Abstract
Background:
When deciding medical treatment, patients’ perspectives are important. There is limited knowledge about patients’ views when choosing non-operative treatment or anterior cruciate ligament (ACL) reconstruction (ACLR) after ACL injury.
Purpose:
To describe reasons that influenced patients’ decisions for non-operative treatment or ACLR after ACL injury.
Study Design:
Cross-sectional study.
Methods:
This study recruited a total of 223 patients (50% men), aged 28 ± 8 years who had sustained ACL injury, either unilateral or bilateral. Subjects were, at different time points after injury, asked to fill out a questionnaire about their choice of treatment, where an ACLR treatment decision was made, some responded before and some after the ACLR treatment. A rating of the strength of 10 predetermined reasons in their choice of treatment graded as 0 (no reason) to 3 (very strong reason), was done.
Results:
Patients with unilateral ACL injury treated with ACLR (110 patients) rated “inability to perform physical activity at the same level as before the injury due to impaired knee function” (96%), “fear of increased symptoms during activity” (87%) and “giving way episodes” (83%) as strong or very strong reasons in their treatment decision. Patients with bilateral ACL injury treated with ACLR (109 knees) rated similar reasons as patients with unilateral ACLR and also “low confidence in the ability to perform at the preinjury activity level without ACLR” (80%) as strong or very strong reasons. Patients with unilateral ACL injury treated non-operatively (46 patients) rated “advice from clinician” (69%) as a strong or very strong reason. Patients with bilateral ACL injury treated non-operatively (25 knees) rated “absence of giving way episodes” (62%), and “no feeling of instability” (62%) as strong or very strong reasons.
Conclusion:
Inability to perform physical activity, fear of increased symptoms, and giving way episodes were reasons that patients with ACL injury considered when making decisions about ACLR. When choosing non-operative treatment, patients considered the absence of instability or giving way symptoms, being able to perform physical activity, and advice from clinicians.
Level of evidence:
4
Keywords: ACL, ACL reconstruction, treatment decision
INTRODUCTION
The treatment options for anterior cruciate ligament (ACL) injury are structured rehabilitation alone (non-operative treatment) or structured rehabilitation in combination with ACL reconstruction (ACLR).1-4 Non-operative treatment can be an effective first-line treatment for many patients with ACL injury.5-7 Surgical treatment may be indicated if the patient has functional instability in activities of daily living, wants to resume sport activities that involve cutting and pivoting, or has an occupation that requires knee stability after completing a high-quality rehabilitation program.8-12
Patients report good knee function after non-operative treatment,1,2,13 and there is limited evidence regarding whether non-operative treatment or ACLR is superior in terms of functional outcomes. However, the activity level and sports participation of those post ACL injury is often reduced regardless of treatment.2,7 After ACLR, return to sport rates are rather disappointing, with about 65% of patients returning to their preinjury activity level and 55% to competitive sport.14 Surgical treatment may reduce the risk for subsequent meniscal injuries,15-17 but does not alter the risk of developing radiographic osteoarthritis compared to non-operative treatment.16,18,19
Management of an ACL injury is proposed to be individualized and the patient's functional demands and preferences are central to any treatment decision.20 Orthopaedic surgeons and physical therapists rated functional limitations (i.e. instability) and the patient's wishes to return to sport as the most important reasons for recommending ACLR.21 Patients chose early ACLR based on assumptions of future knee problems, whereas the choice of late ACLR was based on experience of knee function.22 However, knowledge regarding the patient perspective on the underlying reasons that affect the treatment decision after ACL injury is limited. Patients and clinicians might have different views about treatment. Patients’ views are important in the choice of treatment, together with clinicians’ experience and scientific evidence – all perspectives should be considered when practicing in an evidence-based way.23 The aim of this study was to describe reasons that influenced patients’ decisions for non-operative treatment or ACLR after ACL injury.
MATERIAL AND METHODS
Design
This was a cross-sectional study, approved by the Regional Ethics Committee at Linköping University, approval numbers: 02-374, 2010/10-31, 2012/74-32 2013/3-32. Written, informed consent to participate was obtained from all patients prior to the study.
