Bilateral Anterior Cruciate Ligament Injuries Research Articles

Patients with Bilateral ACL Reconstruction (ACLR) have 3x the Rate of Posterior Tibial Slope Greater than 12-Degrees Compared to Unilateral ACLR: MRI and Radiographic Evaluation

Objectives: Increased posterior tibial slope (PTS) is a risk factor for primary anterior cruciate ligament (ACL) tear and graft failure, but PTS has not been well-defined in those who have experienced bilateral ACL injuries. We aimed to compare PTS angles, as well as the rate of elevated PTS (>12° on lateral radiograph; >7° on MRI), between patients who underwent bilateral ACL reconstruction (ACLR) vs unilateral ACLR. A secondary purpose was to examine whether these associations remained consistent on both plain radiographs and MRIs. Methods: We retrospectively identified patients who underwent primary ACLR at our institution from the years 2012 to 2020. Patients with non-simultaneous bilateral ACLR (n=53) were propensity matched to those with unilateral ACLR (n=53) by age, sex, and BMI. Exclusion criteria were: rotated lateral radiographs, inadequate quality MRI, concomitant ligament injury or fracture. Unilateral ACLRs with less than 5-year follow-up were further excluded. Three blinded readers measured PTS on lateral radiographs, while medial (MPTS) and lateral PTS (LPTS) were measured on MRI. Bivariate regression was performed to determine correlation between radiograph and MRI measurements. Results: A final cohort of 106 patients was analyzed (mean age: 27.4 ± 10.5 years, 49.1% male, BMI: 25.5 ± 4.3). PTS in the bilateral ACLR cohort was significantly greater than the unilateral ACLR cohort on radiographs (11.26° vs 10.13°, p=0.044) and LPTS (7.32° vs 6.08°, p=0.012), but not MPTS (4.55° vs 4.17°, p=0.467). The percentage of bilateral patients with radiograph PTS >12° was 41.0%, compared to 13.2% in unilateral cohort (p=0.012). The bilateral cohort had a significantly greater rate of LPTS >7° compared to unilateral patients (53.8% vs 32.1%, p=0.016), but not MPTS (p=0.467). On MRI, LPTS (5.93° ± 3.20°) was significantly greater than MPTS (5.12° ± 2.78°, p<0.001). There was weak correlation between MPTS-radiograph ( R=0.24, p=0.02) and LPTS-radiograph was not significantly correlated ( R=0.03, p=0.810). Conclusions: Patients who underwent bilateral ACLR had significantly greater PTS on radiographs and LPTS on MRI compared to those with unilateral ACLR. The rate of PTS >12° was 3.1x greater among bilateral ACLR compared to unilateral ACLR. PTS measurements on radiographs demonstrated weak-to-negligible correlation with MRI measurements, suggesting future normative PTS values should be reported specific to the imaging modality.

Posterior Tibial Slope in Patients Undergoing Bilateral Versus Unilateral ACL Reconstruction: MRI and Radiographic Analyses

Background: An increased posterior tibial slope (PTS) is a risk factor for primary anterior cruciate ligament (ACL) tears and graft failure, but the PTS has not been well-defined in those who have experienced bilateral ACL injuries. Purpose: The primary aim was to compare the PTS, as well as the rate of an elevated PTS (>12° on lateral radiography; >7° on magnetic resonance imaging [MRI]), between patients who have undergone bilateral ACL reconstruction (ACLR) versus unilateral ACLR. A secondary purpose was to examine whether these associations remained consistent on both plain radiography and MRI. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We retrospectively identified patients who underwent primary ACLR at our institution from the years 2012 to 2020. Patients who underwent nonsimultaneous bilateral ACLR (n = 53) were matched to those who underwent unilateral ACLR (n = 53) by age, sex, and body mass index. Exclusion criteria were rotated lateral radiographs, MRI scans of inadequate quality, and concomitant ligament injuries or fractures. Those who had undergone unilateral ACLR with <5-year follow-up were further excluded. There were 3 blinded readers who measured the PTS on lateral radiographs, while the medial PTS (MPTS) and lateral PTS (LPTS) were measured on MRI scans. Bivariate regression was performed to determine the correlation between radiographic and MRI measurements. Results: The PTS on radiography (11.26° vs 10.13°, respectively; P = .044) and the LPTS on MRI (7.32° vs 6.08°, respectively; P = .012) in the bilateral ACLR group were significantly greater than those in the unilateral ACLR group but not the MPTS on MRI (4.55° vs 4.17°, respectively; P = .590). The percentage of patients in the bilateral group with a radiographic PTS >12° was 41.0% compared with 13.2% in the unilateral group (P = .012). The bilateral group had a significantly higher rate of an LPTS >7° compared with the unilateral group (53.8% vs 32.1%, respectively; P = .016) but not for an MPTS >7° (P = .190). On MRI, the LPTS (6.90°± 2.73°) was significantly greater than the MPTS (4.41°± 2.92°) (P < .001). There was a weak correlation between MPTS and radiographic PTS measurements (R = 0.24; P = .021), but LPTS and radiographic PTS measurements were not significantly correlated (R = 0.03; P = .810). Conclusion: Patients who underwent bilateral ACLR had a significantly greater PTS on radiography and a significantly greater LPTS on MRI compared with those who underwent unilateral ACLR. The rate of a radiographic PTS >12° was 2.4 times greater among patients undergoing bilateral ACLR compared with those undergoing unilateral ACLR. PTS measurements on radiography demonstrated a weak to negligible correlation with PTS measurements on MRI, suggesting that future normative PTS values should be reported specific to the imaging modality.

