Femoroacetabular impingement (FAI) causes pain and chondrolabral damage via mechanical overload during movement of the hip. It is caused by many different types of pathoanatomy, including the cam ‘bump’, decreased head–neck offset, acetabular retroversion, global acetabular overcoverage, prominent anterior–inferior iliac spine, slipped capital femoral epiphysis, and the sequelae of childhood Perthes’ disease. Both evolutionary and developmental factors may cause FAI. Prevalence studies show that anatomic variations that cause FAI are common in the asymptomatic population. Young athletes may be predisposed to FAI because of the stress on the physis during development. Other factors, including the soft tissues, may also influence symptoms and chondrolabral damage. FAI and the resultant chondrolabral pathology are often treated arthroscopically. Although the results are favourable, morphologies can be complex, patient expectations are high and the surgery is challenging. The long-term outcomes of hip arthroscopy are still forthcoming and it is unknown if treatment of FAI will prevent arthrosis

Introduction: In severe Legg-Calve-Perthes (LCPD) disease with subluxated femoral head, the acetabulum sometimes takes a bicompartmental appearance. This study analyzed acetabular pathoanatomy using a 3-D CT program. Materials and Methods: A 3-D CT software program that affords the section of 2-D image in any plane was used to analyze the acetabular pathoanatomy, with specific reference to the morphology of the inner surface of the acetabulum. Thirteen children with the bicompartmental acetabulae (12 LCPD and 1 AVN subsequent to septic hip arthritis) were evaluated. Results: The anterior half of the acetabulum was concentric. The contour of the acetabular margin in the posterior half of the acetabulum consisted of two different arcs – an arc of the iliac acetabulum (superior) and the other arc of the acetabular fossa of the ischium (medial). The junction of these two arcs was located at the triradiate cartilage, which was increased in mediolateral thickness at this point. The osteochondral articular margin of the ischium posterior to the non-articular acetabular fossa was thickened forming a ridge. The mediolateral thickness of the non-articular acetabular fossa was thinner than that of the normal contralateral side. The combination of these focal morphologic changes of the acetabular fossa rendered the bicompartmental appearance on plain AP radiograph of the pelvis. Discussion: The authors conclude that bicompartmentalization of the acetabulum apparently reflects the altered biomechanics of the hip joint due to the subluxated femoral head. The abnormal osteocartilaginous hypertrophy appears to be caused by synovial irritation and an eccentric molding effect of the subluxated femoral head

Background. This study analyzes position of the peroneal tendons and status of the superior peroneal retinaculum (SPR) whenever a lateral malleolar bony flake fracture occurs. Methods. Twenty-four patients had a lateral malleolar bony fleck on anteroposterior ankle radiographs, either in isolation or associated with other hindfoot injuries. We studied size of the bony flecks, presence or absence of peroneal tendon dislocation and pathoanatomy on CT scans. Results. In 11 patients, a small bony fleck lies within the superior peroneal retinaculum and contiguous periosteum, which are stripped off the lateral fibula (Class II lesions). Tendons dislocate into the subperiosteal pouch thus formed, resembling Class I lesions without associated bony avulsion. Treatment for Class II is same as for Class I injuries. In 8 patients with big bony fleck, tendons dislocate into the fracture site and SPR is intact (Class III lesions). Surgical approach for tendon relocation and bone fixation differs. In particular, the intact attachment of the SPR on the bony fleck must not be incised. The healing process of neglected Class III lesions resembles a groove deepening procedure, representing an attempt to form a stable platform for the dislocated tendons. A neglected Class II lesion resembles a neglected Class I lesion. In Class IV lesions, observed in 5 patients with 2-part calcaneal fracture/dislocation, SPR remains intact and peroneal tendons are not dislocated. The invariably large fleck results from the displacing lateral calcaneal fragment abutting against the fibula, whereas the dislocating tendons cause the bony avulsions in Classes II and III. Conclusions. Due to pathoanatomical differences, surgical approach and natural history of neglected lesions differ depending on size of the bony fleck. The SPR must not be incised in case of big Class III flecks. Beware of false negatives when probing the peroneal tendons intra-operatively in Class III and IV lesions

Recognized anatomic variations that lead to patella instability include patella alta and trochlea dysplasia. Lateralization of the extensor mechanism relative to the trochlea is often considered to be a contributing factor; however, controversy remains as to the degree this contributes to instability and how this should be measured. As the tibial tuberosity-trochlear groove (TT-TG) is one of most common imaging measurements to assess lateralization of the extensor mechanism, it is important to understand its strengths and weaknesses. Care needs to be taken while interpreting the TT-TG value as it is affected by many factors. Medializing tibial tubercle osteotomy is sometimes used to correct the TT-TG, but may not truly address the underlying anatomical problem. This review set out to determine whether the TT-TG distance sufficiently summarizes the pathoanatomy, and if this assists with planning of surgery in patellar instability. Cite this article: Bone Jt Open 2022;3(3):268–274

Introduction: Tibial pilon fractures are complex and difficult to manage. Results with extensile approaches, rigid internal fixation and bone grafting remain poor. Percutaneous treatment does not allow anatomic restoration. Current classifications are not helpful. Understanding the anatomy and behaviour of the fracture would allow development of logical algorithms for treatment. Method: We have analysed plain radiographs and CT scans in a consecutive series of 126 pilon fractures and have defined the fracture anatomy and developed a new classification. Results: There are six constant articular fragments: anterior, anterolateral (insertion of AITFL), medial, posterior, posterolateral (insertion of PITFL) and die-punch. Two main fracture families exist depending on the articular fracture pattern. T-type and V/Y-type fractures. A lateral disruption type fracture represents a further important group. An evolution of fracture is evident within the groups. T-type fractures tend to occur in varus and result from higher energy injuries in younger patients. V/Y-type fractures tend to occur in valgus and result from lower energy injuries in older patients. Conclusions: We have defined distinct articular fragments, allowing development of safe direct surgical exposures. Stabilisation of the tibial fracture with fine-wire fixators or plates may be employed. The Pathoanatomy could be used in optimal design of such plates. Defining the fracture types gives us a useful and reproducible classification of injury

There has been a marked increase in the number of hip arthroscopies performed over the past 16 years, primarily in the management of femoroacetabular impingement (FAI). Insights into the pathoanatomy of FAI, and high-level evidence supporting the clinical effectiveness of arthroscopy in the management of FAI, have fuelled this trend. Arthroscopic management of labral tears with repair may have superior results compared with debridement, and there is now emerging evidence to support reconstructive options where repair is not possible. In situations where an interportal capsulotomy is performed to facilitate access, data now support closure of the capsule in selective cases where there is an increased risk of postoperative instability. Preoperative planning is an integral component of bony corrective surgery in FAI, and this has evolved to include computer-planned resection. However, the benefit of this remains controversial. Hip instability is now widely accepted, and diagnostic criteria and treatment are becoming increasingly refined. Instability can also be present with FAI or develop as a result of FAI treatment. In this annotation, we outline major current controversies relating to decision-making in hip arthroscopy for FAI. Cite this article: Bone Joint J 2022;104-B(5):532–540

A profound understanding of the pathoanatomy of the patellofemoral joint is considered to be fundamental for navigated knee arthroplasty. Previous studies used less sophisticated imaging modalities such as photography and plain radiographs or direct measurement tools like probes and micrometers to define the morphology of the trochlear groove, with differing results. This may be due to the complexity of the biomechanics and the geometry of this joint. Our primary goal was to compare normal, osteoarthritic and dysplastic PFJs in terms of angles and distances. To do this we first had to establish a reliable frame of reference. Computed tomography scans of 40 normal knees (> 55 years old), 9 knees with patellofemoral osteoarthritis (group A) and 12 knees with trochlear dysplasia (group B) were analyzed using 3D software. The femurs were orientated using a robust frame of reference. A circle was fitted to the trochlear groove. The novel trochlear axis was defined as a line joining the centres of two spheres fitted to the trochlear surfaces, lateral and medial to the trochlear groove. The relationship between the femoral trochlea and the tibiofemoral joint was measured in term of angles and distances (offsets). T-test for paired samples was used (p< 0.05). The study was approved by the institutional review conforming to the state laws and regulations. The normal trochlear groove closely matched a circle (RMS 0.3mm). It was positioned laterally in relation to the mechanical, anatomical, and trans-condylar axes of the femur. It was not co-planar with any of the three axes. After aligning to the new trochlear axis, the trochlear groove appeared more linear than when other axes were used. In comparison to the normal knees; the medial trochlear was smaller in group A (p=0.0003)- see figure 2. The lateral trochlear was smaller in group B (p=0.04). The trochlear groove was smaller in groups B (p=0.0003). Both trochlear centers in groups A+B were more centralized (p=0.00002–0.03). The medial trochlear center was more distal in group A (p=0.03) and the lateral trochlear center was more distal in group B (p=0.00009). The trochlear groove started more distal in group B (p=0.0007). A better understanding of the 3-dimensional geometry can help better treat or even prevent the progression of disease to the stage of patellofemoral osteoarthritis. In osteoarthritic and dysplastic patellofemoral joints, the trochlea is both smaller and more distally located along the femur. These two factors may contribute to excessive loads that lead to early joint wear. These differences could have biomechanical implications and give us an insight into why joints fail. The data collected may also help in improving current designs and current navigational and surgical techniques used for the treatment of patellofemoral osteoarthritis

