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.
In a series of 450 patients over 70 years of age with displaced fractures of the femoral neck sustained between 1995 and 1997 treatment was randomised either to internal fixation or replacement. Depending on age and level of activity the latter was either a total hip replacement or a hemiarthroplasty. Patients who were confused or bed-ridden were excluded, as were those with rheumatoid arthritis. At ten years there were 99 failures (45.6%) after internal fixation compared with 17 (8.8%) after replacement. The rate of mortality was high at 75% at ten years, and was the same in both groups at all times. Patient-reported pain and function were similar in both groups at five and ten years. Those with successfully healed fractures had more hip pain and reduction of mobility at four months compared with patients with an uncomplicated replacement, and they never attained a better outcome than the latter patients regarding pain or function. Primary replacement gave reliable long-term results in patients with a displaced fracture of the femoral neck.
The December 2012 Trauma Roundup360 looks at: more is not always better, especially when its chemotherapy; new hope for skeletal metastasis; biopsy tracts; intra-operative imaging of sarcomas; curettage with adjuvant therapy; amputation and distal tibial osteosarcoma; and diaphyseal tibial tumours.
The Cementless Oxford Unicompartmental Knee Replacement
(OUKR) was developed to address problems related to cementation,
and has been demonstrated in a randomised study to have similar
clinical outcomes with fewer radiolucencies than observed with the
cemented device. However, before its widespread use it is necessary
to clarify contraindications and assess the complications. This
requires a larger study than any previously published. We present a prospective multicentre series of 1000 cementless
OUKRs in 881 patients at a minimum follow-up of one year. All patients
had radiological assessment aligned to the bone–implant interfaces
and clinical scores. Analysis was performed at a mean of 38.2 months
(19 to 88) following surgery. A total of 17 patients died (comprising
19 knees (1.9%)), none as a result of surgery; there were no tibial
or femoral loosenings. A total of 19 knees (1.9%) had significant
implant-related complications or required revision. Implant survival
at six years was 97.2%, and there was a partial radiolucency at
the bone–implant interface in 72 knees (8.9%), with no complete radiolucencies.
There was no significant increase in complication rate compared
with cemented fixation (p = 0.87), and no specific contraindications
to cementless fixation were identified. Cementless OUKR appears to be safe and reproducible in patients
with end-stage anteromedial osteoarthritis of the knee, with radiological
evidence of improved fixation compared with previous reports using
cemented fixation. Cite this article:
Antibiotic impregnated articulating spacers are
used in two-stage revision total knee arthroplasty to deliver local antibiotic
therapy while preserving function. We have observed infection control
in greater than 95% of cases with functional outcomes approaching
those seen in revision for aseptic loosening. Higher failure has
been observed with methicillin resistant organisms.
We report the long-term clinical and radiological outcomes of the Aequalis total shoulder replacement with a cemented all-polyethylene flat-back keeled glenoid component implanted for primary osteoarthritis between 1991 and 2003 in nine European centres. A total of 226 shoulders in 210 patients were retrospectively reviewed at a mean of 122.7 months (61 to 219) or at revision. Clinical outcome was assessed using the Constant score, patient satisfaction score and range of movement. Kaplan-Meier survivorship analysis was performed with glenoid revision for loosening and radiological glenoid loosening ( Younger patient age and the curettage technique for glenoid preparation correlated with loosening. The rate of glenoid revision and radiological loosening increased with duration of follow-up, but not until a follow-up of five years. Therefore, we recommend that future studies reporting radiological outcomes of new glenoid designs should report follow-up of at least five to ten years.
The December 2012 Hip &
Pelvis Roundup360 looks at: swimming against the tide with resurfacing; hip impingement surgery; the relationship between obesity and co-morbidities and joint replacement infection; cemented hips; cross-linked polyethylene notching; whether cement is necessary in oncological arthroplasty; and how total hip replacement may result in weight gain.
Blood metal ions have been widely used to investigate
metal-on-metal hip replacements, but their ability to discriminate
between well-functioning and failed hips is not known. The Medicines
and Healthcare products Regulatory Agency (MHRA) has suggested a
cut-off level of 7 parts per billion (ppb). We performed a pair-matched, case-control study to investigate
the sensitivity and specificity of blood metal ion levels for diagnosing
failure in 176 patients with a unilateral metal-on-metal hip replacement.
We recruited 88 cases with a pre-revision, unexplained failed hip
and an equal number of matching controls with a well-functioning
hip. We investigated the 7 ppb cut-off level for the maximum of
cobalt or chromium and determined optimal mathematical cut-off levels
from receiver-operating characteristic curves. The 7 ppb cut-off level for the maximum of cobalt or chromium
had a specificity of 89% and sensitivity 52% for detecting a pre-operative
unexplained failed metal on metal hip replacement. The optimal cut-off
level for the maximum of cobalt or chromium was 4.97 ppb and had
sensitivity 63% and specificity 86%. Blood metal ions had good discriminant ability to separate failed
from well-functioning hip replacements. The MHRA cut-off level of
7 ppb provides a specific test but has poor sensitivity.