Primary Repair versus Reconstruction in Patients with Bilateral Anterior Cruciate Ligament Injuries: What Do Patients Prefer?

Purpose The purpose is to evaluate knee preference and functional outcomes of patients with primary anterior cruciate ligament (ACL) repair in one knee and ACL reconstruction in the contralateral side. Methods All patients who underwent both procedures were retrospectively reviewed at minimum two-year follow-up. Patients were asked to complete questionnaires regarding their operated knees' preferences during rehabilitation, daily activities, sports activities, and overall function. Furthermore, the Subjective International Knee Documentation Committee, Forgotten Joint Score-12, and Anterior Cruciate Ligament-Return to Sport after Injury were completed. Results Twenty-one patients were included. All patients underwent ACL reconstruction first, which was displayed at younger age at surgery (24 vs. 33 years, p = 0.010) and longer follow-up (10.2 vs. 2.3 years, p < 0.001), respectively. Thirty-three percent preferred the repaired knee, 11% the reconstructed knee, and 56% had no preference; however, 78% indicated that their repaired knee was less painful during rehabilitation and 83% reported earlier range of motion (ROM) return following repair, which was similar for both knees in 17%. Eighty-three percent of patients indicated better function and progression during rehabilitation with their repaired knee and 11% with their reconstructed knees. No statistical differences were found in patient-reported outcomes between both procedures (all p > 0.4). Objective laxity assessment showed mean side-to-side difference of 0.6 mm between both sides in favor of the reconstructed knee. Conclusion This study showed that ACL repair and ACL reconstruction lead to similar functional outcomes. However, patients undergoing both procedures may have less pain, earlier ROM return, and faster rehabilitation progression following primary repair.

Graft Survivorship After Anterior Cruciate Ligament Reconstruction Based on Tibial Slope

Background: Increased tibial slope (TS) is believed to be a risk factor for anterior cruciate ligament (ACL) tears. Increased TS may also promote graft insufficiency after ACL reconstruction. Purpose: To delineate the relationship between TS and single as well as multiple graft insufficiencies after ACL reconstruction. Study Design: Cohort study; Level of evidence 3. Methods: We retrospectively identified 519 patients who had sustained ACL graft insufficiency after primary or revision ACL reconstruction (1 graft insufficiency, group A; 2 graft insufficiencies, group B; and ≥3 graft insufficiencies, group C). In addition, a subgroup analysis was conducted in 63 patients who received all surgical interventions by 2 specialized high-volume, single-center ACL surgeons. TS was measured by an observer with >10 years of training using lateral knee radiographs, and intrarater reliability was performed. Multiple logistic and univariate Cox regression was used to assess the contribution of covariates (TS, age, sex, and bilateral ACL injury) on repeated graft insufficiency and graft survival. Results: The study included 347 patients, 119 female and 228 male, who were 24 ± 9 years of age at their first surgery (group A, n = 260; group B, n = 62; group C, n = 25). Mean TS was 9.8°± 2.7° (range, 3°-18°). TS produced the highest adjusted odds ratio (1.73) of all covariates for repeated graft insufficiency. A significant correlation was found between TS and the number of graft insufficiencies (r = 0.48; P < .0001). TS was significantly lower in group A (9.0°± 2.3°) compared with group B (12.1°± 2.5°; P < .0001) and group C (12.0°± 2.6°; P < .0001). A significant correlation was seen between the TS and age at index ACL tear (r = −0.12; P = .02) as well as time to graft insufficiency (r = −0.12; P = .02). A TS ≥12° had an odds ratio of 11.6 for repeated ACL graft insufficiency. Conclusion: The current results indicate that patients with a markedly increased TS were at risk of early and repeated graft insufficiency after ACL reconstruction. Because the TS is rarely accounted for in primary and revision ACLR, isolated soft tissue procedures only incompletely address recurrent graft insufficiency in this subset of patients.

