Higher hamstring-to-quadriceps isokinetic strength ratio during the first post-operative months in patients with quadriceps tendon compared to hamstring tendon graft following ACL reconstruction

Adolescent Patients Exhibit Significant Improvements in Strength and Functional Performance From 6 to 9 Months After ACL Reconstruction With Quadriceps Autograft

Purpose

To investigate differences between the 6-month and 9-month return to sport (RTS) assessments in adolescent patients undergoing anterior cruciate ligament reconstruction (ACLR) with quadriceps tendon autograft.

Methods

A retrospective review was performed of consecutive adolescent patients who underwent ACLR between June 2017 and October 2019. Patients completed a structured RTS test 6 and 9 months after surgery consisting of isometric and isokinetic strength testing, the Lower Quarter Y-Balance Test, and single-legged hop testing. The recovery of muscle strength, assessed via isometric/isokinetic and hop testing, was defined by a limb symmetry index (LSI) ≥90%. Differences were compared between the 2 RTS test time points.

Results

In total, 27 patients (16 female, 11 male) were identified with a mean age of 15 years (range, 13-17 years). There were statistically significant improvements in isometric quadriceps strength (LSI, 85.0 ± 17.2 vs 92.5 ± 11.3; P = .04) and hamstring strength (LSI, 87.9 ± 11.2 vs 99.0 ± 10.5; P < .01). There were improvements in isokinetic knee extension at both 60°/s (LSI, 75.2 ± 16.7 vs 83.3 ± 13.8) and 180°/s (LSI, 79.9 ± 15.4 vs 83.4 ± 11.2), but the differences were only statistically significant at 60°/s (P = .02 and P = .17, respectively). There were no significant differences in isokinetic testing of knee flexion at either 60°/s or 180°/s. There were no statistically significant differences in the anterior reach component of the Lower Quarter Y-Balance Test at 6 and 9 months. Patients demonstrated statistically significant improvements on single- legged hop testing with mean LSIs >95% for each of the 4 tests at 9 months postop.

Conclusions

Adolescent patients undergoing ACLR with quadriceps tendon autograft demonstrated significant improvements in quadriceps strength between 6 and 9 months postoperatively.

Level of Evidence

Level IV, therapeutic case series.

Predicting Autologous Hamstring Graft Diameter in the Pediatric Population Using Preoperative Magnetic Resonance Imaging and Demographic Data

BACKGROUND

Anterior cruciate ligament (ACL) reconstruction before 18 years of age has been linked with an increased risk for failure when the graft diameter is <8 mm.

PURPOSE/HYPOTHESIS

The purpose of this study was to determine whether autologous hamstring graft size can be reliably predicted with the use of preoperative magnetic resonance imaging (MRI) measurements. We hypothesized that the average of multiple axial cross-sectional area MRI measurements for the semitendinosus tendon and gracilis tendon would alone accurately predict graft diameter. Additionally, factoring in specific demographic data to the MRI cross-sectional areas would provide a synergistic effect to the accuracy of graft diameter predictions.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

We retrospectively reviewed 51 pediatric patients undergoing ACL reconstructions (age <18 years) performed using either a quadruple-strand semitendinosus tendon or combined double-bundle semitendinosus tendon-gracilis tendon autograft. Preoperative axial MRI scans at multiple points along the craniocaudal axis-specifically, at the level of the joint line, 3 cm cephalad to the medial tibial plateau, and 5 cm cephalad to the medial tibial plateau-were used to determine the combined cross-sectional area of the semitendinosus and gracilis tendons. The MRI measurements were analyzed using Pearson correlation as well as regression analysis to evaluate strength of correlation between measurements. Binomial linear regression was used to analyze the same predictive variables assessed by multiple regression.

RESULTS

The predicted graft diameter was within 0.5 mm of the intraoperative graft size in 37 of 51 (72.5%) patients and within 1 mm of the intraoperative graft size in 49 of 51 (96.1%). With the addition of demographics, the accuracy of predictions increased to 78.4% within 0.5 mm and 98% within 1 mm of the actual graft size. Additionally, 38 of 42 patients whose true graft diameter was ≥8 mm were correctly classified, giving a sensitivity of 90.4%. For those whose true graft diameter was <8 mm, 8 of 9 patients were correctly classified; therefore, the specificity was 88.9%.

CONCLUSION

The results of our study suggest that taking the average of multiple preoperative MRI measurements can be used to accurately predict autologous hamstring graft size when approaching pediatric patients undergoing ACL reconstruction.

Effects of Autograft Types on Muscle Strength and Functional Capacity in Patients Having Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial

BACKGROUND

The effects of different autograft types for anterior cruciate ligament reconstruction (ACL-R) on muscle function are sparsely investigated in randomized controlled trials. Our aim was to investigate the effects of quadriceps tendon autograft (QTB) vs. semitendinosus-gracilis autograft (StG) on thigh muscle strength and functional capacity, and a patient-reported outcome 1 year after ACL-R, and to compare the results to healthy controls.

METHODS

ACL-R patients (n = 100) and matched controls (CON, n = 50) were recruited, with patients being randomly assigned to QTB (n = 50) or StG (n = 50) ACL-R. One year after ACL-R, bilateral knee extensor (KE) and flexor (KF) muscle strength (isometric, dynamic, explosive, limb symmetry index [LSI], hamstring:quadriceps ratio [HQ ratio]) were assessed by isokinetic dynamometry, along with functional capacity (single leg hop distance [SHD]) and a patient-reported outcome (International Knee Documentation Committee [IKDC] score).