Participants
The population consisted of three cohorts, of a total of 223 patients aged 28 ± 8 years, with ACL injury a median 25 months (interquartile range [IQR] 45, range 0.5-245) before answering the questionnaire. One cohort had undergone unilateral ACLR (n = 110), one cohort had undergone unilateral non-operative treatment (n = 46) and one cohort had bilateral ACL injuries (n = 67), which had been treated with ACLR in both knees (n = 47), ACLR in one knee (n = 15) or with non-operative treatment in both knees (n = 5) (Table 1). Patients with unilateral ACL injury were recruited during 2008-2013, from a wait list for ACLR or by searching medical records in orthopaedic clinics, at two medium-sized cities in Sweden. The inclusion criterion was age 15-45 years at the time of follow-up. Patients were excluded if they had other major activity-limiting disorders, a combined intracondylar fracture, a total rupture of the medial or lateral collateral ligament, or a posterior cruciate ligament injury.
Table 1.
Descriptive statistics for all participants.
| Total cohort, N = 223 | Unilateral ACL Injury | Bilateral ACL injury | ||||
|---|---|---|---|---|---|---|
| ACLR n = 110 | Non-operative treatment, n = 46 | ACLR both knees, n = 47 | ACLR one knee, n = 15 | Non-operative treatment both knees, n = 5 | ||
| Age, y Mean ± SD (95% CI) | 26 ± 8 (24-28) | 32 ± 9 (29-34) | 28 ± 6 (27-29) | 29 ± 8 (26-32) | 37 ± 5 (34-41) | |
| Male/female, n | 54/56 | 22/23* | 24/23 | 9/6 | 3/2 | |
| Months from injury to questionnaire | 13 (21; 0.5-245) | 13 (15; 12-37) | First injury | 93 (40; 47-158) | 73 (66; 38-150) | 70 (94; 28-151) |
| Second injury | 46 (27; 13-107) | 43 (33; 7-96) | 63 (74; 12-102) | |||
| Months from ACLR to questionnaire | -0.2 (2; -14-31)† | First ACLR | 82 (41; 42-148) | 42 (65; 8-141) | ||
| Second ACLR | 36 (26; 6-86) | 20 (50; 4-70) | ||||
| Months from injury to ACLR | 8 (12; 0.5-246) | First injury | 7 (5; 0.5-44) | 14 (23; 6-50) | ||
| Second injury | 8 (9; 0-50) | 37 (47; 10-69) | ||||
| Preinjury Tegner Activity Scale score | 8 (2; 1-9) | 7(5; 2-9) | First injury | 9 (2; 4-10) | 9 (2; 3-9) | 7 (6; 1-9) |
| Second injury | 7 (2; 4-9) | 7 (3; 3-9) | 7 (6; 1-9) | |||
Values: median (interquartile range; range) unless otherwise stated.
ACL = Anterior cruciate ligament; ACLR = Anterior cruciate ligament reconstruction SD = standard deviations; CI = confidence intervals.
One missing for sex
n = 75 answered the questionnaire before ACLR
Patients with bilateral ACL injuries (which occurred at different time points), were recruited after their second injury, during 2010-2011 from one of five orthopaedic clinics in southeast Sweden via medical record review. The inclusion criteria were age 18-45 years at the time of follow-up and maximum 12 years between first ACL injury and follow-up. Both patients with unilateral and bilateral ACL injury were contacted by mail.
Outcome measures
All patients completed a questionnaire regarding the reason (s) that they considered when deciding between ACLR or non-operative treatment. This was done when the treatment decision was being made, but at different time points after injury, and for some after ACLR treatment was undergone (Table 1). In the cohort of patients with bilateral ACL injuries, both knees were evaluated, and patients graded the strength of the reasons for each knee separately.
The questionnaire was developed and modified at the Unit of Physiotherapy, Linköping University, with reasons derived from a previous study where 36 patients treated with ACLR were asked at follow up, why they chose to have ACLR.22 The final version of the questionnaire included 10 predefined reasons (e.g. “giving way” as a reason to be graded by patients who chose ACLR; “no giving way” as a reason to be graded by patients who chose non-operative treatment). Each reason was graded 0 (no reason) to 3 (very strong reason) (Table 2). Patients could elaborate in free text if they considered other reasons were important to their choice of treatment.
Table 2.
