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1. Knee extension chain, and pathologic processes may exist proximal or

2. Knee flexion distal to the knee. Pelvic obliquity or leg-length inequal-
3. Internal tibial rotation ity must be recognized, because these problems affect
4. External tibial rotation the knee. Abnormal foot function is not uncommon
C. Neuromuscular tests—resisted hip flexion (L2, L3); patellar and causes various knee ailments, including patellar
reflex (L3–L4) tendinitis and lateral knee pain.235 Increased pronation
D. Palpation of the foot or a rigid, supinated configuration con-
1. Bony structures and soft tissue attachments tributes to knee problems.34,210–213,226 Failure to recog-
2. Tendons nize that a foot abnormality is causing a knee problem
3. Ligaments may delay treatment and recovery.
III. Supine A patient with knee problems should be evaluated
A. Inspection frequently with a motion examination both on and
1. Tibial lengths (knees bent) off a treadmill (using various speeds). A foot that
2. Anteroposterior tibial alignment (knees bent) looks as though it is one configuration often will
3. Femoral lengths (knees bent) actually function as the opposite when in motion.212
4. Leg-length measurement (anterosuperior iliac spine to Videotapes or films also help in diagnosing difficult
medial malleolus) problems.34
5. Valgus–varus angulation
6. Swelling or atrophy (girth measurements)
COMMON LESIONS
7. Skin
B. Selected tissue tension tests Ligamentous Injuries
1. Non–weight-bearing (active–passive) tests
a. Flexion–extension—measured with goniometer
HISTORY
b. Lateral and medial rotation The patient will invariably recall the traumatic event. The
2. Joint-play movements therapist should attempt to determine the exact mechanism
a. Anterior–posterior glide of injury.
b. Valgus–varus tilt Onset. One of the most common mechanisms of injury
c. Internal–external rotation occurs when a football player is tackled from the side with the
d. Patellar mobility foot planted and the knee slightly flexed. The victim is usu-
e. Distraction ally struck while trying to turn or cut away. The forces on the
3. Ankle range of motion knee include a valgus stress, external rotation of the tibia on
4. Passive hip flexion–extension, abduction–adduction, the femur, and usually an anterior movement of the tibia on
and straight-leg raise the femur. With sufficient force, the medial capsule is torn
5. Special tests for: first, followed by the MCL, then the ACL.178 The medial
a. Ligamentous instability meniscus is invariably torn as well, completing the “terrible
b. Meniscal tears triad of O’Donoghue.”
c. Patellofemoral joint involvement A minor medial ligament sprain is a common lesion that
C. Neuromuscular tests—resisted dorsiflexion (L5) usually results from an external rotation strain of the tibia on
D. Palpation the femur. An external force may or may not be involved.
1. Muscles A force against the anterior thigh, which can drive the
2. Effusion femur backward on the tibia, while the knee is close to full
3. Skin extension, tends to stress the ACL. This is especially true if the
IV. Prone tibia is in a position—or forced into a position—of internal
A. Inspection rotation with respect to the femur. In fact, forced internal
1. Soft tissues rotation of the tibia on the femur in itself may tear the ACL.
2. Skin Internal rotary strains are thought by some to be the primary
B. Selected tissue tension tests cause of isolated ACL lesions.180,355
1. Passive hip internal–external rotation A force driving the tibia backward on the femur will stress
2. Resisted knee flexion the PCL. This seems to be true regardless of whether or not
C. Neuromuscular tests—medial hamstring reflex (L5) the knee is flexed, because the PCL remains relatively taut in
D. Palpation most positions of the knee. An example of such an injury is
1. Muscles the previously described dashboard injury.
2. Skin In the case of a force driving the knee into hyperextension,
A knee examination is never done in isolation. The the posterior capsule tends to give way first, then the ACL,
knee is only a single component of the closed kinetic and finally the PCL.180
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516 PART II ■ CLINICAL APPLICATIONS—PERIPHERAL JOINTS

In cases of severe ligamentous injuries, sometimes the PHYSICAL EXAMINATION

patient attempts to continue activities (e.g., return to the field
In the acute stage, once joint effusion, considerable pain,
in a football game) immediately after the injury. This is espe-
and significant muscle guarding have developed, it may prove
cially true in the case of a complete MCL rupture, as no fibers
very difficult to perform some of the evaluation procedures.
remain intact from which pain can arise. The pain often sub-
In any case, the knee must be examined, sparing the patient
sides after a few minutes if the patient is in a highly moti-
as much discomfort as possible and ensuring that no harm
vating situation. No effusion ensues because the capsule is
is imposed by the tests. The value of immediate, on-the-
usually torn, allowing the fluid to leak out of the joint cavity.
spot examination before the onset of effusion cannot be
In partial ligamentous injuries, the patient is less likely to
overemphasized.
continue activity because of persisting pain after the injury.
In severe injuries the patient may describe painful effu-
I. Acute Lesion with Effusion
sion occurring within a few minutes after the injury; this is
A. Observation. The patient may hobble into the office, per-
highly suggestive of hemarthrosis, and an intra-articular frac-
haps on crutches. The knee is held slightly flexed with
ture must be ruled out by the physician. Slower development
only toe-touch weight bearing, if any. The shoe, sock,
of effusion (e.g., during several hours) suggests synovial effu-
and trousers are removed with difficulty.
sion secondary to capsular irritation. This is common with
B. Inspection. Joint effusion is obvious, especially in the
mild and moderate ligamentous injuries.
suprapatellar region. The patient stands with the leg
Site of Pain. The patient usually will point to a localized
held semiflexed, often unable to place the heel on the
area that corresponds well to the site of the tear as being the pri-
floor.
mary site of pain. The exception is an isolated ACL tear, which
1. The Helfet test cannot be done because the knee can-
is relatively rare and may result in more generalized discomfort.
not be fully extended.
