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Low failure rate by means of DLBP fixation of undisplaced femoral neck fractures

Authors:
  • Medisch Spectrum Twente, Enschede, the Netherlands

Abstract and Figures

Background: This study evaluated the clinical results of a new implant in the internal fixation of undisplaced femoral neck fractures. Method: Irrespective of their age, 149 patients with undisplaced (Garden I and II) femoral neck fractures were included in a prospective multicentre clinical cohort study and were treated by internal fixation by means of the Dynamic Locking Blade Plate (DLBP). The mean age was 69 years and the follow-up at least one year. Results: The DLBP fixation resulted in 6 out of 149 failures caused by AVN (2x), non-union (2x), loss of fixation (3x) or combination of these. Conclusion: The fixation of undisplaced femoral neck fractures by the DLBP resulted in a low failure rate of 4 %.
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DOI 10.1007/s00068-016-0659-4
Eur J Trauma Emerg Surg (2017) 43:475–480
ORIGINAL ARTICLE
Low failure rate by means of DLBP fixation of undisplaced
femoral neck fractures
A. D. P. van Walsum1 · J. Vroemen2 · H. M. J. Janzing3 · T. Winkelhorst4 ·
J. Kalsbeek1 · W. H. Roerdink5
Received: 25 September 2015 / Accepted: 7 March 2016 / Published online: 19 March 2016
© The Author(s) 2016. This article is published with open access at Springerlink.com
Introduction
The biology plays a leading role in the survival of the fem-
oral head and the bone healing of this intracapsular frac-
ture. Critical biological factors are the (re)-vascularisation
of the femoral head and the type of bone healing of the
femoral neck fractures. The viability of the femoral head
after a femoral neck fracture is dependent on preservation
of the remaining vascularity and on revascularisation and
repair of the necrotic areas before collapse of the necrotic
bone segment can occur. Although the vascularisation of
the femoral head in the undisplaced fracture is less dam-
aged than in the displaced fractures, the incidence of avas-
cular necrosis for undisplaced femoral neck fractures is 4.0
versus 9.5 % for the displaced fractures [1]. To preserve the
remaining vascularisation of the femoral head we must do
no further vascular harm during insertion of implants in the
head of femur. Therefore, any iatrogenic fracture displace-
ment should be avoided, especially rotation of the femo-
ral head on insertion of our implants. One of the sources
of revascularisation of the femoral head is the vascular
ingrowth across the uniting fracture line. It is of clinical
importance that these ingrowing tender vascular buds can
be torn repeatedly if there is persistent motion at the frac-
ture site as a result of inadequate fracture stabilisation [2].
Enlarging the volume of metal in the femoral head may fur-
ther compromise the revascularisation of the femoral head
and this may increase the incidence of avascular necrosis
[3, 4]. Unlike diaphyseal fractures, the femoral neck frac-
ture cannot heal by periosteal (external) callus formation.
Consequently, the bone healing is by primary osteonal
reconstruction that requires an anatomical reduction and
absolute stability [57]. Only when the undisplaced femo-
ral neck fracture is secured by stable fixation, revascularisa-
tion of the femoral head can take place and the fracture can
Abstract
Background This study evaluated the clinical results of a
new implant in the internal fixation of undisplaced femoral
neck fractures.
Method Irrespective of their age, 149 patients with
undisplaced (Garden I and II) femoral neck fractures
were included in a prospective multicentre clinical cohort
study and were treated by internal fixation by means of the
Dynamic Locking Blade Plate (DLBP). The mean age was
69 years and the follow-up at least one year.
Results The DLBP fixation resulted in 6 out of 149 fail-
ures caused by AVN (2x), non-union (2x), loss of fixation
(3x) or combination of these.
Conclusion The fixation of undisplaced femoral neck
fractures by the DLBP resulted in a low failure rate of 4 %.
Keywords Femoral neck fracture · Intracapsular hip
fracture · Hip fracture · Undisplaced · Non displaced ·
Internal fixation · Osteosynthesis · Avascular necrosis ·
Rotational stability
* A. D. P. van Walsum
vwalsum@gmail.com
1 Department of Trauma Surgery, Medisch Spectrum Twente,
Koningsplein 1, 7512 KZ Enschede, The Netherlands
2 Department of Trauma Surgery, Amphia Ziekenhuis,
Molengracht 21, 4818 CK Breda, The Netherlands
3 Department of Trauma Surgery, VieCuri Medical Centre,
Tegelseweg 210, 5912 BL Venlo, The Netherlands
4 Department of Trauma Surgery, Canisius Wilhelmina, Weg
door Jonkerbos 100, 6532 SZ Nijmegen, The Netherlands
5 Department of Trauma Surgery, Deventer Ziekenhuis, Nico
Bolkesteinlaan 75, 7416 SE Deventer, The Netherlands
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476
A. D. P. van Walsum et al.
1 3
heal by primary osteonal reconstruction. The term “stable”,
in the context of fixation of femoral neck fractures, means
that transverse shear- and the rotational inter fragmentary
movements (IFM) are minimalized while allowing the con-
trolled axial compression IFM.
Approximately 20 % of the intracapsular hip frac-
tures are undisplaced [12]. Common treatment is internal
fixation of the fracture, but alternative treatments are con-
servative treatment or replacement arthroplasty. The con-
ventional implants used for the fixation of femoral neck
fractures are the sliding hip screw devices and multiple par-
allel screws or pins. The failure rate after internal fixation
of undisplaced femoral neck fractures is 8–14 % [813].
The potential disadvantages of the conventional implants
are rotational and/or angular instability combined with a
relative high implant volume in the femoral head [14]. The
aim of this study was to register the results in the internal
fixation of undisplaced femoral neck fractures by means of
the DLBP. This device is characterised by angular and rota-
tional stability, dynamic compression and a low implant
volume in the head of femur.
