This study tests the biomechanical properties of adjacent locked
plate constructs in a femur model using Sawbones. Previous studies
have described biomechanical behaviour related to inter-device distances.
We hypothesise that a smaller lateral inter-plate distance will
result in a biomechanically stronger construct, and that addition
of an anterior plate will increase the overall strength of the construct. Sawbones were plated laterally with two large-fragment locking
compression plates with inter-plate distances of 10 mm or 1 mm.
Small-fragment locking compression plates of 7-hole, 9-hole, and
11-hole sizes were placed anteriorly to span the inter-plate distance.
Four-point bend loading was applied, and the moment required to
displace the constructs by 10 mm was recorded.Objectives
Methods
The painful subluxed or dislocated hip in adults
with cerebral palsy presents a challenging problem. Prosthetic dislocation
and heterotopic ossification are particular concerns. We present
the first reported series of 19 such patients (20 hips) treated
with hip resurfacing and proximal femoral osteotomy. The pre-operative
Gross Motor Function Classification System (GMFCS) was level V in
13 (68%) patients, level IV in three (16%), level III in one (5%) and
level II in two (11%). The mean age at operation was 37 years (13
to 57). The mean follow-up was 8.0 years (2.7 to 11.6), and 16 of the
18 (89%) contactable patients or their carers felt that the surgery
had been worthwhile. Pain was relieved in 16 of the 18 surviving
hips (89%) at the last follow-up, and the GMFCS level had improved
in seven (37%) patients. There were two (10%) early dislocations;
three hips (15%) required revision of femoral fixation, and two
hips (10%) required revision, for late traumatic fracture of the
femoral neck and extra-articular impingement, respectively. Hence
there were significant surgical complications in a total of seven
hips (35%). No hips required revision for instability, and there
were no cases of heterotopic ossification. We recommend hip resurfacing with proximal femoral osteotomy
for the treatment of the painful subluxed or dislocated hip in patients
with cerebral palsy.
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:
This review is aimed at clinicians appraising
preclinical trauma studies and researchers investigating compromised bone
healing or novel treatments for fractures. It categorises the clinical
scenarios of poor healing of fractures and attempts to match them
with the appropriate animal models in the literature. We performed an extensive literature search of animal models
of long bone fracture repair/nonunion and grouped the resulting
studies according to the clinical scenario they were attempting
to reflect; we then scrutinised them for their reliability and accuracy
in reproducing that clinical scenario. Models for normal fracture repair (primary and secondary), delayed
union, nonunion (atrophic and hypertrophic), segmental defects and
fractures at risk of impaired healing were identified. Their accuracy
in reflecting the clinical scenario ranged greatly and the reliability
of reproducing the scenario ranged from 100% to 40%. It is vital to know the limitations and success of each model
when considering its application.
Most hip fractures treated with modern internal
fixation techniques will heal. However, failures occasionally occur and
require revision procedures. Salvage strategies employed during
revision are based on whether the fixation failure occurs in the
femoral neck, or in the intertrochanteric region. Patient age and
remaining bone stock also influence decision making. For fractures
in young patients, efforts are generally focused on preserving the
native femoral head via osteotomies and repeat internal fixation.
For failures in older patients, some kind of hip replacement is
usually selected. Disuse osteopenia, deformity, bone loss, and stress-risers
from previous internal fixation devices all pose technical challenges
to successful reconstruction. Attention to detail is important in
order to minimise complications. In the majority of cases, good
outcomes have been reported for the various salvage strategies. Cite this article:
Although it is clear that opening-wedge high
tibial osteotomy (HTO) changes alignment in the coronal plane, which is
its objective, it is not clear how this procedure affects knee kinematics
throughout the range of joint movement and in other planes. Our research question was: how does opening-wedge HTO change
three-dimensional tibiofemoral and patellofemoral kinematics in
loaded flexion in patients with varus deformity?Three-dimensional
kinematics were assessed over 0° to 60° of loaded flexion using
an MRI method before and after opening-wedge HTO in a cohort of
13 men (14 knees). Results obtained from an iterative statistical
model found that at six and 12 months after operation, opening-wedge
HTO caused increased anterior translation of the tibia (mean 2.6
mm, p <
0.001), decreased proximal translation of the patella
(mean –2.2 mm, p <
0.001), decreased patellar spin (mean –1.4°,
p <
0.05), increased patellar tilt (mean 2.2°, p <
0.05) and
changed three other parameters. The mean Western Ontario and McMaster
Universities Arthritis Index improved significantly (p <
0.001)
from 49.6 (standard deviation ( The three-dimensional kinematic changes found may be important
in explaining inconsistency in clinical outcomes, and suggest that
measures in addition to coronal plane alignment should be considered. Cite this article:
The aims of this study were to assess the efficacy
of a newly designed radiological technique (the radial groove view)
for the detection of protrusion of screws in the groove for the
extensor pollicis longus tendon (EPL) during plating of distal radial
fractures. We also aimed to determine the optimum position of the
forearm to obtain this view. We initially analysed the anatomy of
the EPL groove by performing three-dimensional CT on 51 normal forearms.