In the case of effusion, especially hemarthrosis, the entire
2. Girth measurements at the suprapatellar region are
knee area is likely to be painful; the patient is less able to local-
ize the site of injury. Also, in severe injuries involving several increased from effusion.
structures, localization is less likely because of generalized pain. 3. Some redness of the skin over the knee may be
The knee is largely innervated by the L3 segment, although noticed. The skin may be somewhat shiny from being
it also receives contributions from L4 to S2. Referred pain stretched.
into these segments is possible, although this does not seem to C. Selective tissue tension tests
occur as frequently with acute ligamentous lesions as it does 1. Active movement
with chronic, degenerative problems. a. Weight-bearing flexion–extension is impossible.
Nature of Pain and Disability. In the absence of sig- b. In the supine position, active movement is limited in
nificant effusion, the pain is described as a continuous, deep, a capsular pattern because of joint effusion, with
fairly localized pain, which is increased by any movement tend- pain especially at the extremes of both motions.
ing to further stress the ligament (partial tear). When consid- Passive overpressure is met with a muscle-spasm
erable effusion exists, a more intense, aching, throbbing pain end feel.
is described that is aggravated by weight bearing and virtually 2. Passive movements. Flexion–extension is limited in a
any movement. Hemarthrosis is, as a rule, more painful than capsular pattern (about 15° loss of extension and 60
synovial effusion. to 90° loss of flexion) with no crepitus and a muscle-
If a moderately severe tear or complete rupture is left to spasm end feel.
heal, the pain will largely subside. The patient may walk quite 3. Resisted movements
comfortably but cannot perform some particular activity such a. Should be strong and painless, barring concurrent
as running, jumping, cutting, walking down stairs, or squatting tendon injury
without having the knee give way. If carefully assessed, the b. Quantitative determination of muscle strength
particular disabilities will correspond to activities that tend to must be deferred because of the acute condition.
move the knee into directions that the stretched or ruptured 4. Passive joint-play movements of the femorotibial joint
ligament is meant to check. Some examples include: may be hypermobile and painful. (Be aware of possible
false-negative results from muscle guarding.)
1. Inability to turn quickly—MCL or LCL a. Anterior glide
2. Inability to run forward—ACL b. Posterior glide
3. Inability to descend stairs easily, squat, or run backward— c. Medial-lateral glide
PCL or posterior capsule. d. Internal–external tibial rotation
e. Patellar mobility cannot be validly assessed if signifi-
An MCL rupture will usually result in considerable disability, cant effusion is present.
whereas isolated cruciate tears may cause little or no disability f. Superior tibiofibular joint. Joint-play movement
if quadriceps muscle function is good.230 here may be painful in an LCL sprain.
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CHAPTER 15 ■ KNEE 517

D. Palpation abnormal joint mechanics. The meniscus tear compounds

1. There is likely to be localized tenderness at the site of the instability and the tendency for the knee to buckle.
the tear. There may be referred tenderness in nearby
areas as well. MANAGEMENT
2. Effusion is easily confirmed by the tap test or by emp-
The approach to management of ligamentous injuries depends
tying the suprapatellar pouch while palpating the lat-
on several factors, including the patient’s age and desired
eral patellar margins. Posterior capsular distension may
activity level and the nature of the pathologic process. It is
also be noted. Hemarthrosis may accompany (1) a cru-
important to determine the severity of the injury and whether
ciate tear, (2) a meniscus tear extending to the periph-
the lesion is acute or chronic. Traditionally, ligamentous
eral attachment, (3) a severe capsular tear, or (4) an
lesions have been graded as follows:
intra-articular fracture.
3. The joint is warm and slightly moist. Grade I: Mild sprain, with no gross loss of integrity of
E. Ligamentous stability and special tests (see Physical Exam- the ligament fibers. On examination there is no
ination, above) joint-play hypermobility.
II. Acute Lesion without Effusion. Some effusion follows most Grade II: Moderate tear, with partial loss of integrity
ligament injuries at the knee, but the absence of significant of the ligament, manifested as mild joint-play
effusion does not necessarily mean that the injury is mild. On instability
the contrary, complete medial capsular ruptures, usually with Grade III: Severe tear or complete rupture of the lig-
tearing of all or part of the MCL, may not be followed by ament resulting in moderate to marked joint-play
much joint effusion because the fluid escapes the confines hypermobility
of the joint capsule through the defect.
There are two primary differences between a patient pre- This classification is useful for general communication pur-
senting with effusion and one presenting without. In the poses, but it cannot be used as an absolute guide to clinical
absence of effusion the patient presents with less of a gait management; it does not adequately represent the broad con-
disturbance—the knee is not maintained in as much flexion, tinuum of ligamentous injuries, nor does it take into account
and the patient may be able to walk without aids. Also, the other individual factors such as the patient’s age, activity level,
available range of motion is greater. Generally, the patient motivational status, or the stage of the lesion.
