Incidence and risk factors for cyclops syndrome after anterior cruciate ligament reconstruction: A systematic literature review

Female Sex, Older Age, Earlier Surgery, Anticoagulant Use, and Meniscal Repair Are Associated With Increased Risk of Manipulation Under Anesthesia or Lysis of Adhesions for Arthrofibrosis After Anterior Cruciate Ligament Reconstruction: A Systematic Review

PURPOSE

To determine what patient or surgical factors are associated with an increased risk of arthrofibrosis requiring manipulation under anesthesia (MUA) or lysis of adhesions (LOA) after anterior cruciate ligament reconstruction (ACLR).

METHODS

A systematic review was performed in adherence to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Cochrane, Embase, and Medline databases were searched for studies published through February 2023. Inclusion criteria were studies that identified risk factors for MUA and/or LOA after ACLR. Studies investigating arthrofibrosis after multiligamentous knee injuries or ACL repair were excluded.

RESULTS

Eleven studies including a total of 333,876 ACLRs with 4,842 subsequent MUA or LOA (1.45%) were analyzed. Increasing age was associated with an increased risk in 3 studies (P < .001, P < .05, P < .01) but was found to have no association another two. Other factors that were identified by multiple studies as risk factors for MUA/LOA were female sex (4 studies), earlier surgery (5 studies), use of anticoagulants other than aspirin (2 studies), and concomitant meniscal repair (4 studies).

CONCLUSIONS

In total, 1.45% of the patients who underwent ACLR and were included in this systematic review had to undergo a subsequent MUA/LOA to treat arthrofibrosis. Female sex, older age, earlier surgery, use of anticoagulants other than aspirin, and concomitant meniscal repair were associated with increased risk of MUA/LOA. The modifiable risks, including use of anticoagulants and time between injury and surgery, can be considered when making treatment decisions.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III-IV studies.

Cyclops syndrome following anterior cruciate ligament reconstruction: Can relapse occur after surgery?

Symptomatic cyclops lesions are complications that can be seen at rates of up to approximately 10% after anterior cruciate ligament reconstruction. However, recurrent cyclops lesions have rarely been documented. There are case rare series in the literature regarding the treatment of recurrent cyclops lesion. Future large studies are needed to investigate factors contributing to the development of cyclops lesions and syndrome and treatment options.

Risk of Revision and Reoperation After Quadriceps Tendon Autograft ACL Reconstruction Compared With Patellar Tendon and Hamstring Autografts in a US Cohort of 21,973 Patients

BACKGROUND

The use of quadriceps tendon (QT) autografts has increased in the past 10 years. However, there remains a dearth of large studies examining the effects of graft selection on anterior cruciate ligament reconstruction (ACLR) that includes QT grafts.

PURPOSE

To evaluate the risk of subsequent surgical outcomes, including revision and reoperation, for a large cohort of patients with primary ACLR according to autograft selection.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Data from a US health care system ACLR registry were used to conduct a cohort study. Primary isolated autograft ACLRs were identified (2012-2021). The exposure of interest was autograft type: QT, bone-patellar tendon-bone (BPTB), and hamstring tendon (HT). Multivariable Cox regression models were used to evaluate the risk of aseptic revision (defined as a subsequent surgery where removal and replacement of the original graft for noninfectious reasons was required) and risk of aseptic reoperation (defined as any subsequent surgery for noninfectious reasons where the graft was left intact) according to autograft selection.

RESULTS

The study sample comprised 21,973 ACLRs performed by 290 surgeons at 53 hospitals. QT, BPTB, and HT autografts were used in 1103 (5.0%), 9519 (43.3%), and 11,351 (51.7%) ACLRs, respectively. In adjusted models, no significant differences were observed in revision risk (hazard ratio [HR], 1.06; 95% CI, 0.60-1.89; P = .837) or reoperation risk (HR, 1.00; 95% CI, 0.70-1.43; P = .993) within 4 years of follow-up when comparing QT ACLR with BPTB ACLR. Additionally, no differences in 4-year revision (HR, 0.62; 95% CI, 0.34-1.12; P = .111) or reoperation (HR, 1.24; 95% CI, 0.85-1.80; P = .262) risks were observed when comparing QT ACLR with HT ACLR. HT ACLRs were noted to have a higher risk of revision (HR, 1.52; 95% CI, 1.25-1.84; P < .001) compared with BPTB ACLRs but a lower risk of reoperation (HR, 0.86; 95% CI, 0.75-0.98; P = .024).

