ChatGPT can yield valuable responses in the context of orthopaedic trauma surgery.

Purpose: To assess the possibility of using Generative Pretrained Transformer (ChatGPT) specifically in the context of orthopaedic trauma surgery by questions posed to ChatGPT and to evaluate responses (correctness, completeness and adaptiveness) by orthopaedic trauma surgeons. Methods: ChatGPT (GPT-4 of 12 May 2023) was asked to address 34 common orthopaedic trauma surgery-related questions and generate responses suited to three target groups: patient, nonorthopaedic medical doctor and expert orthopaedic surgeon. Three orthopaedic trauma surgeons independently assessed ChatGPT's responses by using a three-point response scale with a response range between 0 and 2, where a higher number indicates better performance (correctness, completeness and adaptiveness). Results: A total of 18 (52.9%) of all responses were assessed to be correct (2.0) for the patient target group, while 22 (64.7%) and 24 (70.5%) of the responses were determined to be correct for nonorthopaedic medical doctors and expert orthopaedic surgeons, respectively. Moreover, a total of 18 (52.9%), 25 (73.5%) and 28 (82.4%) of the responses were assessed to be complete (2.0) for patients, nonorthopaedic medical doctors and expert orthopaedic surgeons, respectively. The average adaptiveness was 1.93, 1.95 and 1.97 for patients, nonorthopaedic medical doctors and expert orthopaedic surgeons, respectively. Conclusion: The study results indicate that ChatGPT can yield valuable and overall correct responses in the context of orthopaedic trauma surgery across different target groups, which encompassed patients, nonorthopaedic medical surgeons and expert orthopaedic surgeons. The average correctness scores, completeness levels and adaptiveness values indicated the ability of ChatGPT to generate overall correct and complete responses adapted to the target group. Level of Evidence: Not applicable.

A practical guide to the implementation of AI in orthopaedic research, Part 6: How to evaluate the performance of AI research?

Artificial intelligence's (AI) accelerating progress demands rigorous evaluation standards to ensure safe, effective integration into healthcare's high-stakes decisions. As AI increasingly enables prediction, analysis and judgement capabilities relevant to medicine, proper evaluation and interpretation are indispensable. Erroneous AI could endanger patients; thus, developing, validating and deploying medical AI demands adhering to strict, transparent standards centred on safety, ethics and responsible oversight. Core considerations include assessing performance on diverse real-world data, collaborating with domain experts, confirming model reliability and limitations, and advancing interpretability. Thoughtful selection of evaluation metrics suited to the clinical context along with testing on diverse data sets representing different populations improves generalisability. Partnering software engineers, data scientists and medical practitioners ground assessment in real needs. Journals must uphold reporting standards matching AI's societal impacts. With rigorous, holistic evaluation frameworks, AI can progress towards expanding healthcare access and quality. Level of Evidence: Level V.

Validity and Reliability of Finger-Strength Testing in 6 Common Grip Techniques for the Assessment of Bouldering Ability in Men.

OBJECTIVE: To determine the criterion validity and test-retest reliability of isometric finger-strength testing in 6 differentiated grip techniques for the assessment of bouldering ability among male climbers. METHODS: We recruited participants at climbing gyms in Sweden and through online advertisements. We included climbers over 15 years of age with a minimum bouldering performance level of 17 International Rock Climbing and Research Association (IRCRA) for men and 15 IRCRA for women. We tested unilateral, maximal isometric peak finger strength in the front 3 drag, half crimp, closed crimp, 35 sloper, 45 × 90-mm, and 90 × 90-mm pinch through maximal force deloaded of a force plate. We analyzed criterion validity, test-retest reliability, and capacity to determine bouldering performance ability using a stepwise multivariable regression model. RESULTS: Women were excluded from the analysis due to insufficient sample size (n = 16). Thirty-two male participants were included in the primary analysis. The median (interquartile range) age in the advanced and elite group was 27 (25; 35) and 23 (22; 32) years, respectively. The half crimp for the participants' weak and strong hand displayed the highest ability to determine bouldering grade performance, explaining 48% to 58% of the variance. In the stepwise regression, maximal strength in the half crimp and the front 3 drag collectively explained 66% of the variance for performance. CONCLUSION: Strength in the half crimp proved the most important performance indicator. The results of this study provide a reliable and valid framework for maximal isometric peak finger-strength testing in advanced and elite male boulderers.

