Acquired multi-segment foot kinematics in haemophilic children, adolescents and young adults with or without haemophilic ankle arthropathy.

INTRODUCTION AND AIM: The ankle joint remains vulnerable in children with haemophilia and is the primary joint affected. The purpose of this study was to dynamically characterize the segmental foot and ankle kinematics of male children, adolescents and young adults with or without ankle arthropathy. METHODS: The barefoot multi-segment foot kinematics of 70 ankles from 35 haemophilia subjects between 6 and 20 years old were captured with the Rizzoli Multi-Segment Foot Model. Joint damage of the tibiotalar and subtalar joints was scored using the IPSG-MRI score. The feet of patients with or without evidence of ankle arthropathy were compared with those of matched typically developing boys via a nonpaired comparison. The differences between the affected and nonaffected sides of patients with unilateral ankle arthropathy were assessed using a paired comparison. RESULTS: Subjects without arthropathy demonstrated a nonsignificant trend towards a higher frontal plane range of motion (RoM) at the midfoot upon loading response and a lower sagittal plane RoM at the midfoot during midstance. No differences were observed between the affected side group and their matched control group. The affected side of unilaterally affected subjects exhibited a nonsignificant tendency towards a higher frontal plane RoM at the ankle joint upon loading response and terminal stance compared to the healthy side. CONCLUSION: Most patients maintained physiological rocker function of the ankle and had no (mal)adaptive motion patterns in the more distal joints of the foot. Therefore, established structural lesions may remain subclinical with respect to moderate functional activities like walking.

Correction of excessive intraarticular varus deformities in total knee arthroplasty is associated with deteriorated postoperative ankle function.

PURPOSE: The aim of this study was to demonstrate, whether the degree of limb alignment correction in varus knee osteoarthritis correlated with an increase in ankle symptoms and to define a cut-off value concerning the degree of correction above which to expect ankle problems. METHODS: Ninety-nine consecutive patients with preoperative intraarticular varus knee deformities who underwent total knee arthroplasty were retrospectively analyzed. Patients were examined clinically (Knee Society Score, Forgotten Joint Score, Foot Function Index, Range of Motion of the knee and ankle joint, pain scales) as well as radiologically. The mean follow-up time was 57 months. RESULTS: The degree of operative limb alignment correction strongly correlated with the Foot Function Index (R = 0.91, p < 0.05). Given this, higher degrees of knee malalignment corrections were associated with worse postoperative outcomes in the knee and ankle joint-despite postoperative improved joint line orientations. Subsequently, a cut-off value for arthritic varus deformities (14.5°) could be calculated, above which the prevalence of ankle symptoms increased manifold [OR = 15.6 (3.2-77.2 95% CI p < 0.05)]. Furthermore, ROM restrictions in the subtalar joint were associated with a worse outcome in the ankle joint. CONCLUSIONS: When correcting excessive intraarticular varus knee osteoarthritis, surgeons have to be aware of possible postoperative ankle symptoms and should consider ankle deformities or decreased subtalar ROM before operative procedures. LEVEL OF EVIDENCE: III.

Arthroereisis for Symptomatic Flexible Flatfoot Deformity in Young Children: Radiological Assessment and Short-Term Follow-Up.

The purpose of this study is to recognize those young patients with symptomatic flexible flatfoot deformity who need treatment and to provide radiological evidence that arthroereisis is capable of relocating the talus properly over the calcaneus. We included 28 feet in 14 children who underwent subtalar arthroereisis in association with percutaneous triple-hemisection Achilles tendon lengthening. Selected for arthroereisis were children with symptomatic flexible flatfoot deformity who complained of foot and leg pain, had decreased endurance in sports activities and long walks, who did not respond to conservative treatment modalities for at least 6 months, and in whom at radiological assessment on stance position with the medial arch support orthosis the talonavicular joint lateral subluxation still remained, with Meary's angle in anteroposterior (A/P) and lateral view remaining increased. The mean age at surgery was 10.71 ± 1.58 (range 8 to 14) years. The minimum follow-up duration was 19 months, with mean follow-up duration of 35.14 ± 9.82 (range 19 to 60) months. For estimation of the efficacy of the surgical procedure, the American Orthopaedic Foot and Ankle Society (AFOAS) rating scale was used preoperatively and postoperatively in all patients. The mean preoperative AFOAS ankle-hind foot rating score was 65.14 ± 7.16 (range 58 to 75) points. The mean postoperative AFOAS score was 88.851 ± 5.61 (range 83 to 97) points and the 2-tailed p value <.0001. After arthroereisis surgical treatment, all AOFAS scores and all foot angles improved significantly, except the calcaneal inclination angle which improved slightly.

