Category:
Trauma; Ankle
Introduction/Purpose:
The anterior distal tibial tubercle (Tillaux-Chaput tubercle) frequently fractures in the wake of malleolar fractures. It provides attachment to the ...anterior tibiofibular syndesmosis and may be considered a fourth or anterior malleolus (AM). In analogy to posterior malleolar fractures, AM fractures may extend into the tibial incisura and tibial plafond. We analyzed the pathoanatomy of AM fractures and associated injuries in ankle fractures in adults.
Methods:
Over a course of 9 years, 140 patients (average age 58.3 years) with 140 acute malleolar fractures (OTA/AO 44) involving the anterolateral distal tibial rim were analyzed with CT imaging. All components of the malleolar fractures were analyzed and classified. Fracture patterns were compared with those of all 1,379 patients treated for malleolar fractures at our institution during the same 9-year period. Patients with fractures of the tibial pilon (OTA/AO 43) and patients aged less than 18 years were excluded as the frequent anterolateral distal tibial fractures along the physeal growth plate in adolescents are beyond the scope of this analysis. Fractures were classified according to the most frequent patterns and possible treatment options.
Results:
Of the 140 AM fractures, 52.9% were classified type 1 (extra-articular avulsion), 35.7% type 2 (incisura and plafond involvement), and 11.4% type 3 (impaction of the anterolateral plafond). The fibula was fractured in 87.1%, the medial malleolus in 67.1%, and the posterior malleolus in 69.3%. Isolated AM fractures were seen in only 6 cases (4.3%). The severity of AM fractures correlated negatively with that of posterior malleolar fractures (p<0.001). The proportion of pronation-abduction fractures increased and the proportion of supination external rotation fractures decreased with increasing severity of AM fractures (p=0.055). Fractures involving the AM had a prevalence of 12.6% of all ankle fractures and occurred significantly more frequently in pronation-type injuries (p<0.001). No supination-abduction fractures were seen with AM involvement. The interclass correlation coefficient for the proposed classification of AM fractures was 0.961 (95% CI 0.933-0.980) for interobserver agreement and 0.941 (95% CI 0.867-0.974) for intraobserver agreement.
Conclusion:
Knowledge of the 3D pathoanatomy of AM fractures and associated injuries may help with surgical planning. CT imaging should be employed generously in the assessment of complex ankle fractures, particularly with pronation injuries. In analogy to posterior malleolar fractures, fixation of displaced AM fractures potentially restores syndesmotic stability, congruity of the tibial incisura thus facilitating fibular reduction and joint congruity at the anterolateral tibial plafond. Proposed treatment options include transosseous suture for syndesmotic avulsions (type 1), screw fixation for fractures involving the incisura and plafond (type 2), and elevation of the impacted plafond with buttress plating for type 3 fractures.
Category:
Ankle Arthritis
Introduction/Purpose:
There are limited studies on the outcomes of conversion to fusion following a failed ankle replacement. The primary aim of this NJR data linkage study ...is to determine the outcomes of conversion to fusion following a failed ankle replacement.
Methods:
A data linkage study combined National Joint Registry Data and NHS Digital data. The primary outcome of failure is defined as a further fusion procedure or amputation. Life tables and Kaplan Meier survival charts demonstrated survivorship. Cox proportional hazards regression models with the Breslow method used for ties were fitted to compare failure rates.
Results:
131 patients underwent conversion to fusion. The mean time from primary replacement was 33.8 months (range 1-100). The mean age was 63.3 (range 33-85), there were 73 males (55.7%). The mean BMI was 30.7 (SD 5.3) mean ASA was 2.0 and the mean Charlson co-morbidity score was 2.5. The most commonly revised implant was the Mobility in 45.0%, Zenith in 16.8% and Box in 11.5%.105 (80.2%) were as a single stage and 26 (19.8%) as a 2 stage procedure. The 1 year survivorship was 96.0% (95% CI 90.6%-98.3%), 2 year survivorship was 83.8% (95% CI 75.4%-89.5%) and 5 year survivorship was 72.4% (95% CI 62.0%-80.4%) A Cox regression model adjusting for individual factors did not find any risk factor significantly increased the risk of failure.