Does Playing Football (Soccer) Really Increase the Risk of Knee Osteoarthritis? A Systematic Review and Meta-analysis.

OBJECTIVE: To evaluate the relationship between football (soccer) participation and tibiofemoral knee osteoarthritis (OA), considering the influence of competitive level and previous knee injuries. DESIGN: Etiology systematic review with meta-analysis. LITERATURE SEARCH: PubMed, Embase, AMED, and Cochrane were searched for relevant publications. STUDY SELECTION CRITERIA: Studies of football players that included a control group consisting of mainly sedentary nonfootball players, and the relationship of knee OA, were considered. The studies had to report radiographically verified knee OA and specify football activity. DATA SYNTHESIS: Eleven studies, involving 1805 football players and 4022 control individuals were included. Subgroups consisting of data regarding level of play and previous injuries were also synthesized. RESULTS: The overall prevalence of knee OA among football players was increased among professional and recreational players, compared with controls. When knee injuries were excluded, there was no difference in knee OA between football players and controls (OR = 1.25; 95% CI: 0.61, 2.54). Football players with a previous knee injury had a greater risk of knee OA when compared with football players with no history of previous knee injury (OR = 4.16; 95% CI: 1.97, 8.77). CONCLUSION: Football players were at increased risk of knee OA. However, after excluding participants with a history of previous knee injury, there were no differences in knee OA between football players and controls. Previous knee injury was important for developing knee OA. Playing football, in the absence of major knee injuries, did not increase the risk of knee OA. J Orthop Sports Phys Ther 2024;54(5):1-12. Epub 26 February 2024. doi:10.2519/jospt.2024.12029.

No Association Between Hamstrings-to-Quadriceps Strength Ratio and Second ACL Injuries After Accounting for Prognostic Factors: A Cohort Study of 574 Patients After ACL-Reconstruction.

BACKGROUND: The stress on the anterior cruciate ligament (ACL) induced by the quadriceps can be attenuated by activation of the hamstrings by exerting an opposing torque to the anterior translation of tibia. Consequently, considering the ratio between strength of the hamstrings-to-quadriceps (HQ-ratio) may be of value to reduce the odds of second ACL injuries. The objective was therefore to evaluate (1) the association between HQ-ratio and the occurrence of a second ACL injury in patients after ACL-reconstruction within 2 years of return to preinjury sport level and (2) to compare the HQ-ratio between males and females after ACL reconstruction. METHODS: Patients who had undergone primary ACL reconstruction and participated in knee-strenuous activity preinjury were included. Demographics, the occurrence of a second ACL injury, and muscle strength test results before returning to preinjury sport level were extracted from a rehabilitation registry. The endpoint was set at a second ACL injury or 2 years after return to preinjury sport level. A multivariable logistic regression was used to analyze the association between the HQ-ratio and a second ACL injury. RESULTS: A total of 574 patients (50.0% female) with a mean age of 24.0 ± 9.4 years at primary ACL reconstruction were included. In the univariable logistic regression analysis, the odds of sustaining a second ACL injury decreased by 3% for every 1% increase in the HQ-ratio (OR 0.97 [95% CI 0.95-1.00], p = 0.025). After adjusting for the time from reconstruction to return to preinjury sport level, sex, preinjury sport level, graft choice, age, and body mass index, the results were no longer significant (OR 0.98 [95% CI 0.95-1.01], p = 0.16). Females had a higher HQ-ratio compared with males for both the ACL-reconstructed and uninjured side (3.7% [95% CI 5.7; 1.8%], p = 0.0002 and 3.3% [95% CI 4.6; 2.1], p < 0.001, respectively). CONCLUSION: The HQ-ratio did not significantly affect the odds for sustaining a second ACL injury upon return to preinjury sports level after primary ACL reconstruction. Females had a significant higher HQ-ratio than males for both the ACL reconstructed and uninjured side.

