The purpose of this study was twofold: first,
to determine whether the five-year results of hip resurfacing arthroplasty
(HRA) in Canada justified the continued use of HRA; and second,
to identify whether greater refinement of patient selection was
warranted. This was a retrospective cohort study that involved a review
of 2773 HRAs performed between January 2001 and December 2008 at
11 Canadian centres. Cox’s proportional hazards models were used
to analyse the predictors of failure of HRA. Kaplan–Meier survival
analysis was performed to predict the cumulative survival rate at
five years. The factors analysed included age, gender, body mass
index, pre-operative hip pathology, surgeon’s experience, surgical
approach, implant sizes and implant types. The most common modes
of failure were also analysed. The 2773 HRAs were undertaken in 2450 patients: 2127 in men and
646 in women. The mean age at operation was 50.5 years ( The failure rates of HRA at five years justify the ongoing use
of this technique in men. Female gender is an independent predictor
of failure, and a higher failure rate at five years in women leads
the authors to recommend this technique only in exceptional circumstances
for women. Cite this article:
Multiple drilling is reported to be an effective treatment for osteonecrosis of the head of femur, but its effect on intra-osseous pressure has not been described. We undertook multiple drilling and recorded the intra-osseous pressure in 75 osteonecrotic hips in 60 patients with a mean age of 42 years (19 to 67). At a mean follow-up of 37.1 months (24 to 60), 42 hips (56%) had a clinically successful outcome. The procedure was effective in reducing the mean intra-osseous pressure from 57 mmHg (SD 22) to 16 mmHg (SD 9). Hips with a successful outcome had a mean pressure of 26 mmHg (SD 19). It was less effective in preventing progression of osteonecrosis in hips with considerable involvement and in those with a high intra-osseous pressure in the intertrochanteric region (mean 45 mmHg (SD 25)). This study is not able to answer whether a return of the intra-osseous pressure to normal levels is required for satisfactory healing.
We dissected 20 cadaver hips in order to investigate the anatomy and excursion of the trochanteric muscles in relation to the posterior approach for total hip replacement. String models of each muscle were created and their excursion measured while the femur was moved between its anatomical position and the dislocated position. The position of the hip was determined by computer navigation. In contrast to previous studies which showed a separate insertion of piriformis and obturator internus, our findings indicated that piriformis inserted onto the superior and anterior margins of the greater trochanter through a conjoint tendon with obturator internus, and had connections to gluteus medius posteriorly. Division of these connections allowed lateral mobilisation of gluteus medius with minimal retraction. Analysis of the excursion of these muscles revealed that positioning the thigh for preparation of the femur through this approach elongated piriformis to a maximum of 182%, obturator internus to 185% and obturator externus to 220% of their resting lengths, which are above the thresholds for rupture of these muscles. Our findings suggested that gluteus medius may be protected from overstretching by release of its connection with the conjoint tendon. In addition, failure to detach piriformis or the obturators during a posterior approach for total hip replacement could potentially produce damage to these muscles because of over-stretching, obturator externus being the most vulnerable.
The term developmental dysplasia of the hip (DDH)
describes a spectrum of disorders that results in abnormal development
of the hip joint. If not treated successfully in childhood, these
patients may go on to develop hip symptoms and/or secondary osteoarthritis
in adulthood. In this review we describe the altered anatomy encountered
in adults with DDH along with the management options, and the challenges
associated with hip arthroscopy, osteotomies and arthroplasty for
the treatment of DDH in young adults. Cite this article:
A total of 219 hips in 192 patients aged between
18 and 65 years were randomised to 28-mm metal-on-metal uncemented
total hip replacements (THRs, 107 hips) or hybrid hip resurfacing
(HR, 112 hips). At a mean follow-up of eight years (6.6 to 9.3)
there was no significant difference between the THR and HR groups
regarding rate of revision (4.0% (4 of 99) Cite this article:
We performed a three-year radiostereometric analysis (RSA) study of the Elite Plus femoral component on 25 patients undergoing primary total hip replacement. Additional assessments and measurements from standard radiographs were also made. Subsidence of the stem occurred at the cement-stem interface. At 36 months the subsidence of the stem centroid was a mean of 0.30 mm (0.02 to 1.28), and was continuing at a slow rate. At the same time point, internal rotation and posterior migration of the femoral head had ceased. One stem migrated excessively and additional assessments suggested that this was probably due to high patient demand. The failure rate of 4% in our study is consistent with data from arthroplasty registers but contrasts with poor results from another RSA study, and from some clinical studies. We believe that the surgical technique, particularly the use of high-viscosity cement, may have been an important factor contributing to our results.
