Maximizing quadriceps strength after ACL reconstruction

The primary objectives of ACL surgery and rehabilitation are to restore knee function to preinjury levels and promote long-term joint health. Often these goals are not achieved, however. The quadriceps is critical to dynamic joint stability, and weakness of this muscle group is related to poor functional outcomes. Because of this, identifying strategies to minimize quadriceps weakness following ACL injury and reconstruction is of great clinical interest. This article reviews the current literature and critically discusses current rehabilitation approaches to restore quadriceps muscle function after ACL reconstruction.     

Muscle strength and hop performance criteria prior to return to sports after ACL reconstruction

Purpose  

The purpose of this article is to present recommendations for new muscle strength and hop performance criteria prior to a return to sports after anterior cruciate ligament (ACL) reconstruction.     

Documentation of strength training for research purposes after ACL reconstruction

Purpose

The purpose of this systematic literature review was to evaluate strength training protocol documentation during rehabilitation after anterior cruciate ligament (ACL) reconstruction. The aim was further to present recommendations concerning what components (i.e. methods, principles and training variables) could be considered vital to document when it comes to strength training for research purposes after ACL reconstruction.

Methods

A search of the PUBMED/MEDLINE, CINAHL and SportDiscus databases was made of relevant literature relating to strength training after ACL reconstruction. The database search was based on relevant medical subject headings terms (strength/resistance/weight training, anterior cruciate ligament reconstruction/rehabilitation). The literature was reviewed regarding the way methods and variables were documented in strength training protocols during rehabilitation after ACL reconstruction in peer-reviewed original prospective articles.

Results

The systematic literature search identified 139 citations published between January 1983 and May 2012. Six studies contained a strength training programme-part of the rehabilitation protocol after ACL reconstruction that met the inclusion criteria. Basic information (i.e. training frequency, intensity, volume, progression or the duration of the training period) regarding the strength training protocols used during rehabilitation after ACL reconstruction was not documented in full in four of the studies.

Conclusion

The results clearly indicate the need of a more standardised and detailed way of documenting strength training for research purposes after ACL reconstruction in order to increase the value of future studies on this subject. This review gives recommendations on strength training protocol documentation after ACL reconstruction to facilitate this goal.

Level of evidence

IV.     

Landing adaptations after ACL reconstruction

PURPOSE: The purpose of this study was to determine whether fully rehabilitated ACL reconstructed (ACLr) recreational athletes utilize adapted lower-extremity joint kinematics and kinetics during a high-demand functional task. METHODS: The kinematic and kinetic performance of 11 healthy and 11 hamstring ACLr recreational athletes were compared during a 60-cm vertical drop landing. RESULTS: At initial ground contact, the ACLr group demonstrated greater hip extension and ankle plantarflexion compared with the healthy group. The peak vertical ground-reaction force was not different between groups, but the ACLr group delayed the time to its occurrence. The knee extensors provided the major energy absorption function for both groups; however, the ACLr group performed 37% more ankle plantarflexor work and 39% less hip extensor work compared with the healthy group. CONCLUSIONS: The hamstring ACLr recreational athletes utilized an adapted landing strategy that employed the hip extensor muscles less and the ankle plantarflexor muscles more. The harvesting of the medial hamstring muscles for ACL reconstruction may contribute to the utilization of this protective landing strategy.     

Prospective study of kinesthesia after ACL reconstruction

Previous studies used a variety of methods to assess kinesthesia, thus no consensus exists regarding kinesthetic adaptation after anterior cruciate ligament (ACL) reconstruction. This study prospectively examined whether kinesthesia is adapted after ACL reconstruction, and then discussed the actual angular velocity required to properly assess kinesthesia in ACL-reconstructed patients. 31 patients were evaluated using the threshold to detect passive motion (TTDPM) test, which was applied preoperatively, and at 3, 6, and 12 months following surgery. TTDPMs were measured at 15° or 45° of knee flexion toward both extension and flexion with angular velocities of 0.1°/s or 0.2°/s. ACL-reconstructed knees showed significantly impaired TTDPMs compared to healthy knees before the operation at 15° of knee flexion toward extension and at 45° of knee flexion toward both extension and flexion at 0.2°/s (15° of knee flexion toward extension, P=0.036; 45° of knee flexion toward extension, P=0.015; 45° of knee flexion toward flexion, P=0.030). However, there were no significant differences after 3 months of follow-up. On the basis of these results, applying 0.2°/s seems appropriate to assess TTDPM for patients with an ACL reconstruction, and kinesthesia is adapted within 12 months after the operation. Sensory function and biomechanical stability are also adapted following ACL reconstruction.     

