Category:
Bunion; Midfoot/Forefoot
Introduction/Purpose:
The outcomes of Hallux Valgus (HV) surgical treatment are perfectible.
First ray dysmorphia in HV appears to incorporate a first metatarsal ...(M1) hyperpronation and a valgus deviation of M1 distal articular surface. Those could play a role in first ray destabilization and misalignment in HV. However, we do not know whether correction of these deformities could improve HV surgical treatment outcomes.
Therefore, we performed a study to assess the impact of M1 distal supination osteotomy, M1 distal varization osteotomy, and combination of both on HV clinical and radiological outcomes.
We hypothesized that M1 distal supination osteotomies would improve surgical outcomes in HV.
Methods:
We conducted an IRB-approved multicenter randomized control trial.
HV with an indication for surgical correction were included. HV requiring surgery of the lesser metatarsals were excluded. Feet were randomly divided into 4 groups corresponding to 4 different types of surgery (Figure):
1. Control, classical M1 distal chevron.
2. Supination M1 distal chevron
3. Varization M1 distal chevron
4. Combination of the latter two.
Preoperative evaluation and 6-months follow-up were performed. Demographics, AOFAS score, complications, and patient satisfaction (Likert Scale) were collected.
On conventional weight-bearing radiographs before and 6 months after surgery, we measured the Hallux Valgus Angle(HVA), the Intemetatarsal Angle(IMA) the Distal Metatarsal Articular Angle(DMAA), the Okuda's M1 head shape classification(from round to angular) and the sesamoid position according to Hardy and Clapham.
Normality of different variables was assessed using the Shapiro-Wilk test. Groups were compared using ANOVA for normal and Kruskall Wallis for nonnormal variables. Post-hoc pairwise analyses were performed with Dunn-Bonferoni’s test.
Results:
100 HV were included. 8 were lost to follow-up.
The Control (n=24), Supination (n=20), Varization (n=26) and Combination (n=22) groups were comparable on age, gender, BMI, and preoperative radiological parameters.
At 6 months, there was no difference on AOFAS improvement (p=0.39) and patients satisfaction (p=0.14) whereas there were significant differences on HVA (p < 0.001), IMA (p < 0.001), DMAA (p < 0.001), Okuda's classifcation (p < 0.001) and sesamoid position (p < 0.001) between groups.
We found lower HVA values for Combination VS Control (p < 0.001), Combination VS Varization (p < 0.001), Supination VS Control (p < 0.001) and Supination VS Varization (p = 0.005).
Asymptomatic recurrences (HVA>15°) were present in 5 cases in Control (20.8%), and 2 in Varization (7.7%). Asymptomatic Hallux Varus (HVA < 0°) were present in 4 cases in Combination (18.2%), and 1 in Supination (5%).
Conclusion:
Distal M1 supination osteotomies showed better improvement in radiological parameters without showing clinical benefit.
The combination of supination and varization osteotomies could lead to overcorrection while the classic M1 distal chevron could lead to insufficient corrections.
Routinely performing a supination osteotomy in HV surgical management may lead to erroneous correction and we recommend an à la carte treatment.
These results are preliminary and we recommend more patients and longer follow-up to confirm these findings.
Category:
Ankle; Basic Sciences/Biologics
Introduction/Purpose:
Chronic Lateral Ankle Instability (CLAI) represents a significant socioeconomic burden. Paradoxically, its management has changed ...little over the years, notably because research is divided into functional and mechanical instability, whereas CLAI encompasses both. Sprain simulators can encompass both functional and mechanical instability by assessing the maximal ankle inversion velocity (MIV) during a simulated inversion trauma. We built a sprain simulator capable of producing a sudden ankle inversion motion during walking.
We aimed to differentiate subjects with chronic lateral ankle instability (CLAI) from controls and quantify functional CLAI as well as impairments in activities of daily living and sports using a sprain simulator.
Methods:
Forty-five physically active subjects were included and assigned to a CLAI group, a control group, or excluded according to the International Ankle Consortium selection criteria.
Each subject walked on a treadmill with instability boots after completing the Identification of Functional Ankle Instability (IdFAI) and the Foot Ankle Ability Measurement (FAAM) questionnaires.
