The aim of our study was to investigate whether placing of the femoral component of a hip resurfacing in valgus protected against spontaneous fracture of the femoral neck. We performed a hip resurfacing in 20 pairs of embalmed femora. The femoral component was implanted at the natural neck-shaft angle in the left femur and with a 10° valgus angle on the right. The bone mineral density of each femur was measured and CT was performed. Each femur was evaluated in a materials testing machine using increasing cyclical loads. In specimens with good bone quality, the 10° valgus placement of the femoral component had a protective effect against fractures of the femoral neck. An adverse effect was detected in osteoporotic specimens. When resurfacing the hip a valgus position of the femoral component should be achieved in order to prevent fracture of the femoral neck. Patient selection remains absolutely imperative. In borderline cases, measurement of bone mineral density may be indicated.
The purpose of this study was to assess the stability of a developmental pelvic reconstruction system which extends the concept of triangular osteosynthesis with fixation anterior to the lumbosacral pivot point. An unstable Tile type-C fracture, associated with a sacral transforaminal fracture, was created in synthetic pelves. The new concept was compared with three other constructs, including bilateral iliosacral screws, a tension band plate and a combined plate with screws. The pubic symphysis was plated in all cases. The pelvic ring was loaded to simulate single-stance posture in a cyclical manner until failure, defined as a displacement of 2 mm or 2°. The screws were the weakest construct, failing with a load of 50 N after 400 cycles, with maximal translation in the craniocaudal axis of 12 mm. A tension band plate resisted greater load but failure occurred at 100 N, with maximal rotational displacement around the mediolateral axis of 2.3°. The combination of a plate and screws led to an improvement in stability at the 100 N load level, but rotational failure still occurred around the mediolateral axis. The pelvic reconstruction system was the most stable construct, with a maximal displacement of 2.1° of rotation around the mediolateral axis at a load of 500 N.
The purpose of this study was to identify changing
trends in the pattern of distribution of the type and demographics
of fractures of the hip in the elderly between 2001 and 2010. A
retrospective cross-sectional comparison was conducted between 179
fractures of the hip treated in 2001, 357 treated in 2006 and 454
treated in 2010. Patients aged <
60 years and those with pathological
and peri-prosthetic fractures were excluded. Fractures were classified
as stable extracapsular, unstable extracapsular or intracapsular
fractures. The mean age of the 179 patients (132 women (73.7%)) treated
in 2001 was 80.8 years (60 to 96), 81.8 years (61 to 101) in the
357 patients (251 women (70.3%)) treated in 2006 and 82.0 years
(61 to 102) in the 454 patients (321 women (70.1%)) treated in 2010
(p = 0.17). There was no difference in the gender distribution between
the three study years (p = 0.68). The main finding was a steep rise in the proportion of unstable
peritrochanteric fractures. The proportion of unstable extracapsular
fractures was 32% (n = 57) in 2001, 35% (n = 125) in 2006 and 45%
(n = 204) in 2010 (p <
0.001). This increase was not significant
in patients aged between 60 and 69 years (p = 0.84), marginally
significant in those aged between 70 and 79 years (p = 0.04) and
very significant in those aged >
80 years (p <
0.001). The proportion
of intracapsular fractures did not change (p = 0.94). At present, we face not only an increasing number of fractures
of the hip, but more demanding and complex fractures in older patients
than a decade ago. This study does not provide an explanation for
this change. Cite this article:
We The triple-strand technique significantly increased the tensile
strength (p = 0.0001) and gap resistance (p = 0.01) of bovine tendon
repairs, and might have advantages in human application for accelerated
post-operative rehabilitation.