Technique Article: Tarsal Coalition Resection Using Kirschner Wires Across the Subtalar Joint in a Two-Incision Approach.

Subtalar coalitions are a significant cause of morbidity, especially in the pediatric population. Arthrodesis was considered the standard of care, with coalitions involving >50% of the joint until the mid-1990s. Today, some are recommending resection of the coalition first and to save hindfoot arthrodesis as a salvage procedure. As a result, resection of talocalcaneal coalitions is becoming more common, and optimizing the surgical technique is a necessity in the field of orthopedics. We present a technique to optimize surgical resection of talocalcaneal coalitions by using Kirschner wires inserted from the lateral side, which allows us to demarcate the coalition. This gives us a greater ability to perform a more complete resection and also helps prevent iatrogenic trauma to the articulating surface.

Functional and Radiological Outcomes After Tarsal Coalition Resections: A Minimum 5-Year Follow-Up.

Few studies have evaluated the long-term functional and radiological outcomes of tarsal coalition resections. This study aimed to report and compare the functional and radiological outcomes after talocalcaneal (TC) and calcaneonavicular (CN) coalition resections. Thirty-three patients between 12 and 35 years old with symptomatic tarsal coalitions participated, each undergoing tarsal coalition resections (24 TC and 9 CN). The range of motion, visual analog scale score, American Orthopedic Foot and Ankle Society hindfoot scale, Maryland foot score, tripod index, and modified Kellgren-Lawrence scale for subtalar osteoarthritis were used to evaluate the functional and radiological outcomes. The mean age at the time of surgery and mean follow-up in the TC group were 17.8 ± 5.6 years (range 13 to 35) and 6.2 ± 1.7 years (range 5 to 12), respectively, and 16.0 ± 4.4 years (range 12 to 23) and 7.7 ± 3.0 years (range, 5 to 12) in the CN group. There was no difference in the range of motion, outcome scores, tripod index score, and modified Kellgren-Lawrence scale score between patients in the 2 groups. A positive correlation was noted between the size of the TC coalition, coalition/joint surface ratio, and hindfoot valgus angle regarding outcome scores. However, there was no association between the modified Kellgren-Lawrence scale score and outcome scores. At the minimum 5-year follow-up, the functional and radiological outcomes were similar between TC and CN resections. Subtalar joint osteoarthritis developed in all patients with TC resections and most patients with CN resections, but patients did not have functional impairment.

Bilateral Triple Talocalcaneal, Calcaneonavicular, and Talonavicular Tarsal Coalition: A Case Report.

We report a rare case of a female, aged 42 years, with symptomatic bilateral triple tarsal coalition, that is, talocalcaneal, calcaneonavicular, and talonavicular tarsal coalition. The patient was treated conservatively by adjusting her activities. At the 12-month follow-up, the patient was asymptomatic. Bilateral triple tarsal coalition is a rare disorder, especially in nonsyndromic patients. The purpose of this case report was to highlight this rare type of multiple bilateral tarsal coalitions and to discuss the relevant existing literature.

Subtalar joint alignment in ankle osteoarthritis.