Metal interference screw fixation combinations show high revision rates in primary hamstring tendon ACL reconstruction.

BACKGROUND: Different fixation methods in anterior cruciate ligament reconstruction (ACLR) have been associated with different revision rates, specifically in the early postoperative period. However, most previous research has either grouped together different fixation types or evaluated femoral-sided fixation or tibial-sided fixation separately. Therefore, the purpose of this study was to determine ACL revision rates for specific combinations of femoral and tibial fixation methods within 2 years of primary hamstring tendon autograft ACLR based on data from the Swedish National Knee Ligament Registry (SNKLR). METHODS: Patients that underwent primary hamstring tendon autograft ACLR between 2005 and 2018 in the SNKLR were included. The collected data included patient characteristics (age, sex, body mass index [BMI]), activity at time of injury, surgical information (concomitant injuries, time from injury to surgery, fixation types at the femur and tibia), and subsequent revision ACLR. Revision rate within 2 years of the index procedure was chosen, as ACLR fixation is most likely to contribute to ACLR revision within the first 2 years, during graft maturation. RESULTS: Of the 23,238 included patients undergoing primary hamstring ACLR, 581 (2.5%) underwent revision ACLR within 2 years of the index procedure. Among the combinations used for > 300 patients, the femoral metal interference screw/tibial metal interference screw fixation combination had the highest revision rate followed by metal interference screw/resorbable screw and Endobutton/AO screw fixation combinations, with respective revision rates of 4.0, 3.0, and 3.0%. The lowest revision rate within 2 years of ACLR was found in the Endobutton/metal interference screw with backup Osteosuture fixation combination, used in 433 cases, with a failure rate of 0.9%. CONCLUSION: Different early ACL revision rates were found across different combinations of femoral and tibial fixation devices within 2 years of primary hamstring tendon autograft ACLR. Metal interference screw fixation, particularly when performed on both the femoral and tibial sides, most frequently resulted in revision ACLR. These findings may be helpful for surgeons in selecting appropriate fixation devices for hamstring ACLR. LEVEL OF EVIDENCE: IV.

Better Safe Than Sorry? A Systematic Review with Meta-analysis on Time to Return to Sport After ACL Reconstruction as a Risk Factor for Second ACL Injury.

OBJECTIVE: To compare the time to return to sport (RTS) between patients who did and did not suffer a second anterior cruciate ligament (ACL) injury after ACL reconstruction. DESIGN: Etiology systematic review with meta-analysis. LITERATURE SEARCH: Cochrane Library, Embase, Medline, AMED, and PEDro databases were searched in August 2021 and again in November 2022. STUDY SELECTION CRITERIA: Clinical studies reporting time to RTS after ACL reconstruction and second ACL injury were eligible. DATA SYNTHESIS: We pooled continuous data (time [months] and proportions [%]), with random-effects meta-analyses. Pooled estimates were summarized in forest plots. A qualitative data synthesis was also performed. RESULTS: Twenty-one studies were included in the meta-analysis and 33 in the qualitative synthesis. Pooled incidence of second ACL injury was 16.9% (95% confidence interval [CI]: 12.8, 21.6). Patients who suffered a second ACL injury returned to sport significantly earlier (25 days; 95% CI: 9.5, 40.4) than those who did not suffer another injury. There was no difference in time to RTS for professional athletes who suffered a second ACL injury and those who did not. The certainty of evidence was very low. CONCLUSION: There was very low-certainty evidence that patients who suffered a second ACL injury had returned to sport 25 days earlier than patients who did not have another injury. For professional athletes, there was no difference in time to RTS between athletes who suffered a second ACL injury and athletes who did not. J Orthop Sports Phys Ther 2024;54(3):1-15. Epub 30 November 2023. doi:10.2519/jospt.2023.11977.

A practical guide to the implementation of AI in orthopaedic research - part 1: opportunities in clinical application and overcoming existing challenges.