Narrow Notch Width is a Risk Factor for Anterior Cruciate Ligament Injury in the Pediatric Population: A Multicenter Study

PurposeThe purposes of this study were to evaluate the notch width index (NWI) as a risk factor for anterior cruciate ligament (ACL) rupture in the pediatric and adolescent patient population via multicenter analysis and to detect any differences in the NWI among cohorts having sustained either a unilateral or bilateral ACL rupture.MethodsA consecutive series of patients ≤19 years old was enrolled from January 1999 through July 2010 at 2 academic pediatric orthopaedic tertiary-care hospitals. Demographic and anatomic morphology data were collected for 3 cohorts: unilateral ACL ruptures, bilateral ACL ruptures, and a control group. A single blinded reviewer determined notch width measurements via T2 coronal magnetic resonance imaging sequences in a standardized manner, using a previously described technique.ResultsOf the 68 patients included for analysis, 22 sustained unilateral ACL rupture, 23 sustained bilateral ruptures, and 23 comprised the control group. There was a statistically significant difference appreciated in direct comparison of the NWI in the bilateral rupture group and the control group, as well as between the unilateral rupture group and the control group. There was no statistically significant difference between the NWI in the unilateral versus the bilateral rupture group.ConclusionGiven the known inconsistencies in the existing literature, our findings provide further support of a narrow NWI as a significant contributing factor to both unilateral and bilateral ACL injury risk in the pediatric and adolescent patient population.Level of EvidenceIII, retrospective cohort study.

PATIENTS FOCUS ON PERFORMANCE OF PHYSICAL ACTIVITY, KNEE STABILITY AND ADVICE FROM CLINICIANS WHEN MAKING DECISIONS CONCERNING THE TREATMENT OF THEIR ANTERIOR CRUCIATE LIGAMENT INJURY

When deciding medical treatment, patients' perspectives are important. There is limited knowledge about patients' views when choosing non-operative treatment or anterior cruciate ligament (ACL) reconstruction (ACLR) after ACL injury. To describe reasons that influenced patients' decisions for non-operative treatment or ACLR after ACL injury. Cross-sectional study. This study recruited a total of 223 patients (50% men), aged 28 ± 8 years who had sustained ACL injury, either unilateral or bilateral. Subjects were, at different time points after injury, asked to fill out a questionnaire about their choice of treatment, where an ACLR treatment decision was made, some responded before and some after the ACLR treatment. A rating of the strength of 10 predetermined reasons in their choice of treatment graded as 0 (no reason) to 3 (very strong reason), was done. Patients with unilateral ACL injury treated with ACLR (110 patients) rated "inability to perform physical activity at the same level as before the injury due to impaired knee function" (96%), "fear of increased symptoms during activity" (87%) and "giving way episodes" (83%) as strong or very strong reasons in their treatment decision. Patients with bilateral ACL injury treated with ACLR (109 knees) rated similar reasons as patients with unilateral ACLR and also "low confidence in the ability to perform at the preinjury activity level without ACLR" (80%) as strong or very strong reasons. Patients with unilateral ACL injury treated non-operatively (46 patients) rated "advice from clinician" (69%) as a strong or very strong reason. Patients with bilateral ACL injury treated non-operatively (25 knees) rated "absence of giving way episodes" (62%), and "no feeling of instability" (62%) as strong or very strong reasons. Inability to perform physical activity, fear of increased symptoms, and giving way episodes were reasons that patients with ACL injury considered when making decisions about ACLR. When choosing non-operative treatment, patients considered the absence of instability or giving way symptoms, being able to perform physical activity, and advice from clinicians. 4.

Bilateral Anterior Cruciate Ligament (ACL) Tears treated by double bundle grafting

Anterior Cruciate Ligament (ACL) tears are orthopaedic injury, particularly in athlete and youth populations. ACL is composed of longitudinally oriented bundles of collagen tissue arranged in fascicular subunits within larger functional bands. Ligament is surrounded by synovium, thus making it extra-synovial. Unilateral ACL tear is common & seen by sports medicine orthopaedic surgeons. But bilateral ACL injury is extremely rare and reported only three times in the previous literature. In this case of bilateral ACL tear, which was surgically treated and managed by performing arthroscopic double bundle ACL reconstruction in left knee using quadruplet hamstring graft. This particular surgery is a rare practice adopted by orthopaedic surgeons. We would like to highlight that, performing double bundle grafting not only helped the patient back into his sports field in shorter duration, but also shows that orthopaedic surgeons are espousing newer techniques and accomplishment of such procedure opening new dimension in ACL tear management.