CONCLUSION

In this large multicenter study using data from an ACLR registry, the authors found no difference in the risk of revision or reoperation when QT was compared with BPTB or HT autograft with the numbers available, but they did find a 1.5 times higher risk of revision when HT autograft was compared with BPTB autograft. Surgeons may use this information when choosing the appropriate graft for ACLR in their patients.

Hamstring Anterior Cruciate Ligament Autograft Contributes to a Delayed Symptomatic Cyclops Lesion: A Case Report

Cyclops lesions are characterized as fibroid nodules with granulation tissue that looks similar to a cyclops eye during arthroscopy. These are rare postoperative complications following anterior cruciate ligament reconstruction (ACLR), presenting typically within six months of their reconstruction. This case report presents a 21-year-old male, three years following hamstring autograft ACLR, with a symptomatic cyclops lesion. Contrary to the reported literature, this delayed presentation showed a painful flexion contracture of the knee and intraoperative findings consistent with a cyclops lesion. The treatment consisted of surgical debridement and notchplasty with subsequent posterior medial and lateral meniscal horn repairs. This case report presents a lesson to indicate that cyclops lesions can occur in a delayed setting following ACLR and to show a technique for successful surgical management of the lesion.

Two-stage ligament reconstruction with remnant preservation as treatment of knee dislocation

OBJECTIVE

The purpose of this study was to evaluate the clinical outcomes of two-stage reconstruction (peripheral reconstruction in phase I and central anterior cruciate ligament (ACL) / posterior cruciate ligament (PCL) reconstruction in phase II) with remnant preservation for patients with knee dislocation.

METHODS

A total of 70 patients (10 IIIM, 17 IIIL, and 43 IV) with knee dislocation were randomly divided into the remnant-preserved group and the simple reconstruction group. Patients underwent two-stage reconstruction, including the reconstruction of collateral ligament in phase I and the reconstruction of ACL/PCL in phase II (12 weeks after phase I). Grafts were harvested from the semitendinosus and gracilis tendons from both lower limbs. After the surgery, the joint flexion and extension, bone tunnel and ligament healing, and joint stability were evaluated.

RESULTS

After the surgery, the lateral stability recovered in all patients, and X-ray revealed a good position of bone tunnel. Follow-up was performed at 12 months postoperatively and ranged from 24 to 91 months. At the final follow-up, knee flexion angle, IKDC, Lysholm, and Tegner scores were all higher in both groups compared to the preoperative period. Notably, the remnant-preserved group showed superior results in these parameters compared to the simple reconstruction group. There was statistical significance between the two groups in terms of the Lachman test.

CONCLUSION

The knee function was well recovered after two-stage ligament reconstruction with remnant preservation.

Recurrent cyclops lesion after primary anterior cruciate ligament reconstruction using bone tendon bone allograft: A case report

BACKGROUND

Cyclops lesions are a known complication of anterior cruciate ligament (ACL) reconstruction, with symptomatic cyclops syndrome occurring in up to 11% of surgeries. Recurrent cyclops lesions have been rarely documented; this case study documents the successful treatment of a recurrent cyclops lesion.

CASE SUMMARY

A 28-year-old female presented following a non-contact injury to the right knee. Workup and clinical exam revealed an ACL tear, and arthroscopic reconstruction was performed. Two years later a cyclops lesion was discovered and removed via arthroscopic synovectomy. Seven months postoperatively, the patient presented with pain, stiffness, and difficulty achieving terminal extension. A smaller recurrent cyclops lesion was diagnosed, and a repeat synovectomy was performed. The patient recovered fully.

CONCLUSION

To the best of our knowledge, this is the first documented case of recurrent cyclops lesion after bone-patellar tendon-bone allograft ACL reconstruction presenting as cyclops syndrome.

