Central quadriceps tendon for anterior cruciate ligament reconstruction. Part I: Morphometric and biomechanical evaluation

Minimally Invasive Harvesting of Triple-Fold Superficial Layer Quadriceps Autograft for Knee Ligament Reconstruction

Graft selection plays a critical role in anterior cruciate ligament reconstruction. Autograft options, including hamstrings, bone-patellar tendon-bone, and quadriceps, offer distinct advantages and disadvantages. Soft tissue quadriceps tendon autografts are increasingly favored due to their strength, size compatibility, and potential for enhanced graft healing. This technique offers minimal skin incision, a longer graft, and reduced morbidity, as it specifically targets the superficial band of the quadriceps tendon.

Harvest location has a minimal impact on differences in cross-sectional area of quadriceps tendon in anterior cruciate ligament reconstruction

PURPOSE

Anterior cruciate ligament (ACL) reconstruction with quadriceps tendon (QT) has been gaining popularity. However, it is unknown how differences in harvest location of the QT affect its thickness and cross-sectional area (CSA). The present study aimed to clarify the differences in thickness and CSA of the QT based on location of tendon harvesting.

METHODS

Patients scheduled for, or who underwent, ACL reconstruction were prospectively included in the study. The short-axis images on ultrasound were used to assess the CSA of the QT at 30 and 60 mm proximal to the superior pole of the patella. QT autografts with CSAs greater than or equal to 10 mm of width were included and measured at three different locations, namely the center, medial one-third, and lateral one-third at the widest diameter of the QT. Patients with less than 10-mm width of the QT at 60 mm proximal to the superior pole of the patella were excluded. The thickness and CSA were compared based on the location of tendon harvest.

RESULTS

Thirty-seven patients were recruited for the study. The mean thickness and CSA were larger in the center of the QT compared to the lateral one-third at 30 mm proximal to the superior pole of the patella (thickness, 6.7 ± 1.3 mm vs. 5.9 ± 1.3 mm; P = 0.009; CSA, 65.6 ± 11.4 mm2 vs. 58.8 ± 11.9 mm2; P = 0.036). There were no significant differences in thickness and CSA of the QT among the three assessment locations at 60 mm proximal to the superior pole of the patella (n.s.).

CONCLUSION

The thickness and CSA of QT was greater in the center compared to the lateral one-third at 30 mm proximal to the QT insertion point. However, the difference in value was clinically non-significant, and therefore, harvest location of the QT autograft may not meaningfully impact intraoperative graft diameter. As a result, surgeons may choose the harvest location without concern for resultant graft diameter as long as the enough length of QT is secured.

LEVEL OF EVIDENCE

III.

Role of Quadriceps Tendon Autograft in Primary and Revision Anterior Cruciate Ligament Reconstruction

» The quadriceps tendon (QT) autograft is becoming increasingly popular in both primary and revision anterior cruciate ligament reconstruction (ACLR).» The biomechanical properties of the QT are similar to those of the native ACL, the hamstring tendon (HT), and bone-patellar tendon-bone (BTB) autografts.» QT autograft allows surgeons to be flexible with their graft size and reconstruction technique.» The QT autograft performs in a similar fashion to the BTB and HT autografts, with excellent patient-reported outcomes, consistent postoperative knee stability, and low rates of postoperative complications including graft failure and donor site morbidity.» There are emerging data that the QT autograft is a viable option in revision ACLR.

ACL Reconstruction With Quadriceps Soft Tissue Autograft Versus Bone-Patellar Tendon-Bone Autograft in Cutting and Pivoting Athletes: Outcomes at Minimum 2-Year Follow-up

Background

The optimal graft choice for anterior cruciate ligament (ACL) reconstruction (ACLR) in the high-level cutting and pivoting athlete remains controversial. Studies have shown similar outcomes when directly comparing bone-patellar tendon-bone (BPTB) autograft versus quadriceps soft tissue (QST) autograft in the general population. However, no studies have directly compared these 2 grafts in athletes participating in cutting and pivoting sports.

Hypothesis

It was hypothesized that, compared with BPTB autograft, the QST autograft would result in similar patient-reported outcomes and rates of retear, return to sport, and complications.

Study Design

Cohort study; Level of evidence, 3.

Methods

A retrospective review was performed on athletes participating in cutting and pivoting sports (soccer, American football, lacrosse, and basketball) who underwent primary ACLR with either BPTB autograft or QST autograft chosen by the athlete between January 2015 and January 2019. The International Knee Documentation Committee (IKDC) subjective knee evaluation and Lysholm Knee Scoring Scale were used to evaluate patient-reported outcomes. Return-to-sport and complication rates were identified. Descriptive statistics were expressed using Mann-Whitney test or Student t test for continuous variables and the chi-square test for categorical variables.

Results

A total of 68 athletes (32 QST, 36 BPTB) were included for analysis. The percentage follow-up was 89% (32/36) for the QST autograft group and 86% (36/42) for the BPTB autograft group. The 2-year IKDC score (QST, 90.5 ± 6.6 vs BPTB, 89.7 ± 7.8) and 2-year Lysholm score (QST, 91.3 ± 7.5 vs BPTB, 90.5 ± 8.6) were similar between groups. The percentage of athletes able to return to sport within the follow-up period was also similar (88% vs 83%; P = .63). There were 2 retears requiring revision in the BPTB group (6%) and no retears in the QST group (P = .18). One contralateral ACL rupture occurred in the QST group (3%) and 4 in the BPTB group (11%) (P = .21).

Conclusion

The QST and BPTB autografts demonstrated similar patient-reported outcomes, return-to-sport rates, and complication rates after primary ACLR at 2-year follow-up. Both autografts appear to be reliable and consistent options for ACLR in the cutting and pivoting athlete.

Mid-Term Outcomes of the All-Soft Quadriceps Tendon Autograft Are Noninferior to Hamstring Autograft in Primary Anterior Cruciate Ligament Reconstruction: Comparison With Minimum 5-Year Follow-Up

PURPOSE

To compare the 5-year clinical and functional outcomes of the soft-tissue quadriceps tendon (QT) with those of the hamstring tendon (HT) autograft.

METHODS

A retrospective review of patients undergoing anterior cruciate ligament reconstruction using either soft-tissue QT or double-tendon HT autograft with at least 5 years of follow-up was conducted. Surgical technique included anteromedial portal creation for the femoral tunnel and transtibial technique for the tibia. Graft fixation was achieved with interference composite screws for the QT and combination of interference composite screw and suture button for the HT cohort. The 2 groups were compared for differences in outcomes, including International Knee Documentation Committee (IKDC) score, Lysholm score, return to sport, and complications.

RESULTS

A total of 37 patients with QT autograft and 46 HT autografts were included in the study, with a mean follow up of 69.9 months and 70.9 months, respectively. The QT group demonstrated a larger graft size on average (9.64 mm vs 7.90 mm, P < .001). The IKDC and Lysholm scores were similar between the 2 groups at 2-years' postoperatively. At 5 years' postoperatively, the QT group demonstrated significantly greater IKDC (P = .018) and Lysholm (P = .007) scores. The cohorts demonstrated similar rates of achieving minimal clinically important difference thresholds at both 2 and 5 years' postoperatively. The 2 groups also demonstrated comparable rates of return to sport, time to return, and postoperative complications.

CONCLUSIONS

Although the QT autograft demonstrated increased patient-reported outcome scores when compared with the HT at 5 years' postoperatively, there was no clinically significant difference between the cohorts at 2 or 5 years' postoperatively. The QT autograft is an effective alternative to HT autograft with noninferior results to the HT autograft at mid-term follow-up.

LEVEL OF EVIDENCE

III, retrospective comparison study.

Graft-Specific Surgical and Rehabilitation Considerations for Anterior Cruciate Ligament Reconstruction with the Quadriceps Tendon Autograft

Anterior cruciate ligament reconstruction (ACLR) with a bone-patellar tendon-bone (BPTB) or hamstring tendon (HT) autograft has traditionally been the preferred surgical treatment for patients returning to Level 1 sports. More recently, international utilization of the quadriceps tendon (QT) autograft for primary and revision ACLR has increased in popularity. Recent literature suggests that ACLR with the QT may yield less donor site morbidity than the BPTB and better patient-reported outcomes than the HT. Additionally, anatomic and biomechanical studies have highlighted the robust properties of the QT itself, with superior levels of collagen density, length, size, and load-to-failure strength compared to the BPTB. Although previous literature has described rehabilitation considerations for the BPTB and HT autografts, there is less published with respect to the QT. Given the known impact of the various ACLR surgical techniques on postoperative rehabilitation, the purpose of this clinical commentary is to present the procedure-specific surgical and rehabilitation considerations for ACLR with the QT, as well as further highlight the need for procedure-specific rehabilitation strategies after ACLR by comparing the QT to the BPTB and HT autografts.

Level of Evidence

Level 5.

