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356
E. Jacquez et al.
palpated to determine the specic site of maximum
tenderness. The range of motion of the knee is
measured with the knee in straight extension as 0°
of exion; normal full exion is approximately
135°.
The collateral ligaments are then assessed by
stabilizing the thigh with one hand and placing a
varus or valgus stress on the knee with the other
hand. A normal knee will have a small amount of
medial and lateral laxity in the collateral ligaments. However, any laxity which is excessive or
if pain is elicited should be noted. The cruciate
ligaments can also be assessed. The anterior cruciate ligament is best assessed using the Lachman
test. The examiner should stand by the patient’s
feet. The femur is stabilized with one hand holding the distal medial thigh. The tibia is then held
with a thumb at the lateral joint line. The examiner then attempts to displace the tibia forward in
relation to the femur. Translation less than 5mm
should be noted and the anterior cruciate ligament should be felt to “snap taut” in the normal
knee. Injury to the posterior cruciate ligament
can be demonstrated by noting the degree of
recurvatum (back-knee) which can be obtained
passively compared to the contralateral knee.
Also, with both knees exed 60–90° and the
patient supine, the tibia on the decient side will
be noted to sag posteriorly compared to the uninjured leg when viewed from the side. A posterior
drawer can be performed with the knee bent at
90° and exerting a posterior force on the tibia.
There should be less than 5 mm of translation.
Comparison to the contralateral knee is very
important for examination of the collateral and
cruciate ligaments.
The menisci are examined by palpation of
their outer margin along the joint line at the proximal tibial articular surface. In addition, meniscal
tears can be detected by the McMurray maneuver. This is done by exing the knee internally
and externally rotating the tibia and then extending the knee with a valgus force applied. If a
reproducible snap is palpated or pain elicited at
the joint line, this is suggestive of a tear. Patients
with meniscal tears will also report pain when
asked to squat down with the knees exed. The
most sensitive test for the meniscus is simple
joint line tenderness.
Imaging
All of the available imaging techniques have been
utilized in the evaluation of patients with knee
problems. Plain radiographs are the most commonly obtained studies (Fig. 14.4). Plain radiographs are helpful in the evaluation of fractures
and subluxation of the joint, and the condition of
the articular surfaces can be investigated. The standard series of routine X-rays of the knee should
include a standing anteroposterior (AP) radiograph of both knees, a lateral view and a merchant
or “sunrise view.” The sunrise view is a view taken
with the knee in 45° of exion with the beam
directed inferiorly and parallel to the patellar articular surface. There should be a space of 5–10mm
between the ends of the femoral condyles and the
tibial surface and beneath the patellar surface and
the femoral trochlea. This “clear space” is in fact
occupied by the articular cartilage.
a
b
Fig. 14.4 (a) Standing, weight-bearing AP radiograph of
both knees in an 87-year-old female with osteoarthritis of
both knees with a windswept deformity (right knee valgus, left knee varus alignment). Note the asymmetric
space between the medial and lateral femoral condyles
and the tibial surface. (b) Sunrise view of the bilateral
knees, useful in evaluating the patellofemoral joint space,
reasonably well preserved in this patient
14 Knee Osteoarthritis andArthroplasty
357
Routine radiography is an excellent tool for
the evaluation of the knee for trauma, arthritis,
and alignment. Plain radiographs, however, only
demonstrate the osseous structures. As mentioned earlier, the soft tissues provide stability
and allow the knee to function. Arthrography has
been used in the past to evaluate the knee for
meniscal pathology. However, this technique was
inaccurate and invasive. The development of
arthroscopy allows the direct visualization of the
structures within the knee in a minor surgical
procedure. However, this technique is also invasive and while arthroscopy is accurate, the procedure is relatively expensive compared to an
imaging modality alone. Nuclear medicine studies are of limited use in the knee. These studies
are sensitive; however, the specicity of these
studies is limited. Magnetic resonance imaging
(MRI) has provided a dramatic step forward in
the ability to diagnose soft tissue injury to the
knee. MRI provides accurate and non-invasive
evaluation of all the soft tissue structures within
the knee (Fig.14.5). MRI is currently the study of
a
choice for the evaluation of intra-articular pathology within the knee.