who does not develop much joint swelling has less pain and The stage of the lesion—how acute or chronic it is—is also
disability. The clinician must carefully assess joint-play move- a somewhat arbitrary designation. For the sake of this discus-
ments to determine whether the absence of effusion reflects sion, we will base this classification on specific clinical cri-
a minor lesion or a very severe injury. Information acquired teria that may reflect the nature of the existing inflammatory
during the patient interview is also instructive. process. In an acute lesion, the patient cannot bear weight
If significant instability is present on one or more joint- without pain and a significant limp; there is significant loss of
play movements, a physician experienced in such injuries knee motion, with a painful, muscle-spasm end feel; and there
must be notified at once, because immediate surgery may is obvious swelling or effusion. In a chronic lesion, the patient
be indicated. can walk with minimal pain and without a significant limp;
III. Chronic Ligament Ruptures. Patients occasionally present knee motion is relatively free, or, if restricted, is limited by stiff-
with chronic ligament ruptures. The primary complaint is ness (nonpainful end feel); and there is little or no swelling.
functional instability or giving way of the knee with particu- A subacute lesion presents with some combination of acute or
lar activities. The patient may walk without a limp or obvious chronic criteria.
disability; the only significant findings may be (1) difficulty Grade I and II Sprains. After mild to moderate knee liga-
performing some specific function such as running, turning ment injury, the patient should be able to return to a normal
sharply, squatting, descending stairs, or running backward, level of activity. In first-degree sprains, treatment is relatively
(2) quadriceps muscle atrophy, especially if the joint was unimportant and is designed mostly to prevent pain. In second-
swollen or immobilized, (3) hypermobility on one or more degree sprains, the critical factor in treatment is protection
joint-play movements or ligamentous stability tests, and to allow healing. The rehabilitation program should be started
(4) a positive Helfet test. early, with more progressive exercise techniques and func-
Laxity of one of the medial stabilizing structures—the tional activities added later. The general strengthening exer-
medial capsule or MCL—is most likely to result in some dis- cises usually do not need to be modified, although for medial
ability. Often this is combined with ACL rupture. The result is lesions care must be taken to avoid valgus stress at the knee,
instability of anterior glide and external rotation of the tibia and for lateral lesions varus stress should be avoided.
on the femur. Functionally, the patient cannot turn away Friction massage at the site of the lesion, applied trans-
from the involved side without the leg giving way, a real versely to the direction of the ligament fibers with the knee in
problem for a young, active person. The medial meniscus different degrees of flexion–extension, may help prevent the
may be torn at the time of injury or some time later from healing ligament from adhering to adjacent tissues and may
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518 PART II ■ CLINICAL APPLICATIONS—PERIPHERAL JOINTS

help align newly produced collagen along the normal lines metrics of the hamstrings and quadriceps to encourage co-
of stress (see Box 8-3).60 Take care not to apply friction at the contractions. Range of motion is limited and protected. Based
proximal attachment of the MCL, because occasionally a on the studies of Daniels,62 Daniels et al.,63 Henning et al.,132,133
periosteal disruption results here in the development of a bony and Paulos et al.,278 the range is limited from 90° of flexion to
outcropping (Pellegrini-Stieda syndrome).348 (Although this is 45° of extension. This is because the ACL undergoes a decel-
undoubtedly an inevitable result of the original injury, the use eration strain at about 30° with maximum strain at 0° extension.
of massage may be held suspect should some medicolegal A protected exercise program is allowed in this range. Iso-
question develop.) metric internal and external rotation exercises, added once
MCL Tear (Grade III Sprain). MCL tears do not usually the patient has 90° flexion, decrease any abnormal tibial rota-
require surgical repair.25,85,130,140,296,329 The normal course for tion.320,321 Special emphasis is placed on hamstring exercises.
these injuries is reexamination under anesthesia followed by During all phases of the exercise program, electrical stimula-
arthroscopy of the knee.240 It is necessary, however, to prove tion with maximum contraction is desirable to maintain mus-
that an isolated MCL injury is present, with no involvement cle integrity.331
of the meniscal or cruciate structures. Patients with a com- Functional knee braces have been suggested for perma-
bined MCL–ACL injury will most likely have an ACL recon- nent use in sports activities involving cutting or rotational
struction without MCL repair. The MCL has an excellent stresses.20,81,329,334,339 There are two types, featuring hinge posts
secondary support system. Weight-bearing forces tend to com- with or without shells to encompass the thigh. Gait studies
press the medial side, thus aiding in stability, and the injury can have shown that under low loading conditions, most func-
be protected adequately with bracing. Three conditions must tional knee braces limit excessive anterior tibial translation.
be met for healing to occur at the MCL: (1) the ligament fibers However, under conditions of high loading that more closely
must remain in continuity or within a well-vascularized soft tis- simulate high activity levels, there is little or no control of
sue bed; (2) there must be enough stress to stimulate and anterior tibial translation.
direct the healing process; and (3) there must be protection ACL repair or reconstruction, like nonsurgical rehabilita-
from harmful stresses.360 tion, typically demands a protocol that minimizes any quadri-
Whether surgical repair is used or not, the knee is usually ceps muscle activity involving anterior translation of the tibia.
