Knee (Orthopedic)

Posture and general appearance
Ambulation
Special Tests
ROM
Strength
Joint mobility (tibiofemoral and patellofemoral joint, also: acetabulofemoral joint)
Palpation
Muscle length testing (hamstrings, hip flexors)
Squatting mechanics

Meniscus

Meniscus tears can be traumatic or degenerative.

Individuals who sustain a meniscal tear report a similar history as an individual with an ACL tear, such as feeling a “pop” while suddenly changing direction with or without contact. The rate of medial meniscal tears increases over time, whereas lateral meniscal tears do not. Prolonged delays in ACL reconstruction are related to increased occurrence of meniscus injuries.

Surgical Outcomes:
The clinical course for most patients after meniscus injury managed with or without surgery is satisfactory, though these patients will report lower knee function compared to the general population. Patients who have nonoperative management for meniscus tear have similar to better outcomes in terms of strength and perceived knee function in the short term and intermediate term compared to those who had APM (Arthroscopic Partial Meniscectomy).
Impairments in proprioception and muscle strength and poor patient-reported outcomes are present early after meniscal injury and in the short-term time period (less than 6 months) after APM. Most of these impairments and limitations in patient-reported outcomes may resolve within 2 years after APM. However, perceived knee function and quality of life are lower than for healthy controls as much as 4 years after APM. 
Young patients who have meniscus repair have similar to better perceived knee function, less activity loss, and higher rates of return to activity compared to those who have APM. Elite and competitive athletes or athletes younger than 30 years are likely to return to sport less than 2 months after APM, and athletes older than 30 years are likely to return by 3 months after APM.
Kise randomized 140 participants into 2 treatment groups: exercise therapy (n = 70) or APM. The authors reported no clinically relevant differences in KOOS change scores from baseline to 2-year follow-up between groups (0.9 points; 95% CI: –4.3, 6.1). Both groups demonstrated similar improvements from baseline to 2-year follow-up. The exercise group had greater improvement in muscle strength at 3 and 12 months.

Diagnosis:
Twisting injury, tearing sensation at time of injury, delayed effusion (6-24 hours post injury), history of "catching" or "locking," pain with forced hyperextension, pain with maximum passive knee flexion, pain with audible click with McMurray's Maneuver, joint-line tenderness, discomfort or a sense of locking or catching in the knee over the medial or lateral joint line during the Thessaly Test when performed at 20 deg knee flexion. (The last item with Thessaly has high sensitivity for medial and lateral meniscus indicating high true positive, rule-in)

Meniscal Pathology Composite Score: (3 positive findings is 90% specificity, 5 is 99%)
-History of "catching" or "locking."
-Pain with forced hyperextension.
-Pain with passive knee flexion.
-Joint-line tenderness.
-Pain or audible click with McMurray's maneuver

McMurray's Test: tibial IR + varus stress = lat. men., tibial ER + valgus stress = med. men. Positive if pain, locking, snapping, clicking.
Thessaly's Test: single leg stance with examiner supporting for stability, 5 deg of flexion with rotation, then 20 deg of flexion with rotation 3x. Positive if pain or catching/locking.

Outcome Measures:
30 sec CST, stair-climb test, TUG, 6-minute walk test
For return to activity or sport: single-leg hop test
Physical Impairment Measures:
Modified stroke test for effusion assessment, assessment of knee active range of motion, maximum voluntary isometric or isokinetic quadriceps strength testing, joint-line tenderness

Interventions:
Clinicians should provide supervised, progressive range-of-motion exercises, progressive strength training of the knee and hip muscles, and neuromuscular training to patients with knee meniscus tears and articular cartilage lesions and after meniscus or articular cartilage surgery. (B)
Østerås randomized 75 participants with degenerative meniscus tear to receive either 12 weeks of specialized exercise therapy (n = 38) or no physical therapy (n = 37). Improvements in pain, muscle strength, and patient-reported measures were significantly higher in the exercise therapy group compared to the no-therapy group after the intervention period and 12 months later.