A simulated trauma was unexpectedly triggered by the observer.
Maximal inversion velocities (MIV) were measured at this very moment using inertial moment units.
We normalized these values by the average MIV of the 5 stance phases of the same foot preceding the simulated trauma (Ratio MIV).
Normality of data were assessed with the Shapiro-Wilk test. The groups were compared using Student T test for normal and Mann-Whitney U test for nonnormal variables. Multivariate linear regressions were performed to assess the relation between, the IdFAI, the FAAM Activities of Daily Living Subscale, the FAAM Sports Subscale and the explanatory variables.
Results:
Twenty-six ankles were excluded, 32 composed the CLAI group and 32 the control group.
Mean MIV were 213.5+/-54.7°/s and 177+/-64.2°/s (p=0.02), and mean Ratio MIV were 1.22+/-0.13 and 1.08+/-0.08 (p < 0.001) in the CLAI and Control groups respectively.
In multivariate analysis, Ratio MIV was associated with higher values of IdFAI (β=42.8 12.9;72.8,p=0.006), lower values of FAAM Activities of Daily Living Subscale (β=-14.1 -27.8;-0.5,p=0.04) and lower values of FAAM Sports Subscale (β=-7.2 -13.7;- 0.6,p=0.03) whereas MIV was not.
Conclusion:
Inversion velocities caused by a sprain simulator clearly differentiated CLAI from controls in our study. Ratio MIV showed good ability to quantify functional CLAI as well as impairments in activities of daily living and sports. This tool should be used in future studies in an attempt to provide a complete picture of CLAI encompassing its functional and mechanical aspects which may lead to improved LAS and CLAI management.
Objectives:
Subtle syndesmotic instability (SSI) is a difficult albeit important diagnosis to make, as undiagnosed instability frequently leads to posttraumatic ankle arthritis. Stressed conventional ...radiographs, ultrasonography, bilateral comparative conventional computed tomography (CT) and magnetic resonance imaging (MRI) serve as important diagnostic tools, however, the current diagnostic gold-standard is arthroscopic assessment, an invasive surgical method. The advent of weight-bearing computed tomography (WBCT) is considered to be an important additional diagnostic tool for improved non-invasive SSI diagnosis, particularly by utilizing distal tibiofibular syndesmotic (DTFS) area and volume measurements. However, to date, no studies have assessed WBCT diagnostic accuracy for chronic SSI. The purpose of this study was to prospectively evaluate the diagnostic accuracy of WBCT area and volumetric measurements in patients with suspected chronic SSI, when compared to the gold-standard arthroscopic assessment.
Methods:
In this IRB-approved prospective comparative study, 11 patients with suspected SSI were enrolled from July 2019 to December 2020. Patients were assessed preoperatively by bilateral standing WBCT. Raw 3D WBCT was automatically segmented by dedicated software. WBCT measurements included semi-automatic DTFS area (1cm proximally to tibial dome apex) and DTFS volumes (1, 3 and 5cm proximally to tibial dome apex). Threshold values for WBCT abnormality were defined based on currently available data (area>105mm2 and volumes>796mm3, >3062 mm3, and >6733 mm3 for 1, 3 and 5cm, respectively). Subjects underwent surgical treatment including DTFS instability arthroscopic assessment, defined as positive when a 3mm diameter sphere could enter the syndesmotic incisura. Confirmed unstable cases were treated with open reduction/internal fixation. WBCT measurements sensitivity, specificity, positive and negative predictive values (PPV/NPV) and accuracy were calculated using confirmed arthroscopic instability as diagnostic gold standard. Paired t-tests/Wilcoxon analysis was used to compare measurements. P-values<0.05 were considered significant.
