Sagittal alignment of the lumbosacral spine, and specifically pelvic incidence (PI), has been implicated in the development of spine pathology, but generally ignored with regards to diseases of the hip. We aimed to determine if increased PI is correlated with higher rates of hip osteoarthritis (HOA). The effect of PI on the development of knee osteoarthritis (KOA) was used as a negative control. We studied 400 well-preserved cadaveric skeletons ranging from 50 to 79 years of age at death. Each specimen’s OA of the hip and knee were graded using a previously described method. PI was measured from standardised lateral photographs of reconstructed pelvises. Multiple regression analysis was performed to determine the relationship between age and PI with HOA and KOA.Objectives
Methods
Tapered fluted titanium stems are increasingly
used for femoral revision arthroplasty. They are available in modular and
non-modular forms. Modularity has advantages when the bone loss
is severe, the proximal femur is mis shapen or the surgeon is unfamiliar
with the implant, but it introduces the risk of fracture of the
stem at the junction between it and the proximal body segment. For
that reason, and while awaiting intermediate-term results of more recently
introduced designs of this junction, non-modularity has attracted
attention, at least for straightforward revision cases. We review the risks and causes of fracture of tapered titanium
modular revision stems and present an argument in favour of the
more selective use of modular designs. Cite this article:
This study aimed to determine the long-term functional,
clinical and radiological outcomes in patients with Schatzker IV
to VI fractures of the tibial plateau treated with an Ilizarov frame.
Clinical, functional and radiological assessment was carried out
at a minimum of one year post-operatively. A cohort of 105 patients
(62 men, 43 women) with a mean age of 49 years (15 to 87) and a
mean follow-up of 7.8 years (1 to 19) were reviewed. There were
18 type IV, 10 type V and 77 type VI fractures. All fractures united
with a mean time to union of 20.1 weeks (10.6 to 42.3). No patient
developed a deep infection. The median range of movement (ROM) of
the knee was 110o and the median Iowa score was 85. Our study demonstrates good long-term functional outcome with
no deep infection; spanning the knee had no detrimental effect on
the ROM or functional outcome. High-energy fractures of the tibial plateau may be treated effectively
with a fine wire Ilizarov fixator. Cite this article:
Adverse reaction to wear and corrosion debris
is a cause for concern in total hip arthroplasty (THA). Modular junctions
are a potential source of such wear products and are associated
with secondary pseudotumour formation. We present a consecutive series of 17 patients treated at our
unit for this complication following metal-on-highly cross-linked
polyethylene (MoP) THA. We emphasise the risk of misdiagnosis as
infection, and present the aggregate laboratory results and pathological
findings in this series. The clinical presentation was pain, swelling or instability.
Solid, cystic and mixed soft-tissue lesions were noted on imaging
and confirmed intra-operatively. Corrosion at the head–neck junction
was noted in all cases. No bacteria were isolated on multiple pre-
and intra-operative samples yet the mean erythrocyte sedimentation
rate was 49 (9 to 100) and C-reactive protein 32 (0.6 to 106) and
stromal polymorphonuclear cell counts were noted in nine cases. Adverse soft–tissue reactions can occur in MoP THA owing to corrosion
products released from the head–neck junction. The diagnosis should
be carefully considered when investigating pain after THA. This
may avoid the misdiagnosis of periprosthetic infection with an unidentified
organism and mitigate the unnecessary management of these cases
with complete single- or two-stage exchange. Cite this article:
Non-modular tapered fluted, titanium stems are
available for use in femoral revision. The combination of taper
and flutes on the stem provides axial and rotational stability,
respectively. The material and surface properties of the stem promotes
bone on-growth. If the surgeon is confident and reasonably experienced
in the surgical use of this sort of design and the case is relatively
straightforward, a non-modular design is effective. It also potentially reduces
implant inventory, and circumvents the potential problems of taper
junction corrosion and fatigue fracture. There are reports of excellent
survival, good clinical and functional results and evidence of subsequent
increase in proximal bone stock. Cite this article: Bo
The aim of this study was to examine whether asymmetric loading
influences macrophage elastase (MMP12) expression in different parts
of a rat tail intervertebral disc and growth plate and if MMP12
expression is correlated with the severity of the deformity. A wedge deformity between the ninth and tenth tail vertebrae
was produced with an Ilizarov-type mini external fixator in 45 female
Wistar rats, matched for their age and weight. Three groups were
created according to the degree of deformity (10°, 30° and 50°).
