Impact of sex and gender on post-COVID-19 syndrome, Switzerland, 2020

BackgroundWomen are overrepresented among individuals with post-acute sequelae of SARS-CoV-2 infection (PASC). Biological (sex) as well as sociocultural (gender) differences between women and men might account for this imbalance, yet their impact on PASC is unknown.AimWe assessed the impact of sex and gender on PASC in a Swiss population.MethodOur multicentre prospective cohort study included 2,856 (46% women, mean age 44.2 ± 16.8 years) outpatients and hospitalised patients with PCR-confirmed SARS-CoV-2 infection.ResultsAmong those who remained outpatients during their first infection, women reported persisting symptoms more often than men (40.5% vs 25.5% of men; p < 0.001). This sex difference was absent in hospitalised patients. In a crude analysis, both female biological sex (RR = 1.59; 95% CI: 1.41-1.79; p < 0.001) and a score summarising gendered sociocultural variables (RR = 1.05; 95% CI: 1.03-1.07; p < 0.001) were significantly associated with PASC. Following multivariable adjustment, biological female sex (RR = 0.96; 95% CI: 0.74-1.25; p = 0.763) was outperformed by feminine gender-related factors such as a higher stress level (RR = 1.04; 95% CI: 1.01-1.06; p = 0.003), lower education (RR = 1.16; 95% CI: 1.03-1.30; p = 0.011), being female and living alone (RR = 1.91; 95% CI: 1.29-2.83; p = 0.001) or being male and earning the highest income in the household (RR = 0.76; 95% CI: 0.60-0.97; p = 0.030).ConclusionSpecific sociocultural parameters that differ in prevalence between women and men, or imply a unique risk for women, are predictors of PASC and may explain, at least in part, the higher incidence of PASC in women. Once patients are hospitalised during acute infection, sex differences in PASC are no longer evident.

Development and internal validation of a prediction model for long-term opioid use-an analysis of insurance claims data

ABSTRACT

In the United States, a public-health crisis of opioid overuse has been observed, and in Europe, prescriptions of opioids are strongly increasing over time. The objective was to develop and validate a multivariable prognostic model to be used at the beginning of an opioid prescription episode, aiming to identify individual patients at high risk for long-term opioid use based on routinely collected data. Predictors including demographics, comorbid diseases, comedication, morphine dose at episode initiation, and prescription practice were collected. The primary outcome was long-term opioid use, defined as opioid use of either >90 days duration and ≥10 claims or >120 days, independent of the number of claims. Traditional generalized linear statistical regression models and machine learning approaches were applied. The area under the curve, calibration plots, and the scaled Brier score assessed model performance. More than four hundred thousand opioid episodes were included. The final risk prediction model had an area under the curve of 0.927 (95% confidence interval 0.924-0.931) in the validation set, and this model had a scaled Brier score of 48.5%. Using a threshold of 10% predicted probability to identify patients at high risk, the overall accuracy of this risk prediction model was 81.6% (95% confidence interval 81.2% to 82.0%). Our study demonstrated that long-term opioid use can be predicted at the initiation of an opioid prescription episode, with satisfactory accuracy using data routinely collected at a large health insurance company. Traditional statistical methods resulted in higher discriminative ability and similarly good calibration as compared with machine learning approaches.

A Multi-component Intervention (NEXpro) Reduces Neck Pain-Related Work Productivity Loss: A Randomized Controlled Trial Among Swiss Office Workers

Purpose Neck pain is common among office workers and leads to work productivity loss. This study aimed to investigate the effect of a multi-component intervention on neck pain-related work productivity loss among Swiss office workers. Methods Office workers, aged 18-65 years, and without serious neck-related health problems were recruited from two organisations for our stepped-wedge cluster randomized controlled trial. The 12-week multi-component intervention included neck exercises, health-promotion information, and workplace ergonomics. The primary outcome of neck pain-related work productivity loss was measured using the Work Productivity and Activity Impairment Questionnaire and expressed as percentages of working time. In addition, we reported the weekly monetary value of neck pain-related work productivity loss. Data was analysed on an intention-to-treat basis using a generalized linear mixed-effects model. Results Data from 120 participants were analysed with 517 observations. At baseline, the mean age was 43.7 years (SD 9.8 years), 71.7% of participants were female (N = 86), about 80% (N = 95) reported mild to moderate neck pain, and neck pain-related work productivity loss was 12% of working time (absenteeism: 1.2%, presenteeism: 10.8%). We found an effect of our multi-component intervention on neck pain-related work productivity loss, with a marginal predicted mean reduction of 2.8 percentage points (b = -0.27; 95% CI: -0.54 to -0.001, p = 0.049). Weekly saved costs were Swiss Francs 27.40 per participant. Conclusions: Our study provides evidence for the effectiveness of a multi-component intervention to reduce neck pain-related work productivity loss with implications for employers, employees, and policy makers.Trial Registration ClinicalTrials.gov, NCT04169646. Registered 15 November 2019-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04169646 .