RESULTS

KE muscle strength of the operated leg was lower (9-11%) in QTB vs. StG as was KE LSI, while KF muscle strength was lower (12-17%) in StG vs. QTB as was KF LSI. HQ ratios were lower in StG vs. QTB. Compared with the controls, KE and KF muscle strength were lower in StG (10-22%), while KE muscle strength only was lower in QTB (16-25%). Muscle strength in the StG, QTB, and CON groups was identical in the non-operated leg. While SHD and IKDC did not differ between StG and QTB, SHD in both StG and QTB was lower than CON. The IKDC scores improved significantly 1 year following ACL-R for both graft types.

CONCLUSION

One year after ACL-R, muscle strength is affected by autograft type, with StG leading to impairments of KE and KF muscle strength, while QTB results in more pronounced impairments of KE only. Functional capacity and patient-reported outcome were unaffected by autograft type, with the former showing impairment compared to healthy controls.

CLINICAL TRIALS REGISTRATION NUMBER

NCT02173483.

Utilizing a contralateral hamstring autograft facilitates earlier isokinetic and isometric strength recovery after anterior cruciate ligament reconstruction: a randomised controlled trial

PURPOSE

To compare muscle strength and patient reported outcomes following ACLR using a semitendinosus (ST) graft from the ipsilateral (IL) leg compared to a graft from the contralateral (CL) leg.

METHODS

One-hundred and forty patients with an ACL injury were randomized to IL or CL ACLR. Patients were assessed at 6, 12 and 24 months with isokinetic and isometric muscle strength measured using Biodex. Patient-reported outcomes and manual stability measurements were also recorded.

RESULTS

Patient-related outcomes improved over time for both groups with no significant differences between groups at any time point. No differences between groups in objective knee assessment scores or rerupture rates were found. The IL group was significantly weaker in knee flexion strength at all time points compared to the CL group, additionally the IL group did not recover flexor strength within 2 years.

CONCLUSION

This study demonstrated that utilizing an ST graft harvested from the uninjured limb for ACLR facilitates early isokinetic and isometric strength recovery, with no significant adverse outcomes demonstrated in other measurements and therefore be performed to reduce the risk of long-term strength deficits in the injured leg LEVEL OF EVIDENCE: II.

Implications for Early Postoperative Care After Quadriceps Tendon Autograft for Anterior Cruciate Ligament Reconstruction: A Technical Note

The quadriceps tendon (QT) has become increasingly used by orthopaedic surgeons as an alternative autograft choice in anterior cruciate ligament reconstruction. As its use increases, athletic trainers and other rehabilitation clinicians will treat a greater number of patients with this autograft type. The recently developed, minimally invasive technique for harvest of the all-soft tissue autograft has many benefits, including versatility, decreased donor-site morbidity, and enhanced cosmesis. Early clinical trials revealed that the QT autograft resulted in decreased anterior knee pain and similar strength and functional outcomes to those of more common autograft types. From a rehabilitation perspective, many characteristics should be considered, such as the importance of early knee extension and quadriceps activation. Therefore, the purpose of this technical note is to expose athletic trainers to the QT autograft so that they may provide the best care for patients after anterior cruciate ligament reconstruction.

Quadriceps tendon anterior cruciate ligament reconstruction

Quadriceps tendon is a promising alternative graft option for anterior cruciate ligament (ACL) reconstruction, which can be harvested with or without a bone block as well as a full or partial thickness graft. Therefore, quadriceps tendon graft could be used in primary and revision ACL reconstruction based on the requirements (tunnel size, tunnel position, etc.). The all soft tissue, partial thickness quadriceps tendon graft in detail and pitfalls of the harvest are described in the present review. After quadriceps tendon harvest, especially in soccer players, who need a strong quadriceps to strike a ball with power, the postoperative rehabilitation may need to be adapted. LEVEL OF EVIDENCE: V.

Physical Fitness after Anterior Cruciate Ligament Reconstruction: Influence of Graft, Age, and Sex

Functional tests are used to facilitate return-to-sports decisions after anterior cruciate ligament reconstruction (ACLR). This study presents comprehensive physical fitness test data acquired in highly active patients within the first year after ACLR, for comparison between different grafts, age groups, and sexes. The outcomes from a specific seven-item test battery and isokinetic strength test data were extracted from a patient database. Results were compared to normative data from age- and sex-matched controls and between subgroups of patients. A total of 245 patients (94 women, 23.8 ± 8.4 years, pre-injury Tegner 7.4 ± 1.6) were tested 185 ± 44 days after surgery. In 116 patients (47.3%), one or more test results were classified as "poor" or "very poor" after comparison with normative data, with failures being most frequent during single-leg squat jump and plyometric strength tests. Test failures were more prevalent in adults than in adolescents <19 years (61.4%-62.2% vs. 24.5%, p < 0.001) and in men (61.6% vs. 24.5%, p < 0.001), but no differences were found between grafts. Isokinetic knee extensor strength was lower by 24.1% on the injured side. Six months after ACLR, nearly 50% of highly active patients presented with strength and functional fitness deficits. These deficits are particularly prevalent in older patients and men.

