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The corrective power of the Cotton osteotomy
Fuß & Sprunggelenk – FussSprungg 14 (2016) 9—13
Online verfügbar unter www.sciencedirect.com
ScienceDirect Original Article
The corrective power of the Cotton osteotomy Das Korrekturpotenzial der Cotton-Osteotomie Ryan T. Scott a, Bradly W. Bussewitz b, Christopher F. Hyer c, Gregory C. Berlet c, Terrence M. Philbin c,∗ a
The CORE Institute, Phoenix, AZ, USA Steindler Orthopedic Clinic, Iowa City, IA, USA c Orthopedic Foot and Ankle Center, Westerville, OH, USA b
Received 23 September 2015; accepted 25 January 2016 Available online 11 March 2016
KEYWORDS
Summary
Cotton; medial cuneiform osteotomy; pes planus; medial column
The Cotton osteotomy is a plantarflexion osteotomy of the medial cuneiform, which is typically utilized in the reconstruction of adult acquired pes planus, posterior tibialis tendon dysfunction stage II (Johnson and Strom), and forefoot varus. The purpose of this paper is to give an estimate of the angular correction in the sagittal plane for each millimeter of bone graft used in the Cotton osteotomy using 20 cadaveric specimens. We have demonstrated that a surgeon will gain roughly 1.9 degrees of plantar flexion of the medial column for every one millimeter graft inserted into the medial cuneiform. While we have not established the amount of correction that should be done, the effect of increasing the wedge size has been demonstrated and may be helpful to surgeons when performing the Cotton osteotomy.
SCHLÜSSELWÖRTER
Zusammenfassung
Cotton; Osteotomie des cuneiforme mediale; pes planus; mediale Säule
Die Cotton-Osteotomie stellt eine plantarflektierende Korrekturosteotomie des Os cuneiforme mediale dar. Sie wird typischerweise angewendet bei der Korrektur des Erwachsenen- Plattfußes zur Aufrichtung der medialen Fußwölbung. Zu den Indikationen zählen auch das Tibialis Posterior Insuffizienz- Syndrom Grad II oder der Vorfuß Varus. Mit der vorliegenden Arbeit soll dem Anwender das Ausmaß der Korrektur in Abhängigkeit der Transplantatgröße verdeutlicht werden. An Hand der Auswertung von 20 Kadaver-Präparaten kann mit einer plantarflektierenden Korrektur von 1,9◦ je eingebrachtem mm eines Knochentransplantates bei der Cotton Osteotomie gerechnet werden. Diese Ergebnisse sollen dem Operateur helfen, das Ausmass der gewünschten Korrektur zu bestimmen.
∗
Corresponding author: Terrence M. Philbin DO, Orthopedic Foot and Ankle Center, 300 Polaris Parkway, Suite 2000, Westerville, OH 43082, USA. Tel.: +1-614-895-8747; Fax: +1-614-895-2112. E-Mail: [email protected] (T.M. Philbin). http://dx.doi.org/10.1016/j.fuspru.2016.01.004
10
R.T. Scott et al.
Introduction It is beyond dispute that the open wedge osteotomy of the medial cuneiform results in plantarflexion of the first ray. This osteotomy is typically utilized in the conjunction of other osseous procedures in the reconstruction of adult acquired pes planus, posterior tibialis tendon dysfunction stage II (Johnson and Strom), and forefoot varus [1,5,12]. Cotton initially described this opening wedge medial cuneiform osteotomy to restore the ‘‘triangle of support’’ in 1936 [1]. In doing so, this allows for angulation of the medial column, reducing the forefoot varus, recreating the medial longitudinal arch. This osteotomy typically accompanies multiple other surgical procedures including posterior tibialis debridement / advancement, flexor digitorum longus tendon transfer, calcaneal slide osteotomy, and Evans calcaneal osteotomy for the correction of both pediatric and acquired pes planus. The Cotton osteotomy is indicated in patients who have a fixed forefoot varus, especially following a lateral column lengthening. Advantages of the Cotton osteotomy include preservation of the metatarsalcuneiform motion and a predictable union rate [11]. However, this osteotomy is relatively contraindicated in patients with osteoarthritis of the first tarsal-metatarsal (TMT) joint [2]. In this case a first TMT arthrodesis may be more beneficial. The osteotomy is described as a centrally located, dorsal to plantar osteotomy through the medial cuneiform, leaving the plantar cortex intact. The osteotomy is then distracted via a lamina spreader or osteotome to stretch the surrounding soft tissue. The appropriate sized bone graft is then inserted maintaining the anticipated correction. Fixation is determined via surgeon preference and comfort level. Other techniques include the use of interpositional plates for maintenance of the osteotomy. Currently there are no published guidelines for surgeons to follow in the management of forefoot varus in flatfoot reconstructions. The purpose of this paper is to give an estimate of the angular correction in the sagittal plane for each millimeter of bone graft used in the Cotton osteotomy.