The mean horizontal angle of the groove was 17.8° (14° to 23°).
We found that the ideal position of the fluoroscopic beam to obtain
this view was 20° in the horizontal plane and 5° in the sagittal
plane. We then intra-operatively assessed the use of the radial groove
view for detecting protrusion of screws in the EPL groove in 93
fractures that were treated by volar plating. A total of 13 protruding
screws were detected. They were changed to shorter screws and these
patients underwent CT scans of the wrist immediately post-operatively.
There remained one screw that was protruding. These findings suggest
that the use of the radial groove view intra-operatively is a good
method of assessing the possible protrusion of screws into the groove
of EPL when plating a fracture of the distal radius. Cite this article:
Intramedullary tibial nailing was performed in ten paired cadavers and the insertion of a medial-to-lateral proximal oblique locking screw was simulated in each specimen. Anatomical dissection was undertaken to determine the relationship of the common peroneal nerve to the cross-screw. The common peroneal nerve was contacted directly in four tibiae and the cross-screw was a mean of 2.6 mm (1.0 to 10.7) away from the nerve in the remaining 16. Iatrogenic injury to the common peroneal nerve by medial-to-lateral proximal oblique locking screws is therefore a significant risk during tibial nailing.
Components from 73 failed knee replacements (TKRs) consisting of rotating-platform, mobile-bearing and fixed-bearing implants were examined to assess the patterns of wear. The patterns were divided into low-grade (burnishing, abrasion and cold flow) and high-grade (scratching, pitting/metal embedding and delamination) to assess the severity of the wear of polyethylene. The rotating-platform group had a higher incidence of low-grade wear on the upper surface compared with the fixed-bearing group. By contrast, high-grade wear comprising scratching, pitting and third-body embedding was seen on the lower surface. Linear regression analysis showed a significant correlation of the wear scores between the upper and lower surfaces of the tibial insert (R2 = 0.29, p = 0.04) for the rotating-platform group, but no significant correlation was found for the fixed-bearing counterpart. This suggests that high-grade wear patterns on the upper surface are reduced with the rotating-platform design. However, the incidence of burnishing, pitting/third-body embedding and scratching wear patterns on the lower surface was higher compared with that in the fixed-bearing knee.
Hip arthrodesis remains a viable surgical technique
in well selected patients, typically the young manual labourer with
isolated unilateral hip disease. Despite this, its popularity with
patients and surgeons has decreased due to the evolution of hip
replacement, and is seldom chosen by young adult patients today.
The surgeon is more likely to encounter a patient who requests conversion
to total hip replacement (THR). The most common indications are
a painful pseudarthrosis, back pain, ipsilateral knee pain or contralateral
hip pain. Occasionally the patient will request conversion because
of difficulty with activities of daily living, body image and perceived
cosmesis. The technique of conversion and a discussion of the results
are presented. Cite this article:
The April 2013 Wrist &
Hand Roundup360 looks at: whether botox is just for Hollywood; supercharging nerve repairs; YouTube research; options for Keinbock’s disease; volar plates; driving and plasters; symptomatic radial malunion; and MRI and acute scaphoid fractures.
