Should the Ipsilateral Hamstrings Be Used for Anterior Cruciate Ligament Reconstruction in the Case of Medial Collateral Ligament Insufficiency? Biomechanical Investigation Regarding Dynamic Stabilization of the Medial Compartment by the Hamstring Muscles

Double-Bundle Medial Collateral Ligament Reconstruction Improves Anteromedial Rotatory Instability

BACKGROUND

New techniques have been proposed to better address anteromedial rotatory instability in a medial collateral ligament (MCL)-injured knee that require an extra graft and more surgical implants, which might not be feasible in every clinical setting.

PURPOSE

To investigate if improved resistance to anteromedial rotatory instability can be achieved by using a single-graft, double-bundle (DB) MCL reconstruction with a proximal fixation more anteriorly on the tibia, in comparison with the gold standard single-bundle (SB) MCL reconstruction.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eight fresh-frozen human cadaveric knees were tested using a 6 degrees of freedom robotic simulator in intact knee, superficial MCL/deep MCL-deficient, and reconstruction states. Three different reconstructions were tested: DB MCL no proximal tibial fixation and DB and SB MCL reconstruction with proximal tibial fixation. Knee kinematics were recorded at 0°, 30°, 60°, and 90° of knee flexion for the following measurements: 8 N·m of valgus rotation (VR), 5 N·m of external tibial rotation, 5 N·m of internal tibial rotation, combined 89 N of anterior tibial translation and 5 N·m of external rotation for anteromedial rotation (AMR) and anteromedial translation (AMT). The differences between each state for every measurement were analyzed with VR and AMR/AMT as primary outcomes.

RESULTS

Cutting the superficial MCL/deep MCL increased VR and AMR/AMT in all knee positions except at 90° for VR (P < .05). All reconstructions restored VR to the intact state except at 90° of knee flexion (P < .05). The DB MCL no proximal tibial fixation reconstruction could not restore intact AMR/AMT kinematics in any knee position (P < .05). Adding an anterior-based proximal tibial fixation restored intact AMR/AMT kinematics at ≥30° of knee flexion except at 90° for AMT (P < .05). The SB MCL reconstruction could not restore intact AMR/AMT kinematics at 0° and 90° of knee flexion (P < .05).

CONCLUSION

In this in vitro cadaveric study, a DB MCL reconstruction with anteriorly placed proximal tibial fixation was able to control AMR and AMT better than the gold standard SB MCL reconstruction.

CLINICAL RELEVANCE

In patients with anteromedial rotatory instability and valgus instability, a DB MCL reconstruction may be superior to the SB MCL reconstruction, without causing extra surgical morbidity or additional costs.

A novel surgical technique for revision anterior cruciate ligament reconstruction using an isolated rectus femoris tendon autograft

INTRODUCTION

Only a few anatomic studies have described an isolated rectus femoris tendon autograft for anterior cruciate ligament (ACL) reconstruction. This study aims to demonstrate a new surgical technique utilising the rectus femoris tendon for ACL reconstruction. This study hypothesises that the rectus tendon autograft will yield satisfying postoperative outcomes in terms of stability, with minimal complications at the harvest site.

METHODS

This retrospective study investigated the outcomes of 28 revision ACL reconstructions using a rectus tendon autograft with a mean follow-up of 41.7 (range, 24.0-64.8) months. A 3 cm longitudinal incision was used to harvest the rectus tendon with an open tendon stripper. Intraoperative collected data included the length of the tendon and thickness of a 4-fold graft. Further outcome parameters include anterior cruciate ligament stability and range of motion. Additionally, postoperative complications, especially donor site morbidity, were documented in type and frequency.

RESULTS

The mean tendon length measured 32.4 cm (range, 30-35 cm). After preparing a 4-fold graft, the mean diameter was 9.2 mm (range, 8.0-10 mm) at the tibial and 9.0 mm (range, 7.5-10 mm) at the femoral end. Stability evaluated by the Lachman test improved significantly from 2 (Interquartile range (IQR), 2-3) preoperatively to 0 (IQR, 0-1) postoperatively (p < .001). Rerupture of the anterior cruciate ligament graft was observed in 2 patients (7.1%). Four patients showed a persistent extension deficit of about 5 degrees postoperatively. Two of them underwent revision surgery due to a Cyclops lesion. Only one patient complained of prolonged pain at the harvest site (3.6%).

CONCLUSION

The 4-fold rectus tendon represents a novel autograft technique in revision ACL reconstruction. This study provides evidence of appropriate graft dimensions and satisfying postoperative outcomes regarding stability. The technique is associated with a low complication rate at the harvest site.

STUDY DESIGN

Case series; Level of evidence, IV.

Load Sharing of the Deep and Superficial Medial Collateral Ligaments, the Effect of a Partial Superficial Medial Collateral Injury, and Implications on ACL Load

BACKGROUND

Injuries to the deep medial collateral ligament (dMCL) and partial superficial MCL (psMCL) can cause anteromedial rotatory instability; however, the contribution of each these injuries in restraining anteromedial rotatory instability and the effect on the anterior cruciate ligament (ACL) load remain unknown.

PURPOSE

To investigate the contributions of the different MCL structures in restraining tibiofemoral motion and to evaluate the load through the ACL after MCL injury, especially after combined dMCL/psMCL injury.

STUDY DESIGN

Controlled laboratory study.

METHODS

Sixteen fresh-frozen human cadaveric knees were tested using a 6 degrees of freedom robotic simulator. Tibiofemoral kinematic parameters were recorded at 0°, 30°, 60°, and 90° of knee flexion for the following measurements: 8-N·m valgus rotation, 4-N·m external tibial rotation (ER), 4-N·m internal tibial rotation, and a combined 89-N anterior tibial translation and 4-N·m ER for both anteromedial rotation (AMR) and anteromedial translation (AMT). The kinematic parameters of the 3 different MCL injuries (dMCL; dMCL/psMCL; dMCL/superficial MCL (sMCL)) were recorded and reapplied either in an ACL-deficient joint (load sharing) or before and after cutting the ACL (ACL load). The loads were calculated by applying the principle of superposition.

RESULTS

The dMCL had the largest effect on reducing the force/torque during ER, AMR, and AMT in extension and the psMCL injury at 30° to 90° of knee flexion (P < .05). In a comparison of the load through the ACL when the MCL was intact, the ACL load increased by 46% and 127% after dMCL injury and combined dMCL/psMCL injury, respectively, at 30° of knee flexion during ER. In valgus rotation, a significant increase in ACL load was seen only at 90° of knee flexion.

CONCLUSION

The psMCL injury made the largest contribution to the reduction of net force/torque during AMR/AMT at 30° to 90° of flexion. Concomitant dMCL/psMCL injury increased the ACL load, mainly during ER.

CLINICAL RELEVANCE

If a surgical procedure is being considered to treat anteromedial rotatory instability, then the procedure should focus on restoring sMCL function, as injury to this structure causes a major loss of the knee joint's capacity to restrain AMR/AMT.

Effect of a Partial Superficial and Deep Medial Collateral Ligament Injury on Knee Joint Laxity

BACKGROUND

Injuries to the medial collateral ligament (MCL), specifically the deep MCL (dMCL) and superficial MCL (sMCL), are both reported to be factors in anteromedial rotatory instability (AMRI); however, a partial sMCL (psMCL) injury is often present, the effect of which on AMRI is unknown.

PURPOSE

To investigate the effect of a dMCL injury with or without a psMCL injury on knee joint laxity.

STUDY DESIGN

Controlled laboratory study.

METHODS

Sixteen fresh-frozen human cadaveric knees were tested using a 6 degrees of freedom robotic simulator. The anterior cruciate ligament (ACL) was cut first and last in protocols 1 and 2, respectively. The dMCL was cut completely, followed by an intermediary psMCL injury state before the sMCL was completely sectioned. Tibiofemoral kinematics were measured at 0°, 30°, 60°, and 90° of knee flexion for the following measurements: 8 N·m of valgus rotation (VR), 4 N·m of external tibial rotation, 4 N·m of internal tibial rotation, and combined 89 N of anterior tibial translation and 4 N·m of external tibial rotation for both anteromedial rotation (AMR) and anteromedial translation. The differences between subsequent states, as well as differences with respect to the intact state, were analyzed.

RESULTS

In an ACL-intact or -deficient joint, a combined dMCL and psMCL injury increased external tibial rotation and VR compared with the intact state at all angles. A significant increase in AMR was seen in the ACL-intact knee after this combined injury. Cutting the dMCL alone showed lower mean increases in AMR compared with the psMCL injury, which were significant only when the ACL was intact in knee flexion. Moreover, cutting the dMCL had no effect on VR. The ACL was the most important structure in controlling anteromedial translation, followed by the psMCL or dMCL depending on the knee flexion angle.

CONCLUSION

A dMCL injury alone may produce a small increase in AMRI but not in VR. A combined dMCL and psMCL injury caused an increase in AMRI and VR.

CLINICAL RELEVANCE

In clinical practice, if an increase in AMRI at 30° and 90° of knee flexion is seen together with some increase in VR, a combined dMCL and psMCL injury should be suspected.

Moment arm and torque generating capacity of semitendinosus following tendon harvesting for anterior cruciate ligament reconstruction: A simulation study

Altered semitendinosus (ST) morphology and distal tendon insertion following anterior cruciate ligament reconstruction (ACLR) may reduce knee flexion torque generating capacity of the hamstrings via impaired ST force generation and/or moment arm. This study used a computational musculoskeletal model to simulate mechanical consequences of tendon harvest for ACLR on ST function by modeling changes in ST muscle tendon insertion point, moment arm, and torque generating capacity across a physiological range of motion. Simulated ST function was then compared between ACLR and uninjured contralateral limbs. Magnetic resonance imaging from 18 individuals with unilateral history of ACLR involving a hamstring autograft was used to analyse bilateral hamstring muscle (ST, semimembranosus, bicep femoris long head and short head) morphology and distal ST tendon insertion. The ACLR cohort was sub-grouped into those with and without ST regeneration. For each participant with ST regeneration (n = 7), a personalized musculoskeletal model was created including postoperative remodeling of ST using OpenSim 4.1. Knee flexion and internal rotation moment arms and torque generating capacities of hamstrings were evaluated. Bilateral differences were calculated with an asymmetry index (%) ([unaffected limb-affected limb]/[unaffected limb + affected limb]*100%). Smaller moment arms or knee torques within injured compared to uninjured contralateral limbs were considered a deficit. Compared to uninjured contralateral limbs, ACLR limbs with tendon regeneration (n = 7) had minor reductions in knee flexion (5.80% [95% confidence interval (CI) = 3.97-7.62]) and internal rotation (4.92% [95% CI = 2.77-7.07]) moment arms. Decoupled from muscle morphology, altered ST moment arms in ACLR limbs with tendon regeneration resulted in negligible deficits in knee flexion (1.20% [95% CI = 0.34-2.06]) and internal rotation (0.24% [95% CI = 0.22-0.26]) torque generating capacity compared to uninjured contralateral limbs. Coupled with muscle morphology, ACLR limbs with tendon regeneration had substantial deficits in knee flexion (19.32% [95% CI = 18.35-20.28]) and internal rotation (15.49% [95% CI = 14.56-16.41]) torques compared to uninjured contralateral limbs. Personalized musculoskeletal models with measures of ST distal insertion and muscle morphology provided unique insights into post-ACLR ST and hamstring function. Deficits in knee flexor and internal rotation moment arms and torque generating capacities were evident in those with ACLR even when tendon regeneration occurred. Future studies may wish to implement this framework in personalized musculoskeletal models following ACLR to better understand individual muscle function for injury prevention and treatment evaluation.

Medial Patellofemoral Ligament Reconstruction Using Pedicled Quadriceps Tendon Autograft Yields Similar Clinical and Patient-Reported Outcomes but Less Donor-Site Morbidity Compared With Gracilis Tendon Autograft

PURPOSE

To compare clinical and patient-reported outcome measures (PROMs) in patients with recurrent patellar dislocation after medial patellofemoral ligament (MPFL) reconstruction using either a gracilis tendon (GT) or quadriceps tendon autograft (QT).

METHODS

All MPFL reconstruction performed between 2017 and 2019 were reviewed retrospectively. Only patients with isolated MPFL reconstruction, without any major patellofemoral risk factors and a minimum follow-up of 24 months, were included in the study. Patients were matched with respect to sex, age, and body mass index. All patients were evaluated clinically and using PROMs.

RESULTS

A total of 64 patients with an average follow up of 28.7 ± 7.5 months were included in this study. The mean Kujala score (GT: 84.8 ± 12.9, QT: 88.9 ± 10.1), Lysholm score (GT: 89.4 ± 10.2, QT: 88.4 ± 5.0), and visual analog scale score for pain (GT: 1.9 ± 1.8, QT: 1.1 ± 1.3) did not significantly differ between both groups. Tegner activity level was significantly greater (P = .027) in the QT group (5.5 ± 1.9) compared with the GT group (4.6 ± 1.8), but within the minimal clinically important differences. Occasional patellar instability events, but no recurrent dislocation, were reported in 12.5% in the GT group and 6.3% in the QT group (P = .39). Of all patients, 90.6% in the QT and 68.8% in the HT group exceeded the PASS for the Kujala score (P = .06). Significantly more patients (59.4%) treated with GT reported donor-site morbidity in the form of sensitivity deficit at the lower leg compared with those treated with QT (3.1%, P = .001).

CONCLUSIONS

GT and QT MPFL reconstruction have comparable PROMs and patellar redislocation rates 2 years' postoperatively. Significantly more patients treated with GT reported lower-leg sensitivity deficit compared with those treated with QT.

LEVEL OF EVIDENCE

Level III, retrospective case-control study.

Primary Versus Revision ACL Reconstruction Using Quadriceps Autograft: A Matched-Control Cohort Study

Background

The incidence of anterior cruciate ligament (ACL) reconstruction is increasing, and quadriceps tendon (QT) autograft is gaining popularity for both primary and revision ACL reconstruction.

Purpose

To evaluate the differences in the patient-reported functional outcomes, concomitant injuries, and graft failure in primary versus revision ACL surgery using QT autograft.

Study Design

Cohort study; Level of evidence, 3.

Methods

A total of 376 patients with primary ACL reconstruction and 138 patients with revision ACL reconstruction were retrospectively retrieved from a prospectively collected ACL registry. A minimally invasive technique was used for QT autograft harvesting. The surgical procedure and rehabilitation protocol were identical in both groups. To maintain a homogeneous cohort for the study, the groups were matched by age, sex, and preinjury outcome scores (Lysholm knee score, Tegner activity level, and visual analog scale [VAS] for pain). Initial baseline assessments of outcome scores were compared with scores collected at the 2-year postoperative mark.

Results

The mean age of the primary group and revision group was 32.9 ± 10.2 years (range, 18-55 years) and 32.3 ± 9.9 years (range, 19-55 years) respectively. Significant preinjury to postoperative improvements were noted in Lysholm (88.2 ± 16.4 vs 83.5 ± 15.0; P = .007) and VAS pain (0.9 ± 1.3 vs 1.5 ± 1.6; P = .001) scores after primary ACL reconstruction compared with revision reconstruction. However, no significant difference was found in Tegner activity level (6.7 ± 1.8 vs 5.9 ± 1.8; P > .430). Primary ACL injury was associated with significantly higher concomitant medial collateral ligament injuries (P = .019), while the revision group was associated with significantly higher concomitant cartilage (P = .001) and meniscal (P = .003) injuries. A significantly higher graft failure rate was noted in the revision group compared with the primary ACL reconstruction group (13.0% vs 5.6%; P = .005).

Conclusion

Both primary and revision ACL reconstruction with QT autograft had acceptable functional outcomes. The primary group had better outcomes than the revision group, possibly due to the lower prevalence of meniscal and cartilage injuries in the primary group compared with the revision group. The revision group was associated with higher graft failure than the primary group. QT autograft is a viable graft choice for both primary and revision ACL reconstruction.

Management after acute injury of the anterior cruciate ligament (ACL). Part 3: Recommendation on surgical treatment

PURPOSE

The aim of this consensus project was to give recommendations regarding surgical treatment of the anterior cruciate ligament (ACL) injured patient.

METHODS

For this consensus process, an expert, steering and rating group was formed. In an initial online meeting, the steering group, together with the expert group, formed various key topic complexes for which multiple questions were formulated. For each key topic, a structured literature search was performed by the steering group. The results of the literature review were sent to the rating group with the option to give anonymous comments until a final consensus voting was performed. Sufficient consensus was defined as 80% agreement.

RESULTS

During this consensus process, 30 topics regarding the surgical management and technique of ACL reconstruction were identified. The literature search for each key question resulted in 30 final statements. Of these 30 final statements, all achieved consensus.

CONCLUSIONS

This consensus process has shown that surgical treatment of ACL injury is a complex process. Various surgical factors influence patient outcomes. The proposed treatment algorithm can be used as a decision aid for the surgeon.

LEVEL OF EVIDENCE

Level V.

Reconstruction of the Medial Collateral Ligament Complex With a Flat Allograft Semitendinosus Tendon

The aim of this Technical Note is to reconstruct the medial collateral ligament complex with the superior medial collateral ligament and posterior oblique ligament as anatomically as possible. An allograft or contralateral semitendinosus autograft is used for anatomic reconstruction of the superior medial collateral ligament and posterior oblique ligament. After bony fixation, the tendon bundles are sutured to the remnants of the medial collateral ligament complex. Thus, the tubular grafts are pulled apart to form a flat shape that resembles that of the normal medial ligaments.

A prospective randomized controlled study of hamstring and bone-free quadriceps tendons autografts in arthroscopic ACL reconstruction

INTRODUCTION

Anterior cruciate ligament (ACL) reconstruction is one of the most common surgical procedures worldwide. However, the ideal graft source is still debatable. This study compared hamstring (HT) and bone-free quadriceps (QT) tendon autografts in terms of muscle strength and patient-reported outcomes.

METHODS

Between June 2018 and December 2019, 46 patients were enrolled in the study and randomly assigned to one of two groups for the ACL reconstruction surgery-the HT autograft group or the QT autograft group. An experienced examiner performed preoperative and postoperative examinations. The HUMAC NORM isokinetic machine (Computer Sports Medicine International-CSMI, 2004) was used to assess flexor and extensor thigh muscle strength. Both groups received the same surgical technique and fixation method. All patients were examined after three, six, nine, and 12 months. The final evaluations were performed at the 24-month follow-up. Patients' scores on the International Knee Documentation Committee (IKDC) evaluation form and the Lysholm Knee Scoring Scale were used to evaluate patient-reported outcomes. The two groups were also compared in terms of postoperative complications and activity levels.

RESULTS

The difference between preoperative and postoperative knee flexor peak torques (FPT) was lower in the QT group than in the HT group. The average difference between preoperative and postoperative knee extensor peak torque (EPT) was higher in the QT group than in the HT group. As a result, the HT group had a lower postoperative H/Q ratio (flexor strength normalized to body mass divided by extensor strength normalized to body mass) than the QT group (p < 0.001). The mean IKDC scores for the HT and QT groups were 90.13 ± 6.99 and 87.12 ± 6.61, respectively. The scores of the two groups postoperatively were close, and both groups showed significant improvement. The average graft size in the QT group was significantly greater than that in the HT group. Saphenous nerve palsy was the most common complication in the HT group (22%). Thigh hematomas were observed in two patients in the QT group and required urgent intervention (12%).

CONCLUSION

After ACL reconstruction, we found a significant decrease in strength at the donor sites in both techniques, with similar patient-reported measures and stability outcomes. The H/Q strength ratio was higher in the QT group postoperatively, which may have a protective effect on the reconstructed ligament. Level of Evidence I It is a randomized controlled trial.

[New treatment methods in competitive sports : What can we learn from the medical care of top athletes?]

BACKGROUND

As elite sport becomes more professional, the medical-psychological care of athletes is an important factor in providing them with the best possible support and thus optimising their performance. Our experience in the fields of prevention, conservative and surgical treatment, and rehabilitation also provides valuable insights for the treatment of our patients in daily practice.

PREVENTION

Designed to improve static and dynamic muscle strength, kinaesthetic sensitivity, and neuromuscular control, the FIFA 11+ injury prevention programme is a three-part warm-up programme that is widely used in coaching and recreational sports.

CONSERVATIVE TREATMENT

Platelet-rich plasma (PRP) is probably the most widely used orthobiologic treatment modality for the conservative management of tendon, muscle and cartilage injuries. Its effectiveness depends on the underlying pathology and the affected body region. The best evidence exists for the treatment of patellar tendinitis ("jumper's knee") and epicondylitis humeri radialis ("tennis elbow").

SURGICAL TREATMENT

The treatment of ACL injuries in competitive athletes is challenging due to the high physical demands. Prompt surgical intervention, anatomical reconstruction and additional extra-articular stabilisation are associated with improved surgical outcomes. Graft selection must be individualised, adapted to the needs of the athletes and our patients.

REHABILITATION

Electromyography (EMG) is a diagnostic tool to identify muscular imbalances in rehabilitation and, at the same time, to help reduce them through biofeedback training.

COGNITIVE TRAINING

Training for the development of basic cognitive skills helps to optimise performance through its potentially positive influence on the executive functions of athletes.

Contribution of the Medial Hamstrings to Valgus Stability of the Knee

Background

Multiligament knee injuries involving the medial side are common. When performing surgical reconstruction, use of the medial hamstrings (HS) as grafts remains controversial in this setting.

Purpose

To determine the role of the medial HS in stabilizing the valgus knee for different types of medial-sided knee injury.

Study Design

Controlled laboratory study.

Methods

A biomechanical study on 10 cadaveric knees was performed. Valgus load (force moment of 10 N/m) was applied at 0°, 30°, and 60° of flexion, and the resultant rotation was recorded using an optoelectronic motion analysis system. Measurements were repeated for 4 different knee states: intact knee, superficial medial collateral ligament (sMCL) injury, deep medial collateral ligament (dMCL) injury, and posterior oblique ligament (POL) injury. For each state, 4 loading conditions (+ loaded; - unloaded) of the semitendinosus (ST) and gracilis (GRA) tendons were tested: ST+/GRA+, ST+/GRA-, ST-/GRA+, and ST-/GRA-.

Results

At 0° of flexion, combined unloading of the ST and GRA (ST-/GRA-) increased valgus laxity on the intact knee compared with the ST+/GRA+ condition (P < .05). For all medial-sided injury states (isolated sMCL; combined sMCL and dMCL; and combined sMCL, dMCL, and POL damage), ST-/GRA- increased valgus laxity at 0° and 30° of flexion versus ST+/GRA+ (P < .05 for all). The absolute value of valgus laxity increased with the severity of medial-sided ligament injury. Isolated ST unloading increased valgus laxity for the intact knee and the MCL-injured knee (combined sMCL and dMCL) at 0° of flexion (P < .05 vs ST+/GRA+). Isolated unloading of the GRA had no effect on valgus knee stability.

Conclusion

The medial HS tendons contributed to the stabilization of the knee in valgus, and this was even more important when the medial side was severely affected (POL damage). This stabilizing effect was greater between 0° and 30°, in which the POL is the main valgus stabilizer.

Clinical Relevance

When deciding on graft selection for multiligament knee injury reconstruction, the surgeon should be aware of the effect of harvesting the medial HS tendon on valgus laxity.

The Anterior Fibers of the Superficial MCL and the ACL Restrain Anteromedial Rotatory Instability

BACKGROUND

There is limited knowledge about how the anterior cruciate ligament (ACL) and capsuloligamentous structures on the medial side of the knee act to control anteromedial rotatory knee instability.

PURPOSE

To investigate the contribution of the medial retinaculum, capsular structures (anteromedial capsule, deep medial collateral ligament [MCL], and posterior oblique ligament), and different fiber regions of the superficial MCL to restraining knee laxity, including anteromedial rotatory instability.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eight fresh-frozen human cadaveric knees were tested using a 6 degrees of freedom robotic testing system in a position-controlled mode. Loads of 10 N·m valgus rotation, 5 N·m tibial external rotation, 5 N·m tibial internal rotation, and 134 N anterior tibial translation in 5 N·m external rotation were applied at different flexion angles. The motion of the intact knee at 0° to 120° of flexion was replicated after sequential excision of the sartorial fascia; anteromedial retinaculum; anteromedial capsule; anterior, middle, and posterior fibers of the superficial MCL; the deep MCL; the posterior oblique ligament; and the ACL. The reduction in force/torque indicated the contribution of each resected structure to resisting laxity. A repeated-measures analysis of variance with a post hoc Bonferroni test was used to analyze the relative force and torque changes from the intact state.

RESULTS

The superficial MCL was the most important restraint to valgus rotation from 0° to 120° and provided the largest contribution to resisting external rotation between 30° and 120° of knee flexion, gradually increasing from 25.2% ± 7.4% at 30° to 36.9% ± 15.4% at 90°. The posterior oblique ligament contributed significantly to resisting valgus rotation only in extension (17.2% ± 12.1%) but was the major restraint to internal rotation at 0° (46.7% ± 13.1%) and 30° (30.4% ± 17.7%) of flexion. The sartorial fascia and anteromedial retinaculum resisted ER at all knee flexion angles (P < .05) and was the single most important restraint in the extended knee (19.5% ± 11%). The capsular structures (anteromedial capsule and deep MCL) had a combined contribution of 20% ± 11.5% at 0° and 23.4% ± 10.5% at 120° of knee flexion but were less important from 30° to 90°. The ACL was the primary restraint to anterior tibial translation in external rotation between 0° and 60° of flexion (50.2% ± 16.9% at 30°), but the superficial MCL was more important at 90° to 120° of knee flexion (36.8% ± 16.4% at 90°). The anterior, middle, and posterior regions of the superficial MCL contributed differently to the simulated laxity tests. The anterior fibers were the most important part of the superficial MCL in resisting external rotation and combined anterior tibial translation in external rotation.

CONCLUSION

The superficial MCL not only was the primary restraint to valgus rotation throughout the range of knee flexion but also importantly contributed to resisting anterior tibial translation in external rotation, particularly in deeper flexion in the cadaveric model. The anterior fibers of the superficial MCL are the most important superficial MCL fibers in resisting anterior tibial translation in external rotation. This study suggests that a medial reconstruction that reproduces the function of the posterior MCL fibers and posterior oblique ligament may not best control anteromedial rotatory instability.

CLINICAL RELEVANCE

Based on these data, there is a need for an individualized medial reconstruction to address different types of medial injury patterns and instabilities.

Risk Factors for Revision or Rerupture After Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis

BACKGROUND

The rerupture or need for revision after anterior cruciate ligament reconstruction (ACLR) is a serious complication. Preventive strategies that target the early identification of risk factors are important to reduce the incidence of additional surgery.

PURPOSE

To perform a systematic review and meta-analysis to investigate risk factors for revision or rerupture after ACLR.

STUDY DESIGN

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

METHODS

Literature searches were performed in PubMed, Embase, and Web of Science from database inception to November 2021 and updated in January 2022. Quantitative, original studies reporting potential adjusted risk factors were included. Odds ratios (ORs) were calculated for potential risk factors.

RESULTS

A total of 71 studies across 13 countries with a total sample size of 629,120 met the inclusion criteria. Fifteen factors were associated with an increase in the risk of revision or rerupture after ACLR: male sex (OR, 1.27; 95% CI, 1.14-1.41), younger age (OR, 1.07; 95% CI, 1.05-1.08), lower body mass index (BMI) (OR, 1.03; 95% CI, 1.00-1.06), family history (OR, 2.47; 95% CI, 1.50-4.08), White race (OR, 1.32; 95% CI, 1.08-1.60), higher posterolateral tibial slope (OR, 1.15; 95% CI, 1.05-1.26), preoperative high-grade anterior knee laxity (OR, 2.30; 95% CI, 1.46-3.64), higher baseline Marx activity level (OR, 1.07; 95% CI, 1.02-1.13), return to a high activity level/sport (OR, 2.03; 95% CI, 1.15-3.57), an ACLR within less than a year after injury (OR, 2.05; 95% CI, 1.81-2.32), a concomitant medial collateral ligament (MCL) injury (OR, 1.62; 95% CI, 1.31-2.00), an anteromedial portal or transportal technique (OR, 1.36; 95% CI, 1.22-1.51), hamstring tendon (HT) autografts (vs bone-patellar tendon-bone [BPTB] autografts) (OR, 1.60; 95% CI, 1.40-1.82), allografts (OR, 2.63; 95% CI, 1.65-4.19), and smaller graft diameter (OR, 1.21; 95% CI, 1.05-1.38). The other factors failed to show an association with an increased risk of revision or rerupture after ACLR.

CONCLUSION

Male sex, younger age, lower BMI, family history, White race, higher posterolateral tibial slope, preoperative high-grade anterior knee laxity, higher baseline Marx activity level, return to a high activity level/sport, an ACLR within less than a year from injury, a concomitant MCL injury, an anteromedial portal or transportal technique, HT autografts (vs BPTB autografts), allografts, and smaller graft diameter may increase the risk of revision or rerupture after ACLR. Raising awareness and implementing effective preventions/interventions for risk factors are priorities for clinical practitioners to reduce the incidence of revision or rerupture after ACLR.

Anatomic Flat Double-Bundle Medial Collateral Ligament Reconstruction

Several surgical techniques have been described to restore the anatomy of the medial collateral ligament, involving suture repair and reconstruction, with the latter having been associated with superior postoperative outcomes. Recently, a growing interest in anatomic isometric medial collateral ligament reconstruction (MCLR) has been developed, involving careful evaluation and finding the most appropriate location for the femoral placement of the allograft. Therefore, the purpose of this article is to describe anatomic MCLR aiming to restore medial knee stability by focusing on isometric positions within the native anatomy of the MCL.

Combined press-fit and extracortical fixation in patellar tendon anterior cruciate ligament reconstruction results in reliable graft fixation and early bone block incorporation

BACKGROUND

Anterior cruciate ligament (ACL) reconstruction with bone-patellar-tendon-bone (BPTB) autograft has the potential biological advantage of direct bone-to-bone healing over soft tissue grafts. The primary aim of this study was to investigate possible graft slippage and therefore fixation strength in a modified BPTB autograft technique with suspensory fixation on both sides for primary ACL reconstruction until bony integration takes place.

METHODS

Twenty-one patients undergoing primary ACL reconstruction with a modified BPTB autograft (bone-on-bone (BOB) technique) between August 2017 and August 2019 were included in this prospective study. A computed tomography (CT) scan of the affected knee was performed directly postoperatively, as well as 3 months postoperatively. Examiner-blinded parameters for graft slippage, early tunnel widening, bony incorporation, as well as remodeling of the autologous refilled patellar harvest site were investigated.

RESULTS

A series of 21 patients treated with a BPTB autograft with this technique underwent two CT investigations. Comparison of CT scans showed no bone block displacement and therefore no graft slippage in the patient cohort. Only one patient showed signs of early tunnel enlargement. Radiological bone block incorporation took place showing bony bridging of the graft to the tunnel wall in 90% of all patients. Furthermore, 90% showed less than 1 mm bone resorption of the refilled harvest site at the patella.

CONCLUSIONS

Our findings suggest graft fixation stability and reliability of anatomic BPTB ACL reconstruction with a combined press-fit and suspensory fixation technique by absence of graft slippage within the first 3 months postoperatively.

Revision ACL reconstruction using quadriceps, hamstring and patellar tendon autografts leads to similar functional outcomes but hamstring graft has a higher tendency of graft failure

PURPOSE

The purpose of this study was to evaluate the differences in the patient-reported functional outcomes, and graft failure in revision ACL reconstruction using quadriceps tendon (QT), Hamstring tendon (HT) and bone-patellar tendon-bone (BPTB) autografts.

METHODS

Between 2010 and 2020, 97 patients who underwent revision ACL reconstruction (40 patients received a QT, 26 an HT and 31 a BPTB graft) met the inclusion criteria. Pre-injury and at 2-year postoperatively patients were evaluated for patient-reported functional outcomes; Lysholm knee score, Tegner activity level and VAS (visual analogue scale) for pain; and graft failure. Patient-reported outcomes and graft failure were compared between the QT, HT and BPTB groups. The patients with graft failure were not included for outcome analysis at 2-years of follow-up.

RESULTS

All three revision groups with QT, HT and BPTB autograft did not differ significantly in terms of age, sex, time from injury to surgery, concomitant injuries and single-stage or double-stage procedures (n.s.). No significant difference was found in the pre-injury patient-reported outcome; Lysholm knee score, Tegner activity and VAS for pain (n.s.) between the three groups. At the 2-year follow-up functional outcomes improved in all three groups and all the patients returned to pre-injury activity level; however, no significant difference was found in functional outcomes at the 2-year follow-up between the three groups (n.s.). Graft failure occurred in 4 (10%), 5 (19%) and 3 (10%) patients of QT, HT and BPTB groups, respectively. However, the rate of failure did not differ significantly between groups.

CONCLUSION

All three autografts (QT, HT and BPTB) demonstrated satisfactory patient-reported outcomes in revision ACL reconstruction. Compared with QT and BPTB grafts, HT graft showed a higher tendency for failure rates. With the increasing incidence of revision ACL reconstruction, surgeons should be aware of all the available graft options. The findings of this study will assist the surgeons in the graft selection for revision ACL reconstruction.

LEVEL OF EVIDENCE

Level III.

Preoperative ultrasound can accurately predict the diameter of double-stranded peroneus longus tendon autografts

PURPOSE

This study aimed to determine the correlation between the intraoperative diameter of double-stranded peroneus longus tendon (2PLT) and length of the PLT autograft and preoperative ultrasound (US) measurements, as well as radiographic and anthropometric measurements. The hypothesis was that US can accurately predict the diameter of 2PLT autografts during operation.

METHODS

Twenty-six patients underwent ligament reconstruction with 2PLT autografts were included. Preoperative US was used to calculate the in situ PLT cross-sectional area (CSA) at seven levels (0, 1, 2, 3, 4, 5, 10 cm proximal to the harvest start point). Femoral width, notch width, notch height, maximum patellar length, and patellar tendon length were determined on preoperative radiographs. Intraoperative measurements of PLT were made, including all fiber lengths of PLT and diameters of 2PLT using sizing tubes calibrated to 0.5 mm.

RESULTS

CSA at 1 cm proximal to the harvest site had the highest correlation with the diameter of 2PLT (r = 0.84, P < 0.001). Calf length had the highest correlation with PLT length (r = 0.65, P < 0.001). The diameter of the 2PLT autografts could be predicted by the following formula: 4.6 + 0.2 × [sonographic CSA of PLT at 1 cm level]; the length of PLT could be predicted by the following formula: 5.6 + 0.5 × Calf length.

CONCLUSION

The diameter of 2PLT and length of PLT autografts can be accurately predicted by preoperative US and calf length measurements, respectively. Accurate preoperative prediction of the diameter and length of autologous grafts can provide the most suitable and individualized graft for patients.

LEVEL OF EVIDENCE

IV.

Quadriceps autograft is a viable graft choice for arthroscopic ACL reconstruction in patients over 50 years of age

PURPOSE

The purpose of this study was to evaluate the patient-reported outcomes, graft failure, quadriceps rupture and sports preference after arthroscopic ACL reconstruction in patients older than 50 years who underwent arthroscopic ACL reconstruction with a quadriceps tendon (QT) autograft.

METHODS

Between 2010 and 2020, prospectively collected data were obtained from an institutional database. Patients older than 50 years with primary arthroscopic ACL reconstruction and a minimum of 2 years of follow-up were included. Patients undergoing a revision ACL reconstruction or undergoing a primary ACL reconstruction using a graft other than a QT autograft, and patients with a contralateral knee injury or osteoarthritis (Ahlbäck stage 2 or higher) were excluded. A minimally invasive technique was used for QT autograft harvesting. Patients were evaluated for pre-injury and 2-year follow-up Lysholm knee score, Tegner activity level, Visual Analog Scale (VAS) for pain, graft failure, quadriceps tendon rupture, and return to sport.

RESULTS

A total of 57 patients were included in the study. The mean age of the cohort was 54.9 ± 5.2 (range 50-75). Of the 57 reconstructions, 16 (28%) were isolated ACL reconstructions, while 41 (72%) were complex reconstructions (concomitant meniscus, cartilage and/or collateral ligament injuries). At the 2-year follow-up Lysholm knee score, Tegner activity level and VAS for pain improved to pre-injury level and no significant difference was noted between pre-injury and 2-year follow-up functional scores (n.s.). No case of graft failure or quadriceps tendon rupture was reported. No significant difference was noted in the pre-injury and postoperative sports preference (n.s.) and all patients return to their desired sports activity.

CONCLUSION

Arthroscopic ACL reconstruction by using QT autograft in highly active older patients provides satisfactory patient-reported functional outcomes and allows recovery of the pre-injury level of activity. QT autograft is a good graft option in patients older than 50 years.

LEVEL OF EVIDENCE

Level IV.

Surgeon's experience, sports participation and a concomitant MCL injury increase the use of patellar and quadriceps tendon grafts in primary ACL reconstruction: a nationwide registry study of 39,964 surgeries

PURPOSE

To investigate the influence of surgeon-related factors and clinic routines on autograft choice in primary anterior cruciate ligament reconstruction (ACLR).

METHODS

Data from the Swedish National Knee Ligament Registry (SNKLR), 2008-2019, were used to study autograft choice (hamstring; HT, patellar; PT, or quadriceps tendon; QT) in primary ACLR. Patient/injury characteristics (sex, age at surgery, activity at time of injury and associated injuries) and surgeon-/clinic-related factors (operating volume, caseload and graft type use) were analyzed. Surgeon/clinic volume was divided into tertiles (low-, mid- and high-volume categories). Multivariable logistic regression was performed to assess variables influencing autograft choice in 2015-2019, presented as the odds ratio (OR) with a 95% confidence interval (CI).

RESULTS

39,964 primary ACLRs performed by 299 knee surgeons in 91 clinics were included. Most patients received HT (93.7%), followed by PT (4.2%) and QT (2.1%) grafts. Patients were mostly operated on by high-volume (> 28 ACLRs/year) surgeons (68.1%), surgeons with a caseload of ≥ 50 ACLRs (85.1%) and surgeons with the ability to use ≥ two autograft types (85.9%) (all p < 0.001). Most patients underwent ACLR at high-volume (> 55 ACLRs/year) clinics (72.2%) and at clinics capable of using ≥ two autograft types (93.1%) (both p < 0.001). Significantly increased odds of receiving PT/QT autografts were found for ACLR by surgeons with a caseload of ≥ 50 ACLRs (OR 1.41, 95% CI 1.11-1.79), but also for injury during handball (OR 1.31, 95% CI 1.02-1.67), various other pivoting sports (basketball, hockey, rugby and American football) (OR 1.59, 95% CI 1.24-2.03) and a concomitant medial collateral ligament (MCL) injury (OR 4.93, 95% CI 4.18-5.80). In contrast, female sex (OR 0.87, 95% CI 0.77-0.97), injury during floorball (OR 0.71, 95% CI 0.55-0.91) and ACLR by mid-volume relative to high-volume surgeons (OR 0.62, 95% CI 0.53-0.73) had significantly reduced odds of receiving PT/QT autografts.

CONCLUSION

An HT autograft was used in the vast majority of cases, but PT/QT autografts were used more frequently by experienced surgeons. Prior research has demonstrated significant differences in autograft characteristics. For this reason, patients might benefit if surgery is performed by more experienced surgeons.

LEVEL OF EVIDENCE

Level III.

Shape differences in the semitendinosus following tendon harvesting for anterior cruciate ligament reconstruction

Following hamstring autograft anterior cruciate ligament reconstruction (ACLR), muscle length, cross-sectional area, and volume are reduced. However, these discrete measures of morphology do not account for complex three-dimensional muscle shape. The primary aim of this study was to determine between-limb semitendinosus (ST) shape and regional morphology differences in young adults following tendon harvest for ACLR and to compare these differences with those in healthy controls. In this cross-sectional study, magnetic resonance imaging was performed on 18 individuals with unilateral ACLR and 18 healthy controls. Bilaterally, ST muscles were segmented, and shape differences assessed between limbs and compared between groups using Jaccard index (0-1) and Hausdorff distance (mm). Length (cm), peak cross-sectional area (cm² ), and volume (cm³ ) were measured for the entire muscle and proximal, middle, and distal regions, and compared between limbs and groups. Compared to healthy controls, the ACLR group had significantly (p < 0.001, Cohen's d = -2.33) lower bilateral ST shape similarity and shape deviation was significantly (p < 0.001, d = 2.12) greater. Shape deviation was greatest within the distal region of the ACLR (Hausdorff: 23.1 ± 8.68 mm). Compared to both the uninjured contralateral limb and healthy controls, deficits in peak cross-sectional area and volume in ACLR group were largest in proximal (p < 0.001, d = -2.52 to -1.28) and middle (p < 0.001, d = -1.81 to -1.04) regions of the ST. Overall, shape analysis provides unique insight into regional adaptations in ST morphology post-ACLR. Findings highlight morphological features in distal ST not identified by traditional discrete morphology measures. Clinical significance: Following ACLR, risk of a secondary knee or primary hamstring injury has been reported to be between 2-to-5 times greater compared to those without ACLR. Change in semitendinosus (ST) shape following ACLR may affect force transmission and distribution within the hamstrings and might contribute to persistent deficits in knee flexor and internal rotator strength.

Technique of ACL Reconstruction With Autologous Quadriceps Tendon Bone Graft and Femoral Press Fit Fixation

Background:

Recently, there has been an increase in interest in the quadriceps tendon (QT) as an alternative autologous graft option for primary anterior cruciate ligament (ACL) reconstruction.

Indication:

Anterior cruciate ligament reconstruction in skeletally mature patients (high-risk patients for re-rupture and patients with medial instability).

Technique Description:

The QT graft is harvested with a 4-cm skin incision over the superior pole of the patella. A double knife and an oscillating saw are used to obtain the QT graft with a bone block from the patella (65 mm x 10 mm graft and 15 mm bone block). Then an arthroscopy is carried out with assessment of the ACL tear and treatment of further intraarticular injuries. ACL reconstruction begins with debridement of the femoral insertion to expose the land marks. The medial portal is used for femoral tunnel drilling with the knee in more than 110° of flexion. A special portal aiming device is introduced via the anteromedial portal and a guide wire is placed in the area of the femoral anteromedial insertion. This guide wire is gradually overdrilled with various drills and dilators of increasing size. The final diameter should be 0.5 mm smaller than the diameter of the bone block of the graft to allow for press-fit fixation. Then, the tibial tunnel is drilled using a tibial drill guide leaving the tibial stump of the original ACL intact. The graft is pulled into the joint through the tibial tunnel until the bone block stops at the femoral tunnel entrance. The bone block is then pushed through the medial portal into the femoral tunnel (press-fit fixation). The tibial fixation is performed with an interference screw and optionally with an extracortical button.

Results:

Prior studies with 2 years follow-up have shown that the clinical outcomes in primary and revision ACL reconstruction were not significantly different between the use of QT grafts with femoral press-fit fixation and the use of hamstring grafts with femoral suspension fixation.

Discussion/Conclusion:

Quadriceps tendon bone autograft and femoral press-fit fixation provides an excellent alternative as a graft choice in ACL reconstruction. The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

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.

Instabilität des Kniegelenks – medial oder anteromedial?

Hintergrund

Verletzungen des medialen Bandkomplexes gehören zu den häufigsten Knieverletzungen. Sie heilen zwar meist mit konservativer Therapie problemlos aus, persistierende Instabilitäten erhöhen aber die Belastung der Kreuzbänder und benötigen speziell bei deren Beteiligung eine adäquate Therapie.

Anatomie und Biomechanik

Der mediale Seitenbandkomplex besteht im Wesentlichen aus dem oberflächlichen Seitenband (sMCL), welches der primäre Stabilisator gegen Valgus ist, dem tiefen Seitenband (dMCL) mit dessen schräg verlaufendem ventralem Anteil (AML), die nur sekundäre Stabilisatoren gegen Valgus darstellen, aber primär gegen Außenrotation stabilisieren, und dem hinteren Schrägband (POL), das in vollständiger Streckung gegen Valgus sowie gegen Innenrotation stabilisiert.

Therapie

Chronische Instabilitäten bzw. höhergradige Verletzungen mit Dislokation der Bandstümpfe oder multiligamentäre Verletzungen bedürfen einer operativen Versorgung. Im Akutstadium zeigen Avulsionsverletzungen bei anatomischer Refixation gutes Heilungspotenzial, während bei intraligamentären Verletzungen zusätzlich zur Naht der Bandanteile eine Augmentation mit Sehnenmaterial empfohlen wird. Bei chronischen Instabilitäten ist die Differenzierung des Instabilitätsmusters ausschlaggebend für die Wahl der Rekonstruktionstechnik (reine sMCL-Rekonstruktion oder kombinierte Rekonstruktion von sMCL und AML). In beiden Fällen kommt die hier beschriebene Technik mit flachem Transplantat der Anatomie näher als bei konventionellen Verfahren.

Diskussion

Rekonstruktionstechniken unter Verwendung flacher Sehnentransplantate, die alle betroffenen Bandanteile adressieren, haben sich biomechanisch als sehr effektiv erwiesen, komplexe mediale Instabilitäten suffizient zu behandeln. Ob diese auch klinisch überlegen sind, werden zukünftige klinische Studien zeigen müssen.

A Triple-Strand Anatomic Medial Collateral Ligament Reconstruction Restores Knee Stability More Completely Than a Double-Strand Reconstruction: A Biomechanical Study In Vitro

BACKGROUND

There are many descriptions of medial collateral ligament (MCL) reconstruction, but they may not reproduce the anatomic structures and there is little evidence of their biomechanical performance.

PURPOSE

To investigate the ability of "anatomic" MCL reconstruction to restore native stability after grade III MCL plus posteromedial capsule/posterior oblique ligament injuries in vitro.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twelve cadaveric knees were mounted in a kinematic testing rig to impose tibial displacing loads while the knee was flexed-extended: 88-N anteroposterior translation, 5-N·m internal-external rotation, 8-N·m valgus-varus, and combined anterior translation plus external rotation (anteromedial rotatory instability). Joint motion was measured via optical trackers with the knee intact; after superficial MCL (sMCL), deep MCL (dMCL), and posterior oblique ligament transection; and then after MCL double- and triple-strand reconstructions. Double strands reproduced the sMCL and posterior oblique ligament and triple-strands the sMCL, dMCL, and posterior oblique ligament. The sMCL was placed 5 mm posterior to the epicondyle in the double-strand technique and at the epicondyle in the triple-strand technique. Kinematic changes were examined by repeated measures 2-way analysis of variance with posttesting.

RESULTS

Transection of the sMCL, dMCL, and posterior oblique ligament increased valgus rotation (5° mean) and external rotation (9° mean). The double-strand reconstruction controlled valgus in extension but allowed 5° excess valgus in flexion and did not restore external rotation (7° excess). The triple-strand reconstruction restored both external rotation and valgus throughout flexion.

CONCLUSION

In a cadaveric model, a triple-strand reconstruction including a dMCL graft restored native external rotation, while a double-strand reconstruction without a dMCL graft did not. A reconstruction with the sMCL graft placed isometrically on the medial epicondyle restored valgus rotation across the arc of knee flexion, whereas a reconstruction with a more posteriorly placed sMCL graft slackened with knee flexion.

CLINICAL RELEVANCE

An MCL injury may rupture the anteromedial capsule and dMCL, causing anteromedial rotatory instability. Persistent MCL instability increases the likelihood of ACL graft failure after combined injury. A reconstruction with an anteromedial dMCL graft restored native external rotation, which may help to unload/protect an ACL graft. It is important to locate the sMCL graft isometrically at the femoral epicondyle to restore valgus across flexion.

MCL Reconstruction Using a Flat Tendon Graft for Anteromedial and Posteromedial Instability

The main principles of the present medial collateral ligament (MCL) reconstruction techniques are (1) to approximate the natural anatomy and (2) to restore the main passive restraining structures in anteromedial and posteromedial knee instability. Therefore, we describe a technique using a flat tendon graft instead of tubular grafts with point-to-point bone fixation. Moreover, we address the deep MCL, a relevant restraint to anteromedial instability.

Treatment of Combined Injuries to the ACL and the MCL Complex: A Consensus Statement of the Ligament Injury Committee of the German Knee Society (DKG)

Background:

Different indications and treatment options for combined injuries to the anterior cruciate ligament (ACL) and medial collateral ligament complex (MCL) are not clearly defined.

Purpose:

To perform a modified Delphi process with the Committee for Ligament Injuries of the German Knee Society (DKG) in order to structure and optimize the process of treating a combined injury to the ACL and MCL.

Study Design:

Consensus statement.

Methods:

Scientific questions and answers were created based on a comprehensive literature review using the central registers for controlled studies of Medline, Scopus, and Cochrane including the terms medial collateral ligament, anterior cruciate ligament, MCL, ACL, and outcome used in various combinations. The obtained statements passed 3 cycles of a modified Delphi process during which each was readjusted and rated according to the available evidence (grades A-E) by the members of the DKG Ligament Injuries Committee and its registered guests.

Results:

The majority of answers, including several questions with >1 graded answer, were evaluated as grade E (n = 16) or C (n = 10), indicating that a low level of scientific evidence was available for most of the answers. Only 5 answers were graded better than C: 3 answers with a grade of A and 2 answers with a grade of B. Only 1 answer was evaluated as grade D. An agreement of >80% (range, 83%-100%) among committee members was achieved for all statements.

Conclusion:

The results of this modified Delphi process offer a guideline for standardized patient care in cases of combined injuries to the ACL and MCL.

Medial soft-tissue complex of the knee: Current concepts, controversies, and future directions of the forgotten unit

The medial side of the knee is comprised of ligaments, myotendinous and meniscal structures that work as a unit to stabilize the joint. The superficial medial collateral ligament is its core structure. Still, all elements of the medial side have load-sharing relationships, leading to a cascade of events in the scenario of insufficiency of any of them. Understanding the medial soft tissue structures as part of a unit is of utmost importance because the most common ligaments damaged in knee injuries belong to it. Surprisingly, there is a lack of high-level evidence published around the issue, and most studies focus on the superficial medial collateral ligament, overlooking the complexity of these injuries. Acknowledging the consequences for joint biomechanics and treatment outcomes, interest in this area is growing between researchers. Emerging evidence may become a game-changer in the future management of these injuries. Based on a thorough research of published literature, this review provides a current biomechanical concepts and clinical guidance to treat these injuries.

Ultrasound-based evaluation revealed reliable postoperative knee stability after combined acute ACL and MCL injuries

Purpose

Anterior cruciate ligament (ACL) injuries are often combined with lesions of the medial collateral ligament (MCL). The aim of this study was to evaluate treatment outcome of combined acute ACL and MCL lesions using functional US and clinical examination.

Methods

Patients aged > 18 years undergoing primary ACL reconstruction with concomitant operative (group 1) or non-operative treatment of the MCL (group 2) between 2014 and 2019 were included after a minimum follow-up of 12 months. Grade II MCL injuries with dislocated tibial or femoral avulsions and grade III MCL ruptures underwent ligament repair whereas grade II injuries without dislocated avulsions were treated non-operatively. Radiological outcome was assessed with functional US examinations. Medial knee joint width was determined in a supine position at 0° and 30° of knee flexion in unloaded and standardized loaded (= 15 Dekanewton) conditions using a fixation device. Clinical examination was performed and patient-reported outcomes were assessed by the use of the subjective knee form (IKDC), Lysholm score, and the Tegner activity scale.

Results

A total of 40 patients (20 per group) met inclusion criteria. Mean age of group 1 was 40 ± 12 years (60% female) with a mean follow-up of 33 ± 17 months. Group 2 showed a mean age of 33 ± 8 years (20% female) with a mean follow-up of 34 ± 15 months. Side-to-side differences in US examinations were 0.4 ± 1.5 mm (mm) in 0° and 0.4 ± 1.5 mm in 30° knee flexion in group 1, and 0.9 ± 1.1 mm in 0° and 0.5 ± 1.4 mm in 30° knee flexion in group 2, with no statistically significant differences between both groups. MCL repair resulted in lower Lysholm scores (75 ± 19 versus 86 ± 15; p < 0.05). No significant differences could be found for subjective IKDC or Tegner activity scores among the two groups.

Conclusion

A differentiated treatment concept in combined ACL and MCL injuries based on injury patterns leads to reliable postoperative ligamentous knee stability in US-based and clinical examinations. However, grade II and III MCL lesions with subsequent operative MCL repair (group 1) result in slightly poorer subjective outcome scores.

Level of evidence

Retrospective cohort study; Level III

Longitudinal Changes of Patellar Alignment Before and After Anterior Cruciate Ligament Reconstruction With Hamstring Autograft

BACKGROUND

Evidence has suggested that after anterior cruciate ligament (ACL) reconstruction (ACLR), individuals exhibit patellar malalignment; however, it is unknown if patellar alignment changes over time.

PURPOSE

To examine the longitudinal changes in patellar alignment before, 6 months after, and 3 years after ACLR and to compare these variations, if present, with patellar alignment in controls.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A total of 35 patients who had ACLR using hamstring autograft (19 male; age, 29.9 ± 7.7 years; body mass index, 23.8 ± 2.5) and 20 controls (13 male; age, 30.4 ± 4.8 years; body mass index, 24.3 ± 2.7) participated. All patients underwent bilateral knee magnetic resonance imaging with the knee in extension and 30° of flexion using sagittal T2-weighted, fat-saturated fast spin-echo images to assess patellar alignment in 6 degrees of freedom: anterior-posterior, medial-lateral, and superior-inferior translations; flexion; tilt; and spin. Patients who had ACLR were assessed before (ACL-deficient state) and 6 months and 3 years after ACLR, while control participants were only assessed once. One-way repeated-measures analysis of variance was used to examine patellar alignment across time in the ACLR group. If changes were present, the independent t test was carried out to examine the differences between ACLR knees and control knees.

RESULTS

In the knee-extended condition, greater patellar lateral displacement was observed at the ACL-deficient state and 6 months after ACLR compared with 3 years after ACLR within the ACLR group (P < .001 and P = .043, respectively) and compared with the control group (P = .001 and P = .039, respectively). Greater patellar lateral tilt was observed at the ACL-deficient state compared with 3 years after ACLR (P = .003) and compared with the control group (P = .018). In the knee-flexed condition, greater anterior displacement was observed at the ACL-deficient state compared with 3 years after ACLR (P = .001) and compared with the control group (P = .011), and it was also observed at 6 months after ACLR compared with the control group (P = .019). Less lateral spin was observed at the ACL-deficient state (P = .042) and 6 months after ACLR (P = .004) compared with 3 years after ACLR and compared with the control group (P = .004 for both). No patellar alignment measures in the ACLR knees at 3 years were significantly different from those of the controls.

CONCLUSION

Patellar malalignment in individuals before and after ACLR subjected to longitudinal changes, and the differences in alignment between ACLR and controls diminished over 3 years.

Comparing Knee Laxity After Anatomic Anterior Cruciate Ligament Reconstruction Using Quadriceps Tendon Versus Semitendinosus Tendon Graft

Background:

The choice of graft in anterior cruciate ligament (ACL) reconstruction is still under discussion. The hamstrings are currently the most used grafts for primary ACL reconstruction in Europe. However, increased interest has arisen in the quadriceps tendon (QT) as an alternative autologous graft option for primary ACL reconstruction.

Purpose:

To evaluate knee stability and the subjective outcome after ACL reconstruction using either autologous QT graft in implant-free femoral press-fit fixation technique or semitendinosus tendon (ST) graft.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

We evaluated 50 patients who underwent ACL reconstruction, including 25 patients who received autologous ipsilateral QT graft (QT group) and 25 patients who received the ipsilateral ST graft (ST group). The follow-up for this prospective comparative study was at least 2 years after surgery, comprising KT-1000 arthrometer testing, pivot-shift test, Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm score, and rerupture rate.

Results:

The mean patient age was 31.72 years (9 women, 16 men) in the QT group and 32.08 years (13 women, 12 men) in the ST group. The mean ± standard deviation postoperative side-to-side difference assessed using KT-1000 arthrometer was 1.56 ± 1.56 mm for the QT group and 1.64 ± 1.41 mm for the ST group, with no significant difference. No significant difference was found on any of the KOOS subscale scores (P = .694) or the Lysholm score (P = .682). No rerupture or positive pivot-shift test occurred during follow-up. No difference was found in donor-site morbidity between the study groups.

Conclusion:

Clinical outcomes were not significantly different between QT and ST grafts in the current study. Thus, the QT may serve as a good alternative graft for primary ACL reconstruction.

Graft Failure, Revision ACLR, and Reoperation Rates After ACLR With Quadriceps Tendon Versus Hamstring Tendon Autografts: A Registry Study With Review of 475 Patients

BACKGROUND

It has been indicated that anterior cruciate ligament reconstruction (ACLR) with a quadriceps tendon (QT) graft has a higher risk of revision compared with ACLR performed with a hamstring tendon (HT) graft.

PURPOSE/HYPOTHESIS

To investigate whether ACLR with QT graft had a higher risk of graft failure, revision ACLR, or reoperation compared with HT graft in a high-volume center. We hypothesized that there would be no between-group differences.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

This was a registry study with review of medical records. Our study cohort consisted of patients who underwent primary ACLR with either QT or HT graft performed at Copenhagen University Hospital Hvidovre between January 2015 and December 2018. The cohort was identified from the Danish Knee Ligament Reconstruction Registry and linked to the Danish National Patient Registry to identify all hospital contacts after ACLR. The outcome variables were graft failure (rerupture or >3-mm side-to-side difference in anteroposterior [AP] laxity), revision ACLR, reoperation due to cyclops lesion, reoperation due to meniscal injury, and reoperation due to any reason. AP laxity and pivot shift were assessed at 1 year. Kaplan-Meier estimates were used to evaluate the rates of events at 2 years, and comparison was performed with Cox regression analysis.

RESULTS

A total of 475 patients (252 HT, 223 QT) were included. The rate of graft failure at 2 years was 9.4% for the QT group and 11.1% for the HT group (P = .46). For the QT and HT groups, respectively, the rate of revision ACLR was 2.3% and 1.6% (P = .60), the rate of reoperation due to cyclops lesion was 5.0% and 2.4% (P = .13), and the rate of reoperation due to meniscal injury was 4.3% and 7.1% (P = .16). The rate of reoperation due to any reason was 20.5% and 23.6% (P = .37). At 1-year follow-up, AP laxity was 1.4 mm for QT and 1.5 mm for HT (P = .51), and the proportion of patients with a positive pivot shift was 29-30% for both groups.

CONCLUSION

QT and HT grafts yielded similar rates of graft failure, revision ACLR, and reoperation at 2 years of follow-up after ACLR. Graft failure was found in 9% to 11% of patients. Patients with QT ACLR showed a non-statistically significant trend of higher risk for reoperation due to cyclops lesion, and those with HT showed a non-statistically significant trend of higher risk for reoperation due to meniscal injury.

Comparison of hamstring and quadriceps tendon autografts in anterior cruciate ligament reconstruction with gait analysis and surface electromyography

BACKGROUND

Anterior cruciate ligament (ACL) tear is the most frequent ligamentous injury of the knee joint. Autografts of hamstring (HS) or quadriceps tendons (QT) are used for primary ACL reconstruction. In this study, we planned to examine whether harvesting an HS graft is related to a deficit in dynamic knee stabilisation and strength revealed by dynamic valgus as compared with QT graft or the uninjured leg. Furthermore, if this deficit exists, is it compensated by higher neuromuscular activity of the quadriceps muscle?

MATERIALS AND METHODS

Adult patients who had undergone ACL reconstruction with QT or HS autografts were included in this two-armed cohort study. Clinical outcome was assessed by clinical data analysis, physical examination and the Lysholm Score and Knee Injury and Osteoarthritis Score (KOOS). In addition, gait analysis and non-invasive surface electromyography were performed.

RESULTS

A complete data set of 25 patients (QT: N = 8, HS: N = 17) was analysed. There was no significant demographic difference between the groups. Time between surgery and follow-up was significantly longer for the QT group. Significant differences regarding clinical outcome were not found between the treated and untreated leg or between the two groups, with excellent scores at the time of follow-up. Gait analysis revealed no significant differences of varus-valgus angles. Significant differences in surface electromyography were only found in the QT group with increased vastus medialis obliquus activity of the treated legs (p < 0.01).

CONCLUSIONS

Our results suggest that harvesting of HS grafts for primary ACL reconstruction will not lead to a medial collapse and consequently impaired medial stabilisation of the knee when compared with QT grafts.

LEVEL OF EVIDENCE

IV.

In situ cross-sectional area of the quadriceps tendon using preoperative magnetic resonance imaging significantly correlates with the intraoperative diameter of the quadriceps tendon autograft

PURPOSE

Preoperative assessment to determine the sizes of potential autografts is necessary for individualized anterior cruciate ligament reconstruction (ACLR). However, no study has investigated the prediction of the intraoperative diameter of the quadriceps tendon (QT) autograft based upon preoperative imaging. This study investigated the correlation between the intraoperative diameter of a QT autograft and in situ thickness or cross-sectional area (CSA) measured using preoperative MRI.

METHODS

Thirty-one knees of 31 patients (mean age 20.9 ± 5.0 years) who underwent individualized anatomic ACLR using all soft tissue QT autograft were included retrospectively. At 15 mm proximal to the superior pole of the patella, the maximum QT thickness was assessed in the sagittal plane and the CSA was assessed at the central 10 mm of the QT in the axial plane. The angle between the axial plane and a line perpendicular to the QT longitudinal axis was used to calculate an adjusted CSA using a cosine function. Intraoperatively, each QT autograft was harvested with 10 mm width and the diameter was measured using a graft sizing device.

RESULTS

Intra- and inter-observer reliabilities of all measurements using preoperative MRI were excellent (intra-class correlation coefficient, 0.833-0.970). Significant correlations were observed between the thickness, CSA, or adjusted CSA, and the intraoperative diameter (R = 0.434, 0.607, and 0.540, respectively; P < 0.05).

CONCLUSIONS

The CSA correlated most strongly with the QT autograft diameter. For individualized anatomic ACLR, measuring in situ CSA can be useful for preoperative planning of appropriate graft choices prior to surgery.

LEVEL OF EVIDENCE

III.

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.

Quadriceps tendon autograft for anterior cruciate ligament reconstruction is associated with high revision rates: results from the Danish Knee Ligament Registry

PURPOSE

The quadriceps tendon (QT) has recently gained interest as an anterior cruciate ligament reconstruction (ACLR) autograft. There is a paucity of data from large cohort studies on failures and revision rates after ACLR using the QT graft. The purpose of the present study is to use the Danish Knee Ligament Reconstruction Registry (DKRR) to compare revision rates, objective knee stability and subjective clinical outcomes in patients who have undergone ACLR with QT, hamstring tendon (HT), and patellar tendon (PT) as a graft for ACLR. It was hypothesized that QT autografts would result in similar objective knee stability and revision rates as HT and PT autografts.

METHODS

Data on primary ACLRs in the DKRR from 2005 through 2017 were analyzed. Knee injury and Osteoarthritis Outcome Scores (KOOS), Tegner activity scale scores, sagittal knee laxity, pivot-shift tests at 1-year follow-up and revision rates at 2-year follow-up were compared for the three autograft cohorts.

RESULTS

A total of 531 QT, 14,213 HT and 1835 PT ACLR were registered in the DKLR between 2005 and 2017. QT autograft was associated with statistically significant increased laxity (1.8 mm) compared to HT autograft (1.5 mm) (p < 0.001) and more positive pivot shift. There was a significant higher revision rate for QT (4.7%), compared to PT (1.5%) and HT (2.3%) autografts at 2-year follow-up (p < 0.002).

CONCLUSION

Quadriceps tendon autografts for ACLR was associated with higher revision rates than HT and PT grafts. QT graft was also associated with small increased objective knee laxity and more positive pivot shift than HT and PT grafts.

LEVEL OF EVIDENCE

III.

Return to Play and Career Length After Anterior Cruciate Ligament Reconstruction Among Canadian Professional Football Players

BACKGROUND

For many athletes, a tear of the anterior cruciate ligament (ACL) represents a significant injury that requires a prolonged period away from the sport with substantial rehabilitation.

HYPOTHESIS

There will be no difference in return to play (RTP) and career length after hamstring tendon (HT) ACL reconstruction in a group of Canadian Football League professional players as compared with what has been already been reported in the literature among professional football players.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Data on athletes who sustained an ACL injury were collected by team physicians and head athletic trainers from 2002 to 2017 from 2 Canadian Football League teams. Patient details included age at the time of injury, initial injury date, position, practice versus game injury, and primary versus rerupture with injury-specific data, such as affected limb, concomitant injuries, graft choice, and procedure performed. RTP rates and career length data were collected through publically available internet sources. Comparisons between the non-RTP and RTP groups were made with independent-sample t tests. Binomial logistic regression was performed to determine variables (ie, games preinjury, graft type, meniscal injury, collateral ligament injury) that contributed to players not being able to RTP.

RESULTS

A total of 44 ACL reconstructions were performed over the study period (HT, n = 32 [72.7%]; bone-patellar tendon-bone [BPTB], n = 8 [18.2%]; allograft, n = 4 [9.1%]). Overall, 69.8% (n = 30) were able to RTP in at least 1 game, while 30.2% (n = 13) did not return. Mean time to return was 316.1 days (range, 220-427 days), or 10.4 months. For those players who did RTP, mean career length after ACL reconstruction was 2.8 seasons, or 34.4 games. The majority (56.8%) of injuries occurred early in the season. Breakdown by graft type demonstrated RTP rates among HT, BPTB, and allograft of 64.5% (n = 20), 87.5% (n = 7), and 75% (n = 3), respectively. Career length among HT, BPTB, and allograft was 2.9, 2.4, and 3 seasons. Logistic regression analysis found only concomitant medial collateral ligament (MCL) injuries to be a negative predictor for RTP. Meniscal injuries were associated with a decreased RTP rate and career length, but this was not statistically significant.

CONCLUSION

The RTP rates after ACL reconstruction in this study are similar to those reported in National Football League players. A concomitant injury to the MCL injury was a negative predictor of RTP. Meniscal injuries demonstrated a trend for decreased RTP rate and career length, but this was not a significant predictor. A large portion of injuries occur early in the season, and further study should be done to examine potential preventative strategies to reduce ACL injuries.

Graft choice in combined anterior cruciate ligament and medial collateral ligament reconstruction

There is a concern regarding which grafts should be used in combined anterior cruciate ligament (ACL) and medial collateral ligament (MCL) reconstructions, with a paucity of recommendations focused on this specific topic.

Expert opinions suggest the use of allograft-only reconstructions to limit donor-site morbidity or using at least one allograft and one autograft.

When a hamstring tendon autograft is harvested, techniques that maintain both the integrity of the sartorius fascia and the gracilis are recommended because of the role that the ST-G-S (semitendinosus-gracilis-sartorius) complex plays in valgus stability in the setting of an MCL-deficient knee.

Cite this article: EFORT Open Rev 2020;5:221-225. DOI: 10.1302/2058-5241.5.190049

Graft Choice for Anterior Cruciate Ligament Reconstruction With a Concomitant Non-surgically Treated Medial Collateral Ligament Injury Does Not Influence the Risk of Revision

PURPOSE

To compare the risk of anterior cruciate ligament (ACL) revision and the patient-reported outcome after ACL reconstruction with a concomitant non-surgically treated medial collateral ligament (MCL) injury with regard to 3 ACL graft choices; the use of semitendinosus (ST), the use of semitendinosus-gracilis (ST-G), and the use of patellar tendon (PT) autograft. It was hypothesized that the use of ST-G would be associated with a greater risk of ACL revision and poorer patient-reported knee function.

METHODS

Patients older than 15 years of age registered for a primary ACL reconstruction with a concomitant non-surgically treated MCL injury in the Swedish National Knee Ligament Registry were assessed for eligibility. Three groups were created according to ACL autograft choice; the ST, the ST-G, and the PT group. The primary outcomes were ACL revision and the 1- and 2-year Knee injury and Osteoarthritis Outcome Score (KOOS), including the KOOS patient acceptable symptom state (PASS). Cox regression analysis was applied to determine the proportional hazard ratio (HR) of primary ACL reconstruction survival. The KOOS was compared using the Mann-Whitney U test and Fisher exact test.

RESULTS

A total of 622 patients (mean age 29.7 years, 42.4% women) were included. There was no difference in the risk of ACL revision for either the ST group (HR 1.354; 95% confidence interval [CI] 0.678-2.702 or the PT group (HR 0.837; 95% CI 0.334-2.100), compared with the ST-G group. The ST group reported a greater mean 2-year KOOS sports and recreation (68.5, standard deviation [SD] 28.5) than the ST-G group (57.4 [SD 27.6], P = .010) and the PT group (54.1 [SD 30.3], P = .006). The ST group was superior in terms of achieving PASS in sports and recreation (55.3%; 95% CI 44.1-66.1%) compared with both the ST-G (37.4%; 95% CI 29.8-45.5%; P = .014) and the PT group (33.9%; 95% CI 22.1-47.4%; P = .009).

CONCLUSIONS

The risk of ACL revision did not differ between HT and PT autografts in patients undergoing ACL reconstruction with a non-surgically treated MCL injury. However, the use of ST-G was associated with poorer 2-year patient-reported knee function compared with the ST.

LEVEL OF EVIDENCE

Retrospective comparative trial, Level III.

Quadriceps tendon vs. patellar tendon autograft for ACL reconstruction using a hardware-free press-fit fixation technique: comparable stability, function and return-to-sport level but less donor site morbidity in athletes after 10 years

INTRODUCTION

The use of quadriceps tendon-patellar bone (QTB) autograft for anterior cruciate ligament (ACL) reconstruction is gaining momentum. Yet, long-term results that compare this procedure with established methods are lacking. The aim of this study was to report and compare long-term results of ACL reconstruction using QTB autografts versus bone-patellar tendon-bone (BPTB) autografts, both anchored using a hardware-free press-fit fixation technique.

MATERIALS AND METHODS

60 athletes (Tegner score ≥6) with primary ACL rupture were prospectively randomized into two groups. 56 patients were evaluated after a mean duration of 12.2 ± 1.9 months (range 10-14) and 43 patients after 10.3 ± 0.2 years (range 10-11).

RESULTS

On final follow-up, 90% of patients scored very good and good results in the functional Lysholm score (mean 99 ± 7.1, range 74-100 points). Normal or almost normal IKDC score was reported by 84% of the patients (mean 97 ± 9.5, range 60-100 points). The activity level decreased in the Tegner score from median of 7 before injury to 6 after 10 years. The KT-1000 arthrometer showed a difference in the anterior translation of less than 3 mm (mean 1.0 ± 1.2, range - 1 to 5 mm) in 91% of the patients. Significant degeneration was radiologically detected in one patient per group. No tunnel widening was seen in any patient. Up to 97% of all patients were satisfied with the operative procedure. No significant differences were found in the mentioned parameters between the two groups and also in comparison with the 1-year results. The only significant difference was in the donor site morbidity. Significantly more patients in the BPTB group had complaints during kneeling both at 1 (p < 0.001) and 10 years (p = 0.019). Squatting was also subjectively more problematic in the BPTB group than in the QTB group both after 1 (p = 0.003) and 10 years (p = 0.046).

CONCLUSIONS

This study shows equally good functional, clinical and radiological long-term results for both hardware-free methods of ACL reconstruction. These results clinically confirm the safety of press-fit anchoring after 10 years. The failure rate in this study was very low, with only one re-rupture in 10 years. The increased donor site morbidity when using the BPTB autograft compared to the QTB autograft supports already reported data. It was also seen in this study for the implant-free press-fit techniques.

STUDY DESIGN

Prospective and randomized, level of evidence 2.

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.

The use of allograft tissue in posterior cruciate, collateral and multi-ligament knee reconstruction

PURPOSE

Currently both autograft and allograft tissues are available for reconstruction of posterior cruciate, collateral and multi-ligament knee injuries. Decision-making is based on a complex interplay between anatomical structures, functional bundles and varying biomechanical requirements. Despite theoretically better biological healing and reduced risk of disease transmission autografts are associated with donor site morbidity as well as being limited by size and quantity. The use of allografts eliminates donor-site morbidity but raises cost and issues of clinical effectiveness. The purpose of this paper is to review current concepts and evidence for the use of allografts in primary posterior cruciate, collateral and multi-ligament reconstructions.

METHODS

A narrative review of the relevant literature was conducted for PCL, collateral ligament and multi-ligament knee reconstruction. Studies were identified using a targeted and systematic search with focus on recent comparative studies and all clinical systematic reviews and meta-analyses. The rationale and principles of management underpinning the role of allograft tissue were identified and the clinical and functional outcomes were analysed. Finally, the position of postoperative physiotherapy and rehabilitation was identified.

RESULTS

The review demonstrated paucity in high quality and up-to-date results addressing the issue especially on collaterals and multi-ligament reconstructions. There was no significant evidence of superiority of a graft type over another for PCL reconstruction. Contemporary principles in the management of posterolateral corner, MCL and multi-ligament injuries support the use of allograft tissue.

CONCLUSION

The present review demonstrates equivalent clinical results with the use of autografts or allografts. It remains, however, difficult to generate a conclusive evidence-based approach due to the paucity of high-level research. When confronted by the need for combined reconstructions with multiple grafts, preservation of synergistic muscles, and adapted postoperative rehabilitation; the current evidence does offer support for the use of allograft tissue.

LEVEL OF EVIDENCE

IV.

Dynamic Restraints of the Medial Side of the Knee: The Semimembranosus Corner Revisited

BACKGROUND

Little is known about the dynamic restraints of the semimembranosus muscle (SM).

PURPOSE AND HYPOTHESIS

The goal of the present study was to elucidate the role of (1) passive and (2) active restraints to medial-side instability and to analyze (3) the corresponding tightening of the posteromedial structures by loading the SM. It was hypothesized that points 1 to 3 will significantly restrain medial knee instability. This will aid in understanding the synergistic effect of the semimembranosus corner.

STUDY DESIGN

Controlled laboratory study.

METHODS

Nine knees were tested in a 6 degrees of freedom robotic setup and an optical tracking system. External rotation (ER; 4 N·m), internal rotation (4 N·m), anteromedial rotation (4-N·m ER and 89-N anterior tibial translation), and valgus rotation (8 N·m) were applied at 0°, 30°, 60°, and 90°, with and without an SM load of 75 N. Sequential cutting of the medial collateral ligament and posterior oblique ligament was then performed. At the intact state of the knee and after each cut, the aforementioned simulated laxity tests were performed.

RESULTS

The medial collateral ligament was found to be the main passive stabilizer to ER and anteromedial rotation, resulting in 9.3° ± 6.8° ( P < .05), 8.1° ± 3.6° ( P < .05), and 7.6° ± 4.2° ( P < .05) at 30°, 60°, and 90°, respectively. Conversely, after the posterior oblique ligament was cut, internal rotation instability increased significantly at early flexion angles (9.3° ± 3.2° at 0° and 5.2° ± 1.1 at 30°). Loading the SM had an overall effect on restraining ER ( P < .001) and anteromedial rotation ( P < .001). This increased with flexion angle and sectioning of the medial structures and resulted in a pooled 2.8° ± 1.7° (not significant), 5.4° ± 2° ( P < .01), 7.5° ± 2.8° ( P < .001), and 8.3° ± 4.4° ( P < .001) at 0°, 30°, 60°, and 90° when compared with the unloaded state.

CONCLUSION

The SM was found to be a main active restraint to ER and anteromedial rotation, especially at higher flexion angles and in absence of the main passive medial restraints. The calculated tensioning effect was small in all flexion angles for all simulated laxity tests.

CLINICAL RELEVANCE

A complete semimembranosus avulsion may indicate severe medial knee injury, and refixation should be considered in multiligament injury.

Reefing of the Posteromedial Capsule in Anteromedial Rotatory Instability

The posterior oblique ligament (POL) is the main component of the posteromedial corner (PMC) of the knee and plays a crucial role in acting as a secondary restraint against translation, rotation, and valgus forces. Injuries to the PMC often occur in association with acute or chronic deficiency of the anterior cruciate ligament and may result in anteromedial rotatory instability. A surgical technique for treatment of acute and chronic injuries of the posteromedial structures was first established by Hughston in 1973. This procedure involves an advancement and reefing of the POL and adherent posterior capsule to the stout tissue of the intact medial collateral ligament, potentially using suture anchors if the POL tissue is detached from bone. Additionally, in cases of residual laxity, the semimembranosus tendon may be advanced anteriorly to improve dynamic stabilization. This procedure appears to be useful in cases of moderate posteromedial insufficiency and avoids retrieval of a medial tendon graft from the region of the medially stabilizing hamstrings or from the healthy contralateral side.

There is no difference between quadriceps- and hamstring tendon autografts in primary anterior cruciate ligament reconstruction: a 2-year patient-reported outcome study

PURPOSE

Graft choice for anterior cruciate ligament (ACL) reconstruction is crucial, however the optimal graft source remains a topic of controversy. The purpose of this study is to compare subjective and functional patient-reported outcomes (PRO) after single-bundle ACL reconstruction using quadriceps tendon (QT) or hamstring tendon (HT) autografts for single-bundle ACL reconstruction. We hypothesize that there is no difference in patient-reported functional outcomes after ACL reconstruction using either HT- or QT autograft.

METHODS

All data were extracted from a prospectively collected ACL registry. A total of 80 patients with at least 2-year follow-up were included in this study. A total of 40 patients with primary ACL reconstruction using a QT autograft harvested via a minimally invasive technique were matched by sex, age and pre-injury Tegner and Lysholm score to 40 patients who received HT autografts. Subjective and functional PRO scores including Lysholm score, Tegner activity level and visual analogue scale for pain were obtained at 6, 12 and 24 months after index surgery.

RESULTS

No significant difference between the QT and the HT group was seen at any follow-up in regard to any of the PRO scores for function or pain. 24 months post-surgery the mean Tegner activity score of the HT group was significantly (p = 0.04) lower compared to the pre-injury status. At final follow-up, 27 patients (67.5%) in the QT group and 32 patients (80.0%) in the HT returned to their pre-injury activity level (n.s.). A total of 37 patients (92.5%) of the QT cohort and 35 patients (87.5%) of the HT cohort reported "good" or "excellent" results according to the Lysholm score (n.s.). "No pain" or "slight pain" during severe exertion was reported by 33 patients (82.5%) with QT autograft and 28 patients (82.4%) with HT autograft (n.s.).

CONCLUSION

There is no significant difference between PRO 2 years post-operative using either QT or HT autografts. Both QT and HT grafts show acceptable and comparable PRO scores making the QT a reliable graft alternative to HT for primary ACL reconstruction.

LEVEL OF EVIDENCE

III.

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

PURPOSE

The aim of this study was to compare isokinetic quadriceps and hamstring muscle strength in patients following anterior cruciate ligament (ACL) reconstruction who received either hamstring (HT) or quadriceps (QT) tendon autografts at two time intervals within the first year after surgery.

METHODS

One hundred twenty-four patients, 81 males (age 22.0 ± 6.2 years) and 43 females (age 20.9 ± 8.7 years), participated in this study. ACL reconstruction was performed with either quadriceps tendon autografts (QT; n = 61) or hamstring tendon autografts (HT; n = 63). Two isokinetic muscle strength tests (t1: 5.5 ± 1.2 months; t2: 7.6 ± 1.6 months) were performed at an angular velocity of 60°/s in both the injured and contralateral knees. An independent t test as well as a two-factor analysis of variance with repeated measurements was used. The significance level was set at p < 0.05.

RESULTS

A statistically significant lower knee extensor strength was observed in the QT group within one year after surgery (p < 0.001). Additionally, data showed a significant higher H/Q ratio in QT patients compared to the HT group at t1 (p < 0.001) and t2 (p = 0.001) as well as a significant effect over time (p < 0.001) and interaction effect of time and graft (p = 0.007). Side-to-side values for extensor muscle strength were significantly (p < 0.001) greater in HT graft patients, while QT patients showed significantly (p < 0.001) greater values for flexor muscle strength at both time points of isokinetic testing, respectively.

CONCLUSION

The results of this study indicate that graft choice has an impact on extensor strength in the first months after ACL reconstruction; however, there is no impact on flexor strength. The finding of a higher H/Q ratio in patients with QT grafts within the first months following surgery is possibly of clinical relevance. This may potentially be associated with lower stress on the maturing ACL graft. Furthermore, normal thigh strength can be restored over time.

LEVEL OF EVIDENCE

III.