modified step-cut medial malleolar osteotomy for osteochondral grafting of the talus

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FOOT &ANKLE INTERNATIONAL Copyright © 2008 by the American Orthopaedic Foot & Ankle Society DOI: 10.3113/FAI.2008.1107 Modified Step-Cut Medial Malleolar Osteotomy for Osteochondral Grafting of the Talus Keun-Bae Lee, MD, PhD; Hyun-Kee Yang, M.D; Eun-Sun Moon, MD, PhD; Eun-Kyoo Song, MD, PhD Gwangju, Korea ABSTRACT Background: Osteochondral grafting for the treatment of osteo- chondral lesions of the talus (OLT) usually requires a medial malleolar osteotomy (MMO) to achieve adequate intraartic- ular exposure. This study describes the technique used and the results obtained using a modified step-cut MMO for osteo- chondral grafting of talar dome lesions. Materials and Method: Eleven feet in ten patients underwent modified step-cut MMO prior to osteochondral grafting for OLT. The patients included three women and seven men with a mean age of 40 (range, 20 to 51) years. Modified step-cut MMO consisted of an oblique osteotomy, which was made at approximately 45 degrees to the transverse plane of the proposed traditional step-cut osteotomy, and a vertical osteotomy to the axilla on the medial tibial plafond. Results: In all patients, modified step-cut MMO provided better perpendicular access to lesions than traditional step-cut osteotomy. In all cases, the osteochondral graft plug was accurately set perpendicular to the defect area, and all ten patients experienced uncomplicated osteotomy healing at a mean 8 weeks postoperatively without loss of reduction or malreduction. Conclusion: Modified step-cut MMO is an excel- lent, reproducible method for perpendicular access to a talar dome lesion. Level of Evidence: IV, Retrospective Case Study Key Words: Modified Step-Cut Medial Malleolar Osteotomy; Osteochondral Grafting; Osteochondral Lesion of the Talus No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. Corresponding Author: Keun-Bae Lee, MD, PhD Department of Orthopedic Surgery Chonnam National University Medical School & Hospital 8 Hakdong, Donggu, Gwangju, 501-757 Korea E-mail: [email protected] For information on prices and availability of reprints, call 410-494-4994 x226 INTRODUCTION Osteochondral grafting for the treatment of osteochon- dral lesions of the talus (OLT) usually necessitates medial malleolar osteotomy to achieve adequate intraarticular expo- sure. Technical options that have been described for medial malleolar osteotomy include straight transverse, inverted U or V shape, crescentic, oblique, chevron and step- cut osteotomy. 1,3,5 10 However, these approaches with the exception of oblique, chevron and step-cut osteotomy, provide limited exposure, because the osteotomy is at or below the level of the ankle joint. Recently, most surgeons have described using an oblique or step-cut osteotomy. 9,11 The former is a straightforward procedure and provides wide exposure, but has the disadvantages of nonunion, rota- tional deformity, and translation. 8 On the other hand, a step-cut osteotomy provides wide exposure, a broad cancel- lous surface for healing and has greater intrinsic stability. 1,9 However, osteochondral autografting requiring perpendicular access to a chondral defect is sometimes compromised during step-cut osteotomy, especially for centrally extended postero- medial lesions. 4 To address this disadvantage, we developed a modified step-cut osteotomy, which provides perpendicular access for osteochondral autografting and yet maintains the advantages of a traditional step-cut osteotomy. MATERIALS AND METHODS A retrospective review of 32 consecutive osteochondral autograft procedures for OLT performed at our institution from October 2004 to September 2006, identified 11 feet in ten patients that underwent a modified step-cut medial malleolar osteotomy. The patients included three women and seven men of mean age 40 (range, 20 to 51) years. One patient underwent bilateral procedures. Candidates for osteochondral grafting were selected based on the following criteria: the finding of a chondral lesion by MRI or the suspicion of an osteochondral lesion based on medical history and physical examination, no improvement of symptoms 1107 at TOBB Ekonomi ve Teknoloji Üniversitesi on December 21, 2014 fai.sagepub.com Downloaded from

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Page 1: Modified Step-Cut Medial Malleolar Osteotomy for Osteochondral Grafting of the Talus

FOOT & ANKLE INTERNATIONAL

Copyright © 2008 by the American Orthopaedic Foot & Ankle SocietyDOI: 10.3113/FAI.2008.1107

