- Email: [email protected]
Preoperative Planning and Intraoperative Technique for Accurate Realignment of the Dwyer Calcaneal Osteotomy
The Journal of Foot & Ankle Surgery 51 (2012) 743–748
Contents lists available at ScienceDirect
The Journal of Foot & Ankle Surgery journal homepage: www.jfas.org
Preoperative Planning and Intraoperative Technique for Accurate Realignment of the Dwyer Calcaneal Osteotomy Bradley M. Lamm, DPM, FACFAS 1, Martin G. Gesheff, BS 2, Heather L. Salton, DPM, AACFAS 3, Travis W. Dupuis, DPM, FACFAS 4, Ferras Zeni, MD 5 1
Head of Foot and Ankle Surgery, International Center for Limb Lengthening, Rubin Institute for Advanced Orthopedics, Sinai Hospital of Baltimore, Baltimore, MD Research Program Coordinator, International Center for Limb Lengthening, Rubin Institute for Advanced Orthopedics, Sinai Hospital of Baltimore, Baltimore, MD Podiatrist, University of Washington Medicine/Valley Medical Center, Renton, WA 4 Chief of Podiatric Surgery, Conroe Regional Medical Center, Conroe, TX 5 Orthopedic Surgeon, Henry Ford Health System, West Bloomfield, MI 2 3
a r t i c l e i n f o
a b s t r a c t
Level of Clinical Evidence: 4 Keywords: calcaneal varus CORA foot deformity hindfoot pes cavus surgery tuber varus
The Dwyer calcaneal osteotomy is an effective procedure for the correction of calcaneal varus deformity. However, no intraoperative method has been described to determine the amount of bone resection. We describe a simple intraoperative method for assuring accurate bone resection and measure the realignment effects of the Dwyer calcaneal osteotomy. We also review radiographic outcomes associated with 20 Dwyer calcaneal osteotomies (in 17 patients) using the intraoperative realignment technique described in this report. Preoperative and postoperative radiographs at a mean of 2.5 (range 1.5 to 5) years taken after Dwyer osteotomy were measured and compared, which revealed a mean reduction in calcaneal varus of 18 (range 2 to 36 ) (p < .001), a mean decrease in the calcaneal inclination angle of 5 (range –40 to 7 ) (p < .05), a mean decrease in medial calcaneal translation of 10 (range 0 to 18) mm (p < .001) relative to the tibia, and a mean dorsal translation of 2 (range 0 to 7) mm (p ¼ .002). In an effort to attempt to structurally realign the calcaneus to a more rectus alignment, by means of Dwyer osteotomy, we recommend the use of the intraoperative bone wedge resection technique described in this report. Our experience with the patients described in this report demonstrates the usefulness of the intraoperative method that we describe in order to accurately restore the axial tibial and calcaneal relationship. Ó 2012 by the American College of Foot and Ankle Surgeons. All rights reserved.
Calcaneal osteotomies have long been used for the correction of various hindfoot deformities and have proven to be powerful realignment surgical procedures. The goal of these calcaneal osteotomies, whether they involve an opening or closing wedge or medial or lateral displacement, is to realign the hindfoot relative to the long axis of the tibia. The first calcaneal osteotomy was described by Gleich in 1893 for pes planovalgus (1). Gleich stated that it was essential to restore the normal angular relationship of the calcaneus to the floor (1). Several surgical techniques have been described for correction of a varus heel. In 1955, Dwyer first described the lateral closing wedge osteotomy of the calcaneus for pes cavus deformity, using a lateral oblique approach (2). The 8- to 12-mm wedge osteotomy was
Financial Disclosure: None reported. Conflict of Interest: None reported. Address correspondence to: Bradley M. Lamm, DPM, FACFAS, Head of Foot and Ankle Surgery, International Center for Limb Lengthening, Rubin Institute for Advanced Orthopedics, Sinai Hospital of Baltimore, 2401 West Belvedere Avenue, Baltimore, MD 21215. E-mail address: [email protected] (B.M. Lamm).
performed just proximal and parallel to the peroneus longus tendon. Completion of the osteotomy through the medial cortex ensured complete closure of the osteotomy. Dwyer stated that the heel should be positioned in a neutral to slight valgus position; however, he made no mention of his method in determining the size of calcaneal wedge to resect (2,3). Since Dwyer’s first publication, many other techniques for wedge osteotomies (lateral closing, lateral opening wedge, and medial opening wedge) have been reported (4–8). In 1963, Dwyer revised the procedure to a medial opening wedge osteotomy for treatment of residual talipes equinovarus (4). Lengthening of the Achilles tendon with a slide technique and an autograft tibial wedge was used for the medial opening wedge osteotomy. However, the medial approach was fraught with complications, including neurovascular compromise, lack of complete skin closure, and graft failure. In addition, Lemperg and Smith reported delayed wound healing at a mean of 5.4 weeks with the medial approach (9). Eventually, complications associated with a medial opening wedge calcaneal osteotomy limited the popularity of the procedure (4,9,10). Although Mann and Coughlin have reported sural nerve entrapment and inadequate wedge resection as complications, the lateral closing
1067-2516/$ - see front matter Ó 2012 by the American College of Foot and Ankle Surgeons. All rights reserved. http://dx.doi.org/10.1053/j.jfas.2012.08.004
744
B.M. Lamm et al. / The Journal of Foot & Ankle Surgery 51 (2012) 743–748
Fig. 1. (A–H) Dwyer calcaneal osteotomy planning and procedure. Illustration of the planning and intraoperative technique for the realignment Dwyer calcaneal osteotomy. Copyright 2012, Rubin Institute for Advanced Orthopedics, Sinai Hospital of Baltimore.
wedge osteotomy has proven to be a safe and effective method for treatment of calcaneal varus that allows for early postoperative weightbearing (8,11). The difficulty with closing wedge osteotomies is in determining the amount of bone resection necessary to correct the deformity. In 1985, Krackow et al described a preoperative technique using a tracing of the calcaneal axial radiograph to assess the amount of wedge to resect. A calcaneal tracing is made on paper, which is then cut and rotated until the desired correction is achieved. Although this is an adequate approach for calculating the amount of wedge resection, it is a cumbersome method to apply intraoperatively. In addition, this template tracing method ignores the tibial axis and the relationship of the calcaneus to the leg. Although few authors report using this technique, most are vague as to how they determine the size of their calcaneal wedge resection (8,12). Weseley and Barenfeld discussed the mechanism of action of the Dywer calcaneal osteotomy (10). First, they described resection of an
adequate wedge of bone to realign the calcaneal tuberosity lateral to the weightbearing line of the tibia to prevent the recurrence of deformity. Next, they believed that altering the plane of the subtalar joint causes the talus to sit more medial to the calcaneus, which allows the tibia to exert a corrective force on the foot, assuming that the calcaneus is in anatomical alignment. Finally, they stated that the Dwyer calcaneal osteotomy allows the Achilles tendon to become a corrective force instead of a deforming force because the calcaneus is no longer in varus. We present a simple and reproducible surgical technique to provide the correct amount of bone wedge resection when the Dwyer calcaneal osteotomy is used to establish a rectus alignment of the calcaneal tuber in regard to the weightbearing substrate and the long axis of the tibia. In addition, we outline the deformity correction principles for accurate realignment of the Dwyer calcaneal osteotomy. Finally, we review the radiographic effects of this surgical technique in a series of patients.