The results of further soft-tissue release of 79 feet in 60 children with recurrent idiopathic congenital talipes equinovarus were evaluated. The mean age of the children at the time of re-operation was 5.8 years (15 months to 14.5 years). Soft-tissue release was performed in all 79 feet and combined with distal calcaneal excision in 52 feet. The mean follow-up was 12 years (4 to 32). At the latest follow-up the result was excellent or good in 61 feet (77%) according to the Ghanem and Seringe scoring system. The results was considered as fair in 14 feet (18%), all of whom had functional problems and eight had anatomical abnormalities. Four feet (5%) were graded as poor on both functional and anatomical grounds. The results were independent of the age at which revision was undertaken.
Disruption of the extensor mechanism in total
knee arthroplasty may occur by tubercle avulsion, patellar or quadriceps
tendon rupture, or patella fracture, and whether occurring intra-operatively
or post-operatively can be difficult to manage and is associated
with a significant rate of failure and associated complications.
This surgery is frequently performed in compromised tissues, and
repairs must frequently be protected with cerclage wiring and/or
augmentation with local tendon (semi-tendinosis, gracilis) which
may also be used to treat soft-tissue loss in the face of chronic
disruption. Quadriceps rupture may be treated with conservative
therapy if the patient retains active extension. Component loosening
or loss of active extension of 20° or greater are clear indications
for surgical treatment of patellar fracture. Acute patellar tendon
disruption may be treated by primary repair. Chronic extensor failure
is often complicated by tissue loss and retraction can be treated
with medial gastrocnemius flaps, achilles tendon allografts, and
complete extensor mechanism allografts. Attention to fixing the
graft in full extension is mandatory to prevent severe extensor
lag as the graft stretches out over time.
Since 1996 more than one million metal-on-metal
articulations have been implanted worldwide. Adverse reactions to
metal debris are escalating. Here we present an algorithmic approach
to patient management. The general approach to all arthroplasty
patients returning for follow-up begins with a detailed history,
querying for pain, discomfort or compromise of function. Symptomatic
patients should be evaluated for intra-articular and extra-articular
causes of pain. In large head MoM arthroplasty, aseptic loosening
may be the source of pain and is frequently difficult to diagnose.
Sepsis should be ruled out as a source of pain. Plain radiographs
are evaluated to rule out loosening and osteolysis, and assess component
position. Laboratory evaluation commences with erythrocyte sedimentation
rate and C-reactive protein, which may be elevated. Serum metal
ions should be assessed by an approved facility. Aspiration, with
manual cell count and culture/sensitivity should be performed, with
cloudy to creamy fluid with predominance of monocytes often indicative
of failure. Imaging should include ultrasound or metal artifact
reduction sequence MRI, specifically evaluating for fluid collections
and/or masses about the hip. If adverse reaction to metal debris
is suspected then revision to metal or ceramic-on-polyethylene is indicated
and can be successful. Delay may be associated with extensive soft-tissue
damage and hence poor clinical outcome.
Our aim was to determine the success rate of repeated debridement and two-stage cementless revision arthroplasty according to the type of infected total hip replacement (THR). We enrolled 294 patients (294 hips) with an infected THR in the study. There were 222 men and 72 women with a mean age of 55.1 years (24.0 to 78.0). The rate of control of infection after the initial treatment and after repeated debridement and two-stage revisions was determined. The clinical (Harris hip score) and radiological results were evaluated. The mean follow-up was 10.4 years (5.0 to 14.0). The eventual rate of control of infection was 100.0% for early superficial post-operative infection, 98.4% for early deep post-operative infection, 98.5% for late chronic infection and 91.0% for acute haematogenous infection. Overall, 288 patients (98%) maintained a functioning THR at the latest follow-up. All the allografts appeared to be united and there were no failures. These techniques effectively controlled infection and maintained a functional THR with firm fixation in most patients. Repeated debridement and two-stage or repeated two-stage revisions further improved the rate of control of infection after the initial treatment and increased the likelihood of maintaining a functional THR.
Fractures of the femoral neck in children are
rare, high-energy injuries with high complication rates. Their treatment has
become more interventional but evidence of the efficacy of such
measures is limited. We performed a systematic review of studies
examining different types of treatment and their outcomes, including
avascular necrosis (AVN), nonunion, coxa vara, premature physeal
closure (PPC), and Ratliff’s clinical criteria. A total of 30 studies
were included, comprising 935 patients. Operative treatment and
open reduction were associated with higher rates of AVN. Delbet
types I and II fractures were most likely to undergo open reduction
and internal fixation. Coxa vara was reduced in the operative group,
whereas nonunion and PPC were not related to surgical intervention. Nonunion
and coxa vara were unaffected by the method of reduction. Capsular
decompression had no effect on AVN. Although surgery allows a more
anatomical union, it is uncertain whether operative treatment or
the type of reduction affects the rate of AVN, nonunion or PPC,
because more severe fractures were operated upon more frequently.
