This document reports on three cases of pseudarthrosis (nonunion) of rib fractures that were treated with open reduction and internal fixation using locking compression plates. In the first case, a 56-year-old man presented with persistent pain 8 months after rib fractures. Imaging showed a pseudarthrosis of the ninth rib. Osteosynthesis with a locking compression plate resulted in pain relief. The second case involved a 44-year-old man with pseudarthroses of multiple ribs treated with plates on three ribs, resulting in pain relief. The third case was a 42-year-old man with three rib pseudarthroses treated with plates, who had partial pain relief and later hardware removal

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BY
T HE J OURNAL
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AND J OINT
S URGERY, I NCORPORATED
Pseudarthrosis of the Ribs Treated with a
Locking Compression Plate
A Report of Three Cases
By T.J. Gardenbroek, MD, M. Bemelman, MD, and L.P.H. Leenen, MD, PhD
Investigation performed at the Department of Traumatology, University Medical Center Utrecht, Utrecht, The Netherlands
P
seudarthrosis of rib fractures is rarely observed, and, to
our knowledge, only nine cases have been described in
the English-language literature1-9. In one case the suggested treatment consisted of restriction of movement. In three
cases resection of the pseudarthrosis was described, and in two
cases an association with a synovial cyst was found.
We present three cases in which pseudarthroses of rib
fractures were treated with open reduction and internal fixation with use of locking compression plates. All patients were
informed that data concerning their cases would be submitted
for publication, and they consented.
Case Report
ASE 1. A fifty-six-year-old man experienced thoracic
trauma eight months prior to the time of presentation.
He sustained fractures of the eighth, ninth, and tenth ribs on
the left side. A thoracic drain was placed to treat a pneumothorax, and the rib fractures were treated nonoperatively. Eight
months after the injury, the patient complained of persistent
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pain, especially during deep inhalation and coughing. The
patient had a visual analog score of 6 (of 10) for pain. Physical
examination revealed a painful area on the left side of the
thorax. Conventional radiography showed a pseudarthrosis of
the ninth rib; the fractures of the eighth and tenth ribs
were consolidated. A computed tomography scan confirmed
the diagnosis and suggested interposition of tissue within the
fracture of the ninth rib. Because of the duration of the
complaints and the lack of improvement with nonoperative
measures, osteosynthesis of the ninth rib was performed. Interposition of muscle tissue within the fracture was confirmed
during the operation, and the tissue was removed. Osteosynthesis was carried out with use of a small-fragment locking
compression plate with self-drilling unicortical screws (Synthes;
West Chester, Pennsylvania). Intraoperatively, the patient had
development of a pneumothorax, for which a pleural drain was
introduced. After a follow-up period of nineteen months, the
patient was completely pain-free, with a visual analog scale
score of 1.
Fig. 1
Locking compression plate drilling guide with an integrated drill with limited penetration (LCP Universal Drill Guide
3.5, item number 323.505; Synthes).
Disclosure: The authors did not receive any outside funding or grants in support of their research for or preparation of this work. Neither they nor a
member of their immediate families received payments or other benefits or a commitment or agreement to provide such benefits from a commercial
entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, division, center, clinical practice,
or other charitable or nonprofit organization with which the authors, or a member of their immediate families, are affiliated or associated.
J Bone Joint Surg Am. 2009;91:1477-9
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doi:10.2106/JBJS.H.00830
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pleura at all screw locations. Furthermore, injury to the upper
part of the right lung, due to the manual pre-drilling, was revealed. The third rib showed no parietal pleural penetration; at
most, there was a translucent subpleural spot where the drill of
the locking compression plate guide had reached subpleural
tissue. As a result of these findings, two subsequent patients with
pseudarthrosis of the ribs were managed with the new technique.
Fig. 2-A
Figs. 2-A and 2-B Case 3. Fig. 2-A Preoperative three-dimensional
computed tomography scan showing the characteristics of
pseudarthroses of the sixth, seventh, and eighth ribs.
Therapeutic Considerations
While planning the first operation, we presumed that the shortest
self-drilling locking head screws would not penetrate the second
cortex of the rib sufficiently to create a pneumothorax. In practice,
this proved otherwise. Because of this complication, we developed
a different technique involving the use of the locking compression
plate drilling guide with an integrated drill with limited penetration
(LCP Universal Drill Guide 3.5, item number 323.505; Synthes) (Fig. 1).