B.M. Lamm et al. / The Journal of Foot & Ankle Surgery 51 (2012) 743–748
Patients and Methods This is an institutional review board–approved retrospective chart and radiograph review of consecutive patients treated with a Dwyer calcaneal osteotomy for correction of calcaneal tuber varus between January 2001 and December 2007. All of the patients came from the clinical practice of the senior author (B. M. L.), who also performed all of the operations. The patients were retrospectively identified using the surgical research database at the Rubin Institute. Seventeen patients who underwent a total of 20 Dwyer osteotomies using the intraoperative measurement method described in this report were identified by means of chart review and were included in the study. A chart review was performed to examine patient demographics as well as diagnosis, ancillary procedures, complications, and time to full weightbearing. Preoperative and postoperative radiographs were obtained, including hindfoot alignment (13) and lateral foot views. Using these radiographs, we measured the calcaneal inclination angle, the angle between the mid-diaphyseal line (anatomic axis) of the tibia and the calcaneal bisection line, and the distance between the tibial and calcaneal bisection lines at the level of the floor and the dorsal calcaneal translation by the distance of the posterior dorsal calcaneus fragment to dorsal anterior calcaneus both preoperatively and postoperatively. These measurements were completed using an incremental goniometer and rounded to the nearest degree by 3 authors (H.L.S., T.W.D., F.Z.) and was verified by the senior author (B.M.L.). Statistical Methods SPSS 17.0 (SPSS, Inc. Chicago, IL) was used to analyze all data. Differences between groups were evaluated with a 2-tailed Student’s t test. Statistical differences were considered significant at the 5% (p .05) level. The statistical analyses were carried out by the senior author (B.M.L.). Deformity Planning The deformity correction principles for accurate realignment of the Dwyer calcaneal osteotomy begin with obtaining proper axial weightbearing radiographs. To identify the level and magnitude of calcaneal deformity, the proximal (tibial anatomic axis) and distal (calcaneal bisection) reference lines are drawn. Thereafter, the normal calcaneal axis 10 mm medial and parallel to the calcaneal bisection line is drawn. The center of rotation angulation (CORA) is located at the intersection of the proximal and distal normal reference lines. Note the CORA is located in the calcaneal body and the magnitude of the deformity is measured by the angle between proximal and distal reference lines (Fig.1A-C). Surgical Technique The patient is positioned supine on a radiolucent table with a bump under the hemi sacrum to obtain a foot-forward position. The tourniquet is inflated around the thigh after adequate sterile prepping and draping of the lower extremity. Under fluoroscopic guidance, a free 1.8-mm wire, used to determine the orientation of the oblique skin incision, is placed on the lateral aspect of the calcaneus. The skin is marked along this oblique wire from anterior to the Achilles tendon insertion on the calcaneus to anterior to the insertion of the plantar fascia. An incision 5 cm in length is made along the lateral aspect of the heel. Careful dissection is performed to avoid injury to the sural nerve,
745
although the incision is typically posterior to the course of the sural nerve. The periosteal layer is incised in line with the skin incision, and then the periosteum is freed proximally, distally, dorsally, and plantarly. Using a long leg calcaneal axial fluoroscopic image, 2 guide wires are inserted into the calcaneus. The skin is retracted anteriorly to insert the first pin perpendicular to the bisection line of the tibia. A second wire posterior to the first is then advanced perpendicular to the lateral wall of the calcaneus (Fig. 1D). The 2 wires are placed in a manner that allows them to converge just lateral to the medial cortex, thus ensuring preservation of the medial cortical hinge of the calcaneus. Both wires are inserted parallel to the plantar surface of the foot. The correct placement of both calcaneal pins allows for accurate and reproducible calcaneal wedge resection. Using a micro sagittal saw, the calcaneus is then cut in a wedge fashion along each wire, with care taken to maintain the medial cortex. The orientation of the cut is essentially perpendicular to the inclination of the calcaneus. The wedge is removed and the calcaneus realigned to a vertical position (parallel to the anatomical axis of the tibia), using fluoroscopy (Fig. 1E and F). In cases in which the calcaneus is still medially displaced relative to the long axis of the tibia, the medial cortical hinge is broken with an osteotome, allowing the tuberosity to be translated laterally (Fig. 1G and H). The posterior calcaneal tuberosity is then temporarily fixated with 2 posterior to anterior guide pins (plantarly and dorsally) placed perpendicularly across the osteotomy site. The guide pins are placed just proximal to the Achilles insertion through 1 small posterior incision. Partially threaded large-diameter cannulated screws are inserted one at a time to ensure that the calcaneal position is maintained. The 2 screws must be confirmed under fluoroscopy to adequately compress the osteotomy site (Fig. 1G). The wounds are then closed and the tourniquet is deflated. A dry sterile dressing is applied with a postoperative boot and the patient is instructed to remain non-weightbearing for 4 weeks (Figs. 2-4).
Results Seventeen patients, 12 (70.59%) women and 5 (29.41%) men, were included. The mean age at the time of surgery was 31 (range 8 to 60) years. A total of 20 Dwyer calcaneal osteotomies were performed, 10 (50%) right and 10 (50%) left feet, with a mean follow-up of 2.5 (range 1.5 to 5) years. The etiology of the varus deformity included 9 (45%) isolated calcaneal varus, 3 (15%) residual clubfoot, 2 (10%) with a history of a cerebral hemispherical stroke, 2 (10%) with Charcot– Marie–Tooth disease, 2 (10%) with poliomyelitis, 1 (5.00%) subtalar contracture, and 1 (5.00%) residual varus after a prior posterior calcaneal osteotomy (Table 1). The hindfoot alignment view was used to measure the degree of calcaneal varus and amount of translation of the calcaneus relative to the tibia. The mean calcaneal varus deformity was 25 (range 2 to 56 ) preoperatively, and decreased to 7 (range 0 to 31 ) postoperatively. The mean degree of varus calcaneal correction was 18 (range 2 to 36 ) (p < .001). Translation of the calcaneal bisection line relative to the anatomic axis of the tibia showed a mean medial translation of 14 mm preoperatively, and this reduced by a mean of
Fig. 2. Preoperative radiographs of a 30-year-old patient with residual clubfoot and a calcaneal varus on the left. (A) Standing hindfoot alignment view shows calcaneal varus on the left status before surgery. (B) Lateral radiograph before surgery. Copyright 2012, Rubin Institute for Advanced Orthopedics, Sinai Hospital of Baltimore.