BACKGROUND: Although it has been proposed that in mid-stage ankle osteoarthritis, the subtalar joint can compensate for deformities above the ankle joint, the evidence is weak. We thus investigated subtalar joint alignment in different stages of ankle osteoarthritis using weightbearing computed tomography (CT) scans. METHODS: The subtalar joint of 88 patients with osteoarthritis of the ankle joint and a control group of 27 healthy volunteers were assessed. Subgroups were performed according to the ankle deformity (varus and valgus) and stage of ankle joint osteoarthritis. Subtalar joint alignment was assessed on weightbearing CT scans. RESULTS: A more valgus subtalar joint alignment was found in patients with varus ankle osteoarthritis. No significant difference of the subtalar joint alignment was evident when comparing different stages of ankle osteoarthritis. CONCLUSIONS: Varus ankles compensate in the subtalar joint for deformities above the ankle joint. Compensation does not correlate with the stage of ankle osteoarthritis.

Following the correction of varus deformity of the knee through total knee arthroplasty, significant compensatory changes occur not only at the ankle and subtalar joint, but also at the foot.

PURPOSE: This study aimed to assess radiological changes of the ankle joint, subtalar joint and foot following the correction of varus deformity of the knee with total knee arthroplasty (TKA). It was hypothesized that following the correction of varus deformity by TKA, compensatory reactions would occur at the subtalar joint in accordance with the extent of the correction. METHODS: For this prospective study, 375 knees of patients who underwent TKA between 2011 and 2012 were enrolled. The varus angle of the knee, talar tilt of the ankle joint (TT), ground-talar dome angle of the foot (GD), anterior surface angle of the distal tibia and lateral surface angle of the distal tibia, heel alignment ratio (HR), heel alignment angle (HA), and heel alignment distance (HD) were measured on radiographs obtained pre-operatively and at post-operative 6 months. RESULTS: The mean correction angle in varus deformity of the knee was 10.8 ± 4.1°. TT and GD changed significantly from 0.4 ± 1.9° and 6.5 ± 3.1° pre-operatively to 0.1 ± 1.8° and 0.2 ± 2.1°, respectively (p = 0.007, p < 0.001). No correlation was found between the preop-postop variance in mechanical axis of the lower extremity (MA) and TT, but there was a strong correlation between the preop-postop variance in MA and GD (r = 0.701). HR, HA and HD also changed significantly post-operatively, and the preop-postop variance in MA showed correlations with the preop-postop variances in HR, HA and HD (r = 0.206, - 0.348, and - 0.418). TT and the three indicators of hindfoot alignment all shifted to varus whereas GD was oriented in valgus. CONCLUSION: Following the correction of varus deformity of the knee through TKA, significant compensatory changes occurred not only at the ankle and subtalar joints, but also at the foot. The findings of this study are useful in predicting the orientation of changes in the ankle and subtalar joints and the foot following TKA, and in determining the sequence of surgery when both the ankle and knee have a problem. In other words, changes in the parts of the lower extremity below the ankle joint following the correction of varus deformity of the knee must be considered when TKA is planned and performed. Patients who have problems at the ankle, subtalar, and foot joints in addition to varus deformity of the knee are recommended to undergo knee joint correction first. LEVEL OF EVIDENCE: II.

Calcaneal Apophyseal Fracture Followed by Subtalar Joint Instability in a Young Female: A Case Report.

Calcaneal apophyseal fractures are usually considered sport-related injuries. Previous repetitive microtrauma has been proposed as a predisposing factor for such injuries. However, unlike previously reported cases, in our patient, the fracture resulted from acute trauma after stepping on uneven ground. Although the first treatment option for such cases is closed reduction, most cases will require surgical treatment. Furthermore, lesions accompanying this injury have not been sufficiently considered. We report the case of a 9-year-old female with a calcaneal apophyseal fracture treated by fixation of the avulsed proximal part of the apophysis using Kirschner wires and a cerclage wire. However, subsequently, instability developed in the subtalar joint. Fifteen months after the first osteosynthesis, surgery was performed to fixate the subtalar joint and secure the insertion region of the tendo calcaneus. After the first surgery, subtalar joint instability might have developed because of simultaneous disruption of the subtalar ligaments at the initial injury. Subsequently, the instability could have caused failure of the first fixation. Debridement and fixation of the subtalar joint in the second surgery provided a stable subtalar joint. A calcaneal apophyseal fracture might be associated with additional injuries at the hindfoot. Before treating these cases, other injuries that might be obscured by the more apparent injuries should be considered. Accompanying soft tissue injuries, such as subtalar joint ligament lesions, can be revealed with magnetic resonance imaging evaluation. To the best of our knowledge, this is the first report of an apophyseal fracture of the calcaneus followed by subtalar joint instability.

