used dual-energy x-ray absorptiometry (DEXA) to evaluate the extent of periprosthetic bone remodelling around a
Early evidence has emerged suggesting that ceramic-on-ceramic
articulations induce a different tissue reaction to ceramic-on-polyethylene
and metal-on-metal bearings. Therefore, the aim of this study was
to investigate the tissue reaction and cellular response to ceramic
total hip arthroplasty (THA) materials We investigated tissue collected at revision surgery from nine
ceramic-on-ceramic articulations. we compared our findings with
tissue obtained from five metal-on-metal THA revisions, four ceramic-on-polyethylene
THAs, and four primary osteoarthritis synovial membranes. The latter
were analyzed to assess the amount of tissue fibrosis that might
have been present at the time of implantation to enable evaluation,
in relation to implantation time, of any subsequent response in
the tissues.Aims
Patients and Methods
We report the case of a 19-year-old man with inguinal lymphadenopathy caused by metallic debris from the loosening of a
Twenty patients each with a fractured femoral neck had a
We describe 129 patients with disabling instability of the knee due to deficiency of the anterior cruciate ligament. They were treated by replacement of the ligament with a Leeds-Keio
Autologous retransfusion and no-drainage are
both blood-saving measures in total hip replacement (THR). A new combined
intra- and post-operative autotransfusion filter system has been
developed especially for primary THR, and we conducted a randomised
controlled blinded study comparing this with no-drainage. A total of 204 THR patients were randomised to autologous blood
transfusion (ABT)
(n = 102) or no-drainage (n = 102). In the ABT group, a mean of
488 ml ( The use of a new intra- and post-operative autologous blood transfusion
filter system results in less total blood loss and a smaller maximum
decrease in haemoglobin levels than no-drainage following primary
THR. Cite this article:
The Kent hip is a distally-locked femoral stem which was developed to address severe proximal bone loss, severe bony deformity and peri-prosthetic fracture. We reviewed the results of 145 consecutive Kent hips implanted into 141 patients between 1987 and 2000. The indications for implantation were aseptic loosening (75 hips), septic loosening (two), peri-prosthetic and prosthetic fracture (37), severe bony deformity (24), and fracture through a proximal femoral metastasis (seven). The median time to full weight-bearing after surgery was two days and the mean length of follow-up was 5.1 years (2 to 15). Further revisions were required for 13 femoral stems. With removal of the stem for any reason as an end-point, the cumulative survival at five, ten and 15 years was 93%, 89% and 77%, respectively. In patients aged ≥ 70 years, the cumulative survival at 15 years was 92%, compared with 68% in those aged <
70 years. Because of these findings, we recommend the use of interlocking stems in patients aged ≥ 70 years, particularly in those with a peri-prosthetic fracture, for whom alternative methods are limited. Outcome scores and survival data, compared with other systems, indicate that the Kent hip should be used with caution in younger patients.
We assessed the long-term results of 58 Souter-Strathclyde total elbow replacements in 49 patients with rheumatoid arthritis. The mean length of follow-up was 9.5 years (0.7 to 16.7). The mean pre-operative Mayo Elbow Performance Score was 30 (15 to 80) and at final follow-up was 82 (60 to 95). A total of 13 elbows (22.4%) were revised, ten (17.2%) for aseptic loosening, one (1.7%) for instability, one (1.7%) for secondary loosening after fracture, and one elbow (1.7%) was removed because of deep infection. The Kaplan-Meier survival rate was 70% and 53% at ten and 16 years, respectively. Failure of the ulnar component was found to be the main problem in relation to the loosening. Anterior transposition of the ulnar nerve had no influence on ulnar nerve paresthaesiae in these patients.
