Foot and Ankle Specialist Dr. Praveen Vohra's Published Articles
Continued Research by Dr. Praveen Vohra
Ultrasound-guided Plantar Fascia Release Technique
Background: Ultrasound-guided plantar fascia release offers the surgeon clear visualization of anatomy at the surgical site. This technique uses small arthroscopic dissecting instruments through a 0.5-cm incision, allowing the surgeon to avoid the larger and more tissue-disruptive incision that is traditionally used for plantar heel spur resection and plantar fascia releases.
Methods: Forty-one patients (46 feet) were selected for the study. The mean patient age was 47 years. Twenty-nine were considered obese with a body mass index greater than 30 kg/m2. Patients were functionally and subjectively evaluated 4 weeks after surgery using the American Orthopedic Foot and Ankle Society Ankle and Hindfoot Rating Scale.
Results: Results from the study show a significant improvement (P= .05 confidence level) 4 weeks postoperatively for the 41 patients (46 feet), compared to their preoperative condition. The mean pretest score was 33.6 (range 10–52); this score improved to 88.0 (range 50–100), 4 weeks postoperatively. There were no postoperative infections or complications.
Conclusions: The ultrasound-guided plantar fascia release technique is a practical surgical procedure for the relief of chronic plantar fascia pain because the surgeon is able to clearly visualize the plantar fascia by ultrasound. In addition, there is minimal disruption to surrounding tissue because small instruments are passed through a small 0.5-cm incision. The traditional open method of heel spur surgery, in contrast, uses a larger skin incision of
Assoc 99(3): 183-190, 2009)
Insertional heel pain with or without the spur is most commonly related to mechanical factors.1-4 Other proposed causes of heel pain include bursitis, periostitis, nerve entrapment, trauma, degeneration of the plantar heel fat-pad, and seronegative arthridities.5-1Up to 90% of patients can receive complete relief of symptoms with conservative therapy alone (Table 1).1-9, 11-31 When conservative methods, including extracorporeal shockwave therapy, fail to alleviate heel pain, surgical intervention may be indicated. The most widely used surgical technique used today was popularized by DuVries.32 Variations of this procedure are based on the location of the incision and the amount of fascia and bone that is resected (Table 2;Fig. 1).9, 16, 17, 32-37 Alternative surgical techniques include endoscopy and coblation.3, 8, 38 The endoscopic plantar fascia release technique has been reported to be an effective alternative to relieving plantar heel pain.3 The coblation technique for repair of inflamed and degenerated tendon, ligament, and fascia offers promise for treatment of the plantar fascia, but longterm studies are needed.39 Advancement in diagnostic technology has enabled the ultrasound to become a reliable, cost-effective, diagnostic, and therapeutic instrument for visualizing foot pathology.40-42 These advancements have sparked interest in the use of ultrasound to assist the surgeon in the management of plantar fascia pain (Figs. 2 and 3). The rationale for the technique is based in part on a previous ultra-
sound study that positively correlated the thickness of the medial, central, and lateral plantar fascia bands with heel pain (Table 3).2 Hence, the purpose of this ultrasound study is to determine the effectiveness of the ultrasound-guided plantar release in relieving heel pain.
Ultrasound imaging is based on the recorded echo of transmitted sound waves from a given object, such as tendon, bone, or foreign material. The transmitted sound wave is reflected back as an echo to a transducer and the signal is then received and processed by the machine. The ultrasound image visualized on the monitor is produced from acoustic impedance mismatches at the interface between objects. For example, when sound waves encounter an object of high-mass density (eg, bone), a high acoustic impedance mismatch is produced and object images will appear hyperechoic or brighter on ultrasound (Fig. 3). An object with lower-mass density (eg, air, blood, abscess, inflammation) will produce a low acoustic impedance mismatch when sound waves are encountered, and such objects will appear hypoechoic or black on the ultrasound image. Painful plantar fascia is often inflamed, thickened, and appears black or hypoechoic. The noninflamed plantar fascia bands will appear thinner and remain hypoechoic. Therefore, the difference in the plantar fascia band thickness guides the surgeon to select the appropriate thicker band to resect.
