We performed a series of 16 anatomical dissections
on Caucasian cadaver material to determine the surgical anatomy
of the medial femoral circumflex artery (MFCA) and its anastomoses.
These confirmed that the femoral head receives its blood supply
primarily from the MFCA via a group of posterior superior nutrient
arteries and the posterior inferior nutrient artery. In terms of
anastomoses that may also contribute to the blood supply, the anastomosis
with the inferior gluteal artery, via the piriformis branch, is
the most important. These dissections provide a base of knowledge
for further radiological studies on the vascularity of the normal
femoral head and its vascularity after dislocation of the hip.
We report the results of six trauma and orthopaedic
projects to Kenya in the last three years. The aims are to deliver both
a trauma service and teaching within two hospitals; one a district
hospital near Mount Kenya in Nanyuki, the other the largest public
hospital in Kenya in Mombasa. The Kenya Orthopaedic Project team
consists of a wide range of multidisciplinary professionals that
allows the experience to be shared across those specialties. A follow-up
clinic is held three months after each mission to review the patients.
To our knowledge there are no reported outcomes in the literature
for similar projects. A total of 211 operations have been performed and 400 patients
seen during the projects. Most cases were fractures of the lower
limb; we have been able to follow up 163 patients (77%) who underwent
surgical treatment. We reflect on the results so far and discuss
potential improvements for future missions.
Femoroacetabular impingement causes groin pain
and decreased athletic performance in active adults. This bony conflict
may result in femoroacetabular subluxation if of sufficient magnitude. The ligamentum teres has recently been reported to be capable
of withstanding tensile loads similar to that of the anterior cruciate
ligament, and patents with early subluxation of the hip may become
dependent on the secondary restraint that is potentially provided
by the ligamentum teres. Rupture of the ligamentum may thus cause
symptomatic hip instability during athletic activities. An arthroscopic reconstruction of the ligamentum teres using
iliotibial band autograft was performed in an attempt to restore
this static stabiliser in a series of four such patients. Early
clinical results have been promising. The indications, technique
and early outcomes of this procedure are discussed.
Few studies have examined the order in which
a spinal osteotomy and total hip replacement (THR) are to be performed
for patients with ankylosing spondylitis. We have retrospectively
reviewed 28 consecutive patients with ankylosing spondylitis who
underwent both a spinal osteotomy and a THR from September 2004
to November 2012. In the cohort 22 patients had a spinal osteotomy
before a THR (group 1), and six patients had a THR before a spinal
osteotomy (group 2). The mean duration of follow-up was 3.5 years
(2 to 9). The spinal sagittal Cobb angle of the vertebral osteotomy
segment was corrected from a pre-operative kyphosis angle of 32.4
(SD 15.5°) to a post-operative lordosis 29.6 (SD 11.2°) (p <
0.001). Significant improvements in pain, function and range of
movement were observed following THR. In group 2, two of six patients
had an early anterior dislocation. The spinal osteotomy was performed
two weeks after the THR. At follow-up, no hip has required revision
in either group. Although this non-comparative study only involved
a small number of patients, given our experience, we believe a spinal osteotomy
should be performed prior to a THR, unless the deformity is so severe
that the procedure cannot be performed. Cite this article:
The introduction of a trabecular tantalum rod
has been proposed for the management of early-stage osteonecrosis of
the femoral head but serves as a single-point of support of the
necrotic lesion. We describe a technique using two or three 4.2
mm (or later 4.7 mm) tantalum pegs for the prevention of collapse
of the necrotic lesion. We prospectively studied 21 patients (26
hips) with non-traumatic osteonecrosis of the femoral head treated
in this manner. Of these, 21 patients (24 hips) were available for
radiological and clinical evaluation at a mean follow-up of 46 months
(18 to 67). Radiological assessment showed that only eight hips
deteriorated according to the Association Research Circulation Osseous
classification, and four hips according to the Classification of
the Japanese Investigation Committee of Health and Welfare. Functional
improvement was obtained with an improvement in the mean Harris
hip score from 65.2 (33.67 to 95) to 88.1 (51.72 to 100), the mean
Merle D’Aubigné-Postel score from 13 (6 to 18) to 16 (11 to 18),
a mean visual analogue score for pain from 5.2 (0 to 9.5) to 2.6
(0 to 7), and the mean Short-Form 36 score from 80.4 (56.8 to 107.1)
to 92.4 (67.5 to 115.7). Of these 24 hips followed for a minimum
of 18 months, three were considered as failures at the final follow-up,
having required total hip replacement. One of the hips without full
follow-up was also considered to be a failure. In more than two-thirds
of the surviving hips a satisfactory clinical outcome was achieved
with promising radiological findings. The estimated mean implant
survival was 60 months (95% confidence interval 53.7 to 66.3).