[Limited versus Extended Lateral Approach for Osteosynthesis of Calcaneal Fractures - Comparison of Temporal and Dynamic Parameters of the Gait Cycle]. / Limitovaný versus extenzivní laterální prístup pri osteosyntéze zlomenin patní kosti ­ srovnání casových a dynamických parametru krokového cyklu.

PURPOSE OF THE STUDY Currently, operative treatment is preferred in dislocated calcaneal fractures. Most frequently used is the extended lateral approach, the disadvantage of which is the risk of early complications. Therefore, less invasive operative techniques are sought that would reduce the risk of such complications. The presented study aimed to compare the two different surgical approaches with respect to the restoration of gait stereotype using the objective pedobarography. We assume that the limited operative approach in osteosynthesis of intra-articular calcaneal fractures results in comparable or earlier restoration of gait stereotype with regard to temporal and dynamic parameters compared to the extended lateral approach. MATERIAL AND METHODS The research study comprised a total of 22 patients who underwent the surgical treatment of intra-articular calcaneal fractures, divided into two groups by the applied operative approach. The first group consisted of 10 patients treated with less invasive sinus tarsi operative approach (ST). For osteosynthesis a calcaneal nail (C-nail, Medin, CR) was used. The second group consisted of 12 patients, to whom extended lateral approach (EXT) was applied. For osteosynthesis a calcaneal plate 3.5 mm (DePuy Synthes, Switzerland) was used. Pedobarographic measurement using a tensometric platform was performed in all the patients, always six months post-operatively. Temporal and dynamic variables of the gait cycle during the interaction of the foot with the ground were monitored. RESULTS In the EXT group, significant differences between the injured and healthy foot were found in walking 6 months after the surgery in most of temporal and dynamic variables. The ST group, however, showed no significant differences between the values for the injured and healthy foot in most of temporal and dynamic variables. DISCUSSION Six months after the surgery, the patients continue to carefully load the heel, regardless of the selected surgical approach, due to which the pressure at this place is significantly reduced and tends to be transferred to the midfoot or forefoot. This finding corresponds with previous studies. The patients undergoing a less invasive surgical approach load both the operated and healthy feet. Also, with regards to temporal parameters, as early as 6 months after the surgery correct gait stereotype is restored under the heel in these patients. We believe this is achieved thanks to less pain due to a limited extent of the surgical approach. On the very contrary, the extended lateral approach can cause deterioration of conditions for the restoration of gait stereotype due to the presence of extensive scarring on the heel side with a limited mobility of talocalcaneal joint or also an impaired mobility of peroneal tendons outside the ankle bone. CONCLUSIONS Six months after the surgical treatment of calcaneal fractures changes still persist in gait stereotype. The analysis of temporal and dynamic gait parameters in the followed-up group of patients reveals that the limited sinus tarsisurgical approach results in an earlier restoration of gait stereotype compared to the extended lateral approach. A higher number of patients in the respective groups is necessary in order to obtain more general results. Key words:sinus tarsi; extended lateral approach; plantar pressure; force; contact time.

Biomechanical markers and theoretical concepts related to haemophilic ankle and subtalar joint arthropathy: introducing the term 'haemophilic tarsal pan-arthropathy'.

