Interact Surg (2007) 2: 52–61 © Springer 2007 DOI 10.1007/s11610-007-0021-y
ORIGINAL ARTICLE
The chevron osteotomy for correction of hallux valgus H.-J. Trnka, S. Hofstaetter Fusszentrum Wien, Alserstraße 43/8D, 1080 Vienna, Autriche
Abstract: Introduction: The chevron osteotomy has become widely accepted for correction of mild and moderate hallux valgus deformities. The purpose of this study was to present the evolution of the chevron osteotomy at one institution over a period of 12 years. Methods: Between April, 1991 and September, 1992, fifty-two consecutive patients with mild to moderate hallux valgus deformity underwent sixty-six distal chevron osteotomies at our institution. This was followed by 85 patients with 100 feet in the period from 1992 to 1995 and a group of 45 patients with 55 feet from 1994 to 1995. The final patient group included 61 patients with 89 feet operated from 2000 to 2002. Conclusion: The chevron osteotomy is a reliable technique to correct hallux valgus deformities. Our recommendation after reviewing the results of the various modifications of the chevron technique revealed that the addition of a lateral release and a screw fixation will lead to the most reliable results. Keywords: Hallux valgus – Chevron
Introduction The first reports of a distal metatarsal osteotomy to correct a hallux valgus deformity date back to Reverdin [1] who described in 1881 a subcapital closing wedge osteotomy for the correction of hallux valgus deformity. The chevron osteotomy has become widely accepted for correction of mild and moderate hallux valgus deformities. In the initial reports by Austin and Leventen [2] and Miller and Croce [3] no fixation was mentioned. They suggested that the shape of the osteotomy and impaction of the cancellous capital fragment upon the shaft of the first metatarsal provided sufficient stability to forego fixation. The purpose of this study was to present the evolution of the chevron osteotomy at one institution over a period of 12 years. The technique which was originally performed between 1991 and 1992 was a simple chevron osteotomy without a lateral soft tissue release. In light of
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publications of Kitaoka in 1991 [4] and R. Mann [5], a more radical lateral soft tissue procedure was added to the originally described technique. This now more radical lateral release entailed a higher risk of postoperative head displacement which made temporary fixation necessary. The method which was chosen was the K-wire fixation. The downside of the temporary wire fixation was the necessity of the K-wire removal. So the next step was the fixation of the chevron osteotomy with a Herbert type screw.
Materials and methods Between April 1991 and September 1992, fifty-two consecutive patients with mild to moderate hallux valgus deformity underwent sixty-six distal chevron osteotomies at our institution. This was followed by 85 patients with 100 feet in the period from 1992 to 1995 and a group of 45 patients with 55 feet from 1994 to 1995. The final patient group included 61 patients with 89 feet operated from 2000 to 2002. All patients had failed non-operative management, including shoe wear modification, nonsteroidal anti-inflammatory drugs, and orthotics. All patients had moderate to severe pain related to the hallux valgus deformity. Although no patient underwent surgery for cosmesis alone, cosmetic concerns and difficulty with shoe wear secondarily influenced the patient’s decision to undergo surgery.
Clinical assessment Preoperatively patients underwent physical examination and assessment of functional limitation, pain level and range of motion of the first metatarsophalangeal joint. At both the preoperative and final follow-up, patients underwent physical examination and assessment using the modified American Orthopaedic Foot and Ankle Society’s hindfoot-metatarsophalangeal-interphalangeal scale [6]. This 100-point questionnaire, which combines subjective and objective data, includes the clinical parameters of pain (30 points), functional restriction
53 (15 points), footwear restriction (10 points), tender and painful callus (10 points), alignment (5 points), and stiffness of the metatarsophalangeal joint (5 points). Additionally, patients were asked to rate their feet for overall satisfaction and cosmesis as excellent, good, fair, or poor). The range of motion of the hallux was measured by placing one goniometer arm parallel to the hallux and the other goniometer arm parallel to the plantar aspect of the foot.