Risk Factors of Loss of Knee Range of Motion after Primary Anterior Cruciate Ligament Reconstruction following Preoperative Recovery of Knee Range of Motion

The loss of knee range of motion (ROM) is not an uncommon complication after anterior cruciate ligament reconstruction (ACLR). However, the risk factors of loss of knee ROM remain debatable. The purpose of this study was to evaluate the incidence and risk factors of loss of knee ROM at 12 months after primary ACLR performed after regaining full knee ROM preoperatively. Consecutive patients who underwent primary ACLR after regaining full ROM between January 2014 and January 2020 were retrospectively reviewed. Patients who received a surgical arthrolysis within 12 months after ACLR or those who had a loss of knee ROM at 12 months postoperatively were defined as the loss of ROM group. Possible risk factors of loss of knee ROM, including patient demographic, preoperative, surgical, and postoperative factors, were assessed. The notch wide index and radiographic parameters of the tibial spines; medial tibial spine height/tibial length (TL), lateral tibial spine height (LTSH)/TL, and tibial spine width (TSW)/TL, were also assessed. A total of 141 patients (141 knees) were included (mean age, 25.8 ± 11.4 years; male/female, 56/85). Of the 141 patients, three received surgical arthrolysis within 12 months, and 23 had a loss of knee ROM at 12 months after ACLR. On comparing patients with and without loss of knee ROM, significant differences were found in the age (p = 0.04), LTSH/TL (p = 0.02), and TSW/TL (p = 0.02). A multivariate regression analysis showed that the age (odds ratio [OR]; 1.05, 95% confidence interval [CI]: 1.01-1.09, p = 0.02), LTSH/TL (OR: 1.44, 95% CI: 1.01-2.1, p = 0.04), and TSW/TL (OR: 0.79, 95% CI: 0.65-0.97, p = 0.02) were identified as significant independent risk predictors of loss of knee ROM. This study showed that the incidence of loss of knee ROM at 12 months after primary ACLR was 18.4% (26/141). An older age, a higher LTSH/TL, and a smaller TSW/TL may be associated with loss of knee ROM at 12 months after ACLR.

Risk Factors for Symptomatic Cyclops Lesion Formation after Anterior Cruciate Ligament Reconstruction

Objective  To evaluate the incidence of symptomatic cyclops lesions requiring surgical treatment after anterior cruciate ligament (ACL) reconstruction and to establish possible intraoperative risk factors related to it. Methods  Three hundred and eighty-nine patients aged between 18 and 50 years who underwent primary ACL reconstruction were retrospectively evaluated. Patients were divided into groups according to the presence or absence of symptomatic cyclops lesions, and their characteristics were compared. Patients with associated lesions that required additional surgical procedures (except anterolateral extra-articular procedures) were not included. The rate of symptomatic cyclops lesions was recorded and the following parameters were evaluated: age, gender, time from injury to surgery, graft type and diameter, femoral tunnel perforation technique, fixation type, presence of knee hyperextension, preservation of the ACL remnant, associated anterolateral extra-articular procedure, associated meniscal injury and participation in sports. Results  389 patients were evaluated and 26 (6.7%) patients developed cyclops. The patients with and without cyclops lesions did not differ in age, time from injury to surgery, graft type or diameter, surgical technique, femoral fixation method, presence of knee hyperextension, remnant preservation and associated meniscal injury. The group with cyclops lesion had a higher proportion of females (10 (38.4%) vs 68 (18.7%); OR = 2.7; p  = 0.015), higher proportion of extra-articular reconstruction (18 (11.8%) vs 8 (3.4%); OR = 3.8; p  = 0.001) and higher proportion of sports practice (23 (8.6%) vs 3 (2.5%); OR = 3.6; p  = 0.026). Conclusion  In our series, 6.7% of the patients required arthroscopic removal of cyclops lesions. Female gender, associated extra-articular reconstruction and sports practice were factors related to this lesion. Remnant preservation had no relationship with cyclops lesion formation.

The Presence of a 'Sentinel' Vessel as an Anatomical Reference during Hamstring Tendon Harvesting-A Prospective Study

BACKGROUND

The identification of the branch of the inferior medial genicular artery (bIMGA) in anterior cruciate ligament reconstructions (ACLRs) has previously been considered a landmark by some surgeons, but its consistency remains debated. The aim of this investigation was to evaluate the variability in the appearance and location of bIMGA and to assess its validity as a reliable landmark during hamstring tendon harvesting procedures.