Combining evidence from clinical trials in conditional or accelerated approval

Conditional (European Medicines Agency) or accelerated (U.S. Food and Drug Administration) approval of drugs allows earlier access to promising new treatments that address unmet medical needs. Certain post-marketing requirements must typically be met in order to obtain full approval, such as conducting a new post-market clinical trial. We study the applicability of the recently developed harmonic mean χ 2 $$ {\chi}^2 $$ -test to this conditional or accelerated approval framework. The proposed approach can be used both to support the design of the post-market trial and the analysis of the combined evidence provided by both trials. Other methods considered are the two-trials rule, Fisher's criterion and Stouffer's method. In contrast to some of the traditional methods, the harmonic mean χ 2 $$ {\chi}^2 $$ -test always requires a post-market clinical trial. If the p $$ p $$ -value from the pre-market clinical trial is ≪ 0.025 $$ \ll 0.025 $$ , a smaller sample size for the post-market clinical trial is needed than with the two-trials rule. For illustration, we apply the harmonic mean χ 2 $$ {\chi}^2 $$ -test to a drug which received conditional (and later full) market licensing by the EMA. A simulation study is conducted to study the operating characteristics of the harmonic mean χ 2 $$ {\chi}^2 $$ -test and two-trials rule in more detail. We finally investigate the applicability of these two methods to compute the power at interim of an ongoing post-market trial. These results are expected to aid in the design and assessment of the required post-market studies in terms of the level of evidence required for full approval.

Development and validation of a prognostic model for the early identification of COVID-19 patients at risk of developing common long COVID symptoms

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic demands reliable prognostic models for estimating the risk of long COVID. We developed and validated a prediction model to estimate the probability of known common long COVID symptoms at least 60 days after acute COVID-19.

METHODS

The prognostic model was built based on data from a multicentre prospective Swiss cohort study. Included were adult patients diagnosed with COVID-19 between February and December 2020 and treated as outpatients, at ward or intensive/intermediate care unit. Perceived long-term health impairments, including reduced exercise tolerance/reduced resilience, shortness of breath and/or tiredness (REST), were assessed after a follow-up time between 60 and 425 days. The data set was split into a derivation and a geographical validation cohort. Predictors were selected out of twelve candidate predictors based on three methods, namely the augmented backward elimination (ABE) method, the adaptive best-subset selection (ABESS) method and model-based recursive partitioning (MBRP) approach. Model performance was assessed with the scaled Brier score, concordance c statistic and calibration plot. The final prognostic model was determined based on best model performance.

RESULTS

In total, 2799 patients were included in the analysis, of which 1588 patients were in the derivation cohort and 1211 patients in the validation cohort. The REST prevalence was similar between the cohorts with 21.6% (n = 343) in the derivation cohort and 22.1% (n = 268) in the validation cohort. The same predictors were selected with the ABE and ABESS approach. The final prognostic model was based on the ABE and ABESS selected predictors. The corresponding scaled Brier score in the validation cohort was 18.74%, model discrimination was 0.78 (95% CI: 0.75 to 0.81), calibration slope was 0.92 (95% CI: 0.78 to 1.06) and calibration intercept was -0.06 (95% CI: -0.22 to 0.09).

CONCLUSION

The proposed model was validated to identify COVID-19-infected patients at high risk for REST symptoms. Before implementing the prognostic model in daily clinical practice, the conduct of an impact study is recommended.