immobilized in a hinge cast or brace cast to minimize atrophy This means using midrange quadriceps work, avoiding termi-
and prevent valgus stress.122 Rehabilitation after most MCL nal knee extension, and emphasizing hamstring strengthening
injuries can progress fairly rapidly (2 to 8 weeks). The treat- to provide active stabilization. The advanced phase of treat-
ment program is similar to that for second-degree sprains. ment features eccentric quadriceps exercise and the removal
Weight bearing with crutches is continued until full knee of the extension stop of the rehabilitative brace.9,52,81,339
extension without an extension lag can be demonstrated and Surgical Rehabilitation. The operative methods of sta-
the patient can walk normally without gait deviations. Return bilization are intra-articular or extra-articular. Extra-articular
to sports is not permitted until a normal gait pattern has been reconstruction involves taking a structure that lies outside of
achieved. Functional proprioceptive neuromuscular facilita- the joint capsule and moving it so that it can affect the mechan-
tion (PNF) patterns stressing tibial rotation should be incorpo- ics of the knee in a manner that mimics normal ACL func-
rated for strengthening with resistance as the patient becomes tion.157,222,223 The iliotibial band is the most commonly used
stronger. As strength improves, the patient should engage in structure. However, long-term results have been disappoint-
functional activities to enhance dynamic stability of the knee. ing.338 This procedure is effective in reducing the pivot-shift
MCL sprains vary in severity and response to treatment. The phenomena that is found in anterolateral rotational instability
physician and the patient’s response to treatment will deter- but cannot match the normal biomechanics of the ACL.157,220–223
mine the timing of progression through the stages of treat- The rehabilitation after an extra-articular reconstruction is
ment for a specific injury. aggressive and permits an earlier return to functional activities
ACL Tear (Grade III Sprain). Ruptures of the ACL may but is not recommended for high-level patients.285
occur as a result of a direct blow to the knee with the foot Intra-articular reconstruction involves placing a structure
planted. Much more often, however, they are the result of a within the knee that will roughly follow the course of the ACL
noncontact twisting injury associated with a hyperextension or and will functionally replace the ACL. Bone–patellar tendon–
varus or valgus stress to the knee. After the diagnosis of injury bone grafts are the current state of the art, using human auto-
of the ACL, the patient is faced with various treatment options. grafts or allografts.75,76,87,96–98,101,157,261,262,295,359 Intra-articular ACL
The conservative approach is to allow the acute phase of the reconstruction using various tissues, including the patellar ten-
injury to pass and to then implement a vigorous rehabilitation don, iliotibial band, and combinations of hamstring tendons
program. If it becomes apparent that normal function cannot (semitendinosus, semitendinosus–gracilis), has been exten-
be recovered, and if the knee remains unstable, then recon- sively described in the literature.3,4,7,33,46,54,92,96,115,123,137,156,167,249
structive surgery to considered. Noyes and colleagues258 reported that the patellar tendon graft
Nonoperative Rehabilitation. In the nonsurgical patient, had a strength of 168% of the ACL, whereas the semitendi-
after control of swelling and pain, treatment begins with iso- nosus had 70%, the gracilis 49%, and the quadriceps or patel-
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CHAPTER 15 ■ KNEE 519

lar retinaculum only 21%. Currently, either the patellar tendon structures that surround the joint. It is clear that rehabilitation
or semitendinosus autografts are the most widely used ACL that incorporates early joint motion is beneficial for reduction
substitutes to reconstruct the ACL-deficient knee.282 In intra- of pain, minimizing capsular contractions and decreasing scar
articular procedures, the site must undergo revascularization formation that can limit joint motion, and is beneficial for artic-
followed by reorganization of collagen.38,48,261 These procedures, ular cartilage.26 Aquatic therapy programs342,359 and closed-
therefore, usually necessitate a slower, longer rehabilitation chain kinetic exercises are often emphasized.270 Aquatic therapy
process than extra-articular reconstruction.37,38,260,277,330 is often used to initiate a fast-paced walking or running pro-
Allegoric tissue grafts from cadavers and amputation spec- gram. A study by Tovin and associates342 suggests that a reha-
imens pose an attractive option—they are readily available in bilitation program for patients with intra-articular ACL
various tissues (fasciae late, hamstring tendons) and because of constructions performed in a pool is effective in reducing joint
lack of rigid size constraints may be used in quantities that pro- effusion and facilitating recovery of lower extremity function,
vide greater mechanical strength than the corresponding auto- as indicated by Lysholm scores.216 The results also suggest that
genous tissue.75,112,154,199,243,254,276,314–317 However, the enthusiasm aquatic therapy is as effective as other exercise approaches
surrounding the use of allograft replacement of the ACL has for restoring knee range of motion and quadriceps femoris
recently declined because of the small but tangible risk of muscle strength, but not as effective in restoring hamstring
infectious disease transmission.282 muscle strength.
Much as been written regarding the rehabilitation of the Rehabilitation with a closed kinetic chain program results in
patient who has undergone ACL reconstructive surgery. A anteroposterior knee laxity values that are closer to normal, and
body of literature has addressed the bone–patella tendon– earlier return to normal daily activities, compared with rehabil-
bone complex (BPB) graft because this has been the gold itation with an open kinetic chain program.26 Closed-chain exer-
standard. Many protocols have been presented to manage such cises appear to be more effective than open-chain exercises at
patients.65,74,97,98,129,219,222,223,255,256,276,279,282,290,294,297,302,305–311,337,359 increasing the joint compressive forces and, thus, minimizing
With the use of securely fixed, high-strength, isometric grafts, the anteroposterior translation of the tibia.107,270,352,353 Closed-
the progressive rehabilitation protocol includes early protected chain knee extension has been advocated as a safe exercise for
motion, neuromuscular rehabilitation, and patellofemoral joint patients after ACL reconstruction, and research suggests that
mobilization. Traditional rehabilitation after ACL reconstruc-
closed-chain exercises are safer than open-chain ones because
tion is lengthy: an athlete with such an injury will usually require
there is less stress on the graft.132,265,283 An open-chain action
a year before returning to full activity. Rehabilitation depends
primarily emphasizes concentric work, but a closed-chain
very much on the surgical procedure performed.84,259,309,359 Tra-
movement brings a more balanced action of concentric, eccen-
ditionally, rehabilitation has been conservative, but in recent
tric, and isometric contraction. However, PNF strengthening
years the trend has been to become more aggressive in reha-
patterns that stress tibial rotation are essentially the only way
bilitation of the reconstructed ACL primarily as a result of the
to concentrate on strengthening the rotation component of
reports of Shelbourne and co-workers.305–310 This has been
referred to as an accelerated protocol. They have demonstrated knee motion, which is essential to normal function of the knee.