A total of 30 discs and vertebrae were evaluated immunohistochemically
for immunolocalisation of MMP12 expression, and 15 discs were analysed
by western blot and zymography in order to detect pro- and active
MMP12.Objectives
Methods
The management of spinal deformity in children
with univentricular cardiac pathology poses significant challenges to
the surgical and anaesthetic teams. To date, only posterior instrumented
fusion techniques have been used in these children and these are
associated with a high rate of complications. We reviewed our experience
of both growing rod instrumentation and posterior instrumented fusion
in children with a univentricular circulation. Six children underwent spinal corrective surgery, two with cavopulmonary
shunts and four following completion of a Fontan procedure. Three
underwent growing rod instrumentation, two had a posterior fusion
and one had spinal growth arrest. There were no complications following
surgery, and the children undergoing growing rod instrumentation
were successfully lengthened. We noted a trend for greater blood
loss and haemodynamic instability in those whose surgery was undertaken
following completion of a Fontan procedure. At a median follow-up
of 87.6 months (interquartile range (IQR) 62.9 to 96.5) the median
correction of deformity was 24.2% (64.5° (IQR 46° to 80°) We believe that early surgical intervention with growing rod
instrumentation systems allows staged correction of the spinal deformity
and reduces the haemodynamic insult to these physiologically compromised
children. Due to the haemodynamic changes that occur with the completed
Fontan circulation, the initial scoliosis surgery should ideally
be undertaken when in the cavopulmonary shunt stage. Cite this article:
Tapered, fluted, modular, titanium stems are
increasingly popular in the operative management of Vancouver B2 and
selected B3 peri-prosthetic femoral fractures. We have reviewed
the results at our institution looking at stem survival and clinical
outcomes and compared this with reported outcomes in the literature.
Stem survival at a mean of 54 months was 96% in our series and 97%
for combined published cases. Review of radiology showed maintenance
or improvement of bone stock in 89% of cases with high rates of
femoral union. Favourable clinical outcome scores have reported
by several authors. No difference in survival or clinical scores
was observed between B2 and B3 fractures. Tapered stems are a useful
option in revision for femoral fracture across the spectrum of femoral
bone deficiency. Cite this article:
The aim of this prospective randomised study
was to compare the clinical and radiological results of a cemented
all-polyethylene Ultima acetabular component with those of a cementless
porous-coated acetabular component (PFC) following total hip replacement
(THR). A total of 287 patients received either a polyethylene acetabular
component (group A) or a cobalt–chromium porous-coated component
(group B) with an identical cemented femoral component and 28 mm
cobalt-chromium head, thus making it the largest study of its type.
Patients were evaluated radiologically and clinically using the
Harris hip score (HHS). Group A comprised 183 patients (73 male,
110 female) with a mean age of
71.3 years (55 to 89). Group B comprised 104 patients (48 male,
56 female) with a mean age of 69.8 years (56 to 89). A total of
16 patients (13 in Group A, three in Group B) did not have post-operative
data for analysis. The mean follow-up in group A was 7.52 years
(0.4 to 15.0) and in Group B 7.87 years (0.5 to 14.0). At final follow-up the mean HHS was similar between groups A
and B (74.5 (25 to 100) and 78.0 (37 to 100), respectively; p =
0.068). The total number of revisions for any cause was 28, 17 of
which were in group A and 11 in group B. The ten-year survivorship
was 86.8% (95% confidence interval (CI) 78.4 to 92.1) and 89.2%
(95% CI 78.3 to 94.8) for groups A and B, respectively (log-rank
p-value = 0.938). A total of 20 cemented and two cementless acetabular
components had evidence of acetabular radiolucencies or acetabular
component migration at last follow-up (p = 0.001). These results indicate that patients with a cemented all-polyethylene
and cementless porous-coated polyethylene lined acetabular component
have similar long-term clinical outcomes.
Tapered, fluted, modular, titanium stems have
a long history in Europe and are increasing in popularity in North America.
We have reviewed the results at our institution looking at stem
survival and clinical outcomes. Radiological outcomes and quality
of life assessments have been performed and compared to cylindrical
non-modular cobalt chromium stems. Survival at five years was 94%.
This fell to 85% at ten years due to stem breakage with older designs.
Review of radiology showed maintenance or improvement of bone stock
in 87% of cases. Outcome scores were superior in tapered stems despite
worse pre-operative femoral deficiency. Tapered stems have proved
to be a useful alternative in revision total hip arthroplasty across
the spectrum of femoral bone deficiency.
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.
There is little information about the management
of peri-prosthetic fracture of the humerus after total shoulder replacement
(TSR). This is a retrospective review of 22 patients who underwent
a revision of their original shoulder replacement for peri-prosthetic
fracture of the humerus with bone loss and/or loose components.
There were 20 women and two men with a mean age of 75 years (61
to 90) and a mean follow-up 42 months (12 to 91): 16 of these had
undergone a previous revision TSR. Of the 22 patients, 12 were treated
with a long-stemmed humeral component that bypassed the fracture.
All their fractures united after a mean of 27 weeks (13 to 94).
Eight patients underwent resection of the proximal humerus with
endoprosthetic replacement to the level of the fracture. Two patients
were managed with a clam-shell prosthesis that retained the original
components. The mean Oxford shoulder score (OSS) of the original
TSRs before peri-prosthetic fracture was 33 (14 to 48). The mean
OSS after revision for fracture was 25 (9 to 31). Kaplan-Meier survival
using re-intervention for any reason as the endpoint was 91% (95%
confidence interval (CI) 68 to 98) and 60% (95% CI 30 to 80) at
one and five years, respectively. There were two revisions for dislocation of the humeral head,
one open reduction for modular humeral component dissociation, one
internal fixation for nonunion, one trimming of a prominent screw
and one re-cementation for aseptic loosening complicated by infection,
ultimately requiring excision arthroplasty. Two patients sustained
nerve palsies. Revision TSR after a peri-prosthetic humeral fracture associated
with bone loss and/or loose components is a salvage procedure that
can provide a stable platform for elbow and hand function. Good
rates of union can be achieved using a stem that bypasses the fracture.
There is a high rate of complications and function is not as good as
with the original replacement.
There is a postulated association between increased serum metal ions and pseudotumour formation in patients with metal-on-metal hip replacements. The primary aim of this study was to assess the prevalence of pseudotumour in 31 asymptomatic patients with a large femoral head (LFH) metal-on-metal hip implant. This was compared to the prevalence of pseudotumour in 20 matched asymptomatic patients with a hip resurfacing (HRA) and 24 matched asymptomatic patients with a standard metal-on-polyethylene (MOP) total hip. A secondary objective was to assess possible correlation between increased serum metal ions and pseudotumour formation Ultrasound examination of the three groups was performed at a minimum follow up of two years. Serum metal ions were measured in the metal-on-metal LFH and HRA groups at a minimum of two years.Purpose
Method
Dislocation after revision total hip is a common complication. The purpose of this study was to assess whether a large femoral head (36/40mm) would result in a decreased dislocation rate compared to a standard head (32mm). A randomized clinical trial was undertaken to assess the effect of large femoral heads on dislocation after revision total hip. Patients undergoing revision hip arthroplasty at seven centers were randomized to 32mm head or 36/40mm head. Patients were stratified according to surgeon. Primary endpoint was dislocation. Rates were compared with Fishers exact test. Secondary outcome measures were quality of life: WOMAC, SF-36 and satisfaction. One hundred eighty four patients were randomized: 92 in the 32mm head group and 92 in the large head group. Baseline demographics were similar in the two groups. Patients were followed from two to five years postoperativelyPurpose
Method
Electrothermal arthroscopic capsulorrhaphy (ETAC) was a technology introduced for orthopaedic surgery without good scientific clinical evidence supporting its use. This multicentre randomized clinical trial provides the scientific clinical evidence comparing ETAC to Open Inferior Capsular Shift (ICS), by measuring disease-specific quality of life at 2-years post-operatively, in patients with shoulder instability due to capsular redundancy. Fifty-four subjects (37 females and 17 males; mean age 23.3 years (SD = 6.9; 15–44 years) with multidirectional instability (MDI) or multidirectional laxity with antero-inferior instability (MDL-AII) were randomized intra-operatively to ETAC (n = 28) or Open ICS (n = 26) using concealed envelopes, computer-generated, variable block randomization with stratification by surgeon and type of instability. Outcomes were measured at baseline, 3 and 6 months, 1 and 2 years. The Western Ontario Shoulder Instability (WOSI) Index is a quality of life outcome measure that is scored on a visual analog scale from 0 to 100, where a higher score represents better quality of life. Two functional assessments included the American Shoulder and Elbow Society (ASES) Score and the Constant Score. Post-operative recurrent instability and surgical time were also measured. Analyses included ANOVA of repeated measures with Bonferroni adjustments for multiple comparisons, Chi-square and independent t-tests (p < 0.05).Purpose
Method
This prospective, expertise-based randomized clinical trial compares arthroscopic to open shoulder stabilization by measuring the disease-specific quality of life outcome in patients with traumatic unidirectional anterior shoulder instability, and determining the incidence of recurrent instability at 2-years post-operatively. One hundred and ninety-six patients were randomly allocated to arthroscopic (n=98) or open (n=98) repair using an expertise-based approach with a surgeon specializing in one type of surgery. Randomization was performed using computer-generation, variable block sizes and concealed envelopes. Outcomes were measured at baseline, 3 and 6 months, 1 and 2 years post-operatively. These outcomes included the Western Ontario Shoulder Instability (WOSI) Index quality of life outcome and the American Shoulder and Elbow Society (ASES) functional outcome. Both outcomes were measured on a visual analog scale from 0 to 100, where a higher score represents better quality of life or function. Recurrent instability was categorized as traumatic/atraumatic, and as a subluxation/dislocation. Analyses included ANOVA of repeated measures and independent t-tests. Bonferroni adjustments for pairwise contrasts were made for multiple comparisons. Chi-squared analyses were performed on recurrence. Statistical significance was reported at p < 0.05.Purpose
Method
The outcome following isolated liner exchange for revision knee arthroplasty, while an attractive option for its simplicity, has a mixed outcome reported in the literature. We report our experience in patients who had a minimum of two years follow-up. From our database we identified 44 cases in 41 patients who had an isolated liner exchange for a failed primary knee replacement. Twenty were female and the mean body mass index was 33 (range 20 to 49). The mean time to revision from their index procedure was 76 months (range 8 to 152). The mean age at revision was 69 years (range 45 to 90). Patients were assessed by use of validated quality of life questionnaires: Oxford-12, UCLA Activity Level, WOMAC and SF-12. Patients current scores were compared to pre-operative scores in 19 cases. Radiographs were assessed for polyethylene wear, osteolysis and alignment with respect to the mechanical axis. Intra-operative findings were compared to radiographic findings.Purpose
Method
Scapulothoracic fusion (STF) for painful winging
of the scapula in neuromuscular disorders can provide effective pain
relief and functional improvement, but there is little information
comparing outcomes between patients with dystrophic and non-dystrophic
conditions. We performed a retrospective review of 42 STFs in 34
patients with dystrophic and non-dystrophic conditions using a multifilament
trans-scapular, subcostal cable technique supported by a dorsal
one-third semi-tubular plate. There were 16 males and 18 females
with a mean age of 30 years (15 to 75) and a mean follow-up of 5.0
years (2.0 to 10.6). The mean Oxford shoulder score improved from
20 (4 to 39) to 31 (4 to 48). Patients with non-dystrophic conditions
had lower overall functional scores but achieved greater improvements
following STF. The mean active forward elevation increased from
59° (20° to 90°) to 97° (30° to 150°), and abduction from 51° (10°
to 90°) to 83° (30° to 130°) with a greater range of movement achieved
in the dystrophic group. Revision fusion for nonunion was undertaken
in five patients at a mean time of 17 months (7 to 31) and two required
revision for fracture. There were three pneumothoraces, two rib
fractures, three pleural effusions and six nonunions. The main risk
factors for nonunion were smoking, age and previous shoulder girdle surgery. STF is a salvage procedure that can provide good patient satisfaction
in 82% of patients with both dystrophic and non-dystrophic pathologies,
but there was a relatively high failure rate (26%) when poor outcomes
were analysed. Overall function was better in patients with dystrophic
conditions which correlated with better range of movement; however,
patients with non-dystrophic conditions achieved greater functional
improvement.
The purpose of this study was to compare and evaluate the cost-effectiveness of the MIS Anterolateral Approach to that of the MIS Posterolateral and MIS Direct Lateral Approach. A prospective randomized control trial was designed and conducted to compare the MIS Anterolateral Approach to that of the MIS Posterolateral and MIS Direct Lateral Approach. Contemporary methods for economic evaluation were used to ascertain direct and indirect costs (in Canadian dollars) along with clinical effectiveness outcomes (SF6D and Pat5D utility measures). University and hospital ethics was obtained and patients were recruited and consented to participate in the RCT resulting in the assignment of 130 patients MIS hip arthroplasty procedures. Baseline patient demographics, comorbidity, quality of life, and utility were obtained for all patients. In-hospital costing data was obtained including operating room and patient room costs as well as medication, rehab and complications. Post-discharge costs were calculated from direct and indirect costs of medication, rehab, medical costs and complications until one year post-operatively. Clinical effectiveness measures were administered at intervals until one year post-operatively.Purpose
Method
This review summarises the opinions and conclusions
reached from a symposium on infected total knee replacement (TKR)
held at the British Association of Surgery of the Knee (BASK) annual
meeting in 2011. The National Joint Registry for England and Wales
reported 5082 revision TKRs in 2010, of which 1157 (23%) were caused
by infection. The diagnosis of infection beyond the acute post-operative
stage relies on the identification of the causative organism by
aspiration and analysis of material obtained at arthroscopy. Ideal
treatment then involves a two-stage surgical procedure with extensive
debridement and washout, followed by antibiotics. An articulating
or non-articulating drug-eluting cement spacer is used prior to
implantation of the revision prosthesis, guided by the serum level
of inflammatory markers. The use of a single-stage revision is gaining popularity
and we would advocate its use in certain patients where the causative
organism is known, no sinuses are present, the patient is not immunocompromised,
and there is no radiological evidence of component loosening or
osteitis. It is our opinion that single-stage revision produces high-quality
reproducible results and will soon achieve the same widespread acceptance
as it does in infected hip arthroplasty.
Bearing surfaces used for total hip arthroplasty must have characteristics including bio-compatibility, low friction and low wear rate. Bearing combinations are generally characterised as Soft on Hard/Hard. In general, all newer bearing combinations have reduced wear but may present with other issues that impact on patient outcomes. The Australian Orthopaedic Association – National Joint Replacement Registry classifies bearing surfaces into six categories. These are metal on polyethylene, ceramic on polyethylene, metal on metal, ceramic on ceramic, ceramic on metal and a sixth category relating to a small number of procedures where the bearing surface is yet to be classified. 147,422 conventional total hip arthroplasty procedures have been recorded by the Registry between 1 September 1999 and 31 December 2008 and analysis has been performed of the cumulative percentage revision in relation to bearing surface.Introduction
Materials
Bone morphogenetic proteins (BMPs) are members of the TGF-beta superfamily of growth factors and are known to regulate proliferation and expression of the differentiated phenotype of chondrocytes, osteoblasts, and osteoclasts. To investigate the osteoblastic differentiation gene expressions that contribute to BMP-7 dependent ostogenesis, we performed gene expression profiling of BMP-7-treated mouse bone marrow stromal cells. D1 cells (mouse bone marrow stromal cells) were cultured in osteogenic differentiation medium (ODM) for 3 days, and then treated with BMP-7 for 24 hr. Total RNA was extracted using Trizol, purified using RNeasy columns. Total RNA was amplified and purified using the Ambion Illumina RNA amplification kit to yield biotinylated cRNA. The data analysis up- and down-regulation developmental processes (anterior/posterior patterning, ectoderm development, embryogenesis, gametogenesis, mesoderm development, other development process, and segment specification) genes expression fold.Introduction
Methods
The non-operative treatment of idiopathic clubfoot has become increasingly accepted worldwide as the initial standard of care. The Ponseti method has become particularly popular as a result of published short and long-term success rates in North America. Non-compliance with abduction bracing has been proven to be a major risk factor for recurrence of clubfoot. The purpose of this retrospective study was to identify those patients who were non-compliant with the abduction bracing post casting and to then assess the rate and severity of recurrence. One-hundred and fifty children (184 feet) with unilateral or bilateral clubfoot who were treated with the Ponseti method by the senior author from 1999 to 2008 were reviewed. We identified those patients who were non-compliant with the abduction bracing. Compliance was defined as three months full time wear followed by twelve months night-time/nap-time wear. Recurrence was classified as minor, defined as those requiring an extra-articular surgical procedure and major, requiring an intra-articular procedure. We identified fifty children with seventy clubfeet who were followed up for a minimum of 12 months. None of these patients were compliant with brace wearing. Of the 70 feet, 40 (57%) required surgical intervention. There were 30 (43%) feet with no clinical recurrence. In 5 of the bilateral cases only one of the feet had required corrective surgery. In the 29 patients who required surgical intervention we identified 52 procedures (37 extra-articular and 15 intra-articular). Compliance with the post correction abduction bracing protocol is crucial to avoid recurrence of a clubfoot deformity treated with the Ponseti method. Despite non-compliance however there is a significant proportion of patients who do not require any surgical intervention. We recommend initiating the Ponseti technique on all patients with clubfeet rather than being selective due to anticipated compliance issues with the family.
UK military forces have been deployed in Afghanistan since 2006 as part of the International Stabilisation Assistance Force. The Operation is supported by a 50-bedded hospital. In 2007 the Defence Medical Services introduced a massive haemorrhage policy. In asymmetric warfare gunshot wounds (GSW), improvised explosive devices (IED) and mine injuries are prevalent and we hypothesized that they would require significant blood products. We prospectively collected data from consecutive trauma resuscitations over 3 months (January to March 2008). Pre-hospital time points, mechanism of injury, injury distribution, injury severity score (ISS), new injury severity score (NISS), surgical procedures, blood product utilisation and outcome were recorded. 115 trauma resuscitations were performed over the study period. Median pre-hospital time was 95 minutes (range 30–325), with median 64 minutes to the arrival of the Medical Emergency Response Team helicopter. The cause of injury was landmine (20), IED (31) and GSW (40); mean number of involved body systems was 1.4, 1.8 and 1.5 respectively and injured structures 2.8, 3.5 and 2.3 respectively (IED>
GSW p<
0.05). Mean ISS was 16, 16.8, 14.9 and NISS 18.7, 20.9, and 17.9 respectively. Blood transfusion was required in 3 mine, 14 IED and 17 GSW casualties (mine<
IED &
GSW, p<
0.05) with 10.6, 11.4, and 13.9 units of blood transfused per casualty. Injury severity for casualties is high with multiple injuries to body systems irrespective of mechanism. Anti-personnel mine injuries were significantly less likely to require transfusion. Large quantities of blood products were still required when necessary in all mechanisms of trauma. It is therefore recommended that during the pre-hospital time the major transfusion protocol should be placed on stand-by.
We suggested a new concept of buffered implant fixation. It is a cementless fixation using a buffer instead of the cement between the bone and the implant. We investigated the feasibility of the buffered implant fixation using a rat model. In our previous study, we measured the amount of bone around the implant to compare the buffered implant fixation with the cemented fixation. The results showed the difference in change of Bone Volume/Total Volume (BV/TV) with time between the buffered fixation and the cemented fixation. Now, in this study, we are comparing the mechanical interface strength between two fixations. After micro CT scanning, the specimens were used for mechanical push-out test to measure the interface shear strength at the buffer-bone or cement-bone interface. The distal side of the femur was carefully removed to expose the whole distal region of the implant while the proximal side of femur was cut carefully with diamond saw (Metsaw, R&
B Inc., Korea) until the proximal end of cement or buffer is exposed. The femur was embedded into a push-out jig with a plaster. The push-out jig was mounted in a material testing machine (KSU-10M, Kyungsung testing machine, Korea) and loaded at a rate of 0.01mm/s. The apparent interface strength was calculated by dividing the peak force by the surface area of the buffer or cement. After 2 weeks, the apparent interface strength is 217.0 ± 280.0(average ± standard deviation) for buffer and 472.4 ± 381.1 for cement; after 4 weeks, 92.9 ± 67.6 and 268.1 ± 197.9; after 12 weeks, 441.9 ± 467.1 and 201.8 ± 132.3, respectively. The buffered fixation showed gain in strength with time while the cemented fixation showed reverse tendency but the interaction by ANOVA was not significant (p=0.125). Even though the excellence of buffer fixation was not clearly confirmed because of small sample size and high variance, the feasibility of the buffer fixation was shown. However, further studies are necessary to improve the buffered implant fixation. To enhance the cell adhesion and biocompatibility, it is necessary to modify the surface of polyetheretherketone (PEEK) such as by plasma treatment or biological coating. Also, an animal test using a higher level animal such as dog or pig is necessary.
Spontaneous osteonecrosis of the knee (SPONK) usually involves a single condyle or plateau. The medial femoral condyle is most often involved and spontaneous osteonecrosis of medial tibial plateau is a rare condition, representing only 2 % of all necrosis reported in the knee. Therefore, SPONK with both involvement of medial femoral condyle(MFC) and medial tibial plateau(MTP) might be extremely rare. SPONK in each MFC or MTP respectively might be extended into corresponding side of the knee at their advanced final stage, howevere, in that situations, significant degenerative change would accompany and it might be difficult to differentiate final staged SPONK form severe osteoarthritis. To the best of our knowledge, SPONK affecting both medial femoral condyle and medial tibial plateau without significant secondary osteoarthritis changes is not reported, even though it was difficult to know which occurred first. We experienced 3 patients with histologically proven osteonecrosis of the medial tibial condyle and medial tibial plateau, and report their radiologic features. All 3 patients showed similar ridiograhic patterns. Medial portion of medial tibial plateau and lateral portion of medial femoral condyle showed longitudinal fracture like-subchondral collapse. Standing anteroposterior radiograph at 30 degree knee flexion showed well fitted features such as “locked” medial condyle. Varus angulation was present. Significant degenerative changes was not shown except for subchondral sclerosis. T1-weighted coronal and Fat suppressed T2-weighted MR images showed subchondral collapse with ill-defined diffuse bone marrow edema changes on both tibial and femoral condyles. At surgical findings, longitudinal track-like groove was shown in both medial femoral condyle and medial tibial plateau. Articular cartilage was denuded and showed glistening surface with bone defect of lateral side of medial femoral condyle and medial side of tibial articular surface. Histological analysis shows necrotic bone, surrounded by an area of fibrovascular granulation tissue on both femoral and tibial sides. Total knee arthoplasty was performed in all 3 patients. As a result of very low prevalence of both involvement of MFC and MTP and limited number of our cases, we could not conclude that radiologic features in our cases are typical radiologic pattern of both involvement. However, based on our cases, we believe that this characteristic radiologic features may considered as one of the possible various radiologic findings of simultaneous involvement in MFC and MTP and allow diagnosis for SPONK with both involvement in MFC and MTP to be facilitated.
The cemented and cementless implant fixations are popular in orthopaedic arthroplasty. However, these implant fixations have some problems such as cement failure, wear debris, stress shielding, revision and so on. To overcome these problems, we are developing a new concept of buffered implant fixation which uses a bone-friendly buffer between the implant and the bone. In this study, we performed a finite element analysis to evaluate the buffered implant fixation in comparison with cemented and cementless implant fixations in mechanical aspects. In addition, we investigated the effect of buffer taper angle to the stress distribution in the buffered implant fixation. Three-dimensional FEA of the cemented, cementless and buffered fixation were performed using the ABAQUS program. In these FEA, the ‘standardized femur’, which is the composite femur model supplied by Pacific Research Lab., was used as the bone model and the CPT stem and the Versys Fibermetal Midcoat stem were modeled for the cemented fixation and the cementless fixation, respectively. These three-dimensional models were meshed using the tetrahedral elements with 4 nodes (C3D4) and the additional contact definitions. The buffered implant fixation is similar with the polished cemented fixation except the material between the implant and the bone. The polyetheretherketone (PEEK) was selected as the buffer material. Also, several taper angles of buffer were simulated to change the stress distributions in the buffered fixation. The external load three times of mean body weight (74.3 kg) was cyclically loaded at the femoral head with the angle of 20° in adduction and 6° in flexion while the distal end of femur was fixed. In the buffered implant fixation, the taper-locked effects were observed. The buffered fixation had greater cyclic compression for the bone compared to the cemented fixation. Also, the failure probability of the buffer in the buffered fixation was less than that of the cement in the cemented fixation. The risk factors in the buffer were 0.148 for the tension and 0.176 for the compression while, the risk factors of cement in the polished cemented implant fixation were over than 1. Moreover, the buffered fixation had widely distributed compression compared to the cementless fixation and the stress distribution could be modified easily to change the taper angle of buffer. The FEA results showed that the buffered implant fixation would provide an appropriate mechanical environment.
The anterior pelvic plane has been introduced as a concept of the reference plane to image free navigation-assisted cup placement of total hip arthroplasty. With the neutral pelvis, the anteversion relative to the conventional coordinate system is equal to the that of relation to the anatomical coordinate system. This is the rationale of image free navigation system. But, currently, two major concerns about image-free navigation assisted total hip arthroplasty are tilting of anatomic coordinate system and the cutaneous palpation procedure. Therefore, it was the goal of this study to provide both the bone anterior pelvic plane (Bone_APP) and the overlying soft tissue plane (Soft_APP) simultaneously, and to find possible correlations of biometrical parameters and effect of ante-version were an additional motivation of this study. 23 Korean adult patients underwent image-free navigation-assisted total hip arthroplasty. The tilting of Bone_APP, soft tissue thickness on ASIS, pubis, and then tilting of Soft_APP, and anteversion of cup were measured with reconstructed CT and 3D workstation system. The average age was 66.1 years, the average height was 162.5cm at a weight of 59.2 kg. The average body mass index was 22.3. And the average lumbar lordosis was measured as 30.4 degrees. The soft tissue on the level of the pubis was 17.6 mm thicker than that on the level of ASIS in average. In all cases, Soft_APP was positive, that is from 3.5 to 16.5 degrees of backward rotation. We also found a high-intersubject variability in the Bone_APP from 13.4 of forward rotatation to 23 degrees of backward rotation. Overall, there are no correlation between biometrical parameters and difference of navigated data to others measured on CT. Averaged navigated data was 22.4 degrees. The average anatomic, operative, and planar anteversion were 29.2, 27.2 and 21.3 degrees respectively. The value of anteversion measured on the transverse plane and sagittal plane shows higher than navigated anteversion in paired comparison. This could be comprehended that the navigation system had under-estimated the anteversion than that of transverse and sagittal plane, This means navigation assessed pelvic plane as back ward tilting rather than forward tilting intraoperatively. None of cases showed the Bone_APP was parallel to conventional coordinate system. Comparing the variable bone APP tilt, all of cases showed an backward tilted soft tissue plane. There were no correlation between bone APP and biometrical parameters. Overall, navigated data were less than anatomic and operative anteversion. Rather than anatomic coordinate system (Bone-APP), backward tilting due to overlying soft tissue (Soft-APP) might to make the navigated data have the tendency to under-estimated the anteversion of cup measured with CT. In conclusion, anterior pelvic plane does not satisfactory reliability with should be easily identified during operation. Image-free navigation system would take into account variations of individuals including both bone tilt and soft tissue plane.
We report the outcome at ten to 15 years of two-stage revision for hip infection in 99 patients using the Prostalac articulated hip spacer system. All the patients were contacted to determine their current functional and infection status using the Oxford-12, Short form-12, and Western Ontario and McMaster University Osteoarthritis Index questionnaires. A total of 11 of the 99 patients had a further infection, of whom seven responded to repeat surgery with no further sequelae. The mean interval between the stages was five months (1 to 36). We were able to review 48 living patients, with a mean age of 72 years (46 to 86), 34 (71%) of whom provided health-related quality-of-life outcome scores. The mean follow-up was 12 years (10 to 15). The long-term success rate was 89% and with additional surgery this rose to 96%. The mean global Western Ontario and McMaster University Osteoarthritis Index score was 80.6 ( Two-stage revision for hip infection using a Prostalac interim spacer offers a predictable and lasting solution for patients with this difficult problem.
There is an ever-increasing clinical need for the regeneration and replacement of tissue to replace soft tissue lost due to trauma, disease and cosmetic surgery. A potential alternative to the current treatment modalities is the use of tissue engineering applications using mesenchymal stem cells that have been identified in many tissue including the infrapatellar fat pad. In this study, stem cells isolated from the infrapatellar fat pad were characterised to ascertain their origin, and allowed to undergo adipogenic differentiation to confirm multilineage differentiation potential. The infrapatellar fat pad was obtained from total knee replacement for osteoarthritis. Cells were isolated and expanded in monolayer culture. Cells at passage 2 stained strongly for CD13, CD29, CD44, CD90 and CD105 (mesenchymal stem cell markers). The cells stained poorly for LNGFR and STRO1 (markers for freshly isolated bone marrow derived stem cells), and sparsely for 3G5 (pericyte marker). Staining for CD34 (haematopoetic marker) and CD56 (neural and myogenic lineage marker) was negative. For adipogenic differentiation, cells were cultured in adipogenic inducing medium consisting of basic medium with 10ug/ml insulin, 1uM dexamthasone, 100uM indomethacin and 500uM 3-isobutyl-1-methyl xanthine. By day 16, many cells had lipid vacuoles occupying most of the cytoplasm. On gene expression analyses, the cells cultured under adipogenic conditions had almost a 1,000 fold increase in expression of peroxisome proliferator-activated receptor gamma-2 (PPAR gamma-2) and 1,000,000 fold increase in expression of lipoprotein lipase (LPL). Oil red O staining confirmed the adipogenic nature of the observed vacuoles and showed failure of staining in control cells. Our results show that the human infrapatellar fat pad is a viable potential autogeneic source for mesenchymal stem cells capable of adipogenic differentiation as well as previously documented ostegenic and chondrogenic differentiation. This cell source has potential use in tissue engineering applications.
