Surgical Approaches to the Knee

Use: primary TKA, many revision TKAs, infection washout, extensile anterior joint access.

1. Supine position, tourniquet if used, knee free to flex.
2. Midline skin incision, respecting prior scars.
3. Develop full-thickness flaps only as much as needed.
4. Make medial parapatellar arthrotomy through quadriceps tendon, medial retinaculum and around patella.
5. Protect patellar tendon insertion at the tibial tubercle.
6. Evert or sublux patella according to exposure and extensor tension.
7. Release medial sleeve only as needed for deformity correction or exposure.
8. Close arthrotomy securely with knee flexion check.

Pitfalls: high arthrotomy extension into quadriceps, patellar tendon avulsion, excessive medial stripping, patellar devascularisation and weak closure.

Use: selected primary TKA when patellar mobility and body habitus allow less extensile exposure.

1. Supine position with standard anterior skin incision.
2. For subvastus, identify the inferior border of vastus medialis and elevate it from the septum.
3. For midvastus, split VMO fibres in line with fibres for a short distance.
4. Continue medial arthrotomy while preserving quadriceps tendon continuity as much as possible.
5. Sublux rather than forcibly evert the patella if exposure is limited.
6. Convert to medial parapatellar if exposure is unsafe.

Pitfalls: using it in a stiff, obese, muscular or revision knee; inadequate exposure; VMO injury; forced patellar eversion.

Use: selected valgus TKA, lateral patellar tracking problems, lateral plateau access and lateral-sided pathology.

1. Supine position with anterior or lateralised incision depending indication.
2. Plan skin bridge and prior incisions carefully.
3. Develop lateral parapatellar arthrotomy.
4. Protect patellar tendon and lateral retinacular blood supply.
5. Release contracted lateral structures in a controlled sequence when used for valgus TKA.
6. Close lateral arthrotomy and balance extensor tracking.

Pitfalls: poor skin bridge, lateral wound problems, uncontrolled lateral release, peroneal nerve stretch in severe valgus correction.

Use: posteromedial tibial plateau fragment, medial column buttress, posterior medial corner access.

1. Supine with hip externally rotated and knee flexed, or prone/lateral according to surgeon preference and target.
2. Mark joint line, medial tibial border, pes region and planned plate position.
3. Identify and protect saphenous vein and nerve branches.
4. Develop interval around pes tendons and medial gastrocnemius according to fragment location.
5. Expose posterior medial tibia subperiosteally where buttress plate is needed.
6. Reduce fragment directly and apply posterior or posteromedial buttress fixation.

Pitfalls: saphenous injury, inadequate posterior buttress, excessive soft-tissue stripping, plate placed too anterior for posterior shear.

Use: posterolateral corner reconstruction, fibular-based reconstructions, selected posterolateral plateau fragments.

1. Position supine with figure-of-four, lateral or prone depending procedure.
2. Mark biceps femoris, fibular head, Gerdy tubercle and joint line.
3. Identify common peroneal nerve proximally and distally; protect it throughout.
4. Develop the interval required for LCL, popliteus, biceps or plateau work.
5. Avoid aggressive retraction across the fibular neck.
6. Repair or reconstruct structures with nerve visible and protected.

Pitfalls: missing the common peroneal nerve, tunnel convergence in multiligament reconstruction, skin bridge compromise and unrecognised postoperative foot drop.