Subsequent Anterior Cruciate Ligament Reconstruction Research Articles

Influence of Surgeon Experience and Clinic Volume on Subjective Knee Function and Revision Rates in Primary ACL Reconstruction: A Study from the Swedish National Knee Ligament Registry.

Anterior cruciate ligament reconstruction (ACLR) performed by high-volume surgeons/clinics has been associated with increased graft individualization and decreased operating times, complication rates, and total costs. To investigate the influence of surgeon/clinic volume on subjective knee function and revision surgery rates at 2 years after primary ACLR. Cohort study; Level of evidence, 3. Data from the Swedish National Knee Ligament Registry were used to study patients who underwent primary ACLR between 2008 and 2019. Surgeons/clinics were categorized based on a combination of total caseload volume (cutoff: 50 ACLRs/surgeon, 500 ACLRs/clinic) and annual volume (cutoff: 29 ACLRs/year/surgeon, 56 ACLRs/year/clinic). The thresholds of minimal important change (MIC), Patient Acceptable Symptom State (PASS), and treatment failure (TF) relative to the Knee injury and Osteoarthritis Outcome Score (KOOS) and KOOS4 (mean score of the KOOS Pain, Symptoms, Sports/Rec, and QoL subscales) were applied. Adjusted multivariable logistic regression was performed to assess variables influencing the MIC, PASS, or TF of the KOOS and KOOS4. Adjusted Cox regression analysis was conducted to determine the hazard ratio of subsequent ACLR. Of 35,371 patients, 16,317 had 2-year follow-up outcome data and were included. Patients who underwent primary ACLR by high-volume surgeons had significantly higher MIC and PASS rates and lower TF rates when compared with patients who underwent the procedure by low-volume surgeons: MICKOOS4: 70.6% vs 66.3%; PASSKOOS4: 46.0% versus 38.3%; and TFKOOS4: 8.7% versus 11.8% (all P < .02). Significantly decreased odds of achieving MICKOOS4 (OR, 0.74; 95% CI, 0.62-0.88) and PASSKOOS4 (OR, 0.71; 95% CI, 0.60-0.84) were found for ACLRs performed by low-volume surgeons. Clinic volume did not influence the odds of reaching MIC, PASS, or TF. Overall, 804 patients (2.3%) underwent subsequent ACLR at <2 years, with significantly higher revision rates among patients operated on at high-volume clinics (2.5% vs 1.7%; P < .001). However, in the adjusted Cox regression, surgeon/clinic volume had no influence on subsequent ACLR rates. High-volume surgeons/clinics had decreased time to surgery, operating time, perioperative complication rates, and use of thromboprophylaxis and nonroutine antibiotics (P < .001). Patients who underwent primary ACLR by high-volume surgeons experienced increased improvement and satisfaction regarding subjective knee function. Factors other than surgical volume influenced subsequent surgery rates. Patients might benefit from undergoing primary ACLR by high-volume providers.

Unsupervised Machine Learning of the Combined Danish and Norwegian Knee Ligament Registers: Identification of 5 Distinct Patient Groups With Differing ACL Revision Rates

Background: Most clinical machine learning applications use a supervised learning approach using labeled variables. In contrast, unsupervised learning enables pattern detection without a prespecified outcome. Purpose/Hypothesis: The purpose of this study was to apply unsupervised learning to the combined Danish and Norwegian knee ligament register (KLR) with the goal of detecting distinct subgroups. It was hypothesized that resulting groups would have differing rates of subsequent anterior cruciate ligament reconstruction (ACLR) revision. Study Design: Cohort study; Level of evidence, 3. Methods: K-prototypes clustering was performed on the complete case KLR data. After performing the unsupervised learning analysis, the authors defined clinically relevant characteristics of each cluster using variable summaries, surgeons’ domain knowledge, and Shapley Additive exPlanations analysis. Results: Five clusters were identified. Cluster 1 (revision rate, 9.9%) patients were young (mean age, 22 years; SD, 6 years), received hamstring tendon (HT) autograft (91%), and had lower baseline Knee injury and Osteoarthritis Outcome Score (KOOS) Sport and Recreation (Sports) scores (mean, 25.0; SD, 15.6). Cluster 2 (revision rate, 6.9%) patients received HT autograft (89%) and had higher baseline KOOS Sports scores (mean, 67.2; SD, 16.5). Cluster 3 (revision rate, 4.7%) patients received bone–patellar tendon–bone (BPTB) or quadriceps tendon (QT) autograft (94%) and had higher baseline KOOS Sports scores (mean, 65.8; SD, 16.4). Cluster 4 (revision rate, 4.1%) patients received BPTB or QT autograft (88%) and had low baseline KOOS Sports scores (mean, 20.5; SD, 14.0). Cluster 5 (revision rate, 3.1%) patients were older (mean age, 42 years; SD, 7 years), received HT autograft (89%), and had low baseline KOOS Sports scores (mean, 23.4; SD, 17.6). Conclusion: Unsupervised learning identified 5 distinct KLR patient subgroups and each grouping was associated with a unique ACLR revision rate. Patients can be approximately classified into 1 of the 5 clusters based on only 3 variables: age, graft choice (HT, BPTB, or QT autograft), and preoperative KOOS Sports subscale score. If externally validated, the resulting groupings may enable quick risk stratification for future patients undergoing ACLR in the clinical setting. Patients in cluster 1 are considered high risk (9.9%), cluster 2 patients medium risk (6.9%), and patients in clusters 3 to 5 low risk (3.1%-4.7%) for revision ACLR.

