GLOBUS MEDICAL, INC.
`EXHIBIT 1017
`IPR2015-to be assigned
`(Globus v. Bonutti)
`
`Page 1 of 16
`
`

`
`Subtalar Distractional Realignment Arthrodesis with Wedge Bone
`Grafting and Lateral Decompression for Calcaneal Malunion
`
`Chen, Yeung-Jen MD; Huang, Tsung-Jen MD; Hsu, Kuo—Yao MD; Hsu, Robert Wen—Wei
`MD; Chen, Chung-Wu MD
`
`The Journal of Trauma: Injury, Infection, and Critical Care . 45(4):729-737, October 1998.
`
`Author Information
`
`From the Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Chang Gung Medical College, Taipei, Taiwan,
`
`Republic of China.
`
`Address for reprints: Yeung-Jen Chen, MD, Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Chang Gung
`
`Medical College, 5, Fu-Hsing Street, Kweishan, Taoyuan Taiwan, Republic of China; fax: 8863-3284564.
`
`Abs tract
`
`Background: The purpose ofthis study was to evaluate prospectively the efficacy of subtalar distractional realignment
`
`arthrodesis in the treatment of calcaneal malunion associated with subtalar arthritis, collapse of height, talonavicular subluxation,
`
`rnalaligmnent ofthe heel axis, and widening heel with calcaneofibular abutment.
`
`Cited Here...: Thirty- four patients with severe calcaneal rnalunion were treated with a lateral approach, lateral decompression,
`
`medial subtalar capsulotomy, and distraction and realignment ofthe subtalar joint with an anteriorly and laterally tapered wedge
`
`bone graft. The patients were evaluated with a functional rating scale and radiographs, both before and after surgery.
`
`Cited Here...: Thirty—two ofthe 34 patients were evaluated at a mean of 71 months (range, 60-92 months) after the arthrodesis.
`
`Solid subtalar fiision was achieved in 31 ofthe 32 patients. The average gain of subtalar distraction was 12 mm Neutral or mild
`
`valgus alignment was achieved in 26 of the 32 patients. The mean postoperative score (83) showed significant improvement
`
`over the mean preoperative score (47). Overall, the functional rating scale revealed excellent or good results in 26 patients and
`
`fair results in 6 patients.
`
`Conclusion: Coupled with wedge bone grafting, the subtalar distractional realignment arthrodesis achieved restoration of
`
`hindfoot height and axial alignment with a good union rate and significant improvement in the majority ofpatients with calcaneal
`malunion
`
`Late complications of calcaneal fracture include (1) incongruous subtalar joint with osteoarthritis; (2) decreased calcaneal height
`
`with change oftalocalcaneal angle; (3) widening ofthe heel with calcaneofibular abutment and impingement on tendons or
`
`nerves; (4) rnalalignment ofthe heel axis; and (5) collapse of the midfoot arch with resulting flat foot. [11 All of these problems
`
`are caused by superior and lateral translation ofthe tuberosity firagment along the shear fiacture line, causing a decrease in
`
`calcaneal height with lateral extrusion (Figu_re l). |_2,6,7[ Failure to correct this displacement in a calcaneal fiacture will lead to
`
`the destruction of the normal structure ofthe calcaneus, resulting in an abnormal relationship between the calcaneus and the
`
`ankle and foot. |8— l O]
`
`Page 2 of 16
`Page 2 of 16
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`

`
`Figure 1. Coronal CT scan demonstrating the superior and lateral displacement of the tubcrositywith varus deformity.
`
`The most eflfective treatment for calcaneal malunion with subtalar osteoarthritis is arthrodesis. 7,l1,12| In situ subtalar
`
`arthrodesis without correction of the associated malalignment and deformities, however, cannot completely solve the problems
`ofcalcaneal malunion. The objectives of arthrodesis in the treatment of calcaneal malunion are biomechanically similar to the
`objectives of arthrodesis in major joints ofthe lower extremity, such as the hip joint and the knee joint. An ideal arthrodesis in
`joints ofthe lower extremity should also provide proper alignment and leg length. When subtalar arthrodesis is performed on
`patients with calcaneal rnalunion, therefore, proper restoration of calcaneal geometry during the arthrodesis procedure is crucial
`to the restoration of function
`
`It has been estimated that 1 degree of dorsiflexion ofthe ankle joint increases the force across the Achilles tendon by about 1%.