BACKGROUND: Although regular factor replacement can reduce the incidence of joint bleeds and slow down the development of haemophilic arthropathy, the ankle joint remains particularly vulnerable even in children with haemophilia on primary or secondary prophylaxis and is now the primary joint affected. The heterogeneity in the pathoaetiology of haemophilic ankle arthropathy means that the functional consequences of early stage of ankle arthropathy are difficult to define as early morphological and structural changes can be observed in clinically asymptomatic ankles. In this context, understanding biomechanics of the normal and arthritic foot is complex and difficult to quantify unless considering the foot as multiple functional segments using more sophisticated assessment tools such as multisegment foot models. However, this understanding can undoubtedly aid in the analysis of an underlying clinical problem and provide a strategic basis for a more optimal management. AIMS: The purpose of this narrative review was firstly to revise information on the anatomy and biomechanics of the foot and ankle. Finally, related biomechanical markers of human motor performance, which are potentially implicated in the development of haemophilic ankle arthropathy, will be discussed based on published literature and expert opinion. MATERIALS AND METHODS: Searches in published literature were limited to the year 2000 onwards. RESULTS: Although the ankle (tibiotalar joint) is the most commonly affected joint, associated subtalar joint (SJT) involvement is often seen. This would therefore imply that an alternative phraseology might be better. DISCUSSION AND CONCLUSION: In this context, the authors propose the use of 'haemophilic tarsal pan-arthropathy' (HTPA) which encompasses both tibiotalar and subtalar joints.

Subtalar instability: imaging features of subtalar ligaments on 3D isotropic ankle MRI.

BACKGROUND: MRI analysis of subtalar ligaments in the tarsal sinus has not been well performed. We retrospectively investigated the appearance of subtalar ligaments using 3D isotropic MRI and compared imaging findings of subtalar ligaments between patients with subtalar instability (STI) and controls. METHODS: Preoperative MRIs of 23 STI patients treated with arthroscopic subtalar reconstruction were compared to MRIs of 23 age- and sex-matched control subjects without STI. Thickness and width of anterior capsular ligament (ACL) and interosseous talocalcaneal ligament (ITCL) as well as thickness of calcaneofibular ligament (CFL) and anterior talofibular ligament (ATFL) were measured. Abnormalities in ACL, ITCL, CFL, ATFL, cervical ligament, and inferior extensor retinaculum were analyzed. RESULTS: STI patients had significantly smaller ACL thickness and ACL width than controls (ACL thickness: 1.73 mm vs. 2.22 mm, p = 0.007; ACL width: 7.21 mm vs. 8.80 mm, p = 0.004). ACL thickness of ≤2.1 mm had a sensitivity of 66.7% and a specificity of 66.7% for diagnosis of STI. ACL width of ≤7.9 mm had a sensitivity of 80.0% and a specificity of 76.2% for the diagnosis of STI. However, thickness and width of ITCL, thickness of CFL, or thickness of ATFL was not significantly different between the two groups. Absence or complete tear of ACL was significantly more frequent in STI patients than that in controls (34.8% vs. 8.7%, p = 0.035). Complete tear of CFL and ATFL was more common in STI patients than that in controls, although the difference between the two groups was not statistically significant. Abnormalities of ITCL, cervical ligament, or inferior extensor retinaculum were not significantly different between the two groups. CONCLUSIONS: MRI features of thin or narrow ACLs may suggest STI. Absence or complete tear of ACL was significantly more common in STI patients than that in controls.

Painful stress reaction in the posterior subtalar joint after resection of os trigonum or posterior talar process.

INTRODUCTION: The resection of os trigonum or posterior talar process as treatment for posterior ankle impingement is an established operation. However, the authors encountered several painful stress reactions in the posterior subtalar joint during follow-up resulting in persisting incapacity to do sports. METHODS: From March 2011 to July 2015, 29 patients with 30 feet were operated (22 endoscopic, 8 open resections). Average follow-up time was 43 ± 13 months. Complications were grouped into "none", "temporary disadvantage" and "permanent damage". The following radiographic parameters were measured: (1) length of posterior talar process or os trigonum, (2) length of the uncovered calcaneal joint surface after resection, (3) amount of resection. RESULTS: The rate of permanent damage was 13.3% (4 of 30 feet), and all four of these patients developed a painful stress reaction in the posterior subtalar joint. One temporary disadvantage (persistent pain for three months) was found. All patients with major complications showed retrospectively what we call the "risk configuration" -the radius of the talus ending within the subtalar joint. The length of the uncovered calcaneal joint surface was therefore significantly larger (6.4 mm ± 3.33) in feet with permanent damage than in feet without (1.06 mm ± 2.15, P < 0.001). CONCLUSION: The resection of os trigonum or posterior talar process has a complication rate of 13.3% with persisting inability to do sports due to painful stress reaction in the posterior subtalar joint. The only risk factor found was the "risk configuration". In such cases, the resection has to be made not anterior into the subtalar joint and patients have to be informed about this possible complication. STUDY DESIGN: Retrospective case series; Evidence Level 4.