Our study aimed to examine if a mobile-bearing total knee replacement
(TKR) offered an advantage over fixed-bearing designs with respect
to rates of secondary resurfacing of the patella in knees in which
it was initially left unresurfaced. We examined the 11-year report of the New Zealand Joint Registry
and identified all primary TKR designs that had been implanted in
>
500 knees without primary resurfacing of the patella. We examined
how many of these were mobile-bearing, fixed-bearing cruciate-retaining
and fixed-bearing posterior-stabilised designs. We assessed the rates
of secondary resurfacing of the patella for each group and constructed
Kaplan-Meier survival curves.Objectives
Methods
We hypothesised that meniscal tears treated with mesenchymal stem cells (MSCs) together with a conventional suturing technique would show improved healing compared with those treated by a conventional suturing technique alone. In a controlled laboratory study 28 adult pigs (56 knees) underwent meniscal procedures after the creation of a radial incision to represent a tear. Group 1 (n = 9) had a radial meniscal tear which was left untreated. In group 2 (n = 19) the incision was repaired with sutures and fibrin glue and in group 3, the experimental group (n = 28), treatment was by MSCs, suturing and fibrin glue. At eight weeks, macroscopic examination of group 1 showed no healing in any specimens. In group 2 no healing was found in 12 specimens and incomplete healing in seven. The experimental group 3 had 21 specimens with complete healing, five with incomplete healing and two with no healing. Between the experimental group and each of the control groups this difference was significant (p <
0.001). The histological and macroscopic findings showed that the repair of meniscal tears in the avascular zone was significantly improved with MSCs, but that the mechanical properties of the healed menisci remained reduced.
The use of joint-preserving surgery of the hip
has been largely abandoned since the introduction of total hip replacement.
However, with the modification of such techniques as pelvic osteotomy,
and the introduction of intracapsular procedures such as surgical
hip dislocation and arthroscopy, previously unexpected options for
the surgical treatment of sequelae of childhood conditions, including
developmental dysplasia of the hip, slipped upper femoral epiphysis
and Perthes’ disease, have become available. Moreover, femoroacetabular
impingement has been identified as a significant aetiological factor
in the development of osteoarthritis in many hips previously considered to
suffer from primary osteoarthritis. As mechanical causes of degenerative joint disease are now recognised
earlier in the disease process, these techniques may be used to
decelerate or even prevent progression to osteoarthritis. We review
the recent development of these concepts and the associated surgical
techniques. Cite this article:
Two-stage revision surgery for infected total knee replacement offers the highest rate of success for the elimination of infection. The use of articulating antibiotic-laden cement spacers during the first stage to eradicate infection also allows protection of the soft tissues against excessive scarring and stiffness. We have investigated the effect of cyclical loading of cement spacers on the elution of antibiotics. Femoral and tibial spacers containing vancomycin at a constant concentration and tobramycin of varying concentrations were studied The elution of tobramycin increased proportionately with its concentration in cement and was significantly higher at all sampling times from five minutes to 1680 minutes in loaded components compared with the control group (p = 0.021 and p = 0.003, respectively). A similar trend was observed with elution of vancomycin, but this failed to reach statistical significance at five, 1320 and 1560 minutes (p = 0.0508, p = 0.067 and p = 0.347, respectively). However, cyclically loaded and control components showed an increased elution of vancomycin with increasing tobramycin concentration in the specimens, despite all components having the same vancomycin concentration. The concentration of tobramycin influences both tobramycin and vancomycin elution from bone cement. Cyclical loading of the cement spacers enhanced the elution of vancomycin and tobramycin.
We evaluated two reconstruction techniques for a simulated posterolateral corner injury on ten pairs of cadaver knees. Specimens were mounted at 30° and 90° of knee flexion to record external rotation and varus movement. Instability was created by transversely sectioning the lateral collateral ligament at its midpoint and the popliteus tendon was released at the lateral femoral condyle. The left knee was randomly assigned for reconstruction using either a combined or fibula-based treatment with the right knee receiving the other. After sectioning, laxity increased in all the specimens. Each technique restored external rotatory and varus stability at both flexion angles to levels similar to the intact condition. For the fibula-based reconstruction method, varus laxity at 30° of knee flexion did not differ from the intact state, but was significantly less than after the combined method. Both the fibula-based and combined posterolateral reconstruction techniques are equally effective in restoring stability following the simulated injury.
In Neer type II (Robinson type 3B) fractures
of the distal clavicle the medial fragment is detached from the coracoclavicular
ligaments and displaced upwards, whereas the lateral fragment, which
is usually small, maintains its position. Several fixation techniques
have been suggested to treat this fracture. The aim of this study
was to assess the outcome of patients with type II distal clavicle
fractures treated with coracoclavicular suture fixation using three
loops of Ethibond. This prospective study included 14 patients with
Neer type II fractures treated with open reduction and coracoclavicular
fixation. Ethibond sutures were passed under the coracoid and around
the clavicle (UCAC loop) without making any drill holes in the proximal
or distal fragments. There were 11 men and three women with a mean
age of 34.57 years (29 to 41). Patients were followed for a mean
of 24.64 months (14 to 31) and evaluated radiologically and clinically
using the Constant score. Fracture union was obtained in 13 patients at
a mean of 18.23 weeks (13 to 23) and the mean Constant score was
96.07 (91 to 100). One patient developed an asymptomatic fibrous
nonunion at one year. This study suggests that open reduction and
internal fixation of unstable distal clavicle fractures using UCAC
loops can provide rigid fixation and lead to bony union. This technique avoids
using metal hardware, preserves the acromioclavicular joint and
provides adequate stability with excellent results. Cite this article:
Transarticular screw fixation with autograft
is an established procedure for the surgical treatment of atlantoaxial instability.
