Uninjured Knee Research Articles

Do Bone-Patellar Tendon-Bone ACL-Reconstructed Knees Have More Signs of Patellofemoral Posttraumatic Osteoarthritis Than Their Uninjured Contralateral Knees at 2 Years?

Background:The prevalence of patellofemoral joint (PFJ) osteoarthritis ranges from 8% to 47% at 7 to 10 years after anterior cruciate ligament reconstruction (ACLR) using bone–patellar tendon–bone (BTB) autograft. In performing BTB ACLR, some hypothesize that either trauma caused by harvest of the BTB autograft or altered biomechanics contributes to PFJ posttraumatic osteoarthritis.Purpose/Hypothesis:To determine whether knees with ACLR using a BTB autograft show early signs of posttraumatic osteoarthritis as compared with the contralateral uninjured knee 2 years after ACLR. We hypothesized that a BTB autograft will not increase the prevalence of PFJ osteoarthritis.Study Design:Cohort study; Level of evidence, 3.Methods:Bilateral knee 3-T magnetic resonance imaging (MRI) scans were collected in 57 patients (mean age, 20.3 years; 28 men) from a single site at a minimum of 2 years after ACLR. Structural MRI assessment of the knees was performed using the MRI Osteoarthritis Knee Score semiquantitative scoring system by a board-certified musculoskeletal radiologist. The presence of cartilage defects in the patellofemoral compartment was compared between the reconstructed and contralateral uninjured knees using logistic regression analyses.Results:There were no significant differences in the prevalence of cartilage defects (full thickness or any thickness) in the PFJ between the BTB ACLR knees and the contralateral control knees: 38.6% of BTB ACLR knees had PFJ cartilage defects versus 31.6% of contralateral control knees (P > .391). The 95% CI for the difference between these groups was –9.0% to 23.0%.Conclusion:When comparing BTB ACLR knees with the uninjured contralateral knees in the study patients, we failed to observe statistically significant differences in the prevalence of PFJ cartilage lesions of full thickness or any thickness. These results should be used in shared decision-making with athletes when choosing the appropriate autograft during reconstruction. Our wide 95% CIs secondary to a smaller sample size demonstrate a need for larger studies in this area to more accurately describe the difference between the operative and contralateral knees.

Radiographic assessment of the tibiofemoral relationship in anterior cruciate ligament deficient knees

BackgroundThe intercondylar roof line is one of the indicators used during anterior cruciate ligament (ACL) reconstruction to see the relation to the position of the tibial tunnel. The tibial tunnel can be made posteriorly in the anteriorly subluxated tibia. During ACL reconstruction, the tibiofemoral relationship of the opposite or normal knee should be considered. The purpose of this study was to examine the radiographic tibiofemoral relationship of the sagittal plane in a standing position in ACL deficient knees. MethodsIn this study, 64 patients were evaluated for inclusion. Lateral radiographs of the injured and uninjured knee were obtained preoperatively in a standing position. The knee was fully extended with the opposite foot on a step, asking the patients to bear weight fully on one leg. The tibiofemoral relationship was evaluated in the radiographs. ResultsThe mean value of anterior tibial subluxation was 1.2 mm in the injured side and −1.6 mm in the uninjured side. The tibia was located in a significantly anterior position in the injured knee (p < 0.0001). The mean distance of the space for the ACL was 9.7 mm in the injured side and 10.7 mm in the uninjured side (p < 0.01). Roof-plateau angle averaged 63.6° in the injured side and 67.4° in the uninjured side (p < 0.001). ConclusionThe tibiofemoral relationship of the ACL deficient knee was different from that of normal knee in the standing position. The relationship of the normal knee should be considered during ACL reconstruction and the risk of secondary lesions in the ACL deficient knee in activities of daily life should be considered.

Kinetic and Kinematic analysis of ACL reconstruction in association with lateral-extrarticular tenodesis of the knee in revision surgery: a pilot study.

Background.Anterior cruciate ligament reconstructions are a very frequent surgery. The key role of the anterolateral ligament in the knee rotational stability has been undelighted in recent years. Extra-articular tenodesis in association with ACL reconstructions, serves to eliminate anterolateral rotatory instability. The aim of our study is to compare treated knees with the contralateral uninjured knee in those cases whom been treated with ACL arthroscopic reconstruction and lateral extra-articular tenodesis in revision surgery, and evaluate clinical results with kinematic and kinetic examinations methods.Materials and methods.Sixteen patients (10 males and 6 females) with ages from 21 to 37 had been treated at the Orthopaedic Clinic of Udine for failure of previous ACL reconstruction. In all patients was performed ACL arthroscopic reconstruction with the association of a lateral extra-articular tenodesis (Coker-Arnold). We have decided to asses the patients at one year after surgery with GNRB arthrometer and Bioval inertial sensor system.Results.All patients treated with arthroscopic ACL reconstruction and lateral extra-articular tenodesis have regained pre-injury sagittal knee stability and gait dynamics.Conclusions.Clinical and instrumental evaluation showed how a combination of procedures can restore the kinematic and stability of a joint, even if the procedures performed are not anatomical. These are only preliminary data. (www.actabiomedica.it)