Association of Emergency Department Evaluation With Public Insurance Use and Treatment Delays for ACL Injury.

Utilization of an emergency department (ED) visit for anterior cruciate ligament (ACL) injury is associated with high cost and diagnostic unreliability. Patients initially evaluated at an ED for an ACL injury would be more likely to be from a lower income quartile, use public insurance, and experience a delay in treatment. Cohort study; Level of evidence, 3. Patients in the Rhode Island All Payers Claims Database who underwent ACL reconstruction (ACLR) between 2012 and 2021 were identified using the Current Procedure Terminology (CPT) code 29888. Patients were stratified into 2 cohorts based on CPT codes for ED or in-office services within 1 year of ACLR. A chi-square analysis was used to test for differences between cohorts in patient and surgical characteristics. Multivariable linear and logistic regression were used to determine how ED evaluation affected timing and outcome variables. While adjusting for patient and operative characteristics, patients in the ED cohort were more likely to have Medicaid (29% vs 12.5%; P < .001) and be in the lowest income quartile (44.6% vs 32.1%; P < .001). ED visit and Medicaid status were associated with increased time to (1) diagnostic magnetic resonance imaging, adding 7.97 days on average (95% CI, 4.14-11.79 days; P < .001) and 8.40 days (95% CI, 3.44-13.37 days; P = .001), respectively; and (2) surgery, adding 20.30 days (95% CI, 14.10-26.49 days; P < .001) and 12.88 days (95% CI, 5.15-20.60 days; P = .001), respectively. Patients >40 years who were evaluated in the ED were 2.5 times more likely to require subsequent ACLR (odds ratio, 2.50 [95% CI, 1.01-6.21]; P = .049). In this study, patients who visited the ED within 1 year before ACLR were more likely to have a lower income, public insurance, increased time to diagnostic imaging, and increased time to surgery, as well as decreased postoperative physical therapy use and increased subsequent ACLR rates in the 40-49 years age-group.

Influence of Posterior Tibial Slope on the Risk of Recurrence After Anterior Cruciate Ligament Reconstruction

Background. Anterior cruciate ligament (ACL) graft rupture has multifactorial causes, with traumatic factors being the most prevalent. Modern literature presents conflicting data regarding the influence of the posterior tibial slope on the risk of traumatic ACL graft rupture.&#x0D; Aim of the study to determine if there is a correlation between the posterior tibial slope and ACL graft injury in patients who have previously undergone ACL reconstruction.&#x0D; Methods. This was a single-center cohort retrospective study that included patients diagnosed with a complete ACL rupture and who had undergone ACL reconstruction using standard techniques without graft rupture at the last follow-up. Inclusion criteria for the first group included a diagnosis of traumatic ACL rupture followed by reconstruction, a graft composed of semitendinosus and gracilis tendons (St+Gr), femoral fixation with a cortical button, tibial fixation with a sleeve and screw, and the absence of graft rupture at the time of the study. This group included 30 consecutive patients (15 males and 15 females) with a mean age of 36.3 years (min 17, max 59). Inclusion criteria for the second group included an indirect traumatic mechanism of ACL graft rupture and subsequent revision ACL reconstruction. This group consisted of 33 patients (23 males and 10 females) with a mean age of 33.0 years (min 19, max 60). The lateral (LPTS) and medial (MPTS) posterior tibial slopes were measured on lateral knee radiographs.&#x0D; Results. The median time from surgery to the last follow-up in the first group was 65 months (IQR 60; 66), while in the second group, it was 48 months (IQR 9; 84). The median MPTS in the first group was 7.8 (IQR 5.3; 9.4), while in the second group, it was 8.5 (IQR 7.5; 11). The median LPTS in the first group was 9.9 (IQR 8.4; 12.1), whereas in the second group, it was 12.0 (IQR 9; 15.4). There was no statistically significant difference in MPTS and LPTS based on gender in both groups and the entire sample (p0.05). When comparing LPTS values between both groups, a statistically significant difference (p = 0.04) was found, with higher LPTS values in patients in the second group (with ACL graft injury).&#x0D; Conclusion. Increased posterior tibial slope, particularly LPTS, is identified as a potential predictor of ACL graft rupture. The study demonstrates the impact of LPTS on the risk of ACL graft rupture (p0.05) in cases of indirect traumatic injury.

