Hindfoot disorders are complex 3D deformities. Current literature has assessed their influence on the full leg alignment, but the superposition of the hindfoot on plain radiographs resulted in different measurement errors. Therefore, the aim of this study is to assess the hindfoot alignment on Weight-Bearing CT (WBCT) and its influence on the radiographic Hip-Knee-Ankle (HKA) angle. A retrospective analysis was performed on a study population of 109 patients (mean age of 53 years ± 14,49) with a varus or valgus hindfoot deformity. The hindfoot angle (HA) was measured on the WBCT while the HKA angle, and the anatomical tibia axis angle towards the vertical (TA. X. ) were analysed on the Full Leg radiographs. The mean HA in the valgus hindfoot group was 9,19°±7.94, in the varus hindfoot group −7,29°±6.09. The mean TA. X. was 3,32°±2.17 in the group with a valgus hindfoot and 1,89°±2.63 in the group with a varus hindfoot, which showed to be statistically different (p<0.05). The mean HKA Angle was −1,35°±2.73 in the valgus hindfoot group and 0,4°±2.89 in the varus hindfoot group, which showed to be statistically different (p<0.05). This study demonstrates a higher varus in both the HKA and TA. X. in valgus hindfoot and a higher tibia valgus in varus hindfoot. This contradicts the previous assumption that a varus hindfoot is associated with a varus knee or vice versa. In clinical practice, these findings contribute to a better understanding of deformity corrections of both the hindfoot and the knee

The relationship between hindfoot and forefoot kinematics is an important factor in the planning of ankle arthrodesis and ankle arthroplasty surgery. As more severe ankle deformities are corrected, improved techniques are required to assess and plan hindfoot to forefoot balancing. Gait analysis has previously been reported in patients with ankle arthritis without deformity. This group of patients have reduced intersegment motion in all measured angles. We have looked at a small group of patients with hindfoot deformity and ankle arthritis awaiting fusion or replacement. Using the Oxford Foot Model we have assessed lower limb kinematics with a focus on hindfoot to forefoot relationships. The results of our pilot study are in variance to previous studies in that we have shown that in the presence of hindfoot/ankle deformity, the forefoot range of motion increases. We feel that these data may impact on surgical planning

Introduction

Hind foot Charcot deformity is a disastrous complication of diabetic neuropathy and can lead to instability, ulceration and major amputation. The treatment of these patients is controversial. Internal stabilization and/or external fixation have demonstrated variable results of limb salvage and some authorities thus advise patients to undergo elective major amputation. However, we report a series of 9 diabetic patients with severe hind foot deformity complicated by ulceration in 5/9, who underwent acute corrective internal fixation with successful correction of deformity, healing of ulceration in 4/5 patients and limb salvage in all cases.

Varus ankle osteoarthritis (OA) is typically associated with peritalar instability, which may result in altered subtalar joint position. This study aimed to determine the extent to which total ankle replacement (TAR) in varus ankle OA can restore the subtalar position alignment using 3-dimensional semi-automated measurements on WBCT. Fourteen patients (15 ankles, mean age 61) who underwent TAR for varus ankle OA were retrospectively analyzed using semi- automated measurements of the hindfoot based on pre-and postoperative weightbearing WBCT (WBCT) imaging. Eight 3-dimensional angular measurements were obtained to quantify the ankle and subtalar joint alignment. Twenty healthy individuals were served as a control groups and were used for reliability assessments. All ankle and hindfoot angles improved between preoperative and a minimum of 1 year (mean 2.1 years) postoperative and were statistically significant in 6 out of 8 angles (P<0.05). Values The post-op angles were in a similar range to as those of healthy controls were achieved in all measurements and did not demonstrated statistical difference (P>0.05). Our findings indicate that talus repositioning after TAR within the ankle mortise improves restores the subtalar position joint alignment within normal values. These data inform foot and ankle surgeons on the amount of correction at the level of the subtalar joint that can be expected after TAR. This may contribute to improved biomechanics of the hindfoot complex. However, future studies are required to implement these findings in surgical algorithms for TAR in prescence of hindfoot deformity

Several emerging reports suggest an important involvement of the hindfoot alignment in the outcome of knee osteotomy. At present, studies lack a comprehensive overview. Therefore, we aimed to systematically review all biomechanical and clinical studies investigating the role of the hindfoot alignment in the setting of osteotomies around the knee. A systematic literature search was conducted on multiple databases combining “knee osteotomy” and “hindfoot/ankle alignment” search terms. Articles were screened and included according to the PRISMA guidelines. A quality assessment was conducted using the Quality Appraisal for Cadaveric Studies (QUACS) - and modified methodologic index for non-randomized studies (MINORS) scales. Three cadaveric, fourteen retrospective cohort and two case-control studies were eligible for review. Biomechanical hindfoot characteristics were positively affected (n=4), except in rigid subtalar joint (n=1) or talar tilt (n=1) deformity. Patient symptoms and/or radiographic alignment at the level of the hindfoot did also improve after knee osteotomy (n=13), except in case of a small pre-operative lateral distal tibia- and hip knee ankle (HKA) angulation or in case of a large HKA correction (>14.5°). Additionally, a pre-existent hindfoot deformity (>15.9°) was associated with undercorrection of lower limb alignment following knee osteotomy. The mean QUACS score was 61.3% (range: 46–69%) and mean MINORS score was 9.2 out of 16 (range 6–12) for non-comparative and 16.5 out of 24 (range 15–18) for comparative studies. Osteotomies performed to correct knee deformity have also an impact on biomechanical and clinical outcomes of the hindfoot. In general, these are reported to be beneficial, but several parameters were identified that are associated with newly onset – or deterioration of hindfoot symptoms following knee osteotomy. Further prospective studies are warranted to assess how diagnostic and therapeutic algorithms based on the identified criteria could be implemented to optimize the overall outcome of knee osteotomy. Remark: Aline Van Oevelen and Arne Burssens contributed equally to this work

Lateral approach open calcaneal osteotomy is the described gold standard procedure in the management of hindfoot deformity. With development of minimally invasive surgery, a MIS approach has been described, citing fewer wound complications and lower risk of sural nerve injury. This audit compares MIS to the traditional procedure. A retrospective review of all patients undergoing calcaneal osteotomy in Northumbria Trust in the past 5 years was performed. A total of 105 osteotomies were performed in 97 patients; 28 (13M:15F) in MIS group and 77 (40M:37F) had an open approach. The average age was 52.1 (range 16–83) for MIS and 51.5 (range 18–83) in the open group. All patients were followed up for development of wound complication, nerve injury and fusion rate. Wound complications were similar (10.7% in MIS group vs 10.3% in Open group) with no significant difference (p=0.48). Patients were treated for infection in 3(3.8%) cases in the open group and 2(7.1%) in the MIS group. This difference was not significant (p=0.43). 4 (14.3%) patients in the MIS group had evidence of sural nerve dysfunction post-operatively (managed expectantly), compared to 12(15.5%) patients in the open group (p=0.44). Of these, 2 went on to undergo neuroma exploration. There was no difference in nerve dysfunction in varus or valgus correction. Mean translation in the open group was measured as 7.3mm(SD=1.91;3 to 13mm) and 7.5mm(SD=1.25;5 to 10mm) in the MIS group. Translation was similar in varus or valgus correction. Non-union occurred in 2 patients in the MIS group and none in the open group (p= 0.06). MIS calcaneal osteotomy is a safe technique, that works as effectively as osteotomy performed through an open approach. There were lower rates of nerve injury, wound complication and infection, but this was not significantly different comparing groups. There was a higher risk of non-union in MIS technique

Applications of weightbearing computed tomography (WBCT) imaging in the foot and ankle have emerged over the past decade. However, the potential diagnostic benefits are scattered across the literature, and a concise overview is currently lacking. Therefore, we aimed to systematically review all reported diagnostic applications per anatomical region in the foot and ankle. A systematic literature search was performed in the electronic databases PubMed, EMBASE, Cochrane Library, and Web of Science. Search terms consisted of “weightbearing/standing CT and ankle, hind-, mid- or forefoot”. English language studies analyzing the diagnostic applications of WBCT were included. Studies were excluded if they simulated weightbearing CT, described normal subjects, included cadaveric samples or samples were case reports. The modified Methodological Index for Non-Randomized Studies (MINORS) was applied for quality assessment. The added value was defined as the review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and registered in the Prospero database (CRD42019106980). A total of 48 studies (prospective N=8, retrospective N=36, cohort study N=1, diagnostic N=2, prognostic comparative study N=1) were found to be eligible for review. The following diagnostic applications were identified per anatomical area in the foot: ankle (osteoarthritis N=5, ligament injury N=6); hindfoot (deformity N=9); midfoot (Lisfranc injury N=2, flatfoot deformity N=13, osteoarthritis N=1); forefoot (hallux valgus N=12). The identified studies contained diagnostic applications that could not be used on plain radiographs. The mean MINORS equaled 10.1 on a total of 16 (range: 8 to 12). Diagnostic applications of weightbearing CT imaging are most frequently studied in hindfoot deformity, but other area's areas are on the rise. Post-processing of images was identified as the main added value compared to WBRX. However, the findings should be interpreted with caution as the average quality score was moderate. Therefore, future prospective studies are warranted to consolidate the role of WBCT in diagnostic and therapeutic algorithms

Aims. To assess if older symptomatic children with club foot deformity differ in perceived disability and foot function during gait, depending on initial treatment with Ponseti or surgery, compared to a control group. Second aim was to investigate correlations between foot function during gait and perceived disability in this population. Methods. In all, 73 children with idiopathic club foot were included: 31 children treated with the Ponseti method (mean age 8.3 years; 24 male; 20 bilaterally affected, 13 left and 18 right sides analyzed), and 42 treated with primary surgical correction (mean age 11.6 years; 28 male; 23 bilaterally affected, 18 left and 24 right sides analyzed). Foot function data was collected during walking gait and included Oxford Foot Model kinematics (Foot Profile Score and the range of movement and average position of each part of the foot) and plantar pressure (peak pressure in five areas of the foot). Oxford Ankle Foot Questionnaire, Disease Specific Index for club foot, Paediatric Quality of Life Inventory 4.0 were also collected. The gait data were compared between the two club foot groups and compared to control data. The gait data were also correlated with the data extracted from the questionnaires. Results. Our findings suggest that symptomatic children with club foot deformity present with similar degrees of gait deviations and perceived disability regardless of whether they had previously been treated with the Ponseti Method or surgery. The presence of sagittal and coronal plane hindfoot deformity and coronal plane forefoot deformity were associated with higher levels of perceived disability, regardless of their initial treatment. Conclusion. This is the first paper to compare outcomes between Ponseti and surgery in a symptomatic older club foot population seeking further treatment. It is also the first paper to correlate foot function during gait and perceived disability to establish a link between deformity and subjective outcomes. Cite this article: Bone Joint Open 2020;1-7:384–391

We present our experience with a medial approach for triple arthrodesis for correction of severe rigid hindfoot deformity in patients who were at risk for wound complications with a standard lateral approach. Between 1995 and 2002, we treated 17 patients with a rigid hindfoot valgus deformity, and for whom a triple arthrodesis was planned, using a single medial incision. The indication for surgery was pain refractory to shoe wear, orthotic and brace modifications. The severity of the hindfoot deformity itself was not sufficient an indication for this procedure, since during the same time period, 157 triple arthrodesis procedures were performed using a two incision technique, many of which were associated with severe hindfoot varus or valgus deformities. The medial incision was indicated specifically for patients who were at risk for wound complications following correction of the hindfoot valgus deformity due to stretching of the lateral skin. There were 15 patients with rheumatoid arthritis (RA), and two patients who had deformity of the hind-foot following a crush injury associated with scarring of the lateral skin over the sinus tarsi. In addition to standard weight bearing radiographs of the foot and ankle, non-invasive vascular studies were performed in 5/17 patients pre-operatively who on clinical examination were considered to have peripheral vascular disease. Immunosuppressant medication(s) were not discontinued prior to surgery for the patients with RA, and were renewed once wound healing occurred. The surgery was performed in a standard manner for each patient, with an extensile medial incision, the use of a laminar spreader to facilitate exposure and joint debridement, and removal of appropriate bone wedges to improve correction. Cannulated partially threaded 5.0 mm (for the talonavicular and calcaneocuboid joints) and 6.5 mm (for the subtalar joint) screws were used in each patient. All 17 patients were examined a mean of 4.5 years following surgery (range 2.5–8), and the examination focused on the success of arthrodesis, the presence of ankle arthritis, as well as hindfoot deformity. Other outcome parameters were not specifically examined since these patients had multiple additional lower limb deformities, as well as arthritides of the foot and ankle unrelated to the performance of the triple arthrodesis. The correction obtained was compared with preoperative radiographs. There were no wound healing complications in any patient. Arthrodesis was obtained in 16/17 patients. In one patient with RA, a non-union of the calcaneocuboid joint was noted radiographically, but had been present for 6 years, and was asymptomatic. There was no loss of correction, however hindfoot valgus was present in three patients, caused by arthritis of the ankle associated with valgus tibiotalar deformity. Two additional patients had since undergone a total ankle replacement for correction of arthritis not associated with deformity, and one had undergone an ankle arthrodesis 2 years following the triple arthrodesis for correction of severe arthritis as well as tibiotalar deformity. On the anteroposterior foot radiograph, the talus-first metatarsal angle improved from a mean of 26 degrees (range 15–45), to a mean of 5 degrees (range 0–15). The talocalcaneal angle was not measured, since reproducible preoperative measurements could not be obtained. The axial talocalcaneal angle was not measured. The medial approach to triple arthrodesis is a reliable procedure, and can be used with a predictable outcome in patients who are at risk for wound healing complications for correction of hindfoot valgus deformity

Introduction. Charcot Arthropathy related foot and ankle deformities are a serious challenge. Surgical treatment of these deformities is now well established. The traditional surgical method of extensive surgical exposure, excision of bone, acute correction and internal fixation is not always appropriate in presence of active ulceration, deep infection and poor bone quality. Minimally invasive osteotomies and gradual correction of deformities with a circular frame are proving helpful in minimizing complications. We present our experience with the use of Taylor Spatial Frame (TSF) in 10 patients with recurrent ulceration and deformity. Materials and Methods. Our indication for the treatment with TSF is recurrent or intractable ulceration with or without active bone infection or a history of infection in a deformed foot and/or ankle. There are 2 female and 8 male patients in this cohort. We used a long bone module for ankle and hindfoot deformities (3 patients) and a forefoot 6×6 butt frame (7 patients) for midfoot deformities. An osteotomy through midfoot was performed in all chronic stable midfoot deformity cases and a calcaneal osteotomy and gradual correction through ankle in when hindfoot and ankle deformities co-existed. Results. Our outcome measures are a complete healing of ulcer and infection without recurrence, clinically plantigrade foot and ability to wear regular shoes or diabetic footwear. We achieved this outcome in 9 out of 10 patients. Successful patients remain ulcer free at minimum 7 and maximum 14 years follow up. Complications included eight episodes of pin infection that responded to oral antibiotics only and two pin breakages. Conclusions. Our results confirm that Taylor Spatial Frame treatment is a good alternative to traditional surgery in high-risk complex Charcot neuroarthropathy foot and ankle deformities

Grice-Green subtalar arthrodesis was initially reported to correct valgus hindfoot deformities in patients with poliomyelitis. Nowadays, the indications of the Grice-Green arthrodesis have been significally broadened. The aim of this study is to analyse the indications of treatment and evaluate the results of the Grice-Green arthrodesis in children. During the period 1986–2006, 17 children with valgus hindfoot deformities were treated in our department. In 12 of them the procedure was performed in both feet and in the rest (5 patients) unilaterally. The mean age at operation was 8.8 years. The most common group of patients suffered from cerebral palsy (10 patients), followed by the patients suffering from myelomeningocele (4 patients), 2 patients suffered from overcorrection following treatment of congenital equinovarus and one patient from Charcot Marie Tooth disease. In neine patients the operation was combined with Achilles tendon lengthening, capsulotomies, tendon transfers, tendonotomies, and Evans arthrodesis. In all operations bone graft from the tibia or the fibula was used. Postoperatively a balow knee non weightbearing cast was applied for 8 weeks followed by a weightbearing cast for 4 weeks. The results were avaluated according to Alman and Zimbies criteria. The mean follow up of the patients was 4.2 years. The results in 24 feet were considered excellent and in 5 cases satisfactory. In all cases subtalar arthrodesis was achieved. Grice-Green arthrodesis is a very useful operative technique for the correction of severe valgus hindfoot deformities in children. The results of the technique are usually good and the operation does not influence the normal growth of the foot. An accurate preoperative planning and a good surgical technique is neccesary for good results

Introduction: Total ankle replacement is proving a reliable procedure for ankle arthrosis. Some authors have recommended that significant hindfoot deformity should be a contraindication. This study aims to provide guidance on the management of this difficult problem. Methods: 170 consecutive total ankle replacements were performed in 147 patients, aged 32–83 (mean 65) between 1999 and 2006 by a single surgeon. All surviving patients (5 deaths) were followed up prospectively on an annual basis, for a mean of 3 years (1–8 years). Comparison was made between Group A (45 ankles with a hindfoot deformity of > 10° varus or valgus) and Group B (the remaining 120 ankles). Results: There was no statistical difference between the 2 groups for age, sex or indication for surgery (osteoarthritis in 81%). Group A comprised 8 valgus and 36 varus ankles. 23/36 varus ankles had a deformity of > 20°. 6 revisions (13%) were performed in Group A (5 of these related to instability – all preoperatively varus of > 20 degrees). 10 revisions (8%) were performed in Group B (2 related to instability). 6 ankles underwent intra-operative deltoid release and 6 had pre or post-operative calcaneal osteotomy. Only one of these required revision for instability. 4 ankles underwent post-operative lateral ligament reconstruction. These ankles all failed due to instability. The mean postoperative American Foot and Ankle Society score in Group A was 85, compared to 78 in Group B. Discussion: Our study reveals that patients with significant hindfoot deformity may benefit from total ankle replacement. However, the risk of revision due to instability and need for further surgery is higher, especially with a varus deformity of > 20°. Almost a quarter of these ankles required revision. Potential solutions may be to correct the deformity with additional calcaneal osteotomy or medial release, whereas lateral ligament reconstruction alone is inadequate

Patients with a hindfoot deformity impose a particular challenge when performing a total knee arthroplasty (TKA). This could be attributed to the lack of insights concerning the outcome towards the hindfoot alignment. Our objective was to perform a systematic review of the literature to investigate the influence of TKA on hindfoot alignment and vice-versa. In accordance with the Methodological Index For Non-Randomized Studies (MINORS) statement standards, we performed a systematic review. Electronic databases Pubmed, EMBASE, Web of Science, Google Scholar and Cochrane Library were searched to identify capable studies studying the influence between TKA and hindfoot malalignment. We indentified four prospective cohort studies, seven retrospective cohort studies and one case-control study. All twelve articles addressed the influence of TKA on hindfoot alignment. Seven out of nine studies which noticed an improvement of hindfoot alignment after TKA, found a significant improvement (p<0.05). Aditionally three of these studies reported a significant improvement only in valgus hindfeet (p<0.05). On the topic of hindfoot alignment influencing TKA, we identified two studies. These studies reported an impact of hindfoot alignment on the weightbearing and described that 87% of hindfeet remained in valgus alignment after TKA. Available data suggests that alignment in valgus hindfeet can improve after TKA, though long term results are not present. Contrary to last, improvement of hindfoot alignment is not expected in varus hindfeet. Furthermore hindfoot alignment deformity may cause a reduction of the long term survival of the knee prosthesis and therefore should be taken in to account

We reported the outcomes of patients with Charcot neuropathy who underwent hind foot deformity correction using retrograde intramedullary nail arthrodesis. Twenty one feet in 20 patients, aged 45 to 83 years, with a mean BMI of 32.7 and a median ASA score of 3, were included in this study. All patients presented with severe hindfoot deformities and 15 had recurrent ulceration. All patients were treated with hindfoot corrective fusion and seven patients also underwent simultaneous mid foot fusion using a bolt or locking plate. After a mean follow up of 26 months, none of the cases required any form of amputation. Eighty percent of patients with ulceration achieved healing and all but one patient returned to independent ambulation. One nail fracture and three mid foot metal work failure resulted in fixation failure requiring revision surgery. Distal locking screw displacement occurred only with standard screws but not with hydroxyapatite-coated screws. The AAOS-FAO score improved from 50.7 to 65.2 (p=0.015). The EQ-5D-5L improved from 0.63 to 0.67 (p=0.012) and the SF-36 PCS from 25.2 to 29.8 (p=0.003). Single stage deformity correction with intramedullary hindfoot arthrodesis nail is a viable treatment option for severe Charcot hindfoot deformity with ulceration and instability

Introduction We report a modified technique using peroneus brevis for reconstruction of the anterior talofibular and calcaneo-fibular ligaments in the ankle for chronic instability. Method The surgery was carried out using a double drill-hole in the distal fibula with either a complete or partial tendon graft. An examination under anaesthetic with ankle arthroscopy has been utilised to confirm the clinical diagnosis and assess the articular surfaces. In appropriate cases a translational os calcis osteotomy is added to correct varus hindfoot deformity. Forty-five procedures were carried out over a 10-year period. The patients were retrospectively assessed with a case note review, and an updated clinical evaluation. The assessment focussed on pain, stability and impact on daily living. Results Our results compare favourably with existing techniques for lateral ligament reconstruction, with most patients being satisfied with the improvement in pain relief and stability. These will be discussed in detail. Complications included superficial wound infections and sensory neurological symptoms. There were two failures following surgery both of which were associated with a high body mass index and joint laxity. Conclusion This procedure provides anatomical reconstruction, is technically undemanding and gives adequate pain relief, stability and return to sporting activity. With careful patient selection, including treatment of intra-articular pathology and hindfoot deformity, it is a useful alternative to the methods currently available

Aims: Hindfoot deformity in varus position is an aetiology of chronic ankle instability without laxity. In this condition, a Dwyer osteotomy has to be performed. Methods: Between 1992 and 2000, 15 patients have been operated on, with this technique. The mean varus deformity was of 5û (3û to 10û).13 patients had sporting activities, 8 of them in competition. Instability during sporting activity were present in 60% of cases. Associated lesions were reported in 6 cases. A Dwyer procedure using a 1/3 tube plate þxed with two screws were performed in all cases. Associated procedures were performed at the same time as such as a lateral ligamentoplasty or a þrst metatarsal osteotomy. All patients were reviewed clinically and radiologically using AOFAS score. Results: The mean follow-up was of 3.5 years (1 to 9 years). The only one complication reported was a skin necrosis, treated by a cutaneous ßap in a patient operated on with Dwyer and ligamentoplasty in the same procedure. No ankle instability was reported. Mild pain was reported in 10 patients and 50% of them only for sporting activities.11 patients returned to sporting activity and 33% of them at the same level. The mean Kita-oka score was of 92 (85 to 100). The patients were satisþed and very satisþed in 80 of cases. Conclusions: Dwyer lateral closing wedge calcaneal osteotomy is successful for the treatment of chronic ankle instability without laxity and with varus hindfoot deformity. When laxity is associated with varus deformity an operative procedure in two steps is necessary to avoid wound complication. Dwyer osteotomy has to be performed þrst

Surgical resection of the persistently painful talocalcaneal tarsal coalition has not been shown to reliably relieve symptoms in patients with coalitions that are large and have associated hindfoot valgus and subtalar arthrosis. It has been recommended that these patients undergo triple arthrodesis, a procedure that is known to lead to premature arthrosis of the ankle joint. To avoid additional stress on this important joint, treatment of this patient group using calcaneal lengthening osteotomy (CLO), with or without resection of the coalition, has been performed at our institution for the last 15 years. A retrospective review of all patients with talocalcaneal coalitions who had undergone CLO was performed. Clinical and radiographic records were reviewed. Demographic data, and pre- and post-operative pain and function were recorded. Pre- and post-operative radiographs and computed tomography (CT) scans were reviewed and measurements recorded. CT scans were used to calculate the degree of hindfoot valgus and the size of the coalition. Patients were invited to return for clinical examination and follow-up x-rays if two years had passed since their operation. They completed American foot and ankle hindfoot scores, VAS pain scores and were asked satisfaction questionnaires. Radiographic measurements were performed. There were 13 patients who underwent 19 CLOs. Of these 13 patients, eight patients with 13 CLO’s returned for clinical examination and radiographs. Five patients had nine CLO’s to correct deformity without resection of a large middle facet talocalcaneal coalition with severe hindfoot deformity. All patients had restoration of normal foot shape with improvement in comfort and function. One patient had improvement in comfort and function following bilateral simultaneous coalition resection of cartilaginous coalition and CLO to correct significant hindfoot deformity. Two patients had improvement in pain and function in a foot that had residual pain and deformity following prior talocalcaneal coalition resection. CLO, usually accompanied by a heel cord lengthening, is a useful operation both in the failed middle facet resection where there is persistent pain and deformity, and also in the very large coalition with associated deformity and/or arthrosis that is not appropriate for resection. It corrects the foot deformity, improves comfort and function, maintains motion in Chopart’s joints and therefore, unlike triple arthrodesis, avoids additional stresses in the ankle joint

Background. A calcaneal medial osteotomy (CMO) is a surgical procedure frequently performed to correct a valgus alignment of the hindfoot. However currently little is known on its accurate influence on hindfoot alignment (HA). Aim. To assess the influence of a CMO on HA in both 2D and 3D measurements using weightbearing CT (WBCT). Methods. Twelve patients with a mean age of 49,4 years (range 18–67yrs) were prospectively included. Indications for surgical correction by a CMO with a solitary translation of the calcaneus consisted of an adult acquired flat foot stage II (N=10) and a talocalcaneal coalition (N=2). Fixation of the osteotomy was performed either using a step plate or double screw. A WBCT was obtained pre- and post-operative. HA was assessed by an angle between the anatomical tibia axis and the axis connecting the inferior calcaneus point and the middle of the talus in the coronal plane (HA. 2D. ) using Curvebeam® software. The tibia in the HA was separately assessed by the anatomical tibia axis (TA. X 2D. ). The same method was translated in 3D using 3-Matic® software with a Cartesian coordinate system originating in the inferior point of the calcaneus (HA. 3D. and TA. x 3D. ). Results. Both the mean pre-op HA. 2D. =12.8°± 4.5 and HA. 3D. =21.1°± 8.4 of valgus improved significantly post-operatively to a HA. 2D. =4.2°±4.5 and a HA. 3D. =11,9°± 6.1 (P < 0.001). Additionally, the mean pre-op TA. X 2D. = 4°± 2.6 and TA. X 3D. = 7,2 °± 3.2 showed a significant improvement to a TA. X 2D. = 3.1°± 2.7 and a TA. X 3D. = 6.1 °± 3.4 post-operatively (P < 0.05). The inter-rater reliability of the 2D measurement method with a mean ICC. HA2D. =0.74 and a mean ICC. TA2D. = 0.77 showed to be lower when compared to the 3D measurement method with a mean ICC. HA3D. =0.94 and a mean ICC. TA3D. =0.89. Conclusion. This study shows an effective correction of the valgus position from the calcaneus measured both in 2D and 3D when using a surgical CMO. The novelty is the marked influence on the tibia, which could now be accurately assessed using a weightbearing CT and additional 3D measurements. This resulted in 10% of the achieved HA correction, when analyzed both in 2D and 3D. This information could be of use when performing a pre-operative planning of a hindfoot deformity

Background. There have been multiple techniques described to determine hindfoot alignment radiographically. The 2-dimensional nature of radiographs fails to take into account the contribution of the remainder of the foot to overall alignment. A new radiographic technique has been published in which the hindfoot alignment is calculated using the Ground Reaction Force Calcanea Offset. This technique accounts for the individual forefoot contribution to alignment, but is still limited by it´s 2-dimensional nature. The purpose of this study was to compare the hindfoot moment arm (HMA) described by Saltzman and the hindfoot alignment angle (HAA) described by Williamson, with a technique determining the ground reaction force calcaneal offset (GRF-CT) using 3-dimensional weight bearing CT Scans. Methods. The HMA, HAA, and GRF-CT 3-D weight bearing CT scans were measured by three different investigators. Each of these measurements were calculated twice on separate occasions by each investigator to determine the intra- and inter-observer reliability. Results. 104 patients underwent weight bearing hindfoot alignment radiographs and 3-dimensional weight bearing CT scans including 33 patients with varus and 71 patients with valgus hindfoot deformities. There was excellent intra- and inter-observer reliability with all three measurement techniques (P< 0.01), however the GRF-CT showed the best intra- and inter-observer reliability with the lowest standard deviation (P< 001). Conclusions. The GRF-CT technique is more reliable than traditional radiographic techniques for measuring the hindfoot alignment. While the intra- and inter-observer reliability is good for all three techniques, the GRF-CT technique resulted in the best intra- and inter-observer reliability with the lowest standard deviation. This technique provides the most accurate hindfoot alignment as it takes into account the effect of forefoot on overall alignment, preventing inaccuracies of projection and foot orientation in contrast to traditional radiographic techniques, which may be valuable in surgical decision making

We report a single surgeon series of 33 arthroscopic subtalar fusions performed through a 2-portal sinus tarsi approach on 32 patients between March 2004 and February 2009. Background pathologies included primary arthrosis, post-traumatic arthritis, planovalgus foot, rheumatoid disease, sinus tarsi syndrome and CTEV. 97% [32/33] of fusions as assessed by both clinical and radiological means were achieved within 16 weeks [76% [25/33] within 12 weeks] with only a single outlier which had fused by 22 weeks. There were no deep infections, thrombotic events or neuromas. Five patients suffered complications of which four were successfully treated with a satisfactory outcome. One patient developed persistent pain and was eventually referred to another centre for further management. In our experience arthroscopic subtalar fusion surgery has been demonstrated to give excellent outcomes with minimal complications. Furthermore, it is a technique allowing surgery even in patients with significant hindfoot deformity. It is a suitable operation even for patients with a compromised soft tissue envelope which would normally preclude an open procedure