Reasons that could influence the treatment decision. The importance of each reason was rated using a response model from 0 (no reason) to 3 (very strong reason) regarding the influence on decision-making for ACLR or non-operative treatment after ACL injury.
| Reasons evaluated by patients who had chosen ACLR | Reasons evaluated by patients who had chosen non-operative treatment |
|---|---|
| Pain | Absence of pain |
| Swelling | Absence of swelling |
| Giving way episodes | Absence of giving way episodes |
| Feeling of instability | No feeling of instability |
| Inability to perform physical activity at the same level as before the injury, due to impaired knee function | Ability to perform physical activity at the same level as before the injury (function) |
| Inability to perform physical activity at the same level as before the injury, due to fear of increased symptoms during activity | Ability to perform physical activity at the same level as before the injury, without fear of increased symptoms during activity |
| Low confidence in the ability to perform at the preinjury activity level, without ACLR | Low confidence in the ability to perform at the preinjury activity level, with ACLR |
| Fear of future deterioration of the knee joint (e.g. OA or meniscus injuries) without ACLR | Fear of future deterioration of the knee joint (e.g. OA or meniscus injuries) with ACLR |
| Advice from clinician (e.g. orthopaedic surgeon, physiotherapist) (health professionals) | Advice from clinician (e.g. orthopaedic surgeon, physiotherapist) (health professionals) |
| Advice from other (e.g. family, friend) | Advice from other (e.g. family, friend) |
| Other reasons (free text option/comments from interview) | Other reasons (free text option/comments from interview) |
ACLR = anterior cruciate ligament reconstruction; OA = osteoarthritis. Bold text is the short form of each reason that is used in Figure 1-4.
The patients also answered a question about their preinjury activity level. Answers were converted to a Tegner Activity Scale score, which grades activities on a scale from 0 (corresponds to sick leave due to knee problems) to 10 (equal to participation in elite soccer).24,25
PROCEDURES
Patients with unilateral ACL injury answered the questionnaire on paper, and patients with bilateral ACL injury answered by phone, with all calls conducted by the same researcher (AF). The researcher read the questions and completed the questionnaire in accordance to patient's answers. This approach was used to ensure correct data entry because the questionnaire was not specifically developed for bilateral injuries.
Statistical analysis
Statistical analyses were conducted using SPSS version 23 (IBM Corp. Released 2015. IBM SPSS Statistics for Windows, Version 23.0. Armonk, NY: IBM Corp.). Responses were analysed separately for each cohort. For the 67 patients with bilateral injury, responses for each knee were assessed separately, 134 treatment decisions, leading to treatment decisions of a total of 290 ACL-injured knees (Table 1). Means and standard deviations (SD) or medians, interquartile ranges (IQR) and range were calculated as appropriate, for descriptive statistics. Between-group comparisons were made between patients who chose non-operative treatment and those who chose ACLR, using Students’ t test (age), Chi-square test (sex) and Mann-Whitney U test (time from injury to follow-up and Tegner Activity Scale score), as appropriate. Activity level (Tegner Activity Scale score) was compared between patients with unilateral ACL injury and patients with bilateral ACL injury using a Mann-Whitney U test. Within the group of patients with bilateral ACL injuries, group comparisons were made between the first and second response for each knee, using Wilcoxon signed rank test. The significance level was set at p < 0.05.
The percentages for each response option for the reasons were calculated as the number of answers in each response option divided by the total numbers of answers for the specific reason. There was variation in the number of responses for each reason because some patients did not rank all ten reasons.
Free text responses were analyzed by one researcher (HTG) and reviewed by the research group until consensus was reached for which categories the free text could be grouped into. Free text comments that revealed new reasons, not stated among the pre-defined reasons, were listed and are reported in the results.
RESULTS
Patients treated with unilateral ACLR were younger compared to those treated with non-operative treatment (p < 0.001). There were no significant differences in sex (p = 0.982) or time since injury (p = 0.053) between patients treated with unilateral ACLR and those treated with non-operative treatment. Patients treated with unilateral ACLR had higher pre-injury activity level compared to patients treated with non-operative treatment (Tegner Activity Scale score median 8, IQR 2, range 1-9 vs. median 7, IQR 5, range 2-9, p = 0.004) (Table 1).
