Descriptive epidemiology of the Multicenter ACL Revision Study (MARS) cohort

A comparative study on 3D printing-assisted arthroscopic IDEAL point femoral tunnel positioning for anterior cruciate ligament reconstruction versus conventional arthroscopic positioning

BACKGROUND

This study aimed to investigate the feasibility and precision of using a 3D-printed template for femoral tunnel placement in guiding the optimal positioning of the Internal anatomical stop and Low tension maintenance (IDEAL) bone tunnel during single-bundle anterior cruciate ligament (ACL) reconstruction.

METHODS

A retrospective analysis was conducted on 40 patients who underwent arthroscopic single-bundle ACL reconstruction at our hospital between April 2021 and November 2021. In the direct vision group, the IDEAL bone tunnel was positioned using radiofrequency localization directly visualized at the stump. In the 3D-printed positioning group, preoperative CT scans and Digital Imaging and Communications in Medicine (DICOM) data were employed. Following the Quadrant method by Bernard, the femoral tunnel's depth was set at 25% and its height at 29%. Postoperative plain CT scans enabled the reconstruction of 3D models for both groups. The accuracy of femoral tunnel placement was then compared.

RESULTS

The central locations of the bone tunnels in the direct vision group were at a mean depth of 25.74 ± 1.84% and a height of 29.22 ± 2.97%. In the 3D printing localization group, these values were 25.39 ± 2.98% for depth and 28.89 ± 2.50% for height, respectively. No significant differences were found in tunnel positioning between the groups. Both groups demonstrated statistically significant improvements in International Knee Documentation Committee Subjective Knee Form (IKDC) and Lysholm scores postoperatively, with no significant differences observed 12 months post-surgery.

CONCLUSION

The findings of this study suggest that 3D printing-assisted arthroscopic IDEAL point femoral tunnel positioning and conventional arthroscopic positioning are feasible and effective for ACL reconstruction. Using 3D printing technology to design femoral anchor points in ACL reconstruction allows for the customization of anterior fork reconstruction and precise bone tunnel positioning, supporting the goal of individualized and accurate reconstruction.

Hyperbaric oxygen therapy enhances graft healing and mechanical properties after anterior cruciate ligament reconstruction: An experimental study in rabbits

Hyperbaric oxygen therapy (HBOT) has proven successful in wound healing. However, its potential effects on anterior cruciate ligament (ACL) injuries remain uncertain. This study aimed to investigate the impact of HBOT on graft healing following ACL reconstruction in rabbits. Male New Zealand rabbits underwent ACL reconstruction and were randomly divided into two groups: the HBOT group and the ambient air group. The HBOT group received 100% oxygen at 2.5 atmospheres absolute for 2 h daily for 5 consecutive days, starting from the first day after surgery. The ambient air group was maintained in normal room air throughout the entire period. After 12 weeks following the surgery, animals were euthanized, and their knees were harvested for analysis. The HBOT group demonstrated superior graft maturation and integration in comparison to the ambient air group, as evidenced by lower graft signal intensity on magnetic resonance imaging, decreased femoral and tibial tunnel size, and higher bone mineral density values on high-resolution peripheral quantitative computed tomography scans. Additionally, biomechanical testing indicated that the HBOT group had greater load to failure and stiffness values than the ambient air group. In conclusion, the adjuvant use of HBOT improved ACL graft maturation and integration, reduced tunnel widening, and enhanced the biomechanical properties of the graft. These results may provide important insights into the potential clinical application of HBOT as a therapeutic intervention to enhance graft healing after ACL reconstruction, paving the way for further research in this area.

Peroneus longus tendon autograft versus allograft in revision ACLR: A retrospective comparison

PURPOSE

The use of peroneus longus tendon (PLT) autografts in primary anterior cruciate ligament reconstruction (ACLR) has increased recently, but there is a lack of research on its use in revision ACLR. This study aimed to compare the clinical outcomes and complications between revision ACLR using allografts and PLT autografts.

MATERIALS AND METHODS

Fifty-nine patients who underwent arthroscopic revision of ACLR with complete clinical follow-ups between 2012 and 2021 were retrospectively reviewed. Allograft was used in 44 of these patients, and PLT autograft was used in 15 of them. Lysholm knee score, Tegner activity score, Lachman, and anterior drawer tests were performed after a mean follow-up of 60months (range: 19-116). The American Orthopaedic Foot and Ankle Society (AOFAS) scale was used to evaluate the donor ankle functions. Clinical outcomes and complications were compared between groups.

RESULTS

Both groups showed significantly improved functional outcomes compared to their preoperative assessments. However, both groups had similar clinical results at the final follow-up, including Lysholm knee score, Tegner activity scale, knee range of motion, return to sports, time to return to daily activities, and rate of re-rupture. No major complications were seen in any of the patients. The AOFAS score was 99.13±2.64 in the PLT autograft group without loss of ankle muscle strength, deformity, instability, and permanent iatrogenic neurovascular injuries. The cumulative cost of the allograft group was significantly higher than the PLT autograft group.

CONCLUSIONS

The PLT autograft might be an alternative autograft option to allografts due to similar clinical outcomes, low donor site morbidity, and reduced cost in ACLR revisions, especially if the primary ACLR was performed using grafts harvested around the knee.

LEVEL OF EVIDENCE

III; retrospective comparative study.

App-based analysis of the femoral tunnel position in ACL reconstruction using the quadrant method

PURPOSE

The purpose of this study was to examine the intra- and interobserver variability of an app-based analysis of the femoral tunnel position using the quadrant method in primary anterior cruciate ligament reconstruction.

MATERIALS AND METHODS

Between 12/2020 und 12/2021 50 patients who underwent primary anterior cruciate ligament reconstruction were included in this retrospective study. Intraoperative strictly lateral fluoroscopic images of the knee with marked femoral tunnel were analyzed by four observers using the quadrant method. For retest reliability analysis, measurements were repeated once by 2 observers after 4 weeks.

RESULTS

The femoral tunnel position of all included patients averaged 27.86% in the depth relation and 15.61% in the height relation. Statistical analysis showed an almost perfect intra- and interobserver reliability in the depth and height relation. The ICC was 0.92 in the depth relation and 0.84 in the height relation. The Pearson's correlation coefficient in the depth and height relation of observer 1 (0.94/0.81) was only slightly different from the Pearson's correlation coefficient of observer 2 (0.92/0.85). The app-based tunnel analysis took on average 59 ± 16 s per measurement.

CONCLUSION

The femoral tunnel analysis with the app-based quadrant method has an almost perfect intra- and interobserver reliability. By smartphone camera, a fast and highly accurate, if necessary also intraoperative, control of the tunnel position can be performed.

LEVEL OF EVIDENCE

Level 3-diagnostic retrospective cohort study.

Finite element graft stress for anteromedial portal, transtibial, and hybrid transtibial femoral drillings under anterior translation and medial rotation: an exploratory study

Stress concentration on the Anterior Cruciate Ligament Reconstruction (ACLr) for femoral drillings is crucial to understanding failures. Therefore, we described the graft stress for transtibial (TT), the anteromedial portal (AM), and hybrid transtibial (HTT) techniques during the anterior tibial translation and medial knee rotation in a finite element model. A healthy participant with a non-medical record of Anterior Cruciate Ligament rupture with regular sports practice underwent finite element analysis. We modeled TT, HTT, AM drillings, and the ACLr as hyperelastic isotropic material. The maximum Von Mises principal stresses and distributions were obtained from anterior tibial translation and medial rotation. During the anterior tibia translation, the HTT, TT, and AM drilling were 31.5 MPa, 34.6 Mpa, and 35.0 MPa, respectively. During the medial knee rotation, the AM, TT, and HTT drilling were 17.3 MPa, 20.3 Mpa, and 21.6 MPa, respectively. The stress was concentrated at the lateral aspect of ACLr,near the femoral tunnel for all techniques independent of the knee movement. Meanwhile, the AM tunnel concentrates the stress at the medial aspect of the ACLr body under medial rotation. The HTT better constrains the anterior tibia translation than AM and TT drillings, while AM does for medial knee rotation.

Donor age has no relevant role in biomechanical properties of allografts used in anterior cruciate ligament (ACL) reconstruction: A systematic review

PURPOSE

Surgeons generally consider the donor age as a factor that negatively influences the quality of allograft used in anterior cruciate ligament (ACL) reconstruction, however, the available evidence does not clearly support this statement. The purpose of the study was to investigate if donor age influences the biomechanical properties of allografts used in ACL reconstruction.

METHODS

A comprehensive literature search was conducted for all relevant articles using MEDLINE (PubMed), Scopus, and Cochrane Collaboration Library, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Studies including the analysis of the correlation between biomechanical properties of the allografts and donor age were selected. The role of donor age was labelled as 'none' if absent, 'higher' or 'lower' if the properties were higher or lower in older specimens with respect to younger. The correlation was defined as 'weak' or 'strong' according to each study definition.

RESULTS

No conflicting role of donor age was reported for modulus of elasticity, load to failure, strain, stiffness and displacement. The only parameters where the significant results were consistent were the tensile strength and the stress (low or moderate correlations). When considering the tested samples with a donor's age <65 years, a significant role of age was reported in only four out of 13 groups of graft tested (patellar tendon, fascia lata, anterior tibialis tendon and posterior tibialis tendon).

CONCLUSION

The current literature did not allow to state that the donor age negatively influences the biomechanical properties of allografts, making it impossible to identify a clear age cut-off value to exclude them from ACL reconstruction procedures.

LEVEL OF EVIDENCE

Level IV, systematic review.