Modified Step-Cut Medial Malleolar Osteotomy for Osteochondral Grafting ofthe Talus

Keun-Bae Lee, MD, PhD; Hyun-Kee Yang, M.D; Eun-Sun Moon, MD, PhD; Eun-Kyoo Song, MD, PhDGwangju, Korea

ABSTRACT

Background: Osteochondral grafting for the treatment of osteo-chondral lesions of the talus (OLT) usually requires a medialmalleolar osteotomy (MMO) to achieve adequate intraartic-ular exposure. This study describes the technique used andthe results obtained using a modified step-cut MMO for osteo-chondral grafting of talar dome lesions. Materials and Method:Eleven feet in ten patients underwent modified step-cut MMOprior to osteochondral grafting for OLT. The patients includedthree women and seven men with a mean age of 40 (range,20 to 51) years. Modified step-cut MMO consisted of anoblique osteotomy, which was made at approximately 45 degreesto the transverse plane of the proposed traditional step-cutosteotomy, and a vertical osteotomy to the axilla on the medialtibial plafond. Results: In all patients, modified step-cut MMOprovided better perpendicular access to lesions than traditionalstep-cut osteotomy. In all cases, the osteochondral graft plugwas accurately set perpendicular to the defect area, and allten patients experienced uncomplicated osteotomy healing ata mean 8 weeks postoperatively without loss of reduction ormalreduction. Conclusion: Modified step-cut MMO is an excel-lent, reproducible method for perpendicular access to a talardome lesion.

Level of Evidence: IV, Retrospective Case Study

Key Words: Modified Step-Cut Medial Malleolar Osteotomy;Osteochondral Grafting; Osteochondral Lesion of the Talus

No benefits in any form have been received or will be received from a commercialparty related directly or indirectly to the subject of this article.

Corresponding Author:Keun-Bae Lee, MD, PhDDepartment of Orthopedic SurgeryChonnam National University Medical School & Hospital8 Hakdong, Donggu,Gwangju, 501-757KoreaE-mail: [email protected] information on prices and availability of reprints, call 410-494-4994 x226

INTRODUCTION

Osteochondral grafting for the treatment of osteochon-dral lesions of the talus (OLT) usually necessitates medialmalleolar osteotomy to achieve adequate intraarticular expo-sure. Technical options that have been described for medialmalleolar osteotomy include straight transverse, invertedU or V shape, crescentic, oblique, chevron and step-cut osteotomy.1,3,5–10 However, these approaches with theexception of oblique, chevron and step-cut osteotomy,provide limited exposure, because the osteotomy is at orbelow the level of the ankle joint. Recently, most surgeonshave described using an oblique or step-cut osteotomy.9,11

The former is a straightforward procedure and provideswide exposure, but has the disadvantages of nonunion, rota-tional deformity, and translation.8 On the other hand, astep-cut osteotomy provides wide exposure, a broad cancel-lous surface for healing and has greater intrinsic stability.1,9

However, osteochondral autografting requiring perpendicularaccess to a chondral defect is sometimes compromised duringstep-cut osteotomy, especially for centrally extended postero-medial lesions.4 To address this disadvantage, we developeda modified step-cut osteotomy, which provides perpendicularaccess for osteochondral autografting and yet maintains theadvantages of a traditional step-cut osteotomy.

MATERIALS AND METHODS

A retrospective review of 32 consecutive osteochondralautograft procedures for OLT performed at our institutionfrom October 2004 to September 2006, identified 11 feetin ten patients that underwent a modified step-cut medialmalleolar osteotomy. The patients included three womenand seven men of mean age 40 (range, 20 to 51) years.One patient underwent bilateral procedures. Candidates forosteochondral grafting were selected based on the followingcriteria: the finding of a chondral lesion by MRI or thesuspicion of an osteochondral lesion based on medical historyand physical examination, no improvement of symptoms

1107

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1108 LEE ET AL. Foot & Ankle International/Vol. 29, No. 11/November 2008

after 3 months or more of nonoperative treatment, and atalus lesion size of more than 1.5cm2 by arthroscopy. Meanlesion size in the ten study subjects was 1.8 (range, 1.5 to2.4) cm2. Donor grafts (6-, 8-, or 10-mm diameter and 10 to15 mm deep) were harvested from the upper lateral femoralcondyle of the ipsilateral knee. Ten feet received two graftsand one 3 grafts. Average followup was 14.5 (range, 12.0 to20.2) months.