Double-Bundle and Single-Bundle ACL Reconstruction Techniques Did Not Differ in Terms of Clinical Outcomes at 2 or 5 Years.

Sasaki S, Tsuda E, Hiraga Y, Yamamoto Y, Maeda S, Sasaki E, Ishibashi Y. Prospective randomized study of objective and subjective clinical results between double-bundle and single-bundle anterior cruciate ligament reconstruction. Am J Sports Med. 2016 Apr;44(4):855-64. ### Question: What is the relative effectiveness of double-bundle anterior cruciate ligament (ACL) reconstruction with hamstring tendon graft (DB-HT) and rectangular-tunnel single-bundle ACL reconstruction with patellar tendon graft (RTSB-PT) at 2 years? ### Design: Randomized (unclear allocation concealment), unblinded, controlled trial with a mean of 3.2 years of follow-up. ### Setting: 1 clinical center at Hirosaki University, Hirosaki, Japan. ### Patients: 150 patients (mean age, 26 years; 58% women) who needed ACL reconstruction. Exclusion criteria were skeletal immaturity with an open physis of the femur or tibia, bilateral ACL injury or multiple knee ligament injury, revision ACL surgery, knee osteoarthritis, knee surgery with high tibial osteotomy or medial patellofemoral ligament reconstruction, or failure to complete the study questionnaire. 91% of patients completed follow-up. ### Intervention: DB-HT (n = 76) or RTSB-PT (n = 74). For the DB-HT technique, the semitendinosus tendon was used in 94% of patients. The graft was split and used for the anteromedial bundle (AMB) and posterolateral bundle (PLB). The femoral and tibial tunnel positions were created according to accepted anatomical guidelines. The femoral tunnel for the AMB was made with use of either a transtibial or outside-in technique. Fixation on the femur and tibia was done with a cortical-button suspension technique. For the RTSB-PT technique, the bone blocks of the bone-patellar tendon-bone grafts …

Relationship Between Posterior-Inferior Tibial Slope and Bilateral Noncontact ACL Injury.

Is there a correlation between increased posterior-inferior tibial slope angle and noncontact anterior cruciate ligament (ACL) injury? Does increasing the posterior-inferior tibial slope angle increase the risk of bilateral ACL injury? A computerized relational database (Access 2007; Microsoft Inc, Redmond, Washington) was used to conduct a retrospective review of patients undergoing bilateral or unilateral ACL reconstruction surgery or treatment by a single surgeon between 1995 and 2013. Included in the study were patients with bilateral and unilateral ACL injuries and patellofemoral pain syndrome with no associated ACL deficiency. Exclusion criteria included concomitant ligament injury, previous ACL reconstruction, and previous knee surgery. Also excluded were patients who did not have plain lateral radiographs. Fifty patients were randomly selected from each group. After controlling for age and Tegner activity level, the authors found that the posterior-inferior tibial slope angle was a significant predictor (P=.002) of noncontact ACL injury. Mean posterior-inferior tibial slope angle for the bilateral, unilateral, and control groups was 11.8°±2.3°, 9.3°±2.4°, and 7.5°±2.3°, respectively. In the group with unilateral ACL injury vs the group without ACL deficiency, a 1° increase in posterior-inferior tibial slope angle (P=.03) was associated with a 20% increase in unilateral ACL injury. In those with bilateral ACL injury vs those without ACL deficiency, a 1° increase in posterior-inferior tibial slope angle (P=.001) increased bilateral knee injury by 34%. The difference between the mean angles of the control group without ACL deficiency and both the bilateral injury and unilateral injury cohorts was statistically significant (P=.003). Increased posterior-inferior tibial slope angle is associated with an increased risk of noncontact bilateral and unilateral ACL injury. [Orthopedics. 2017; 40(1):e136-e140.].

