- Discussion:
- lateral plateau frxs include:
-
type I fractures:
-
type II fractures:
-
type III fractures:
-
local compression frx which are similar to
type iii frx;
- Surgical Stratedgy:
- extensile surgical approach that exposes whole frx zone & adjacent normal tissue;
- comminuted
type II fractures will often require more extensive exposure than
type I fractures, however, in
both cases, "booking open" the fracture site will yield exellent access to the entire lateral compartment;
- fixation strategy involves anatomic reduction & stable fixation of comminuted articular surface
w/ subchondral reduction & buttressing of split frag that forms lateral wall;
- PreOp Planning (positioning, and implants);
- w/ significant frx shortening (and resultant valgus) consider using
AO large distractor & relying on
ligamentotaxis to maintain reduction and provide exposure;
- usually is distractor is placed on the same side as the frx;
- one pin is inserted into the femoral condyle and one in the mide tibia;
-
supine position:
- tape a rolled sheet onto the table (as with a total knee replacement), inorder to
allow the knee to remain hyperflexed during the procedure (when required);
-
supine w/ leg flexed:
- leg can be positioned as for arthroscopy;
- a leg holder is applied to the proximal thigh, and the table is broken to allow the knee to flex past 90 deg;
- the opposite leg is then held in a GYN leg holder;
- this technique allows varus to be applied to the knee which improves fracture exposure;
- Limited Hockey Stick Incision:
- discussion:
- most useful in situations where only cannulated screws will be used (and plate butressing is not required);
- if butressing is necessary, consider
external fixation (
circular frame fixation);
- stategy involves booking open the fracture site which yields excellent exposure of the lateral
compartment, especially if arthroscopy is used (placed underneath the meniscus);
- this approach is also especially useful w/ concomitant meniscal tears;
- this incision should not interfere w/ total knee incision (should it be necessary in the future);
-
technique: (see:
lateral capsular anatomy of the knee);
- incision is made from a point above the fibular head to Gerdy's tubercle;
- it can be biased either anteriorly or posteriorly to lie directly over the fracture;
- carry the dissection directly down to the IT band, and then palpate the anterior frx line;
- split the IT band in line with its fibers directly over the fracture site;
- the fracture site and the joint capsule are now visible;
- just below the joint line, make a horizontal inframeniscal incision, which extends from a point
anterior to the frx fragment to a point posterior to the frx fragment;
- infra-meniscal incision needs to be large enough to allow the meniscus to be elevated and the frx to be "booked open";
- once the split fragment is booked open, there should be excellent access to the compartment;
- examples:
- Longitudinal Incision:
- most indicated when a butress plate is required;
- this approach will not interfere w/ a TKR incision if one is needed in the future;
- slightly lateral parapatellar (or midline incision) is made from about 10 cm above the patella to about 3-4 cm below the lowest extent of the frx;
- incision is carried directly down to the superificial retinaculum, and a full thickness flap is elevated once underneath the superficial retinaculum;
- the flap is mobilized laterally and distally, so that with the knee flexed Gerdy's tuberlce is exposed;
- deep dissection: (see:
lateral capsular anatomy of the knee);
- most important step in reconstruction of any intra articular frx, is to expose fracture w/o devasclarizing the fragments;
- flex the knee to 90 deg, and incise thru the IT band (along its fibers) directly over the split frx site;
- Alternative Extensile Measures:
-
anterior meniscal detachment:
- see:
lateral meniscus;
- just below the joint line, make a horizontal inframeniscal incision, which extends from a point anterior to the frx
fragment to a point posterior to the frx fragment;
- infra-meniscal incision needs to be large enough to allow the meniscus to be elevated and the frx to be "booked open";
- sharply detach the anterior horn of menisci from its bony insertion;
- the anterior horn will later be repaired at the end of the case;
- this allows the surgeon to pull up on meniscus together w/ the attached capsule, for more optimal view of articular surface;
- meniscus is retracted proximally, and the joint inspected directly;
- if the arthrotomy is made above the meniscus, the meniscus will keep most of articular surface hidden from view;
- the knee is hyperflexed and internally rotated;
- meniscal re-attachment:
- two small drill holes are made at the origin of the anterior horn and are directed to exit medial to the patellar tendon;
- pass a suture thru the meniscus, and use a suture passer to thread the sutures thru the drill holes;
-
tubercle osteotomy:
- however, always avoid tubercle osteotomy in
bicondylar frx since, this might be the only intact portion of bone anteriorly;
- if tibial tubercle is already fractured, then it may be detached - as would be in an osteotomy;
-
patellar tendon Z-plasty:
- contra-indicated if there is concomitant tibial tubercle frx;
- for improved exposure, consider cutting the patella in a "Z pattern" (longitudinal split w/ half attach to tubercle and half
attached to patella) with repair of the tendon with heavy suture at the end of the case (see repair of
patellar tendon rupture);
- in this technique, the adjacent parapatellar retinaculum should be left intact;
-
wide IT band flap:
- a wide exposure is required for comminuted type II frx;
- knee is flexed to 90 deg, and the iliotibial band is retracted or split to expose midlateral capsule;
- incision is made thru the lateral 1/3 of the quadriceps, it is continued down along the lateral edge of the patella,
and is then continued down along lateral edge of the patella (incising the lateral retiancular expansion);
- the incision is continued distally below the frx line;
- a second deep capsular incision is made thru the inferior 1/3 of the IT band (crossing Gerdy's tubercle) which is split in line with
its fibers so that it intersects with the longitudinal capsular incision;
- alternatively the capsular incision is carried below Gerdy's tuberlce, and the tubercle is then
detached with an osteotome and the IT band is left attached to facilitate subsequent wound closure;
- this tongue of IT band and capsule is then elevated superiorly off the tibia, elevating the meniscus off the tibia in the process;
- this technique has been criticized for devascularizing the frx fragment;
- Reduction:
- knee is stressed into varus position for visualization of lateral plateau;
- if a depressed split fracture is difficult to reduce, consider application of a
universal distractor to assist w/ the reduction;
- further periosteal stripping may be necessary to assist w/ reduction;
- staying w/in periosteal sleeve avoids damage to
anterior tibial muscle and
anterior tibial artery;
- depressed articular fragments are elevated with a punch, supported by
bone graft, and buttressed with a lateral
T or L shaped plate;
- bone graft that supports the elevated fragments cannot hold them in anatomic relationship and
is often secondarily depressed when the patient starts ROM exercises;
- Post Operative Care and Compications:
Meniscal detachment to approach lateral tibial plateau fractures.
The use of an anterior incision of the meniscus for exposure of tibial plateau fractures requiring open reduction and internal fixation.
A New Surgical Approach in the Treatment of Depressed Lateral Condylar Fractures of the Tibia.
Gossling HR, Peterson Ca. COOR 140: 96, 1979.
A New Surgical Approach to Fractures of the Lateral Tibial Plateau.
Perry CR, Evans LG, Rice S, Fogerty J, Burdge RE. JBJS-Am 66: 1236, 1984.
Early weight bearing of lateral tibial plateau fractures.
The arterial vascularization of the lateral tibial condyle: anatomy and surgical applications.
Anatomic location of the peroneal nerve at the level of the proximal aspect of the tibia: Gerdy's safe zone.
