Session 8: Foot and Ankle

19. November
09:30 - 10:30
Lokale: 01+02
Chairmen: Ellen H Pedersen & Jens K Johansen

59. No clinically relevant difference between operative and non-operative treatment in tendon elongation measured with the Achilles tendon resting angle (ATRA) 1 year after acute Achilles tendon rupture
Ebrahim Rahdi, Allan Cramer, Maria Swennergren Hansen, Håkon Sandholdt, Per Hölmich, Kristoffer Weisskirchner Barfod
Ebrahim Rahdi: Sports Orthopedic Research Center – Copenhagen (SORC-C), Arthroscopic Center, Department of Orthopedic Surgery, Copenhagen University Hospital, Hvidovre Allan Cramer: Sports Orthopedic Research Center – Copenhagen (SORC- C), Arthroscopic Center, Department of Orthopedic Surgery, Copenhagen University Hospital, Hvidovre Maria Swennergren Hansen: Sports Orthopedic Research Center – Copenhagen (SORC-C), Arthroscopic Center, Department of Orthopedic Surgery, Copenhagen University Hospital, Hvidovre; Physical Medicine and Rehabilitation Research – Copenhagen (PMR-C), Hvidovre Håkon Sandholdt: Department of Clinical Research Center, Copenhagen University Hospital, Hvidovre Per Hölmich: Sports Orthopedic Research Center – Copenhagen (SORC- C), Arthroscopic Center, Department of Orthopedic Surgery, Copenhagen University Hospital, Hvidovre Kristoffer Weisskirchner Barfod: Sports Orthopedic Research Center – Copenhagen (SORC-C), Arthroscopic Center, Department of Orthopedic Surgery, Copenhagen University Hospital, Hvidovre

Background: Studies have shown that elongation of the injured Achilles tendon after acute Achilles tendon rupture (ATR) is negatively associated with clinical outcomes. The difference between operative and non- operative treatment on the length of the Achilles tendon is only sparsely investigated.
Aim: The aim of the study was to investigate if the operative and non-operative treatment of ATR had different effects on tendon elongation.
Materials and Methods: The study was performed as a registry study in the Danish Achilles tendon database (DADB). The primary outcome of the study was an indirect measure of Achilles tendon length: the Achilles tendon resting angle (ATRA) at 1-year follow-up. The variable of interest was treatment (operative or non-operative).
Results: From August 2015 to January 2019, 438 patients (154 operatively treated and 284 non-operatively treated) were registered with full baseline data and had their ATRA correctly registered at 1-year follow-up in DADB. The analysis did not show a clinically relevant nor statistically significant difference in ATRA between operative and non-operatively treated patients at 1-year follow-up (mean difference - 1.2°; 95% CI -2.5; 0.1; n.s) after adjustment for potential confounders.
Interpretation / Conclusion: There were neither clinically relevant nor statistically significant differences in terms of the ATRA at 1-year follow-up between the operative and non-operatively treated patients. This finding suggests that operative treatment does not lead to a clinically relevant reduction in tendon elongation compared to non-operative treatment and it should therefore not be used as an argument in the choice of treatment.

60. Acute Achilles tendon rupture – Investigation of a genetic contribution to the etiology. A registry study from the Danish Twin Registry.
Allan Cramer, Kristoffer Weisskirchner Barfod, Per Hölmich, Kaare Christensen, Dorthe Almind Pedersen
Sports Orthopedic Research Center – Copenhagen (SORC-C), Department of Orthopedic Surgery, Hvidovre Hospital; The Danish Twin Registry, University of Southern Denmark, Odense; Department of Epidemiology, Biostatistics and Biodemography, University of Southern Denmark, Odense

