Calcaneal lengthening using ipsilateral fibula autograft in the treatment of symptomatic pes valgus in adolescents

Background Evans calcaneal lengthening osteotomy is used to treat symptomatic flexible flatfoot when conservative treatment fails. Grafts such as autologous iliac bone grafts, allografts, and xenografts are implanted at the osteotomy site to lengthen the lateral column of the hindfoot. This study aimed to present the outcomes of an autologous mid-fibula bone graft used for calcaneal lengthening in symptomatic pes valgus in adolescents. Methods We retrospectively examined 23 ft of 13 adolescents who underwent surgery between July 2014 and January 2018. The radiological and clinical outcomes (American Orthopaedic Foot and Ankle Society ankle-hindfoot scale scores) were assessed during a mean follow-up of 49.7 (range, 30.9–73.4) months. The mean distance of the lengthening site was measured to evaluate graft sinking or collapse. The Goldberg scoring system was used to determine the degree of union at the donor and recipient sites. Results The calcaneal pitch and the anteroposterior and lateral talo-first metatarsal (Meary) angles showed significant correction, from 14.4 to 19.6 (p < 0.001), and from 14.5 to 4.6 (p < 0.001) and 13.5 to 8.5 (p < 0.001), respectively. The mean distance of the lengthening site showed no significant change (p = 0.203), suggesting no graft sinking or postoperative collapse. The lateral distal tibial angle showed no significant difference (p = 0.398), suggesting no postoperative ankle valgus changes. Healing of the recipient and donor sites occurred in 23 and 21 ft, respectively. The American Orthopaedic Foot and Ankle Society ankle-hindfoot scores improved significantly, from 68.0 to 98.5 (p < 0.001). Conclusions Evans calcaneal lengthening using an ipsilateral mid-fibula bone autograft resulted in significant improvement in clinical and radiological outcomes without ankle valgus deformity. Hence, it could be a treatment option for lateral column calcaneal lengthening in adolescents.

Biomechanical Effects of Graft Shape for the Evans Lateral Column Lengthening Procedure: A Patient-Specific Finite Element Investigation

Background: The Evans calcaneal lengthening osteotomy procedure is widely used for correcting progressive collapsing foot deformity. However, it can result in overcorrection and degenerations of the calcaneocuboid joint. Different shapes of graft have been used in the Evans calcaneal osteotomy, but potential differences in their biomechanical effects is still unclear. The present study was designed to explore the biomechanical effects of graft shape and improve the Evans procedure to avoid or minimize detrimental effects. Methods: Twelve patient-specific finite element models were established and validated. A triangular or rectangular wedge of varying size was inserted at the lateral edge of calcaneus, and the degree of correction was quantified. The stress in spring ligaments and plantar fascia and the contact characteristics of the talonavicular and calcaneocuboid joints were calculated and compared accordingly. Results: The rectangular graft provided a much higher degree of correction than triangular grafts did. However, the contact characteristics of the calcaneocuboid joint and talonavicular joint were abnormal, with clear sensitivity to increased graft size, and the modeled strain of the spring ligament increased. Conclusion: The finite element analysis predicts that the rectangular grafts provide a higher degree of correction, but risks overcorrection compared with triangular grafts. The triangular graft may have a lower degree of disturbance to the biomechanical behaviors of the midtarsal joint. Clinical Relevance: The model shows that both the shape and size of an Evans osteotomy bone wedge can have effects on the contiguous joints and ligamentous structures. Those effects should be considered when selecting a bone wedge for an Evans calcaneal osteotomy. Level of Evidence: Level III, case-control study.

Talus morphology differs between flatfeet and controls, but its variety has no influence on extent of surgical deformity correction

Background Progressive collapsing foot deformity (PCFD) is a complex 3-dimensional (3-D) deformity with varying degrees of hindfoot valgus, forefoot abduction, and midfoot varus. The first aim of this study was to perform a 3-D analysis of the talus morphology between symptomatic PCFD patients that underwent operative flatfoot correction and controls. The second aim was to investigate if there is an impact of individual talus morphology on the success of operative flatfoot correction. Methods We reviewed all patients that underwent lateral calcaneal lengthening for correction of PCFD between 2008 and 2018 at our clinic. Radiographic flatfoot parameters on preoperative and postoperative radiographs were assessed. Additionally, 3-D surface models of the tali were generated using computed tomography (CT) data. The talus morphology of 44 flatfeet was compared to 3-D models of 50 controls without foot or ankle pain of any kind. Results Groups were comparable regarding demographics. Talus morphology differed significantly between PCFD and controls in multiple aspects. There was a 2.6° increased plantar flexion (22.3° versus 26°; p = 0.02) and medial deviation (31.7° and 33.5°; p = 0.04) of the talar head in relation to the body in PCFD patients compared to controls. Moreover, PCFD were characterized by an increased valgus (difference of 4.6°; p = 0.01) alignment of the subtalar joint. Satisfactory correction was achieved in all cases, with an improvement of the talometatarsal-angle and the talonavicular uncoverage angle of 5.6° ± 9.7 (p = 0.02) and 9.9° ± 16.3 (p = 0.001), respectively. No statistically significant correlation was found between talus morphology and the correction achieved or loss of correction one year postoperatively. Conclusion The different morphological features mentioned above might be contributing or risk factors for progression to PCFD. However, despite the variety of talar morphology, which is different compared to controls, the surgical outcome of calcaneal lengthening osteotomy was not affected. Level of evidence III.

Talar-Tarsal Stabilization: Rationale and Preliminary Outcomes

Category: Ankle; Hindfoot Introduction/Purpose: While surgical stabilization of the subtalar joint (arthroeresis) in children remains controversial in the USA, it is practiced worldwide, with reportedly good outcomes. Our purpose is to present a series of patients who met our criteria for calcaneal lengthening, but who opted instead for the less invasive option of talo-tarsal stabilization (TTS). In particular we wanted to assess the incidence of untoward outcomes that may manifest within the first year postoperatively, namely peroneal spasm or painful loosening of the implant, and discuss the management of these problems. Methods: With IRB approval, we conducted this retrospective review of 32 patients (60 feet) who underwent talo-tarsal stabilization (TTS) for flexible planovalgus deformity and had a minimum of 1 year follow-up. The etiology was idiopathic for the majority, with a few being neurogenic or syndromic. The age range at insertion was 6-15 years, with the younger patients having neuromuscular etiology or underlying syndromes. Concomitant procedures, included percutaneous Achilles lengthening (33 feet), Kidner (9), supramalleolar rotational osteotomy (1), and guided growth for ankle valgus (2). We assessed hindfoot flexibility and alignment, obvserved the gait pattern and compared weightbearing AP and lateral radiographs taken preoperatively and at least one year postoperatively. Results: At a minimum of 1 year follow-up, 50 implants (85%) were retained and the patients reported satisfactory outcomes. Henceforth, those patients will be monitored on a prn basis. In the early post-immobilization phase, peroneal spasm occurred in 3 patients (5 feet). This resolved with Botox injection in the peroneus brevis in 3 patients and required transfer of the peroneus brevis to the peroneus longus in one. One patient experienced early migration of hte implants, and these were repositioned with a good outcome. Due to lingering discomfort, Implants were removed in five patients (10 feet = 15 %). None of these patients have collapsed and required salvage hindfoot osteotomy or calcaneal lengthening. Conclusion: For the child with flat feet and unremitting pain talar-tarsal stabilization, combined with other procedures as indicated, offers advantages over the accepted methods of medial shift osteotomy or calcaneal lengthening. It is less invasive, well tolerated and may prove to be definitive. The outcome at 1 year is a good forecast of whether or not further treatment will be required. Osteotomy may be obviated.