A deficient anterior cruciate ligament does not lead to quadriceps avoidance gait

Without an intact anterior cruciate ligament (ACL) to resist anterior tibial translation, it is commonly believed that ACL-deficient patients employ alterations in walking. Although there is no consensus in the literature about the specific kinematic and kinetic adaptations in these patients with ACL tears, the gait adaptation of quadriceps avoidance is perhaps the one most popularized. The purpose of our study was to determine whether quadriceps avoidance is common in patients with ACL-deficiency. We used a video-based motion analysis system and surface electromyography (EMG) to study 18 patients with ACL-deficiency. All patients demonstrated an internal knee extension moment during early mid-stance (similar to normal subjects). Quadriceps EMG activity was noted throughout most of stance. No patients demonstrated an internal knee flexion moment, a decreased internal knee extension moment or a decreased duration of quadriceps EMG activity during stance. The findings of this study would suggest that quadriceps avoidance as a gait adaptation in ACL-deficient patients may be less common than previously reported.     

Mechanism of quadriceps femoris muscle weakness in patients with anterior cruciate ligament reconstruction

The purpose of this study was to investigate gamma loop function in the quadriceps femoris muscle in patients who with less than 6 month-history of anterior cruciate ligament (ACL) reconstruction. For this purpose, we compared the response to vibration stimulation in 10 patients with ACL repair and 12 normal healthy subjects, by measuring the maximal voluntary isometric contraction (MVC) and integrated electromyograms (I-EMG) of the quadriceps muscles. Pre-vibration data were obtained from each subject by measuring the MVC of the knee extension and the I-EMG from the vastus medialis, vastus lateralis, and rectus femoris muscles. Vibration stimulation was applied to the infrapatellar tendons, followed immediately by repeating the MVC and I-EMG recording. Prolonged vibration resulted in a significant decrease of both MVC and I-EMG in the control group. In contrast, the same stimulus failed to elicit changes in ACL-repair group. Our results suggest the presence of abnormal gamma loop function in the quadriceps femoris muscle of patients with ACL repair, which may explain the muscle weakness often described in such patients.     

The effectiveness of preoperative exercise programmes on quadriceps strength prior to and following anterior cruciate ligament (ACL) reconstruction: A systematic review

Objectivesto evaluate the effectiveness of preoperative exercise programmes on quadriceps strength prior to and following anterior cruciate ligament (ACL) reconstruction.DesignSystematic review.Methodsa systematic review was undertaken, included studies were evaluated using the Modified Downs and Black checklist which is appropriate for determining the quality of randomised and non-randomised studies. Scientific databases searched included PubMED, EBSCO Health, CINAHL, Medline, and Cochrane Library databases from inception to March 2021.ResultsTen studies met the inclusion criteria. There were six randomised studies and four prospective studies. The level of evidence is categorised as ‘limited’ due to heterogenicity and only six studies reported quadriceps strength increases. Five studies demonstrated preoperative exercise of 4–16 weeks duration can significantly increase preoperative quadriceps strength. One study demonstrated preoperative OKC exercise produced significantly stronger preoperative quadriceps compared to CKC exercise. One study showed no between group (intervention vs control) quadriceps strength difference pre or 12 weeks postoperatively.Conclusions4–16 weeks of preoperative exercise could increase quadriceps strength preoperatively but any persistent postoperative strength benefit from undertaking a standardised preoperative intervention is unclear. There is considerable variation and methodological limitations across the included studies and the composition of optimal preoperative ACLR exercise is currently unknown.     

