VOL. 91-B, No. 5, MAY 2009 627
Percutaneous fusion of the sacroiliac joint
with hollow modular anchorage screws
CLINICAL AND RADIOLOGICAL OUTCOME
A. Khurana,
A. R. Guha,
K. Mohanty,
S. Ahuja
From University
Hospital of Wales,
Cardiff, Wales
„ A. Khurana, MRCS, MS, MSc,
Specialist Registrar, Trauma &
Orthopaedics
„ A. R. Guha, FRCS, MS,
Specialist Registrar, Trauma &
Orthopaedics
„ K. Mohanty, FRCS,
FRCS(Orth), MSc, Consultant
Orthopaedic Surgeon
„ S. Ahuja, FRCS, FRCS(Orth),
MSc, Consultant Orthopaedic
Surgeon
Department of Orthopaedics
University Hospital of Wales,
Heath Park, Cardiff & Vale NHS
Trust, Cardiff CF14 4XW, UK.
Correspondence should be sent
to Mr A. Khurana at; e-mail:
ashish.khurana@doctors.org.uk
©2009 British Editorial Society
of Bone and Joint Surgery
doi:10.1302/0301-620X.91B5.
21519 $2.00
J Bone Joint Surg [Br]
2009;91-B:627-31.
Received 8 July 2008;
Accepted after revision 15
January 2009
We reviewed 15 consecutive patients, 11 women and four men, with a mean age of 48.7
years (37.3 to 62.6), who between July 2004 and August 2007 had undergone percutaneous
sacroiliac fusion using hollow modular anchorage screws filled with demineralised bone
matrix.
Each patient was carefully assessed to exclude other conditions and underwent pre-
operative CT and MR scans. The diagnosis of symptomatic sacroiliac disease was confirmed
by an injection of local anaesthetic and steroid under image intensifier control.
The short form-36 questionnaire and Majeed’s scoring system were used for pre- and
post-operative functional evaluation. Post-operative radiological evaluation was performed
using plain radiographs.
Intra-operative blood loss was minimal and there were no post-operative clinical or
radiological complications. The mean follow-up was for 17 months (9 to 39). The mean short
form-36 scores improved from 37 (23 to 51) to 80 (67 to 92) for physical function and from 53
(34 to 73) to 86 (70 to 98) for general health (p = 0.037). The mean Majeed’s score improved
from 37 (18 to 54) pre-operatively to 79 (63 to 96) post-operatively (p = 0.014). There were 13
good to excellent results. The remaining two patients improved in short form-36 from a
mean of 29 (26 to 35) to 48 (44 to 52). Their persistent pain was probably due to concurrent
lumbar pathology.
We conclude that percutaneous hollow modular anchorage screws are a satisfactory
method of achieving sacroiliac fusion.
The sacroiliac joint may be the source of pain
in 10% to 32% of patients presenting with
low back pain.1,2 There is no consensus about
the management of sacroiliac joint pain.
Several methods of treatment have been
described, with varying degrees of success.1,3,4
Operative treatment usually takes the form of
sacroiliac fusion.5,6 Open arthrodesis has
been described using the Smith-Petersen5 or a
midline fascial-splitting approach,7 which can
cause wound problems.
In this study, we describe a technique of per-
cutaneous sacroiliac fusion and present its clin-
ical and radiological outcome.
Patients and Methods
We reviewed 15 consecutive patients who had
undergone a sacroiliac fusion at our hospital
for a chronic non-traumatic condition between
July 2004 and August 2007. These who had
additional pelvic pathology or required further
surgery were excluded from the study, as were
others operated on for injuries of the sacroiliac
joint. We recorded the patient’s demographics,
diagnosis and post-operative complications.
There were 11 women and four men, with a
mean age of 48.7 years (37.3 to 62.6).
Each patient had a sacroiliac fusion by a per-
cutaneous technique using hollow modular
anchorage screws (Aescalup Ltd, Tuttlingen,
Germany) packed with a bone substitute.
Diagnosis. The diagnosis of sacroiliac joint dis-
ease was based on the clinical presentation,
radiological investigations and diagnostic
injections. The aetiology in these patients is
shown in Table I. Clinical evaluation consisted
of Patrick’s test,8 Gaenslen’s test,9 and tender-
ness over the posterior sacroiliac joint. A full
clinical and neurological examination, includ-
ing sacroiliac joint injections, was performed
to exclude any other cause of low back pain.
Plain radiographs focused on the sacroiliac
joint were used to identify signs of arthritis or
sclerosis. Further radiological examination
included a CT scan of the sacroiliac joint and
an MR scan of both the lumbosacral spine and
the sacroiliac joint to demarcate the joint
pathology in detail. An MR scan is a more

628 A. KHURANA, A. R. GUHA, K. MOHANTY, S. AHUJA
THE JOURNAL OF BONE AND JOINT SURGERY
accurate method of identifying coexisting neurological
pathology or compression in the lumbosacral spine,
whereas a CT scan will confirm the extent of arthritis of the
sacroiliac joint. Confirmatory diagnostic injections into the
sacroiliac joint were performed by a consultant radiologist
under fluoroscopic guidance with the patient lying prone
and with a caudal tilt of approximately 20° of the C-arm.