Effectiveness of a Brief Hypnotic Induction in Third Molar Extraction: A Randomized Controlled Trial (HypMol)

Third molar extraction is a painful treatment for patients, and thus, it can be used to investigate the effects of analgesics on pain. Hypnosis can help to reduce pain and to decrease the intake of postoperative systemic analgesics. In this study, the effectiveness of a brief hypnotic induction for patients undergoing third molar extractions was investigated. Data were collected from 33 patients with third molar extractions on the right and left sides. Patients received 2 different types of pain interventions in this monocentric randomized crossover trial. Third molar extraction was conducted on 1 side with reduced preoperative local anesthetics and an additional brief hypnotic induction (Dave Elman technique). The other side was conducted with regular preoperative local anesthetics without a brief hypnotic induction (standard care). Intake of postoperative systemic analgesics was allowed in both treatments. Patients' expectations about hypnosis were assessed at baseline. The primary outcome was the area under the curve with respect to ground of pain intensity after the treatment. Secondary outcomes were the amount of postoperative analgesics consumed and the preferred treatment. There was no evidence that the area under the curve with respect to ground of pain differed between the 2 interventions (controlling for gender), but the patients' expectations affected the effectiveness of the brief hypnotic induction. This means that patients with high expectations about hypnosis benefit more from treatment with reduced preoperative local anesthetics and additional brief hypnotic induction. PERSPECTIVE: Hypnosis is used as a treatment to reduce pain in general and dental settings. In this study, additional a brief hypnotic induction with reduced preoperative local anesthetic use did not generally reduce posttreatment pain after third molar extraction more than regular local anesthetics. The expectation of the patients about the effectiveness of hypnosis affected the effectiveness of the brief hypnotic induction so that patients with high expectations had a larger benefit from a brief hypnotic induction than patients with low expectations.

Radiological, Clinical and Functional Outcomes of Combined Dorsal and Volar Locking Plate Osteosynthesis for Complex Distal Radius Fractures

PURPOSE

The purpose of this study was to assess the short- to mid-term radiologic, clinical, and functional outcomes of patients treated with combined dorsal and volar locking plating for internal fixation of complex, comminuted, intra-articular, distal radius fractures.

METHODS

We performed a retrospective review of 34 patients treated with combined dorsal and volar locking plates for the internal fixation of complex, comminuted, intra-articular distal radius fractures. Radiographic and clinical parameters were recorded at a mean of 48 months after surgery. Activities of daily living and quality of life were assessed by the Disabilities of the Arm, Shoulder, and Hand and Patient-Rated Wrist Evaluation questionnaires.

RESULTS

Compared with the contralateral wrist, the treated wrist regained 73% of flexion, 81% of extension, 86% of ulnar deviation, 90% of radial deviation, 98% of pronation, 99% of supination, and 93% of grip strength. Mean Disabilities of the Arm, Shoulder, and Hand and Patient-Rated Wrist Evaluation scores were 11 (range, 0-78) and 11 (range, 0-77), respectively. Radial height and radial inclination were restored anatomically in 24% and 41% of patients, respectively, while volar tilt and ulnar variance were restored in 68% of patients.

CONCLUSION

The overall functional and radiologic outcome of patients with comminuted intra-articular complex distal radius fractures treated with the combined dorsovolar plate osteosynthesis was good to excellent.

LEVEL OF EVIDENCE

Therapeutic IV.

No evidence for an effect of the first COVID-19 lockdown on work stress conditions in office workers

Background

The COVID-19 pandemic has forced around 50 % of employees of Switzerland into a working from home setting during March and April 2020. Working from home appears to change the work experience of office workers considerably. The aim of this analysis was to investigate the effect of the first COVID-19 lockdown on work stress conditions.

Methods

We based this longitudinal analysis on control group data from an ongoing stepped-wedge cluster randomized controlled trial. Office workers from two Swiss organizations, aged 18-65 years, were included. Baseline data from January 2020 (before the COVID-19 pandemic) were compared with follow-up data collected during the fourth and fifth week of the first lockdown (April 2020). Work stress conditions were measured using the Job-Stress-Index (JSI). The JSI indicates the ratio of work-related resources (e.g., appreciation at work) and stressors (e.g., work organisation) on a scale from 0 (stressors < resources) to 100 (stressors > resources). Paired sample t-tests were performed for statistical analysis.

Results

Data from 75 participants were analysed. Fifty-three participants were female (70.7 %). The mean age was 42.8 years (range from 21.8 to 62.7) at baseline. At baseline, the mean JSI was 47.6 (SD = 5.0), with 77.7 (SD = 12.4) for resources and 22.3 (SD = 10.1) for stressors. At follow-up, the mean JSI was 47.4 SD = 4.5), with 77.5 (SD = 11.7) for resources and 21.4 (SD = 9.6) for stressors. We found no evidence for a difference in JSI (estimate = 0.67, 95 % CI: -0.33 to 0.66, p-value = 0.50), its index of resources (estimate = 0.23, 95 % CI: -1.32 to 1.69, p-value = 0.82) or the index of work stressors (estimate = 1.4, 95 % CI: -0.32 to 2.02, p-value = 0.15) between measurement time points.