Previous Isolated Medial Bucket-Handle Meniscus Repair Significantly Increases Risk of Subsequent Ipsilateral Anterior Cruciate Ligament Reconstruction

(1) To define the incidence of surgically treated isolated bucket-handle meniscus tears (BHMTs); (2) to investigate risk of subsequent ipsilateral anterior cruciate ligament reconstruction (ACLR) in patients who underwent previous isolated bucket handle (BH) meniscus repair; and (3) to investigate the risk of subsequent ACLR for various types of surgically treated meniscal tears. A retrospective review of a national database was conducted to identify patients, aged 10 to 40 years, who underwent primary isolated BH meniscus surgery from 2015 to 2020. Patients were stratified by operative method. A control group of 500,000 age-matched patients was randomly selected to establish a benchmark rate of ACLR. Kaplan-Meier analysis was performed to compare the timing and incidence of subsequent ipsilateral ACLR after primary isolated BH meniscus surgery to the control group within 2 and 5 years. In total, 1,767 patients with isolated BHMTs treated with surgery were identified and met inclusion criteria. The incidence of isolated BHMTs among all surgically treated (repair or meniscectomy) meniscal injuries was 1.67%. Isolated BH repairs had significantly greater odds of ACLR within 5 years compared to the control group (odds ratio [OR] 6.09; 95% confidence interval [CI] 2.86-12.99; P < .001). Medial BH repairs had the greatest odds of ACLR within 5 years (OR 9.15; 95% CI 4.27-19.57; P < .001). Lateral BH repair was not associated with subsequent ipsilateral ACLR within 5 years (OR 2.63; CI 0.37-18.90; P= .340). Isolated BHMTs comprised 1.67% of all surgically treated meniscal injuries. Patients who underwent prior surgery for isolated BHMT were at increased risk of undergoing subsequent ipsilateral ACLR compared with the general population. Isolated medial BHMTs treated with repair had the highest risk for subsequent ACLR. Level III, retrospective cohort study.

Delayed ACL reconstruction increases rates of concomitant procedures and risk of subsequent surgery.

To utilise a large cross-sectional database to analyse the effects of time duration between diagnosis of anterior cruciate ligament (ACL) tear and ACL reconstruction (ACLR) on concomitant procedures performed and subsequent surgery within 2years. An analysis from 2015 to 2018 was performed using the Mariner PearlDiver Patient Records Database. Current Procedural Terminology (CPT), and International Classification of Diseases (ICD-10) codes identified patients with a diagnosis of ACL tear who underwent subsequent ACLR. Patients were stratified in biweekly and bimonthly increments based on the time duration between initial diagnosis of ACL tear and surgical treatment. Chi-squared analysis was used to compare categorical variables, and trend analysis was performed with Cochran-Armitage independence testing. Of 11,867 patients who underwent ACLR, 76.1% underwent surgery within 2months of injury diagnosis. Patients aged 10-19 were most likely to undergo surgery within 2months of injury diagnosis (83.5%, P < 0.0001). As duration from injury diagnosis to ACLR increased from < 2months to > 6months, rates of concomitant meniscectomy increased from 9.1% to 20.5% (P < 0.0001). The overall 2-year subsequent surgery rate was 5.3%. The incidence of revision ACLR was highest for patients who underwent surgery > 6months after diagnosis (P < 0.0001), whilst the incidence of ipsilateral lysis of adhesions and manipulation under anaesthesia (MUA) was highest for patients who underwent surgery < 2months after diagnosis (P < 0.0001). ACLR at 6-8weeks after diagnosis demonstrated the lowest risk for concomitant procedures as well as 2-year subsequent surgery. The majority of patients undergo ACL reconstruction within 2months of initial ACL tear diagnosis. Delayed surgery greater than 6months after the diagnosis of an ACL rupture leads to increased need for concomitant meniscectomy as well as higher risk for revision ACLR within 2years, but immediate surgery may increase risk for knee arthrofibrosis. IV.

Repeat Anterior Cruciate Ligament Injury and Return to Sport in Australian Soccer Players After Anterior Cruciate Ligament Reconstruction With Hamstring Tendon Autograft

Background: Soccer is the most commonly played team sport in the world and a high-risk sport for anterior cruciate ligament (ACL) injury and subsequent ACL reconstruction (ACLR). Purpose: To assess the rate of further ACL injury in patients who have undergone ACLR with hamstring tendon autograft after soccer injuries in Australia and to determine factors associated with repeat ACL injury and return to soccer. Study Design: Case-control study; Level of evidence, 3. Methods: From a prospectively collected database, a series of 1000 consecutive ACLRs using hamstring autografts performed in soccer players were identified. Patients were surveyed at a minimum 5 years after reconstruction, including details of further ACL injuries to either knee, return to soccer or other sports, and psychological readiness per the Anterior Cruciate Ligament Return to Sport after Injury (ACL-RSI) scale. Results: Of the 862 participants reviewed, ACL graft rupture occurred in 85 (10%) and contralateral ACL rupture in 68 (8%) within 5 years after the reconstruction. The 5-year ACL graft survivorship was 94% for females and 88% for males. The survivorship of the contralateral ACL was 92% for males and 90% for females. When compared with those aged >25 years, the odds of ACL graft rupture was increased by 4 to 5 times in those aged 19 to 25 years and 3 to 7 times in those ≤18 years. Further ACL injury to the graft or contralateral knee occurred in 44% of males aged ≤18 years. Risk factors for further ACL injury were younger age at time of surgery, male sex, and return to soccer. Graft diameter did not influence ACL graft rupture rates, and 70% of patients returned to soccer after ACLR. The mean ACL-RSI score was 59, and patients who reported more fear of reinjury on this scale were less likely to have returned to soccer. Conclusion: The prevalence of ACL graft rupture (10%) and contralateral ACL rupture (8%) was near equivalent over 5 years in this large cohort of mostly recreational Australian soccer players. ACLR with hamstring autograft is a reliable procedure, allowing 70% of patients to return to soccer in this high-risk population. Risk factors for further ACL injury are progressively younger age at time of surgery, male sex, and return to soccer. Graft diameter was not a factor in ACL graft rupture, indicating that other factors, particularly age, are of primary importance.