746
B.M. Lamm et al. / The Journal of Foot & Ankle Surgery 51 (2012) 743–748
Fig. 3. Intraoperative radiographs. (A) Intraoperative axial fluoroscopic view shows our technique for placement of the guide pins (1.8 mm) in the calcaneus. The proximal guide pin is perpendicular to the anatomical axis of the tibia and the distal guide pin is perpendicular to the anatomical axis of the calcaneus. A saw is used to cut along each guide pin and the wedge of bone removed to create a vertical calcaneal position. (B) The vertical calcaneal position is temporarily fixated with 2 guide pins for the cannulated screws. (C) Two cannulated screws are inserted, one at a time in order for the calcaneal position to be maintained. (D) A lateral fluoroscopic view shows the stacked screws inserted perpendicular to the osteotomy site. Copyright 2012, Rubin Institute for Advanced Orthopedics, Sinai Hospital of Baltimore.
10 mm postoperatively (p < .001). The mean final calcaneal (bisection line) position was 4 mm medial to the anatomic axis of the tibia (Table 2). A total of 7 (35%) feet underwent lateral translation of the calcaneal tuberosity in addition to angular correction.
The lateral view radiograph was used to determine the mean calcaneal inclination angle and mean dorsal translation. The mean calcaneal inclination angle was 19 (range 12 to 44 ) preoperatively and 14 (range 0 to 25 ) postoperatively, yielding a mean decrease
Fig. 4. Final postoperative radiographs. (A) Final postoperative standing hindfoot alignment view shows a vertical calcaneus. (B) Final postoperative lateral radiograph. Copyright 2012, Rubin Institute for Advanced Orthopedics, Sinai Hospital of Baltimore.
B.M. Lamm et al. / The Journal of Foot & Ankle Surgery 51 (2012) 743–748
Table 1 Patient characteristics (N ¼ 20 procedures in 17 patients)
Table 3 Ancillary procedures performed in addition to the Dwyer calcaneal osteotomy (N ¼ 20 procedures in 17 patients)
Variable
Value (count [%])
Gender Side Etiology
12 (70.59) women, 5 (29.41) men 10 (50) right, 10 (50) left 9 (45) isolated calcaneal varus 3 (15) residual clubfoot 2 (10) history of stroke 2 (10) Charcot–Marie–Tooth 2 (10) poliomyelitis 1 (5) subtalar contracture 1 (5) residual varus due to prior posterior calcaneal osteotomy 2 (10) Mean (y) Minimum (y) Maximum (y) 31 8 60 2.5 1.5 5
Complications Measure Age at surgery Duration of follow-up
747
of 5 (range 40 to 7 ) (p < .05). The mean postoperative dorsal calcaneal translation was 2 (range 0 to 7) mm (p ¼ .002) (Table 2). Dwyer osteotomy fixation varied initially with 2 (10%) osteotomies fixated with 2 staples and 2 (10%) osteotomies with a single cannulated screw. However, the subsequent 16 (80%) patients were fixated with 2 cannulated screws. Multiple ancillary procedures were performed along with the Dwyer osteotomy. Ancillary soft tissue procedures included 6 (30%) tendon transfers, 6 (30%) tendon lengthenings, 5 (25%) plantar fascia releases, and 2 (10%) lateral ankle stabilizations. Ancillary osseous procedures included 3 (15%) first metatarsal procedures, 1 (5%) anterior calcaneal osteotomy, 1 (5%) midfoot osteotomy, and 1 (15%) ipsilateral leg lengthening with external fixation (Table 3). Patients spent a mean of 6 (range 4 to 28) weeks non-weightbearing and a total of 10 (range 4 to 32) weeks until full weightbearing in normal shoe gear was achieved. The patient who underwent the simultaneous leg-lengthening procedure with external fixation was not made full weightbearing until 28 weeks postoperatively. There were 2 (10% of procedures, 11.77% of patients) postoperative complications. One (5%) patient who was diabetic required surgical debridement for wound dehiscence and healed uneventfully thereafter, and 1 (5%) other patient was not completely corrected and required a revision calcaneal osteotomy with lateral translation only. Discussion Preoperative planning, including radiographic and clinical assessment, is critical to the success of surgery. Although the effectiveness of radiographs for identification of the level and extent of osseous deformity has been well documented, the literature reports only limited use of axial radiographs (14). Harris and Beath (15) were the first to develop a frontal plane radiograph of the heel, which was later refined by Kleiger and Mankin (16) into what is now known as a long-leg calcaneal axial view. In 1976, another frontal plane technique, the hindfoot alignment view, was described by Cobey (17) and later modified by Buck et al (18), Johnson et al (19), and Saltzman and el-Khoury (20). Because the degree of calcaneal varus and relationship of the calcaneus relative to the tibia is determined by the axial
Table 2 Preoperative and postoperative radiographic measures (N ¼ 20 procedures in 17 patients) Measure
Preoperative
Postoperative
p Value
Calcaneal varus ( ) Calcaneal inclination ( ) Dorsal translation (mm) Medial translation (mm)
25 19 0 14
7 14 2 4
<.001 <.05 .002 <.001
Ancillary Procedure Performed Soft tissue procedure Tendon transfer Tendon lengthening Plantar fascia release Lateral ankle stabilization Osseous procedure Metatarsal osteotomy Anterior calcaneal osteotomy Midfoot osteotomy
Frequency (% of feet) 6 6 5 2
(30) (30) (25) (20)
3 (15) 1 (5) 1 (5)
radiographs, they are extremely important when choosing the appropriate procedure(s). It is also essential to assess forefoot to hindfoot relationship preoperatively to determine if surgical correction of the forefoot is necessary. The mobility of the forefoot, whether it is flexible, semiflexible or fixed, can be assessed by supinating and pronating the midtarsal joint while maintaining the subtalar joint in neutral position. If the forefoot is fixed, the forefoot should be corrected along with the Dwyer. For example, calcaneal varus combined with a fixed forefoot valgus can be corrected simultaneously with a dorsiflexion osteotomy/fusion of the medial column or a rotational osteotomy of the midfoot. A semi-flexible or flexible forefoot that is diagnosed in combination with a calcaneal varus may not need to be addressed. The normal position of the calcaneus is 5 to 10 mm lateral to the mid-diaphyseal line of the tibia (14). This position is critical for normal gait and locomotion. The position of the heel is important, because the ground reaction force vector should originate at the plantar lateral portion of the hindfoot to create a slight valgus moment arm on the subtalar joint and initiate normal gait (21). Thus, the need to assess both preoperative and intraoperative calcaneal alignment is critical to proper angular realignment