Removal of the posterior arch of C1 may affect the rate of fusion.
This study assessed the rate of atlantoaxial fusion using transarticular
screws with or without removal of the posterior arch of C1. We reviewed
30 consecutive patients who underwent atlantoaxial fusion with a
minimum follow-up of two years. In 25 patients (group A) the posterior
arch of C1 was not excised (group A) and in five it was (group B).
Fusion was assessed on static and dynamic radiographs. In selected
patients CT imaging was also used to assess fusion and the position
of the screws. There were 15 men and 15 women with a mean age of
51.2 years (23 to 77) and a mean follow-up of 7.7 years (2 to 11.6).
Stable union with a solid fusion or a stable fibrous union was achieved
in 29 patients (97%). In Group A, 20 patients (80%) achieved a solid
fusion, four (16%) a stable fibrous union and one (4%) a nonunion.
In Group B, stable union was achieved in all patients, three having
a solid fusion and two a stable fibrous union. There was no statistically
significant difference between the status of fusion in the two groups.
Complications were noted in 12 patients (40%); these were mainly
related to the screws, and included malpositioning and breakage.
The presence of an intact or removed posterior arch of C1 did not
affect the rate of fusion in patients with atlantoaxial instability
undergoing C1/C2 fusion using transarticular screws and autograft. Cite this article:
An understanding of the remodelling of tendon is crucial for the development of scientific methods of treatment and rehabilitation. This study tested the hypothesis that tendon adapts structurally in response to changes in functional loading. A novel model allowed manipulation of the mechanical environment of the patellar tendon in the presence of normal joint movement via the application of an adjustable external fixator mechanism between the patella and the tibia in sheep, while avoiding exposure of the patellar tendon itself. Stress shielding caused a significant reduction in the structural and material properties of stiffness (79%), ultimate load (69%), energy absorbed (61%), elastic modulus (76%) and ultimate stress (72%) of the tendon compared with controls. Compared with the material properties the structural properties exhibited better recovery after re-stressing with stiffness 97%, ultimate load 92%, energy absorbed 96%, elastic modulus 79% and ultimate stress 80%. The cross-sectional area of the re-stressed tendons was significantly greater than that of stress-shielded tendons. The remodelling phenomena exhibited in this study are consistent with a putative feedback mechanism under strain control. This study provides a basis from which to explore the interactions of tendon remodelling and mechanical environment.
Surgical marking during tendon surgery is often used for technical
and teaching purposes. This study investigates the effect of a gentian
violet ink marker pen, a common surgical marker, on the viability
of the tissue and cells of tendon.
Objectives
Methods
The aim of this review is to address controversies
in the management of dislocations of the acromioclavicular joint. Current
evidence suggests that operative rather than non-operative treatment
of Rockwood grade III dislocations results in better cosmetic and
radiological results, similar functional outcomes and longer time
off work. Early surgery results in better functional and radiological
outcomes with a reduced risk of infection and loss of reduction compared
with delayed surgery. Surgical options include acromioclavicular fixation, coracoclavicular
fixation and coracoclavicular ligament reconstruction. Although
non-controlled studies report promising results for arthroscopic
coracoclavicular fixation, there are no comparative studies with
open techniques to draw conclusions about the best surgical approach.