Figure 1. Simulated weight bearing initial radiograph identifying Meary’s angle.
ligament and medial column ligaments was performed to simulate a medial column instability in conjunction with posterior tibial tendon dysfunction. Weight bearing simulated lateral radiographs were taken of each specimen prior to incision, identifying lateral talo-first metatarsal angle (Meary’s angle) (Figure 1). Mearys angle was determined by bisecting the central aspect of the talus and following that line down the central aspect of the medial column, with a normal value of ‘‘0’’. Then, an anterior medial incision was made over the medial cuneiform extending distally to the base of the first metatarsal. The incision was taken directly down to bone. The soft tissue was then reflected off the osseous structures. The length, width, and depth of the medial cuneiform was measured with a standard ruler. The medial cuneiform osteotomy was made in the central aspect of the cuneiform via visual and fluoroscopic guidance. The sequentially sized trapezoidal Cotton corrective wedges (Wright Medical Technology — Memphis, TN) (4.5, 5.5, and 6.5 mm) were then inserted into the osteotomy until flush with the dorsal cortex (Figure 2). It should be noted that the plantar cortex was maintained ensuring angular correction instead of lengthening of the medial column.
Materials and methods Twenty fresh-frozen cadaver legs, 9 male and 11 females, of similar ages (average 78.7 years) were used for examination at SCARS (San Diego Cadaver Anatomy Research Symposium). Specimens were allowed to thaw to room temperature prior to the investigation. Transection of the plantar spring
Figure 2. Plantarflexion of the first ray with the 6.5 mm corrective wedge.
Cotton Osteotomy The specimens were placed into the weight-bearing jig and fluoroscopic imaging was obtained with the corresponding corrective wedge. Meary’s angle was once again measured revealing the corrective power of each of the wedges. This was performed sequentially utilizing all 3 of the Cotton corrective wedges for each of the specimens. The jig consisted of a mortise joint made out of Plexiglas. The foot was then loaded (20-30 pounds of pressure) from the most proximal aspect of the tibia in each specimen to simulate weight bearing. This was performed with the foot loaded across the inferior arm of the jig. The weight bearing model was standardized for all specimens to ensure reproducibility. The jig allowed us to re-create identical reference points for all of our fluoroscopic images to ensure accuracy. Mean change in Meary’s angle was assessed using a paired t-test with a Bonferroni correction for multiple comparisons after assessing normality. Total angular correction using each of the respective cotton wedges was assessed with using a linear mixed model accounting for repeated measures.
Results Anatomy of the medial cuneiform consisted of a mean length 26.5 ± 5.7 mm (20.0 — 39.9),
11
Figure 3. Average angular correction (in degrees) noted from the Cotton wedges.
width 21.9 ± 4.6 mm (14.4 — 31.0), and height 31.3 ± 3.7 mm (27.0 — 39.7). There was a mean change in Meary’s angle by 7.8 ± 1.6 degrees with the Cotton osteotomy and insertion of the 4.5 wedge as compared to the pre-operative radiograph (p < 0.001). This angular change increased by a mean change of 2.9 ± 1.0 degrees with 5.5 mm wedge (p < 0.001) and 3.0 ± 1.2 degree change with the 6.5 mm graft (p < 0.001). The total degree change was 7.8 ± 1.6 degrees, 10.6 ± 2.4 degrees, 13.6 ± 2.1 degrees respective to 4.5, 5.5, and 6.5 mm Cotton wedge grafts (p < 0.001) (Figure 3). The mean correction seen was 1.9 ± 0.2 degrees for each millimeter of wedge graft. (Figure 4) Figure 4
Figure 4. Total corrective change in Meary’s angle based on the cumulative addition of the 4.5, 5.5, and 6.5 Cotton wedges.
