Neel Desai

Patient Predictors of Early Revision Surgery After Anterior Cruciate Ligament Reconstruction A Cohort Study of 16,930 Patients With 2-Year Follow-up

Background: Revision surgery is one of the most important endpoints during follow-up after anterior cruciate ligament (ACL) reconstruction. Purpose: To investigate if commonly known patient factors can predict revision surgery after ACL reconstruction. Study Design: Cohort study; Level of evidence, 2. Methods: This prospective cohort study was based on data from the Swedish National Knee Ligament Register during the period of January 1, 2005, through December 31, 2013. Patients who underwent primary ACL reconstruction with hamstring tendon or bone–patellar tendon–bone autografts were included. Follow-up started on the date of primary ACL reconstruction, and follow-up ended with ACL revision surgery, after 24 months of follow-up, or on December 31, 2013, whichever occurred first. The analyzed patient variables were activity at the time of injury, sex, age, height, weight, body mass index, smoking, and the use of smokeless tobacco. The primary study endpoint was revision surgery, defined as replacement of a primary ACL reconstruction. Relative risk (RR) and 95% CIs were calculated and adjusted for confounding factors using multivariate statistics. Results: A total of 16,930 patients were included (males, n = 9767 [57.7%]; females, n = 7163 [42.3%]). The 2-year revision rate was 1.82% (95% CI, 1.62%-2.02%). There was no significant difference between male and female revision rates (1.74% [95% CI, 1.48%-2.00%] vs 1.93% [95% CI, 1.61%-2.25%], P = .383). In both males and females there was a significantly increased risk of revision surgery associated with soccer playing and adolescence (age 13-19 years) (males: RR = 1.58 [95% CI, 1.12-2.23], P = .009 and RR = 2.67 [95% CI, 1.91-3.73], P < .001, respectively; females: RR = 1.43 [1.01-2.04], P = .045 and RR = 2.25 [95% CI, 1.57-3.24], P < .001, respectively). A combination of these predictors were associated with a further increased risk of revision surgery (males: RR = 2.87 [95% CI, 1.79-4.60], P < .001; females: RR = 2.59 [95% CI, 1.69-3.96], P < .001). Conclusion: Soccer players and adolescents had an increased risk of revision surgery after ACL reconstruction, with a respective factor of 1.5 and 2.5. Individuals with a combination of these 2 predictors carried an almost 3-fold higher risk of revision surgery. There were no significant associations for sex, height, weight, body mass index, or tobacco use.

Level of Evidence in Anterior Cruciate Ligament Reconstruction Research A Systematic Review

Background: There have been numerous studies on anterior cruciate ligament (ACL) reconstruction. Considering the vast number of studies, a quick assessment reveals rather few with a high level of evidence. Purpose: The primary aim was to categorize the study type and level of evidence of studies on primary ACL reconstruction by applying the level of evidence rating system proposed by the Oxford Centre for Evidence-Based Medicine. The secondary aims were to correlate the level of evidence with the impact factor of the journal, to evaluate the level of evidence over time, and to evaluate the geographic distribution of the included studies. Study Design: Systematic review. Methods: An electronic search was performed using the databases PubMed, EMBASE, and Cochrane Library. Studies published from January 1995 to August 2011 were included. Therapeutic studies written in English that report on isolated primary ACL reconstruction with clinical outcome measurements related to the reconstruction were included. Categorization and implementation of the level of evidence were performed. Correlation between the level of evidence and the impact factor of the journal was analyzed together with linear regression models to reveal any significant trends over time. Results: A total of 7154 studies were analyzed, of which 1510 were included. Analysis of the study types revealed that case series (n = 494; 32.7%) was the most frequent study type. Randomized controlled trials represented 9.2% (n = 139) of the sample, whereas meta-analyses were rare. Single-bundle studies were the most common studies (n = 1333; 88.3%), followed by double-bundle (n = 98; 6.5%) and single- versus double-bundle (n = 79; 5.2%). The journals Arthroscopy, Knee Surgery Sports Traumatology Arthroscopy (KSSTA), and American Journal of Sports Medicine (AJSM) represented 43.5% (n = 657) of the included studies. Arthroscopy had the highest number of publications in general and in level 4 and 5 studies, whereas AJSM had the lowest number of the 3. AJSM had the highest number of level 1 and 2 studies in general. The mean level of evidence calculated without level 5 studies was 3.15 for Arthroscopy, 3.20 for KSSTA, and 2.9 for AJSM. There was a significant correlation (P < .05) between the impact factor of the journal and mean level of evidence of the journal and the proportion high level of evidence studies (levels 1 and 2). There was a significant (P < .05) trend toward higher mean level of evidence over time. Conclusion: Most therapeutic studies on primary ACL reconstruction were of low level of evidence, and there was a positive correlation between the journal’s impact factor and the mean level of evidence and the proportion of high level of evidence studies. There was significant trend toward higher mean level of evidence over time.