Muscle fiber conduction velocity in the vastus lateralis and medialis muscles of soccer players after ACL reconstruction

The neural factors underlying the persistency of quadriceps weakness after anterior cruciate ligament reconstruction (ACLR) have been only partially explained. This study examined muscle fiber conduction velocity (MFCV) as an indirect parameter of motor unit recruitment strategies in the vastus lateralis (VL) and medialis (VM) muscles of soccer players with ACLR. High-density surface electromyography (HDsEMG) was acquired from VL and VM in nine soccer players (22.7 ± 2.9 years; BMI: 22.08 ± 1.72 kg·m⁻²; 7.7 ± 2.2 months post-surgery). Voluntary muscle force and the relative myoelectrical activity from the reconstructed and contralateral sides were recorded during linearly increasing isometric knee extension contractions up to 70% of maximal voluntary isometric force (MVIF). The relation of MFCV and force was examined by linear regression analysis at the individual subject level. The initial (intercept), peak (MFCV₇₀), and rate of change (slope) of MFCV related to force were compared between limbs and muscles. The MVIF was lower in the reconstructed side than in the contralateral side (−%20.5; P < .05). MFCV intercept was similar among limbs and muscles (P > .05). MFCV₇₀ and MFCV slope were lower in the reconstructed side compared to the contralateral for both VL (−28.5% and −10.1%, respectively; P < .001) and VM (−22.6% and −8.1%, respectively; P < .001). The slope of MFCV was lower in the VL than VM, but only in the reconstructed side (−12.4%; P < .001). These results suggest possible impairments in recruitment strategies of high-threshold motor units (HTMUs) as well as deficits in sarcolemmal excitability, fiber diameter, and discharge rate of knee extensor muscles following ACLR.     

Sensibility loss after ACL reconstruction with hamstring graft

Injury to the infrapatellar branch of the saphenous nerve (IPBSN), is known to cause regional hypoesthesia of the lower leg after anterior cruciate ligament (ACL) reconstruction. The aim of this study was to determine if the orientation of the graft harvest incision does influence the prevalence of postoperative hypoesthesia. Furthermore,to describe change, if any, of the hypoesthetic area, during the first postoperative year.Our hypothesis was that an oblique incision parallel to the nerve branch would reduce the incidence of this complication and the area with hypoesthesia after ACL reconstruction, compared to the vertical incision. Secondly, that the area with hypoesthesia is reduced over time. Fifty patients underwent a primary ACL reconstruction using hamstring graft. Twenty-five patients were operated using a vertical incision for graft harvest,and 25 were operated using a slightly oblique incision.Twelve days after surgery and at a one year follow-up the patients had their sensibility of the lower leg examined. We found that hypoesthesia is a common complication (88%) after hamstring ACL surgery. Change from vertical to slightly oblique incision did not reduce the morbidity.Furthermore, the area with sensory loss,felt by the patient shortly after surgery, was shown to decrease significantly by 46.3 percent after one year.     

Calcification of the patellar tendon after ACL reconstruction

Extensive calcification of the patellar tendon following ACL reconstruction with central-third bone–patellar tendon–bone autograft is a rarely seen complication. A 45-year-old male patient underwent combined intraarticular reconstruction of ACL with 1/3 central patellar bone–tendon–bone graft and extraarticular reconstruction with modified MacIntosh technique. Two cm of calcification of the patellar tendon was observed incidentally when he underwent a high tibial osteotomy due to medial compartment degeneration, secondary to varus malalignment, 18 months after the ACL surgery. The calcification, being painless, was left untouched during the surgery. At the final examination, 136 months postoperatively, the patient still had no complaint relating to the patellar tendon.     

Analysis of sequential cytokine release after ACL reconstruction

Purpose  

Rupture of the anterior cruciate ligament is common and may necessitate surgical reconstruction. Surgical reconstruction aims to restore normal kinematics and biology within the knee. The acute phase response after surgical reconstruction remains poorly defined but may influence graft integration through modulation of host tissue remodelling.     

Analysis of tunnel widening after double-bundle ACL reconstruction

Purpose

The purpose of this study was to evaluate the tunnel widening using a multi-planar reformation of MRI (Magnetic Resonance Imaging) in the orientation of the tunnel. The hypotheses of this study were as follows: (1) tunnel widening would be reduced with the above-mentioned technique, (2) the degree of tunnel widening would be different at the site of the tunnels, and (3) the time interval from surgery to MRI acquisition would affect the magnitude of tunnel widening.

Methods

Forty double-bundle ACL reconstructed patients who underwent postoperative MRI were enrolled in this study. The postoperative MRI was performed at 26.7?±?7.4?months in terms of time. The tunnel widening was examined using a multi-planar reformation of MRI in the orientation of the tunnel. Site-specific analysis was performed according to the depth (the entrance, mid, and exit portion) and wall (anterior, posterior, medial, and lateral walls). The correlation between MRI and widening was also evaluated.

Results

The mean tunnel widening of the femoral AM (Anteromedial), femoral PL (Posterolateral), tibial AM, and tibial PL in terms of the most widened diameter was 1.9 (25.4), 2.1 (30.8), 2.5 (32.8), and 3.2?mm (44.5%), respectively. The tibial PL tunnel showed significant widening than the other tunnels. At the entrance, tunnel widening occurred mostly, followed by the order of the mid and exit portion. Correlation analysis of the time interval of MRI acquisition and tunnel widening showed little association.

Conclusions

Tunnel widening after a double-bundle ACL reconstruction using an outside-in technique with press-fitting of the graft was acceptable compared to previously published studies. The tibial PL tunnel showed the most widening among the 4 tunnels examined with the tunnel entrance being most widened area.

Level of evidence

Therapeutic case series, Level IV.     

Individualized ACL reconstruction

The pivot shift test is the only physical examination test capable of predicting knee function and osteoarthritis development after an ACL injury. However, because interpretation and performance of the pivot shift are subjective in nature, the validity of the pivot shift is criticized for not providing objective information for a complete surgical planning for the treatment of rotatory knee laxity. The aim of ACL reconstruction was eliminating the pivot shift sign. Many structures and anatomical characteristics can influence the grading of the pivot shift test and are involved in the genesis and magnitude of rotatory instability after an ACL injury. The objective quantification of the pivot shift may be able to categorize knee laxity and provide adequate information on which structures are affected besides the ACL. A new algorithm for rotational instability treatment is presented, accounting for patients’ unique anatomical characteristics and objective measurement of the pivot shift sign allowing for an individualized surgical treatment. Level of evidence V.     

Hamstring tendons regeneration after ACL reconstruction: an overview

Despite the long lasting research the ideal method of reconstructing the ACL has not been found so far. The last year’s attention has shifted to the use of the multistrand hamstring tendon grafts. High ultimate tensile load, multiple-bundle replacement that better approximates the anatomy of the normal ACL and low donor site morbidity are the main advantages of this ACL replacement graft. These theoretical advantages have been multiplied when surprisingly studies have shown that semitendinosus and grascillis tendons actually regenerate after harvesting for use as ACL autografts. In this review article we summarize the current knowledge concerning the hamstring regeneration and we focus on issues that have clinical relevance or issues that have not been answered so far.     

Second-look arthroscopic findings of 208 patients after ACL reconstruction

The aim of this study is to report the arthroscopic subjective findings of reconstructed anterior cruciate ligament (ACL) with good clinical outcome. Graft used for reconstruction was either patella bone-tendon-bone (PBTB) autograft or hamstring tendon [quadrupled semitendinous and gracilis tendon (QSGT)] autograft. From March 1997 to September 2003, among 716 ACL reconstructions 209 knees (208 patients) were available for second-look arthroscopy at a mean 21.2-month (range, 14–70 months) postoperative period. The second-look arthroscopy focused on the evaluation of (1) continuity of the reconstructed ACL graft, (2) subjective graft tension using a probe, (3) the extent of synovial coverage, (4) the prevalence of cyclops or cyclops-like lesion, and (5) bony change after notchplasty. Patellar tendon autograft was used in 80 knees, hamstring tendon autograft in 129 knees. Just prior to second-look arthroscopy two objective clinical evaluations, KT-2000 arthrometer and Lysholm knee score, were performed to verify good clinical outcomes. A comparison between the hamstring tendon group and the patella tendon group, hamstring group showed slightly better results in Lysholm knee scores and KT-2000 arthrometer but there were no statistically significant differences (p>0.05). Undetected partial graft tear was seen in 21 knees (10%). With regard to graft tension, a total of 181 grafts (87%) showed normal tension and 28 (13%) showed slight lax tension. The overall synovial coverage was poor in nine (4%) knees. The synovial coverage was slightly better in the hamstring tendon group. A total of 45 knees (21.5%) showed cyclops-like lesion in variable sizes and locations. Reformation of the notch was seen in 85 knees (40%). In conclusion, the findings of second-look arthroscopy of reconstructed ACL in good clinical outcome patients showed approximately 10% partial graft tear, 5% poor synovial coverage, 20% cyclops-like lesion, and 40% some notch reformation.     