A delay in treatment beyond 24 hours was associated with a higher
incidence of AVN. Cite this article:
Venous thromboembolism (VTE) remains an immediate
threat to patients following total hip and knee replacement. While
there is a strong consensus that steps should be taken to minimise
the risk to patients by utilising some forms of prophylaxis for
the vast majority of patients, the methods utilised have been extremely
variable. Clinical practice guidelines (CPGs) have been published
by various professional organisations for over 25 years to provide recommendations
to standardise VTE prophylaxis. Historically, these recommendations
have varied widely depending in underlying assumptions, goals, and
methodology of the various groups. This effort has previously been
exemplified by the American College of Chest Physicians (ACCP) and
the American Academy of Orthopaedic Surgeons (AAOS). The former
group of medical specialists targeted minimising venographically
proven deep vein thrombosis (DVT) (the vast majority of which are
asymptomatic) as their primary goal prior to 2012. The latter group of
surgeons targeted minimising symptomatic VTE. As a result prior
to 2012, the recommendations of the two groups were widely divergent.
In the past year, both groups have reassessed the current literature
with the principal goals of minimising symptomatic VTE events and
bleeding complications. As a result, for the first time the CPGs
of these two major subspecialty organisations are in close agreement.
We reviewed 59 bone graft substitutes marketed
by 17 companies currently available for implantation in the United Kingdom,
with the aim of assessing the peer-reviewed literature to facilitate
informed decision-making regarding their use in clinical practice.
After critical analysis of the literature, only 22 products (37%)
had any clinical data. Norian SRS (Synthes), Vitoss (Orthovita),
Cortoss (Orthovita) and Alpha-BSM (Etex) had Level I evidence. We question
the need for so many different products, especially with limited
published clinical evidence for their efficacy, and conclude that
there is a considerable need for further prospective randomised
trials to facilitate informed decision-making with regard to the
use of current and future bone graft substitutes in clinical practice. Cite this article:
Dislocation is a common and well-studied complication after total hip replacement. However, subluxation, which we define as a clinically recognised episode of incomplete movement of the femoral head outside the acetabulum with spontaneous reduction, has not been studied previously. Out of a total of 2521 hip replacements performed over 12 years by one surgeon, 30 patients experienced subluxations which occurred in 31 arthroplasties. Data were collected prospectively with a minimum follow-up of two years. Subluxation occurred significantly more frequently after revision than after primary hip replacement, and resolved in 19 of 31 cases (61.3%). In six of the 31 hips (19.4%) the patient subsequently dislocated the affected hip, and in six hips (19.4%) intermittent subluxation continued. Four patients had a revision operation for instability, three for recurrent dislocation and one for recurrent subluxation. Clinical and radiological comparisons with a matched group of stable total hips showed no correlation with demographic or radiological parameters. Patients with subluxing hips reported significantly more concern that their hip would dislocate, more often changed their behaviour to prevent instability and had lower postoperative Harris hip scores than patients with stable replacements.
We describe the longer term clinical and radiological findings in a prospectively followed series of 49 rheumatoid patients (58 shoulders) who had undergone Neer II total shoulder replacement. The early and intermediate results have been published previously. At a mean follow-up of 19.8 years (16.5 to 23.8) 14 shoulders survived. Proximal migration of the humeral component was associated with progressive loosening of the glenoid and humeral components, but was independent of the state of the rotator cuff at the time of operation. Despite these changes the range of movement was preserved. Most patients had little or no pain in the shoulder, could sleep undisturbed and could attend to personal hygiene and grooming.
Periprosthetic joint infection (PJI) is a devastating
complication which can follow a total joint arthroplasty (TJA).
Although rare, this ongoing threat undermines the success of TJA,
a historically reputable procedure. It has haunted the orthopedic
community for decades and several ongoing studies have provided
insights and new approaches to effectively battle this multilayered
problem.
We present a comparison of patient-reported outcomes
(PROMs) in relation to patient age, in patients who had received
a total (TKR) or unicompartmental knee replacement (UKR). The outcome
was evaluated using the Oxford knee score (OKS), EuroQol (EQ-5D)
and satisfaction scores. Patients aged 65 to 84 years demonstrated
better pre-operative function scores than those aged <
65 years
(OKS, p = 0.03; EQ-5D, p = 0.048) and those aged
≥ 85 years (OKS, p = 0.03). Post-operative scores were comparable
across age groups, but a linear trend for greater post-operative
improvement in OKS and EQ-5D was seen with decreasing age (p <
0.033). The overall mean satisfaction score at six months was 84.9,
but those aged <
55 years exhibited a lower mean level of satisfaction (78.3)
compared with all other age groups (all p <
0.031). The cumulative
overall two-year revision rate was 1.3%. This study demonstrates
that good early outcomes, as measured by the OKS and EQ-5D, can
be anticipated following knee replacement regardless of the patient’s
age, although younger patients gain greater improvement. However,
the lower satisfaction in those aged
<
55 years is a concern, and suggests that outcome is not fully
encapsulated by the OKS and EQ-5D evaluation, and raises the question
whether the OKS alone is an appropriate measure of pain and function
in younger, more active individuals. Cite this article: