Little biomechanical information is available about kinematically aligned (KA) total knee arthroplasty (TKA). The purpose of this study was to simulate the kinematics and kinetics after KA TKA and mechanically aligned (MA) TKA with four different limb alignments. Bone models were constructed from one volunteer (normal) and three patients with three different knee deformities (slight, moderate and severe varus). A dynamic musculoskeletal modelling system was used to analyse the kinematics and the tibiofemoral contact force. The contact stress on the tibial insert, and the stress to the resection surface and medial tibial cortex were examined by using finite element analysis.Objectives
Materials and Methods
To assess the effect of high tibial and distal femoral osteotomies
(HTO and DFO) on the pressure characteristics of the ankle joint. Varus and valgus malalignment of the knee was simulated in human
cadaver full-length legs. Testing included four measurements: baseline
malalignment, 5° and 10° re-aligning osteotomy, and control baseline
malalignment. For HTO, testing was rerun with the subtalar joint
fixed. In order to represent half body weight, a 300 N force was applied
onto the femoral head. Intra-articular sensors captured ankle pressure.Aims
Materials and Methods
Nail patella syndrome (NPS) is a skeletal dysplasia with patellofemoral
dysfunction as a key symptom. We present the first in-depth radiological
evaluation of the knee in a large series of NPS patients and describe
the typical malformations. Conventional radiological examination of 95 skeletally mature
patients with NPS was performed. Patellar morphology was classified
according to the Wiberg classification as modified by Baumgartl
and Ficat criteria, and trochlear shape was classified according
to the Dejour classification.Aim
Patients and Methods
Tibial nonunion represents a spectrum of conditions
which are challenging to treat, and optimal management remains unclear
despite its high rate of incidence. We present 44 consecutive patients
with 46 stiff tibial nonunions, treated with hexapod external fixators
and distraction to achieve union and gradual deformity correction.
There were 31 men and 13 women with a mean age of 35 years (18 to
68) and a mean follow-up of 12 months (6 to 40). No tibial osteotomies
or bone graft procedures were performed. Bony union was achieved
after the initial surgery in 41 (89.1%) tibias. Four persistent
nonunions united after repeat treatment with closed hexapod distraction,
resulting in bony union in 45 (97.8%) patients. The mean time to
union was 23 weeks (11 to 49). Leg-length was restored to within
1 cm of the contralateral side in all tibias. Mechanical alignment
was restored to within 5° of normal in 42 (91.3%) tibias. Closed
distraction of stiff tibial nonunions can predictably lead to union
without further surgery or bone graft. In addition to generating
the required distraction to achieve union, hexapod circular external
fixators can accurately correct concurrent deformities and limb-length
discrepancies. Cite this article:
The aim of the current study was to analyse the effects of posterior cruciate ligament (PCL) deficiency on forces of the posterolateral corner structure and on tibiofemoral (TF) and patellofemoral (PF) contact force under dynamic-loading conditions. A subject-specific knee model was validated using a passive flexion experiment, electromyography data, muscle activation, and previous experimental studies. The simulation was performed on the musculoskeletal models with and without PCL deficiency using a novel force-dependent kinematics method under gait- and squat-loading conditions, followed by probabilistic analysis for material uncertain to be considered.Objectives
Methods
We report the outcomes of 20 patients (12 men,
8 women, 21 feet) with Charcot neuro-arthropathy who underwent correction
of deformities of the ankle and hindfoot using retrograde intramedullary
nail arthrodesis. The mean age of the patients was 62.6 years (46
to 83); their mean BMI was 32.7 (15 to 47) and their median American
Society of Anaesthetists score was 3 (2 to 4). All presented with
severe deformities and 15 had chronic ulceration. All were treated
with reconstructive surgery and seven underwent simultaneous midfoot
fusion using a bolt, locking plate or a combination of both. At
a mean follow-up of 26 months (8 to 54), limb salvage was achieved
in all patients and 12 patients (80%) with ulceration achieved healing
and all but one patient regained independent mobilisation. There was
failure of fixation with a broken nail requiring revision surgery
in one patient. Migration of distal locking screws occurred only
when standard screws had been used but not with hydroxyapatite-coated
screws. The mean American Academy of Orthopaedic Surgeons Foot and
Ankle (AAOS-FAO) score improved from 50.7 (17 to 88) to 65.2 (22
to 88), (p = 0.015). The mean Short Form (SF)-36 Health Survey Physical
Component Score improved from 25.2 (16.4 to 42.8) to 29.8 (17.7
to 44.2), (p = 0.003) and the mean Euroqol EQ‑5D‑5L score improved
from 0.63 (0.51 to 0.78) to 0.67 (0.57 to 0.84), (p = 0.012). Single-stage correction of deformity using an intramedullary
hindfoot arthrodesis nail is a good form of treatment for patients
with severe Charcot hindfoot deformity, ulceration and instability
provided a multidisciplinary care plan is delivered. Cite this article:
Rotator cuff tears are among the most frequent upper extremity injuries. Current treatment strategies do not address the poor quality of the muscle and tendon following chronic rotator cuff tears. Hypoxia-inducible factor-1 alpha (HIF-1α) is a transcription factor that activates many genes that are important in skeletal muscle regeneration. HIF-1α is inhibited under normal physiological conditions by the HIF prolyl 4-hydroxylases (PHDs). In this study, we used a pharmacological PHD inhibitor, GSK1120360A, to enhance the activity of HIF-1α following the repair of a chronic cuff tear, and measured muscle fibre contractility, fibrosis, gene expression, and enthesis mechanics. Chronic supraspinatus tears were induced in adult rats, and repaired 28 days later. Rats received 0 mg/kg, 3 mg/kg, or 10 mg/kg GSK1120360A daily. Collagen content, contractility, fibre type distribution and size, the expression of genes involved in fibrosis, lipid accumulation, atrophy and inflammation, and the mechanical properties of the enthesis were then assessed two weeks following surgical repair.Objectives
Methods
Stress fractures occurring in the pubis and ischium
after peri-acetabular osteotomy (PAO) are not well recognised, with
a reported incidence of 2% to 3%. The purpose of this study was
to analyse the incidence of stress fracture after Bernese PAO under
the care of two high-volume surgeons. The study included 359 patients
(48 men, 311 women) operated on at a mean age of 31.1 years (15
to 56), with a mean follow-up of 26 months (6 to 64). Complete follow-up
radiographs were available for 348 patients, 64 of whom (18.4%)
developed a stress fracture of the inferior pubic ramus, which was
noted at a mean of 9.1 weeks (5 to 55) after surgery. Most (58;
91%) healed. In 40 of the patients with a stress fracture (62.5%),
pubic nonunion also occurred. Those with a stress fracture were
significantly older (mean 33.9 years (16 to 50) Cite this article:
Patients with an acute Achilles tendon rupture (ATR) take a long
time to heal, have a high incidence of deep vein thrombosis (DVT)
and widely variable functional outcomes. This variation in outcome
may be explained by a lack of knowledge of adverse factors, and
a subsequent shortage of appropriate interventions. A total of 111 patients (95 men, 16 women; mean age 40.3, standard
deviation 8.4) with an acute total ATR were prospectively assessed.
At one year post-operatively a uniform outcome score, Achilles Combined
Outcome Score (ACOS), was obtained by combining three validated,
independent, outcome measures: Achilles tendon Total Rupture Score,
heel-rise height test, and limb symmetry heel-rise height. Predictors
of ACOS included treatment; gender; age; smoking; body mass index;
time to surgery; physical activity level pre- and post-injury; symptoms; quality
of life and incidence of DVT. Aims
Patients and Methods
Fractures around total knee arthroplasties pose
a significant surgical challenge. Most can be managed with osteosynthesis
and salvage of the replacement. The techniques of fixation of these
fractures and revision surgery have evolved and so has the assessment
of outcome. This specialty update summarises the current evidence
for the classification, methods of fixation, revision surgery and
outcomes of the management of periprosthetic fractures associated
with total knee arthroplasty. Cite this article:
The fundamental concept of open reduction and internal fixation
(ORIF) of ankle fractures has not changed appreciably since the
1960s and, whilst widely used, is associated with complications
including wound dehiscence and infection, prominent hardware and
failure. Closed reduction and intramedullary fixation (CRIF) using
a fibular nail, wires or screws is biomechanically stronger, requires
minimal incisions, and has low-profile hardware. We hypothesised
that fibular nailing in the elderly would have similar functional
outcomes to standard fixation, with a reduced rate of wound and
