Tribocorrosion at the head–neck taper interface
– so-called ‘taperosis’ – may be a source of metal ions and particulate
debris in metal-on-polyethylene total hip arthroplasty (THA). We examined the effect of femoral head length on fretting and
corrosion in retrieved head–neck tapers Head length was observed to affect fretting (p = 0.03), with
28 mm + 8 mm femoral heads showing greater total fretting scores
than all other head lengths. The central zone of the femoral head
bore taper was subject to increased fretting damage (p = 0.01),
regardless of head length or stem offset. High-offset femoral stems
were associated with greater total fretting of the bore taper (p
= 0.04). Increased fretting damage is seen with longer head lengths and
high-offset femoral stems, and occurs within a central concentric
zone of the femoral head bore taper. Further investigation is required
to determine the effect of increased head size, and variations in
head–neck taper design. Cite this article:
The rate of surgical site infection after elective
foot and ankle surgery is higher than that after other elective orthopaedic
procedures. Since December 2005, we have prospectively collected data on
the rate of post-operative infection for 1737 patients who have
undergone elective foot and ankle surgery. In March 2008, additional
infection control policies, focused on surgical and environmental
risk factors, were introduced in our department. We saw a 50% reduction in the rate of surgical site infection
after the introduction of these measures. We are, however, aware
that the observed decrease may not be entirely attributable to these
measures alone given the number of factors that predispose to post-operative
wound infection. Cite this article:
The February 2015 Foot &
Ankle Roundup360 looks at: Syndesmosis screw removal in randomised controlled trial; Diagnostic value of Hawkins sign; Chevron rules supreme?; Diabetes and ankle replacement; Fixed-bearing ankle replacement; Fusion for osteomyelitis of the ankle; ‘Reformed’ fallers.
Periprosthetic joint infection (PJI) is one of
the most feared and challenging complications following total knee arthroplasty.
We provide a detailed description of our current understanding regarding
the management of PJI of the knee, including diagnostic aids,
pre-operative planning, surgical treatment, and outcome. Cite this article:
Patellofemoral complications are common after
total knee replacement (TKR). Leaving the patellar unsurfaced after
TKR may lead to complications such as anterior knee pain, and re-operation
to surface it. Complications after patellar resurfacing include
patellar fracture, aseptic loosening, patellar instability, polyethylene
wear, patellar clunk and osteonecrosis. Historically, patellar complications
account for one of the larger proportions of causes of failure in
TKR, however, with contemporary implant designs, complication rates
have decreased. Most remaining failures relate to patellofemoral
tracking. Understanding the causes of patellofemoral maltracking
is essential to prevent these complications as well as manage them
when they occur. Cite this article:
Instability after total knee replacement (TKR)
accounts for 10% to 22% of revision procedures. All patients who
present for evaluation of instability require a thorough history to
be taken and physical examination, as well as appropriate imaging.
Deep periprosthetic infection must be ruled out by laboratory testing
and an aspiration of the knee must be carried out. The three main
categories of instability include flexion instability, extension instability
(symmetric and asymmetric), and genu recurvatum. Most recently,
the aetiologies contributing to, and surgical manoeuvres required
to correct, flexion instability have been elucidated. While implant
design and patient-related factors may certainly contribute to the
aetiology, surgical technique is also a significant factor in all
forms of post-operative instability. Cite this article:
Dislocation remains among the most common complications
of, and reasons for, revision of both primary and revision total
hip replacements (THR). Hence, there is great interest in maximising
stability to prevent this complication. Head size has been recognised
to have a strong influence on the risk of dislocation post-operatively.
As femoral head size increases, stability is augmented, secondary
to an increase in impingement-free range of movement. Larger head
sizes also greatly increase the ‘jump distance’ required for the
head to dislocate in an appropriately positioned cup. Level-one
studies support the use of larger diameter heads as they decrease
the risk of dislocation following primary and revision THR. Highly cross-linked
polyethylene has allowed us to increase femoral head size, without
a marked increase in wear. However, the thin polyethylene liners
necessary to accommodate larger heads may increase the risk of liner
fracture and larger heads have also been implicated in causing soft-tissue
impingement resulting in groin pain. Larger diameter heads also
impart larger forces on the femoral trunnion, which may contribute
to corrosion, metal release, and adverse local tissue reactions.
