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:
Ankle
Introduction/Purpose:
The indications for total ankle arthroplasty (TAA) have greatly expanded over the past decade. This rapid growth has been made possible with evidence-based ...medicine. Patient-reported outcomes (PROs) have been the primary outcome measure in many of these studies. To evaluate the quality of the evidence underlying expanded indications for TAA, we must first understand what PROs have been used in the evaluation of outcomes of TAA.
Methods:
The goal of this study was to conduct a systematic review of the literature from 2010 to 2021 capturing all studies of TAA to determine what PRO instruments were used, and what facets of TAA practice were studied. Studies reporting on outcomes and PROs following a TAA procedure were selected to review from the PubMed database between January 2010 and July 2021. Results from one hundred sixty-three studies were reviewed and pooled for analysis for this study.
Results:
After the evaluation of one hundred sixty-three studies, twenty-four separate PRO measures were identified in the literature. The PROs that were most reported in the literature from 2010 to 2021 were American Orthopedic Foot and Ankle Score (AOFAS) (49.1%), 36-Item Short Form Survey (SF-36) (40.5%), visual analog scale - pain (VAS) (35.6%), Ankle Osteoarthritis Scale (AOS) Questionnaire (17.8%), and Short Musculoskeletal Function Assessment (SMFA) (14.7%). The independent variables in these studies included a wide range of modifiable and unmodifiable patient factors such as age (27 studies), BMI (23 studies), smoking (8 studies), and preoperative coronal plane deformity (5 studies). A significant portion of the studies (41%) advocating for expanded indications did so based on the failure to find a difference in groups.
Conclusion:
The most commonly used PROs for TAA were AOFAS, SF-36, and VAS. The AOFAS score which had been the most commonly used PRO in 2009, is still today despite the determination in 2011 that it is not valid and there is a substantial risk for bias. Newer, validated PRO instruments, such as PROMIS, have not yet attained significant implementation in studies of TAA. The vast majority of the evidence supporting the expanded indications for TAA has come from studies with negative results. Caution should be exercised in interpreting these results and their study implications.
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.
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
Introduction/Purpose:
The Hindfoot Moment Arm (HMA) has been used to evaluate the hindfoot alignment with the Saltzman weightbearing XRay images (1), and was recently ...introduced into the field of weightbearing CT (WBCT) by Saltzman et al (2). The authors of this study have noticed that when using the Saltzman WBCT HMA technique, it is very difficult to determine the specific 'one' image in coronal plane scans with the widest tibial diaphyseal to draw the long axis of the tibia. The purpose of this study was to introduce a modified technique of measuring HMA in WBCT scans and compare the inter and intra-observer reliabilities between the modified and the Saltzman WBCT HMA techniques.
Methods:
WBCT scans of ten healthy limbs were loaded in CubeVue software. The foot was aligned in the correct orientation in the transverse plane based on the 2nd ray and the heel and the HMA was evaluated using the modified and Saltzman techniques. Using the modified technique, the sagittal plane thickness of one scan cut was increased to include the full width and length of the tibia and the axis of the distal tibia was identified by connecting two circles tangential to both cortices of the tibia. The weightbearing point of the calcaneus was located and the HMA was evaluated by measuring the perpendicular distance of the calcaneus weightbearing point to the axis of the distal tibia with varus a negative and valgus alignment a positive value. Intraclass correlation coefficient (ICC) model was used to assess the intra- and interobserver reliability of the two HMA techniques in SAS 9.4.
Results:
Both techniques had excellent intra- and interobserver reliability (Saltzman WBCT HMA intra-observer ICC=0.97, Saltzman WBCT HMA inter-observer ICC=0.94, the modified WBCT HMA intra-observer ICC=0.99, the modified WBCT HMA inter-observer ICC=0.91) (Table 1).
Conclusion:
The modified WBCT HMA was equivalent to the Saltzman technique in both inter and intra-observer reliabilities. The authors found that the modified technique was easier and less time consuming to perform in identifying the axis of the tibia since the modified technique uses multiple cuts to restore the full thickness of tibia, which not only reduces potential error, but also saves time during measurements. Compared with a relatively shorter tibia in one cut, the reconstructed tibia provides a longer and clearer shaft to work with, which allows both proximal and distal circles to be drawn with higher precision (Figure 1).
1. Saltzman, C. L., & El-Khoury, G. Y. (1995). The hindfoot alignment view. Foot & Ankle International, 16(9), 572-576.
2. Arena, C. B., Sripanich, Y., Leake, R., Saltzman, C. L., & Barg, A. (2021). Assessment of hindfoot alignment comparing weightbearing radiography to weightbearing computed tomography. Foot & Ankle International, 42(11), 1482-1490.
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
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:
Ankle; Sports; Other
Introduction/Purpose:
The isokinetic test has been used diffusely as a way to evaluate the functional results after the rehabilitation of musculoskeletal injuries. In ...the ankle, in particular, most studies are related to lateral ligament injuries and Achilles tendon's injuries. However, different protocols are used and a lack of normative values is observed in the literature. The aim of this work is to perform a global isokinetic evaluation on healthy ankles in order to propose reference values for future patients.
Methods:
We evaluated 100 participants (200 ankles) using the Biodex 3 System for the eversion, inversion, dorsiflexion and plantar flexion movements of the ankle. The sample consisted of individuals aged 20-60 years, with an active life and practice of recreational physical activity (non-athlete) and without previous injuries. Five repetitions for strength (N / m) and work (J) at a speed of 30o / sec and 10 repetitions for power (W) at a speed of 120o / sec were performed in our protocol. Agonist / antagonist ratio and the Muscle Deficiency Index, which globally assesses the balance between the sides for each movement, were also evaluated, as well as the demographic variables. Different statistical analyzes were performed for each parameter.
Results:
The mean age was 38.5 years and BMI 25.8 (CI 2.7 and 0.8 respectively) in 69 men and 31 women. In 78% of participants, the dominant ankle was the right one. The non-dominant side was consistently stronger (higher peak torque) in all movements (p<0.001 - Wilcoxon Test). The mean values obtained for force in each movement were 29.9N/m for eversion, 34.8N/m (CI 1.6) for inversion, 48.6N/m (2.0) for dorsiflexion and 140.2 N/m for plantar flexion. Such parameters for men and women were also obtained (p<0.001) and there was no correlation between age or BMI with the maximum torque (N/m) through Spearman's Correlation. The ratio of eversors / inverters was 88.8% (CI 3.1) and that of dorsiflexors / plantar flexors was 36.1% (1.3). Limb symmetry Index were >= 90% between sides in all four moviments (91,99% for eversion, 98,57% for inversion, 96,96% for dorsiflexion and 94,72% for plantarflexion).
Conclusion:
The non-dominant side was stronger in this evaluation of the two hundred healthy ankles. However, this difference was within the expected range for the limb symmetry index and for the MDI, showing that limb dominance is not relevant for the isokinetic assessment of the ankle. In the studied sample, the demographic variables (except gender) did not show any correlation with the evaluated parameters, especially with the maximum torque. Normative values of torque forces and agonist/antagonist balances were proposed. The results have implications for rehabilitation protocols and criteria for returning to sports.
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.