`[Q1 This increase in force is caused by the lowering ofthe longitudinal arch and the greater degree of dorsiflexion in the foot as
`a result of changes in calcaneal geometry after fiacture. Restoration of calcaneal height along with the subtalar arthrodesis may
`correct this phenomenon. Romash described a technique of subtalar arthrodesis for calcaneal malunion that restores normal
`calcaneal geometry along with the arthrodesis via an osteotomy that recreates the primary fiacture. LQ] Carr et al. described a
`method of subtalar distraction bone—b1ock fiision to restore lost calcaneal height. [11 The surgical method used on the patients in
`the present study is a modification ofthis subtalar distraction arthrodesis that changes the location of the incision to
`the
`need for sott—tissue dissection. The procedure also incorporates wedging ofthe bone block to correct the varus/valgus
`rnalalignment ofthe hindfoot associated with correction of the heel height. The purpose of this study was to evaluate the results
`ofthis modified method and to assess the eifectiveness ofusing a wedge— shaped bone graft in subtalar fusion. A clinical
`
`assessment rating system together with radiography were used to evaluate the results.
`
`Back to Top
`
`PATIENTS AND METHODS
`
`From May 1988 to May 1992, 34 patients underwent distraction subtalar fiision and lateral decompression ostectomy at Chang
`Gung Memorial Hospital. Thirty-two ofthese 34 patients were followed with clinical and radio graphic evaluations. Two of the
`34 patients were unavailable for follow—up and were excluded from the study. Among the 32 patients receiving follow-up, 4 had
`bilateral involvement. There were 25 men and 7 women, with an average age of 36 years (range, 21-65 years). All of the
`patients received primary management elsewhere. Six ofthem had received no previous treatment, 22 had received casting
`without reduction, and four had received axial reduction with casting (Table 1). The average time fiom injury until the operation
`was 16 months (range, 4-26 months). All patients had failed to respond adequately to such nonoperative treatments as
`nonsteroidal anti- inflammatory drugs, physical therapy, and shoe modification They all suifered fiom painfiil subtalar joint and
`
`Page 3 of 16
`Page 3 of 16
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`

`
`widening ofthe heel with calcaneofibular abutment. The associated abnormalities included talonavicular joint subluxation in nine
`patients, protruding plantar cortex defonnity in eight patients, medial hindfoot pain with posterior tarsal tunnel syndrome in three
`patients, and stiflhess ofthe first metatarophalangeal joint caused by bony entrapment of the flexor hallux longus in one patient
`(Table 1).
`
`X
`
`3
`3
`4
`
`4
`3
`3
`3
`4
`4
`
`,
`03:8
`
`In ur‘
`(gioslftvivijél
`
`Sex/Age
`
`Tfggjgggfn
`
`Agggggggé
`
`F(fn"§;”t;]‘:f
`
`1
`
`3
`
`4
`5
`6
`7
`8
`C1
`
`M/19
`M/47
`M/39
`
`M/34
`M/36
`M/28
`F/26
`M/41
`M/26
`
`13
`23
`11
`
`4
`15
`22
`15
`12
`16
`
`2
`1
`2
`
`1
`2
`3
`1
`
`2
`
`68
`52
`52
`
`52
`76
`77
`80
`50
`55
`
`3
`Bilateral
`
`1. 2. 3
`1
`1, 3
`
`1, 2. 4
`Bilateral
`
`1. 4
`1, 2, 3
`
`3
`1, 2. 3
`
`1. 3
`3
`1. 3
`Bilateral
`
`Pain
`Y
`
`Activity
`X
`Y
`
`won.»
`X
`\’
`
`Functional Assessment
`1
`Q3531
`X
`Y
`
`Shoe
`X
`Y
`
`.
`MF;;;§n H'j§jjf;°*
`X
`Y
`X
`Y
`
`1
`1
`2
`
`3
`1
`1
`1
`3
`2
`
`3
`3
`3
`
`4
`3
`3
`3
`4
`3
`
`2
`1
`2
`
`3
`2
`1
`1
`3
`2
`
`3
`3
`4
`
`4
`3
`8
`3
`4
`4
`
`1
`2
`3
`
`3
`1
`1
`2
`3
`3
`
`3
`3
`3
`
`3
`3
`2
`2
`3
`3
`
`1
`1
`1
`
`2
`1
`1
`1
`2
`1
`
`2
`1
`2
`
`3
`2
`1
`1
`3
`2
`
`1
`1
`2
`
`2
`1
`1
`1
`2
`2
`
`2
`2
`2
`
`3
`2
`1
`1
`3
`2
`
`1
`1
`2
`
`2
`1
`1
`1
`2
`2
`
`3
`2
`3
`
`4
`3
`2
`2
`4
`3
`
`1
`1
`1
`
`3
`1
`1
`1
`2
`1
`
`.
`F“gggf;a'
`X
`Y
`
`P(54)
`F160)
`P(44)
`
`P(27)
`P(54)
`F036)
`H66)
`P(29)
`H441
`
`G(951
`G(95)
`G(76)
`
`F158)
`G(95)
`E(100)
`G195)
`F(62l
`(3176)
`
`Racliographzc Assessment
`
`Heel mm (emu
`X
`Y
`C
`
`T(;;"g';'§;‘;‘
`Y
`
`X
`
`7.8
`7.8
`
`7.7
`7.7
`7.9
`7.0
`7.8
`
`7.8
`8.0
`7.7
`7.2
`7.6
`7.9
`7.6
`7.9
`7.0
`7.6
`7.3
`
`C
`
`2
`0
`
`2
`1
`1
`2
`1
`
`3
`2
`O
`2
`O
`5
`O
`1
`O
`2
`O
`
`10
`11
`12
`18
`14
`15
`16
`17
`16
`19
`20
`21
`
`22
`23
`
`24
`25
`26
`27
`28
`29
`30
`31
`32
`
`M/39
`M/57
`M/41
`17/29
`MK}?
