Eric Hamrin Senorski

While modern medicine evolves continuously, evidence-based research methodology remains: how register studies should be interpreted and appreciated

One of the goals for researchers is to get their work published and acknowledged, preferably with multiple citations. A winning tactic to accomplish this is to present novel results and findings. Interestingly, it often happens that the most cited papers are those that contradict other reports or are proved to be fundamentally wrong [14]. So, it does not really matter how likely a result is to be true or clinically valuable—a spectacular result can entrench the findings of a study and influence clinical practice. It goes without saying that the most important factor of all in this quest is that a significant P value is presented. Today, it is generally accepted that significance, often defined as a P value of <0.05, means impact and evidence. However, this is an incorrect appreciation of the P value and could lead to an inappropriate approach to this statistical method. It has been shown that P values and hypothesis-testing methods are commonly misunderstood by researchers [6, 11, 17] In just a few decades, the scientific stage has undergone some dramatic changes. Novel studies are produced at a “faster than ever” pace, and technological advances enable insights into areas that would previously have been referred to as science fiction. However, the purpose of research will always be the same—to serve as a firm foundation to practise evidence-based medicine and ultimately improve the treatment of our patients. Is the explosive evolvement of research publications and technological advances always beneficial when it comes to fulfilling this purpose? As we are served with a steady stream of new “significant”

Low 1-Year Return-to-Sport Rate After Anterior Cruciate Ligament Reconstruction Regardless of Patient and Surgical Factors: A Prospective Cohort Study of 272 Patients:

Background: There is insufficient knowledge about the way that concomitant injuries affect the short-term likelihood of a return to a knee-strenuous sport after anterior cruciate ligament (ACL) reconstruction. Hypotheses/Purpose: The purpose was to study whether patient characteristics, concomitant injuries, and graft choice at primary ACL reconstruction can predict return to sport (RTS) 1 year after surgery. The hypotheses were that younger age at the time of ACL reconstruction would positively affect RTS, while the presence of concomitant injuries would negatively affect RTS 1 year after surgery. Study Design: Case-control study; Level of evidence, 3. Methods: Data were extracted from a rehabilitation-specific register and the Swedish National Knee Ligament Register. Twelve months after surgery, all patients were evaluated for RTS via the Tegner Activity Scale. The primary outcome was a return to knee-strenuous sport, defined as a Tegner Activity Scale ≥6. Univariable and multivariable logistic regression analyses were performed with patient characteristics, concomitant knee injuries, and graft choice as independent variables. Results: A total of 272 patients (51% female) with a mean ± SD age of 25.0 ± 9.2 years were included. In the multivariable analysis, a favorable odds ratio (OR) for returning to sport was found for patients of male sex (OR, 2.58; 95% CI, 1.43-4.65; P = .0016), younger age at the time of ACL reconstruction (OR, 2.32; 95% CI, 1.59-3.33; P < .0001), a higher preinjury score on the Tegner Activity Scale (OR, 1.45; 95% CI, 1.13-1.87; P = .0038), and an absence of injury to the meniscus (OR, 1.92; 95% CI, 1.10-3.36; P = .023) and medial collateral ligament (OR, 7.61; 95% CI, 1.42-40.87; P = .018). In addition, the absence of cartilage injury was favorable in terms of RTS in the univariable analysis (OR, 2.48; 95% CI, 1.40-4.39; P = .0018). Conclusion: Positive predictors of a return to knee-strenuous sport 1 year after ACL reconstruction were male sex, younger age, a high preinjury level of physical activity, and the absence of concomitant injuries to the medial collateral ligament and meniscus.