Effect of walking on in vivo tibiofemoral cartilage strain in ACL-deficient versus intact knees

Anterior cruciate ligament (ACL) rupture alters knee kinematics and contributes to premature development of osteoarthritis. However, there is limited data regarding the in vivo biomechanical response of tibiofemoral cartilage to activities of daily living (ADLs) in ACL-deficient knees. In this study, eight otherwise healthy participants with chronic unilateral ACL deficiency completed a stress test to assess the effect of 20 min of level treadmill walking at a speed of 2.5 mph on tibiofemoral cartilage in their ACL-deficient and contralateral ACL-intact knees. Three-dimensional surface models developed from pre- and post-activity magnetic resonance (MR) images of the injured and uninjured knees were used to determine compressive strain across multiple regions of tibiofemoral cartilage (medial and lateral tibial plateaus, medial and lateral femoral condyles, medial aspect of femoral condyle adjacent to intercondylar notch of the femur). In the ACL-deficient knees, we observed significantly increased cartilage strain in the region of the medial femoral condyle adjacent to the intercondylar notch (6% in deficient vs. 2% in contralateral, p = 0.01) as well as across the medial and lateral tibial plateaus (4% vs. 3%, p = 0.01) relative to the contralateral ACL-intact knees. Increased compressive strain at the medial intercondylar notch and tibial plateau suggests alterations in mechanical loading or the response to load in these regions, presumably related to altered knee kinematics. These changes may disrupt cartilage homeostasis and contribute to subsequent development of osteoarthritis.

Risk of overconstraining femorotibial rotation after anatomical ACL reconstruction using bone patella tendon bone autograft.

Numerous studies have focused on the anteroposterior stability after anterior cruciate ligament (ACL) reconstruction, with less emphasis on rotational stability. It has been hypothesized that bone patella tendon bone (BTB) autograft for ACL reconstruction restores knee rotation closely to normal due to its comparable fiber orientation to the native ACL. Twenty patients with unilateral ACL rupture and an uninjured contralateral knee were included in this study. The ACL was reconstructed using the medial third of the patellar tendon. Tunnel placement was controlled by fluoroscopy. Implant-free press-fit graft fixation was used on both femoral and tibial side. Bone blocks were carefully placed to restore fiber orientation of both the anteromedial and posterolateral bundle, similar to the native ACL. Rotatory laxity of both knees was measured at 0° and 25° of flexion pre- and post-surgery, using an active opto-electronical motion-analysis system (LUKOTRONIC AS 100®). All measurements were performed under general anesthesia during surgery. Knee rotation was reduced significantly in both 0°and 25° of flexion following ACL reconstruction (p < 0.001). The side to side difference (SSD) of the rotatory laxity in extension was greater in the ACL-deficient knee (14.9° ± 8.9°), but decreased significantly after ACL reconstruction (- 5.9° ± 7.7°, minus value means less than in the uninjured knee). There was a similar finding at 25° of knee flexion where greater rotation of the ACL-deficient knee (5.7° ± 10.3°) prior to surgery changed to lower degree of rotation after surgery (- 11.3° ± 8.4°) in comparison to the uninjured knee. ACL reconstruction with a BTB graft in anatomical position using press-fit implant-free fixation is able to restore rotatory knee stability close to the intact contralateral knee. Despite the fact that the BTB graft offers fiber orientation close to the natural ACL, the surgeon should be aware of the potential risk of over-constraining the knee in terms of rotation. II.

Do Pediatric Patients With Anterior Cruciate Ligament Tears Have a Higher Rate of Familial Anterior Cruciate Ligament Injury?

Background:Several studies have examined the anterior cruciate ligament (ACL) injury history among relatives of patients undergoing ACL reconstruction (ACLR), but they have primarily analyzed adults with variable results.Hypothesis:We hypothesized that he rate of familial ACL injuries among pediatric patients with ACL tears would be greater than that among pediatric patients with uninjured knees.Study Design:Cohort study; Level of evidence, 3.Methods:Pediatric patients (≤18 years of age) who underwent ACLR between January 2009 and May 2016 were contacted to complete a questionnaire on subsequent complications and family history of ACL tears. A control cohort was recruited from children with uninjured knees seen in the concussion clinic of our institution. Binary logistic regression was used to determine the factors predictive of having a familial ACL tear history or complications.Results:Overall, 450 pediatric patients with primary ACL tears were included. Age at the time of surgery was 14.9 ± 2.2 years with a follow-up of 4.3 ± 2.1 years. When compared with 267 control patients, those with an ACL tear reported a higher rate of first-degree relatives with an ACL injury history (25.1% vs 12.0%; P < .001). In multivariate analysis, children with ACL injury had nearly 3 times (odds ratio [OR], 2.7) higher odds of having a first-degree relative with an ACL tear (95% CI, 1.7-4.2; P < .001). Patients were stratified by the number of first-degree relatives with ACL tears: no relatives, 1 relative, or ≥2 relatives. Children with ≥2 first-degree relatives were more likely to sustain a postoperative graft failure (OR, 5.1; 95% CI 1.7-15.2; P = .003) or a complication requiring surgical intervention (OR, 7.5; 95% CI, 2.6-22.0; P < .001).Conclusion:A family history of ACL injury is more likely in pediatric patients with ACL tears than in uninjured children. Further, patients undergoing primary ACLR as well as a strong family history of ACL tears are more likely to sustain a postoperative graft rupture or complication requiring surgery.

