1120 THE JOURNAL OF BONE AND JOINT SURGERY
evision of a total knee arthroplasty may require an
extensile approach to permit a satisfactory exposure
without compromising the attachment of the patellar
tendon. It has been assumed that a rectus snip is a
relatively benign form of release, but the effect of using
this approach on function, pain and patient satisfaction
is not known.
From January 1997 to December 1999, 107 patients
who underwent revision of total knee arthroplasty were
followed up at a minimum of two years (mean 40.5
months) and assessed by the Oxford Hip Score, the
Western Ontario and McMaster Universities
Osteoarthritis Index (WOMAC), the Short-Form (SF)-
12 and patient satisfaction. Co-morbidity, surgical
exposure, the Hospital for Special Surgery (HSS) knee
scores and the range of movement were also used. A
standard medial parapatellar approach was used in 57
patients and the rectus snip in 50. The two groups were
equivalent for age, sex and co-morbidity scores. The
WOMAC function, pain, stiffness and satisfaction scores
demonstrated no statistical difference. The use of a
rectus snip as an extensile procedure has no effect on
outcome.
J Bone Joint Surg [Br] 2003;85-B:1120-2.
Received 30 January 2003; Accepted after revision 23 June 2003
Adequate exposure is a prerequisite for revision arthroplasty
of the knee. Flexion to 110˚ is desirable to allow safe deliv-
ery of the components. Flexion of less than 90˚ under gen-
eral anaesthesia indicates that a simple medial parapatellar
approach may be inadequate.
1-2
To achieve more flexion
will require freeing the proximal extensor mechanism or the
insertion into the tibial tuberosity. The proximal approach
may involve dividing the quadriceps mechanism, the lateral
retinaculum, the tendon of vastus lateralis or a combination
of the three. Isolated division of the rectus sheath, the ‘rec-
tus snip’, has been attributed to Insall
3
who had been using
it since 1988. Various modifications have been subsequently
described
4
which provide excellent exposure of the knee
without jeopardising the patellar tendon. Typically at the
apical end of the standard medial parapatellar incision, the
rectus portion is isolated and divided obliquely, extending
superiorly and laterally (Fig. 1).
5
As this technique main-
tains the musculotendinous bridge of vastus medialis and
vastus lateralis, it allows a relatively easy repair and should
allow normal post-operative rehabilitation.
Objective measurement of isokinetic strength demon-
strated that knees undergoing a rectus snip are not as strong
as normal knees, but do not differ significantly from those
which have had a standard medial parapatellar approach.
5
However, little evidence as to the comparable effects on
function, pain and scores for satisfaction has been
reported.
6,7
Patients and Methods
Between January 1st 1997 and December 31st 1999, 117
patients consecutively underwent revision total knee arthro-
plasty (TKA). Only three surgeons performed these pro-
cedures. The clinical diagnosis was of aseptic loosening in
67 and second-stage reconstruction of infected cases in 50.
Co-morbidity was based on recording scores of co-existing
conditions and categorizing them as 0, 1, 2, 3+ as based on
the Charlson index.
8
Pre-operative bone loss was assessed in
both the tibia and the femur according to Engh’s classifica-
tion and confirmed at removal of each component at the
time of operation.
9
Surgical treatment. All the operations were carried out
using the PFC total knee revision systems (DePuy, Warsaw,
Indiana). The use of a medial parapatellar, or extensile
R
Knee
The extensile rectus snip exposure in revision of
total knee arthroplasty
R. M. D. Meek, N. V. Greidanus, R. W. McGraw, B. A. Masri
From the University of British Columbia, Vancouver, Canada
R. M. D. Meek, MBChB, MD, FRCS (Tr & Orth), Clinical and Research
Fellow
Division of Lower Limb Reconstruction and Oncology, Department of
Orthopaedics
N. V. Greidanus, MD, MPh, FRCSC, Assistant Professor
R. W. McGraw, MD, FRCSC, Emeritus Professor
B. A. Masri, MD, FRCSC, Associate Professor and Head of Adult Recon-
struction Department
Division of Adult Lower Limb Reconstruction and Oncology
Vancouver General Hospital, University of British Columbia, 910 West 10th
Avenue, Suite 3114, Vancouver, V5Z 4E3, British Columbia, Canada.
Correspondence should be sent to Mr R. M. D. Meek at the Southern Gen-
eral Hospital, 1345 Govan Road, Glasgow G41 4TF, Scotland.
©2003 British Editorial Society of Bone and Joint Surgery
doi:10.1302/0301-620X.85B8.14214 $2.00