The Utility of Limb Symmetry Indices in Return-to-Sport Assessment in Patients With Bilateral Anterior Cruciate Ligament Reconstruction

Background: The incidence of contralateral anterior cruciate ligament (ACL) injury after ACL reconstruction (ACLR) is high. Often, return-to-sport (RTS) tests of strength and functional hopping rely on limb symmetry indices (LSIs) to identify deficits, although the utility of these measures in athletes with bilateral ACL injuries is unknown. Purpose/Hypothesis: The aim of this study was to investigate if LSIs used as RTS criteria in female patients after unilateral ACLR were appropriate for female patients with bilateral ACL involvement. The hypothesis tested was that asymmetries with traditional LSI measures would be present in a population after unilateral ACLR but would not be present in a population with bilateral ACLR due to the lack of a healthy internal control limb. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 45 female subjects were classified into 3 groups: after second (contralateral) ACLR (ACLR-B; n = 15); after primary unilateral ACLR (ACLR-U; n = 15); and uninjured controls (CTRL; n = 15). After being cleared for RTS, each subject completed a single-legged hop for distance (SLHD), triple hop for distance (THD), and triple-crossover hop for distance (CHD) test, in addition to an isometric quadriceps strength test on both limbs. Means and LSI ([involved limb/uninvolved limb] × 100) were calculated for each test. Limb symmetry deficits were defined by LSI <90%. Results: Analysis of functional hop testing revealed a side × group interaction for SLHD (P = .001), THD (P = .019), and CHD (P = .04). Side-to-side differences were found in the ACLR-U group for all hop tests (P = .001-.003) and in the ACLR-B group for SLHD (P = .002) and THD tests (P = .024). No side-to side differences were seen in the CTRL group (P > .05). A side × group interaction was found for isometric quadriceps strength (P = .006), with lower LSI seen in the ACLR-U group (81% ± 17.6%) compared with the CTRL group (102.2% ± 10.8%) and the ACLR-B group (95.6% ± 24.9%). Although no interaction was seen, side-to-side differences were noted in the THD in the ACLR-U group (P = .013) and ACLR-B group (P = .024) and in the CHD in the ACLR-U group (P = .001). Despite absence of an LSI deficit, bilateral peak quadriceps strength in the ACLR-B group was comparable to the involved limb of the ACLR-U group and less than in the CTRL group (P = .012). Conclusion: Both the ACLR-U and the ACLR-B groups demonstrated side-to-side deficits during functional hop tests; however, these deficits were not identified according to the clinically accepted LSI values of ≥90%, calling into question the efficacy of current RTS criteria. At the time of RTS, only individuals in the ACLR-U group demonstrated an altered LSI in quadriceps strength. Significantly lower quadriceps strength of both limbs in the ACLR-B group was seen compared with the CTRL group, despite no LSI deficits in quadriceps strength. Current use of LSIs during strength and performance tests may not be an appropriate means of identifying residual deficits in female patients after bilateral ACLR at time of RTS. Furthermore, a better indicator of strength performance in this population may need to include a comparison of strength performance values to the normative values of healthy controls.

Bilateral ACL Reconstructions with Hamstring Autografts.

Bilateral anterior cruciate ligament (ACL) injuries are rare with incidence between 2 and 4%, and presently no definitive guidelines for proper management exist. Ideal treatment protocol remains controversial between a single-stage and two-stage bilateral ACL reconstruction. The purpose of this study is to evaluate the outcome of single-stage bilateral ACL reconstruction with hamstring tendon autografts in bilateral ACL injuries. A prospective study was undertaken including a total of 14 consecutive patients with bilateral ACL deficient knee who underwent single-stage bilateral ACL reconstruction with hamstring tendon autograft with a mean follow-up duration of 28 months (24-38 months). Functional outcomes were evaluated by range of movements, International Knee Documentation Committee (IKDC), Lysholm and Tegner activity score, and stability tests. The mean age was 30 years (range 18-42 years). Average duration of rehabilitation was 8 weeks. Time to return to full-time work and full sports was 5.6 weeks and 6.2 months, respectively. Clinical examination demonstrated full range of motion; a total of 12 patients (86%) had a negative Lachman test and 13 patients (93%) had a negative pivot shift at the final follow-ups. The mean IKDC evaluation score was 89 points, the mean Tegner activity score was 7 points, and the mean Lysholm knee score was 91 points. A total of 12 patients (86%) returned to their preinjury level of activity and an overall greater than 90% satisfaction rate was achieved. Single-stage bilateral ACL reconstruction using hamstring autografts is clinically safe, effective, and cost-effective with better patient compliance and with comparable functional outcome as opposed to two-stage ACL reconstructions.

RISK FACTORS FOR BILATERAL ANTERIOR CRUCIATE LIGAMENT INJURIES.