Results:
When compared to non-injured sides, DTFS area and volumes were significantly higher in injured ankles at 1cm (667 vs 554mm3) and 3cm (2331 vs 2038mm3). Medial gutter volumes were also increased in injured sides (398 vs 370 mm3). DTFS volumes at 5cm and lateral gutter volumes were not different. Nine of eleven patients had confirmed arthroscopic DTFS instability. Considering WBCT area measurements, 4/11 patients were found to be positive (>105mm2), including 3 true positives (+WBCT/+Arthroscopy), 1 false positive (+WBCT/-Arthroscopy), 6 false negatives (-WBCT/+Arthroscopy), and 1 true negative (-WBCT/-Arthroscopy), leading to a 33.3% sensitivity, 50%, specificity, 75% PPV 75%, 14.3% NPV and 36% accuracy. When analysing WBCT DTFS volumes (1cm), 3/11 patients were found positive (>796mm3), depicting 3 true positives, 0 false positives, 2 true negatives and 6 false negatives, with resultant diagnostic accuracy of: 33.3% sensitivity, 100% specificity, 100% PPV, 25% NPV 25%, and 45% accuracy.
Conclusions:
This is the first study to prospectively assess the diagnostic accuracy of WBCT area and volume measurements in detecting chronic SSI and to compare it to the arthroscopic diagnostic gold standard. When compared to uninjured side, DTFS area and volumetric measurements were significantly increased in injured sides of patients with suspected SSI, including medial gutter volumes, consistent with associated deltoid ligament instability. However, interestingly, we observed a diagnostic accuracy for WBCT area and volumetric measurements to be lower than initially expected. Further incorporation of additional patients, as well as introduction of an external rotational stress can potentially optimize the WBCT diagnostic accuracy for chronic SSI.
BACKGROUNDFactors that may affect surgical decompression results in tarsal tunnel syndrome are not known. METHODSA retrospective single-center study included patients who had undergone surgical ...tibial nerve release. The effectiveness of decompression was evaluated according to whether the patient would or would not be willing to undergo another surgical procedure in similar preoperative circumstances. RESULTSThe patients stated for 43 feet (51%) that they would agree to a further procedure in similar circumstances. Six feet with space-occupying lesions on imaging had improved results, but neurolysis failed in 9 feet with bone-nerve contact. Neurolysis was significantly less effective when marked hindfoot valgus (p = 0.034), varus (p = 0.014), or fasciitis (p = 0.019) were present. CONCLUSIONSIf imaging reveals a compressive space-occupying lesion, surgery has a good prognosis. In feet with static hindfoot disorders or plantar fasciitis, conservative treatment must be optimized. Bone-nerve contact should systematically be sought.
Category:
Bunion; Midfoot/Forefoot
Introduction/Purpose:
Hallux valgus (HV) and progressive collapsing foot deformity (PCFD) are very common foot and ankle conditions in the adult population. Both ...could potentially disrupt the tripod construct of the foot which leads to chronic pain and arthritis. Several procedures were described to address HV deformity depending on deformity characteristics. PCFD could alter the management plan for HV if they occur simultaneously. The aim of this study was to detect the prevalence of PCFD in HV patients and study the frequency of individual PCFD classes.
Methods:
In this retrospective IRB approved study, patients > 18 years old who were evaluated for symptomatic hallux valgus and had a weight bearing computed tomography (WBCT) imaging were included. Patients were considered for further analysis if they have a hallux valgus angle (HVA) > 15° or inter-metatarsal angle (IMA) > 9°. All relevant demographic data were extracted. Two fellowship trained foot and ankle orthopaedic surgeon measured the following parameters: foot and ankle offset (FAO%) (Class A), talo-navicular coverage angle (TNCA) (Class B), Meary’s angle (Class C) and middle facet subluxation (MFS%) (Class D). Cases that showed FAO% > 4.6% and MFS% > 28.7% were diagnosed as PCFD. The prevalence of PCFD classes (A,B,C and D) was calculated using threshold values for its respective radiographic marker. Descriptive statistics were performed.
Results:
Thirty-four cases were included. 16 cases were females (46.06%) and 16 (46.06%) were right side. The average age was 52.51 years (SD ± 17.75), the average BMI was 30.14 (SD ± 7.15). The average HVA was 26.82 (SD ± 9.98) and the average IMA was 15.41 (SD ± 3.53). 13 patients (38.24%) had MFS% and FAO% above the threshold values. The average FAO was 4.75% (SD ± 4.92) and the average MFS was 29.17% (SD ± 15.89). Prevalence of Class A (FAO%) was 20 (58.82%), Class B (TNCA) was 12 (35.29%), Class C (Meary’s angle) was 15 (44.12%) and Class D (MFS%) was 16 (47.06%).
Conclusion:
Progressive collapsing foot deformity is prevalent in the hallux valgus population (38.24%). Class C which indicates medial column instability was prevalent in 44.12% of the cases. Given this high prevalence of PCFD, we believe that in addition to the classic hallux valgus parameters, PCFD classes evaluation could favor a surgical approach over another such as first tarsometatarsal joint procedures over isolated distal first metatarsal procedures to correct the HV deformity and simultaneously halt PCFD progression.
Category:
Hindfoot; Other
Introduction/Purpose:
The use of bio-integrative implants in orthopedic surgery is growing exponentially. Advantages, such as reduced implant-related artifact production, ...lower removal rates, and superior bone interaction, have been advocated. However, while many biomechanical and histological reports could sustain its structural and biological properties, only some clinical studies were produced that could support its use. Therefore, this trial intended to determine the bio-integrative screws' capacity to reach the same clinical and radiographical outcomes of current metallic screws in calcaneus osteotomies. Our main hypothesis was that metallic and bio-integrative screws would not present differences when comparing bone healing and complications.
Methods:
This was a single center, in parallel groups, randomized non-inferiority clinical trial (NCT05018130) that included patients undergoing a calcaneal sliding osteotomy from November 2021 to January 2023. Patients were randomized in a 1 to 1 ratio by software in the metallic or bio-integrative groups, and allocation occurred after anesthesia was carried out. Surgeries were performed by a single surgeon respecting the same technique, using two canulated 4mm screws, either titanium or fiber, according to the treatment group. The primary outcome was determined by bone using weight-bearing computed tomography (WBCT) in the 6th postoperative week. At least 50% of bone trabeculae crossing the osteotomy site needed to be observed to be considered positive. Secondary outcomes included minor and major complications and bone healing, assessed in the 2nd, 4th, 6th, 12th, 24th, and 48th weeks of follow-up. Two assessors performed readings. Between-group differences were measured with ANOVA and chi-square tests.
Results:
After twenty-nine patients were assessed initially, 22 subjects were found eligible and included in the study. Groups were similar demographically (ps>0.37), with ten patients allocated to the bio-integrative and 12 to the metallic group. The mean follow- up was 31.64 weeks (min 6; max 48) with no losses through the endpoints. Considering WBCT bone healing at six weeks, the bio (80%) and the metallic (75%) groups had similar rates (p=0.58). At 12 weeks, bone healing was slightly higher in the bio-integrative group (100% vs. 92%; p=0.004). No major complications were observed. Minor complications were similar between groups (10% in bio; 16% in metallic; p=0.56) and composed of superficial infections (one bio, one metallic) and delayed wound healing (one metallic), all resolved by six weeks.
Conclusion:
Bio-integrative screws presented similar results to metallic screws when used in calcaneus osteotomies, considering bone healing and complications. No differences were found in a medium to long-term follow-up, and no major complications were reported. This non-inferiority clinical trial could contribute to the body of literature supporting the use of bio-integrative screws in clinical practice. Larger and longer trials are necessary to determine the superiority of any implant and its impact on orthopedic surgery.
Category:
Midfoot/Forefoot; Bunion
Introduction/Purpose:
Progressive collapsing foot deformity (PCFD), Hallux Valgus (HV), and Midfoot Arthritis (MA) are diseases that benefit from the Lapidus ...procedure due to its capability to provide a stable medial column while correcting the underlying deformity. However, the technique does not go without complications. First metatarsal shortening/dorsiflexion are not uncommon, which could be exacerbated by local anatomy/revision surgery settings. Restoring length and sagittal plane position (plantarflexion) of the first ray when treating these pathologies is paramount. Performing a primary distraction and plantarflexion fusion with an allograft wedge (LapiCotton) has been advocated in the literature, potentially allowing improved deformity correction, but with the risk of increased non-union rate. The objective of this study was to report medium-term follow-up results of the LapiCotton in patients with collapsed feet.
Methods:
This IRB-approved comparative prospective study assessed patients diagnosed with PCFD, HV, and MA undergoing a Lapidus bone-block fusion (LapiCotton) between August 2020 and November 2022. All patients were operated on by a single fellowship-trained foot and ankle surgeon after clinical evaluation and a weight-bearing computed tomography (WBCT). After adequate joint preparation and trials, a Lapidus pre-shaped wedge allograft was placed and fixed using available implants. Adjunctive procedures were carried out as needed. Patients were kept non-weight bearing for six weeks and followed clinically, performing a WBCT at three months and subsequent follow-up. Non-Union and complications were documented. Bone healing was determined by at least 50% of bone trabeculae crossing both graft interfaces at the WBCT. Forefoot arch angle (FFA), Meary’s angle, talonavicular coverage angle (TNCA), middle facet subluxation (MFS), and foot and ankle offset (FAO) were also obtained. Two fellowship-trained readers performed all assessments. P-values >0.05 were considered significant.
Results:
Fifty-eight patients (60 feet) were included, mean age 53.87 (range:18-77)/BMI 31.70 (SD:7.96). Twenty-four PCFD, 19 HV, and 17 MA had an average 15.47 months (4-31) follow-up. Cuneiform-Post implants were used in 62%, plates/screws in 25%, and Lapidus nails in 13%. Median allograft size was 9mm (mode:8mm,5-19mm). Minor complications were observed in 3% (two superficial dehiscences) and major in 7% (three deep infections 5%, and one EHL contracture 2%). Healing at the 3-month WBCT occurred in 94.8% and only in 66% at the most-recent WBCT (mean:11.08 months; 6-20). The clinical non-union rate demanding reoperation was eight clinical non-unions 13%. Mean FFA (pre:6.89,SD:6.63; postop:14.21,SD:5.48; p< 0.001), Meary (pre:15.17,SD:8.12; postop:6.31,SD:5.61; p< 0.001), TNCA (pre:26.75,SD:11.77; postop:11.59,SD:7.91; p< 0.001), MFS (pre:36.3,SD:26; postop:23.49,SD:17.35; p< 0.001), and FAO (pre:6.71,SD:5.81; postop:2.2,SD:4.33; p< 0.001) improved after the interventions.
Conclusion:
Although the Lapidus bone-block arthrodesis (LapiCotton) restored many of the markers associated with foot collapse and alignment, non-union rated was noted in 13% what is on the top range of non-union rates reported in the literature for Lapidus arthrodesis. The use of allograft wedges in the fusion site probably explains our findings. The fact that the sample was heterogeneous and composed of considerably severe deformities should also be considered. Also, important to highlight that WBCT findings of fusion site healing was initially 94% at 3-months and only 66% at most recent follow-up). Additional studies and longer-term follow up are needed.
Category:
Hindfoot; Other
Introduction/Purpose:
Treatment of Progressive Collapsing Foot Deformity (PCFD) is controversial and surgical procedures utilized usually depend on the type and rigidity of ...deformities present (PCFD classes and stages), degree of soft tissue involvement, and surgeon’s preference. Multiple surgical procedures are usually performed concomitantly to achieve adequate correction. Prospective data regarding the utilization of hindfoot joint-sparing reconstructive procedures in the treatment of flexible PCFD is scarce, and little is known about the influence of the different procedures utilized to treat PCFD in deformity correction and patient-reported outcomes (PROs). The objective of this prospective study was to evaluate the most used hindfoot joint-sparing procedures utilized by a single-surgeon to treat flexible PCFD, and the influence of the utilized procedures in deformity pattern corrections, and PROs.
Methods:
IRB-approved, prospective, and comparative cohort study. Adult PCFD patients with flexible deformity (stage 1), no history of surgical treatment, and that failed conservative treatment for >3-months were enrolled. Patients underwent surgical treatment by a single-surgeon. Patients were excluded if a hindfoot fusion procedure was needed intra-operatively to achieve correction. Types, numbers, and sizes of surgical procedures utilized were recorded. Weight-bearing CT (WBCT) measurements of overall 3D deformity, Classes A (hindfoot valgus), B (abduction), C (medial column instability), D (peritalar subluxation), and E (ankle valgus tilt) were assessed preoperatively, and at first 3-months WBCT. PROs were recorded preoperatively and at the most recent follow-up. Descriptive statistics were used to report the frequency of deformity and procedures utilized. Pre and postoperative measurements and PROs were compared with paired T-tests/Wilcoxon. Multivariate regression analysis was used to correlate procedures utilized with deformity correction and PROs. P-values of >0.05 were considered significant.
Results:
A total of 29 patients included (28 feet, 79%F, 21%M), mean age and BMI of respectively 47.6-years and 34kg/m2. Average number of procedures performed was five and mean follow-up was 19.1 months (range, 3 to 40). Frequency and sizes of medial displacement calcaneal osteotomy (MDCO), first ray plantarflexion procedure (Cotton/LapiCoton), and lateral column lengthening (LCL) procedures were, respectively: 100% (8.9mm displacement), 100% (66% Lapicotton/34% Cotton, 8.3mm wedge-opening) and 39% (6.8mm wedge-opening). Soft-tissue procedures performed: 83% Posterior tibial tendon (re-tensioning/FDL transfer/allograft reconstruction), 34% peroneal tendon (brevis-to-longus and brevis lengthening), 76% gastrocnemius-recession, 38% spring ligament (re-tensioning/reconstruction/augmentation) and 31% deltoid ligament (re- tensioning/reconstruction/augmentation). Significant improvement postoperatively was observed in all PCFD measurements performed and PROs (Figure). However, no direct correlation was found between procedures performed/measurement improvements and PROs.
Conclusion:
In this prospective comparative cohort study of flexible PCFD patients undergoing surgical treatment with hindfoot joint sparing surgical procedures, we observed significant postoperative improvement in all deformity patterns assessed (Classes A, B, C, and D) as well as PROs. MDCO and first ray plantarflexion procedures (Cotton or LapiCotton) were the most commonly utilized procedures and were performed in all cases. Even though deformity correction and PRO improvements were observed postoperatively, no direct correlation was observed between PROs and specific surgical procedures performed or deformity pattern corrections (PCFD classes).
Category:
Midfoot/Forefoot; Bunion
Introduction/Purpose:
Interpositional arthroplasty (IPA) is a motion-preserving surgery in patients with advanced hallux rigidus. Literature displays several ...complications after the procedure including transfer metatarsalgia, cock-up deformity and infection. In a finite element model, shortening of the first metatarsal was associated with increased plantar pressure on lateral rays during gait. Additionally, there are reports of a positive correlation between first metatarsal shortening after hallux valgus surgery and transfer metatarsalgia of the second, third and fourth metatarsophalangeal joints. The goals of this study were to report the outcomes and complications of IPA using acellular dermal allograft (IPA-ADA) as well as study the changes in the length of the proximal phalanx of the hallux (P1) and the first metatarsal (M1) following the procedure.
Methods:
In this IRB-approved retrospective study, we assessed patients who underwent IPA-ADA in a single academic institute during the period 2019-2022. All patients’ demographic data, surgical details, complications, and patient-reported outcomes (PROs) were extracted. On standing conventional anteroposterior (AP) foot views, we measured the lengths of the first metatarsal (M1), the second metatarsal (M2), the proximal phalanx of the big toe (P1) and the entire length of the hallux (HX). The ratio of M1/M2 and P1/HX were calculated. The first metatarsophalangeal joint space was measured at the medial and lateral aspects of the joint on the AP view. All measurements were recorded pre-operatively, at six weeks follow-up and at the final follow-up. Descriptive statistics were performed, comparison between groups was performed using analysis of variance (ANOVA) or Kruskal Wallis test according to data normality. The Dunn-Bonferroni test was then performed for pairwise group comparisons.A p-value < 0.05 was considered significant.
Results:
Eleven patients were included, 9 being females (81.81%). Six were hallux rigidus Coughlin grade III (54.55%) and 5 were grade IV (45.45%). The average age was 59 years (SD±6.78) and the body mass index (BMI) was 26 (SD±4.79). At the final follow- up, there was significant shortening of the first ray in comparison to the pre-operative length evidenced by lower M1/M2 (82.63 SD±2.29 versus 75.42 SD±5.1; p=0.001) and P1/HX ratio 53.38 ± 2.29 versus 48.98 SD ± 7.92; p=0.001). Although there was no significant difference between M1/M2 at 6 weeks and at the final follow-up (p=0.716), there was a significant negative correlation between follow-up length and M1/M2 (r= -0.76, p=0.003). Follow-up was (19.95 months; range 3-39). Complications and PROs are listed in Figure 1.