Radiological study of the secondary reduction effect of early functional exercise on displaced intra-articular calcaneal fractures after internal compression fixation.

PURPOSE: Early post-operative exercise and weight-bearing activities are found to improve the functional recovery of patients with displaced intra-articular calcaneal fractures (DIACFs). We hypothesized that early functional exercise after surgery might have a secondary reduction effect on the subtalar joint, in particular the smaller fracture fragments that were not fixed firmly. A prospective study was conducted to verify this hypothesis. METHODS: From December 2012 to September 2013, patients with unilateral DIACFs were enrolled and received a treatment consisting of percutaneous leverage and minimally invasive fixation. After surgery, patients in the study group started exercising on days two to three, using partial weight bearing starting week three, and full weight bearing starting week 12. Patients in the control group followed a conventional post-operative protocol of partial weight bearing after week six and full weight bearing after the bone healed. Computed tomography (CT) scanning was performed at post-operative day one, week four, week eight, and week 12 to reconstruct coronal, sagittal, and axial images, on which the maximal residual displacements of the fractures were measured. Function was evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) scoring scale at the 12th post-operative month. RESULTS: Twenty-eight patients in the study group and 32 in the control group were followed up for more than 12 months; their data were collected and used for the final analysis. Repeated-measures analysis of variance (ANOVA) of the maximal residual displacements of the fracture measured on CT images revealed significant differences between the study and the control groups. There were interaction effects between group and time point. Except for the first time point, the differences between the groups at all studied time points were significant. In the study group, the differences between all studied time points were significant. Strong correlations were observed between the AOFAS score at post-operative month 12 and the maximal residual displacement of the fractures on the CT images at postoperative week 12. CONCLUSIONS: Early functional exercise and weight bearing activity can smooth and shape the subtalar joint and reduce the residual displacement of the articular surface, improving functional recovery of the affected foot. Therefore, early rehabilitation functional exercise can be recommended in clinical practice.

Intraoperative Three-Dimensional Navigation for Talocalcaneal Coalition Resection.

Talocalcaneal tarsal coalitions are a common source of foot pain, stiffness, and deformity. These coalitions are treated symptomatically with rest and periods of immobilization. When those measures fail, surgical resection is attempted. This procedure is an anatomic challenge with the consequence of leaving residual coalition. The residual coalition primarily results from difficulty with intraoperative imaging because fluoroscopy does not provide adequate detail of this area. Some investigators have recommended intraoperative computed tomography after resection with reasonable results. We describe the combination of an intraoperative computed tomography with a navigated instrument system for resection of talocalcaneal coalitions. The use of a navigated probe and burr aids in defining the most anterior, posterior, and medial extents of the coalition. This technique reduces the morbidity, with less bone removed and preservation of intact subtalar articulations and allows for an efficient, thorough, and controlled resection.

Ball and Socket Ankle: Mechanism and Computational Evidence of Concept.