Persistent groin pain after seemingly successful
total hip replacement (THR) appears to have become more common.
Recent studies have indicated a high incidence after metal-on-polyethylene
and metal-on-metal conventional THR and it has been documented in
up to 18% of patients after metal-on-metal resurfacing. There are many
causes, including acetabular loosening, stress fracture, and iliopsoas
tendonitis and impingement. The evaluation of this problem requires
a careful history and examination, plain radiographs and an algorithmic approach
to special diagnostic imaging and tests. Non-operative treatment
is not usually successful. Specific operative treatment depending
on the cause of the pain usually involves revision of the acetabular
component, iliopsoas tenotomy or other procedures, and is usually
successful. Here, an appropriate algorithm is described.
The computed neck-shaft angle and the size of the femoral component were recorded in 100 consecutive hip resurfacings using imageless computer-navigation and compared with the angle measured before operation and with actual component implanted. The reliability of the registration was further analysed using ten cadaver femora. The mean absolute difference between the measured and navigated neck-shaft angle was 16.3° (0° to 52°). Navigation underestimated the measured neck-shaft angle in 38 patients and the correct implant size in 11. Registration of the cadaver femora tended to overestimate the correct implant size and provided a low level of repeatability in computing the neck-shaft angle. Prudent pre-operative planning is advisable for use in conjunction with imageless navigation since misleading information may be registered intraoperatively, which could lead to inappropriate sizing and positioning of the femoral component in hip resurfacing.
We studied the effect of trochanteric osteotomy in 192 total hip replacements in 140 patients with congenital hip disease. There was bony union in 158 hips (82%), fibrous union in 29 (15%) and nonunion in five (3%). The rate of union had a statistically significant relationship with the position of reattachment of the trochanter, which depended greatly on the pre-operative diagnosis. The pre-operative Trendelenburg gait substantially improved in all three disease types (dysplasia, low and high dislocation) and all four categories of reattachment position. A persistent Trendelenburg gait post-operatively was noticed mostly in patients with defective union (fibrous or nonunion). Acetabular and femoral loosening had a statistically significant relationship with defective union and the position of reattachment of the trochanter. These results suggest that the complications of trochanteric osteotomy in total hip replacement for patients with congenital hip disease are less important than the benefits of this surgical approach.
The rate and mode of early failure in 463 Birmingham hip resurfacings in a two-centre, multisurgeon series were examined. Of the 463 patients two have died and three were lost to follow-up. The mean radiological and clinical follow-up was for 43 months (6 to 90). We have revised 13 resurfacings (2.8%) including seven for pain, three for fracture, two for dislocation and another for sepsis. Of these, nine had macroscopic and histological evidence of metallosis. The survival at five years was 95.8% (95% confidence interval (CI) 94.1 to 96.8) for revision for all causes and 96.9% (95% CI 95.5 to 98.3) for metallosis. The rate of metallosis related revision was 3.1% at five years. Risk factors for metallosis were female gender, a small femoral component, a high abduction angle and obesity. We do not advocate the use of the Birmingham Hip resurfacing procedure in patients with these risk factors.
This preliminary study evaluates a combination
of bone morphogenetic protein (BMP)-7 and non-vascularised autologous
fibular grafting (AFG) for the treatment of osteonecrosis of the
femoral head. BMP-7/AFG combination was applied in seven pre-collapse femoral
heads (five Steinberg stage II, two stage III) in six patients.
Pre- and post-operative evaluation included clinical (Harris hip
score (HHS), visual analogue scale (VAS) for pain) and radiological
assessment (radiographs, quantitative CT) at a mean follow-up of
4 years (2 to 5.5). A marked improvement of function (mean HHS increase of 49.2)
and decrease of pain level (mean VAS decrease of 5) as well as retention
of the sphericity of the femoral head was noted in five hips at
the latest follow-up, while signs of consolidation were apparent
from the third post-operative month. One patient (two hips) required
bilateral total hip replacement at one year post-operatively. In
the series as a whole, quantitative-CT evaluation revealed similar densities
between affected and normal bone. Heterotopic ossification was observed
in four hips, without compromise of the clinical outcome. In this limited series AFG/BMP-7 combination proved a safe and
effective method for the treatment of femoral head osteonecrosis,
leading to early consolidation of the AFG and preventing collapse
in five of seven hips, while the operative time and post-operative
rehabilitation period were much shorter compared with free vascularised fibular
grafts. Cite this article:
This paper reviews the current knowledge relating to the management of adult patients with congenital hip disease. Orthopaedic surgeons who treat these patients with a total hip replacement should be familiar with the arguments concerning its terminology, be able to recognise the different anatomical abnormalities and to undertake thorough pre-operative planning in order to replace the hip using an appropriate surgical technique and the correct implants and be able to anticipate the clinical outcome and the complications.