Predictors of Contralateral Anterior Cruciate Ligament Reconstruction A Cohort Study of 9061 Patients With 5-Year Follow-up

Background: Identifying predictors of contralateral anterior cruciate ligament (ACL) reconstruction is important to focus preventive strategies and related research on high-risk groups. Purpose: To investigate predictors of contralateral ACL reconstruction in patients who have already undergone a primary ipsilateral reconstruction. Study Design: Cohort study; Level of evidence, 2. Methods: This study was based on data from the Swedish National Knee Ligament Register from January 1, 2005, to December 31, 2013. Patients aged 13 to 59 years who underwent primary ipsilateral (index) ACL reconstruction with hamstring tendon or bone–patellar tendon–bone autografts were included. Follow-up started on date of index ACL reconstruction and ended either with primary contralateral ACL reconstruction, after 5 years of follow-up, or on December 31, 2013, whichever occurred first. The investigated variables were patient sex, age at index reconstruction, activity at the time of index injury, timing of surgery, graft selection, graft harvest site, and meniscal and chondral injury. The study end point was primary contralateral ACL reconstruction. Relative risks (RRs) and 95% CIs were calculated and adjusted for confounding factors using multivariate statistics. Results: A total of 9061 participants were included (n = 5196 males [57.3%] and 3865 females [42.7%]), of which 270 participants (3.0%) underwent primary contralateral ACL reconstruction during the 5-year follow-up. There was no difference in contralateral reconstruction rates between males and females (3.0% vs 2.9%, P = .695). Age <20 years significantly increased the risk of contralateral reconstruction (males: RR = 2.4 [95% CI, 1.7-3.4] and females: RR = 2.9 [95% CI, 1.9-4.5]; P < .001). Among female patients undergoing reconstruction using autograft hamstring, harvest of a contralateral hamstring tendon significantly increased this risk (RR = 3.4 [95% CI, 1.4-7.9]; P = .006). Conclusion: In both male and female participants, age <20 years predicted an almost 3 times higher 5-year risk of contralateral ACL reconstruction. Among female participants undergoing reconstruction with autograft hamstring, a contralateral harvest predicted a more than 3 times higher 5-year risk of contralateral ACL reconstruction. Patient sex, activity at the time of index injury, graft selection, meniscal injury, and chondral injury were not predictors of contralateral ACL reconstruction.

A Randomized Controlled Trial With Mean 16-Year Follow-up Comparing Hamstring and Patellar Tendon Autografts in Anterior Cruciate Ligament Reconstruction