Alternative large bearings including large ceramic heads and dual
mobility bearings may mitigate some of these risks, and several
of these devices have been used with clinical success. Cite this article:
We report the kinematic and early clinical results
of a patient- and observer-blinded randomised controlled trial in which
CT scans were used to compare potential impingement-free range of
movement (ROM) and acetabular component cover between patients treated
with either the navigated ‘femur-first’ total hip arthroplasty (THA) method
(n = 66; male/female 29/37, mean age 62.5 years; 50 to 74) or conventional
THA (n = 69; male/female 35/34, mean age 62.9 years; 50 to 75).
The Hip Osteoarthritis Outcome Score, the Harris hip score, the
Euro-Qol-5D and the Mancuso THA patient expectations score were
assessed at six weeks, six months and one year after surgery. A
total of 48 of the patients (84%) in the navigated ‘femur-first’
group and 43 (65%) in the conventional group reached all the desirable
potential ROM boundaries without prosthetic impingement for activities
of daily living (ADL) in flexion, extension, abduction, adduction
and rotation (p = 0.016). Acetabular component cover and surface
contact with the host bone were >
87% in both groups. There was
a significant difference between the navigated and the conventional
groups’ Harris hip scores six weeks after surgery (p = 0.010). There
were no significant differences with respect to any clinical outcome
at six months and one year of follow-up. The navigated ‘femur-first’
technique improves the potential ROM for ADL without prosthetic
impingement, although there was no observed clinical difference
between the two treatment groups. Cite this article:
Flexor digitorum longus transfer and medial displacement
calcaneal osteotomy is a well-recognised form of treatment for stage
II posterior tibial tendon dysfunction. Although excellent short-
and medium-term results have been reported, the long-term outcome
is unknown. We reviewed the clinical outcome of 31 patients with
a symptomatic flexible flat-foot deformity who underwent this procedure
between 1994 and 1996. There were 21 women and ten men with a mean
age of 54.3 years (42 to 70). The mean follow-up was 15.2 years
(11.4 to 16.5). All scores improved significantly (p <
0.001).
The mean American Orthopedic Foot and Ankle Society (AOFAS) score improved
from 48.4 pre-operatively to 90.3 (54 to 100) at the final follow-up.
The mean pain component improved from 12.3 to 35.2 (20 to 40). The
mean function score improved from 35.2 to 45.6 (30 to 50). The mean
visual analogue score for pain improved from 7.3 to 1.3 (0 to 6).
The mean Short Form-36 physical component score was 40.6 ( Cite this article:
Vascularised fibular grafts (VFGs ) are a valuable
surgical technique in limb salvage after resection of a tumour.
The primary objective of this multicentre study was to assess the
risk factors for failure and complications for using a VFG after
resection of a tumour. The study involved 74 consecutive patients (45 men and 29 women
with mean age of 23 years (1 to 64) from four tertiary centres for
orthopaedic oncology who underwent reconstruction using a VFG after
resection of a tumour between 1996 and 2011. There were 52 primary
and 22 secondary reconstructions. The mean follow-up was 77 months
(10 to 195). In all, 69 patients (93%) had successful limb salvage; all of
these united and 65 (88%) showed hypertrophy of the graft. The mean
time to union differed between those involving the upper (28 weeks;
12 to 96) and lower limbs (44 weeks; 12 to 250). Fracture occurred
in 11 (15%), and nonunion in 14 (19%) patients. In 35 patients (47%) at least one complication arose, with a
greater proportion in lower limb reconstructions, non-bridging osteosynthesis,
and in children. These complications resulted in revision surgery
in 26 patients (35%). VFG is a successful and durable technique for reconstruction
of a defect in bone after resection of a tumour, but is accompanied
by a significant risk of complications, that often require revision
surgery. Union was not markedly influenced by the need for chemo-
or radiotherapy, but should not be expected during chemotherapy.