QUADRICEPS AUTOGRAFT IN ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION: A LITERATURE REVIEW

ABSTRACT Introduction: Anterior cruciate ligament injury is one of the most prevalent musculoskeletal injuries. Therefore, several surgical techniques and graft types have been described for its reconstruction. Autologous hamstring tendon graft is one of the most frequently used, but use of the quadriceps tendon graft has gained prominence in recent years. Objective: To review the literature to compare the outcomes of patients undergoing anterior cruciate ligament reconstruction (ACLR) with quadriceps tendon (QT) autograft versus hamstring tendon (HT) autograft. Methods: A literature review was conducted through PubMed to locate studies (Level of evidence I-III) comparing the outcomes of the QT autograft vs. the HT autograft in patients undergoing primary ACL reconstruction. Patients were assessed on the basis of re-rupture rate, ligament instability, patient-reported outcome scores, previous pain, and isokinetic tests. Results: Six studies were selected according to inclusion criteria. A total of 481 patients were evaluated, 243 in the QT group and 238 in the HT group. The total re-rupture rate was 1.6% (8 of 481), with 6 in the HT group and 2 in the QT group, but with no statistical difference between groups. One study found increased ligament instability in the HT group and another study found greater instability in the QT group, both with statistical significance. Regarding the patient-reported functional scores, only 01 study found statistical difference, with better results in the QT group. There was no difference in previous pain between groups in the selected studies. Regarding the isokinetic test, one study found a difference in flexor force in the HT group (p <0.01), with no difference in extensor force, while another two studies found an increased extensor force deficit in the QT group within up to 01 year of follow-up. The flexor/ extensor muscle strength ratio was higher in the QT group in both studies. Conclusion: ACL reconstruction with QT graft presents re-rupture rates, ligament instability, functional scores and donor site morbidity that are similar to the HT graft, in addition to preserving greater flexor force in proportion to extensor force. Level of evidence: IV; Review study.

Quadriceps Tendon Autograft in Anterior Cruciate Ligament Reconstruction

Quadriceps tendon (QT) autograft in anterior cruciate ligament reconstruction has received increased attention, as more studies compare clinical outcomes between QT, bone-patellar tendon-bone (BPTB), and hamstring tendon (HT) autografts. Biomechanically, QT has similar properties to BPTB and to HT. QT has shown equivalent stability, patient-reported outcome measures, strength and graft failure rates, and decreased donor site morbidity compared with BPTB and HT. All three autografts have excellent clinical outcomes. Ultimately, anterior cruciate ligament graft selection should be a discussion between a physician and their patient while considering a patient's age, activity level, and occupation.

Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis of Outcomes for Quadriceps Tendon Autograft Versus Bone-Patellar Tendon-Bone and Hamstring-Tendon Autografts

BACKGROUND

Comprehensive studies evaluating quadriceps tendon (QT) autograft for anterior cruciate ligament (ACL) reconstruction are lacking. The optimal choice of graft between bone-patellar tendon-bone (BPTB), hamstring tendon (HT), and QT is still debatable.

HYPOTHESIS

The current literature supports the use of QT as a strong autograft with good outcomes when used in ACL reconstruction.

STUDY DESIGN

Meta-analysis; Level of evidence, 2.

METHODS

A systematic search of the literature was performed in PubMed, MEDLINE, Cochrane, and Ovid databases to identify published articles on clinical studies relevant to ACL reconstruction with QT autograft and studies comparing QT autograft versus BPTB and HT autografts. The results of the eligible studies were analyzed in terms of instrumented laxity measurements, Lachman test, pivot-shift test, Lysholm score, objective and subjective International Knee Documentation committee (IKDC) scores, donor-site pain, and graft failure.

RESULTS

Twenty-seven clinical studies including 2856 patients with ACL reconstruction met the inclusion criteria. Comparison of 581 QT versus 514 BPTB autografts showed no significant differences in terms of instrumented mean side-to-side difference (P = .45), Lachman test (P = .76), pivot-shift test grade 0 (P = .23), pivot-shift test grade 0 or 1 (P = .85), mean Lysholm score (P = .1), mean subjective IKDC score (P = .36), or graft failure (P = .50). However, outcomes in favor of QT were found in terms of less donor-site pain (risk ratio for QT vs BPTB groups, 0.25; 95% CI, 0.18-0.36; P < .00001). Comparison of 181 QT versus 176 HT autografts showed no significant differences in terms of instrumented mean side-to-side difference (P = .75), Lachman test (P = .41), pivot-shift test grade 0 (P = .53), Lysholm score less than 84 (P = .53), mean subjective IKDC score (P = .13), donor-site pain (P = .40), or graft failure (P = .46). However, outcomes in favor of QT were found in terms of mean Lysholm score (mean difference between QT and HT groups, 3.81; 95% CI, 0.45-7.17; P = .03).

CONCLUSION

QT autograft had comparable clinical and functional outcomes and graft survival rate compared with BPTB and HT autografts. However, QT autograft showed significantly less harvest site pain compared with BPTB autograft and better functional outcome scores compared with HT autograft.

