REVIEW
Proximal metatarsal osteotomy and distal soft tissuereconstruction as treatment for hallux valgus deformity
Michael J. Coughlin and J. Speight Grimes
Boise, Idaho, USA(Received for publication on October 26, 2004)(Revised for publication on March 2, 2005)(Accepted for publication on April 21, 2005)

Abstract. The correction of a hallux valgus deformity with a proximal 1 st metatarsal osteotomy anddistal soft tissue repair is achieved with a three-incision technique. A lateral soft tissue release and reconstruction at the ﬁrst metatarsophalangeal joint releases contracted structures including the lateralcapsule, the transverse inter-metatarsal ligament and the conjoint adductor tendon. Rarely is the lateral sesamoid excised. Through a medial incision, the medial eminence or exostosis is resected. The
sesamoids are realigned and the medial capsule is reefed. With a third incision, a proximal ﬁrst metatarsal osteotomy is performed that corrects a widened 1–2 intermetatarsal angle. With correction of thehallux valgus and the 1–2 intermetatarsal angle, pronation of the hallux is corrected. This correction isroutinely used for hallux valgus deformities characterized by subluxation of the metatarsophalangeal
joint. In the presence of a mild hallux valgus deformity an osteotomy may not be necessary. With
degenerative arthritis or a congruent metatarsophalangeal joint, alternative surgical procedures areindicated. (Keio J Med 54 (2): 60–65, June 2005)
Key words: Hallux valgus, bunion, osteotomy

may be indicated. A hallux valgus deformity characterized by a congruent ﬁrst metatarsophalangeal joint
may require extra-articular osteotomies to achieveadequate correction. In the presence of signiﬁcantspasticity or degenerative arthritis, an arthrodesis may
be preferable.

Indications
A distal soft tissue repair combined with a ﬁrst
metatarsal osteotomy is indicated for an incongruent(subluxated) hallux valgus deformity. Typically, hallux
valgus angular deformity of 30 or greater and anintermetatarsal angle of 12 or greater are the main
surgical indication. Rigidity of the metatarsal cuneiform
joint characterized by a lateral intermetatarsal facet
requires a ﬁrst metatarsal osteotomy or some other typeof proximal procedure. With an intermetatarsal angleof less than 12 , a distal soft tissue reconstruction
alone may be sufﬁcient to achieve correction of thedeformity.

Advantages of the Procedure
A distal soft tissue repair and realignment may be
performed with or without a proximal ﬁrst metatarsal
osteotomy. A soft tissue procedure can be utilized for
mild hallux valgus deformities; with moderate andsevere deformities the osteotomy may be added. This
type of procedure maintains ﬁrst ray strength, a normal
weight bearing pattern, and metatarsophalangeal jointmotion. These factors may be sacriﬁced with either anarthrodesis or an excisional arthroplasty of the ﬁrst
metatarsophalangeal joint. A crescentic osteotomy
maintains ﬁrst ray length. A closing wedge osteotomy
tends to shorten the ﬁrst ray and an opening wedge

Contraindications
For a hallux valgus angular deformity greater than50 or an intermetatarsal angle greater than 25 , acomplete correction of the deformity may not be possible and a ﬁrst metatarsophalangeal joint arthrodesis

Presented at the 1374th Meeting of the Keio Medical Society in Tokyo, September 29, 2004
Reprint requests to: Dr. Michael J. Coughlin, Boise, Idaho, USA
60

Keio J Med 2005; 54 (2): 60–65

osteotomy tends to lengthen the ﬁrst ray. Changing thelength of the ﬁrst metatarsal may change tension of soft
tissue structures affecting the ﬁrst metatarsophalangeal
joint function.
Disadvantages
This surgical technique is technically demanding andrequires careful balancing of both the lateral and medial soft tissue structures with the procedure.
Preoperative Patient Education
Preoperatively, the patient should be apprised ofcommon risks of surgical procedures including overcorrection (hallux varus), and under correction (recurrent hallux valgus). A malunion or delayed union ornonunion of the osteotomy site is infrequent but mayoccur. Injury to the dorsal branch of the medial cutaneous nerve may lead to a neuroma or anesthesia along
the medial border of the hallux.
Preoperative Assessment
Following a routine physical examination, weightbearing dorsal plantar, lateral, and axial (sesamoid)
views should be obtained. The magnitude of the hallux
valgus and 1–2 intermetatarsal angle should be quantiﬁed. The degree of sesamoid subluxation is measured.
The presence of degenerative arthrosis of the ﬁrst MTP
joint should be noted as well (Fig. 1).
Special Surgical instruments needed:
Weitlaner retractor
Homan retractors
Stryker TPS power unit with quick-change adaption
for Kirschner wire, power drill, sagittal saw, crescenticsaw.
Crescentic saw blade (Stryker crescentic blade#2296-31-416S7 or #277-31-416S1; or Zimmer-Hall
crescentic blade #5053-176).
Positioning and Anesthesia
The patient is typically positioned in a supine position with a bump placed under buttock of the involved
extremity. Surgery is performed under a peripheral anesthetic block (popliteal and saphenous nerve block) or
ankle block just proximal to the medial malleolus. The
foot is then cleansed and draped in the usual fashion.
An Esmarch bandage is used to exsanguinate the footand is also used as a tourniquet. Cast padding or bias
stockinet is placed just above the medial malleolar
region.

