Tibial Tubercle transfer
For: Patients with pain from maltracking of the knee cap (patella), that fails to improve with conservative measures (physio/ orthotics/ weight reduction/ activity modification) and that have a documented (normally by CT) laterally placed tibial tubercle.
It works best in patients with a pain patern of being worse on stair desent (as opposed to ascent) and have grade 3 or less degenerative changes behind the knee cap.
Surgery is under general anaesthetic.
Surgery takes about 30 minutes.
A 4 inch curved scar on the outside of the top of the shin area is made (generally heals "nicely"), the tibial tuberosity (prominent bit a hansbreadth below the knee cap) is datached along with a thin section of bone 5-7mm thick and 6cm long from the main shin bone, (smaller and it can break, larger and it weakens the main shin bone). The tubercle is moved across appoximately 12-144mm depending on the planning and assessment scan. It is fixed in place with 2 stainless stell screws. Bone wax is applied to reduce bleeding from the bone surfaces.
Surgical scar is closed with dissolvable stiches/ Local aneasthetic is applied, dressings and finally a lightwieght support known as a cricket pad splint.
Post surgery almost all patients go home the same day. Full weight through the leg is encouraged.
In the morning following surgery dressings are unravelled, a water proof dressing applied and a shower encouraged. Cricket pad splint is used when on the move but can be removed for sitting and sleep.
Review at day 12, if able to do a straight leg raise and comfort levels are good, splint is discarded but walking with crutches for a full 4 weeks.
At day 12 regular use of an exercise bike is encouraged.
Week 4 discard crutches, increase exercise bike resistance
Week 6 recovered for sedentary talks.
Reciprocal stair desent typically takes 9 weeks.
Contact sports 6 months.
Generally a succesful proceedure in the right patient, however
All patients will have a patch of skin numbess on the outside of the scar, about the size of a large lemon, the patch lessens over time but does not resolve. In general it is well tolerated.
Continuation of back of knee cap graunching
Uncommon or rare
Failure to relieve pain
Fracture of the tibia (not happened to me but is well reported)
Splintering of the detached bone fragment (if it is too smal)
There is always a risk of infection
There is always a risk of thrombosis
Pain from the screws leading to advice of screw removal.