Background: There is no consensus in the current literature on which surgical options render the best long-term results after anterior cruciate ligament (ACL) reconstruction in terms of clinical outcomes and the development of radiographic osteoarthritis (OA). Purpose: To investigate the long-term clinical and radiographic results after ACL reconstruction using either a patellar tendon (PT) autograft or a hamstring tendon (HT) autograft. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: This multicenter study was based on 2 previous randomized cohorts consisting of 193 patients who underwent unilateral primary ACL reconstruction using either a PT autograft or an HT autograft. The index surgical procedure was performed between September 1995 and January 2000. Clinical assessments, including knee laxity measurements, functional outcomes, patient-reported outcomes, and bilateral standing radiographs, were performed at the final follow-up examination. Results: At the long-term follow-up, 147 (76%) patients were examined: 61 in the PT group and 86 in the HT group. The mean (±SD) follow-up time was 191.9 ±15.1 months for the HT group and 202.6 ± 10.4 months for the PT group. Knee laxity measurements revealed significantly more patients with a normal pivot-shift test finding in the HT group compared with the PT group (71% vs 51%, respectively; P = .048); however, no significant differences were found in terms of the manual Lachman test or the KT-1000 arthrometer manual maximum test. The patients in the PT group had significantly more difficulty knee walking (P = .049). There were no significant differences between the study groups in terms of patient-reported outcomes or range of motion in the reconstructed knee. In both groups, significantly more signs of radiographic OA were found in the reconstructed knee than in the contralateral healthy knee. However, there were no significant differences between the groups in terms of radiographic OA. Conclusion: Only minor and mostly insignificant differences were found between the PT and HT autograft groups in this long-term randomized controlled trial. In both groups, significantly more signs of radiographic OA were found in the reconstructed knee than in the contralateral knee.

Comparison of Anatomic Double- and Single-Bundle Techniques for Anterior Cruciate Ligament Reconstruction Using Hamstring Tendon Autografts A Prospective Randomized Study With 5-Year Clinical and Radiographic Follow-up

Background: The aim of this prospective randomized study was to compare the outcomes of the anatomic double-bundle (DB) and anatomic single-bundle (SB) techniques 5 years after anterior cruciate ligament (ACL) reconstruction. Since more effective restoration of rotational laxity is considered the main advantage of the DB technique, the pivot-shift test was the primary outcome variable of the study. Hypothesis: Double-bundle ACL reconstruction will result in a better outcome in terms of the pivot-shift test. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: A total of 105 patients (33 women, 72 men; median age, 27 years; range, 18-52 years) were randomized and underwent ACL reconstruction (DB group, n = 53; SB group, n = 52). All reconstructions were performed anatomically by identifying the ACL footprints, using the anteromedial portal for the femoral tunnel drilling, and utilizing interference screw for tibial and femoral fixation. A single blinded observer examined the patients preoperatively and at follow-up (median, 64 months; range, 55-75 months). Multiple subjective and objective clinical evaluation tests and radiographic assessments of osteoarthritis (OA) were performed using the Ahlbäck, Kellgren-Lawrence, and Fairbank grading systems at 6 weeks postoperatively and at the final follow-up evaluation. Results: Preoperatively, no differences were found between the study groups, apart from the preinjury Tegner activity level, which was lower in the DB group (SB: mean, 7.8 [range, 3-9]; DB: mean, 7.3 [range, 0-9]; P = .02). Eighty-seven patients (83%) were available for examination at the 5-year follow-up. Statistical differences could not be found between the groups in terms of the pivot-shift test, KT-1000 arthrometer laxity measurements, manual Lachman test, single-legged-hop test, square-hop test, range of motion, Lysholm knee scoring scale, Tegner activity scale, or Knee injury and Osteoarthritis Outcome Score. Correspondingly, no differences were found between the groups regarding the presence of OA at follow-up. However, a significant increase of OA was found within the DB group at the 5-year follow-up. Both groups improved at follow-up compared with the preoperative assessment in terms of the laxity tests, hop tests, and scoring scales. Conclusion: At the 5-year follow-up of an unselected group of patients, anatomic DB reconstruction was not superior to anatomic SB reconstruction in terms of the pivot-shift test.

Validation of Quantitative Measures of Rotatory Knee Laxity.