Anterior cruciate ligament tear increases the risk of venous thromboembolism: a population-based cohort study.

Previous studies highlighted an increased risk of venous thromboembolism (VTE) among patients with anterior cruciate ligament reconstruction (ACLR); however, the risk for those with ACL tear but without undergoing ACLR has not been reported yet. The aim of this study was to evaluate the risk of VTE among ACL tear individuals with or without ACLR derived from the general population. A cohort study was conducted using data from the IQVIA Medical Research Database of the United Kingdom. Up to five non-ACL tear individuals (n = 22,235) were matched to each case of ACL tear (n = 4474) by age, sex, body mass index and entry-time. The relation of ACL tear to VTE [pulmonary embolism (PE) and deep vein thrombosis (DVT)] was examined using a multivariable Cox proportional hazard model. A sub-cohort analysis, in which the ACL tear individuals were stratified into those with ACLR and those without ACLR, was also conducted. VTE developed in 13 individuals with ACL tear and nine individuals without ACL tear (incidence rates: 3.1 vs. 0.4/1000 person-years), with multivariable-adjusted hazard ratio (HR) being 6.59 (95% CI 2.28-19.08) in 1-year follow-up. For ACL tear individuals with ACLR, the HR was 11.44 (95% CI 2.71-48.28), and for those without ACLR, the HR was 6.02 (95% CI 1.44-24.25), compared with individuals without ACL tear. This large-sample population-based cohort study provides the first evidence on an increased risk of VTE in ACL tear individuals regardless of subsequent ACLR, which supports the necessity for monitoring venous-thromboembolic complications in the target population, including those without ACLR. III.

Return to play in paediatric & adolescent patients following anterior cruciate ligament reconstruction

BackgroundThere is an increased risk of anterior cruciate ligament (ACL) rupture and subsequent ACL reconstruction in patients <18 years old due to their high levels of sporting participation. PurposeThe purpose of this study was to assess the rate and timing of return to play (RTP) in paediatric and adolescent patients following ACL reconstruction, and to compare the outcomes between those undergoing ACL reconstruction with bone patella tendon bone autograft (BTB) and hamstring tendon (HT) autograft. Study DesignLevel of Evidence: Level III; Retrospective Comparative Cohort Study. MethodsThe institutional ACL registry was screened for patients <18 that had undergone a primary ACL reconstruction. Outcomes were analysed for patients undergoing either a BTB or HT autograft for rate and timing of return to play, functional outcomes and subsequent knee injuries. Statistical analysis was performed using SPSS. Results358 (BTB; 253, HT; 105) patients were followed up for 24-months (95% follow up). 86 athletes (27 BTB; 59 HT) were aged 13–15 years old with no significant difference in RTP rate or timing between graft types, however, there was a difference in ipsilateral re-ruptures (10.2% HT vs 0% BTB p = 0.03). 272 athletes (226 BTB; 46 HT) were aged 16–18 years old with no significant difference in RTP rate or timing between graft types, or ipsilateral re-ruptures (8.7% HT vs 2.7% BTB p = 0.07). Concurrent ligament, meniscal or chondral injuries found at the time was treated as necessary. ConclusionPaediatric and adolescent patients undergoing ACL reconstruction with either BTB or HT had high rates of return to play. This was seen in both subgroups with 13–15-year-olds mostly receiving a HT graft repair and 16–18-year-olds mainly receiving a BTB repair. A moderate re-rupture rate was seen at 24-months. However longer follow up is needed to truly see the long-term impact of such an injury at such a young age.

Superior Outcome of Early ACL Reconstruction versus Initial Non-reconstructive Treatment With Late Crossover to Surgery: A Study From the Swedish National Knee Ligament Registry

Background: Although comparable clinical and functional outcomes have been reported after nonsurgical and surgical anterior cruciate ligament (ACL) treatment, few studies have investigated the effects of early versus late ACL reconstruction with initial rehabilitation. Purpose: To determine patient-reported knee function in patients who initially undergo nonreconstructive treatment after an ACL injury but who later choose to undergo ACL reconstruction as compared with (1) patients undergoing ACL reconstruction close to the index injury and (2) patients treated nonreconstructively at 1 to 10 years of follow-up. Study Design: Cohort study; Level of evidence, 2. Methods: Results from the Knee injury and Osteoarthritis Outcome Score (KOOS) were extracted from the Swedish National Knee Ligament Registry for patients treated with nonreconstruction, early ACL reconstruction, and initial nonreconstruction but subsequent ACL reconstruction (crossover group). The KOOS4 (a mean of 4 KOOS subscales) was analyzed cross-sectionally at baseline and at the 1-, 2-, 5-, and 10-year follow-ups. Additionally, the Patient Acceptable Symptom State (PASS) was applied to all KOOS subscales from baseline to the 10-year follow-up. Results: A total of 1,074 crossover, 484 nonreconstruction, and 20,352 early ACL reconstruction cases were included. The crossover group reported lower KOOS4 values than the group undergoing early ACL reconstruction at baseline and at all follow-ups (mean difference [95% CI]): baseline, −6.5 (−8.0 to −5.0); 1 year, −9.3 (−10.9 to −7.7); 2 years, −4.8 (−6.3 to −3.2); 5 years, −6.1 (−8.8 to −3.4); and 10 years, −10.9 (−16.3 to −5.2). Additionally, a smaller proportion of the crossover cohort achieved a PASS on KOOS subscales at baseline and through the 1-, 2-, 5-, and 10-year follow-ups as compared with the early ACL reconstruction cohort. No differences were observed between crossover and nonreconstruction cases on either the KOOS4 or the PASS at any follow-up. Conclusion: A greater proportion of patients treated with early ACL reconstruction reported acceptable knee function and superior overall knee function as compared with patients who decided to cross over from nonreconstructive treatment to ACL reconstruction.