This study investigates the use of porous biphasic ceramics as graft extenders in impaction grafting of the femur during revision hip surgery. Impaction grafting of the femur was performed in four groups of sheep. Group one received pure allograft, group two 50% allograft and 50% BoneSave, group three 50% allograft and 50% BoneSave type 2 and group four 10% allograft and 90% BoneSave as the graft material. Function was assessed using an index of pre- and post-operative peak vertical ground reaction force ratios. Changes in bone mineral density were measured by dual energy X ray absorptiometry (DEXA) scanning. Loosening and subsidence were assessed radiographically and by histological examination of the explanted specimens. There was no statistically significant difference between the four groups after 18 months of unrestricted functional loading for all outcome measures.
The Gamma nail is frequently used in unstable
peri-trochanteric hip fractures. We hypothesised that mechanical failure
of the Gamma nail was associated with inadequate proximal three-point
fixation. We identified a consecutive series of 299 Gamma nails
implanted in 299 patients over a five-year period, 223 of whom fulfilled
our inclusion criteria for investigation. The series included 61
men and 162 women with a mean age of 81 years (20 to 101). Their fractures
were classified according to the Modified Evans’ classification
and the quality of fracture reduction was graded. The technical
adequacy of three points of proximal fixation was recorded from
intra-operative fluoroscopic images, and technical inadequacy for
each point was defined. All patients were followed to final follow-up
and mechanical failures were identified. A multivariate statistical
analysis was performed, adjusting for confounders. A total of 16
failures (7.2%) were identified. The position of the lag screw relative
to the lateral cortex was the most important point of proximal fixation,
and when inadequate the failure rate was 25.8% (eight of 31: odds
ratio 7.5 (95% confidence interval 2.5 to 22.7), p <
0.001). Mechanical failure of the Gamma nail in peri-trochanteric femoral
fractures is rare (<
1%) when three-point proximal fixation is
achieved. However, when proximal fixation is inadequate, failure
rates increase. The strongest predictor of failure is positioning
the lateral end of the lag screw short of the lateral cortex. Adherence
to simple technical points minimises the risk of fixation failure
in this vulnerable patient group. Cite this article:
A cadaver study using six pairs of lower limbs was conducted to investigate the accuracy of computer navigation and standard instrumentation for the placement of the Birmingham Hip Resurfacing femoral component. The aim was to place all the femoral components with a stem-shaft angle of 135°. The mean stem-shaft angle obtained in the standard instrumentation group was 127.7° (120° to 132°), compared with 133.3° (131° to 139°) in the computer navigation group (p = 0.03). The scatter obtained with computer-assisted navigation was approximately half that found using the conventional jig. Computer navigation was more accurate and more consistent in its placement of the femoral component than standard instrumentation. We suggest that image-free computer-assisted navigation may have an application in aligning the femoral component during hip resurfacing.
We aimed to identify the incidence, outcome and prognostic factors associated with spindle cell sarcomas of bone (SCSB). We studied 196 patients with a primary non-metastatic tumour treated with the intent to cure. The results were compared with those of osteosarcoma patients treated at our hospital during the same period. The overall incidence of SCSB was 7.8% of all patients with a primary bone sarcoma. The five- and ten-year survival rates were 67.0% and 60.0%, respectively, which were better than those of patients with osteosarcoma treated over the same period. All histological subtypes had similar outcomes. On univariate analysis, factors that were significantly associated with decreased survival were age >
40 years, size >
8 cm, the presence of a pathological fracture, amputation, involved margins and a poor response to pre-operative chemotherapy. Multivariate analyses showed that age >
65 years, amputation and involved margins were all statistically significant prognostic factors. Involved margins and poor response to pre-operative chemotherapy were associated with an increased risk of local recurrence. SCSB has a better prognosis than osteosarcoma when matched for age. Most prognostic factors for osteosarcoma also seem to apply to SCSB. Patients with SCSB should be treated in the same way as patients of the same age with osteosarcoma.