Localized Anterior Arthrofibrosis After Soft-Tissue Quadriceps Tendon Anterior Cruciate Ligament Reconstruction Is More Common in Patients Who Are Female, Undergo Meniscal Repair, and Have Grafts of Larger Diameter

PURPOSE

To determine factors associated with localized anterior arthrofibrosis (cyclops lesion), such as graft size, warranting early reoperation for lysis of adhesions after anterior cruciate ligament reconstruction (ACLR) with all-soft tissue quadriceps tendon (ASTQT) autograft.

METHODS

All primary ASTQT autograft ACLRs within a single surgeon's prospectively collected registry with minimum 6-month follow-up were included. Patients who underwent multiligament knee reconstruction or cartilage restoration procedures were excluded. Localized anterior arthrofibrosis was defined as the requirement for a second procedure to achieve debridement and lysis of adhesions owing to the inability to regain terminal extension within 6 months of ACLR. The sex-specific incidence of arthrofibrosis was evaluated relative to age, weight, femoral and tibial tunnel sizes, meniscal repair, and meniscectomy by a binary logistic regression.

RESULTS

This study included 721 patients (46% female patients). There were 52 cases of localized anterior arthrofibrosis (7.2%). Female patients had a greater incidence of arthrofibrosis than male patients. Male patients with a femoral tunnel diameter of 9.25 mm or greater had an increased incidence of arthrofibrosis compared with those with a diameter of less than 9.25 mm, whereas a similar cutoff was not found to be statistically significant for female patients. Concomitant meniscal repair was associated with an increased risk of arthrofibrosis.

CONCLUSIONS

Female sex and concomitant meniscal repair were associated with an increased localized anterior arthrofibrosis incidence. Furthermore, ASTQT with a femoral tunnel diameter of 9.25 mm or greater in male patients was associated with an increased incidence of arthrofibrosis. LEVEL OF EVIDENCE: Level III, retrospective, comparative prognostic trial.

Quadriceps Tendon Versus Hamstring Tendon Autografts for Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis

BACKGROUND

Autograft choice in anterior cruciate ligament reconstruction (ACLR) remains controversial, with increasing interest in the usage of quadriceps tendon (QT) autograft versus traditional hamstring tendon (HT) use. The current study undertakes an in-depth review and comparison of the clinical and functional outcomes of QT and HT autografts in ACLR.

HYPOTHESIS

The QT autograft is equivalent to the HT autograft and there will be little or no significant difference in the outcomes between these 2 autografts.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

The PUBMED, EMBASE, MEDLINE, and CENTRAL databases were systematically searched from their inception until November 2020. All observational studies comparing ACLR QT and HT autografts were assessed for their methodological quality. Patient outcomes were compared according to patient-reported outcome measures (International Knee Documentation Committee [IKDC], Cincinnati, Lysholm, Tegner, and visual analog scale [VAS] measures), knee extensor and flexor torque limb symmetry indices (LSIs), hamstring to quadriceps (H/Q) ratios, functional hop capacity, knee laxity, ipsilateral graft failure, and contralateral injury.

RESULTS

A total of 20 observational studies comprising 28,621 patients (QT = 2550; HT = 26,071) were included in the quantitative meta-analysis. In comparison with patients who received an HT autograft, those who received a QT autograft had similar postoperative Lysholm (mean difference [MD], 0.67; P = .630), IKDC (MD, 0.48; P = .480), VAS pain (MD, 0.04; P = .710), and Cincinnati (MD, -0.85; P = .660) scores; LSI for knee flexor strength (MD, 6.06; P = .120); H/Q ratio (MD, 3.22; P = .160); hop test LSI (MD, -1.62; P = .230); pivot-shift test grade 0 (odds ratio [OR], 0.80; P = .180); Lachman test grade 0 (OR, 2.38; P = .320), side-to-side laxity (MD, 0.09; P = .650); incidence of graft failure (OR, 1.07; P = .830) or contralateral knee injury (OR, 1.22; P = .610); and Tegner scores (MD, 0.11; P = .060). HT autografts were associated with a higher (better) side-to-side LSI for knee extensor strength (MD, -6.31; P = .0002).

CONCLUSION

In this meta-analysis, the use of the QT autograft was equivalent to the HT autograft in ACLR, with comparable graft failure and clinical and functional outcomes observed. However, HT autografts were associated with better LSI knee extensor strength.

Quadriceps tendon autograft for anterior cruciate ligament reconstruction: state of the art

The ideal graft for anterior cruciate ligament reconstruction (ACLR) continues to be debated. Although first described in 1984, use of the quadriceps tendon (QT) autograft has only recently gained popularity. The biomechanical properties of the QT autograft are favourable compared to bone-patellar tendon-bone (BPTB) and doubled hamstring (HS) grafts with a higher load to failure and a modulus of elasticity that more closely approximates the native anterior cruciate ligament (ACL). The QT graft can be harvested with or without a bone plug, as either a full thickness or a partial thickness graft, and even through minimally invasive techniques. The surgeon must be aware of potential harvest risks including patellar fracture or a graft that is of insufficient length. Numerous short-term studies have shown comparable results when compared to BPTB or hamstring HS autografts with similar graft failure rates, patient-reported outcomes. A major advantage of QT ACLR is reduced donor site morbidity compared to BPTB. However, some persistent quadriceps weakness after QT ACLR has also been reported. The current literature shows that use of the QT autograft for ACLR provides equivalent clinical results compared to other autografts with less donor site morbidity. However, future studies with longer follow-up and higher level of evidence are needed to identify specific populations where the QT may have additional advantage.

A Minimally Invasive and Simple Technique of Superficial Quadriceps Tendon Graft Harvesting

Quadriceps tendon (QT) graft is a versatile graft for anterior and posterior cruciate ligament reconstruction. Advantages of quadriceps tendon autograft are the superior quality of graft, customization of graft size, reduced anterior knee pain, reduced risk of neurovascular injury, reduced incidence of arthrofibrosis compared to BPTB graft, preservation of ACL agonists, i.e., hamstrings, implantation of thicker graft and better patella mobility. Considering its advantages over other available autografts, its popularity is now increasing among surgeons. Conventionally, quadriceps tendon graft is harvested by an open technique, which produces an ugly scar and delays rehabilitation. In this article, we describe a minimally invasive technique of quadriceps tendon graft harvesting with a 2-2.5-cm vertical skin incision. Our technique does not require any specialized instrumentation, unlike other reported minimally invasive QT graft harvesting techniques, as we harvest the graft with a close tendon stripper.

Minimally Invasive Anterior Cruciate Ligament With Quadriceps Tendon Graft: A Proximal-to-Distal Harvest Technique

Recent systematic reviews have shown anterior cruciate ligament reconstruction using quadriceps tendon (QT) grafts to have superior clinical outcomes compared with traditional bone-patella tendon-bone and hamstring tendons grafts. Using minimally invasive techniques to harvest the QT graft can reduce postoperative pain and intraoperative surgical time. This technique is usually performed with a distal-to-proximal approach but often has issues of inadvertently harvesting a graft short of the desired length or causing a hematoma. As an alternative, we introduce a minimally invasive approach with a proximal-to-distal harvest technique that results in better visualization of tissue planes, more consistent graft sizes, lower risk of inadvertent arthrotomy, and reduced risk of hematoma. The minimally invasive QT graft harvest with a proximal-to-distal approach can offer unique advantages over the current standard distal-to-proximal approach.

Quadriceps tendon autograft for primary anterior cruciate ligament reconstruction show comparable clinical, functional, and patient-reported outcome measures, but lower donor-site morbidity compared with hamstring tendon autograft: A matched-pairs study with a mean follow-up of 6.5 ​years

OBJECTIVES

To compare clinical and functional outcomes of patients after primary anterior cruciate ligament reconstruction (ACLR) using quadriceps tendon- (QT-A) and hamstring tendon (HT-A) autograft with a minimum follow-up (FU) of 5 years.

METHODS

Between 2010 and 2014, all patients undergoing ACLR were recorded in a prospectively administered database. All patients with primary, isolated QT-A ACLR and without any concomitant injuries or high grade of osteoarthritis were extracted from the database and matched to patients treated with HT-A. Re-rupture rates, anterior-posterior (ap) knee laxity, single-leg hop test (SLHT) performance, distal thigh circumference (DTC) and patient-reported outcome measures (PROMs) were recorded. Between group comparisons were performed using chi-square-, independent-samples T- or Mann-Whitney-U tests.

RESULTS

45 QT-A patients were matched to 45 HT-A patients (n ​= ​90). The mean FU was 78.9 ​± ​13.6 months. 18 patients (20.0%/QT-A: N ​= ​8, 17.8%; HT-A: n ​= ​10, 22.2%; p ​= ​.60) sustained a graft rupture and 17 subjects (18.9%/QT-A: n ​= ​9, 20.0%; HT-A: n ​= ​8, 17.8%; p ​= ​.79) suffered a contralateral ACL injury. In high active patients (Tegner activity level ≥ 7) rerupture rates increased to 37.5% (HT-A) and 22.2% (QT-A; p ​= ​.32), respectively. Patients with graft failure did not differ between both groups in terms of mean age at surgery (QT-A: 26.5 ​± ​11.6 years, HT-A: 23.3 ​± ​9.5 years, p ​= ​.63) or graft thickness (mean graft square area: QT-A: 43.6 ​± ​4.7 mm², HT-A: 48.1 ​± ​7.9 mm², p ​= ​.27). No statistical between-group differences were found in ap knee laxity side-to-side (SSD) measurements (QT-A: 1.9 ​± ​1.2 ​mm, HT-A: 2.1 ​± ​1.5 ​mm; p ​= ​.60), subjective IKDC- (QT-A: 93.8 ​± ​6.8, HT-A: 91.2 ​± ​7.8, p ​= ​.17), Lysholm- (QT-A 91.9 ​± ​7.2, HT-A: 91.5 ​± ​9.7, p ​= ​.75) or any of the five subscales of the KOOS score (all p ​> ​.05). Furthermore, Tegner activity level (QT-A: 6(1.5), HT-A: 6(2), p ​= ​.62), VAS for pain (QT-A: 0.5 ​± ​0.9, HT-A: 0.6 ​± ​1.0, p ​= ​.64), Shelbourne-Trumper score (QT-A: 96.5 ​± ​5.6, HT-A: 95.2 ​± ​8.2, p ​= ​.50), Patient and Observer Scar -Assessment scale (POSAS) (QT-A: 9.4 ​± ​3.2, HT-A: 10.7 ​± ​4.9, p ​= ​.24), SSD-DTC (QT-A: 0.5 ​± ​0.5, HT.- A: 0.5 ​± ​0.6, p ​= ​.97), return to sports rates (QT-A: 82.1%, HT-A: 86.7%) and SLHT (QT -A: 95.9 ​± ​3.8%, HT-A: 93.7 ​± ​7.0%) did not differ between groups. Donor-site morbidity (HT-A n ​= ​14, 46.7%; QT-A n ​= ​3, 11.5%; p ​= ​.008) was statistically significantly lower in the QT-A group. Five patients (11.1%) of the HT-group and three patients (6.7%) in the QT-group required revision surgery (p ​= ​.29).

CONCLUSION

Patient-reported outcome measures, knee laxity, functional testing results and re-rupture rates are similar between patients treated with QT- and HT- autografts. However, patients with QT-autograft have a smaller tibial postoperative scar length and lower postoperative donor-site morbidity. There is a tendency towards higher graft rupture rates in highly active patients treated with HT autograft.

LEVEL OF EVIDENCE

II.

ACL Graft Matching: Cadaveric Comparison of Microscopic Anatomy of Quadriceps and Patellar Tendon Grafts and the Femoral ACL Insertion Site

BACKGROUND

The optimal graft choice between the bone-patellar tendon-bone (BPTB) and the quadriceps tendon remains controversial. Studies evaluating the microscopic anatomy of the quadriceps tendon-patellar bone (QTB) and BPTB grafts for anterior cruciate ligament (ACL) reconstruction are currently lacking.

HYPOTHESIS

The relationship between post-ACL reconstruction graft bending angle (GBA) and the angle corresponding to the GBA (cGBA) would indicate that the BPTB can bend more than the QTB at the femoral tunnel aperture.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twenty paired human cadaveric knees fixed at <10° of knee joint flexion (mean age, 82.5 years) underwent histological sectioning and staining with Masson trichrome and toluidine blue. The femoral ACL insertion, QTB graft, and BPTB graft were microscopically analyzed. The width of the direct insertion, thickness of the uncalcified fibrocartilage and calcified fibrocartilage, ligament attachment angle, and cGBA for each group were measured. Eighteen patients who underwent ACL reconstruction with QTB or BPTB autograft were included for the evaluation of GBA using computed tomography images at 1 week postoperatively.

RESULTS

The mean insertion widths of the femoral ACL, QTB, and BPTB were 7.81, 9.07, and 6.54 mm, respectively. The QTB was 16% wider than the ACL, while the BPTB was 16% narrower than the ACL. The mean insertion thicknesses of the femoral ACL, QTB, and BPTB were 0.53, 0.94, and 0.38 mm, respectively. The QTB was 77% thicker than the ACL (P < .001), while the BPTB was 28% thinner than the ACL (P = .017). The mean ligament attachment angles of the femoral ACL, QTB, and BPTB were 20.3°, 30.2°, and 33.3°, respectively, and the QTB and the BPTB were 49% and 64% larger, respectively, than the ACL. The mean cGBAs of the femoral ACL, QTB, and BPTB were 33.9°, 35.1°, and 12.3°, respectively. The BPTB was 64% smaller than the ACL, while there was no significant difference between the QTB and the ACL. The mean GBA was 57.7°.

CONCLUSION

The insertion width and thickness were significantly greater and smaller in the QTB and BPTB grafts, respectively, than in the ACL. The relationship between GBA after ACL reconstruction and cGBA in knee extension indicates that at the femoral tunnel aperture, the BPTB can bend more than the QTB.

CLINICAL RELEVANCE

QTB graft may allow more anatomic ACL reconstruction to be performed.

Estimating the adequacy of the free quadriceps tendon autograft length using anthropometric measures in anterior cruciate ligament reconstruction

OBJECTIVE

This prospective study aimed to predict the adequacy of free quadriceps tendon (QT) autograft length using simple anthropometric measures.

MATERIALS AND METHODS

One hundred and eighty-four consecutive patients who underwent knee high-resolution MRI were enrolled in this study. The QT and native anterior cruciate ligament (ACL) length were measured using the oblique sagittal section. The adequate free QT length was calculated using the native ACL length and 30 mm for femoral and tibial tunnels in each patient. A QT shorter than the calculated length was considered inadequate. Age, sex, height, weight, body mass index, thigh circumference, and activity score were used to predict the adequacy of QT length with regression analysis.

RESULTS

There were 92 men and 92 women with a mean age of 34.1 ± 8.0 years (range 18-45). The mean QT and ACL lengths were 69.0 ± 8.8 mm (range 48.1-90.3 mm) and 35.6 ± 2.5 mm (range 29.2-42.6 mm), respectively. The QT and the ACL lengths were longer in men (p < 0.001 for both). Twenty-three men and 39 women (total: 62, 33.7%) had inadequate QT length for a free QT autograft, and 6 patients (3 males, 3 females, 3.3%) had inadequate QT length with the bone block technique. There was a weak positive correlation between QT length and height (p < 0.001), weight (p < 0.001), and activity score (p = 0.007). Height was the only independent variable that predicted the QT length adequacy (r² = 0.051, p = 0.009) but ROC analysis showed that height did not have an ability to detect a subject with an inadequate QT length (AUC: 0.384, 95% CI 0.300-0.468).

CONCLUSIONS

Free QT autografts may be inadequate in one-third of the patients, while a QT autograft with a bone block is almost always sufficient. Inadequate free QT autograft is more common in women. Although QT length correlated with height, it cannot be used as an accurate diagnostic tool to identify patients with an inadequate QT autograft. Preoperative measurement of the ACL and QT lengths by MRI might be beneficial to decide whether QT is usable, especially when harvesting without a bone block.

LEVEL OF EVIDENCE

Level II, diagnostic, prospective cohort study.

Postoperative Anterior Cruciate Ligament Reconstruction Quadricep and Patella Tendon Rupture, Infection, and Lysis of Adhesions Decreased Despite Changing Graft Trends Over the Past Decade

Purpose

To investigate recent trends in postoperative complications following anterior cruciate ligament (ACL) reconstruction.

Methods

Patients who underwent ACL reconstruction surgery were identified in a national insurance database and separated into 2 cohorts based on the date of their initial surgery comprising the years 2010 to 2012 and 2016 to 2018, respectively. Patients were matched 1:1 based on comorbidities and Elixhauser Comorbidity Index. All patients were assessed for postoperative complications within 18 months of surgery. Rate of complication was compared between cohorts.

Results

Overall, the all-cause complication rate was 2%. There were significantly more quadriceps tendon rupture, patella tendon rupture, lysis of adhesion, and infection in the early cohort. There were significantly more instances of deep vein thrombosis in the late cohort. We found no significant difference in manipulations under anesthesia between the 2 cohorts.

Conclusions

Patients who underwent surgery in the late cohort had lower rates of postoperative complications, except for deep vein thrombosis. The rate of postoperative quadriceps tendon rupture decreased despite considerable increase in the use of quadriceps tendon autograft.

Clinical Relevance

As there has been an increased use of quadriceps tendon autografts, but little is known about the postoperative complications after ACL reconstruction with these grafts. This information has the potential to improve patient outcomes.

Anterior cruciate ligament reconstruction using quadriceps tendon autograft is a viable option for small-statured female patients

PURPOSE

The choice of graft for anterior cruciate ligament (ACL) reconstruction remains controversial. The quadriceps tendon (QT) autograft is a good alternative for ACL reconstruction. However, concerns regarding its use in short-statured patients, related to donor site morbidity, anterior knee pain, or loss of muscle strength remain. This study aimed to compare muscle strength and morbidity between patients with short and normal statures following ACL reconstruction with a QT autograft.

METHODS

A total of 73 female patients (mean age, 33.8 ± 11.5 years) who underwent primary ACL reconstruction between 2016 and 2019 were included. Patients were categorized into two groups: group S, with a height ≤ 163 cm, and group L, with a height > 163 cm. Muscle strength, harvesting site morbidity, and ACL-return to sport after injury scale (ACL-RSI) were evaluated, with a mean timing of the follow-up of 9.0 ± 2.3 months.

RESULTS

The mean quadriceps strength for the isokinetic measurements at 60° and 240° was 65.0% and 74.0% in group S, respectively, and 70.0% and 75.7% in group L, respectively. There was no significant difference in the postoperative muscle strength or mean ACL-RSI (group S, 70.0; group L, 65.9) between the groups. No donor site morbidity was observed in either group.

CONCLUSION

Muscle strength recovery, morbidity, and readiness to return to sports were similar in both groups, which supports the possibility of QT autografts for patients with a small stature. The results of this study may provide useful information for surgeons who are hesitant to perform QT autografts because of patient physique.

LEVEL OF EVIDENCE

IV.

Closure of the Quadriceps Tendon Autograft Harvest Site for Anterior Cruciate Ligament Reconstruction: A Systematic Review

BACKGROUND

The quadriceps tendon (QT) autograft is a commonly used and effective graft option for anterior cruciate ligament reconstruction (ACLR). Surgical techniques vary, and there is no current standard of care for management of the QT autograft harvest site.

PURPOSE

To examine the literature on patient-reported outcomes and complications after ACLR with a QT autograft and to further clarify the frequency with which the harvest site is closed and potential biomechanical implications.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic review according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines was performed using multiple medical databases. Level 1 to 4 studies on patients undergoing ACLR with a QT autograft were included. There were 2 independent reviewers who analyzed all studies. Study quality was analyzed using the methodological index for non-randomized studies checklist.

RESULTS

Overall, 13 studies with a total of 650 patients were included. The mean patient age for all studies was 31 years (range, 14-59 years) with a mean follow-up of 21.2 months (range, 6-84 months). Of the 13 studies, 12 studies (92%) documented patient sex, comprising 331 female patients (55%) and 274 male patients (45%). There were 8 studies (62%) that reported the use of a bony QT autograft in 273 patients, and 5 studies (38%) reported the use of a soft tissue QT autograft in 377 patients. The graft length harvested was most commonly 7 to 8 cm, while the tendon width harvested was 10 mm. Moreover, 5 studies (38%) did not discuss closure of the harvest site, while 2 studies (15%) only closed the harvest site if a capsular rent was present. The surgical technique for harvest-site closure varied when reported in 7 studies (54%). Good to excellent clinical outcomes were reported in 80% of patients when the harvest site was closed.

CONCLUSION

Based on the results of this study, there is no consensus on whether the QT defect should be closed after harvesting the graft for ACLR. It has been reported that closure of the harvest site is performed if there is a capsular rent present. Several techniques are utilized to close the QT autograft harvest site; however, it is unclear if there is a difference in outcomes based on the technique used. Future studies should further clarify whether there are any biomechanical and clinical advantages to closing the QT autograft harvest site.

Quadriceps tendon vs hamstring autograft in primary ACL reconstruction – a comparative study with minimum two-year follow-up

Recently there has been growing interest in the quadriceps tendon (QUAD) as a valid option for reconstruction of the anterior cruciate ligament (ACLR). The aims of the study is to compare the out- comes achieved in anatomic ACLR involving QUAD vs. Hamstring (HT) autografts. A total of 52 consecutive patients underwent an ACLR, 25 patients with QUAD graft and 27 with HT graft. The same surgical technique, fixation method and postoperative protocol were used in both groups. The following parameters were evaluated: functional status (Lysholm, Tegner, subjective IKDC scores), joint stability (Lachman and pivot shift tests), surgical reoperation rate, complications, degree of satisfaction and return to previous level of activity. Descriptive statistics were analysed using the Student’s t-test. Forty four patients were evaluated (20 QUAD, 24 HT), with a mean follow-up of 27.4 months. Two patients were re-operated in the QUAD group (including one ACL revision), and one patient in the HT group required an ACL revision. There were no significant differences between the two groups in postoperative scores: Lysholm (96.05 vs. 96.05), IKDC (86.2 vs. 91.2) and Tegner (6 vs. 5) scales. The percentage of negative Lachman and pivot shift tests was similar in the two groups (45% vs. 50% and 40% vs. 45.8%, respectively). There were no significant differences between the groups in the degree of satisfaction (95.8% vs. 80%, p = .16) or in the percentage who returned to their previous level of activity (62.5% vs. 45%, p = .17). The use of a QUAD graft in ACL reconstruction leads to similar clinical and functional outcomes to those obtained with HT.

Biomechanical properties of common graft choices for anterior cruciate ligament reconstruction: A systematic review

BACKGROUND

This systematic review explores the differences in the intrinsic biomechanical properties of different graft sources used in anterior cruciate ligament (ACL) reconstruction as tested in a laboratory setting.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, two authors conducted a systematic review exploring the biomechanical properties of ACL graft sources (querying PubMed, Cochrane, and Embase databases). Using the keywords "anterior cruciate ligament graft," "biomechanics," and "biomechanical testing," relevant articles of any level of evidence were identified as eligible and included if they reported on the biomechanical properties of skeletally immature or mature ACL grafts solely and if the grafts were studied in vitro, in isolation, and under similar testing conditions. Studies were excluded if performed on both skeletally immature and mature or non-human grafts, or if the grafts were tested after fixation in a cadaveric knee. For each graft, failure load, stiffness, Young's modulus, maximum stress, and maximum strain were recorded.

FINDINGS

Twenty-six articles were included. Most studies reported equal or increased biomechanical failure load and stiffness of their tested bone-patellar tendon-bone, hamstring, quadriceps, peroneus longus, tibialis anterior and posterior, Achilles, tensor fascia lata, and iliotibial band grafts compared to the native ACL. All recorded biomechanical properties had similar values between graft types.

INTERPRETATION

Most grafts used for ACL reconstruction are biomechanically superior to the native ACL. Utilizing a proper graft, combined with a standard surgical technique and a rigorous rehabilitation before and after surgery, will improve outcomes of ACL reconstruction.

Addition of the Sartorius Tendon Improves Biomechanics of a Four-Strand Hamstring Anterior Cruciate Ligament Autograft

PURPOSE

The purpose of this study was to quantify and compare the biomechanical properties and change in graft size when adding the sartorius tendon as a fifth strand to a four-strand ST-G hamstring autograft. Additionally, the sartorius tendon was tested individually to quantify its independent biomechanical properties.

METHODS

Four-strand and five-strand hamstring tendon grafts were harvested from matched cadaveric knees (mean age: 81.6 ± 9.8). These matched grafts were biomechanically tested using a MTS servohydraulic test system at a rate of testing representative of physiologic tears. The mean diameter, cross-sectional area, and ultimate load to failure were quantified and compared with a one-sided, paired Student's t-test. A P < .05 was considered statistically significant.

RESULTS

The mean diameter of the five-strand graft was significantly larger than the four-strand graft (9.30 ± .84 mm vs 8.10 ± .42 mm; P = .002). The average ultimate load to failure of the five-strand graft was 65.3% higher than the four-strand graft (2984.05 ± 1085.11 N vs. 1805.03 ± 557.69 N; P = .009) and added 14.8% to the diameter of the four strand ST-G autograft.

CONCLUSIONS

The addition of the sartorius tendon to a four-strand hamstring autograft significantly increased ultimate load to failure by 65%, graft cross-sectional area by 32%, and graft diameter by 15% compared to a traditional four-strand ST-G autograft. This information can be helpful to surgeons who wish to improve the strength of a four-strand ST-G autograft and for undersized grafts as an alternative to allograft supplementation.

CLINICAL RELEVANCE

The addition of the sartorius to the four-strand ST-G hamstring autograft significantly increases the ultimate load to failure and overall graft diameter, which can be particularly helpful in undersized autografts as an alternative to allograft supplementation.

Full thickness quadriceps tendon grafts with bone had similar material properties to bone-patellar tendon-bone and a four-strand semitendinosus grafts: a biomechanical study

PURPOSE

Despite increasing interest in utilizing quadriceps tendon (QT) grafts in anterior cruciate ligament reconstruction (ACLR), data on the optimal quadriceps graft thickness are limited. The purpose of this study was to characterize the mechanical properties for the quadriceps tendon, comparing full-thickness (FT) QT grafts with and without bone to a partial-thickness (PT) QT graft, and comparing the three QT grafts to four-stranded semitendinosus (4-SST) and bone-patellar tendon-bone (BTB) grafts and one experimental graft, the two-stranded rectus femoris (RF).

METHODS

Forty-eight (n = 48) young cadaveric grafts (mean age 32 ± 6 years) were utilized for testing with N = 8 specimens in each of the following groups; (1) FT QT with bone, (2) FT QT without bone, (3) PT QT without bone, (4) BTB, (5) RF, and (6) 4-SST. Each specimen was harvested and rigidly fixed in custom clamps to a dynamic tensile testing machine for biomechanical evaluation. Graft ultimate load and stiffness were recorded. Independent groups one-factor ANOVAs and Tukey's pairwise comparisons were performed for statistical analyses.

RESULTS

FT QT with bone and 4-SST grafts demonstrated similar ultimate loads to BTB grafts (both n.s), whereas PT QT demonstrate statistically significantly lower ultimate loads to BTB grafts (n.s) and 4-SST grafts (n.s). Furthermore, no statistically significant differences were observed between the ultimate loads of FT QT vs. PT QT grafts without bone (n.s) or between FT QT with vs. without bone (n.s). FT QT grafts with bone did not demonstrate statistically significantly greater ultimate loads than PT QT grafts without bone (n.s). The RF graft demonstrated statistically significantly lower ultimate loads to BTB grafts (p < 0.005) and 4-SST grafts (p < 0.014).

CONCLUSIONS

Full thickness QT grafts with bone had similar material properties to BTB and a 4-SST grafts, while Partial thickness QT graft without bone had significantly lower material properties than BTB and 4-SST, in a biomechanical setting.

Anterior Cruciate Ligament Rupture in Skeletally Immature Patients

In the past 20 years, sports injuries in pediatric and adolescent athletes have increased dramatically, with anterior cruciate ligament (ACL) injuries accounting for more than 25% of all knee injuries at this age. Diagnosis is based on detailed clinical history, physical examination, and imaging assessment, where magnetic resonance imaging plays a central role. The growing immature skeleton presents specific characteristics, which require unique methods for surgical reconstruction, ideally avoiding the physes or minimizing the risk of damaging them. Specific rehabilitation protocols are needed, and these patients face a higher risk of recurrent and contralateral ACL injury. Nonsurgical treatment or delayed reconstruction has been associated with persistent instability, activity modifications, worst functional outcomes, and increased risk of irreparable injuries to menisci and articular cartilage. Consequently, surgical stabilization is the preferred treatment for most patients, despite the eventual risk of angular deformities or limb-length discrepancies due to iatrogenic physeal injury. A variety of surgical techniques have been described, depending on the skeletal maturity and growth remaining. Targeted prevention programs play a key role in reducing the risk of ACL injury, are easy to implement, and require no additional equipment. High-quality evidence supports its use in all pediatric athletes.

Biomechanics of hamstring tendon, quadriceps tendon, and bone-patellar tendon-bone grafts for anterior cruciate ligament reconstruction: a cadaveric study

PURPOSE

The three most commonly used autografts for anterior cruciate ligament reconstruction (ACL) are: bone-patellar tendon-bone (BTB), hamstring tendons (HT), and quadriceps tendon (QT). A cadaveric study was performed to determine if there were any differences in mechanical and structural properties under biomechanical testing.

METHODS

Twenty-seven graft specimens were harvested from 9 human cadaveric legs. Mean donor age was 75.2 years (range 53-85 years). Twenty-two specimens (8 HT, 7 QT, and 7 BTB) completed cyclic preconditioning from 50 to 800 N for 200 cycles and a load to failure test at an extension rate of 1 mm/s. Structural and mechanical properties of BTB, HT, and QT grafts were compared using a one-way ANOVA and Tukey's honest significant difference.

RESULTS

There was no difference in the ultimate load to failure (N) across all 3 graft types (p = 0.951). Quadriceps tendon demonstrated greater cross-sectional area (mm²) when compared to both HT and BTB (p = 0.001) and was significantly stiffer (N/mm) than HT but not BTB (p = 0.004). Stress (N/mm²) of the HT at ultimate load was greater than QT but not BTB (p = 0.036). Elastic modulus (MPa) of HT was greater than both QT and BTB (p = 0.016).

CONCLUSION

There was no difference in the ultimate load to failure of BTB, HT, and QT grafts harvested from the same specimens. All 3 grafts had similar loads to failure with a significant increase in stiffness when compared to the native ACL. Furthermore, QT demonstrated more favourable structural properties compared to HT and BTB with greater cross-sectional area to both HT and BTB and greater stiffness compared to HT.

Association Between Neuromuscular Variables and Graft Harvest in Soft Tissue Quadriceps Tendon Versus Bone-Patellar Tendon-Bone Anterior Cruciate Ligament Autografts

Background:

Quadriceps tendon (QT) autografts are increasingly popular for anterior cruciate ligament reconstruction (ACLR). However, no study has compared QT autografts with bone–patellar tendon–bone (BTB) autografts regarding the electromechanical delay (EMD), the peak torque (PT), and the rate of force development (RFD) in the superficial quadriceps muscles (rectus femoris [RF], vastus medialis [VM], and vastus lateralis [VL]).

Hypotheses:

We hypothesized (1) there would be a significantly lower PT, lower RFD, and longer quadriceps EMD of the operative limb for the QT versus the BTB autograft; (2) the PT, the RFD, and the quadriceps EMD of the operative limb would be significantly depressed compared with those of the nonoperative limb, regardless of the surgical technique; and (3) there would be greater increases in the RF EMD than in the VM or the VL EMD.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A total of 34 patients (age, 18-40 years), who had undergone ACLR (QT, n = 17; BTB, n = 17) at least 1 year before testing and performed 3 perceived maximal effort isometric tests, which were time synchronized with surface electromyography (EMG) on their operative and nonoperative limbs, were included in this study. EMD, PT, and RFD data were analyzed using a 2 (limb) × 2 (graft) × 3 (repetition) mixed repeated-measures analysis of variance.

Results:

The EMD, the PT, and the RFD were not significantly affected by graft choice. For the VL, a significant repetition × graft × limb interaction was detected for the VL EMD (P = .027; ηp = 0.075), with repetition 3 having longer EMD than repetition 2 (mean difference [MD], 16 milliseconds; P = .039). For the RF EMD, there was a significant repetition × limb interaction (P = .027; ηp = 0.074), with repetition 3 being significantly longer on the operative versus the nonoperative limb (MD, 24 milliseconds; P = .004). Further, the operative limb EMD was significantly longer for repetition 3 versus repetition 2 (MD, 17 milliseconds; P = .042). For the PT, there was a significant effect for repetition (P = .003; ηp = 0.114), with repetition 1 being significantly higher than both repetitions 2 (MD, 8.52 N·m; P = .001) and 3 (MD, 7.79 N·m; P = .031). For the RFD, significant limb (P = .034; ηp = 0.092) and repetition (P = .010; ηp = 0.093) effects were seen, with the nonoperative limb being significantly faster than the operative limb (MD, 23.7 N·m/s; P = .034) and repetition 1 being significantly slower than repetitions 2 (MD, -20.46 N·m/s; P = .039) or 3 (MD, −29.85 N·m/s; P = .002).

Conclusion:

The EMD, the PT, and the RFD were not significantly affected by graft type when comparing QT and BTB autografts for ACLR; however, all neuromuscular variables were affected regardless of the QT or the BTB harvest.

Qualitative and Quantitative Anatomy of the Human Quadriceps Tendon in Young Cadaveric Specimens

Background:

A detailed understanding of the anatomy of the quadriceps tendon (QT) is clinically relevant, owing to its increased use as a graft in anterior cruciate ligament reconstruction.

Purpose:

To qualitatively and quantitatively describe the anatomy of the QT in younger adult specimens.

Study Design:

Descriptive laboratory study.

Methods:

A total of 18 nonpaired cadaveric knees with a mean age of 30.1 years (range, 18-38 years) were utilized for this study. A 3-dimensional coordinate measuring system was used to assess the structural relationships between the different layers of the QT and their attachments to the patella, and QT thickness was measured medially, centrally, and laterally at 2-cm intervals from the patellar eminence line (PEL; defined as a straight line between the medial and lateral patellar eminences) and proximally.

Results:

In all specimens, 3 distinct layers formed the QT. The first (superficial) layer was formed by the rectus femoris, which was fused to the second layer with an unclearly defined direct attachment to the patella. The median length of the QT was 86.9 mm (range, 68.4-98.9 mm). The second (middle) layer consisted of the vastus medialis and vastus lateralis and was found to have fibers running in an oblique direction that attached on the patella. A “fuse point,” where the proximal part of the rectus femoris started to merge to the second layer, was identified at a median of 48.7 mm (range, 27.9-62.6 mm) from the PEL. The third (deep) layer consisted of the vastus intermedius. The median thickness of the graft centrally at 20, 40, 60, 80, and 100 mm from the PEL was 8.5, 7.2, 7.5, 6.5, and 5.4 mm, respectively.

Conclusion:

Overall, 3 different layers of the QT were consistently found in all specimens. The first layer was fused with the second layer, and the direction of the fibers of the second layer or the vastus medialis and vastus lateralis was oblique. The median length of the QT was 86.9 mm, and the thickness of the tendon diminished proximally.

Clinical Relevance:

This study allows for a better understanding of QT anatomy when harvesting the tendon as a graft for ligamentous reconstruction.

Anterior Cruciate Ligament Reconstruction with Quadriceps Tendon-Patellar Bone Autograft and Dual Tibial Fixation

Anterior cruciate ligament ruptures are a relatively common injury in the athletic population, and surgical reconstruction is often indicated to restore knee stability. While hamstring tendon and patellar bone-tendon-bone autografts are a well-established graft choice in this population, there has been a growing body of literature supporting the benefits of quadriceps tendon autograft. Our technique illustrates a full-thickness quadriceps tendon-patellar bone autograft with dual tibial fixation using an interference screw and backup suspensory anchor fixation.

Evolution in ACL Autograft Harvesting Techniques: Transition to Minimally Invasive Autograft Harvesting

Surgical techniques for anterior cruciate ligament (ACL) reconstruction continue to evolve. Harvesting techniques for commonly used ACL autografts such as bone patellar tendon bone, hamstring, and quadriceps tendon have similarly continued to progress. Traditional larger incisions for graft harvesting that were described in the 1980s have given way to smaller or more minimally invasive techniques. Advantages of these techniques are primarily anatomy based and include the following: decreased nerve complaints such as hypoesthesia or dysesthesia, improved cosmesis, decreased surgical site pain or morbidity, and, in the case of hamstring harvesting, easier tendon identification. The current literature supports reproducible minimally invasive or modified graft harvesting techniques for bone patellar tendon bone, hamstring, and quadriceps tendon autografts. Specialized instrumentation is available to simplify the harvesting process. Each of these techniques is described in detail outlining surgical steps, technical considerations, and precautions. Knowledge and review of these techniques provides the surgeon with greater flexibility and options when choosing and harvesting autograft tissue for ACL reconstruction.

Minimally invasive harvesting of the quadriceps tendon: Technical note

The quadriceps tendon is gaining preference as an autograft over conventional grafts for the primary reconstruction of the anterior and posterior cruciate ligaments and of the medial patello-femoral ligament. In the past, the use of the quadriceps tendon was associated with considerable morbidity and less favourable outcomes compared to other grafts, specifically due to post-operative weakness of the quadriceps and other complications such as patellar fracture and rupture of the extensor apparatus. These problems are partially ascribable to the graft harvesting method used (large incision, bone block>2cm, and full-thickness tendon harvesting). Recent technical advancements have made reproducible harvesting of quadriceps grafts possible, thereby largely preventing the complications. In this study we describe an original quadriceps tendon harvesting technique in which a minimally invasive approach allows the collection of a sufficiently long graft, while sparing the deep layer of the quadriceps tendon. This technique decreases intra-operative morbidity and improves the post-operative outcomes.

Bone Versus All Soft Tissue Quadriceps Tendon Autografts for Anterior Cruciate Ligament Reconstruction: A Systematic Review

PURPOSE

To examine existing literature on objective and patient-reported outcomes and complications after anterior cruciate ligament reconstruction (ACLR) with bone-quadriceps-tendon (B-QT) or soft tissue-quadriceps tendon (S-QT) to further clarify the role of graft type in primary ACLR.

METHODS

In accordance with PRISMA guidelines, PubMed, Embase, and Medline were searched in October 2019 for English-language, human studies of all evidence levels on patients undergoing primary ACLR with B-QT or S-QT autograft.

RESULTS

24 of 1,381 studies satisfied criteria, with 20 using B-QT (1,534 patients, mean age 29.6 years [range 14 to 59], mean follow-up 41.2 months [range 12 to 120]) and 5 using S-QT (181 patients, mean age 32.4 years [range 15 to 58), mean follow-up 25.5 months [range 12 to 46]). International Knee Documentation Committee (IKDC) scores were 67.3 to 89.5 with B-QT and 80.4 to 81.6 with S-QT. Lysholm scores were 85.7 to 97.4 with B-QT and 81.6 to 89.2 with S-QT. More B-QT patients demonstrated rotatory laxity on pivot shift compared with S-QT (0% to 39% versus 0%, respectively). The most common complication was graft rupture, and no differences were observed between graft choices (B-QT 0% to 9% versus S-QT 0% to 3.8%).

CONCLUSIONS

The main findings from this review report that more B-QT patients demonstrated postoperative rotatory instability than S-QT patients, and that there are no differences in graft rupture between the 2 graft choices. Although statistical conclusions may not be drawn because of heterogeneity in reporting, it appears that the B-QT group featured much wider major and minor complication profiles.

LEVEL OF EVIDENCE

IV, systematic review of level I-IV studies.

Quadriceps tendon autograft is an effective alternative graft for posterior cruciate ligament reconstruction in isolated or multiligament injuries: a systematic review

IMPORTANCE

High-grade posterior cruciate ligament (PCL) tears can be a significant cause of patient morbidity and knee instability. The graft of choice for operative repair remains controversial, although recently there has been increased interest in quadriceps tendon (QT) as an autologous graft option.

OBJECTIVE

The purpose of this study was to perform a systematic review to assess reported clinical outcomes of PCL reconstructions using QT autografts.

EVIDENCE REVIEW

A comprehensive review of clinical studies was performed evaluating PCL reconstruction with QT autograft including a systematic search of PubMed, Scopus, Cochrane and Google Scholar databases, and reference lists of relevant papers. Clinical results, stability results, functional outcomes, range-of-motion outcomes, complications and morbidity, and the conclusions of each study were evaluated.

FINDINGS

Seven studies were included in the review of clinical results, including 145 subjects undergoing PCL reconstructions with QT autograft. All studies evaluated quadriceps tendon bone (QT-B) grafts. Among these seven studies, two included isolated PCL reconstruction while five included multiligamentous knee injury reconstruction. These studies suggest that QT-B autograft offers a viable graft option for primary PCL reconstruction with generally favourable patient-reported outcomes, knee stability and range of motion reported along with relatively low complication rates.

CONCLUSIONS AND RELEVANCE

Use of the QT-B autograft may be a reasonable graft option for PCL reconstruction. However, high-quality prospective studies are required to evaluate the long-term safety, efficacy and functional outcomes.

LEVEL OF EVIDENCE

Level IV (Systematic review of Level IV studies).

Comparing Bone-Tendon Autograft With Bone-Tendon-Bone Autograft for ACL Reconstruction: A Matched-Cohort Analysis

Background:

Anterior cruciate ligament (ACL) reconstruction (ACLR) using bone-tendon-bone (BTB) autograft is associated with increased postoperative anterior knee pain and pain with kneeling and has the risk of intra- and postoperative patellar fracture. Additionally, graft-tunnel mismatch is problematic, often leading to inadequate osseous fixation. Given the disadvantages of BTB, an alternative is a bone-tendon autograft (BTA) procedure that has been developed at our institution. BTA is a patellar tendon autograft with the single bone plug taken from the tibia.

Purpose/Hypothesis:

The purpose of this study was to evaluate the short-term outcomes of BTA ACLR. We hypothesized that this procedure will provide noninferior failure rates and clinical outcomes when compared with a BTB autograft, as well as a lower incidence of anterior knee pain, pain with kneeling, and patellar fracture.

Methods:

A consecutive series of 52 patients treated with BTA ACLR were retrospectively identified and compared with 50 age-matched patients who underwent BTB ACLR. The primary outcome was ACL graft failure, while secondary outcomes included subjective instability, anterior knee pain, kneeling pain, and functional outcome scores (Single Assessment Numeric Evaluation, Lysholm, and International Knee Documentation Committee subjective knee form).

Results:

At a mean follow-up of 29.3 months after surgery, there were 2 reruptures in the BTA cohort (4.0%) and 2 in the BTB cohort (4.0%). In the BTA group, 18% of patients reported anterior knee pain versus 36% of the BTB group (P = .04). A total of 22% of patients noted pain or pressure with kneeling in the BTA cohort, as opposed to 48% in the BTB cohort (P = .006). There were no differences in functional scores. In the BTA group, 94.2% of patients reported that their knees subjectively felt stable, as compared with 86% in the BTB group (P = .18).

Conclusion:

This study demonstrated that the BTA ACLR leads to similarly low rates of ACL graft failure requiring revision surgery, with significantly decreased anterior knee pain and kneeling pain when compared with a BTB. Additionally, the potential complications of graft-tunnel mismatch and patellar fracture are eliminated with the BTA ACLR technique.

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.

Open Full-Thickness Quadriceps Tendon Autograft Harvest With Repair for Anterior Cruciate Ligament Reconstruction

Historically, one of the most common graft choices for anterior cruciate ligament (ACL) reconstruction in the pediatric population has been the hamstring autograft. Although pediatric ACL reconstructions with a hamstring autograft have allowed a majority of children and adolescents to return to athletics, it has been reported that anywhere between 6% and 38% of these patients will go on to experience subsequent graft rupture. The quadriceps tendon autograft is an alternative to the hamstring tendon autograft that demonstrates superior preliminary outcomes, and we currently recommend it for skeletally immature patients undergoing primary and revision ACL reconstruction. This paper aims to describe our technique for an open full-thickness quadriceps tendon harvest with repair.

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.

Every layer of quadriceps tendon's central and medial portion offers similar tensile properties than Hamstrings or Ilio-Tibial Band Grafts

PURPOSE

The aim of our cadaveric study was to compare the mechanical properties of different parts of the quadriceps' tendon in a load to failure analysis as compared to three other, and most common types of grafts that are used to perform ligament's reconstruction.

METHODS

Ten fresh-frozen cadavers (5 women, 5 men) were selected from our anatomical department. Mean age at death was 64 years (48-87 years). Tendons were harvested to prepare (1) different quadriceps tendon's specimens: lateral portion (QTlat), medial portion superficial layer (QTMsup) and deep layer (QTMdeep) and central portion superficial (QTCsup) and deep layers (QTCdeep) (2) Patellar Tendon (PT), (3) Gracilis+Semi-Tendinosus specimens (GST). Specimens were stored at - 40 °C in a freezing solution. Specimens were securely attached to a dedicated loading platform, measurements were done using a validated software. Load to failure testing was then carried out. Young's Elastic moduli, ultimate Stress (MPa) and Deformation (%) were analysed.

RESULTS

The elastic moduli of the PT was significantly higher than all other grafts, all medial and central QT layers (superficial and deep) were significantly higher than its lateral part (QTlat). In terms of Ultimate Stress, all grafts were significantly greater than QTlat, PT and GST were significantly superior to QT central portions and to ITB but there did not differ with the medial portion of QT. ITB ultimate stress values were significantly higher than QTlat. The ultimate deformations of all grafts were similar.

CONCLUSIONS

This study provides reference values in in order to characterize different parts of the QT that presents anatomically and Mechanically with complex characteristics. Every Layer of Quadriceps Tendon's Central and Medial Portion Offered Similar Mechanical Properties than Two Strand Hamstrings or Ilio-Tibial Band.

Anterior Cruciate Ligament Reconstructions With Quadriceps Tendon Autograft Result in Lower Graft Rupture Rates but Similar Patient-Reported Outcomes as Compared With Hamstring Tendon Autograft: A Comparison of 875 Patients

BACKGROUND

Graft rupture is a devastating outcome after anterior cruciate ligament (ACL) reconstruction (ACLR). Little is known about graft rupture rates as well as clinical and functional outcomes after ACLR with quadriceps tendon (QT) autografts.

PURPOSE

To compare QT with hamstring tendon (HT) autografts in terms of the rates of graft and contralateral ACL rupture as well as patient-reported outcome measures.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

All primary ACLRs performed between 2010 and 2016 were followed prospectively for 24 months through the recording of graft ruptures and contralateral ACL injuries as well as patient-administered questionnaires.

RESULTS

A total of 875 patients were included in the study. Three factors-graft type, age group, and activity level-had a significant value in predicting the need for revision surgery. The odds of revision surgery were 5.5 times greater in children younger than 15 years than in adults older than 45 years, 3.6 times greater in patients with high activity levels than low activity levels, and 2.7 times greater in patients receiving an HT autograft as compared with a QT autograft. A significantly higher rate of ipsilateral graft ruptures versus contralateral ACL injuries was observed in the HT group (4.9% vs 2.3%; odds ratio, 2.1; P = .01) but not in the QT group (2.8% vs 2.3%). The difference in the ratios of graft and contralateral ACL ruptures was even more pronounced in highly active patients treated with HT autografts (11.1% vs 4.2%; odds ratio, 2.6; P = .01) as compared with QT autografts (5.0% vs 2.8%; P = .48). Two-year measures of Lysholm scores (mean ± SD: QT, 86.0 ± 22.3; HT, 89.4 ± 16.4) and Tegner activity scores (QT, 6.1 ± 2.0; HT, 5.7 ± 1.9) as well as visual analog scale pain (QT, 0.8 ± 1.3; HT, 0.7 ± 1.1) did not differ between grafts.

CONCLUSION

Graft choice does not influence clinical and functional outcomes 2 years after ACLR. However, 3 factors-graft type, age group, and activity level-have a significant value in predicting the need for revision surgery. Patients treated with HT autografts have a significantly higher, activity-dependent risk of revision surgery and experience more ipsilateral graft ruptures than subsequent contralateral ACL injuries when compared with patients treated with QT autografts. Young age and high activity level are significant predictors for ACL revision surgery.

Anatomical study of quadriceps tendon for anterior cruciate ligament reconstruction

Background

The quadriceps tendon is a promising alternative graft choice for anterior cruciate ligament (ACL) reconstruction. Morphology of the graft directly affects the biomechanical properties. However, a few studies are evaluating the anatomical structures of quadriceps tendon as a graft in Asian population.

Objective

To define the anatomical structures of quadriceps tendon as a graft for ACL reconstruction.

Methods

Forty-nine quadriceps tendons were dissected and analyzed. Measurements were also done including length, width, and thickness.

Results

The maximum length of superficial quadriceps tendon was 63.2 ± 12.5 mm (range 37.6–83.4). The maximum length of tendon at the deepest part was 57.2 ± 11.5 (range 30.9–83.4). The maximum length of quadriceps tendon was located at 61.4% ± 13% (range 31.8–83.6) from medial edge of the patella insertion (approximately 5 mm lateral from the center of quadriceps tendon insertion). The width of quadriceps tendon at patella insertion was 42.4 ± 3.8 mm (range 33.8–50.5). The thickness of quadriceps tendon at its maximum length on patella insertion was 6.9 ± 2.0 mm (range 1.5–9.5). Positive correlation between the height of cadaver and the maximum length of quadriceps tendon was noted.

Conclusions

The maximum length of quadriceps tendon was located 5 mm lateral from the center of quadriceps tendon insertion. Thus, we recommend marking midline of the quadriceps tendon insertion as a medial border of the harvested graft to get maximum length of the graft. Graft length measurement using superficial anatomy should be cautioned because graft shortening might occur.

Quadriceps tendon autograft for primary ACL reconstruction: a Bayesian network meta-analysis

Background

The purpose of the current study was to clarify the role of the quadriceps tendon (QT) autograft for primary ACL reconstruction. Thus, a Bayesian network meta-analysis comparing patients undergoing a primary ACL reconstruction with QT versus patellar tendon (PT) and hamstring tendon (HT) autografts was conducted.

Material and methods

This Bayesian network meta-analysis was conducted according to the PRISMA extension statement for reporting systematic reviews incorporating network meta-analyses of health care interventions. In January 2020, the main databases were accessed. Articles comparing the outcomes of the QT autograft versus HT autograft and/or PT autograft for primary ACL reconstruction were included in the present study. The statistical analysis was performed with STATA Software/MP, through a Bayesian hierarchical random-effect model analysis.

Results

Data from a total of 2603 knees were analysed. The overall mean follow-up was 35.0 months. Among the different grafts were evidenced comparable values of IKDC, Tegner and Lysholm score. The QT autograft detected comparable rate of Lachman test > 3 mm, Pivot shift test > 3 m and instrumental laxity > 3 mm. The QT autograft showed a lower rate of autograft failure above all. The QT autograft detected the reduced rate of AKP than the PT.

Conclusion

Quadriceps tendon autograft may represent a feasible option for primary ACL reconstruction. These results must be interpret within the limitations of the present network meta-anlaysis.

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.

Patient-Reported Knee Outcome Scores With Soft Tissue Quadriceps Tendon Autograft Are Similar to Bone-Patellar Tendon-Bone Autograft at Minimum 2-Year Follow-up: A Retrospective Single-Center Cohort Study in Primary Anterior Cruciate Ligament Reconstruction Surgery

Background:

Quadriceps tendon (QT)–bone autografts used during anterior cruciate ligament (ACL) reconstruction have provided comparable outcomes and decreased donor-site morbidity when compared with bone–patellar tendon–bone (BPTB) autografts. No study has directly compared the outcomes of the all–soft tissue QT autograft with that of the BPTB autograft.

Hypothesis:

Patient-reported knee outcome scores and rates of postoperative complication after primary ACL reconstruction with QT autografts are no different from BPTB autografts at a minimum 2-year follow-up.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A total of 75 patients who underwent primary autograft ACL reconstruction with QT or BPTB autografts between January 1, 2015, and March 31, 2016, at a single hospital center were contacted by telephone and asked to complete the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation, Tegner activity level scale, and Lysholm knee scoring scale. Information about the subsequent surgeries performed on the operative knee was also collected. Statistical analysis was performed using the Kruskal-Wallis test and the Fisher exact test for categorical data.

Results:

Fifty patients (28 QT, 22 BPTB) completed the surveys at a mean follow-up of 33.04 months (range, 24-44 months). For the QT versus the BPTB group respectively, the median IKDC scores were 94.83 (interquartile range [IQR], 7.61) versus 94.83 (IQR, 10.92) (P = .47), the median Tegner scores were 6 (IQR, 2.5) versus 6 (IQR, 2.75) (P = .48), and the median Lysholm scores were 95 (IQR, 9) versus 95 (IQR, 13) (P = .27). Additionally, 2 QT patients and 3 BPTB patients required follow-up arthroscopy for arthrolysis (P = .64). There was 1 graft failure in the QT group requiring revision surgery.

Conclusion:

There was no statistical difference in patient-reported knee outcomes or graft complication rates between the QT and BPTB autograft groups at a minimum 2-year follow-up after primary ACL reconstruction. This study highlights that the all–soft tissue QT autograft may be a suitable graft choice for primary ACL reconstruction.

Comparison of Neuromuscular Firing Patterns of the Superficial Quadriceps in Soft Tissue Quadriceps Tendon Versus Bone-Patellar Tendon-Bone ACL Autografts

Background:

Soft tissue quadriceps tendon (QT) autografts are increasingly popular as a primary graft choice for anterior cruciate ligament reconstruction (ACLR), but no study has compared superficial quadriceps activity levels and leg extension strength for QT versus bone–patellar tendon–bone (BTB) autografts.

Hypothesis:

Harvesting the central portion of the QT will alter rectus femoris (RF) firing patterns during maximum voluntary isometric contraction.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A total of 34 patients (age range, 18-40 years) who underwent ACLR using a BTB (n = 17) or QT (n = 17) autograft at a single institution participated in this study. Participants, who had no neuromuscular injury or prior surgery on either lower extremity, were at least 1 year after ACLR, and were cleared for full activity. Postoperative rehabilitation protocols were consistent across participants. Synchronized electromyography (EMG) and isometric torque data were collected from participants in the seated position with the hips flexed to 90° and the knee at 60° of flexion. Participants were asked to extend their knees as quickly as possible and perform maximum voluntary isometric contraction for 3 seconds. A practice trial and 3 test trials were completed with 30-second rest intervals. Mixed (2 graft × 2 limb) analyses of variance were used to examine differences in average and peak torque values and RF/vastus lateralis (VL) and RF/vastus medialis (VM) ratios. Lysholm and International Knee Documentation Committee (IKDC) scores were compared between groups using unpaired t tests.

Results:

Significantly lower values were seen for the operative compared with the nonoperative extremity for average (P = .008; η² = 0.201) and peak torque (P < .0001; η² = 0.321), with no significant difference between graft types. Additionally, no significant differences in RF/VL or RF/VM ratios between limbs or graft types were observed.

Conclusion:

At 1 year after ACLR, QT and BTB autografts showed similar isometric strength deficits, with no differences in quadriceps muscle EMG ratios seen between the 2 graft types. The results support the use of a QT autograft for ACLR, as its graft harvest does not adversely affect quadriceps firing patterns in comparison with BTB graft harvest.

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.

Systematic Review of Publications Regarding Quadriceps Tendon Autograft Use in Anterior Cruciate Ligament Reconstruction

Purpose

To perform a systematic review with quantitative and qualitative analysis of publications to date focusing on the use of quadriceps tendon (QT) autografts in anterior cruciate ligament (ACL) reconstruction and to define the regional variability, type of publication, level of evidence, journal of publication, and type of QT graft used.

Methods

The PubMed, Scopus, and Google Scholar databases were systematically queried for journal articles relating to QT autografts used for ACL reconstruction through 2018. These publications were filtered for relevance and then analyzed and differentiated by publication characteristics.

Results

Most articles were published in the United States and Europe, and most articles evaluating clinical outcomes were Level of Evidence III. Over 60% of the publications (115 of 187) focusing on QT for ACL reconstruction were published within the past 10 years, and 30% (56 of 187) were published within the past 3 years. The results not only showed a recent increase in the number of publications regarding QT as a choice for the autograft harvest site in ACL reconstruction over time, but also yielded informative data regarding the publication journal, country or region, and level of evidence.

Conclusions

This evaluation shows the increasing interest in the scientific evaluation of QT as a source of autograft tissue for ACL reconstruction.

Clinical Relevance

Increased production of high-quality research will allow surgeons to feel more confident in their use of the QT as an autograft option in ACL reconstruction.

Magnetic resonance imaging of the quadriceps tendon autograft in anterior cruciate ligament reconstruction

BACKGROUND

Quadriceps tendon (QT) autograft is emerging as a popular technique for primary anterior cruciate ligament (ACL) reconstruction. Studies have shown that it has comparable outcomes to bone-patellar tendon-bone (BPTB) and hamstring tendon (HT) autografts while mitigating post-operative complications associated with these grafts.

PURPOSE

To provide a literature summary of the important pre- and post-operative magnetic resonance imaging (MRI) findings of the quadriceps tendon and pertinent postoperative complications associated with the QT harvest. Radiologists should be familiar with MR findings after autologous graft harvest of the quadriceps tendon for reconstruction of the ACL.

LEVEL OF EVIDENCE

Level IV.

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.

Quadriceps Tendon Graft Anatomy in the Skeletally Immature Patient

Background:

The quadriceps tendon (QT) is increasingly considered for primary and revision anterior cruciate ligament reconstruction in skeletally immature patients, as it may be harvested as a purely soft tissue graft with considerable tissue volume. Because of distinct rectus tendon (RT) separation from the QT complex, the potential for RT retraction exists and could lead to QT weakness after QT graft harvest.

Purpose:

To describe the anatomy of the pediatric QT and clarify decussation of the RT and QT to avoid the risk of delayed RT retraction and QT weakness after QT graft harvest.

Study Design:

Descriptive epidemiology study.

Methods:

Nine cadaveric knee specimens (aged 4-11 years) underwent gross dissection. Coronal-plane width and depth of the QT were measured at intervals proximal to the superior pole of the patella at distances of 0.0, 0.5, 1.0, and 1.5 times the length of the patella. The distance was measured from the superior patellar pole to the point of RT separation from the remainder of the deeper/posterior QT.

Results:

The median patellar length was 28 mm (interquartile range, 26-37 mm). The coronal-plane width of the QT was larger superficially/anteriorly when closest to the patella but wider when measured deeper/posteriorly as the tendon extended proximally. The median distance between the superior pole of the patella and RT separation from the QT was 0.95 times the patellar length. The distance to widening of the deeper/posterior aspect of the QT was 1.14 times the patellar length proximal to the patella.

Conclusion:

The RT begins a distinct separation from the QT above the superior pole of the patella at a median of 0.95 times the patellar length in skeletally immature specimens. The deeper/posterior aspect of the QT begins to increase in coronal-plane width proximally after a distance of 1.14 times the patellar length above the knee, while the superficial/anterior aspect of the tendon continues to narrow. Awareness of the separation of the RT from the QT, and the coronal-plane width variation aspects of the QT proximally, is important for surgeons utilizing the QT as a graft to avoid inadvertent release of the RT from the rest of the QT complex.

Comparison of Short-term Biodex Results After Anatomic Anterior Cruciate Ligament Reconstruction Among 3 Autografts

Background:

An individualized approach to anterior cruciate ligament reconstruction (ACLR) typically includes criteria-based postoperative rehabilitation. However, recent literature has suggested residual quadriceps weakness up to 12 months after ACLR, especially with a quadriceps tendon (QT) autograft.

Hypothesis:

The QT would have poorer quadriceps strength symmetry at 5 to 8 months compared with the hamstring tendon (HS) and patellar tendon (BPTB), but there would be no significant difference at 9 to 15 months among all 3 groups.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Patients who underwent anatomic primary ACLR with an autograft were reviewed retrospectively. Isometric quadriceps and hamstring strength measurements were obtained clinically at 5 to 8 months and 9 to 15 months postoperatively. Return-to-running and return-to-play criteria included greater than 80% and 90% quadriceps strength symmetry, respectively.

Results:

A total of 73 patients with 5- to 8-month follow-up were identified, and 52 patients had 9- to 15-month data. The QT group had a significantly lower quadriceps index at 5 to 8 months (69.5 ± 17.4) compared with the BPTB (82.8 ± 14.6; P = .014) and the HS (86.0 ± 18.6; P = .001) groups. More patients with an BPTB autograft met criteria for return to running and return to play (60% and 47%, respectively) compared with the QT group (26% and 13%, respectively) at 5 to 8 months. Given the sample sizes available, we observed no significant difference in the quadriceps index and return-to-play and return-to-running criteria at 9 to 15 months among those undergoing ACLR with a QT, BPTB, or HS graft.

Conclusion:

Patients undergoing ACLR with a QT graft demonstrated clinically meaningful quadriceps asymmetry at 5 to 8 months and 9 to 15 months postoperatively. Additionally, fewer patients in the QT group met criteria for return to play and running at 5 to 8 months than the BPTB and HS groups. These data suggest that a longer time to return to play and specific rehabilitation protocols that emphasize quadriceps strengthening may be necessary because of residual quadriceps weakness after ACLR with a QT graft.