Therex Study Guides

Knee Reviewer - PTA 215 Ther Ex I

This reviewer covers the big knee exam topics: post-surgical progression for TKA, UKA, partial meniscectomy, and ACL reconstruction; special tests; conservative care; tibiofemoral and patellofemoral mechanics; and the best open kinetic chain and closed kinetic chain exercises plus common contraindications. Basically: the knee, but with less drama than the actual knee.

TKA / UKA ACL Reconstruction Meniscus Patellofemoral Pain OA Special Tests OKC vs CKC

1) Quick anatomy and movement review

Tibiofemoral joint

• Main motions: flexion and extension, with small amounts of rotation when the knee is flexed.
• Open chain: the tibia moves on the femur.
• Closed chain: the femur moves on the tibia.
• Screw-home mechanism: during the last part of extension, the knee “locks” for stability. In open chain the tibia externally rotates on the femur; in closed chain the femur internally rotates on the tibia.
• Unlocking: popliteus helps unlock the knee by reversing that locking motion.

Arthrokinematics you should know

MotionWhat rolls / glidesMobilization ideaOpen-chain knee extensionTibia rolls and glides anteriorly on femur.Anterior tibial glide can help extension.Open-chain knee flexionTibia rolls and glides posteriorly on femur.Posterior tibial glide can help flexion.Closed-chain extensionFemur rolls anteriorly and glides posteriorly on tibia.Posterior femoral glide can help terminal extension.Closed-chain flexionFemur rolls posteriorly and glides anteriorly on tibia.Anterior femoral glide can help flexion in weight-bearing.

Patellofemoral joint

• The patella improves the quadriceps’ leverage by increasing the moment arm.
• As the knee flexes, the patella glides inferiorly; as the knee extends, it glides superiorly.
• Medial and lateral tilt or glide problems can contribute to patellofemoral pain.
• The contact area changes as the knee bends more, so symptoms may worsen with stairs, squatting, kneeling, or long sitting.

Memory helper: If flexion is limited, think posterior tibial glide in open chain. If extension is limited, think anterior tibial glide in open chain. The patella likes to travel opposite the quadriceps pull direction: up in extension, down in flexion.

2) When structures are most vulnerable

ACL

Most stressed by anterior translation of the tibia, especially with twisting, pivoting, deceleration, and hyperextension. Open-chain terminal knee extension can increase anterior shear.

PCL

Most stressed by posterior translation of the tibia, often with a direct blow to the tibia or deep flexion positions. Resisted hamstrings can increase posterior pull on the tibia.

MCL

Most stressed by valgus force, especially with the knee partly flexed.

LCL

Most stressed by varus force, especially with the knee partly flexed.

Meniscus

Twisting on a loaded knee, deep squatting, and sudden directional change increase stress. The posterior horns take a beating in deep flexion.

Patellofemoral joint

Compression rises with stairs, squats, running hills, jumping, and prolonged sitting. Greater flexion usually means greater patellofemoral load.

3) Special tests of the knee and what they tell you

TestWhat it checksPositive findingLachman testACL integrity.Excess anterior tibial translation or soft end feel.Anterior drawerACL integrity.Too much anterior movement of tibia.Pivot shiftAnterolateral rotary instability from ACL deficiency.Subluxation/reduction or giving-way feeling.Posterior drawerPCL integrity.Excess posterior tibial translation.Posterior sag signPCL injury.Tibia sags backward when knee is flexed.Valgus stress testMCL integrity.Medial joint laxity or pain.Varus stress testLCL integrity.Lateral joint laxity or pain.McMurray testMeniscal tear.Click, pain, or locking with rotation plus flexion/extension.Thessaly testMeniscal tear.Joint-line pain, catching, or locking during standing rotation.Apley compressionMeniscus involvement.Pain or click with compression and rotation.Patellar grind / Clarke testPatellofemoral irritation.Retropatellar pain with quadriceps contraction.Patellar apprehensionPatellar instability/dislocation tendency.Fear, guarding, or attempt to stop the test.Noble compression / Ober-related findingsIT band tightness/friction contribution.Lateral knee pain or excessive tightness.

Clinical pearl: One test by itself is rarely the whole movie. Combine the test with the history, swelling pattern, mechanism of injury, ROM, joint line tenderness, and function.

4) Conservative treatment by condition

Knee osteoarthritis

• Education, activity pacing, weight management, and symptom monitoring.
• Pain control: ice, heat as appropriate, relative rest during flares.
• ROM work, especially extension if the knee starts living in a bent position.
• Strengthening: quadriceps, glutes, hamstrings, calf.
• Low-impact aerobic exercise: walking, cycling, aquatic exercise.
• Balance and functional training: sit-to-stand, step-ups, gait training.
• Assistive device if needed to unload symptoms and improve safety.

