Cotton Osteotomy in Flatfoot Reconstruction: a Retrospective
Review of Consecutive Cases
Yes
Troy Boffeli DPM, FACFAS, DPM, Katherine Schnell, DPM
Regions Hospital / HealthPartners Institute for Education and Research - Saint Paul, MN
STATEMENT OF PURPOSE
The Cotton osteotomy or opening wedge medial cuneiform osteotomy is a useful adjunctive
flatfoot reconstructive procedure that is commonly performed but rarely reported which is in part
due to the adjunctive nature of the procedure. The Cotton procedure is relatively quick to
perform and is intended to correct forefoot varus deformity after rearfoot fusion or osteotomy to
achieve a rectus forefoot to rearfoot relationship. Proper patient selection is critical since
preoperative findings of medial column joint instability, concomitant hallux valgus deformity, or
DJD of the medial column may be better treated with arthrodesis of the naviculocuneiform or first
tarsometatarsal joints. Procedure indications also include elevatus of the first ray which can be a
primary deformity in hallux limitus or iatrogenic deformity following base wedge osteotomy for
hallux valgus. The present retrospective series highlights our experience with the use of the
Cotton osteotomy as an adjunctive procedure when used in flatfoot reconstructive surgery.
METHODOLOGY
After institutional review board approval, we performed a retrospective analysis of consecutive
patients treated with Cotton osteotomy as part of flatfoot reconstruction from April 2001 to
December 2015. All osteotomies were performed by one surgeon (TJB) as an adjunctive
procedure in correction of pes valgus deformity and PTTD. Inclusion criteria included a clinic
follow-up at 10 weeks with appropriate preoperative radiographs with no joint proximal joint
fault or midfoot DJD or hallux valgus. Postoperative weight bearing (WB) radiographs were taken
at 10 weeks. Patients who did not have WB radiographs at 10 weeks or were lost to follow-up
prior to their 10 week post-operative appointment were excluded. Both investigators evaluated
postoperative radiographs to determine interval to radiographic incorporation of the allograft,
which was defined as bridging of the interface between the graft and native bone by bone callus
or trabeculae at 3 out of 4 cortices and obliteration of the graft interface as previously described
(1). Graft displacement and subsidence were also evaluated. Meary’s angle was also measured on
preoperative and 10 week postoperative digital lateral WB radiographs (Figure 1). Clinical healing
was determined by absence of pain at the surgical site with palpation and weightbearing. Other
data collected included age, gender, tobacco use at the time of procedure, and chronic medical
comorbidities including diabetes, Vitamin D deficiency, and chronic pain. Type of fixation and
adjunctive procedures were recorded. Complications including need for revision surgery, nonunion or delayed union, and neuritis or nerve symptoms related to the Cotton osteotomy were
also assessed.
SURGICAL TECHNIQUE
A consistent surgical technique was used in all cases regarding medial cuneiform osteotomy and
bone grafting although use and type of fixation was variable. Surgery was performed with the
patient in the supine position under general anesthesia with a popliteal block. A thigh tourniquet
is preferable due to adjunctive procedures. The medial dorsal cutaneous nerve (MDCN), extensor
hallucis longus (EHL), and tibialis anterior (TA) tendon were marked out pre-operatively and a
longitudinal dorsal incision was made medial to the EHL tendon which was centered over the
medial cuneiform (Figure 2a). The MDCN was carefully freed and protected as needed and the
incision was carried down to bone. The periosteum was reflected along the dorsal and medial
aspect of the medial cuneiform using a periosteal elevator. Care was taken to preserve the
ligaments. An osteotomy guide wire was placed centrally within the cuneiform along the lateral
cortex from dorsal to plantar. The pin was placed parallel to the first TMT joint from dorsal to
planar rather than perpendicular to the weight bearing surface which was confirmed on lateral
imaging. The osteotomy was made from dorsal to plantar using an oscillating saw. The plantar
cortex was preserved to serve as a hinge along with the plantar soft tissues. An osteotome was
used as a lever to break the lateral cortex and greenstick fracture the plantar cortex. A tricortical
wedge was then cut from an iliac crest allograft on the back table. The base of the wedge was 5-7
mm thick and 2.5 cm from dorsal to plantar which tapered down to 0 mm (Figure 2d-f). A
distractor was used to open the osteotomy and the allogenic wedge was press fit by hand
followed by gentle tamping to seat the graft (Figure 2b, c). Graft placement was confirmed with
intra-operative fluoroscopy (Figure 2g, h). Internal fixation is generally not necessary but k-wires
or spanning plate fixation can be used depending on bone quality and intra-operative stability of
the graft (Figure 3). Standard layered closure was then performed and the patient was placed in a
removable splint or below knee fracture boot. All patients were kept non-weightbearing (NWB)
for 6 weeks followed by progressive WB in a fracture boot for an additional 4 weeks followed by
transitioning back to full WB in shoes.