Conclusions

The first COVID-19 lockdown did not result in a difference of work stress conditions among our sample of Swiss office workers. Improved working times and work-life balance may have contributed to this finding.

Key messages

Improved working times and work-life balance may have contributed to stable task-related stressors and resources in the early phase of the lockdown.

Other, non-work-related environmental stressors should be investigated to explain COVID-19-related changes in mental and physical health.

No Evidence for a Decrease in Physical Activity Among Swiss Office Workers During COVID-19: A Longitudinal Study

PURPOSE

The COVID-19 lockdown interrupted normal daily activities, which may have led to an increase in sedentary behavior (Castelnuovo et al., 2020). The aim of this study was to investigate the effect of the COVID-19 pandemic on the level of physical activity among Swiss office workers.

METHODS

Office workers from two Swiss organizations, aged 18-65 years, were included. Baseline data from January 2020 before the COVID-19 pandemic became effective in Switzerland were compared with follow-up data during the lockdown phase in April 2020. Levels of physical activity were assessed using the International Physical Activity Questionnaire. Paired sample t-tests or Wilcoxon signed-rank test were performed for statistical analysis.

RESULTS

Data from 76 participants were analyzed. Fifty-four participants were female (71.1%). The mean age was 42.7 years (range from 21.8 to 62.7) at baseline. About 75% of the participants met the recommendations on minimal physical activity, both before the COVID-19 pandemic and during the lockdown. Weak statistical evidence for a decline in total physical activity in metabolic equivalent of task minutes per week (MET min/week) was found (estimate = -292, 95% CI from - ∞ to 74, p-value = 0.09), with no evidence for a decrease in the three types of activity: walking (estimate = -189, 95% CI from - ∞ to 100, p-value = 0.28), moderate-intensity activity (estimate = -200, 95% CI from - ∞ to 30, p-value = 0.22) and vigorous-intensity activity (estimate = 80, 95% CI from - ∞ to 460, p-value = 0.74). Across the three categories "high," "moderate," and "low" physical activity, 17% of the participants became less active during the lockdown while 29% became more active.

CONCLUSION

The COVID-19 pandemic did not result in a reduction in total physical activity levels among a sample of Swiss office workers during the first weeks of lockdown. Improved work-life balance and working times may have contributed to this finding.

CLINICAL TRIAL REGISTRATION

www.ClinicalTrials.gov, NCT04169646. Registered 15 November 2019 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04169646.

Extraarticular Supramalleolar Osteotomy in Asymmetric Varus Ankle Osteoarthritis

BACKGROUND

In recent years, supramalleolar osteotomy has become a valuable alternative for treatment of ankle osteoarthritis. The aim of this study was to investigate whether the preoperative stage of ankle osteoarthritis or tilt of the talus in the ankle mortise impacts radiologic and clinical outcomes following a supramalleolar osteotomy.

METHODS

Forty-four patients who underwent a supramalleolar osteotomy for posttraumatic asymmetric varus ankle osteoarthritis were included. Subgroups were formed according to the preoperative stage of ankle osteoarthritis and the tilt of the talus in the ankle mortise. The radiographic and clinical outcomes of each subgroup were compared, and survival rates calculated.

RESULTS

Ankles with a preoperative Takakura stage of 2 and 3a showed a significant higher survival rate at 5 years (88% [95% CI, 67-100] and 93% [95% CI, 80-100]) compared with ankles with a preoperative Takakura stage of 3b (47% [95% CI, 26-86]; P = .044). The 5-year survival rate for patients with a preoperative tilt of the talus in the ankle mortise of 4-10 degrees was 85% (95% CI, 68-100), while patients with a preoperative tilt of >10 degrees showed a 5-year survival rate of 65% (95% CI, 46-93; P = .117).

CONCLUSION

Supramalleolar osteotomy was a valuable treatment option for early to mid-stage posttraumatic asymmetric varus ankle osteoarthritis.

LEVEL OF EVIDENCE

Level IV, retrospective cohort study.

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.

Imaging of the subtalar joint: A novel approach to an old problem

Evaluation of the subtalar joint using conventional radiographs is difficult. The purpose of this study was to assess how the posterior facet of the subtalar joint is projected on eight standard radiographic views of the foot and ankle. Weightbearing computed tomography (CT) scans of 27 volunteers without ankle pathology were performed. Eight standard views of the foot and ankle (antero-posterior [AP] view, mortise view, subtalar view, four different Broden views) were reconstructed using digitally reconstructed radiographs (DRRs). The appearance of the posterior facet of the subtalar joint was assessed for each view. In addition, the position of the joint line was projected onto three-dimensional (3-D) models of the calcaneus. We found (i) on the AP view of the ankle joint, the posterior part of the posterior facet is visualized and appears convex (calcaneal side); (ii) on the mortise view of the ankle joint, a slightly more anterior part (compared to the AP view) is visualized and appears either convex or flat; (iii) on the subtalar view, the anterior part of the posterior facet is visualized and appears either convex, flat or concave; and (iv) using the Broden views, the posterior and anterior part of the posterior facet can be visualized. This study clarifies which parts of the posterior facet of the subtalar joint are visualized on eight standard views of the foot and ankle. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Evaluation of Different Recruitment Methods: Longitudinal, Web-Based, Pan-European Physical Activity Through Sustainable Transport Approaches (PASTA) Project

Background

Sufficient sample size and minimal sample bias are core requirements for empirical data analyses. Combining opportunistic recruitment with a Web-based survey and data-collection platform yields new benefits over traditional recruitment approaches.

Objective

This paper aims to report the success of different recruitment methods and obtain data on participants’ characteristics, participation behavior, recruitment rates, and representativeness of the sample.

Methods

A longitudinal, Web-based survey was implemented as part of the European PASTA (Physical Activity through Sustainable Transport Approaches) project, between November 2014 and December 2016. During this period, participants were recruited from 7 European cities on a rolling basis. A standardized guide on recruitment strategy was developed for all cities, to reach a sufficient number of adult participants. To make use of the strengths and minimize weakness, a combination of different opportunistic recruitment methods was applied. In addition, the random sampling approach was applied in the city of Örebro. To reduce the attrition rate and improve real-time monitoring, the Web-based platform featured a participant’s and a researchers’ user interface and dashboard.

Results

Overall, 10,691 participants were recruited; most people found out about the survey through their workplace or employer (2300/10691, 21.51%), outreach promotion (2219/10691, 20.76%), and social media (1859/10691, 17.39%). The average number of questionnaires filled in per participant varied significantly between the cities (P<.001), with the highest number in Zurich (11.0, SE 0.33) and the lowest in Örebro (4.8, SE 0.17). Collaboration with local organizations, the use of Facebook and mailing lists, and direct street recruitment were the most effective approaches in reaching a high share of participants (P<.001). Considering the invested working hours, Facebook was one of the most time-efficient methods. Compared with the cities’ census data, the composition of study participants was broadly representative in terms of gender distribution; however, the study included younger and better-educated participants.

Conclusions

We observed that offering a mixed recruitment approach was highly effective in achieving a high participation rate. The highest attrition rate and the lowest average number of questionnaires filled in per participant were observed in Örebro, which also recruited participants through random sampling. These findings suggest that people who are more interested in the topic are more willing to participate and stay in a survey than those who are selected randomly and may not have a strong connection to the research topic. Although direct face-to-face contacts were very effective with respect to the number of recruited participants, recruiting people through social media was not only effective but also very time efficient. The collected data are based on one of the largest recruited longitudinal samples with a common recruitment strategy in different European cities.

The effect of foot type on the Achilles tendon moment arm and biomechanics

BACKGROUND

The aim was to calculate the Achilles tendon moment arm in different degrees of plantarflexion for pes planus, pes cavus and normal arched feet.

METHODS

99 patients (99 radiographs; 40 males, 59 females; mean age 49 years, SD 15) with a healthy ankle joint and a preoperative weightbearing lateral radiograph of the foot were included. Three groups (pes planus, pes cavus and normal-arched feet) with equal sample sizes (n=33) were formed. On radiographs, the angle formed between a horizontal line and the line connecting the insertion of the Achilles tendon with the center of rotation of the ankle, was measured. The interrater reliabilities (ICC) of the angle alpha were compared on radiographs and on MRIs. Using the angle alpha, the Achilles tendon moment arm was calculated in different plantarflexion positions.

RESULTS

The ICC of alpha was higher on radiographs (0.84, [0.73-0.91]) than on MRIs (0.61, [0.27-0.81]). The average alpha was statistically significantly different (normal arched foot 31 degrees (°), pes planus 24°, pes cavus 36°, p=0.021), resulting in a significant shorter Achilles tendon moment arm for pes cavus than for pes planus (p<0.0001) and normal arched feet (p=0.006) in neutral position.