Patients and methods
Classification
According the conventional Garden classification an undis-
placed intracapsular fracture is defined as Garden grade I or
II fracture. This classification is based only on the AP radi-
ograph and includes all fractures impacted into any degree
of valgus (Garden I) and the undisplaced fractures (Garden
II). Consequently, also the fractures that show angulation
on the lateral radiograph are included and classified as
undisplaced.
Patients
Included were undisplaced femoral neck fractures in adult
patients irrespective the age of the patient. Excluded were
pathological fractures, concomitant fractures of the lower
extremity, symptomatic arthritis, local infection or inflam-
mation, inadequate local tissue coverage, morbid obesity
and any mental or neuromuscular disorder, which would
create an unacceptable risk of fixation failure or complica-
tions in postoperative care.
Implant
The DLBP consists of a 2-hole standard 135° side-plate
combined with a low-volume cannulated dynamic locking
blade. The side plate provides angular stability combined
with dynamic axial compression of the fracture. Two side
wings at the tip of the blade provide rotational stable fixa-
tion of the locking blade in the femoral head combined
with a high weight-bearing surface. The expandable impac-
tion anchors lock the blade in the femoral head and prevent
perforation and backing out of the implant and further aug-
ment the rotational stability. The DLBP is now marketed as
the Gannet (Fig. 1).
Technique
If there is any (anterior) angulation of the femoral neck
with dorsal displacement of the femoral head, anatomi-
cal reduction is performed by internal rotation and ante-
rior manual compression. To do no further vascular harm,
the reduction should be performed gently and accurately
as excessive longitudinal traction and rotation may result
in additional vascular damage by tearing the still surviv-
ing retinacular vessels. By a ±7 cm lateral approach
a 3.0-mm 135° guide wire is placed in the centre/centre
position in femoral head. After length measuring cannu-
lated reaming is performed up to 5 mm subchondrally in
the femoral head. Next the locking blade together with
a two-hole side plate is mounted on the introducer. The
Fig. 1 Design of the dynamic locking blade plate
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477
Low failure rate by means of DLBP fixation of undisplaced femoral neck fractures
1 3
complete implant is introduced over the guide wire and
gently tapped in while the mounted side plate functions
as a rotational guide. After the side plate is seated along
the lateral cortex, the introducer is released and the lock-
ing blade further tapped in the femoral head up to 5 mm
subchondrally. Next, the side plate is fixed to the proximal
femur by two self-tapping cortical screws. By turning the
setscrew, in the shaft of the locking blade in clockwise
direction, the impaction anchors are expanded by which
the blade is locked within the femoral head. On removal,
turning the setscrew anti clockwise retracts the impaction
anchors. After removal of the cortical screws, the locking
blade together with the side plate is tapped out by means
of an extractor mounted on the locking blade. The patients
were mobilised postoperatively by permissive weight bear-
ing as tolerated by the patient. The implant characteristics
and operative technique are further illustrated in YouTube
video (gannet implant) (Fig. 2).
Methods
The Garden classification is based on the pre-operative
AP radiograph of the hip. The (anterior) angulation of the
fracture is assessed on the lateral pre-operative radiograph
of the hip. Postoperative AP and lateral radiographs were
used to assess fracture healing. Union was defined by an
absence of visible margins of the fracture. Angular instabil-
ity was assessed radiologically by secondary interfragmen-
tary angulation and/or transverse shear. Interfragmentary
rotation was radiologically assessed by the observation of
a cortical step and diameter mismatch at the fracture site.
Non-union was identified by either displacement of the
fracture or clearly visible margins of the fracture 1 year
postoperatively. Avascular necrosis was defined accord-
ing to the Steinberg classification from stage 2 and upward
[15]. Failure of fixation is defined as the need for revision
surgery because of non-union, avascular necrosis or cut out
Fig. 2 a, b AP en lateral X-ray
of undisplaced femoral neck
fracture of the right hip, c, d AP
and lateral X-ray of undisplaced
femoral neck fracture of the
right hip after DLBP fixation
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478
A. D. P. van Walsum et al.
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of the implant. The corrected Tip Apex Distance (TAD) on
the first postoperative X-rays assessed the position of the
locking blade in the femoral head [16]. A TAD greater then
25 mm is predictive of a higher extrusion rate. The impac-
tion at the fracture site was assessed by measuring the
degree of telescoping of the dynamic blade with correction
for magnification. Mobility was assessed by the need of
walking aids: no walking aids, one crutch, two crutches or
a walker.
Results
One Level-1 Community Trauma center (Medische
Spectrum Twente, Enschede) and four Level-2 Commu-
nity teaching hospitals (Deventer Ziekenhuis, Deventer;
Amphia Ziekenhuis, Breda; Canisius Wilhelmina Zieken-
huis, Nijmegen and VieCuri Medisch Centrum, Venlo)
participated. Between 01-08-2010 and 19-12-2013, and
384 consecutive patients with femoral neck fractures were
treated by means of the DLBP. Of these 384 patients, 172
a suffered undisplaced femoral neck fracture and 212 a dis-
placed femoral neck fracture. This manuscript addresses
the results of the patients who are treated for undisplaced
fractures. 172 patients with undisplaced (Garden I and II)
femoral neck fractures were included irrespective of the age
of the patient. Seven patients were lost for follow-up and
16 patients died during the follow-up period. This resulted
in 149 patients with a mean age of 69 years (35–101) with
a follow-up of at least 1 year from injury. Surgery was
undertaken by (orthopaedic) trauma surgeons (85 %), and
trainee surgeons (15 %). 79 % of operations took place
within 24 h. The average operating time was 39 min. There
were six general medical complications: one deep infec-
tion (healed without intervention surgery, two postoperative
bleedings and three pneumonia). Implant-related complica-
tions consisted of suboptimal expansion of the impaction
anchors in four cases. In two younger patients this was
caused by the high bone density, and in two elderly patients
by technical implant problems with the expansion mecha-
nism. Neither perforation, nor backing-out of the dynamic
blade was observed. No secondary rotational or angular
instability was observed. No breakage of the blade, plate
or screws occurred. The internal fixation of undisplaced
(Garden I and II) femoral neck fractures resulted in 6 out
of 149 failures (4.0 %) caused by AVN (2×), non-union
(2×), loss of fixation (3×) or combination of these. All of
the six failed fixations were revised by arthroplasty. Five
of the failures were classified as a Garden I fracture and
one Garden II. AVN was observed in two out of six failures
(one Garden I, one Garden II). In two out of the six failures
anterior angulation (posterior displacement) was more than
20°. The mean impaction of the healed fractures was 5 mm
with a mean age of 69 years. The mean age in the failure
group was 71 years. The average TAD in the healed frac-
ture group was 22 mm and 24 mm in the failure group.