Conclusion:
Conversion to fusion following a failed ankle replacement has high rates of further surgery. Further prospective studies are required to determine risk factors for failure to improve outcomes for these patients.
Category:
Midfoot/Forefoot; Other
Introduction/Purpose:
Lateral Column Lengthening (LCL), Medial Displacement Calcaneal Osteotomy (MDCO) and Cotton Osteotomy (CO) are considered the work-horse ...surgical procedures for Progressive Collapsing Foot Deformity (PCFD) correction. The amount of three-dimensional correction induced by each isolated procedure cannot be established in the clinical setting since procedures are frequently performed in combination based on deformity severity and surgeon's preference. Understanding the influence of each one of the procedures, as well as their magnitudes, in the overall 3D correction of the deformity would be extremely helpful in the surgical planning of PCFD. Therefore, our simulated weightbearing cadaveric study aimed to assess the amount of 3D correction induced by different magnitudes of isolated and combined LCL, MDCO, and CO procedures, using weightbearing CT (WBCT) imaging.
Methods:
In this cadaveric study 12 below-knee specimens with no deformity were used. They were mounted on a frame under 360N of axial load, while keeping conventional stance level tension to tendinous structures. Each group of four specimens underwent isolated and progressive magnitudes of MDCO (6, 10 and 14mm), LCL (6, 8 and 10mm) and CO (4, 8 and 12mm). Following isolated correction, the specimens were randomized into different amounts of combined correction, first with two procedures (only moderate correction; four specimens each combination) and then with three procedures (combined mild, moderate and large corrections; four specimens each). The 3D measurement Foot and Ankle Offset (FAO), representing the relative position between the center of the ankle joint and the weight bearing tripod of the foot, was calculated from WBCT datasets for each specimen in each one of the tested corrected conditions. Comparison between the different conditions was performed using Paired T-Test/Wilcoxon.
Results:
All isolated performed corrective procedures (MDCO, LCL and CO) significantly influenced FAO measurements (All p- values <0.05). When applied in isolation, every 1mm increase in MDCO, LCL and CO decreased FAO values by respectively 0.8%, 0.36%, and 0.29%, highlighting the importance of the heel position in the overall 3D position of the foot. Combination of two moderate-sized procedures decreased FAO values significantly (p<0.05) and more pronouncedly, with combination of MDCO and LCL decreasing FAO by an average of 7.2%, MDCO and CO by 6.2% and LCL and CO by 3.9%, with no significant differences between the three. As expected, combination of the three procedures lead to pronounced and significant decreased of FAO values by respectively 5.2%, 8.5% and 14.2% for mild, moderate, and large corrections. The combination of the three large sized corrections was significantly higher than mild and moderate corrections (p=0.002).
Conclusion:
In this cadaveric WBCT study we assessed the influence of different magnitudes of isolated and combined MDCO, LCL and CO in foot and ankle 3D alignment. We found that all isolated procedures significantly decreased FAO measurements, with every 1mm increase in MDCO, LCL and CO decreasing FAO by respectively 0.8%, 0.36%, and 0.29%. Combination of two procedures and three procedures also lead to significant and more pronounced alignment change. The data presented in this study can serve as baseline predictive values of foot alignment correction when planning the use of MDCO, LCL and CO for surgical treatment of PCFD.
Category:
Ankle Arthritis; Ankle
Introduction/Purpose:
Tendinopathy of the flexor hallucis longus is a common condition that occurs with considerable frequency, but in some specific situations, due ...to a content (tendon)/continent (retomalleolar groove) conflict, could manifest a scenario in which the tendon suffers entrapment during its entry to the tunnel and clinically represented as hallux saltans
Methods:
We present a case report of a young active patient without any of the conditions or etiological agents previously described in the literature that could explain the cause of this rare condition. After failing conservative treatment, we performed arthroscopic release of the tendon and the fibrous tunnel, achieving direct visualization and minimal soft tissue injury
Results:
At 6 months, the patient resumed sports and activity of daily living without any type of sequelae.