Artificial intelligence (AI) has the potential to transform medical research by improving disease diagnosis, clinical decision-making, and outcome prediction. Despite the rapid adoption of AI and machine learning (ML) in other domains and industry, deployment in medical research and clinical practice poses several challenges due to the inherent characteristics and barriers of the healthcare sector. Therefore, researchers aiming to perform AI-intensive studies require a fundamental understanding of the key concepts, biases, and clinical safety concerns associated with the use of AI. Through the analysis of large, multimodal datasets, AI has the potential to revolutionize orthopaedic research, with new insights regarding the optimal diagnosis and management of patients affected musculoskeletal injury and disease. The article is the first in a series introducing fundamental concepts and best practices to guide healthcare professionals and researcher interested in performing AI-intensive orthopaedic research studies. The vast potential of AI in orthopaedics is illustrated through examples involving disease- or injury-specific outcome prediction, medical image analysis, clinical decision support systems and digital twin technology. Furthermore, it is essential to address the role of human involvement in training unbiased, generalizable AI models, their explainability in high-risk clinical settings and the implementation of expert oversight and clinical safety measures for failure. In conclusion, the opportunities and challenges of AI in medicine are presented to ensure the safe and ethical deployment of AI models for orthopaedic research and clinical application. Level of evidence IV.

Differences in postoperative knee function based on concomitant treatment of lateral meniscal injury in the setting of primary ACL reconstruction.

BACKGROUND: Concomitant lateral meniscal (LM) injuries are common in acute anterior cruciate ligament (ACL) ruptures. However, the effect of addressing these injuries with various treatment methods during primary ACL reconstruction (ACLR) on patient-reported outcomes (PROs) is unknown. Therefore, the purpose of this study was to compare postoperative Knee injury and Osteoarthritis Outcome Score (KOOS) at 2-, 5-, and 10-years after isolated primary ACLR to primary ACLR with various treatment methods to address concomitant LM injury. METHODS: This study was based on data from the Swedish National Knee Ligament Registry. Patients ≥ 15 years with data on postoperative KOOS who underwent primary ACLR between the years 2005 and 2018 were included in this study. The study population was divided into five groups: 1) Isolated ACLR, 2) ACLR + LM repair, 3) ACLR + LM resection, 4) ACLR + LM injury left in situ, and 5) ACLR + LM repair + LM resection. Patients with concomitant medial meniscal or other surgically treated ligament injuries were excluded. RESULTS: Of 31,819 included patients, 24% had LM injury. After post hoc comparisons, significantly lower scores were found for the KOOS Symptoms subscale in ACLR + LM repair group compared to isolated ACLR (76.0 vs 78.3, p = 0.0097) and ACLR + LM injury left in situ groups (76.0 vs 78.3, p = 0.041) at 2-year follow-up. However, at 10-year follow-up, no differences were found between ACLR + LM repair and isolated ACLR, but ACLR + LM resection resulted in significantly lower KOOS Symptoms scores compared to isolated ACLR (80.4 vs 82.3, p = 0.041). CONCLUSION: The results of this study suggest that LM injury during ACLR is associated with lower KOOS scores, particularly in the Symptoms subscale, at short- and long-term follow-up. However, this finding falls below minimal clinical important difference and therefore may not be clinically relevant. LEVEL OF EVIDENCE: III.

Swedish Olympic athletes report one injury insurance claim every second year: a 22-year insurance registry-based cohort study.