Introduction

Tibial patho-morphology has been described as a factor that predisposes to medial compartment osteoarthritis of the knee in 2D analysis. The aim of this study was to investigate whether the morphology of normal and pre-OA medial compartments are really different in 3 dimensions.

Introduction

The trochlear groove plays a major role in the mechanics and patho-mechanics of the patellofemoral joint. Our primary goal was to compare normal, osteoarthritic and dysplastic PFJs in terms of angles and distances.

Tibial Pilon fractures pose a difficult management problem. For logical fracture treatment, precise understanding of the 3-D anatomy is essential.

We have studied a consecutive series of 126 pilon fractures. Digitised X-rays and CT scans were analysed using a CAD programme.

We have defined six main fragments at the articular surface, their relative frequency and their proportion: Anterior (A) present in 89%, 28% of area. Posterior (P) present in 89%, 40% of area. Medial (M) present in 74%, 29% of area. Anterolateral (AL) present in 34%, 8% of area. Posterolateral (PL) present in 21%, 9% of area. Die-punch (DP) present in 43%, 4% of area.

The primary fracture line varied in orientation from coronal (93%) to sagittal (7%), in contrast to the classic description.

Within those cases where the primary fracture line was coronal we found hitherto undescribed variations in the articular pattern, there being ‘T’, ‘V’, ‘Y’ and pure split fractures with respect to the medial fragment. Fractures which displace into varus show a “T” configuration, those in valgus a “Y” or “V” configuration, (p < 0.001). Fractures with no coronal mal-alignment produce a talo-fibular joint disruption.

Once recognised these different articular patterns require individual techniques for anatomic reduction and fixation.

Background: Tibial Pilon fractures pose a difþcult management problem. For logical fracture treatment, precise understanding of the 3-D anatomy is essential. Methods: We have studied a consecutive series of 126 pilon fractures. Digitised Xrays and CT scans were analysed using a CAD programme. Results: We have deþned 6 main fragments, at the articular surface. The primary fracture line varied in orientation from coronal (93%) to sagittal (7%), in contrast to the classic description. Observation of the articular fracture patterns revealed ñTñ, ñVñ, ñYñ and pure split fractures with respect to the medial fragment. Fractures, which displace into varus, show a ÒTÒ conþguration, those in valgus a ÒYÒ or ÒVÒ conþguration, (p < 0.001). Fractures with no coronal mal-alignment produce a talo-þbular joint disruption. These different articular patterns require individual techniques for anatomic reduction and þxation.

The Os subfibulare, or round ossicles at the tip of the lateral malleolus, are often regarded as accessory bone. Some patients with such fragments, however, complain of ankle pain and repeated sprain. This study addresses whether these fragments are unnecessary and ignorable?

Materials and method: From 1986 to 1998, we treated 54 ankles in 52 patients surgically. The average age at surgery was 18 years; the mean follow up period was 4.7 years. The whole the fragment was fixed to the lateral malleolus using a tension band.

Results: Each fragment was attached to at least one ligament. We classified these attachments as follows:

Type I a: only ATFL was attached to one fragment

There were 7 Type I a, 37 Type I b, 6 Type I c, and 4 Type II. Fifty-one ankles (94%) developed bony union and three united fibrously. The talar tilt was restored from 9.8 to 4.7 degrees after surgery. The American Orthopaedic Foot and Ankle Societyñs clinical rating system for the ankle-hindfoot improved from 77 to 98 and ankle pain decreased dramatically.