Progressive retroversion of a cemented stem is
predictive of early loosening and failure. We assessed the relationship
between direct post-operative stem anteversion, measured with CT,
and the resulting rotational stability, measured with repeated radiostereometric
analysis over ten years. The study comprised 60 cemented total hip
replacements using one of two types of matt collared stem with a
rounded cross-section. The patients were divided into three groups
depending on their measured post-operative anteversion (<
10°,
10° to 25°, >
25°). There was a strong correlation between direct
post-operative anteversion and later posterior rotation. At one
year the <
10° group showed significantly more progressive retroversion
together with distal migration, and this persisted to the ten-year
follow-up. In the <
10° group four of ten stems (40%) had been
revised at ten years, and an additional two stems (20%) were radiologically
loose. In the ‘normal’ (10° to 25°) anteversion group there was
one revised (3%) and one loose stem (3%) of a total of 30 stems,
and in the >
25° group one stem (5%) was revised and another loose (5%)
out of 20 stems. This poor outcome is partly dependent on the design
of this prosthesis, but the results strongly suggest that the initial
rotational position of cemented stems during surgery affects the
subsequent progressive retroversion, subsidence and eventual loosening.
The degree of retroversion may be sensitive to prosthetic design
and stem size, but <
10° of anteversion appears deleterious to
the long-term outcome for cemented hip prosthetic stems. Cite this article:
In 2012 we reviewed a consecutive series of 92
uncemented THRs performed between 1986 and 1991 at our institution
using the CLS Spotorno stem, in order to assess clinical outcome
and radiographic data at a minimum of 21 years. The series comprised
92 patients with a mean age at surgery of 59.6 years (39 to 77)
(M:F 43;49). At the time of this review, seven (7.6%) patients had died and
two (2.2%) were lost to follow-up. The 23-year Kaplan–Meier survival
rates were 91.5% (95% confidence intervals (CI) 85.4% to 97.6%;
55 hips at risk) and 80.3% (95% CI, 71.8% to 88.7%; 48 hips at risk)
respectively, with revision of the femoral stem or of any component
as endpoints. At the time of this review, 76 patients without stem
revision were assessed clinically and radiologically (mean follow-up
24.0 years (21.5 to 26.5)). For the 76 unrevised hips the mean Harris
hip score was 87.1 (65 to 97). Femoral osteolysis was detected in
five hips (6.6%) only in Gruen zone 7. Undersized stems were at
higher risk of revision owing to aseptic loosening (p = 0.0003).
Patients implanted with the stem in a varus position were at higher risk
of femoral cortical hypertrophy and thigh pain (p = 0.0006 and p
= 0.0007, respectively). In our study, survival, clinical outcome and radiographic data
remained excellent in the third decade after implantation. Nonetheless,
undersized stems were at higher risk of revision owing to aseptic
loosening. Cite this article:
Dislocation is one of the most common causes
of patient and surgeon dissatisfaction following hip replacement
and to treat it, the causes must first be understood. Patient factors
include age greater than 70 years, medical comorbidities, female
gender, ligamentous laxity, revision surgery, issues with the abductors,
and patient education. Surgeon factors include the annual quantity
of procedures and experience, the surgical approach, adequate restoration
of femoral offset and leg length, component position, and soft-tissue
or bony impingement. Implant factors include the design of the head
and neck region, and so-called skirts on longer neck lengths. There
should be offset choices available in order to restore soft-tissue
tension. Lipped liners aid in gaining stability, yet if improperly placed
may result in impingement and dislocation. Late dislocation may
result from polyethylene wear, soft-tissue destruction, trochanteric
or abductor disruption and weakness, or infection. Understanding
the causes of hip dislocation facilitates prevention in a majority
of instances. Proper pre-operative planning includes the identification
of patients with a high offset in whom inadequate restoration of
offset will reduce soft-tissue tension and abductor efficiency.