Radiographic assessment Preoperatively, and at the time of the final follow-up (at minimum 2 years), anteroposterior and lateral weightbearing radiographs were obtained. The hallux valgus angle, the first intermetatarsal angle, and the congruency of the first metatarsophalangeal joint were measured as recommended by the American Orthopaedic Foot and Ankle Society [7]. All preoperative and follow-up radiographic measurements were made by the same investigator in a blinded fashion.
Fig. 1. Skin incision over the first web space
Indications and contraindications The indication for the chevron osteotomy with lateral soft tissue release is a hallux valgus deformity with an intermetatarsal 1-2 angle up to 16˚. In case of a wide metatarsal head and shaft, this may be stretched up to 18 degrees. The lateral soft tissue release may be spared if the hallux can be manually stretched in varus and the sesamoid position is less than Grade 2. A contraindication is first metatarsophalangeal (MTP) arthritis with intraarticular pain and major first tarso-metatarsal instability. Age is generally no contraindication.
Fig. 2. Release of the metatarso-sesamoidal ligament
Surgical Technique This department’s staff and residents (under supervision) performed all procedures under peripheral nerve blockade and Esmarch tourniquet. A dorsomedial incision was made over the first metatarsophalangeal joint from midshaft of the proximal phalanx to approximately midshaft of the metatarsal, this was changed to a midside skin incision in 1992. Starting in September 1992, a lateral soft tissue release was added. The lateral soft tissue release is performed through a second dorsal skin incision over the first web space (Fig. 1). During the approach to the first web space several structures need to be looked at. The first important structure is the deep branch of the superficial peroneal nerve. The second structure is the first dorsal metatarsal artery and especially its branch the dorsomedial hallucal artery [8]. The best technique to avoid these structures is the blunt mobilisation of the soft tissues with the tip of the thumb. Once the first intermetatarsal space is widened a laminar spreader is inserted. Now the
Fig. 3. The great toe is brought into 20˚ varus to demonstrate the release of the lateral structures
lateral capsule and the adductor tendon are exposed. Then the lateral joint capsule (metatarso-sesamoid ligament) is incised horizontally just superior to the lateral sesamoid (Fig. 2). The lateral capsule is perforated at the first MTP joint line, and the great toe is forced manually into about 20˚ varus position (Fig. 3). Usually it
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Fig. 4. Medial skin incision for the osteotomy
Fig. 6. The medial eminence is minimally resected Fig. 5. Inverted L-type capsular incision
is not necessary to release the adductor tendon or the intermetatarsal ligament. One suture is placed through the lateral aspect of the first metatarsal and the medial periosteum of the second metatarsal. This suture is tied after the osteotomy is completed. The leg is now externally rotated. A second skin incision is made at the medial aspect of the first MTP joint (Fig. 4). The medial MTP joint capsule is opened with an inverted L-type incision (Fig. 5). The joint is inspected for degenerative changes. The metatarsal head is now exposed, and Hohmann retractors are placed dorsal and plantar just extraarticular of the first metatarsophalangeal joint. The plantar Hohmann retractor protects the plantar artery to the metatarsal head, and the dorsal retractor protects the dorsal intraarticular blood supply originating from the capsule. The medial eminence is now minimally shaved to achieve a plane surface but also to preserve as much metatarsal head width as possible (Fig. 6). This is one of the most important principles if a chevron osteotomy is carried out in a moderate to severe deformity. The original description described a resection of the medial eminence at this point of the surgery, with this, the