Non-ionic contrast was used to confirm that the needle was
in the joint and local anaesthetic and corticosteroid were
introduced. Surgery was offered to patients only when the
clinical symptoms and signs were confirmed by the radio-
logical findings, the injection relieved the patient’s pain,
and no other pathological process could be identified. Of
the 15 patients, six had undergone spinal surgery previ-
ously. Each patient had low back pain or pain in the
buttock as their principal symptom. Unilateral fusion was
carried out in 11 cases and bilateral procedures in four.
Surgical technique. Adequate bowel preparation is of para-
mount importance to ensure a clear fluoroscopic view of
the sacrum and screws. Patients are given a liquid diet for
24 hours pre-operatively and laxatives on the night before
surgery. Patients are positioned supine on a radiolucent
operating table and a lateral view is taken to identify the
starting point for the guide wire. An incision of approxi-
mately 1.5 cm is used and a guide wire is introduced into
the centre of the triangular portion of the sacroiliac joint,
just under the iliac overhang. Inlet and outlet views are used
to advance the guide wire. The inlet view is used to guide
the wire in the anteroposterior (AP) plane (Fig. 1) and the
outlet view gives a true AP view of the sacrum. The aim is
to place the guide wire between the superior and inferior
end-plates of the first sacral vertebra (Fig. 2). Once the
guide wire is in a satisfactory position, a 10 mm hollow
modular anchorage screw is inserted over it. The cannu-
lated screw is packed with a bone substitute (DBX, Demin-
eralised Bone Matrix, Synthes Inc, West Chester,
Pennsylvania). Post-operatively, patients were mobilised
partially weight-bearing for six weeks, after which they
gradually increased the weight taken until they were fully
weight-bearing at 12 weeks.
Outcome measures. The outcome was assessed indepen-
dently by two authors (AK and ARG). Pre- and post-
operative functional evaluation was performed using the
short form (SF)-36 questionnaire10 and Majeed’s scoring
system.11 The SF-36 is a reliable, validated scoring system
which gives a measure of quality of life. Majeed’s scoring
system was originally developed to assess functional out-
come after pelvic injuries. It is based on five criteria: pain,
standing, sitting, sexual function and performance at
work.
Each patient had AP, inlet and outlet views of the pelvis
taken at three and six months post-operatively, and at final
follow-up. These are not a very accurate method of con-
firming fusion, but we took the absence of clinical symp-
toms and signs and the absence of any radiological signs of
metal failure or lucency to indicate fusion of the sacroiliac
joint. Further radiological evaluation was performed only if
patients reported continuing symptoms. In these cases we
obtained a CT scan to determine whether or not fusion had
occurred, and an MR scan to identify any alternative source
of pain. Two patients reported continuing symptoms after
12 months’ follow-up and underwent CT and MR scanning.
Statistics. Wilcoxon’s signed-ranks test was used as a non-
parametric alternative to the t-test to compare the pre- and
post-operative results. Statistical calculations were per-
formed using SPSS software version 14 (SPSS Inc., Chicago,
Illinois). A p-value < 0.05 was considered significant.
Results
The mean follow-up was for 17 months (9 to 39).
The mean SF-36 scores improved from 37 (23 to 51) to
80 (67 to 92) for physical function and from 53 (34 to 73)
to 86 (70 to 98) for general health (Table II). These differ-
ences were statistically significant (p = 0.037). The mean
Majeed score improved from 37 (18 to 54) pre-operatively
to 79 (62 to 96) post-operatively (p = 0.014). Based on
Majeed’s score, 13 patients had good or excellent results.
The remaining two improved from 21 and 33 to 57 and 64,
respectively. Their SF-36 scores improved from a mean of
29 (23 to 35) to 48 (44 to 52).
Intra-operative blood loss was minimal (< 50 ml) in all
cases. No patient required autologous bone grafting. There
were no post-operative neurological or wound complica-
tions. There were no obvious problems with screw place-
ment, such as breach of the anterior cortex or the nerve
root foramen. There were no cases of implant failure. The
mean post-operative hospital stay was 2.7 days (1 to 7).
Fusion was obtained in all patients and none required fur-
ther surgery. In the two patients with a fair result, fusion
was confirmed with a CT scan.
Discussion
The sacroiliac joint may be the source of pain in a signifi-
cant number of patients with low back pain1,2 and may be
a source of persistent pain after lumbar fusion.2 It allows
approximately 2° to 4° of movement in the sagittal plane.
As it is a synovial joint, it can develop degenerative
changes.5,12 Sacroiliac dysfunction is a term used to
describe pain from the joint with no demonstrable lesion,
but with a presumed underlying biomechanical dis-
order.13,14 It is diagnosed by Patrick’s8 and Gaenslen’s9
Table I. Aetiology
Diagnosis Number
Osteoarthritis 7
Sacroiliac joint
Dysfunction 4
Instability 3
Inflammatory arthritis 1