Preoperative Knee Instability Affects Residual Instability as Evaluated by Quantitative Pivot-Shift Measurements During Double-Bundle ACL Reconstruction.

Background:The pivot-shift test is an important indicator of functional outcomes after anterior cruciate ligament (ACL) reconstruction (ACLR). Preoperative instability as indicated by the pivot-shift test is associated with residual instability after ACLR. Few studies have used quantitative means to evaluate the pivot shift after ACLR.Purpose:To investigate the relationship between preoperative and residual instability and to identify the risk factors for residual instability by using quantitative measurements of the pivot shift.Study Design:Case-control study; Level of evidence, 3.Methods:A total of 91 patients undergoing primary double-bundle ACLR were retrospectively enrolled. Quantitative measurements of instability for ACL-deficient knees (ACLD) and uninjured contralateral knees (intact) preoperatively, as well as ACLR knees intraoperatively, were performed under general anesthesia using the pivot-shift test, with inertial sensors to measure acceleration and external rotational (ER) angular velocity. The ratios of intact to ACLD (ACLD/I) and intact to ACLR (ACLR/I) were measured. Patients who showed an ACLR/I of >1 were classified into the residual instability group, and those with an ACLR/I of ≤1 were classified into the noninstability group. Regarding demographic, surgical, and quantitative measurement factors, between-group comparisons and multivariate logistic regression were conducted for predictors of residual instability. Receiver operating characteristic curves were used to evaluate the correlations between ACLD/I and ACLR/I and the cutoff value of ACLD/I in predicting residual instability.Results:The predictive factors for intraoperative residual instability included female sex (odds ratio [OR], 0.3 [95% CI, 0.1-0.9]; P = .034) and ACLD/I for acceleration (OR, 1.6 [95% CI, 1.2-2.1]; P < .001), and ACLD/I for ER angular velocity (OR, 1.9 [95% CI, 1.2-3.1]; P = .013). Correlations between ACLD/I and ACLR/I were moderate with respect to both acceleration (r = 0.435; P < .001) and ER angular velocity (r = 0.533; P < .001). The cutoff points for ACLD/I were 4.9 for acceleration (sensitivity, 65.1%; specificity, 85.7%; area under the curve [AUC], 0.76) and 2.4 for ER angular velocity (sensitivity, 80.0%; specificity, 50.0%; AUC, 0.74).Conclusion:Greater preoperative instability was a risk factor for residual instability as measured intraoperatively by a quantitatively evaluation in the pivot shift during ACL reconstruction. Quantitative measurements of instability during the pivot shift mechanism under general anesthesia may enable surgeons to predict postoperative residual instability.

Neuromuscular Training Improves Self-Reported Function and Single-Leg Landing Hip Biomechanics in Athletes After Anterior Cruciate Ligament Reconstruction.

Background:Neuromuscular training (NMT) has been shown to attenuate high-risk biomechanics in uninjured athletes. At the time that athletes return to sport after anterior cruciate ligament (ACL) reconstruction (ACLR), they demonstrate hip biomechanical deficits associated with injury to the reconstructed knee versus the uninjured contralateral knee.Purpose:The primary purpose of the study was to examine whether an NMT program can improve single-leg drop (SLD) landing hip biomechanics for athletes after ACLR. Secondarily, we compared the posttraining SLD hip biomechanics of athletes after ACLR with a control group of athletes who also completed the NMT program.Study Design:Controlled laboratory study.Methods:A total of 18 ACLR and 10 uninjured athletes were recruited and completed a 12-session NMT program. A knee-specific questionnaire and biomechanics of an SLD task was evaluated for each athlete before and after NMT. Paired t tests were used to compare pre- and posttraining International Knee Documentation Committee (IKDC) scores. Repeated-measures analysis of variance (ANOVA) was performed to assess the main effects and interactions of testing session × limb for the ACLR athletes. A 2-way ANOVA was conducted to quantify the interactions and main effects of group × limb.Results:There was a significant increase (P = .03) in IKDC scores from pre- to posttraining. For the ACLR athletes, there was a significant session × limb interaction for hip external rotation moment (P = .02) and hip abduction angle (P = .013). Despite increases in hip external rotation moment, no significant changes from pre- to posttraining were observed for the involved limbs. No significant changes were observed for hip abduction angle of the involved limbs between training sessions. Significant main effects of session (P < .05) revealed that athletes landed with greater hip excursion, lower hip flexion moment, and lower ground-reaction force after training. The posttraining comparison between the ACLR and control groups found no significant group × limb interactions for any of the hip kinematic or kinetic variables. A significant main effect of group (P < .05) revealed that the ACLR athletes landed with greater hip flexion angle and hip external rotation moment.Conclusion:ACLR athletes demonstrated an improvement in SLD hip biomechanics and neuromuscular control after participating in an NMT program.Clinical Relevance:This evidence indicates a potential role for NMT to improve hip biomechanics during an SLD task so as to reduce ACL injury risk.