Therefore, restricted weight-bearing within this period is advocated. Cite this article:
A total of seven patients (six men and one woman)
with a defect in the Achilles tendon and overlying soft tissue underwent
reconstruction using either a composite radial forearm flap (n =
3) or an anterolateral thigh flap (n = 4). The Achilles tendons
were reconstructed using chimeric palmaris longus (n = 2) or tensor
fascia lata (n = 2) flaps or transfer of the flexor hallucis longus
tendon (n = 3). Surgical parameters such as the rate of complications
and the time between the initial repair and flap surgery were analysed.
Function was measured objectively by recording the circumference
of the calf, the isometric strength of the plantar flexors and the
range of movement of the ankle. The Achilles tendon Total Rupture
Score (ATRS) questionnaire was used as a patient-reported outcome
measure. Most patients had undergone several previous operations
to the Achilles tendon prior to flap surgery. The mean time to flap
surgery was 14.3 months (2.1 to 40.7). At a mean follow-up of 32.3 months (12.1 to 59.6) the circumference
of the calf on the operated lower limb was reduced by a mean of
1.9 cm ( These otherwise indicate that reconstruction of the Achilles
tendon combined with flap cover results in a successful and functional
reconstruction. Cite this article:
The August 2014 Foot &
Ankle Roundup360 looks at: calcaneotibial nail in ankle fractures; reamer irrigator aspirator for ankle fusion; periprosthetic bone infection; infection in ankle fixation; cheap and cheerful OK in MTP fusion plates; sliding fibular graft for peroneal tendon pathology and fusion for failed ankle replacement.
Giant cell tumour is the most common aggressive
benign tumour of the musculoskeletal system and has a high rate of
local recurrence. When it occurs in proximity to the hip, reconstruction
of the joint is a challenge. Options for reconstruction after wide
resection include the use of a megaprosthesis or an allograft-prosthesis
composite. We performed a clinical and radiological study to evaluate
the functional results of a proximal femoral allograft-prosthesis
composite in the treatment of proximal femoral giant cell tumour
after wide resection. This was an observational study, between 2006
and 2012, of 18 patients with a mean age of 32 years (28 to 42)
and a mean follow-up of 54 months (18 to 79). We achieved excellent
outcomes using Harris Hip Score in 13 patients and a good outcome
in five. All allografts united. There were no complications such
as infection, failure, fracture or resorption of the graft, or recurrent
tumour. Resection and reconstruction of giant cell tumours with
proximal femoral allograft–prosthesis composite is a better option
than using a prosthesis considering preservation of bone stock and excellent
restoration of function. A good result requires demanding bone banking techniques, effective
measures to prevent infection and stability at the allograft-host
junction. Cite this article:
The aim of this study was to evaluate the functional
and oncological outcome of extracorporeally irradiated autografts
used to reconstruct the pelvis after a P1/2 internal hemipelvectomy. The study included 18 patients with a primary malignant bone
tumour of the pelvis. There were 13 males and five females with
a mean age of 24.8 years (8 to 62). Of these, seven had an osteogenic
sarcoma, six a Ewing’s sarcoma, and five a chondrosarcoma. At a
mean follow-up of 51.6 months (4 to 185), nine patients had died
with metastatic disease while nine were free from disease. Local
recurrence occurred in three patients all of whom eventually died of
their disease. Deep infection occurred in three patients and required
removal of their graft in two while the third underwent a hindquarter
amputation for extensive flap necrosis. The mean Musculoskeletal Tumor Society functional score of the
16 patients who could be followed-up for at least 12 months was
77% (50 to 90). Those 15 patients who completed the Toronto Extremity
Salvage Score questionnaire had a mean score of 71% (53 to 85). Extracorporeal irradiation and re-implantation of bone is a valid
method of reconstruction after an internal hemipelvectomy. It has
an acceptable morbidity and a functional outcome that compares favourably
with other available reconstructive techniques. Cite this article:
In this randomised controlled trial, we evaluated
the role of elastic compression using ankle injury stockings (AIS)
in the management of fractures of the ankle. A total of 90 patients
with a mean age of 47 years (16 to 79) were treated within 72 hours
of presentation with a fracture of the ankle, 31 of whom were treated
operatively and 59 conservatively, were randomised to be treated
either with compression by AIS plus an Aircast boot or Tubigrip
plus an Aircast boot. Male to female ratio was 36:54. The primary
outcome measure was the functional Olerud–Molander ankle score (OMAS).