Factors Affecting the Achievement of a Patient-Acceptable Symptom State 1 Year After Anterior Cruciate Ligament Reconstruction: A Cohort Study of 343 Patients From 2 Registries

Background: There is insufficient knowledge regarding the influence of concomitant injuries on the recovery of short-term subjective knee function after anterior cruciate ligament (ACL) reconstruction. Purpose: To determine whether patient characteristics, concomitant injuries, and graft choice during ACL reconstruction can predict which patients achieve acceptable knee function 1 year after reconstruction. Study Design: Case-control study; Level of evidence, 3. Methods: Data from 1 physical therapist–specific and 1 surgeon-specific register were used. Patients who had completed the Knee injury and Osteoarthritis Outcome Score (KOOS) at 1-year follow-up were included. Additional intraoperative information was extracted from a database. The primary outcome was achieving a patient-acceptable symptom state (PASS) for each subscale of the KOOS. Univariable and multivariable logistic regression models were used, with patient sex, age, and preinjury level of physical activity as covariates. Results: A total of 343 patients (51% females) were included. The proportion of patients achieving PASS 1 year after ACL reconstruction varied between 40% and 85% among the KOOS subscales. Younger age at reconstruction and male sex provided favorable odds of achieving acceptable knee function across the KOOS subscales. Patients without cartilage injury had increased odds of achieving PASS in the KOOS sport and recreation subscale; the increase was 1.63-fold (95% CI, 1.01-2.64; P = .045). Patients receiving patellar tendon autograft had a 0.41-fold (95% CI, 0.19-0.85; P = .017) decrease in odds of achieving PASS on the KOOS quality of life (QoL) subscale. In the multivariable analysis, increased odds of achieving PASS on the KOOS QoL subscale were associated with the absence of meniscal injury (odds ratio, 1.62; 95% CI, 1.04-2.54; P = .035), and increased odds were found for hamstring tendon autograft (OR, 2.63; 95% CI, 1.25-5.56; P = .011). Conclusion: More than half of the patients reported an acceptable symptom state on 4 of the 5 KOOS subscales 1 year after ACL reconstruction. A lack of consistency was noted related to the effect of concomitant knee injuries and graft choice on acceptable knee function. However, younger age and male sex were favorable, nonmodifiable characteristics that increased the odds of early acceptable function.

Management of ACL Injuries in Handball

For a handball player, an anterior cruciate ligament (ACL) injury does not only represent a career-threatening injury in the short term but also a potential cause of osteoarthritis in the long term. ACL reconstruction is highly recommended in case of desire to resume handball practice. Many types of surgical techniques are currently available. Arthroscopic intra-articular ACL reconstruction with autologous tendon grafts is the first choice of treatment. In patients with big knee laxities, additional extraarticular stabilization may be required. Meniscus preservation is important for optimal knee function and for the prevention of osteoarthritis in the long term. Although most of the players will be able to return to sports (RTS) after ACL reconstruction, this cannot be guaranteed. RTS can generally be considered after a thorough rehabilitation period of 6–9 months. In young players under the age of 20, the risk of a secondary ACL injury of the contralateral knee or a recurrent graft tear in the operated knee is around 30%. For these reasons, return to sports should be preceded by functional assessments, including strength measurements and hop tests. The development of interdisciplinary strategies to bridge the frequent gap between physiotherapy and return to competition is highly recommended to allow for a safe RTS practice.

Preoperative knee laxity measurements predict the achievement of a patient-acceptable symptom state after ACL reconstruction: a prospective multicenter study

Objective To determine whether patient-related factors, concomitant injuries and preoperative knee laxity could predict a patient acceptable symptom state (PASS) in the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF) at 1 and 2 years follow-up after anterior cruciate ligament (ACL) reconstruction in a multicentre cohort. Methods Patients between 14 and 50 years of age who underwent single-bundle ACL reconstruction with hamstring tendon autograft within 1 year from the index injury were eligible. Additionally, only patients who completed the IKDC-SKF questionnaire at 1 or 2 years of follow-ups were included. Preoperative knee laxity assessment of patients in the awake state was performed using rolimeter, the Lachman and the pivot-shift test. The pivot shift was graded according to the IKDC criteria and also quantified by the use of non-invasive technology for (1) lateral tibial translation and (2) tibial acceleration. The quantitative pivot shift (QPS) was examined in the awake state and under anaesthesia (EUA). Univariable logistic regression models were performed with achieving PASS in the IKDC as the dependent variable. Results A total of 86 patients had complete data on the IKDC-SKF score at 1-year follow-up, of which 67 patients (77.9%) achieved PASS (age 24.8±9.3 years, 43% females). Two-year data were available for 50 patients, of which 39 patients (78.9%) achieved PASS (age 23.9±9.2 years, 42.0% females). A low-grade manual pivot shift according to IKDC grading had increased odds of achieving PASS at 1 year (OR=2.96 (95% CI 1.01 to 8.66), P<0.05) compared with patients who displayed a high-grade pivot shift preoperatively. However, this was not confirmed by the preoperative QPS measures (awake: tibial translation; OR=0.99,(95% CI 0.72 to 1.35), (n.s.), acceleration; OR=1.04,(95% CI 0.68 to 1.59), (n.s.) EUA: tibial translation; OR=1.02 (95% CI 0.78 to 1.31), (n.s.), acceleration; OR=1.14 (95% CI 0.93 to 1.40), (n.s.)). None of the studied variables of patient characteristics, concomitant injuries or knee joint laxity predicted PASS at the 2-year follow-up. Conclusion Almost four in every five patients were able to achieve PASS 1 and 2 years after anatomic single-bundle ACL reconstruction. The presence of preoperative low-grade pivot shift increased the odds of achieving an acceptable level of knee function 1 year after ACL reconstruction compared with high-grade pivot shift; however, QPS did not confirm achievement of PASS in this study. Level of evidence Level III, prospective cohort.