and translation. In this retrospective study, 7 (35%) feet underwent lateral translation of the calcaneal tuberosity at the time of initial surgery. Although a normal anatomic axial relationship of the tibia and calcaneus was not achieved in all cases, we did see a statistically significant mean reduction in the medial position of the calcaneus relative to the tibia (10 mm, p < .05). Assuming that an adequate wedge is resected, our study suggests that lateral translation should be performed more routinely in association with a Dwyer osteotomy to obtain a complete anatomical correction. Another potential means of enhancing the degree of correction is by making the osteotomy more anterior, which is closer to the apex of the deformity. While translating the calcaneus laterally, the surgeon must be careful not to simultaneously translate the calcaneus superiorly or inferiorly, because this can, in effect, lengthen or shorten the Achilles tendon and alter its tension. Although dorsal translation of the calcaneal tuberosity was seen in 8 (47.06%) of our patients, the mean translation was only 2 mm and caused a minimal effect in the form of a mean decrease in the calcaneal inclination angle of 5 . Rigid fixation should be a consideration when performing the Dwyer calcaneal osteotomy with or without translation. Use of one screw for fixation may result in angulation of the calcaneal tuberosity because of tension on soft tissues or rotation around the screw during screw insertion. Thus, using 2 points of fixation is recommended to prevent this from occurring. We understand that the results of this case series can only be used for hypothesis generation, although we feel that the measurements described can be useful to surgeons undertaking Dwyer osteotomy with the intent of making the orientation of the calcaneus rectus relative to the ground and the long axis of the tibia. The measurements, having
748
B.M. Lamm et al. / The Journal of Foot & Ankle Surgery 51 (2012) 743–748
been performed by the surgeons, could have been biased, and we did not make any attempt to measure the influence of clinical exposures on an outcome of interest. Moreover, we did not associate the radiographic and surgical findings to clinical outcomes in terms of foot-related quality of life, pain, or activity level. We believe, however, that the results of this preliminary work could be useful to future investigators interested in further clarifying the utility of accurately resecting an osseous wedge from the calcaneus when treating heel varus deformities. Although the Dwyer calcaneal osteotomy is a well-known hindfoot surgical procedure, little has been written to define accurate reference points and surgical technique for realignment. As evidenced by our retrospective study, the Dwyer calcaneal osteotomy demonstrated reduction of the calcaneal varus, calcaneal inclination, and medial calcaneal translation. Our intraoperative Dwyer calcaneal osteotomy surgical technique is simple, accurate, and reproducible by providing the correct amount of wedge resection for calcaneal realignment. In addition, our technique takes into account the needed calcaneal translation to restore normal tibia calcaneal alignment. Only one patient diagnosed with Charcot–Marie–Tooth disease required a revision Dwyer osteotomy and only one patient developed a postoperative wound complication. It is important to remember that even with the use of this intraoperative technique, careful preoperative evaluation and preoperative planning with axial radiographs and a thorough clinical examination to evaluate the presence of associated deformities are crucial to the success of this procedure.
3. 4. 5. 6. 7. 8. 9. 10. 11. 12.
13.
14. 15. 16. 17. 18.
References 1. Gleich A. Beitrag zur operativen plattfussbehandlung. Arch Klinn Chir 46: 358–362, 1893. 2. Dwyer FC. A new approach to the treatment of pes cavus. Sixieme Congress de Chirurgie Orthopedique, Bern, 30 aout – 3 septembre 1954. Societe Internationale
19. 20. 21.
de Chirurgic Orthopedique et de Traumatologie, Imprimerie Lielens, Bruxelles, 1955. p. 551. Dwyer FC. Osteotomy of the calcaneum for pes cavus. J Bone Joint Surg Br 41-B(1):80–86, 1959. Dwyer FC. The treatment of relapsed club foot by insertion of a wedge into the calcaneum. J of Bone Joint Surg Br 45-B(1):67, 1963. Barenfeld PA, Weseley MS, Munters M. Dwyer calcaneal osteotomy. Clin Orthop Relat Res 53:147–153, 1967. Ayres MJ, Bakst RH, Baskwill DF, Pupp G. Dwyer osteotomy: a retrospective study. J Foot Surg 26(4):322–328, 1987. Robinson DS, Clark B Jr, Prigoff MM. Dwyer osteotomy for treatment of calcaneal varus. J Foot Surg 27(6):541–544, 1988. Krackow KA, Hales D, Jones L. Preoperative planning and surgical technique for performing a Dwyer calcaneal osteotomy. J Pediatr Orthop 5(2):214–218, 1985. Lemperg RK, Smith TW. The calcaneal osteotomy of Dwyer: an indication for Kiel bone. Acta Orthop Scand 47(1):125–128, 1976. Weseley MS, Barenfeld PA. Mechanism of the Dwyer calcaneal osteotomy. Clin Orthop Relat Res 70:137–140, 1970. Mann RA, Coughlin MJ. Surgery of the Foot and Ankle, Mosby, St Louis, MO, 1993. Boffeli TJ, Collier RC. Surgical technique for combined Dwyer calcaneal osteotomy and peroneal tendon repair for correction of peroneal tendon pathology associated with cavus foot deformity. J Foot Ankle Surg 51(1):135–140, 2012. Mendicino RW, Catanzariti AR, John S, Child B, Lamm BM. Long leg calcaneal axial and hindfoot alignment radiographic views for frontal plane assessment. J Am Podiatr Med Assoc 98(1):75–78, 2008. Paley D. Ankle and foot considerations. In: Principles of Deformity Correction, pp. 571–645, edited by D Paley, Springer, Berlin, 2002. Harris RI, Beath T. Hypermobile flat-foot with short tendo achillis. J Bone Joint Surg Am 30A(1):116–140, 1948. Kleiger B, Mankin HJ. A Rentgenographic study of development of the calcaneus by means of the posterior tangential view. J Bone Joint Surg Am 43-A:961–969, 1961. Cobey JC. Posterior roentgenogram of the foot. Clin Orthop Relat Res Jul-Aug(118):202–207, 1976. Buck P, Morrey BF, Chao EY. The optimum position of arthrodesis of the ankle. A gait study of the knee and ankle. J Bone Joint Surg Am 69(7):1052–1062, 1987. Johnson JE, Lamdan R, Granberry WF, Harris GF, Carrera GF. Hindfoot coronal alignment: a modified radiographic method. Foot Ankle Int 20(12):818–825, 1999. Saltzman CL, el-Khoury GY. The hindfoot alignment view. Foot Ankle Int 16(9):572–576, 1995. Lamm BM, Paley D. Deformity correction planning for hindfoot, ankle, and lower limb [review]. Clin Podiatr Med Surg 21(3):305–326, 2004.