METHODS

This prospective, single-center study comprised 213 patients who underwent ACLR over a period of two years. The surgical procedures were conducted by the same surgical team, maintaining uniformity in the approach. The study sought correlations between patient demographics, level of activity, and the potential for successful identification of the bIMGA.

RESULTS

A statistically significant association between patient activity levels and successful identification of the bIMGA (p = 0.035) was observed. No significant correlations were found concerning patient demographic characteristics. bIMGA demonstrated a substantial degree of anatomical variability, rendering its consistent identification in the surgical field challenging.

CONCLUSIONS

Given the observed variability and the associated difficulty in its identification, the use of the bIMGA as a dependable anatomical reference during ACL graft harvesting is not recommended. This study confirms the inconsistency of bIMGA as a traditional landmark, underscoring the need for research aimed at identifying more consistent and reliable anatomical references to enhance the precision of surgical interventions in ACLR.

Editorial Commentary: Risk Factors of Cyclops Syndrome in Quadriceps Autograft Anterior Cruciate Ligament Reconstruction: More Helpful Data in Weighing Graft Choice

Arthrofibrosis after anterior cruciate ligament (ACL) reconstruction can be a devastating complication with risk factors and causes not well established. Cyclops syndrome is a subtype involving localized scar anterior to the graft, which is typically treated with arthroscopic debridement. ACL quadriceps autograft is a newly popular graft option for which clinical data continue to develop. However, recent research shows possible increased risk of arthrofibrosis with quadriceps autograft. Possible causes include inability to achieve active terminal knee extension after extensor mechanism graft harvesting; patient characteristics, including female sex, and social, psychological, musculoskeletal, and hormonal differences; larger graft diameter; concomitant meniscus repair; exposed collagen fibers of the graft abrading the fat pad or tibial tunnel or intercondylar notch; smaller notch size; intra-articular cytokine; and biomechanical stiffness of the graft.

Postoperative regular use of a self-rehabilitation mobile application for more than two weeks reduces extension deficit and cyclop syndrome after anterior cruciate ligament reconstruction

PURPOSE

To investigate the minimum use that correlates with the best outcomes in term of complications associated with self-directed rehabilitation mobile application and to explore the user profile and usage habits.

METHODS

This was a single-center retrospective study of 356 patients who underwent ACL reconstruction surgery between November 2019 and August 2020. Complications were defined as the presence of an extension deficit ≥ 5° after 6 weeks and/or the presence of cyclops syndrome. The demographics, sports competition level and number of connections were collected by the application.

RESULTS

The complication rate was reduced 4.2-fold with at least 2 weeks of use (2.4% (3/123) (with 0.8% (1/123) of cyclops syndrome) versus 10.8% (23/212) (with 3.3% (7/212) cyclops syndrome), p = .04). The mean duration of use was 20 ± 23 days with a frequency of 2.1 ± 2.3 connections per day. The usage rate was 50% in week 1, 35% in week 2, and 24% in week 3. There was one peak in the abandon rate during the first few days of use and a second peak at Day 10 when physiotherapy sessions started. There were two dips in the abandon rate associated with the follow-up visits at Days 21 and 45. Greater use was found in older patients (p = .0001) and female patients (p = .04).

CONCLUSIONS

When using the application for a minimum of 2 weeks, the risk of complications was reduced 4.2-fold. The typical users of a self-directed rehabilitation application after ACL surgery in this study were women and patients over 30 years of age.

LEVEL OF EVIDENCE

IV, retrospective.

Less than 1% risk of donor-site quadriceps tendon rupture post-ACL reconstruction with quadriceps tendon autograft: a systematic review

PURPOSE

The purpose of this study is to develop a comprehensive complications profile for quadriceps tendon-autograft anterior cruciate ligament reconstruction (QT ACL-R).

METHODS

A traditional and grey literature search was conducted in accordance with PRISMA and R-AMSTAR guidelines. PubMed, EMBASE, MEDLINE, CINAHL, Cochrane, Web of Science, and many grey literature sources were searched from inception to May 29, 2022. All studies were searched and screened in duplicate with included studies being of all levels of evidence, reporting complications, and with patients of all ages undergoing primary ACL reconstruction with quadriceps tendon autograft in the last 15 years. Studies were excluded if they had cadaveric or animal subjects or were reviews. Risk of bias assessment was conducted using MINORS criteria for non-randomised studies and Cochrane's RoB 2.0 for randomised studies. Data were summarised with weighted event rates generated under a random-effects model.