The aim of this study has been to identify which risk factors can influence bilateral anterior cruciate ligament injury. Thirty-two operated patients took part in this survey during the period of ten years. There were 5 women and 27 men, with average age of 30.46 years (19-55). The respondents filled in the questionnaire by answering the questions regarding the time when getting injured and operated, mechanism of injuries, genetic and anthropometric data, characteristics of sports and every day activities. The incidence of reconstructed bilateral injuries in relation to unilateral ones was 2.3% (50/2168). The age of respondents and side of the injured knee did not correlate significantly with the achieved subjective physical activity level after the second knee surgery. The average time from the first injury to operation was 10 months and 4.3 years since that moment up to the injury of the other knee. It took more than 9 months on average until the reconstruction of contralateral anterior cruciate ligament. The most of athletes were injured in football matches. Three-quarters of athletes returned to competition activities after the first operation, which caused the same injury of the contralateral knee. Anterior cruciate ligament rupture of the contralateral knee most often occurs in young active athletes within the first four years after the initial reconstruction. Its frequency is not affected by sex, side of extremity, genetic predisposition, type of sport, concomitant injuries and the choice of graft. Returning to the same or higher level of sports activities after the first reconstruction is one of the preconditions for injuring the other knee in the same way.

THE EFFECT OF EDUCATIONAL LECTURE ON REDUCING REINJURY AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

BackgroundAlthough anterior cruciate ligament (ACL) injury prevention programs have been published, little is known about ACL reinjury prevention after ACL reconstruction. On the other hand, we have held educational lectures...

Patient-Reported Knee Function, Quality of Life, and Activity Level After Bilateral Anterior Cruciate Ligament Injuries

Background: About 12% of patients who have undergone primary anterior cruciate ligament (ACL) reconstruction sustain a contralateral ACL injury within 5 years. Purpose: To investigate patient-reported knee function, quality of life, and activity level in patients with bilateral ACL injuries. Study Design: Cohort study; Level of evidence, 3. Methods: A search of hospital records identified 147 patients, aged 18 to 45 years, with bilateral ACL injuries. Of these, 83 met the inclusion criteria, having had their first ACL injury up to 12 years ago with no other major injuries to the knee joint. Sixty-six of these patients (80% of total; 47% female; mean age, 29.1 ± 7.2 years) answered a questionnaire packet. Patients who had undergone unilateral ACL reconstruction (n = 182) were used for comparison. Results: Patients with bilateral ACL injuries had a median Lysholm knee score of 82 (range, 34-100). The mean EuroQol index (EQ-5D) score of the overall health status was 0.77 ± 0.22, and the mean EQ-5D visual analog scale score was 75.5 ± 17.6. The median Tegner activity level was 9 (range, 1-9) before any injuries, 7 (range, 1-9) before the second ACL injury, and 4 (range, 1-9) at the time of follow-up. The activity level before the second injury was higher compared with the follow-up for patients who had undergone unilateral ACL reconstruction. At follow-up, 23% of the patients with bilateral ACL injuries returned to their previous activity, and 12% of patients returned to the same level as before their injuries compared with 43% (P = .004) and 28% (P = .01) in patients who had undergone unilateral ACL reconstruction, respectively. Patients with bilateral ACL injuries had significantly lower values in the Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales for pain, function in sports and recreation, and knee-related quality of life as well as the ACL Deficiency Quality of Life (ACL-QOL) score compared with patients who had undergone unilateral ACL reconstruction. Conclusion: Patients with bilateral ACL injuries reported poorer knee function and quality of life compared with those who had undergone unilateral ACL reconstruction. Their activities had changed, and they were dissatisfied with their current activity level. They had a high activity level before their first and second ACL injuries but an impaired activity level after their contralateral injury at follow-up.

Association between intercondylar notch narrowing and bilateral anterior cruciate ligament injuries in athletes