Meniscus injury

• Reduce irritation: avoid twisting and deep loaded flexion early on.
• Control swelling and pain.
• Restore ROM carefully, especially extension.
• Strengthening: quads, hips, hamstrings as tolerated.
• Progress to proprioception, balance, and functional drills.

Ligament injury

• Protect the tissue while it heals: brace if ordered, reduce instability stress.
• Control swelling, regain extension, then flexion.
• Early quadriceps activation is a big deal.
• Hip and core strengthening help reduce ugly mechanics later.
• Progress to neuromuscular control, landing mechanics, and directional control once allowed.

Patellofemoral pain syndrome

• Modify activities that spike symptoms: stairs, hills, deep squats, jumping, prolonged sitting.
• Strengthen quadriceps, especially with attention to mechanics, plus glute medius and glute max.
• Stretch tight structures if needed: calves, hamstrings, quadriceps, hip flexors, IT band contributors.
• Patellar taping or bracing may help some patients.
• Movement retraining matters: avoid dynamic valgus and poor step-down control.

Watch out: Mechanical locking, major instability, large effusion, inability to bear weight, unexplained night pain, fever, or red-hot swelling are not “walk it off” situations.

5) Post-surgical progression: TKA and UKA

From the lecture: acute/protection phase is about 1–4 weeks, subacute/moderate protection up to 6 weeks, and chronic/minimal protection 6–12 weeks.

PhaseMain goalsTypical interventionsCommon precautionsAcute / Protection
1-4 weeksControl pain/swelling, protect healing tissue, regain basic ROM, activate quads, safe mobility.Bed mobility, transfers, gait training with appropriate assistive device, ankle pumps, quad sets, glute sets, heel slides, gentle extension work, short walks, education.No aggressive forcing. Watch incision, swelling, DVT signs, infection signs. Avoid pillow under the knee for long periods if extension is limited.Subacute / Moderate Protection
up to 6 weeksImprove ROM, normalize gait, improve weight acceptance and basic function.Single-leg stands as allowed, continued gait training, stair training with appropriate device, sit-to-stand, mini-squats, step-ups, terminal knee extension, balance work.Do not let compensations run the show. Keep swelling under control.Chronic / Minimal Protection
6-12 weeksStrength, endurance, balance, independence with daily tasks.Progressive CKC strengthening, bike, treadmill or walking progression, functional squats, step training, balance challenges, endurance training.Avoid high-impact activity unless specifically cleared. Persisting flexion contracture is the villain here.

Big priorities after TKA/UKA: get the knee straight, wake up the quadriceps, control swelling, and restore a decent gait pattern. Those four carry a lot of the grade.

6) Post-surgical progression: ACL reconstruction

From the lecture: max protection 0–4 weeks, moderate protection 4–10 weeks, and minimal protection 11–24 weeks.

PhaseMain goalsGood choicesAvoid / be careful withMax protection
0-4 weeksProtect graft, reduce swelling, restore extension, improve flexion gradually, regain quad control, safe gait.Quad sets, SLR with no lag, heel slides, patellar mobs, weight shifting, gait training, gentle CKC in protected ranges, NMES if used by clinic.Open-chain resisted knee extension near terminal range early on because it can increase anterior tibial shear. Pivoting and twisting are out.Moderate protection
4-10 weeksBuild strength and neuromuscular control, improve balance, continue ROM normalization.Mini-squats, leg press in controlled range, step-ups, bridges, hamstring and hip strengthening as appropriate, balance training, stationary bike.Too much load too fast, poor landing mechanics, swelling rebound after exercise.Minimal protection
11-24 weeksAdvanced strength, agility, running progression, return-to-function skills.Lunges, deeper squats as tolerated, single-leg control drills, hopping progression, agility, deceleration training, sport-specific drills when cleared.Returning to cutting/pivoting before strength and control are ready. The graft is not impressed by confidence alone.

Test-friendly concept: Early rehab loves closed-chain quadriceps work in safe ranges because it tends to create less anterior shear at the tibia than some open-chain knee extension positions.

7) Post-surgical progression: partial meniscectomy

A partial meniscectomy usually progresses faster than a meniscus repair because tissue was trimmed rather than stitched and protected.

• Early phase: reduce swelling, restore extension and flexion, normalize gait, activate quads.
• Middle phase: mini-squats, step-ups, bike, bridges, balance training, progressive strengthening.
• Later phase: higher-level CKC strengthening, single-leg control, jogging and agility as symptoms and surgeon protocol allow.

Difference to remember: Meniscus repair = slower and more protected. Partial meniscectomy = faster progression.

8) Meniscus repair progression versus partial meniscectomy

From the lecture: meniscus repair phases were listed as acute/max protection 0–4 weeks, subacute/mod protection 4–12 weeks, and chronic/min protection 12 weeks to 6 months.

