Chapter 16 The Knee and Related Structures 2007

Chapter 16: The Knee and Related Structures © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Complex joint that endures great amounts of trauma due to extreme amounts of stress that are regularly applied n Hinge joint w/ a rotational component n Stability is due primarily to ligaments, joint capsule and muscles surrounding the joint n Designed for stability w/ weight bearing and mobility in locomotion © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

© 2007 Mc. Graw-Hill Higher Education. All rights reserved.

Knee Joint Anatomy n Tibiofemoral joint n condyles of the femur n n n Tibial plateaus n n ______________________________________ flattened, very slightly concave “Screw home mechanism” n n ___________________________________ © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

Knee Anatomy - Ligaments n 4 main ligaments- help stabilize knee jt n Medial Collateral (Tibial Collateral) n ____________________ n Attaches to medial femoral condyle and anterior medial tibia n Lateral Collateral (Fibular Collateral) n ________________ n Attaches to lateral femoral condyle and head of fibula © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

Knee Anatomy - Ligaments n Anterior Cruciate (ACL) n ___________________ n attaches to lateral femoral condyle → medial tibia n Posterior Cruciate (PCL) n ___________________ n attaches to medial femoral condyle →lateral tibia © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

© 2007 Mc. Graw-Hill Higher Education. All rights reserved.

Knee Anatomy - Menisci n firbrocartilage discs n Functions: 1)__________________ _2) absorption and dissipation of force 3) congruency of the surface to improve wt distribution 4) n Thicker along the lateral portion © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

Menisci Cont Poor blood supply (only outer 1/3 receives direct blood supply) n __________________ n The medial is more commonly injured because of its attachment to the MCL ligament & more securely attached to the tibia (which makes it less mobile) n © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

Knee Joint Anatomy n Patellofemoral joint n patella n ______________________ n femur n Patellofemoral groove n Q angle n The angle of pull of quadriceps on the patella n normal is 13 degrees male/ 18 female n How to measure? © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

© 2007 Mc. Graw-Hill Higher Education. All rights reserved.

Knee Anatomy - Muscles n Muscles-contribute to jt stability n Quadriceps (EXT): Vastus lateralis, vastus medialis, rectus femoris, vastus intermedius; quads also aid in patella alignment n Hamstrings (Flex): Semitendinosus (IR), Semimembranosus (IR), Biceps Femoris (ER) n Gastroc (Flex), Sartorius (Flex/IR), Gracilis (Flex/IR) © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

Prevention of Knee Injuries n Physical Conditioning and Rehabilitation n Total body conditioning is required n Strength, flexibility, cardiovascular and muscular endurance, agility, speed and balance Muscles around joint must be conditioned (flexibility and strength) to maximize stability n Must avoid abnormal muscle action through flexibility n n In an effort to prevent injury, extensibility of hamstrings, erector spinae, groin, quadriceps and gastrocnemius is important © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Rehab (16 -11), Functional Prophylactic Knee Braces (Fig 16 -4) n n n Used to prevent and reduce severity of knee injuries Provide degree of support to unstable knee Can be custom molded and designed to control rotational forces and tibial translation © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Patellofemoral- “Cho-Pat” strap (Fig 16 -21) and horseshoe knee sleeve (Fig 16 -20) n Used for several different conditions © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

Treatment of Knee Injuries n Normal acute protocol and NSAIDs n ________________ n Control swelling, fit for crutches if necessary, increase ROM and strength n Return to competition the safest and quickest way possible thru rehab, functional activities, and sports specific activities © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