Contents lists available at ScienceDirect
The Journal of Foot & Ankle Surgery journal homepage: www.jfas.org
Preoperative Planning and Intraoperative Technique for Accurate Realignment of the Dwyer Calcaneal Osteotomy Bradley M. Lamm, DPM, FACFAS 1, Martin G. Gesheff, BS 2, Heather L. Salton, DPM, AACFAS 3, Travis W. Dupuis, DPM, FACFAS 4, Ferras Zeni, MD 5 1
Head of Foot and Ankle Surgery, International Center for Limb Lengthening, Rubin Institute for Advanced Orthopedics, Sinai Hospital of Baltimore, Baltimore, MD Research Program Coordinator, International Center for Limb Lengthening, Rubin Institute for Advanced Orthopedics, Sinai Hospital of Baltimore, Baltimore, MD Podiatrist, University of Washington Medicine/Valley Medical Center, Renton, WA 4 Chief of Podiatric Surgery, Conroe Regional Medical Center, Conroe, TX 5 Orthopedic Surgeon, Henry Ford Health System, West Bloomfield, MI 2 3
a r t i c l e i n f o
a b s t r a c t
Level of Clinical Evidence: 4 Keywords: calcaneal varus CORA foot deformity hindfoot pes cavus surgery tuber varus
The Dwyer calcaneal osteotomy is an effective procedure for the correction of calcaneal varus deformity. However, no intraoperative method has been described to determine the amount of bone resection. We describe a simple intraoperative method for assuring accurate bone resection and measure the realignment effects of the Dwyer calcaneal osteotomy. We also review radiographic outcomes associated with 20 Dwyer calcaneal osteotomies (in 17 patients) using the intraoperative realignment technique described in this report. Preoperative and postoperative radiographs at a mean of 2.5 (range 1.5 to 5) years taken after Dwyer osteotomy were measured and compared, which revealed a mean reduction in calcaneal varus of 18 (range 2 to 36 ) (p < .001), a mean decrease in the calcaneal inclination angle of 5 (range –40 to 7 ) (p < .05), a mean decrease in medial calcaneal translation of 10 (range 0 to 18) mm (p < .001) relative to the tibia, and a mean dorsal translation of 2 (range 0 to 7) mm (p ¼ .002). In an effort to attempt to structurally realign the calcaneus to a more rectus alignment, by means of Dwyer osteotomy, we recommend the use of the intraoperative bone wedge resection technique described in this report. Our experience with the patients described in this report demonstrates the usefulness of the intraoperative method that we describe in order to accurately restore the axial tibial and calcaneal relationship. Ó 2012 by the American College of Foot and Ankle Surgeons. All rights reserved.
Calcaneal osteotomies have long been used for the correction of various hindfoot deformities and have proven to be powerful realignment surgical procedures. The goal of these calcaneal osteotomies, whether they involve an opening or closing wedge or medial or lateral displacement, is to realign the hindfoot relative to the long axis of the tibia. The first calcaneal osteotomy was described by Gleich in 1893 for pes planovalgus (1). Gleich stated that it was essential to restore the normal angular relationship of the calcaneus to the floor (1). Several surgical techniques have been described for correction of a varus heel. In 1955, Dwyer first described the lateral closing wedge osteotomy of the calcaneus for pes cavus deformity, using a lateral oblique approach (2). The 8- to 12-mm wedge osteotomy was
Financial Disclosure: None reported. Conflict of Interest: None reported. Address correspondence to: Bradley M. Lamm, DPM, FACFAS, Head of Foot and Ankle Surgery, International Center for Limb Lengthening, Rubin Institute for Advanced Orthopedics, Sinai Hospital of Baltimore, 2401 West Belvedere Avenue, Baltimore, MD 21215. E-mail address: [email protected] (B.M. Lamm).
performed just proximal and parallel to the peroneus longus tendon. Completion of the osteotomy through the medial cortex ensured complete closure of the osteotomy. Dwyer stated that the heel should be positioned in a neutral to slight valgus position; however, he made no mention of his method in determining the size of calcaneal wedge to resect (2,3). Since Dwyer’s first publication, many other techniques for wedge osteotomies (lateral closing, lateral opening wedge, and medial opening wedge) have been reported (4–8). In 1963, Dwyer revised the procedure to a medial opening wedge osteotomy for treatment of residual talipes equinovarus (4). Lengthening of the Achilles tendon with a slide technique and an autograft tibial wedge was used for the medial opening wedge osteotomy. However, the medial approach was fraught with complications, including neurovascular compromise, lack of complete skin closure, and graft failure. In addition, Lemperg and Smith reported delayed wound healing at a mean of 5.4 weeks with the medial approach (9). Eventually, complications associated with a medial opening wedge calcaneal osteotomy limited the popularity of the procedure (4,9,10). Although Mann and Coughlin have reported sural nerve entrapment and inadequate wedge resection as complications, the lateral closing
1067-2516/$ - see front matter Ó 2012 by the American College of Foot and Ankle Surgeons. All rights reserved. http://dx.doi.org/10.1053/j.jfas.2012.08.004
744
B.M. Lamm et al. / The Journal of Foot & Ankle Surgery 51 (2012) 743–748
Fig. 1. (A–H) Dwyer calcaneal osteotomy planning and procedure. Illustration of the planning and intraoperative technique for the realignment Dwyer calcaneal osteotomy. Copyright 2012, Rubin Institute for Advanced Orthopedics, Sinai Hospital of Baltimore.
wedge osteotomy has proven to be a safe and effective method for treatment of calcaneal varus that allows for early postoperative weightbearing (8,11). The difficulty with closing wedge osteotomies is in determining the amount of bone resection necessary to correct the deformity. In 1985, Krackow et al described a preoperative technique using a tracing of the calcaneal axial radiograph to assess the amount of wedge to resect. A calcaneal tracing is made on paper, which is then cut and rotated until the desired correction is achieved. Although this is an adequate approach for calculating the amount of wedge resection, it is a cumbersome method to apply intraoperatively. In addition, this template tracing method ignores the tibial axis and the relationship of the calcaneus to the leg. Although few authors report using this technique, most are vague as to how they determine the size of their calcaneal wedge resection (8,12). Weseley and Barenfeld discussed the mechanism of action of the Dywer calcaneal osteotomy (10). First, they described resection of an
adequate wedge of bone to realign the calcaneal tuberosity lateral to the weightbearing line of the tibia to prevent the recurrence of deformity. Next, they believed that altering the plane of the subtalar joint causes the talus to sit more medial to the calcaneus, which allows the tibia to exert a corrective force on the foot, assuming that the calcaneus is in anatomical alignment. Finally, they stated that the Dwyer calcaneal osteotomy allows the Achilles tendon to become a corrective force instead of a deforming force because the calcaneus is no longer in varus. We present a simple and reproducible surgical technique to provide the correct amount of bone wedge resection when the Dwyer calcaneal osteotomy is used to establish a rectus alignment of the calcaneal tuber in regard to the weightbearing substrate and the long axis of the tibia. In addition, we outline the deformity correction principles for accurate realignment of the Dwyer calcaneal osteotomy. Finally, we review the radiographic effects of this surgical technique in a series of patients.