12 demonstrates the cumulative corrective power of the Cotton osteotomy between each of the respective wedges in degrees. The 4.5 mm wedge gives the most overall correction initially (4 mm — 12 mm).
Discussion The dorsal opening wedge medial cuneiform osteotomy, initially described by Cotton, is used in the treatment of flexible flatfoot and forefoot varus [6]. The potential unmasking of a forefoot varus is often noted during the sequential reconstruction of the pes planus deformity. If a forefoot varus is present then a Cotton osteotomy is necessary [7—9,11]. Scott et al noted that although the Cotton osteotomy resulted in increased average pressures within the medial forefoot, a compensatory significant decrease in lateral forefoot pressures was not observed [10]. This makes the Cotton osteotomy a popular adjunctive procedure to the hindfoot osteotomies and tendon rebalancing procedures. Jacobs and Oloff demonstrated excellent results (87.5%) in younger patients (mean age 18.4) following Cotton osteotomy in combination of medial column procedures for treatment of congenital painful pes planus [4]. Advantages of the Cotton over first TMT arthrodesis include more predictable union, preservation of first ray mobility, and the ability to vary the amount of correction to restore the ‘‘triangle of support’’ described by Cotton [3]. Accurate measurements of the degree of plantarflexion of the first ray depend on foot posture during the radiographic exam. For example, if the patient is hyper pronating the plantarflexion angle may be less; while if they are standing with their feet fairly supinated, it may be more. This is a potential concern that should be addressed during the pre-operative (and proper instructions to the patients to stand with the arch relaxed, not supinated, when the x-rays are taken). Pre-operative planning is essential in the treatment of congenital pes planus as well as posterior tibial tendon dysfunction. We have demonstrated the extent of correction according to Cotton wedge size. It is predicted that a surgeon will gain roughly 1.9 degrees of plantar flexion of the medial column for every one millimeter graft inserted into the medial cuneiform. Determining the appropriate sized graft offers improved graft harvest, allograft prep time, or possibly expedite fixation selection (if desired). However, this assumes that the surgeon has made radiographic measurements to determine the amount of correction desired. Because patients can stand with varying amounts of supination in
R.T. Scott et al. the foot during x-ray examinations, it should be realized that radiographic measurements are still only estimates and should be confirmed by assessment in the operating room. One potential weakness to this study includes the use of a cadaveric model. Unfortunately, flatfoot cadaveric models were not readily available for use in this study. Weight bearing was simulated during this construct. The simulated weight bearing was in an isolated plane from dorsal to plantar, not involving internal and external rotation of the foot or ankle. We feel that the large difference in the initial correction is due to the overall varying foot structure in the cadaveric model. The laxity of the soft tissue in the preserved feet varied among the different specimens restricting / controlling the amount of angular correction. In conclusion, while we have not established the amount of correction that should be done, the effect of increasing the wedge size has been demonstrated and may be helpful to surgeons when performing the Cotton osteotomy. With this data, the surgeon can pre-operatively estimate the size of the wedge graft needed to achieve the desired correction. Obviously, clinical judgment should be used particularly to assess the prominence of the adjacent metatarsals in relationship to the 1st metatarsal in determining the amount of correction.
Conflict of interest Drs. Christopher Hyer and Gregory Berlet are consultants for Wright Medical Technology. DJO Global funded the cadaveric lab.