Conclusion: The fragment at the tip of the lateral malleolus is the origin site of the lateral ligaments. This fragment can be united with the lateral malleolus. We believe that the fragments are keystones of the lateral ankle ligament complex.

Flat-top talus (FTT) is a complication well-known to those treating clubfoot. Despite varying anecdotal opinions, its association with different treatments, especially the Ponseti method, remains uncertain. This systematic review aimed to establish the aetiology and prevalence of FTT, as well as detailing management strategies and their efficacy. A systematic review was conducted according to PRISMA guidelines to search for articles using MEDLINE, EMBASE and Web of Science until November 2021. Studies with original data relevant to one of three questions were included: 1) Possible aetiology 2) Prevalence following different treatments 3) Management strategies and their outcomes. 32 original studies were included, with a total of 1473 clubfeet. FTT may be a pre-existing feature of the pathoanatomy of some clubfeet as well as a sequela of treatment. It can be a radiological artefact due to positioning or other residual deformity. The Ponseti method is associated with a higher percentage of radiologically normal tali (57%) than both surgical methods (52%) and non-Ponseti casting (29%). Only one study was identified that reported outcomes after surgical treatment for FTT (anterior distal tibial hemiepiphysiodesis). The cause of FTT remains unclear. It is seen after all treatment methods but the rate is lowest following Ponseti casting. Guided growth may be an effective treatment. Key words:. Clubfoot, Flat-top talus, Ponseti method, guided growth. Disclosures: The authors have no relevant disclosures

The Cierny and Mader classification assists with decision-making in the management of osteomyelitis by strafying the host status and the pathoanatomy of disease. However the anatomical type IV represents a heterogenous group with regards to treatment requirements and outcomes. We propose that modification of the Cierny and Mader anatomical classification with an additional type V classifier (diffuse corticomedullary involvement with an associated critical bone defect) will allow more accurate stratification of patients and tailoring of treatment strategies. A retrospective review of 83 patients undergoing treatment for Cierny and Mader anatomical type IV osteomyelitis of the appendicular skeleton at a single centre was performed. Risk factors for the presence of a critical bone defect were female patients (OR 3.1 (95% CI 1.08– 8.92)) and requirement for soft tissue reconstruction (OR 3.35 (95% CI 1.35–8.31)); osteomyelitis of the femur was negatively associated with the presence of a critical bone defect (OR 0.13 (95% CI 0.03–0.66)). There was no statistical significant risk of adverse outcomes (failure to eradicate infection or achieve bone union) associated with the presence of a critical-sized bone defect. The median time to bone union was ten months (95% CI 7.9–12.1 months). There was a statistically significant difference in the median time to bone union between cases with a critical bone defect (12.0 months (95% 10.2–13.7 months)) and those without (6.0 months (95% CI 4.8–7.1 months)). This study provided evidence to support the introduction of a new subgroup of the Cierny and Mader anatomical classification (Type V). Using a standardised approach to management, comparable early outcomes can be achieved in patients with Cierny and Mader anatomical type V osteomyelitis. However, to achieve a successful outcome, there is a requirement for additional bone and soft tissue reconstruction procedures with an associated increase in treatment time

Introduction. The Cierny and Mader classification assists with decision-making by stratifying host status and the pathoanatomy of the disease. However, the anatomical type IV represents a heterogenous group with regards to treatment requirements and outcomes. We propose that modification of the Cierny and Mader anatomical classification with an additional type V classifier (diffuse corticomedullary involvement with an associated critical bone defect) will allow more accurate stratification of patients and tailoring of treatment strategies. Materials & Methods. A retrospective review of 83 patients undergoing treatment for Cierny and Mader anatomical type IV osteomyelitis of the appendicular skeleton at a single centre was performed. Results. Risk factors for the presence of a critical bone defect were female patients (OR 3.1 (95% CI 1.08–8.92)) and requirement for soft tissue reconstruction (OR 3.35 (95% CI 1.35–8.31)); osteomyelitis of the femur was negatively associated with the presence of a critical bone defect (OR 0.13 (95% CI 0.03–0.66)). There was no statistically significant risk of adverse outcomes (failure to eradicate infection or achieve bone union) associated with the presence of a critical-sized bone defect. The median time to bone union was ten months (95% CI 7.9–12.1 months). There was a statistically significant difference in the median time to bone union between cases with a critical bone defect (12.0 months (95% 10.2–13.7 months)) and those without (6.0 months (95% CI 4.8–7.1 months)). Conclusions. This study provided evidence to support the introduction of a new subgroup of the Cierny and Mader anatomical classification (Type V). Using a standardised approach to management, comparable early outcomes can be achieved in patients with Cierny and Mader anatomical type V osteomyelitis. However, to achieve a successful outcome, there is a requirement for additional bone and soft tissue reconstruction procedures with an associated increase in treatment time