Difference of Knee Strength Recovery Between Revision and Primary ACL Reconstruction

Different grafting procedures are available to restore knee stability after revision anterior cruciate ligament (ACL) reconstruction. We compared knee strength recovery between ACL revision surgery and primary reconstruction. One hundred and ten patients with ACL revision surgery were matched with 110 patients with primary reconstruction based on the graft procedure. The isokinetic knee strength had been assessed for the first 9 months post-surgery. Knee laxity, function, and activity score were also evaluated. Limb symmetry index for knee extensor and flexor strength was not different at 4-, 6- and 9-months post-surgery between revision surgery and primary reconstruction. These results depended on ipsilateral or contralateral graft choice. Ipsilateral hamstring tendon (HT) and contralateral bone-patellar-tendon-bone (BPTB) graft procedures were similar for a revision of a BPTB graft failure. Contralateral HT procedure was better than ipsilateral BPTB procedure for a revision of a HT graft failure. The early recovery of isokinetic knee strength after ACL revision surgery regardless of the HT or BPTB procedures, was similar to the recovery after primary ACL reconstruction with the same graft technique. These results apparently depended on a temporary quadriceps arthrogenic muscle inhibition and on a persistent donor site morbidity, concerning the new and the previous grafts, respectively.

Risk factors of knee reinjury after anterior cruciate ligament reconstruction

PURPOSE

This study aimed to investigate whether the return to level I sports, concomitant injuries, foot-related problems, and other factors would increase the risk of knee reinjury after anterior cruciate ligament reconstruction (ACLR).

METHODS

This study used a prospective cohort study design. Online enrolment from August 2018 to January 2019 in ACL Community Indonesia recruited 148 patients who had undergone ACLR less than one month prior to injury. Knee injury occurrence after ACLR was diagnosed through a physical examination and positive MRI or arthroscopic findings.

RESULTS

During the study, 55 knee reinjuries occurred. The proportional hazards model analysis revealed that the risk of knee reinjury at 12 and 24 months for patients who returned to level I sports (hazards ratio (HR)=3.17 and HR=3.90, respectively) was significantly higher than that of the patients who did not return to sports and that the risk for those who returned to level II/III sports did not significantly increase at 12 or 24 months. Patients with concomitant meniscus injury had a significantly higher risk of knee reinjury at 12 and 24 months (HR=3.33 and HR=2.25, respectively) than those without, and the risk of knee reinjury for patients with concomitant posterior cruciate ligament injury was significantly higher at 12 months (HR=3.05) but not at 24 months. Fewer knee symptoms after ACLR were significantly associated with a lower risk of knee reinjury (HR=0.98) at 12 and 24 months.

CONCLUSIONS

The return to level I sports, concomitant meniscus and posterior cruciate ligament injury, and knee symptoms after ACLR may increase the risk of knee reinjury for post-ACLR patients.

Quadriceps Tendon With Bone Autograft Has Better Stability and Magnetic Resonance Imaging Maturation Than Hamstring Tendon Autograft After Anterior Cruciate Ligament Reconstruction in Patients With Knee Hyperextension

PURPOSE

To compare the clinical outcomes of anterior cruciate ligament (ACL) reconstruction between methods using quadriceps tendon with bone (QTB) and hamstring tendon (HT) in patients with hyperextension of the knee.

METHODS

The medical records of patients with knee hyperextension greater than 8° who underwent arthroscopic ACL reconstruction between October 2010 and October 2020 with follow-up for at least 2 years (median, 3 years; interquartile range [IQR], 2.0-4.6 years) were retrospectively reviewed. Side-to-side difference in anterior translation, pivot-shift test grade, Lysholm score, and graft intensity using the Howell grade on magnetic resonance imaging at final follow-up were compared between the QTB and HT groups.

RESULTS

The HT and QTB groups consisted of 42 patients and 21 patients, respectively. The overall mean age was 21.5 years (range, 14-48 years), and the median Tegner Activity Scale score was 6 (range, 3-9). Postoperatively, the median side-to-side difference in anterior translation was 1.75 mm (IQR, 1-3 mm) in the HT group and 1.0 mm (IQR, 0-1.75 mm) in the QTB group (P = .01). Pivot-shift testing showed grade 0 in 74.7%, grade 1 in 18.7%, and grade 2 in 6.6% of patients in the HT group and grade 0 in 85.7% and grade 1 in 14.3% of those in the QTB group (P = .03). The median postoperative Lysholm score was 99 in both groups. Graft signal intensity showed a significant between-group difference: grade I in 52%, grade II in 36%, and grade III in 12% of patients in the HT group versus grade I in 85.7%, grade II in 9.5%, and grade III in 4.8% of those in the QTB group (P = .03).

CONCLUSIONS

In patients who underwent ACL reconstruction for hyperextension of the knee, QTB yielded better clinical outcomes than HT with respect to anterior stability, rotational stability, and graft signal intensity on median 2-year follow-up magnetic resonance imaging.

LEVEL OF EVIDENCE

Level III, retrospective case-control study.

High flexion femoral side remnant preservation positioning technique: a new method for positioning the femoral tunnel in anterior cruciate ligament reconstruction

PURPOSE

The aim of this study is to find a new method for femoral side preservation positioning in anterior cruciate ligament (ACL) reconstruction and test the accuracy and precision of this method.

METHOD

Fifty patients with isolated ACL rupture (42 males and 8 females) who underwent single-bundle ACL reconstruction in our hospital between July 2022 and July 2023 were included. The lowest point of the cartilage margin of the lateral wall of the intercontinental fossa and the tibial plateau plumb line at 120° of knee flexion were used as the anatomical landmarks for positioning of the femoral tunnel for ACL reconstruction surgery. Femoral side remnant preservation was performed in all cases. Three-dimensional CT was performed 3 days postoperatively to collect the data, which were analyzed using Mimics 21.0 software. We measured the posterior cortical distance of the femoral condyle at 90° of knee flexion and the vertical distance from the center of the bone tunnel to the cortical extension line behind the femur. All femoral tunnel positions were marked on a 4 × 4 grid and visualized using the quadrant method.

RESULTS

Using the new positioning method in 50 knees, the average distance of x was 25.26 ± 2.76% of t and the average distance of y was 23.69 ± 6.19% of h. This is close to the results of previous studies, where x was 24.2 ± 4.0% of t and the average distance of y was 21.6 ± 5.2% of h. Most femoral tunnel positions were located in the same area. The D values were distributed as follows: 60% in the range of 0 to 2 mm, 24% in the range of 2 to 4 mm, and 16% more than 4 mm. The E values were distributed as follows: 80% in the range of 0 to 4 mm and 20% more than 4 mm.

CONCLUSION

In arthroscopic ACL reconstruction, the knee was flexed at 120° and the lowest point of the cartilage edge of the lateral wall of the intercondylar fossa and the tibial plateau plumb line were used as anatomical landmarks for the positioning of the femoral bone tunnel, which resulted in more accurate femoral bone tunnel positioning, better reproducibility, and better preservation of the femoral stump compared to traditional positioning methods.

Study on the use of 3D printed guides in the individualized reconstruction of the anterior cruciate ligament

OBJECTIVE

Evaluation of the accuracy and effectiveness of 3D printed guides to assist femoral tunnel preparation in individualised reconstruction of the anterior cruciate ligament.

METHODS

Sixty patients who attended the Affiliated Hospital of Binzhou Medical College for autologous hamstring single bundle reconstruction of the anterior cruciate ligament from October 2018 to October 2020 were selected and randomly divided into two groups, including 31 cases in the 3D printing group (14 males and 17 females, mean age 41.94 ± 10.15 years) and 29 cases in the control group (13 males and 16 females, mean age 37.76 ± 10.34 years). Patients in both groups were assessed for intraoperative femoral tunnel accuracy, the number of intraoperative positioning and the time taken to prepare the femoral tunnel, the length of the anteromedial approach incision, the pre-planned bone tunnel length and intraoperative bone tunnel length in the 3D printed group, IKDC score and Lysholm score preoperatively and at 3, 6 and 12 months postoperatively, the Lachman、pivot-shift test preoperatively and at 6 months postoperatively, gait analysis to assess internal and external rotation in flexion of the knee at 12 months postoperatively and postoperative complications in both groups.

RESULTS

There was no statistical difference in functional knee scores and anteromedial approach incision length between the 3D printed and control groups (p > 0.05), while there was a statistical difference in the accuracy of tunnel positioning, the time taken to prepare the femoral bone tunnel and the degree of external rotation of the knee in flexion between the two groups (p < 0.05). There was no statistical difference between the preoperative planning of the bone tunnel length and the intraoperative bone tunnel length (p > 0.05).

COMPLICATIONS

One case in the 3D printing group developed intermuscular vein thrombosis in the affected lower limb after surgery, which disappeared after treatment, while three cases in the control group developed intermuscular vein thrombosis in the affected lower limb. No complications such as bone tunnel rupture, deep vein thrombosis in the lower limb and infection occurred in either group.

CONCLUSION

3D printed guides assisted with individualized ACL reconstruction may improve the accuracy of femoral tunnel positioning, which is safe and effective, while reducing the operative time and the number of intraoperative positioning, without increasing the length of incision, and may obtain higher functional scores and rotational stability of the knee joint, which is in line with the concept of individualized ACL reconstruction.

Editorial Commentary: The Number One Cause of Anterior Cruciate Ligament Reconstruction Graft Failure Is a Misplaced Femoral Tunnel: Over-the-Top Technique Plus Lateral Extra-Articular Tenodesis Is Recommended

Patient factors (notably high tibial slope and narrow femoral intercondylar notch width) and surgical factors (including meniscus treatment and anterior cruciate ligament [ACL] tunnel position) contribute to ACL reconstruction failure. The number one cause of failure is a misplaced ACL femoral tunnel. Tunnel malposition leads to a higher incidence of postoperative meniscal lesions, inferior clinical outcomes, and higher revision rates.