metatarsal head width was substantially reduced and the lateral shift of the metatarsal head was limited, without sacrifying stability. At this point, the V-osteotomy is planned and performed, care being taken to ensure that each cut is made precisely to give stability, which is the essence of the procedure. A 1.0 mm Kirschner wire is drilled a little bit dorsal to the centre of the exposed medial eminence. This wire is generally inclined 20˚ from medial to lateral, aiming at the head of the fourth metatarsal. In the situation of an elevated position of the first metatarsal the inclination may be increased. If shortening or lengthening of the first metatarsal is needed, the wire maybe aimed to the fifth or third metatarsal head. (Fig. 7a,b). By using a saw guide (Fig. 8) two cuts are then made with an oscillating power saw so that they form an angle of 60 degrees proximal to the drill hole. Once the capital fragment is freely mobile the metatarsal shaft is pulled medially by using a towel clip, while pushing the metatarsal head laterally with the help of the thumb of the other hand (Fig. 9). When the joint surfaces are in correct alignment and the metatarsal head is in place as planned preoperatively, the capital fragment is firmly impacted onto the metatarsal shaft. In the situation that
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Fig. 9. The metatarsal head is pushed laterally while the metatarsal shaft is pulled medially
Fig. 7a,b. A guide wire marks the apex of the osteotomy. It should be 10˚ inclined from medial to lateral, and pointing at the head of the 4th metatarsal
Fig. 10. A guide wire for the 3.0 CharlotteTM multi use compression screw (Wright Medical technology) is placed
Fig. 8. The osteotomy is performed using an osteotomy guide
the DMAA is increased, a wedge from the distal dorsal cut may be excised to place the metatarsal head in a more varus position. If there is only a minor increase of the DMAA this may also be achieved by impacting the metatarsal head onto the shaft. From 1994 to 2000 a temporary 1.4 mm K-wire is inserted from medial to lateral across the osteotomy. The K-wire is then bent on the cortex (Figs. 10-11a). From 2000
until now, a guide-wire for a cannulated Charlotte multi use compression screw (Wright Medical technology) is then inserted from the distal dorsal metatarsal shaft obliquely to lateral plantar of the metatarsal head (Fig. 11b). It is now advised to check the position of the osteotomy and the guide wire with a C-arm or a fluoroscan. The length of the screw is now measured and the screw is inserted after predrilling (Figs. 12-14). Then the medial eminence is excised in line with the metatarsal shaft, taking care not to excise too much bone off the metatarsal head. Attention is now directed towards the medial capsule, and a wedge of about 5 mm is removed from the short arm of the L-type capsular incision. While an assistant holds the great toe in a slightly overcorrected position, the medial joint capsule is repaired with u-type sutures, and the first web space sutures are tightened (Fig. 15). Starting immediately postoperatively ice application to the foot is helpful to reduce swelling. Provided that the bone quality was intraoperatively sufficient, patients are
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Fig. 13. Prepare a countersunk area with the CharlotteTM cannulated head drill
Fig. 11a,b. Length determination using the depth gauge Fig. 14. Insertion of the screw until the head is completely countersunk within the bone
Fig. 12. Predrilling with the CharlotteTM cannulated drill
allowed to walk with a postsurgical type shoe (Fig. 16) on the same day limited to 4 weeks. Weekly changes of the tape dressing are necessary. An alternative for weekly dressing changes is the postoperative hallux valgus sock which also reduces the postoperative edema (Fig. 17). Radiographs are taken intraoperatively and at 4 weeks follow-up. After radiographic union is achieved, normal dress shoes with a more rigid sole are allowed. After 4 weeks, physiotherapy is recommended to achieve normal forefoot function.