Do Patient Demographic and Socioeconomic Factors Influence Surgical Treatment Rates After ACL Injury?

Anterior cruciate ligament (ACL) injuries may be managed nonoperatively in certain patients and injury patterns; however, complete ACL ruptures are commonly reconstructed to restore anterior and lateral rotatory stability of the knee. While ACL reconstruction is well-studied, the literature is sparse with regard to which socioeconomic patient factors are associated with patients undergoing ACL reconstruction rather than nonoperative management after diagnosis of an ACL injury. The current study seeks to evaluate this relationship between patient demographics as well as socioeconomic factors and the rate of surgery following ACL injuries. Patients ≤65 years of age with a primary ACL injury between 2011 and 2018 were retrospectively identified in the New York Statewide Planning and Research Cooperative System database. International Classification of Disease 9/10 and Current Procedural Terminology codes were used to identify these patients and their subsequent ACL reconstructions. Logistic regression was performed to determine the effect of patient factors on the likelihood of having surgery after the diagnosis of an ACL injury. Compared to White patients, African American patients were significantly less likely to undergo ACL reconstruction following an ACL injury (OR=0.65, 95% CI, 0.573-0.726). Patients older than 35 had decreased odds of undergoing ACL reconstruction compared to younger patients, with patients 55-64 having the lowest odds (OR=0.166, 95% CI, 0.136-0.203). Patients with Medicaid (OR=0.84, 95% CI, 0.757-0.933) or self-pay insurance (OR=0.67, 95% CI, 0.565-0.793), and those with worker's compensation (OR=0.715, 95% CI, 0.621-0.823) had decreased odds of undergoing ACL reconstruction relative to patients with private insurance. Patients with higher Social Deprivation Index (SDI) were significantly more likely to be treated nonoperatively after ACL injuries compared to those with lower SDI (mean nonoperative SDI score, 61, operative SDI, 56, P<0.0001). In patients with ACL injuries, there are socioeconomic and patient-related factors that are associated with increased odds of undergoing ACL reconstruction. These factors are important to recognize as they represent a source of potential inequality in access to care and an area with potential for improvement.

A Multi-Systems Approach to Human Movement after ACL Reconstruction: The Musculoskeletal System.

Several negative adaptations to the musculoskeletal system occur following anterior cruciate ligament (ACL) injury and ACL reconstruction (ACLR) such as arthrogenic muscle inhibition, decreased lower extremity muscle size, strength, power, as well as alterations to bone and cartilage. These changes have been associated with worse functional outcomes, altered biomechanics, and increased risk for re-injury and post-traumatic osteoarthritis. After ACL injury and subsequent ACLR, examination and evaluation of the musculoskeletal system is paramount to guiding clinical decision making during the rehabilitation and the return to sport process. The lack of access many clinicians have to devices necessary for gold standard assessment of muscle capacities and force profiles is often perceived as a significant barrier to best practices. Fortunately, testing for deficits can be accomplished with methods available to the clinician without access to costly equipment or time-intensive procedures. Interventions to address musculoskeletal system deficits can be implemented with a periodized program. This allows for restoration of physical capacities by adequately developing and emphasizing physical qualities beginning with mobility and movement, and progressing to work capacity and neuromuscular re-education, strength, explosive strength, and elastic or reactive strength. Additional considerations to aid in addressing strength deficits will be discussed such as neuromuscular electrical stimulation, volume and intensity, eccentric training, training to failure, cross-education, and biomechanical considerations. The American Physical Therapy Association adopted a new vision statement in 2013 which supported further development of the profession’s identity by promoting the movement system, yet validation of the movement system has remained a challenge. Application of a multi-physiologic systems approach may offer a unique understanding of the musculoskeletal system and its integration with other body systems after ACLR. The purpose of this clinical commentary is to highlight important musculoskeletal system considerations within a multi-physiologic system approach to human movement following ACLR.Level of Evidence5

Patients Aged 50 Years and Older Have Greater Complication Rates After Anterior Cruciate Ligament Reconstruction: A Large Database Study