References [1] F.J. Cotton, Foot Statics and Surgery, New Engl J Med (1936) 24—27. [2] S.L. Haddad, R.A. Mann, Flatfoot Deformity in Adults, in: R.A. Mann, M.J. Coughlin, C.L. Saltzman (Eds.), Surgery of the Foot and Ankle, Mosby, Inc., Philadelphia, PA, 2007, pp. 1007—1086. [3] C.B. Hirose, J.E. Johnson, Plantarflexion opening wedge medial cuneiform osteotomy for correction of fixed forefoot varus associated with flatfoot deformity, Foot Ankle Int 25 (2004) 568—574. [4] A.M. Jacobs, L.M. Oloff, Surgical management of forefoot supinatus in flexible flatfoot deformity, J Foot Surg 23 (1984) 410—419. [5] K.A. Johnson, D.E. Strom, Tibialis posterior tendon dysfunction, Clinical orthopaedics and related research (1989) 196—206.
Cotton Osteotomy [6] A.C. League, B.G. Parks, L.C. Schon, Radiographic and pedobarographic comparison of femoral head allograft versus block plate with dorsal opening wedge medial cuneiform osteotomy: a biomechanical study, Foot Ankle Int 29 (2008) 922—926. [7] J.S. Ling, K.A. Ross, C.P. Hannon, C. Egan, N.A. Smyth, M.V. Hogan, J.G. Kennedy, A plantar closing wedge osteotomy of the medial cuneiform for residual forefoot supination in flatfoot reconstruction, Foot Ankle Int 34 (2013) 1221—1226. [8] M. Lutz, M. Myerson, Radiographic analysis of an opening wedge osteotomy of the medial cuneiform, Foot Ankle Int 32 (2011) 278—287.
13 [9] J.J. McCormick, J.E. Johnson, Medial column procedures in the correction of adult acquired flatfoot deformity, Foot Ankle Clin 17 (2012) 283—298. [10] A.T. Scott, T.M. Hendry, J.M. Iaquinto, J.R. Owen, J.S. Wayne, R.S. Adelaar, Plantar pressure analysis in cadaver feet after bony procedures commonly used in the treatment of stage II posterior tibial tendon insufficiency, Foot Ankle Int 28 (2007) 1143—1153. [11] C.J. Tankson, The Cotton osteotomy: indications and techniques, Foot Ankle Clin 12 (2007) 309—315, vii. [12] D. Yarmel, G. Mote, A. Treaster, The Cotton osteotomy: a technical guide, J Foot Ankle Surg 48 (2009) 506—512.
Online verfügbar unter www.sciencedirect.com
ScienceDirect Original Article
The corrective power of the Cotton osteotomy Das Korrekturpotenzial der Cotton-Osteotomie Ryan T. Scott a, Bradly W. Bussewitz b, Christopher F. Hyer c, Gregory C. Berlet c, Terrence M. Philbin c,∗ a
The CORE Institute, Phoenix, AZ, USA Steindler Orthopedic Clinic, Iowa City, IA, USA c Orthopedic Foot and Ankle Center, Westerville, OH, USA b
Received 23 September 2015; accepted 25 January 2016 Available online 11 March 2016
KEYWORDS
Summary
Cotton; medial cuneiform osteotomy; pes planus; medial column
The Cotton osteotomy is a plantarflexion osteotomy of the medial cuneiform, which is typically utilized in the reconstruction of adult acquired pes planus, posterior tibialis tendon dysfunction stage II (Johnson and Strom), and forefoot varus. The purpose of this paper is to give an estimate of the angular correction in the sagittal plane for each millimeter of bone graft used in the Cotton osteotomy using 20 cadaveric specimens. We have demonstrated that a surgeon will gain roughly 1.9 degrees of plantar flexion of the medial column for every one millimeter graft inserted into the medial cuneiform. While we have not established the amount of correction that should be done, the effect of increasing the wedge size has been demonstrated and may be helpful to surgeons when performing the Cotton osteotomy.
SCHLÜSSELWÖRTER
Zusammenfassung
Cotton; Osteotomie des cuneiforme mediale; pes planus; mediale Säule
Die Cotton-Osteotomie stellt eine plantarflektierende Korrekturosteotomie des Os cuneiforme mediale dar. Sie wird typischerweise angewendet bei der Korrektur des Erwachsenen- Plattfußes zur Aufrichtung der medialen Fußwölbung. Zu den Indikationen zählen auch das Tibialis Posterior Insuffizienz- Syndrom Grad II oder der Vorfuß Varus. Mit der vorliegenden Arbeit soll dem Anwender das Ausmaß der Korrektur in Abhängigkeit der Transplantatgröße verdeutlicht werden. An Hand der Auswertung von 20 Kadaver-Präparaten kann mit einer plantarflektierenden Korrektur von 1,9◦ je eingebrachtem mm eines Knochentransplantates bei der Cotton Osteotomie gerechnet werden. Diese Ergebnisse sollen dem Operateur helfen, das Ausmass der gewünschten Korrektur zu bestimmen.