Fig. 15. Closing of the medial capsule with U-type sutures
Results Comparing the 2 year and 5 year follow-up [9] of our first 52 patients with 66 feet, 43 patients (57 feet) were available for all three assessment periods: preoperative,
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Fig. 16. Rathgeber postoperative shoe (OFA Rathgeber. Germany)
Fig. 18a. 21-year-old female patient before surgery
Fig. 17. Postoperative hallux valgus compression stocking- to use after the suture removal
two-year, and five-year follow-up. Between two and five years of follow-up, there was only a minimal change in overall patient satisfaction (23 very satisfied at two years versus 24 at five years) and average halluxmetatarsophalangeal-interphalangeal scale score (91 points each). Range of motion of the first metatarsophalangeal joint decreased from 72 degrees preoperatively to 61 degrees at the two-year follow-up and was maintained
at 62 degrees at the five-year follow-up Radiographic evaluation revealed a preoperative average hallux valgus angle of 29 degrees (range: 16 degrees to 50 degrees) and a preoperative average intermetatarsal angle of 13 degrees (range: 10 degrees to 20 degrees). At the two-year followup, the hallux valgus and intermetatarsal angles averaged 15 degrees (range, 0 degrees to 40 degrees) and 8 degrees (range: 0 degrees to 20 degrees), respectively. At the fiveyear follow-up, the hallux valgus and intermetatarsal angles averaged 16 degrees (range: 0 degrees to 40 degrees) and 9 degrees (range: 2 degrees to 20 degrees), respectively. An increase of metatarsophalangeal joint arthrosis was noted in eight feet at the two-year followup and in eleven feet between the two- and five-year follow-ups (Fig. 18a,b). Because age is still an issue in the indication for a chevron osteotomy, we compared thirty feet in patients less than fifty years old with twenty-seven feet in patients fifty years old or older. Clinically, we found no statistically significant differences between these two groups in preoperative hindfoot-metatarsophalangealinterphalangeal scale scores (P = 0.82), metatarsophalangeal flexion (P = 0.28), or metatarsophalangeal extension (P = 0.36). Analysis of the results at the twoyear follow-up revealed a limited plantarflexion in the older group (younger, 21 degrees; older, 15 degrees; P = 0.10). The older group lost an average of 11 degrees of flexion (range, 0 to 30 degrees). We found no statistically
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Fig. 18b. The same patient 2 years after surgery (original Austin without lateral release) Fig.19a. 51-year-old female patient before surgery
significant differences in metatarsophalangeal extension (P = 0.23), cosmesis (P = 0.21), or patient satisfaction (P = 0.24); however, the difference in hindfoot-metatarsophalangeal-interphalangeal scale scores was significant (P = 0.04). Similar differences were noted at the five-year follow-up. We found no statistical difference between the two age groups in metatarsophalangeal flexion (P = 0.40), cosmesis (0.134), hindfoot-metatarsophalangeal-interphalangeal scale score (P = 0.949), and patient satisfaction (P = 55); however the difference in metatarsophalangeal extension was significant (P = 0.05). Both groups had increased metatarsophalangeal flexion and lost metatarsophalangeal extension. In comparing the radiographic results (hallux valgus and intermetatarsal angles) of the thirty feet in patients aged less than fifty years with the twenty-seven feet in patients aged fifty years or more, we found no differences. Analyzing the results of the series of patients where the lateral soft tissue release was included and comparing these with the series operated according to the original Austin technique [10], a much better correction of the hallux valgus angle, intermetatarsal angle and most importantly sesamoid position was observed [11] (Fig. 19a,b).
Reviewing the results of the series of the chevron osteotomy with lateral soft tissue release and K-wire fixation on 45 patients with 55 feet, similar correction as in the group with lateral soft tissue release without fixation, no statistically significant differences were observed. The advantage to the modified technique was that after an average followup of 34 months there was no case of metatarsal head displacement or loss of correction [12] (Figs. 20a,b,c). The results of the study of patients who underwent the chevron with screw fixation revealed an average preoperative AOFAS score of 55 points (range, 10 to 88 points ± 17 SD), and 90 points (range, 29 to 100 points ± 14 SD) at the final follow-up. Range of motion of the first metatarsophalangeal joint averaged 72 degrees (range 40 to 105 ± 17 SD) preoperativel, and at follow-up 69 degrees (range, 20 to 100 degrees ± 18 SD). Radiographic evaluation revealed a preoperative average hallux valgus angle of 32 degrees (range, 20 to 48 degrees ± 6 SD) and a preoperative average intermetatarsal angle of 14 degrees (range, 10 to 20 degrees ± 3 SD). This was corrected by surgery to an average hallux valgus angle of 5 degrees (range, –14 to 40
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Fig. 20a. 5-year-old female patient before surgery
Fig. 19b. The same patient 2 years after surgery (Austin with lateral release)
degrees ± 8 SD) and an average intermetatarsal angle of 5.8 degrees (range, 0 to 12 degrees ± 3 SD) (Fig. 21a,b).