PURPOSE: To describe injury incidence, time trends in injury incidence, and injury characteristics among Swedish Olympic athletes over 22 years based on insurance data, as a first step to inform injury preventive measures among Olympic athletes. METHODS: The cohort comprised 762 elite athletes (54% males; age 26.5 ± 5.9 years) in 38 sports in the Swedish Olympic Committee support program 'Top and Talent' between 1999 and 2020, with total 3427 athlete-years included. Acute and gradual onset injuries were reported to the insurance registry by the athletes' medical staff. RESULTS: A total of 1635 injuries in 468 athletes were registered. The overall injury incidence was 47.7 injuries/100 athlete-years (one injury per athlete every second year). An increasing trend in injury incidence was observed in the first decade 2001 to 2010 (annual change 6.0%, 95% CI 3.3-8.8%), while in the second decade 2011 to 2020 no change was evident (0.4%, 95% CI - 1.9 to 2.7%). Gymnastics, tennis, and athletics had the highest incidence (100.0, 99.3, and 93.4 injuries/100 athlete-years, respectively). Among sport categories, mixed and power sports had the highest incidence (72.8 and 69.5 injuries/100 athlete-years, respectively). Higher incidences were seen in the younger age groups (≤ 25 years) in mixed and skill sports. The injury incidence was comparable between male and female athletes, and summer and winter sports. Most injuries occurred in the lower limb, and specifically the knee (24%), foot/ankle (15%) and spine/pelvis (13%). CONCLUSION: The results on injury patterns in different sports and age groups may guide preventive focus for health and performance teams working with Olympic athletes. LEVEL OF EVIDENCE: II.

Effect of Quadriceps and Hamstring Strength Relative to Body Weight on Risk of a Second ACL Injury: A Cohort Study of 835 Patients Who Returned to Sport After ACL Reconstruction.

Background: Anterior cruciate ligament (ACL) injuries are common sports-related injuries with a high risk of reinjury after return to sport (RTS). Rehabilitation aims to regain symmetrical knee strength and function to minimize the risk of a second ACL injury after RTS. Purpose: To determine the effect of absolute quadriceps and hamstring strength, normalized by body weight, on the risk of a second ACL injury during the first 2 years after RTS in patients who have undergone ACL reconstruction (ACLR). Study Design: Cohort study; Level of evidence, 3. Methods: Data from patients after index ACLR at the time of RTS were extracted from a rehabilitation registry-Project ACL. Patients who had performed isokinetic tests for quadriceps and hamstring strength and hop tests before RTS were included. The endpoint was a second ACL injury or a follow-up of 2 years after RTS after ACLR. Results: A total of 835 patients (46% women), with a mean age of 23.9 ± 7.7 years, were included. During the study period, 69 (8.3%) second ACL injuries (ipsilateral and contralateral) occurred. Greater relative quadriceps strength in the injured leg increased the risk of a second ACL injury (relative risk [RR], 1.69 [95% CI, 1.05-2.74]; P = .032). In patients who had recovered symmetrical quadriceps strength (limb symmetry index ≥90%), there was no effect of quadriceps strength on the risk of second ACL injury (RR, 1.33 [95% CI, 0.69-2.56]; P = .39). Quadriceps strength on the healthy side or hamstring strength, regardless of side, had no effect on the risk of a second ACL injury. Conclusion: Greater relative quadriceps strength in the injured leg at the time of RTS after ACLR was associated with an increased risk of a second ACL injury. There was no effect of relative quadriceps strength on the risk of a second ACL injury in patients who had recovered symmetrical quadriceps strength.

High-level soccer players have a low rate of return to performance after hip arthroscopy for femoroacetabular impingement syndrome.

PURPOSE: Femoroacetabular impingement syndrome (FAIS) is a known cause of impaired sports performance in athletes and the relationship between FAIS and soccer players has previously been described. Hip arthroscopy is a viable treatment option that can facilitate athletes' return to sport (RTS). The aim of this study was to evaluate the RTS and return to performance (RTP) with objective measurements in high-level soccer players after hip arthroscopy for FAIS. METHOD: Soccer players, with a hip sports activity scale (HSAS) level of 7 or 8 before symptom onset and undergoing hip arthroscopy for FAIS between 2011 and 2019 were identified in the Gothenburg hip arthroscopic registry. A total of 83 high-level soccer players, with a mean age of 23.9 (SD 4.4) years at surgery, were included. To verify the activity level and further stratify players as elite or sub-elite, player statistics were collected from soccer-specific scout webpages and the Swedish national soccer association. The return to sport was defined as return to one game of soccer. Return to performance was defined as playing at the same level, or higher, and participating in at least 80% of the number of games played the season before symptom onset or the season before surgery either the first or second season after hip arthroscopy. RESULTS: In total, 71 (85.5%, 95% confidence interval (CI) 76.1-92.3%) of the players returned to sport the first or second season after surgery. Compared to the season before symptom onset, 31 (37.3%, 95% CI 27.0-48.7%) players returned to performance the first or second season after surgery, and 32 (38.6%, 95% CI 28.1-49.9%) players returned to performance the first or second season after surgery compared to the season before surgery. CONCLUSION: A high rate of elite and sub-elite soccer players return to soccer after hip arthroscopy for FAIS. However, less than half of the players RTP when evaluating performance through level of play and number of games played. LEVEL OF EVIDENCE: Level IV.

