Principles of Deformity echecs16.info Paley and J. E. Herzenberg. New York, Springer-Verlag, , pp., $ This is an extremely well-illustrated. Dror Paley. Kevin D. Indications for Correction of Lower Limb Deformities. Preoperative Basic Principles of Deformity Correction Using Circular. External . Principles of Deformity Correction - Dror Paley - Google Books. Download Ebook : principles of deformity correction in PDF Format. also.
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Principles of Deformity Correction is a comprehensive text on the analysis, planning, PDF · Normal Lower Limb Alignment and Joint Orientation. Dror Paley. Principles of Deformity Correction is a comprehensive text on the analysis, DRM-free; Included format: PDF; ebooks can be used on all reading devices. Request PDF on ResearchGate | Principles of Deformity Correction | Normal lower limb alignment and joint Dror Paley at Paley Orthopedic and Spine Institute.
About this book Introduction Principles of Deformity Correction is a comprehensive text on the analysis, planning, and treatment of lower limb deformities in an accessible and instructive format. It teaches the analysis, planning, and methods of deformity correction. A foundation of understanding normal alignment is presented, using new nomenclature that is easy to remember and can even be derived without memorization. The work offers detailed information on deformities and malalignment, radiographic assessment, mechanical and anatomic axis planning, osteotomies, and hardware considerations. The book is extensively illustrated to avoid confusion and to leave little to the imagination. The planning is further facilitated via an exercise workbook and an animated CD-ROM which are available separately.
This Long-standing anteroposterior radiographs strategy was selected more frequently with of the lower extremities on a inch cas- small distal femoral deformities.
Preopera- sette of a series of patients were reviewed. To tive distal femoral deformity joint obliquity simulate the clinical setting and to diminish relative to the normal valgus in the remain- bias, films of 46 consecutive patients present- ing 14 cases averaged The 20 remaining adult radiographs The proximal tibial joint orientation was were masked to patient identity and formed restored to within 3" of normal varus in 2 1 of the study set.
Preoperative proximal tibial Three separate observers of different levels joint orientation was within 3" of normal of orthopaedic experience were engaged in varus in four cases and did not require correc- this related study: a junior staff member, a tion. In the other 24 limbs, correction of clinical fellow, and a junior resident.
All ra- proximal tibial deformity was pursued in 22 diographs were marked for measurement cases. For two cases, the magnitude of proxi- with a soft lead pencil, and after the measure- mal tibial deformity was small relative to the ments were recorded all markings were com- femoral deformity, and a residual deformity pletely erased with an alcohol swab.
Indepen- accepted or overcompensated through the dent measurements were performed twice by distal femoral correction. Preoperative proxi- each observer on the full series of 20 radio- mal tibial deformity joint obliquity relative graphs, with a minimum ten-day interval be- to the normal varus in the remaining 22 tween successive measurements.
Angles were casesaveraged 9. Joint orientation was goniometer; each observer used the same in- restored to within 3 " of normal varus in 17 of strument for both sets of measurements. These mity is principally based on measurements of are presented in Table 3, and include the radiographs. The precision reproducibility arithmetic mean X , the standard deviation of those measurements is a function of ex- of the sample, and the root mean trinsic and intrinsic sources of error.
Extrin- square of the differences. Intrinsic sources of error include inter- Texas. The standard deviation is included in observer variability and intraobserver repro- the tabulated summary, but for two succes- ducibility.
To eliminate interobserver differ- sive measurements it is very closely related to ences in the authors' data, all radiographic the mean of the differences and less valuable.
Precision of Radiographic Clinical Onhopaedics and Related Research through a femoral half-pin, which was man- zyxwvutsrq Measurements aged by extension of the frame proximally to include the fracture; this healed uneventfully.
Two patients developed knee flexion con- MAD 1. However, in one of these two patients Proximal tibial orientation 0. A single case of peroneal nerve palsy was noted after an acute proximal tibial cor- rection that resolved rapidly after reversing The root mean square of the differences is a the maneuver and completing the correction more useful summary statistic to express vari- gradually.
One patient was noted postopera- ability between paired successive measure- tively to have paresis of the extensor hallucis ments.
This is derived from the square root that has persisted, and a second patient devel- of the mean of the sum of the squares of the oped a flexion contracture of the hallux that differences in successive measurements.
One Table 3 illustrates the limited variation in case of premature consolidation in an adult successive measurements from long radio- patient was successfully managed by gradual graphs by several observers with different lev- distraction osteoclasis.
One pediatric patient els ofexperience. This is consistent with previ- was unable to complete treatment because of ously published data where long radiographs intolerance of the device and limited compli- zyxwvu are used to assess mechanical ance, resulting in a residual 20" internal rota- Based on the pooled 60 pairs of measure- tion deformity and mm LLD. One pediat- ments from all three observers, the variability ric patient with severe bowing secondary to of the MAD determined from long radio- hemoglobinopathy developed a recurrent graphs is 1.