∗
Corresponding author: Terrence M. Philbin DO, Orthopedic Foot and Ankle Center, 300 Polaris Parkway, Suite 2000, Westerville, OH 43082, USA. Tel.: +1-614-895-8747; Fax: +1-614-895-2112. E-Mail: [email protected] (T.M. Philbin). http://dx.doi.org/10.1016/j.fuspru.2016.01.004
10
R.T. Scott et al.
Introduction It is beyond dispute that the open wedge osteotomy of the medial cuneiform results in plantarflexion of the first ray. This osteotomy is typically utilized in the conjunction of other osseous procedures in the reconstruction of adult acquired pes planus, posterior tibialis tendon dysfunction stage II (Johnson and Strom), and forefoot varus [1,5,12]. Cotton initially described this opening wedge medial cuneiform osteotomy to restore the ‘‘triangle of support’’ in 1936 [1]. In doing so, this allows for angulation of the medial column, reducing the forefoot varus, recreating the medial longitudinal arch. This osteotomy typically accompanies multiple other surgical procedures including posterior tibialis debridement / advancement, flexor digitorum longus tendon transfer, calcaneal slide osteotomy, and Evans calcaneal osteotomy for the correction of both pediatric and acquired pes planus. The Cotton osteotomy is indicated in patients who have a fixed forefoot varus, especially following a lateral column lengthening. Advantages of the Cotton osteotomy include preservation of the metatarsalcuneiform motion and a predictable union rate [11]. However, this osteotomy is relatively contraindicated in patients with osteoarthritis of the first tarsal-metatarsal (TMT) joint [2]. In this case a first TMT arthrodesis may be more beneficial. The osteotomy is described as a centrally located, dorsal to plantar osteotomy through the medial cuneiform, leaving the plantar cortex intact. The osteotomy is then distracted via a lamina spreader or osteotome to stretch the surrounding soft tissue. The appropriate sized bone graft is then inserted maintaining the anticipated correction. Fixation is determined via surgeon preference and comfort level. Other techniques include the use of interpositional plates for maintenance of the osteotomy. Currently there are no published guidelines for surgeons to follow in the management of forefoot varus in flatfoot reconstructions. The purpose of this paper is to give an estimate of the angular correction in the sagittal plane for each millimeter of bone graft used in the Cotton osteotomy.
Figure 1. Simulated weight bearing initial radiograph identifying Meary’s angle.
ligament and medial column ligaments was performed to simulate a medial column instability in conjunction with posterior tibial tendon dysfunction. Weight bearing simulated lateral radiographs were taken of each specimen prior to incision, identifying lateral talo-first metatarsal angle (Meary’s angle) (Figure 1). Mearys angle was determined by bisecting the central aspect of the talus and following that line down the central aspect of the medial column, with a normal value of ‘‘0’’. Then, an anterior medial incision was made over the medial cuneiform extending distally to the base of the first metatarsal. The incision was taken directly down to bone. The soft tissue was then reflected off the osseous structures. The length, width, and depth of the medial cuneiform was measured with a standard ruler. The medial cuneiform osteotomy was made in the central aspect of the cuneiform via visual and fluoroscopic guidance. The sequentially sized trapezoidal Cotton corrective wedges (Wright Medical Technology — Memphis, TN) (4.5, 5.5, and 6.5 mm) were then inserted into the osteotomy until flush with the dorsal cortex (Figure 2). It should be noted that the plantar cortex was maintained ensuring angular correction instead of lengthening of the medial column.