Discussion Hallux valgus correction is probably one of the most common surgeries in orthopaedic surgery. Over the last 150 years, more than 130 surgical procedures have been described. Distal osteotomies of the first metatarsal are primarily advocated for mild to moderate hallux valgus deformities. The chevron or also called Austin osteotomy is one of the gold standards for correction of mild to moderate hallux valgus deformities. The purpose of this paper was to present the scale of the modification we went through during the last 12 years since we used this technique. In the early years of this technique it was limited to patients 50 years and younger. This was represented by the study of Johnson et al. [13] which established a contraindication for using a chevron osteotomy in patients older than fifty years. Trnka [9] and Schneider [14] have proven that age is not a limiting factor for the chevron osteotomy.
Another important issue that was stretched out over the years was the combination of a lateral soft tissue release and a distal chevron osteotomy. Earlier reports have expressed concern of increased AVN if a lateral release is performed in addition to a chevron osteotomy, Jahss, Mann and Kenzora have all suggested that AVN frequently accompanies, citing incidence of up to 40%. [15-17], Pochatko [18] and Trnka [11] could not support this in their publications and found no increased AVN. The indication for the chevron osteotomy was over many years limited to mild hallux valgus deformities [19,20]. Designed primarily without fixation the concern was stability and loss of fixation. As it became more obvious that a lateral soft tissue release is important for correction of more severe deformities this concern gained weight. According to papers by Harper [21], and Sarrafian [22] lateral displacement is limited up to 50% of metatarsal width. This is certainly true for the chevron osteotomy without internal fixation. Since we use the screw fixation we were able to stretch the indication to intermetatarsal angles of up to 19˚ in the situation of a wide metatarsal head. Trnka et al. reported in 2000 [9] a series of fortythree patients (fifty-seven feet) with preoperative, twoyear, and five-year follow-up. Radiographic evaluation revealed a preoperative average HV angle of 29˚and a
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Fig. 20b. The same patient after surgery (Austin with lateral release and pin fixation)
Fig. 20c. The same patient at 2 years FV
Fig. 21a. 43-year-old female patient before surgery
Fig. 21b. The same patient 2 years after surgery (Austin with lateral release and screw fixation)
61 preoperative average IM angle of 13˚. At the two-year follow-up, the HV and IM angles averaged 15˚ and 8˚ respectively. At the five-year follow-up, the HV and IM angles averaged 16˚ and 9˚. The results at these two follow-up periods proved that the chevron osteotomy is a reliable procedure for mild and moderate hallux valgus deformity and that there are no differences in outcome based on age. Schneider et al. reported [14] in 2004 a series of 112 feet (73 patients) with a minimum follow-up of ten years. For 47 feet (30 patients), the results were compared with those from an interim follow-up of 5.6 years. The AOFAS-score improved from a pre-operative mean of 46.5 points to a mean of 88.8 points after a mean of 12.7 years. The first metatarsophalangeal (MTP) angle showed a mean preoperative value of 27.6 degrees and was improved to 14.0 degrees. The first intermetatarsal (IM) angle improved from a preoperative mean value of 13.8 degrees to 8.7 degrees. The mean pre-operative grade of sesamoid subluxation was 1.7 on a scale from 0 to 3 and improved to 1.2. Measured on a scale from 0 to 3, arthritis of the first MTP joint progressed from a mean of 0.8 to 1.7. The progression of arthritis of the first MTP joint between 5.6 and 12.7 years postoperatively was statistically significant. Excellent clinical results following chevron osteotomy not only proved to be consistent, but showed further improvement over a longer follow-up period. The mean radiographic angles were constant without recurrence of the deformity. So far, the statistically significant progression of first MTP joint arthritis has not affected the clinical result, but this needs further observation. Sanhudo [23] retrospectively reviewed 50 feet with moderate to severe hallux valgus deformity in 34 patients with a mean FU of 30 months. There was a mean AOFAS score improvement of 39.6 (44.5 to 84.1) points. The hallux valgus angle and intermetatarsal angle improved a mean of 22.7 degrees and 10.4 degrees, respectively. He concluded that the chevron osteotomy is also indicated for moderate to severe hallux valgus deformity. Over a period of 12 years we have modified and developed the chevron osteotomy. By reviewing each step of the development with clinical studies [9-12] we now perform a chevron osteotomy with lateral soft tissue release and single screw fixation. We have found that this is a reliable technique for the mild and moderate, and even severe hallux valgus deformities with a wide metatarsal head.