App-Based Analysis of Fluoroscopic Images According to Bernard-Hertel Method for the Determination of Femoral Tunnel Positioning in Anterior Cruciate Ligament Reconstruction

The accurate positioning of the femoral tunnel is crucial for the success of anterior cruciate ligament reconstruction. Malpositioning of the tunnel is believed to be one of the most important reasons for graft failure. While use of anatomic landmarks and industry-supplied aiming devices aid the surgeon in placing the drill pin in the correct position, fluoroscopic imaging is an additional tool used intraoperatively to verify pin placement. While interpretation of fluoroscopic imaging is frequently based on eyeball measurement, a more accurate analysis of a lateral image uses the quadrant method by Bernard-Hertel. This method has been primarily used for scientific research due to its complexity and has not been integrated into clinical routine yet. We present a digital app-based approach to easily quantify the femoral pin position based on the quadrant method. This approach is mobile and easy to use. Quantification of pin position of femoral bone tunnel on a lateral fluoroscopic image may be used for quality control and teaching purposes or may provide the surgeon with additional information during ACL reconstruction.

Femoral Tunnel Malposition, Increased Lateral Tibial Slope, and Decreased Notch Width Index Are Risk Factors for Non-Traumatic Anterior Cruciate Ligament Reconstruction Failure

PURPOSE

To identify risk factors for patients who sustain nontraumatic anterior cruciate ligament reconstruction (ACLR) failure.

METHODS

A retrospective analysis was performed on patients undergoing primary or revision ACLR in our institution between 2010 and 2018. Patients sustaining insidious-onset knee instability without history of trauma were identified as nontraumatic ACLR failure and assigned to the study group. The control group of subjects who showed no evidence of ACLR failure with minimum 48-month follow-up were matched in a 1:1 ratio based on age, sex, and body mass index. Anatomic parameters including tibial slope (lateral [LTS], medial [MTS]); tibial plateau subluxation (lateral [LTPsublx], medial [MTPsublx]); notch width index (NWI); and lateral femoral condyle ratio were measured with magnetic resonance imaging or radiography. Graft tunnel position was assessed using 3-dimensional computed tomography and reported in 4 dimensions: deep-shallow ratio (DS ratio) and high-low ratio for femoral tunnel, anterior-posterior ratio and medial-lateral ratio for tibial tunnel. Interobserver and intraobserver reliability were evaluated by the intraclass correlation coefficient (ICC). Patients' demographic data, surgical factors, anatomic parameters, and tunnel placements were compared between the groups. Multivariate logistic regression and receiver operating characteristic curve analysis was used to discriminate and assess the identified risk factors.

RESULTS

A total of 52 patients who sustained nontraumatic ACLR failure were included and matched with 52 control subjects. Compared to patients with intact ACLR, those who sustained nontraumatic ACLR failure showed significantly increased LTS, LTPsublx, MTS, and deceased NWI (all P < .001). Moreover, the average tunnel position in the study group was significantly more anterior (P < .001) and superior (P = .014) at the femoral side and more lateral (P = .002) at the tibial side. Multivariate regression analysis identified LTS (odds ratio [OR] = 1.313; P = .028), DS ratio (OR = 1.091; P = .002), and NWI (OR = 0.813; P = .040) as independent predictors of nontraumatic ACLR failure. LTS appeared to be the best independent predictive factor (area under the curve [AUC] = 0.804; 95% confidence interval [CI], 0.721-0.887), followed by DS ratio (AUC = 0.803; 95% CI, 0.717-0.890), and NWI (AUC = 0.756; 95% CI, 0.664-0.847). The optimal cutoff values were 6.7° for increased LTS (sensitivity = 0.615, specificity = 0.923); 37.4% for increased DS ratio (sensitivity = 0.673, specificity = 0.885); and 26.4% for decreased NWI (sensitivity = 0.827, specificity = 0.596). Intraobserver and interobserver reliability was good to excellent, with ICCs ranging from 0.754 to 0.938 for all radiographical measurements.

CONCLUSIONS

Increased LTS, decreased NWI, and femoral tunnel malposition are predictive risk factors for nontraumatic ACLR failure.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

[Influence of the bony alignment on the ligaments of the knee joint]

In recent years biomechanical and clinical studies have shown that the three-dimensional bony alignment of the lower extremities has a relevant influence on the ligamentous structures of the knee and consequently on the stability of the knee joint. Therefore, in the case of pathological ligamentous damage of the knee joint, a possible malalignment must always be thoroughly evaluated and if necessary, included in the treatment planning. Varus malalignment plays an important role especially with respect to the cruciate ligaments as well as the posterolateral ligamentous structures and has been identified as a significant risk factor for failure after surgical reconstruction of these ligamentous structures. Similar data have also been published for valgus malalignment particularly with respect to its negative influence on the anterior cruciate ligament and the medial capsuloligamentous complex. Alignment deviations in the sagittal plane, especially the inclination of the tibial articular surface (slope), have been extensively investigated in several recent studies. It has been demonstrated that the tibial slope has a relevant influence on the anteroposterior stability of the knee joint and hence on the cruciate ligaments. First clinical studies on the surgical correction of the axis in selected patients showed very promising results with the potential of protecting ligament reconstructions against repeated failure; however, further data especially regarding the importance and the exact indications for an additional alignment correction are necessary.

Patient specific instrumentation in ACL reconstruction: a proof-of-concept cadaver experiment assessing drilling accuracy when using 3D printed guides

INTRODUCTION

Accurate positioning of the femoral tunnel in ACL reconstruction is of the utmost importance to reduce the risk of graft failure. Limited visibility during arthroscopy and a wide anatomical variance attribute to femoral tunnel malposition using conventional surgical techniques. The purpose of this study was to determine whether a patient specific 3D printed surgical guide allows for in vitro femoral tunnel positioning within 2 mm of the planned tunnel position.

MATERIALS AND METHODS

A patient specific guide for femoral tunnel positioning in ACL reconstruction was created for four human cadaveric knee specimens based on routine clinical MRI data. Fitting properties were judged by two orthopedic surgeons. MRI scanning was performed both pre- and post-procedure. The planned tunnel endpoint was compared to the actual drilled femoral tunnel.

RESULTS

This patient specific 3D printed guide showed a mean deviation of 5.0 mm from the center of the planned femoral ACL origin.

CONCLUSION

In search to improve accuracy and consistency of femoral tunnel positioning in ACL reconstruction, the use of a patient specific 3D printed surgical guide is a viable option to explore further. The results are comparable to those of conventional techniques; however, further design improvements are necessary to improve accuracy and enhance reproducibility.

Location and Progression of Chondral Injuries at the Time of Revision ACL Surgery Varies by Sex

PURPOSE

To quantify progression of chondral and meniscal injuries between primary and revision anterior cruciate ligament (ACL) surgery.

METHODS

Patients who underwent both index and revision ACL reconstruction between 2000 and 2020 at our institution were identified, and dates of injury and surgery, demographics, and clinical data were obtained from operative reports. Outerbridge grade was recorded in each compartment, along with presence and location of meniscal injury. The frequency of each injury between first and second cases was calculated. Differences in injury and progression were compared over time as well as between patient sex and age.

RESULTS

The study included 189 patients (96 female, 93 male). Age at first surgery was 31.7 ± 13.2 years. Mean time to second injury was 3.3 ± 3.0 years. In total, 116 patients had a new or previous chondral injury (odds ratio, 1.6; 95% CI, 1.2-2.1). The medial femoral condyle (31%) and the patella (21%) accounted for the highest proportion of new injury to articular surfaces, whereas new injury to menisci was comparable between the medial (25%) and lateral (23%) meniscus. At the time of revision ACL reconstruction, females had a high prevalence of chondral injuries to the lateral compartment, whereas males had a high prevalence of chondral injury to the medial femoral condyle. The prevalence of new chondral injuries was comparable between sexes, with males having a slightly higher proportion. While time between surgeries, sex, and age had graphical evidence of moderating risk, the effects were small and imprecise.

CONCLUSIONS

Revision ACL reconstruction carried a 1.6 increase in the odds for new or progressive chondral lesions in our cohort. At the time of revision, females had a relatively higher proportion of lateral-sided chondral injuries, whereas males had a relatively higher proportion of medial femoral condyle injuries. The greatest increase in the prevalence of new and progressive lesions was observed in the medial femoral condyle and trochlea. This progression appeared to be moderated by time between surgeries, patient sex, and age; however, the differences were small and imprecise.

STUDY DESIGN

Level IV, therapeutic case series.

Comparative study of functional outcomes of arthroscopic anterior cruciate ligament reconstruction using anteromedial portal and translateral all-inside technique

Background

Anterior Cruciate Ligament (ACL) injuries are common in the active population of the Armed Forces. Symptomatic instability prompts individuals to seek a cure or a sheltered appointment. Despite the increasing numbers of ACL reconstructions performed, the outcomes have not been so spectacular with only a meager percentage of our patients returning to preinjury levels of activity. With the premise that an all-inside ACL reconstruction is likely to result in better functional outcomes, the aim of this study was to compare the short-term functional outcomes of a large consecutive series of patients undergoing ACL reconstruction using the translateral all-inside ACL reconstruction technique (AI) and standard anteromedial portal technique (AM) with a minimum follow-up of one year.

Methods

A total of 240 patients with isolated ACL tear underwent ACL reconstruction via the AI or AM technique. Their preoperative and postoperative scores were compared to look for any significant differences in functional outcomes.

Results

The two groups were matched for age, BMI, mechanism of injury, and interval from injury to surgery. There was no difference in their preoperative scores. Postoperatively, although there were significant improvements across both groups, there was no significant difference between the groups at any point of time.

Conclusion

The AI technique has garnered interest in recent literature in addressing ACL injuries. This study found no discernible benefit of the AI technique when compared to the AM technique in terms of functionality following an ACL reconstruction at any point of time up to 1 year following surgery.