Background: The etiology and pathogenesis of acute Achilles tendon rupture (ATR) are complex and not fully understood. Some studies have shown possible associations between specific genes and ATR. No twin studies have yet investigated the genetic component of ATR.
Aim: To identify a possible genetic component in the risk of ATR.
Materials and Methods: The study was performed as a registry study using the Danish Twin Registry and the Danish National Patient Registry. Twins registered with the diagnosis codes DS86.0 and DS86.0A were retrieved and the probandwise concordances for monozygotic (MZ, ~100% identical genetics) and same-sex dizygotic (ssDZ, ~50% identical genetics) were calculated. If the probandwise concordance rate in the MZ twins was larger compared to the ssDZ twins, the results suggest a genetic component of the etiology.
Results: From 1994 to 2014, 577 twin pairs were registered in the Danish Twin Registry with at least one of the twins having had an ATR. Of those, 122 were MZ (5 concordant pairs, 117 discordant pairs) with a probandwise concordance rate of 0.079 (CI 95% 0.027;0.170) and 230 were ssMZ (5 concordant pairs and 225 discordant pairs) with a probandwise concordance rate of 0.043 (CI 95% 0.014;0.095). No statistically significant difference between the groups was found (p-value 0.31).
Interpretation / Conclusion: If one twin of a pair have had an ATR, this study found a risk of ATR for the second twin of 8% for a MZ twin and 4% for a ssDZ. The larger probandwise concordance rate for MZ twins compared to ssDZ speaks for a genetic component in the etiology, however the finding was not statistically significant and no definite conclusions can be made.

61. Estimation of Patient Acceptable Symptom State (PASS) and Treatment Failure (TF) threshold values for the Achilles tendon Total Rupture Score (ATRS) at 6 months, 1 year, and 2 years after acute Achilles tendon rupture.
Allan Cramer, Lina Holm Ingelsrud, Maria Swennergren Hansen, Per Hölmich, Kristoffer Weisskirchner Barfod
Sports Orthopedic Research Center – Copenhagen (SORC-C), Department of Orthopedic Surgery, Copenhagen University Hospital Hvidovre; Clinical Orthopaedic Research Hvidovre (CORH), Department of Orthopaedic Surgery, Copenhagen University Hospital Hvidovre; Physical Medicine & Rehabilitation Research-Copenhagen (PMR-C), Department of Physical and Occupational Therapy, and Clinical Research Centre, Copenhagen University Hospital Hvidovre

Background: Interpretation of the Achilles tendon Total Rupture Score (ATRS) is challenging as there is no knowledge regarding at what score the result of treatment is considered satisfactory by the patients.
Aim: 1) to describe the proportion of patients who find their symptom level to be satisfactory, to reflect treatment failure or neither, and 2) to estimate the Patient Acceptable Symptom State (PASS) and the Treatment Failure (TF) threshold values for ATRS at 6 months, 1 year, and 2 years after ATR.
Materials and Methods: The nationwide Danish Achilles tendon Database (DADB) includes patients treated operatively or non- operatively after ATR. From 1 May 2020, the included patients were asked at 6 months, 1 year, or 2 years after their ATR whether they considered their symptom level to be satisfactory (PASS anchor question), and if not, if they considered their symptom level to reflect treatment failure (TF anchor question). Patients who on 1 January 2021 had answered both the anchor questions and the ATRS were included in the study population for the given time point. The PASS and TF threshold values of ATRS at each follow-up time point were estimated using the adjusted predictive modeling method, which is based on logistic regression.
Results: 166 (51%) patients were included at 6 months, 248 (50%) patients at 1 year, and 287 (57%) patients at 2 years. The proportion of patients who considered their symptom level to be satisfactory was 61% at 6 months, 50% at 1 year, and 66% at 2 years. The proportion of patients who considered their symptom level to reflect treatment failure was 5% at 6 months, 11% at 1 year, and 10% at 2 years. The ATRS PASS threshold value (95% CI) was 49 (46-52) at 6 months, 57 (54-60) at 1 year, and 52 (49-55) at 2 years. TF threshold value (95% CI) was 30 (23-36) at 6 months, 33 (26-40) at 1 year and 35 (29-39) at 2 years.
Interpretation / Conclusion: The PASS threshold value for ATRS ranged between 49 and 57. The TF threshold values ranged between 30 and 35. The values can help interpret the outcome of ATR when measured with the ATRS. At 6 months to 2 years after ATR, 50-66% of the patients had a satisfactory symptom level, while 5- 11% considered their symptom levels to reflect treatment failure.