The variability was corrected by a second application of the of measurement of the joint orientation line fixator.
Superficial pin-tract infections to relieve symptoms if present and to protect were encountered in almost all patients, but adjacent joints from the development of these responded to oral antibiotics or re- osteoarthrosis. Intuition and biomechanical moval of the involved wire. There were no analysis4.
One patient transmission across joints will result in pre- fell and sustained a subtrochanteric fracture mature joint degeneration secondary to the zyxwvutsrqponm Number April, Correction by the llizarov Method for stabilization of fragments either too prox- deformity, but the natural history of asymp- tomatic deformities has not been adequately imal or distal for internal fixation.
Because the surrounding soft-tis- tion. Without prospective data, it is difficult sue envelope is minimally disturbed, it can to specify indications for surgical treatment also be applied in cases of previous or active of asymptomatic deformities.
Analy- The apex of deformity and the optimal site sis of the precision of successive radiographic for a corrective osteotomy may be too proxi- measurements of the type used in this study mal or distal to allow effective rigid internal suggeststhe improvement in results is signifi- fixation, which is contraindicated in a limb cant.
Despite metic- nal fixation. The apparatus is bulky and zyxw ulous preoperative planning, intrinsic factors sometimes worn for prolonged periods. Ahlback, S. Acta Radiol. The chief advantage of this approach is the 2. Atar, D. Unilateral dynamic external fixation zarov technique. Orthopedics , Danielsson, L. Denham, R. Fowler, J. Bone Joint Surg. Green, S. Grill, F.
Helfet, D. North Am. McKellop, H. McLaren, A. Merchant, T. Henderson, R. Ortho- J. Moreland, J. Hernborg, J. Bone Orthop. Joint Surg. Hsu, R. Odenbring, S. Paley, D. Ilizarov, G. A,: The tension-stress effect on the gene- Pediatr. Part I. The influence of Kautz, D. A,: The tension-stress effect on the gene- tive planning and the Ilizarov techniques.
Part The influence of the Clin. Johnson, E. Kempf, I. Petersen, T. Kettelkamp, D. A,: Degenerative arthritis of the knee Price, C. Orthofix device for limb lengthening. Knapp, R. Puno, R. A,, oral deformity. Stetten, M.
Korzinek, K. Trauma Surg. A,: Approaches to planning lower ex- Rhinelander, F. Sangeorzan, B. Trauma , Schlenzka, D. A,, and Gowda, M. Sledge, S. The normal plafond malleolar angle is 9 degrees. The shape of the talar dome has been described as section of a cone. Modified with permission from Springer-Verlag .
Tibial mid-diaphysial line normally passes through the lateral process of the talus on a lateral view radiograph. The lateral process of the talus approximately represents the center of rotation of the ankle joint. The angle between the floor or plantar foot in stance and the anatomic axis of the tibia is the plantigrade angle.
The normal plantigrade angle is 90 degrees. Reproduced with permission from Springer-Verlag . The bisection of the calcaneus is parallel to the anatomic axis of the tibia. The center of the heel is approximately 5 to 10 mm lateral to the anatomic axis of the tibia Fig. The hindfoot alignment Saltzman radiograph allows for visualization of the ankle joint and relationship of the calcaneus and tibia.
This view also provides assessment of the lateral translation of the calcaneus in relation to the tibia 10 mm. The long calcaneal axial view radiograph allows visualization of the subtalar joint and shows the positional relationship of the calcaneus and tibia. The shape of the calcaneus also can be assessed for osseous varus. The posterior and middle facets of the subtalar joint are stepped; the middle facet sustentaculum tali is more proximal and medial.
The lateral translation of the heel to the tibia is critical for normal gait and locomotion. The ground reaction force vector GRV originates at the plantar lateral portion of the foot and extends through the anterolateral aspect of the tibial plafond Fig. In the sagittal plane, the plantar aspect of calcaneus is inclined by approxi- mately 20 to 30 degrees.
Equinus is noted with a lower calcaneal pitch or with a decreased calcaneal inclination angle. The calcaneus is observed with a higher calcaneal pitch or an increased calcaneal inclination . Center of the calcaneus is normally 10 mm lateral to the anatomic axis of the tibia. GRV originates from the plantar lateral midfoot and passes anterior and lateral to the center of the ankle joint.
The GRV also passes medial to the knee toward the 10th thoracic vertebra. Osteotomy rules Bone deformity correction can be planned by drawing axis lines for each joint segment and for each diaphysial segment. The intersection of each pair of axis lines is called the CORA.
In the frontal plane, one can use mechanical or ana- tomic axis lines for planning. In the sagittal plane, only anatomic axis lines are used for planning . The geometric result from osteotomy correction is directly related to the CORA.