Assessing the Knee Joint n Determining the mechanism of injury is critical n History- Current Injury n Past history n Mechanism- what position was your body in? n ______________ n Did you hear or feel anything? n Could you move your knee immediately after injury or was it locked? n ___________ n Where was the pain © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n History - Recurrent or Chronic Injury n What is your major complaint? n When did you first notice the condition? n Is there recurrent swelling? n _______________________________ n Does it ever feel like giving way? n What does it feel like when ascending and descending stairs? n _________________ © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Observation n Walking, half squatting, going up and down stairs n Swelling, ecchymosis n Assessment of muscle symmetry/atrophy n What is the athlete’s level of function? n n n Does the athlete limp? Full weight bearing? Does athlete exhibit normal knee mechanics during function? © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Palpation n Should assess bony structures checking for pain, bony deformity, warmth, swelling, spasms, and crepitus n Soft tissue n n n Lateral ligaments _______ Assess for pain and tenderness _____________ © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Special Tests for Knee Instability n Laxity is a positive sign for injury n n n Translation (tibial translation) refers to the glide of tibial relative to the femoral As the damage to stabilization structures increases, laxity and translation also increase Valgus and Varus Stress Tests n n Used to assess the integrity of the MCL and LCL respectively Testing at 0 degrees incorporates capsular testing while testing at 30 degrees of flexion isolates the ligaments © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

Valgus Stress Test Varus Stress Test © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Lachman Drawer Test n Will not force knee into painful flexion immediately after injury n Reduces hamstring involvement n At 30 degrees of flexion an attempt is made to translate the tibia anteriorly on the femur n A positive test indicates damage to the ACL © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

ACL, PCL and Meniscus Testing n Anterior Drawer- n Posterior Drawern Mc. Murray’s Click- © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Apley’s Compression Test n Hard downward pressure is applied w/ rotation n Pain indicates a meniscal injury n Used to detect meniscus tear © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

Recognition and Management of Specific Injuries n Medial Collateral Ligament Sprain n Cause of Injury n n Result of severe blow or outward twist – valgus force Signs of Injury - Grade I n n n Little fiber tearing or stretching ____________ Little or no joint effusion Some joint stiffness and point tenderness on lateral aspect _____________ © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Signs of Injury (Grade II) n n n Complete tear of deep capsular ligament and partial tear of superficial layer of MCL No gross instability; _________ Slight swelling ____________________ Pain along medial aspect of knee Signs of Injury (Grade III) n n n Complete tear of supporting ligaments ___________________ Minimum to moderate swelling Immediate pain followed by ache _____________________ Positive valgus stress test © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Care n RICE for at least 24 hours n Crutches if necessary n Knee immobilizer may be applied n Move from isometrics and STLR exercises to bicycle riding and isokinetics n Return to play when all areas have returned to normal § Continued bracing may be required © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Care n n Conservative non-operative approach for isolated grade 2 and 3 injuries _____________________ Follow with 2 -3 week period of protection with functional hinge brace When normal range, strength, power, flexibility, endurance and coordination are regained athlete can return § Some additional bracing and taping may be required © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Lateral Collateral Ligament Sprain n Cause of Injury n n n Signs of Injury n n ____________________ Direct blow is rare** WHY? Pain and tenderness over LCL Swelling and effusion around the LCL Joint laxity w/ varus testing Care n Following management of MCL injuries depending on severity © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Anterior Cruciate Ligament Sprain n Cause of Injury n n n MOI – athlete decelerates with foot planted and turns in the direction of the planted foot forcing tibia into internal rotation May be linked to inability to decelerate valgus and rotational stresses - landing strategies Male versus female © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

ACL – c/s cont Research is quite extensive in regards to impact of femoral notch, ACL size and laxity, malalignments (Q-angle) faulty biomechanics n ________________________________ n ________________ n © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

© 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Signs of Injury n n Experience pop w/ severe pain and disability Rapid swelling at the joint line Positive anterior drawer and Lachman’s Care n n n RICE; use of crutches Arthroscopy may be necessary to determine extent of injury Could lead to major instability in incidence of high performance W/out surgery joint degeneration may result Age and activity may factor into surgical option Surgery may involve joint reconstruction w/ grafts (tendon), transplantation of external structures § Will require brief hospital stay and 3 -5 weeks of a brace § Also requires 4 -6 months of rehab © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Posterior Cruciate Ligament Sprain n Cause of Injury n n Signs of Injury n n Most at risk during 90 degrees of flexion Fall on bent knee is most common mechanism _____________ Feel a pop in the back of the knee Tenderness and relatively little swelling in the popliteal fossa ____________________ Care n n n RICE Non-operative rehab of grade I and II injuries should _____________ Surgical versus non-operative § Surgery will require 6 weeks of immobilization in extension w/ full weight bearing on crutches § ROM after 6 weeks and PRE at 4 months © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Meniscus Injuries n Cause of Injury n Medial meniscus is more commonly injured due to ligamentous attachments and decreased mobility § Also more prone to disruption through twisting and valgus forces n n ____________________ Signs of Injury n n n Diagnosis is difficult Effusion developing over 48 -72 hour period Joint line pain and loss of motion Intermittent locking and giving way Pain w/ squatting © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