PurposeTo assess the use of anterior cruciate ligament (ACL) reconstruction in older adults and to compare postoperative complication and revision surgery rates between patients older than and younger than 50 years old.MethodsRetrospective data were obtained using the PearlDiver database for patients who underwent arthroscopic ACL reconstruction from January 2010 to December 2017. Trends in the annual performance of ACL reconstruction were determined using nonparametric test of trends of ranks. Patients in each age group were matched based on sex and the Charlson Comorbidity Index. The incidence of postoperative complications within 90 days and subsequent knee surgery within 2 years of ACL reconstruction was collected. Postoperative complication rates were compared between matched age groups using the χ2 test.ResultsA total of 20,993 patients aged 50 years and older and 154,817 patients younger than 50 years underwent ACL reconstruction between 2010 and 2017. The use of ACL reconstruction in patients aged 50 years or older decreased over time (P = .044). Patients aged 50 years or older were more likely to experience at least 1 postoperative complication within 90 days compared to patients younger than 50 years (2.5% vs 2.1%, P = .007). Older patients were 1.3 times as likely to experience deep vein thrombosis (P = .002) and 1.8 times as likely to experience pulmonary embolism (P < .001). Younger patients were more likely to undergo subsequent ACL reconstruction and experience knee pain, stiffness, and wound infection postoperatively (P < .001, P < .001, P = .041). 1.6% of patients aged 50 years or older underwent total knee arthroplasty within 2 years.ConclusionsACL reconstruction in patients aged 50 years or older is associated with greater complication rates but lower rates of subsequent knee surgery relative to patients younger than 50 years of age. Younger patients were more prone to surgical complications whereas older patients experienced more medical complications. The increased incidence of VTE in this population suggests that thrombotic prophylaxis may be considered.Level of EvidenceLevel III, retrospective comparative observational trial.

Pediatric Tibial Spine Fractures: Exploring Case Burden by Age and Sex.

Background:Pediatric tibial spine fractures (TSFs) are a well-known clinical entity, but the epidemiology of these injuries is not fully understood. Further, there are limited data on outcomes after TSF treatment, specifically the proportion of patients requiring subsequent anterior cruciate ligament (ACL) reconstruction.Purpose:To describe the distribution of TSF case burden by age and sex and to determine the proportion of patients undergoing subsequent ACL reconstruction or developing ACL insufficiency.Study Design:Descriptive epidemiology study.Methods:The Truven Health MarketScan database was queried to identify patients aged 7 to 18 years with TSFs between 2016 and 2018. Diagnosis and initial treatment (surgical vs nonoperative) were recorded based on database coding. Case burden by age and sex was calculated. The database, which includes longitudinal data, was then queried for subsequent diagnoses of ACL insufficiency as well as subsequent ACL reconstruction procedures performed among the patients.Results:We found 876 cases of TSF, 71.3% of which were treated nonoperatively. The male to female ratio for case burden was 2.2:1. Cases peaked at age 13 to 14 years for boys and age 11 to 12 years for girls. Of all cases identified, 3.7% also had either a diagnosis code for ACL laxity entered in a delayed fashion into the database or a later procedure code for ACL reconstruction (considered together to represent “subsequent ACL insufficiency”). Only 15 subsequent ACL reconstructions (1.7% of cases) were found, all of which were among boys and 9 of which were among boys aged 13 to 14 years.Conclusion:This longitudinal study is the largest epidemiological analysis of pediatric TSFs to date. We found low rates of subsequent ACL insufficiency and ACL reconstruction, with boys aged 13 to 14 years accounting for most of those cases. Rates of subsequent ACL reconstruction were lower than previously reported. Boys accounted for more than two times as many TSF cases as girls.

Occurrence of inadequate ACL healing after Dynamic Intraligamentary Stabilization and functional outcome—a multicentre case series

IntroductionDynamic Intraligamentary Stabilization (DIS) is a technique for preservation, anatomical repair and stabilization of a freshly injured anterior cruciate ligament (ACL). The main purpose of this study was to evaluate the short-term re-operation rate when compared to traditional autograft reconstruction.MethodsFour, from the developer independent, centres enrolled patients that underwent ACL repair by DIS, according to the specific indications given by MRI imaging at a minimum follow-up of 12 months. The re-operation rate was recorded as primary outcome. Secondary outcome measures were the postoperative antero-posterior knee laxity (using a portable Rolimeter®), as well as the Tegner, Lysholm and IKDC Scores.ResultsA total of 105 patients were investigated with a median follow-up of 21 months. Thirteen patients were lost to follow-up. Of the remaining 92 patients 15 (16.3%) had insufficient functional stability and required subsequent ACL reconstruction. These patients were excluded from further analysis, leaving 77 consecutive patients for a 12 months follow-up. The median age at time of surgery was 30 years for that group. At time of follow-up a median antero-posterior translation difference of 2 mm was measured. None of these patients reported subjective insufficiency (giving way), but in 14 patients (18.2%), the difference of antero-posterior translation was more than 3 mm. We found a median Tegner Score of 5.5, a median Lysholm Score of 95.0 and a median IKDC Score of 89.4.ConclusionThe main finding of this multicentre study is a relevant re-operation rate of 16.3%. Another 18.2% showed objective antero-posterior laxity (≥ 3 mm) during testing raising the suspicion of postoperative non-healing. The failure rate of DIS in this study is higher than for reconstruction with an autologous tendon graft. However, our successfully treated patients had a good clinical and functional outcome based on antero-posterior knee laxity and clinical scores, comparable to patients treated by autograft reconstruction.

Low annual hospital volume of anterior cruciate ligament reconstruction is not associated with higher revision rates.

