We report our experience of using a computer
navigation system to aid resection of malignant musculoskeletal tumours
of the pelvis and limbs and, where appropriate, their subsequent
reconstruction. We also highlight circumstances in which navigation
should be used with caution. We resected a musculoskeletal tumour from 18 patients (15 male,
three female, mean age of 30 years (13 to 75) using commercially
available computer navigation software (Orthomap 3D) and assessed
its impact on the accuracy of our surgery. Of nine pelvic tumours,
three had a biological reconstruction with extracorporeal irradiation,
four underwent endoprosthetic replacement (EPR) and two required
no bony reconstruction. There were eight tumours of the bones of
the limbs. Four diaphyseal tumours underwent biological reconstruction.
Two patients with a sarcoma of the proximal femur and two with a
sarcoma of the proximal humerus underwent extra-articular resection
and, where appropriate, EPR. One soft-tissue sarcoma of the adductor
compartment which involved the femur was resected and reconstructed
using an EPR. Computer navigation was used to aid reconstruction
in eight patients. Histological examination of the resected specimens revealed tumour-free
margins in all patients. Post-operative radiographs and CT showed
that the resection and reconstruction had been carried out as planned
in all patients where navigation was used. In two patients, computer
navigation had to be abandoned and the operation was completed under
CT and radiological control. The use of computer navigation in musculoskeletal oncology allows
accurate identification of the local anatomy and can define the
extent of the tumour and proposed resection margins. Furthermore,
it helps in reconstruction of limb length, rotation and overall
alignment after resection of an appendicular tumour. Cite this article:
We summarise and highlight the safety concerns
within the field of trauma and orthopaedic surgery with particular
emphasis placed on current controversies and reforms within the United
Kingdom National Health Service.
Third-body wear is believed to be one trigger for adverse results
with metal-on-metal (MOM) bearings. Impingement and subluxation
may release metal particles from MOM replacements. We therefore
challenged MOM bearings with relevant debris types of cobalt–chrome
alloy (CoCr), titanium alloy (Ti6Al4V) and polymethylmethacrylate
bone cement (PMMA). Cement flakes (PMMA), CoCr and Ti6Al4V particles (size range
5 µm to 400 µm) were run in a MOM wear simulation. Debris allotments
(5 mg) were inserted at ten intervals during the five million cycle
(5 Mc) test. Objectives
Methods
The December 2014 Children’s orthopaedics Roundup360 looks at: predicting drift in supracondylar fractures; do normal hips dislocate?; the burden of trampoline fractures; muscle eversion activity is strongly predictive of outcome in CTEV; the modified Dunn osteotomy; plaster and moulded casts; and psychology and fractures.
The February 2014 Trauma Roundup360 looks at: predicting nonunion; compartment Syndrome; octogenarian RTCs; does HIV status affect decision making in open tibial fractures?; flap timing and related complications; proximal humeral fractures under the spotlight; restoration of hip architecture with bipolar hemiarthroplasty in the elderly; and short
There has been extensive discussion about the
effect of delay to surgery on mortality in patients sustaining a fracture
of the hip. Despite the low level of evidence provided by many studies,
a consensus has been accepted that delay of >
48 hours is detrimental
to survival. The aim of this prospective observational study was
to determine if early surgery confers a survival benefit at 30 days. Between 1989 and 2013, data were prospectively collected on patients
sustaining a fracture of the hip at Peterborough City Hospital.
They were divided into groups according to the time interval between
admission and surgery. These thresholds ranged from <
6 hours
to between 49 and 72 hours. The outcome which was assessed was the
30-day mortality. Adjustment for confounders was performed using
multivariate binary logistic regression analysis. In all, 6638 patients
aged >
60 years were included. Worsening American Society of Anaesthesiologists grade (p <
0.001), increased age (p <
0.001) and extracapsular fracture
(p <
0.019) increased the risk of 30-day mortality. Increasing mobility score (p = 0.014), mini mental test score
(p <
0.001) and female gender (p = 0.014) improved survival.
After adjusting for these confounders, surgery before 12 hours improved
survival compared with surgery after 12 hours (p = 0.013). Beyond
this the increasing delay to surgery did not significantly affect
the 30-day mortality. Cite this article:
The use of pulsed electromagnetic fields (PEMF)
to stimulate bone growth has been recommended as an alternative to
the surgical treatment of ununited scaphoid fractures, but has never
been examined in acute fractures. We hypothesised that the use of
PEMF in acute scaphoid fractures would accelerate the time to union
by 30% in a randomised, double-blind, placebo-controlled, multicentre
trial. A total of 53 patients in three different medical centres
with a unilateral undisplaced acute scaphoid fracture were randomly
assigned to receive either treatment with PEMF (n = 24) or a placebo
(n = 29). The clinical and radiological outcomes were assessed at
four, six, nine, 12, 24 and 52 weeks. A log-rank analysis showed that neither time to clinical and
radiological union nor the functional outcome differed significantly
between the groups. The clinical assessment of union indicated that
at six weeks tenderness in the anatomic snuffbox (p = 0.03) as well
as tenderness on longitudinal compression of the scaphoid (p = 0.008) differed
significantly in favour of the placebo group. We conclude that stimulation of bone growth by PEMF has no additional
value in the conservative treatment of acute scaphoid fractures.