B.M. Lamm et al. / The Journal of Foot & Ankle Surgery 51 (2012) 743–748
Patients and Methods This is an institutional review board–approved retrospective chart and radiograph review of consecutive patients treated with a Dwyer calcaneal osteotomy for correction of calcaneal tuber varus between January 2001 and December 2007. All of the patients came from the clinical practice of the senior author (B. M. L.), who also performed all of the operations. The patients were retrospectively identified using the surgical research database at the Rubin Institute. Seventeen patients who underwent a total of 20 Dwyer osteotomies using the intraoperative measurement method described in this report were identified by means of chart review and were included in the study. A chart review was performed to examine patient demographics as well as diagnosis, ancillary procedures, complications, and time to full weightbearing. Preoperative and postoperative radiographs were obtained, including hindfoot alignment (13) and lateral foot views. Using these radiographs, we measured the calcaneal inclination angle, the angle between the mid-diaphyseal line (anatomic axis) of the tibia and the calcaneal bisection line, and the distance between the tibial and calcaneal bisection lines at the level of the floor and the dorsal calcaneal translation by the distance of the posterior dorsal calcaneus fragment to dorsal anterior calcaneus both preoperatively and postoperatively. These measurements were completed using an incremental goniometer and rounded to the nearest degree by 3 authors (H.L.S., T.W.D., F.Z.) and was verified by the senior author (B.M.L.). Statistical Methods SPSS 17.0 (SPSS, Inc. Chicago, IL) was used to analyze all data. Differences between groups were evaluated with a 2-tailed Student’s t test. Statistical differences were considered significant at the 5% (p .05) level. The statistical analyses were carried out by the senior author (B.M.L.). Deformity Planning The deformity correction principles for accurate realignment of the Dwyer calcaneal osteotomy begin with obtaining proper axial weightbearing radiographs. To identify the level and magnitude of calcaneal deformity, the proximal (tibial anatomic axis) and distal (calcaneal bisection) reference lines are drawn. Thereafter, the normal calcaneal axis 10 mm medial and parallel to the calcaneal bisection line is drawn. The center of rotation angulation (CORA) is located at the intersection of the proximal and distal normal reference lines. Note the CORA is located in the calcaneal body and the magnitude of the deformity is measured by the angle between proximal and distal reference lines (Fig.1A-C). Surgical Technique The patient is positioned supine on a radiolucent table with a bump under the hemi sacrum to obtain a foot-forward position. The tourniquet is inflated around the thigh after adequate sterile prepping and draping of the lower extremity. Under fluoroscopic guidance, a free 1.8-mm wire, used to determine the orientation of the oblique skin incision, is placed on the lateral aspect of the calcaneus. The skin is marked along this oblique wire from anterior to the Achilles tendon insertion on the calcaneus to anterior to the insertion of the plantar fascia. An incision 5 cm in length is made along the lateral aspect of the heel. Careful dissection is performed to avoid injury to the sural nerve,
745
although the incision is typically posterior to the course of the sural nerve. The periosteal layer is incised in line with the skin incision, and then the periosteum is freed proximally, distally, dorsally, and plantarly. Using a long leg calcaneal axial fluoroscopic image, 2 guide wires are inserted into the calcaneus. The skin is retracted anteriorly to insert the first pin perpendicular to the bisection line of the tibia. A second wire posterior to the first is then advanced perpendicular to the lateral wall of the calcaneus (Fig. 1D). The 2 wires are placed in a manner that allows them to converge just lateral to the medial cortex, thus ensuring preservation of the medial cortical hinge of the calcaneus. Both wires are inserted parallel to the plantar surface of the foot. The correct placement of both calcaneal pins allows for accurate and reproducible calcaneal wedge resection. Using a micro sagittal saw, the calcaneus is then cut in a wedge fashion along each wire, with care taken to maintain the medial cortex. The orientation of the cut is essentially perpendicular to the inclination of the calcaneus. The wedge is removed and the calcaneus realigned to a vertical position (parallel to the anatomical axis of the tibia), using fluoroscopy (Fig. 1E and F). In cases in which the calcaneus is still medially displaced relative to the long axis of the tibia, the medial cortical hinge is broken with an osteotome, allowing the tuberosity to be translated laterally (Fig. 1G and H). The posterior calcaneal tuberosity is then temporarily fixated with 2 posterior to anterior guide pins (plantarly and dorsally) placed perpendicularly across the osteotomy site. The guide pins are placed just proximal to the Achilles insertion through 1 small posterior incision. Partially threaded large-diameter cannulated screws are inserted one at a time to ensure that the calcaneal position is maintained. The 2 screws must be confirmed under fluoroscopy to adequately compress the osteotomy site (Fig. 1G). The wounds are then closed and the tourniquet is deflated. A dry sterile dressing is applied with a postoperative boot and the patient is instructed to remain non-weightbearing for 4 weeks (Figs. 2-4).
Results Seventeen patients, 12 (70.59%) women and 5 (29.41%) men, were included. The mean age at the time of surgery was 31 (range 8 to 60) years. A total of 20 Dwyer calcaneal osteotomies were performed, 10 (50%) right and 10 (50%) left feet, with a mean follow-up of 2.5 (range 1.5 to 5) years. The etiology of the varus deformity included 9 (45%) isolated calcaneal varus, 3 (15%) residual clubfoot, 2 (10%) with a history of a cerebral hemispherical stroke, 2 (10%) with Charcot– Marie–Tooth disease, 2 (10%) with poliomyelitis, 1 (5.00%) subtalar contracture, and 1 (5.00%) residual varus after a prior posterior calcaneal osteotomy (Table 1). The hindfoot alignment view was used to measure the degree of calcaneal varus and amount of translation of the calcaneus relative to the tibia. The mean calcaneal varus deformity was 25 (range 2 to 56 ) preoperatively, and decreased to 7 (range 0 to 31 ) postoperatively. The mean degree of varus calcaneal correction was 18 (range 2 to 36 ) (p < .001). Translation of the calcaneal bisection line relative to the anatomic axis of the tibia showed a mean medial translation of 14 mm preoperatively, and this reduced by a mean of
Fig. 2. Preoperative radiographs of a 30-year-old patient with residual clubfoot and a calcaneal varus on the left. (A) Standing hindfoot alignment view shows calcaneal varus on the left status before surgery. (B) Lateral radiograph before surgery. Copyright 2012, Rubin Institute for Advanced Orthopedics, Sinai Hospital of Baltimore.