61

Surgical Technique
1. A 3 cm. longitudinal incision is placed in the ﬁrst
intermetatarsal web space in the interval between
the ﬁrst and second metatarsals.
2. The incision is deepened to an adventitious bursa
which is identiﬁed between the metatarsal heads.
The adductor hallucis tendon is identiﬁed at its
insertion into the lateral sesamoid and the plantar
base of the proximal phalanx. An incision is madealong the dorsal border of the lateral sesamoid
releasing the soft tissue contracture between thelateral sesamoid and the ﬁrst metatarsal (Fig. 2).
3. The dissection is deepened along the lateral borderof the sesamoid releasing the attachment of theconjoint tendon. Approximately 2 cm. proximal tothis point, the tendon is severed and the proximal
muscle is allowed to retract. A suture is placed inthe proximal tendon. The sesamoid is not removed
except in the case of a severe contracture or severe
arthrosis.
4. The Weitlaner retractor is placed into the intermetatarsal space separating the ﬁrst and secondmetatarsals. With tension placed between themetatarsal head, the transverse intermetatarsal theligament is sectioned. Care is taken to prevent any
injury to the underlying common digital nerve inthe ﬁrst web space. Following releasing of the ligament, an elevator is passed along the ﬁbular sesamoid to insure there are no remaining adhesions
between the sesamoid and the metatarsal head. The
lateral metatarsal capsule is freed from its insertion
on the metatarsal head leaving a cuff of tissue thatcan be later repaired. With a severe deformity there
may be a gap present along the distal lateral soft
tissue. At the conclusion of the procedure the conjoined tendon stump and the lateral capsule are
sutured into soft tissue along the lateral ﬁrst metatarsal head to promote the formation of scar tissue
along the lateral aspect of the metatarsophalangeal
joint. All sutures are tied at the conclusion of theprocedure.
5. A longitudinal incision is centered over the medial
eminence extending from the midportion of theproximal phalanx to a point 1 cm. to 2 cm. proximal
to the medial eminence. The incision is carefully
deepened through the subcutaneous tissue to thejoint capsule and then deepened in both a dorsal
and plantar direction. It is important to create a fullthickness ﬂap to prevent the possibility of woundedge necrosis. The dorsal neurovascular bundle isidentiﬁed and protected.
6. An inverted ‘‘L’’ shaped capsular incision is used torelease the dorsal medial capsule. The capsule isreleased at its two weakest attachments (proximal62

Coughlin MJ and Grimes JS: Proximal metatarsal osteotomy and distal soft tissue reconstruction as treatment for hallux valgus deformityand dorsal) (Fig. 3). This leaves a very strong distaland plantar capsular attachment. This approachgives an excellent exposure of the medial eminence
as well as the medial sesamoid and the dorsal medial cortex of the ﬁrst metatarsal.
7. The metatarsophalangeal joint is then carefully
inspected and the sagittal sulcus is identiﬁed. The
sagittal sulcus is not a reliable reference for resection of the medial eminence. With a small eminence, the sulcus may be the site of the osteotomy
but with a more severe deformity the sulcus may
have migrated too far laterally and using this as areference for an osteotomy will often lead toan excessive resection. The medial eminence isresected with the sagittal saw at a point 2 mm.
medial to the sagittal sulcus and the osteotomy isdirected in a line with the longitudinal axis of theﬁrst metatarsal diaphysis (Fig. 4). The removal ofexcessive bone should be avoided as this may leadto a hallux varus deformity. Any sharp edges on thedorsal, distal or plantar aspect are removed with arongeur. (Following removal of the medial eminence, the surgeon should next determine the ﬂexibility of the metatarsal cuneiform joint. If the deformity is easily corrected then an osteotomy may
not be necessary. A distal soft tissue realignment
will sufﬁce. If there is resistance to correction of theintermetatarsal angle due to rigidity of the metatarsal cuneiform joint, a proximal ﬁrst metatarsal
osteotomy should be performed.)
8. A third longitudinal incision, 3 cm. in length, iscentered over the dorsal proximal ﬁrst metatarsal.
It is deepened along the medial aspect of theextensor hallucis longus tendon to the bone. The
periosteum is reﬂected 1.5 cm. distal to the metatarsal cuneiform joint where a crescentic osteotomy
is performed using the crescentic blade (Stryker
crescentic blade #2296-31-416S7 or #277-31-416S1;
or Zimmer-Hall crescentic blade #5053-176). The
concavity points in a proximal direction.
9. The plane of the osteotomy is neither perpendicular to the ﬁrst metatarsal shaft nor to theplantar aspect of the foot but proximally half way
in-between (Fig. 5). This way the saw blade is ofadequate length to transect the metatarsal but stillleaves a large surface area. Care should also betaken to avoid injury to the communicating arteryin the ﬁrst intermetatarsal space. It may be necessary to complete the osteotomy with a 3 mm. to4 mm. wide osteotome.
10. Often there is a small ridge of bone on the lateral
aspect of the distal fragment that must be removed
with a rongeur in order to displace the osteotomysite.
11. The osteotomy is displaced by rotating the distal

fragment in a lateral direction. The small osteotome
is positioned along the lateral aspect of the proximal fragment to stabilize it. The distal fragment isthen rotated along the osteotomy site and displaced
2 mm. to 3 mm. laterally (Fig. 6).
12. The osteotomy is then ﬁxed with a 0.062 Kirschner
wire. Next, a 3.5 mm. drill hole is created in thedistal fragment approximately 1 cm. from theosteotomy site and oriented in a proximal direction
parallel to the Kirschner wire. Then a 2.0 mm. drill
hole is drilled into the proximal fragment and afully threaded 4.0 mm. screw is used to stabilize theosteotomy site (Fig. 7).
13. Attention is directed to the medial incision. A small
drill hole is placed in the dorsal aspect of themetaphysis and the proximal capsule is repairedwith interrupted 0 absorbable suture. The toe isheld in a derotated corrected position. The dorsal
capsular incision is then repaired with interrupted
2-0 absorbable suture. On occasion, a phalangeal
ostetomy is performed to gain added angular correction (Fig. 8).
14. Finally attention is directed to the intermetatarsal
incision. With the metatarsals compressed in a medial lateral direction, the intermetatarsal sutures
are tied. The conjoined tendon is sutured obliquely
across the lateral metatarsophalangeal joint andsecured with interrupted 2-0 absorbable suture.
Further sutures are placed in order to get goodstability to the lateral capsule.
15. Intra-operative ﬂuoroscopy is helpful to ascertain
the correction of the alignment of the osteotomy
and the distal soft tissue repair.
Postoperative Care
A bulky gauze and tape compression dressing is applied at the conclusion of surgery and changed every
ten days for eight weeks (Fig. 9). The patient is initiallypermitted to ambulate with crutches and a postoperative shoe. Weight bearing is allowed on the lateral
aspect of the foot and the heel. A radiographic is
obtained postoperatively to assess the position of theosteotomy and soft tissue realignment. The compression dressing may be used to realign the hallux and adjust either valgus or varus alignment over the course of
postoperative care.
Typically the procedure is performed on a outpatientbasis but may be kept overnight depending on pain
management. In an ofﬁce setting under local anesthesia,
six weeks following surgery, hardware is removed. The
patient, is instructed in passive range of motion which iscommenced ten days after surgery. Physical therapy isoccasionally used if a patient has difﬁculty in achieving
dorsiﬂexion and plantar ﬂexion. Crutches are usuallyKeio J Med 2005; 54 (2): 60–65

63Fig. 4

Removal of the medial eminence.

Fig. 1 Pre-operative radiograph demonstrating moderate hallux
valgus deformity.

Fig. 5

Fig. 2Lateral view of crescentic osteotomy.

Lateral capsular release and abductor tendon release.

Fig. 6

Fig. 3‘‘L’’ shaped capsular incision.

The ostetomy is shift 2–3 mm lateral-ward.

64Coughlin MJ and Grimes JS: Proximal metatarsal osteotomy and distal soft tissue reconstruction as treatment for hallux valgus deformity

Fig. 7

Internal ﬁxation is placed.

Fig. 9Clinical appearance of the foot following surgery.

Fig. 10

Correct position of the saw blade in a coronal plane.

Fig. 8 Post-operative radiograph following DSTR with PMO andphalangeal osteotomy.

discontinued three to four days after surgery. Three tofour months following surgery athletic activities areinitiated. Between three and six months are required
for swelling of the foot to subside.
Pitfalls in the Surgical Technique
The most common complications are under correction and over correction. The osteotomy must be
carefully performed as well as the distal soft tissuereconstruction.
Orientation of the crescentic osteotomy has changed
over the last decade. Initially the concavity face wasoriented distally. However this created a bump along
the medial arch and there was an increased chance ofover correction leading to hallux varus. With reversalof the osteotomy (concavity facing proximally) the riskof over correction has been markedly reduced.
Over correction can develop due to excessive medial
eminence resection, to over reeﬁng of the medial cap-sule, or to over correction of the osteotomy. Intraoperative ﬂuoroscopy or radiograph will help to avoid
these complications. Delayed union of the osteotomy isuncommon (less than 1% of my patients). If this occurs,a below knee walking cast applied for six weeks will
frequently lead to successful union.
Malunion at the osteotomy site can occur with plantar ﬂexion or dorsiﬂexion. Plantar ﬂexion is uncommon.
Dorsiﬂexion can occur either early or late. The positionof the saw blade in cutting the osteotomy is probably
the most frequent cause of dorsiﬂexion malunion. Theosteotomy should be perpendicular to the long axis of
the ﬁrst metatarsal (Fig. 10). Often the lower extremity

Keio J Med 2005; 54 (2): 60–65

will rotate in the lateral direction causing the surgeon to
inadvertently rotate the saw in a medial direction. Thus
when the osteotomy is displaced the ﬁrst metatarsal
elevates. To avoid this, it is helpful to place a Kirscher
wire in a vertical direction to the ﬁrst metatarsal shaft.
When one performs the osteotomy, the alignment ischecked with the Kirschner wire in order to perform aperpendicular cut.
The other cause of dorsiﬂexion malunion is earlyweight bearing or osteoporotic bone. In an unreliable
patient or a patient with osteoporosis, a below knee cast
may be warranted.

65

In a group of 140 adult patients treated with a similar
technique by me,2 the average preoperative hallux valgus angle was 30 and the average postoperative hallux
valgus angle was 10 for an average correction of 20 .
The average intermetatarsal angle was corrected from apreoperative value of 15 to a postoperative value of 5
for an average correction of 9 . When patients wererated with an AOFAS score preoperatively and postoperatively these adult patients noted an average preoperative AOFAS score of 57 points and an average
postoperative AOFAS score of 91 points.
Conclusion

Results
The technique I have described was performed in 27
juvenile patients (33 feet) over an eleven year period.1
The patient were followed for an average of 60 months.
A ﬁnal follow up the average preoperative hallux valgus angle was 31 and the average postoperative hallux
valgus angle was 8 for an average correction of 23 .
The average preoperative intermetatarsal angle was
14.4 and the average postoperative intermetatarsal
angle was 6 for an average correction of 8.4 . The
average forefoot narrowing was 5.5 mm. In a study
reported by Mann et al.3 on 79 adult patients (109feet) using the same technique, the average hallux
valgus correction was 24 and the average correctionof the intermetatarsal angle was 8 . The incidence ofunder correction was 2% and 12% had a hallux varus
deformity.

We have found the distal soft tissue repair withproximal ﬁrst metatarsal osteotomy to be a very reliable
procedure to be used in the treatment of moderate andsevere hallux valgus deformities. Attention to the surgical technique is important in order to achieve reliablyreliable results.
Bibliography
1. Coughlin MJ: Roger A. Mann Award. Juvenile hallux valgus: etiology and treatment. Foot Ankle Int 1995; 16: 682–697
2. Coughlin M. Jones C: Prospective evaluation of hallux valgus
treatment with proximal ﬁrst metatarsal osteotomy. Presented
Annual Summer Meeting of the American Orthopaedic Foot andAnkle Society, Boston MA, July 20, 2005
3. Mann RA, Rudicel S, Graves SC: Repair of hallux valgus with adistal soft-tissue procedure and proximal metatarsal osteotomy. A
long-term follow-up. J Bone Joint Surg Am 1992; 74: 124–129