The ball and socket ankle joint is a morphologically abnormal joint characterized by rounding of the articular surface of the talus. Other than anecdotal observation, little evidence has been presented to describe the development of this deformity. The purpose of the present study was to review ankle and subtalar joint mechanics and to kinematically examine the functional combination of these joints as a mechanism of the ball and socket ankle deformity. We reviewed functional representations of the ankle joint, subtalar joint, and ball and socket ankle deformity. A computational study of joint kinematics was then performed using a 3-dimensional model derived from a computed tomography scan of a ball and socket deformity. The joint kinematics were captured by creating a "virtual map" of the combined kinematics of the ankle and subtalar joints in the respective models. The ball and socket ankle deformity produces functionally similar kinematics to a combination of the ankle and subtalar joints. The findings of the present study support the notion that a possible cause of the ball and socket deformity is bony adaptation that compensates for a functional deficit of the ankle and subtalar joints.

An Incidental Finding of a Talonavicular and Talocalcaneal Joint Coalition After a Tibial Pilon Fracture: A Case Report.

It has been proposed that patients with talocalcaneal and talonavicular coalitions have decreased ankle joint range of motion. It has also been reported that rotational forces regularly absorbed by the talocalcaneal joint are transferred to the ankle joint in patients with coalitions, increasing the stress on the ankle joint after trauma. To the best of our knowledge, only 1 reported study has detailed the increased stress placed on the ankle joint secondary to a coalition. We present a case study of a 53-year-old female who experienced a traumatic fall and subsequent right ankle fracture. Advanced imaging studies revealed a comminuted tibial pilon fracture and talocalcaneal and talonavicular joint coalitions. She underwent open reduction and internal fixation for treatment of the fracture, and the coalitions were not treated because they were asymptomatic. She was kept non-weightbearing for 6 weeks postoperatively and was returned to a regular sneaker at 10 weeks postoperatively. The postoperative films revealed stable intact fixation and pain-free gait with no increased restriction in her ankle joint range of motion. The hardware was removed at 13 months postoperatively. She had not experienced increased pain or arthritic changes at 15 months postoperatively.

A Three-Dimensional Finite Element Analysis of Displaced Intra-Articular Calcaneal Fractures.

A better understanding of displaced intra-articular calcaneal fractures, their effect on joint mechanics, and the relationship between altered mechanics and osteoarthritis could aid in the development or refinement of treatment methods. Finite element modeling is accepted as the reference standard for evaluating joint contact stresses. The objective of the present study was to analyze the in vivo joint mechanical data from finite element modeling for normal and injured subtalar joints. A 3-dimensional model of the ankle-hindfoot was developed and validated. Both height loss and width increases in the calcaneus were simulated. Next, they were used to investigate the relationship between calcaneal height or width and the contact mechanics of the posterior facet of the subtalar joint. The contact area/joint area ratio increased in the subtalar joint with injury when the calcaneal width increased. Moreover, the peak contact pressure and the proportion of the area under high contact pressure (>6 MPa) increased. The contact area/joint area ratio decreased with reduced calcaneal height, but the peak contact pressure remained almost constant. The width increases of the calcaneus somewhat limited the subtalar joint motion, especially for eversion; however, the height loss mostly resulted in subtalar rotatory instability. The height loss diminished the subtalar joint's stability in eversion, internal rotation, and external rotation. The results of the present study support the advisability of surgery for these complex injuries. Reestablishing the calcaneal height and width could restore the normal kinematics and contact stress distribution in the subtalar joint, improve the tibiotalar position, and diminish long-term degeneration in the ankle.

Arthroscopic Medial Approach for Modified Double Arthrodesis of the Foot.

The single medial incision subtalar joint and talonavicular joint arthrodesis has been shown to be a useful alternative for the correction of hindfoot valgus deformity. We describe an arthroscopic method of joint preparation using this approach. The present case report included 6 consecutive patients aged 35 to 72 (mean ± standard deviation 55.8 ± 15.54) years (4 males [66.7%] and 2 females [33.3%]), who had undergone the medial approach for modified double arthrodesis of the foot. Of the 6 patients, 3 (50.0%) had undergone arthroscopic joint preparation and 3 (50.0%) traditional (manual) joint preparation. Osteobiologic agents were used in all patients. We found a shorter tourniquet time for the patients who had undergone an arthroscopic approach, with a mean of 110 ± 7.21 minutes, compared with a traditional joint preparation, with a mean of 121.3 ± 8.08 minutes. We also found a shorter time to radiographic union in the patients who had undergone an arthroscopic approach, all of whom showed signs of union at 6 weeks. Only 2 of the 3 patients in the traditional joint preparation group had achieved union at a mean of 10 ± 2.83 weeks, with 1 case resulting in nonunion. This technique could be a viable alternative to traditional methods of joint preparation by decreasing the operative time and improving the union rates.