Results of surgical treatment of arthrofibrosis after ACL reconstruction

We prospectively studied 31 knee arthrolyses performed for loss of motion after intra-articular anterior cruciate ligament (ACL) reconstruction. The arthrolysis was performed on average 10.6 months after the reconstruction (range 4–25). Seven knees were localized forms. They were treated with arthroscopic removal of a fibrous nodule and scar tissue anterior to the ACL, which was preserved. Twenty-four knees were global forms and treated arthroscopically (14) or in open procedure (10). Suprapatellar, medial, and lateral gutter adhesions were sectioned, and fibrous tissue was removed from the anterior compartment. A posteromedial and/or posterolateral capsulotomy was necessary in 7 knees. The ACL graft was nonfunctional and/or malpositioned in 19 knees. The results were evaluated with the IKDC form with an average follow-up of 3.5 years (range 1.5–7). Preoperatively the localized forms had an average extension loss of 11° and an average flexion loss of 14° compared to the opposite knee. At follow-up all the knees were satisfactory for symptoms. All except one achieved a satisfactory motion (within 5° of extension loss and 15° of flexion loss) and a satisfactory final result. Global forms had a greater preoperative flexion loss (average 34°) and extension loss (average 17°). At follow-up 58% were satisfactory for symptoms and 71% for arc of motion. However, the final result was satisfactory in only 37%. In conclusion, local forms have a good prognosis. In global forms motion may be improved by surgery, but the final result is downgraded by symptoms. Arthrolyses performed within 8 months from index operation had a better outcome.     

Self-reported patient outcomes after ACL reconstruction with allograft tissue

PURPOSE: Self-reported outcomes after primary ACL reconstruction using allograft tissues were compared at > or = 5 yr (group 1) and at 2-4 yr (group 2) after surgery. METHODS: The IKDC Subjective Knee Evaluation and Current Health Assessment and the Knee Outcome Survey Activities of Daily Living Scale (KOS-ADLS) and the Sports Activity Scale (KOS-SAS) were mailed to 335 consecutive former patients at > or = 2 yr after surgery. RESULTS: Surveys were completed and returned by 64.6% of former patients. Time after surgery for group 1 (N = 90) and group 2 (N = 116) was 7.8 +/- 2.7 and 2.8 +/- 0.8 yr, respectively. Groups did not differ for IKDC Subjective Knee Evaluation or KOS-ADLS scores, although group 1 displayed a lower mean KOS-SAS score. Pooled IKDC Subjective Knee Evaluation scores were 42.7% normal (A), 22.8% nearly normal (B), 24.8% abnormal (C), or 9.7% severely abnormal (D). Pooled standardized IKDC Subjective Knee Evaluation z scores were -0.80 +/- 1.4 standard deviations below the reported population mean for unimpaired individuals with 33.5% scoring at or above the normative population mean, 28.2% scoring < 1 standard deviation below the normative population mean, 18.8% scoring between 1 and 2 standard deviations below the normative population mean, and 19% scoring > or = 2 standard deviations below the normative population mean. Pooled KOS-ADLS scores were 62.1% (> or = 90%), 18% (89-80%), 10.2% (79-70%), and 9.7% (< 70%). Pooled KOS-SAS scores were 49.5% (102/206, > or = 90%), 25.7% (53/206, 89-80%), 9.7% (20/206, 79-70%), and 15.1% (31/206, < 70%). Groups displayed comparable knee function before injury and at the time of the survey. Pooled knee-function scores decreased from 9.5 +/- 1.6 before injury to 8 +/- 2.5 current function (84% return). Both groups displayed decreases in current sports activity level from strenuous to moderate and frequency from 4-7 to 1-3 times per week. CONCLUSIONS: Self-reported outcomes did not differ between groups for the IKDC Subjective Knee Evaluation or for the KOS-ADLS score, although group 1 displayed decreased mean KOS-SAS scores, suggesting decreased perceived sporting activity knee function at > or = 5 yr after surgery. Decreased sports activity level and frequency are comparable with self-reported outcome studies after primary ACL reconstruction using autograft tissues.