that this program returns the patient to normal function early, Because the PNF patterns are done in open kinetic chain,
results in fewer patellofemoral problems, and reduces the num- they should only involve active contraction through the func-
ber of surgeries to obtain extension, all without compromising tional movement pattern.285
stability.306 Rehabilitation proceeds through a controlled ambu- Along with the early controlled weight bearing and closed-
lation phase, light activity phase, and return to activity phase. chain exercises, which act to stimulate muscle and joint
The most frequent problems encountered after ACL surgery mechanoreceptors, sensorimotor activities (e.g., balance board
are quadriceps weakness, patellar irritability, flexion contrac- exercises, slide board training, mini-trampoline activities)
tures, and joint stiffness.359 Early restoration of full extension to reestablish balance and neuromuscular control should also
(1 to 4 weeks) is imperative to successful outcome, as is aware- begin early in the rehabilitation process (see Figs. 14-44
ness of potential complications that may limit progress such as through 14-46; also see Figs 15-63 through 15-65).135 Training
arthrofibrosis.282 Joint mobilization is initiated in the form of progression should begin with patients early in therapy with
early patellar mobilization and tibiofemoral mobilization to balance board activities with the patient in a bipedal stance and
improve extension. The clinician instructs the patient in self- progress to single-leg stance in the more-advanced phase. Sev-
mobilization of the patella techniques as part of the home eral authors advocate the use of balance board propriocep-
program. tive training well past the acute postsurgical rehabilitation
The accelerated protocol emphasizes immediate motion, phase, not only for restoration of function but for its prophy-
including full extension, immediate weight bearing within tol- lactic effect on ligament reinjury.42,134,135,346
erance, and early closed-chain exercise for strengthening and An early goal of proprioceptive training is to achieve sym-
neuromuscular control. metric bipedal gait. Once achieved, a running gait retraining
After reconstructive surgery, immobilization of the knee or program improves symmetry of lower limb musculature con-
restricted motion without muscle contraction leads to unde- tribution, which may prevent abnormal loading of the liga-
sired outcomes for the ligamentous, articular, and muscular ments and soft tissue and increase strength and endurance
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520 PART II ■ CLINICAL APPLICATIONS—PERIPHERAL JOINTS

during sports competitions.136 Hewett et al.136 suggest the use Eccentric quadriceps exercises are started as soon as the patient
of gait training on a treadmill in front of a mirror to provide can tolerate them.
simultaneous visual and verbal trainer feedback to the patient. A common surgical procedure for PCL repair is reposi-
Incline treadmill running can increase range of motion across tioning of the origin of the medial gastrocnemius muscle.179
all joints, but especially at the hip. Backward incline training This transfer acts dynamically during weight acceptance and
also should be used to increase range of motion and to the push-off phases of gait. In this case both quadriceps and
increase quadriceps functional strength while simultaneously gastrocnemius muscles are of primary importance with respect
reducing patellofemoral stress (see Fig. 15-67).47,324 For the ath- to exercise. Once the quadriceps have achieved 80% of the
lete simultaneous gait retraining and a progressive plyometric strength of the normal leg on Cybex or a similar testing device,
program teaches the athlete to properly initiate, control, and hamstring exercises are added. The length of time to return
decelerate ground reaction forces that will be encountered in to sports is about the same as for injury of the ACL.
running, jumping, cutting, and other activities. Functional In addition to hamstring training to prevent anterior sub-
exercises such as balance beam walking, vertical jumping, luxation for ACL injuries and quadriceps training to increase
single-leg and double-leg hopping, shuttle runs, and rope structural stiffness and knee strength for PCL injuries,108,166,353
skipping can be progressively incorporated into the train- it is important to include dynamic joint control training.56,153,352
ing program. Return to sports depends on strength, skill Even if the hamstrings and quadriceps are strengthened, it is
acquisition, and response of the knee to activity. important that they function quickly and adequately during
PCL Tear (Grade III Sprain). Isolated tears of the poste- unexpected trauma by improving neuromuscular coordination.
rior cruciate ligament are not common. It is more likely that Training should consist of balance and proprioception activities,
the PCL is injured concurrently with the ACL, MCL, LCL, or functional development of the feet to grasp the ground, stabi-
menisci. The majority of PCL injuries result from a direct blow lization of the stance position, and improvement of reactions to
to the flexed knee. Hyperflexion and hyperextension injuries sudden additional forces applied by the clinician.153
have also been shown to result in PCL ruptures. The PCL may LCL Tears (Grade III Sprain). The lateral aspect of the
also be injured when the tibia is forced posteriorly on the knee is well supported by secondary stabilizers and can be
fixed femur or the femur is forced anteriorly on the fixed treated nonsurgically.240,275 Isolated injury to the LCL is
tibia.220 Isolated PCL disruptions often have a good progno- rare, and when it does occur, it is critical to rule out other
sis when treated nonoperatively.55,61,66 Their prognosis after ligamentous injuries. When the secondary restraints, lateral
direct surgical repair is somewhat better than ACL repair capsule, and cruciate ligaments are torn, functional instability
because of a more generous blood supply; however, com- is common and surgical correction is usually required. Reha-
bined injuries to the PCL and posterolateral corner can be bilitation after repair follows the guidelines for PCL rehabili-
particularly troublesome (see Flexor Mechanism Disorders tation and for posterolateral rotatory instability. Athletes or
below). The knee with a torn ACL usually has symptoms of other persons placing unusual demands on the functional
instability, but the knee with a torn PCL has symptoms of capacity of the knee must undergo a more rigorous retrain-
disability: medial compartment arthritis, patellofemoral arthri- ing program. For these patients especially, exercises should
tis, and swelling and pain related to activity. PCL rehabili- approximate the type of loading normally imposed on the
tation closely follows ACL rehabilitation protocol, with a joint. Most athletic activities, as well as routine activities of
few exceptions: daily living, involve relatively high loading conditions. Isoki-
netic exercise equipment with variable speed adjustments is a
• No isolated hamstring exercises are performed dung the
convenient means of providing high-speed resistance to vari-
first 6 to 8 weeks.