Risk Factors for Ipsilateral Versus Contralateral Reinjury After ACL Reconstruction in Athletes: A Systematic Review and Meta-analysis

Background

Anterior cruciate ligament (ACL) reinjury after ACL reconstruction (ACLR) can occur on the ipsilateral or contralateral side. Limited evidence exists regarding the difference between the incidence of reinjury to either knee, which is important in developing interventions to prevent ACL reinjury.

Purpose

To compare the reinjury rate of the ACL on the ipsilateral side versus the contralateral side in athletes after ACLR and investigate the risk factors that may cause different reinjury rates between the sides.

Study Design

Systematic review; Level of evidence, 4.

Methods

A systematic review was performed based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies that involved ACL reinjury in athletes after ACLR were reviewed. Considering several risk factors, including age and sex, a comparison of ACL reinjury incidence on the ipsilateral and contralateral sides was performed using a meta-analysis.

Results

Of the 17 selected studies, 3 were found to be at high risk of bias, and thus, 14 (n = 3424 participants) studies were included in the meta-analysis. In this athletic population, the contralateral ACL had a significantly higher rupture rate than the ipsilateral graft (risk ratio [RR], 1.41; P < .0001). Female athletes were found to have a greater risk of ACL reinjury on the contralateral versus the ipsilateral side (RR, 1.65; P = .0005), but different results were found in male athletes. (RR, 0.81; P = .21). There was no statistical difference in the incidence rate of ACL reinjury to either side in adolescent athletes (RR, 1.15; P = .28).

Conclusion

The contralateral ACL was more vulnerable to reinjury than the ipsilateral side in athletes after ACLR. Female athletes were more likely to reinjure their contralateral native ACL, while the same trend was not found in their male counterparts. The reinjury rate was comparable in both knees in adolescent athletes.

The apex of the deep cartilage is a stable landmark to position the femoral tunnel during remnant-preserving anterior cruciate ligament reconstruction

PURPOSE

The aim of this retrospective cohort study was to investigate whether the apex of the deep cartilage (ADC) could help surgeons position the femoral tunnel accurately in remnant-preserving anterior cruciate ligament (ACL) reconstruction (ACLR).

METHODS

In the current retrospective cohort study, a total of 134 patients who underwent ACLR between 2016 and 2020 were included. The femoral tunnel position was located using ADC as the landmark. The patients were divided into two groups: the remnant-preserving group (RP group, n = 68) underwent remnant-preserving ACLR, and the nonremnant group (NRP group, n = 66) underwent traditional ACLR with remnant removal. Postoperatively, the femoral tunnel position was evaluated on 3D-CT. The length from the ADC to the shallow cartilage margin (L) and to the centre of the femoral tunnel (l) and the length from the centre of the femoral tunnel to a low cartilage ratio in the direction from high to low (H) were measured.

RESULTS

The l/L values of the RP and NRP groups were both 0.4 ± 0.1 after rounding (n.s.), and the H values were 9.3 ± 1.6 mm and 9.3 ± 1.7 mm, respectively (n.s.). There was no significant difference in l/L or H between the two groups. The estimation plot also showed high consistency of H and l/L of the two groups. The inter- and intraobserver reliability of I, L, l/L, and H were almost perfect.

CONCLUSIONS

The apex of the deep cartilage is a good landmark for positioning the femoral tunnel in remnant-preserving ACL reconstruction.

LEVEL OF EVIDENCE

Level III.

Poorer patient-reported knee function and quality of life, but not activity level, after revision ACL reconstruction compared with primary ACL reconstruction: a matched-pair analysis with a minimum 5-year follow-up

BACKGROUND

An appropriate method for comparing knee function and activity level between patients with primary and revision anterior cruciate ligament reconstruction (ACLR) is to perform a matched-group analysis. The aim was to assess and compare knee function, knee-related quality of life and activity level between patients with revision ACLR and primary ACLR at a minimum of 5 years of follow-up.

METHODS

Patients aged ≤ 40 years old who underwent revision ACLR between 2010 and 2015 and a matched control group (primary ACLR) (1:1) with age ± 2 years, year of ACLR, sex, and pre-injury sport and Tegner Activity Scale (TAS) were retrospectively identified in our clinic database. The preoperative Knee injury and Osteoarthritis Outcome Score (KOOS) and surgical data were extracted and analyzed. Patients were mailed KOOS and EQ-5D questionnaires at a minimum of 5-years after revision ACLR. Study-specific questions about knee function, limitation in sport, satisfaction, and activity level according to the TAS (all scales of 1-10, 10 best) were also asked by telephone.

RESULTS

Seventy-eight patients with a revision ACLR (mean age ± SD, 29.9 ± 6.0 years) matched with seventy-eight patients with a primary ACLR (30.2 ± 5.8 years) were included. The follow-up for the revision ACLR group was 7.0 ± 1.5 years and for the primary ACLR group 7.7 ± 1.6 years. The revision ACLR group reported poorer KOOS scores in all subscales (p < 0.05) except the Symptoms subscale, poorer EQ-5D VAS (mean 79.2 ± 20.1 vs 86.0 ± 20.1, p = 0.012), and less satisfaction with current knee function (median 7 (6-8) vs 8 (7-9), p < 0.001). Patients with revision ACLR also experienced greater limitation in sports (median 7 (4-8) vs 8 (6-9), p < 0.001). There were no significant differences in the EQ-5D (mean 0.86 ± 0.17 vs 0.89 ± 0.11, p = 0.427), activity level (median 2 (2-5) vs 4 (2-7), p = 0.229), or satisfaction with activity level (median 8 (5-9) vs 8 (6-10), p = 0.281) between the groups.

CONCLUSIONS

At a minimum 5-year follow-up, the revision ACLR group reported poorer knee function and quality of life, less satisfaction with knee function and a greater limitation in sports but no differences in activity level and satisfaction with activity level compared with the primary ACLR group.

Histopathological Analysis of the Degree of Tendinosis in Failed Anterior Cruciate Ligament Grafts

INTRODUCTION

After reconstruction of the anterior cruciate ligament, the modification processes in the transplanted tendon tissue directly influence the biomechanical properties of the knee. The histopathological alterations in failed grafts have hardly been studied.

OBJECTIVE

Our study focused on examining the presence and extent of tendinosis (low or high grade) in the tendon tissue of failed anterior cruciate ligament reconstructions. We considered its relationship to the type of transplant, the symptoms, the arthroscopic appearance, the mode of trauma, and the timing of the failure.

MATERIALS AND METHODS

The tendon tissue of failed anterior cruciate ligament reconstructions in 30 patients was gathered during revision surgery and its histopathology was analysed for the occurrence of structural alterations. The classification of the tendinosis as low or high grade was semiquantitative based on five qualities. We used a standardised questionnaire to collect patient data and we used the Marburg Arthroscopy Score for the intraoperative evaluation of the graft.

RESULTS

We found histological vitality and, except for two samples, structural alterations consistent with tendinosis, predominantly high grade, in all failed anterior cruciate ligament grafts. No direct link could be proved between the degree of tendinosis and the type of graft used, the symptoms (except for instability) or the timing of the graft failure, the mode of trauma, or the arthroscopic appearance of the failed plasty. However, the accumulation of high-grade tendinosis in patients with hamstring tendons, subjective instability, and graft failure between 1 to 5 years postoperatively was noteworthy.

CONCLUSION

Structural alterations consistent with tendinosis could be detected, with different expressions, in the vital tendon tissue of anterior cruciate ligament reconstructions. This indicates that the graft is subject to repetitive microtrauma. However, it is still unclear how tendinosis influences the failure of anterior cruciate ligament reconstructions.

Relationship between graft failure following anterior cruciate ligament reconstruction and hamstring autograft diameter

With the increase in the number of individuals participating in sports, anterior cruciate ligament (ACL) injuries are also increasing gradually and the number of patients requiring surgical treatment is increasing in parallel. The primary aim of this study was to investigate the relationship between the need for revision surgery and graft diameter following primary ACL reconstruction (ACLR) using hamstring autografts. The secondary aim of the study was to clarify relationships between anthropometric characteristics and graft diameter. Patients who underwent ACLR with hamstring autografts were included in this retrospective study. The age, body mass index, height, and weight of all patients were recorded preoperatively and the diameters of the grafts were recorded during surgery. The relationship between revision rate and graft diameter and the relationships between anthropometric measurements and graft diameter were investigated for these patients at least one year after surgery. This study included 58 people with graft diameters of ≤7 mm and 261 people with graft diameters of >7 mm. A statistically significant difference was found between the graft diameters of the group that needed revision surgery and the group that did not (p<0.001). A positive relationship was also found between the patient's height and graft diameter (r=0.168). In this study, it was found that the risk of ACL revision surgery increased by 5.5 times among patients with graft diameters of ≤7 mm. The positive relationship between the patient's height and graft diameter can make a significant difference in terms of the need for revision surgery.

Influence of Staphylococcus epidermidis on Collagen Crimp Patterns of Soft Tissue Allograft

BACKGROUND

Postoperative infections, commonly from Staphylococcus epidermidis, may result in anterior cruciate ligament graft failure and necessitate revision surgery. In biomechanical studies, S. epidermidis has been shown to establish biofilms on tendons and reduce graft strength.

PURPOSE/HYPOTHESIS

The goal of this study was to determine the effect of bacterial bioburden on the collagen structure of tendon. It was hypothesized that an increase in S. epidermidis biofilm would compromise tendon crimp, a pattern necessary for mechanical integrity, of soft tissue allografts.

STUDY DESIGN

Controlled laboratory study.

METHODS

Cultures of S. epidermidis were used to inoculate tibialis anterior cadaveric tendons. Conditions assessed included 5 × 10⁵ colony-forming units or concentrated spent media from culture (no living bacteria). Incubation times of 30 minutes, 3 hours, 6 hours, and 24 hours were utilized. Second-harmonic generation imaging allowed for visualization of collagen autofluorescence. Crimp lengths were determined using ImageJ and compared based on incubation time.