Computed tomography (CT) is another
excellent imaging modality for cross-sectional evaluation of both the osseous and soft
tissue structures of the knee. In the setting of
periarticular trauma such as tibial plateau
fractures, CT scans are invaluable to the treating surgeon as they characterize and evaluate
fracture patterns and incongruity about the
joint surface and significantly help with surgical planning. Additionally, CT can detect the
presence of air or fluid within the joint and
any bony or soft tissue masses or infectious
processes about the knee.
Knee Pathology
Soft tissue injury is common in the knee. A knee
with a bloody effusion after an injury has an incidence as high as 80% of signicant soft tissue
injury. The differential diagnosis of a posttraumatic bloody effusion in the absence of an
intra-articular fracture includes most commonly
a meniscal tear, an ACL tear, or a patellar
dislocation.
b
Fig. 14.5 (a) Normal T1-weighted magnetic resonance
imaging (MRI) sagittal image of the medial meniscus. (b)
Schematic illustration showing the section cut of (a)
Meniscal Tears
Tears of the meniscus can occur in two settings.
One is the result of a specic injury. This usually
involves a twisting injury with the knee in some
exion. Swelling and pain are noted immediately
after the injury. There is increased pain with
attempts at movement and there is a limitation in
the range of motion. Pain with squatting down or
arising from a chair is commonly reported. The
torn meniscus can block regular joint motion.
Occasionally, the knee can be gently manipulated
to reduce the torn meniscal fragment and motion
will be restored. However, the fragment will frequently re-displace and intermittent locking may
occur. This form of tear is usually in younger
patients with stout meniscal tissue.
In older individuals, the meniscal tissues
soften and the edges become torn and frayed. As
358
E. Jacquez et al.
this occurs, the frayed edges can become
entrapped between the edges of the bone initiating a tear which can extend into the meniscal
substance. This tear can occur with little or no
trauma with minimal swelling and pain initially.
The diagnosis is made by complaints of pain
along the medial or lateral joint line, medial or
lateral joint line tenderness, effusion, and, rarely,
locking. Patients with locking will frequently
require arthroscopic surgery to debride the torn
portion of the meniscus. In older patients with
meniscal tears, if the tear does not cause mechanical symptoms, it frequently can be treated with
nonsteroidal anti-inammatory medications and
an intra-articular corticosteroid injection. These
treatments will reduce the effusion and pain.
With continued activity, the soft meniscal tissue
can be worn down and a stable edge reestablished. However, for some persistently symptomatic cases, arthroscopic meniscectomy is
curative (Fig.14.6).
Ligament Injuries
Injury to the ligamentous structures manifest as
instability in the knee. The four major ligaments
of the knee are the medial collateral ligament, lateral collateral ligament, anterior cruciate ligament, and posterior cruciate ligament. Their
location and function is described in detail in a
previous section of this chapter. In addition to
pain and swelling, patients will report a sense of
the knee shifting or giving way. This may be with
only specic activities, such as descending stairs
Fig. 14.6 Arthroscopic image of a frayed, torn medial
meniscus in an active 69-year-old female
or when turning on the loaded extremity. The initial management of these injuries is rest, ice, and
elevation. A splint or knee immobilizer can also
be helpful to protect the knee. As the initial pain
subsides, it is important to begin to work on
restoring the range of motion using a brace to
protect the injured ligament. As the pain further
decreases, strengthening is begun. If the knee
remains unstable after the strengthening program
is completed, the patient may be a candidate for
surgical reconstruction.
Patellofemoral Pathology
The patellofemoral joint is one of the most common areas of pain in the knee. Common complaints are anterior knee pain which is aggravated
by activities involving high loads on a exed
knee, such as stair climbing, running, and bicycling. This pain can be the result of degenerative
changes in the patellofemoral articulation or a
result of maltracking of the patella within the
trochlear groove. A grinding or snapping sensation may also be noted. Pain is usually relieved
by rest; however, if the patient is sitting for a
prolonged period of time with the knee exed,
such as in a theater, on a plane, or during a long
car ride, anterior knee pain will result. Frequently,
patients will try to change the position of the
knee to relieve their discomfort. This symptom is
referred to as “movie sign” and is indicative of
stress in the patellofemoral joint. Softening of
the articular surface is referred to as chondromalacia patella. This can be a primary problem or it
may be secondary to excessive trauma to the
joint due to maltracking of the patella within the
trochlear groove.
The treatment of these conditions is primarily
nonoperative. Improving the patellar tracking
can be done through a series of exercises to
retrain the quadriceps, abductor strengthening at
the hip, and through patellar mobilization exercises. The exercise program needs to be maintained for a minimum of 6–8 weeks to
demonstrate benet. The symptoms can frequently be recurrent. If the symptoms are recurrent and do not respond to the nonoperative
Healthy knee
Knee osteoarthritis
14 Knee Osteoarthritis andArthroplasty
359
regimen and patellar maltracking is evident,
operative intervention may be indicated.
Operative intervention is directed at correcting
the patellar tracking and to maximize the quadriceps function with postoperative physical
therapy.
Arthritis
While numerous etiologies of arthritis in the knee
exist, including rheumatoid and septic, this section will focus on the most commonly encountered form seen and managed by orthopedists:
osteoarthritis. This progressive, degenerative,
and debilitating condition affects over 250 million people worldwide and is likely to increase in
prevalence with the continued upward shift of the
mean population age. While it is now known that
a cascade of inammatory changes and both
chondral and associated soft tissue remodeling is
involved in the pathogenesis of osteoarthritis, it
remains debated as to the exact sequence or predisposing conditions that initiate the degenerative
pathways that cause this painful process to occur.
Ultimately, the end result is cartilage wear, osteophyte formation, and potential imbalance of the
normal alignment of the knee joint (Fig.14.7).
The management of arthritic symptoms within
the knee is similar to the management of arthritis
elsewhere. The nonoperative management of
arthritis within the knee consists of a vemodality approach. The rst line of therapy is the
use of nonsteroidal anti-inammatory drugs
(NSAIDs). These medications will reduce the
pain and swelling associated with the knee.
Although all of the NSAIDs function in a similar
fashion, there is a wide variation in individual
patient response. Therefore, minimally two or
three different NSAIDs should be tried. The most
common side effect of this course of treatment is
gastritis and gastrointestinal (GI) intolerance.
The second line of treatment of arthritis is the
selected use of intra-articular corticosteroid medication. This can be effective in patients who
have an acute exacerbation of the arthritic pain.
The injection can quiet their pain and restore
them to a baseline level of discomfort. The injection should not be utilized for the control of baseline pain. If the injection is required at a frequency
of greater than once every 3months, some other
course of treatment should be initiated, such as
surgery. If the knee is injected more frequently
three times per year, the corticosteroid may have
a detrimental effect on the articular cartilage.
Other forms of injections include hyaluronic acid
derivatives and platelet-rich plasma. These injections do not have the detrimental effect of corticosteroids, although they are often not as
effective.
Physical therapy can be very helpful in the
treatment of arthritis of the knee. As the soft tissue sleeve is very important to the function of the
knee, optimizing functions of the soft tissues can
reduce the symptoms of arthritis. The physical
therapy should be directed at maintaining the
range of motion of the knee and optimizing the
strength of the quadriceps and the hamstring
Fig. 14.7 Comparison
illustration of healthy
and arthritic knee joints
Cartilage
Fibula
Osteophytes
Tibia
Worn
cartilage
Exposed
bone
Cartilage erosion
Meniscal
damage
360
E. Jacquez et al.
muscles. In the late stages of degenerative arthritis, physical therapy may worsen the patient’s
symptoms and should be limited to a program
within the patient’s tolerance.
Assistive devices such as a cane or crutch
may aid in the management of arthritis of the
knee. This can limit the stress across the painful
knee and improve the patient’s walking tolerance. The nal approach to the management of
arthritis of the knee is modication of activities.
This includes alterations of the patient’s activities such as sports, work environment, and possibly even assisting in arranging special parking
for the patient. Frequently, patients with signicant knee arthritis are also overweight. Weight
loss in these patients can signicantly reduce
symptoms and the need for other treatment
modalities. As the force across the knee joint
may be three to ve times the patient’s body
weight, weight loss can have a signicant impact
on a patient’s knee symptoms.
Surgical Reconstruction forArthritis
When all nonoperative measures have failed to
relieve the symptoms of knee arthritis, surgical
intervention should be contemplated. The surgical correction of knee arthritis can be separated
into treatments which retain the patient’s articular surfaces and knee replacement. Nonreplacement options include the use of
arthroscopy to “clean out” the knee; this procedure can remove the small cartilage fragments
that accumulate in arthritic joints and debride any
loose articular fragments and degenerative meniscal tears. This procedure should be reserved for
patients with minimal arthritis only and is contraindicated for moderate to severe arthritis as it will
frequently worsen the symptoms. In that setting,
the patient is a candidate for knee replacement.
Patients with osteoarthritis of the knee will
frequently develop angular deformities. The most
common deformity is varus angulation of the
knee. This results from erosion of the medial
compartment of the knee. As the deformity progresses, a greater portion of the weight-bearing
stress is concentrated in the medial compartment
of the knee. Osteotomy is a procedure to realign
the articulation. The proximal tibia is transected
and a wedge of bone is removed from the lateral
aspect or a wedge can be inserted on the medial
side. This will result in a correction of the alignment and the varus deformity. It also redistributes
some of the weight-bearing stress to the lateral
compartment and can result in improved symptoms in the knee. The result is generally successful for 5–10years. Osteotomy is contraindicated
in knees which are stiff or unstable. When the
symptoms return, knee replacement surgery is
indicated.
Arthrodesis or fusion of the knee is an option
for the management of young active patients, particularly physical laborers. This will result in a
stiff straight knee that will allow the patient to
ambulate and stand for long periods of time without difculty. However, signicant limitations
also exist. The gait pattern is signicantly abnormal. In addition, patients will have difculty sitting, particularly in conned spaces such as public
transportation and theaters. Resection arthroplasty is a procedure where the articular surfaces
are resected and a brous pseudoarthrosis forms
within the joint space. Pain may be decreased;
however, the knee is signicantly unstable, requiring a brace for ambulation. Arthrodesis and resection arthroplasty are not commonly performed
anymore as replacements are the mainstay of
operative management of the arthritic knee.
Currently, these procedures are reserved for the
management of a failed total knee replacement.
Total knee replacement (TKR) is commonly
utilized to relieve the symptoms of knee arthritis
and restore function (Fig.14.8). Approximately
250,000 arthroplasties are performed annually in
the United States; the average age of patients
receiving a TKR is 65–70 years. Successful
results can be obtained in over 95% of patients
with survivorship at 10–15 years of 90%.
Components are typically xed with polymethylmethacrylate (PMMA) bone cement. Noncemented components, those used with porous
ingrowth surfaces for bone ingrowth, have previously been associated with a higher incidence of
loosening and pain, though advances continue to
be made in this technique.
The proximal tibia is cut perpendicular to the
long axis of the shaft, and the femoral articular
14 Knee Osteoarthritis andArthroplasty
Fig. 14.8 Standing AP radiograph of both knees 2weeks
after one stage bilateral knee replacements
surface is cut using specic guides to remove the
femoral trochlea, distal and posterior femoral
condyles. The anterior cruciate ligament is
removed; however, the posterior cruciate ligament can be resected or retained depending on
the design of the implant chosen. For proper
function of the arthroplasty, the MCL, LCL, and,
if retained, PCL must be carefully balanced. The
components are then xed to the surfaces of the
tibia and femur with bone cement. The patella is
normally resurfaced as well after resecting the
articular surface parallel to the anterior surface.
The patient is mobilized quickly following the
procedure, and full weight-bearing may be allowed
immediately. Perineural anesthesia, introduced as
a single shot preoperatively or infused via catheter
for patients remaining under observation postoperatively, has dramatically improved peri-procedural discomfort and enabled earlier mobilization.
The critical element of postoperative therapy is the
restoration of motion. If motion is not restored
within the rst 3–6weeks, maturation of scar tissue may prevent major gains in motion after that
point. Many total knee replacements are now performed as outpatient procedures, with patients
returning home on postoperative day zero.
Frequently, however, these patients will
require physical therapy after discharge to continue to work on the range of motion and ambulation in the rst few weeks after surgery. While the
total rehabilitation period after total knee replace-
361
ment is between 3 and 6 months, patients are
functionally mobile after 2–3 weeks. Knee
replacement can be performed bilaterally in one
stage in medically healthy patients. The initial
increase in debilitation postoperatively is offset
by a reduction in the overall period of rehabilitation after sequential unilateral TKR.
Aseptic loosening of the implants after TKR
occurs at a low rate. Several studies have documented a 15-year survivorship of greater than 90%
and less than 0.5% per year rate of aseptic loosening after cemented TKR.If a TKR is noted to be
loose prior to 5 years, it should be evaluated for
deep infection. Deep sepsis is associated with early
loosening after total knee replacement. Young age,
marked obesity, and high demand will also negatively impact the long-term survival of the replacement. To date, the best data for non- cemented TKR
is equal to the cemented replacement. Several studies suggest poorer results when cement is not used,
particularly for xation of the tibial component.
Increased tibial loosening and pain have been noted
with these devices. At present, due to the generally
increased cost for non- cemented porous-coated
implants and poorer clinical results, the use of these
devices is difcult to justify.
The majority of complaints after cemented
TKR are from the patellofemoral joint, which
can be the result of poor soft tissue alignment at
the time of arthroplasty. This may lead to painful
subluxation or dislocation of the patellar component. If inadequate bone is resected from the
patella at the time of resurfacing, a marked
increase in the patellofemoral stress can be noted
which may become painful. Some surgeons have
advocated not resurfacing the patella; however,
several studies now demonstrate a higher rate of
patellofemoral complaints after TKR without
patellar resurfacing. If signicant patellofemoral
arthritis exists at the time of arthroplasty, patients
with weights greater than 60 kg and heights
greater than 160cm will have more pain postoperatively if the patella is not resurfaced.
The most common complication after TKR is
thromboembolic disease (TED). The rate of
asymptomatic deep venous thrombosis ranges
from 25 to 50% of cases without prophylaxis in
patients evaluated with venography or duplex
362
E. Jacquez et al.
Doppler analysis. Similar to patients receiving
total hip replacement (THR), it is currently recommended that all patients receive some form
of prophylaxis against TED.Mechanical methods, such as the pneumatic compression stockings, appear to have a greater benet after THR
compared to TKR.Aspirin and low molecular
weight heparin are two common medications
used although there are several other anti-coagulant medications on the market as well. Some
form of anti-coagulant medication is recommended and necessary.
Deep infection occurs at a rate of approximately 1% after TKR for osteoarthritis over the
life of the implant. The most common organisms are skin ora, primarily Staphylococcus
aureus and S. epidermidis. In particular to knee
replacement, the relatively thin soft tissue envelope at the inferior aspect of the skin incision
can lead to wound dehiscence and allow entry of
the ora into the joint (Fig.14.9). Any area of
skin breakdown after TKR should be treated
aggressively to prevent deep infection. This is
particularly true in patients with prior incisions
and in those with diabetes or signicant vascular disease.
If a deep infection is established, the only
way to eradicate the infection is to remove the
implants and all of the bone cement and thoroughly debride the joint. An antibiotic impregnated cement spacer is often placed into the
joint space although single stage revisions can
be performed. The patient should receive
6 weeks of intravenous (IV) antibiotics. After
6 weeks, the knee can be reimplanted if adequate soft tissue and bone remain. However,
due to the inevitable scarring, the clinical result
is compromised. There is some evidence suggestive that deep infections identied early
enough can be managed without sacricing initial implants, though results from this practice
vary.
Occasionally after TKR, the range of motion
of the knee does not progress well after surgery.
If the patient is less than 2–6weeks after surgery,
a gentle manipulation of the knee in the operating
room under anesthesia may be benecial. If the
motion cannot be restored, particularly if the
patient is beyond 6 weeks after replacement,
additional surgery may be necessary to restore
functional range of motion.
Fig. 14.9 Infection and surgical wound breakdown status
post total knee replacement
Summary andConclusions
The knee is a complex joint with function provided by the combination of osseous and soft
tissue structures. The soft tissue envelope plays
a signicant role in the pathology of the knee
and in the management of these conditions.
With careful history, physical examination, and
appropriate use of the available diagnostic
modalities, knee pathology can be accurately
diagnosed and successful treatment instituted.
Successful management of knee pathology
includes treatment of the specic etiology, but
optimal management of the soft tissue envelope
with directed physical therapy is essential to an
optimal outcome.
14 Knee Osteoarthritis andArthroplasty
363
Further Reading
Heck DA, Murray DG. Biomechanics in the knee. In:
Evarts CM, editor. Surgery of the musculoskeletal
system. 2nd ed. NewYork, NY: Churchill Livingston;
1990. p.3243–54.
Katz JN, Arant KR, Thornhill TS. Knee osteoarthritis.
In: Schoenfeld AJ, Blauwet CA, Katz JN, editors.
Principles of orthopedic practice for primary care providers. Cham: Springer; 2021.
Mora JC, Przkora R, Cruz-Almeida Y.Knee osteoarthri-
tis: pathophysiology and current treatment modalities.
J Pain Res. 2018;11:2189–96.
Rand JA, Ilstrup DM. Survivorship analysis of total
knee arthroplasty. Cumulative rates of survival of
9200 total knee arthroplasties. J Bone Joint Surg Am.
1991;73(3):397–409.
Ruiz-Pérez JS, Gómez-Cardero P, Rodríguez- Merchán
EC. The infected total knee arthroplasty. In:
Rodríguez-Merchán E, Gómez-Cardero P, editors.
Comprehensive treatment of knee osteoarthritis.
Cham: Springer; 2020.
Stavrakis A, Arshi A, Chiou D, Hsiue P, Horneff JG 3rd,
Photopoulos C. Cemented versus noncemented total
knee arthroplasty outcomes. J Am Acad Orthop Surg.
2022;30(6):273–80.
Stern SH, Insall JN. Posterior stabilized prosthesis.
Results after follow-up of nine to twelve years. J Bone
Joint Surg Am. 1992;74(7):980–6.
Windsor RE, Bono JV.Infected total knee replacements. J
Am Acad Orthop Surg. 1994;2:44–53.
The Foot andAnkle
PaulS.Cooper, NicholasD.Casscells,
andJuliaA.McCann
15
Anatomy
The bony anatomy of the foot and ankle consists
of the distal tibia and bula in the leg and the 26
major bones that compose the foot, 28 if you
include the sesamoids. The tibia distally terminates into the metaphyseal plafond with its
medial malleolus. The lateral surface of the distal
tibia has a sulcus to accommodate the adjacent
bula, forming the distal tibiobular joint. The
distal bula which lies laterally and slightly posterior to the tibia is held there by the inferior tibiobular ligaments. The bula forms the lateral
malleolus of the ankle joint. The relationship of
the bula to the tibia is not static. With ankle dorsiexion, the bula laterally translates, proximally migrates, and externally rotates.
The ankle is a diarthrodial joint (Figs. 15.1
and 15.2). It consists of an articulation between
the talus and the mortise of the tibia and bula.
Dorsiexion of the ankle joint is coupled with
eversion of the foot, and plantar exion is combined with inversion. The distal bula provides a
static buttress over the talus laterally and bears
P. S. Cooper · N. D. Casscells · J. A. McCann (*)
MedStar Georgetown Orthopedic Institute,
Georgetown University School of Medicine,
Washington, DC, USA
Department of Orthopedics, MedStar Georgetown
University Hospital, Washington, DC, USA
e-mail: Nick.casscells@gunet.georgetown.edu;
Julia.A.McCann@medstar.net
1/6 of the transmitted weight during the stance
phase of gait. The foot is composed of seven tarsals, ve metatarsals, and 14 phalanges. Three
anatomic groupings are dened for descriptive
purposes: the hindfoot, the midfoot, and the forefoot (Fig.15.3). The hindfoot consists of the talus
and calcaneus bones. The talus consists of a body,
neck, and head. Two-thirds of the talus is covered
by articular cartilage. There is no muscle or tendon attachments on this bone. The talar dome is
the superior portion of the body which articulates
with the mortise of the tibia and bula. The dome
is wider anteriorly, which allows for stability in
the mortise during dorsiexion. Posteriorly, a
sulcus is formed between the posterolateral and
posteromedial tubercles to accommodate the
exor hallucis longus (FHL) tendon. If prominent, this structure is often referred to as the
Stieda process or os trigonom if detached from
the talus. The inferior surface of the talus articulates with the corresponding facet of the calcaneus to create a subtalar joint. The calcaneus is
the largest bone in the foot, with its longitudinal
axis directed dorsally and laterally. Its superior
surface articulates with the talus and three facets—anterior, medial, and posterior—to form the
subtalar joint (Fig. 15.4). The large posterior
facet articulates with the corresponding articular
facet on the inferior surface of the talus. The middle facet overlies the sustentaculum tali (a dense,
medial projection of the calcaneus that contains a
groove to accommodate the FHL tendon sheath)
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2024
W. F. Postma et al. (eds.), Essentials of Orthopedic Surgery,
https://doi.org/10.1007/978-3-031-66215-7_15
365
366
ab
ab c
P. S. Cooper et al.
Fig. 15.1 (a, b) Photographic diagrammatic and radio-
logic anatomy of the normal ankle in anteroposterior
views. (c) Note equal width of cartilage spaces and alignment of lateral talus with posterior cortex (arrow) on mor-
Fig. 15.2 Photographic (a) and radiologic (b) anatomy
of the normal ankle in lateral projection. (Reprinted from
Orthopedic Radiology, Weissman BNW & Sledge CB,
tise view. (Reprinted from Orthopedic Radiology,
Weissman BNW & Sledge CB, The Ankle, p. 590,
Copyright Saunders (1985), with permission from
Elsevier)
The Ankle, p.591, Copyright Saunders (1985), with permission from Elsevier)
and is often merged with the anterior facet. The
middle facets and anterior facets articulate with
the undersurface of the talar head.
The midfoot consists of the navicular, cuboid,
and three cuneiform bones. The tarsonavicular
bone articulates with the talar head and lies medially to the cuboid bone. It functions as a keystone
for the medial longitudinal arch of the foot. The
distal surface is composed of three facets that
articulate with the medial, middle, and lateral
cuneiform bones, respectively. The medial pole
of the navicular is also the primary insertion site
for the posterior tibial tendon. In 10% of people,
an unfused accessory navicular bone may be
present, also known as an os navicular. The
cuboid bone forms an articulation with the calcaneus proximally and the fourth and fth metatarsals distally. Laterally, a groove within the cuboid
accommodates the peroneus longus tendon as it
courses plantarly. It is not uncommon to have a