Single-Leg Squat After Anterior Cruciate Ligament Reconstruction: An Analysis of the Knee Valgus Angle at 6 and 12 Months.

Background:Deficits in neuromuscular control are common after anterior cruciate ligament (ACL) reconstruction and may be associated with further knee injury. The knee valgus angle during a single-leg squat (SLS) is one measure of neuromuscular performance.Purpose:To determine whether the knee valgus angle during SLS changes between 6 and 12 months after ACL reconstruction and to assess how the operative knee valgus angle compares with that of the contralateral side.Study Design:Case series; Level of evidence, 4.Methods:A cohort of 100 patients with uninjured contralateral knees were assessed at 6 and 12 months after primary hamstring autograft ACL reconstruction. Participants performed the SLS on each leg, and the knee valgus angle was measured via frame-by-frame video analysis at 30° of flexion and at each patient’s maximum knee flexion angle.Results:For the operative limb at 30° of flexion, a small but statistically significant reduction was noted in the valgus angle between 6 and 12 months (5.46° vs 4.44°; P = .002; effect size = 0.24). At 6 months, a slightly higher valgus angle was seen in the operative limb compared with the nonoperative limb (5.46° vs 4.29°; P = .008; effect size = 0.27). At maximum flexion, no difference was seen between limbs in the valgus angle at either 6 or 12 months, and no change was seen in the operative limb between 6 and 12 months. At 6 months and 30° of knee flexion, 13 patients had a valgus angle greater than 10°. This group also had a higher mean valgus angle in the contralateral limb compared with the contralateral limb in the other 87 patients (8.5° vs 3.65°; P < .001).Conclusion:During a controlled SLS, the knee valgus angle remained essentially constant, and minimal limb asymmetries were present over the 6- to 12-month postoperative period, a time when athletes typically increase their activity levels. Whether changes or asymmetries will be seen with more dynamically challenging tasks remains to be determined. When present, high valgus angles were commonly bilateral.

Do BTB ACLR Knees have more MRI signs of PTOA than their Contralateral Normal Knee at 2 Years?

Objectives:The prevalence of patellofemoral joint (PFJ) osteoarthritis (OA) ranges from 8-47% 7-10 years after anterior cruciate ligament reconstructions (ACLR) using bone-patellar tendon-bone (BTB) autograft. In performing BTB ACLR, some hypothesize that either trauma caused by harvest of the patellar bone autograft or altered biomechanics lead to PFJ post traumatic osteoarthritis (PTOA). Our objective was to evaluate by 3T MRI whether the ACLR knees had more signs of early PTOA compared to the contralateral knee within the MOON nested cohort. We hypothesize that a BTB autograft harvested using a minimally traumatic technique will not increase the risk of PFJ OA.Methods:MRIs of operative and contralateral uninjured knees were collected in 60 patients (28 males, mean age 21 years) from a single site in the Multicenter Orthopaedic Outcomes Network (MOON) nested cohort at minimum 2 years post BTB ACLR. Harvesting the patellar block for the BTB autograft was performed using an oscillating saw with a narrow blade, being careful not to extend the cut into the posterior cortex of the patella, and with gentle elevation of the bone block with an osteotome. MRI was performed at 3T (Philips, Achieva) and the imaging protocol included intermediate-weighted sagittal turbo spin-echo (TSE) imaging, axial and coronal fat-saturated TSE imaging, and 3D coronal gradient echo imaging. Structural MRI assessment of the knees was performed using the MRI Osteoarthritis Knee Score (MOAKS) semi-quantitative scoring system by a board-certified musculoskeletal radiologist. The prevalence of cartilage defects in each knee compartment (medial, lateral, patellofemoral), meniscal tears (medial, lateral; yes/no), bone marrow edema-like lesions (BMEL; medial, lateral, patellofemoral; yes/no), effusion (yes/no) and Hoffa synovitis (yes/no) were compared between the reconstructed and contralateral uninjured knees. Hypothesis testing was performed for the PF joint using a logistic regression model where the dependent variable was presence/absence of cartilage loss and the independent variable was knee status (surgical or contralateral).Results:There were no significant differences in the prevalence of cartilage defects (any lesions or full thickness loss) in the PFJ between the surgical BTB ACLR knees and the uninjured non-operative contralateral control knees. 38.3% of BTB ACLR knees had PFJ cartilage defects versus 31.7% of contralateral control knees with PFJ cartilage defects (p>0.05) (Table 1). The BTB ACLR knees had more cartilage defects in the medial and lateral tibiofemoral compartments, more meniscal tears, BMEL, effusion and Hoffa synovitis, than the contralateral knees. Figure 1 shows examples of PFJ cartilage defects on MRI for the reconstructed and contralateral uninjured knees. At 2 years follow-up, KOOS symptoms, sports, pain, and activities of daily living scores were maintained at a high level ranging from 88-98.Conclusion:Although prior studies suggest BTB ACLR increases the risk of PFJ OA, the current study shows no difference in MRI signs of early PTOA in the PFJ. Cartilage defects comparing reconstructed vs. contralateral uninjured knees 2 years after surgery based on MRI were not different. These results should be used in shared decision making with athletes in choosing the appropriate autograft during reconstruction. Future studies will investigate the influence of cartilage defects found in the medial and lateral compartments further.