Conclusion:
Hallux saltans is a rare condition mostly idiopathic in its origin. After conservative measures fail, surgical management is an option, which consists of resecting FHL enlargement to its original width and freeing the fibro-osseous tunnel in the back of the talus in order to solve the space conflict during its normal gliding. An arthroscopic approach is optimal as it allows a good visualization without harming soft tissues and allowing a quicker recovery.
Category:
Hindfoot; Ankle; Other
Introduction/Purpose:
Equinovarus foot deformities typically present with equinus contractures, hindfoot varus, dorsiflexion of the medial midfoot, and adduction ...deformities of the forefoot. Whether of neurologic or muscular origin, all forms result muscular imbalance. Flexor hallucis longus (FHL) transfer to peroneus brevis (PB) is indicated when both peroneal muscles are in unrepairable condition to restore active eversion. However, in cases of muscle paralysis where the PB is still in continuity, we recommend a novel technique where FHL is tenodesed proximal to the peroneal retinaculum within the leg to avoid the additional morbidity associated with more distal fixation or tenodesis.
Methods:
Surgical intervention first involved a posterolateral approach to the ankle and an Achilles tendon Z-lengthening to fix her equinus contracture. The ankle and subtalar joint capsules were contracted requiring release. Flexor digitorum longus (FDL) and FHL were tenotomized, which immediately corrected her claw toes. Since the tendon had already been released, we were able to deliver the FHL tendon into the posterolateral leg wound. The peroneal fascia and sheath were opened proximal to the superior peroneal retinaculum to prevent tendon subluxation. PB was identified by confirming that it produced foot eversion and by visualizing the peroneus longus (PL). The tension of PB was confirmed by observing that it did not cause tension at PL insertion on the plantar 1st ray. FHL was then transferred to the PB utilizing a Pulvertaft weave technique with the tendon appropriately tensioned in mid eversion in the middle of the Blix curve (Figure 1).
Results:
After FHL transfer, the patient was immediately allowed to weight bear as tolerated in a short leg cast. This was due to her deconditioned state to limit atrophy and the effects of prolonged recumbency in this medically fragile young woman. The patient ultimately was casted for 10 weeks total as she was unable to tolerate a CAM boot or other orthotic due to the weight and problems with the fit. At 4 months follow up, her foot is corrected and she is able to stand in a neutral, plantigrade position. Using a new AFO, she can walk without issue. Her foot remains well balanced and plantigrade.
Conclusion:
This simple FHL transfer technique decreases morbidity since the transfer occurs within the leg, proximal to the superficial peroneal retinaculum (SPR). The transfer pulls on the paralyzed, but intact PB instead of routing the FHL to the 5th metatarsal base or PB stump. This technique is only recommended if PB is intact but non-functional. It should be noted that adequate tensioning is essential for a successful transfer. Benefits of this procedure include no cluttering under the SPR and no risk of scarring that region which can lead to decreased tendon excursion.
Category:
Midfoot/Forefoot; Basic Sciences/Biologics; Hindfoot
Introduction/Purpose:
The current classification system of progressive collapsing foot deformity (PCFD) is comprised of 5 possible ...classes that describe different deformity components. Each class is defined by clinical and radiographic findings. These components are ostensibly independent from one another during evaluation and treatment. However, PCFD is understood to be a complex, three-dimensional deformity occurring in many regions along the foot and ankle. The question remains whether a deformity in one area impacts other areas. The objective of this study is to assess how each one of the classes is influenced by other classes by evaluating each associated angular measurement. We hypothesized that positive and linear correlations would occur for each class with at least one other class and that this influence would be high.
Methods:
In this IRB-approved retrospective case-control study, we assessed 32 feet diagnosed with PCFD and 28 controls matched on gender, BMI and age. All measurements were performed using weight-bearing CT (WBCT) scans and completed by two foot and ankle surgeons. The classes and their associated radiographic measurements were defined as follows: Class A (hindfoot valgus) measured by the hindfoot moment arm (HMA), class B (midfoot abduction) measured by the talonavicular coverage angle (TNCA), class C (medial column instability) measured by the talus-first metatarsal (Meary) angle, class D (peritalar subluxation) measured by the medial facet uncoverage (MFU), and class E (ankle valgus) measured using the talar tilt angle (TTA). Multivariate analyses were completed comparing each class measurement to the other classes. Data were checked for multicollinearity with the Belsley-Kuh-Welsch technique. Heteroskedasticity and normality of residuals were assessed respectively by the Breusch-Pagan test and the Shapiro-Wilk test. A p-value <0.05 was considered significant.
Results:
After removing confounding variables, each class was separately evaluated. In Class A, Meary was positively correlated (rs=0.46; p=0.009) with HMA, explaining 21% of changes in this angle (R2=0.21). Class B evaluation showed that MFU was correlated with TNCA (rs=0.76; p=0.001), explaining 63% of TNCA variations (R2=0.63). In Class C, HMA (rs=0.71; p=0.001) and MFU (rs =0.75; p=0.001) were correlated to Meary's angle and both measures explained 58% of changes in this angle (R2=0.58).
When assessing Class D, TNCA (rs =0.76; p=0.001) and Meary (rs=0.75; p=0.001) correlated with MFU and were responsible for 63% of variations on this angle. Finally, Class E deformity, determined by TTA, was not correlated with any other measurement.
Conclusion:
This study was able to find relations between components of PCFD deformity with exception of ankle valgus (Class E). Measurements associated with each class were found to be influenced by others, and in some instances with pronounced strength. The presented data may support the notion that PCFD is a three-dimensional complex deformity and suggests a possible relation among its ostensibly independent features. Further, these results support the concept that a specific component correction may impact other misalignments, decreasing the necessity for adjuvant procedures. This could have a direct effect in clinical practice, changing how providers assess PCFD and plan treatments.
The surgical treatment of end-stage tibiotalar arthritis continues to be a controversial topic. Advances in surgical technique and implant design have lead to improved outcomes after both ankle ...arthrodesis (AA) and total ankle arthroplasty (TAA), yet a clear consensus regarding the most ideal form of treatment is lacking. In this study, the outcomes and complications following AA and TAA are compared in order to improve our understanding and decision-making for care and treatment of symptomatic tibiotalar arthritis.
Studies reporting on outcomes and complications following TAA or AA were obtained for review from the PubMed database between January 2006 and July 2016. Results from studies reporting on a minimum of 200 total ankle arthroplasties or a minimum of 80 ankle arthrodesis procedures were reviewed and pooled for analysis. All studies directly comparing outcomes and complications between TAA and AA were also included for review. Only studies including modern third-generation TAA implants approved for use in the USA (HINTEGRA, STAR, Salto, INBONE) were included.
A total of six studies reporting on outcomes following TAA and five reporting on outcomes following AA met inclusion criteria and were included for pooled data analysis. The adjusted overall complication rate was higher for AA (26.9%) compared to TAA (19.7%), with similar findings in the non-revision reoperation rate (12.9% for AA compared to 9.5% for TAA). The adjusted revision reoperation rate for TAA (7.9%) was higher than AA (5.4%). Analysis of results from ten studies directly comparing TAA to AA suggests a more symmetric gait and less impairment on uneven surfaces after TAA.
Pooled data analysis demonstrated a higher overall complication rate after AA, but a higher reoperation rate for revision after TAA. Based on the existing literature, the decision to proceed with TAA or AA for end-stage ankle arthritis should be made on an individual patient basis.
Category:
Hindfoot; Ankle; Ankle Arthritis; Midfoot/Forefoot
Introduction/Purpose:
Markers used for diagnosis and severity grading are well studied in patients with Progressive Collapsing Foot ...Deformity (PCFD). Medial facet subluxation (MFS) in weight-bearing computerized tomography (WBCT) has been established as an early indicator of peritalar subluxation (PTS). When the disease affects the ankle leading to a valgus talar tilt (class E), structures distal to this topography may behave differently, trying to compensate for proximal deformity. The aim of this study is to assess predictors of deformity in PCFD patients with and without valgus of the ankle. Our hypothesis is that MFS cannot be used in Class E patients as an accurate marker for the evaluation and staging of PCFD.