`M/24
`M/27
`M/29
`H29
`M/31
`F/59
`M/34
`
`M/33
`M/29
`
`M/41
`M/41
`F731
`M/38
`F/23
`M/39
`MB?
`M/21
`M/31
`
`19
`21
`13
`16
`9
`18
`17
`13
`13
`26
`19
`26
`
`18
`21
`
`17
`23
`14
`19
`15
`12‘
`14
`17
`17
`
`1
`1
`2
`2
`1
`2
`'2
`1
`1
`3
`1
`3
`
`1
`2
`
`2
`3
`2
`2
`2
`2
`3
`2
`2
`
`74
`59
`60
`68
`65
`55
`69
`61
`48
`86
`65
`75
`
`70
`68
`
`58
`52
`65
`52
`65
`63
`53
`70
`82
`
`3
`4
`4
`4
`4
`3
`4
`4
`3
`3
`4
`4
`
`3
`3
`
`3
`3
`4
`4
`4
`4
`3
`4
`3
`
`1
`3
`2
`2
`3
`1
`2
`S
`1
`1
`3
`2
`
`1
`2
`
`2
`2
`2
`2
`2
`2
`1
`2
`1
`
`3
`4
`4
`4
`4
`3
`4
`4
`4
`3
`4
`4
`
`8
`3
`
`3
`3
`4
`3
`4
`4
`3
`4
`3
`
`2
`3
`2
`3
`3
`2
`2
`3
`2
`1
`3
`2
`
`1
`2
`
`2
`2
`2
`2
`2
`2
`2
`2
`2
`
`3
`4
`4
`4
`4
`3
`4
`4
`3
`3-
`4
`4
`
`3
`4
`
`3
`3
`4
`4
`4
`4
`3
`4
`3
`
`1
`4
`2
`1
`8
`1
`1
`3
`1
`1
`4
`1
`
`1
`1
`
`1
`1
`2
`2
`2
`3
`1
`2
`1
`
`3
`3
`3
`3
`3
`3
`2
`8
`3
`2
`3
`3
`
`P
`3
`
`2
`2
`3
`3
`3
`3
`3
`3
`2
`
`1
`2
`2
`1
`2
`1
`1
`2
`1
`1
`2
`1
`
`1
`
`1
`1
`1
`1
`2
`1
`1
`1
`1
`
`1
`3
`2
`2
`8
`2
`1
`3
`2
`1
`3
`1
`
`1
`
`2
`1
`2
`2
`2
`2
`1
`2
`1
`
`1
`2
`2
`2
`2
`1
`1
`2
`1
`1
`2
`1
`
`1
`1
`
`2
`1
`2
`2
`2
`2
`1
`2
`1
`
`1
`3
`2
`2
`3
`2
`2
`3
`2
`1
`3
`2
`
`1
`2
`
`2
`2
`2
`2
`2
`2
`2
`2
`2
`
`1
`2
`2
`2
`2
`1
`2
`2
`1
`1
`2
`2
`
`1
`2
`
`2
`2
`2
`2
`2
`2
`1
`2
`1
`
`2
`4
`3
`3
`4
`3
`2
`4
`3
`2
`4
`3
`
`2
`3
`
`2
`2
`3
`3
`2
`3
`3
`3
`2
`
`1
`2
`1
`1
`8
`1
`1
`2
`1
`1
`2
`1
`
`1
`1
`1
`1
`1
`1
`1
`1
`1
`
`F162)
`P(27)
`P(39)
`P(39)
`P(27)
`P(54)
`P(49l
`P(27)
`P(49)
`F(66)
`P(27)
`P(41)
`
`F(66')
`H51)
`
`H62]
`F(64)
`P(39)
`P(44)
`P(43)
`P(39)
`F(56l
`P189)
`F(64)
`
`G(95)
`F(5T)
`G(79)
`G(81)
`F(56'l
`G(95)
`G(88l
`F(62l
`G(95l
`E(100')
`F(57)
`G(88)
`
`E(100)
`G-(88)
`
`G(86)
`G(88'}
`G(81)
`G(B1)
`(3179)
`G(76‘)
`G(95)
`G(81)
`G(95)
`
`1. 3
`Bilateral
`
`1, 4
`
`6.1
`6.1
`6.1
`6.4
`5.7
`6.2
`5.4
`5.4
`6.0
`6.3
`6.5
`5.9
`6.1
`6.1
`5.9
`5.6
`6.3
`6.0
`6.1
`5.9
`6.0
`5.7
`5.9
`6.1
`6.4
`6.4
`6.6
`6.8
`6.2
`5.6
`6.1
`5.8
`5.9
`6.0
`5.7
`6.1
`
`7.4
`7.5
`7.4
`7.6
`6.5
`7.5
`7.8
`6.8
`7.0
`7.3
`7.6
`7.4
`6.9
`7,2
`6.9
`6.3
`7.5
`7.5
`7.1
`6.9
`7.4
`6.7
`7.6
`7.6
`7.6
`7.5
`7.6
`7.4
`7.5
`6.8
`7.2
`6.6
`7.2
`7.3
`7.0
`7.6
`
`15
`9
`17
`12
`18
`11
`8
`16
`20
`10
`8
`15
`23
`13
`8
`20
`12
`12
`16
`9
`10
`18
`20
`16
`8
`16
`12
`12
`15
`6
`11
`10
`10
`10
`9
`12
`
`7
`2
`7
`4
`7
`5
`3
`8
`9
`4
`4
`5
`10
`7
`4
`12
`7
`6
`8
`3
`5
`7
`10
`8
`4
`9
`7
`5
`7
`2
`4
`7
`4
`6
`5
`5
`
`0
`
`1
`O
`O
`0
`3
`O
`1
`1
`2
`
`7.8
`
`7.9
`7 .8
`7.1
`7.6
`7.0
`7.6
`7.4
`7.5
`8.0
`
`Previous treatment: 1. neglected; 2, casting in situ: 3, axial reduction. Associated deformity: 1. talonavicular subluxatlon; 2, medial cortex protruding; 3. plantar osteophyte; 4. avulsion fracture
`of posterior tuberosity. Functional assessment: X. preoperative: Y, postoperative. The numbers below each item represent the results (also see Table 2). Functional score: E. excellent: G. good;
