Abstract
Minimal or Less Invasive Approaches
Limited medial parapatellar incision – 2–3 inch medial incision; Best for unicompartmental implant; patellar visualization poor; Less invasive but limited visualization therefore overall joint inspection is compromised.
MIS TKR approaches - Mini midvastus approach popularised by S.B. Haas - Ideal BMI 30 or less; Incision length 10cm; Vastus incision about 2–3cm; Vastus incision beyond 5–6cm places motor branch to VMO at risk; Coupled with downsized cutting blocks, allows predictable ability to perform TKR; Sliding window concept; Patella eversion not necessary.
Mid Subvastus approach – 10cm skin incision; Sub vastus dissection up to septum (watch for bleeders!); VERY difficult in muscular males!
Standard Incisions
Standard medial parapatellar approach - Familiar to most surgeons; Medial arthrotomy facilitates exposure for almost all procedures; Can become more extensile by incising the quad tendon further proximal; Release of posteromedial capsule and semi-membraneosus allows exposure posteriorly.
Quad snip - Used occasionally in the fixed varus, flexion contracted knee; More commonly used in revisions; Allows patella eversion without risk of distal avulsion; Motor strength appears to return to baseline level postoperatively.
V-Y quadriceps turndown - Technique: initial medial parapatellar arthrotomy, an oblique tenotomy angled toward the tendinous portion of the vastus lateralis and then extended distally; The quadriceps segment is than retracted downward to expose the joint; Tenotomy is closed with robust non-absorbable sutures holding the knee in extension; Postoperative flexion is dictated by integrity of repair while flexing knee at time of closure. Disadvantages include extensor lag, as well as effecting ultimate ROM.
Tibial tubercle osteotomy a la Whiteside - Medial arthrotomy; Tubercle segment is 6–8cm long, 2cm wide and 1–1.5cm thick; Segment is beveled distally so as to avoid stress riser; Leave lateral soft tissue intact; Closure with wires preferred although screws or cables have been used as well.
