Keywords
humeral fractures - humeral neck fractures/surgery - fracture fixation internal -
radiography
Introduction
Proximal humerus fractures are extremely common in orthopedic practice. Its incidence
is expected to increase even more due to the longevity and higher activity level of
the elderly population. According to Horak et al[1] they represent 5% of all fractures.[1] Conservative treatment of dislocated fractures does not result in good outcomes,
and most cases are surgically treated.[2]
[3] Although common, these fractures are still considered a therapeutic challenge, with
a wide range of fixation techniques, but still no clear evidence of superiority between
them, especially when the wide variability of individual characteristics and of fracture
patterns are considered.[4] Rigid implants, although widely used, may not be suitable for some patients, especially
those with osteoporotic bones.[2]
[4]
[5] Arthroplasty surgeries have not been able to obtain better functional results compared
with reconstructive surgeries, which are mostly reserved as salvage methods for synthesis
failures.[2]
[6]
[7] This is reinforced by the concept of controlled impaction, well demonstrated by
Resch et al[7] in different studies. In addition, some authors believe that the ideal implant would
be a semi-rigid device that allows the bone compaction process and fracture remodeling
during the healing process and concurrently offers stability to osteosynthesis.[2]
[8]
[9]
[10]
[11] Supported by the literature and based on these principles, we feel that the use
of threaded pins, respecting concepts of controlled impaction/semi-rigid fixation,
is an appropriate technique for proximal humeral fractures treatment.
The primary objective of the present study was to evaluate proximal humerus fractures
consolidation by radiographic examination of patients submitted to percutaneous fixation
with threaded pins. The secondary objective was to identify aspects predisposing to
loss of reduction.
Material and Methods
The present study evaluated retrospectively 46 patients with acute, proximal humeral
fractures surgically treated with reduction and percutaneous 3.5-mm threaded pins
fixation within 2 weeks from the day of trauma. Four patients who, although treated
with this technique, presented three-part fractures not requiring an intervention
at the greater tubercle after closed reduction, were excluded. As such, the sample
consisted of 42 patients. All of the patients were operated on by four senior surgeons
from our service. The sample included 35 women and 7 men, who were followed-up for
a minimum period of 2 months postoperatively. A total of 11 patients were from the
public healthcare system, and 31 patients were from the private healthcare system.
Threaded pins reduction and positioning were performed under intraoperative radiological
visualization using an image intensifier. Maintenance of fracture reduction and lesion
consolidation were evaluated at anteroposterior, scapular and Velpeau radiographic
views at the 1st, 2nd and 4th weeks postoperatively. The Velpeau view is an alternative to the axillary view without
sling removal; the patient is placed in 20° to 30° posterior inclination, with the
trunk under the chassis, which is located inferiorly to the shoulder, and then the
beam is positioned superiorly to the shoulder, perpendicularly to the horizontal plane
([Figure 1]). Threaded pins were removed between the 4th and 5th weeks after the procedure. In addition, radiographs were taken on the 2nd, 4th, and 8th weeks after the removal of the wire ([Figures 2]
[3]
[4]
[5]). The patients were immobilized with a Velpeau sling during the postoperative period
until the removal of the pin. Passive shoulder movements were only allowed after the
removal of the implants. Nonconsolidation was defined as cases requiring reintervention
or evolving to pseudarthrosis within 4 to 5 weeks. Loss of reduction was defined as
any surgical humeral neck deviation in postoperative radiographs performed up to the
removal of the pin compared to intraoperative radiographs.
Fig. 1 Velpeau radiographic view.
Fig. 2 Preoperative radiograph (A); Postoperative radiograph after 4 weeks (B, C); Postoperative radiograph after 2 months (D).
Fig. 3 Preoperative radiograph (A); Intraoperative radiographs (B, C, D); Postoperative radiograph after 4 months (E, F, G).
Fig. 4 Preoperative radiograph (A, B); Intraoperative radiographs (C, D); Postoperative radiograph after 4 months (E, F).
Fig. 5 Preoperative radiograph (A); Postoperative radiographs after 4 weeks (B); Postoperative radiograph after 3 months (C).
Results
The mean age of the 42 patients included in the study was 58.5 years old, whereas
the median age was 63.5 years old ([Table 1]). From the total of 42 patients, 38 presented fracture consolidation (90.4%) ([Table 2]). In addition, reduction was sustained in 35 patients (83.3%) and lost in 7 patients
(16.6%) ([Table 3]). Among the 7 patients with loss of the surgically obtained reduction, only 3 presented
no fracture consolidation (42.8%). All of the cases of loss of reduction presented
the surgical neck medialization after pin fixation. The three patients with no consolidation
were submitted to a reintervention with a locked proximal humerus plate ([Figure 6]). One patient had loss of reduction at the immediate postoperative period and he
was submitted to a reintervention within 24 hours, consisting of open reduction and
fixation with threaded pins; although evolving to consolidation, this subject was
excluded from the good outcome group. Thus, 4 patients were included in the nonconsolidation
group (9.5%). The mean age of the patients with sustained reduction, loss of reduction
and submitted to reintervention was 56.6 (±17.6), 66.7 (±15.7) and 73.6 (±8.6) years
old, respectively. ([Table 4]). Cases with loss of reduction included a more distal fracture and some lesions
with fragment comminution, in contrast to cases with sustained postoperative reduction.