The secondary outcome measures were; the American Orthopaedic Foot
and Ankle Society score (AOFAS); the Short Form (SF)-12v2 Quality
of Life score; and the frequency of deep vein thrombosis (DVT). Compression using AIS reduced swelling of the ankle at all time
points and improved the mean OMAS score at six months to 98 (95%
confidence interval (CI) 96 to 99) compared with a mean of 67 (95%
CI 62 to 73) for the Tubigrip group (p <
0.001). The mean AOFAS
and SF-12v2 scores at six months were also significantly improved
by compression. Of 86 patients with duplex imaging at four weeks,
five (12%) of 43 in the AIS group and ten (23%) of 43 in the Tubigrip
group developed a DVT (p = 0.26). Compression improved functional outcome and quality of life following
fracture of the ankle. DVTs were frequent, but a larger study would
be needed to confirm that compression with AISs reduces the incidence
of DVT. Cite this article:
The December 2013 Wrist &
Hand Roundup360 looks at: Scapholunate instability; three-ligament tenodesis; Pronator quadratus; Proximal row carpectomy; FPL dysfunction after volar plate fixation; Locating the thenar branch of the median nerve; Metallosis CMCJ arthroplasties; and timing of flap reconstruction
Smart trials are total knee tibial trial liners
with load bearing and alignment sensors that will graphically show quantitative
compartment load-bearing forces and component track patterns. These
values will demonstrate asymmetrical ligament balancing and misalignments
with the medial retinaculum temporarily closed. Currently surgeons
use feel and visual estimation of imbalance to assess soft-tissue
balancing and tracking with the medial retinaculum open, which results
in lower medial compartment loads and a wider anteroposterior tibial
tracking pattern. The sensor trial will aid the total knee replacement
surgeon in performing soft-tissue balancing by providing quantitative
visual feedback of changes in forces while performing the releases
incrementally. Initial experience using a smart tibial trial is
presented.
The December 2012 Shoulder &
Elbow Roundup360 looks at: whether allograft is biomechanically superior in large Hill-Sachs defects; glenoid bone loss in shoulder dislocators; repairing irreparable cuff tears; acromioclavicular joint injuries; whether more radiographs equals more surgery; whether reverse TSR is cheaper than hemiarthroplasty; autologous chondrocyte implantation in the shoulder; and fracture of the clavicle.
The Oxford mobile-bearing unicompartmental knee
replacement (UKR) is an effective and safe treatment for osteoarthritis
of the medial compartment. The results in the lateral compartment
have been disappointing due to a high early rate of dislocation
of the bearing. A series using a newly designed domed tibial component
is reported. The first 50 consecutive domed lateral Oxford UKRs in 50 patients
with a mean follow-up of three years (2.0 to 4.3) were included.
Clinical scores were obtained prospectively and Kaplan-Meier survival
analysis was performed for different endpoints. Radiological variables
related to the position and alignment of the components were measured. One patient died and none was lost to follow-up. The cumulative
incidence of dislocation was 6.2% (95% confidence interval (CI)
2.0 to 17.9) at three years. Survival using revision for any reason
and aseptic revision was 94% (95% CI 82 to 98) and 96% (95% CI 85
to 99) at three years, respectively. Outcome scores, visual analogue
scale for pain and maximum knee flexion showed a significant improvement
(p <
0.001). The mean Oxford knee score was 43 ( Clinical results are excellent and short-term survival has improved
when compared with earlier series. The risk of dislocation remains
higher using a mobile-bearing UKR in the lateral compartment when
compared with the medial compartment. Patients should be informed
about this complication. To avoid dislocations, care must be taken
not to elevate the lateral joint line.
In this paper, we consider wound healing after
total knee arthroplasty.