746
B.M. Lamm et al. / The Journal of Foot & Ankle Surgery 51 (2012) 743–748
Fig. 3. Intraoperative radiographs. (A) Intraoperative axial fluoroscopic view shows our technique for placement of the guide pins (1.8 mm) in the calcaneus. The proximal guide pin is perpendicular to the anatomical axis of the tibia and the distal guide pin is perpendicular to the anatomical axis of the calcaneus. A saw is used to cut along each guide pin and the wedge of bone removed to create a vertical calcaneal position. (B) The vertical calcaneal position is temporarily fixated with 2 guide pins for the cannulated screws. (C) Two cannulated screws are inserted, one at a time in order for the calcaneal position to be maintained. (D) A lateral fluoroscopic view shows the stacked screws inserted perpendicular to the osteotomy site. Copyright 2012, Rubin Institute for Advanced Orthopedics, Sinai Hospital of Baltimore.
10 mm postoperatively (p < .001). The mean final calcaneal (bisection line) position was 4 mm medial to the anatomic axis of the tibia (Table 2). A total of 7 (35%) feet underwent lateral translation of the calcaneal tuberosity in addition to angular correction.
The lateral view radiograph was used to determine the mean calcaneal inclination angle and mean dorsal translation. The mean calcaneal inclination angle was 19 (range 12 to 44 ) preoperatively and 14 (range 0 to 25 ) postoperatively, yielding a mean decrease
Fig. 4. Final postoperative radiographs. (A) Final postoperative standing hindfoot alignment view shows a vertical calcaneus. (B) Final postoperative lateral radiograph. Copyright 2012, Rubin Institute for Advanced Orthopedics, Sinai Hospital of Baltimore.
B.M. Lamm et al. / The Journal of Foot & Ankle Surgery 51 (2012) 743–748
Table 1 Patient characteristics (N ¼ 20 procedures in 17 patients)
Table 3 Ancillary procedures performed in addition to the Dwyer calcaneal osteotomy (N ¼ 20 procedures in 17 patients)
Variable
Value (count [%])
Gender Side Etiology
12 (70.59) women, 5 (29.41) men 10 (50) right, 10 (50) left 9 (45) isolated calcaneal varus 3 (15) residual clubfoot 2 (10) history of stroke 2 (10) Charcot–Marie–Tooth 2 (10) poliomyelitis 1 (5) subtalar contracture 1 (5) residual varus due to prior posterior calcaneal osteotomy 2 (10) Mean (y) Minimum (y) Maximum (y) 31 8 60 2.5 1.5 5
Complications Measure Age at surgery Duration of follow-up
747
of 5 (range 40 to 7 ) (p < .05). The mean postoperative dorsal calcaneal translation was 2 (range 0 to 7) mm (p ¼ .002) (Table 2). Dwyer osteotomy fixation varied initially with 2 (10%) osteotomies fixated with 2 staples and 2 (10%) osteotomies with a single cannulated screw. However, the subsequent 16 (80%) patients were fixated with 2 cannulated screws. Multiple ancillary procedures were performed along with the Dwyer osteotomy. Ancillary soft tissue procedures included 6 (30%) tendon transfers, 6 (30%) tendon lengthenings, 5 (25%) plantar fascia releases, and 2 (10%) lateral ankle stabilizations. Ancillary osseous procedures included 3 (15%) first metatarsal procedures, 1 (5%) anterior calcaneal osteotomy, 1 (5%) midfoot osteotomy, and 1 (15%) ipsilateral leg lengthening with external fixation (Table 3). Patients spent a mean of 6 (range 4 to 28) weeks non-weightbearing and a total of 10 (range 4 to 32) weeks until full weightbearing in normal shoe gear was achieved. The patient who underwent the simultaneous leg-lengthening procedure with external fixation was not made full weightbearing until 28 weeks postoperatively. There were 2 (10% of procedures, 11.77% of patients) postoperative complications. One (5%) patient who was diabetic required surgical debridement for wound dehiscence and healed uneventfully thereafter, and 1 (5%) other patient was not completely corrected and required a revision calcaneal osteotomy with lateral translation only. Discussion Preoperative planning, including radiographic and clinical assessment, is critical to the success of surgery. Although the effectiveness of radiographs for identification of the level and extent of osseous deformity has been well documented, the literature reports only limited use of axial radiographs (14). Harris and Beath (15) were the first to develop a frontal plane radiograph of the heel, which was later refined by Kleiger and Mankin (16) into what is now known as a long-leg calcaneal axial view. In 1976, another frontal plane technique, the hindfoot alignment view, was described by Cobey (17) and later modified by Buck et al (18), Johnson et al (19), and Saltzman and el-Khoury (20). Because the degree of calcaneal varus and relationship of the calcaneus relative to the tibia is determined by the axial
Table 2 Preoperative and postoperative radiographic measures (N ¼ 20 procedures in 17 patients) Measure
Preoperative
Postoperative
p Value
Calcaneal varus ( ) Calcaneal inclination ( ) Dorsal translation (mm) Medial translation (mm)
25 19 0 14
7 14 2 4
<.001 <.05 .002 <.001
Ancillary Procedure Performed Soft tissue procedure Tendon transfer Tendon lengthening Plantar fascia release Lateral ankle stabilization Osseous procedure Metatarsal osteotomy Anterior calcaneal osteotomy Midfoot osteotomy
Frequency (% of feet) 6 6 5 2
(30) (30) (25) (20)
3 (15) 1 (5) 1 (5)
radiographs, they are extremely important when choosing the appropriate procedure(s). It is also essential to assess forefoot to hindfoot relationship preoperatively to determine if surgical correction of the forefoot is necessary. The mobility of the forefoot, whether it is flexible, semiflexible or fixed, can be assessed by supinating and pronating the midtarsal joint while maintaining the subtalar joint in neutral position. If the forefoot is fixed, the forefoot should be corrected along with the Dwyer. For example, calcaneal varus combined with a fixed forefoot valgus can be corrected simultaneously with a dorsiflexion osteotomy/fusion of the medial column or a rotational osteotomy of the midfoot. A semi-flexible or flexible forefoot that is diagnosed in combination with a calcaneal varus may not need to be addressed. The normal position of the calcaneus is 5 to 10 mm lateral to the mid-diaphyseal line of the tibia (14). This position is critical for normal gait and locomotion. The position of the heel is important, because the ground reaction force vector should originate at the plantar lateral portion of the hindfoot to create a slight valgus moment arm on the subtalar joint and initiate normal gait (21). Thus, the need to assess both preoperative and intraoperative calcaneal alignment is critical to proper angular realignment