Interventions following surgery:
In a RCT, the AROM  group (n = 14) using an adjustable pedal arm stationary cycle ergometer had significantly better gait measures (presence or absence of antalgic gait and limp during gait) early after partial meniscectomy compared to the control group (n = 14) who did not have supervised therapy. No differences were reported between the groups over time in range of motion, effusion, or IKDC 2000 scores.
Clinicians may use early progressive active and passive knee motion with patients after knee meniscal and articular cartilage surgery. (B)
Clinicians should consider strength training and functional exercise to increase quadriceps and hamstrings strength, quadriceps endurance, and functional performance following meniscectomy. (B)
Neuromuscular re-ed is indicated.
Clinicians should provide supervised, progressive range-of-motion exercises, progressive strength training of the knee and hip muscles, and neuromuscular training to patients with knee meniscus tears and articular cartilage lesions and after meniscus or articular cartilage surgery. (B)
Neuromuscular electrical stimulation can be used with patients following meniscal or chondral injuries to increase quadriceps muscle strength. (B)

Interventions (MedBridge OCS Prep):
If painful, PROM. Limit excessive knee flexion exercises (increases sheer forces). Regular force on the meniscus is necessary for healing. Stress must be placed on meniscus for nutrition. Too little exercise isn't good and too much exercise isn't good. Minimum of 6 weeks before returning to program. This means a gradual buildup until the 6 week mark. Manual therapy can be beneficial. Motor control exercises.
If in acute phase, reduce aggravation. Limit pivoting exercises until more stable. Locking the knee and performing straight leg raises. 
If they have accompanied ACL tear (which may be involved with meniscal tear), resisted flexion/extension exercises has less shear on ACL when at 90-60 deg. 15-0 deg increases shearing forces placing increased stress on ACL. 
With chronic meniscus tear, they likely have OA. Also patients with OA may have a chronic meniscus tear accompanying OA. Knee exercises is extremely beneficial for OA. Manual therapy being very affective for OA. Extension mobilizations with distraction (even if they have a little bit of pain on meniscus at end range adding the distraction). Extension mobilization with abduction/adduction at end range to gap medial/lateral knee. End range knee flexion can be provocative to meniscus. Can provide knee flexion with gapping mobilization. you can do PROM repeated motions in flexion making sure the pain isn't getting worse as you administer. Can also add the IR/ER with flexion. As they build tolerance, you can increase the motion. 

Articular Cartilage

Injuries to the articular cartilage can be the result of acute trauma or repetitive minor trauma. Some individuals who sustain articular surface injury do not seek treatment. Many lesions are nonprogressive and remain asymptomatic, while some experts believe that even small asymptomatic lesions may increase in size and eventually become painful if left untreated.

Diagnosis:
The ICD diagnosis of an articular cartilage defect and the associated ICF diagnosis of joint pain and mobility impairments are made with a low level of certainty when the patient presents with the following clinical findings:
-Acute trauma with hemarthrosis (0-2 hours) (associated with osteochondral fracture)
-Insidious onset aggravated by repetitive impact
-Intermittent pain and swelling
-History of “catching” or “locking”
-Joint-line tenderness

Outcome Measures:
30 sec CST, stair-climb test, TUG, 6-minute walk test
For return to activity or sport: single-leg hop test
Physical Impairment Measures:
Modified stroke test for effusion assessment, assessment of knee active range of motion, maximum voluntary isometric or isokinetic quadriceps strength testing, joint-line tenderness

Interventions:
Clinicians should provide supervised, progressive range-of-motion exercises, progressive strength training of the knee and hip muscles, and neuromuscular training to patients with knee meniscus tears and articular cartilage lesions and after meniscus or articular cartilage surgery. (B)

Forty-eight patients with full-thickness articular cartilage lesions with poor knee function participated in a 3-month rehabilitation program consisting of cardiovascular training, progressive strength training of the knee and hip muscles, and neuromuscular training. Statistically significant increases in hop score and KOOS score were achieved.

Interventions following surgery
Clinicians may use early progressive active and passive knee motion with patients after knee meniscal and articular cartilage surgery. (B)
Clinicians should provide supervised, progressive range-of-motion exercises, progressive strength training of the knee and hip muscles, and neuromuscular training to patients with knee meniscus tears and articular cartilage lesions and after meniscus or articular cartilage surgery. (B)
Neuromuscular electrical stimulation can be used with patients following meniscal or chondral injuries to increase quadriceps muscle strength. (B)