Surgery performed in low-volume centres has been associated with longer operating time, longer hospital stays, lower functional outcomes, and higher rates of revision surgery, complications and mortality. This has been reported consistently in the arthroplasty literature, but there is a paucity of data regarding the relationship between surgical volume and outcome following anterior cruciate ligament (ACL) reconstruction. The purpose was to compare ACL reconstruction failure rates between hospitals performing different annual surgical volumes. All patients from the Norwegian Knee Ligament Register having primary autograft ACL reconstruction between 2004 and 2016 were included. Hospital volume was divided into quintiles based on the number of ACL reconstructions performed annually, defined arbitrarily as: 1-12 (V1), 13-24 (V2), 25-49 (V3), 50-99 (V4) and ≥ 100 (V5) annual procedures. Kaplan-Meier estimated survival curves and survival percentages were calculated with revision ACL reconstruction as the end point. Secondary outcome measures included (1) mean change in Knee Injury and Osteoarthritis Outcome Score (KOOS) Quality of Life (QoL) and Sport subsections from pre-operative to 5-year follow-up and (2) subjective failure defined as KOOS QoL < 44. Twenty thousand eight hundred and fifty patients met the inclusion criteria and 1195 (5.7%) underwent subsequent revision ACL reconstruction over the study period. Revision rates were lower in the lower volume hospitals compared with the higher volume hospitals (p < 0.001). There was no clinically significant difference in improvement between pre-operative and 5-year follow-up KOOS scores between hospital volume categories, but a higher proportion of patients having surgery at lower volume hospitals reported a subjective failure. Patients in the lower volume categories (V1-3) were more often male and older compared to the higher volume hospitals (V4-5). Concomitant meniscal injuries and participation in pivoting sports were most common in V5 compared with V1 (p < 0.001). Median operative time decreased as hospital volume increased, ranging from 90min at V1 hospitals to 56min at V5 hospitals (p < 0.001). Patients having ACL reconstruction at lower volume hospitals had a lower rate of subsequent revision surgery relative to higher volume hospitals. However, complications occurred more frequently, operative duration was longer, and the number of patients reporting a subjective failure of ACL reconstruction was highest at these lower volume hospitals. Level III.

Has platelet-rich plasma any role in partial tears of the anterior cruciate ligament? Prospective comparative study.

BACKGROUNDPartial tears of the anterior cruciate ligament (ACL) are frequent, and there is still considerable controversy surrounding their diagnosis, natural history and treatment. AIMTo examine patient-reported outcomes, physical examination and magnetic resonance imaging (MRI) findings of partial ACL tears treated with an intraarticular injection of platelet-rich plasma (PRP) compared to a control group. METHODSFrom January 2015 to November 2017, consecutive patients from a single institution with partial ACL tears treated nonoperatively were prospectively evaluated. Partial tears were defined as a positive Lachman test with a clear end-point, a negative pivot-shift and less than 3 mm of side-to-side difference using the KT1000 arthrometer. Patients in group 1 were treated with one intraarticular injection of PRP and specific physical therapy protocol. Control group consisted of patients treated only with physical therapy. Prospective analyzed data included physical examination, Tegner activity level and Lysholm and International Knee Documentation Committee scores. Baseline MRI findings and at 6 mo follow-up were reviewed. Failure was defined as those patients with clinical instability at follow-up that required a subsequent ACL reconstruction. RESULTSA total of 40 patients where included, 21 treated with PRP injection with a mean follow-up of 25 mo [standard deviation (SD): 3.6] and 19 in the control group with a mean follow-up of 25 mo (SD: 5.68). Overall failure rate was 32.0% (n = 13). No significant differences were observed between groups regarding subjective outcomes, return to sport and failure rate. MRI findings revealed an improvement in the ACL signal in half of the patients of both groups. However, we did not find a significant relationship between MRI findings and clinical outcomes.CONCLUSIONOverall, 95.0% of patients returned to sports at a mean follow-up of 25 mo. Mean time to return to sports was 4 mo. Out of these patients, almost 30.0% in each group had a new episode of instability and required surgery at a median time of 5 mo in group 1 and 8 mo in group 2. The addition of PRP alone was not sufficient to enhance any of the outcome measures evaluated, including MRI images, clinical evaluation and failure rate.

Knee laxity and functional knee outcome after contralateral ACLR are comparable to those after primary ACLR

PurposeTo evaluate and compare knee laxity and functional knee outcome between primary and contralateral anterior cruciate ligament (ACL) reconstruction.MethodsPatients who underwent primary and subsequent contralateral ACL reconstruction (ACLR) at Capio Artro Clinic, Stockholm, Sweden, from 2001 to 2017, were identified in our local database. The inclusion criteria were: the same patients who underwent primary and contralateral hamstring tendon or bone-patellar tendon-bone autograft ACLR and no associated ligament injuries. The KT-1000 arthrometer, with an anterior tibial load of 134 N, was used to evaluate knee laxity preoperatively and 6 months postoperatively. The Knee injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and at the 1-year follow-up.ResultsA total of 326 patients with isolated primary and contralateral ACLR met the inclusion criteria (47.9% males; mean age at primary ACLR 23.9 ± 9.4 years and contralateral ACLR 27.9 ± 10.1 years). The arthrometric laxity measurements were available for primary and contralateral ACLR for 226 patients. The mean preoperative and postoperative anterior tibial translation (ATT), as well as the mean ATT reduction from preoperatively to postoperatively, did not differ significantly between primary and contralateral ACLR. The KOOS was available for primary and contralateral ACLR for 256 patients. No significant differences were found preoperatively and at the 1-year follow-up between primary and contralateral ACLR for any of the five KOOS subscales.ConclusionThe findings in this study showed that anterior knee laxity and functional knee outcome after contralateral ACLR are comparable to those after primary ACLR. It is important for clinicians to counsel patients about their expectations after contralateral ACLR. This study shows that the results after contralateral ACLR in terms of knee laxity and functional knee outcome are predictable and likely to be comparable to those after primary ACLR.Level of evidenceLevel III.