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2. Austin DW, Leventen EO (1981) A new osteotomy for hallux valgus: a horizontally directed ‘‘V’’ displacement osteotomy of the metatarsal head for hallux valgus and primus varus. Clin Orthop 157: 25-3 3. Miller S, Croce WA (1979) The Austin procedure for surgical correction of hallux abducto valgus deformity. J Am Podiatry Assoc 69: 110-8 4. Kitaoka HB, Franco MG, Weaver AL, Ilstrup DM (1991) Simple bunionectomy with medial capsulorrhaphy. Foot Ankle 12: 86-91 5. Mann RA, Pfeffinger L (1991) Hallux valgus repair. DuVries modified McBride procedure. Clin Orthop 213-8 6. Kitaoka HB, Alexander IJ, Adelaar RS, et al. (1994) Clinical Rating Systems for the Ankle-Hindfoot, Midfoot, Hallux, and Lesser Toes. Foot Ankle Int 15: 349-53 7. Smith RW, Reynolds JC, Stewart MJ (1984) Hallux valgus assessment: report of research committee of American Orthopaedic Foot and Ankle Society. Foot Ankle 5: 92-103 8. Jones KJ, Feiwell LA, Freedman EL, Cracchiolo A (1995) III: The effect of chevron osteotomy with lateral capsular release on the blood supply to the first metatarsal head. J Bone Joint Surg Am 77: 197-204 9. Trnka HJ, Zembsch A, Easley ME, et al. (2000) The chevron osteotomy for correction of hallux valgus. Comparison of findings after two and five years of follow-up. J Bone Joint Surg Am 82-A: 1373-8 10. Trnka HJ, Hofmann S, Salzer M, Ritschl P (1996) Clinical and radiological results after Austin bunionectomy for treatment of hallux valgus. Arch Orthop Trauma Surg 115: 171-5 11. Trnka HJ, Zembsch A, Wiesauer H, et al. (1997) Modified Austin procedure for correction of hallux valgus. Foot Ankle Int 18: 119-27 12. Muhlbauer M, Zembsch A, Trnka HJ (2001) [Short-term results of modified chevron osteotomy with soft tissue technique and guide wire fixation-a prospective study]. Z Orthop Ihre Grenzgeb 139: 435-9 13. Johnson KA, Cofield RH, Morrey BF (1979) Chevron osteotomy for hallux valgus. Clin Orthop 142: 44-7 14. Schneider W, Aigner N, Pinggera O, Knahr K (2004) Chevron osteotomy in hallux valgus. Ten-year results of 112 cases. J Bone Joint Surg Br 86: 1016-20 15. Jahss MH (1981) Hallux valgus: further considerations-the first metatarsal head. Foot Ankle 2: 1-4 16. Mann RA (1982) Complications associated with the Chevron osteotomy. Foot Ankle 3: 125-9 17. Meier PJ, Kenzora JE (1985) The risks and benefits of distal first metatarsal osteotomies. Foot Ankle 6: 7-17 18. Pochatko DJ, Schlehr FJ, Murphey MD, Hamilton JJ (1994) Distal chevron osteotomy with lateral release for treatment of hallux valgus deformity. Foot Ankle Int 15: 457-61 19. Mann RA (1990) Bunion surgery: decision making. Orthopedics 13: 951 20. Mann RA, Donatto KC (1997) The chevron osteotomy: a clinical and radiographic analysis. Foot Ankle Int 18: 255-61 21. Harper MC. (1989) Correction of Metatarsus primus varus with the Chevron metatarsal osteotomy. An analysis of corrective factors. Clin Orthop 253: 180-98 22. Sarrafian SK (1985) A method of predicting the degree of functional correction of the metatarsus primus varus with a distal lateral displacement osteotomy in hallux valgus. Foot Ankle 5: 322-6 23. Sanhudo JA (2006) Correction of moderate to severe hallux valgus deformity by a modified chevron shaft osteotomy. Foot Ankle Int 27: 581-5