RESULTS

Incubation time positively correlated with increasing S. epidermidis bioburden. Both fine and coarse crimp patterns lengthened with increasing incubation time. Significant coarse crimp changes were observed after only 30-minute incubations (P < .029), whereas significant fine crimp lengthening occurred after 6 hours (P < .0001). No changes in crimp length were identified after incubation in media lacking living bacteria.

CONCLUSION

The results of this study demonstrate that exposure to S. epidermidis negatively affects collagen crimp structure. Structural alterations at the collagen fiber level occur within 30 minutes of exposure to media containing S. epidermidis.

CLINICAL RELEVANCE

Our study highlights the need for antimicrobial precautions to prevent graft colonization and maximize graft mechanical strength.

Accuracy of Femoral Tunnel Placement between Anteromedial and Anterolateral Visualisation Portals in Anterior Cruciate Ligament Reconstruction - Outcomes of a CT based Cross-Sectional Study

Introduction

Anatomical femoral tunnel placement is critical for anterior cruciate ligament reconstruction (ACLR). Tunnel placement may vary with different surgical techniques. The aim of this study was to compare the accuracy of femoral tunnel placement between the Anteromedial (AM) and Anterolateral (AL) visualisation portals on post-operative CT scans among a cohort of ACLR patients.

Materials and methods

This cross-sectional study was conducted from January 2018 to March 2020 after obtaining ethics clearance. Patients who went for arthroscopic ACLR in our institute were divided into an AM (group 1) and an AL (group 2) based on the visualisation portal for creating the femoral tunnel and a 3D CT scan was done. The femoral tunnel position was calculated in deep to shallow and high to low direction using the Bernard Hertel grid. Femoral tunnel angle was measured in the 2D coronal image. Statistical analysis was done with the data collected.

Results

Fifty patients with an average age of 26.36 (18-55) years ±7.216 SD were enrolled in the study. In this study, the AM technique was significantly more accurate (p<0.01) than the AL technique in terms of femoral tunnel angle. Furthermore, the deep to the shallow position was significantly (p= 0.018) closer to normative values, as determined by the chi-square test. The chances of error in tunnel angle in femoral condyle are 2.6 times greater in the AL technique (minimal clinical difference).

Conclusion

To conclude, in ACLR the anteromedial visualisation portal can facilitate accurate femoral tunnel placement compared to the anterolateral visualisation portal.

Failure Rates and Complications After Multiple-Revision ACL Reconstruction: Comparison of the Over-the-Top and Transportal Drilling Techniques

Background

Multiple-revision anterior cruciate ligament reconstruction (ACLR) presents several technical challenges, often due to residual hardware, tunnel widening, malposition, or staged surgeries.

Purpose

To compare failure and complication rates between the over-the-top (OTT) and transportal drilling (TD) techniques in patients undergoing surgery for failed revision ACLR.

Study Design

Cohort study; Level of evidence, 3.

Methods

The medical records of patients with at least 2 revision ACLRs using either the OTT or TD technique were reviewed retrospectively. Data on patient demographics, graft characteristics, number of revisions, concomitant procedures, complications, and failures were collected. Between-group comparisons of continuous and categorical variables were conducted with the independent-samples t test and the Fisher exact or chi-square test, respectively.

Results

A total of 101 patients undergoing multiple-revision ACLR with OTT (n = 37, 37%) and TD (n = 64, 63%) techniques were included for analysis. The mean follow-up time was 60 months (range, 12-196 months). There were no significant differences in age, sex, body mass index, laterality, or follow-up length between groups (P > .05). Allograft was the graft used most frequently (n = 64; 67.3%) with no significant differences between groups in graft diameter (P > .05). There were no statistically significant differences between groups regarding rate of concurrent medial and lateral meniscus, cartilage, or lateral extra-articular procedures (P > .05). There was also no significant66 between-group difference in complication rate (OTT: n = 2 [5.4%]; TD: n = 8 [13%]) or graft failure rate (OTT: n = 4 [11%]; TD: n = 14 [22%]) (P > .05 for both).

Conclusion

The results of this study showed notably high failure and complication rates in challenging multiple-revision ACLR. Complication and failure rates were similar between techniques, demonstrating that the OTT technique is a valuable alternative that can be used in a revision ACLR, particularly as a single-stage approach when the single-stage TD technique is not possible.

Effect of Tibiofemoral Rotation Angle on Graft Failure After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Coronal and sagittal malalignment of the knee are well-recognized risk factors for failure after anterior cruciate ligament (ACL) reconstruction (ACLR). However, the effect of axial malalignment on graft survival after ACLR is yet to be determined.

PURPOSE

To evaluate whether increased tibiofemoral rotational malalignment, namely, tibiofemoral rotation angle (TFA) and tibial tubercle-trochlear groove (TT-TG) distance, is associated with graft failure after ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

In this retrospective matched control study of a single center's database, 151 patients who underwent revision ACLR because of graft failure (ACLR failure group, defined as symptomatic patients with anterior knee instability and an ACL graft tear appreciated on magnetic resonance imaging [MRI] and confirmed during arthroscopic surgery) were compared with a matched control group of 151 patients who underwent primary ACLR with no evidence of failure after ≥2-year follow-up (intact ACLR group). Patients were matched by sex, age, and meniscal injury during primary ACLR. Axial malalignment was assessed on preoperative MRI through the TFA and the TT-TG distance. Sagittal alignment was measured through the posterior tibial slope on MRI. The optimal TFA cutoff associated with graft failure was identified by a receiver operating characteristic curve. The Kaplan-Meier curve with log-rank analysis was performed to evaluate the influence of the TFA on ACLR longevity.

RESULTS

The mean age was 25.7 ± 10.4 years for the ACLR failure group and 25.9 ± 10.0 years for the intact ACLR group. Among all the included patients, 174 (57.6%) were male. In the ACLR failure group, the mean TFA was 5.8°± 4.5° (range, -5° to 16°), while it was 3.0°± 3.3° (range, -3° to 15°) in the intact ACLR group (P < .001). Neither the TT-TG distance nor the posterior tibial slope presented statistical differences between the groups. The receiver operating characteristic curve suggested an optimal TFA cutoff of 4.5° for graft failure (area under the curve = 0.71; P < .001; sensitivity, 68.2%; specificity, 75.5%). Considering this a threshold, patients who had a TFA ≥4.5° had 6.6 times higher odds of graft failure compared with patients with a TFA <4.5° (P < .001). Survival analysis demonstrated a 5-year survival rate of 81% in patients with a TFA <4.5°, while it was 44% in those with a TFA ≥4.5° (P < .001).

CONCLUSION

An increased TFA was associated with increased odds of ACLR failure when the TFA was ≥4.5°. Measuring the TFA in patients with ACL tears undergoing reconstruction may inform the surgeon about additional factors that may require consideration before ACLR for a successful outcome.

Nonoperative Treatment for Traumatic Partial Graft Rupture After Anterior Cruciate Ligament Reconstruction: A 2-Year Follow-up Study

Background

There are no studies on the nonoperative treatment of traumatic partial anterior cruciate ligament (ACL) graft rupture.

Purpose/Hypothesis

The purpose of this study was to compare the clinical and radiological outcomes and failure rates between nonoperative treatment and revision ACL reconstruction for traumatic partial ACL graft rupture. We hypothesized that the outcomes and failure rates would be comparable and that nonoperative treatment of traumatic partial ACL graft rupture can produce satisfactory outcomes.

Study Design

Cohort study; Level of evidence, 3.

Methods

We retrospectively evaluated 2114 patients treated for isolated ACL rupture between January 2000 and June 2020. Patients with traumatic partial graft rupture after ACL reconstruction with minimum 2-year follow-up data were included. Patients who met all the following conditions were candidates for nonoperative treatment: (1) Lachman or pivot-shift grade 0 or 1 at 6 months after ACL reconstruction, (2) ACL graft with low to intermediate signal intensity on 1-year postoperative magnetic resonance imaging (MRI), and (3) MRI after reinjury showing definite evidence of trauma, some fibers remaining in continuity of the ACL graft, and no anterior tibial subluxation in the sagittal plane. The patients were divided into 2 groups according to treatment method: nonoperative treatment (group A) and revision ACL reconstruction (group B). Clinical scores, laxity test results, radiological outcomes, and graft failures were compared between the groups.

Results

In total, 47 patients had traumatic partial graft rupture (group A, n = 10; group B, n = 37). There were no significant differences between the 2 groups in terms of clinical scores, laxity tests, radiological outcomes, or graft failure.

Conclusion

The clinical and radiological outcomes of nonoperative treatment of traumatic partial graft rupture after ACL reconstruction were comparable with those of revision ACL reconstruction. Nonoperative treatment of traumatic partial ACL graft rupture can produce satisfactory outcomes in selected patients.

Single Femoral Tunnel for Anterior Cruciate Ligament Reconstruction With Bone-Patellar Tendon-Bone Graft and Lemaire's Extra-Articular Tenodesis as a Good Alternative for Combined Anterior Cruciate Ligament and Anterolateral Ligament Revision Surgeries

The literature has shown a significant decrease in failure rates when the anterior cruciate ligament (ACL) reconstruction was associated with an extra-articular reinforcement technique such as the anterolateral ligament (ALL) or the iliotibial band tenodesis (ITBT) using the modified Lemaire technique. As much as there is a progressive decrease in the failure rates of ACL reconstructions when the ALL reconstruction technique is associated, there are still and will be cases that will result in graft rupture. These cases will require more alternatives for revision, which are always challenging for the surgeon, where the lateral approaches represent complicating factors, especially because of the distortion of the lateral anatomy (by the previous approach for ALL reconstruction), previous reconstruction tunnels, and the presence of fixation materials. We present here a safe technique that offers great stability to the fixation of the graft and is easy to perform, using a single tunnel for the passage of the ACL and ITBT grafts, allowing a single fixation for both. In this way, we performed a lower-cost surgery, with a lower risk of lateral condyle fracture and tunnel confluence. This technique is indicated to be used in cases of revision after failure of combined ACL reconstruction with ALL.

Association of Tibial Tubercle-Trochlear Groove Distance With Risk of ACL Graft Failure

Background

Limited evidence suggests a positive correlation between tibial tubercle-trochlear groove (TT-TG) distance and the risk of native anterior cruciate ligament (ACL) tear. The relationship between TT-TG distance and the risk of ACL graft failure is unknown.

Hypothesis

TT-TG distance is independently associated with risk of ACL graft failure.

Study Design

Cohort study; Level of evidence, 3.

Methods

All patients who underwent ACL revision surgery between 2010 and 2018 at a single institution were identified. A control cohort underwent primary ACL reconstruction (ACLR) between 2006 and 2015, with no evidence of graft failure at 8.1 ± 2.5 years postoperatively. Record review included anthropometrics, graft type, and estimated Tegner activity score at ≥6 months after primary ACLR. Magnetic resonance imaging (MRI) scans after native ACL tear (controls) or graft failure (revision cohort) were assessed for (1) TT-TG distance, (2) proximal tibial slopes, (3) depth of tibial plateau concavity, and (4) tunnel position (revision cohort). Associations between ACL graft failure and MRI measurements, surgical variables, and patient characteristics were evaluated with logistic regression analyses. Sensitivity analyses, excluding patients with tunnel malposition, were performed to confirm multivariable results in patients with "ideal" tunnel placement.

Results

Participants included 153 patients who underwent revisions and 144 controls. Controls were older than the patients who underwent revision (26.6 ± 8.8 vs 20.6 ± 7.3 years; P < .001). The mean TT-TG distance and lateral posterior tibial slope (PTS) were smaller for the control group than for the revision group (TT-TG: 9.3 ± 3.9 vs 11.2 ± 4.2 mm; P < .001; lateral PTS: 6.2° ± 3.3° vs 7.2° ± 3.6°; P = .01). TT-TG distance, lateral PTS, and age were associated with risk of ACL graft failure by multivariable analysis (OR, 1.15; 95% CI, 1.07-1.23; P < .001; OR, 1.13; 95% CI, 1.04-1.22; P = .004; and OR, 0.90; 95% CI, 0.87-0.94; P < .001, respectively). With sensitivity analyses, TT-TG distance, lateral PTS, and age at index surgery remained significantly and independently associated with ACL graft failure.

Conclusion

Increased TT-TG distance, increased lateral PTS, and younger age are independently associated with increased odds of ACL graft failure. Patients with these characteristics may require a more comprehensive strategy to reduce the risk of ACL reinjury.

Anterior cruciate ligament failure and management

Anterior cruciate ligament (ACL) reconstruction failure can be defined as abnormal knee function due to graft insufficiency with abnormal laxity or failure to recreate a functional knee according to the expected outcome. Traumatic ruptures have been reported as the most common reason for failure. They are followed by technical errors, missed concomitant knee injuries, and biological failures. An in-depth preoperative examination that includes a medical history, clinical examinations, advanced imaging, and other appropriate methods is of utmost importance. There is still no consensus as to the ideal graft, but autografts are the favorite choice even in ACL revision. Concomitant meniscal treatment, ligamentous reconstruction, and osteotomies can be performed in the same surgical session to remove anatomical or biomechanical risk factors for the failure. Patient expectations should be managed since outcomes after ACL revision are not as good as those following primary ACL reconstruction.

Revision anterior cruciate ligament reconstruction

Anterior cruciate ligament (ACL) graft failure from rupture, attenuation, or malposition may cause recurrent subjective instability and objective laxity, and occurs in 3% to 22% of ACL reconstruction (ACLr) procedures. Revision ACLr is often indicated to restore knee stability, improve knee function, and facilitate return to cutting and pivoting activities. Prior to reconstruction, a thorough clinical and diagnostic evaluation is required to identify factors that may have predisposed an individual to recurrent ACL injury, appreciate concurrent intra-articular pathology, and select the optimal graft for revision reconstruction. Single-stage revision can be successful, although a staged approach may be used when optimal tunnel placement is not possible due to the position and/or widening of previous tunnels. Revision ACLr often involves concomitant procedures such as meniscal/chondral treatment, lateral extra-articular augmentation, and/or osteotomy. Although revision ACLr reliably restores knee stability and function, clinical outcomes and reoperation rates are worse than for primary ACLr.

Comparison of the Clinical Outcomes of Revision and Primary ACL Reconstruction: A Matched-Pair Analysis With 3-5 Years of Follow-up

BACKGROUND

There are limited studies designed by matching related factors to compare clinical outcomes and return to sport (RTS) between patients undergoing revision anterior cruciate ligament reconstruction (R-ACLR) and primary ACLR (P-ACLR).

PURPOSE

(1) To compare the outcomes between R-ACLR and P-ACLR in a matched-pair analysis with 3- to 5-year follow-up and (2) to evaluate patient-reported factors for not returning to preinjury-level sport.

STUDY DESIGN

Cohort study; Level of evidence, 4.

METHODS

Patients who underwent R-ACLR between September 2016 and November 2018 were propensity matched by age, sex, body mass index, passive anterior tibial subluxation, and generalized hypermobility in a 1:1 ratio to patients who underwent P-ACLR during the same period. By combining in person follow-up at 2 years postoperatively and telemedicine interview at the final follow-up (January 2022), knee stability and clinical scores were compared, including International Knee Documentation Committee (IKDC), Lysholm, and Tegner. Status of RTS was requested, specifically whether the patient returned to preinjury level of sport. Patient-reported reasons for not returning were analyzed.

RESULTS

There were 63 matched pairs in the present study. Knee stability was similar in terms of KT-2000 arthrometer, Lachman test, and pivot-shift test results between the groups at 2 years of follow-up. At the final follow-up, no significant difference was found between groups for postoperative clinical scores (IKDC, Tegner, and Lysholm) (P > .05). There was a significant difference in total RTS: 53 (84.1%) in the P-ACLR cohort and 41 (65.1%) in the R-ACLR cohort (P = .014). No significant difference was shown in terms of RTS at the same level: 35 (55.6%) in P-ACLR and 31 (49.2%) in R-ACLR (P = .476). Significantly more patients showed fear of reinjury: 26 of 32 (81.3%) in the R-ACLR group as compared with 15 of 28 (53.5%) in the P-ACLR group (P < .021).

CONCLUSION

R-ACLR resulted in similar clinical scores (IKDC, Tegner, and Lysholm) but significantly lower RTS versus P-ACLR at 3 to 5 years of follow-up. Fear of reinjury was the most common factor that caused sport changes in patients with R-ACLR.

Scapholunate instability: why are the surgical outcomes still so far from ideal?

The wrist is a universal joint with intrinsic and extrinsic ligaments that function and fail as ligamentous complexes. Those related to scapholunate instability (SLI) include the dorsal scapholunate complex (DSLC), volar radiolunate complex and scaphotrapeziotrapezoid complex. Together the DSLC, scaphoid and lunate create an 'acetabulum' for the capitate, with the dorsal intercarpal ligament being a labrum to contain the capitate. SLI results from failure of the DSLC, typically from its scaphoid attachments. Failure of the lunate and or triquetral attachments increases the instability. DSLC failure leads to radioscaphoid instability, which is the symptomatic clinical problem. SLI reconstruction with open surgery and trans-osseous tendon graft techniques have been challenging. We discuss a biological arthroscopic approach to identify, mobilize and debride the disrupted DSLC. This ligament/capsular/periosteum sheet is then advanced and secured to the debrided footprint. Thereby reconstituting the acetabulum, labrum and scaphoid stability.

Failure modes after anterior cruciate ligament reconstruction: a systematic review and meta-analysis

PURPOSE

The reason for graft failure after anterior cruciate ligament reconstruction (ACLR) is multifactorial. Controversies remain regarding the predominant factor and incidence of failure aetiology in the literature. This review aimed to provide a meta-analysis of the literature to evaluate the relative proportion of various failure modes among patients with ACLR failure.

METHODS

The PubMed, Embase, Cochrane Library, Web of Science, and EBSCO databases were searched for literature on ACLR failure or revision from 1975 to 2021. Data related to causes for ACLR surgical failure were extracted, and a random effects model was used to pool the results, which incorporates potential heterogeneity. Failure modes were compared between different populations, research methods, graft types, femoral portal techniques, and fixation methods by subgroup analysis or linear regression. Funnel plots were used to identify publication bias and small-study effects.

RESULTS

A total of 39 studies were analyzed, including 33 cohort studies and six registry-based studies reporting 6578 failures. The results showed that among patients with ACLR failure or revision, traumatic reinjury was the most common failure mode with a rate of 40% (95% CI: 35-44%), followed by technical error (34%, 95% CI: 28-42%) and biological failure (11%, 95% CI: 7-15%). Femoral tunnel malposition was the most common cause of the technical error (29%, 95% CI: 18-41%), with more than two times higher occurrence than tibial tunnel malposition (11%, 95% CI: 6-16%). Traumatic reinjury was the most common factor for ACLR failure in European populations and in recent studies, while technical errors were more common in Asian populations, earlier studies, and surgery performed using the transtibial (TT) portal technique. Biological factors were more likely to result in ACLR failure in hamstring (HT) autografts compared to bone-patellar tendon-bone (BPTB) autografts.

CONCLUSION

Trauma is the most important factor leading to surgical failure or revision following ACLR. Technical error is also an important contributing factor, with femoral tunnel malposition being the leading cause of error resulting in failure.

Influence of Staphylococcus epidermidis biofilm on the mechanical strength of soft tissue allograft

We sought to determine the impact of bacterial inoculation and length of exposure on the mechanical integrity of soft tissue tendon grafts. Cultures of Staphylococcus epidermidis were inoculated on human tibialis posterior cadaveric tendon to grow biofilms. A low inoculum in 10% growth medium was incubated for 30 min to replicate conditions of clinical infection. Growth conditions assessed included inoculum concentrations of 100, 1000, 10,000 colony-forming units (CFUs). Tests using the MTS Bionix system were performed to assess the influence of bacterial biofilms on tendon strength. Load-to-failure testing was performed on the tendons, and the ultimate tensile strength was obtained from the maximal force and the cross-sectional area. Displacements of tendon origin to maximal displacement were normalized to tendon length to obtain strain values. Tendon force-displacement and stress-strain relationships were calculated, and Young's modulus was determined. Elastic modulus and ultimate tensile strength decreased with increasing bioburden. Young's modulus was greater in uninoculated controls compared to tendons inoculated at 10,000 CFU (p = 0.0011) but unaffected by bacterial concentrations of 100 and 1000 CFU (p = 0.054, p = 0.078). Increasing bioburden was associated with decreased peak load to failure (p = 0.043) but was most significant compared to the control under the 10,000 and 1000 CFU growth conditions (p = 0.0005, p = 0.049). The presence of S. epidermidis increased elasticity and decreased ultimate tensile stress of human cadaveric tendons, with increasing effect noted with increasing bioburden.

No Difference Could Be Detected in Clinical Outcomes of 5-Strand and Quadruple Hamstring Autografts of Similar Diameter in Anterior Cruciate Ligament Reconstruction: A Retrospective Cohort Study

Background: There are few studies examining the clinical outcomes of 5-strand autografts in anterior cruciate ligament reconstruction (ACL-R). Purpose: We aimed to compare the clinical outcomes of ACL-R using 5-strand (5HS) and 4-strand (4HS) hamstring autografts of similar graft diameter to study the potential effects of autograft strand number on clinical outcomes. Methods: Patients who underwent ACL-R from 2013 to 2018 at a single academic institution and received a 4HS or 5HS autograft were included. Exclusion criteria were less than 2-year follow-up and any additional ligamentous reconstruction. Revision ACL-R and cyclops lesions were assessed at a minimum 2 years of postoperative follow-up. Objective measures of ability to return to sport were assessed at 6 months. Results: The mean graft diameters for 4HS (n = 51) and 5HS (n = 23) autografts were 8.3 ± 0.7 mm and 8.4 ± 0.7 mm, respectively. The mean follow-up for the 4HS and 5HS cohorts was 3.0 ± 1.5 years and 3.3 ± 1.3 years, respectively. The 4HS and 5HS cohorts had revision ACL-R rates of 15.7% (8/51) and 8.7% (2/23), respectively. Cyclops lesions occurred in 5.9% of 4HS patients and 13.0% of 5HS patients. We found no statistically significant differences between groups on objective measures of ability to return to sport. Conclusion: This retrospective cohort study detected no difference in revision ACL-R rates, frequency of cyclops lesions, or objective measures of ability to return to sport in patients who received 4HS or 5HS autografts of similar diameter for ACL-R. Further comparative study with larger sample sizes is warranted.

Elevated Posterior Tibial Slope Is Associated With Anterior Cruciate Ligament Reconstruction Failures: A Systematic Review and Meta-Analysis

PURPOSE

To evaluate the association of posterior tibial slope (PTS) with anterior cruciate ligament (ACL) reinjury following primary ACL reconstruction.

METHODS

PubMed, Scopus, Embase, and CINAHL databases were searched from inception through March 1, 2021, to retrieve relevant studies. Comparative studies reporting PTS measurements in a cohort of patients experiencing ACL graft failure versus patients with intact primary ACL reconstruction or studies comparing patients undergoing revision ACL reconstruction versus primary ACL reconstruction were included for analysis. A random-effects model was used to calculate the overall standardized mean difference (SMD) between groups. The following inclusion criteria were used: English language; full text available; Level I, II, or III evidence; studies in humans; and skeletally mature patients.

RESULTS

After we systematically screened 1,912 studies, 15 studies met the inclusion/exclusion criteria. Radiographic measurements were used in 6 studies reporting medial PTS in 411 ACL failures versus 2808 controls. Patients with ACL failure had significantly greater medial PTS compared with controls (SMD 0.50; 95% confidence interval [CI] 0.23-0.77; P < .001). Magnetic resonance imaging (MRI) was used in 9 studies reporting lateral PTS measurements in 641 patients with a failed ACL reconstruction compared with 705 controls. Seven of the MRI studies also measured medial PTS in 552 failures versus 641 controls. Patients with ACL failure had significantly greater lateral PTS on MRI (SMD 0.58; 95% CI 0.13-1.03; P = .012) and medial PTS on MRI (SMD 0.59; 95% CI 0.23-0.96; P = .001) compared with controls.

CONCLUSIONS

The present meta-analysis demonstrated that patients with elevated PTS on radiographs and MRI are at increased risk for ACL graft failure after primary ACL reconstruction.

LEVEL OF EVIDENCE

Level III, meta-analysis of Level III studies.

Revision Soft-Tissue Allograft Anterior Cruciate Ligament Reconstruction Is Associated With Lower Patient-Reported Outcomes Compared With Primary Anterior Cruciate Ligament Reconstruction in Patients Aged 40 and Older

PURPOSE

To evaluate patient-reported outcomes (PROs) and graft failure rates in revision allograft anterior cruciate ligament reconstruction (ACLR) in patients aged 40 and older and compare them with primary ACLRs.

METHODS

Patients aged 40 and older who underwent arthroscopic soft-tissue allograft ACLR between 2005 and 2016 with a minimum 2-year follow-up were retrospectively reviewed. Patients were grouped based on revision versus primary ACLR. The rate of achieving an International Knee Documentation Committee (IKDC) patient acceptable symptom state (PASS) score was recorded. Patient satisfaction, PROs, and graft failure were compared between groups using the χ² test, Fisher exact test, and Mann-Whitney U test.

RESULTS

We identified 32 patients who underwent revision ACLR and 201 patients who underwent primary ACLR aged 40 and older who met inclusion criteria with a mean follow-up of 6.2 and 6.9 years, respectively (P = .042). There was a lower rate of concomitant meniscal repair in the primary ACLR group (6% vs 21.9%, P = .007) There were no other differences in chondral injuries, mechanism of injury, or meniscal injuries between groups. The median IKDC score was greater in the primary ACLR group as compared with the revision ACLR group (83.9 vs 70.6, P < .001). Patients who underwent revision ACLR were less likely to achieve the IKDC PASS threshold (82.5% vs 56.3%, P = .001) and were less likely to report satisfaction as compared with patients who underwent primary ACLR (90.5% vs 78.1%, P =.038). No difference in graft failure rates was identified between groups (8% vs 15.6%, P = .180).

CONCLUSIONS

Revision allograft ACLR in patients aged 40 and older was associated with lower PROs compared with primary ACLR. Patients who underwent revision ACLR failed to meet the IKDC PASS threshold more often and were dissatisfied with procedure results more than twice as often as patients that underwent primary ACLR.

LEVEL OF EVIDENCE

III, retrospective cohort study.

Bridge-Enhanced Anterior Cruciate Ligament Repair for Mid-Substance Tear With Concomitant Lateral Meniscus Radial Repair

In recent years, repair of the injured anterior cruciate ligament (ACL) has been subject to a renewed interest as novel arthroscopic techniques have been developed. Specifically, the bridge-enhanced ACL repair is a technique composed of a resorbable protein-based implant combined with autologous blood that is used to bridge the gap between 2 torn edges of a mid-substance ACL tear. This implant is believed to help facilitate healing of a primary suture repair and suture cinch and has since demonstrated noninferiority to ACL reconstruction with autograft at 2-year follow-up. The purpose of this Technical Note is to describe a step-by-step surgical technique of a mid-substance ACL repair using the bridge-enhanced ACL repair system in a case with a concomitant lateral meniscus radial repair.

Varus collapse following anterior closing wedge proximal tibial osteotomy for ACL revision reconstruction: a case series

A slope-correcting anterior closing wedge proximal tibial osteotomy is a powerful tool for correcting increased posterior tibial slope in the setting of a failed anterior cruciate ligament reconstruction. This case series documents three cases in which patients collapsed into varus following an anterior closing wedge proximal tibia osteotomy. Two patients had osteotomies fixated with a “suture-staple” construct, and all had medical comorbidities or reported noncompliance post-operatively. Therefore, meticulous care during the planning, execution, and rehabilitation phases is critical as multiple factors throughout the arc of care may contribute towards anterior closing wedge proximal tibial osteotomy varus collapse. Careful optimization of medical comorbidities and rigid fixation with either a plate and screws or compression staples should be used rather than a “suture-staple” to mitigate this risk.

Level of evidence: IV.

Arthroscopic Bone Graft Technique for Two-Stage Revision Anterior Cruciate Ligament Reconstruction

Revision anterior cruciate ligament reconstruction is an increasingly common procedure, with 2-stage surgery often required to address large bone defects and malpositioned tunnels. The arthroscopic bone grafting technique described herein uses morselized allograft bone to provide reproducible fill of asymmetrical bone defects without autograft harvest or additional loss of native bone. The second stage of the anterior cruciate ligament reconstruction can typically proceed 6 months following bone grafting.

Trends in Primary Anatomical Single-Bundle Anterior Cruciate Ligament Reconstruction Practice in Adult Patients Prevalent Among Arthroscopy Surgeons of Six Southern States of India

BACKGROUND

Although guidelines from multiple scientific studies decide the general trend in ACLR practice, there is often a variation between scientific guidelines and actual practice.

METHODS

A 17-member committee comprised of sports surgeons with experience of a minimum of 10 years of arthroscopy surgery finalized a survey questionnaire consisting of concepts in ACL tear management and perioperative trends, intraoperative and post-operative practices regarding single-bundle anatomic ACLR. The survey questionnaire was mailed to 584 registered sports surgeons in six states of south India. A single, non-modifiable response was collected from each member and analyzed.

RESULTS

324 responses were received out of 584 members. A strong consensus was present regarding Hamstring tendons preference for ACLR, graft diameter ≥ 7.5 mm, viewing femoral footprint through the anterolateral portal, drilling femoral tunnel from anteromedial portal guided by ridges and remnants of femoral footprint using a freehand technique, suspensory devices to fix the graft in femur and interference screw in the tibia and post-operative bracing. A broad consensus was achieved in using a brace to minimize symptoms of instability of an ACL tear and antibiotic soaking of graft. There was no consensus regarding the timing of ACLR, preferred graft in athletes, pre-tensioning, extra-articular procedure, and return to sports. There was disagreement over hybrid tibial fixation and suture tapes to augment graft.

CONCLUSION

Diverse practices continue to prevail in the management of ACL injuries. However, some of the consensuses reached in this survey match global practices. Contrasting or inconclusive practices should be explored for potential future research.

Controversies in ACL revision surgery: Italian expert group consensus and state of the art

Background

Revision ACL reconstruction is a complex topic with many controversies and not-easy-to-make decisions. The authors’ aim is to provide some feasible advice that can be applied in daily clinical practice with the goal of facilitating the decision-making process and improving the outcomes of patients subjected to revision ACL reconstruction.

Methods

A national survey with seven questions about the most controversial topics in revision ACL reconstruction was emailed to members of two societies: SIOT and SIAGASCOT. The participants’ answers were collected, the most recent literature was analyzed, and a consensus was created by the authors, according to their long-term surgical experience.

Conclusions

The decision-making process in revision ACL reconstruction starts with a standardized imaging protocol (weight-bearing radiographs, CT scan, and MRI). One-stage surgery is indicated in almost all cases (exceptions are severe tunnel enlargement and infection), while the choice of graft depends on the previously used graft and the dimensions of the tunnels, with better clinical outcomes obtained for autografts. Additional procedures such as lateral extra-articular tenodesis in high-grade pivot-shift knees, biplanar HTO in the case of severe coronal malalignment, and meniscal suture improve the clinical outcome and should be considered case by case.

Level of evidence

V (Expert opinion).

Descriptive Characteristics and Outcomes of Patients Undergoing Revision Anterior Cruciate Ligament Reconstruction With and Without Tunnel Bone Grafting

BACKGROUND

Lytic or malpositioned tunnels may require bone grafting during revision anterior cruciate ligament reconstruction (rACLR) surgery. Patient characteristics and effects of grafting on outcomes after rACLR are not well described.

PURPOSE

To describe preoperative characteristics, intraoperative findings, and 2-year outcomes for patients with rACLR undergoing bone grafting procedures compared with patients with rACLR without grafting.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 1234 patients who underwent rACLR were prospectively enrolled between 2006 and 2011. Baseline revision and 2-year characteristics, surgical technique, pathology, treatment, and patient-reported outcome instruments (International Knee Documentation Committee [IKDC], Knee injury and Osteoarthritis Outcome Score [KOOS], Western Ontario and McMaster Universities Osteoarthritis Index, and Marx Activity Rating Scale [Marx]) were collected, as well as subsequent surgery information, if applicable. The chi-square and analysis of variance tests were used to compare group characteristics.

RESULTS

A total of 159 patients (13%) underwent tunnel grafting-64 (5%) patients underwent 1-stage and 95 (8%) underwent 2-stage grafting. Grafting was isolated to the femur in 31 (2.5%) patients, the tibia in 40 (3%) patients, and combined in 88 patients (7%). Baseline KOOS Quality of Life (QoL) and Marx activity scores were significantly lower in the 2-stage group compared with the no bone grafting group (P≤ .001). Patients who required 2-stage grafting had more previous ACLRs (P < .001) and were less likely to have received a bone-patellar tendon-bone or a soft tissue autograft at primary ACLR procedure (P≤ .021) compared with the no bone grafting group. For current rACLR, patients undergoing either 1-stage or 2-stage bone grafting were more likely to receive a bone-patellar tendon-bone allograft (P≤ .008) and less likely to receive a soft tissue autograft (P≤ .003) compared with the no bone grafting group. At 2-year follow-up of 1052 (85%) patients, we found inferior outcomes in the 2-stage bone grafting group (IKDC score = 68; KOOS QoL score = 44; KOOS Sport/Recreation score = 65; and Marx activity score = 3) compared with the no bone grafting group (IKDC score = 77; KOOS QoL score = 63; KOOS Sport/Recreation score = 75; and Marx activity score = 7) (P≤ .01). The 1-stage bone graft group did not significantly differ compared with the no bone grafting group.

CONCLUSION

Tunnel bone grafting was performed in 13% of our rACLR cohort, with 8% undergoing 2-stage surgery. Patients treated with 2-stage grafting had inferior baseline and 2-year patient-reported outcomes and activity levels compared with patients not undergoing bone grafting. Patients treated with 1-stage grafting had similar baseline and 2-year patient-reported outcomes and activity levels compared with patients not undergoing bone grafting.

Practice Patterns for Revision Anterior Cruciate Ligament Reconstruction in an Integrated Health Care System

Background

While surgeons with high caseload volumes deliver higher value care when performing primary anterior cruciate ligament reconstruction (ACLR), the effect of surgeon volume in the revision setting is unknown.

Purposes

To determine the percentage of revision ACLR procedures that comprise the practice of high-, medium-, and low-volume surgeons and to analyze associated referral and practice patterns.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

We retrospectively investigated all revision ACLR procedures performed between 2015 and 2020 in a single health care system. Surgeons were categorized as low (≤17), medium (18-34), or high (≥35) volume based on the number of annual ACLR procedures performed. Patient characteristics, activity level, referral source, concomitant injuries, graft type, and treatment variables were recorded, and a comparison among surgeon groups was performed.

Results

Of 4555 ACLR procedures performed during the study period, 171 (4%) were revisions. The percentage of revision ACLR procedures was significantly higher for high-volume (5%) and medium-volume (4%) surgeons compared with low-volume surgeons (2%) (P < .01). Patients undergoing revision ACLR by a high-volume surgeon had a significantly higher baseline activity level (P = .01). Allografts were used significantly more often by low-volume surgeons (70%) compared with medium-volume (35%) and high-volume (25%) surgeons (P < .01). Bone-patellar tendon-bone (BPTB) and quadriceps tendon (QT) autografts were used significantly more often by high-volume (32% BPTB, 39% QT) and medium-volume (38% BPTB, 14% QT) surgeons compared with low-volume surgeons (15% BPTB, 10% QT) (P < .01). High-volume surgeons were more likely to perform revision on patients with cartilage injuries (P = .01), perform staged revision ACLR (P = .01), and choose meniscal repair (54% high vs 22% medium and 36% low volume; P = .03), despite similar rates of concomitant meniscal tears, compared with low- and medium-volume surgeons.

Conclusion

In this registry study of an integrated health care system, high-volume surgeons were more likely to perform revision ACLR on patients with higher activity and competition levels. Additionally, high-volume surgeons more commonly performed staged revision ACLR, chose meniscus-sparing surgery, and favored the use of autografts compared with low-volume surgeons.

A Biomechanical Comparison of the LaPrade Technique Versus a Novel Technique for Reconstruction of Medial-Sided Knee Injuries

BACKGROUND

Medial-sided knee injuries can lead to symptomatic valgus laxity or anteromedial rotatory instability and may require surgery, particularly in the setting of cruciate tears and tibial-sided medial collateral ligament (MCL) avulsions. The LaPrade (LP) technique utilizes 2 free grafts to reconstruct the superficial MCL (sMCL) and the posterior oblique ligament (POL). An alternative MCL reconstruction devised by the senior author comprises an anatomic single-bundle reconstruction using a free graft to reconstruct the sMCL with advancement and imbrication of the posteromedial capsule/POL (MCL anatomic reconstruction with capsular imbrication [MARCI] technique). These techniques have not been biomechanically compared with one another.

PURPOSE

To identify if one of these reconstruction techniques better restores valgus and rotational medial knee stability throughout the range of motion.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 20 fresh-frozen, male (mean age, 43.7 years [range, 20-63 years]), midfemur-to-toe-matched cadaveric knees were utilized. All reconstructions were performed by a single fellowship-trained sports medicine surgeon. Left and right specimens within matched pairs were randomized to 1 of the 2 treatment groups: LP or MARCI. Each specimen was tested in 3 phases: (1) intact knee, (2) destabilized (MCL and POL completely severed), and (3) reconstructed (post-LP or post-MARCI reconstruction). We quantified valgus angulation defined by medial joint line opening, as well as internal and external tibial rotation at 0°, 20°, 30°, 60°, and 90° of knee flexion under applied external moments/torques at each phase.

RESULTS

There were significant differences between the MARCI and LP reconstruction groups in valgus stability compared with the intact state (P = .021), with the MARCI reconstruction more closely approximating the intact knee. There was no overall difference between the MARCI and LP reconstruction techniques for internal rotation (P = .163), with both closely resembling the intact state. For external rotation, the effect of the reconstruction technique was dependent on the knee flexion angle (P < .001). At the highest angles, there were no differences between reconstructions; however, for lower knee flexion angles, the MARCI technique more closely resembled the intact state.

CONCLUSION

Although both techniques improved knee stability compared with destabilized conditions, the MARCI technique better approximated intact stability during valgus at knee flexion angles from 0° to 90° and external rotation loads at knee flexion angles ≤30° in a cadaveric model.

CLINICAL RELEVANCE

The MARCI technique provides an alternative option to improve valgus stability throughout the range of motion. It utilizes a POL advancement without the potential limitations seen in the LP technique, such as multiple tunnel complexity and collision, particularly in the multiple ligament-injured knee.