Static anteroposterior knee laxity tests are poorly correlated to quantitative pivot shift in the ACL-deficient knee: a prospective multicentre study

Objective To determine the relationship between preoperative static knee joint laxity and non-invasive quantitative pivot shift (QPS) in patients with anterior cruciate ligament (ACL) rupture. Methods Patients with an ACL injury participating in a multicentre trial were analysed if they had complete preoperative data on the following laxity tests: the rolimeter, the KT-1000 (134 N and manual maximum force), the Lachman, the anterior drawer and QPS. The QPS was assessed via a non-invasive inertial sensor system and an image analysis system for tibial acceleration and lateral tibial translation, respectively. Awake examination and examination under anaesthesia (EUA) were performed. Correlation between absolute values of static laxity and the QPS for each leg was assessed by Spearman’s rho. The Lachman and the anterior drawer were dichotomised into low- and high-grade, and differences between the groups in terms of continuous values of QPS were assessed. Results A total of 58 patients were included (41.4% women, mean age 27.1±9.8 years). Awake static laxity and QPS acceleration were negatively correlated in the ACL-deficient knee, meaning that a greater acceleration correlated to a lesser static tibial translation, and vice versa. The mean QPS acceleration correlated with the static tests as follows: the rolimeter r=−0.30 (P=0.024), the KT-1000 134 N r=−0.25 (P=0.06) and the KT-1000 manual maximum r=−0.37 (P=0.004). A negative correlation between awake QPS acceleration and the static tests was also shown for the non-involved knee. Patients with a high-grade Lachman’s test in the EUA had significantly greater QPS acceleration (P=0.0002) and QPS translation (P<0.001) compared with patients with a low-grade. The corresponding analysis for the anterior drawer showed a significantly greater QPS translation in the high-grade group (P=0.01), while no differences were found in the QPS acceleration. Conclusion Static anteroposterior and dynamic knee laxities, as presented by QPS, are poorly correlated in the ACL-deficient knee and should therefore be considered as separate entities of the knee examination. These findings strengthen the implementation of non-invasive technology for quantification of the pivot shift when establishing treatment algorithms for ACL reconstruction. Level of evidence Level III, prospective cohort.

Unique simultaneous avulsion fracture of both the proximal and distal insertion sites of the anterior cruciate ligament

February is a busy month for the ambulance skiing patrol at the skiing resorts in Norway and on this day, a call regarding an 11-year-old boy on one of the hills reached the team. What no one knew at that moment was that this boy had suffered a unique injury and that his X-rays would reveal something that, prior to this, had never been described in the history of mankind. This patient had suffered a simultaneous avulsion fracture of both the femoral and tibial insertion sites of the anterior cruciate ligament without suffering any other injuries to the knee. The injury was treated conservatively and at 1-year follow-up, the patient was completely recovered.