Fractures of the odontoid in children with an open basilar synchondrosis differ from those which occur in older children and adults. We have reviewed the morphology of these fractures and present a classification system for them. There were four distinct patterns of fracture (types IA to IC and type II) which were distinguished by the site of the fracture, the degree of displacement and the presence or absence of atlantoaxial dislocation. Children with a closed synchondrosis were classified using the system devised by Anderson and D’Alonzo. Those with an open synchondrosis had a comparatively lower incidence of traumatic brain injury, a higher rate of missed diagnosis and a shorter mean stay in hospital. Certain subtypes (type IA and type II) are likely to be missed on plain radiographs and therefore more advanced imaging is recommended. We suggest staged treatment with initial stabilisation in a Halo body jacket and early fusion for those with unstable injuries, severe displacement or neurological involvement.
Rotator cuff tears are a common cause of shoulder pain and dysfunction. Therefore, the purpose of this in-vitro biomechanical study was conducted to determine the effects of simulated tears and subsequent repairs of the rotator cuff tendons on joint kinematics. Eight paired fresh-frozen cadaveric shoulder specimens (mean age: 66.0 ± 8.7 years) were tested using a custom loading apparatus designed to simulate unconstrained motion of the humerus. Cables were sutured to the rotator cuff tendons and the deltoid. Loads were applied to the cables based on variable ratios of electromyographic (EMG) data and average physiological cross-sectional area (pCSA) of the muscles. An electromagnetic tracking device (Flock of Birds, Ascension Technologies, VT) was used to provide real-time feedback of abduction angle, to which the loading ratio was varied correspondingly. 2 and 4cm tears were made starting at the rotator cuff interval and extending posteriorly. Specimens were randomised to receive either single or double suture anchor repair. In order to quantify repeatability, five successive tests on each of the intact, torn, and repaired cases were performed. Statistical significance was established using One- and Two-way Repeated Measured ANOVAs (p<
0.05). Rotator cuff tears caused alteration in glenohumeral kinematics. A 2cm tear caused the humerus to consistently move posterior through the arc of abduction; however, as the tear increased to 4cm the humerus moved anteriorly, returning towards the intact state. Double row suture anchor repairs more accurately reproduced the kinematics of the intact specimen compared to single row suture anchor repair. The initial posterior displacement in the plane of elevation with the sectioning of the supraspinatus is related to the diminished anterior moment on the glenohumeral joint. As the tear proceeds into the infraspinatus, the anterior and posterior forces become more balanced and a return to near normal intact kinematics was observed. This study demonstrates that double row suture anchor repair more accurately reproduces active shoulder kinematics of the intact shoulder specimens.
This study compared the effect of a computer-assisted and a traditional surgical technique on the kinematics of the glenohumeral joint during passive abduction after hemiarthroplasty of the shoulder for the treatment of fractures. We used seven pairs of fresh-frozen cadaver shoulders to create simulated four-part fractures of the proximal humerus, which were then reconstructed with hemiarthroplasty and reattachment of the tuberosities. The specimens were randomised, so that one from each pair was repaired using the computer-assisted technique, whereas a traditional hemiarthroplasty without navigation was performed in the contralateral shoulder. Kinematic data were obtained using an electromagnetic tracking device. The traditional technique resulted in posterior and inferior translation of the humeral head. No statistical differences were observed before or after computer-assisted surgery. Although it requires further improvement, the computer-assisted approach appears to allow glenohumeral kinematics to more closely replicate those of the native joint, potentially improving the function of the shoulder and extending the longevity of the prosthesis.
We performed a retrospective review of case notes and X-rays. A control group of 22 patients, in whom anterior surgery was completed, matched to age, sex and type of curve, was used.
Of the seven patients with lost signal three were syndromic and four were associated with syrinx. In all seven, loss of signal occurred on clamping of segmental vessels. All seven had no residual neurological deficit post-operatively and had uncomplicated posterior correction the following week. All four patients in whom inadequate correction was achieved after anterior release and repositioning had idiopathic curves. Of these two were thoracic and two were thoracolumbar. Mean pre-operative Cobb angle was 67 (range 59–85) compared to a mean of 56 (range 42–68) in the control group. Mean pre-operative stiffness index was 91% (range 85%–100%) compared to a mean stiffness index of 65% (range 53–80) in the control population.