Soft Tissue Fixation Strategies of Human Quadriceps Tendon Grafts: A Biomechanical Study

PURPOSE

To evaluate the effects of different stitching methods and suture diameters on the graft fixation of soft tissue human quadriceps tendon grafts for anterior cruciate ligament (ACL) reconstruction.

METHODS

The Krackow locking stitch (K), whipstitch (W), and baseball stitch (B) were combined with either a 2× no. 2 (#2) or a 1× no. 5 (#5) braided composite suture for graft fixation of 36 human quadriceps tendons in 6 groups. Biomechanical testing was performed using a cyclic protocol with loads between 0 and 100 N. The maximum load until failure, cyclic elongation, and failure mode were recorded.

RESULTS

The highest mean maximum load to failure was observed in the 2 Krackow stitch groups. The K#2 group had significantly higher load to failure values compared with those of the W#2 and B#2 groups (K#2, 553 ± 82 N vs W#2, 392 ± 107 N, P = .0349; K#2 vs B#2 366 ± 118 N, P = .0129). The mean cyclic elongation was lowest in the Krackow groups (K#2, 10.59 ± 2.63 mm; K#5, 13.66 ± 2.3 mm). The regular failure mode was the rupture of the suture for the Krackow stitch (8 of 12) and suture pullout for the whipstitch (11 of 12) and baseball stitch groups (12 of 12).

CONCLUSIONS

The double Krackow stitch with no. 2 braided composite suture exhibits a high maximum load to failure combined with a low amount of elongation in a biomechanical study for human quadriceps tendon soft tissue graft fixation. Unlike the whipstitch and the baseball stitch, it can solidly prevent suture pullout.

CLINICAL RELEVANCE

A safe soft tissue graft fixation technique is especially important for quadriceps tendon grafts with their laminar anatomical structure and physiologically varying diameter. Unlike other grafts for ACL replacement, it fully relies on the soft tissue suture fixation to resist the pullout force.

Hamstring-to-Quadriceps Ratio in Female Athletes with a Previous Hamstring Injury, Anterior Cruciate Ligament Reconstruction, and Controls

Muscle strength imbalances around the knee are often observed in athletes after anterior cruciate ligament (ACL) surgery and hamstring muscle injury. This study examined three hamstrings-to-quadriceps (H:Q) strength ratio types (conventional, functional, and mixed) in thirteen female athletes with a history of hamstring injury, fourteen basketball players following ACL reconstruction and 34 controls. The conventional (concentric H:Q) peak torque ratio was evaluated at 120°·s⁻¹ and 240°·s⁻¹. The functional (eccentric hamstring to concentric quadriceps) torque ratio was evaluated at 120°·s⁻¹. Finally, the mixed (eccentric hamstrings at 30°·s⁻¹ to concentric quadriceps at 240°·s⁻¹) torque ratio was calculated. Both ACL and the hamstring-injured groups showed a lower quadriceps and hamstrings strength compared with controls (p < 0.05). However, non-significant group differences in the H:Q ratio were found (p > 0.05). Isokinetic assessment of muscle strength may be useful for setting appropriate targets of training programs for athletes with a history of ACL surgery or hamstring strain. However, isokinetic evaluation of the H:Q ratio is not injury—specific and it does not vary between different methods of calculating the H:Q ratio.

Transphyseal Anterior Cruciate Ligament Reconstruction in the Skeletally Immature: Quadriceps Tendon Autograft Versus Hamstring Tendon Autograft

Background:

It is unclear what the optimal graft choice is for performing anterior cruciate ligament (ACL) reconstruction in a skeletally immature patient.

Purpose:

To evaluate outcomes and complications of skeletally immature patients undergoing transphyseal ACL reconstruction with a hamstring tendon autograft versus a quadriceps tendon autograft.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Between 2012 and 2016, 90 skeletally immature patients from a single institution underwent primary transphyseal ACL reconstruction with either a quadriceps tendon autograft or a hamstring tendon autograft based on surgeon preference (n = 3). Patient demographic, injury, radiographic, and surgical variables were documented. Outcome measures included the Lysholm score, Single Assessment Numeric Evaluation (SANE), Tegner activity score, pain, satisfaction, and complications such as graft tears and physeal abnormalities.

Results:

A total of 83 patients (56 hamstring tendon, 27 quadriceps tendon) were available for a minimum follow-up of 2 years or sustained graft failure. The mean age of the patients was 14.8 ± 1.4 years at the time of ACL reconstruction. No differences in chronological age, bone age, sex, patient size, or mechanism of injury were noted between groups. There were no differences in surgical variables, except that the quadriceps tendon grafts were larger than the hamstring tendon grafts (9.6 ± 0.6 mm vs 7.8 ± 0.7 mm, respectively; P < .001). Patient outcomes at a mean follow-up of 2.8 ± 0.9 years revealed no differences based on graft type, with mean Lysholm, SANE, pain, satisfaction, and Tegner scores of 96, 93, 0.6, 9.6, and 6.6, respectively, for the quadriceps tendon group and 94, 89, 0.9, 9.2, and 7.1, respectively, for the hamstring tendon group. While there were no physeal complications in either group, patients undergoing ACL reconstruction with a hamstring tendon autograft were more likely to tear their graft (21% vs 4%, respectively; P = .037).

Conclusion:

Skeletally immature patients undergoing ACL reconstruction can be successfully managed with either a quadriceps tendon autograft or a hamstring tendon autograft with good short-term outcomes, high rates of return to sport, and low rates of physeal abnormalities. The primary differences between grafts were that the quadriceps tendon grafts were larger and were associated with a lower retear rate. ACL reconstruction performed with a quadriceps tendon autograft may reduce early graft failure in skeletally immature patients.

The effect of deafness on the physical fitness parameters of elite athletes

The purpose of this study is to determine the health-related physical fitness parameters of athletes, who are deaf. The study group consisted of 137 deaf athletes (52 females and 85 males with a mean age of 23.99±6.56 years) who have participated in the 2017 Deaflympics games. The assessed parameters included the isokinetic muscle strength, core endurance, balance assessments, grip strength, and body composition. At the end of the study, the following results were obtained. Hamstring/quadriceps ratio was in the range of 53%–54%, which was within 50%–60% of the normal limit. Endurance of the anterior and posterior core muscles was low as compared to the normative data. The athletes’ balance was better with their eyes open than closed; and the grip strength was low as compared to the normative data in the literature. Also, the body fat percentage of deaf female athletes were similar to ones in healthy individuals with sedentary lifestyle, whereas male ones had slightly lower body fat mass percentage. These results can be used as the initial reference parameters to define the training program requirements of deaf athletes.

Clinical outcomes after ACL reconstruction with free quadriceps tendon autograft versus hamstring tendons autograft. A retrospective study with a minimal follow-up two years

OBJECTIVE

The aim of this retrospective study was to compare the clinical outcomes of anatomic single bundle ACL reconstruction using either a free quadriceps tendon autograft or a quadrupled hamstring autograft with a minimum follow-up of 24 months.

METHODS

Consecutive patients undergoing ACL reconstruction using either a free quadriceps tendon autograft or hamstring tendon autograft from January 2013 to December 2014 were included. ACL reconstruction was done in all patients due to isolated ACL tears. Patients with associated cartilage lesions > Outerbridge III, meniscal lesions in need of meniscectomy or repair as well as patients with prior knee surgery on the affected or contralateral knee were excluded. The primary outcome evaluation was the side-to-side difference in instrumented Lachman testing. Secondary outcome evaluation consisted in the Lysholm, modified Cincinnati and SF-36 scores. Side-to-side difference in range of motion and thigh diameter was also documented.

RESULTS

After applying the inclusion/exclusion criteria, a total of 82 patients were identified and 72 (87.8%) presented to the hospital for follow-up. There were 39 patients with quadriceps graft (30.64 ± 8.71, range: 18-53 years) and 33 patients with hamstrings (28.60 ± 6.74, range: 18-46 years). No statistically significant difference between groups was detected with regard to KT-1000 measurements (p = 0.326). No significant difference was found between the mean postoperative Lysholm (p = 0.299), the modified Cincinnati (p = 0.665) and the general SF-36 scores between groups (p = 0.588). Less side-to-side thigh diameter difference was noted in the quadriceps graft group (p = 0.026).

CONCLUSION

In conclusion, similar clinical results, in terms of stability and subjective measures, can be obtained after ACL reconstruction both with a free quadriceps and a 4-strand hamstring tendons autograft.

LEVEL OF EVIDENCE

Level III, Therapeutic Study.

Quadriceps Recovery After Anterior Cruciate Ligament Reconstruction With Quadriceps Tendon Versus Patellar Tendon Autografts

Background

Quadriceps tendon (QT) autografts are being increasingly used for anterior cruciate ligament reconstruction (ACLR). A paucity of studies exist that compare QT autografts with alternative graft options. Additionally, concerns exist regarding quadriceps recovery after graft harvest insult to the quadriceps muscle-tendon unit.

Purpose/Hypothesis

The purpose of this study was to compare quadriceps recovery and functional outcomes in patients with QT versus bone-patellar tendon-bone (BPTB) autografts. The hypothesis was that those with QT autografts would demonstrate superior outcomes.

Study Design

Cohort study; Level of evidence, 3.

Methods

Active patients with a history of primary, unilateral ACLR with soft tissue QT or BPTB autografts participated. Quadriceps recovery was quantified using variables of strength, muscle size, and activation. Knee extensor isometric and isokinetic strength was measured bilaterally with an isokinetic dynamometer and normalized to body weight. Quadriceps activation was measured with the superimposed burst technique. The maximal cross-sectional area of each quadriceps muscle was measured bilaterally using magnetic resonance imaging. Assessors of muscle size were blinded to the graft type and side of ACLR. Functional tests included hop tests and step length symmetry during walking, measured via spatiotemporal gait analysis. Self-reported function was determined with the International Knee Documentation Committee (IKDC) questionnaire. Neuromuscular and functional outcomes were expressed as limb symmetry indices (LSIs: [surgical limb/nonsurgical limb]*100%). Wilcoxon rank-sum tests were used to compare the LSIs and IKDC scores between groups.

Results

There were 30 study participants (19 male, 11 female; median age, 22 years [range, 14-41 years]; median time since surgery, 8 months [range, 6-23 months]), with 15 patients in each group. There were no significant between-group differences in demographic variables or outcomes. LSIs were not significantly different between the QT versus BPTB group, respectively: knee extensor isokinetic strength at 60 deg/s (median, 70 [range, 41-120] vs 68 [range, 37-83]; P = .285), activation (median, 95 [range, 85-111] vs 92 [range, 82-105]; P = .148), cross-sectional area of the vastus medialis (median, 79 [range, 62-104] vs 77 [range, 62-95]; P = .425), single-leg hop test (median, 88 [range, 35-114] vs 77 [range, 49-100]; P = .156), and step length symmetry (median, 99 [range, 93-104] vs 98 [range, 92-103]; P = .653). The median IKDC scores between the QT and BPTB groups were also not significantly different: 82 (range, 67-94) versus 83 (range, 54-94); respectively (P = .683).

Conclusion

Patients with QT autografts demonstrated similar short-term quadriceps recovery and postsurgical outcomes compared with patients with BPTB autografts.

ACL reconstruction with quadriceps tendon graft and press-fit fixation versus quadruple hamstring graft and interference screw fixation - a matched pair analysis after one year follow up

Background

The objective of the study was to compare the results of a primary anterior cruciate ligament reconstruction (ACLR) using the press-fit fixation technique for a quadriceps tendon (QT) graft to a standard quadrupled hamstring (HT) graft with interference screw fixation.

Methods

A retrospective cohort study with a 12-month follow up provided data for 92 patients. Exclusion criteria were accompanying ligament injuries and contralateral ACL injury. Patients who suffered a graft failure, which was defined as a side-to-side difference of > 3 mm, or infection were rated ‘D’ according to the IKDC and excluded from further evaluation. Forty-six patients underwent primary ACLR using the press-fit fixation technique for autologous bone QT graft. These patients were matched in terms of age, gender, accompanying meniscus tear and cartilage injury to 46 patients who underwent standard HT graft with interference screw fixation. Patients were evaluated according to the Lachman test, Pivot-Shift test, IKDC score, Tegner score, Rolimeter measurements, one-leg hop test, thigh circumference and donor side morbidity.

Results

No significant differences in Tegner score (p = 0.9), subjective or objective IKDC score (p = 0.9;p = 0.6), knee stability (Lachman Test p = 0.6; Pivot-Shift Test p = 0.4; Side-to-Side Difference p = 0.4), functioning testing (One-Leg Hop Test p = 0.6; Thigh Circumference p = 0.4) or donor side morbidity (p = 0.4) were observed at the follow up. The Lachman test was negative for 85% of the QT group and 83% of the HT group. The Pivot Shift Test was negative for 80% of the QT group and 85% of the HT group. The mean side-to-side difference was 1.6 ± 0 .2mm in both groups. The one-leg hop test revealed a collateral-side jumping distance of 96.2 ± 8.5% for the QT group and 95.5 ± 8.5% for the HT group. The thigh circumference of the injured leg was 98.3 ± 3.0% on the uninjured side in the QT group and 99.7 ± 3.0% in the HT group. A knee walking test resulted in no discomfort for 90% of the QT group and 85% of the HT group. The graft failure rate was 7.3% in the QT group and 9.8% in the HT group.

Conclusion

QT grafts fixated using the press-fit technique are a reliable alternative for primary ACL surgery.

Return to Sport and Reoperation Rates in Patients Under the Age of 20 After Primary Anterior Cruciate Ligament Reconstruction: Risk Profile Comparing 3 Patient Groups Predicated Upon Skeletal Age

BACKGROUND

With sports specialization and level of competition on the rise, anterior cruciate ligament reconstruction (ACLR) in athletes under the age of 20 has increased significantly in recent years. Reports have demonstrated that the revision ACLR rate is higher and return to sport (RTS) rate is lower in this population.

PURPOSE

To evaluate the 2-year clinical outcomes of 3 cohorts of primary ACLR in pediatric and adolescent athletes under the age of 20 based on skeletal age with a focus on RTS and the incidence of second surgery.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

This is a prospective evaluation of 324 athletes younger than 20 years of age who underwent ACLR with minimum 2-year follow-up. The surgical technique was selected predicated on skeletal age, which includes the all-epiphyseal technique with hamstring autograft in the youngest cohort in elementary and middle school (group 1), the partial transphyseal and complete transphyseal with hamstring autograft performed for athletes in the middle cohort (group 2), and bone-tendon-bone autograft in the skeletally mature high school athletes (group 3).

RESULTS

The mean chronological age of the entire cohort was 15 years (range, 8-19 years) with 55% males. The 3 cohorts included 49 patients (15%) in group 1 (mean age, 12 years), 66 (20%) in group 2 (mean age, 14.3 years), and 209 (65%) in group 3 (mean age, 16.2 years). Group 2 athletes had a significantly higher revision ACLR rate (20%) compared with group 1 (6%; P = .039) and group 3 (6%; P = .001). Similarly, group 2 athletes had significantly lower RTS rates (85%) compared with group 1 (100%) and group 3 (94%).

CONCLUSION

The rate of revision ACLR was significantly higher and the RTS rates significantly lower in group 2 compared with groups 1 and 3. This age-related risk profile may be used to counsel athletes and parents preoperatively regarding the expectations of surgery with respect to revision ACLR and RTS rates.

No difference between full thickness and partial thickness quadriceps tendon autografts in anterior cruciate ligament reconstruction: a systematic review

PURPOSE

The purpose of this review was to compare outcomes and complication profiles of anterior cruciate ligament reconstruction (ACL-R) between full thickness (FT-Q) and partial thickness (PT-Q) quadriceps tendon (QT) autografts.

METHODS

As per PRISMA guidelines, PubMed, EMBASE, and MEDLINE were searched in September 2017 for English language, human studies of all levels of evidence on patients undergoing primary ACL-R with FT-Q or PT-Q. This search was repeated in March 2018 to capture additional articles. Data regarding postoperative outcomes and complications were abstracted. Due to heterogeneous reporting, data were not combined in meta-analysis and were summarized descriptively.

RESULTS

Upon screening 3670 titles, 18 studies satisfied inclusion/exclusion criteria. The second search identified an additional two studies for a total of 20 studies (50% case-control, 50% case series). These studies examined 1212 patients (1219 knees) of mean age 29.8 years (range 15-59) followed a mean of 42.2 months (range 12-120). FT-Q and PT-Q autografts were used in eight studies (50.5% of knees), and thirteen studies (49.5% of knees), respectively. Only one study directly compared FT-Q to PT-Q. Instrumented laxity was less than 3 mm in 74.8 and 72.4% of the FT-Q and PT-Q groups, respectively. Postoperative IKDC Subjective Knee Form scores were similar between the FT-Q (82.5) and PT-Q (82.1) groups. Postoperative quadriceps strength, measured as a percentage of the contralateral side, were similar in the FT-Q (89.5%) and PT-Q (85.1%) groups. Graft failure rates for the FT-Q and PT-Q groups were 3.7 and 3.0%, respectively.

CONCLUSION

Across the 20 studies included in this review, there appeared to be no difference in outcomes or complications between either FT-Q or PT-Q in primary ACL-R. Moreover, primary ACL-R using QT autografts appears to have successful outcomes with a low rate of graft failure, irrespective of tendon thickness. While further comparative studies are needed to better delineate the optimal thickness of quadriceps tendon for primary ACL-R, these data suggest that, in primary ACL-R, either FT-Q or PT-Q is efficacious and, in the clinical setting, surgeons may be justified in using either graft thickness.

LEVEL OF EVIDENCE

IV, Systematic Review of Level III and IV studies.

Angle-specific analysis of isokinetic quadriceps and hamstring torques and ratios in patients after ACL-reconstruction

Background

Strength deficits, muscle imbalances, and quadriceps inhibition are common after the surgical reconstruction of the anterior cruciate ligament (ACL), even after the patient’s returned-to-sport. Typically, asymmetries between the operated and non-operated leg as well as the hamstring/quadriceps (HQ) ratio are calculated using maximum isokinetic torque values. Moreover, the knee flexion angles, which correspond to the measured torque values, were not considered. Therefore, the aim of the study was to evaluate the usage of an angle-specific approach for the analysis of isokinetic data in patients after an ACL-reconstruction.

Methods

A cross-sectional laboratory study design was used to investigate the influence of leg (operated vs. non-operated) and two velocities on angle-specific isokinetic data. Concentric quadriceps and hamstring torques and ratios of 38 patients were assessed 6.6 months after ACL-reconstruction with a hamstring tendon graft. At a velocity of 60°/s and 180°/s, angle-specific torques and HQ-ratios were analyzed with conventional discrete parameters and a Statistical Parametric Mapping procedure, which evaluates continuous data. The relationship between angle-specific and conventional HQ-ratios was evaluated with Pearson correlation coefficients.

Results

Angle-specific torques and HQ-ratios were different between the operated and non-operated leg and between velocities. In the operated leg, the quadriceps deficit was higher at 60°/s in knee flexion angles > 50°. The HQ-ratios decreased with greater knee flexion at both velocities, but with a different magnitude. Around 30°, the HQ-ratios reached 1.0 and did not differ between the velocities, while leg differences were present from 40 to 60°. At the higher testing velocity, the maximum flexion torque occurred at greater knee flexion, whereas the maximum extension torque were present at a similar joint angle. The correlation coefficients between conventional and angle-specific HQ-ratios were low in knee angles < 35° and > 65° and varied according to leg and velocity.

Conclusions

The angle specific approach is recommended for future ACL-research, as it reveals strength deficits and imbalances, which were not captured by conventional parameters. The results provide a rationale for more specific joint angle and/or velocity based training and may help for return-to-sport decisions.

Quadriceps Tendon Autograft in Anterior Cruciate Ligament Reconstruction: A Systematic Review

PURPOSE

To systematically review the current evidence to ascertain whether quadriceps tendon autograft (QT) is a viable option in anterior cruciate ligament reconstruction.

METHODS

A literature review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Cohort studies comparing QT with bone-patellar tendon-bone autograft (BPTB) or hamstring tendon autograft (HT) were included. Clinical outcomes were compared, with all statistical analyses performed using IBM SPSS Statistics for Windows, version 22.0, with P < .05 being considered statistically significant.

RESULTS

We identified 15 clinical trials with 1,910 patients. In all included studies, QT resulted in lower rates of anterior knee pain than BPTB. There was no difference in the rate of graft rupture between QT and BPTB or HT in any of the studies reporting this. One study found that QT resulted in greater knee stability than BPTB, and another study found increased stability compared with HT. One study found that QT resulted in improved functional outcomes compared with BPTB, and another found improved outcomes compared with HT, but one study found worse outcomes compared with BPTB.