ous muscle groups, while monitoring the percent of maximal
• Closed chain exercises are emphasized, allowing for ham-
torque output. Such exercises result in strengthening and also
string strengthening but protecting against posterior tibial
optimize the training effect of the exercise program.
translation through the quadriceps–hamstring force–couple
Running, jumping, and athletic activities are not permitted
and compressive forces across the joint.
until strength is nearly normal, range of motion is full, and nor-
The recovery process proceeds essentially the same as the mal femorotibial rotation has returned. Such activities are
ACL rehabilitation program. gradually progressed from straight-ahead jogging to straight-
Acute PCL repair with augmentation appears to have a bet- ahead running, then running with gentle turns, and finally run-
ter success rate than does delayed reconstruction.240,275 Early ning with abrupt stops and turns. Clinical signs of healing, such
postoperative motion after PCL repair usually is not recom- as restoration of strength and range of motion with no pain
mended. A period of 4 to 6 weeks of immobilization is advo- on stress testing, in no way signify return of normal strength to
cated to allow the bone grafts to heal before initiating joint the injured ligament.253 Restoration of ligamentous strength
motion. The focus of rehabilitation for both surgical and non- requires a maturation process of collagen aggregation and
surgical patients is on quadriceps exercises. In conservative realignment that may take several months to a year.2,132
rehabilitation the hamstrings are omitted in the early exercise Any advantages of returning to activities involving inter-
phase because they may accentuate posterior subluxation. mittent high loading of the knee must be weighed against the
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CHAPTER 15 ■ KNEE 521

risk that the still-weakened structure may give way prema- sponding to the site of the tear where the coronary ligament
turely, possibly resulting in a more serious injury than the has been sprained.
original one. In making judgments about appropriate activity Nature of Pain and Disability. The onset is usually sud-
levels, the desires of the coach and the highly motivated young den, with an immediate deep pain associated with giving way
athlete must often take second priority to knowledge of the of the joint. If hemarthrosis occurs, pain is typically severe and
rate and mechanisms of tissue healing. generalized, arising within minutes of the injury. If a longitu-
dinal tear of the medial meniscus extends anteriorly past the
Meniscus Lesions midpoint of the meniscus, the lateral portion may slip over the
dome of the medial femoral condyle (Fig. 15-15). This grossly
Meniscus lesions affecting the knee are common, especially
interferes with normal knee mechanics, with a resultant imme-
in athletes. Once it has been determined through examina-
diate locking of the joint so that the last 20 to 30° of extension
tion that a meniscus lesion exists, it is important to classify the
are lost. An injury involving such immediate locking is usually
injury as a tear confined to the periphery or a tear involving
preceded by one or more previous minor incidences of giving
the body of the meniscus. Often arthroscopy or arthrography
way followed by effusion; the developing longitudinal tear
will assist the physician in making this distinction. An antero-
finally extends anteriorly far enough to cause such locking.
medial coronary ligament sprain accompanies most tears
The person suffering a meniscus tear hesitates to resume
involving the body of the medial meniscus.
activity immediately after the injury, unlike the person suf-
fering a ligamentous sprain. Synovial effusion, causing a gen-
HISTORY
eralized pressure sensation, may arise within hours after the
Onset. The menisci move with the tibia in flexion– injury. Effusion nearly always accompanies a medial meniscus
extension and with the femur in rotation. If, during flexion, tear, but not always a lateral tear.
external tibial rotation is forced instead of the internal rota- In an untreated meniscus tear, the acute stage may com-
tion that should normally occur, abnormal stresses are applied pletely subside with restoration of motion. The person may
to the menisci, and a tear is possible. The same, of course, resume normal activities with little or no pain. The complaint,
applies to the case of forced internal tibial rotation during however, is one of intermittent buckling of the joint for no
knee extension. Similarly, flexion or extension in the absence apparent reason, even during simple walking. Occasional or
of the normal rotary movement that should accompany it may persistent clicking of the joint may be reported. Chronic or
result in a meniscus tear. The medial meniscus, being less intermittent effusion may also occur, probably from altered
mobile, is more susceptible to injury. Because tibial rotation joint mechanics resulting in undue stress to the joint capsule.
is impossible in the fully extended knee, the history is one of
twisting on a semiflexed knee. Again, athletes, especially those PHYSICAL EXAMINATION
wearing cleated shoes and involved in contact sports, are par-
I. Acute Stage
ticularly prone to meniscus injuries, occasionally in conjunc- A. Observation
tion with ligament tears. 1. The patient may hobble in on crutches with the knee
Meniscus tears may also occur with hyperflexion of the held slightly flexed and touching down only the toe.
