In this study we used subject-specific finite
element analysis to investigate the mechanical effects of rotational acetabular
osteotomy (RAO) on the hip joint and analysed the correlation between
various radiological measurements and mechanical stress in the hip
joint. We evaluated 13 hips in 12 patients (two men and ten women, mean
age at surgery 32.0 years; 19 to 46) with developmental dysplasia
of the hip (DDH) who were treated by RAO. Subject-specific finite element models were constructed from
CT data. The centre–edge (CE) angle, acetabular head index (AHI),
acetabular angle and acetabular roof angle (ARA) were measured on
anteroposterior pelvic radiographs taken before and after RAO. The
relationship between equivalent stress in the hip joint and radiological measurements
was analysed. The equivalent stress in the acetabulum decreased from 4.1 MPa
(2.7 to 6.5) pre-operatively to 2.8 MPa (1.8 to 3.6) post-operatively
(p <
0.01). There was a moderate correlation between equivalent
stress in the acetabulum and the radiological measurements: CE angle
(R = –0.645, p <
0.01); AHI (R = –0.603, p <
0.01); acetabular
angle (R = 0.484, p = 0.02); and ARA (R = 0.572, p <
0.01). The equivalent stress in the acetabulum of patients with DDH
decreased after RAO. Correction of the CE angle, AHI and ARA was
considered to be important in reducing the mechanical stress in
the hip joint. Cite this article:
The February 2015 Trauma Roundup360 looks at: Evaluating the syndesmosis in ankle fractures; Calcaneal fracture management an ongoing problem; Angular stable locking in low tibial fractures did not improve results; Open fractures: do the seconds really count?; Long-term outcomes of tibial fractures; Targeted performance improvements in pelvic fractures
The February 2015 Hip &
Pelvis Roundup360 looks at: Hip arthroplasty in Down syndrome; Bulk femoral autograft successful in acetabular reconstruction; Arthroplasty follow-up: is the internet the solution?; Total hip arthroplasty following acetabular fracture; Salvage arthroplasty following failed hip internal fixation; Bone banking sensible financially and clinically; Allogenic blood transfusion in arthroplasty.
We report our early experience with the use of
a new prosthesis, the Modular Hemipelvic Prosthesis II, for reconstruction
of the hemipelvis after resection of a primary malignant peri-acetabular
tumour involving the sacroiliac joint. We retrospectively reviewed the outcome of 17 patients who had
undergone resection of a pelvic tumour and reconstruction with this
prosthesis between July 2002 and July 2010. One patient had a type I+II+III+IV resection (ilium + peri-acetabulum
+ pubis/ischium + sacrum) and 16 had a type I+II+IV resection (ilium
+ acetabulum + sacrum). The outcome was assessed at a mean follow-up
of 33 months (15 to 59). One patient was alive with disease, 11
were alive without disease and five had died of disease. The overall
five-year survival rate was 62.4%. Six patients had a local recurrence.
The mean Musculoskeletal Tumour Society score was 58% (33 to 77).
Deep infection occurred in two patients, problems with wound healing
in five and dislocation in one. For patients with a primary malignant peri-acetabular sarcoma
involving the sacroiliac joint, we believe that this new prosthesis
is a viable option for reconstruction of the bony defect left following
resection of the tumour. It results in a satisfactory functional
outcome with an acceptable rate of complications. Cite this article:
We hypothesised that a minimally invasive peroneus
brevis tendon transfer would be effective for the management of
a chronic rupture of the Achilles tendon. In 17 patients (three
women, 14 men) who underwent minimally invasive transfer and tenodesis
of the peroneus brevis to the calcaneum, at a mean follow-up of
4.6 years (2 to 7) the modified Achilles tendon total rupture score
(ATRS) was recorded and the maximum circumference of the calf of
the operated and contralateral limbs was measured. The strength
of isometric plantar flexion of the gastrocsoleus complex and of
eversion of the ankle were measured bilaterally. Functional outcomes
were classified according to the four-point Boyden scale. At the latest review, the mean maximum circumference of the calf
of the operated limb was not significantly different from the pre-operative
mean value, (41.4 cm, 32 to 50 This procedure may be safely performed, is minimally invasive,
and allows most patients to return to pre-injury sport and daily
activities. Cite this article:
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.