`F, fair: P. poor. Numbers in parentheses are the actual scores. Radiographic results: T~M Angle. talonavicular angle; X. preoperative; Y. postoperative; C. uninjured foot.
`
`Table 1. Patient data
`
`Preoperative and postoperative radiographic evaluations included lateral and axial x-ray films as well as computed tomographic
`(CT) scans of both feet (Fige 1). These evaluations provided information about the congruity ofthe subtalar joint, heel height
`(Figtye 2), lateral talo-first metatarsal angle (Fige 2), [_l_4_]t1biotalar abutment, calcaneofibular abutment, talonavicular
`subluxation, widening ofthe heel, and the coronal axes ofthe hindfoot. The coronal axes of the hindfoot, evaluated with axial
`radiographs or the coronal CT scans, were measured as the angle formed between the longitudinal axes bisecting the talus and
`the longitudinal axes bisecting the calcaneal tuberosity (Figure 1). [11] Based on these findings, preoperative estimations of the
`required height for distraction in the subtalar joint, the amount ofrequired resection in the lateral prominence, and the degree of
`varus/valgus hindfoot malalignment were made. Follow—up radiographs were evaluated to determine the postoperative status of
`the hindfoot in which arthrodesis and realignment had been attempted. Degenerative changes ofthe surrounding joints were
`evaluated as well.
`
`Page 4 of 16
`Page 4 of 16
`
`

`
`Figure 2. Lateral view of foot. Heel heightequals the calcaneal height plus the talar height (the distance from A to Alprimel). The lateral talo—first metatarsal angle is formed byline B—C and C-
`D.
`
`Mn .<;/1/‘ff
`
`F3
`
`Each patient's progress was analyzed using a clinical assessment rating system (Table 2) and radiography. The clinical
`
`assessment system included a subjective and an objective evaluation. [_l§1 The radiographic results were evaluated on the basis
`
`of calcaneal height, tahis-first metatarsal angles, and orientation ofthe coronal axes of the hindfoot.
`
`Page 5 of 16
`Page 5 of 16
`
`

`
`
`
`Subjective (70 points}
`
`Objective (38 points)
`
`
`
`Score ItemItem Score
`
`
`
`
`
`Pair:
`
`None
`
`Miid
`
`Moder'ate
`
`Severe
`
`Activity limitation
`None
`
`Mild
`
`Moderate
`
`Severe
`
`Work
`
`Same job
`Same with l'i3Sli"lC3llOf‘t
`
`Change job
`None
`
`Shoe wear
`
`No limitation
`
`Wider, flat
`
`(3ustorn~rnade
`
`20
`
`15
`
`10
`
`5
`
`20
`
`15
`
`10
`
`5
`
`20
`15
`
`10
`5
`
`TD
`
`8
`
`4
`
`Ankie motion
`
`100 to 85%
`
`85 to 70%
`
`Less than '?U%
`
`Foot motion
`100 to 75%
`
`75 to 50%
`
`Less than 50%
`
`Hindfoot axis
`
`Neutral mild vaigue
`Mild varus
`
`Moderate varus
`Severe varus
`
`10
`
`8
`
`4
`
`10
`
`8
`
`4
`
`ti")
`8
`
`4
`0
`
`;‘::-96; good, 95-—»-76; fair,
`
`75~———50; poor,
`
`Scoring System: excellent,
`«.2150.