Elective implant removal was performed in 9 % due to
suspected local complaints caused by the side plate or the
(dynamized) blade. In all patients the implant removal,
including the retraction of the anchors, went straight-
forward. Four per cent of the patients with healed femo-
ral neck fractures needed more walking aids than before
fracture.
Discussion
The most common treatment of undisplaced femoral neck
fractures is internal fixation by sliding hip screw devices or
multiple parallel screws or pins. However, alternative treat-
ments are conservative treatment or replacement arthro-
plasty. A review study by Conn and Parker confirmed a
non-union rate of 30–45 % for conservative treatment [11].
The recent review study concluded that the non-union rate
with secondary displacement was at least 30 % for the con-
servative treatment of undisplaced femoral neck fractures
[13]. To avoid the complications of avascular necrosis and
non-union, arthroplasty was advocated in the treatment of
undisplaced femoral neck fractures [17]. However, hemi-
arthroplasty is complicated by deep infection (3 %), super-
ficial infection (15 %), periprosthetic fracture (3 %), dislo-
cation (5 %), loosening (10 %), acetabular wear (20 %) and
a potentially higher mortality compared to internal fixation
[11].
The failure rate after internal fixation of undisplaced
femoral neck fractures remains relatively low [8]. Nev-
ertheless internal fixation is not without complications.
Parker described 6.4 % non-union, 4.0 % avascular necro-
sis and revision surgery in 7.7 % [11]. The review study
by Van Embden demonstrated a non-union rate of 4–8.5 %,
avascular necrosis in 2–4 % and revision surgery of 8–15 %
after osteosynthesis of undisplaced femoral neck fractures
[13]. The still considerable failure rate after internal fixa-
tion of undisplaced femoral neck fractures cannot be solely
attributed to the implants. Other factors such as a-traumatic
surgical technique and the positioning of the implant are as
important as the choice of implant.
In this study the DLBP fixation proved to provide sta-
ble fixation of the undisplaced femoral neck fractures with
a failure rate of 6 out of 149 (4 %). However, in two of
these failed fractures the lateral radiograph showed more
than 20° of anterior angulation (32° and 40°). Therefore,
it seems controversial if these so-called stable Garden 1
and 2 fractures, with significant anterior angulation (pos-
terior displacement), really behave as stable fractures or
should be classified as unstable. If only the Garden I and
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479
Low failure rate by means of DLBP fixation of undisplaced femoral neck fractures
1 3
II fractures with an angulation on lateral imaging of less
than 20° were classified as stable, the failure rate in this
study would drop from 4.0 to 2.9 %. The stability of the
DLBP fixation is further demonstrated by the fact that nei-
ther secondary, rotational or angular instability nor perfo-
ration or backing-out of the dynamic blade was observed.
Furthermore, a TAD greater then 25 mm did not prove to
be predictive of a higher extrusion rate as is the case with
the standard implants. The vascularity of the head of femur
after DLBP fixation is as such that AVN led to failure only
in 1.2 % of the included patients. The viability and stability
are also apparent from the low degree of fracture impaction
with a mean of 5 mm.
The DLBP was designed to follow the biology of the
femoral neck fracture. Therefore, the DLBP is a low-
volume, dynamic implant, providing angular and rota-
tional stability. The volume (of the proximal 25 mm of the
implant in the femoral head) of the DLPB is 1500 mm3
compared to 2600 mm3 for the DHS and 2800 mm3 for
DHS spiral blade. The volume of three Asnis screws is
2700 mm3. The square diameter of the DLBP is 31 mm2
compared to 133 mm2 for the DHS/DHS Spiral Blade and
99 mm2 for three Asnis screws. The weight-bearing sur-
face of the DLBP is 338 mm2 compared with 221 mm2 for
the DHS. Torsion test showed that the rotational stability
of the DLBP triples that of the DHS [14]. The resulting
failure rate of the DLBP fixation of the undisplaced femo-
ral neck fractures is low (4 %) and compares favourably
with the results of the common implants (8–14 %). The
most commonly used implants are the multiple parallel
screws or pins and the sliding hip screw devices (SHS)
with both comparable results. The potential implant-
related factors in the failure rate for the screw fixation
are the intrinsic lack of angular and rotational stability.
The stability reached is dependent of the exact position-
ing of the screws and is, therefore, surgeon dependent.
The SHS also lacks rotational stability with the added risk
of iatrogenic rotation of the head during insertion of the
implant [14, 1820]. Another potential risk factor is the
relative high implant volume in the femoral head for the
screw fixation and the SHS devices [21]. In the operative
treatment of femoral neck fractures minimal invasiveness
seems to be more than the length of the skin incision.