Patient-Reported and Quantitative Outcomes of Anatomic Anterior Cruciate Ligament Reconstruction With Hamstring Tendon Autografts

Background:The pivot-shift test has become more consistent and reliable and is a meaningful outcome measurement after anterior cruciate ligament reconstruction (ACLR).Purpose/Hypothesis:The purpose of this investigation was to assess patient-reported outcomes (PROs) and the quantitative pivot shift (QPS) preoperatively, at time zero immediately after anatomic ACLR, and after 24 months as well as the relationship between PROs and the QPS. It was hypothesized that anatomic ACLR would restore rotatory stability measured by the pivot-shift test and that QPS measurements would be positively correlated with PROs.Study Design:Cohort study; Level of evidence, 2.Methods:The ACL-injured and contralateral uninjured knees from 89 of 107 (83.2%) enrolled patients at 4 international centers were evaluated using a standardized pivot-shift test. Tibial acceleration was assessed with an inertial sensor, and lateral compartment translation was measured using an image analysis system preoperatively, at time zero immediately postoperatively, and at follow-up after 2 years. PROs were assessed at 12 and 24 months postoperatively with the International Knee Documentation Committee (IKDC) subjective knee form, Cincinnati Knee Rating System (CKRS), Marx activity rating scale, and activity of daily living score (ADLS).Results:The mean patient age at surgery was 27 years (range, 15-45 years). A positive pivot shift preoperatively (side-to-side difference in tibial acceleration, 2.6 ± 4.0 m/s2; side-to-side difference in anterior tibial translation, 2.0 ± 2.0 mm) was reduced at time zero postoperatively (side-to-side difference in tibial acceleration, –0.5 ± 1.3 m/s2; side-to-side difference in anterior tibial translation, –0.1 ± 1.0 mm). All PROs improved from preoperatively to final follow-up at 24 months: from 56.5 to 85.5 points for the IKDC (P = .0001), from 28.8 to 32.4 points for the CKRS (P = .04), from 11.2 to 7.9 points for the Marx (P < .0001), and from 75.7 to 91.6 points for the ADLS (P < .0001). Neither preoperative nor time zero postoperative rotatory laxity assessed by the pivot-shift test correlated with PROs at 24-month follow-up. A graft retear was observed in 4 patients (4.5%) within 2 years of follow-up.Conclusion:Anatomic ACLR resulted in significantly improved and acceptable PROs at 2-year follow-up and a low failure rate. Anatomic ACLR restored QPS measurements of anterior tibial translation and tibial acceleration to those of the contralateral knee immediately after surgery while still under anesthesia, but there was no correlation between the QPS preoperatively or at time zero after ACLR and PROs at 2-year follow-up.

