We performed a retrospective examination of the
anteroposterior pelvic CT scout views of 419 randomly selected patients between
April 2004 and August 2009 in order to determine the prevalence
of cam-type femoroacetabular deformity in the asymptomatic population.
The CT scans had all been undertaken for conditions unrelated to
disorders of the hip. The frequency of cam-type femoroacetabular
deformity was assessed by measuring the α-angle of each hip on the
anteroposterior images. The α-angles were classified according to
the Copenhagen Osteoarthritis Study. Among 215 male hips (108 patients)
the mean α-angle was 59.12° (37.75° to 103.50°). Of these, a total
of 30 hips (13.95%) were defined as pathological, 32 (14.88%) as
borderline and 153 (71.16%) as normal. Among 540 female hips (272
patients) the mean α-angle was 45.47° (34.75° to 87.00°), with 30
hips (5.56%) defined as pathological, 33 (6.11%) as borderline and
477 (88.33%) as normal. It appears that the cam-type femoroacetabular
deformity is not rare among the asymptomatic population. These anatomical
abnormalities, as determined by an increased α-angle, appear to
be twice as frequent in men as in women. Although an association
between osteoarthritis and femoroacetabular impingement is believed
to exist, a long-term epidemiological study is needed to determine
the natural history of these anatomical abnormalities.
Osteoarthritis is extremely common and many different causes for it have been described. One such cause is abnormal morphology of the affected joint, the hip being a good example of this. For those joints with femoroacetabular impingement (FAI) or developmental dysplasia of the hip (DDH), a link with subsequent osteoarthritis seems clear. However, far from being abnormal, these variants may be explained by evolution, certainly so for FAI, and may actually be normal rather than representing deformity or disease. The animal equivalent of FAI is coxa recta, commonly found in species that run and jump. It is rarely found in animals that climb and swim. In contrast are the animals with coxa rotunda, a perfectly spherical femoral head, and more in keeping with the coxa profunda of mankind. This article describes the evolutionary process of the human hip and its link to FAI and DDH. Do we need to worry after all?
The February 2014 Knee Roundup360 looks at: whether sham surgery is as good as arthroscopic meniscectomy; distraction in knee osteoarthritis; whether trans-tibial tunnel placement increases the risk of graft failure in ACL surgery; whether joint replacements prevent cardiac events; the size of the pulmonary embolism problem; tranexamic acid and knee replacement haemostasis; matching the demand for knee replacement and follow-up; predicting the length of stay after knee replacement; and popliteal artery injury in TKR.
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.
The February 2013 Knee Roundup360 looks at: mobile-bearing TKRs; arthroscopic ACL reconstruction; the use of chondrocytes for osteochondral defects; ACL reconstruction and the return to pivoting sports; ACLs and the MOON study; the benefit of knee navigation; and trabecular metal.
The purpose of this study was to assess whether
the use of a joint-sparing technique such as curettage and grafting was
successful in eradicating giant cell tumours of the proximal femur,
or whether an alternative strategy was more appropriate. Between 1974 and 2012, 24 patients with a giant cell tumour of
the proximal femur were treated primarily at our hospital. Treatment
was either joint sparing or joint replacing. Joint-sparing treatment
was undertaken in ten patients by curettage with or without adjunctive
bone graft. Joint replacement was by total hip replacement in nine patients
and endoprosthetic replacement in five. All 11 patients who presented
with a pathological fracture were treated by replacement. Local recurrence occurred in five patients (21%): two were treated
by hip replacement, three by curettage and none with an endoprosthesis.
Of the ten patients treated initially by curettage, six had a successful
outcome without local recurrence and required no further surgery.
Three eventually needed a hip replacement for local recurrence and
one an endoprosthetic replacement for mechanical failure. Thus 18
patients had the affected joint replaced and only six (25%) retained
their native joint. Overall, 60% of patients without a pathological
fracture who were treated with curettage had a successful outcome. Cite this article:
Metal-on-metal hip arthroplasty gained significant
favor in the first decade of the millennium. However, the past several
years have seen increasing reports of failure, pseudotumor and other
adverse reactions. This study presents the results of a single center’s
15-year experience with metal-on-metal total hip arthroplasty as
strong evidence that metal-on-metal is going, going, gone.
