Key developments in orthopaedic surgery
SECTION: Pg. 775
LENGTH: 2238 words
* How has arthroscopy
revolutionised joint surgery?
* How are digital
cameras and mobile phones improving management?
* What advantages do
the new bioabsorbable implants offer?
SIMON P FROSTICK BA, BM, MA (Oxon), FRCS
(Engl), DM (Oxon)
Professor of Orthopaedics, University of
VISHAL SAHNI MS, FRCS (Glasg), FRCS (Trauma
& Orthopaedics), M Ch (Orthopaedics)
Specialist Registrar, Royal Liverpool
We are witnessing an explosion of treatment
possibilities in both elective orthopaedics and orthopaedic trauma. The levels
of intervention are increasing, backed by evidence for the efficacy of the
treatment choices, availability of appropriate equipment and an improved
knowledge about the anatomy, physiology and biochemistry of musculoskeletal
This increase in our ability to successfully
undertake surgical treatment of our patients has inevitably resulted in
subspecialisation among orthopaedic surgeons. It is no longer possible for
there to be a general orthopaedic surgeon' who dabbles in all aspects of the
These changes also have a number of
implications for GPs. They need to be aware of the special interests of various
orthopaedic surgeons at their local hospital. A referral for a said condition
should be made preferably to an orthopaedician with a declared interest in that
condition. Also, if the local hospital does not cover all subspecialties, in
the best interest of patients GPs should be informed of this and provided with
a list of subspecialists from the nearby region.
* Arthroscopy The
majority of soft tissue pathologies in the knee are now treated
arthroscopically, but more recently there has been an increase in the use of
arthroscopic techniques in other joints, especially the shoulder.
Arthroscopic examinations of joints allow
surgeons to closely examine the internal structures. This has revolutionised
our understanding of pathological lesions and enabled surgeons to develop new
and effective solutions.
In the knee, anterior cruciate ligament
repair, meniscal repair and cartilage transfer operations are now relatively
common procedures. In the shoulder we now have the ability to undertake nearly
all soft tissue procedures arthroscopically.
In the Liverpool Upper limb Unit nearly 100
per cent of shoulder stabilisation procedures are performed using a variety of
arthroscopic techniques. A major advantage of this approach is that we can
fully assess the type of instability and the type and extent of any structural
lesions that are encountered.
Although the diagnosis of the instability is
a clinical diagnosis, an arthroscopic approach to the surgical treatment allows
us to tailor the procedure to the individual patient and to modify the
procedure with ease if any unexpected lesion is found.
Arthroscopy has also highlighted how little
we were able to see by open means: for example, a labral tear involving the
superior labrum and long head of biceps tether - referred to as a SLAP (superior
labrum anterior-posterior) tear - has only been identified since surgeons have
performed arthroscopy of the shoulder.
In our experience a SLAP tear is a common
cause of shoulder pain and disability, and repair results in an early return to
Since the first report of the SLAP lesion, an
increasing number of variations of the tear have been reported. Again it is our
experience that there is an almost infinite variety of superior labral lesions,
some of which need repair and some debridement. Some of the lesions are
associated with anterior dislocations, others exist in isolation and some are
probably degenerative in origin.
A spin-off of our understanding of the
arthroscopic pathoanatomy in shoulder instability is that we have a much
greater understanding of those types of instability that are not associated
with any structural lesion except for a loose capsule. In the past these
patients would be referred to as habitual dislocators or voluntary dislocators,
terms that have little meaning and even less understanding.
Now, however, it is apparent that there is a
spectrum of patients who have loose shoulders: at one extreme are patients who
have a collagen abnormality such as Ehlers-Danlos
syndrome, but there is a much larger population who also have
moderately loose shoulders. However, if it is associated with symptoms like
pain, a feeling of looseness', weakness and recurrent subluxations or
dislocations of the shoulder, they are said to have multi-directional
Approximately 80 per cent of these patients
benefit from physiotherapy and rehabilitation, while in the remaining 20 per
cent arthroscopic capsular shrinkage (ACS) may have a role.1,2 In ACS the
looseness of the capsule is reduced by heat at a specific temperature, delivered
through the end of a probe to shrink the capsule.
* Minimally invasive
joint replacement In the last five years or so minimally invasive surgery has
become headline news and joint replacements carried out using small incisions
have been very much in vogue. In the case of hip replacement the incision is
just over 7cm long rather than the 20-30cm incisions seen in conventional hip
replacement surgery - and some surgeons now prefer two even smaller incisions.3
More importantly the surgeon gains access to
the joint by going between muscles, tendons and ligaments, rather than cutting
through these soft tissues.4 Much of the pain associated with conventional hip
replacement surgery and recovery is due to severing these tissues, and so post-
operative pain in minimally invasive surgery is considerably reduced. Further,
patients can get up and walk sooner, their rehabilitation time is faster and
they return to their everyday activities much more quickly. Hip replacement as
a day-case procedure is now on the horizon.
In the last few years our laboratory-based
research and clinical knowledge have improved our understanding of joint
replacements and why and how they fail. This applies equally to joints of the
From small joints of the hand to the shoulder
joint, almost all joint replacements of the upper limb are now established, but
we are still constantly seeing and seeking improvements and new designs as well
as searching for better bearing surfaces. Anaesthetic and surgical techniques
have also developed. There is now no justification for allowing a patient with
significant arthritis to suffer with pain, and early referral in such cases is
Regional blocks and advanced anaesthetic
techniques have allowed us to reduce our dependence on general anaesthetic,
which has meant that fewer patients have to go through post-operative
A shorter incision and bone conserving
resurfacing arthroplasty, such as the Copeland hemiarthroplasty for the
shoulder, may mean that in the near future the Liverpool Upper Limb Unit might
offer patients shoulder replacement as day-case surgery - until now, patients
have been kept as inpatients for up to 7-8 days. Costs will be reduced, and patients
will be returned to their home environment much more quickly, which most of
* Digital imaging and
transfer The use of digital imaging by digital cameras or mobile phones in
orthopaedics has helped patients and doctors alike. Mobile phones with
high-resolution cameras are used to transmit radiographs to off-site
consultants to allow them to give advice regarding management.