Intercondylar notch narrowing is a risk factor for anterior cruciate ligament (ACL) injuries, but it is unclear whether a narrow intercondylar notch correlates with bilateral ACL injuries. To determine whether a narrow intercondylar notch is associated with bilateral ACL knee injuries in athletes, using magnetic resonance imaging (MRI) and radiography to investigate the notch size. A retrospective case-control study. This was a comparative cohort study on 50 subjects of which 25 patients with sport trauma-associated bilateral ACL injuries, 30 with unilateral ACL injuries, and 20 healthy subjects. The notch width index (NWI) was measured as the ratio of the width of the intercondylar notch to the femoral condylar width on radiography and the MRI slice containing the region near the ACL attachment site on the femoral side (NWI-A) and on the following posterior slice (NWI-P). The mean NWI values on radiography were 0.257 (SD 0.040), 0.332 (SD 0.036), and 0.341 (SD 0.027) in the bilateral, unilateral, and control groups, respectively, with significant differences between the bilateral and unilateral groups and the bilateral and healthy groups. On MRI, the mean NWI-A values were 0.236 (SD 0.025), 0.243 (SD 0.048), and 0.266 (SD 0.030), respectively, with a significant difference between the bilateral and healthy groups. The mean NWI-P values were 0.239 (SD 0.021), 0.258 (SD 0.038), and 0.273 (SD 0.033), respectively, with significant differences between the bilateral and unilateral groups and the unilateral and healthy groups. A cutoff value of 0.25 for NWI-P gave an odds ratio of 22.667 for the risk of developing bilateral ACL knee injuries. The intercondylar notch was significantly narrower in subjects with bilateral ACL injuries than in healthy subjects. NWI measurement using coronal MRI is useful for judging intercondylar notch narrowing. The risk for ACL injuries is very high when NWI is ≤0.25. Preventive measures for the unaffected knee are required for patients with a narrow intercondylar notch.

Bilok Interference Screws for Anterior Cruciate Ligament Reconstruction: Clinical and Radiographic Outcomes

The purpose of this study was to evaluate the clinical effectiveness and radiographic response of a poly-L-lactide (PLLA)/beta-tricalcium phosphate (TCP) interference screw for anterior cruciate ligament (ACL) reconstruction. In a consecutive series of patellar tendon autograft ACL reconstructions, all patients had both ends fixed with PLLA/beta-TCP screws. Inclusion criteria were positive Lachman and pivot-shift tests and closed or nearly closed growth plates. Exclusionary criteria were posterior cruciate ligament tears and bilateral ACL or multiple ligament injuries. Tegner, Lysholm, Cincinnati, and International Knee Documentation Committee activity scores; Lachman and pivot-shift data; radiographic examinations; and KT measurements (MEDmetric, San Diego, CA) were obtained. In this study 41 patients met the criteria (31 male and 10 female patients), at a mean follow-up of 34 months (range, 24 to 44 months). Of these patients, 40 were available for follow-up (1 had died). Postoperatively, the mean Cincinnati score was 83 (64 preoperatively), the mean Tegner score was 5.5 (3.2 preoperatively), the mean Lysholm score was 88 (59 preoperatively), and the mean International Knee Documentation Committee activity score was 3.0 out of 4 (1.8 preoperatively). No patients had positive postoperative Lachman or pivot-shift tests. The maximum difference based on KT manual examinations 3 mm or less. Adverse events included screw breakage during insertion. Postoperative radiographs showed rapid bone plug incorporation. Radiographic tunnel obliteration with bony ingrowth was shown at 2 and 3 years' follow-up. The PLLA/beta-TCP interference screw performed well clinically based on both subjective and objective results. Radiographic screw incorporation into the adjacent bone was apparent at 3 years. Level IV, therapeutic case series.

Profile of Bilateral Anterior Cruciate Ligament Injuries: A Retrospective Follow-up Study

To assess the mechanism of injury of anterior cruciate ligaments, surgical results, and radiographic findings among patients with bilateral knee injuries, and to compare these features with those of patients sustaining unilateral injuries. From 1977 to 1988, among 458 patients with injury of anterior cruciate ligament operated in our hospital, 11 were of bilateral injury, in whom 10 could be followed up. A laxity score was calculated to evaluate laxity of 7 joints. A notch width index was measured to show the narrowing of femoral notch. The mean follow-up duration was 3 years 3 months. All 10 patients with bilateral injury of anterior cruciate ligaments were female, and 90% had non-contact injuries. The mean (standard deviation) laxity score was significantly higher in the bilateral injury group than in the unilateral injury group (3.3 [1.4] versus 2.2 [1.4] points; p<0.05). The mean notch width index was significantly lower in the bilateral injury group than in the healthy group (0.278 [0.025] versus 0.294 [0.031]; p<0.05). The mean age at the time of the first injuries was significantly lower among the bilateral injury group than among the unilateral injury group (16.6 [2.1] years versus 19.8 [6.1]; p<0.05). The level of return to full sporting activities was low in the bilateral group. These results suggest that several factors are involved in the occurrence of the anterior cruciate injuries. Besides being younger at the time of the first injury, patients in bilateral injury group had higher mean laxity score and lower mean notch width index than unilateral injury group. Most of the injuries in bilateral group were of non-contact type.