Patients with bilateral ACLR reported higher pre-injury activity level before their first injury compared to patients treated with unilateral ACLR (p = 0.005) (Table 1). Patients with bilateral ACL injury (treated with ACLR or non-operative treatment) had a significantly higher pre-injury activity level compared to patients with unilateral ACL injury (treated with ACLR or non-operative treatment) (Tegner Activity Scale score median 8, IQR 2, range 1-10 vs. median 7, IQR 3, range 1-9, p = 0.025). Both groups consisted of both athletes and non-athletes, and had similar Tegner Scale score (Table 1).
Reasons influencing the decision for ACLR
Among patients treated with unilateral ACLR, the most common reasons rated as a very strong or strong reason for choosing ACLR were “inability to perform physical activity at the same level as before the injury due to impaired knee function” (96%), “inability to perform physical activity at the same level as before the injury due to fear of increased symptoms during activity” (87%) and “giving way episodes” (83%) (Figure 1).
Figure 1.
Reasons for choosing ACL reconstruction in the cohort of patients with unilateral ACL injury. Numbers in the bars indicate numbers of patients. Explanation of the reasons is presented in Table 2.
Among patients with bilateral ACL injuries, the most common reasons rated as a very strong or strong reason for choosing ACLR were “inability to perform physical activity at the same level as before the injury due to impaired knee function” (94%), “giving way episodes” (85%) and “low confidence in the ability to perform at the preinjury activity level without ACLR” (80%) (Figure 2).
Figure 2.
Reasons for ACL reconstruction in the cohort of patients with bilateral ACL injury. Numbers in the bars indicate numbers of treatment decisions. Explanation of the reasons is presented in Table 2.
Reasons influencing the decision to choose non-operative treatment
Among patients with unilateral ACL injury, the most common reasons rated as a very strong or strong reason for choosing non-operative treatment were “advice from clinician” (69%), “low confidence in the ability to perform at the preinjury activity level with ACLR” (50%) and “absence of swelling” (50%) (Figure 3).
Figure 3.
Reasons for non-operative treatment in the cohort of patients with unilateral ACL injury. Numbers in the bars indicate numbers of patients. Explanation of the reasons is presented in Table 2.
Among patients with bilateral ACL injury, the most common reasons rated as a very strong or strong reason for choosing non-operative treatment were; “absence of giving way episodes” (62%), “no feeling of instability” (62%) and “ability to perform physical activity at the same level as before the injury” (57%) (Figure 4).
Figure 4.
Reasons for non-operative treatment in the cohort of patients with bilateral ACL injury. Numbers in the bars indicate numbers of treatment decisions. Explanation of the reasons is presented in Table 2.
Comparisons between first and second rating
Among all patients with bilateral ACL injury (i.e. those who chose ACLR and those who chose non-operative treatment), advice from clinician (p = 0.024) and advice from family/friends (p = 0.041) were rated lower in the decision-making for treatment of the second ACL injury compared to treatment of the first ACL injury. All other reasons were rated similar for the first and second injured knee (p > 0.05).
Free text option results
Patients who chose ACLR commented in free text that: current or future occupation demanded knee stability that an ACLR would give (n = 2), previous knee surgeries gave the experience of “knowing the knee” (n = 1) or they “had read about professional athletes” (n = 1). One patient with unilateral ACL injury chose non-operative treatment after a previous negative experience of anesthesia.
Among the patients with bilateral ACL injury; the treatment of the second injured knee was affected by how the first injury was treated (n = 24), function was affected due to a severe meniscus injury (associated to the ACL injury) and ACLR was recommended (n = 7), ACLR was dissuaded by the orthopaedic surgeon (n = 2) and ACLR implies a long rehabilitation and possibly absence from work (n = 2).
DISCUSSION
The key finding of this study was that patients emphasized the ability to perform physical activity, knee stability, episodes of giving way and advice from clinicians when making decisions about treatment after ACL injury. Decisions for non-operative treatment and decisions for ACLR were influenced by different reasons. Patients with unilateral ACL injury considered different reasons when choosing non-operative treatment compared to patients with bilateral ACL injuries.
Patients who chose ACLR consistently rated reasons related to physical activity and instability as strong for their treatment decision. In contrast, for patients who chose non-operative treatment, the underlying reasons for choosing treatment were not as consistent, nor as strong in the ratings. One explanation is that surgical treatment is preceded by a specific decision, while non-operative treatment may not always have been preceded by a concrete decision to choose non-operative treatment or to refrain from ACLR. A treatment strategy of rehabilitation plus optional delayed ACLR involves start of non-operative treatment,1 which means that a decision on ACLR may be taken later.