Osteotomy rule 1 states that when the osteotomy and the axis of correction of angulation ACA pass through a CORA, the bone ends and axis lines will realign by angulation without translation. The axes of the bone proximal and distal to the osteotomy will completely realign when the magnitude of correction equals the magnitude of angulation Fig. Osteotomy rule 2 states that when the ACA passes through the CORA but the osteotomy is at a level different from that of the CORA, the axes of the bone will realign with angulation and translation at the osteotomy site Fig.
Osteotomy rule 1: If the osteotomy and CORA are at the same location, no translation or angulation occurs. An opening, neutral, or closing wedge osteotomy can be used. Osteotomy rule 2: If the osteotomy is made away from the CORA, the segments must be translated to align the proximal and distal axes.
Osteotomy rule 3: If the osteotomy is made away from the CORA, the segments will be translated and not realigned. The level of the CORA depends on the cause of the deformity. With con- genital deformities of the distal tibia, the CORA usually is at the level of the joint line, whereas in developmental deformities of the distal tibia, the CORA is related to physis.
Deformities occurring as a result of fracture can have a CORA at any level, depending on the level of the fracture and associated translation B. If the plane of translation is the same as that of angulation, the CORA will appear to be at the same level in all views. If the plane of translation is different from the plane of angulation, the CORA will appear to be at different levels in different views. Deformities with the CORA located in the diaphysis of a long bone are more easily corrected by osteotomy performed at the level of the CORA osteotomy rule 1.
Articulator deformities can be more difficult to correct because the CORA is located at the joint line.
Such deformities require translation because the osteotomy must be made distant to the CORA osteotomy rule 2. To minimize loss of bone contact after an angulation-translation osteotomy, a technique called focal dome osteotomy can be used.
This is performed by focusing the center of the circular bone cut at the CORA . Frontal plane deformities Compensatory joint motion must be assessed before realignment surgery is performed.
The magnitude of the deformity determines the amount of necessary subtalar joint compensation. The degree of compensation that can be achieved depends on the amount of available subtalar joint range of motion. The normal subtalar joint range of motion is 15 degrees of eversion and 30 degrees of inversion. Thus, the largest amounts of distal tibial deformity that can be compensated for are 30 degrees of valgus and 15 degrees of varus when normal subtalar joint range of motion is present Fig.
When deformities are larger than the available subtalar joint motion, additional compensation occurs through the forefoot by supination or pronation. Full compensation occurs at the subtalar joint for distal tibial valgus 30 degrees and varus 15 degrees with a mobile subtalar joint.
Deformities typically become symptomatic when the needed joint motion exceeds the available joint motion. Varus of the distal tibia or tibial plafond is typically tolerated less well than is valgus, because the available subtalar joint compensation with eversion is less than with inversion. Ankle varus deformities that exceed subtalar joint eversion motion lead to compensatory forefoot pronation.
The arch height increases as the first ray plantar flexes to compensate for the excess varus, thereby decreasing the weight-bearing surface of the foot. Ankle valgus deformities that exceed subtalar joint inversion motion lead to compensatory forefoot supination. The arch height decreases as the first ray dorsiflexes to compensate, thereby increasing the weight-bearing surface of the foot. In the normal foot, the GRV passes lateral to the midpoint of the ankle joint because the anatomic axis of the calcaneus is lateral to that of the tibia.
This means that normally, a lateral moment arm acts on the tibiotalar joint, increasing the load on the lateral side of the joint. This is resisted passively by a normal length, normally located lateral malleolus and actively by the tibialis posterior muscle.
When the lateral malleolus is proximally or laterally migrated e. Similarly, when posterior tibial tendon dysfunction is present, the valgus moment arm goes unchecked, leading to increased lateral joint forces.
These two examples serve as visible demonstrations of the effect of the laterally located moment arm. Varus deformities of the distal tibia or tibial plafond move the GRV medially and are unlikely to lead to ankle degenerative joint changes. Furthermore, the medial tilt of the ankle leads to weight bearing across the broad medial malleolar cartilage, which is solidly fixed to the tibia with bone instead of fibrous tissue, as Fig. Varus of the distal tibia produces limited ankle joint arthritis.
Valgus of the distal tibia produces early ankle joint arthritis and disruption of the ankle mortise. Although varus deformities of the ankle do not lead to ankle joint degeneration, they are more frequently symptomatic than are valgus deformities because of the more limited compensatory subtalar motion available eversion.
Degenerative changes and lateral impingement may develop in the subtalar joint because of ankle varus deformities Fig. Valgus ankle deformities increase the lateral moment arm and overload the lateral side of the ankle joint despite being well compensated by the ample subtalar inversion motion available.
Consequently, the abnormal mechanics leads to late degenerative changes. The tibialis posterior is unable to neutralize the increased moment arm forces but increases the joint reactive forces in trying.