It is envisaged that this scheme can include
GPs and if so, it should benefit the patient greatly by making specialist
advice available to them instantaneously.
As the specifications and clarity of imaging
continues to improve, the use of this ingenious method may increase even
* Robotic surgery and
computer-assisted surgery Both robotic surgery and CAS are now in use on an
experimental basis for total knee replacement in some NHS hospitals and show
some promise with regard to precision.5 However, they will have to be evaluated
rigorously for cost- effectiveness, increased operative time, learning curve
and actual benefit to the patient.
The robot assists the surgeon in performing
the surgery rather than performing the surgery itself. In conventional knee
replacement, a surgeon uses specialised cutting blocks, eyeballing', feel and
experience to make appropriate bone cuts for the best fitting of an implant.
Once a cut is made the bone cannot be
replaced and hence the carpenter's advice measure twice, cut once' is vital in
knee replacement surgery.
Robotic surgery and CAS use infrared cameras,
digitalised bone images and simple tracking devices to achieve alignment within
2deg and 2mm of total accuracy.
The potential benefits to the patient are
reduced risk of fat embolism as an intra-medullary rod is not used, and accurate
alignment and placement of the implant may extend its lifespan. Also, better
vision' may allow shorter incisions and minimally invasive surgery.
* Biomaterials Many
surgeons are now moving towards using devices made from bioabsorbable polymers
such as polylactic acid (PLA) and polyglycolic acid (PGA), including
interference screws, suture anchors and meniscal repair devices.
Bioabsorbable implants offer several
advantages over their metallic counterparts:
* Secure initial
fixation strength while allowing degradation
* Magnetic resonance
imaging (MRI) is not distorted
* Easier to revise
because there is no need for implant removal prior to revision surgery
* Though not visible
on radiographs, visible with MRI
In recent years suture anchors have become
popular for both open and arthroscopic repairs of avulsed ligaments or tendons,
most commonly for Bankart and rotator cuff repairs.
A knotless suture anchor is another step
forward and obviates the need for arthroscopically-tied, time-consuming and
bulky knots. A knotless suture anchor obviates the need for arthroscopic
knot-tying while providing a direct, secure, low-profile suture anchor repair.6
In the Liverpool Upper Limb Unit the use of
knotless anchors has reduced surgical time and increased the efficiency of the
fiascos Orthopaedics has been quick to embrace new technology, but new
technologies are not always without their faults. Two recent incidents
involving technological problems with the 3M Capital Hip System and the Sulzer
Hip System have put surgeons in a sombre mood and reinforced the conviction
that if new technology is to be used, checks and balances must be applied with
* The 3M Capital Hip
System In 1998 a hazard notice was issued by the Medical Devices Agency UK9
after poor short-term performance of the femoral component of the 3M Capital
Hip System was noted.
Between 1991 and 1997 the number of 3M
Capital Cemented Hip Systems (Capital Hip) sold to hospitals in the UK was
4688. The health authorities were advised to recall all patients who had
undergone the 3M Capital Hip System for clinical and radiological review. It
asked for consideration of revision surgery if the patient had evidence of
loosening of the femoral component.
A subsequent enquiry after reviewing data on
3700 implants concluded that the poorer performance of the Capital Hip, had it
been analysed separately, would have been apparent by the end of 1993, long
* The Sulzer Hip
System in USA A similar situation involved the Sulzer Inter-Op uncemented
acetabular implant, which was a part of the Sulzer Hip System. A manufacturing
error in the production left a machine oil residue on the implant that
prevented it from bonding to the patient's bone, and this forced the company to
recall nearly 25,000 hip implants. Unfortunately nearly 17,500 of these had
already been implanted in patients.
Due to this error a large number of patients
who had this cup implanted would require or already underwent a revision hip
operation, thereby increasing morbidity and mortality.
1 Lo IK, Bishop JY, Miniaci A, Flatow L.
Multidirectional instability: surgical decision making. Instr Course Lect
2 Frostick SP, Sinopidis C, Al Maskari S et
al. Arthroscopic capsular shrinkage of the shoulder for the treatment of
patients with multidirectional instability: minimum 2-year follow-up.
3 Berger RA. The technique of minimally
invasive total hip arthroplasty using the two-incision approach. Instr Course
4 Siguier T, Siguier M, Brumpt B.
Mini-incision anterior approach does not increase dislocation rate: a study of
1037 total hip replacements. Clin Ortho 2004;426:164-173
5 Siebert W, Mai S, Kober R, Heeckt PF.
Technique and first clinical results of robot-assisted total knee replacement.
6 Yian E, Wang C, Millett PJ, Warner JJ.
Arthroscopic repair of SLAP lesions with a bioknotless suture anchor.
7 Guidance on the selection of prostheses for
primary total hip replacement. National Institute for Clinical Excellence,
London: NICE, 2000 www.nice.org.uk
8 Total hip replacement: A guide to best
practice. London: British Orthopaedic Association, 1999. www.boa.co.uk
9 3M Capital Hip System; The lessons learned
from an investigation. London: The Royal College of Surgeons, 2001
LOAD-DATE: November 8, 2004
2004 CMP Information Ltd