Proprioception deficiency in articular cartilage lesions of the knee

ABSTRACTPurposeThe purpose of this study is to investigate the proprioceptive function of patients with isolated articular cartilage lesions of the knee as compared to normal controls.MethodsThe Cartilage group consisted of eight subjects with radiologically and arthroscopically confirmed, isolated, unilateral, articular cartilage lesions of the knee (Outerbridge grade III or IV). They were compared to 50 normal controls. Knee proprioception was assessed by dynamic postural stabilometry using the Biodex Balance SD System. Patient-reported outcome measures (PROMs) were used to evaluate all subjects.ResultsProprioception of the injured knee of the Cartilage group was significantly poorer compared to that of the control group (p < 0.001). A significant proprioceptive deficit also was observed when the uninjured knees of the Cartilage group were compared to those in the Control group (p = 0.003). There was no significant proprioceptive difference between the injured and the contra-lateral uninjured knee of the Cartilage group (p = 0.116). A significant correlation was found between the proprioception measurements of the injured and uninjured knee of the Cartilage group (r = 0.76, p = 0.030). A significant difference was observed in all PROMs (p < 0.001) between the Cartilage and Control groups.ConclusionsPatients with isolated articular cartilage lesions of the knee had a significant proprioceptive deficit as compared to normal controls. The deficiency was profound and even affected the proprioceptive function of the contra-lateral uninjured knee. This study has shown that articular cartilage lesions have a major influence on knee proprioception. However, it remains uncertain as to whether a proprioceptive deficit leads to osteoarthritis or is a consequence of it.

The arthroscopic popliteus bypass reconstruction for posterolateral instabilities of the knee - clinical results &gt; 2 year follow up

Aims and Objectives:Injuries of the posterior cruciate ligament (PCL) are most often accompanied by injuries of the posterolateral corner (PLC) and the ligamentum collaterale fibulare (LCL). This leads to a combined dorsal- and external rotational instability. Prior to this study a novel arthroscopic technique was developed to treat posterolateral injuries (Popliteus Bypass Graft). To date, there are no long term results reported for arthroscopic techniques to treat these injuries. This study evaluated the clinical outcome of patients undergoing this surgery with a minimum follow up of 2 years.Materials and Methods:In the ongoing study, 47 patients with posterolateral instabilities of the knee were treated with an arthroscopic reconstruction of the popliteus bypass graft in combination with a PCL reconstruction. Patients with a minimum follow up of 2 years were included in this study. The clinical outcome was evaluated by subjective and objective scores for stability, pain and activity level: Lysholm, Tegner, KOOS, Dial test, subjective scores (0-10) for function (0 good, 10 poor) und pain (0 no pain, 10 intense pain). The dorsal stability was measured with the rolimeter.Results:At the time of the abstract submission 17 patients where evaluated. The mean age at the time of the operation was 36.8 (±15.5) years, the mean BMI was 27.7 (±5.5). The mean time from the injury to the treatment was 6.9 (±5.3) months. The mean follow up time was 46.35 (±12.7) months. The mean postoperative Lysholm score was 88.7 (± 13.4). The mean Tegner score was 6.0 (±2.2) preoperative and changed to 5.3 (±2.2) postoperative. The KOOS score was evaluated for pain 87.2 (±19.5), symptoms 92.5 (±11.1), daily activity 89.2 (±16.9), function 73.1 (±28.9) and life quality 78.5 (±21.7). The mean Rolimeter measurement for the uninjured knee was 7.16mm (±2.2) compared to the operated side with 8,18mm (±1.7). The VAS score for function was 1.6 (±2.1) and 1.6 (±2.2) for pain.Conclusion:The arthroscopic reconstruction of posterolateral injuries provides good clinical and subjective results after a minimum follow up of 2 years.

Do Looks or Measurements Really Matter When It Comes to ACL Tears?: Commentary on an article by Steve Bayer, BA, et al.: "Knee Morphological Risk Factors for Anterior Cruciate Ligament Injury. A Systematic Review".

Do Looks or Measurements Really Matter When It Comes to ACL Tears?: Commentary on an article by Steve Bayer, BA, et al.: "Knee Morphological Risk Factors for Anterior Cruciate Ligament Injury. A Systematic Review".

Modified Iliotibial Band Tenodesis Is Indicated to Correct Intraoperative Residual Pivot Shift After Anterior Cruciate Ligament Reconstruction Using an Autologous Hamstring Tendon Graft: A Prospective Randomized Controlled Trial