The management of failed autologous chondrocyte
implantation (ACI) and matrix-assisted autologous chondrocyte implantation
(MACI) for the treatment of symptomatic osteochondral defects in
the knee represents a major challenge. Patients are young, active
and usually unsuitable for prosthetic replacement. This study reports
the results in patients who underwent revision cartilage transplantation
of their original ACI/MACI graft for clinical or graft-related failure.
We assessed 22 patients (12 men and 10 women) with a mean age of
37.4 years (18 to 48) at a mean of 5.4 years (1.3 to 10.9). The
mean period between primary and revision grafting was 46.1 months
(7 to 89). The mean defect size was 446.6 mm2 (150 to
875) and they were located on 11 medial and two lateral femoral condyles,
eight patellae and one trochlea. The mean modified Cincinnati knee score improved from 40.5 (16
to 77) pre-operatively to 64.9 (8 to 94) at their most recent review
(p <
0.001). The visual analogue pain score improved from 6.1
(3 to 9) to 4.7 (0 to 10) (p = 0.042). A total of 14 patients (63%)
reported an ‘excellent’ (n = 6) or ‘good’ (n = 8) clinical outcome,
5 ‘fair’ and one ‘poor’ outcome. Two patients underwent patellofemoral
joint replacement. This study demonstrates that revision cartilage
transplantation after primary ACI and MACI can yield acceptable
functional results and continue to preserve the joint. Cite this article:
The incidence of acute and chronic conditions
of the tendo Achillis appear to be increasing. Causation is multifactorial
but the role of inherited genetic elements and the influence of
environmental factors altering gene expression are increasingly
being recognised. Certain individuals’ tendons carry specific variations
of genetic sequence that may make them more susceptible to injury.
Alterations in the structure or relative amounts of the components
of tendon and fine control of activity within the extracellular
matrix affect the response of the tendon to loading with failure
in certain cases. This review summarises present knowledge of the influence of
genetic patterns on the pathology of the tendo Achillis, with a
focus on the possible biological mechanisms by which genetic factors
are involved in the aetiology of tendon pathology. Finally, we assess
potential future developments with both the opportunities and risks
that they may carry. Cite this article:
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
Dislocation is one of the most common causes
of patient and surgeon dissatisfaction following hip replacement
and to treat it, the causes must first be understood. Patient factors
include age greater than 70 years, medical comorbidities, female
gender, ligamentous laxity, revision surgery, issues with the abductors,
and patient education. Surgeon factors include the annual quantity
of procedures and experience, the surgical approach, adequate restoration
of femoral offset and leg length, component position, and soft-tissue
or bony impingement. Implant factors include the design of the head
and neck region, and so-called skirts on longer neck lengths. There
should be offset choices available in order to restore soft-tissue
tension. Lipped liners aid in gaining stability, yet if improperly placed
may result in impingement and dislocation. Late dislocation may
result from polyethylene wear, soft-tissue destruction, trochanteric
or abductor disruption and weakness, or infection. Understanding
the causes of hip dislocation facilitates prevention in a majority
of instances. Proper pre-operative planning includes the identification
of patients with a high offset in whom inadequate restoration of
offset will reduce soft-tissue tension and abductor efficiency.
Component position must be accurate to achieve stability without impingement.
Finally, patient education cannot be over-emphasised, as most dislocations occur
early, and are preventable with proper instructions. Cite this article:
The issues surrounding raised levels of metal
ions in the blood following large head metal-on-metal total hip replacement
(THR), such as cobalt and chromium, have been well documented. Despite
the national popularity of uncemented metal-on-polyethylene (MoP)
THR using a large-diameter femoral head, few papers have reported
the levels of metal ions in the blood following this combination.
Following an isolated failure of a 44 mm Trident–Accolade uncemented
THR associated with severe wear between the femoral head and the
trunnion in the presence of markedly elevated levels of cobalt ions
in the blood, we investigated the relationship between modular femoral head
diameter and the levels of cobalt and chromium ions in the blood
following this THR. A total of 69 patients received an uncemented Trident–Accolade
MoP THR in 2009. Of these, 43 patients (23 men and 20 women, mean
age 67.0 years) were recruited and had levels of cobalt and chromium
ions in the blood measured between May and June 2012. The patients
were then divided into three groups according to the diameter of
the femoral head used: 12 patients in the 28 mm group (controls),
18 patients in the 36 mm group and 13 patients in the 40 mm group.