Background: Prior attempts to quantify the pivot-shift examination have been too invasive or impractical for clinical use. A noninvasive method for quantifying rotatory knee laxity is needed. Hypothesis: Greater quantitative measurements of rotatory knee laxity (both of the involved knee as well as compared with the contralateral healthy knee) are associated with an increasing clinical pivot-shift grade. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 103 patients undergoing anatomic single-bundle anterior cruciate ligament (ACL) reconstruction at 4 international centers underwent a standardized pivot-shift test preoperatively on both knees while anesthetized. Clinical grading of the pivot shift was performed according to the International Knee Documentation Committee (IKDC) knee ligament rating system. Two different quantitative technologies were used to measure rotatory knee laxity: an inertial sensor and an image analysis were independently used to measure tibial acceleration and lateral compartment translation, respectively, during the pivot-shift test. Patients were dichotomized to “high-grade” (abnormal and severely abnormal) or “low-grade” (normal and nearly normal) rotatory knee laxity groups based on the clinical pivot-shift test result of the involved side. Tibial acceleration and lateral compartment translation of the involved knee and the side-to-side difference between the involved and contralateral knees were separately compared between the high- and low-grade rotatory knee laxity groups utilizing t tests; significance was set at P < .05. Results: Forty-three patients were in the low-grade rotatory knee laxity group, and 60 patients were in the high-grade rotatory knee laxity group. Patients in the high-grade knee laxity group had significantly higher lateral compartment translation as measured with the image analysis (involved knee: 3.8 ± 2.3 mm; side-to-side difference: 2.5 ± 2.4 mm) compared with patients in the low-grade group (involved knee: 2.0 ± 1.4 mm; side-to-side difference: 1.4 ± 1.5 mm) (both P < .01). As measured with the inertial sensor, tibial acceleration for patients in the high-grade group was significantly higher (involved knee: 7.2 ± 5.3 m/s2; side-to-side difference: 4.2 ± 5.4 m/s2) compared with patients in the low-grade group (involved knee: 4.2 ± 1.6 m/s2; side-to-side difference: 1.2 ± 1.2 m/s2) (both P < .01). Conclusion: The inertial sensor and image analysis techniques were able to detect differences between low- and high-grade pivot-shift test results. A quantitative assessment of the pivot-shift test could augment the diagnosis of an ACL injury and improve the ability to detect changes in rotatory knee laxity over time.

A Comparison of Anatomic Double- And Single-bundle Techniques for Anterior Cruciate Ligament Reconstruction, A Prospective Randomized Study with A 5-year Follow-up

Objectives: The purpose of this study was to compare the mid-term outcome after arthroscopic anterior cruciate ligament (ACL) reconstruction with either the anatomic double-bundle (DB) or anatomic single-bundle (SB) technique using hamstring tendon autografts in an unselected group of patients. Methods: 103 patients (33 women, 70 men; median age, 27 years; range, 18-52 years) were randomized and underwent ACL reconstruction (DB group; n=53 and SB group; n=50). All reconstructions were performed anatomically, identifying the ACL footprints, using the anteromedial portal for the femoral tunnel drilling and utilizing interference screw for tibial and femoral fixation. One blinded observer examined the patients both preoperatively and at follow-up (median, 64 months; range, 55-75 months). Radiographic evaluation of OA was performed using the Ahlbäck, Kellgren-Lawrence and Fairbanks grading systems in the early postoperative period and at follow up. Results: Preoperatively, no differences were found between the study groups apart from the pre-injury Tegner activity level, which was lower in the DB group (p=0.02). Eighty-seven patients (83%) were available for examination at 5-year follow-up. There were no significant differences between the groups in terms of the pivot-shift test, KT-1000 arthrometer laxity measurements, manual Lachman test, One-leg-hop test, Square-hop test, range of motion, Lysholm knee scoring scale, Tegner activity scale and Knee Injury and Osteoarthritis Outcome Score (KOOS). Correspondingly, no differences were found between the groups regarding the presence of OA at follow-up. Both DB and SB groups improved significantly at follow-up compared with the preoperative assessment. Conclusion: At mid-term follow-up of an unselected group of patients, anatomic DB reconstruction was not superior to anatomic SB reconstruction in terms of the pivot-shift test or subjective and objective outcome variables, as seen in this prospective randomized study. Furthermore, there was no difference in terms of the presence of OA at follow-up.