Low occurrence of MRI spinal changes in elite climbing athletes; a cross-sectional study.

OBJECTIVES: To examine the occurrence of magnetic resonance imaging (MRI) changes in the thoracolumbar spine among elite climbing athletes. METHODS: All climbers of the Swedish national sport climbing team (n = 8), and individuals having trained for selection to the national team (n = 11), were prospectively included. A control group, matched in age and sex, were recruited. All participants underwent a thoracolumbar MRI (1.5 T, T1- and T2-weighted imaging), evaluated according to Pfirrmann classification, modified Endplate defect score, Modic changes, apophyseal injuries and spondylolisthesis. Pfirrmann ≥ 3, Endplate defect score ≥ 2 and Modic ≥ 1 was defined as degenerative findings. RESULTS: Fifteen individuals, 8 women, participated in both the climbing group (mean age 23.1, SD 3.2 years) and the control group respectively (mean age 24.3, SD 1.5 years). In the climbing group, 6.1% of the thoracic and 10.6% of the lumbar intervertebral discs showed signs of degeneration according to Pfirrmann. One disc with a grade above 3 was present. Modic changes in the thoracic/lumbar spine were prevalent in 1.7%/1.3% of the vertebrae. Degenerative endplate changes according to the Endplate defect score were found in 8.9% and 6.6% of the thoracic and lumbar spinal segments of the climbing group, respectively. Two apophyseal injuries were found, while no participants displayed signs of spondylolisthesis. There was no difference in point-prevalence of radiographic spinal changes between climbers and controls (0.07 < p < 1.0). CONCLUSION: In this small cross-sectional study, only a low proportion of elite climbers displayed changes of the spinal endplates or intervertebral discs, as opposed to other sports with high spinal loads. Most observed abnormalities were low grade degenerative changes and did not differ statistically compared to controls.

Arthroscopic iliopsoas tenotomy after total hip arthroplasty: safe method for the right patient.

PURPOSE: To evaluate the outcome of arthroscopic treatment for iliopsoas impingement after total hip arthroplasty (THA) 2 years after surgery using patient reported outcomes (PROM). METHODS: In this study 12 patients (13 hips) were included from a local hip arthroscopy registry. Patients completed web-based PROMs preoperatively and at a minimum of 2 years postoperatively. The PROMs included the International Hip Outcome Tool short version (iHOT-12), the Copenhagen Hip and Groin Outcome Score (HAGOS), the European Quality of Life-5 Dimensions Questionnaire (EQ-5D), the Hip Sports Activity Scale (HSAS) for physical activity level, the Visual Analog Scale (VAS) for overall hip function and a single question regarding overall satisfaction with the surgery. RESULTS: The mean age was 64.4 years (±15.1SD), mean body mass index (BMI) was 26.6 (±4.3SD), mean follow-up time was 49.8 months (±25SD). Comparing PROMs preoperatively with 2-year follow up showed an improvement for many of the PROMs used. The PROMs scores were iHOT-12 (24.9 vs 34.5, p = 0.13), HAGOS subscales (symptoms 38.2 vs 54.5, p = 0.05; pain 36 vs 53, p = 0.04; sport 14.1 vs 35.1, p = 0.03; daily activity 31 vs 47.5, p = 0.04; physical activity 21.8 vs 24, p = 0.76; quality of life 24 vs 35, p = 0.03), EQ-VAS (57.9 vs 58, p = 0.08), EQ-5D (0.34 vs 0.13, p = 0.07) and VAS for overall hip function (43.1 vs 46.2, p = 0.14). In total, 10 out of the 12 patients (83%) were satisfied with the intervention. CONCLUSION: Patients undergoing surgery for iliopsoas impingement after previous THA showed improved self-reported hip function where most patients were satisfied with treatment.

