- Discussion:
- need to reflect capsule medially & laterally from upper 1 cm of proximal tibia;
- performed circumferentially using either elevator or osteotome;
- this capsular reflection relieves minor contractures and provides access for
retractors to protect the posterior structures;
- any rim osteophytes from the femur and tibia are removed;
- MCL and Deep Capsular Exposure: (
MCL)
- to fully expose medial tibial plateau, medial subperiosteal sleeve is developed
and elevated to beyond the mid coronal line to enter the semimembranosus bursa;
- begin using a knife, but once the dissection proceeds further medially, complete
the capsular elevation with a curved 1/2 inch osteotome;
- strip approximately 1 cm beneath the joint line;
- any rim osteophytes from the femur and tibia are removed;
-
cautions: 
- it is important to distinguish between a fixed varus knee and a knee w/ pseudolaxity
due to loss of the medial joint space;
- in the later case, the MCL may be attenuated and can easily be "overstripped" during
the initial exposure (when this happens, a larger spacer is needed to restore stability);
- w/ a fixed
varus knee, further capsular elevation may be required;
- in the report by K. Saeki et al, the authors evalauated the effect of MCL release in TKR;
- 6 knees from cadavers were tested for change in stability after release of the MCL w/
PCL retaining and substituting TKR;
- superficial MCL was released, followed by release of the PCL;
- knee then was converted to a posterior-stabilized implant;
- after MCL release, valgus laxity was statistically significantly greater at 30°, 60°, and 90°
flexion after PCL sacrifice than it was when the PCL was retained;
- posterior-stabilizing post added little to varus and valgus stability;
- ref: Stability After Medial Collateral Ligament Release in Total Knee Arthroplasty
Kazuhiko Saeki, MD CORR 2001;2001:184-189
- Latereal Capsular Exposure:
- this part of the case is easier once the knee is flexed and the patella is everted;
- transect the anterior ligamentous attachments of the lateral meniscus to the tibia;
- retractor is placed underneath the patella, to place patella tendon under tension;
- w/ care to avoid injuring the tendon and its insertion into the tubercle, use the
knife to remove adhesions between the patellar tendon and the proximal tibia
(proximal to the tibial tubercle);
- as the dissection proceeds laterally, switch to an osteotome;
- use an osteotome to circumferentially strip the capsule and the insertion of the
iliotibial tract off the proximal 1 cm of the lateral tibia;
- this step is often best performed after the proximal tibial cut (while the knee is
flexed and the patella is everted);
- lateral inferior
geniculate artery is ligated at the joint line;
- w/ a
valgus knee, further lateral dissection may be required;
- excision of patello-femoral ligaments:
- this is necessary for
patellar eversion;
- attach a Kocher clamp to cuff of retinaculum attached to medial side of patella;
- retract the Kocher to partially evert the patella so that the patellofemoral ligaments
are placed under tension;
- use curved Mayo's to spread under the patellofemoral ligament and then incise it;