62. Patient reported outcome measures for ankle instability. An analysis of 17 existing questionnaires.
Christian Fugl Hansen, Kenneth Chukwuemeka Obionu, Jonathan Comins, Michael Rindom Krogsgaard
Department of Orthopedic Surgery M, Bispebjerg and Frederiksberg Copenhagen University Hospitals

Background: Chronic ankle instability (CAI) is a common condition. The effect of non-surgical and surgical treatment can be evaluated by patient reported outcome measures (PROMs). It is imperative that there is at least one adequately validated PROM for this purpose. Content validity is ensured by patient involvement when developing the PROM, and construct validity is statistically assessed using modern test theory (MTT) models.
Aim: To i) evaluate the content validity and the measurement properties of all PROMs that might be relevant for evaluating patients with ankle instability, and ii) determine the most valid of these PROMs
Materials and Methods: Two searches were performed in PubMed and SCOPUS (November 2019), one to identify PROMs used for patients with ankle instability and one to identify all validity studies of these PROMs. Quality assessment of development and construct validity was performed in accordance with current guidelines.
Results: The first search found seventeen PROMs relevant for ankle instability. The second search found fifty- six relevant validity studies. These were included in the quality assessment. Three PROMs were developed with input from patients and were thus potential candidates: the Cumberland Ankle Instability Tool (CAIT), the Lower-Extremity Functional Scale (LEFS), and the Foot and Ankle Ability Measure (FAAM). CAIT had never been validated using MTT-models and the validity could not be determined. LEFS had been validated four times with MTT-models for patients with an ankle injury, but all analyses revealed inadequate fit to the statistical model. FAAM had been validated with MTT models several times with various results. One study of patients with instability found adequate fit to the MTT model.
Interpretation / Conclusion: Three of seventeen PROMs were developed with patient input. Of these, only FAAM exhibited fit to an MTT model for patients with ankle instability. According to current guidelines, no existing PROM possesses adequate content and construct validity for patients with ankle instability. Based on the present analyses, FAAM is suggested as the best choice as an outcome measure for these patients.

63. Heel-rise Height (HRH) shows better capability than Achilles tendon resting angle (ATRA) in reflecting patient limitations and return to previous activities one year after acute Achilles tendon rupture.
Allan Cramer, Maria Swennergren Hansen, Per Hölmich, Kristoffer Weisskirchner Barfod
Sports Orthopedic Research Center – Copenhagen (SORC-C), Arthroscopic Center, Department of Orthopedic Surgery, Hvidovre Hospital; Physical Medicine & Rehabilitation Research - Copenhagen (PMR-C); Department of Physical and Occupational Therapy, Hvidovre Hospital

Background: Studies have shown that tendon elongation following acute Achilles tendon rupture (ATR) is negatively correlated with clinical outcomes. Knowledge about how the indirect measures of elongation, the heel-rise height (HRH) and the Achilles tendon resting angle (ATRA), correlate with other outcomes is limited.
Aim: To examine if the indirect length measures correlated with patient limitations and return to previous activities one year after ATR.
Materials and Methods: The study was performed as a registry study in the Danish Achilles tendon Database (DADB). The analyses investigated if HRH (limb symmetry index (LSI)) and relative ATRA one year after rupture, correlated with return to the same type of work, return to the same type of sport, satisfaction with the result, and the Achilles tendon total rupture score (ATRS) at the same time point. The correlations were calculated using Pearson’s correlation coefficient and point-biserial correlation coefficient.
Results: From August 2015 to January 2019, 477 patients were registered in DADB one year after ATR with the outcomes of interest. HRH (LSI) showed statistically significantly fair correlations to satisfaction with the result (r=0.32) and ATRS (r=0.35). Additionally, it showed statistically significantly poor correlation to the same type of work (r=0.29) but did not statistically significantly correlate with return to the same type of sport. Relative ATRA showed statistically significantly poor correlations to satisfaction with the result (r=0.13) and ATRS (r=0.09) but did not correlate statistically significantly with return to the same type of work or return to the same type of sport.
Interpretation / Conclusion: Neither relative ATRA nor HRH (LSI) showed strong correlations to return to work, return sport, satisfaction with the result, or ATRS. When comparing the relative ATRA and HRH (LSI), HRH (LSI) seems to be a better outcome in reflecting patient limitations and return to previous activities one year after ATR.