Sports activity and quality of life improve after isolated ACL, isolated PCL, and combined ACL/PCL reconstruction.

PURPOSE: To compare patient-reported outcomes following isolated anterior cruciate ligament reconstruction (ACL-R), isolated posterior cruciate ligament reconstruction (PCL-R), and combined ACL-R and PCL-R (ACL/PCL-R), at a minimum follow-up of 2 years. METHODS: This was a prospective observational registry cohort study based on the Swedish National Knee Ligament Registry. Patients undergoing isolated ACL-R, isolated PCL-R, and combined ACL/PCL-R between 2005 and 2019 were eligible for inclusion. Demographic characteristics as well as injury- and surgery-related data were queried from the SNKLR. To evaluate functional outcomes, the Knee Injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and at 1- and 2-year follow-ups and compared between the treatment groups. RESULTS: In total, 45,169 patients underwent isolated ACL-R, 192 patients isolated PCL-R, and 203 patients combined ACL/PCL-R. Preoperatively, and at the 1- and 2-year follow-ups, KOOS subscales were highest for the isolated ACL-R group, followed by the isolated PCL-R, and lowest for the combined ACL/PCL-R groups. Significant improvements were observed across all treatment groups in the majority of KOOS subscales between the preoperative, and 1- and 2-year follow-ups. All treatment groups showed the greatest improvements between the preoperative and 2-year follow-ups in the knee-related quality of life (mean improvement: isolated ACL-R, + 28 points; isolated PCL-R, + 23 points; combined ACL/PCL-R, + 21 points) and the function in sport and recreation (mean improvement: isolated ACL-R, + 26 points; isolated PCL-R, + 20 points; combined ACL/PCL-R, + 19 points) subscales. CONCLUSION: Clinically relevant improvements in knee function can be expected after isolated ACL-R, isolated PCL-R, and combined ACL/PCL-R. Functional improvements were particularly pronounced in the KOOS function in sport and recreation subscale, indicating the importance of knee stability for sports activity. This study facilitates more comprehensive patient education about functional expectations after surgical treatment of isolated and combined ACL and PCL injuries. LEVEL OF EVIDENCE: Level 2.

Different patient and activity-related characteristics result in different injury profiles for patients with anterior cruciate ligament and posterior cruciate ligament injuries.

PURPOSE: To compare patient characteristics including patient sex, age, body mass index (BMI), activities at the time of injury and injury profiles in patients with anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) injuries. METHODS: Data were obtained from the Swedish National Knee Ligament Registry. Two study groups were created: (1) index ACL reconstruction (ACL group) and (2) index PCL reconstruction (PCL group). Between-group differences were investigated using Fisher's exact test and Fisher's non-parametric permutation test for dichotomous variables and continuous variables, respectively. RESULTS: Of 39,010 patients, 38,904 were ACL injuries. A larger proportion of patients with combined injuries to the PCL, meniscus and cartilage were female, aged > 25 years and with a BMI of > 35 kg/m2 compared with patients with combined injuries to the ACL, meniscus and cartilage. An isolated ACL injury was more commonly found in males, while all other injury profiles of ACL, including combined injuries with meniscus, cartilage and collateral ligament injuries, were more frequently observed in females. The PCL injuries were sustained either during pivoting sports, non-pivoting sports or were traffic-related. CONCLUSION: Different patient characteristics (BMI, age and sex), and activities at the time of injury (sport- versus traffic-related activities), resulted in distinct injury profiles for the ACL and PCL groups. These findings provide valuable information of the way specific injury patterns of cruciate ligament injuries occur, and subsequently may help clinicians with the diagnostic process of ACL and PCL injuries. LEVEL OF EVIDENCE: III.