Patients with plantar fasciitis who underwent 6 months of unsuccessful treatment were included in this study. Forty-one patients (14 males and 27 females) with a mean age of 47 years were clinically diagnosed with plantar fasciitis and met the study inclusion criteria. Each patient was evaluated with the American Orthopedic Foot and Ankle Society Ankle and Hindfoot Rating Scale at the time of surgery and 4 weeks postoperatively. The scale was modified to rate heel pain and measured both functional and subjective out- comes (Table 4). Patients were used as their own control, and during the 4 weeks after surgery, they were evaluated for surgical complications such as infection, hypoesthesia of the heel, or heel pain during weightbearing.
Five patients with bilateral plantar fasciitis and 36 with unilateral plantar fasciitis were included in this review. A diagnosis of plantar fasciitis was initially based on the patient’s history of poststatic dyskinesia and physical findings of pain on palpation of the plantar fascia at its calcaneal insertion. Patients were excluded if they had any of the following: 1) a history of inflammatory arthritis, 2) a connective-tissue disorder, 3) recent trauma to the heel or plantar fascia, 4) a congenital defect of the lower extremity, 5) previous heel surgery, 6) nonsteroidal anti-inflammatory medication use within 2 weeks, or 7) a corticosteroid heel injection within the previous 2 weeks. If the plantar fascia pain was not alleviated conservatively, ultrasound examination was performed in the office to locate symptomatic and asymptomatic plantar fascia bands. The same examination was also performed prior to anesthesia with a linear 7.0-MHz ultrasound transducer (Accustom128XT; Acuson Corp, Mountain View, California). Ultrasound examinations were performed while the patients were positioned supine with their feet hanging over the edge of the examination table. A bead of acoustic gel was applied to the cover of the head of the transducer, which was then placed longitudinally on the plantar aspect of the foot (Fig. 4). Ultrasound scanning was performed during dynamic dorsiflexion of the toes to stretch the plantar fascia, allowing its margins to be delineated. Images were recorded on emulsion film with a multi-image camera (Fuji Corp, Hyogo-ken, Japan). Transverse sonograms were also obtained to determine the location of the symptomatic plantar fascia bands proximally near insertion into the calcaneus (Figs. 5–7).
Prior to intervenous and local anesthesia, the symptomatic region of plantar fascia is marked. Then the foot is anesthetized by an infiltrative block, with a 50/50-combination mixture of 0.5% plain bupivacaine and 2% plain lidocaine. The foot is then exsanguinated and hemostasis maintained with the inflation of a pneumatic ankle tourniquet. Attention is then directed to the medial aspect of the heel, to a point slightly anterior and inferior to the attachment of the plantar fascia. The plantar fascia bands are identified by direct ultrasound and thickness measurements are taken. A
Figure 5. Transverse placement of the ultrasound transducer on the plantar surface of the foot at the origin of the bands of plantar fascia.
0.5-cm long linear plantar medial incision is made, which is gently retracted and widened with a blunt dissecting probe. The foot is then dorsiflexed and a reverse cutting knife with direct ultrasound visualization is used to transect a portion of the fascia from a lateral to medial direction (Figs. 8–12). When the fascia is transected, the defect created allows the first layer of plantar muscles to be identified with the ultrasound device. The reverse cutting knife is then removed. The incision site is irrigated with copious amounts of sterile saline. All areas are visualized with diagnostic ultrasound to ensure complete release of band fibers. Skin edges are reapproximated with 4-0 simple nylon sutures, and 0.25 mL of dexamethasone sodium phosphate (4 mg/mL) is then infiltrated into the surgical site. Poviodine topical solution (10%) and nonadhering petroleum gauze are placed on the incision site, and a dry sterile compressive dressing is then placed around the foot to support the medial arch (Fig. 13). Sutures are removed between 10 and 14 days postoperatively. In addition, after surgery, patients are placed into a CAM walker (Zinco Industries, Inc, Pasadena, California) and allowed to bear weight as tolerated for up to 2 weeks and then placed in a surgical shoe for 2 weeks. Patients are returned to regular shoe gear as tolerated. Physical therapy begins 4 weeks postoperatively and includes stretching, whirlpool, phonophoresis, and use of night splints.
Figure 6. Ultrasound anteroposterior view of the calcaneus depicting the medial calcaneal tubercle as the medial imaging plane (A), the calcaneal sulcus as the central imaging plane (B), the lateral tubercle as the lateral imaging plane (C), and the plantar fascia band (D).
Figure 7. Illustration of Figure 6. (Courtesy of AnneErickson, MA, CMI, Veterans Affairs Medical Center,Brooklyn, New York.)
The 4-week postoperative Ankle and Hindfoot Rating Scale for all patients represents a significant improvement (P = .05 confidence level) regardless of weight compared to their preoperative levels. The mean pretest score of 33.6 (range, 10–52) improved to 88.0 (range, 50–100). There were no incidents of postoperative complications.
Figure 8. Blunt probe used to isolate plantar fascia.
Figure 9. Triangular knife used to release inflamed plantar fascia.
Figure 10. Surgical release of plantar fascia bands. The foot is dorsiflexed to place tension on the plantar fascia. Longitudinal placement of the ultrasound transducer at the proximal origin of the plantar fascia is accomplished to visualize the inflamed plantar fascia band and to release it.
Figure 11. Plantar view illustration of the surgical release of the plantar fascia bands. (Courtesy of Anne Erickson, MA, CMI.)
Ultrasound-guided plantar fascia release offers the surgeon visualization of the local anatomy at the surgical site and enables more precise anatomical dissection. In addition, there is minimal tissue trauma to the adjacent anatomy surrounding the plantar fascia because of the small size of the dissecting instruments.
In the present review, there were no postoperative complications of infection, hypoesthesia, or sharp heel pain. However, some complications have been reported by other authors. Lester and Buchanan45 noted that 42% of patients had heel hypoesthesia postoperatively. Their procedure consisted of spur resection, release of all first-layer plantar musculature, and fascial release. Such extensive dissection may have resulted in transaction of the abductor digiti quinti muscle and the calcaneal nerve branches. Baxter and Thigpen46 report 18% of patients continued to have heel pain with weightbearing after open neurolysis procedures were performed. Leach et al47 performed open fascial release, resection of the fascia, or both
Figure 12. Lateral view illustration of the surgical release of the plantar fascia bands. (Courtesy of Anne Erickson, MA, CMI.)
Figure 13. Immediate postoperative bandage of the foot after ultrasound release of the inflamed plantar fascia bands. for chronic plantar fascial pain and reported unresolved heel pain in 7% of patients. Similarly, Snider et al48 performed fascial release and calcaneal osteotomies and reported 11% of patients with unresolved heel pain. Postoperative complications for endoscopic plantar fascia release procedures and have been reported by Barrett and Day,49 who reported complications in 19% of patients, and by Jerosch,50 who reported complications in 11% of patients.
It is recommended that patients either begin or continue using custom orthoses after surgery to prevent excess strain placed on the plantar fascia and adjacent structures. Additionally, physical therapy is important postoperatively to help strengthen the remaining nontransected bands of plantar fascia.
Because there is minimal trauma, excellent visibility of the plantar fascia, and a high patient satisfaction rate, we believe that the ultrasound-guided instep plantar fasciotomy technique is a practical procedure for the relief of plantar fasciitis. A drawback to this study was the inability of many of the original group of patients to return to the office for a long-term follow-up examination using the American Orthopedic Foot and Ankle Society Ankle and Hindfoot Rating Scale.
Acknowledgment: Cheri Mettler, AA, for technical assistance; Anne Erickson, MA, CMI, for Medical Illustration; Mike Yu, BS, William Collwell, Jamie Kanger for imaging; the Danville, Illinois Veterans Affairs Library Staff for literature assistance; and Brian Kincaid, DC, for sonographic assistance.
Financial Disclosure: None reported. Conflict of Interest: None reported.