Reasons related to fear (e.g. “inability to perform physical activity at the same level as before the injury due to fear of increased symptoms during activity”) and confidence (e.g. “low confidence in the ability to perform at the preinjury activity level without ACLR”) were important considerations for patients when choosing ACLR. Therefore, it might be important to address psychological reasons in the shared decision-making process after an ACL injury. On the other hand, “fear of increased symptoms” and “low confidence in the ability to perform” might be poor reasons upon which to base a decision for ACLR. Fear and low confidence might hinder successful rehabilitation, regardless of treatment, and may be associated with a lower return to sport rate.26-28
The strongest reasons influencing the choice for non-operative treatment were “advice from clinician”, “low confidence in the ability to perform at the preinjury activity level with ACLR” and “absence of swelling”. For patients with bilateral ACL injuries, the strongest reasons for choosing non-operative treatment were “absence of giving way episodes”, “no feeling of instability” and “ability to perform physical activity at the same level as before the injury”. Patients with unilateral ACL injury rated “advice from clinician” as the most common strong reason for choosing non-operative treatment. Some patients declared that the orthopaedic surgeon decided that ACLR was not an option for them.
The choice for non-operative treatment could be influenced by socioeconomic factors, which were not assessed. Household income and/or level of education, affects the likelihood of undergoing operative treatment after injury,33 and could have influenced clinician's advice. On the contrary, for patients who had suffered bilateral ACL injuries, the clinician's impact on the treatment decision was lower. Instead, these patients pointed to the absence of reasons that, when present (e.g. instability), are an indication for ACLR. Hence, these patients may be familiar with the treatment recommendations.8,9,11,29 Having experience from previous injury and knowledge about the care and treatment process, may empower patients to make decisions about their health care.30,31
In the present study, patients who chose non-operative treatment were older than patients who chose ACLR. This could suggest that patients suffering from an ACL injury later in life might be more willing to try non-operative treatment. The high proportion of patients who chose non-operative treatment and who rated advice from clinician as strong could also indicate that clinicians more frequently recommend non-operative treatment to older patients. Although clinical practice guidelines do not state that age should be a reason in itself,11 Swedish orthopaedic surgeons and physiotherapists consider young age (<25 years) as an important reason to recommend ACLR.21 Data from the Swedish National Knee Ligament Register indicate that older patients who chose ACLR had a greater improvement in patient-reported outcomes compared to younger patients.32 Although, selection of older patients for ACLR might be stricter to patients who had major instability, with the perceived potential to have greater benefit from reconstruction. In contrast, in younger patients, ACLR may be performed as a routine treatment. The difference in age between patients who choose ACLR and patients who chose non-operative treatment could also be due to differences in activity demands. Younger patients, in the middle of their athletic career, may emphasize activity demands when choosing ACLR. In our study, patients who chose ACLR reported a higher pre-injury activity level, which supports previous work.21,25
Limitations
One limitation of the present study is that patients rated the strength of predefined reasons, which introduce a risk that patients rate a reason that they may not have previously considered. No systematically recording of concomitant injuries was done, which is a limitation because the complexity of the knee injury may affect the treatment decision.
The cross-sectional design meant that patients responded at different time points after ACL injury. Some patients responded before their ACLR, and some after. There was also a wide range in time from injury and treatment to completing the questionnaire. Patients with bilateral ACL injuries rated the strength of the reasons at one occasion. Therefore, it is possible that thoughts about the treatment decision for the first injured knee influenced the treatment decision for the second injured knee, because of patient's experience of the result of that treatment method. An attempt was made to lower the risk of confusion and to clearly separate the grading of the reasons for the two injured knees. This was done by calling patients who had bilateral ACL injuries to allow them to respond to the questions for one knee at the time.
Differences in clinical routines and health care systems over the world decreases possibilities for generalizability of the results of the present study. A tradition of early ACLR for professional athletes for example, might not allow for enough rehabilitation to evaluate whether a non-operative approach, with a structured rehabilitation that aims to regain strength and function, is a possible treatment.
In an ongoing prospective study, patients are being asked to report symptoms, function and activity demands before choice of treatment, and reasons for choice of treatment close to the decision. This will further enlighten the patient perspective.