This readily available device enables controlled drilling
to a depth of 6 mm. In order to evaluate whether this technique would work in practice, we performed a laboratory test
on a human cadaver. Three ribs were exposed on the right side
of the thorax in the midaxillary plane.
We tested three different operative techniques of reconstruction with a locking compression plate. On the upper
rib, the first technique was performed with normal manual
pre-drilling of both cortices and insertion of non-self-drilling
(green) unicortical screws. Care was taken not to penetrate the
pleura. On the middle rib, the shortest self-drilling (blue)
locking head screws were inserted without any pre-drilling.
On the last rib, our third technique was used. With use
of the previously described locking compression plate drilling
guide (item number 323.505), holes were drilled to the maximum depth permitted by the drill (6 mm). Subsequently, the
shortest self-tapping screws (10 mm) were inserted.
The three ribs were then carefully extracted, with the
parietal and visceral pleurae being left intact. Inspection of the
dorsal side of the first two ribs showed penetration of the parietal
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CASE 2. A forty-four-year-old man experienced thoracic trauma
six months before the time of presentation. He sustained seven
rib fractures (involving the third through ninth ribs) on the left
side. The patient experienced persistent pain on mobilization
after nonoperative therapy. He had a visual analog scale score of
7 (of 10) for pain. Compression of the entire left side of the
thorax during physical examination was painful. Conventional
radiography revealed pseudarthrosis of the third, sixth, seventh,
eighth, and ninth ribs; the fourth and fifth ribs were healed.
Because of the severity and persistence of pain, osteosynthesis
was performed on the seventh, eighth, and ninth ribs. The
surgical approach was through one incision. During the operation, hypertrophic pseudarthroses with completely mobile
fracture ends were seen at all three levels. Osteosynthesis was
performed with use of three small-fragment locking compression plates. The locking compression plate drilling guide with
an integrated drill with limited penetration was used to prepare
drill-holes, which were filled with non-self-drilling unicortical
screws. The postoperative course was uneventful, and, after
twenty-six months of follow-up, the patient was completely
pain-free, with a visual analog scale score of 1 for pain.
Fig. 2-B
Three-dimensional computed tomography scan, made eighteen months
after the placement of three locking compression plates, showing
complete consolidation of the three nonunion sites.

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CASE 3. A forty-two-year-old man experienced high-energy
thoracic trauma with multiple rib fractures (involving the
fourth through tenth ribs) on the left side. During the outpatient clinic visits, the patient complained of persistent pain
in the left flank. He had a visual analog scale score of 7 (of 10)
for pain. A three-dimensional computed tomography reconstruction revealed pseudarthroses of the sixth, seventh, and
eighth ribs (Fig. 2-A). Because of the patient’s complaints of
persistent pain, osteosynthesis of the sixth, seventh, and eighth
ribs was performed. Through one incision, the three hypertrophic pseudarthroses were identified and osteosynthesis was
performed with use of three locking compression plates, each
with six non-self-drilling unicortical screws, after drilling with
use of the drill guide with the limited-penetration drill-bit. The
postoperative course was uneventful. Eighteen months after
the placement of the three locking compression plates, the
patient still experienced some discomfort with certain movements, probably because of the hardware. However, the character of the pain differed completely in comparison with the
preoperative pain. The patient had a visual analog scale score of
3 for pain. A three-dimensional computed tomography scan
showed complete consolidation of the fracture sites (Fig. 2-B).
Because of the discomfort, the implants were removed. The
patient then had a visual analog scale score of 1 for pain.
Discussion
seudarthrosis of the rib is rare; therefore, nonoperative
measures seem warranted in most cases. However, the crosssectional surface area of a single rib is not greater than 60
square mm10. Thus, in some cases a sufficiently large contact
surface may not be present to allow the healing process to
occur. Given that ribs move an average of 25,000 times per day
with respiration, it is surprising that pseudarthrosis of the ribs
is not seen more frequently. It is possible the phenomenon is
not often recognized or is asymptomatic.
The first patient in the present study had an isolated
pseudarthrosis of one rib, with consolidation of the adjacent
ribs. These findings suggest that stability was not an issue,
which was supported by the observation that the pseudarthrosis was due to soft-tissue interposition.