Background: The indications for the addition of anterolateral soft tissue augmentation to anterior cruciate ligament (ACL) reconstruction and its effectiveness remain uncertain. Purpose: To determine if modified iliotibial band tenodesis (MITBT) can improve clinical outcomes and reduce the recurrence of ACL ruptures when added to ACL reconstruction in patients with a residual pivot shift. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: Patients with a primary ACL rupture satisfying the following inclusion criteria were enrolled: first ACL rupture, involved in pivoting sports, skeletally mature, no meniscal repair performed, and residual pivot shift relative to the contralateral uninjured knee immediately after ACL reconstruction. Patients were randomized to group A (no further surgery) or group B (MITBT added) and were followed up for 2 years. The patient-reported outcome (PRO) measures used were the International Knee Documentation Committee (IKDC) score, Knee injury and Osteoarthritis Outcome Score (KOOS) subscale of sport/recreation (Sport/Rec), KOOS subscale of quality of life (QoL), Lysholm knee score (LKS), Tegner activity scale (TAS), recurrent ACL ruptures, or need for further surgery in either knee. Analysis of variance was used to compare PROs; the Wilcoxon test was used for the TAS; and the chi-square test was used for recurrence of ACL ruptures, meniscal injuries, and contralateral ACL ruptures (P < .05). Results: A total of 55 patients were randomized: 27 to group A (female:male ratio = 15:12; mean age, 22.3 ± 3.7 years) and 28 to group B (female:male ratio = 17:11; mean age, 21.8 ± 4.1 years). At 2-year follow-up, group A had a similar IKDC score (90.9 ± 10.7 vs 94.2 ± 11.2; respectively; P = .21), lower KOOS Sport/Rec score (91.5 ± 6.4 vs 95.3 ± 4.4, respectively; P = .02), similar KOOS QoL score (92.0 ± 4.8 vs 95.1 ± 4.3, respectively; P = .14), lower LKS score (92.5 ± 4.8 vs 96.8 ± 8.0, respectively; P = .004), lower TAS score (median, 7 [range, 7-9] vs 8 [range, 8-10], respectively; P = .03), higher rate of recurrence (14.8% vs 0.0%, respectively; P < .001), similar rate of meniscal tears (14.8% vs 3.6%, respectively; P = .14), and similar rate of contralateral ACL ruptures (3.7% vs 3.6%, respectively; P = .99) relative to group B. Conclusion: The augmentation of ACL reconstruction with MITBT reduced the risk of recurrent ACL ruptures in knees with a residual pivot shift after ACL reconstruction and improved KOOS Sport/Rec, LKS, and TAS scores. Registration: ACTRN12618001043224 (Australian New Zealand Clinical Trials Registry)

Posterolateral corner reconstruction in combined injuries of the knee: Improved stability with Larson's fibular sling reconstruction and comparison with LaPrade anatomical reconstruction

BackgroundThe goal of this prospective cohort study was to present the clinical results of a two-year follow-up of a Larson's posterolateral corner reconstruction (fibular sling) in patients with symptomatic instability of the knee. These data were compared with data of an anatomical reconstruction of the posterolateral corner as described by LaPrade et al. (combined tibial tunnel and fibular sling) [1]. MethodsEleven patients underwent a Larson's posterolateral corner reconstruction. Cruciate ligament ruptures were reconstructed if present. Multiple subjective knee outcome scores (VAS satisfaction score, Tegner, Lysholm, Noyes score, and IKDC subjective knee score) were obtained pre-operatively and two years after surgery. Laxity of the joint was measured using bilateral varus stress radiographs. ResultsAll patients had concomitant ACL or PCL surgery. VAS satisfaction, the Tegner, Noyes and the IKDC subjective knee score all improved significantly. Median varus laxity of the injured knee on varus stress radiographs improved significantly from 6.2° (3.1–10.1) to 3.9° (1.1–5.7), p = .0076. Post-operative varus laxity did not return to the level of the uninjured knee: 2.7° (1–5.7), p = .028. In comparison with our data on the reconstruction technique according to LaPrade, no statistically significant differences in clinical outcome were observed. ConclusionReconstruction of the posterolateral corner in combined injuries of the knee using a Larson fibular sling technique results in improved varus stability but not to the level of the uninjured knee. Functional knee scores improved significantly.We found no differences in functional and radiological outcome between the Larson's fibular sling reconstruction and LaPrade anatomical reconstruction. Level of evidenceIV

Isolated gracilis tendon harvesting is not associated with loss of strength and maintains good functional outcome.

The gracilis tendon is a commonly used autologous graft. Most information on knee function and outcomes after its harvest is related to both semitendinosus- and gracilis tendon harvest. Therefore this study analyzed the effect of isolated gracilis tendon harvest from healthy, uninjured knees on thigh muscle strength and patient reported outcome measures (PROMs). Stabilization of the acromioclavicular joint because of chronic instability was performed with autologous gracilis tendon in 12 patients. After a mean of 44 ± 25months after surgery, isokinetic peak-torque measurements of specific functions of the gracilis muscle were performed: knee flexion in a sitting position (flexion angles 0-90°) and in prone position (flexion angles > 70°), internal tibial rotation and hip adduction. The contralateral limb was control. Knee specific PROMs were collected including IKDC-2000 subjective evaluation form, Lysholm score, the Marx Activity Rating Scale and SF-36 health survey. No significant side-to-side differences were found regarding torque measurements. Excellent results were shown regarding the PROMs, which even in terms of IKDC-2000 (97 vs. 82 points, p = 0.001) exceeded significantly the age- and gender matched reference-data. Isolated gracilis tendon harvesting was not associated with loss of strength in knee flexion, internal tibial rotation and thigh adduction. Additionally, good functional outcome as well as excellent knee-specific subjective outcome was found. III.