CONCLUSIONS
Inability to perform physical activity, fear of increased symptoms, and giving way episodes were reasons that patients with ACL injury considered when making decisions about ACLR. When choosing non-operative treatment, patients considered the absence of instability or giving way symptoms, being able to perform physical activity, or that clinicians had advised non-operative treatment. Patients who chose non-operative treatment were older and not as physically active before injury compared to patients who choose ACLR.
REFERENCES
- 1.Frobell RB Roos EM Roos HP, et al. A randomized trial of treatment for acute anterior cruciate ligament tears. N Engl J Med. 2010;363:331-42. [DOI] [PubMed] [Google Scholar]
- 2.Moksnes H Risberg MA. Performance-based functional evaluation of non-operative and operative treatment after anterior cruciate ligament injury. Scand J Med Sci Sports. 2009;19:345-55. [DOI] [PubMed] [Google Scholar]
- 3.Meuffels DE Favejee MM Vissers MM et al. Ten year follow-up study comparing conservative versus operative treatment of anterior cruciate ligament ruptures. A matched-pair analysis of high level athletes. Br J Sports Med. 2009;43:347-51. [DOI] [PubMed] [Google Scholar]
- 4.Schub DL Schmitz LM Sakamoto FA, et al. Long-term outcomes of postoperative septic arthritis after anterior cruciate ligament reconstruction. Am J Sports Med. 2012;40:2764-70. [DOI] [PubMed] [Google Scholar]
- 5.Failla MJ Arundale AJ Logerstedt DS, et al. Controversies in knee rehabilitation: anterior cruciate ligament injury. Clin Sports Med. 2015;34:301-12. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Smith TO Postle K Penny F, et al. Is reconstruction the best management strategy for anterior cruciate ligament rupture? A systematic review and meta-analysis comparing anterior cruciate ligament reconstruction versus non-operative treatment. Knee. 2014;21:462-70. [DOI] [PubMed] [Google Scholar]
- 7.Ericsson YB Roos EM Frobell RB. Lower extremity performance following ACL rehabilitation in the KANON-trial: impact of reconstruction and predictive value at 2 and 5 years. Br J Sports Med. 2013;47:980-5. [DOI] [PubMed] [Google Scholar]
- 8.Marx RG Jones EC Angel M, et al. Beliefs and attitudes of members of the American Academy of Orthopaedic Surgeons regarding the treatment of anterior cruciate ligament injury. Arthroscopy. 2003;19:762-70. [DOI] [PubMed] [Google Scholar]
- 9.Beaufils P Hulet C Dhenain M, et al. Clinical practice guidelines for the management of meniscal lesions and isolated lesions of the anterior cruciate ligament of the knee in adults. Orthop Traumatol Surg Res. 2009;95:437-42. [DOI] [PubMed] [Google Scholar]
- 10.Shea KG Carey JL Richmond J, et al. The American Academy of Orthopaedic Surgeons evidence-based guideline on management of anterior cruciate ligament injuries. J Bone Joint Surg Am. 2015;97:672-4. [DOI] [PubMed] [Google Scholar]
- 11.Meuffels DE Poldervaart MT Diercks RL, et al. Guideline on anterior cruciate ligament injury. Acta Orthop. 2012;83:379-86. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Spindler KP Wright RW. Clinical practice. Anterior cruciate ligament tear. N Engl J Med. 2008;359:2135-42. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Frobell RB Roos HP Roos EM, et al. Treatment for acute anterior cruciate ligament tear: five year outcome of randomised trial. Br J Sports Med. 2015;49:700. [DOI] [PubMed] [Google Scholar]
- 14.Ardern CL Taylor NF Feller JA, et al. Fifty-five per cent return to competitive sport following anterior cruciate ligament reconstruction surgery: an updated systematic review and meta-analysis including aspects of physical functioning and contextual factors. Br J Sports Med. 2014;48:1543-52. [DOI] [PubMed] [Google Scholar]
- 15.Bernstein J. Early versus delayed reconstruction of the anterior cruciate ligament: a decision analysis approach. J Bone Joint Surg Am. 2011;93:e48. [DOI] [PubMed] [Google Scholar]