CONCLUSION

The data suggests that it is feasible to use radiographs to measure the Achilles tendon moment arm. The maximum Achilles tendon moment arm is reached at different angles of ankle flexion for pes cavus, pes planus and normal-arched feet. This has to be taken into consideration when planning surgeries.

The Effect of Three Foot Types on the Achilles Tendon Lever Arm

Category:

Hindfoot

Introduction/Purpose:

During locomotion, propulsion of the body is created by the force of the triceps surae complex as it is transmitted to the metatarsal heads. The amount and pattern of the resulting propulsion force highly depends on the moment arm of the Achilles tendon. To our knowledge, no data exists on how and to which extent position and morphology of the foot affects the moment arm of the Achilles tendon. The aim of this study was 1) to develop a method to determine the Achilles tendon moment arm, and 2) to calculate the Achilles tendon moment arm with the foot in different degrees of dorsi- and plantarflexion for 3 foot types (normal arched foot, pes planus, and pes cavus).

Methods:

99 study participants with a healthy ankle joint (males, 40; females, 59; mean age 49 [range, 14 – 78] years) were included. Participants’ foot type was classified as a normal arched foot (n = 33), as pes planus (n = 33), or as pes cavus (n = 33) based on the calcaneal inclination angle (CI) (Figure 1). Besides the foot type, the foot length (FL), the calcaneal insertion of the Achilles tendon (ATI), the angle (a) between the line (L) connecting ATI with the center of rotation of the ankle (COR) and the horizontal line (L’) were measured on the lateral radiographs. The interrater reliabilities of measuring a on radiographs and on MRIs were compared. The lever arm of the Achilles tendon (L’calculated) was calculated as following (foot and tibia were regarded as two rigid segments; the influences of other muscles were neglected): L’calculated = cos(a - plantarflexion)*L

Results:

The interrater reliability of a was higher on radiographs (ICC = 0.84, [0.73 – 0.91]) than on MRIs (ICC = 0.61, [0.27 – 0.81]). The ICC comparing a measured on MRIs and radiographs was 0.63 [0.50-0.74]. There was no difference in FL between the three foot types (p = 0.199). However, the average a was significantly different (normal arched foot 31°, pes planus 24°, pes cavus 36°, p = 0.021), resulting in a statistically significant shorter Achilles tendon lever arm for pes cavus than for pes planus (p < 0.0001) and normal arched feet (p = 0.006) in neutral position. The maximum lever arm for the three different foot types was reached at different degrees of plantarflexion (Figure 2).

Conclusion:

The assessment of the Achilles tendon lever arm using radiographs is reliable. The foot configuration determines the lever arm of the Achilles tendon for a given flexion position of the foot. It also determines the plantarflexion position where the Achilles tendon reaches the maximum of its lever arm. This has to be taken into consideration when planning surgeries that change a or L, as they may also result in changes of plantarflexion power.

Complications, Reoperations, and Postoperative Outcomes of Simultaneous Supramalleolar Osteotomy and Total Ankle Replacement in Misaligned Osteoarthritic Ankles in Comparison to Total Ankle Replacement Alone

Category:

Ankle Arthritis

Introduction/Purpose:

A key for success in total ankle replacement (TAR) is a balanced ankle joint with a physiological loading of the implant, minimizing the wear of the polyethylene insert. Theoretically, in ankles with distal tibial deformities, this can be achieved with a correcting tibial resection cut. As an alternative, supramalleolar osteotomy (SMOT) can be used for balancing the ankle during TAR surgery. To date, however, no data exist whether a SMOT in addition to TAR results in better outcome over time, and which are the additional risks with such extensive surgery. The aim of the study was therefore 1) to determine the risk of a simultaneously performed SMOT in comparison to TAR only, and 2) to compare the postoperative clinical outcomes.

Methods:

Between 2002 and 2014, 23 patients (male, 12; female, 11; mean age 60 [22-72] years) underwent simultaneously a SMOT and a TAR for treatment of a severe misaligned osteoarthritic ankle (tibial anterior surface angle [TAS] <84° [n=9] or >96° [n=1], or tibial lateral surface angle [TLS] <70° [n=13]) (SMOT&TAR group). Statistical matching was applied to extract a subgroup out of 510 TAR patients from our prospectively collected database with the same baseline characteristics, including similar preoperative alignments (control group). The matched 23 TAR patients (male, 16; female, 7; mean age 58 [35 - 79] years) were compared regarding additional procedures, complications and reoperations. Pre- and postoperative alignment measured on radiographs and clinical outcome (range of motion [ROM], pain on the visual analogue scale [VAS] and AOFAS hindfoot score) were compared.

Results:

While more additional osteotomies were done in the SMOT&TAR group (calcaneus, 5:1; fibula, 7:1), more ligament reconstructions and tendon transfers were done in control group (ligament reconstruction, 0:6; tendon transfer, 0:6). There was no difference, neither in the complication rate nor in the reoperation rate between both groups. However, there was a tendency of instability, subsequent polyethylene wear and cyst formation in the TAR group. The postoperative TAS was closer to neutral in the SMOT&TAR (pre- to postoperatively: 82.9° to 90.4° vs. 82.6° to 87.8°). While ROM was lower in the SMOT&TAR (30°) than in the TAR group (39°) (p=0.01), there was no difference in the clinical outcome (VAS pain 1.2 vs. 1.5 [p=0.58], AOFAS score 82 vs. 82 [p=0.99]).

Conclusion:

A SMOT performed simultaneously with TAR for the treatment of a severely deformed ankle resulted in a more neutral and better balanced ankle, and it was not associated with a greater risk of complications or reoperations. The only disadvantage was a slightly smaller ROM. Thus, SMOT should be considered in TAR with greater hindfoot deformities at the distal tibia as it is more powerful to address deforming forces. As shown, SMOT and TAR can be done simultaneously without taking greater risks.

Subtalar Joint Alignment in Ankle Osteoarthritis

Category:

Ankle Arthritis, Hindfoot

Introduction/Purpose:

The influence of the subtalar joint on the evolution of ankle joint osteoarthritis is still a matter of debate. Although subtalar joint compensation of deformities above the ankle joint was proposed until mid-stage of ankle osteoarthritis, the evidence of this assumption is weak. In this study, we investigated the subtalar joint alignment in different stages of ankle joint osteoarthritis using weightbearing CT scans. The influence of the tibio-talar tilt and presence of subtalar joint osteoarthritis was additionally assessed. We hypothesized, that the subtalar joint compensates for deformities above the ankle joint in early- to mid-stage of ankle osteoarthritis. We also hypothesized, that subtalar joint compensation increases with a pronounced tibio-talar tilt and decreases with the presence of subtalar joint osteoarthritis.

Methods:

We included patients with ankle joint osteoarthritis treated in our institution from January 2013 to April 2016. A control group of 28 patients was additionally assessed. Varus and valgus ankles were subdivided according to the modified Takakura classification, the tilt of the talus in the ankle mortise and stage of subtalar joint osteoarthritis. The type of ankle osteoarthritis was diagnosed on a plain weightbearing anterior to posterior radiograph of the ankle. The medial distal tibial angle (TAS) and the angle between the tibial shaft and the surface of the talar dome (TTS) were measured. The subtalar joint alignment was assessed using weightbearing CT scans. Two angles were assessed: The subtalar inclination angle (SIA) was measured to investigate the subtalar compensation. For assessment of the morphology of the talus, the inftal-subtal angle (ISA) was determined.

Results:

This analysis showed significant differences of the subtalar inclination between varus feet and the controls (SIA, P=.001). Regarding the talar morphology, significant differences were found between varus/ valgus feet and the controls (ISA, P=.001 and .036, respectively). No significant differences of the subtalar joint inclination and talar morphology could be identified comparing different stages of ankle joint osteoarthritis inside the varus or valgus group. No relationship between the tilt of the talus in the ankle joint mortise and the subtalar joint inclination or talar morphology was identified. Neither presence nor absence of subtalar joint osteoarthritis influenced the subtalar joint inclination and talar morphology.

Conclusion:

Varus ankles compensate in the subtalar joint for deformities above the ankle joint. Compensation had no influence on the stage of ankle osteoarthritis, extent of the tibio-talar tilt and stage of subtalar joint osteoarthritis. Consequently, the progression of ankle joint osteoarthritis is more depended on the supramalleolar alignment and integrity of the periarticular structures (i.e. ligaments and tendons) than on the osseous alignment of the subtalar joint.

