Progressive collapsing foot deformity (PCFD) is a complex foot deformity with varying degrees of hindfoot valgus, forefoot abduction, forefoot varus, and collapse or hypermobility of the medial column. In its management, muscle and tendon balancing are important to address the deformity. Peroneus brevis is the primary evertor of the foot, and the strongest antagonist to the tibialis posterior. Moreover, peroneus longus is an important stabilizer of the medial column. To our knowledge, the role of peroneus brevis to peroneus longus tendon transfer in cases of PCFD has not been reported. This study evaluates patient reported outcomes including pain scores and any associated surgical complications for patients with PCFD undergoing isolated peroneus brevis to longus tendon transfer and gastrocnemius recession. Patients with symptomatic PCFD who had failed non-operative treatment, and underwent isolated soft tissue correction with peroneus brevis to longus tendon transfer and gastrocnemius recession were included. Procedures were performed by a single surgeon at a large University affiliated teaching hospital between January 1 2016 to March 31 2021. Patients younger than 18 years old, or undergoing surgical correction for PCFD which included osseous correction were excluded. Patient demographics, medical comorbidities, procedures performed, and pre and post-operative patient related outcomes were collected via medical chart review and using the appropriate questionnaires. Outcomes assessed included Visual Analogue Scale (VAS) for foot and ankle pain as well as sinus tarsi pain (0-10), patient reported outcomes on EQ-5D, and documented complications. Statistical analysis was utilized to report change in VAS and EQ-5D outcomes using a paired t-test. Statistical significance was noted with p<0.05. We analysed 43 feet in 39 adults who fulfilled the inclusion criteria. Mean age was 55.4 ± 14.5 years old. The patient reported outcome mean results and statistical analysis are shown in Table one below. Mean pre and post-operative foot and ankle VAS pain was 6.73, and 3.13 respectively with a mean difference of 3.6 (p<0.001, 95% CI 2.6, 4.6). Mean pre and post-operative sinus tarsi VAS pain was 6.03 and 3.88, respectively with a mean difference of 2.1 (p<0.001, 95% CI 0.9, 3.4). Mean pre and post-operative EQ-5D Pain scores were 2.19 and 1.83 respectively with a mean difference of 0.4 (p=0.008, 95% CI 0.1, 0.6). Mean follow up time was 18.8 ± 18.4 months. Peroneus brevis to longus tendon transfer and gastrocnemius recession in the management of symptomatic progressive collapsing foot deformity significantly improved sinus tarsi and overall foot and ankle pain. Most EQ-5D scores improved, but did not reach statistically significant values with the exception of the pain score. This may have been limited by our cohort size. To our knowledge, this is the first report in the literature describing clinical results in the form of patient reported outcomes following treatment with this combination of isolated soft tissue procedures for the treatment of PCFD. For any figures or tables, please contact the authors directly

Peroneal spastic flatfeet without coalition or other known etiologies in adolescence remain a challenge to manage. We present eight such cases with radiological and surgical evidence of bony abnormalities in the subtalar region just anterior to the posterior facet. All patients had presented as tertiary referrals with recalcitrant pain and had undergone a trial of orthotics and physiotherapy. Diagnostic workup included a clinical and radiographic evaluation. Clinical examination consisted of gait examination, foot alignment, range of motion, torsional profile of the lower limbs and marking of symptomatic foci. All patients had standing weightbearing AP and lateral projections of the foot and ankle. CT and/or MRI scans of the foot were performed in axial coronal and saggital planes. Coalitions and other intraarticular known pathologies were ruled out. All patients had bilateral flatfeet but unilateral peroneal spasm. All patients had an accessory talar facet in front of the posterior subtalar facet. This caused lateral impingement between the facet and the calcaneum, confirmed by bone edema around the sinus tarsi. All patients had stiff subtalar joints with very limited movement under anaesthesia, indicating peroneal muscle contracture. Patients were treated with a combination of facet excision, peroneal lengthening and calcaneal lengthening to correct the flatfoot and prevent lateral impingement. We propose a mechanism of subtalar impingement between the anterior extra-articular part of the talar lateral process and the Gissane angle and believe that resection of the accessory facet without addressing the the primary driving force for impingement, which is the structural malalignment in flatfeet, would only give partial relief of symptoms. This impingement appears to occur with growth spurts in adolescents, in patients with known flatfeet