- 16.Chalmers PN Mall NA Moric M et al. Does ACL reconstruction alter natural history?: A systematic literature review of long-term outcomes. J Bone Joint Surg Am. 2014;96:292-300. [DOI] [PubMed] [Google Scholar]
- 17.Dunn KL Lam KC Valovich McLeod TC. Early Operative Versus Delayed or Nonoperative Treatment of Anterior Cruciate Ligament Injuries in Pediatric Patients. J Athl Train. 2016;51:425-7. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Ajuied A Wong F Smith C, et al. Anterior cruciate ligament injury and radiologic progression of knee osteoarthritis: a systematic review and meta-analysis. Am J Sports Med. 2014;42:2242-52. [DOI] [PubMed] [Google Scholar]
- 19.Nordenvall R Bahmanyar S Adami J et al. Cruciate ligament reconstruction and risk of knee osteoarthritis: the association between cruciate ligament injury and post-traumatic osteoarthritis. a population based nationwide study in Sweden, 1987-2009. PLoS One. 2014;9:e104681. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Renström PA. Eight clinical conundrums relating to anterior cruciate ligament (ACL) injury in sport: recent evidence and a personal reflection. Br J Sports Med. 2013;47:367-72. [DOI] [PubMed] [Google Scholar]
- 21.Grevnerts HT Fältström A Sonesson S, et al. Activity demands and instability are the most important factors for recommending to treat ACL injuries with reconstruction. Knee Surg Sports Traumatol Arthrosc. 2018; 26:2401-2409. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Swirtun LR Eriksson K Renström P. Who chooses anterior cruciate ligament reconstruction and whyϿ. A 2-year prospective study. Scand J Med Sci Sports. 2006;16:441-6. [DOI] [PubMed] [Google Scholar]
- 23.van Baalen S Boon M. An epistemological shift: from evidence-based medicine to epistemological responsibility. J Eval Clin Pract. 2015;21:433-9. [DOI] [PubMed] [Google Scholar]
- 24.Tegner Y Lysholm J. Rating systems in the evaluation of knee ligament injuries. Clin Orthop Relat Res. 1985;198:43-9. [PubMed] [Google Scholar]
- 25.Fältström A Hägglund M Kvist J. Patient-reported knee function, quality of life, and activity level after bilateral anterior cruciate ligament injuries. Am J Sports Med. 2013;41:2805-13. [DOI] [PubMed] [Google Scholar]
- 26.Sonesson S Kvist J Ardern C, et al. Psychological factors are important to return to pre-injury sport activity after anterior cruciate ligament reconstruction: expect and motivate to satisfy. Knee Surg Sports Traumatol Arthrosc. 2017;25:1375-84. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 27.Ross CA Clifford A Louw QA. Factors informing fear of reinjury after anterior cruciate ligament reconstruction. Physiother Theory Pract. 2017;33:103-14. [DOI] [PubMed] [Google Scholar]
- 28.Christino MA Fantry AJ Vopat BG. Psychological Aspects of Recovery Following Anterior Cruciate Ligament Reconstruction. J Am Acad Orthop Surg. 2015;23:501-9. [DOI] [PubMed] [Google Scholar]
- 29.Paschos NK Howell SM. Anterior cruciate ligament reconstruction: principles of treatment. EFORT Open Rev. 2016;1:398-408. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 30.Edwards PK Mears SC Lowry Barnes C. Preoperative Education for Hip and Knee Replacement: Never Stop Learning. Curr Rev Musculoskelet Med. 2017;10:356-64. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 31.Gammon J Mulholland CW. Effect of preparatory information prior to elective total hip replacement on post-operative physical coping outcomes. Int J Nurs Stud. 1996;33:589-604. [DOI] [PubMed] [Google Scholar]
- 32.Desai N Björnsson H Samuelsson K, et al. Outcomes after ACL reconstruction with focus on older patients: results from The Swedish National Anterior Cruciate Ligament Register. Knee Surg Sports Traumatol Arthrosc. 2014;22:379-86. [DOI] [PubMed] [Google Scholar]
- 33.Nordenvall R Marcano AI Adami J, et al. The Effect of Socioeconomic Status on the Choice of Treatment for Patients With Cruciate Ligament Injuries in the Knee: A Population-Based Cohort Study. Am J Sports Med. 2017;45:535-40. [DOI] [PubMed] [Google Scholar]