The dysplasia cup, which was devised as an adjunct to the Birmingham Hip Resurfacing system, has a hydroxyapatite-coated porous surface and two supplementary neutralisation screws to provide stable primary fixation, permit early weight-bearing, and allow incorporation of morcellised autograft without the need for structural bone grafting. A total of 110 consecutive dysplasia resurfacing arthroplasties in 103 patients (55 men and 48 women) performed between 1997 and 2000 was reviewed with a minimum follow-up of six years. The mean age at operation was 47.2 years (21 to 62) and 104 hips (94%) were Crowe grade II or III. During the mean follow-up of 7.8 years (6 to 9.6), three hips (2.7%) were converted to a total hip replacement at a mean of 3.9 years (2 months to 8.1 years), giving a cumulative survival of 95.2% at nine years (95% confidence interval 89 to 100). The revisions were due to a fracture of the femoral neck, a collapse of the femoral head and a deep infection. There was no aseptic loosening or osteolysis of the acetabular component associated with either of the revisions performed for failure of the femoral component. No patient is awaiting a revision. The median Oxford hip score in 98 patients with surviving hips at the final review was 13 and the 10th and the 90th percentiles were 12 and 23, respectively.
The Kent hip is a distally-locked femoral stem which was developed to address severe proximal bone loss, severe bony deformity and peri-prosthetic fracture. We reviewed the results of 145 consecutive Kent hips implanted into 141 patients between 1987 and 2000. The indications for implantation were aseptic loosening (75 hips), septic loosening (two), peri-prosthetic and prosthetic fracture (37), severe bony deformity (24), and fracture through a proximal femoral metastasis (seven). The median time to full weight-bearing after surgery was two days and the mean length of follow-up was 5.1 years (2 to 15). Further revisions were required for 13 femoral stems. With removal of the stem for any reason as an end-point, the cumulative survival at five, ten and 15 years was 93%, 89% and 77%, respectively. In patients aged ≥ 70 years, the cumulative survival at 15 years was 92%, compared with 68% in those aged <
70 years. Because of these findings, we recommend the use of interlocking stems in patients aged ≥ 70 years, particularly in those with a peri-prosthetic fracture, for whom alternative methods are limited. Outcome scores and survival data, compared with other systems, indicate that the Kent hip should be used with caution in younger patients.
Different calcaneal plates with locked screws were compared in an experimental model of a calcaneal fracture. Four plate models were tested, three with uniaxially-locked screws (Synthes, Newdeal, Darco), and one with polyaxially-locked screws (90° ± 15°) (Rimbus). Synthetic calcanei were osteotomised to create a fracture model and then fixed with the plates and screws. Seven specimens for each plate model were subjected to cyclic loading (preload 20 N, 1000 cycles at 800 N, 0.75 mm/s), and load to failure (0.75 mm/s). During cyclic loading, the plate with polyaxially-locked screws (Rimbus) showed significantly lower displacement in the primary loading direction than the plates with uniaxially-locked screws (mean values of maximum displacement during cyclic loading: Rimbus, 3.13 mm ( The increased stability of a plate with polyaxially-locked screws demonstrated during cyclic loading compared with plates with uniaxially-locked screws may be beneficial for clinical use.
We reviewed the long-term results at ten to 12 years of 118 total hip replacements in 109 patients using a second-generation hemispherical cementless acetabular component (Reflection) designed to address the problem of backside wear. Five patients (five hips) died and six patients (seven hips) were lost to follow-up. The remaining 98 patients (106 hips) had a mean age of 62.9 years (34.0 to 86.2) A rate of revision for aseptic loosening of 0.9%, and predictable results were found with respect to radiological evidence of fixation, lack of pain, walking ability, range of movement and function. One component was revised for aseptic loosening, and of the 101 hips (95.2%) that did not have a revision, minor osteolytic lesions of the pelvis were seen in six (5.9%). Kaplan-Meier survival analysis for the total cohort of 118 hips revealed a 96.4% survival at both ten (95% confidence interval 90 to 98) and 12 years (95% confidence interval 86 to 98).