Probably more important is the minimal invasiveness to
the femoral head characterised by a low volume and a
low cross section of he implant in the femoral head and
neck. The hypothesised advantageous characteristics of
the DLBP are the combination of angular and rotational
stability and low implant volume. Although the results of
the DLBP in this study are promising, we recognise that
this observational cohort study is not the strongest study
design to prove this. Also it is recognised that functional
evaluation was limited.
Conclusion
Based on the good clinical results, internal fixation seems
to be the optimum treatment for the undisplaced femoral
neck fracture. However, the failure rate of 8–14 % is still
disturbing. Although not all failures are implant-related,
the choice of implant plays a role in the final outcome. The
possible implant-related factors are the lack of angle and/or
rotational stability in combination of a high implant volume
in the head of femur. The DLBP (Gannet) was designed to
improve the stability of the femoral neck fracture paired to
minimal invasiveness to the femoral head. The low failure
rate of the DLBP fixation of undisplaced femoral neck frac-
tures of 4.0 % seems to be promising and further supports
the treatment algorithm that no effort should be spared to
preserve the femoral head after an undisplaced femoral
neck fracture by internal fixation irrespective of the age of
the patient.
Compliance with ethical standards
Financial support No financial support was received for this study.
Conflict of interest Ariaan van Walsum declares he shares the Intel-
lectual Property rights of the Dynamic Locking Blade Plate. Jos Vroe-
men, Heinrich Janzing, Tomas Winkelhorst, Jorn Kalsbeek and Willem
Roerdink declare that they have no conflict of interest.
Compliance with ethical requirements This study was approved
by the appropriate medical ethics committee.
Open Access This article is distributed under the terms of the
Creative Commons Attribution 4.0 International License (http://crea-
tivecommons.org/licenses/by/4.0/), which permits unrestricted use,
distribution, and reproduction in any medium, provided you give
appropriate credit to the original author(s) and the source, provide a
link to the Creative Commons license, and indicate if changes were
made.
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... In a prospective multicenter cohort study in the Netherlands 172 patients with an undisplaced FNF were treated with the DLBP. The results of this study showed a failure rate of 4% [13]. Another recent prospective cohort study of 106 patients of 60 years and younger with displaced FNF demonstrated a DLBP related failure rate of 13.2% [14]. ...
... The failure rate or revision rate of the DHS in patients ≤65 years with displaced FNFs described in today's literature is 32-44% [8,17]. The failure rate of the DLBP in patients of 60 years and younger with a displaced FNF in a previous cohort study was 13.2% [14]. Analysis of our data showed a failure rate of 15% for the DLBP in patients of 65 years and younger (non-published data). ...
... The expandable impaction anchors lock the blade in the femoral head and prevent perforation and backing out of the implant and further augment the rotational stability. The DLBP is now marketed as the Gannet [13]. ...
Article
Full-text available
Background: The Dynamic Locking Blade Plate (DLBP) was recently introduced for fixation of displaced femoral neck fractures (FNF) and has been well received. Although the results of this implant in young patients are promising, the DLBP has not yet been compared to a standard device such as the Dynamic Hip Screw (DHS). The aim of this study is to compare the clinical outcome and costs of displaced FNF treated with internal fixation by means of either the DLBP or the DHS in patients up to 65 years of age. We hypothesize that the DLBP is superior compared to the DHS in terms of revision surgery rate, union rate, incidence of avascular necrosis and implant related failure. Methods: The DEFENDD (DisplacEd Femoral Neck fractures Dlbp versus Dhs) trial is a multicentre randomized controlled trial that will include 266 patients of 18-65 years with a displaced FNF. Patients will be randomized to receive either a DLBP or a DHS with a 1:1 allocation using a random block size, stratified for centre. Clinical follow up will last 1 year and questionnaires will be obtained up to 2 years. The main outcome parameter is the incidence of revision surgery within 1 year, due to either non-union, avascular necrosis (AVN) or cut out of the implant. Secondary study parameters are the incidence of avascular necrosis, non-union, (implant related) complications, functional outcome, elective removal of the implant and health-related quality of life and costs. Discussion: The outcome of the DEFENDD trial will provide high-level evidence of which implant is favourable for the treatment of femoral neck fractures in young patients (≤65 years). Trial registration: Netherlands Trial Register, NL7300 Registration date 25-09-2018.
... The dynamic locking blade plate (DLBP) is a relatively new implant with demonstrated increased fracture-implant construct stability. It has been used for fixation of displaced and undisplaced FNFs since 2010 [12][13][14]. ...
... The FNFs of all included patients were fixated with the DLBP. The DLBP is a barreled side-plate combined with a cannulated locking blade (Fig. 2) [13,14]. Perioperative care was given according to the local hospital protocols, including pre-operative antibiotic prophylaxis, direct fullweight-bearing of the operated hip after surgery according to patients' pain perception and functional capacities, and antithrombotic prophylaxis. ...
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Purpose In this study, we aimed to determine the correlation between the preoperative posterior tilt of the femoral head and treatment failure in patients with a Garden type I and II femoral neck fracture (FNF) treated with the dynamic locking blade plate (DLBP). Methods Preoperative posterior tilt was measured in a prospective documented cohort of 193 patients with a Garden type I and II FNF treated with the DLBP. The correlation between preoperative posterior tilt and failure, defined as revision surgery because of avascular necrosis, non-union, or cut-out, was analyzed. Results Patients with failed fracture treatment (5.5%) had a higher degree of posterior tilt on the initial radiograph than the patients with uneventful healed fractures: 21.4° and 13.8°, respectively (p = 0.03). The failure rate was 3.2% for Garden type I and II FNF with a posterior tilt < 20° and 12.5% if the preoperative posterior tilt was ≥ 20°. A posterior tilt of ≥ 20° was associated with an odds ratio of 4.24 (95% CI 1.09–16.83; p = 0.04). Conclusion Garden type I and II FNFs with a significant preoperative posterior tilt (≥ 20°) seem to behave like unstable fractures and have a four times higher risk of failure. Preoperative posterior tilt ≥ 20° of the femoral head should be considered as a significant predictor for failure of treatment in Garden type I and II FNFs treated with the DLBP.