Coccydynia is a painful disorder characterised by coccygeal pain which is typically exaggerated by pressure. It remains an unsolved mystery because of the perceived unpredictability of the origin of the pain, some psychological traits that may be associated with the disorder, the presence of diverse treatment options, and varied outcomes. A more detailed classification based on the aetiology and pathoanatomy of coccydynia helps to identify patients who may benefit from conservative and surgical management. This review focuses on the pathoanatomy, aetiology, clinical features, radiology, treatment and outcome of coccydynia

Abstract. Introduction. Recent reports show that spinopelvic mobility influences outcome following total hip arthroplasty. This scoping review investigates the relationship between spinopelvic parameters (SPPs) and symptomatic femoroacetabular impingement (FAI). Methods. A systematic search of EMBASE, PubMed and Cochrane for literature related to SPPs and FAI was undertaken as per PRISMA guidelines. Clinical outcome studies and prospective/retrospective studies investigating the role of SPPs in symptomatic FAI were included. Review articles, case reports and book chapters were excluded. Information extracted pertained to symptomatic cam deformities, pelvic tilt, acetabular version, biomechanics of dynamic movements and radiological FAI signs. Results. The search identified 42 papers for final analysis out of 1168 articles investigating the link between SPPs and pathological processes characteristic of FAI. Only one (2.4%) study was of level 1 evidence, five (11.9%) studies) were level 2, 17 (40.5%) were level 3 and 19 (45.2%) were level 4. Three studies associated FAI pathology with a greater pelvic incidence (PI), while four associated it with a smaller PI. Anterior pelvic tilt was associated with radiographic overcoverage parameters of FAI. In dynamic movements, decreased posterior pelvic tilt was a common feature in symptomatic FAI patients at increased hip flexion angles. FAI patients additionally demonstrated reduced sagittal pelvic ROM during dynamic hip flexion. Six studies found kinematic links between sagittal spinopelvic movement and sagittal and transverse plane hip movements. Conclusions. Our study shows that spinopelvic parameters can influence radiological and clinical manifestations of FAI, with pelvic incidence, acetabular version and muscular imbalances being aetiologically implicated. These factors may be amenable to non-surgical therapy. Individual spinopelvic mechanics may predispose to the development of FAI. If FAI pathoanatomy already exists, sagittal pelvic parameters can influence whether FAI symptoms develop and is an area of further research interest

Unstable pelvic injuries in young children with an immature pelvis have different modes of failure from those in adolescents and adults. We describe the pathoanatomy of unstable pelvic injuries in these children, and the incidence of associated avulsion of the iliac apophysis and fracture of the ipsilateral fifth lumbar transverse process (L5-TP). We retrospectively reviewed the medical records of 33 children with Tile types B and C pelvic injuries admitted between 2007 and 2014; their mean age was 12.6 years (2 to 18) and 12 had an immature pelvis. Those with an immature pelvis commonly sustained symphyseal injuries anteriorly with diastasis, rather than the fractures of the pubic rami seen in adolescents. Posteriorly, transsacral fractures were more commonly encountered in mature children, whereas sacroiliac dislocations and fracture-dislocations were seen in both age groups. Avulsion of the iliac apophysis was identified in eight children, all of whom had an immature pelvis with an intact ipsilateral L5-TP. Young children with an immature pelvis are more susceptible to pubic symphysis and sacroiliac diastasis, whereas bony failures are more common in adolescents. Unstable pelvic injuries in young children are commonly associated with avulsion of the iliac apophysis, particularly with displaced SI joint dislocation and an intact ipsilateral L5-TP. Cite this article: Bone Joint J 2015; 97-B:696–704