Non-rigid coracoclavicular fixation with tendon graft or synthetic
materials, or rigid acromioclavicular fixation with a hook plate,
is preferable to fixation with coracoclavicular screws owing to
significant risks of loosening and breakage. The evidence, although limited, also suggests that anatomical
ligament reconstruction with autograft or certain synthetic grafts
may have better outcomes than non-anatomical transfer of the coracoacromial
ligament. It has been suggested that this is due to better restoration
horizontal and vertical stability of the joint. Despite the large number of recently published studies, there
remains a lack of high-quality evidence, making it difficult to
draw firm conclusions regarding these controversial issues. Cite this article:
Lateral epicondylitis, or ’tennis elbow’, is
a common condition that usually affects patients between 35 and
55 years of age. It is generally self-limiting, but in some patients
it may continue to cause persistent symptoms, which can be refractory
to treatment. This review discusses the mechanism of disease, symptoms
and signs, investigations, current management protocols and potential
new treatments. Cite this article:
We studied the effect of trochanteric osteotomy in 192 total hip replacements in 140 patients with congenital hip disease. There was bony union in 158 hips (82%), fibrous union in 29 (15%) and nonunion in five (3%). The rate of union had a statistically significant relationship with the position of reattachment of the trochanter, which depended greatly on the pre-operative diagnosis. The pre-operative Trendelenburg gait substantially improved in all three disease types (dysplasia, low and high dislocation) and all four categories of reattachment position. A persistent Trendelenburg gait post-operatively was noticed mostly in patients with defective union (fibrous or nonunion). Acetabular and femoral loosening had a statistically significant relationship with defective union and the position of reattachment of the trochanter. These results suggest that the complications of trochanteric osteotomy in total hip replacement for patients with congenital hip disease are less important than the benefits of this surgical approach.
Lateral clavicular physeal injuries in adolescents
are frequently misinterpreted as acromioclavicular dislocations. There
are currently no clear guidelines for the management of these relatively
rare injuries. Non-operative treatment can result in a cosmetic
deformity, warranting resection of the non-remodelled original lateral
clavicle. However, fixation with Kirschner (K)-wires may be associated
with infection and/or prominent metalwork. We report our experience
with a small series of such cases. Between October 2008 and October 2011 five patients with lateral
clavicular physeal fractures (types III, IV and V) presented to
our unit. There were four boys and one girl with a mean age of 12.8
years (9 to 14). Four fractures were significantly displaced and
treated operatively using a tension band suture technique. One grade
III fracture was treated conservatively. The mean follow-up was
26 months (6 to 42). All patients made an uncomplicated recovery. The mean time to
discharge was three months. The QuickDASH score at follow-up was
0 for each patient. No patient developed subsequent growth disturbances. We advocate the surgical treatment of significantly displaced
Grade IV and V fractures to avoid cosmetic deformity. A tension
band suture technique avoids the problems of retained metalwork
and the need for a secondary procedure. Excellent clinical and radiological
results were seen in all our patients. Cite this article:
The need for bone tissue supplementation exists in a wide range
of clinical conditions involving surgical reconstruction in limbs,
the spine and skull. The bone supplementation materials currently
used include autografts, allografts and inorganic matrix components;
but these pose potentially serious side-effects. In particular the
availability of the autografts is usually limited and their harvesting
causes surgical morbidity. Therefore for the purpose of supplementation
of autologous bone graft, we have developed a method for autologous
extracorporeal bone generation. Human osteoblast-like cells were seeded on porous granules of
tricalcium phosphate and incubated in osteogenic media while exposed
to mechanical stimulation by vibration in the infrasonic range of
frequencies. The generated tissue was examined microscopically following
haematoxylin eosin, trichrome and immunohistochemical staining.Objectives
Methods
We report the results at a mean of 24.3 years
(20 to 32) of 61 previously reported consecutive total hip replacements carried
out on 44 patients with severe congenital hip disease, performed
with reconstruction of the acetabulum with an impaction grafting
technique known as cotyloplasty. The mean age of the patients at
operation was 46.7 years (23 to 68) and all were women. The patients
were followed post-operatively for a mean of 24.3 years (20 to 32), using
the Merle d’Aubigné and Postel scoring system as modified by Charnley,
and with serial radiographs. At the time of the latest follow-up,
28 acetabular components had been revised because of aseptic loosening
at a mean of 15.9 years (6 to 26), and one at 40 days after surgery
because of repeated dislocations. The overall survival rate for aseptic
failure of the acetabular component at ten years was 93.1% (95%
confidence interval (CI) 86.5 to 96.7) when 53 hips were at risk,
and at 23 years was 56.1% (95% CI 49.4 to 62.8), when 22 hips remained
at risk. These long-term results are considered satisfactory for
the reconstruction of an acetabulum presenting with inadequate bone
stock and circumferential segmental defects. Cite this article: