The in vivo relationship between anterior neutral tibial position and loss of knee extension after transtibial ACL reconstruction

Evaluation under loading detects medial meniscus extrusion in patients with reconstructed anterior cruciate ligament and restricted knee extension

PURPOSE

Some patients who undergo anterior cruciate ligament (ACL) reconstruction experience abnormal mechanical stress in the meniscus. Medial meniscal extrusion (MME) is reflected in the pathological condition of the meniscus, which expands owing to repetitive mechanical stress. Thus, the effect of the reconstructed ACL on increasing MME under weight-bearing conditions remains unclear. This study investigated the effect of ACL reconstruction on meniscal extrusion under non-weight-bearing and weight-bearing conditions.

METHODS

Seventeen patients who underwent unilateral ACL reconstruction (ACL group) and 20 age-matched healthy volunteers (control group) were enrolled. Ultrasonography was performed in the supine, standing, and walking positions in preoperative and postoperative ACL patients. MME during walking was evaluated based on the dynamic behavior of extrusion, and kinetic and kinematic data were synchronously obtained. Moreover, the ACL group underwent magnetic resonance imaging (MRI) evaluation at two points: preoperatively and 12 months postoperatively, and the ultrasound findings were compared.

RESULTS

MME in the supine position measured using both ultrasonography and MRI was not significantly different preoperatively and postoperatively in the ACL group. However, postoperative MME and dynamic behavior of extrusion under standing and walking conditions were significantly higher than those in the preoperative state (dynamic behavior: 0.9 ± 0.4 mm preoperatively, 1.2 ± 0.4 mm postoperatively). Moreover, the deficits in knee extension during walking persisted postoperatively and were significantly higher than those in the control group.

CONCLUSION

MME in patients with ACL reconstruction including meniscus repair was different under mechanical stress compared to the non-weight bearing condition.

Rehabilitation And Advances In Surgical Reconstruction For Anterior Cruciate Ligament Insufficiency: What Has Changed Since The 1960s? - State Of The Art

Anterior cruciate ligament (ACL) insufficiency can be disabling, given the physical and sports activity constraints that negatively impact the quality of life. Consequently, surgery is the main approach for most active patients. Nonetheless, ACL reconstruction (ACLR) cannot be successful without adequate preoperative and postoperative rehabilitation. Since the 1960s, post-ACLR rehabilitation has evolved, mainly from advances in surgery, coupled with a better understanding of the biological concepts of graft revascularization, maturation and integration, which have impacted ACL postoperative rehabilitation protocols. However, new technologies do involve a definite learning curve which could affect rehabilitation programs and produce inconsistent results. The development of rehabilitation protocols cannot be defined without an accurate diagnosis of ACL injury and considering the patient's main physical demands and expectations. This article discusses how postoperative rehabilitation following ACLR has changed from the 1960s to now, focussing on surgical technique (type of tendon graft, fixation devices, and graft tensioning), biological concepts (graft maturation and integration), rehabilitation protocols (prevention of ACL injuries, preoperative rehabilitation, postoperative rehabilitation), criteria to return to sports, patient's reported outcomes and outcome. Although rehabilitation plays an essential role in managing ACL injuries, it cannot be fully standardised preoperatively or postoperatively. Preoperative and postoperative rehabilitation should be based on an accurate clinical diagnosis, patients' understanding of their injury, graft tissue biology and biomechanics, surgical technique, the patient's physical demands and expectations, geographical differences in ACL rehabilitation and future perspectives.

Clinical and Radiological Outcomes of Anteromedial Portal Versus Transtibial Technique in ACL Reconstruction: A Systematic Review

Background:

The drilling technique used to make a femoral tunnel is critically important for determining outcomes after anterior cruciate ligament (ACL) reconstruction. The 2 most common methods are the transtibial (TT) and anteromedial (AM) techniques.

Purpose:

To determine whether graft orientation and placement affect clinical outcomes by comparing clinical and radiological outcomes after single-bundle ACL reconstruction with the AM versus TT technique.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

Articles in PubMed, EMBASE, the Cochrane Library, ISI Web of Science, Scopus, and MEDLINE were searched from inception until April 25, 2020, using the following Boolean operators: transtibial OR trans-tibial AND (anteromedial OR trans-portal OR independent OR three portal OR accessory portal) AND anterior cruciate ligament.

Results:

Of 1270 studies retrieved, 39 studies involving 11,207 patients were included. Of these studies, 14 were clinical, 13 were radiological, and 12 were mixed. Results suggested that compared with the TT technique, the AM technique led to significantly improved anteroposterior and rotational knee stability, International Knee Documentation Committee (IKDC) scores, and recovery time from surgery. A higher proportion of negative Lachman (P = .0005) and pivot-shift test (P = .0001) results, lower KT-1000 arthrometer maximum manual displacement (P = .00001), higher Lysholm score (P = .001), a higher incidence of IKDC grade A/B (P = .05), and better visual analog scale score for satisfaction (P = .00001) were observed with the AM technique compared with the TT technique. The AM drilling technique demonstrated a significantly shorter tunnel length (P = .00001). Significant differences were seen between the femoral and tibial graft angles in both techniques. Low overall complication and revision rates were observed for ACL reconstruction with the AM drilling technique, similar to the TT drilling technique.

Conclusion:

In single-bundle ACL reconstruction, the AM drilling technique was superior to the TT drilling technique based on physical examination, scoring systems, and radiographic results. The AM portal technique provided a more reproducible anatomic graft placement compared with the TT technique.

Patient-Reported Outcomes and Knee Mechanics Correlate With Patellofemoral Deep Cartilage UTE-T2* 2 Years After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Patellofemoral joint degeneration and dysfunction after anterior cruciate ligament reconstruction (ACLR) are increasingly recognized as contributors to poor clinical outcomes.

PURPOSE

To determine if greater deep cartilage matrix disruption at 2 years after ACLR, as assessed by elevated patellofemoral magnetic resonance imaging (MRI) ultrashort echo time-enhanced T2* (UTE-T2*), is correlated with (1) worse patient-reported knee function and pain and (2) gait metrics related to patellofemoral tracking and loading, such as greater external rotation of the tibia at heel strike, reduced knee flexion moment (as a surrogate of quadriceps function), and greater knee flexion angle at heel strike.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

MRI UTE-T2* relaxation times in patellar and trochlear deep cartilage were compared with patient-reported outcomes and ambulatory gait metrics in 60 patients with ACLR at 2 years after reconstruction. ACLR gait metrics were compared with those of 60 uninjured reference patients matched by age, body mass index, and sex. ACLR UTE-T2* values were compared with those of 20 uninjured reference patients.

RESULTS

Higher trochlear UTE-T2* values were associated with worse Knee injury and Osteoarthritis Outcome Scores (KOOS) Sport/Recreation subscale scores (rho = -0.32; P = .015), and showed a trend for association with worse KOOS Pain subscale scores (rho = -0.26; P = .045). At 2 years after ACLR, greater external rotation of the tibia at heel strike was associated with higher patellar UTE-T2* values (R = 0.40; P = .002); greater knee flexion angle at heel strike was associated with higher trochlear UTE-T2* values (rho = 0.39; P = .002); and greater knee flexion moment showed a trend for association with higher trochlear UTE-T2* values (rho = 0.30; P = .019). Patellar cartilage UTE-T2* values, knee flexion angle at heel strike, and external rotation of the tibia at heel strike were all elevated in ACLR knees as compared with reference knees (P = .029, .001, and .044, respectively).

CONCLUSION

Patellofemoral deep cartilage matrix disruption, as assessed by MRI UTE-T2*, was associated with reduced sports and recreational function and with gait metrics reflective of altered patellofemoral loading. As such, the findings provide new mechanistic information important to improving clinical outcomes related to patellofemoral dysfunction after ACLR.

Effect of Graft Type on Thigh Circumference, Knee Range of Motion, and Lower-Extremity Strength in Pediatric and Adolescent Males Following Anterior Cruciate Ligament Reconstruction

CONTEXT

To treat anterior cruciate ligament (ACL) injury, ACL reconstruction (ACLR) surgery is currently a standard of the care. However, effect of graft type including bone-patellar tendon-bone (BTB), hamstring tendon, or iliotibial band (ITB) on thigh size, knee range of motion (ROM), and muscle strength are understudied.

OBJECTIVE

To compare postoperative thigh circumference, knee ROM, and hip and thigh muscle strength in adolescent males who underwent ACLR, based on the 3 different autograft types: BTB, hamstring (HS), and ITB.

SETTING

Biomechanical laboratory.

PARTICIPANTS

Male ACLR patients who are younger than 22 years of age (total N = 164).

INTERVENTION

At 6- to 9-month postoperative visits, thigh circumference, knee ROM, and hip and thigh muscle strength were measured.

MAIN OUTCOME MEASURES

Deficits of each variable between the uninvolved and ACLR limb were compared for pediatric and adolescent ACLR males in the BTB, HS, and ITB cohorts. Baseline characteristics, including physical demographics and meniscus tear status, were compared, and differences identified were treated as covariates and incorporated in analysis of covariance.

RESULTS

Data were from 164 adolescent male ACLR patients [mean age 15.7 (1.2) years]. There were no statistical differences in thigh circumference, knee ROM, hip abductor, and hip-extensor strength among the 3 autografts. However, patients with BTB demonstrated 12.2% deficits in quadriceps strength compared with 0.5% surplus in HS patients (P = .002) and 1.2% deficits in ITB patients (P = .03). Patients with HS showed 31.7% deficits in hamstring strength compared with 5.4% deficits in BTB (P = .001) and 7.7% deficits in ITB (P = .001) groups at 6- to 9-month postoperative visits.

CONCLUSION

Adolescent male ACLR patients with BTB and HS autografts demonstrated significant deficits in quadriceps and hamstring strength, respectively, at 6 to 9 months postoperatively. Minimal lower-extremity strength deficits were demonstrated in pediatric male ACLR patients undergoing ITB harvest.

Double-bundle anterior cruciate ligament reconstruction improves tibial rotational instability: analysis of squatting motion using a 2D/3D registration technique

Background

The anterior cruciate ligament-deficient (ACLD) knee requires appropriate treatment for the patient to return to sports. The purpose of this study was to clarify the kinematics of the anterior cruciate ligament-deficient knee in squatting motion before and after double-bundle anterior cruciate ligament reconstruction (DB-ACLR) using a 2D/3D registration technique.

Methods

The subjects of this study were 10 men with confirmed unilateral ACL rupture who underwent DB-ACLR. Computed tomography (CT) of the knee joints was performed before DB-ACLR. Fluoroscopic imaging of the knee motion in squatting before and after DB-ACLR was also performed. The 2D/3D registration technique is a method of calculating positional relationships by projecting the 3D bone model created from the CT data onto the image extracted from the fluoroscopic images. The tibial anteroposterior (AP) and rotational positions were analyzed with reference to the femur.

Results

The tibial AP position of the ACLD knees was significantly anterior to the contralateral knees (p = 0.015). The tibial rotational position of the ACLD knees was significantly internally rotated compared to the contralateral knees (p < 0.001). Both tibial AP and rotational positions improved after DB-ACLR (p < 0.001), with no significant differences compared to the contralateral knees.

Conclusion

DB-ACLR improved not only tibial AP instability but also tibial rotational instability at knee flexion with weight-bearing. DB-ACLR appears to be a useful technique for normalizing the knee joint kinematics of ACLD knees.

MRI UTE-T2* profile characteristics correlate to walking mechanics and patient reported outcomes 2 years after ACL reconstruction

OBJECTIVE

Quantitative magnetic resonance imaging (MRI) ultrashort echo time (UTE) T2* is sensitive to cartilage deep tissue matrix changes after anterior cruciate ligament reconstruction (ACLR). This study was performed to determine whether UTE-T2* profile analysis is a useful clinical metric for assessing cartilage matrix degeneration. This work tests the hypotheses that UTE-T2* depthwise rates of change (profile slopes) correlate with clinical outcome metrics of walking mechanics and patient reported outcomes (PRO) in patients 2 years after ACLR.

DESIGN

Thirty-six patients 2 years after ACLR completed knee MRI, gait analysis, and PRO. UTE-T2* maps were generated from MRI images and depthwise UTE-T2* profiles were calculated for weight-bearing cartilage in the medial compartment. UTE-T2* profiles from 14 uninjured subjects provided reference values. UTE-T2* profile characteristics, including several different measures of profile slope, were tested for correlation to kinetic and kinematic measures of gait and also to PRO.

RESULTS

Decreasing UTE-T2* profile slopes in ACLR knees moderately correlated with increasing knee adduction moments (r = 0.41, P < 0.015), greater external tibial rotation (r = 0.44, P = 0.007), and moderately negatively correlated with PRO (r = -0.36, P = 0.032). UTE-T2* profiles from both ACLR and contralateral knees of ACLR subjects differed from that of uninjured controls (P < 0.015).

CONCLUSIONS

The results of this study suggest that decreasing UTE-T2* profile slopes reflect cartilage deep tissue collagen matrix disruption in a population at increased risk for knee osteoarthritis (OA). That UTE-T2* profiles were associated with mechanical and patient reported measures of clinical outcomes support further study into a potential mechanistic relationship between these factors and OA development.

The Nature of Age-Related Differences in Knee Function during Walking: Implication for the Development of Knee Osteoarthritis

Background

Changes in knee kinematics have been identified in the early stages of osteoarthritis (OA). However, there is a paucity of information on the nature of kinematic change that occur with aging prior to the development of OA, This study applied a robust statistical method (Principal Component Analysis) to test the hypothesis that coupling between primary (flexion) and secondary (anterior-posterior translation, internal-external rotation) joint motions in walking would differ for age groupings of healthy subjects.

Methods

Seventy-four healthy participants divided into three groups with mean ages of 24 ± 2.3 years (younger), 48 ± 4.7years (middle-age) and 64 ± 2.4 years (older) were examined. Principal Component Analysis was used to characterize and statistically compare the patterns of knee joint movement and their relationships in walking.

Results

There were significant differences between the younger group and both the middle-age and older groups in the knee frontal plane angle and the coupling between knee flexion (PC₁, p≤0.04) and the relative magnitudes of secondary plane motions in early and late stance (PC₃, p<0.01). Two additional principal components (PC₂, p = 0.03 and PC₅, p<0.01) described differences in early stance knee flexion and relationship with secondary plane motion through-out stance for the older compared with middle-age group.

Conclusions

It appears there are changes in knee kinematics that occur with aging. The kinematic differences were identified for middle-aged as well as older adults suggesting midlife changes in neuromuscular physiology or behavior may have important consequences. These kinematic measures offer the potential to identify early markers for the risk of developing knee OA with aging.

Motion Task Selection for Kinematic Evaluation After Anterior Cruciate Ligament Reconstruction: A Systematic Review

PURPOSE

To examine the different motion tasks and the protocols used to objectively quantify dynamic stability in terms of knee kinematics at different stages of anterior cruciate ligament reconstruction (ACLR) recovery.

METHODS

A systematic search was done using OVID in Embase, Cochrane Central Register of Controlled Trials, Medline, PsychINFO, and AMED. A combination of the following keywords and their variations were used: anterior cruciate ligament, motion tasks (e.g., jump, hop, gait), and stability. The inclusion criteria were as follows: (1) ACLR subjects were recruited, (2) at least 1 motion task was performed and kinematics data were recorded, and (3) uninjured subjects or the contralateral uninjured limbs were included as a control group. Exclusion criteria were as follows: (1) non-English language publications, (2) retrospective studies and review articles, (3) animal studies, and (4) cadaveric studies.

RESULTS

The search returned 2,195 studies, and 56 were included in this review according to the criteria. A total of 1,086 ACLR subjects were included. Pivoting, landing, walking, running, stair negotiation, and squats were assessed using optoelectronic motion capture, electrogoniometry, or video-radiography.

CONCLUSIONS

The appropriate selection of motion tasks is an integral factor in dynamic stability testing as it evokes different kinematic outcomes in relation to the different stages of ACLR recovery. Stair negotiation and landing tasks are best performed during the early stages of recovery, and landing and pivoting are recommended 6 months after ACLR surgery.

LEVEL OF EVIDENCE

Level II, systematic review of Level I and II studies.

Functional knee assessment with advanced imaging

The purpose of anterior cruciate ligament (ACL) reconstruction is to restore the native stability of the knee joint and to prevent further injury to meniscus and cartilage, yet studies have suggested that joint laxity remains prevalent in varying degrees after ACL reconstruction. Imaging can provide measurements of translational and rotational motions of the tibiofemoral joint that may be too small to detect in routine physical examinations. Various imaging modalities, including fluoroscopy, computed tomography (CT), and magnetic resonance imaging (MRI), have emerged as powerful methods in measuring the minute details involved in joint biomechanics. While each technique has its own strengths and limitations, they have all enhanced our understanding of the knee joint under various stresses and movements. Acquiring the knowledge of the complex and dynamic motions of the knee after surgery would help lead to improved surgical techniques and better patient outcomes.

Does the hyperextension maneuver prevent knee extension loss after arthroscopic anterior cruciate ligament reconstruction?

Background

Disruption of the anterior cruciate ligament (ACL) is one of the most frequent musculoskeletal injuries affecting physically active men and women. In the United States, an estimated 200,000 ACL reconstructions are performed annually. One of the most common complications of ACL reconstruction is loss of extension. The purpose of this study was to assess the effects of the hyperextension maneuver on preventing knee extension loss after arthroscopic ACL reconstruction.

Materials and methods

In this prospective randomized clinical trial study, 100 adult patients with a documented complete ACL tear were randomized to two groups. All patients underwent arthroscopic ACL reconstruction with quadrupled semitendinosus and gracilis autograft by the senior author based on the same technique and instruments. However, the hyperextension maneuver was only performed in 50 patients during autograft fixation on the tibial side (case group). The postoperative rehabilitation protocol was similar for both groups. The knee range of motion and extension limit was evaluated at 2, 6, 12, and 24 weeks and at 1 year postoperatively.

Results

One hundred patients (88 male and 12 female) aged from 17−36 years (average 26.9 years) were included in our study. The two groups were similar regarding age, sex, and dominant side involvement (P >0.4).The difference between the two groups was significant only at 2 weeks (P <0.02). After 2 weeks, although the rate of limited extension was higher in the control group, no significant difference was seen between the groups.

Conclusion

Although the hyperextension technique during graft fixation on the tibial side may induce better range of motion in the first 2 weeks after ACL reconstruction surgery, this effect is not significant after 2 weeks.

Level of evidence

Therapeutic level II.

Comparison of volumetric bone mineral density in the operated and contralateral knee after anterior cruciate ligament and reconstruction: A 1-year follow-up study using peripheral quantitative computed tomography

The purpose of this study was to quantify changes in volumetric bone mineral density (vBMD) in the tibial plateau of the operated and contralateral leg measured using peripheral quantitative computed tomography (pQCT) before and 3, 6, and 12 months after anterior cruciate ligament (ACL) reconstruction. The ACL was reconstructed with a hamstring tendon autograft using press-fit fixation. pQCT measurements of the proximal tibia were obtained in 61 patients after ACL reconstruction, and total, cortical, and trabecular vBMD were calculated. vBMD in the operated leg decreased from baseline to 3 months (-12% [total], -11% [cortical], and -12.6% [trabecular]; p<0.001) and remained below baseline for 12 months after surgery (6 months: -9.5%, -9.4%, and -9.6%, p<0.001; 12 months: -8%, -5%, and -11%, p<0.001). vBMD in the contralateral leg was slightly reduced only 6 months after surgery. Including age and sex as covariates into the analysis did not affect the results. ACL reconstruction contributed to loss in bone mineral density within the first year after surgery. The role of factors such as time of weight-bearing, joint mechanics, post-traumatic inflammatory reactions, or genetic predisposition in modulating the development of posttraumatic knee osteoarthritis after ACL injury should be further elucidated.

Clinical and three-dimensional computed tomographic comparison between ACL transportal versus ACL transtibial single-bundle reconstructions with hamstrings

BACKGROUND

Anterior cruciate ligament (ACL) reconstruction using a single-bundle transtibial technique can achieve good or excellent results in more than 90% of patients, but anatomical and biomechanical studies have questioned its ability to restore knee function. The purpose of this study was to evaluate clinical and tomographic results (patient satisfaction, knee function, and tunnel location) of patients who underwent transportal or transtibial single-bundle ACL reconstruction.

METHODS

Seventy-one patients with ACL tears were included. Forty-one patients were treated by the single-bundle transportal technique and 30 patients were treated by the single-bundle transtibial technique. Clinical and tomographic data were analyzed in both groups.

RESULTS

After a minimum of 2-year period, the transportal group showed more patients with normal clinical tests than the transtibial group (Lachman [p=0.037], pivot shift [0.00], anterior drawer [0.002]; and arthrometer [0.002] tests). Regarding CT evaluation, transportal and transtibial groups obtained the following femoral central tunnel location (mean [SD]), as percentage: 30 (6.5) and 4.2 (6.4) in high-low axis; and 30.9 (5.9) and 33.2 (4.6) in the deep-shallow axis. Values in the tibial side were, respectively: 38 (6.5) and 46.0 (6.8) in the anterior-posterior axis; and 47.2 (2.5) and 46.9 (2.1) in the medial-lateral axis.

CONCLUSION

CT findings showed that the transportal single-bundle technique positions the ACL tunnel closer to the native ACL footprint in both femur and tibia compared with the transtibial single-bundle technique. Moreover, mild asymptomatic instability and extension deficit were observed more often in the transtibial group.