Notas / Notes - Active Congress.......

JUEVES / THURSDAY
138
to numb areas but occasionally can cause extreme pain.
Some approaches are influencing the innervation of the vastus
medialis. Different patterns of this nerve can be described.
Saving the supra- and infra-patellar fat pad has several benefits.
This is important for the patellar blood supply, but also
has biomechanical implications and obscures visualization
of the lateral compartment.
The medial supporting structures are to be respected. Care
should also be taken to the postero-lateral corner during the
balancing and releasing action in this area. Always remember
the minimal distance between the posterior capsule and the
popliteal artery in extension and flexion. As shown by prof. M.
Prettenklieber (Vienna) the distance between the joint capsule
and the popliteal artery is subject to a high degree of variations
and ranges from 2 to 37 mm. It may even decrease in flexion!
The potential pitfalls are iatrogenic!
Our message is :please take care of the important soft tissues
during MIS Total Knee Replacement. Therefore we need to
know anatomy and train our retractor management and assistant
team choreography.
REFERENCES
1. Avoiding the Potential Pitfalls of Minimally Invasive Total
Knee Surgery. Keith Berend and Adolph Lombardi. Orthopedics
2005; 28: 1326
2. Minimal-Incision Total Knee Arthroplasty. M Tenholder and
Giles Dcuderi. Clin Orthop and Rel Res nr 440,p.67-76,
2005
PITFALLS & COMPLICATIONS OF MIS TKA
Peter Bonutti, MD
Bonutti Clinic. Effingham, Illinois (USA)
The purpose of this study was to identify the main pitfalls and
complications associated with minimally invasive total knee
arthroplasty and to describe and define a set of techniques
and tips for avoiding or compensating for these difficulties.
To provide this evaluation, we retrospectively evaluated a
single author’s series of 1,500 consecutive minimally invasive
total knee arthroplasties. The surgeries included in this study
were defined in terms of four categories that minimized the
invasiveness of the TKA:1) Using an incision of 10 centimeters
or less; 2) Reducing the amount of soft tissue disruption,
specifically damage to the quadriceps muscle which typically
incorporates splitting of this muscle; 3) Trying to not dislocate
the patella (subluxing the quadriceps mechanism rather than
completely everting the patella); and 4) Minimizing the amount
of knee joint dislocation (tibial-femoral dislocation).
The study design is a retrospective analysis of patients who
underwent minimally invasive total knee arthroplasty from
January 1999 to January 2007. The data collection included
implant type, need for lateral release, incision size, tourniquet
time, and any intraoperative and postoperative complications.
Preoperative and postoperative data included age, gender,
weight, diagnosis, and Knee Society scores including pain,
stability and range of motion. In addition, a radiographic review
was conducted.
The entire study cohort included 1022 unilateral TKAs and
478 bilateral TKAs in 641 males and 853 females. The mean
Knee Society objective scores improved from 42.9 points
preoperatively to a mean of 93.8 points postoperatively.
Similarly, the Knee Society Functional Scores improved from
48.7 points to 95.2 points at final followup.
There were 62 complications that required any type of intervention
of the 62 revision total knee arthroplasties, 35 were manipulation
under anesthesia, 17 were arthroscopic procedure,
4 soft tissue release and retained cement removal, 4 were full
component revisions (2 for deep infection,1 for suspected
infection but not negative culture,1 for traumatic instability), 3
were tibial component revisions (aseptic loosening, pain), 1
was polyethylene spacer exchange for extensive wear, 1 was
a femur revision, and 1 was a revision from a cemented system
to a cementless for PMMA allergy diagnosed by a dermatologist.
Although the overall tibiofemoral angles averaged 5.4° valgus,
we had some radiographic outliers. Several patients demonstrated
with tibia varus of greater than 3°. These patients are
at increased risk for early aseptic tibial loosening.
Clearly there are risks associated with any new surgical techniques
and most complications occurred early in the learning
curve, although, complications did occur throughout the entire
series. Nevertheless, MIS TKA principles can provide excellent
results, fast recovery, and perhaps less postoperative pain
with improved quadriceps function.
MIS IN TKA
Damian Griffin
Warwick Medical School. Coventry (Great Britain)
MINI-INCISION TKA
David Dalury
John Hopkins Hospital. Baltimore (USA)
Smaller incisions are a natural consequence of surgeon confidence
and experience, instrument design and patient demands.
Several authors have found no increase in complications with
smaller incisions while others have documented more problems
with alignment of implants and wound problems when trying
to minimize the skin incision. While the theoretical advantages
of Mini incision TKR are easier recoveries for patients, surgeons
should never compromise outcomes simply for a smaller incision.
This paper will discuss the pros and cons of MiTKR.