... In addition to the targon system, the emerging dynamic locking plate is also widely used. Van Walsum et al [32] used emerging plates for NDFNFs and found that only 6 cases failed among 149 cases. ...
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Background This paper aimed to review the databases on non-displaced femoral neck fractures in elderly patients. We also discussed the surgical and non-surgical treatments and selection of implants. Methods Reviewed was the literature on non-displaced femoral neck fractures in elderly patients. Four major medical databases and a combination of the search terms of “femoral neck fractures”, “nondisplaced”, “undisplaced”, “non-displaced”, “un-displaced”, “aged”, “the elderly”, and “geriatric” were used to search the literature relevant to the topic of the review. Results Patients who were unable to tolerate the operation and anesthesia could be treated conservatively. Otherwise, surgical treatment was a better choice. Specific surgical strategies and implant selection were important for the patient’s functional recovery. Conclusions The non-displaced femoral neck fractures are relatively stable but carry a risk of secondary displacement. Surgical treatments may be a better option because the implants provide additional stability and allow early exercise and ambulation. Hemiarthroplasty is also an alternative for old patients with higher risks of displacement and avascular necrosis of the femoral head.
... Some studies have found that the stability of femoral neck fractures is of great signi cance for revascularization of the femoral head and plays an important role in promoting bone healing and in reducing the rate of femoral head necrosis [16,17]. Moreover, it has been reported that a large implant volume may interfere with revascularization of the femoral head and increase the incidence of femoral head necrosis [18]. The diameters of the screw bolt and the anti-rotation screw of the FNS in this study were 10 mm and 6.4 mm, respectively; thus, the volume of the FNS implant was signi cantly smaller than that of the three cannulated screws. ...
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Objective: To compare early clinical effects of the femoral neck system (FNS) and three cannulated screws for the treatment of patients with unstable femoral neck fractures. Methods: A retrospective analysis with pair matching of 81 patients who received FNS or cannulated screw internal fixation for Pauwels type-3 femoral neck fracture in our hospital from January 2019 to December 2019 was conducted. Patients who received FNS were the test group, and those who received cannulated screws comprised the control group. Matching requirements were as follows: same sex, similar age and similar body mass index (BMI). A total of 30 pairs were successfully matched, and the average age was 53.84 years. The operation time, intraoperative blood loss, hospital stay, hospitalization cost, postoperative visual analogue scale (VAS) score, time to walking without crutches, Harris score, femoral head necrosis rate and complication rate were compared between the groups. Results: Postoperative re-examination of radiographs showed satisfactory reduction in all patients, and all patients were followed up for 10-22 months. Those in the FNS group had lower postoperative VAS scores, earlier times to walking without crutches, higher Harris scores at the last follow-up and lower complication rates (P<0.05). However, intraoperative blood loss and hospitalization costs were greater in the FNS group (P<0.05). No statistically significant difference in operation time, hospital stay or femoral head necrosis rate was observed between the two groups (P>0.05). Conclusion: For patients with unstable femoral neck fractures, FNS has better clinical efficacy than cannulated screws, though it is also more expensive. The excellent biomechanical performance and clinical efficacy of FNS make it a new choice for the treatment of unstable femoral neck fractures.
... Some studies have found that the stability of femoral neck fractures is of great signi cance to the revascularization of the femoral head, and plays an important role in promoting bone healing and reducing the rate of femoral head necrosis [14,15]. Moreover, It is reported that a large volume of implants may interfere with the revascularization of the femoral head and increase the incidence of femoral head necrosis [16]. The diameter of the screw bolt and the anti-rotation screw of FNS was 10 mm and 6.4 mm, respectively. ...
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Objective: To compare the early clinical effects of femoral neck system and three cannulated screws in the treatment of patients with unstable femoral neck fractures. Methods: A retrospective analysis was conducted on 81 patients who received FNS or cannulated screws internal fixation for Pauwels Type-3 femoral neck fracture in our hospital from January 2019 to December 2019. A pair-matched clinical research was performed. People who received FNS were test group and people received cannulated screws were control group. Matching requirements were as follows: the same gender, the similar age and the similar BMI. A total of 30 pairs were successfully matched, with an average age of 53.84 years old. The operation time, intraoperative blood loss, hospital stay, hospitalization cost, postoperative VAS score, time walking without crutches, Harris score, femoral head necrosis rate and complication rate were compared between the two groups. Results: Postoperative re-examination of radiographs showed satisfactory reduction in all patients, and all the patients were followed up for 10-22 months. Patients in the FNS group had lower postoperative VAS scores, earlier time to walk without crutches, higher Harris scores at the last follow-up and lower complication rate (P<0.05). However, intraoperative blood loss and hospitalization costs in the FNS group were more(P<0.05). There was no statistically significant difference in operation time, hospital stay and femoral head necrosis rate between two group (P>0.05). Conclusion: For patients who were unstable femoral neck fracture, FNS has better clinical efficacy than cannulated screws, though FNS is more expensive. The excellent biomechanical performance and clinical efficacy of FNS make it a new choice for the treatment of unstable femoral neck fracture. Fund program: Key medical research project of Jiangsu Health Committee(K2019010)
... A recent paper describing the outcome of 320 patients treated with internal fixation reported an AVN rate of 4.5% for undisplaced and 11.1% for displaced intracapsular fractures with a minimum follow-up of two years [12]. This doubling of incidence further supports that osteosynthetic treatment should only be used in undisplaced femoral neck fractures [10,19,20]. ...