A total of four patients had identical bilateral prostheses in situ
at phlebotomy: one each in the 28 mm and 36 mm groups and two in
the 40 mm group. There was a significant increase in the mean levels of cobalt
ions in the blood in those with a 36 mm diameter femoral head compared
with those with a 28 mm diameter head (p = 0.013). The levels of
cobalt ions in the blood were raised in those with a 40 mm diameter
head but there was no statistically significant difference between
this group and the control group (p = 0.152). The levels of chromium
ions in the blood were normal in all patients. The clinical significance of this finding is unclear, but we
have stopped using femoral heads with a diameter of ≤ 36 mm, and
await further larger studies to clarify whether, for instance, this
issue particularly affects this combination of components. Cite this article:
Femoroacetabular impingement (FAI) causes pain
and chondrolabral damage via mechanical overload during movement
of the hip. It is caused by many different types of pathoanatomy,
including the cam ‘bump’, decreased head–neck offset, acetabular
retroversion, global acetabular overcoverage, prominent anterior–inferior
iliac spine, slipped capital femoral epiphysis, and the sequelae
of childhood Perthes’ disease. Both evolutionary and developmental factors may cause FAI. Prevalence
studies show that anatomic variations that cause FAI are common
in the asymptomatic population. Young athletes may be predisposed
to FAI because of the stress on the physis during development. Other
factors, including the soft tissues, may also influence symptoms and
chondrolabral damage. FAI and the resultant chondrolabral pathology are often treated
arthroscopically. Although the results are favourable, morphologies
can be complex, patient expectations are high and the surgery is
challenging. The long-term outcomes of hip arthroscopy are still
forthcoming and it is unknown if treatment of FAI will prevent arthrosis.
This study reports the application of a novel method for quantitatively determining differences in the mechanical properties of healthy and torn rotator cuff tissues. In order to overcome problems of stress risers at the grip-tendon interface that can obscure mechanical measurements of small tendons, we conducted our investigation using dynamic shear analysis. Rotator cuff tendon specimens were obtained from 100 patients during shoulder surgery. They included 82 differently sized tears and 18 matched controls. We subjected biopsy samples of 3 mm in diameter to oscillatory deformation under compression using dynamic shear analysis. The storage modulus (G’) was calculated as an indicator of mechanical integrity. Normal tendons had a significantly higher storage modulus than torn tendons, indicating that torn tendons are mechanically weaker than normal tendons (p = 0.003). Normal tendons had a significantly higher mean shear modulus than tendons with massive tears (p <
0.01). Dynamic shear analysis allows the determination of shear mechanical properties of small tissue specimens obtained intra-operatively that could not be studied by conventional methods of tensile testing. These methods could be employed to investigate other musculoskeletal tissues. This pilot study provides some insight into mechanisms that might contribute to the failure of repair surgery, and with future application could help direct the most appropriate treatment for specific rotator cuff tears.
We determined the short-term clinical outcome
and migration within the bone of the humeral cementless component
of the Instrumented Bone Preserving (IBP) total elbow replacement
in a series of 16 patients. There were four men and 12 women with
a mean age at operation of 63 years (40 to 81). Migration was calculated
using radiostereometric analysis. There were no intra-operative
complications and no revisions. At two-year follow-up, all patients
showed a significant reduction in pain and functional improvement
of the elbow (both p <
0.001). Although ten components (63%)
showed movement or micromovement during the first six weeks, 14
(88%) were stable at one year post-operatively. Translation was
primarily found in the proximal direction (median 0.3 mm (interquartile range
(IQR) -0.09 to 0.8); the major rotational movement was an anterior
tilt (median 0.7° (IQR 0.4° to 1.6°)). One malaligned component
continued to migrate during the second year, and one component could
not be followed beyond three months because migration had caused
the markers to break off the prosthesis. This study shows promising early results for the cementless humeral
component of the IBP total elbow replacement. All patients had a
good clinical outcome, and most components stabilised within six
months of the operation. Cite this article:
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.
We describe the technique and results of medial
submuscular plating of the femur in paediatric patients and discuss its
indications and limitations. Specifically, the technique is used
as part of a plate-after-lengthening strategy, where the period
of external fixation is reduced and the plate introduced by avoiding
direct contact with the lateral entry wounds of the external fixator
pins. The technique emphasises that vastus medialis is interposed
between the plate and the vascular structures. A total of 16 patients (11 male and five female, mean age 9.6
years (5 to 17)), had medial submuscular plating of the femur. All
underwent distraction osteogenesis of the femur with a mean lengthening
of 4.99 cm (3.2 to 12) prior to plating. All patients achieved consolidation
of the regenerate without deformity. The mean follow-up was 10.5 months
(7 to 15) after plating for those with plates still Placing the plate on the medial side is advantageous when the
external fixator is present on the lateral side, and is biomechanically
optimal in the presence of a femoral defect. We conclude that medial
femoral submuscular plating is a useful technique for specific indications
and can be performed safely with a prior understanding of the regional
anatomy. Cite this article:
Treatment of an infected total elbow replacement
(TER) is often successful in eradicating or suppressing the infection.
However, the extensor mechanism may be compromised by both the infection
and the surgery. The goal of this study was to assess triceps function
in patients treated for deep infection complicating a TER. Between
1976 and 2007 a total of 217 TERs in 207 patients were treated for
infection of a TER at our institution. Superficial infections and
those that underwent resection arthroplasty were excluded, leaving
93 TERs. Triceps function was assessed by examination and a questionnaire.
Outcome was measured using the Mayo Elbow Performance Score (MEPS). Triceps weakness was identified in 51 TERs (49 patients, 55%).
At a mean follow-up of five years (0.8 to 34), the extensor mechanism
was intact in 13 patients, with the remaining 38 having bone or
soft-tissue loss. The mean MEPS was 70 points (5 to 100), with a
mean functional score of 18 (0 to 25) of a possible 25 points. Infection following TER can often be eradicated; however, triceps
weakness occurs in more than half of the patients and may represent
a major functional problem. Cite this article:
Mobile-bearing unicompartmental knee replacements
(UKRs) with a flat tibial plateau have not performed well in the
lateral compartment, owing to a high dislocation rate. This led
to the development of the Domed Lateral Oxford UKR (Domed OUKR)
with a biconcave bearing. The aim of this study was to assess the
survival and clinical outcomes of the Domed OUKR in a large patient
cohort in the medium term. We prospectively evaluated 265 consecutive knees with isolated
disease of the lateral compartment and a mean age at surgery of
64 years (32 to 90). At a mean follow-up of four years ( The Domed Lateral OUKR gives good clinical outcomes, low re-operation
and revision rates and a low dislocation rate in patients with isolated
lateral compartmental disease, in the hands of the designer surgeons. Cite this article:
We assessed the outcome of patients who were
lost to follow-up after arthroplasty by a single surgeon. The aim was
to validate the surgeon’s data set with the Australian Orthopaedic
Association National Joint Replacement Registry and determine the
outcome of those patients lost to follow-up. Prospective data on patient demographics, operative details and
outcomes of the surgeon’s 1192 primary unicompartmental knee arthroplasty
(UKA) procedures were analysed. There were 69 knees in patients
who were lost to follow-up, among whom the Registry identified 31
deaths and eight revisions. The cumulative percentage revision (CPR) at seven years using
the additional Registry data was 8.8% (95% confidence interval (CI)
7 to 11). Using the surgeon’s data, the CPR at seven years was 8%
(95% CI 6.3 to 10.1) for the best-case scenario where loss to follow-up
was excluded, and 16% (95% CI 13.8 to 19.4) for the worst-case scenario, where
all patients lost to follow-up were deemed to have been revised.
There was a significantly higher mortality rate in those patients
lost to follow-up. This study demonstrates that a national joint registry can be
used by individual surgeons to establish more accurate revision
rates in their arthroplasty patients. This is expected to facilitate
a more rigorous audit of surgical outcomes by surgeons and lead
to more accurate and uniform reporting of the results of arthroplasty
in general.