64. Mid-term results after treatment of complex talus osteochondral defects with HemiCAP implantation.
Jens K. Johansen, Kim H. Andersen, Mostafa Benyahia, Peter Bro-Rasmussen, Lars B. Ebskov
Department of Orthopedic Surgery, Foot and Ankle Division, Hvidovre Hospital, Copenhagen, Denmark

Background: Osteochondral defects (OCDs) of the talus represents a surgical challenge. Primary OCDs with a size less than 150 mm2 /15 mm in diameter, without large cyst formation or other complicating factors can be treated with simple arthroscopic bone marrow stimulation techniques. When confronted with more complex OCDs a HemiCAP metal resurfacing implant of talus might be an option but few follow-up studies exist.
Aim: To evaluate the mid-term results after HemiCAP implantation in patients with complex OCDs during the period 2008-2016.
Materials and Methods: Patients were included during the period 2008-2016. Inclusion criteria’s were: OCD of the medial or lateral talar dome, symptoms for >1 year since last surgery, OCD treated at least 1 year conservatively without effect. Exclusion criteria’s were: defects larger than 20 mm, ankle osteoarthritis Grade >II or other ankle pathology, known allergy to implant material or diabetes. Outcome measures were the American Orthopaedic Foot and Ankle Society Score, the Numerical Rating Scale, Foot and Ankle Outcome Score, sports participation, work level and radiographic evaluation. Implant survival, defined as the implant remaining in situ without revision to total ankle arthroplasty, ankle fusion or removal of the implant was evaluated as well.
Results: 31 patients were included during the period with a mean follow-up of 50 months (11.5 – 81.4). All outcome measures improved significantly. Only one patient had an complication registered which were an infection treated with antibiotics. 13 patients (41,9 %) had an additional procedure performed (eg. arthroscopic debridement, hardware removal, cheilectomy) with none of the patients being revised.
Interpretation / Conclusion: The primary aim of OCD treatment is to reduce pain, and this is achieved with the HemiCAP implant in patients with complex OCDs even tough patient information and selection is mandatory due to the relative high numbers of additional surgery following the HemiCap implantation.

65. The Effect of a Single Hyaluronic Acid Injection in Ankle Arthritis - a Prospective Cohort Study.
Christopher Jantzen, Lars B. Ebskov, Kim H. Andersen, Mostafa Benyahia, Peter Bro-Rasmussen, Jens K. Johansen
Department of Orthopedic Surgery, Foot and Ankle Division, Hvidovre Hospital, Copenhagen, Denmark

Background: Non-operative measures are often used as first line treatment in ankle osteoarthritis (OA). One of these measures consists of hyaluronic acid (HA) injections in the affected ankle joint but the efficiency of this treatment is uncertain with lacking evidence regarding both the effect and number of injections needed.
Aim: To evaluate the effect on Self-reported Foot and Ankle Score (SEFAS) score, visual analogue scale (VAS) score at rest and VAS score at activity prior to and 6 months after a single dose of HA in patients with grade I - IV OA of the ankle.
Materials and Methods: Patients above 18 years were included during the period December 2017 to Marts 2019. All patients were not interested in surgery and had tried other conservative measures without effect. Included patients received a single intra-articular injection of either Cingal (4 mL, 88 mg HA plus 18 mg triamcinolone hexacetonide) or MonoVisc (4 mL, 88 mg HA) in the affected ankle joint, with the latter being used in case of diabetes or surgeon preference. Age, gender, OA-grade, SEFAS- score, VAS at activity and at rest prior to injection and after 6 months was registered. Statistical analysis was conducted in SAS 9.4.
Results: A total of 33 patients were included in the study with 14 being lost to follow-up. As such, 19 patients (31.5 % men and 68.5 % women) with a median age of 55 (range 30-81) were included for analysis. Fifteen (79 %) were injected with Cingal and 4 (21%) with Monovisc. Median SEFAS-score remained unchanged at 21 (p=0.13) while VAS at activity went from 7 to 6 (0.003) and VAS at rest was reduced from 4 to 3 (0.03).
Interpretation / Conclusion: The unchanged SEFAS-score together with the minor changes in VAS at activity and at rest indicates that a single injection of HA might be insufficient to produce at clinical response after 6 months and further studies on the subject should focus on treatment protocols with multiple injections.