Clinical Outcomes of Selective Plantar Fascia Release for Hallux Interphalangeal Joint Ulcers

Ulcers are a risk factor for lower extremity amputation. In over 80% of cases, foot ulcers precede lower extremity diabetic amputations.^1,2 Studies have shown that the 5-year mortality rate after a first-time ulcer is approximately 40% in patients with diabetes and ranges from 52% to 80% after a major amputation.^3,4

Ulcers are not only detrimental to the patient, but have huge economic consequences to patients, society, and countries. In fact, in the United States, the estimated cost of minor lower limb amputation is $43,800 and of major lower limb amputation is $66,215.^5,6 For all these reasons, prevention of ulcers and lower limb amputations is a necessity. 

Ulcers at the plantar and plantar medial aspect of the hallux IPJ are common and often are challenging to treat in patients with diabetes.⁷ One of the most common sites of ulceration in a patient with diabetes is the plantar hallux.⁷ Increased stress and pressure at the hallux may result in callus formation. In persons with diabetes, this may lead to ulceration and possibly amputation. Along with neuropathic factors, hallux IPJ ulcers can occur from structural and mechanical factors. Proximal and distal phalangeal exostosis, degenerative arthritic disease with secondary hallux limitus or rigidus, and an accessory interphalangeal sesamoid bone combined with peripheral neuropathic changes are some of the most common structural causes of ulcers of the plantar aspect of the hallux IPJ.⁷ 

Biomechanical abnormalities that result in an overpronated foot, or hallux limitus or rigidus can predispose to medial hallux ulceration.⁷ With overpronation, the medial column and first ray become unlocked and elevated during midstance and propulsion. This causes final toe-off along the medial aspect of the IPJ and can lead to ulceration. With hallux limitus or rigidus, the limited motion at the metatarsophalangeal joint can lead to compensation distally at the IPJ and result in tissue breakdown and ulceration.

SPFR is a relatively new technique that was first described in 2012 for the management of plantar forefoot ulcers, specifically, at the plantar IPJ and plantar metatarsophalangeal joint of the first, second, third, and fourth rays.⁸ SPFR involves transection of selected fibers of the plantar fascia to decrease pressure on the plantar aspect of the specific ray during walking to achieve healing of the forefoot ulcer. Kim et al⁸ reported that the technique is easy to perform and does not require hospitalization or immobilization. They recommended that SPFR be considered for the management of forefoot ulcers. 

This case series reports the clinical results of using SPFR in the management of plantar hallux IPJ ulcers.

The investigation was conducted with institutional review board approval. A retrospective chart review was conducted of patients who underwent SPFR by a single foot and ankle surgeon from 2018 to 2023. Seventeen extremities in 17 patients were included in the final analysis. Inclusion criteria included patients that had hallux IPJ ulcers, SPFR for the hallux IPJ ulcers, age 18 years or older at the time of surgery, and a minimum follow-up of 6 months. Exclusion criteria included patients that had additional ulcers elsewhere, patients with inadequate follow-up, and patients who received SPFR for ulcers at sites other than the hallux IPJ.

The primary study outcome was to identify the healing rate and time to healing associated with SPFR for hallux IPJ ulcers. Patient charts were reviewed for demographic data, diagnoses, and surgical treatment information. The procedure during which SPFR was conducted was identified as the initial surgery. Only the initial surgery was used to determine time to healing of the ulcer, healing rate, and complications. Patient charts also were reviewed to determine the presence or absence of a postoperative complication, such as infection, wound problems, transfer lesions, revision surgery, need for an additional visit to the operating room, and medical complications. Notes from the follow-up course, emergency department visits, and hospital admissions were evaluated to assess for complications. 

Surgical procedure

The SPFR procedure was performed as described by Kim et al,⁸ but for hallux IPJ ulcers only. The procedure was conducted in both the operating room and the outpatient setting. 

The patient is placed in the supine position with the knees extended and the ankle in the neutral position. First, force is applied to the hallux to identify the plantar fascia band. Second, the plantar fascia band is palpated and marked at the first tarsometatarsal joint. Using a No. 11 blade, a transverse skin incision measuring approximately 1 cm is made in line with the plantar fascia (Figure). The incision is carried down to the medial band of the plantar fascia. Then, with the hallux in dorsiflexion, the plantar fascia band is identified and transected. After the release, the degree of dorsiflexion at the first metatarsophalangeal joint is noted to increase when loaded. The wound is copiously irrigated with normal saline. The skin is closed with a non-absorbable suture, and a simple compression dressing is applied. 

Immediate weightbearing is allowed as tolerated in a surgical shoe. At 2 to 3 weeks after the procedure, the stitches are removed. The plantar foot ulcer is managed with standard care.

Demographics

A total of 17 feet (11 left, 6 right) in 17 patients (13 males, 4 females) were studied (Table 1). Eleven SPFR procedures were performed on the left plantar hallux IPJ, and 6 were performed on the right plantar hallux IPJ. Five SPFR procedures were performed in the office (29.4%), and 12 (70.6%) were performed in the operating room. The mean duration of ulcer onset to SPFR was 5.8 months. The mean area of the ulcer was 0.6 cm². 

Clinical results

The mean time to healing of the hallux IPJ ulcers in all 17 feet was 3 months; 2 ulcers did not heal (Table 2). The mean follow-up time was 28.2 months. Fifteen patients (88.2%) healed after undergoing SPFR. Five patients (29.4%) developed transfer lesions. Seven patients (41.2%) experienced postoperative complications, including ulcer recurrence, transfer lesion, and healing complications.

Typically, a combination of offloading and local wound care is used in the management of neuropathic ulcers.⁹ Conservative options such as offloading are important, because local areas of sustained pressure and friction may decrease local capillary perfusion, leading to local tissue ischemia and trauma to the skin and deeper tissues.¹⁰ Nonsurgical treatment usually is effective in the earlier stages of ulceration. However, it becomes less effective as the ulcer becomes chronic and penetrates the deeper tissue. The ulcer recurrence rate ranges from 30% to 87%.⁹ Surgical intervention is considered when ulcers are unresponsive to conservative treatment.⁹

Surgical options for managing deformities and ulcers of the hallux and first metatarsophalangeal joint can be classified as curative or prophylactic.¹¹ Curative procedures which involve partial or complete resection of bone, and reconstructive procedures involve realignment via soft tissue or osseous techniques.¹¹ Some of the more common curative procedures include exostectomy, accessory bone excision, condylectomy, sesamoidectomy or sesamoid planing, hallux IPJ arthroplasty, first metatarsophalangeal joint cheilectomy, and first metatarsal head resection.¹¹ Prophylactic and reconstructive procedures for diabetes-related pathologies of the first ray include phalangeal osteotomies, first metatarsal osteotomies, hallux interphalangeal arthrodesis, first metatarsophalangeal joint arthrodesis, first metatarsophalangeal joint release, tendon procedures, tenotomies, and tendon transfers.¹¹ 

The importance of healing hallux ulcers is well documented. Lack of aggressive treatment can lead to further complications. In fact, partial first ray resections at any level (partial hallux and/or metatarsal) appear to be associated with a 20% to 50% reamputation rate at a more proximal level.¹² Amputation at the level of the hallux results in the loading forces being shifted to the lesser digits, which has the potential to cause ulceration at a different site.¹³

When local wound care with offloading does not result in ulcer healing, surgical intervention may be considered. As mentioned, surgical options for hallux and first metatarsophalangeal joint deformities and ulcers can be classified into either curative or prophylactic type procedures.¹¹ The authors of the current study prefer the use of an alternative method for managing hallux IPJ ulcers.⁸

Kim et al⁸ introduced the SPFR procedure in 2012. They noted that when the heel is elevated during the push-off phase of the gait cycle, body weight is distributed across all the metatarsal heads. When the proximal phalanges are dorsiflexed, the plantar fascia is pulled over the metatarsal heads, causing a depression of the metatarsal heads and elevation of the longitudinal arch.^8,14 They postulated that the windlass effect on the selected toe is weakened after SPFR and that the pressure under the metatarsal head of the selected toe is decreased during walking as well.⁸ In that study, the healing rate after SPFR was better for ulcers under the toe than for ulcers under the metatarsal head. This finding is what led the authors of the current study to investigate use of the SPFR procedure in patients with hallux IPJ ulcers. 

Kim et al⁸ studied the SPFR procedure for plantar ulcers at the metatarsophalangeal joint, IPJ, and plantar tip of the first, second, third, and fourth toes. Many of the patients in their study had a prior history of Achilles tendon lengthening. The overall wound healing rate in that study was 67%. The healing rate was 44% for metatarsophalangeal joint ulcers and 60% for plantar toe ulcers. The healing rate of hallux IPJ ulcers was not specified. There were no postoperative complications associated with recurrence or infection. In the current case series, an 88.2% healing rate for hallux IPJ ulcers was achieved. However, the rate of transfer lesions (29.4%) and postoperative complications (41.2%) were higher in the current case series than in the study by Kim et al.⁸ The current case series differed as well in that the patients had not undergone prior Achilles tendon lengthening and it included patients with hallux IPJ ulcers only. 

It has been documented that ankle equinus has 3-fold and 4-fold associations with diabetes and the development of ulcers.^15,16 Tendon shortening and neuromuscular deficit result in biomechanical restriction of ankle dorsiflexion, which disrupts the balance of load during gait and increases pressure throughout the plantar foot.¹⁵ Forefoot pressure increases from earlier heel-off transition and prolonged forefoot contact during ambulation.^15,16 Achilles lengthening was not performed in patients prior to the start of the current study. 

Chiu et al¹⁷ recently published a case series on medial band plantar fasciotomy for hallux IPJ ulcers. They described a modification to the open plantar selective band plantar fasciotomy technique. The procedure was performed on 6 patients with plantar hallux IPJ ulcers. In the 4 patients who completed the study, plantar hallux ulcer healing occurred within 13 weeks. Three patients developed transfer lesions to the second toe. The current case series differs from that study in technique and number of patients. Both studies reported complications, including transfer lesions to the second toe. In the current case series, healing of hallux IPJ ulcers occurred at a mean of 3 months. 

This study has several limitations. First, it neither measured nor included biomechanical data to correlate hallux limitus to the development of hallux IPJ ulcers. Measurement of the dorsiflexion angle of the first metatarsophalangeal joint may have strengthened the correlation between hallux limitus and hallux IPJ ulcers and may have strengthened the findings. Second, this study did not address the role of equinus in foot ulcers. Ankle equinus may have been a contributing factor to the transfer lesions that occurred in the current study. In addition, it may be helpful to assess other factors in the role of ulcer healing, such as neuropathy, peripheral arterial disease, previous amputation, duration of diabetes, glycemic control, and nutritional status. Finally, a larger study size and longer follow-up time would be useful.

Diabetic foot ulcers are challenging for both patients and practitioners. The authors of the current series believe that SPFR can be used in the management of hallux IPJ ulcers if both the surgeon and the patient are aware of its potential complications and limitations. Further research is warranted to evaluate the efficacy and reproducibility of the results reported herein. In addition, a comparison study involving patients treated with SPFR versus other surgical procedures for hallux IPJ ulcers would be valuable.