The lateral malleolus wears over time and can move away from the tibia because it is fixed to it via soft tissues and not bone Fig. Varus of the tibial plafond is diagnosed when the LDTA is greater than 92 degrees, as measured on an anteroposterior view radiograph. Valgus defor- mity of the tibial plafond is diagnosed when the LDTA is less than 86 degrees, as measured on an anteroposterior view radiograph. The more proximal the de- formity is from the ankle joint, the less effect it has on the joint orientation.
Sagittal plane deformities Procurvatum and recurvatum deformities in the sagittal plane are compensated through the ankle joint by dorsiflexion and plantar flexion, respectively. The magnitude of the deformity determines the amount of necessary ankle joint compensation. The degree of compensation that can be achieved depends on the amount of available ankle joint range of motion.
The normal ankle joint range of motion is 20 degrees of dorsiflexion and 50 degrees of plantar flexion. Thus, the largest amount of deformity that can be compensated for is 50 degrees of B.
When deformities are larger than the available ankle motion, some additional compen- sation occurs through the subtalar and midfoot joints. For these reasons, ankle procurvatum and recurvatum are well-tolerated if the ankle, subtalar, and midfoot joints are mobile. Procurvatum of the distal tibia or tibial plafond is typically less well tolerated than is recurvatum, because the available ankle joint compensation in dorsiflexion is less than in plantar flexion.
In addition, anterior impingement of the neck of the talus on the anterior lip of the distal tibia halt further compensation Fig. In the normal ankle, the GRV passes anterior to the ankle joint, producing an anterior moment arm on the ankle joint. This is resisted by the triceps surae muscle group. Distal tibial procurvatum is diagnosed as an ADTA greater than 82 degrees, as measured on a mortise lateral view radiograph. Procurvatum deformity of the distal tibia displaces the foot posteriorly, decreasing the lever arm forces on the anterior ankle.
Distal tibial recurvatum is diagnosed when the ADTA is less than 78 degrees, as measured on a mortise lateral view radiograph.
Recurvatum of the distal tibia tilts the cartilage anteriorly and typically presents late with pain. The delayed onset of recurvatum symptoms occurs secondary to the large amount of available compensatory plantar flexion. Recurvatum deformity uncovers the anterior talar dome, thus decreasing the weight-bearing surface of the tibial plafond.
Because force is load per surface area, this greatly increases the force on the anterior ankle joint, leading to late degenerative changes. As with valgus, recurvatum of the distal tibia is well tolerated because of the large amount of available compen- satory range of motion. As with valgus, recurvatum increases the lever arm forces on the ankle and leads to late degenerative changes Fig.
Recurvatum of the ankle decreased ADTA displaces the foot forward, uncovers the talus, and increases shear forces on the ankle. Procurvatum increased ADTA of the ankle displaces the foot posteriorly and can lead to anterior ankle impingement. Reproduced with permission from Springer- Verlag .
Recurvatum deformity displaces the ankle joint center of rotation anteriorly, increasing the anterior lever arm. The only way to reduce these lever arm forces is with the triceps surae muscles. When the foot is plantigrade, the ankle is in equinus.
This decreases the push off strength, and therefore the compensatory ability of the triceps surae during gait, because the gastrocnemius and soleus muscles are not at their optimal length:tension ratio.
Of all angular deformities of the distal tibia, recurvatum is the most likely to produce arthritis. Fixed compensatory motion The compensatory positions of the ankle, subtalar, and midfoot joints may become fixed if the osseous deformity remains for an extended period of time. For example, chronic valgus deformity of the distal tibia compensated by subtalar inversion may become fixed such that if the distal tibial deformity is corrected with a supramalleolar osteotomy, the subtalar inversion contracture is uncovered and the foot ends up in varus.
Similarly, recurvatum deformity of the distal tibia compensated by ankle plantar flexion ends up in equinus after osteotomy correction if the ankle has lost dorsiflexion because of chronic plantar flexion positioning. Therefore, it is essential to identify fixed compensatory motion be- fore performing corrective osteotomy. Usually, this can be accomplished by physical examination. If the foot can be placed in the maximum deformity position, no fixed compensation contracture is present.
If the foot cannot reach the maximum deformity position, fixed compensatory contracture is present. In the case of recurvatum osseous deformity with fixed compensatory equinus contracture, the equinus needs to be corrected when the flexion supramalleolar osteotomy is performed.
Supramalleolar osteotomies to correct distal tibial or ankle plafond deformities stretch the posterior tibial nerve or cause osseous encroachment on the tarsal tunnel. This stretch can cause an acute tarsal tunnel entrapment. Therefore, tarsal tunnel decompressions are prophylactically performed for ankle deformity correction from procurvatum to recurvatum, from varus to valgus, and from internal to external rotation.