`
`Table 2. Clinical assessment rating scale (100 points)
`
`Back to Top
`
`Operative Procedures
`
`The patient was placed in a lateral decubitus position. A 5—cm to 7-cm transverse incision, centered on the sinus tarsi and
`
`parallel to the subtalar joint, was made to expose the lateral subtalar joint and the peroneal tendons. The peroneal tendons and
`
`the skin flap on the lateral cortex ofthe calcaneus were subperiosteally stripped and elevated as a whole (Figure 3). After
`
`subperiosteal dissection ofthe lateral cortex of the calcaneus, the lateral cortex was exposed from the calcaneocuboid joint to
`
`the posterior tuberosity with a deep skin retractor. An ostectomy on the protruding lateral cortex of the calcaneus was
`
`performed from the superiolateral margin of the calcaneus to the plantar and posterior portion of the calcaneus. The
`
`calcaneofibular abutment and peroneal tendon entrapment were then corrected. The subtalar joint space was exposed with a
`
`lamina spreader placed in the sinus tarsi to distract the subtalar joint. A medial subtalar capsulotomy was then performed via this
`
`lateral approach to allow for distraction. An adequate medial subtalar capsulotomy during the distraction from the lateral side of
`
`the subtalarjoint was crucial to avoid further aggravation ofthe hindfoot Varus. The medial subtalar joint space was widely
`
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`distracted to be higher than the lateral joint space. By doing this, the coronal varus deformity was corrected. This procedure
`was performed gently under direct vision to avoid damage to the medial structures. After removal ofthe articular cartilage of the
`subtalar joint, an iliac bone graft, about 1.5 to 2.5 cm inthickness, a wedge—shaped graft that had been oriented so that its
`thickest dimensions were located medially and posteriorly, was inserted at the posterior facet to maintain the distraction. The
`coronal rnalalignment of the hindfoot was simultaneously corrected by adding the medial or lateral height of the wedge bone graft
`to correct the varus or valgus deformity. While inserting a lateral wedge bone graft fiom the lateral subtalar joint space, an
`overdistraction ofthe subtalar joint is necessary to open it as high as the medial edge of the bone graft. Otherwise, it would be
`difficult to insert a lateral wedge bone graft from the lateral side. An anteriorly tapered wedge- shaped graft was used to tilt the
`talus and assist in the distraction ofthe sagittal plane, thus decreasing the tibiotalar abutment and reducing the talonavicular joint
`(Figge 3). The anterior and medial facets ofthe subtalar joints were filled with a cancellous chip bone graft. Once the
`distraction and the realignment were accomplished with the wedge bone graft, fixation was made by inserting a cancellous screw
`(6.5 mm), which was placed in lag fashion, from the posteroinferior cortex of the calcaneal tuberosity, upwardly penetrating the
`bone graft and ending at the talar neck (Figrge 4). While the screw was being inserted, the foot was placed in a dorsiflexion
`position to achieve better postoperative dorsiflexion of the ankle. Ifthe foot is put in a plantar flexion position, the subtalar and
`Chopart's joints may be pushed too far in the plantar direction in relation to the talus, which will result in a decrease iii the range
`of maximal dorsiflexion of the foot.
`
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`Figure 3. (A-C) Operative procedure, lateral view. (A) Skin incision; (B) subtalar distraction with a laminar spreader; (C) subtalar distraction arthrodesis with an anterior wedge bone graft and
`a cannulated screw. The postoperative hindfoot height was increased and talonavicular suhluxation was reduced. (D—F') Operative procedure, axial view. (D) The preoperative eoro nal axes were in
`varus defn rmity. The lateral eortexwas exposed with the suhperiosteal elevation of the skin flap. The protruding cortex was removed completely. (E) The subtalar joint was distracted with the
`laminar spreader. The coronal axes were adjusted into a mild valgus position after a complete medial subtalar capsulotomy to allow more distraction on the medial suhtalarjoint. (F) The valgus
`position was maintained with a wedge bone graft and fixed with a cannulatetl screw. The postoperative hindfnot axis was neutral to mild valgus.
`
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`

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`
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`Figure 4. (A and B) Preoperative and postoperative raentgenograms of a 38-year-old female patient. The talonnvicular suhluxation and anterior tibiotalar abutment were reduced after subtalar
`distraction arthrodesis. Gain in height was 1.5 cm. (C and D) Axial roentgenograms of preoperative and postoperative ealcancus demonstrating thatthe coronal axes were corrected from varus
`to neutral.
`
`Additional procedures included plantar osteophyte resection (eight cases) and medial protruding cortex resection with posterior
`tarsal tunnel release (four cases), made from another incision with the patient in a prone position. In three cases with avulsion
`
`fiactures ofthe posterior tuberosity, a posterolateral incision was made for the distal advancement of the insertion ofthe Achilles
`Page 9 of 16
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`

`
`tendon (Fjggre 5).
`
`Figure 5. (A) Lateral roentgenogram of a 44-year-old male patient, demonstrating subtalar arthritis, loss of heel height, decreased talar inclination, and avulsion of posterior tuherosity. (B)
`Postoperative roentgenogram demonstrating the solid subtalar fusionwith increase of calcaneal height (1.2 cm). The Achilles tendon was reattached with a screw after osteoto my. (C)
`Postoperative CT scan demonstrating solid fusion with mild valgus in the coronal plane.
`
`A strap plaster splint was applied for 2 weeks, followed by an ankle-foot orthosis brace until subtalar union was observed
`radiographically. The brace was removed for bathing, and active-motion exercise were encouraged soon after the operation.
`Partial weight-bearing, as tolerated, was allowed 8 weeks after the operation until subtalar union was achieved.
`
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`RES ULTS
`
`Follow-up analysis of 32 patients, including 4 patients with bilateral involvement, was obtained at a mean follow-up of 64
`months (range, 52-86 months). Solid subtalar fusion was achieved in 31 patients with a mean fusion time of 11.8 weeks (range,
`
`8-20 weeks).
`
`Four patients in the series received an additional medial cortex resection. Three of these four patients had complete relief of
`
`symptoms, and one had persistent mild numbness. In one ofthe four patients, the flexor hallux longus was noted to be
`completely entrapped inside an osteophyte, and the posterior tibial nerve was highly tented by the osteophyte. After medial
`cortex osteotomy, the range of motion ofthe first metatarsophalangeal joint was greatly improved and numbness along the
`
`posterior tibial nerve was relieved. Nine cases oftalonavicular dorsal subluxation were noted. The subluxated joint was
`completely reduced after increasing the height of the calcaneus in seven of the nine patients (Figu_re 4 and Figge 6). The
`
`remaining two patients had mild residual subluxation attributable to inadequate distraction
`
`Figure 6. Lateral roentgenogrnms of preoperative (A) and postoperative (B) calcaneal ma|uni0n. The gain in height was 2.0 cm.
`
`Two superficial wound infections occurred and were treated with antibiotics without complication There was no wound
`disruption or neuroma formation There were two cases of screw penetration through the talar neck with resulting anterior ankle
`pain and three cases of plantar heel pain at the point of insertion ofthe screw. These problems subsided when the screw was
`removed after radiographic evidence of fusion was obtained. Nonunion occurred in one patient because of inadequate
`
`decortication of the talus. Additional secondary bone grafting achieved solid fusion 10 weeks later, and the patient was later
`
`graded as having a "fair result" in the review.
`
`Radiographic assessment revealed an average increase in calcaneal height of 11.8 mm (range, 7-18 mm) in the 32 patients
`(Table 1). The talus-first metatarsal angle was measured, revealing an average decrease of 11 degrees (range, 6-20 degrees).
`
`The average correction inthe coronal axes was about 17 degrees (range, 9-23 degrees). No degenerative changes were
`detected in the neighboring joints of the foot.
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`

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`In subjective functional assessment, 12 patients were free ofpain after work or exercise, 14 had mild discomfort, 6 had
`moderate pain, and none had severe pain. Five patients resumed preinjury sports, 21 patients could run slowly without pain, and
`6 patients could walk well but were unable to jump or run. Sixteen patients returned to their previous jobs, eight returned to the
`same job with some new restrictions on activities, six changed jobs, and two remained unemployed. The average time for return
`to work was 8 months (range, 5- 11 months) after surgery. Twenty- four patients had no limitations in selecting footwear;
`
`however, eight patients continued to wear wider shoes.
`
`The ranges of motion ofthe ankle joint after operation, compared with the uninjured side, were greater than 85% in 16 patients,
`85 to 75% in 14 patients, and 70% in 2 patients. The range of foot motion includes both forefoot and midfoot motion are.
`The range of foot motion (including forefoot and rnidfoot) was 75 to 100% in 24 patients and 50 to 75% in 8 patients. The
`coronal axes of the hindfoot[151 were mild valgus or neutral in 26 patients, mild varus (less than 5 degrees) in 4 patients, and
`
`moderate varus in 2 patients.
`
`The overall functional outcome was rated as excellent or good in 26 patients and as fair in 6 patients (Table 1). The mean
`functional score was 47.4 (of a possible 100) preoperatively and 80.1 postoperatively. The six patients with fair results had
`severe preoperative deformity. The patients with fair functional results expressed a need for analgesics occasionally; however,
`they appreciated the improvement surgery had achieved.
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`
`Statistical Analysis
`
`The mean postoperative functional score of 80.1 was significantly better than the mean preoperative score of 47.4 (p < 0.05).
`The mean postoperative hindfoot height of 7.2 cm showed significant improvement over the mean preoperative hindfoot height
`
`of6.0 cm (p < 0.05) (Table 3).
`
`Preoperative
`
`Postoperative
`
`Improvement
`
`Functional Score
`
`417.4
`
`83.1
`
`35.7
`
`Heel height (Cm)
`
`5.05
`
`7'23
`
`1.18
`
`(p
`
`0.001)
`
`(p «:5, 0.001)
`
`Thirty-two patients received follow~up.
`
`Table 3. Data of mean postoperative improvement
`
`The relationship between the value ofthe distraction and the fiinctional results was analyzed. The patients with excellent or good
`results were classified as group G, and the patients with fair results were classified as group F. The heel height was defined as
`the sum of the height of the talus and the calcaneus (Figge 2). The achievement of correction (%) of heel height was defined as
`the value of subtalar distraction (postoperative heel height minus preoperative heel height) divided by the preoperative loss of
`
`heel height (uninjured heel height minus preoperative heel height). The achievement ofcorrection (%) of heel height and the
`
`postoperative ftmctional score in groups G and F were compared using the chi squared test. A p value < 0.05 was considered
`statistically significant. The average postoperative functional score was 89.8 for group G and 59 for group F. The achievement
`
`of correction was 83.8% in group G and 47.6% in group F. The achievement of correction was significantly better in group G
`
`than in group F (p < 0.05) (Table 4 and Table 5).
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` ———xj
`
`Overall
`
`‘Preoperative
`5.99
`
`Heel Height (cm)
`
`lsostoperative
`7.16
`
`Functional Score
`
`Control
`7.61
`
`Preoperative
`47.8
`
`Postoperative
`80.1
`
`89.8
`58.4
`7.58
`7.27
`6.02
`Group (3
`
`Group F 59 5.87 6.75 7.72 27.3
`
`
`
`
`
`Overall, 28 patients with unilaterai calcaneal malunion. Group (3, patients graded as excellent and good, excluded the bilaterally involved
`22). Group F, patients graded as fair (n = 6). Control, uninjured normal foot (n 2 28).
`
`(n
`
`Ta ble 4. Comparison of heel height and functional score
`
`
`
`Loss of height
`(Gm)
`
`Distraction
`(cm)
`
`Achievement
`of Correction (%)
`
`Postoperative
`Functional Score
`
`80.1
`72.7
`1.17
`1.61
`Overall (n 2 28)
`89.8
`80.1
`1.25
`1.56
`.
`Group G (n
`22)
`
`Group F (n 2 6) 59 1.85 0.88 47.6
`
`
`
`
`Overall, 28 patients with unilateral calcaneal malunion. Group G, patients graded as excellent and good, exoiuded the bilaterally involved
`22). Group F, patients graded as fair (n 2: 6). Correction (%) = subtalar distraction + loss of height [(postoperative height minus preoperative
`(n
`height) + (uninjured height minus preoperative height)].
`
`Table 5. Comparison of postoperative correction of heel height and functional score
`
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`
`DIS CUS S ION
`
`Although in situ subtalar or triple arthrodesis has been a mainstay in the operative treatment ofcalcaneal malunion with
`osteoarthritis, few studies with long-tenn results have been reported that included data on anatomic restoration of the calcaneus
`coupled with the arthrodesis. Poor clinical results in acute calcaneal fracture attributable to anatomic abnormalities have been
`noted. The abnormalities include inadequate reduction ofjoint congruity, height, width, length, and alignment. In treating a
`calcaneal malunion associated with these abnormalities, therefore, anatomic restoration of the calcaneus with a subtalar
`arthrodesis should be emphasized. £l_3] In our study, we performed the distraction subtalar arthrodesis with a wedge bone graft
`and osteotomy on the lateral calcaneal extrusion in an attempt to restore the normal calcaneal height, width, and alignment. After
`follow-up of 4 to 7 years (average, 5 years), the functional scoring system revealed a high rate of satisfaction.
`
`A decortication ofthe subtalar articular surface in an in situ subtalar fusion without distraction will actually decrease the heigit of
`
`the hindfoot and the space between the calcaneus and the malleoli. Wang and Okereke, L10] in a cadaver study, found that the
`forces across the gastrocnemius-solcus were increased in calcaneal malunion because ofthe loss of height that induced a
`decrease in both the talar inclination and the moment arm of the Achilles tendon. After distraction of the subtalar joint in a
`
`collapsed calcancus, the talar inclination was increased and the foot position was shifted to a position of greater plantar flexion
`(F igu_rc 4A, and Figge 4B). The distraction of the subtalar joint with a wedge bone graft in the present series is thus the key not
`only to treating subtalar arthritis but also to rcestablishing a normal relationship at the talocalcaneal joint, increasing the height of
`the hindfoot, reducing the talonavicular subluxation, eliminating the tibiotalar neck abutment, increasing the malleolicalcaneus
`space, and restoring the arch ofthe foot. |l,2,9,l7] These geometrical reconstructions also lead to the restoration of normal
`gastrocnemiussoleus function £10] In the present series, patients with excellent and good results (group G) had a higher rate of
`correction ofthe subtalar joint than patients with fair results (group F) (p < 0.001) (Table 4 and Table 5).
