Talar neck rotation angle in adults with clubfoot deformity: Observed values and intra- and inter-observer reliability using weightbearing CT.

INTRODUCTION: Adults presenting with symptomatic clubfoot represent a challenging cohort of patients. An appreciation of the location and degree of deformities is essential for management. Talar anatomy is often abnormal with varus within the talar neck, however, there are few reproducible methods which quantify talar neck deformity in adults. We describe a technique of assessing talar neck deformity, and report on observed values and intra- / inter-observer reliability. METHODS: This was a single-centre, retrospective study including 96 feet from 56 adult patients with clubfeet (82 feet had clubfoot deformity, 14 were normal). Mean age was 34.3 ± 16.9 years and 31 (55.3%) were male. Weight-bearing CT scans captured as part of routine clinical care were analysed. Image reformats were oriented parallel to the long axis of the talus in the sagittal plane. In the corresponding axial plane two lines were drawn (on separate slices): 1) a line perpendicular to the intermalleolar axis, 2) a line connecting the midpoints of the talar head and narrowest part of the talar neck. The talar neck rotation angle (TNR angle) was the angle formed between these lines. Intraclass correlation coefficients (ICC) were performed for intra- and inter-observer reliability. RESULTS: Mean TNR angle in clubfeet was 27.6 ± 12.2 degrees (95%CI = 25.0 to 30.2 degrees). Mean TNR angle in normal feet was 18.7 ± 5.1 degrees (95%CI = 16.0 to 21.4 degrees) (p < 0.001). The ICC for clubfeet was 0.944 (95%CI = 0.913 to 0.964) for intra-observer agreement, and 0.896 (95%CI = 0.837 to 0.932) for inter-observer agreement. CONCLUSION: This measurement technique demonstrated excellent intra- and inter-observer agreement. It also demonstrated that compared to normal feet, clubfeet had about 9 degrees of increased varus angulation of the talar neck. This technique and data may be used for future research into clubfoot deformity and in planning treatment. LEVEL OF CLINICAL EVIDENCE: 3.

Hindfoot Fusions in the Cavovarus Foot: What Is the Key for a Successful Outcome?

The aim of hindfoot fusions in the cavovarus foot is to establish a painless, plantigrade, balanced and stable foot. A comprehensive clinical and radiographic assessment enables the surgeon to fully understand the patient's deformity and plan a reliable surgical strategy for deformity correction. Pre-operative planning and intraoperative techniques are discussed.

Extracorporeal shock wave treatment in foot and ankle fracture non-unions - A review.

BACKGROUND: The authors reviewed the current evidence and conducted a comprehensive review on the use of extracorporeal shock wave therapy (ESWT) in the treatment of foot and ankle fracture non-unions. METHODS: Four databases were searched to identify relevant studies in the available literature. RESULTS: Eight studies were reviewed, demonstrating union rates of 65%-100% and 90-100% at 3- and 6-months following ESWT treatment respectively. No major complications were seen in any of the studies. Minor complications included local soft tissue swelling, petechiae, bruising and pain. CONCLUSIONS: The literature that is currently available is limited to case series of relatively small sample sizes, highlighting the need for a prospective randomised controlled trial to further investigate the efficacy of ESWT in the treatment of foot and ankle fracture non-unions.

Medial approach for subtalar distraction bone block arthrodesis.

Subtalar distraction bone block arthrodesis is a useful technique commonly employed in the management of calcaneal and talar fracture malunion. Traditionally it is performed via a posterolateral or extensile lateral approach, however such approaches have been associated with wound complications, particularly secondary to the added stress caused by the subtalar distraction crucial to this technique. Medial approaches to the subtalar joint have been used in other procedures but have not been reported in subtalar distraction bone block arthrodesis. A novel case and technique illustrating the medial approach for subtalar distraction bone block arthrodesis is discussed. LEVEL OF CLINICAL EVIDENCE: Level 4.

Validation of a Virtual Reality Simulator for Percutaneous Pedicle Screw Insertion.

INTRODUCTION: Working-hour restrictions, rota gaps and an increasing drive for theatre efficiency have resulted in challenges to surgical training. As a result, Virtual Reality (VR) has emerged as a popular tool to augment this training. Our aim was to evaluate the validity of a VR simulator for performing percutaneous pedicle screw guidewire insertion. MATERIALS AND METHODS: Twenty-four participants were divided into three equal groups depending on prior surgical experience: a novice group (<10 procedures), an intermediate group (10-50 procedures) and an expert group (>50 procedures). All subjects performed four guidewire insertions on a TraumaVision® simulator (Swemac Innovation AB, Linköping, Sweden) in a set order. Six outcome measures were recorded; total score, time, fluoroscopy exposure, wire depth, zone of placement and wall violations. RESULTS: There were statistically significant differences between the groups for time taken (p<0.001) and fluoroscopy exposure (p<0.001). The novice group performed the worst, and the expert group outperformed both intermediates and novices in both categories. Other outcome results were good and less variable. There was an observed learning effect in the novice and intermediate groups between each of the attempts for both time taken and fluoroscopy exposure. CONCLUSIONS: The study contributes constructive evidence to support the validity of the TraumaVision® simulator as a training tool for pedicle screw guidewire insertion. The simulator is less suitable as an assessment tool. The learning effect was evident in the less experienced groups, suggesting that VR may offer a greater benefit in the early stages of training. Further work is required to assess transferability to the clinical setting.

3D imaging for hindfoot alignment assessment: a comparative study between non-weight-bearing MRI and weight-bearing CT.

PURPOSE: The authors compared measurements of hindfoot alignment on MR imaging with weight-bearing CT (WB-CT) to establish the degree of correlation. Forty-seven feet in 44 patients had weight-bearing CT and MRI studies performed on the same day. MATERIALS AND METHODS: Hindfoot alignment on MRI was assessed by two radiologists who calculated tibiocalcaneal angle (TCA) and calcaneofibular ligament angle (CFLA). On WB-CT, foot ankle offset (FAO), calcaneal offset (CO) and hindfoot angle (HA) were assessed by a senior Foot and Ankle Surgeon using dedicated software. Pearson correlation coefficient was used to evaluate the correlation between these measurements. RESULTS: The study group comprised 27 males and 17 females with a mean age of 45 years (range 13-79 years). A statistically significant positive correlation was identified between TCA on MRI and all measurements of hindfoot alignment on WB-CT (p = 0.001-0.005). The CFLA on MRI only had significant correlation with CO on WB-CT (p = 0.03). A significant negative correlation was observed between both MRI parameters (p < 0.001). CONCLUSION: A highly significant correlation between tibiocalcaneal angle on non-weight-bearing ankle MR imaging and hindfoot alignment measurements on weight-bearing CT was identified.

The awareness of hindfoot malalignment on non-weight-bearing ankle MRI.

OBJECTIVE: Hindfoot malalignment is a relatively common clinical finding and several studies have suggested that hindfoot valgus can be identified on non-weight-bearing ankle MRI. The aim of this study was to determine the awareness of hindfoot malalignment on ankle MRI amongst consultant musculoskeletal radiologists. MATERIALS AND METHODS: All MRI studies referred by Foot and Ankle Unit Consultants reported by one of 14 consultant musculoskeletal radiologists between March 2016 and August 2019 were retrieved from the Hospital Radiology Information System. These were reviewed independently by a radiology fellow and a consultant radiologist. Tibiocalcaneal angle (TCA) was measured, and extra-articular talocalcaneal (EA-TCI) and calcaneofibular impingement (EA-CFI) were recorded. Radiology reports were then analysed for mention of hindfoot malalignment and the presence of EA-TCI and EA-CFI. RESULTS: The study group comprised 129 patients, 46 males and 83 females with a mean age of 46.8 years (range 8-84 years). Based on review, hindfoot valgus was present in 78-80 cases (60.5-62%), EA-TCI in 30-36 cases (23.2-27.9%) and EA-CFI in 18-21 cases (14-16.3%). By comparison, MRI reports mentioned hindfoot valgus in 18 cases (2 incorrectly), EA-TCI in 8 cases (1 incorrectly) and EA-CFI in 10 cases (1 incorrectly). CONCLUSION: Hindfoot valgus, EA-TCI and EA-CFI were present relatively commonly on review of ankle MRI studies in patients referred from a specialist Foot and Ankle Unit but were commonly under-reported highlighting a relative lack of awareness of hindfoot malalignment on ankle MRI amongst musculoskeletal radiologists, which could impact negatively on patient management.

How to salvage a salvage endoprosthesis.

Custom-made endoprostheses can be linked to existing well-fixed implants in the treatment of complex periprosthetic femoral fractures. By adopting this salvage approach, secure implants can be retained in favour of patients undergoing more tissue disruptive procedures such as total femoral replacements. In this piece, we present a unique case illustrating a salvage strategy for treating a failed cement-linked salvage endoprosthesis, a complex scenario which to our knowledge has never before been reported.