Dror Paley. New York: Springer; 2001. 750 pages. $225.00.
The frontispiece of Nicholas Andry's 1741 monograph entitled
L'Orthop�die
depicts a seated woman, surrounded by children, holding a yardstick
upon which is written
haec est regula recti
("this is the standard for alignment"). Indeed, both before and
after Andry produced his seminal volume, the relationship between
lameness and limb deformity was recognized by all who proposed methods
for aligning misshapen extremities. As often happened, however,
correction of a deformity at one level of a limb failed to completely
restore the extremity's biomechanical axis because of an unrecognized
malalignment elsewhere in the appendage. Now, 260 years after the
publication of Andry's monograph, Dror Paley has written a remarkable
book that, perhaps for the first time, permits complete fulfillment
of Andry's standard for alignment in the correction of complex limb deformities.
Principles of Deformity Correction
evolved from a course taught by Paley and his coworkers in Baltimore.
The book, which deals exclusively with lower limb deformities, is
divided into two parts. The first ten chapters present a step-by-step
technique for deformity analysis, starting with the basic concepts
of normal and abnormal limb alignment as well as a method for measuring and
recording deviations from the norm. Paley has developed a standardized
nomenclature for describing deformities that takes into consideration
the deviation of a limb's mechanical axis from established normal
values as well as the all-important (but often overlooked) joint-orientation
angles.
Starting with simple frontal plane malalignment (e.g., varus
and valgus) and progressing through deformities in the sagittal
and oblique planes, the reader becomes familiar with Paley's vocabulary
as well as the principles of correction required to eliminate angular
deformities. Translational (offset) deformities are covered next,
followed by combined angulation and translation deformities. Finally,
rotational and then shortening deformities are considered, first
as isolated problems and then in combination with angular and translational
malalignments. At each step in the process of analysis, numerous
line drawings and clinical examples serve to illustrate the underlying
principles. Moreover, for purposes of clarity, distinctive colors
are used to signify the axes of the proximal, distal, and mid-diaphyseal
segments as well as the joint-orientation line, with the same convention
being employed for both drawings and radiographic images.
The second part of the book describes various surgical techniques
designed to correct the deformities once they have been fully analyzed.
While Paley employs the Ilizarov or Taylor ring apparatus to deal
with more complex deformities (especially those requiring distraction
osteogenesis to eliminate shortening), less complicated malalignments are
corrected with a variety of devices, including intramedullary nails,
plates with screws, and monolateral external fixators, especially
those with the capacity to change angulation in a gradual and controlled
manner. At times, a combination of fixation devices is used simultaneously.
For example, to correct a varus deformity of the distal part of
the femur after a dome-shaped osteotomy, Paley advocates first obtaining
precise intraoperative correction that is temporarily secured with
a monolateral external fixator. This is followed by insertion of
an intramedullary nail. The external device is removed immediately
after the nail is interlocked in both fragments.
The author's preferred techniques for Gigli saw osteotomy are
described in detail, with enough full-color cross-section diagrams
to permit safe use of the method. Other techniques for osteotomy, including
Ilizarov's percutaneous corticotomy, are also illustrated.
An entire chapter is devoted to an extensive discussion of the
causes and correction of malalignment of the knee. The author offers
a different strategy for each type of problem, including malalignments due
to congenital deformity, post-traumatic growth arrest, intra-articular
or juxta-articular fracture, and ligamentous laxity, either alone
or in combination with osteoarthritis of the joint.
There is a large chapter on foot and ankle deformities that presents
a multitude of possible corrections for a variety of supramalleolar
and hindfoot deformities. Ilizarov's midfoot distraction osteotomies for
fixed equinus and calcaneal deformities are included in this section.
Thereafter, a chapter on the hip offers insights that can only be
gleaned from a thorough analysis of the three-dimensional characteristics
of hip deformities. The 1800 illustrations that support Paley's
prodigious effort are best exemplified by a two-page spread that
contains sixteen separate line diagrams detailing different varus and
valgus hip osteotomies, depending upon whether the femoral head
is spherical or flat-topped.
A chapter on growth-plate analysis will help the surgeon to plan
the timing of limb-lengthening and growth plate-stapling operations.
The commonly employed tables and charts are included, along with the
simplified method for the prediction of limb-length discrepancy
as developed by Paley and his coauthors. Two wallet-sized cards,
full of useful tables, formulae, and graphs (for use in the clinic) are
tucked into a plastic pocket secured to the book's back cover.
A beautifully illustrated chapter on gait analysis uses ground-reaction
vectors, force-plate information, and pedobarographs to explain
how and why certain compensatory mechanisms successfully mask some
deformities but not others. In this chapter, the importance of Andry's
standard for alignment becomes perfectly obvious.
The last chapter consists of a rather brief discourse on malalignment
issues as they relate to total joint replacement of the knee and
hip. A surgeon specializing in hip or knee replacement who is hoping
to gain a deeper understanding of alignment problems associated
with joint implant surgery will gain little from perusing only the
final chapter of Paley's monograph because, as mentioned earlier,
the book describes an entire system of analysis-complete with its
own vocabulary-that must first be studied and absorbed, lest the
reader become hopelessly bewildered.
Because of the extensive use of abbreviations, Paley's book resembles,
in some ways, an astronaut's training manual. Several section headings
in the book-e.g., IMN (intramedullary nail) and FFC (fixed flexion
contracture)-appear as abbreviations only. While a glossary is available
to help the reader with such abbreviations, familiarity with the author's
unique vocabulary is the only real defense against confusion. But,
just as a NASA lunar flight manual provides the terms needed to
explore new worlds, so too will Paley's
Principles of Deformity Correction
offer the dedicated reader new perspectives on lower limb deformities.
Indeed, in the not-too-distant future, a chief resident in orthopaedic
surgery, upon seeing the radiographic images of a complex limb deformity,
will likely turn to his or her junior resident and say, "Before
showing this film on rounds, we'd better do a Paley PDC."