There have been few reports in the literature of total elbow arthroplasty extending beyond 10 to 15 years. We reviewed 40 patients (41 elbows) with a mean age of 56 years (19 to 83) who had undergone a Coonrad/Coonrad-Morrey elbow arthroplasty by one surgeon for various diagnoses between 1974 and 1994. Surgical selection excluded patients with previous elbow infection or who refused to accept a sedentary level of elbow activity postoperatively. Objective data were collected from charts, radiographs, clinical photographs and supplemented by the referring orthopaedic surgeons’ records and radiographs if health or distance prevented a patient from returning for final review. Subjective outcome was defined by patient satisfaction. Of the 41 elbows, 21 were functional between 10 and 14 years after operation, ten between 15 and 19 years and ten between 20 and 31 years. There were 14 complications and 13 revisions, but no cases of acute infection, or permanent removal of any implant.
We have previously described the short-term outcome of the use of reverse shoulder arthroplasty in the treatment of acute complex proximal humeral fractures in the elderly. We now report the clinical and radiological outcome of 36 fractures at a mean of 6.6 years (1 to 16). Previously, at a mean follow-up of 6 years (1 to 12) the mean Constant score was 58.5; this was reduced to 53 points with the further follow-up. A total of 23 patients (63%) had radiological evidence of loosening of the glenoid component. Nevertheless, only one patient had aseptic loosening of the baseplate at 12 years’ follow-up. The reduction in the mean Constant score with longer follow-up and the further development of scapular notching is worrying. New developments in design, bearing surfaces and surgical technique, and further follow-up, will determine whether reverse shoulder arthroplasty has a place in the management of complex proximal humeral fractures in the elderly.
The cortical strains on the femoral neck and proximal femur were measured before and after implantation of a resurfacing femoral component in 13 femurs from human cadavers. These were loaded into a hip simulator for single-leg stance and stair-climbing. After resurfacing, the mean tensile strain increased by 15% (95% confidence interval (CI) 6 to 24, p = 0.003) on the lateral femoral neck and the mean compressive strain increased by 11% (95% CI 5 to 17, p = 0.002) on the medial femoral neck during stimulation of single-leg stance. On the proximal femur the deformation pattern remained similar to that of the unoperated femurs. The small increase of strains in the neck area alone would probably not be sufficient to cause fracture of the neck However, with patient-related and surgical factors these strain changes may contribute to the risk of early periprosthetic fracture.
1. A bio-electrically controlled limb for forearm amputees is described. 2. The technique of its use and its advantages are listed.
We report the radiological and clinical outcome of a press-fit (SLF) acetabular component at two to three years in two groups of patients having primary total hip replacement. In 69 the implant was coated with hydroxyapatite (HA) and in 40 it was uncoated. The stability of the cup was assessed by measurement of proximal migration and change in the angle of inclination. The clinical results in the two groups did not differ significantly, and the mean proximal linear wear was similar in both. Fewer radiolucent lines (RLLs) were seen on the radiographs of cups coated with HA. The mean proximal migration was studied by calculating regression lines for each patient using migration measurements: for the SLF+HA group the mean slope was 0.06 mm/year and for the SLF–HA group 0.20 mm/year (p = 0.22). The change in the angle of inclination during follow-up was also consistently smaller in HA–coated cups. Using regression methods the SLF+HA group had a mean slope of 0.08°/year and the SLF-HA group 0.44°/year (p = 0.023). Partial HA coating appeared to have no effect on the clinical outcome or on the rate of wear of polyethylene, but there was a trend towards a reduced rate of proximal migration, and a significant reduction in rotational migration and the number of radiolucent lines. This suggests that HA coating enhances the stability of this acetabular component.
The records of 243 patients with Thompson prostheses for displaced femoral neck fractures have been studied. One hundred and seven prostheses were inserted through an anterior approach and 136 by a posterior approach. The short-term results and complications in these otherwise comparable groups are discussed. The infection rate of 18·5 per cent in the group operated upon by the posterior approach was thrice that after operations by the anterior route (6·5 per cent infected). Drained wounds had significantly less infection (6·3 per cent) compared with the undrained group (28 per cent infected). Other factors influencing the infection rate are discussed. The anterior approach offered greater stability. Of the twenty dislocations in the series, nineteen followed operations by the posterior approach. The mortality rate six weeks after operation was 6·5 per cent after the anterior approach and 20·6 per cent after the posterior approach. Statistical analysis significantly favours the anterior approach.