We performed a systematic review and meta-analysis
to compare the efficacy of intermittent mechanical compression combined
with pharmacological thromboprophylaxis, against either mechanical
compression or pharmacological prophylaxis in preventing deep-vein
thrombosis (DVT) and pulmonary embolism in patients undergoing hip
or knee replacement. A total of six randomised controlled trials,
evaluating a total of 1399 patients, were identified. In knee arthroplasty,
the rate of DVT was reduced from 18.7% with anticoagulation alone
to 3.7% with combined modalities (risk ratio (RR) 0.27, p = 0.03;
number needed to treat: seven). There was moderate, albeit non-significant,
heterogeneity (I2 = 42%). In hip replacement, there was
a non-significant reduction in DVT from 8.7% with mechanical compression
alone to 7.2% with additional pharmacological prophylaxis (RR 0.84)
and a significant reduction in DVT from 9.7% with anticoagulation
alone to 0.9% with additional mechanical compression (RR 0.17, p
<
0.001; number needed to treat: 12), with no heterogeneity (I2 =
0%). The included studies had insufficient power to demonstrate
an effect on pulmonary embolism. We conclude that the addition of intermittent mechanical leg
compression augments the efficacy of anticoagulation in preventing
DVT in patients undergoing both knee and hip replacement. Further
research on the role of combined modalities in thromboprophylaxis
in joint replacement and in other high-risk situations, such as fracture
of the hip, is warranted.
The December 2013 Trauma Roundup360 looks at: Re-operation for intertrochanteric hip fractures; Are twin incisions better than one round the acetabulum?; Salvage osteotomy for calcaneal fractures; Posterior dislocation; Should MRSA be covered in open fractures?; Characterising the saline load test; Has it healed: hip fractures under the spotlight; and stem cells present in atrophic non-union.
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 pelvic discontinuity occurs when the superior
and inferior parts of the hemi-pelvis are no longer connected, which
is difficult to manage when associated with a failed total hip replacement.
Chronic pelvic discontinuity is found in 0.9% to 2.1% of hip revision
cases with risk factors including severe pelvic bone loss, female
gender, prior pelvic radiation and rheumatoid arthritis. Common
treatment options include: pelvic plating with allograft, cage reconstruction,
custom triflange implants, and porous tantalum implants with modular augments.
The optimal technique is dependent upon the degree of the discontinuity,
the amount of available bone stock and the likelihood of achieving
stable healing between the two segments. A method of treating pelvic
discontinuity using porous tantalum components with a distraction
technique that achieves both initial stability and subsequent long-term
biological fixation is described. Cite this article:
Direct anterior approaches to the hip have gained
popularity as a minimally invasive method when performing primary
total hip replacement (THR). A retrospective review of a single
institution joint registry was performed in order to compare patient
outcomes after THR using the Anterior Supine Intermuscular (ASI)
approach Cite this article
Metal-on-metal resurfacing of the hip (MoMHR)
has enjoyed a resurgence in the last decade, but is now again in question
as a routine option for osteoarthritis of the hip. Proponents of
hip resurfacing suggest that its survival is superior to that of
conventional hip replacement (THR), and that hip resurfacing is
less invasive, is easier to revise than THR, and provides superior
functional outcomes. Our argument serves to illustrate that none
of these proposed advantages have been realised and new and unanticipated
serious complications, such as pseudotumors, have been associated
with the procedure. As such, we feel that the routine use of MoMHR
is not justified. Cite this article:
The routine use of patient reported outcome measures
(PROMs) in evaluating the outcome after arthroplasty by healthcare
organisations reflects a growing recognition of the importance of
patients’ perspectives in improving treatment. Although widely embraced
in the NHS, there are concerns that PROMs are being used beyond
their means due to a poor understanding of their limitations. This paper reviews some of the current challenges in using PROMs
to evaluate total knee arthroplasty. It highlights alternative methods
that have been used to improve the assessment of outcome. Cite this article:
The common recommended treatment for infected
total hip replacement is two-staged exchange including removal of
all components. However, removal of well-fixed femoral stems can
result in structural bone damage. We recently reported on an alternative
treatment of partial two-stage exchange used in selected cases,
in which a well-fixed femoral stem was left and only the acetabular
component removed, the joint space was debrided thoroughly, an antibiotic-laden
polymethylmethacrylate spacer was moulded using a bulb-type syringe
and placed in the acetabulum, intravenous antibiotics were administered
during the interval, and delayed re-implantation was performed.