Higher aggrecan 1-F21 epitope concentration in synovial fluid early after anterior cruciate ligament injury is associated with worse knee cartilage quality assessed by gadolinium enhanced magnetic resonance imaging 20\u2009years later

BackgroundTo investigate if cartilage related biomarkers in synovial fluid are associated with knee cartilage status 20 years after an anterior cruciate ligament (ACL) injury.MethodsWe studied 25 patients with a complete ACL rupture without subsequent ACL reconstruction or radiographic knee OA. All had a delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) 20 years after the ACL injury, using the T1 transverse relaxation time in the presence of gadolinium (T1Gd) which estimates the concentration of glycosaminoglycans in hyaline cartilage. Synovial fluid samples were aspirated acutely (between 0 and 18 days) and during 1 to 5 follow up visits between 0.5 and 7.5 years after injury. We quantified synovial fluid concentrations of aggrecan (epitopes 1-F21 and ARGS), cartilage oligomeric matrix protein, matrix metalloproteinase-3 and tissue inhibitor of metalloproteinase-1 by immunoassays, and sulfated glycosaminoglycans by Alcian blue precipitation. Western blot was used for qualitative analyses of aggrecan fragments in synovial fluid and cartilage samples.ResultsWestern blot indicated that the 1-F21 epitope was located within the chondroitin sulfate 2 region of aggrecan. Linear regression analyses (adjusted for age, sex, body mass index and time between injury and sampling) showed that acute higher synovial fluid 1-F21-aggrecan concentrations were associated with shorter T1Gd values 20 years after injury, i.e. inferior cartilage quality (standardized effects between − 0.67 and − 1.0). No other statistically significant association was found between molecular biomarkers and T1Gd values.ConclusionHigher acute synovial fluid 1-F21-aggrecan concentrations in ACL injured patients, who managed to cope without ACL reconstruction and were without radiographic knee OA, were associated with inferior knee cartilage quality assessed by dGEMRIC 20 years after injury.

Rate of Force Development Remains Reduced in the Knee Flexors 3 to 9 Months After Anterior Cruciate Ligament Reconstruction Using Medial Hamstring Autografts: A Cross-Sectional Study

Background: Anterior cruciate ligament (ACL) rupture is a serious injury with a high prevalence worldwide, and subsequent ACL reconstructions (ACLR) appear to be most commonly performed using hamstring-derived (semitendinosus tendon) autografts. Recovery of maximal muscle strength to ≥90% of the healthy contralateral limb is considered an important criterion for safe return to sports. However, the speed of developing muscular force (ie, the rate of force development [RFD]) is also important for the performance of many types of activities in sports and daily living, yet RFD of the knee extensor and flexor muscles has apparently never been examined in patients who undergo ACLR with hamstring autograft (HA). Purpose: To examine potential deficits in RFD, maximal muscle strength (ie, maximal voluntary isometric contraction [MVIC]), and functional capacity of ACLR-HA limbs in comparison with the healthy contralateral leg and matched healthy controls 3 to 9 months after surgery. Study Design: Cross-sectional study; Level of evidence: 3. Methods: A total of 23 young patients who had undergone ACLR-HA 3 to 9 months earlier were matched by age to 14 healthy controls; both groups underwent neuromuscular screening. Knee extensor and flexor MVIC and RFD, as well as functional capacity (single-leg hop for distance [SLHD] test, timed single-leg sit-to-stand [STS] test), were assessed on both limbs. Furthermore, patient-reported knee function (Knee injury and Osteoarthritis Outcome Score) was assessed. Results: Knee extensor and flexor MVIC and RFD were markedly compromised in ACLR-HA limbs compared with healthy contralateral limbs (MVIC for extensor and flexor, 13% and 26%, respectively; RFD, 14%-17% and 32%-39%) and controls (MVIC, 16% and 31%; RFD, 14%-19% and 30%-41%) (P < .05-.001). Further, ACLR-HA limbs showed reduced functional capacity (reduced SLHD and STS performance) compared with contralateral limbs (SLHD, 11%; STS, 14%) and controls (SLHD, 20%; STS, 31%) (P < .01-.001). Strength (MVIC) and functional (SLHD) parameters were positively related to the duration of time after surgery (P < .05), although this relationship was not observed for RFD and STS. Conclusion: Knee extensor and flexor RFD and maximal strength, as well as functional single-leg performance, remained substantially reduced in ACLR-HA limbs compared with noninjured contralateral limbs and healthy controls 3 to 9 months after reconstructive surgery.