The followup examinations were performed at 3, 6, 9, 12,and 18 months postoperatively. Clinical evaluation includedpain at the osteotomy site, intraoperative tendon injury,range of motion of the ankle and complications. Unionrate, time to union, loss of reduction and malreduction wereevaluated radiologically. Radiographic union was defined asthe appearance of osseous trabeculae across the osteotomysite. The criteria of clinical union included absence of paincrepitus during ambulation.

Operative technique

We performed diagnostic arthroscopy and investigated thesizes and shapes of medial talar lesions, and when medialmalleolar osteotomy was deemed necessary, it was performedas described below.

The anterior and medial aspects of the medial malleoluswere exposed through an incision slightly anterior to midlineand curved at the malleolus. Two holes were drilled in themedial malleolus with a 2.5-mm drill directed proximallyand laterally toward the apex of the proposed osteotomyto facilitate fragment reduction. A Kirschner wire was thenplaced at the apex of the osteotomy; approximately 1.5 cmabove the anterior margin of the distal tibia at the ankle jointand directed from anterior to posterior to prevent extension ofthe osteotomy. The oblique osteotomy was performed usinga microsagittal saw. It began at the medial edge of the tibialcortex and was aimed obliquely inferiorly and laterally tomake an approximately 45 degree angle to the transverseplane of the proposed traditional step-cut osteotomy. Duringthis procedure, the tibialis posterior tendon was protected.This osteotomy was joined by a vertical osteotomy to theaxilla on the medial tibial plafond. The proximal two thirdsof the vertical plane was then cut using the microsagittal sawand then the distal one third using an osteotome (Figure 1and 2). The osteotomized medial malleolus was then reflectedplantarward on the deltoid ligament, to expose the medialaspect of the talar dome. A medial talar lesion could beaccessed more perpendicularly than is possible with a step-cut osteotomy (Figure 3).

Autograft donor cylinders were harvested from the upperlateral condyle of the ipsilateral knee. Transplantations wereperformed using an osteochondral autograft transfer system(OATS; Arthrex, Naples, FL) and the press-fit technique2

(Figure 4). Subsequently, the malleolus was returned to itsoriginal position, and fixed with compression using two 4.0cancellous lag screws (Figure 5).

Fig. 1: Diagram of the surgical technique of modified step-cut osteotomy.A Kirschner wire is placed at the apex of the osteotomy, approximately 1.5cm above the ankle joint to prevent extension of the osteotomy. An obliquecut of modified step-cut osteotomy (solid line) is made at about 45 degreesobliquely to the transverse plane of a traditional step-cut osteotomy (dottedline)(left). The proximal two-thirds of the vertical plane is cut using amicrosagittal saw and then the distal one-third using an osteotome (right).

Fig. 2: Intraoperative photograph showing modified step-cut medial malle-olar osteotomy.

Postoperatively, a short leg splint was applied and afterthe sutures were removed, a short leg non weightbearingcast was applied. At 4 weeks, an ankle foot orthosiswas fitted and range of motion exercise was encouragedwith non weightbearing for 2 weeks, followed by gradualweightbearing. Full weightbearing was allowed after union.

RESULTS

Intraoperatively, osteochondral grafting with a moreperpendicular access angle than achieved by traditional step-cut osteotomy was achieved in all cases. Osteochondral graftplugs were accurately set perpendicularly to defect areas.Moreover, all ten patients achieved uncomplicated osteotomyunion at a mean of 8 weeks (7 to 10) postoperatively withoutloss of reduction (Figure 5B). No patient complained of anypain or discomfort at the medial malleolar osteotomy siteat final followup. No complications such as intraoperative

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Foot & Ankle International/Vol. 29, No. 11/November 2008 MEDIAL MALLEOLAR OSTEOTOMY 1109

A B

Fig. 3: Three-dimensional projection of modified step-cut osteotomy (A) showing easier perpendicular access to the talar dome lesion than traditional step-cutosteotomy (B).

Fig. 4: Photograph showing osteochondral graft plugs were accurately setperpendicular to the osteochondral defect of the talus.

tendon injury, ankle joint stiffness or postoperative infectionwere observed.