In 19 patients treated with this technique from January 2000 to
January 2011, 89% were free of infection at a mean follow-up of
four years (2 to 11). Since then, disposable silicone moulds have
become available to fabricate spacers in separate femoral and head
units. The head spacer mould, which incorporates various neck taper adapter
options, greatly facilitates the technique of partial two-stage
exchange. We report our early experience using disposable silicone
head spacer moulds for partial two-stage exchange in seven patients
with infected primary hip replacements. Cite this article:
Metaphyseal bone loss is common with revision
total knee replacement (RTKR). Using the Anderson Orthopaedic Research
Institute (AORI) classification, type 2-B and type 3 defects usually
require large metal blocks, bulk structural allograft or highly
porous metal cones. Tibial and femoral trabecular metal metaphyseal
cones are a unique solution for large bone defects. These cones
substitute for bone loss, improve metaphyseal fixation, help correct
malalignment, restore the joint line and may permit use of a shorter
stem. The technique for insertion involves sculpturing of the remaining
bone with a high speed burr and rasp, followed by press-fit of the
cone into the metaphysis. The fixation and osteoconductive properties
of the porous cone outer surface allow ingrowth and encourage long-term
biological fixation. The revision knee component is then cemented
into the porous cone inner surface, which provides superior fixation
compared with cementing into native but deficient metaphyseal bone.
The advantages of the cone compared with allograft include: technical
ease, biological fixation, no resorption, and possibly a lower risk
of infection. The disadvantages include: difficult extraction and
relatively short-term follow-up. Several studies using cones report
promising short-term results for the reconstruction of large bone
defects in RTKR. Cite this article:
Debate has raged over whether a cruciate retaining
(CR) or a posterior stabilised (PS) total knee replacement (TKR) provides
a better range of movement (ROM) for patients. Various sub-sets
of CR design are frequently lumped together when comparing outcomes.
Additionally, multiple factors have been proven to influence the
rate of manipulation under anaesthetic (MUA) following TKR. The
purpose of this study was to determine whether different CR bearing
insert designs provide better ROM or different MUA rates. All primary
TKRs performed by two surgeons between March 2006 and March 2009
were reviewed and 2449 CR-TKRs were identified. The same CR femoral
component, instrumentation, and tibial base plate were consistently
used. In 1334 TKRs a CR tibial insert with 3° posterior slope and
no posterior lip was used (CR-S). In 803 there was an insert with
no slope and a small posterior lip (CR-L) and in 312 knees the posterior
cruciate ligament (PCL) was either resected or lax and a deep-dish,
anterior stabilised insert was used (CR-AS). More CR-AS inserts
were used in patients with less pre-operative ROM and greater pre-operative
tibiofemoral deformity and flexion contracture (p <
0.05). The
mean improvement in ROM was highest for the CR-AS inserts (5.9°
(-40° to 55°) Cite this article:
Pelvic discontinuity represents a rare but challenging
problem for orthopaedic surgeons. It is most commonly encountered
during revision total hip replacement, but can also result from
an iatrogentic acetabular fracture during hip replacement. The general
principles in management of pelvic discontinuity include restoration
of the continuity between the ilium and the ischium, typically with
some form of plating. Bone grafting is frequently required to restore
pelvic bone stock. The acetabular component is then impacted, typically
using an uncemented, trabecular metal component. Fixation with multiple
supplemental screws is performed. For larger defects, a so-called
‘cup–cage’ reconstruction, or a custom triflange implant may be
required. Pre-operative CT scanning can greatly assist in planning
and evaluating the remaining bone stock available for bony ingrowth.
Generally, good results have been reported for constructs that restore
stability to the pelvis and allow some form of biologic ingrowth. Cite this article:
Conventional uncemented femoral implants provide
dependable long-term fixation in patients with a wide range of functional
requirements. Yet challenges associated with proximal–distal femoral
dimensional mismatch, preservation of bone stock, and minimally
invasive approaches have led to exploration into alternative implant designs.
Short stem designs focusing on a stable metaphyseal fit have emerged
to address these issues in total hip replacement (THR). Uncemented
metaphyseal-engaging short stem implants are stable and are associated
with proximal bone remodeling closer to the metaphysis when compared
with conventional stems and they also have comparable clinical performances.
Short stem metaphyseal-engaging implants can meet the goals of a
successful THR, including tolerating a high level of patient function,
as well as durable fixation. Cite this article: