Nonoperative Therapy

Nonoperative therapy (Table 68-1) is an appropriate initial intervention in almost all cases of PTTD. The goals of treatment are pain relief and the return of PTT function when possible. In a flexible deformity, the aim is to control the progressive valgus deformity of the hindfoot. In a rigid deformity, the goal is to support the position of the foot in situ with a brace that accommodates the bony deformities. In addition, symptomatic relief can be addressed with the use of nonsteroidal anti-inflammatory drugs, activity modification, and encouraging weight loss.

Few studies exist on the nonoperative treatment of PTT dysfunction, but it is believed that a well-fitted, custom-molded orthosis can be effective at relieving symptoms, and can delay and sometimes prevent surgical intervention⁶ (Level of Evidence V). Chao and colleagues⁷ performed a study of 49 patients with the diagnosis of PTTD treated with either a molded ankle-foot orthosis (AFO) or University of California Biomechanics Laboratory (UCBL) brace with medial posting (Level IV). Nonobese patients with flexible deformities and less than 10-degree residual forefoot varus with the heel in a neutral position received the UCBL brace. The remaining patients received the molded AFO. In total, 40 feet were treated with a molded AFO, and 13 were treated with a UCBL brace. Patients were divided into three groups based on a functional scoring system, and 67% of patients were found to have excellent to good results. Unfortunately, this study cannot be used to make a comparison between different disease stages because of the nonuniformity of treatment.

Augustin and coworkers⁶ studied the nonoperative treatment of various stages of PTTD with an Arizona AFO brace, a custom-molded leather and polypropylene orthosis (Level IV). Twenty-one patients with PTTD were evaluated just before brace use and after a minimum of 3 months of use using questionnaires and clinical examination. American Orthopaedic Foot and Ankle Society (AOFAS) Hindfoot Scores, Foot Function Index scores, and 36-Item Short Form Health Survey (SF-36) scores all increased significantly except for the change in health perception area of the SF-36. Six of six patients with stage I PTTD showed improvement attributable to the brace. The authors suggest that the Arizona AFO brace is effective at relieving symptoms and either obviating or delaying any surgical intervention, especially in earlier stages. Further studies are needed to determine whether an orthosis can prevent disease progression together with providing symptomatic relief.

Alvarez and coauthors⁸ studied the treatment of stage I and II PTTD in 47 patients with a nonoperative management protocol consisting of physical therapy, an aggressive home exercise program, and an orthosis (Level IV). Over a 4-month period, 39 (83%) patients had successful subjective and functional outcomes, and 42 (89%) patients were satisfied, with 5 (11%) patients requiring surgery.

Operative Treatment

A variety of surgical options exists for patients who do not respond to a trial of conservative treatment. The principal of operative treatment is to perform the least invasive procedure that will decrease pain and improve function.⁹ For stage I PTTD exploration and debridement of the PTT and soft tissue is often a recommended option. (Table 68-2). All tenosynovial tissue should be excised, with debridement of degenerated tendon areas and repair of any tears. Crates and Richardson¹⁰ report on a series of seven patients with stage I PTT dysfunction who were treated with debridement after failure of conservative treatment (Level IV). Six of the seven patients were pain free at 11-month follow-up examination. In Teasdall and Johnson’s study,¹¹ 14 of 19 patients had complete relief of pain after a synovectomy and debridement for stage I PTTD (Level IV). Sixteen patients had a return of function of the PTT as evidenced by the ability to perform a single-limb heel-rise test. Significant pathology within the substance of the tendon may require aggressive resection followed by flexor digitorum longus (FDL) transfer and Achilles lengthening to augment the PTT.

Nonoperative Treatment

Initially, stage II PTTD is treated similarly to stage I, but there are a few studies for nonoperative treatment of more advanced PTTD. Because the foot is flexible, corrective orthoses are utilized to prevent or correct deformity and control pain.¹² Alvarez and coauthors⁸ showed improvement in functional and subjective outcomes in patients with stage II PTTD with physical therapy, an aggressive home exercise program, and an orthosis (Level IV). If corrective orthoses are unable to correct the deformity, a medial posted UCBL device, as suggested by Chao and colleagues,⁷ may be used. Augustin and coworkers⁶ showed that all 12 patients using an Arizona brace showed pain relief referable to the brace and improvement in multiple clinical measurement instruments. If the deformity is severe, an AFO may be needed.⁷ As in stage I, stage II is given a 3- to 6-month trial before advocating surgical intervention.

Operative Treatment

A variety of options exists for the operative treatment of stage II PTT dysfunction. An FDL transfer is an accepted option,¹³ but isolated FDL transfer has failed to demonstrate long-term durability despite short-term success.¹⁴ A bony procedure will oftentimes be necessary to supplement the FDL transfer to improve its longevity. Bony procedures can be divided by position and include medial osteotomy, lateral column lengthening, or a combined procedure.

Medial Osteotomy with Flexor Digitorum Longus Transfer

A medial calcaneal slide osteotomy and FDL tendon transfer is one surgical option that has been shown to provide acceptable results for stage II disease (Table 68-3).¹⁵ Myerson and researchers¹⁶ performed a radiographic analysis of 18 patients 12 to 26 months after such a procedure (Level IV). They found improved radiographic values of the talar-first metatarsal angle and the distance from the medial cuneiform to the floor, concluding that the procedure may offset the weakness of isolated FDL transfer. Myerson and researchers¹⁶ also found high patient satisfaction and functional improvement in 32 patients treated with this procedure for stage II disease at a mean of 20 months after surgery (Level IV).⁵ Guyton and coworkers¹⁷ performed a review of 26 patients who underwent the procedure at a mean of 32 months follow-up (Level IV). All patients except three were able to perform a single-leg toe raise, which none could perform before surgery. Pain relief was rated as excellent by 75% of patients. Patients felt a prolonged period of steady improvement in symptoms and function over time. Radiographic improvement in the alignment of the foot was noted but did not correlate to self-reported improvement in appearance. These early clinical studies suggest that FDL transfer and medial displacement calcaneal osteotomy provide good functional outcome and symptomatic relief.

The decision to remove or retain the PTT when performing a FDL tendon transfer and medial displacement calcaneal osteotomy has been examined. Rosenfeld and investigators¹⁸ performed a prospective study randomizing 12 patients into 2 groups depending on excision or retention of the PTT, and assessed muscle volume and AOFAS scores at 1-year follow-up (Level II). Though the intact tendon group lost posterior tibial muscle volume, all of the posterior tibial muscles in the excised tendon group were replaced by fatty infiltration. The FDL muscle hypertrophied to a greater extent in the excised tendon group, but there was no difference in AOFAS scores between the two groups after surgery. The authors conclude that the FDL undergoes greater hypertrophy and the posterior tibia undergoes fatty infiltration with excision of the PTT, but this does not affect clinical outcome.

Medial Osteotomy with Flexor Hallucal Longus Transfer

Commonly, the FDL tendon has been used in tendon transfer for PTT dysfunction, but this choice has been questioned. The FDL is only 28% of the relative strength of PTT and only 69% of the strength of the antagonistic peroneal brevis (PB). The flexor hallucis longus (FHL) has 50% of the relative strength of the PTT and exceeds the strength of the PB.¹⁹ Sammarco and Hockenbury²⁰ hypothesize that using a stronger muscle would lead to a greater arch correction (Level IV). They retrospectively analyzed a series of 19 patients undergoing an FHL tendon transfer and medial calcaneal osteotomy for stage 2 PTTD. The clinical outcomes using this technique were comparable with those observed in a series of FDL tendon transfer and calcaneal osteotomy, and no improvement was shown in radiographic appearance of the medial longitudinal arch. Despite the new interest in FHL transfer procedures, short-term results have failed to reveal superiority of the FHL to FDL transfer with calcaneal osteotomy. In addition, the FHL tendon requires a more complicated dissection, which places the neurovascular bundle under greater risk.

Lateral Osteotomy

Another option for stage II dysfunction is lateral column lengthening in conjunction with a tendon transfer (Table 68-4). The lengthening can be performed using an osteotomy of the neck of the calcaneus and interposing bone graft or through the calcaneocuboid (CC) joint itself. A version of the procedure by Evans recommends the osteotomy be done 1.5 cm proximal to the CC joint. Sangeorzan and researchers²¹ studied the effect of Evans-type calcaneal lengthening on relations among the hindfoot, midfoot, and forefoot in seven patients who underwent the procedure for symptomatic pes planus (Level IV). The authors note an improvement in the flatfoot deformity. Kitaoka and investigators²² performed a study using a dynamic flatfoot deformity model of nine fresh-frozen foot specimens to investigate their mechanical behavior after CC distraction arthrodesis. Three-dimensional tarsal bone positions were determined using a magnetic tracking system. Arch alignment in simulated toe-off phase of gait was found to be improved significantly but was not reduced anatomically.

No consensus has been reached on the ideal method of lateral column lengthening. Thomas and colleagues²³ analyzed 27 feet treated with lateral column lengthening for painful pes planus at 1-year follow-up examination (Level III). Ten feet underwent Evans-type open-wedge osteotomy with tricortical iliac crest graft, and 17 feet underwent CC distraction arthrodesis. Both groups underwent debridement of PTT with FDL transfer. Radiographic results documented marked improvement in all parameters, with no statistically significant difference between the two groups. Postoperative AOFAS rating score also did not show a statistically significant difference. Twenty of 25 patients in both groups were satisfied, and 96% stated they would have the same surgery again. Of note was a high rate of complications for both groups, specifically the rate of nonunion or delayed union in the CC distraction arthrodesis group. The authors conclude that both procedures offered marked improvement in radiographic parameters and AOFAS score, but both were also associated with a high rate of complications.

Particular concern regarding arthritis of the CC joint with Evans-type procedure has led several authors to recommended abandoning the procedure. The literature, however, is conflicting. A cadaver study demonstrated increased CC joint pressures after an Evans osteotomy with wedge graft.²⁴ In a study from 1983, Phillips and coauthors²⁵ report degenerative changes in CC joint in 6 of the 23 feet (Level IV). A more recent study by Hintermann and coworkers²⁶ reviewed 19 patients who underwent lateral column lengthening by calcaneal osteotomy in conjunction with medial soft-tissue procedures (Level IV). At an average follow-up of 23 months, 2 patients had radiographic signs of CC degeneration, and all 19 patients had satisfactory restoration of the medial arch height. One patient required arthrodesis of the CC joint after 5 months because of painful degenerative joint disease. In addition, Momberger and coworkers²⁷ examined the change in pressure across the CC joint after an Evans-type calcaneal osteotomy using a cadaveric adult flatfoot model. Joint pressures were compared among the normal foot, the created flatfoot, and the corrected flatfoot. Peak pressure across the joint increased significantly from the normal to the created flatfoot but did not change significantly from the flatfoot to the corrected flatfoot model. In some cases, the peak pressure in the flatfoot decreased with correction. These findings led the authors to conclude that the Evans-type osteotomy does not increase pressure across the CC joint. The literature provides an inconclusive picture of the superior method and precludes abandonment of the Evans-type osteotomy.

Combined Medial and Lateral Osteotomies

A technique of combining medial displacement calcaneal osteotomy, lateral column lengthening, FDL transfer, and heel cord lengthening has gained interest (Table 68-5). Pomeroy and Manoli²⁸ performed this procedure in 20 cases of stage II PTT dysfunction, and analyzed the patients radiographically and with the AOFAS scale at an average follow-up of 17.5 months (Level IV). The average foot rating improved from 51.4 to 82.8, and radiographic measurements demonstrated statistically significant correction of the pes planovalgus deformity. Moseir-LaClair and researchers²⁹ analyzed the effect of a similar procedure in 26 patients with 28 stage II feet at a mean follow-up of 5 years (Level IV). The AOFAS score was high after surgery, and there was radiographic improvement of the deformity. Four patients (14%) demonstrated signs of CC arthrosis, but the authors contend that half of these patients had preexisting CC joint arthritis. The authors of both studies suggest that the double osteotomy technique provides symptomatic relief and acceptable correction of pes planovalgus deformity associated with stage 2 PTTD.

Subtalar Fusion

Another proposed operative procedure for stage II PTTD consists of subtalar fusion in conjunction with soft-tissue rebalancing (Table 68-6). Johnson and investigators³⁰ performed a retrospective review of 17 feet with stage II PTT dysfunction treated with subtalar arthrodesis combined with spring ligament repair/reefing and FDL transfer at an average follow-up period of 27 months (Level IV). All patients had successful subtalar joint fusion with an average time to radiographic union of 10.1 weeks. Standing radiographic analysis demonstrated an improvement in the anteroposterior talo-first metatarsal angle, the talonavicular coverage angle, and the medial cuneiform distance to the floor. These early results suggest that FDL transfer with medial soft-tissue reconstruction and subtalar fusion have comparable results with other extra-articular sparing procedures. The authors suggest that this procedure can be an effective and reliable alternative procedure in the treatment of stage II PTT dysfunction.

Nonoperative Treatment

In stage III and IV, the foot is rigid, and the goal is to provide support, reduce pain, and prevent further progression. Augustin and coworkers⁶ showed that three of five patients with stage III PTTD had relief of symptoms referable to the use of an Arizona brace. The foot may be braced in situ with a custom-molded orthosis. Although a solid AFO may sometimes prove useful, often an articulated device is better tolerated. In stage IV disease, a solid device is usually required because orthoses usually provide little control of the deformity.³¹ With the use of braces, particular care must be taken to avoid skin ulceration, which can be caused by the rigidity of the deformity. Although various conservative modalities have been described, advanced PTTD is difficult to manage without surgery.³¹

Operative Treatment

The standard treatment for stage III PTTD remains arthrodesis, although there is debate over the extent of fusion (Table 68-7). Traditionally, the gold standard for treatment of stage III PTTD has been triple arthrodesis^32,33 (Level V). Multiple studies have shown satisfactory results with this procedure, although there is the long-term risk for adjacent ankle arthritis.^34,35 Fortin and Walling³⁶ studied 32 patients who underwent triple arthrodesis for advanced PTTD and found that Foot and Ankle Society Hindfoot scores improved an average of 36 points with high patient satisfaction (Level IV). Jarde and colleagues³⁵ performed a retrospective review of 20 cases of flatfoot deformity secondary to PTTD and found good to excellent results in 70%, although follow-up radiographs showed progression of osteoarthritis (Level IV). The fusion technique should be meticulous and preceded with an anatomic reduction because an in situ fusion carries the risk for future arthrosis at the adjacent joints.¹⁴ Isolated subtalar fusion has been suggested as an alternative in selected groups, but data are limited and it requires further study.³⁷

Stage IV dysfunction is a rare anatomic condition with no specific gold standard. Described treatment modalities include tibiotalocalcaneal arthrodesis or pan-talar fusion, although few reports with these techniques in patients with PTTD have been published.^31,38 Experience with these procedures in other patient populations, such as arthritic or post-traumatic conditions, has shown that they are viable salvage procedures when there is disease involving both the subtalar and tibiotalar compartments.^39,40