DISCUSSION

Various medial malleolar osteotomies have been describedfor the osteochondral grafting of medial talar domelesions.1,3,5–10 The osteotomy should satisfy the followingconditions: excellent lesion exposure, perpendicular accessto lesions, and osteotomy site stability. The senior author(KBL) felt that step-cut osteotomy best met these require-ments, and thus, has consistently used a step-cut osteotomyover the past 3 years.

Traditional step-cut osteotomy, as described by Alexanderand Watson,1 provides wide exposure, greater intrinsicstability, and offers a broad cancellous surface for healing.

A B

Fig. 5: Diagram (A) showing internal fixation of medial malleolar osteotomy using two 4.0 cancellous screws and followup radiograph (B) demonstratinguncomplicated osteotomy union.

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1110 LEE ET AL. Foot & Ankle International/Vol. 29, No. 11/November 2008

Thordarson and Kaku9 reported that in 14 patients, the step-cut medial malleolar osteotomy was followed by uncompli-cated osteotomy healing at 6 weeks postoperatively, withoutloss of reduction, and no patient complained of any pain atthe malleolar osteotomy site at latest followup. However,perpendicular access to a lesion is sometimes compro-mised when this technique is used, especially for centrallyextended posteromedial lesions because the medial edge ofthe tibial cortex in the transverse osteotomy plane oftenprevents perpendicular access by instrumentation for osteo-chondral grafting. Accordingly, we developed the modifiedstep-cut osteotomy technique which provides easy perpen-dicular access to lesions.

A number of technical actions greatly facilitated thisexposure. The osteotomy irritates the articular surface in analready compromised region of the ankle joint. Thus, weperformed the osteotomy at the site of the axilla on the medialtibial plafond. To make the osteotomy easily and precisely,the proximal two thirds of the vertical plane was cut usinga microsagittal saw and then the distal one-third using anosteotome. During the oblique plane osteotomy, the posteriortibial tendon and neurovascular structures were retracted andprotected.

The described modified step-cut medial malleolarosteotomy was found to provide excellent exposure of theentire medial talar dome and better perpendicular access tolesions while maintaining the advantages of the traditionalstep-cut osteotomy.

REFERENCES

1. Alexander, IJ; Watson, JT: Step-cut osteotomy of the medialmalleolus for exposure of the medial ankle joint space. Foot Ankle11:242– 243, 1991.

2. Baltzer, AW; Arnold, JP: Bone-cartilage transplantation from theipsilateral knee for chondral lesions of the talus. Arthroscopy21:159– 166, 2005. http://dx.doi.org/10.1016/j.arthro.2004.10.021

3. Cohen BE, Anderson RB: Chevron-type transmalleolar osteotomy: anapproach to medial talar dome lesions. Techniques in Foot & AnkleSurgery. 1(2):158– 162, 2002. http://dx.doi.org/10.1097/00132587-200212000-00011

4. Muir, D; Saltzman, CL; Tochigi, Y; Amendola, N: Talar dome accessfor osteochondral lesions. Am. J. Sports Med. 34:1457– 1463, 2006.http://dx.doi.org/10.1177/0363546506287296

5. O’Farrell, TA; Costello, BG: Osteochondritis dissecans of the talus.The late results of surgical treatment. J. Bone Joint Surg. 64-B:494–597, 1982.

6. Oznur A: Medial malleolar window approach for osteochondral lesionsof the talus. Foot Ankle Int. 22:841– 842, 2001.

7. Ray, RB; Coughlin, EJ: Osteochondritis dissecans of the talus. J. BoneJoint Surg. 29:697– 706, 1947.

8. Spatt, JF; Frank, NG; Fox, IM: Transchondral fractures of the domeof the talus. J. Foot Surg. 25:68– 72, 1986.

9. Thordarson, DB; Kaku, SK: Results of step-cut medial malleolarosteotomy. Foot Ankle Int. 27:1020– 1023, 2006.

10. Wallen, EA; Fallat, LM: Crescentic transmalleolar osteotomyfor optimal exposure of the medial talar dome. J. Foot Surg.28:389– 394, 1989.

11. Ziran, BH; Abidi, NA; Scheel, MJ: Medial malleolar osteotomyfor exposure of complex talar body fractures. J. Orthop. Trauma. 15;513– 518, 2001. http://dx.doi.org/10.1097/00005131-200109000-00009

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