Massive foreign body reaction and osteolysis following primary anterior cruciate ligament reconstruction with the ligament augmentation and reconstruction system (LARS): a case report with histopathological and physicochemical analysis.

BACKGROUND: Autologous hamstrings and patellar tendon have historically been considered the gold standard grafts for anterior cruciate ligament reconstruction (ACLR). In the last decades, the utilization of synthetic grafts has re-emerged due to advantageous lack of donor site morbidity and more rapid return to sport. The Ligament Augmentation and Reconstruction System (LARS) has demonstrated to be a valid and safe option for ACLR in the short term. However, recent studies have pointed out the notable frequency of associated complications, including synovitis, mechanical failure, and even chondrolysis requiring joint replacement. CASE PRESENTATION: We report the case of a 23-year-old male who developed a serious foreign body reaction with wide osteolysis of both femoral and tibial tunnels following ACLR with LARS. During first-stage arthroscopy, we performed a debridement of the pseudocystic mass incorporating the anterior cruciate ligament (ACL) and extending towards the tunnels, which were filled with autologous anterior iliac crest bone graft chips. Histological analysis revealed the presence of chronic inflammation, fibrosis, and foreign body giant cells with synthetic fiber inclusions. Furthermore, physicochemical analysis showed signs of fiber depolymerization, increased crystallinity and formation of lipid peroxidation-derived aldehydes, which indicate mechanical aging and instability of the graft. After 8 months, revision surgery was performed and ACL revision surgery with autologous hamstrings was successfully carried out. CONCLUSIONS: The use of the LARS grafts for ACLR should be cautiously contemplated considering the high risk of complications and early failure.

Lower rate of acceptable knee function in adolescents compared with young adults five years after acl reconstruction: results from the swedish national knee ligament register.

BACKGROUND: The number of studies with a large cohort of patients that primarily focus on patient-reported outcomes after ACL reconstruction in children and adolescents is limited. The purpose of the present study was to determine whether patient age affects the proportion of patients that achieve a patient-acceptable symptom state (PASS) on the Knee injury and Osteoarthritis Outcome Score (KOOS) subscales one, two, five and 10 years after an ACL reconstruction. METHODS: The patient data in the present study were extracted from the Swedish National Knee Ligament Register (SNKLR). Patients aged between five and 35 years that underwent a primary ACL reconstruction between 1 January 2005 and 31 December 2017 and had completed the KOOS questionnaire at the one-, two-, five- or 10-year follow-up were included. A total of 2,848 patients met the inclusion criteria and were included in the study; 47 paediatric patients (females 5-13, males 5-15 years), 522 adolescents (females 14-19, males 16-19 years) and 2,279 young adults (females 20-35, males 20-35 years). The results from the KOOS were presented as the mean and 95% confidence interval (CI) for the mean. For comparisons between groups, the chi-square test was used for non-ordered categorical variables. For pairwise comparisons between groups, Fisher's exact test (2-sided) was used for dichotomous variables. All the statistical analyses was set at 5%. RESULTS: Adolescents reported a significantly lower score than young adults on the KOOS4 at the two- (68.4 vs. 72.1; P < 0.05), five- (69.8 vs. 76.0; P < 0.05) and 10-year follow-ups (69.8 vs. 78.2; P < 0.05). Moreover, a significantly smaller proportion of adolescents achieved a PASS on each of the KOOS subscales when compared with young adults at the five-year follow-up (Symptoms: 83.3% vs. 91.6%; Pain: 42.9% vs. 55.3%; Function in daily living: 31.4% vs. 41.1%; Function in sports and recreational activities: 42.3% vs. 55.7%; Knee-related quality of life: 50.0% vs. 65.0%; P < 0.05). CONCLUSIONS: A significantly smaller proportion of adolescents achieved a PASS on each of the KOOS subscales when compared with young adults five years after ACL reconstruction. The results of the present study provide important information for physicians and physiotherapists treating young patients after an ACL injury and they can aid in providing realistic expectations in terms of the mid- and long-term outcomes. LEVEL OF EVIDENCE: Prospective Observational Register/Cohort Study, Level II.