Reconstruction of the anterior cruciate ligament in females

Purpose: To compare the clinical results of anterior cruciate ligament reconstruction in female patients using quadruple-looped hamstring autograft versus patellar tendon autograft at minimum 2-year follow-up. Type of Study: Case series. Methods: A prospective clinical review was performed to compare the results of ACL reconstruction with hamstring versus patellar tendon autograft in a group of female patients. Exclusion criteria included chronic injuries (greater than 3 months), associated collateral ligament injuries, Workers’ Compensation or litigation cases, and bilateral anterior cruciate ligament injuries. There were 39 female patients in the hamstring group (average follow-up, 40.9 months) and 37 female patients in the patellar tendon group (average follow-up, 52 months). Both types of grafts were fixed with an EndoButton proximally and with sutures tied over a post or button distally. The postoperative rehabilitation regimen was identical for both groups. Objective parameters evaluated included preinjury and postoperative Tegner and Lysholm scores, side-to-side KT-1000 maximum-manual arthrometer differences, and clinical examination including Lachman and pivot-shift tests. Graft failure was defined by any one of the following: a KT-1000 difference of greater than 5 mm, a 2+ Lachman, a 1+ or greater pivot shift, or revision surgery. Results: The failure rate in the hamstring group was 23% versus 8% in the patellar tendon group, which was not statistically significant ( P > .1). Comparison of preinjury Tegner activity scores to postoperative scores revealed that patients in the hamstring group did not return to their preinjury level of activity (preinjury 6.54 v postoperative 5.17) as well as patients in the patellar tendon group (preinjury 6.20 v postoperative 6.59). Patients in the hamstring group had a significant increase in pain compared with the patellar tendon group ( P = .034). Conclusions: Although not statistically significant, the hamstring group had more failures, more laxity on clinical examination, and more patients with larger KT-1000 arthrometer differences. These results indicate a trend toward increased graft laxity in female patients undergoing reconstruction with hamstring autograft compared with patellar tendon when evaluated by a single surgeon using similar fixation techniques at short- to medium-range follow-up. More studies with larger patient numbers using current fixation techniques are necessary to confirm these findings.

Quadriceps Femoris and Hamstring Muscle Function in a Person With an Unstable Knee

The purpose of this case report is to describe the evaluation, treatment, and short-term outcome for an individual with chronic, progressively worsening instability of the knee during gait associated with anterior cruciate ligament (ACL) insufficiency. The patient was a 34-year-old man who sustained bilateral ACL injuries. Subsequently, an autograft reconstruction of the left knee ACL was performed. Eight months post-reconstruction, the left knee was unstable despite bracing. Gait analysis and tests to determine the presence of muscle inhibition were performed prior to and after 12 weeks of training. Isometric torque of the knee extensors and flexors was measured with the knee in 90 degrees of flexion. A training program primarily consisted of electromyographic biofeedback during thigh muscle exercises, balance exercises, and gait. Muscle inhibition decreased and maximal isometric knee flexion and extension torques increased during the 12-week training period. Gait analysis demonstrated a 50% decrease in the maximum knee extensor moment and an increase in walking speed. Selected gait variables, torque production, and muscle inhibition may change in a person with an unstable knee. The measurement of variables that have previously been documented as mechanisms of knee instability during walking allows for the selection of a specific treatment approach.

Detailed analysis of patients with bilateral anterior cruciate ligament injuries.

To better understand anatomic and other possible predisposing factors for anterior cruciate ligament injuries, we retrospectively studied 31 patients with noncontact, bilateral injuries of this ligament. The 31 patients were carefully matched by age, sex, height, weight, and activity level with 23 control subjects who had no history of knee injury. All 54 subjects underwent a full clinical knee examination, joint hypermobility tests, a hamstring tightness assessment, a computerized tomography scan analysis, and a plain view radiographic analysis, and were asked to provide a complete immediate-family history of knee ligament injury. In addition, the 31 patients in the experimental group underwent a KT-1000 arthrometer knee laxity examination and were also asked to provide an injury profile, including mechanism of injury, treatment received for each injury, and the time interval between injuries. Measurements obtained from the computerized tomography scan analysis demonstrated a significantly wider lateral femoral condyle in the experimental group compared with the control group, indicating that certain anatomic factors may predispose people to anterior cruciate ligament injury. A significant difference was also found in the incidence rate of anterior cruciate ligament injury in the family history of the experimental group compared with the control group, indicating a possible congenital aspect of this injury.