Conclusion:
Interposition arthroplasty using dermal allograft for HR is associated with progressive shortening of the first ray at the level of the first metatarsal as well as the proximal phalanx. Although the study did show shortening of the first ray, the small sample size didn't allow for a correlation between this shortening and complications such as transfer metatarsalgia and cock-up toe deformity. The potential shortening should be considered in the selection of patients, particularly in the setting of an already short first metatarsal or when simultaneous Akin/Moberg osteotomy is planned.
Category:
Ankle; Sports
Introduction/Purpose:
Syndesmotic injuries and residual chronic subtle distal tibiofibular syndesmotic instability (DTFSI) are relatively common injuries, especially in ...athletes prone to suffering high ankle sprains. The diagnosis of subtle DTFSI remains challenging, with a high prevalence of false-negative results using conventional non-invasive clinical-radiographical diagnostic tools. The current gold standard for diagnosis, arthroscopy, is a surgical operation, which is invasive and, therefore, not ideal.
Weightbearing Computed-Tomography (WBCT) has emerged as a possible dynamic non-invasive alternative diagnostic option, with proven high diagnostic accuracy for syndesmotic incisura area measurements in major DTFSI. Our study aimed to assess the capability of semiautomatic weight-bearing computed tomography (WBCT) syndesmotic incisura area in diagnosing subtle chronic syndesmotic instability.
Methods:
In this diagnostic case-control study, patients with suspected unilateral chronic subtle DTFSI underwent bilateral standing weight-bearing CT (WBCT) before surgical treatment. All patients had gold-standard arthroscopic assessment for DTFSI, introducing a 3mm diameter arthroscopic sphere into the syndesmotic incisura for diagnosis. Bilateral syndesmotic incisura areas were measured 10mm proximally to the apex of the distal tibia articular dome using a semiautomatic measurement algorithm. Two tangent lines marked the anterior and posterior borders of the syndesmotic incisura to the anterior and posterior edges of the distal tibia and fibula. Once borders were marked, the incisura area was automatically calculated by the software based on a Hounsfield units (HU) contrast algorithm. A HU threshold of 200HU was utilized. Measurements were done independently by two fellowship-trained readers. Comparisons between injured and control ankles were made using Student T-test or Wilcoxon, according to normality. Measurements' reliability was assessed with the Intraclass Correlation Coefficient (ICC).
Results:
From an initial sample of 32 patients, 20 patients (12 female) with arthroscopically confirmed DTFSI (11 right sides) with a mean age of 31.7 years (range 18 to 55 years) and a mean BMI of 30.35kg/m² (SD +/-8.29 kg/m²) were included in the study. All patients had a history of an old ankle sprain 6 to 182 months before the assessment, and athletic lesions were reported in 53% of the population. ICCs were above 0.98 for both intra and interobserver reliability. The average syndesmotic area was 96.91mm2 (SD +/-27.9mm2) in injured ankles compared to 84.61mm2 (SD +/-26.9 mm2) in uninjured ankles. The difference between injured and non-injured tibiofibular areas was 12.31mm2 (95%CI: 9.04-15.58mm2), which was shown statistically significant (p < 0.001; effect size: 1.43).
Conclusion:
In this case-control study, we assessed the accuracy of semiautomatic WBCT syndesmotic incisura area measurements in diagnosing subtle chronic DTFSI. We found an increased syndesmotic area in injured ankles that reached statistical significance. Due to the minimal differences between injured and uninjured contralateral ankles, larger cohorts would likely solidify this study's findings further. The use of external rotation stress, volumetric assessment, distance, and coverage maps could increase the diagnostic accuracy in DTFSI. However, automatic area measurements have a higher overall reproducibility and applicability in the clinical setting, which could help providers make therapeutic decisions.
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