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One of the most common fractures is that of the intracapsular femoral neck; however, the optimal implant for head-preserving treatment remains controversial. The aim of the study was to compare the outcomes of treating undisplaced intracapsular femoral neck fractures with either the dynamic hip screw (DHS) or the double cannulated screw fixation (CSFN). This retrospective cohort study analysed the data of 453 patients, with a mean age of 76.9 years, whose intracapsular fractures were treated with the DHS or CSFN between 2005 and 2013. The analysis focused on the rates of revision surgeries and complications; however, the impact of confounding exogenous factors, such as smoking and alcohol, were also considered. No significant difference was observed between the revision rates of DHS and CSFN (15.0% vs. 13.1%; p = 0.565). According to the complication rate, the advantage in favour of the CSFN was not significant (20.5% vs. 13.1%, p = 0.038). The use of the DHS was associated with a 13 min longer surgery (p < 0.0001) and a one day longer hospitalization (p = 0.242). Excessive consumption of alcohol was associated with an increased incidence of avascular necrosis (18.6% vs. 8.7%, p = 0.035). The choice of implant showed no significant impact on rates of revision surgery and complications. In terms of socioeconomic factors, the fixation with two cannulated screws was more favourable, making it the more cost-effective and less stressful method.
Article
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Objective: To compare early clinical effects of the femoral neck system (FNS) and three cannulated screws for the treatment of patients with unstable femoral neck fractures. Methods: A retrospective analysis with pair matching of 81 patients who received FNS or cannulated screw internal fixation for Pauwels type-3 femoral neck fracture in our hospital from January 2019 to December 2019 was conducted. Patients who received FNS were the test group, and those who received cannulated screws comprised the control group. Matching requirements were as follows: same sex, similar age, and similar body mass index (BMI). A total of 30 pairs were successfully matched at a 1:1 ratio, including 12 males and 18 females. The average age of the patients in the FNS group was 54.53 ± 6.71 years. In the cannulated screw group, the average age of the patients was 53.14 ± 7.19 years. The operation time, intraoperative blood loss, hospital stay, hospitalization cost, postoperative visual analog scale (VAS) score, time to walking without crutches, Harris score, femoral head necrosis rate, and complication rate were compared between the groups. Results: Postoperative re-examination of radiographs showed satisfactory reduction in all patients, and all patients were followed up for 10-22 months. Those in the FNS group had lower postoperative VAS scores, earlier times to walking without crutches, higher Harris scores at the last follow-up, and lower complication rates (P < 0.05). VAS scores were lower in the FNS group (3.13 ± 1.07 scores) than in the cannulated screw group (3.77 ± 1.04 scores) (P = 0.018). Patients in the FNS group (5.23 ± 1.33 months) recovered to walking without crutches earlier than did those in the cannulated screw group (6.03 ± 1.45 months) (P<0.001). In addition, a statistically higher postoperative Harris score was detected in the FNS group (86.16 ± 7.26) than in the cannulated screw group (82.37 ± 7.52) (P = 0.039). Overall, a higher incidence of complications was observed in the cannulated screw group (9/30) than in the FNS group (2/30) (P = 0.042). However, intraoperative blood loss and hospitalization costs were greater in the FNS group (P < 0.05). Intraoperative blood loss was greater in the FNS group (99.73 ± 4.69) than in the cannulated screw group (30.27 ± 9.04) (P<0.001). In addition, patients in the FNS group (46976 ± 2270 ¥) spent more on hospitalization costs than did those in the cannulated screw group (15626 ± 1732 ¥) (P<0.001). No statistically significant difference in operation time, hospital stay, or femoral head necrosis rate was observed between the two groups (P > 0.05). Conclusion: For patients with unstable femoral neck fractures, FNS has better clinical efficacy than cannulated screws, though it is also more expensive.
Article
Introduction: Posterior tilt of the femoral head in femoral neck fractures (FNF) may influence stability of the fracture and may therefore affect the treatment outcome. Posterior tilt can be measured with different methods. The Lateral Garden Angle (LGA) has been used for this purpose for decades and more recently the Posterior Tilt Measurement (PTM) was introduced. Despite the fact that both methods (LGA and PTM) are used in multiple studies, they have never been compared for reliability in a direct study. The aim of this study is to analyze the intra and inter observer reliability of the LGA described by Garden and the PTM according to Palm. Methods: Four observers measured the posterior tilt on the radiographs of 50 FNF two times with both methods. Intra and inter observer reliability were determined for the LGA and the PTM. Results: The intra observer reliability for both methods is substantial with an intra class coefficient of 0.75. The inter observer reliability of the PTM is also substantial with an intra class coefficient of 0.75 compared to a moderate reliability of the LGA with an intraclass coefficient of 0.60. Conclusion: Based on our results we believe the LGA and the PTM are both reliable methods to measure posterior tilt. Yet the Posterior Tilt Measurement seems to have a better inter observer reliability and therefore has a slight preference over the Lateral Garden Angle.
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Objective: To introduce the research progress of conservative treatment, internal fixation, hip arthroplasty, and multidisciplinary team (MDT) modes in the treatment of femoral neck fracture in the elderly. Methods: By consulting domestic and foreign literature in recent years, the characteristics and application of various treatment methods and new treatment modes for femoral neck fracture in the elderly were summarized and analyzed. Results: The elderly non-displaced femoral neck fracture should be treated surgically, and conservative treatment has a high risk of secondary displacement. The displaced fracture should be operated as soon as possible. There is no difference in long-term functional outcome between hemiarthroplasty and total hip arthroplasty. Hemiarthroplasty has less intraoperative blood loss, shorter operation time, and is suitable for the elderly patients with poor basic condition. Total hip arthroplasty is suitable for the elderly patients with better basic condition and higher demand of life quality. MDT can effectively reduce preoperative waiting time and length of stay, reduce the incidence of medical complications, improve the nutritional status of patients, and reduce the mortality of patients. Conclusion: Significant results have been achieved in the treatment of femoral neck fractures in the elderly by methods such as internal fixation, hip arthroplasty, and MDT.