© 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Care n n Immediate care = PRICE If the knee is not locked, but indications of a tear are present further diagnostic testing may be required § Treatment should follow that of MCL injury n n n If locking occurs, anesthesia may be necessary to unlock the joint w/ possible arthroscopic surgery follow-up W/ surgery all efforts are made to preserve the meniscus -- with full healing being dependent on location Torn meniscus may be repaired using sutures © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Bursitis n Cause of Injury n n Signs of Injury n n Acute, chronic or recurrent swelling ________ = continued kneeling ________ = overuse of patellar tendon Prepatellar bursitis may be localized swelling above knee that is ballotable Presents with cardinal signs of inflammation Swelling in popliteal fossa may indicate a Baker’s cyst Care n n _________________ Aspiration and steroid injection if chronic © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Iliotibial Band Friction Syndrome (Runner’s Knee) n Cause of Injury n n n Signs of Injury n n Repetitive/overuse conditions attributed to malalignment and structural asymmetries Can be the result of running on crowned roads Irritation at band’s insertion Tenderness, warmth, swelling, and redness over lateral femoral condyle Pain with activity Care n n n Correction of mal-alignments Ice before and after activity, proper warm-up and stretching; NSAID’s Avoidance of aggravating activities © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Acute Patella Subluxation or Dislocation n Cause of Injury n n n Deceleration w/ simultaneous cutting in opposite direction (valgus force at knee) ____________________________________ More commonly seen in female athletes Signs of Injury n n n W/ subluxation, pain and swelling, restricted ROM, palpable tenderness over adductor tubercle Dislocations result in total loss of function First time dislocation = assume fx © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Care n n n Immobilize and refer to physician for reduction Ice around the joint Following reduction, immobilization for at least 4 weeks w/ use of crutches After immobilization period, horseshoe pad w/ elastic wrap should be used to support patella Muscle rehab focusing on muscle around the knee, thigh and hip are key (STLR’s are optimal for the knee) © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Chondromalacia patella n Cause n n n Signs of Injury n n n Softening and deterioration of the articular cartilage Possible abnormal patellar tracking due to genu valgum, foot pronation, patella alta, shallow femoral groove, increased Q angle, laxity of quad tendon _______________________________________ Care n Conservative measures § RICE, NSAID’s, isometrics for strengthening § Avoid aggravating activities n Surgical possibilities © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Patellar Tendinitis (Jumper’s or Kicker’s Knee) n Cause of Injury n n n Signs of Injury n n _______________________________________ Pain and tenderness at inferior pole of patella and on posterior aspect of patella with activity Care n n n Avoid aggravating activities Ice, rest, NSAID’s Exercise Patellar tendon bracing Transverse friction massage © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

© 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Osgood-Schlatter Disease n Cause of Condition § ____________________________________________ n n Resolves w/ aging Signs of Condition n n Both elicit swelling, hemorrhaging and gradual a bump occurring at the tibial tubercle Pain with activity and tenderness over anterior proximal tibial tubercle © 2007 Mc. Graw-Hill Higher Education. All rights reserved.

© 2007 Mc. Graw-Hill Higher Education. All rights reserved.

n Care n Conservative § Reduce stressful activity until union occurs (6 -12 months) § Padding may be necessary for protection § Possible casting, ice before and after activity § Isometerics © 2007 Mc. Graw-Hill Higher Education. All rights reserved.