Figure 1. Preop and Postop Meary’s Angle Measurement
Preop
a
Postop
b
42 (9–77)
10M:22F
13R:24L
-17.24 (-35 to -7)
0.51 (-12 to +5)
17.76
18.12 (2.5-96)
21
16 (4 Plate, 12 K-wires)
5
3
1
2
Figure 2. Surgical Technique Pearls for Cotton Osteotomy
a
b
e
c
Table 2. Complications
Postoperative
0
Infection
Hardware Removal 0
Graft Subsidence
0
Nonunion
0
Malunion
0
Delayed Union
1
Sensory neuritis
g
h
Figure 3. Fixation Options for Cotton Osteotomy
b
Variable fixation techniques
were utilized in this
retrospective review including
(a) no fixation, (b) crossing
threaded 0.062” k-wire
fixation, and (c,d) plate
fixation.
c
d
b
c
2
No fixation used, resolved with
2 months of bone stimulation
Plate fixation both cases,
1/2 was resolved at 1 year postop
0/2 required hardware removal
f
(a) The traditional Cotton incision (dashed line) is centered dorsally over the
medial cuneiform. (b,c) Distraction assists with graft placement. (d,e) Tricortical
iliac crest allograft was used in all patients undergoing Cotton osteotomy. The
dorsal thickness of the wedge was 5 to 7mm and wedge depth was
approximately 2.5 to 3cm. (f) The allograft is large enough to provide two
wedge grafts when performing combined Evans / Cotton osteotomy procedures.
(g,h) Intraoperative simulated WB lateral imaging is shown here before and
after graft placement. (g) Note how the distractor can be used to assess optimal
graft size with (h) confirmation of correction of Meary’s angle.
a
d
Thirty-two patients (37 feet) were included in the present study (10 males and 22 females). No
patient was excluded and all cases were consecutive. The average age was 42 (range 9 to 77).
Fixation was used in 16/37(43%) feet. Threaded 0.062” k-wires were used in 12 cases and plate
fixation was used in 4 cases. The average follow-up was 18 months (range 2.5 to 96 months). All
but one patient demonstrated clinical and radiographic healing at the 10 week postoperative visit.
Mearys line improved in all feet, with an average change of -17.2° pre-operatively to 0.5° postoperatively (Table 1). Incorporation of the bone graft was seen in 36/37 feet, with no evidence of
displacement or subsidence in all 37 feet. No patients required removal of the graft or repeat
surgery due to displacement of the graft (Table 2). 1/37 had a delayed union of the graft with
continued pain 4 months after surgery. A CT confirmed no osseous bridge and a bone stimulator
was prescribed. Two months after using the bone stimulator, pain had resolved (Figure 5). She was
seen at 1 year post-op with no further problems of the surgical foot. There was no fixation used in
this case and no displacement of the graft was noted. The patient was a not a smoker and did not
have Vitamin D deficiency. The other post-operative complication involved 2 patients with
neuritis, one which resolved within 1 year after surgery and the other that did not resolve within
4 months after surgery. Both patients with neuritis had plate fixation of the osteotomy but did not
require hardware removal or revision surgery. Adjunctive procedures included gastrocnemius
lengthening (21), STJ fusion (13), Koutsogiannis (22), Evans (12), PT tendon repair (15), FDL tendon
transfer (6), tarsal coalition resection (6), hardware removal (HWR) from previous distal bunion
surgery (3), Kidner procedure (3), bone spur removal (6). Other various procedures that were not
as common included hammertoe repair, cheilectomy, 1st metatarsal phalangeal joint fusion, and
TN fusion (Table 3).
ANALYSIS AND DISCUSSION
d
LITERATURE REVIEW
In 1908, both Riedl and then Young described a closing wedge osteotomy of the medial cuneiform
for hallux valgus correction (2,3). Cotton originally described his signature procedure in 1936 for
pedal deformities of the first metatarsal head where the metatarsal head could not carry any
weight. He described the function of the procedure as restoring the “triangle of support.”
Additionally, he believed that the procedure could be used to correct flatfoot deformity if it was
reinforced with muscular training and exercise (4, 5).
Contemporary indications for the Cotton osteotomy include forefoot supinatus without hallux
valgus or medial column joint fault, rigid forefoot varus, and hallux limitus with elevatus of the
medial column. The procedure is especially useful to realign the forefoot after correction of
rearfoot deformity in the treatment of posterior tibial tendon dysfunction (PTTD) and acquired
flatfoot deformity (6).
The first peer reported outcome of the Cotton osteotomy included 15 flatfoot cases where the
Cotton osteotomy was used as an adjunctive procedures. No nonunions or malunions were
reported and there was a statistically significant improvement of radiographic parameters
including lateral talo-first metatarsal angle (Meary’s angle), calcaneal pitch, and medial cuneiform
to floor distance. Hilrose and Johnson concluded that the Cotton osteotomy was superior to first
tarsometatarsal arthrodesis due to preservation of 1st ray mobility and ease of correction (5).
In recent study, Aiyer demonstrated that the Cotton osteotomy even without fixation was
radiographicaly stable on follow-up. They also showed that the Cotton osteotomy provided
correction of medial arch sag but that it did not improve Meary’s angle (7).
Meary’s angle was
assessed on (a)
preoperative and (b) 10
week postoperative
weight bearing lateral
xrays. The Cotton
osteotomy is particularly
useful to correct
abnormal Meary’s angle
although correction of
deformity may be limited
in cases involving
instability of the medial
column joints. Adjunctive
procedures also
contribute to correction
of Meary’s angle.
Table 1. Results (N=37 Feet)
Mean Age (yrs)
Gender (M:F)
Laterality (R:L)
Mean Preop Meary’s Angle (°)
Mean Postop Meary’s Angle (°)
Mean Change in Meary’s Angle (°)
Follow-up Time (months)
No Fixation (# feet)
Fixation Used (# feet)
Active Smokers(# patients)
Histroy of Chronic Pain (# patients)
Diabetes (# patients)
Vitamin D Deficiency (# patients)
RESULTS
Figure 5. Delayed Union Case
a
b
(a) 1/37 patients had delayed union of the Cotton osteotomy with localized pain
persisting at 4 months postop. (b) CT confirmed minimal bridging at the
osteotomy site with interposed bone graft. Solid osseous bridging was seen at
the calcaneal osteotomy site. pain at the graft site. Complete resolution of pain
was noted at one year postop.
Table 3. Adjunctive Procedures (Total of 112)
Koutsogiannis
Gastrocnemius Lengthening
PT Tendon Repair
Subtalar Joint Fusion
Evans Osteotomy
Other (bunionectomy, cheilectomy)
Tarsal Coalition Resection
Flexor Digitorum Longus Transfer
Hardware Removal
Kidner
22 (20%)
21 (19%)
15 (14%)
13 (12%)
12 (11%)
11 (11%)
6 (5%)
6 (5%)
3 (3%)
3 (3%)
The Cotton Osteotomy is a common and well-accepted adjunctive procedure for correction of
flatfoot deformity with or without posterior tibial tendon dysfunction. In his original article,
Cotton stated that “the operation is simple, not painful, and… in the short review of cases done
since I have devised this operation, there has been no trouble in any” (4). The procedure is
generally thought to be safe and effective.
A search of medical literature identified few reports of outcomes regarding the Cotton osteotomy.
In a review of 16 patients, Hirose and Johnson used a 4.0 or 3.5 screw to fixate the cotton
osteotomy when performed in conjunction with adjunctive flatfoot procedures. They found a
union rate of 100% which is greater than the 77% reported for midfoot arthrodesis and concluded
that an advantage over fusion is more predictable union and preservation of first ray mobility (5).
Luts and Myerson reported on 101 medial cuneiform osteotomies performed in conjunction with
comprehensive flatfoot reconstruction procedures. They did not report nonunions which supports
the theory that the Cotton osteotomy heals predictably (8). Our union rate was very similar, with a
delayed union noted in one patient at four months that resolved with the use of a bone stimulator
after two months. This patient did not have internal fixation of the graft but there was no shift of
the osteotomy. This patient was assessed for bone healing risk factors and did not have vitamin D
deficiency, or history of tobacco use.
Hirose and Johnson reported one postoperative complication in which a painful screw had to be
removed due to screw head prominence. (Hirose & Johnson). We report an incidence of 0/16 for
hardware removals when using k-wire or plate fixation. Although previous studies did not
compare fixation to no fixation groups, there appears to be no difference in union rate between
those that used fixation and those that did not. In our study, union rates and complication profiles
between the groups with fixation (16/37) and without fixation (21/37) were similar. 2/16 patients
with fixation developed neuritis, one of which resolved in less than 1 year post-operatively. The
other patient, who was a smoker, still had neuritis at her 4 month follow-up. Both patients with
neuritis had plate fixation. One of the 21 patients without fixation had a delayed union.
A recent study by Aiyer determined that the Cotton osteotomy even without fixation is stable, as
noted on post-op radiographs (7). He commented on Meary’s angle and concluded that the
Cotton osteotomy did provide correction of medial arch sag but did not improve Meary’s angle
compared to matched controls who did not have a Cotton osteotomy. Our study shows an
improvement in Meary’s angle for all patients. Myerson also reported an improvement of
Meary’s angle from -23 preoperatively to -1 postoperatively and Hirose et al. reported an average
improvement of Meary’s angle of 14 degrees (5, 8). We had similar improvement of Meary’s
angle with an average of 18 degrees of improvement.
This retrospective assessment was undertaken to assess outcome and complications associated
with the Cotton osteotomy when used as an adjunctive procedure in flatfoot reconstructive
surgery. Limitations of this study include the relatively small number of patients in the study,
although all were consecutive which decreases exclusion bias. Also, all procedures were
performed by a single surgeon, which could also be seen as a benefit, because this removes the
inter-surgeon variability with patient selection and procedure technique. We also had a relatively
short follow-up period, with the average follow up being 18 months; however this was sufficient
to assess graft incorporation, nerve complications, hardware issues, and correction of medial arch
deformity. Another limitation is that patient satisfaction scores were not available for review.
Finally, with the variety of procedure combinations performed, it is difficult to determine the
degree to which the Cotton osteotomy contributed to arch alignment. In conclusion, the present
retrospective study of consecutive patients demonstrates that the Cotton osteotomy has a low
complication rate including graft incorporation, reliably corrects medial column deformity, and is
not prone to graft displacement without fixation when used as an adjunctive procedure for
correction of flatfoot deformity.
REFERENCES
1. Shibuya N, Holloway BK, Jupiter DC. A Comparative Study of Incorporation Rates between Non-xenograft and Bovine-based Structural Bone
Graft in Foot and Ankle Surgery. Journal Foot Ankle Surg. Jan-Feb; 51 (1): 164-167, 2014.
2. Riedl A. Osteotomie des Keilbeines bei Hallux Valgus. Arch Klin Chir 88:565, 1909.
3. Young JD. A new operation for adolescent hallux valgus. Univ Pa Med Bull 23: 459, 1910.
4. Cotton FJ. Foot statistics and surgery. N Engl J Med 214: 353-32, 1936.
5. Hirose CB, Johnson JE. Plantarflexion opening wedge medial cuneiform osteotomy for correction of fixed forefoot varus associated with flatfoot
deformity. Foot Ankle Int 25: 568-574, 2004.
6. Yarmel D, Mote G, Treaster A. The Cotton osteotomy: a technical guide. J Foot Ankle Surg 48:506-12, 2009.
7. Aiyer A, Dall GF, Shub S, Myerson MS. graphic Correction Following Reconstruction of Adult Acquired Flat Foot Deformity Using the Cotton
Medial Cuneiform Osteotomy. Foot Ankle Int. Dec; 37 (5): 508-513, 2015.
8. Lutz M, Myerson M. Radiographic Analysis of an Opening Wedge Osteotomy of the Medial Cuneiform. Foot Ankle Int. Mar; 32 (3): 278-87,
2011.