Chapter
Fractures of the proximal femur, commonly termed hip fracture, is a devastating injury for any age of patient. The injury carries a high mortality as well as significant morbidity and impact of function. They can be divided into intracapsular (also called subcapital) fractures and extracapsular fractures. Extracapsular fractures are further subdivided into basicervical, trochanteric, and subtrochanteric fractures. In this chapter we will discuss the epidemiology, assessment, classification, management, and outcome for patients of intracapsular (subcapital) fractures.
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Since cut-out still remains one of the major clinical challenges in the field of osteoporotic proximal femur fractures, remarkable developments have been made in improving treatment concepts. However, the mechanics of these complications have not been fully understood.We hypothesize using the experimental data and a theoretical model that a previous rotation of the femoral head due to de-central implant positioning can initiate a cut-out. In this investigation we analysed our experimental data using two common screws (DHS/Gamma 3) and helical blades (PFN A/TFN) for the fixation of femur fractures in a simple theoretical model applying typical gait pattern on de-central positioned implants. In previous tests during a forced implant rotation by a biomechanical testing machine in a human femoral head the two screws showed failure symptoms (2-6Nm) at the same magnitude as torques acting in the hip during daily activities with de-central implant positioning, while the helical blades showed a better stability (10-20Nm).To calculate the torque of the head around the implant only the force and the leverarm is needed (N [Nm] = F [N] * × [m]). The force F is a product of the mass M [kg] multiplied by the acceleration g [m/s2]. The leverarm is the distance between the center of the head of femur and the implant center on a horizontal line. Using 50% of 75 kg body weight a torque of 0.37Nm for the 1 mm decentralized position and 1.1Nm for the 3 mm decentralized position of the implant was calculated. At 250% BW, appropriate to a normal step, torques of 1.8Nm (1 mm) and 5.5Nm (3 mm) have been calculated.Comparing of the experimental and theoretical results shows that both screws fail in the same magnitude as torques occur in a more than 3 mm de-central positioned implant. We conclude the center-center position in the head of femur of any kind of lag screw or blade is to be achieved to minimize rotation of the femoral head and to prevent further mechanical complications.
Article
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Internal fixation of intracapsular hip fractures results in a high failure rate with non-union and avascular necrosis being the two most important complications. In order to prevent these possible complications treatment should consist of an anatomical reduction and stable fixation by insertion of a low volume, dynamic implant, providing angular and rotational stability to the femoral head. According to these principles a new implant, the dynamic locking blade plate (DLBP) was designed for the fixation of intracapsular hip fractures. We performed a biomechanical analysis in synthetic bone to compare the rotational stability and cut out resistance of the DLBP with a conventional sliding hip screw (SHS) and the more recently developed Twin Hook. The rotational stability of the DLBP proved to be three times higher than the rotational stability of a SHS and two times higher than the Twin Hook. There was no major difference in cut out resistance between the different implants. The design of the DLBP and possible advantages with regard to the healing of an intracapsular hip fracture are discussed.
Article
1 . The arterial pattern and the histological features in the femoral head and neck were studied at necropsy in twenty-five specimens with intracapsular fractures. An improved visual-arteriographic method employing barium sulphate dyed with Prussian blue was used. Twenty-three of the fractures were from a few days to twenty-four weeks old and two were seven and ten years old. Nineteen had been nailed or nail-plated. 2. The results were divided into four groups according to the state of the femoral head. In the first group, four heads were histologically viable and had a normal vascular pattern; in the second group, four showed partial avascular necrosis with part of the head retaining a normal blood supply; in the third group, ten had avascular necrosis in all or most of the head and showed little or no revasculanisation; and in the fourth group, seven showed extensive revascularisation of grossly necrotic heads. Total or subtotal capital necrosis had occurred in 64 per cent and total or partial necrosis in 84 per cent of the specimens. The results indicated that interruption of the retinacular vessels was the cause of gross necrosis; and that in most cases an intact blood supply through the ligamentum teres cannot keep more than a part of the head alive when the other vessels are cut off. Occasionally the ligamentum teres is torn by the nail, or though intact, its blood supply is interrupted. This accounts for completion of avascular necrosis in most cases with total capital necrosis. Viability of the subfoveal area from an intact supply through the ligamentum teres was the main source of revascularisation after capital necrosis. Other sources–from across a uniting fracture line, from growth of soft tissue round the head and neck and from other small viable foci in the head and neck–were much less important and the degree of revascularisation was generally limited. Revascularisation was accompanied by fibrocellular invasion of the marrow, differentiation of cells and the formation of oil cysts whereby the necrotic fat is removed; but bony reconstitution was limited. 3. Six fractures were uniting and another had united by bone making an overall union frequency of 50 per cent considering only the nailed fractures older than two weeks. Four of them (57 per cent) showed total or subtotal capital necrosis. In fractures older than two weeks the frequency of union among the eleven nailed fractures with avascular necrosis was 36 per cent, and it was 100 per cent among the three nailed ones with viable or substantially viable heads. Necrosis of the neck side of the fracture was unrelated to non-union because it soon becomes invaded by fibrovascular tissue and new bone. 4. Fibrosis was the basis of union when the head was dead but examination of older fractures at necropsy is needed to assess the long-term results of revascularisation and union. The clinical desirability or otherwise of capital revascularisation after necrosis also needs to be studied.