hardware problems. A total of 100 patients (25 men, 75 women) over the age of 65
years with unstable ankle fractures were randomised to undergo standard
ORIF or fibular nailing (11 men and 39 women in the ORIF group,
14 men and 36 women in the fibular nail group). The mean age was
74 years (65 to 93) and all patients had at least one medical comorbidity. Complications,
patient related outcome measures and cost-effectiveness were assessed
over 12 months.Aims
Patients and Methods
Risk of revision following total knee arthroplasty (TKA) is higher
in patients under 55 years, but little data are reported regarding
non-revision outcomes. This study aims to identify predictors of
dissatisfaction in these patients. We prospectively assessed 177 TKAs (157 consecutive patients,
99 women, mean age 50 years; 17 to 54) from 2008 to 2013. Age, gender,
implant, indication, body mass index (BMI), social deprivation,
range of movement, Kellgren-Lawrence (KL) grade of osteoarthritis
(OA) and prior knee surgery were recorded. Pre- and post-operative
Oxford Knee Score (OKS) as well as Short Form-12 physical (PCS)
and mental component scores were obtained. Post-operative range
of movement, complications and satisfaction were measured at one
year.Aims
Patients and Methods
Posterior tilt of the pelvis with sitting provides biological
acetabular opening. Our goal was to study the post-operative interaction
of skeletal mobility and sagittal acetabular component position. This was a radiographic study of 160 hips (151 patients) who
prospectively had lateral spinopelvic hip radiographs for skeletal
and implant measurements. Intra-operative acetabular component position
was determined according to the pre-operative spinal mobility. Sagittal
implant measurements of ante-inclination and sacral acetabular angle were
used as surrogate measurements for the risk of impingement, and
intra-operative acetabular component angles were compared with these.Aims
Materials and Methods
Although vertebroplasty is very effective for relieving acute pain from an osteoporotic vertebral compression fracture, not all patients who undergo vertebroplasty receive the same degree of benefit from the procedure. In order to identify the ideal candidate for vertebroplasty, pre-operative prognostic demographic or clinico-radiological factors need to be identified. The objective of this study was to identify the pre-operative prognostic factors related to the effect of vertebroplasty on acute pain control using a cohort of surgically and non-surgically managed patients. Patients with single-level acute osteoporotic vertebral compression fracture at thoracolumbar junction (T10 to L2) were followed. If the patients were not satisfied with acute pain reduction after a three-week conservative treatment, vertebroplasty was recommended. Pain assessment was carried out at the time of diagnosis, as well as three, four, six, and 12 weeks after the diagnosis. The effect of vertebroplasty, compared with conservative treatment, on back pain (visual analogue score, VAS) was analysed with the use of analysis-of-covariance models that adjusted for pre-operative VAS scores.Objectives
Patients and Methods
We report the clinical and radiographic outcomes
of 208 consecutive femoral revision arthroplasties performed in 202
patients (119 women, 83 men) between March 1991 and December 2007
using the X-change Femoral Revision System, fresh-frozen morcellised
allograft and a cemented polished Exeter stem. All patients were
followed prospectively. The mean age of the patients at revision
was 65 years (30 to 86). At final review in December 2013 a total
of 130 patients with 135 reconstructions (64.9%) were alive and
had a non re-revised femoral component after a mean follow-up of
10.6 years (4.7 to 20.9). One patient was lost to follow-up at six
years, and their data were included up to this point.
Re-operation for any reason was performed in 33 hips (15.9%), in
13 of which the femoral component was re-revised (6.3%). The mean
pre-operative Harris hip score was 52 (19 to 95) (n = 73) and improved
to 80 (22 to 100) (n = 161) by the last follow-up. Kaplan–Meier
survival with femoral re-revision for any reason as the endpoint
was 94.9% (95% confidence intervals (CI) 90.2 to 97.4) at ten years;
with femoral re-revision for aseptic loosening as the endpoint it was
99.4% (95% CI 95.7 to 99.9); with femoral re-operation for any reason
as the endpoint it was 84.5% (95% CI 78.3 to 89.1); and with subsidence ≥ 5
mm it was 87.3% (95% CI 80.5 to 91.8). Femoral revision with the
use of impaction allograft bone grafting and a cemented polished
stem results in a satisfying survival rate at a mean of ten years’ follow-up. Cite this article:
