Stenosing tenosynovitis of the ankle with osseous bone formation following an open reduction and internal fixation of the ankle is a rare clinical condition. We report a case of adult-acquired flat foot following an open reduction and internal fixation of a bi-malleolar fracture due to tibialis posterior tendon dysfunction caused by stenosing tenosynovitis. This was managed by open excision of the bony tunnel and debridement, along with calcaneal osteotomy and distalization of the tendon, resulting in good functional outcomes.

BACKGROUND: Posterior Tibial Tendon Dysfunction (PTTD) is commonly seen within musculoskeletal care. The condition\'s prevalence and management is poorly understood. This study aims to demonstrate current practice by multi-professional clinicians across the United Kingdom within the National Health Service.
METHODS: A national (UK) cross-sectional online survey was conducted among multi-professionals who treat PTTD within their NHS practice. The survey covered assessment, management and evaluation. This was shared via social media and professional groups.
RESULTS: Two hundred thirteen surveys were completed, with 153 matching the eligibility criteria. The main respondents were Physiotherapists (48%) and Podiatrists (38%). Ultrasound scanning was used most frequently when considering initial imaging (67%). Many different treatment modalities were used, but a core set of education/advice, foot orthoses, and foot specific as well as general exercise were most commonly chosen. Outcome measures routinely used were pain scale (96/269) and single leg heel raise (84/269), but patient reported outcome measures were not routinely used. The most frequent reason to escalate care was failure to manage symptoms with conservative management (106/123; 86.2%), followed by fixed deformity (10/123; 8.2%).
CONCLUSIONS: This survey provides evidence on current non-surgical management for PTTD from UK NHS practice. It provides a valuable marker for clinicians to use to compare their own practice and can be used in further research as a comparator.

BACKGROUND: The use of subtalar arthroereisis as an adjunct to the surgical treatment of stage 1 flexible progressive collapsing foot deformity (PCFD) is controversial. The aim was to investigate the clinical outcomes and report the implant removal rate of subtalar arthroereisis as an adjunct for stage 1 PCFD.
METHODS: A retrospective study of 212 consecutive feet undergoing operative management of stage 1 PCFD with adjunctive subtalar arthroereisis between October 2010 and April 2018. The primary outcome was the Foot and Ankle Outcome Score (FAOS). Secondary outcomes included Foot and Ankle Disability Index (FADI), Euroqol-5D-5L Index and implant removal rate.
RESULTS: Post-operative clinical FAOS outcomes were collected for 153 feet (72.2%). At mean 2.5-year follow-up, the mean ± standard deviation FAOS for each domain was as follows; Pain: 81.5 ± 18.5, Symptoms: 79.5 ± 12.9, Activities of Daily Living: 82.5 ± 15.4 and Quality of Life: 64.2 ± 23.7. EQ-5D-5L Index was 0.884 ± 0.152. Pre-operative scores were available for 20 of these feet demonstrating a statistically significant improvement in all FAOS, FADI and EQ-5D-5L domains (p < 0.05). The implant removal rate for persistent sinus tarsi pain was 48.1% (n = 102).
CONCLUSIONS: Use of a subtalar arthroereisis implant as an adjunct to conventional procedures in stage 1 flexible PCFD can result in significant improvement in pain and function. Patients should be counselled as to the relatively frequent rate of subsequent implant removal.
METHODS: IV.

UNASSIGNED: Tibialis posterior tendon, deltoid ligament and spring ligament are the three most important structures on the medial aspect of the foot. They contribute to the stability of the foot and ankle and also to the maintenance of the arches of the foot. These structures get affected and dimensions get disrupted in various traumatic and degenerative conditions. Normal range of dimensions of these structures has not been studied in an Indian population. Our objective is to define the normal thicknesses of these structures using a cadaveric model. We also hypothesize that longer the foot, higher stresses on these structures and hence thicker they will be. We aim to assess this hypothesis as well.
UNASSIGNED: Dissection of the medial aspect of the foot was done on twenty cadaveric below knee specimens. Tibialis posterior tendon was identified and its thickness was measured. Deltoid and plantar calcaneonavicular ligaments were identified. Their lengths and thicknesses were measured. Length of the feet was also measured prior to dissection. Statistical analysis was done using the data obtained.
UNASSIGNED: Mean tibialis posterior thickness was 7.0165 ± 0.387 mm. Mean deltoid thickness was 5.124 ± 0.28 mm. Its mean length was 21.328 ± 2.22 mm. Mean plantarcalcaneonavicular ligament thickness was 2.491 ± 1.120 mm. Thicknesses of the tibialis posterior tendon and plantarcalcaneonavicular ligament correlated significantly with the length of the foot.
UNASSIGNED: The thicknesses of the tibialis posterior tendon and plantar calcaneonavicular ligament are shown to be a function of and significantly proportional to the length of the foot. This helps the surgeon to estimate the thicknesses which the structures had prior to the pathology, in order to recreate the non-pathological anatomy after a tendon transfer or a reconstruction procedure. The normal thicknesses of tibialis posterior, deltoid and plantar calcaneonavicular ligaments are described for an Indian setting and deviations can be used to assess various pathologies of the foot and ankle affecting these structures.

BACKGROUND: The Tibialis Posterior tendon (TPT) is the only tendon to encounter the distal tibia and is therefore at greatest risk of injury in fractures of the distal tibia. Although TPT injury has been reported rarely with injuries around the ankle, they often have been missed and present late.
OBJECTIVE: Our aim was to analyse the rate to TPT entrapment in fractures involving the posterior tibia, i.e. Pilon (PLM) and posterior malleolar fractures (PMF).
METHODS: A retrospective analysis of PMF and Pilon fractures over an 8-year period was undertaken. Patients who had undergone surgical fixation of their PMF or PLM were identified from 2014 to 2022, using our prospectively collected database. Any fracture which had undergone a preoperative CT was included. Analysis of their pre-operative CT imaging was utilised to identify TPT entrapment, where if < 50% of the tendon cross section was present in the fracture site, this was denoted as a minor entrapment and if ≥ 50% of the tendon was present in the fracture site was denoted as major.
RESULTS: A total of 363 patients were identified for further analysis, 220 who had a PMF and 143 with PLM injury. The incidence of TPT entrapment was 22% (n = 79) with 64 minor and 15 major entrapments. If the fracture line entered the TPT sheath, there was a 45% rate (72/172) of entrapment as compared to 3.7% (7/190) in fractures not entering the sheath (p < .001). There was no significant difference in TPT entrapment in PMF as compared to PML (p = 0.353).
CONCLUSIONS: In our assessment, we found significant prevalence of 22% of TPT entrapment in fractures involving the posterior tibia. PMF and PLF had no statistically significant difference in the rate of TPT entrapment. Additionally, we found that there was a significant risk of TPT entrapment when the CT images display the fracture line entering the tendon sheath. We recommend that surgeons consider taking care assessing pre-operative imaging to seek to identify the TPT and to assess intraoperatively where entrapment does occur.

The posterior tibial tendon is a gliding tendon which courses around the medial malleolus and fails in posterior tibialis tendon dysfunction (PTTD) leading to a flat foot deformity. Distal tibial bone spurs have been identified as a secondary sign of PTTD although they have not been quantified in detail. The aim of this study was to assess the association of tendon dysfunction with the bony morphology of the tibial retro-malleolar groove. We performed a retrospective review of the clinical presentation, plain radiographs, and 103 magnetic resonance imaging (MRI) scans in 82 consecutive patients with PTTD compared with a non-PTTD group. We carried out a quantitative and qualitative assessment of the presence of plain radiographic bone spurs, stage of PTTD and MRI imaging of the morphology of the tibial bony malleolar groove. Plain radiographic bone spurs, as a secondary sign of PTTD, were present in 21.3% of ankle radiographs. MRI bone spurs were identified in 26/41 (63.4%) for all high-grade partial and complete tears and 7/41 (17.1%) for isolated complete tears compared with only 3.9% of the non-PTTD group. There was a significant association between the presence of bone spurs on MRI imaging and high-grade partial and complete tibialis posterior tears (p < .001; odds ratio of 4.98). Eleven of 103 (10.7%) of spurs were large and in 4/103 (3.9%) were substantial enough to create a tunnel-like hypertrophic groove not previously reported. There is variation in the bony structure of the malleolar groove in PTTD not observed in the non-PTTD group. Further investigation over time may elucidate whether the groove morphology may lead to mechanical attrition of the tibialis posterior tendon and contribute to failure of healing and progressive tendon degeneration.

BACKGROUND: Evidence suggests that tibialis posterior muscle plays an important role in equinovarus foot deformity in patients who had suffered a stroke and it is one of the most frequently injected lower-extremity muscles for the management of spasticity. Our aim was to assess if a needle accurately and safely penetrates the tibialis posterior muscle during the application of dry needling.  METHODS : We conducted a cadaveric descriptive study. Needling insertion of the tibialis posterior was conducted in 11 cryopreserved cadavers with a 70 mm needle. The needle was inserted using two common approaches, at midpoint (posterior/medial approach) and at upper third (anterior approach) of the leg towards the tibialis posterior. The needle was advanced into the tibialis posterior based upon clinician judgement. Cross-sectional anatomical dissections were photographed and analyzed by photometry. Safety was assessed by calculating the distances from the tip and the path of the needle to proximate neurovascular structures.
RESULTS: Accurate needle penetration of the tibialis posterior muscle was observed in all cadavers with both approaches. In general, distances from the needle to the neurovascular bundles were larger with the posterior/medial approach than with the anterior approach, reaching statistically significance for needle tip to nerve (mean difference: 0.6 cm, 95%CI 0.35 to 0.85 cm) and vascular bundle (mean difference: 0.55 cm, 95%CI 0.3 to 0.8 cm) distances (P < 0.001) and needle path to vascular bundle distance (difference: 0.25 cm, 95%CI 0.1 to 0.4 cm, P = 0.045). Age and gender did not influence the main results.
CONCLUSIONS: This cadaveric study suggests that needling of the tibialis posterior muscle can be accurately and safely conducted. Safety seems to be larger with the posterior/medial approach when compared with the anterior approach.

Pigmented villonodular synovitis (PVNS) is a locally aggressive benign tumour of the synovial membrane and tendon sheath. The unique presentation of this tumour is hemosiderin deposition with synovial proliferation. Depending on the situation, surgical excision is always the first line of treatment with adjuvant radiotherapy. Arthroscopic excision is preferred in some intraarticular nodular PVNS cases. This is a rare pigmented villonodular synovitis involving flexor hallusis longus, flexor digitorum longus, and tibialis posterior (TP). The tumour was entirely extra-articular without any joint involvement. The tumour was the diffuse type of PVNS and was treated by excision followed by radiotherapy. There is no recurrence till nine months of follow-up.

The interosseous crural nerve (IOCn) is said to arise distally from muscular branches of the tibial nerve innervating the deep muscles of the posterior compartment of the leg. Here, we present the results of a cadaveric study of the IOCn to clarify this nerve\'s morphology and to discuss its potential clinical relevance. On 26 sides from 13 cadaveric specimens, the IOCn was dissected. The IOCn was identified on 14 out of 26 sides (53.8%). The mean diameter and length of the IOCn were 0.46 mm (range 0.3-0.72 mm) and 20.9 mm (range 13.5-33.0 mm), respectively. The origin of the IOCn was from a branch to the popliteus muscle on all sides. The nerve was found to have vascular, muscular, and ligamentous branches. In 53.8%, the nerve reached the inferior tibiofibular joint, and in 46.2%, the nerve terminated in the interosseous membrane of the leg. At its distal part, the IOCn gave off multiple vascular branches to the fibular artery. On one side (7.1%), the nerve pierced the interosseous membrane and innervated muscles of the anterior compartment of the leg. We believe this to be the first anatomical study of the IOCn. The nerve was found to have vascular, muscular, and ligamentous branches. Surgeons operating in the deep posterior compartment of the leg and ankle and clinicians treating patients with unusual presentations or pathology of the leg and ankle should be aware of this structure.

BACKGROUND: Posterior Tibial Tendon (PTT) dysfunction is considered to have an important role in Progressive Collapsing Foot Deformity (PCFD). The objective of our study was to assess the relationship between PTT status and three-dimensional foot deformity in PCFD.
METHODS: Records from 25 patients with PCFD were included for analysis. The PTT was considered deficient in patients with a positive single heel rise test or a deficit in inversion strength. Three-dimensional foot deformity was assessed using the Foot and Ankle Offset (FAO) from Weight-Bearing-CT imaging. Hindfoot valgus, midfoot abduction and medial longitudinal arch collapse were assessed on X-Rays using hindfoot moment arm, talonavicular coverage angle and Meary\'s angle respectively. Deland and Rosenberg MRI classifications were used to classify PTT degeneration.
RESULTS: PCFD with PTT deficit (13/25) had a mean FAO of 7.75 + /- 3.8% whereas PCFD without PTT deficit had a mean FAO of 6.68 + /- 3.9% (p = 0.49). No significant difference was found between these groups on the hindfoot moment arm and the talonavicular coverage angle (respectively p = 0.54 and 0.32), whereas the Meary\'s angle was significantly higher in case of PCFD with PTT deficit (p = 0.037). No significant association was found between PTT degeneration on MRI and FAO.
CONCLUSIONS: PCFD associated three-dimensional deformity, hindfoot valgus and midfoot abduction were not associated with PTT dysfunction. PTT dysfunction was only associated with a worse medial longitudinal arch collapse in our study. Considering our results, it does not appear that PTT is the main contributor to PCFD.
METHODS: Level III, Retrospective Comparative Study.