Electromyographic predictors of residual quadriceps muscle weakness after anterior cruciate ligament reconstruction

BACKGROUND: Despite the high prevalence of residual quadriceps muscle weakness after anterior cruciate ligament reconstruction, specific predictive factors have not been identified. HYPOTHESIS: Electromyographic analysis is a better predictor of residual muscle weakness than is preoperative strength. STUDY DESIGN: Prospective cohort study. METHODS: The quadriceps muscle strength of 37 patients (25 men, 12 women) was measured before reconstruction and 5 weeks and 6 months after surgery. Quadriceps surface electromyographic signals were recorded during all of the strength tests. Integrated electromyographic analysis and median frequency measurements were computed as deficits on the involved side. Patients also performed a single-legged hop test at the 6-month follow-up examination. RESULTS: The patients had significantly lower strength, integrated electromyographic analysis, and median frequency measurements on the involved side at all three time intervals. The best predictor of the quadriceps muscle strength deficit at 6 months was the combination of the preoperative median frequency deficit and the 5-week postoperative strength deficit. The best predictor of the hop test deficit at 6 months was the combination of preoperative deficits in integrated electromyographic analysis and median frequency. CONCLUSION: Preoperative electromyographic indices of quadriceps muscle function and early postoperative strength were predictive of residual weakness and impaired function 6 months after reconstruction.     

Symmetry tensiomyographic neuromuscular response after chronic anterior cruciate ligament (ACL) reconstruction

Purpose

Quadriceps muscle weakness is common following anterior cruciate ligament (ACL) reconstruction. Tensiomyography is a recent method to assess muscle strength, and one that also enables evaluation of individual muscles. The purpose of this study was to evaluate motor unit recruitment and investigate the effects on mechanical and contractile characteristics of the quadriceps and hamstring muscles after chronic ACL reconstruction.

Methods

This study recruited 20 participants: three males and seven females at 24 months after ACL reconstruction, and three males and seven females with no history of knee injury (control group). All participants underwent tensiomyographic assessment of each thigh muscle, bilaterally, to measure maximal displacement, delay time, contraction time, sustained time, and half-relaxation time. The following muscles were evaluated: vastus medialis, vastus lateralis, rectus femoris, semitendinosus, and biceps femoris. Mean normalized muscle peak torque, mean normalized maximum work done, mean angle to peak torque, and mean time to peak torque based on isokinetic peak torque measurements were calculated in both groups.

Results

Maximal displacement of the vastus medialis on the ACL reconstruction side was significantly higher than for the non-ACL reconstruction side and for the control group (p?=?0.026). Half-relaxation time for the vastus medialis and biceps femoris was significantly higher for both the ACLR and non-ACLR sides compared with the control group (p?=?0.001). There were also significant differences in symmetry in the vastus medialis and biceps femoris when comparing results between the ACL reconstruction group and the control group (p?=?0.034, p?=?0.043, respectively).

Conclusions

The presence of strength and symmetry deficits in the vastus medialis and biceps femoris suggests the need for long-term post-operative training following ACL reconstruction. There are clinical relevant improvements of muscle response and velocity as well as muscle strength in patients with chronic ACLR.

Level of evidence

II.

     

Impact of quadriceps strengthening on response to fatiguing exercise following ACL reconstruction

Objectives

Patients commonly experience altered response to fatiguing exercise after ACL reconstruction (ACLR). The objective of this study was to assess the impact of quadriceps strengthening on response to exercise after ACLR.

Infrapatellar heterotopic ossification after anterior cruciate ligament reconstruction

Reconstruction of the anterior cruciate ligament (ACL) is currently a common procedure. We report a case of ACL reconstruction using an autologous patellar tendon graft, where great infrapatellar heterotopic ossification occurred post-operatively. We found no similar cases in the literature. We discuss about the probable origin.     

Strategies for revision surgery after primary double-bundle anterior cruciate ligament (ACL) reconstruction

Purpose

The purpose of this article was to discuss pre- and intra-operative considerations as well as surgical strategies for different femoral and tibial tunnel scenarios in revision surgery following primary double-bundle anterior cruciate ligament (ACL) reconstruction.

Methods

Based on the current literature of ACL revision surgery and surgical experience, an algorithm for revision surgery after primary double-bundle ACL reconstruction was created.

Results

A guideline and flowchart were created using a case-based approached for revision surgery after primary double-bundle ACL reconstruction.

Conclusion

Revision surgery after primary double-bundle ACL reconstruction can be a challenging procedure that requires flexibility and a repertoire of surgical techniques. The combination of pre-operative planning with 3D-CT reconstruction, in addition to careful intra-operative assessment, and the use of this flowchart can simplify the ACL revision procedure.

Level of evidence

V.     

Feasibility,correlates, and validity of the one-leg sit-to-stand test in individuals following anterior cruciate ligament reconstruction

ObjectiveRegular quadriceps strength assessment is important following anterior cruciate ligament reconstruction (ACLR). The one-leg sit-to-stand (OLSTS) test potentially overcomes the barrier of accessibility to specialised testing equipment. However, feasibility and validity testing of OLSTS is lacking in the ACLR population. This study aims to examine the feasibility, correlates, and predictive validity of OLSTS with self-reported running and jumping difficulty in individuals post-ACLR.DesignRetrospective longitudinal study.Methods20 patients with primary unilateral ACLR were tested at 6-months and 1-year post-ACLR. Feasibility was assessed by the number of patients who had safely performed OLSTS at both timepoints. Cross-sectional gender-adjusted Spearman correlations of OLSTS with quadriceps strength, physical impairments, and psychological variables were measured at 6-months. Predictive validity was assessed via ordinal regression, quantifying the associations of OLSTS with self-reported running and jumping difficulty across time-points.ResultsAll patients understood the instructions to and were able to self-administer the OLSTS test safely. OLSTS is a valid measure of quadriceps strength (gender-adjusted Spearman's ρ = 0.53, P = 0.02). Knee pain (ρ = 0.44, P = 0.046) and readiness to return-to-sport (ρ = 0.55, P = 0.02) were additional correlates. Greater OLSTS performance was associated with greater odds of better self-reported running and jumping function (interquartile-range ORs, 12.0 [95% CI: 3.6–45] and 18.5 [95% CI: 5–67], respectively).ConclusionOLSTS is a feasible and valid test of quadriceps strength, demonstrating predictive validity with self-reported running and jumping post-ACLR. OLSTS potentially allows independent tracking of ACLR rehabilitation progress at home – an increasingly urgent necessity in the face of a global pandemic.     

Quantifying the relationship between quadriceps strength and aerobic fitness following anterior cruciate ligament reconstruction

ObjectiveTo quantify the relationship between quadriceps strength and aerobic fitness following ACLR.Methods42 individuals with ACLR (29F/13M, 20.2 ± 3.3years, 71.8 ± 17.4 kg, 171.1 ± 9.4 cm, 21.9 ± 21.5months post-surgery) and 38 healthy controls (24F/14M, 20.1 ± 1.4years, 69.8 ± 10.2 kg, 172.9 ± 8.7 cm) completed quadriceps strength testing using an instrumented dynamometer then completed an incremental treadmill test to determine aerobic fitness (VO₂max). Bivariate Pearson's correlations were calculated between strength and VO₂max. Significant correlations were retained for a regression analysis.ResultsHealthy controls demonstrated significantly greater VO₂max compared to the ACLR group (d = 0.56). Unilateral strength variables were significantly correlated with VO₂max (P ≤ 0.006) for both groups. Normalized peak isokinetic knee extensor torque was retained in the model, which explained 20.5% of the variance in healthy VO₂max and 37.2% of the variance in ACLR VO₂max.ConclusionsAerobic fitness was reduced in the ACLR group in comparison to the healthy controls, despite unrestricted return to activity and similar activity levels between groups. Unilateral quadriceps strength was significantly correlated with aerobic fitness, which may be an indicator that greater unilateral strength may be a proxy for assessing aerobic fitness. Furthermore, sports medicine professionals may consider incorporating techniques and exercises during rehabilitation to improve cardiovascular fitness following ACLR.     

The concept of individualized anatomic anterior cruciate ligament (ACL) reconstruction

Purpose

To describe the concept of individualized anatomic anterior cruciate ligament (ACL) reconstruction.

Methods

The PubMed/Medline database was searched using keywords pertaining to ACL reconstruction. Relevant articles were reviewed in order to summarize important concepts of individualized surgery in ACL reconstruction. Surgical experiences with case examples are also highlighted.

Results

Individualized ACL surgery allows for the customization of surgery to each individual patient. Accounting for graft selection and other characteristics such as anatomy, lifestyle and activity preferences may provide the patient with the best potential for a successful outcome. The surgeon should be comfortable with a variety of graft harvests and surgical techniques when practicing individualized surgery.