CONCLUSIONS

Current literature suggests QT is a viable option in anterior cruciate ligament reconstruction, with published literature showing comparable knee stability, functional outcomes, donor-site morbidity, and rerupture rates compared with BPTB and HT.

LEVEL OF EVIDENCE

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

Quadriceps tendon autograft for arthroscopic knee ligament reconstruction: use it now, use it often

Traditional bone-patellar tendon-bone and hamstring tendon ACL grafts are not without limitations. A growing body of anatomic, biomechanical and clinical data has demonstrated the utility of quadriceps tendon autograft in arthroscopic knee ligament reconstruction. The quadriceps tendon autograft provides a robust volume of tissue that can be reliably harvested, mitigating the likelihood of variably sized grafts and obviating the necessity of allograft augmentation. Modern, minimally invasive harvest techniques offer the advantages of low rates of donor site morbidity and residual extensor mechanism strength deficits. New data suggest that quadriceps tendon autograft may possess superior biomechanical characteristics when compared with bone-patella tendon-bone (BPTB) autograft. However, there have been very few direct, prospective comparisons between the clinical outcomes associated with quadriceps tendon autograft and other autograft options (eg, hamstring tendon and bone-patellar tendon-bone). Nevertheless, quadriceps tendon autograft should be one of the primary options in any knee surgeon's armamentarium.

Knee isokinetic performance following anterior cruciate ligament reconstruction: patellar tendon versus hamstrings graft

OBJECTIVE

To compare knee isokinetic performance six months after reconstruction of the anterior cruciate ligament using grafts from either the patellar tendon or the hamstrings among patients who underwent the same rehabilitation protocol.

METHODS

Thirty-four patients were evaluated (17 with grafts from the patellar tendon and 17 with grafts from the hamstrings). Operated and non-operated knees were compared with regards to the variables of peak torque, work and the hamstring/quadriceps relationship at velocities of 60º/s and 180º/s and power of 180º/s after six months of surgery.

RESULTS

The patients with ACL reconstruction using the patellar tendon (BPTB) showed quadriceps deficits for all variables, but the flexor musculature was balanced. In the hamstring group, both the extensors and the flexors showed deficits for the variables analyzed, except for hamstring power at 180º/s.

CONCLUSION

Patients in the patellar tendon group had a greater quadriceps deficit compared with those in the hamstrings group. Patients in the hamstrings group had a greater muscular deficit in the flexor mechanism compared with the contralateral knee. An unbalanced H/Q ratio was observed regardless of graft type, but this was more evident in the BPTB group.

Isokinetic Extension Strength Is Associated With Single-Leg Vertical Jump Height

Background

Isokinetic strength testing is an important tool in the evaluation of the physical capacities of athletes as well as for decision making regarding return to sports after anterior cruciate ligament (ACL) reconstruction in both athletes and the lay population. However, isokinetic testing is time consuming and requires special testing equipment.

Hypothesis

A single-jump test, regardless of leg dominance, may provide information regarding knee extension strength through the use of correlation analysis of jump height and peak torque of isokinetic muscle strength.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

A total of 169 patients who underwent ACL reconstruction were included in this study. Isokinetic testing was performed on the injured and noninjured legs. Additionally, a single-leg countermovement jump was performed to assess jump height using a jump accelerometer sensor. Extension strength values were used to assess the association between isokinetic muscle strength and jump height.

Results

The sample consisted of 60 female (mean age, 20.8 ± 8.3 years; mean weight, 61.7 ± 6.5 kg; mean height, 167.7 ± 5.3 cm) and 109 male (mean age, 23.2 ± 7.7 years; mean weight, 74.6 ± 10.2 kg; mean height, 179.9 ± 6.9 cm) patients. Bivariate correlation analysis showed an association (r = 0.56, P < .001) between jump height and isokinetic extension strength on the noninvolved side as well as an association (r = 0.52, P < .001) for the involved side. Regression analysis showed that in addition to jump height (beta = 0.49, P < .001), sex (beta = -0.17, P = .008) and body mass index (beta = 0.37, P < .001) affected isokinetic strength. The final model explained 51.1% of the variance in isokinetic muscle strength, with jump height having the strongest impact (beta = 0.49, P < .001) and explaining 31.5% of the variance.

Conclusion

Initial analysis showed a strong association between isokinetic strength and jump height. The study population encompassed various backgrounds, skill levels, and activity profiles, which might have affected the outcome. Even after controlling for age and sex, isokinetic strength was still moderately associated with jump height. Therefore, the jump technique and type of sport should be considered in future research.

Management of Anterior Cruciate Ligament Injury: What's In and What's Out?

Sports medicine physicians have a keen clinical and research interest in the anterior cruciate ligament (ACL). The biomechanical, biologic, and clinical data researchers generate, help drive injury management and prevention practices globally. The current concepts in ACL injury and surgery are being shaped by technological advances, expansion in basic science research, resurging interest in ACL preservation, and expanding efforts regarding injury prevention. As new methods are being developed in this field, the primary goal of safely improving patient outcomes will be a unifying principle. With this review, we provide an overview of topics currently in controversy or debate, and we identify paradigm shifts in the understanding, management, and prevention of ACL tears.