Introduction. The treatment of posterior malleolar fractures is developing. Mason and Molloy (Foot Ankle Int. 2017 Nov;38(11):1229-1235) identified only 49% of posterior malleolar rotational pilon type fractures had syndesmotic instabilities. This was against general thinking that fixation of such a fragment would stabilize the syndesmosis. Methods. We examined 10 cadaveric lower limbs that had been preserved for dissection at the Human Anatomy and Resource Centre at Liverpool University in a solution of formaldehyde. The lower limbs were carefully dissected to identify the ligamentous structures on the posterior aspect of the ankle. To compare the size to the rotational pilon posterior malleolar fracture (Mason and Molloy 2A and B) we gathered information from our posterior malleolar fracture database. 3D CT imaging was analysed using our department PACS system. Results. The PITFL insertion on the posterior aspect of the tibia is very large. The average size of insertion was 54.9×47.1mm across the posterior aspect of the tibia. Medially the PITFL blends into the sheath of tibialis posterior and laterally into the peroneal tendon sheath. 78 posterior lateral and 35 posterior medial fragments were measured. On average, the lateral to medial size of the posteromalleolar fragment was 24.5mm in the posterolateral fragment, and 43mm if there is a posteromedial fragment present also. The average distal to proximal size of the posterolateral fragment was 24.5mm and 18.5mm for the posteromedial fragment. Conclusion. The PITFL insertion on the tibia is broad. In comparison to the average size of the posterior malleolar fragments, the PITFL insertion is significantly bigger. Therefore, for a posterior malleolar fracture to cause posterior syndesmotic instability, a ligamentous injury will also have to occur. This explains the finding by Mason and Molloy that only 49% of type 2 injuries had a syndesmotic injury on testing

Aims. The optimal management of posterior malleolar ankle fractures, a prevalent type of ankle trauma, is essential for improved prognosis. However, there remains a debate over the most effective surgical approach, particularly between screw and plate fixation methods. This study aims to investigate the differences in outcomes associated with these fixation techniques. Methods. We conducted a comprehensive review of clinical trials comparing anteroposterior (A-P) screws, posteroanterior (P-A) screws, and plate fixation. Two investigators validated the data sourced from multiple databases (MEDLINE, EMBASE, and Web of Science). Following PRISMA guidelines, we carried out a network meta-analysis (NMA) using visual analogue scale and American Orthopaedic Foot and Ankle Score (AOFAS) as primary outcomes. Secondary outcomes included range of motion limitations, radiological outcomes, and complication rates. Results. The NMA encompassed 13 studies, consisting of four randomized trials and eight retrospective ones. According to the surface under the cumulative ranking curve-based ranking, the A-P screw was ranked highest for improvements in AOFAS and exhibited lowest in infection and peroneal nerve injury incidence. The P-A screws, on the other hand, excelled in terms of VAS score improvements. Conversely, posterior buttress plate fixation showed the least incidence of osteoarthritis grade progression, postoperative articular step-off ≥ 2 mm, nonunions, and loss of ankle dorsiflexion ≥ 5°, though it underperformed in most other clinical outcomes. Conclusion. The NMA suggests that open plating is more likely to provide better radiological outcomes, while screw fixation may have a greater potential for superior functional and pain results. Nevertheless, clinicians should still consider the fragment size and fracture pattern, weighing the advantages of rigid biomechanical fixation against the possibility of soft-tissue damage, to optimize treatment results. Cite this article: Bone Jt Open 2024;5(3):227–235

Aims. Arthroplasty has become increasingly popular to treat end-stage ankle arthritis. Iatrogenic posterior neurovascular and tendinous injury have been described from saw cuts. However, it is hypothesized that posterior ankle structures could be damaged by inserting tibial guide pins too deeply and be a potential cause of residual hindfoot pain. Methods. The preparation steps for ankle arthroplasty were performed using the Infinity total ankle system in five right-sided cadaveric ankles. All tibial guide pins were intentionally inserted past the posterior tibial cortex for assessment. All posterior ankles were subsequently dissected, with the primary endpoint being the presence of direct contact between the structure and pin. Results. All pin locations confer a risk of damaging posterior ankle structures, with all posterior ankle structures except the flexor hallucis longus tendon being contacted by at least one pin. Centrally-aligned transcortical pins were more likely to contact posteromedial neurovascular structures. Conclusion. These findings support our hypothesis that tibial guide pins pose a considerable risk of contacting and potentially damaging posterior ankle structures during ankle arthroplasty. This study is the first of its kind to assess this risk in the Infinity total ankle system. Cite this article: Bone Jt Open 2021;2(7):503–508

There is an increasing acceptance that the clinical outcomes following posterior malleolar fractures are less than satisfactory. Current ankle classification systems do not account for differences in fracture patterns or injury mechanisms, and as such, the clinical outcomes of these fractures are difficult to interpret. The aim of this study was to analyse our posterior malleolar fractures to better understand the anatomy of the fracture. In a series of 42 consecutive posterior malleolar, who all underwent CT imaging, we have described anatomically different fracture patterns dictated by the direction of the force and dependent on talus loading. We found 3 separate categories. Type 1 – a rotational injury in an unloaded talus resulted in an extraarticular posterior avulsion of the posterior ligaments. This occurred in 10 patients and was most commonly associated with either a high fibular spiral fracture or a low fibular fracture with Wagstaffe fragment avulsion. The syndesmosis was usually disrupted in these patients. Type 2 – a rotational injury in a loaded talus resulting in a posterolateral articular fracture, of the posterior incisura. This occurred in 16 patients and was most commonly associated with a posterior syndesmosis injury, low fibular spiral fracture and an anterior collicular fracture of the medial malleolus. Type 3 – axially loaded talus in plantarflexion causing a posterior pilon. This occurred in 16 patients and was most commonly associated with a long oblique fracture of the fibular and a Y shape fracture of the medial malleolus. The syndesmosis was usually intact in these patients. In conclusion, the anatomy of the posterior malleolar should not be underestimated and requires careful consideration during treatment and categorisation in outcome studies to prevent misinterpretation

Aims. Involvement of the posterior malleolus in fractures of the ankle probably adversely affects the functional outcome and may be associated with the development of post-traumatic osteoarthritis. Anatomical reduction is a predictor of a successful outcome. The purpose of this study was to describe the technique and short-term outcome of patients with trimalleolar fractures, who were treated surgically using a posterolateral approach in our hospital between 2010 and 2014. Patients and Methods. The study involved 52 patients. Their mean age was 49 years (22 to 79). There were 41 (79%) AO 44B-type and 11 (21%) 44C-type fractures. The mean size of the posterior fragment was 27% (10% to 52%) of the tibiotalar joint surface. Results. Reduction was anatomical in all patients with a residual step in the articular surface of ≤ 1 mm. In nine of the C-type fractures (82%), the syndesmosis was stable after fixation of the posterior fragment and a syndesmosis screw was not required. Apart from one superficial wound infection, there were no wound healing problems. At a mean radiological follow-up of 34 weeks (seven to 131), one patient with a 44C-type fracture had widening of the syndesmosis which required further surgery. Conclusion. We conclude that the posterolateral surgical approach to the ankle gives adequate access to the posterior malleolus, allowing its anatomical reduction and stable fixation: it has few complications. Take home message: Fixation of the posterior malleolus in trimalleolar fractures can be easily done via the posterolateral approach whereby anatomical reduction and stable fixation can be reached due to adequate visualisation of the fracture. Cite this article: Bone Joint J 2016;98-B:812–17

Most posterior hindfoot procedures have been described with the patient positioned prone. This affords excellent access to posterior hindfoot structures but has several disadvantages for the management of the airway, the requirement for an endotracheal tube in all patients, difficulty with ventilation and an increased risk of pressure injuries, especially with regard to reduced ocular perfusion. We describe use of the ‘recovery position’, which affords equivalent access to the posterior aspect of the ankle and hindfoot without the morbidity associated with the prone position. A laryngeal mask rather than endotracheal tube may be used in most patients. In this annotation we describe this technique, which offers a safe and simple alternative method of positioning patients for posterior hindfoot and ankle surgery. Cite this article: Bone Joint J 2013;95-B:1317–19

Background. There is an increasing acceptance that the clinical outcomes following posterior malleolar fractures are less than satisfactory. In our previous multicenter study (Powell, BOFAS 2016) we showed that the Olerud-Molander Ankle Score (OMAS) was 79 for unimalleolar fractures and 65 for bi malleolar fractures, however it dropped significantly to 54 in trimalleolar fractures. In creating a treatment guiding classification, we report our results in a system change in management of posterior malleolar fractures in our unit. Method. All fractures were classified according to Mason and Molloy classification (BOFAS 2015, FAI 2017) based on CT scans obtained pre-operatively. This dictated the treatment algorithm. Type 1 fractures underwent syndesmotic fixation. Type 2A fractures underwent ORIF through a posterolateral incision, and type 2B and 3 fractures underwent ORIF through a posteromedial incision. The patient remained NWB for 6 weeks postoperative. Data was collected from December 2014 to July 2017. Results. Patient related outcome measures were obtained in 50 patients with at least 6 month follow up (mean 18 months). According to Mason and Molloy classification there were 17 type 1, 12 type 2A, 10 type 2B and 11 type 3. The mean OMAS for type 1 was 75.9 (Range 30–100, SD 18.4), type 2A 75.0 (range 35–100, SD 21.3), type 2B 74.0 (range 55–100, SD 13.7) and type 3 70.5 (Range 35–100, SD 17.1). An increase in OMAS of 4 is clinically significant. Conclusion. We have been able demonstrate an improvement in OMAS for all posterior malleolar fractures with the treatment algorithm applied using the Mason and Molloy classification. Compared to our previous study we have successfully increased our OMAS scores to what would be expected from unimalleolar fractures. Mason and Molloy type 3 fractures have marginally poorer outcomes, which correlates with a more significant injury, however this does not reach statistical significance

Introduction. Fixation of posterior malleolar fragments associated with ankle fractures aims to stabilise the syndesmosis and prevent posterior subluxation. Haraguchi described 3 types of posterior malleolar fractures, with type 2 being a medial extension injury, these fractures often involve medial and posterior fragments. We describe the techniques and outcomes for a double window posteromedial approach allowing optimal reduction and stabilisation. Methods. A retrospective review was performed at 2 units, Bristol Royal Infirmary and QE Hospitals Birmingham, between August 2014 and April 2016. Inclusion criteria were all patients having this posteromedial approach for closed ankle fracture fixation. Patients were assessed for complications and postoperative ankle function with the Olerud and Molander scoring system. Results. We identified 9 patients treated over an 18 months with average follow up 9 months (range 4–18 months). All had an ankle dislocation reduced on scene or in ED, with 5 having posterior subluxation of the talus on the original films. None were open injuries. All had fixation of a posteromedial malleolar fragment, with 7 requiring a further direct lateral incision. Olerud and Molander ankle function score averaged at 72 (range 60–85) at short term follow up. Discussion. Approaches to the posteromedial fragments have been previously described in 2 ways. One utilises a window just medial to the Achilles tendon taking the neurovascular bundle medially, while the other approaches between tibialis posterior and FDL taking the neurovascular bundle laterally. Neither delivers complete access to an injury that often has sagittal and coronal splits needing individual reduction and fixation. Our approach over the neurovascular bundle allows 2 safe corridors through a single incision facilitating fragment specific fixation of both the medial and posterior components of the injury. Early results suggest this to be a safe and reliable technique to reduce and stabilise complex posteromedial ankle fractures

Injuries to the lateral ligamentous complex of the ankle are common. The most commonly injured ligament is the anterior talofibular ligament (ATFL) followed by the calcaneofibular ligament (CFL). The posterior talofibular ligament (PTFL) is less commonly injured. There are few studies reporting the incidence of PTFL injury and less data available which describes the significance of this injury. We aim to establish an incidence of PTFL injury and allude to the possible significance of such an injury. Methods. A retrospective review of patient notes and magnetic resonance (MR) scans dating from September 2007 to present day was undertaken. Patients complaining of acute or chronic ankle pain, swelling, and instability were included in the study. Exclusion criteria consisted of patients that had undergone previous surgery to the ankle. Routine MR was performed on all patients with oblique axial, coronal and sagittal views taken. Results. 312 patients were included in the study. The incidence of PTFL injury was 10.9%. The PTFL never ruptured in isolation. In 12.3% of patients the PTFL had ruptured with the ATFL and in 28.6% of patients it had ruptured with the CFL. Osteochondral defects were also present in the majority of patients with PTFL failure (57.1%). Conclusion. This study confirms that the PTFL rupture is rare. It is never injured in isolation. The frequency of incidental findings in those patients with PTFL injury is high. The commonest associated injury was an osteochondral lesion of the talus. The inference of our findings is that patients with a PTFL rupture have sustained a more significant ankle injury

The treatment of acquired flat foot secondary to dysfunction of the posterior tibial tendon (PTT) of stage II, as classified by Johnson and Strom, remains controversial. Joint sparing and soft-tissue reconstructive procedures give good early results, but few studies describe those in the medium-term. We studied prospectively the outcome of surgery in 51 patients with classical stage-II dysfunction of the PTT treated by a medial displacement calcaneal osteotomy and transfer of the tendon of flexor digitorum longus. We reviewed 44 patients with a mean follow-up of 51 months (38 to 62). The mean American Orthopaedic Foot and Ankle Society ankle/hindfoot rating scale improved from 48.8 before operation to 88.5 at follow-up. The operation failed in two patients who later had a calcaneocuboid fusion. The outcome in 43 patients was rated as good to excellent for pain and function, and in 36 good to excellent for alignment. There were no poor results

Flexor digitorum longus transfer and medial displacement calcaneal osteotomy is a well-recognised form of treatment for stage II posterior tibial tendon dysfunction. Although excellent short- and medium-term results have been reported, the long-term outcome is unknown. We reviewed the clinical outcome of 31 patients with a symptomatic flexible flat-foot deformity who underwent this procedure between 1994 and 1996. There were 21 women and ten men with a mean age of 54.3 years (42 to 70). The mean follow-up was 15.2 years (11.4 to 16.5). All scores improved significantly (p < 0.001). The mean American Orthopedic Foot and Ankle Society (AOFAS) score improved from 48.4 pre-operatively to 90.3 (54 to 100) at the final follow-up. The mean pain component improved from 12.3 to 35.2 (20 to 40). The mean function score improved from 35.2 to 45.6 (30 to 50). The mean visual analogue score for pain improved from 7.3 to 1.3 (0 to 6). The mean Short Form-36 physical component score was 40.6 (sd 8.9), and this showed a significant correlation with the mean AOFAS score (r = 0.68, p = 0.005). A total of 27 patients (87%) were pain free and functioning well at the final follow-up. We believe that flexor digitorum longus transfer and calcaneal osteotomy provides long-term pain relief and satisfactory function in the treatment of stage II posterior tibial tendon dysfunction.

Cite this article: Bone Joint J 2015;97-B:346–52.

We describe five adolescent patients aged between 13 and 16 years with bipartite ossification of the posteromedial aspect of the talus. All presented without a history of trauma.

All the ankles had a similar radiological appearance. Clinically, some restriction of movement was noted in three ankles and two subtalar joints, In addition, pain was noted over the posteromedial aspect of the ankle in three patients. In each patient the bipartite fragment was excised through a posteromedial approach to the ankle. Complete resolution was achieved at six months in three patients, with the remaining two describing exercise-induced symptoms. In one of these this precluded participation in sport.

Despite numerous anatomical variations within the tarsus, a case series of a bipartite talus has not previously been reported. This anatomical variation should be recognised to avoid misinterpretation as post-traumatic or other pathological processes. In the presence of recalcitrant symptoms excision is an option, but this is not universally successful in abolishing symptoms.

Background. Supination-external rotation (SER) injuries make up 80% of all ankle fractures. SER stage 2 injuries (AITFL and Weber B) are considered stable. SER stage 3 injury includes disruption of the posterior malleolus (or PITFL). In SER stage 4 there is either medial malleolus fracture or deltoid injury too. SER 4 injuries have been considered unstable, requiring surgery. The deltoid ligament is a key component of ankle stability, but clinical tests to assess deltoid injury have low specificity. This study specifically investigates the role of the components of the deep deltoid ligament in SER ankle fractures. Aim. To investigate the effect of deep deltoid ligament injury on SER ankle fracture stability. Methods. Four matched pairs (8 specimens) were tested using a standardised protocol. Specimens were sequentially tested for stability when axially loaded with a custom rig with up to 750N. Specimens were tested with: ankle intact; lateral injury (AITFL and Weber B); additional posterior injury (PITFL); additional anterior deep deltoid; additional posterior deep deltoid; lateral side ORIF. Clinical photographs and radiographs were recorded. In addition, dynamic stress radiographs were performed after sectioning the deep deltoid and then after fracture fixation to assess tilt of the talus in eversion. Results. All specimens with an intact posterior deep deltoid ligament were stable when loaded and showed no talar tilt on dynamic assessment. Once the posterior deep deltoid ligament was sectioned there was instability in all specimens. Surgical stabilisation of the lateral side prevented talar shift but not talar tilt. Conclusion. If the posterior deep deltoid ligament is intact SER fractures may be managed without surgery in a plantigrade cast. Without immobilisation the talus may tilt, risking deltoid incompetence

Introduction. Early clinical examination combined with MRI following a high ankle sprain allows accurate diagnosis of syndesmosis instability. However, patients often present late, and for chronic injuries clinical assessment is less reliable. Furthermore, in many centres MRI may be not be readily available. The aims of the current study were to define MRI characteristics associated with syndesmosis instability, and to determine whether MRI patterns differed according to time from injury. Methods. Retrospectively, patients with an unstable ligamentous syndesmosis injury requiring fixation were identified from the logbooks of two fellowship trained foot and ankle surgeons over a five-year period. After exclusion criteria (fibula fracture or absence of an MRI report by a consultant radiologist), 164 patients (mean age 30.7) were available. Associations between MRI characteristics and time to MRI were examined using Pearson's chi-square tests or Fisher's exact tests (significance set at p< 0.05). Results. Overall, 100% of scans detected a syndesmosis injury if performed acutely (within 6 weeks of injury), falling to 83% if performed after 12 weeks (p=0.001). In the acute group, 93.5% of patients had evidence of at least one of either PITFL injury (78.7%), posterior malleolus bone oedema (60.2%), or a posterior malleolus fracture (15.7%). In 20% of patients with a posterior malleolus bone bruise or fracture, the PITFL was reported as normal. The incidence of posterior malleolus bone bruising and fracture did not significantly differ according to time. Conclusion. For unstable ligamentous syndesmosis injuries, MRI becomes less sensitive over time. Importantly, posterior malleolus bone oedema or fracture may be the only evidence of a posterior injury. Failure to recognise instability may lead to inappropriate management of the patient, long term pain and arthritis. We therefore advocate early MRI as it becomes more difficult to ‘grade’ the injury if delayed

Aims. The Chopart joint complex is a joint between the midfoot and hindfoot. The static and dynamic support system of the joint is critical for maintaining the medial longitudinal arch of the foot. Any dysfunction leads to progressive collapsing flatfoot deformity (PCFD). Often, the tibialis posterior is the primary cause; however, contrary views have also been expressed. The present investigation intends to explore the comprehensive anatomy of the support system of the Chopart joint complex to gain insight into the cause of PCFD. Methods. The study was conducted on 40 adult embalmed cadaveric lower limbs. Chopart joint complexes were dissected, and the structures supporting the joint inferiorly were observed and noted. Results. The articulating bones exhibit features like a cuboid shelf and navicular beak, which appear to offer inferior support to the joint. The expanse of the spring ligament complex is more medial than inferior, while the superomedial part is more extensive than the intermediate and inferoplantar parts. The spring ligament is reinforced by the tendons in the superomedial part (the main tendon of tibialis posterior), the inferomedial part (the plantar slip of tibialis posterior), and the master knot of Henry positioned just inferior to the gap between the inferomedial and inferoplantar bundles. Conclusion. This study highlights that the medial aspect of the talonavicular articulation has more extensive reinforcement in the form of superomedial part of spring ligament and tibialis posterior tendon. The findings are expected to prompt further research in weightbearing settings on the pathogenesis of flatfoot. Cite this article: Bone Jt Open 2024;5(4):335–342

Background. Weightbearing computed tomography scans allow for better understanding of foot alignment in patients with Progressive Collapsing Foot Deformity. However, soft tissue integrity cannot be assessed via WBCT. As performing both WBCT and magnetic resonance imaging is not cost effective, we aimed to assess whether there is an association between specific WBCT and MRI findings. Methods. A cohort of 24 patients of various stages of PCFD (mean age 51±18 years) underwent WBCT scans and MRI. In addition to signs of sinus tarsi impingement, four three-dimensional measurements (talo-calcaneal overlap, talo-navicular coverage, Meary's angle axial/lateral) were obtained using a post processing software (DISIOR 2.1, Finland) on the WBCT datasets. Sinus tarsi obliteration, spring ligament complex and tibiospring ligament integrity, as well as tibialis posterior tendon degeneration were evaluated with MRI. Statistical analysis was performed for significant (P<0.05) correlation between findings. Results. None of the assessed 3D measurements correlated with spring ligament complex or tibiospring ligament tears. Age, body mass index, and TCO were associated with tibialis posterior tendon tears. 75% of patients with sinus tarsi impingement on WBCT also showed signs of sinus tarsi obliteration on MRI. Of the assessed parameters, only age and BMI were associated with sinus tarsi obliteration diagnosed on MRI, while the assessed WBCT based 3D measurements were, with the exception of MA axial, associated with sinus tarsi impingement. Conclusion. While WBCT reflects foot alignment and indicates signs of osseous impingement in PCFD patients, the association between WBCT based 3D measurements and ligament or tendon tears in MRI is limited. Partial or complete tears of the tibialis posterior tendon were only detectable in comparably older and overweight PCFD patients with an increased TCO. WBCT does not replace MRI in diagnostic value. Both imaging options add important information and may impact decision-making in the treatment of PCFD patients

Background. The use of a knotless TightRope for the stabilisation of a syndesmotic injury is a well-recognised mode of fixation. It has been described that the device can be inserted using a “closed” technique. This presents a risk of saphenous nerve entrapment and post-operative pain. Aim. We aimed to establish the actual risk of injury to the Saphenous Nerve using a “closed” technique for the insertion of a TightRope. Method. 20 TightRopes were inserted into Fresh Frozen Cadavers. This was done using the senior authors preferred technique of divergent tightropes with the distal implant directed slightly anterior to the fibula-tibia axis and the proximal implant slightly posterior in order to simulate the greatest risk to the nerve. This was done under image Intensifier guidance to simulate an intraoperative environment. The medial side of the distal tibia was then dissected to directly record and measure the relationship of the TightRope to the Saphenous Nerve. Measurements were taken using digital calipers from the centre of the button on the medial side of the TightRope to the centre of the nerve at the point of closest proximity. Results. 12 TightRopes were found to exit posterior to the nerve, 7 anterior and 1 penetrated through the centre of the nerve. The mean distance from the centre of the button to the nerve was 6.99mm (range 0.72–14.52mm, standard deviation 4.33mm). In 9 of the 20 TightRopes, the nerve was found to be less than 5mm away. Conclusion. Our findings demonstrated that the risks of damaging or indeed entrapping the Saphenous nerve were high, and therefore we would advocate an open incision on the medial side with judicious exploration to ensure there is no damage to the medial neurological structures

Aims. The rationale for exacting restoration of skeletal anatomy after unstable ankle fracture is to improve outcomes by reducing complications from malunion; however, current definitions of malunion lack confirmatory clinical evidence. Methods. Radiological (absolute radiological measurements aided by computer software) and clinical (clinical interpretation of radiographs) definitions of malunion were compared within the Ankle Injury Management (AIM) trial cohort, including people aged ≥ 60 years with an unstable ankle fracture. Linear regressions were used to explore the relationship between radiological malunion (RM) at six months and changes in function at three years. Function was assessed with the Olerud-Molander Ankle Score (OMAS), with a minimal clinically important difference set as six points, as per the AIM trial. Piecewise linear models were used to investigate new radiological thresholds which better explain symptom impact on ankle function. Results. Previously described measures of RM and surgeon opinion of clinically significant malunion (CSM) were shown to be related but with important differences. CSM was more strongly related to outcome (-13.9 points on the OMAS; 95% confidence interval (CI) -21.9 to -5.4) than RM (-5.5 points; 95% CI -9.8 to -1.2). Existing malunion thresholds for talar tilt and tibiofibular clear space were shown to be slightly conservative; new thresholds which better explain function were identified (talar tilt > 2.4°; tibiofibular clear space > 6 mm). Based on this new definition the presence of RM had an impact on function, which was statistically significant, but the clinical significance was uncertain (-9.1 points; 95% CI -13.8 to -4.4). In subsequent analysis, RM of a posterior malleolar fracture was shown to have a statistically significant impact on OMAS change scores, but the clinical significance was uncertain (-11.6 points; 95% CI -21.9 to -0.6). Conclusion. These results provide clinical evidence which supports the previously accepted definitions. Further research to investigate more conservative clinical thresholds for malunion is indicated. Cite this article: Bone Jt Open 2022;3(10):841–849

Talar body fractures are high energy intraarticular injuries that are best management by anatomical reduction and secure fixation to improve outcomes. The talus is relatively inaccessible surgically and requires extensive soft tissue dissection and/or osteotomies to gain adequate open visualisation. There are a small number of case reports on arthroscopic assisted fixation in the literature. This case series reports on the technique and early outcomes of six patients all of whom presented with significant intraarticular displacement and who were managed entirely arthroscopically. The fractures were of the main body of the talus involving the ankle and subtalar joints and all had preoperative CT scans. All six patients underwent posterior ankle and subtalar arthroscopy with cannulated screws used to stabilise the fractures after reduction. Visualisation of the fracture reduction was excellent. After 10 days in a backslab, the patients were protected in a boot and encouraged to actively move their ankles. Weight bearing was permitted once union appeared complete. There were no early complications of infection, avascular necrosis or VTE. There was one patient that had a non-clinically significant migration of a screw. Two patients were lost to follow up early due to being visitors. The mean length of follow up was 12 months in the remainder. The remaining four patients all returned to their preoperative level of activity. All had demonstrable subtalar stiffness. There was no early post-traumatic arthritis. This series represents the largest so far published. The main flaw in this report is the lack of long term follow up. While this report cannot state superiority over open techniques it is a safe, effective and acceptable technique that has significant conceptual benefits

Introduction. Tibial nerve anatomy has not been studied profoundly in comparison to Tarsal Tunnel Syndrome (TTS). Assuming symptoms are caused by an anatomical variant or mechanical cause regarding the tibial nerve, it is essential to investigate the anatomy of this structure taking in consideration that surgical and conservative treatments have shown poor results. Methods. 40 lower-leg specimens were obtained. Dissection started 20 centimeters proximal to the Dellon-McKinnon (DM) line towards the medial aspect of the naviculo-cuneiform joint distally. Anteriorly, dissection began at the tibio-talar medial gutter until the medial aspect of the Achilles tendon posteriorly. The plantar aspect extended from medial to lateral within the parameters previously described, ending at the level of the second metatarsal. Results. The flexor retinaculum had a denser consistency in 22.5% of the cases and the average length was 51.9 mm. The flexor retinaculum as an independent structure was found absent and 77.2% of cases as undistinguished extension of the crural fascia. The lateral plantar nerver (LPN) and abductor digiti minimi (ADM) nerve shared same origin in 80% of cases, 34.5% bifurcated proximal to the DM line, 31.2% distally and 34.3% at the same level. The medial calcaneal nerve (MCN) emerged proximal to the DM line in 100% of specimens. The medial plantar nerve (MPN) has its origin proximal to the DM line in 95% of cases. Conclusion. The flexor retinaculum is an extension of the crural fascia and not an independent structure. The LPN and ADM have the same origin in most cases and this presents as an important finding that must be studied in detail for clinical correlations between the motor and sensatory affections of the ADM and LPN respectively. Finally, the branches of the MCN and MPN are the most constant in their distribution and proximal origin in relation to the Dellon-McKinnon line