Patellofemoral Pain

It is unclear as to what causes PFPS. The patellofemoral joint (PFJ) comprises the articulation between the patella and the trochlear groove of the femur. Age, BMI, height, or quadriceps angle (Q-angle) are not risk factors for the development of PFP. Only one study showed that pronation was a causative factor, indicating that it is not a feature of PFP. There is a strong possibility that hip weakness is a result of PFP and not causative of PFP. This would be due to pain inhibition or PFP causing alterations in movement patterns secondary to pain

Diagnosis:
-Most have difficulty with squatting, stair negotiation, and running. More than half report pain with prolonged sitting. Loading of the joint with a flexed knee being an aggravating factor. (A)
-Clinicians should make the diagnosis of PFP using the following criteria: (1) the presence of retropatellar or peripatellar pain, (2) reproduction of retropatellar or peripatellar pain with squatting, stair climbing, prolonged sitting, or other functional activities loading the PFJ in a flexed position, and (3) exclusion of all other conditions that may cause anterior knee pain, including tibiofemoral pathologies. (B)
-Clinicians may use the patellar tilt test with the presence of hypomobility to support the diagnosis of PFP. (C)
----Patellar tilt test is a measure of lateral retinacular tightness. (Specificity = 0.92 and +LR = 5.4)
----------Pt supine, examiner passively displaces patella laterally. Positive if lateral aspect of patella fails to rise at least to a level that is horizontal to the table indicating tight retinaculum. 

Outcome Measures:
VAS, KOOS-PF, AKPS (Anterior Knee Pain Scale). (A)

Physical Impairment Measures:
Squatting, step-downs, single-leg squat. These tests can assess a patient’s baseline status relative to pain, function, and disability; global knee function; and changes in status throughout the course of treatment. (B)

Physical Impairment Measures
Patellar provocation, patellar mobility, foot position, hip and thigh muscle strength, and muscle length. (C)
-----Muscle length testing: hamstrings (SLR <79 deg), gastrocnemius (ankle DF with knee extension <7 deg), soleus (ankle DF with knee flexed to 90 deg <15 deg), quadriceps (prone knee flexion <134 deg), IT band (Ober test with knee flexed to 90 deg <11 deg with inclinometer)

Interventions:
-The combination of hip- and knee-targeted exercises is preferred over solely knee-targeted exercises to optimize outcomes in patients with PFP. Hip-targeted exercise therapy should target the posterolateral hip musculature. Knee-targeted exercise therapy includes either weight-bearing (resisted squats) or non–weight-bearing (resisted knee extension) exercise. (A)
-Patellar taping: Common methods include the tailored McConnell taping technique, where rigid taping is applied with the aim of reducing any combination of lateral patellar glide, tilt, and rotation, to reduce pain during a functional task (eg, step-down). Other common methods include untailored medial patellar glide–only taping. 
---Clinicians may use tailored patellar taping in combination with exercise therapy to assist in immediate pain reduction, and to enhance outcomes of exercise therapy in the short term (4 weeks). Importantly, taping techniques may not be beneficial in the longer term or when added to more intensive physical therapy. Taping applied with the aim of enhancing muscle function is not recommended. (B)
---Understand that the taping may serve benefit for the patients that have reduced VMO activation and thus less medial pull of the patella. Essentially, tape where the limitations are.
-Clinicians should not prescribe patellofemoral knee orthoses, including braces, sleeves, or straps, for patients with PFP. (B)
-Clinicians should prescribe prefabricated foot orthoses for patients with greater than normal pronation to reduce pain, but only in the short term (up to 6 weeks). If prescribed, foot orthoses should be combined with an exercise therapy program. There is insufficient evidence to recommend custom foot orthoses over prefabricated foot orthoses. (A)
-Clinicians may use gait retraining consisting of multiple sessions of cuing to adopt a forefoot-strike pattern (for rearfoot-strike runners), cuing to increase running cadence, or cuing to reduce peak hip adduction while running for runners with PFP. (C)
-Exercise therapy is the critical component and should be the focus in any combined intervention approach. Interventions to consider combining with exercise therapy include foot orthoses, patellar taping, patellar mobilizations, and lower-limb stretching. (A)

Knee Osteoarthropathy

Symptomology
-Retropatellar pain
-Aggravated by weightbearing activities, squatting, stairs, prolonged siting
-Crepitus  

Physical Examination
-Antalgic gait
-Swelling and/or warmth at the knee
-TTP (tender to palpation) at joint line
-Painful and/or limited knee ROM (flexion/extension)
-Painful and/or limited knee resistive testing