Ulnar nerve function, during and after open reduction and internal fixation of fractures of the distal humerus with subperiosteal elevation of the nerve, was assessed by intra-operative neurophysiological monitoring. Intermittent recording of the compound muscle action potentials was taken from the hypothenar muscles in 18 neurologically asymptomatic patients. The mean amplitude of the compound muscle action potential after surgery was 98.1% (
In an interdisciplinary project involving electronic
engineers and clinicians, a telemetric system was developed to measure
the bending load in a titanium internal femoral fixator. As this
was a new device, the main question posed was: what clinically relevant
information could be drawn from its application? As a first clinical
investigation, 27 patients (24 men, three women) with a mean age
of 38.4 years (19 to 66) with femoral nonunions were treated using the
system. The mean duration of the nonunion was 15.4 months (5 to
69). The elasticity of the plate-callus system was measured telemetrically
until union. Conventional radiographs and a CT scan at 12 weeks
were performed routinely, and healing was staged according to the
CT scans. All nonunions healed at a mean of 21.5 weeks (13 to 37).
Well before any radiological signs of healing could be detected,
a substantial decrease in elasticity was recorded. The relative
elasticity decreased to 50% at a mean of 7.8 weeks (3.5 to 13) and
to 10% at a mean of 19.3 weeks (4.5 to 37). At 12 weeks the mean
relative elasticity was 28.1% (0% to 56%). The relative elasticity
was significantly different between the different healing stages
as determined by the CT scans. Incorporating load measuring electronics into implants is a promising
option for the assessment of bone healing. Future application might
lead to a reduction in the need for exposure to ionising radiation
to monitor fracture healing.
This review considers the surgical treatment
of displaced fractures involving the knee in elderly, osteoporotic patients.
The goals of treatment include pain control, early mobilisation,
avoidance of complications and minimising the need for further surgery.
Open reduction and internal fixation (ORIF) frequently results in
loss of reduction, which can result in post-traumatic arthritis
and the occasional conversion to total knee replacement (TKR). TKR
after failed internal fixation is challenging, with modest functional
outcomes and high complication rates. TKR undertaken as treatment
of the initial fracture has better results to late TKR, but does
not match the outcome of primary TKR without complications. Given
the relatively infrequent need for late TKR following failed fixation,
ORIF is the preferred management for most cases. Early TKR can be
considered for those patients with pre-existing arthritis, bicondylar
femoral fractures, those who would be unable to comply with weight-bearing restrictions,
or where a single definitive procedure is required.
Between October 2001 and September 2009 we lengthened 242 lower-limb segments in 180 patients using the Intramedullary Skeletal Kinetic Distractor (ISKD). Mechanical failure was defined either as breakage of the ISKD or failure of the internal mechanism to activate. Retrieved nails which failed mechanically were examined by the manufacturer for defects. In all, 15 ISKDs in 12 patients (13 limbs) failed mechanically representing an overall failure rate of 6.2%, with fracture of the device occurring in ten of the 15 failures. Two nails in one patient failed to lengthen and had to be replaced. The manufacturer detected an error in the assembly of the nail, which prompted a wide recall. One nail jammed after being forcefully inserted, and two nails failed to lengthen fully. Lengthening was achieved in all 12 patients, although three required a second operation to exchange a defective nail for a new, functioning device. The ISKD is a complex mechanical device which lengthens by the oscillation of two telescopic sections connected by a threaded rod. The junction between these sections is surrounded by a keyring collar. This keyring collar is the weakest part of the device.
Fluoronavigation is an image-guided technology which uses intra-operative fluoroscopic images taken under a real-time tracking system and registration to guide surgical procedures. With the skeleton and the instrument registered, guidance under an optical tracking system is possible, allowing fixation of the fracture and insertion of an implant. This technology helps to minimise exposure to x-rays, providing multiplanar views for monitoring and accurate positioning of implants. It allows real-time interactive quantitative data for decision-making and expands the application of minimally invasive surgery. In orthopaedic trauma its use can be further enhanced by combining newer imaging technologies such as intra-operative three-dimensional fluoroscopy and optical image guidance, new advances in software for fracture reduction, and new tracking mechanisms using electromagnetic technology. The major obstacles for general and wider applications are the inability to track individual fracture fragments, no navigated real-time fracture reduction, and the lack of an objective assessment method for cost-effectiveness. We believe that its application will go beyond the operating theatre and cover all aspects of patient management, from pre-operative planning to intra-operative guidance and postoperative rehabilitation.