Materials and methods Twenty fresh-frozen cadaver legs, 9 male and 11 females, of similar ages (average 78.7 years) were used for examination at SCARS (San Diego Cadaver Anatomy Research Symposium). Specimens were allowed to thaw to room temperature prior to the investigation. Transection of the plantar spring
Figure 2. Plantarflexion of the first ray with the 6.5 mm corrective wedge.
Cotton Osteotomy The specimens were placed into the weight-bearing jig and fluoroscopic imaging was obtained with the corresponding corrective wedge. Meary’s angle was once again measured revealing the corrective power of each of the wedges. This was performed sequentially utilizing all 3 of the Cotton corrective wedges for each of the specimens. The jig consisted of a mortise joint made out of Plexiglas. The foot was then loaded (20-30 pounds of pressure) from the most proximal aspect of the tibia in each specimen to simulate weight bearing. This was performed with the foot loaded across the inferior arm of the jig. The weight bearing model was standardized for all specimens to ensure reproducibility. The jig allowed us to re-create identical reference points for all of our fluoroscopic images to ensure accuracy. Mean change in Meary’s angle was assessed using a paired t-test with a Bonferroni correction for multiple comparisons after assessing normality. Total angular correction using each of the respective cotton wedges was assessed with using a linear mixed model accounting for repeated measures.
Results Anatomy of the medial cuneiform consisted of a mean length 26.5 ± 5.7 mm (20.0 — 39.9),
11
Figure 3. Average angular correction (in degrees) noted from the Cotton wedges.
width 21.9 ± 4.6 mm (14.4 — 31.0), and height 31.3 ± 3.7 mm (27.0 — 39.7). There was a mean change in Meary’s angle by 7.8 ± 1.6 degrees with the Cotton osteotomy and insertion of the 4.5 wedge as compared to the pre-operative radiograph (p < 0.001). This angular change increased by a mean change of 2.9 ± 1.0 degrees with 5.5 mm wedge (p < 0.001) and 3.0 ± 1.2 degree change with the 6.5 mm graft (p < 0.001). The total degree change was 7.8 ± 1.6 degrees, 10.6 ± 2.4 degrees, 13.6 ± 2.1 degrees respective to 4.5, 5.5, and 6.5 mm Cotton wedge grafts (p < 0.001) (Figure 3). The mean correction seen was 1.9 ± 0.2 degrees for each millimeter of wedge graft. (Figure 4) Figure 4
Figure 4. Total corrective change in Meary’s angle based on the cumulative addition of the 4.5, 5.5, and 6.5 Cotton wedges.
12 demonstrates the cumulative corrective power of the Cotton osteotomy between each of the respective wedges in degrees. The 4.5 mm wedge gives the most overall correction initially (4 mm — 12 mm).
Discussion The dorsal opening wedge medial cuneiform osteotomy, initially described by Cotton, is used in the treatment of flexible flatfoot and forefoot varus [6]. The potential unmasking of a forefoot varus is often noted during the sequential reconstruction of the pes planus deformity. If a forefoot varus is present then a Cotton osteotomy is necessary [7—9,11]. Scott et al noted that although the Cotton osteotomy resulted in increased average pressures within the medial forefoot, a compensatory significant decrease in lateral forefoot pressures was not observed [10]. This makes the Cotton osteotomy a popular adjunctive procedure to the hindfoot osteotomies and tendon rebalancing procedures. Jacobs and Oloff demonstrated excellent results (87.5%) in younger patients (mean age 18.4) following Cotton osteotomy in combination of medial column procedures for treatment of congenital painful pes planus [4]. Advantages of the Cotton over first TMT arthrodesis include more predictable union, preservation of first ray mobility, and the ability to vary the amount of correction to restore the ‘‘triangle of support’’ described by Cotton [3]. Accurate measurements of the degree of plantarflexion of the first ray depend on foot posture during the radiographic exam. For example, if the patient is hyper pronating the plantarflexion angle may be less; while if they are standing with their feet fairly supinated, it may be more. This is a potential concern that should be addressed during the pre-operative (and proper instructions to the patients to stand with the arch relaxed, not supinated, when the x-rays are taken). Pre-operative planning is essential in the treatment of congenital pes planus as well as posterior tibial tendon dysfunction. We have demonstrated the extent of correction according to Cotton wedge size. It is predicted that a surgeon will gain roughly 1.9 degrees of plantar flexion of the medial column for every one millimeter graft inserted into the medial cuneiform. Determining the appropriate sized graft offers improved graft harvest, allograft prep time, or possibly expedite fixation selection (if desired). However, this assumes that the surgeon has made radiographic measurements to determine the amount of correction desired. Because patients can stand with varying amounts of supination in
R.T. Scott et al. the foot during x-ray examinations, it should be realized that radiographic measurements are still only estimates and should be confirmed by assessment in the operating room. One potential weakness to this study includes the use of a cadaveric model. Unfortunately, flatfoot cadaveric models were not readily available for use in this study. Weight bearing was simulated during this construct. The simulated weight bearing was in an isolated plane from dorsal to plantar, not involving internal and external rotation of the foot or ankle. We feel that the large difference in the initial correction is due to the overall varying foot structure in the cadaveric model. The laxity of the soft tissue in the preserved feet varied among the different specimens restricting / controlling the amount of angular correction. In conclusion, while we have not established the amount of correction that should be done, the effect of increasing the wedge size has been demonstrated and may be helpful to surgeons when performing the Cotton osteotomy. With this data, the surgeon can pre-operatively estimate the size of the wedge graft needed to achieve the desired correction. Obviously, clinical judgment should be used particularly to assess the prominence of the adjacent metatarsals in relationship to the 1st metatarsal in determining the amount of correction.
Conflict of interest Drs. Christopher Hyer and Gregory Berlet are consultants for Wright Medical Technology. DJO Global funded the cadaveric lab.
References [1] F.J. Cotton, Foot Statics and Surgery, New Engl J Med (1936) 24—27. [2] S.L. Haddad, R.A. Mann, Flatfoot Deformity in Adults, in: R.A. Mann, M.J. Coughlin, C.L. Saltzman (Eds.), Surgery of the Foot and Ankle, Mosby, Inc., Philadelphia, PA, 2007, pp. 1007—1086. [3] C.B. Hirose, J.E. Johnson, Plantarflexion opening wedge medial cuneiform osteotomy for correction of fixed forefoot varus associated with flatfoot deformity, Foot Ankle Int 25 (2004) 568—574. [4] A.M. Jacobs, L.M. Oloff, Surgical management of forefoot supinatus in flexible flatfoot deformity, J Foot Surg 23 (1984) 410—419. [5] K.A. Johnson, D.E. Strom, Tibialis posterior tendon dysfunction, Clinical orthopaedics and related research (1989) 196—206.
Cotton Osteotomy [6] A.C. League, B.G. Parks, L.C. Schon, Radiographic and pedobarographic comparison of femoral head allograft versus block plate with dorsal opening wedge medial cuneiform osteotomy: a biomechanical study, Foot Ankle Int 29 (2008) 922—926. [7] J.S. Ling, K.A. Ross, C.P. Hannon, C. Egan, N.A. Smyth, M.V. Hogan, J.G. Kennedy, A plantar closing wedge osteotomy of the medial cuneiform for residual forefoot supination in flatfoot reconstruction, Foot Ankle Int 34 (2013) 1221—1226. [8] M. Lutz, M. Myerson, Radiographic analysis of an opening wedge osteotomy of the medial cuneiform, Foot Ankle Int 32 (2011) 278—287.
13 [9] J.J. McCormick, J.E. Johnson, Medial column procedures in the correction of adult acquired flatfoot deformity, Foot Ankle Clin 17 (2012) 283—298. [10] A.T. Scott, T.M. Hendry, J.M. Iaquinto, J.R. Owen, J.S. Wayne, R.S. Adelaar, Plantar pressure analysis in cadaver feet after bony procedures commonly used in the treatment of stage II posterior tibial tendon insufficiency, Foot Ankle Int 28 (2007) 1143—1153. [11] C.J. Tankson, The Cotton osteotomy: indications and techniques, Foot Ankle Clin 12 (2007) 309—315, vii. [12] D. Yarmel, G. Mote, A. Treaster, The Cotton osteotomy: a technical guide, J Foot Ankle Surg 48 (2009) 506—512.