Supramalleolar Osteotomy for Tibial Component Malposition in Total Ankle Replacement

Category:

Ankle

Introduction/Purpose:

A key for success in total ankle replacement is a balanced ankle joint. If the tibial component is misaligned, the ligamentous structures, the malleoli and the tendons may be overused, which, may lead to pain and impairment during gait. A misaligned tibial component can be revised using a corrective bone resection and re-insertion of a new component or using a corrective osteotomy of the distal tibia above the stable implant. The aim of this study was to review a series of patients, in whom a corrective supramalleolar osteotomy was performed to realign a misaligned tibial component in total ankle replacement.

Methods:

Twenty-two patients (nine male; 13 female; mean age, 62.6 years; range, 44.7 – 80.0) were treated with a supramalleolar osteotomy to correct a painful dysbalanced ankle, following a varus implanted tibial component. Following radiological and clinical outcomes were recorded preoperatively and at the follow-up examination within the first 24 months: the tibial anterior surface angle (TAS), the tibial lateral surface angle (TLS), patient’s pain measured with the Visual Analogue Scale (VAS), the American Orthopedic Foot and Ankle Society (AOFAS) hindfoot score, range of motion (ROM) of the ankle and patient’s satisfaction. Furthermore, postoperative complications were reviewed.

Results:

The TAS changed on average from 85.2 ± 2.5 degrees preoperatively to 91.4 ± 2.9 degrees postoperatively (p < 0.0001), the AOFAS score increased from 46 ± 14 to 66 ± 16 points (p < .0001) and the VAS pain score decreased from 5.8 ± 1.9 to 3.3 ± 2.4 (p < .001). No statistical difference was found in the TLS and the range of motion. The osteotomy healed in 19 patients (86%), re-osteosynthesis was successful in the remaining three patients. In one of these three patients, a chronic infection of the ankle joint led to a below-knee amputation. Fifteen patients (68%) were (very) satisfied, four (18%) moderately satisfied and three (14 %) patients were not satisfied with the obtained postoperative result.

Conclusion:

The supramalleolar osteotomy was found to be an efficient alternative to correct the misaligned tibial component in total ankle replacement. Pain could be successfully addressed in the majority of the patients. The treatment of a malpositioned, well anchored tibial component with a supramalleolar osteotomy, instead of exchanging the tibial component, allows preservation of the bone stock. However, non-union should be mentioned as a possible complication of this surgery. Nonetheless, this method might be a feasible treatment option, especially for younger patients.

Supramalleolar Osteotomy for Tibial Component Malposition in Total Ankle Replacement

BACKGROUND

Persistent pain despite a total ankle replacement is not uncommon. A main source of pain may be an insufficiently balanced ankle. An alternative to the revision of the existing arthroplasty is the use of a corrective osteotomy of the distal tibia, above the stable implant. This strictly extraarticular procedure preserves the integrity of the replaced joint. The aim of this study was to review a series of patients in whom a corrective supramalleolar osteotomy was performed to realign a varus misaligned tibial component in total ankle replacement. We hypothesized that the supramalleolar osteotomy would correct the malpositioned tibial component, resulting in pain relief and improvement of function.

METHODS

Twenty-two patients (9 male, 13 female; mean age, 62.6 years; range, 44.7-80) were treated with a supramalleolar osteotomy to correct a painful ankle with a varus malpositioned tibial component. Prospectively recorded radiologic and clinical outcome data as well as complications and reoperations were analyzed.

RESULTS

The tibial anterior surface angle significantly changed from 85.2 ± 2.5 degrees preoperatively to 91.4 ± 2.9 degrees postoperatively ( P < .0001), the American Orthopaedic Foot & Ankle Society hindfoot score significantly increased from 46 ± 14 to 66 ± 16 points ( P < .0001) and the patient's pain score measured with the visual analog scale significantly decreased from 5.8 ± 1.9 to 3.3 ± 2.4 ( P < .001). No statistical difference was found in the tibial lateral surface angle and the range of motion of the ankle when comparing the preoperative to the postoperative measurements. The osteotomy healed in all but 3 patients on first attempt. Fifteen patients (68%) were (very) satisfied, 4 moderately satisfied, and 3 patients were not satisfied with the result.

CONCLUSION

The supramalleolar osteotomy was found to be a reliable treatment option for correcting the varus misaligned tibial component in a painful replaced ankle. However, nonunion (14%) should be mentioned as a possible complication of this surgery. Nonetheless, as a strictly extraarticular procedure, it did not compromise function of the previously replaced ankle, and it was shown to relieve pain without having to have revised a well-fixed ankle arthroplasty.

LEVEL OF EVIDENCE

Level IV, case series.