Methods:
In this IRB-approved retrospective case-control study, we analyzed WBCT imaging of 21 consecutive patients with PCFD with valgus of the ankle and 64 controls (flexible PCFD without ankle involvement). MFS (defined by the percentage of uncoverage), middle facet incongruence angle, middle cuneiform-to-floor distance, forefoot arch angle, talonavicular uncoverage angle, hindfoot moment arm (HMA), Foot and Ankle Offset (FAO), and talar tilt angle (TTA) were obtained and compared between groups using one-way ANOVA. A multivariate regression analysis was performed to evaluate which of the measurements influenced the alignment. A partition prediction model was constructed to assess how the variables contributed to the deformity. P values <0.05 indicated statistical significance.
Results:
Differences between groups were found for MFS, HMA, FAO, and TTA, with a lower mean value of MFS in PCFD patients with valgus of the ankle. An inverse relation between MFS and TTA was found, which was demonstrated by an increase in the talar tilt and a decrease in middle facet uncoverage. FAO values were affected by MFS in the control group (R2: 0.25) but not in the ankle valgus group (R2: 0.001), which was influenced mainly by the TTA (R2: 0.53). Additionally, a FAO value higher than 12.14 was found to be a strong predictor of deformity at the ankle.
Conclusion:
Medial facet subluxation was lower in patients with PCFD and valgus of the ankle (Class E), which demonstrates that MFS is a weak predictor of deformity severity. Therefore, this suggests that talar tilt angle and Foot and Ankle Offset should be used as disease markers in this group of patients. Furthermore, a FAO value above 12.14 may be an indicator of ankle involvement in PCFD patients.
Category:
Ankle; Sports; Trauma
Introduction/Purpose:
Numerous radiographic studies examining Weber B fibular fractures demonstrate no change in tibiotalar contact area until the deltoid ligament is ...disrupted. In contrast, more recent studies using weight-bearing CT scan (WBCT) and 3D volume analysis suggest that medial clear space (MCS) volume can in fact increase in the setting of a Weber B fibular fracture even if initial radiographs are reassuring, possibly due to a loss of fibular buttress. This study aims to evaluate the ability of WBCT to quantify the impact of isolated Weber B fractures on MCS volume (3D), as well as understand the implication of increasing fibular displacement among patients with symmetric MCS distance (1D) on initial radiographs.
Methods:
The study group included 18 patients with unilateral Weber B ankle fractures who underwent preoperative bilateral foot and ankle WBCT. The control group consisted of 60 patients without ankle injury who underwent similar imaging.
Measurements on WBCT images included: 1) MCS distance, 2) syndesmotic area, 3) anterior, middle, and posterior distal tibiofibular distance, 4) fibular rotation, 5) distance from fibular tip to plafond, and 6) fibular fracture displacement. Additionally, volumetric measurements included: 1) MCS volume 2) syndesmotic joint volume from the tibial plafond extending to 3cm and 5 cm proximally, and 3) lateral clear space volume were calculated. Area under the receiver operating characteristic (ROC) curve analysis and Delong test were used, and optimal cutoff values to distinguish between stable and unstable Weber B fractures without syndesmotic instability and MCS widening were determined using Youden's J statistic.
Results:
Among patients with unilateral Weber B ankle fractures, all WBCT measurements showed no side-to-side difference in any parameter, except MCS volume (p-values <0.001). When compared to the uninjured side, fibular displacement up to 2cm and up to 4cm increased lateral MCS volume by 37.1% (0.23cm3) and 51.8% (0.3cm3), respectively. Based on ROC analysis and Youden's J statistic, the optimal threshold for differentiating stable from an unstable Weber B fracture was 2.3 mm of displacement (AUC 0.81; sensitivity 77.8%; specificity 80%). The control group showed no difference in any of the measurements between the two sides.
Conclusion:
When using WBCT, 3D MCS volume increases significantly with Weber B fibular fractures, even if 1D distance measurements at the medial clear space are reassuring. This is especially true with fibular displacement greater than 2.3mm and may have an important role in the management of SER II ankle fractures.
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