Both of the latter two patients originally had seven rib
fractures with five (Case 2) and three (Case 3) hypertrophic
pseudarthroses. The hypertrophic character of the nonunions
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suggested a problem with fracture stability. Thus, stabilization
through osteosynthesis seemed to be a logical approach.
The diagnosis of pseudarthrosis of rib fractures should
be considered when a patient complains of persistent pain
during movement and/or deep inspiration. The diagnosis can
be confirmed by means of conventional radiography; however,
in our opinion, a thoracic computed tomography scan is more
accurate for confirming the diagnosis and for providing essential information for preoperative planning. With conventional radiography, it is difficult to determine the exact location
of the pseudarthrosis or pseudarthroses; however, this is of
great importance when open reduction and internal fixation of
three ribs is planned through one incision.
Because of the unique anatomy of the rib, there are specific challenges to internal fixation. The rather flat structure of
the rib provides less screw purchase and could present some
difficulty in achieving rigid osteosynthesis, especially if one
prefers to perform unicortical fixation in order to reduce the
risk of pleural penetration. The use of a locking plate with angled screws instead of a standard non-locking plate is preferable
because it is the most rigid osteosynthesis system available11.
In the case of our first patient (Case 1), we had thought that
the shortest unicortical locking compression plate screws would
be short enough to prevent a pneumothorax, but they were not.
In the cadaver study, it was confirmed that even the shortest selfdrilling unicortical screws (10 mm) will penetrate the second
cortex of the rib. The use of the locking compression plate drill
guide with controlled limited penetration (item number 323.505;
Synthes) seemed to be a safe method in the cadaver study as no
penetration of the pleural tissue was seen. Our other two patients
(Cases 2 and 3) were managed with this new technique, and in
both cases there were no perioperative or postoperative complications and the pseudarthroses healed. This finding supports our
hypothesis that stabilization of a symptomatic pseudarthrosis
should be carried out and that the technique presented here
can result in safe osteosynthesis and bone healing. n
T.J. Gardenbroek, MD
M. Bemelman, MD
L.P.H. Leenen, MD, PhD
Department of Traumatology, Room G04.218, University Medical
Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
E-mail address for T.J. Gardenbroek: tjgardenbroek@gmail.com
References
1. Mith¨ fer K, Giza E. Pseudarthrosis of the first rib in the overhead athlete. Br J
o
Sports Med. 2004;38:221-2.
7. Brower AC, Woodlief RM. Pseudarthrosis at the first sternocostal synchondrosis. AJR Am J Roentgenol. 1980;135:1276-7.
2. Crosby LA, Rubino LJ. Subluxation of the sternoclavicular joint secondary to pseudarthrosis of the first and second ribs. A case report. J Bone Joint Surg Am. 2002;84:623-6.
8. Freiberger RH, Mayer V. Ununited bilateral fatigue fractures of the first
ribs. A case report and review of the literature. J Bone Joint Surg Am. 1964;46:
615-8.
3. Kara M, Alver G, Aksu O, Kavukcu S. Synovial cyst arising from pseudoarthrosis
x
of a rib fracture following trauma. Eur J Cardiothorac Surg. 2002;21:338.
4. Guttentag AR, Salwen JK. Keep your eyes on the ribs: the spectrum of normal
variants and diseases that involve the ribs. Radiographics. 1999;19:1125-42.
9. Aspin J. Anomalous ossification of ribs as a cause of pseudarthrosis. Br J
Radiol. 1950;23:15-7, illust.
5. Morris CS, Beltran JL. Giant synovial cyst associated with a pseudarthrosis of a
rib: MR appearance. AJR Am J Roentgenol. 1990;155:337-8.
10. Mohr M, Abrams E, Engel C, Long WB, Bottlang M. Geometry of human
ribs pertinent to orthopedic chest-wall reconstruction. J Biomech. 2007;40:
1310-7.
6. Borrelly J, Merle M, Hubert J, Grosdidier G, Wack B. [Compression of the brachial
plexus by a pseudarthrosis of the 1st rib]. Ann Chir Main. 1984;3:266-8. French.
11. Synthes Locking Compression Plate application notes. West Chester, PA:
Synthes; 2004.
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