Aims. Total knee arthroplasty (TKA) may provoke ankle symptoms. The aim of this study was to validate the impact of the preoperative mechanical tibiofemoral angle (mTFA), the talar tilt (TT) on ankle symptoms after TKA, and assess changes in the range of motion (ROM) of the subtalar joint, foot posture, and ankle laxity. Methods. Patients who underwent TKA from September 2020 to September 2021 were prospectively included. Inclusion criteria were primary end-stage osteoarthritis (Kellgren-Lawrence stage IV) of the knee. Exclusion criteria were missed follow-up visit, post-traumatic pathologies of the foot, and neurological disorders. Radiological angles measured included the mTFA, hindfoot alignment view angle, and TT. The Foot Function Index (FFI) score was assessed. Gait analyses were conducted to measure mediolateral changes of the gait line and ankle laxity was tested using an ankle arthrometer. All parameters were acquired one week pre- and three months postoperatively. Results. A total of 69 patients (varus n = 45; valgus n = 24) underwent TKA and completed the postoperative follow-up visit. Of these, 16 patients (23.2%) reported the onset or progression of ankle symptoms. Varus patients with increased ankle symptoms after TKA had a significantly higher pre- and postoperative TT. Valgus patients with ankle symptoms after TKA showed a pathologically lateralized gait line which could not be corrected through TKA. Patients who reported increased ankle pain neither had a decreased ROM of the subtalar joint nor increased ankle laxity following TKA. The preoperative mTFA did not correlate with the postoperative FFI (r = 0.037; p = 0.759). Conclusion. Approximately one-quarter of the patients developed ankle pain after TKA. If patients complain about ankle symptoms after TKA, standing radiographs of the ankle and a gait analysis could help in detecting a malaligned TT or a pathological gait. Cite this article: Bone Joint J 2023;105-B(11):1159–1167

Objectives. The objective of this study was to quantify the relative movement between the articular surfaces in the tibiotalar and subtalar joints during normal walking in asymptomatic individuals. Methods. 3D movement data of the ankle joint complex were acquired from 18 subjects using a biplanar fluoroscopic system and 3D-to-2D registration of bone models obtained from CT images. Surface relative velocity vectors (SRVVs) of the articular surfaces of the tibiotalar and subtalar joints were calculated. The relative movement of the articulating surfaces was quantified as the mean relative speed (RS) and synchronization index (SI. ENT. ) of the SRVVs. Results. SI. ENT. and mean RS data showed that the tibiotalar joint exhibited translational movement throughout the stance, with a mean SI. ENT. of 0.54 (. sd. 0.21). The mean RS of the tibiotalar joint during the 0% to 20% post heel-strike phase was 36.0 mm/s (. sd. 14.2), which was higher than for the rest of the stance period. The subtalar joint had a mean SI. ENT. value of 0.43 (. sd. 0.21) during the stance phase and exhibited a greater degree of rotational movement than the tibiotalar joint. The mean relative speeds of the subtalar joint in early (0% to 10%) and late (80% to 90%) stance were 23.9 mm/s (. sd. 11.3) and 25.1 mm/s (. sd 9.5). , respectively, which were significantly higher than the mean RS during mid-stance (10% to 80%). Conclusion. The tibiotalar and subtalar joints exhibited significant translational and rotational movement in the initial stance, whereas only the subtalar joint exhibited significant rotational movement during the late stance. The relative movement on the articular surfaces provided deeper insight into the interactions between articular surfaces, which are unobtainable using the joint coordinate system. Cite this article: C-B. Phan, D-P. Nguyen, K. M. Lee, S. Koo. Relative movement on the articular surfaces of the tibiotalar and subtalar joints during walking. Bone Joint Res 2018;7:501–507. DOI: 10.1302/2046-3758.78.BJR-2018-0014.R1

Aims. The pathogenesis of intraneural ganglion cysts is controversial. Recent reports in the literature described medial plantar intraneural ganglion cysts (mIGC) with articular branches to subtalar joints. The aim of the current study was to provide further support for the principles underlying the articular theory, and to explain the successes and failures of treatment of mICGs. Patients and Methods. Between 2006 and 2017, five patients with five mICGs were retrospectively reviewed. There were five men with a mean age of 50.2 years (33 to 68) and a mean follow-up of 3.8 years (0.8 to 6). Case history, physical examination, imaging, and intraoperative findings were reviewed. The outcomes of interest were ultrasound and/or MRI features of mICG, as well as the clinical outcomes. Results. The five intraneural cysts followed the principles of the unifying articular theory. Connection to the posterior subtalar joint (pSTJ) was identified or suspected in four patients. Re-evaluation of preoperative MRI demonstrated a degenerative pSTJ and denervation changes in the abductor hallucis in all patients. Cyst excision with resection of the articular branch (four), cyst incision and drainage (one), and percutaneous aspiration/steroid injection (two) were performed. Removing the connection to the pSTJ prevented recurrence of mIGC, whereas medial plantar nerves remained cystic and symptomatic when resection of the communicating articular branch was not performed. Conclusion. Our findings support a standardized treatment algorithm for mIGC in the presence of degenerative disease at the pSTJ. By understanding the pathoanatomic mechanism for every cyst, we can improve treatment that must address the articular branch to avoid the recurrence of intraneural ganglion cysts, as well as the degenerative pSTJ to avoid extraneural cyst formation or recurrence. Cite this article: Bone Joint J 2018;100-B:183–9

The subtalar joint is not easy to visualise by standard radiographic methods. Several projections are described including medial and lateral oblique axial views to demonstrate the three compartments of the joint. It is suggested that when visualisation of the subtalar joint is required these views should be routine. Various conditions affecting the subtalar joint and their demonstration by these oblique axial views are discussed

We have developed a method of measuring anterior displacement of the calcaneus on the talus in instability of the subtalar joint and have used the technique to demonstrate anterior instability in 50 patients (72 feet) showing a positive drawer sign. The angle of the posterior facet of the talus was also measured to assess the bony configuration. Our patients with subtalar joint instability could be divided into three categories. The first group had a history of trauma leading to ankle instability (26 cases), the second showed generalised joint laxity (10 cases) and the third were young females with a history of chronic stress on the foot and a poor bony block (14 cases). Satisfactory results were obtained by treating the instability with a brace or by reconstruction of the interosseous talocalcaneal ligament

1 . A small series of fractures of the calcaneum with distortion of the subtalar joint has been reviewed. 2. All were treated by subtalar fusion, in most as part of the primary treatment. 3. In all patients the subtalar joint fused by bone without post-operative plaster immobilisation. 4. Plaster immobilisation is not only unnecessary, it is undesirable. 5. Heavy work, including work on ladders and scaffolding, can be undertaken after subtalar fusion

Thirty-six patients with 39 fresh fractures of the calcaneus were investigated by standard radiography and by computerised tomography. It was found that the size and disposition of the fracture fragments and the degree of involvement of the posterior facet of the subtalar joint were more clearly shown by CT scanning. We recommend this technique for assessment and particularly for pre-operative planning

1. A modification of the Grice extra-articular subtalar arthrodesis is described.

2. The results of this operation are presented.

1. A simple method of subtalar fusion, suitable for use in children, is described.

2. Although it is intended to provide stability for some years until a complete subtalar fusion can be carried out, further operation may not be necessary.

3. Its use is not advocated over the age of eleven or twelve.

Aims. No randomized comparative study has compared the extensile lateral approach (ELA) and sinus tarsi approach (STA) for Sanders type 2 calcaneal fractures. This randomized comparative study was conducted to confirm whether the STA was prone to fewer wound complications than the ELA. Methods. Between August 2013 and August 2018, 64 patients with Sanders type 2 calcaneus fractures were randomly assigned to receive surgical treatment by the ELA (32 patients) and STA (32 patients). The primary outcome was development of wound complications. The secondary outcomes were postoperative complications, pain scored of a visual analogue scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) score, 36-item Short Form health survey, operative duration, subtalar joint range of motion (ROM), Böhler’s angle and calcaneal width, and posterior facet reduction. Results. Although four patients (12.5%) in the ELA groups and none in the STA group experienced complications, the difference was not statistically significant (p = 0.113). VAS and AOFAS score were significantly better in the STA group than in the ELA group at six months (p = 0.017 and p = 0.021), but not at 12 months (p = 0.096 and p = 0.200) after surgery. The operation time was significantly shorter in the STA group than in the ELA group (p < 0.001). The subtalar joint ROM was significantly better in the STA group (p = 0.015). Assessment of the amount of postoperative reduction compared with the uninjured limb showed significant restoration of calcaneal width in the ELA group compared with that in the STA group (p < 0.001). Conclusion. The ELA group showed higher frequency of wound complications than the STA group for Sanders type 2 calcaneal fractures even though this was not statistically significant. Cite this article: Bone Joint J 2021;103-B(2):286–293

Evaluating musculoskeletal conditions of the lower limb and understanding the pathophysiology of complex bone kinematics is challenging. Static images do not take into account the dynamic component of relative bone motion and muscle activation. Fluoroscopy and dynamic MRI have important limitations. Dynamic CT (4D-CT) is an emerging alternative that combines high spatial and temporal resolution, with an increased availability in clinical practice. 4D-CT allows simultaneous visualization of bone morphology and joint kinematics. This unique combination makes it an ideal tool to evaluate functional disorders of the musculoskeletal system. In the lower limb, 4D-CT has been used to diagnose femoroacetabular impingement, patellofemoral, ankle and subtalar joint instability, or reduced range of motion. 4D-CT has also been used to demonstrate the effect of surgery, mainly on patellar instability. 4D-CT will need further research and validation before it can be widely used in clinical practice. We believe, however, it is here to stay, and will become a reference in the diagnosis of lower limb conditions and the evaluation of treatment options. Cite this article: Bone Joint J 2021;103-B(5):822–827

Aims . To assess the effect of high tibial and distal femoral osteotomies (HTO and DFO) on the pressure characteristics of the ankle joint. Materials and Methods. Varus and valgus malalignment of the knee was simulated in human cadaver full-length legs. Testing included four measurements: baseline malalignment, 5° and 10° re-aligning osteotomy, and control baseline malalignment. For HTO, testing was rerun with the subtalar joint fixed. In order to represent half body weight, a 300 N force was applied onto the femoral head. Intra-articular sensors captured ankle pressure. Results. In the absence of restriction of subtalar movement, insignificant migration of the centre of force and changes of maximal pressure were seen at the ankle joint. With restricted subtalar motion, more significant lateralisation of the centre of force were seen with the subtalar joint in varus than in valgus position. Changes in maximum pressure were again not significant. . Conclusion. The re-alignment of coronal plane knee deformities by HTO and DFO altered ankle pressure characteristics. When the subtalar joint was fixed in the varus position, migration of centre of force after HTO was more significant than when the subtalar joint was fixed in valgus. Cite this article: Bone Joint J 2017;99-B:59–65

Aims. There is increasing evidence that flexible flatfoot (FF) can lead to symptoms and impairment in health-related quality of life. As such we undertook an observational study investigating the aetiology of this condition, to help inform management. The hypothesis was that as well as increased body mass index (BMI) and increased flexibility of the lower limb, an absent anterior subtalar articulation would be associated with a flatter foot posture. . Patients and Methods. A total of 84 children aged between eight and 15 years old were prospectively recruited. The BMI for each child was calculated, flexibility was assessed using the lower limb assessment scale (LLAS) and foot posture was quantified using the arch height index (AHI). Each child underwent a sagittal T1-weighted MRI scan of at least one foot. . Results. An absent anterior subtalar articulation (p < 0.001) and increased LLAS (p = 0.001) predicted a low AHI. BMI was not a significant predictive factor (p = 0.566). . Conclusion. This is the first study to demonstrate the importance of the morphology of the subtalar joint on the underlying foot posture in vivo. . Take home message: Flexibility of the lower limb and absence of the anterior facet of the subtalar joint are associated with flexible FF and may influence management of this common condition. Cite this article: Bone Joint J 2016;98-B:564–8

We carried out a retrospective review of 47 intra-articular fractures of the calcaneum treated by open reduction and internal fixation in 45 patients by a single surgeon between 1993 and 2001. The fractures were evaluated before operation by plain radiographs and a CT scan using Sanders’ classification. Osteosynthesis involved a lateral approach and the use of the AO calcaneal plate. The mean follow-up was for ten years (7 to 15). Clinical assessment included the American Orthopaedic Foot and Ankle Society Score (AOFAS), the Creighton-Nebraska Score, the Kerr, Prothero, Atkins Score and the SF-36 Health Questionnaire. The radiological evaluation consisted of lateral and axial views of the os calcis. Arthritic changes in the subtalar joint were assessed with an internal oblique view and were graded using the Morrey and Wiedeman scale. There were 18 excellent (38.3%), 17 good (36.2%), three fair (6.3%) and nine poor (19.2%) results. Five patients had a superficial wound infection and five others eventually had a subtalar arthrodesis because of continuing pain. Restoration of Böhler’s angle was associated with a better outcome. The degree of arthritic change in the subtalar joint did not correlate with the outcome scores or Sanders’ classification. Prompt osteosynthesis should be considered for intra-articular fractures of the calcaneum in order to restore the shape of the hindfoot and Böhler’s angle

We describe the surgical technique and results of arthroscopic subtalar release in 17 patients (17 feet) with painful subtalar stiffness following an intra-articular calcaneal fracture of Sanders’ type II or III. The mean duration from injury to arthroscopic release was 11.3 months (6.4 to 36) and the mean follow-up after release was 16.8 months (12 to 25). The patient was positioned laterally and three arthroscopic portals were placed anterolaterally, centrally and posterolaterally. The sinus tarsi and lateral gutter were debrided of fibrous tissue and the posterior talocalcaneal facet was released. In all, six patients were very satisfied, eight were satisfied and three were dissatisfied with their results. The mean American Orthopaedic Foot and Ankle Society ankle-hindfoot score improved from a mean of 49.4 points (35 to 66) pre-operatively to a mean of 79.6 points (51 to 95). All patients reported improvement in movement of the subtalar joint. No complications occurred following operation, but two patients subsequently required subtalar arthrodesis for continuing pain. In the majority of patients a functional improvement in hindfoot function was obtained following arthroscopic release of the subtalar joint for stiffness and pain secondary to Sanders type II and III fractures of the calcaneum

Aims. To systematically review the outcomes and complications of cosmetic stature lengthening. Methods. PubMed and Embase were searched on 10 November 2019 by three reviewers independently, and all relevant studies in English published up to that date were considered based on predetermined inclusion/exclusion criteria. The search was done using “cosmetic lengthening” and “stature lengthening” as key terms. The Preferred Reporting Item for Systematic Reviews and Meta-Analyses statement was used to screen the articles. Results. A total of 11 studies including 795 patients were included. The techniques used in the majority of the patients were classic 3- or 4-ring Ilizarov fixator (267 patients; 33.6%) and lengthening over nail (LON) (253 patients; 31.8%), while implantable lengthening nail (ILN) was used in the smallest number of patients (63 patients; 7.9%). Mean end lengthening achieved was 6.7 cm (SD 0.6; 1.5 to 13.0), and the mean follow-up duration was 4.9 years (SD 2.1; 41 days to 7 years). Overall, the mean number of problems, obstacles, and complications per patient was 0.78 (SD 0.5), 0.94 (SD 1.0), and 0.15 (SD 0.2), respectively. The most common problem and obstacle was ankle equinus deformity, while the most common complications were deformation of the regenerate after end of treatment and subtalar joint stiffness/deformity. Conclusion. Cosmetic stature lengthening provides favourable height gain, patient satisfaction, and functional outcomes, with low rate of major complications. Clear indications, contraindications, and guidelines for cosmetic stature lengthening are needed. Cite this article: Bone Joint Res 2020;9(7):341–350

Aims. Tibiotalocalcaneal (TTC) fusion is used to treat a variety of conditions affecting the ankle and subtalar joint, including osteoarthritis (OA), Charcot arthropathy, avascular necrosis (AVN) of the talus, failed total ankle arthroplasty, and severe deformity. The prevalence of postoperative complications remains high due to the complexity of hindfoot disease seen in these patients. The aim of this study was to analyze the relationship between preoperative conditions and postoperative complications in order to predict the outcome following primary TTC fusion. Methods. We retrospectively reviewed the medical records of 101 patients who underwent TTC fusion at the same institution between 2011 and 2019. Risk ratios (RRs) associated with age, sex, diabetes, cardiovascular disease, smoking, preoperative ankle deformity, and the use of bone graft during surgery were related to the postoperative complications. We determined from these data which pre- and perioperative factors significantly affected the outcome. Results. Out of the 101 patients included in the study, 29 (28.7%) had nonunion, five (4.9%) required below-knee amputation (BKA), 40 (39.6%) returned to the operating theatre, 16 (15.8%) had hardware failure, and 22 (21.8%) had a postoperative infection. Patients with a preoperative diagnosis of Charcot arthropathy and non-traumatic OA had significantly higher nonunion rates of 44.4% (12 patients) and 39.1% (18 patients) (p = 0.016) and infection rates of 29.6% (eight patients) and 37% (17 patients) compared to patients with traumatic arthritis, respectively (p = 0.002). There was a significantly increased rate of nonunion in diabetic patients (RR 2.22; p = 0.010). Patients with chronic kidney disease were 2.37-times more likely to have a nonunion (p = 0.006). Patients aged over 60 years had more than a three-fold increase in the rate of postoperative infection (RR 3.60; p = 0.006). The use of bone graft appeared to be significantly protective against postoperative infection (p = 0.019). Conclusion. We were able to confirm, in the largest series of TTC ankle fusions currently in the literature, that there remains a high rate of complications following this procedure. We found that patients with a Charcot or non-traumatic arthropathy had an increased risk of nonunion and postoperative infection compared to individuals with traumatic arthritis. Those with diabetes, chronic kidney disease, or aged over 60 years had an increased risk of nonunion. These findings help to confirm those of previous studies. Additionally, our study adds to the literature by showing that autologous bone graft may help in decreasing infection rates. These data can be useful to surgeons and patients when considering, discussing and planning TTC fusion. It helps surgeons further understand which patients are at a higher risk for postoperative complications when undergoing TTC fusion. Cite this article: Bone Joint J. 2020;102-B(3):345–351

Aims. The aim of this study was to present a series of patients with aseptic failure of a total ankle arthroplasty (TAA) who were treated with fusion of the hindfoot using a nail. Patients and Methods. A total of 23 TAAs, in 22 patients, were revised for aseptic loosening and balloon osteolysis to a hindfoot fusion by a single surgeon (NH) between January 2012 and August 2014. The procedure was carried out without bone graft using the Phoenix, Biomet Hindfoot Arthrodesis Nail. Preoperative investigations included full blood count, CRP and ESR, and radiological investigations including plain radiographs and CT scans. Postoperative plain radiographs were assessed for fusion. When there was any doubt, CT scans were performed. Results. The mean follow-up was 13.9 months (4.3 to 37.2). Union occurred at the tibiotalar joint in 22 ankles (95.6%) with one partial union. Union occurred at the subtalar joint in 20 ankles (87%) of cases with two nonunions. The nail broke in one patient with a subtalar nonunion and revision was undertaken. The only other noted complication was one patient who suffered a stress fracture at the proximal aspect of the nail, which was satisfactorily treated conservatively. Conclusion. This study represents the largest group of patients reported to have undergone revision TAA to fusion of the hindfoot with good results. Cite this article: Bone Joint J 2018;100-B:475–9

The April 2015 Foot & Ankle Roundup. 360 . looks at: Plantar pressures linked to radiographs; Strength training for ankle instability?; Is weight loss good for your feet?; Diabetes and foot surgery complications; Tantalum for failed ankle arthroplasty?; Steroids, costs and Morton’s neuroma; Ankle arthritis and subtalar joint

Talonavicular and subtalar joint fusion through a medial incision (modified triple arthrodesis) has become an increasingly popular technique for treating symptomatic flatfoot deformity caused by posterior tibial tendon dysfunction. The purpose of this study was to look at its clinical and radiological mid- to long-term outcomes, including the rates of recurrent flatfoot deformity, nonunion and avascular necrosis of the dome of the talus. A total of 84 patients (96 feet) with a symptomatic rigid flatfoot deformity caused by posterior tibial tendon dysfunction were treated using a modified triple arthrodesis. The mean age of the patients was 66 years (35 to 85) and the mean follow-up was 4.7 years (1 to 8.3). Both clinical and radiological outcomes were analysed retrospectively. In 86 of the 95 feet (90.5%) for which radiographs were available, there was no loss of correction at final follow-up. In all, 14 feet (14.7%) needed secondary surgery, six for nonunion, two for avascular necrosis, five for progression of the flatfoot deformity and tibiotalar arthritis and one because of symptomatic overcorrection. The mean American Orthopaedic Foot and Ankle Society Hindfoot score (AOFAS score) at final follow-up was 67 (between 16 and 100) and the mean visual analogue score for pain 2.4 points (between 0 and 10). In conclusion, modified triple arthrodesis provides reliable correction of deformity and a good clinical outcome at mid- to long-term follow-up, with nonunion as the most frequent complication. Avascular necrosis of the talus is a rare but serious complication of this technique. Cite this article: Bone Joint J 2015; 97-B:668–74