knee, especially during weight bearing. In this position, the 2. Obvious effusion may be present.
femoral condyles have rolled back to articulate with the poste- 3. The patient may have difficulty removing the shoe,
rior aspects of the tibial articular surfaces. The menisci, then, sock, and trousers.
must recede backward during flexion, but can recede only to a B. Inspection
certain point before capsuloligamentous attachments restrict 1. Effusion may be noted, especially in the suprapatellar
their further movement. If further flexion is forced once the region.
menisci have reached their limit of backward movement, the 2. The patient stands with the knee held semiflexed.
menisci are susceptible to being ground between the femoral 3. The Helfet test may not be performed because of
and tibial joint surfaces. This is especially true if rotation is incomplete extension.
forced in hyperflexion, because a rotary movement entails fur- 4. The suprapatellar girth measurement may be increased
ther backward movement of one condyle. Certain occupations, from effusion.
such as mining, in which one must move about in a squatting 5. The skin may appear slightly red and shiny.
position, may predispose to development of meniscal tears C. Selective tissue tension tests
from this mechanism. In athletics, the wrestler is classically 1. Active movements
prone to this type of injury. a. Weight-bearing flexion–extension is impossible.
Site of Pain. The person usually feels “something give” b. Flexion–extension in supine reveals:
in the joint, often with an accompanying deep, sickening type i. A capsular pattern if effusion is present
of pain. If not masked by other injuries or extensive effusion, ii. Considerable loss of extension if the knee is
the patient often can point to the spot on the joint line corre- locked, causing a distorted capsular pattern if
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522 PART II ■ CLINICAL APPLICATIONS—PERIPHERAL JOINTS

effusion is present, a noncapsular pattern if lit- 2. Full range of motion, but perhaps some difficulty or
tle or no effusion is present apprehension when performing weight-bearing
c. Passive overpressure reveals a muscle-guarding end flexion–extension
feel at the extremes of flexion and extension. 3. Possibly a positive Helfet test as a result of altered
d. If the knee is locked, a springy rebound end feel joint mechanics
will be noted moving into extension. 4. Possibly a positive McMurray test if the posterior
2. Passive movements segment of the meniscus is torn
a. Essentially the same as indicated above for active 5. Pain on forced extension if the anterior segment of
movement, with perhaps slightly greater range of the meniscus is torn
movement 6. Positive Apley test when the joint is compressed, but
b. McMurray’s test may not be performed if consider- not when it is distracted
able effusion restricts flexion, because it is applica- 7. Tenderness to palpation at the joint line, usually
ble only from full flexion to 90°. If flexion is possible, corresponding to the site of the lesion
a painful click may be elicited on combined external 8. Perhaps some mild chronic effusion
rotation and extension if a tear exists in the poste- 9. Quantitative quadriceps weakness compared with the
rior portion of the medial meniscus, or on combined other leg
internal rotation and extension if a posterior lateral 10. The clinical examination may be complemented by an
meniscus lesion exists. arthrogram to give the examiner more information
3. Resisted isometric movements. These should be strong about the integrity of the menisci (Fig. 15-29).
and painless unless a tendon or muscle has also been III. Coronary Ligament Sprain
injured. Quantitative strength measurements cannot A. History. The patient usually describes a twisting injury
be made because of the acute condition. followed by some minor swelling and pain over the
4. Passive joint-play movements anteromedial knee region. Rarely is the victim signifi-
a. Rotation opposite the side of the lesion may be cantly disabled immediately after the injury; he or she usu-
painful, especially during Apley’s test with com- ally does not seek medical attention in the acute stage.
pression applied. Distraction with rotation should Acute symptoms usually subside within a few days. If the
relieve the pain. meniscus maintains good mobility during healing, the
b. Otherwise, these movements should be relatively
patient should have no further problems. However, often
normal unless a ligamentous injury also exists.
the coronary ligament becomes adhered to the antero-
D. Palpation
medial margin of the medial tibial condyle as it heals,
1. Tenderness is present at the joint line where a sprain
resulting in reduced mobility of this part of the meniscus.
of the peripheral attachment has occurred. This usu-
In such cases, the person develops a more chronic problem
ally corresponds quite well with the side and site of
characterized by intermittent pain when the adhered tissue
the tear.
is stressed, usually with activities involving external rotation
2. Effusion, as mentioned, nearly always accompanies a
of the tibia on the femur. The persistent nature of the
medial meniscus tear, but not always a lateral tear.
problem eventually prompts the person to seek medical
The tap test and emptying of the suprapatellar pouch
assistance, even though the disorder is otherwise minor.
will confirm the presence of minor effusion.
3. The joint is warm, the skin somewhat moist.
II. Chronic Tear
A. History. The patient describes intermittent giving way of
the joint, often followed by some effusion, especially if
the medial meniscus is at fault. There may be a history
of locking with manipulative reduction by the patient,
a friend, or physician, followed by immediate relief of
pain and restoration of extension. The younger, active
person is usually suffering from a longitudinal tear,
beginning posteriorly and gradually extending anteri-
orly. The older person may have a degenerative hori-
zontal tear, with sliding occurring between the upper A B
and lower portions. The patient notes clicking when the ■ FIG. 15-29. Normal meniscus (A) appears as an un-
femoral condyle passes over a centrally protruding piece interrupted dark wedge (arrow) on an arthrogram. An
of a meniscus. arthrogram of a torn meniscus (B) shows streaks of dye
B. Objective signs within the wedge. (Reprinted with permission from
1. Quadriceps atrophy, especially involving the vastus Kulund DH: The Injured Athlete, 2nd ed. Philadelphia,
medialis JB Lippincott, 1988:176.)