Article
- Non-displaced fractures of the femoral neck are generally internally fixated while preserving the femoral head.- The current guideline states that conservative treatment of non-displaced (impacted) femoral neck fractures may be considered in patients with a 'healthy' patient profile and in patients who have already borne weight on the broken hip.- This literature review shows that conservative treatment of patients with impacted hip fractures fails in approximately 30% of the cases.- In most cases, patients in whom conservative treatment has failed will receive a femoral neck prosthesis or total hip replacement.- The placement of femoral neck prosthesis has a higher surgical and anaesthesiological risk compared to internal fixation of the non-displaced femoral neck fracture.- Given the quality of surgical techniques and improvement in perioperative care, the operative risk is limited and direct internal fixation should be strongly considered for non-displaced femoral neck fractures in all patients whose life expectancy is longer than 2 weeks.
Article
We prospectively studied 1023 patients who sustained an intracapsular hip fracture that was treated with internal fixation using contemporary methods. The overall incidence of avascular necrosis (AVN) was 6.6%. AVN was less common for undisplaced (4.0%) than for displaced fractures (9.5%) and in men (4.9%) than women (11.4%) who had a displaced fracture. The incidence of AVN for those aged less than 60 years and who sustained a displaced fracture was 20.6%, compared to 12.5% for those aged 60-80 years and 2.5% for those aged more than 80 years. Our study showed an increased risk of AVN with younger age and in females with a displaced fracture. We found no association between the incidence of AVN and the interval between injury to surgery.
Article
224 patients with undisplaced femoral neck fractures treated with two parallel Hansson hook pins were studied. After a mean follow-up time of 32 months (S.D. 5.2), 15% had a reoperation. 11% were considered failures, mostly avascular necrosis, and 9% had a secondary arthroplasty. Possible risk factors for poor outcome were analysed. Neither high age nor surgical delay was associated with increased failure rate. Survivors received a questionnaire, and 40% stated that they had mild or severe pain in the hip when walking, 25% had pain at rest and 25 stated that they thought "always" or "often" about their injury. The younger the patient, the more frequent the report of subjective pain. 51% of individuals under 80 years reported pain when walking, compared to 27% aged 80 or older (p=0.016). Corresponding numbers for pain at rest were 32 and 12% (p=0.034). The failure rate did not differ between the age groups, but the younger patients had more reoperations (p=0.046) and thought more frequently about their injury (p=0.016). An undisplaced femoral neck fracture is a major injury with a long-term daily discomfort in about 25% and clinical failure in 11%.
Article
The Dynamic Hip Screw is well established for the treatment of femoral neck fractures. However, cut-out occurs in 1-6% of all cases. This study compared the biomechanical performance of a helical shaped implant (DHS-Blade) to the Dynamic Hip Screw in an unstable femoral neck fracture model. Ten pairs of human cadaveric femora were either instrumented with a DHS-Blade or a Dynamic Hip Screw. Osteotomies were created using a custom-made saw-guide. Cyclic loading was performed by introducing in vivo measured load-trajectories to the femoral head. Starting at 1500 N, the load was stepwise increased until failure of the construct. Radiographs were taken in 5000 cycles increments to identify onset of femoral head migration with respect to the implant. A survival analysis was performed on the cycles to onset of migration. A paired t-test was carried out on the displacements of the femoral head relative to the shaft as determined by optical motion tracking. One hundred percent migrations occurred for the Dynamic Hip Screw compared to 50% for the DHS-Blade. The survival probability in terms of implant anchorage was found higher for the blade (P=0.023). However, significant higher deformation of the repair construct was observed for the DHS-Blade (P=0.004). The study showed superior implant anchorage of the DHS-Blade compared to the DHS, which might reduce the cut-out risk. Nevertheless, the blade allowed higher deformation of the femur mainly resulting in shortening of the neck, which might be due to a systematic loss of fracture reduction.
Article
Fracture healing is a repair process of a mechanical discontinuity loss of force transmission, and pathological mobility of bone. Through a sequence of changes of tissue development and geometry, the original structural integrity is restored. The recovery of rigidity and strength is related to tissue differentiation. In unified theory of non-operative and operative stabilized fractures, the mechanics of primary bone healing involves a complex interplay of physical and biological factors. The different patterns of bone repair respond to physical influences including strain tolerance.
Article
A prospective, randomized trial of 104 consecutive patients with displaced fractures of the femoral neck treated with either a sliding screw plate or four AO cancellous bone screws was performed to study the influence of the fixation device and the fixation procedure on the vascularity of the femoral head. The vitality of the femoral head was determined by 99mTc-MDP scintigraphy performed 2-3 months after the operation. Eighty-seven patients (84 per cent) were available for assessment. The two treatment groups were comparable with regard to age, degree of primary displacement and quality of reduction. There were significantly more (P less than 0.01) avascular femoral heads or femoral heads with reduced vascularity in the sliding screw plate group (14/40, 35 per cent) than in the four AO cancellous bone screw group (5/47, 11 per cent).
Article
With the aid of Tc-MDP-scintimetry 1-2 weeks after nailing of femoral neck fractures, it is possible to distinguish fractures liable to complications. Due to the suspicion that frequent peroperative vascular damage was caused by the four-flanged nail (Rydell), a less traumatizing cylindric nail (Hansson) with an insertion instrument was used. In a prospective investigation in January 1981-February 1982, which included all intracapsular femoral neck fractures, the two above-mentioned methods of osteosynthesis were used randomly. Intravital staining with tetracycline showed the peroperative circulation equivalent in Rydell and Hansson groups. A significant difference in postoperative isotope uptake could be noted between the two groups in 37 patients with undisplaced fractures. In 34 of 45 displaced fractures in the Rydell group evidence of circulatory deficiency appeared in the postoperative scintimetry but in only 23 of 52 of the displaced fractures in the Hansson group, a statistically significant difference. The latter figure corresponds well to the incidence of peroperatively registered severe vascular injury evaluated by tetracycline labelling.