We undertook a retrospective review of 33 patients who underwent total femoral endoprosthetic replacement as limb salvage following excision of a malignant bone tumour. In 22 patients this was performed as a primary procedure following total femoral resection for malignant disease. Revision to a total femoral replacement was required in 11 patients following failed segmental endoprosthetic or allograft reconstruction. There were 33 patients with primary malignant tumours, and three had metastatic lesions. The mean age of the patients was 31 years (5 to 68). The mean follow-up was 4.2 years (9 months to 16.4 years). At five years the survival of the implants was 100%, with removal as the endpoint and 56% where the endpoint was another surgical intervention. At five years the patient survival was 32%. Complications included dislocation of the hip in six patients (18%), local recurrence in three (9%), peri-prosthetic fracture in two and infection in one. One patient subsequently developed pulmonary metastases. There were no cases of aseptic loosening or amputation. Four patients required a change of bushings. The mean Musculoskeletal Tumour Society functional outcome score was 67%, the mean Harris Hip Score was 70, and the mean Oxford Knee Score was 34. Total femoral endoprosthetic replacement can provide good functional outcome without compromising patient survival, and in selected cases provides an effective alternative to amputation.
Peri-prosthetic femoral fracture after total hip replacement (THR) is associated with a poor outcome and high mortality. However, little is known about its long-term incidence after uncemented THR. We retrospectively reviewed a consecutive series of 326 patients (354 hips) who had received a CLS Spotorno replacement with an uncemented, straight, collarless tapered titanium stem between January 1985 and December 1989. The mean follow-up was 17 years (15 to 20). The occurrence of peri-prosthetic femoral fracture during follow-up was noted. Kaplan-Meier survival analysis was used to estimate the cumulative incidence of fracture. At the last follow-up, 86 patients (89 hips) had died and eight patients (eight hips) had been lost to follow-up. A total of 14 fractures in 14 patients had occurred. In ten hips, the femoral component had to be revised and in four the fracture was treated by open reduction and internal fixation. The cumulative incidence of peri-prosthetic femoral fracture was 1.6% (95% confidence interval 0.7 to 3.8) at ten years and 4.5% (95% confidence interval 2.6 to 8.0) at 17 years after the primary THR. There was no association between the occurrence of fracture and gender or age at the time of the primary replacement. Our findings indicate that peri-prosthetic femoral fracture is a significant mode of failure in the long term after the insertion of an uncemented CLS Spotorno stem. Revision rates for this fracture rise in the second decade. Further research is required to investigate the risk factors involved in the occurrence of late peri-prosthetic femoral fracture after the implantation of any uncemented stem, and to assess possible methods of prevention.
Slipped capital femoral epiphysis (SCFE) is relatively
common in adolescents and results in a complex deformity of the
hip that can lead to femoroacetabular impingement (FAI). FAI may
be symptomatic and lead to the premature development of osteoarthritis
(OA) of the hip. Current techniques for managing the deformity include
arthroscopic femoral neck osteochondroplasty, an arthroscopically
assisted limited anterior approach to the hip, surgical dislocation,
and proximal femoral osteotomy. Although not a routine procedure
to treat FAI secondary to SCFE deformity, peri-acetabular osteotomy
has been successfully used to treat FAI caused by acetabular over-coverage. These
procedures should be considered for patients with symptoms due to
a deformity of the hip secondary to SCFE. Cite this article:
Disarticulation of the hip in patients with high-grade tumours in the upper thigh results in significant morbidity. In patients with no disease of the proximal soft tissue a femoral stump may be preserved, leaving a fulcrum for movement and weight-bearing. We reviewed nine patients in whom the oncological decision would normally be to disarticulate, but who were treated by implantation of an endoprosthesis in order to create a functioning femoral stump. The surgery was undertaken for chondrosarcoma in four patients, pleomorphic sarcoma in three, osteosarcoma in one and fibrous dysplasia in one. At follow-up at a mean of 80 months (34 to 132), seven patients were alive and free from disease, one had died from lung metastases and another from a myocardial infarction. The mean functional outcome assessment was 50 (musculoskeletal tumor society), 50 and 60 (physical and mental Short-form 36 scores). Implantation of an endoprosthesis into the stump in carefully selected patients allows fitting of an above-knee prosthesis and improves wellbeing and the functional outcome.
