Foot & Ankle International - June 2017 - 598

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Foot & Ankle International 38(6)

Table 2. Inclusion and Exclusion Criteria.

Table 3. Patient Characteristics (n = 20 Ankles of 20 Patients).

Inclusion Criteria

Characteristic

Age of 20-80 years
Ankle pain for more than 6 months
Swelling of the ankle
Radiological diagnosis of ankle osteoarthritis
Stage 2-4 osteoarthritis on weightbearing radiographs according
to the Tanaka/Takakura classification
Not responsive to conservative treatment for at least 6 months

Age, mean ± SD, y
Sex, n (%)
Male
Female
Height, mean ± SD, cm
Weight, mean ± SD, kg
Body mass index, mean ± SD, kg/m2
Side of ankle, n (%)
Right
Left
Tibial anterior surface angle, mean ± SD, deg
Talar tilt angle, mean ± SD, deg
Radiographic stage according to
Tanaka/Takakura classification, n (%)
1
2
3a
3b
4
Comorbidity, n

Exclusion Criteria
Informed consent not provided
History of intra-articular injections within 6 months
Anemia (hemoglobin levels less than 11 mg/dL)
Thrombocytopenia (platelet levels less than 150 × 103/μL)
History of ankle surgery within the past 12 months
Infections of the ankle or nearby soft tissues
Treatment with oral steroids or steroid injections
Treatment with oral anticoagulant
Systemic inflammatory disease (eg, rheumatoid arthritis)
Undergoing immunosuppressive therapy
Diabetes mellitus
Cancer or malignant lesions
History of fractures in the affected limb
Pregnancy

Value
59.3 ± 11.4
5 (25)
15 (75)
157.2 ± 8.2
66.8 ± 11.4
26.7 ± 4.2
15 (75)
5 (25)
83.0 ± 3.3
6.2 ± 5.8

0 (0)
2 (10)
5 (25)
10 (50)
3 (15)
0

Patient Characteristics
Twenty patients (15 women and 5 men) participated in the
study from December 2013 to June 2015. All the cases
were primary varus ankle OA. The mean age was 59 years
(range, 37-76 years). The mean body mass index was 27
kg/m2 (range, 21.3-39.8 kg/m2). Four patients had bilateral OA, and we treated the ankle with the worse pain.
The mean tibial anterior surface angle and talar tilt angle
were 84 degrees (range, 79-90 degrees) and 6.2 degrees
(range, 1-22.4 degrees), respectively. According to the
Tanaka/Takakura classification,33 2 patients had stage 2, 5
had stage 3a, 10 had stage 3b, and 3 had stage 4 OA (Table
3). None of the patients had comorbidities according to
the Charlson comorbidity index.9 All of the patients completed the treatment protocol and subsequent assessments
for 24 weeks.

Figure 1. (A) A 200-mL venous blood sample in the closed
blood pack system. (B) Plasma was separated from whole
blood at first centrifugation. (C) Platelet-rich plasma (PRP) was
separated at second centrifugation, and then PRP was divided
into 3 small packs.

Preparation of PRP
PRP was prepared at the transfusion department of our hospital by using a closed blood pack system (Blood Separation
Pack; Kawasumi Ltd, Tokyo, Japan) (Figure 1) to minimize the risk of contamination. No commercial PRP preparation kit was used to obtain PRP.14 A week before the first
injection, 200 mL of venous blood was obtained from the
median cubital vein. The blood sample was centrifuged
twice (Himac CR7B3; Hitachi Ltd, Tokyo, Japan) to

produce PRP. The first centrifugation was performed at
800g for 5 minutes to separate erythrocytes, and the second
centrifugation was at 1500g for 8 minutes to concentrate
the platelets. After the 2 cycles of centrifugation, the 8-mL
plasma fraction located just above the buffy coat was
extracted and divided into 3 packs of 2-mL PRP (Figure 1).
They were stored at −30°C until the injection.6,14 Freezing
PRP would not influence the amount of growth factors in
Table of Contents for the Digital Edition of Foot & Ankle International - June 2017