Conclusion

Individualized anatomic ACL reconstruction is founded on the objective evaluation of functional anatomy and individual characteristics, thereby restoring the ACL as closely as possible to the native anatomy and function. The adoption and subsequent use of individualized surgery may facilitate improved clinical as well as objective outcomes, particularly in the long term.

Level of evidence

V.     

Continuous passive motion in rehabilitation after anterior cruciate ligament reconstruction

In a prospective, randomized study, 34 patients (25 male, 9 female; mean age 27±8 years) with unilateral anterior cruciate ligament ruptures and arthroscopic reconstruction with patellar tendon grafts were allocated at random to either early active motion only (AM;n=17) or active motion in combination with continuous passive motion (CPM;n=17). Range of motion was measured with a goniometer and joint swelling with a tape measure, preoperatively and at 6 weeks postoperatively. Neither associated injuries nor the age of the aptients differed in the two groups. There was no difference in the range of motion between the two groups at 6 weeks' follow-up. Joint swelling was more pronounced in the AM group both preoperatively and at 6 weeks' follow-up. In this investigation the range of motion was not improved by CPM. The difference in joint swelling between the two groups may be explained by a persistent preoperative variation in joint effusion due to an imbalanced distribution of acute and chronic cases.     

The relationship between quadriceps strength asymmetry and knee biomechanics asymmetry during walking in individuals with anterior cruciate ligament reconstruction

BackgroundLower extremity movement asymmetries may lead to re-injury and knee osteoarthritis after anterior cruciate ligament (ACL) reconstruction surgery. However, there is no consensus regarding the effect of quadriceps strength asymmetry on lower extremity movement asymmetry after ACL reconstruction.Research questionWhat is the relationship between quadriceps strength asymmetry and asymmetries in lower extremity kinematics and kinetics during walking in individuals who underwent ACL reconstruction surgery?.MethodsIsometric quadriceps strength, kinematic, and kinetic data during walking were collected from 24 men with unilateral ACL reconstruction. Knee joint angles and moments were reduced. Pearson correlation coefficients between asymmetry in selected knee biomechanics and isometric quadriceps strength asymmetry were determined.ResultsThe isometric quadriceps strength of the injured leg was significantly lower than that of the uninjured leg (P < 0.001). Knee flexion angles and knee extension moments were smaller in the injured leg than that in the uninjured leg during both loading response (P = 0.007, P = 0.047) and mid-stance phases (P = 0.005, P = 0.028). Isometric quadriceps strength asymmetry was significantly correlated with asymmetry in the peak knee flexion angle during loading response and mid-stance phases (r = −0.48, P = 0.017, r = −0.48, P = 0.017). Isometric quadriceps strength asymmetry was also significantly correlated with asymmetry in the peak knee extension moment during the mid-stance phase (r = −0.44, P = 0.033).SignificanceIndividuals with ACL reconstruction demonstrate knee movement asymmetry in the sagittal plane. Isometric quadriceps strength asymmetry is significantly correlated with asymmetry in knee flexion angles during the early stance phase and knee extension moments during the mid-stance phase. Rehabilitation programs should emphasise eccentric exercise to beneficially modify quadriceps neuromuscular control.     

A meta-analysis of stability of autografts compared to allografts after anterior cruciate ligament reconstruction

Allografts have recently become increasingly popular for anterior cruciate ligament reconstruction (ACLR) in the United States even though many studies have shown high allograft failure rates (Gorschewsky et al. in Am J Sports Med 33:1202, 2005; Pritchard et al. in Am J Sports Med 23:593, 2005; Roberts et al. in Am J Sports Med 19:35, 2006) and no meta-analysis or systematic review of allograft clinical stability rates in comparison to autog rafts has previously been performed. We hypothesized that allografts would demonstrate overall lower objective stability rates compared to autografts. To test this hypothesis we performed a meta-analysis of autograft and allograft stability data. A pubmed literature search of all allograft series in humans published in English was performed. Articles were then bibliographically cross-referenced to identify additional studies. Series inclusion criteria were arthrometric follow-up data using at least 30 lb or maximum manual force, stratified presentation of stability data and minimum two-year follow-up. Twenty allograft series were thus selected and compared to a previously published data set of all BPTB and Hamstring (HS) autograft ACLR series using the same study inclusion criteria and analytic and statistical methodology. IKDC standards of 0–2 mm (normal) and >5 mm (abnormal) side-to-side differences were adopted to compare studies. Normal stability for all autografts was 72 versus 59% for all allografts (P < 0.01). Abnormal stability was 5% for all autografts versus 14% for all allografts (P < 0.01). Bone-patellar-tendon-bone (BPTB) autograft normal stability was 66% versus 57% for BPTB allografts (P < 0.01). Abnormal BPTB autograft stability was 6 versus 16% for BPTB allograft. Hamstring autograft normal or abnormal stability rates were 77% and 4% and were compared to soft tissue allografts as a group which were 64% and 12% (P < 0.01). This is the first meta-analysis comparing autograft to allograft stability in ACLR. Allografts had significantly lower normal stability rates than autografts. The allograft abnormal stability rate, which usually represents graft failure, was significantly higher than that of autografts: nearly three times greater. It would therefore appear that autografts are the graft of choice for routine ACLR with allografts better reserved for multiple ligament-injured knees where extra tissue may be required.     

Variability in rehabilitation protocols following pediatric anterior cruciate ligament (ACL) reconstruction

ABSTRACT

Objectives: The objective of this study was to assess the variability of publicly available pediatric anterior cruciate ligament (ACL) reconstruction rehabilitation protocols produced by academic orthopedic surgery departments and children’s hospitals.

Methods: A web-based search was performed to identify rehabilitation protocols. Protocol and literature review guided the development of a comprehensive scoring rubric that was used to assess protocols for the presence and timing of postoperative adjunctive therapy and physical therapy recommendations.

Results: A search of 180 academic orthopedic surgery programs and 250 children’s hospitals identified 21 rehabilitation protocols. A majority of these protocols (90%) recommended postoperative adjunctive therapies such as bracing (81%), cryotherapy (43%), electrical muscle stimulation (24%), and/or continuous passive motion (14%). Several protocols (57%) recommended a specific weight-bearing status in the immediate postoperative period, but there was minimal consensus on that status. Conversely, there was more agreement amongst protocols that recommended strength exercises (52%); a majority of protocols suggested quad sets (91%), ankle pumps (73%), leg press (64%), and/or double-leg squats (55%). Ten protocols (48%) recommended initiation of stretches in the first week following surgery, and most commonly suggested patella mobilizations start at an average of 1.9 weeks postop (range 0–8 weeks). Twelve protocols (57%) discussed return to play, with an average recommended return to play at 7.5 months (range 3–11 months) postoperatively. However, few protocols recommended that patients get approval from their surgeon (19%) or pass specific tests (24%) prior to return to play.

Conclusion: Few academic departments of orthopedic surgery or children’s hospitals publish pediatric ACL reconstruction protocols online. Given the substantial variability observed amongst these protocols and recent findings that patients increasingly turn to the internet for medical information, this study suggests that standardization of pediatric ACL reconstruction rehabilitation has the potential to further optimize patient care.     

Effects of closed versus open kinetic chain knee extensor resistance training on knee laxity and leg function in patients during the 8- to 14-week post-operative period after anterior cruciate ligament reconstruction

Open kinetic chain (OKC) knee extensor resistance training has lost favour in ACLR rehabilitation due to concerns that this exercise is harmful to the graft and will be less effective in improving function. In this randomized, single-blind clinical trial OKC and closed kinetic chain (CKC) knee extensor training were compared for their effects on knee laxity and function in the middle period of ACLR rehabilitation. The study subjects were 49 patients recovering from ACLR surgery (37 M, 12 F; mean age=33 years). Tests were carried out at 8 and 14 weeks after ACLR with knee laxity measured using a ligament arthrometer and function with the Hughston Clinic knee self-assessment questionnaire and single leg, maximal effort jump testing (post-test only). Between tests, subjects trained using either OKC or CKC resistance of their knee and hip extensors as part of formal physical therapy sessions three times per week. No statistically significant (one-way ANOVA, p>0.05) differences were found between the treatment groups in knee laxity or leg function. OKC and CKC knee extensor training in the middle period of rehabilitation after ACLR surgery do not differ in their effects on knee laxity or leg function. Exercise dosages are described in this study and further research is required to assess whether the findings in this study are dosage specific.     

Arthroscopic anterior cruciate ligament reconstruction with quadriceps tendon autograft: clinical outcome in 4–7 years

Surgical reconstruction of the anterior cruciate ligament (ACL) is indicated in the ACL-deficient knee with symptomatic instability and multiple ligaments injuries. In the present study, we describe the clinical results of quadriceps tendon-patellar bone autograft for ACL reconstruction. From 1996 to 1998, the graft has been used in 38 patients. Thirty-four patients with complete final follow-up for 4–7 years were analyzed. The average follow-up time was 62 (48–84) months. Thirty-two patients (94%) achieved good or excellent results by Lysholm knee rating. Twenty-six patients (76%) could return to moderate or strenuous activity after reconstruction. Twenty-eight patients (82%) had ligament laxity of less than 2 mm. Finally; 31 patients (91%) were assessed as normal or nearly normal rating by IKDC guideline. Twenty-five patients (73%) had less than 10 mm difference in thigh girth between their reconstructed and normal limbs. Thirty-two (94%) and 31 (91%) patients could achieve recovery of the extensor and flexor muscle strength in the reconstructed knee to 80% or more of normal knee strength, respectively. A statistically significant difference exists in thigh girth difference, extensor strength ratio, and flexor strength ratio before and after reconstruction. Tunnel expansion with more than 1 mm was identified in 2 (6%) tibial tunnels. Our study revealed satisfactory clinical subjective and objective results at 4–7 years follow-up. Quadriceps tendon autograft has the advantage of being self-available, relatively easier arthroscopic technique, and having a suitable size, making it an acceptable graft choice for ACL reconstruction. There is little quadriceps muscle strength loss after quadriceps harvest. A quadriceps tendon-patellar autograft is an adequate graft choice to ACL reconstruction.     

Alterations in medial-lateral postural control after anterior cruciate ligament reconstruction during stair use

BackgroundDynamic postural control during everyday tasks is poorly understood in people following anterior cruciate ligament reconstruction (ACLR). Understanding dynamic postural control can provide insight into potentially modifiable impairments in people following ACLR who are at increased risk for second ACL injury and/or knee osteoarthritis.Research questionDetermine whether measures indicative of dynamic postural control differ between individuals with and without ACLR during stair ascent and descent. Methods: Seventeen individuals with ACLR (>1 yr post-surgery) and 16 age and sex-matched healthy controls participated. Centre of pressure (COP) measures included: i) COP excursion, ii) COP velocity, and iii) dynamic time-toboundary (TTB). Mixed linear models were used to compare COP measures for the ACLR leg, non-ACLR leg, and healthy controls during stair ascent and stair descent.ResultsThere were no statistically significant differences observed during stair ascent (all p > 0.05). Several statistical differences were found during stair descent for individual with ACLR, but not between those with ACLR and healthy controls. The ACLR leg had higher medial-lateral COP excursion (mean difference 1.06 cm, [95 %CI 0.08–2.06 cm], p = 0.036; effect size = 0.38) compared to the non-ACLR leg during stair descent. In addition, the ACLR leg had a lower medial-lateral TTB (mean difference −13 ms [95 %CI −38 to 2 ms], p = 0.005; effect size = 0.49) and medial-lateral TTB normalized to stance time (mean difference −5.8 % [95 %CI −10.3 to 1.3 %], p = 0.012; effect size = 0.80) compared to the non-ACLR leg during stair descent. No statistical differences were observed for anterior-posterior measures during stair descent (all p > 0.05). Significance: Taken together, findings indicate that there are small to large differences in medial-lateral postural control in the ACLR leg compared to the non-ACLR leg during stair descent. Further work is required to understand clinical implication of these novel observations.