Femoral stem version has a major influence on
impingement and early post-operative stability after total hip arthroplasty
(THA). The main objective of this study was to evaluate the validity
of a novel radiological method for measuring stem version. Anteroposterior
(AP) radiographs and three-dimensional CT scans were obtained for
115 patients (female/male 63/72, mean age 62.5 years (50 to 75))
who had undergone minimally invasive, cementless THA. Stem version was
calculated from the AP hip radiograph by rotation-based change in
the projected prosthetic neck–shaft (NSA*) angle using the mathematical
formula ST = arcos [tan (NSA*) / tan (135)]. We used two independent
observers who repeated the analysis after a six-week interval. Radiological
measurements were compared with 3D-CT measurements by an independent,
blinded external institute. We found a mean difference of 1.2° ( We found that femoral tilt was associated with the mean radiological
measurement error (r = 0.22, p = 0.02). The projected neck–shaft angle is a reliable method for measuring
stem version on AP radiographs of the hip after a THA. However,
a highly standardised radiological technique is required for its
precise measurement. Cite this article:
Reported rates of dislocation in hip hemiarthroplasty
(HA) for the treatment of intra-capsular fractures of the hip, range
between 1% and 10%. HA is frequently performed through a direct
lateral surgical approach. The aim of this study is to determine
the contribution of the anterior capsule to the stability of a cemented
HA through a direct lateral approach. A total of five whole-body cadavers were thawed at room temperature,
providing ten hip joints for investigation. A Thompson HA was cemented
in place via a direct lateral approach. The cadavers were then positioned
supine, both knee joints were disarticulated and a digital torque
wrench was attached to the femur using a circular frame with three
half pins. The wrench applied an external rotation force with the
hip in extension to allow the hip to dislocate anteriorly. Each
hip was dislocated twice; once with a capsular repair and once without
repairing the capsule. Stratified sampling ensured the order in
which this was performed was alternated for the paired hips on each
cadaver. Comparing peak torque force in hips with the capsule repaired
and peak torque force in hips without repair of the capsule, revealed
a significant difference between the ‘capsule repaired’ (mean 22.96
Nm, standard deviation ( Cite this article:
We report the results of Vulpius transverse gastrocsoleus
recession for equinus gait in 26 children with cerebral palsy (CP),
using the Gait Profile Score (GPS), Gait Variable Scores (GVS) and
movement analysis profile. All children had an equinus deformity
on physical examination and equinus gait on three-dimensional gait
analysis prior to surgery. The pre-operative and post-operative
GPS and GVS were statistically analysed. There were 20 boys and
6 girls in the study cohort with a mean age at surgery of 9.2 years
(5.1 to 17.7) and 11.5 years (7.3 to 20.8) at follow-up. Of the
26 children, 14 had spastic diplegia and 12 spastic hemiplegia.
Gait function improved for the cohort, confirmed by a decrease in
mean GPS from 13.4° pre-operatively to 9.0° final review (p <
0.001). The change was 2.8 times the minimal clinically important
difference (MCID). Thus the improvements in gait were both clinically and
statistically significant. The transverse gastrocsoleus recession
described by Vulpius is an effective procedure for equinus gait
in selected children with CP, when there is a fixed contracture
of the gastrocnemius and soleus muscles. Cite this article:
Fresh-frozen allograft bone is frequently used
in orthopaedic surgery. We investigated the incidence of allograft-related
infection and analysed the outcomes of recipients of bacterial culture-positive
allografts from our single-institute bone bank during bone transplantation.
The fresh-frozen allografts were harvested in a strict sterile environment
during total joint arthroplasty surgery and immediately stored in
a freezer at -78º to -68º C after packing. Between January 2007
and December 2012, 2024 patients received 2083 allografts with a
minimum of 12 months of follow-up. The overall allograft-associated
infection rate was 1.2% (24/2024). Swab cultures of 2083 allografts
taken before implantation revealed 21 (1.0%) positive findings.
The 21 recipients were given various antibiotics at the individual
orthopaedic surgeon’s discretion. At the latest follow-up, none
of these 21 recipients displayed clinical signs of infection following
treatment. Based on these findings, we conclude that an incidental positive
culture finding for allografts does not correlate with subsequent
surgical site infection. Additional prolonged post-operative antibiotic
therapy may not be necessary for recipients of fresh-frozen bone
allograft with positive culture findings. Cite this article:
We evaluated an operative technique, described
by the Exeter Hip Unit, to assist accurate introduction of the femoral
component. We assessed whether it led to a reduction in the rate
of leg-length discrepancy after total hip arthroplasty (THA). A total of 100 patients undergoing THA were studied retrospectively;
50 were undertaken using the test method and 50 using conventional
methods as a control group. The groups were matched with respect
to patient demographics and the grade of surgeon. Three observers
measured the depth of placement of the femoral component on post-operative
radiographs and measured the length of the legs. There was a strong correlation between the depth of insertion
of the femoral component and the templated depth in the test group
(R = 0.92), suggesting accuracy of the technique. The mean leg-length
discrepancy was 5.1 mm (0.6 to 21.4) pre-operatively and 1.3 mm
(0.2 to 9.3) post-operatively. There was no difference between Consultants
and Registrars as primary surgeons. Agreement between the templated
and post-operative depth of insertion was associated with reduced
post-operative leg-length discrepancy. The intra-class coefficient
was R ≥ 0.88 for all measurements, indicating high observer agreement.
The post-operative leg-length discrepancy was significantly lower
in the test group (1.3 mm) compared with the control group (6.3
mm, p <
0.001). The Exeter technique is reproducible and leads to a lower incidence
of leg-length discrepancy after THA. Cite this article:
Total hip replacement (THR) after acetabular
fracture presents unique challenges to the orthopaedic surgeon.
The majority of patients can be treated with a standard THR, resulting
in a very reasonable outcome. Technical challenges however include
infection, residual pelvic deformity, acetabular bone loss with
ununited fractures, osteonecrosis of bone fragments, retained metalwork,
heterotopic ossification, dealing with the sciatic nerve, and the
difficulties of obtaining long-term acetabular component fixation.
Indications for an acute THR include young patients with both femoral
head and acetabular involvement with severe comminution that cannot
be reconstructed, and the elderly, with severe bony comminution.
The outcomes of THR for established post-traumatic arthritis include
excellent pain relief and functional improvements. The use of modern
implants and alternative bearing surfaces should improve outcomes
further. Cite this article:
The February 2013 Spine Roundup360 looks at: complications with anterior decompression and fusion; lumbar claudication and peripheral vascular disease; increasing cervical instability in rheumatoids; kyphoplasty; cervical stenosis; exercise or fusion for chronic lower back pain; lumbar disc arthroplasty and adjacent level changes; and obese disc prolapses.
Acetabular component orientation in total hip arthroplasty (THA)
influences results. Intra-operatively, the natural arthritic acetabulum
is often used as a reference to position the acetabular component.
Detailed information regarding its orientation is therefore essential. The
aim of this study was to identify the acetabular inclination and
anteversion in arthritic hips. Acetabular inclination and anteversion in 65 symptomatic arthritic
hips requiring THA were measured using a computer navigation system.
All patients were Caucasian with primary osteoarthritis (29 men,
36 women). The mean age was 68 years (SD 8). Mean inclination was
50.5° (SD 7.8) in men and 52.1° (SD 6.7) in women. Mean anteversion
was 8.3° (SD 8.7) in men and 14.4° (SD 11.6) in women. Objectives
Methods
Down’s syndrome is associated with a number of
musculoskeletal abnormalities, some of which predispose patients
to early symptomatic arthritis of the hip. The purpose of the present
study was to review the general and hip-specific factors potentially
compromising total hip replacement (THR) in patients with Down’s
syndrome, as well as to summarise both the surgical techniques that
may anticipate the potential adverse impact of these factors and
the clinical results reported to date. A search of the literature
was performed, and the findings further informed by the authors’
clinical experience, as well as that of the hip replacement in Down
Syndrome study group. The general factors identified include a high
incidence of ligamentous laxity, as well as associated muscle hypotonia
and gait abnormalities. Hip-specific factors include: a high incidence
of hip dysplasia, as well as a number of other acetabular, femoral
and combined femoroacetabular anatomical variations. Four studies
encompassing 42 hips, which reported the clinical outcomes of THR
in patients with Down’s syndrome, were identified. All patients
were successfully treated with standard acetabular and femoral components.
The use of supplementary acetabular screw fixation to enhance component
stability was frequently reported. The use of constrained liners
to treat intra-operative instability occurred in eight hips. Survival
rates of between 81% and 100% at a mean follow-up of 105 months
(6 to 292) are encouraging. Overall, while THR in patients with
Down’s syndrome does present some unique challenges, the overall
clinical results are good, providing these patients with reliable
pain relief and good function. Cite this article:
This review examines the future of total hip arthroplasty, aiming to avoid past mistakes
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.
The October 2014 Spine Roundup360 looks at: microdiscectomy is not exactly a hands-down winner; lumbar spinal stenosis unpicked; Wallis implant helpful in lumbosacral decompression; multidisciplinary rehabilitation is good for back pain; and understanding the sciatic stretch test.
The December 2014 Trauma Roundup360 looks at: infection and temporising external fixation; Vitamin C in distal radial fractures; DRAFFT: Cheap and cheerful Kirschner wires win out; femoral neck fractures not as stable as they might be; displaced sacral fractures give high morbidity and mortality; sanders and calcaneal fractures: a 20-year experience; bleeding and pelvic fractures; optimising timing for acetabular fractures; and tibial plateau fractures.