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CHAPTER 15 ■ KNEE 523

B. Objective findings operative treatment plan. Although long-term results are still
1. Consistent findings on physical examination: unknown, the meniscus should be preserved whenever possi-
a. Point tenderness over the anteromedial joint line ble to avoid the late sequelae of meniscectomy.
b. Pain on external rotation of the tibia on the femur, Clinical, cadaveric, and biomechanical studies have all
but no pain on valgus stress demonstrated significant shear and compression forces gen-
2. Occasionally forced extension hurts as well. Rarely is erated by open kinetic chain exercises that may potentially
effusion present by the time the person is seen clini- create deforming forces not only on reconstructed cruciate
cally. There may be minimal quadriceps atrophy if the ligaments (see above) but also on healing meniscal injuries,
problem has been of long duration. repairs, or transplanted allografts.119,132,175,214,215 For this rea-
son closed kinetic exercises are emphasized. Early on in the
MANAGEMENT rehabilitation program, manual resistance can be applied by
Acute Tear of Body of a Meniscus. If an acute menis- the therapist to emphasize either a dynamic or static muscle
cus tear is suspected on examination, the referring physician contraction using PNF techniques. These exercises can
should be consulted and notified of the positive findings. Usu- be performed parallel to the floor, in half-kneeling, in sup-
ally after arthroscopic evaluation of the knee joint, if an isolated ported plantigrade, or on a therapy ball (see Figs. 15-58
tear is encountered (i.e., one without concomitant ligament through 15-61) so that the actual compression loads placed on
damage), a decision must be made as to whether repair or the knee are probably less than if performed in full weight-
removal is the best treatment. Meniscal repair is a growing bearing positions.43,335 Exercises are initially performed in the
trend in orthopedics. Immobilization is necessary after menis- anatomic planes of motion and progressed to multiangled and
diagonal patterns of motion. Exercises initially may be per-
cal repair. If the procedure is successful, recovery is expected
formed with double leg support and then single leg support
in about 6 months. Most meniscal injuries still require removal
(see Figs. 15-60 and 15-61). Once full weight-bearing restric-
of the torn portion of the meniscus; arthroscopy is the most
tions have been lifted, the patient progresses to higher levels
effective way of doing this.67,240
of full weight-bearing closed kinetic chain exercises. Thera-
If surgery is not planned, treatment in the acute stage is
peutic tubing can be used initially to provide some assistance.
essentially the same as that discussed above for an acute, minor
The patient can start with assisted squats and progress to
ligamentous sprain. Weight bearing must not be allowed on a
assisted lunges. Progression to higher-level closed kinetic chain
locked knee and should be restricted on a knee that cannot
free-weight strengthening exercises depends on the patient’s
fully extend because of effusion. Extension must not be forced goals and abilities. Neuromuscular-proprioceptive training of
in the locked knee, because if the displaced piece of meniscus patients after meniscal injuries is accomplished with a variety
does not slip back, extension may occur only at the expense of of balance boards and other sensorimotor activities (see Fig.
the ACL or articular cartilage. 14-45). In patients who have a total meniscectomy or meniscal
Chronic Tear of Body of a Meniscus. Again, the physi- transplantation, a certain degree of activity modification is nec-
cian should be notified if this is suspected. If arthroscopic essary. For the athlete who places higher functional demands
surgery is not contemplated, the goal is restoration of optimal on the knee, sports-specific agility training is necessary to
joint mechanics: mobilization, strengthening, and instruction in ensure a safe return to athletic competition.
appropriate activity levels are necessary. A particular motion, Coronary Ligament Tear. Cyriax58 was the first to draw
especially extension, must not be encouraged if the restriction attention to sprains of the coronary ligaments, which is very
is secondary to an intra-articular block, as from a displaced common but mostly goes undiagnosed because the localization
piece of meniscus. Throughout meniscal rehabilitation, it is of the pain and nature of the onset resemble a meniscus lesion
important to minimize compressive loading of the joint until or sprain of the coronary ligament. The persistent intermittent
adequate muscular protection and joint reorganization have knee pain is the result of adherence of the anteromedial coro-
been developed. nary ligament to the underlying tibia (Fig. 15-7); the adhesion
Meniscal Repair. Many options for meniscal repair exist is broken with some sudden movement, then adherence recurs
for the orthopaedist. Options such as open repair or arthro- during healing. Scarring results in diminished movement of
scopically assisted inside-out technique have favorable long- the meniscus during rotation, extension, and flexion.124 The dif-
term results.234 Future directions include the potential use ferential diagnosis from a meniscal lesion is extremely impor-
of growth factors and gene therapy to augment meniscus tant and relies on history and clinical examination. In a chronic
repair. There are many views on rehabilitation after menis- situation, the coronary findings will be painful on forced pas-
cus repair. Traditionally, an individual with a meniscal tear sive flexion or extension and on passive lateral knee rotation
has been treated with immobilization, no weight bearing, or (lateral coronary problems are rare).124
both.67–69 After repair, the repair should be protected until The objective of treatment is to restore mobility gradually
healing has occurred. The amount of protection required for to this part of the meniscus. This is accomplished with ultra-
meniscal repair can vary widely with surgical technique and sound and transverse friction massage applied directly to
the surgeon’s experience. It is important for the clinician to the site of the lesion (see Box 8-3). Ten to fifteen minutes of
obtain directions from the physician regarding the post- massage, during three or four treatment sessions, are usually