Fig. 6 Preoperative radiograph (A, B); Postoperative radiographs after 2 weeks with loss of reduction (C, D); Postoperative radiograph 2 months after revision with locking plate (E).
Table 1
|
Mean age (years old)
|
58.47619048
|
|
Median age (years old)
|
63.5
|
|
Range (years old)
|
15–85
|
Table 2
|
CONSOLIDATION
|
|
YES
|
NO
|
TOTAL
|
|
38
|
4
|
42
|
|
0.904
|
0.095
|
1
|
Table 3
|
LOSS OF REDUCTION
|
|
YES
|
NO
|
TOTAL
|
|
7
|
35
|
42
|
|
0.166667
|
0.83333333
|
1
|
Table 4
|
PATIENTS WITH LOSS OF REDUCTION
|
|
DEVIATION
|
AGE
|
CONSOLIDATION
|
HEALTHCARE SYSTEM
|
|
Medial
|
84
|
Absent
|
PRIVATE
|
|
Valgus
|
62
|
Present
|
PRIVATE
|
|
Medial/Anterior/Varus
|
85
|
Present
|
PRIVATE
|
|
Medial/Anterior
|
74
|
Absent
|
PUBLIC
|
|
Medial/Anterior
|
63
|
Absent
|
PUBLIC
|
|
Medial/Varus
|
64
|
Present
|
PUBLIC
|
|
Varus
|
35
|
Present
|
PRIVATE
|
Discussion
The treatment of proximal humerus fractures is controversial. Several techniques are
described, ranging from sling immobilization to arthroplasty replacement. Since different
therapeutic modalities in the same fracture pattern show similar radiographic and
functional results, there is no gold standard. The current literature reports a considerably
high complication rate related to rigid implants, such as loss of reduction, nonconsolidation
and screws cut-out, which is fairly frequent in fixations with locked screw plate,
either due to material mispositioning, fracture remodeling or late necrosis.[10]
[12]
[13]
The percutaneous fixation technique follows the principles of implant design advocated
by Resch, that is, controlled impaction, peak force direction and semi-rigid implant.[2] We believe that humeral neck fixation with threaded pins allows some guided accommodation
of the fracture focus, favoring consolidation. Resch and Hertel describe these two
phenomena as guide impaction and sintering effect.[2]
[7]
[9] Since the pins are removed after consolidation, they can be placed in a subchondral
position, where the humeral head bone is denser, improving fixation. Implant removal
avoids the risk of late complications, such as proximal epiphyseal cut-out. Due to
their lower morbidity, another advantage of percutaneous pins is the lower aggression
to muscular and vascular tissues around the shoulder, resulting in less pain, shorter
hospitalization, better cosmesis and, most importantly, lower damage to the fracture
focus vascularization. Since the clavipectoral fascia is not opened, the fracture
hematoma is maintained, which contributes to bone healing. This may be one of the
reasons why we noticed a bone callus formation in most control radiographies taken
at between 3 to 4 weeks, which is less common in open osteosynthesis with absolute
stability.[14]
[15]
[16] Another advantage of percutaneous fixation with threaded pins is its lower cost
compared to the fixation with plate and locked rods in humeral neck fractures.
In our service, percutaneous fixation with threaded pins has been shown as an alternative
for the surgical treatment of proximal humeral neck fractures due to the favorable
outcomes observed at the radiographic evaluation, with a 90.4% consolidation index,
similar to the rates reported in the literature.[17] In patients < 60 years old, the fracture consolidation rate was 100%.
As a disadvantage, threaded pins are not as effective in providing stability for fracture
fixation as locked plates. In cases with loss of reduction, a lower trace (towards
the diaphysis) and a comminution of both the medial and lateral cortical necks were
observed.[9]
[10]
[18] This finding is consistent with the notion that anatomical fracture reduction and
medial cortical support reconfiguration are critical to consolidation.[10] The mean age of the patients with loss of reduction (66.71 ± 15.7 years old) and
those submitted to reintervention using another method (71.2 ± 8.5 years old) were
higher compared to the mean age from all patients (58.47 ± 18.3 years old) ([Table 5]). This corroborates reports from the literature that older patients have more osteoporotic
bones, making it harder to fix and maintain reduction regardless of the implant.
Table 5
|
Group
|
Mean age (years old)
|
Standard deviation
|
|
Sustained reduction
|
56.2
|
18.1
|
|
Loss of reduction
|
66.7
|
15.7
|
|
Reintervention
|
71.25
|
8.5
|
Compared to methods following the same fixation principles, such as the Humerusblock
system (an implant that attaches a device to the humeral shaft to lock wires), the
present study had a similar rate of reintervention and revision with locked plates.[19] Some complications related to the fixation method, including proximal or distal
wire migration, can be observed when using threaded pins or the Humerusblock system;
such complications require wire removal if the treatment is complete or, at least,
retroceding the migrated wire.[20]
Conclusion
Percutaneous fixation of deviated fractures of the humeral surgical neck with threaded
pins may be considered in the treatment of this type of fracture, with consolidation
(90.4%), complication and nonconsolidation rates (9.5%) similar to those observed
with other fixation methods. Since advanced age, medial cortical loss, and metaphyseal
extension were related to an increased loss of reduction and possibly to nonconsolidation,
these factors should be taken into account when indicating this technique.