ProcedureWhy it mattersUsual rehab vibeMeniscus repairThe repaired tissue needs protection so it can heal.Slower progression, often ROM and weight-bearing precautions, delayed deep flexion and pivoting.Partial meniscectomyDamaged tissue is removed, not repaired.Faster progression, earlier weight-bearing and ROM as tolerated, quicker return to function if symptoms settle.

9) Best OKC and CKC exercises by condition

General ideas

OKC helps when you want...CKC helps when you want...Isolate a muscle group, control the load precisely, or strengthen when weight-bearing is limited.Co-contraction, joint approximation, dynamic stability, proprioception, balance, and carryover to function.

Condition-based choices

ConditionHelpful OKCHelpful CKCOften contraindicated / limited earlyTKA / UKAQuad sets, straight leg raise, short arc quad, heel slides.Sit-to-stand, mini-squat, step-up, terminal knee extension, balance, gait tasks.High-impact loading too early; forcing painful ROM.ACL reconstructionCarefully dosed quad work in allowed ranges, hip strengthening, controlled hamstrings depending on graft/protocol.Weight shifts, mini-squats, leg press in safe ranges, step-ups, bridges, single-leg control drills.Early resisted open-chain terminal extension; pivoting/cutting too soon.PCL injury / reconstructionQuadriceps-focused work is usually favored earlier.Protected CKC as allowed.Aggressive hamstring resistance early, because hamstrings pull tibia posteriorly.Meniscus injury / repairQuad sets, straight leg raise, ROM in allowed range.Shallow CKC strengthening as allowed, balance progression.Deep loaded flexion, twisting, pivoting early; even more restricted after repair.Patellofemoral pain syndromeShort-arc quad or controlled extension in pain-free ranges, hip strengthening.Step-down retraining, mini-squats, wall sits in tolerable ranges, glute-focused tasks.Repeated deep squats, stairs, jumping, or painful high-compression tasks during flare.OASeated knee extension in tolerable range, straight leg raise.Sit-to-stand, mini-squat, step-ups, walking, bike, aquatic exercise.High-impact or prolonged aggravating activities during painful flare.

Why CKC is such a favorite for knees: It improves joint approximation, co-activation, stabilization, proprioception, and functional carryover. In plain English: it teaches the knee to behave in real life, not just on the treatment table.

10) Contraindications and exercise cautions you should remember

• Do not force ROM into severe pain or acute inflammation.
• Avoid valgus collapse during squats, stairs, lunges, and landing drills.
• After ACL reconstruction: watch anterior tibial shear with certain open-chain extension angles early on.
• After PCL injury: be cautious with strong hamstring loading early.
• After meniscus repair: deep flexion and twisting are usually restricted early.
• After arthroplasty: monitor incision, swelling, infection signs, DVT signs, and gait safety.
• With OA flare: reduce high-load compressive work and use tolerable ranges.

Red flags after surgery: calf pain with swelling, sudden shortness of breath, fever, excessive warmth/redness at incision, rapidly increasing pain, or loss of function. That is not “just sore from therapy.”

11) Super high-yield compare-and-contrast

TopicKey differenceTKA vs UKATKA replaces the whole knee surface involved; UKA replaces only one compartment. UKA is usually for more localized compartment disease.ACL vs PCLACL resists anterior tibial translation; PCL resists posterior tibial translation.MCL vs LCLMCL resists valgus stress; LCL resists varus stress.Meniscus repair vs partial meniscectomyRepair needs protection to heal; meniscectomy usually progresses faster.OKC vs CKCOKC isolates; CKC integrates.Patellofemoral pain vs tibiofemoral OAPFPS often hurts with stairs, squats, and sitting; OA often has stiffness, crepitus, pain with loading, and reduced function over time.

12) Last-minute cram sheet

• TKA/UKA: get extension back, activate quads, control swelling, normalize gait.
• ACL rehab: protect graft early, regain extension, progress CKC and neuromuscular control, delay cutting/pivoting until ready.
• Meniscus repair: slower than partial meniscectomy.
• Meniscus tests: McMurray, Thessaly, Apley compression.
• ACL tests: Lachman is the superstar.
• MCL/LCL: valgus = MCL, varus = LCL.
• Flexion mobilization: posterior tibial glide in open chain.
• Extension mobilization: anterior tibial glide in open chain.
• Patella: superior glide with extension, inferior glide with flexion.
• CKC: great for co-contraction, proprioception, and function.

13) Source note

Prepared from the uploaded PTA 215 knee lecture and resistance training lecture, then organized into a student-friendly reviewer format. Use your class protocol, surgeon protocol, and instructor emphasis if they differ on exact timelines or precautions.