`
`Malposition of the heel caused by improper subtalar fusion may contribute to poor results. |l8,l9| If the subtalar joint is fi,1S€Cl
`a varus position, it will lock the transverse tarsal joint, resulting in a rigid forefoot. l6,l 8,20] To prevent this complication, a
`medial subtalar capsulotomy was routinely performed to make the medial subtalar space higher than the lateral space, and this
`tilt was maintained by inserting a wedge bone graft that tapered laterally. The coronal axis of the hindfoot was thus fused in a
`mild valgus position Because the medial subtalar capsulotomy was complete, we achieved the necessary distraction and
`correction for coronal alignment simply by using a laminar spreader from the lateral incision (Figure 3B). No temporary
`intraoperative external skeletal distractor from the medial hindfoot, as mentioned in the previous reports, jl,_l_21 was needed in
`our series. A potential advantage of medial subtalar capsulotomy was the incidental tenolysis ofthe flexor hallux longus, which
`
`in
`
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`
`occasionally is entrapped in scar tissue or a protruding fragment. [2l_] Kalamehi and Evans mentioned the use of bone grafting to
`align the coronal axes while performing a posterior subtalar fusion, jl_7]_ but without any increase in height. In the present series,
`the laterally or medially tapered wedge bone graft not only increased the heel height but also corrected the varus/valgus
`deformity of the hindfoot.
`
`The lateral talocalcaneal angle is a reliable measurement for the assessment ofplanovalgus deformity. iii] In calcaneal rnalunion,
`this angle reflects the changes in calcaneal height and talar inclination. {I} In our study, the talus— first metatarsal angle was used
`instead ofthe lateral talocalcaneal angle, because the lateral talocalcaneal angle is not reliable if the calcaneus is deformed.
`Changes in the talus— first metatarsal angle depended on the amount of subtalar distraction, which was maintained by the height of
`the bone graft (Figire 4A, and Figure 4B). In the sagittal plane, ifthe graft was designed in an anteriorly tapered wedge shape, it
`could also increase the talar inclination as well as the distraction. A good correction was thus achieved both in the talus-first
`
`metatarsal angle and the dorsal subluxation ofthe talus on the navicular (Figge 4A, and Figure 4B).
`
`The lateral calcaneal extrusion is a common source of pain in cases of calcaneal malunion. Ostectomy ofthe lateral protrusion of
`
`the calcaneal wall is effective in treating calcaneofibular impingement and peroneal tendinitis. |22,23,| This procedure is
`
`necessary for restoring the calcanealwidth, and it has been considered to be an important adjuvant to arthrodesis.
`
`l2.l7,23
`
`No patient in this series had residual complaints in the lateral hindfoot. This aspect ofthe procedure also results in more
`
`comfortable use of footwear. Prominent deformity ofthe medial cortex, causing the entrapment ofthe flexor tendons and the
`posterior tibial nerve, has rarely been described before. I 12,21 ,24,25 An additional ostectomy ofthe medial hindfoot was
`indicated when posterior tarsal tunnel syndrome was detected. After medial decompression, pain reliefwas significant.
`
`In this series, 97% ofpatients achieved subtalar union in a single operation, with an average union time of ll .8 weeks. The good
`results were achieved with the extensive decortication of all the articular surfaces ofthe subtalar joint, bone grafting, and the use
`
`of a 6.5~mm-diameter cancelleous screw with rigid compression The anterior and medial fleets should be filled with cancellous
`
`bone graft chips in an attempt to secure a solid subtalar fusion After observing complications associated with single— screw
`breakage, Carr et al advised using two screws for fixation. [_l_] This complication did not occur in our series, however, although
`
`we used single-screw fixation and bone grafting in every facet joint.
`
`In most cases, an incision that parallels the lateral subtalar joint line was used instead of a longitudinal posterolateral Gallie—type
`
`approach[2] (Figme 2A). The modification of the skin incision in this series provided the advantages of less soft-tissue
`
`dissection, good vision of the subtalar joint, superior accessibility in approaching the medial subtalar capsule and the
`
`sustentaculum talus, and decreased likelihood of damage to the sural nerve. The problem of soft—tissue closure alter subtalar
`
`distraction was minimal because the soft tissues ofthe lateral aspect of the hindfoot had been expanded by the protruding
`
`defonnity of the lateral cortex.
`
`The subtalar joint makes some contribution to the range of plant