Component position must be accurate to achieve stability without impingement.
Finally, patient education cannot be over-emphasised, as most dislocations occur
early, and are preventable with proper instructions. Cite this article:
Bioengineering reasons for increased wear and failure of metal-on-metal (MoM) bearings in hip prostheses have been described. Low wear occurs in MoM hips when the centre of the femoral head is concentric with the centre of the acetabular component and the implants are correctly positioned. Translational or rotational malpositioning of the components can lead to the contact-patch of the femoral component being displaced to the rim of the acetabular component, resulting in a ten- to 100-fold increase in wear and metal ion levels. This may cause adverse tissue reactions, loosening of components and failure of the prosthesis.
We performed 96 Birmingham resurfacing arthroplasties of the hip in 71 consecutive patients with avascular necrosis of the femoral head. A modified neck-capsule-preserving approach was used which is described in detail. The University of California, Los Angeles outcome score, the radiological parameters and survival rates were assessed. The mean follow-up was for 5.4 years (4.0 to 8.1). All the patients remained active with a mean University of California, Los Angeles activity score of 6.86 (6 to 9). Three hips failed, giving a cumulative survival rate of 95.4%. With failure of the femoral component as the endpoint, the cumulative survival rate was 98.0%. We also describe the combined abduction-valgus angle of the bearing couple, which is the sum of the inclination angle of the acetabular component and the stem-shaft angle, as an index of the optimum positioning of the components in the coronal plane. Using a modified surgical technique, it is possible to preserve the femoral head in avascular necrosis by performing hip resurfacing in patients with good results.
We review the history and literature of hip resurfacing arthroplasty. Resurfacing and the science behind it continues to evolve. Recent results, particularly from the national arthroplasty registers, have spread disquiet among both surgeons and patients. A hip resurfacing arthroplasty is not a total hip replacement, but should perhaps be seen as a means of delaying it. The time when hip resurfacing is offered to a patient may be different from that for a total hip replacement. The same logic can apply to the timing of revision surgery. Consequently, the comparison of resurfacing with total hip replacement may be a false one. Nevertheless, the need for innovative solutions for young arthroplasty patients is clear. Total hip replacement can be usefully delayed in many of these patients by the use of hip resurfacing arthroplasty.
We have reviewed 42 patients who had revision of metal-on-metal resurfacing procedures, mostly because of problems with the acetabular component. The revisions were carried out a mean of 26.2 months (1 to 76) after the initial operation and most of the patients (30) were female. Malpositioning of the acetabular component resulted in 27 revisions, mostly because of excessive abduction (mean 69.9°; 56° to 98°) or insufficient or excessive anteversion. Seven patients had more than one reason for revision. The mean increase in the diameter of the component was 1.8 mm (0 to 4) when exchange was needed. Malpositioning of the components was associated with metallosis and a high level of serum ions. The results of revision of the femoral component to a component with a modular head were excellent, but four patients had dislocation after revision and four required a further revision.
This study compared component wear rates and pre-revision blood metal ions levels in two groups of failed metal-on-metal hip arthroplasties: hip resurfacing and modular total hip replacement (THR). There was no significant difference in the median rate of linear wear between the groups for both acetabular (p = 0.4633) and femoral (p = 0.0872) components. There was also no significant difference in the median linear wear rates when failed hip resurfacing and modular THR hips of the same type (ASR and Birmingham hip resurfacing (BHR)) were compared. Unlike other studies of well-functioning hips, there was no significant difference in pre-revision blood metal ion levels between hip resurfacing and modular THR. Edge loading was common in both groups, but more common in the resurfacing group (67%) than in the modular group (57%). However, this was not significant (p = 0.3479). We attribute this difference to retention of the neck in resurfacing of the hip, leading to impingement-type edge loading. This was supported by visual evidence of impingement on the femur. These findings show that failed metal-on-metal hip resurfacing and modular THRs have similar component wear rates and are both associated with raised pre-revision blood levels of metal ions.
Hip replacement is a very successful operation and the outcome is usually excellent. There are recognised complications that seem increasingly to give rise to litigation. This paper briefly examines some common scenarios where litigation may be pursued against hip surgeons. With appropriate record keeping, consenting and surgical care, the claim can be successfully defended if not avoided. We hope this short summary will help to highlight some common pitfalls. There is extensive literature available for detailed study.