Hindfoot Arthrodesis with the Blade Plate: Increased Risk of Complications and Nonunion in a Complex Patient Population.

BACKGROUND: Previous hindfoot surgeries present a unique challenge to hindfoot arthrodesis, as the patients may have multiple incisions around the hindfoot. In high-risk patients with compromised soft tissues, a posterior approach can provide an alternative for a fresh soft tissue plane for the surgery. The use of a blade plate construct is widely accepted; however, there are limited data supporting the use of a posterior approach. QUESTIONS/PURPOSES: We asked (1) what proportion of patients treated with this technique achieved osseous union; (2) what complications were observed; (3) were any patient-demographic or health-related factors associated with the likelihood that a patient would have a complication develop? METHODS: Between December 2001 and July 2014, 42 patients received a posterior blade plate. During the period in question, indications for hindfoot arthrodesis using posterior blade fixation were subtalar osteoarthritis below an ankle fusion, malunion or nonunion, failed tibiotalocalcaneal arthrodesis attributable to nonunion of the tibiotalar and/or subtalar joint; or tibiotalar and subtalar osteoarthritis in patients with impaired bone or soft tissue quality (particularly if the soft tissue problem was anterior). During that period, all patients who met those indications were treated with a posterior blade plate. Forty (95%) were included in this study, and two were lost to followup before the 1-year minimum required by the study. Demographics (age, gender, BMI, smoking status, and comorbidities) and surgical data (indication, previous treatment, and additional procedures) were analyzed. Of the 40 patients included, 27 (68%) were male and 13 (33%) were female, with a median of two previous hindfoot or ankle surgeries (range, 0-9 surgeries). The mean age of the patients was 56 ± 13 years. Followup averaged 47 ± 28 months (range, 14-137 months). Twenty-eight of 40 (70%) patients had a tibiotalocalcaneal arthrodesis as a primary (n = 6), primary staged (n = 10), revision (n = 9), or revision staged (n = 3) procedure. Eleven of 40 patients (28%) underwent ankle arthrodesis (primary n = 7, revision n = 4). One of the 40 patients (3%) underwent tibiotalocalcaneal arthrodesis for a failed total ankle arthroplasty. Weightbearing radiographs were used to assess fusion. Osseous fusion was defined as visible trabecular bridging on the lateral and AP ankle views within 6 postoperative months. Delayed union was defined as osseous fusion occurring between 6 and 12 months. Nonunion was defined as no visible trabecular bridging at the latest followup (longer than 12 months). Clinic and surgery notes were reviewed for complications. Univariate analysis was performed to compare patient groups: patients with solid union versus nonunion, and patients with versus without complications. RESULTS: Twenty-nine of 40 (73%) patients had osseous fusion within 6 postoperative months. Four of 40 (10%) patients had a delayed union between 6 and 12 months, and seven of the 40 (18%) patients had nonunions, which occurred in the ankle (n = 3), subtalar (n = 3), or both (n = 1) joints. There were 26 complications observed: 18 (69%) were considered major and eight (31%) were minor. With the numbers available, we did not identify any demographic or surgical factors associated with complications, delayed union, or nonunion. CONCLUSIONS: The proportion of patients treated with a posterior blade plate hindfoot fusion who had delayed union or nonunion is greater than that reported for patients in other series who underwent primary hindfoot arthrodesis with other approaches, and the proportion of patients who had complications develop is high. Further studies are needed to address alternative approaches to achieve hindfoot fusion in patients with complex hindfoot problems. LEVEL OF EVIDENCE: Level IV, therapeutic study.