Factors associated with additional anterior cruciate ligament reconstruction and register comparison: a systematic review on the Scandinavian knee ligament registers

Objective To present an overview of the Scandinavian knee ligament registers with regard to factors associated with additional ACL reconstruction, and studies comparing the Scandinavian registers with other knee ligament registers. Design Systematic review. Data sources Four electronic databases: PubMed, EMBASE, the Cochrane Library and AMED were searched, and 157 studies were identified. Two reviewers independently screened titles, abstracts and full-text studies for eligibility. A modified version of the Downs and Black checklist was applied for quality appraisal. Eligibility criteria for selecting studies Eligible studies were those published since the establishment of the Scandinavian registers in 2004, which reported factors associated with additional ACL reconstruction and compared data from other registers. Results Thirty-one studies met the inclusion criteria and generally displayed good reporting quality. Adolescent age (<20 years) was the most common factor associated with additional ACL reconstruction. The choice of hamstring tendon graft compared with patella tendon, transportal femoral tunnel drilling, smaller graft diameter and utilisation of suspensory fixation devices were associated with additional ACL reconstruction. Concomitant cartilage injury decreased the likelihood of additional ACL reconstruction. Patient sex alone did not influence the likelihood. The demographics of patients undergoing ACL reconstruction in the Scandinavian registers are comparable to registers in other geographical settings. However, there are differences in surgical factors including the presence of intra-articular pathology and graft choice. Summary The studies published from the Scandinavian registers in general have a high reporting quality when regarded as cohort studies. Several factors are associated with undergoing additional ACL reconstruction. The results from the registers may help facilitate treatment decisions.

Factors that affect patient reported outcome after anterior cruciate ligament reconstruction–a systematic review of the Scandinavian knee ligament registers

Objective To perform a systematic review of findings from the Scandinavian knee ligament registers with regard to factors that affect patient reported outcome after anterior cruciate ligament (ACL) reconstruction. Design Systematic review. Data sources Four electronic databases: PubMed, EMBASE, the Cochrane Library and AMED were searched, and 157 studies were identified. Two reviewers independently screened the titles, abstracts and full text articles for eligibility. A modified version of the Downs and Black checklist was applied for quality appraisal. Eligibility criteria for selecting studies Studies published from the Scandinavian registers from their establishment in 2004 and onwards that documented patient reported outcome and provided information on concomitant injuries were eligible. Results A total of 35 studies were included. Younger age at ACL reconstruction, male sex, not smoking and receiving a hamstring tendon autograft positively influenced patient reported outcome. Patients with concomitant cartilage and meniscal injuries reported inferior subjective knee function compared with patients with an isolated ACL tear. One study reported that patients treated non-reconstructively reported inferior knee function compared with patients who had ACL reconstruction. Conclusion Younger age, male sex, not smoking, receiving a hamstring tendon autograft and the absence of concomitant injuries were associated with superior patient reported outcomes after ACL reconstruction.

2 10-year risk-factors of knee function after anterior cruciate ligament reconstruction – a study from the swedish national knee ligament register

Introduction Long-term individual prognosis and risk factors for quality of life and disability following ACL reconstruction remain unknown. To determine 10 year predictors of knee function after anterior cruciate ligament reconstruction. Material and methods Prospectively collected data were extracted on patients who underwent ACL reconstruction between January 2005 and January 2007 from the Swedish National Knee Ligament Register. Patients who had no 10 year follow-up of the Knee injury and Osteoarthritis Outcome Score (KOOS) were excluded. Conditional multivariable regression modelling was used to assess 10 year patient-related and surgery-related risk factors across all KOOS subscales including KOOS4. Result In total, 874 patients with a median age of 27.5 years (11.2–61.5) at ACL reconstruction were included. No patient-related or surgery-related predictor was significant across all subscales of the KOOS. The presence of a concomitant articular cartilage injury resulted in decreased odds OR=0.639–0.796 (p<0.05) for every two-step increase of ICRS grade in four KOOS subscales. A higher preoperative KOOS pain increased the odds of having a favourable KOOS in the subscales of pain, symptom, sport and KOOS4. In a sub-analysis, a higher preoperative body mass index proved to be a significant risk factor in four out of the six KOOS subscales studied. Conclusion This 10 year risk factor analysis identified several factor than can effect long-term knee function after ACL reconstruction. Most of the risk factors were surgery-related and unfortunately non-modifiable. Nevertheless, this information can be helpful to physicians counselling patients’ expectations of outcome after ACL reconstruction.