Effects of knee pain on postural control excluding the musculature of the craniomandibular system

Knee pain can influence postural control in addition to changes in the anatomical structure of the knee joints. Because the influence of imbalances in the craniomandibular system has been proven multiple times, it is the aim of the present work to investigate the influence of various knee diagnoses on postural control excluding occlusal information by means of symmetrical packing using cotton rolls. One hundred and fifteen patients (74male/41female) aged 18-75years with an average BMI of 25.13 ± 3.66 kg/m2 took part in the study, among them 34patients (26male/8female) with cruciate ligament injury, 26(16male/10female) with meniscal lesions, 24(13male/11female) with arthrosis, 21(11male/10female) with patellar pain, and 10(8male/2female) with other painful knee complaints. Postural control was increased using a force platform, the degree of severity of the disorder was recorded using the "Knee Injury and Osteoarthritis Outcome" questionnaire, and the occlusion packed on both sides with cotton rolls in the premolar area. With increasing age, patients with knee arthrosis are more likely to stand on the hindfoot. In those with patellar disorder, increased weight-bearing on the forefoot correlates with increasing BMI. An increase in weight-bearing on the forefoot on the side of the uninjured knee in people with patellar disorder results not only in a reduction in quality of life but also level of daily activity. The percentage weight-bearing on the zones of the feet differs in unilateral knee injuries (in particular, comparison of the side with the knee injury and the uninjured side). Age, BMI or gender are influencing factors. Because various correlations and/or effects in the subgroups of knee injuries are generated, an injury-specific analysis should be carried out. These effects are also identifiable in the subjective assessment of quality of life.

Risk factors for residual anterolateral rotational instability after double bundle anterior cruciate ligament reconstruction: Evaluation by quantitative assessment of the pivot shift phenomenon using triaxial accelerometer

BackgroundExact knowledge of risk factors for residual anterolateral rotatinoal instability (ALRI) after anterior cruciate ligament (ACL) reconstruction is limited. The purpose of this study was to analyse possible risk factors for ALRI after ACL reconstruction. MethodsQuantitative assessment of the pivot shift phenomenon by measuring tibial acceleration was performed in 46 patients during primary double-bundle ACL reconstructions. The absolute value of the acceleration of the injured knee after provisional fixation of the ACL grafts (‘absolute residual acceleration’) and the subtraction of the acceleration of the uninjured knee from absolute residual acceleration (‘relative residual acceleration’) were defined as indicators for residual ALRI. The associations between these indicators and nine candidate risk factors were analysed using univariate and multiple regression analyses. ResultsMultiple regression analysis revealed that absolute residual acceleration was positively associated with both preoperative acceleration difference between injured and uninjured knees (β = 0.469, P < 0.001) and tibial acceleration of the uninjured knee (β = 0.597, P < 0.001). Relative residual acceleration was also positively associated with preoperative acceleration difference between injured and uninjured knees (β = 0.446, P< 0.001), but was negatively associated with tibial acceleration of the uninjured knee (β = −0.763, P < 0.001). ConclusionsPatients with larger preoperative side-to-side difference of the pivot shift phenomenon have higher risk for both absolute and relative residual ALRIs after ACL reconstruction, whereas patients with larger pivot shift phenomenon in their uninjured knees are at higher risk for absolute residual ALRI but not for relative residual ALRI.

Evaluating the Accuracy of Tibial Tunnel Placement After Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction

Background: Anatomic anterior cruciate ligament (ACL) reconstruction improves knee kinematics and joint stability in symptomatic patients who have ACL deficiency. Despite a concerted effort to place the graft within the ACL’s native attachment sites, the accuracy of tunnel placement using contemporary techniques is not well established. Purpose: To use 3-dimensional magnetic resonance imaging (3D MRI) to prospectively evaluate the accuracy of tibial tunnel placement after anatomic ACL reconstruction. Study Design: Case series; Level of evidence, 4. Methods: Forty patients with symptomatic, ACL-deficient knees were prospectively enrolled in the study and underwent 3D MRI of both their injured and uninjured knees before and after surgery through use of a validated imaging protocol. The root ligament of the anterior horn of the lateral meniscus was used as a radiographic reference, and the center of the reconstructed graft was compared with that of the contralateral normal knee. The tunnel angles and intra-articular graft angles were also measured, as was the percentage overlap between the native tibial footprint and tibial tunnel. Results: The reconstructed tibial footprint was placed at a mean ± SD of 2.14 ± 2.45 mm (P < .001) medial and 5.11 ± 3.57 mm (P < .001) posterior to the native ACL footprint. The mean distance between the center of the native and reconstructed ACL at the tibial attachment site was 6.24 mm. Of the 40 patients, 18 patients had a tibial tunnel that overlapped more than 50% of the native footprint, and 10 patients had maximal (100%) overlap. Further, 22 of the 40 patients had less than 50% overlap with the native footprint, and in 12 patients the footprint was missing completely. Conclusion: Despite the use of contemporary surgical techniques to perform anatomic ACL reconstruction, a significant positioning error in tibial tunnel placement remains.