Interventions
-Manual therapy consisting of sustained hold, oscillation mobs, STM
-Hip and knee strengthening
-Modalities for pain control (heat, ice, electrical)
-Medially directed patellar taping, medially wedged insoles if they have lateral compartment OA, laterally wedged subtalar strapped insoles if they have medial compartment OA, walking aid as needed
-Aerobic exercise
-Weight loss

Knee Ligament Sprain

Examination
PCL: posterior drawer test
ACL: Lachman's Test, Anterior Drawer Test, Pivot Shift Test 
LCL & MCL: Varus and Valgus Instability Test (0 deg and 30 deg)
------- At 30 deg of knee flexion, MCL and LCL is more isolated from other medial joint structures like ACL and PCL. 

Outcome Measures
KOOS
IKDC 2000
Physical Performance Measures
Single-legged hop tests (eg, single hop for distance, crossover hop for distance, triple hop for distance, and 6-meter timed hop)

Interventions Following Surgery
-Early weight bearing within 1 week after surgery can be used for patients following ACL reconstruction without incurring detrimental effects on stability or function. (C)
-The use of immediate postoperative knee bracing appears to be no more beneficial than not using a brace in patients following ACL reconstruction. (B) 
-Conflicting evidence exists for the use of functional knee bracing in patients following ACL reconstruction. (D) Think long-term I think
-Clinicians should consider the use of immediate mobilization within 1 week following ACL reconstruction to increase range of motion, reduce pain, and limit adverse changes to soft tissue structures. (B)
-Clinicians should consider the use of cryotherapy to reduce postoperative knee pain immediately post– ACL reconstruction. (C)
-Weight-bearing and non–weight-bearing concentric and eccentric exercises should be implemented within 4 to 6 weeks, 2 to 3 times per week for 6 to 10 months, to increase thigh muscle strength and functional performance after ACL reconstruction. (A)
-Neuromuscular electrical stimulation (NMES) can be used with patients following ACL reconstruction to increase quadriceps muscle strength. (B)
-Neuromuscular electrical stimulation should be used for 6 to 8 weeks to augment muscle strengthening exercises in patients after ACL reconstruction to increase quadriceps muscle strength and enhance short-term functional outcomes. (A)
-Clinicians should consider the use of neuromuscular re-education as a supplementary program to strength training in patients with knee stability and movement coordination impairments. (B)

Interventions With Ligament Deficiency
-The use of functional knee bracing appears to be more beneficial than not using a brace in patients with ACL deficiency. (C)
-Neuromuscular re-education training should be incorporated with muscle strengthening exercises in patients with knee stability and movement coordination impairments. (A)

Patellar Tendinopathy

Symptomology
Hallmark clinical features: pain localized to the inferior pole of the patella and load related pain that increases with the demand on the knee extensors. Other signs and symptoms: pain with prolonged sitting, squatting, and stairs but note that this is also symptoms of PFPS. Pain occurs instantly with loading and usually ceases almost immediately when the load is removed. Pain is rarely experienced in a resting state. Pain may improve with repeated loading (the "warm-up" phenomenon) but there is often increased pain the day after energy storage activities. Clinically, it is noted that dose-dependent pain is a key feature, and assessment should demonstrate that the pain  increases as the magnitude or rate of application of the load on the tendon increases. For example, pain should increase when progressing from a shallow to a deeper squat, and from a smaller to a greater hop height. Studies have suggested that up to 24 hours of pain provocation after energy-storage activities may be acceptable during rehabilitation.

Knee NMES
For muscle re-education: 35-50 pps for pulse frequency, 200-350 microseconds for large muscles for pulse duration, amplitude sufficient for functional activity, on:off time depends on functional activity, ramp time at least 2 seconds.
For muscle strengthening: 35-80 pps for pulse frequency, 200-350 microseconds for large muscles for pulse duration, to >10% MVIC (maximal voluntary isometric contraction) in injured/50% MVIC in uninjured for amplitude, 6-10 seconds on and 50-120 seconds off (1:5) initially for on:off time, at least 2 seconds ramp time, 10-20 minutes to produce 20 repetitions for treatment time, every 2-3 hours when awake for times/day.

Outcome Measures
KOOS (knee injury and osteoarthritis outcome score)

Protocols: https://medicine.osu.edu/departments/sports-medicine/education/medical-professionals/rehabilitation-protocols