and translation. In this retrospective study, 7 (35%) feet underwent lateral translation of the calcaneal tuberosity at the time of initial surgery. Although a normal anatomic axial relationship of the tibia and calcaneus was not achieved in all cases, we did see a statistically significant mean reduction in the medial position of the calcaneus relative to the tibia (10 mm, p < .05). Assuming that an adequate wedge is resected, our study suggests that lateral translation should be performed more routinely in association with a Dwyer osteotomy to obtain a complete anatomical correction. Another potential means of enhancing the degree of correction is by making the osteotomy more anterior, which is closer to the apex of the deformity. While translating the calcaneus laterally, the surgeon must be careful not to simultaneously translate the calcaneus superiorly or inferiorly, because this can, in effect, lengthen or shorten the Achilles tendon and alter its tension. Although dorsal translation of the calcaneal tuberosity was seen in 8 (47.06%) of our patients, the mean translation was only 2 mm and caused a minimal effect in the form of a mean decrease in the calcaneal inclination angle of 5 . Rigid fixation should be a consideration when performing the Dwyer calcaneal osteotomy with or without translation. Use of one screw for fixation may result in angulation of the calcaneal tuberosity because of tension on soft tissues or rotation around the screw during screw insertion. Thus, using 2 points of fixation is recommended to prevent this from occurring. We understand that the results of this case series can only be used for hypothesis generation, although we feel that the measurements described can be useful to surgeons undertaking Dwyer osteotomy with the intent of making the orientation of the calcaneus rectus relative to the ground and the long axis of the tibia. The measurements, having
748
B.M. Lamm et al. / The Journal of Foot & Ankle Surgery 51 (2012) 743–748
been performed by the surgeons, could have been biased, and we did not make any attempt to measure the influence of clinical exposures on an outcome of interest. Moreover, we did not associate the radiographic and surgical findings to clinical outcomes in terms of foot-related quality of life, pain, or activity level. We believe, however, that the results of this preliminary work could be useful to future investigators interested in further clarifying the utility of accurately resecting an osseous wedge from the calcaneus when treating heel varus deformities. Although the Dwyer calcaneal osteotomy is a well-known hindfoot surgical procedure, little has been written to define accurate reference points and surgical technique for realignment. As evidenced by our retrospective study, the Dwyer calcaneal osteotomy demonstrated reduction of the calcaneal varus, calcaneal inclination, and medial calcaneal translation. Our intraoperative Dwyer calcaneal osteotomy surgical technique is simple, accurate, and reproducible by providing the correct amount of wedge resection for calcaneal realignment. In addition, our technique takes into account the needed calcaneal translation to restore normal tibia calcaneal alignment. Only one patient diagnosed with Charcot–Marie–Tooth disease required a revision Dwyer osteotomy and only one patient developed a postoperative wound complication. It is important to remember that even with the use of this intraoperative technique, careful preoperative evaluation and preoperative planning with axial radiographs and a thorough clinical examination to evaluate the presence of associated deformities are crucial to the success of this procedure.
3. 4. 5. 6. 7. 8. 9. 10. 11. 12.
13.
14. 15. 16. 17. 18.
References 1. Gleich A. Beitrag zur operativen plattfussbehandlung. Arch Klinn Chir 46: 358–362, 1893. 2. Dwyer FC. A new approach to the treatment of pes cavus. Sixieme Congress de Chirurgie Orthopedique, Bern, 30 aout – 3 septembre 1954. Societe Internationale
19. 20. 21.
de Chirurgic Orthopedique et de Traumatologie, Imprimerie Lielens, Bruxelles, 1955. p. 551. Dwyer FC. Osteotomy of the calcaneum for pes cavus. J Bone Joint Surg Br 41-B(1):80–86, 1959. Dwyer FC. The treatment of relapsed club foot by insertion of a wedge into the calcaneum. J of Bone Joint Surg Br 45-B(1):67, 1963. Barenfeld PA, Weseley MS, Munters M. Dwyer calcaneal osteotomy. Clin Orthop Relat Res 53:147–153, 1967. Ayres MJ, Bakst RH, Baskwill DF, Pupp G. Dwyer osteotomy: a retrospective study. J Foot Surg 26(4):322–328, 1987. Robinson DS, Clark B Jr, Prigoff MM. Dwyer osteotomy for treatment of calcaneal varus. J Foot Surg 27(6):541–544, 1988. Krackow KA, Hales D, Jones L. Preoperative planning and surgical technique for performing a Dwyer calcaneal osteotomy. J Pediatr Orthop 5(2):214–218, 1985. Lemperg RK, Smith TW. The calcaneal osteotomy of Dwyer: an indication for Kiel bone. Acta Orthop Scand 47(1):125–128, 1976. Weseley MS, Barenfeld PA. Mechanism of the Dwyer calcaneal osteotomy. Clin Orthop Relat Res 70:137–140, 1970. Mann RA, Coughlin MJ. Surgery of the Foot and Ankle, Mosby, St Louis, MO, 1993. Boffeli TJ, Collier RC. Surgical technique for combined Dwyer calcaneal osteotomy and peroneal tendon repair for correction of peroneal tendon pathology associated with cavus foot deformity. J Foot Ankle Surg 51(1):135–140, 2012. Mendicino RW, Catanzariti AR, John S, Child B, Lamm BM. Long leg calcaneal axial and hindfoot alignment radiographic views for frontal plane assessment. J Am Podiatr Med Assoc 98(1):75–78, 2008. Paley D. Ankle and foot considerations. In: Principles of Deformity Correction, pp. 571–645, edited by D Paley, Springer, Berlin, 2002. Harris RI, Beath T. Hypermobile flat-foot with short tendo achillis. J Bone Joint Surg Am 30A(1):116–140, 1948. Kleiger B, Mankin HJ. A Rentgenographic study of development of the calcaneus by means of the posterior tangential view. J Bone Joint Surg Am 43-A:961–969, 1961. Cobey JC. Posterior roentgenogram of the foot. Clin Orthop Relat Res Jul-Aug(118):202–207, 1976. Buck P, Morrey BF, Chao EY. The optimum position of arthrodesis of the ankle. A gait study of the knee and ankle. J Bone Joint Surg Am 69(7):1052–1062, 1987. Johnson JE, Lamdan R, Granberry WF, Harris GF, Carrera GF. Hindfoot coronal alignment: a modified radiographic method. Foot Ankle Int 20(12):818–825, 1999. Saltzman CL, el-Khoury GY. The hindfoot alignment view. Foot Ankle Int 16(9):572–576, 1995. Lamm BM, Paley D. Deformity correction planning for hindfoot, ankle, and lower limb [review]. Clin Podiatr Med Surg 21(3):305–326, 2004.