The indications for use of a glenoid component are: 1.) sufficient degenerative changes on the glenoid to expose the subchondral bone 2.) the glenoid should have sufficient glenoid bone stock to allow for secure and longterm fixation of the component, and 3.) the rotator cuff should be intact or repairable and the humeral head should be centred within the glenoid component. Other factors that secondarily affect the decision to use a glenoid component, include the patient’s age and activity level, which should be such that they are not likely to result in multiple revisions for glenoid wear or loosening. Given these factors most patients with osteoarthritis, the leading indication for prosthetic replacement for arthritis should undergo a total shoulder replacement. Patients with acute proximal humeral fractures, the overall leading indication for prosthetic arthroplasty, should have a hemiarthroplasty. Patients with rotator cuff tear arthropathy or crystalline arthropathy are indicated for hemiarthroplasty due to the massive irreparable cuff tears present in these conditions. Patients with rheumatoid arthritis have variable diseases affecting the rotator cuff and variable degrees of bone loss resulting in the need to individualise the indications for the use of a glenoid to the patient’s pathoanatomy. The reason for use of a glenoid component, when indicated, is the fact that pain relief and function is predictably better when compared to hemiarthroplasty for the same indication and pathoanatomy. Proper insertion of a glenoid component requires wide exposure of the glenoid fossa and bone preparation, which for most general orthopaedic surgeons is difficult and not reproducible. This is, in my opinion, the primary reason that hemiarthroplasty or bipolar arthroplasty is used for treatment of many patients with primary osteoarthritis. Both of these procedures result, on average, in a less favourable outcome than non-constrained total shoulder arthroplasty. Osteoarthritis is characterised by flattening and enlargement of the humeral head and is associated with peripheral osteophyte formation. Loss of articular cartilage results in eburnated bone and on the glenoid side posterior bone loss. Capsular contracture results in loss of passive arcs of motion, particularly anteriorly with loss of external rotation. Posterior subluxation of the humeral head can occur, associated with anterior soft tissue contracture and/or posterior glenoid bone loss. The severity of this pathoanatomy is variable among patients with primary osteoarthritis and each of these factors will have a variable effect on outcome of shoulder arthroplasty as well as the indication for hemiarthroplasty versus total shoulder arthroplasty. In a 2–7 year follow-up multicentre study using the DePuy Global Shoulder in 127 patients, those cases with osteoarthritis without humeral head subluxation, severe glenoid bone loss, or rotator cuff tears had the best results, for pain relief and function, with total shoulder arthroplasty. In patients with severe glenoid bone loss total shoulder has improved function when compared to hemiarthroplasty. This finding supports the data of others that demonstrate less favourable results of hemiarthroplasty for treatment of osteoarthritis in cases with eccentric glenoid wear. Patients with humeral head subluxation have less favourable results regardless of the use of a hemiarthroplasty or total shoulder arthroplasty. The presence of a full thickness reparable rotator cuff tear limited to the supraspinatus tendon does not adversely affect outcome or the ability to use a glenoid component. Patients with less than 10° of external rotation achieve statistically less postoperative forward flexion and external rotation than those patients with greater degrees of preoperative external rotation

Introduction. Coronal plane deformity can pose difficulties with balancing in Total Ankle Replacement (TAR). Current reports outline improved outcomes in the presence of varus deformity. Soft tissue balancing techniques are well described, but are limited by no link to eitiology and pathoanatomy of the deformity. Method. A prospective review of all the TAR by the senior author was performed to identify cases of pre-operative varus greater than 10°. A chart review was performed to identify aetiology, intraoperative findings, and operative techniques to achieve a balanced TAR. X-rays were examined to measure deformity and amount of correction. Volumetric rendering and segmentalisation was performed on pre- and post-CTs to identify anatomical defects, osteophyte formation, rotational and translational changes of the hindfoot joints. Results. Between January 2002 and January 2009 there were thirty-five cases from two hundred and thirty cases with varus deformity greater than 10°, with an average 17° varus angle (range 10° to 30°). Multiple sprains and instability over several years was seen in 62% of patients. Clinically, increasing varus was associated with cavovarus foot position. Incongruent deformities had intact tibial plafond. Congruent deformities had tibial defects in the anteromedial tibial plafond and associated anterolateral tibial ostephyte. Increasing deformity often had lateral fibula osteophytes and ossicles between fibula osteophyte and anterolateral talar body. In more severe cases, 3D analysis showed the talus was anteriorly displaced and internally rotated. Post operative alignment improved from 17° to 1.5°. Conclusion. Understanding the pathoanatomy of the arthritic ankle with coronal plane deformity can help plan the surgical techniques required to correct this often challenging surgical reconstruction