Four uncemented Symax hip stems were extracted at three weeks and nine, 13 and 32 months, respectively, for reasons other than loosening. The reasons for implant removal were infection in two cases, recurrent dislocation in one and acetabular fracture in one. They were analysed to assess the effect and behaviour of an electrochemically deposited, completely resorbable biomimetic BONIT-hydroxyapatite (HA) coating (proximal part) and a DOTIZE surface treatment (distal part) using qualitative histology, quantitative histomorphometry and scanning electron microscopy (SEM). Early and direct bone-implant bonding with signs of active remodelling of bone and the HA coating were demonstrated by histology and SEM. No loose BONIT-HA particles or delamination of the coating were observed, and there was no inflammation or fibrous interposition at the interface. Histomorphometry showed bone-implant contact varying between 26.5% at three weeks and 83.5% at 13 months at the HA-coated implant surface. The bone density in the area of investigation was between 24.6% at three weeks and 41.1% at 32 months. The DOTIZE surface treatment of the distal part of the stem completely prevented tissue and bone apposition in all cases, thereby optimising proximal stress transfer. The overall features of this implant, in terms of geometry and surface texture, suggest a mechanically stable design with a highly active biomimetic coating, resulting in rapid and extensive osseo-integration, exclusively in the metaphyseal part of the stem. Early remodelling of the HA coating does not seem to have a detrimental effect on short-term bone-implant coupling. There were no adverse effects identified from either the BONIT-HA coating or the DOTIZE surface treatment.
Tapered, fluted, modular, titanium stems have
a long history in Europe and are increasing in popularity in North America.
We have reviewed the results at our institution looking at stem
survival and clinical outcomes. Radiological outcomes and quality
of life assessments have been performed and compared to cylindrical
non-modular cobalt chromium stems. Survival at five years was 94%.
This fell to 85% at ten years due to stem breakage with older designs.
Review of radiology showed maintenance or improvement of bone stock
in 87% of cases. Outcome scores were superior in tapered stems despite
worse pre-operative femoral deficiency. Tapered stems have proved
to be a useful alternative in revision total hip arthroplasty across
the spectrum of femoral bone deficiency.
Femoroacetabular impingement (FAI) is commonly
associated with early hip arthritis. We reviewed our series of 1300
hip resurfacing procedures. More than 90% of our male patients,
with an average age of 53 years, had cam impingement lesions. In
this condition, there are anterior femoral neck osteophytes, and
a retroverted femoral head on a normally anteverted neck. It is
postulated that FAI results in collision of the anterior neck of
the femur against the rim of the acetabulum, causing damage to the
acetabular labrum and articular cartilage, resulting in osteoarthritis.
Early treatment of FAI involves arthroscopic or open removal of
bone from the anterior femoral neck, as well as repair or removal
of labral tears. However, once osteoarthritis has developed, hip
replacement or hip resurfacing is indicated. Hip resurfacing can
re-orient the head and re-shape the neck. This helps to restore
normal biomechanics to the hip, eliminate FAI, and improve range
of motion. Since many younger men with hip arthritis have FAI, and
are also considered the best candidates for hip resurfacing, it
is evident that resurfacing has a role in these patients.
Following the recall of modular neck hip stems
in July 2012, research into femoral modularity will intensify over
the next few years. This review aims to provide surgeons with an
up-to-date summary of the clinically relevant evidence. The development
of femoral modularity, and a classification system, is described.
The theoretical rationale for modularity is summarised and the clinical
outcomes are explored. The review also examines the clinically relevant problems
reported following the use of femoral stems with a modular neck. Joint replacement registries in the United Kingdom and Australia
have provided data on the failure rates of modular devices but cannot
identify the mechanism of failure. This information is needed to
determine whether modular neck femoral stems will be used in the
future, and how we should monitor patients who already have them implanted. Cite this article:
We present our experience of the modified Dunn
procedure in combination with a Ganz surgical dislocation of the hip
to treat patients with severe slipped capital femoral epiphysis
(SCFE). The aim was to prospectively investigate whether this technique
is safe and reproducible. We assessed the degree of reduction, functional
outcome, rate of complications, radiological changes and range of
movement in the hip. There were 28 patients with a mean follow-up
of 38.6 months (24 to 84). The lateral slip angle was corrected
by a mean of 50.9° (95% confidence interval 44.3 to 57.5). The mean
modified Harris hip score at the final follow-up was 89.1 ( Cite this article:
Between June 1991 and January 1995, 42 hydroxyapatite-coated CAD-CAM femoral components were inserted in 25 patients with inflammatory polyarthropathy, 21 of whom had juvenile idiopathic arthritis. Their mean age was 21 years (11 to 35). All the patients were reviewed clinically and radiologically at one, three and five years. At the final review at a mean of 11.2 years (8 to 13) 37 hips in 23 patients were available for assessment. A total of four femoral components (9.5%) had failed, of which two were radiologically loose and two were revised. The four failed components were in patients aged 16 years or less at the time of surgery. Hydroxyapatite-coated customised femoral components give excellent medium- to long-term results in skeletally-mature young adults with inflammatory polyarthropathy. Patients aged less than 16 years at the time of surgery have a risk of 28.5% of failure of the femoral component at approximately ten years.