RESULTS

A total of 55 studies (5315 reconstructions) were included: 32 used quadriceps tendon with bone block (B-QT), 19 used all-soft tissue quadriceps tendon (S-QT), and four did not report the QT graft subtype used. Included patients had an age range of 6.2-58 years and an average reported follow-up time of 28.1 months (range, 6-90 months) for non-randomised studies and 34.3 months (range, 0.233-120 months) for randomised studies. Pooled incidence rates for clinically relevant major complications included contralateral ACL injury at 6.0%, postoperative meniscal issues at 5.4%, cyclops lesions at 4.8%, graft failure at 4.1%, patellar fracture at 2.2%, hardware removal at 1.7%, infection at 1.5%, and donor-site quadriceps tendon rupture at 0.7%. Pooled incidence rates for clinically relevant minor complications included anterior knee pain at 9.7%, kneeling pain at 9.5%, sensation deficits at 4.4%, loss of extension at 4.2%, donor-site tendinopathy at 3.9%, cosmetic issues at 1.8%, and hematoma at 1.5%.

CONCLUSIONS

QT ACL-R resembles other graft types in its rates and types of postoperative complications. In this exploratory systematic review, no complications of QT ACL-R were found to be disproportionately represented in the literature. This graft type should remain an option with comparable complication rates to other graft choices.

LEVEL OF EVIDENCE

Level IV.

REGISTRATION

This study was preregistered under PROSPERO with preregistration code CRD42022302078.

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.

Association of COVID-19 Lockdown With Increased Rate of Cyclops Syndrome in Patients With Unexpected Home-Based Self-Guided Rehabilitation After ACL Reconstruction

Background

The risk of cyclops syndrome increases significantly after anterior cruciate ligament (ACL) reconstruction (ACLR) if complete extension is not recovered before the sixth postoperative week. The lockdown in France due to the COVID-19 pandemic led to an absence of supervised rehabilitation, requiring unexpected self-rehabilitation in patients who underwent ACLR just before lockdown.

Purpose

To determine the rate of cyclops syndrome after ACLR in patients who underwent self-rehabilitation during lockdown.

Study Design

Cohort study; Level of evidence, 3.

Methods

A total of 75 patients receiving a hamstring graft for ACLR during the COVID-19 pandemic between February 10, 2022, and March 16, 2020, carried out self-rehabilitation during part of their first 6 postoperative weeks using exercise videos on a dedicated website. Clinical examination was performed at a minimum 1-year follow-up with International Knee Documentation Committee (IKDC), Lysholm, Tegner, and ACL-Return to Sport after Injury (ACL-RSI) scores. This group was compared with a matched-pair control group of 72 patients who underwent surgery in 2019 and completed postoperative supervised rehabilitation with a physical therapist. Rates and reasons for second surgery (arthrolysis, meniscal procedure) were also recorded.

Results

In the COVID group (n = 72; 3 patients were lost to follow-up), the mean follow-up was 14.5 ± 2.1 months (range, 13-21) and rate of reoperation for clinical cyclops syndrome was 11.1% (n = 8). The rate of cyclops syndrome was significantly lower (1.4%) in the control group (P = .01). In the COVID group, 8 patients underwent anterior arthrolysis at a mean of 8.6 months after the primary surgery, and 4 patients underwent another surgical intervention (meniscal procedure [n = 3], device removal [n = 1]). In the COVID group, mean Lysholm was 86.6 ± 14.1 (range, 38-100), Tegner was 5.6 ± 2.3 (range, 1-10), subjective IKDC was 80.3 ± 14.7 (range, 32-100) and ACL-RSI score was 77.3 ± 19.7 (range, 33-100).

Conclusion

The rate of cyclops syndrome after ACLR was significantly greater in the COVID group versus the matched controls. The dedicated website was not effective at supporting self-guided rehabilitation and could benefit from interactive improvements so it is at least as effective as supervised rehabilitation.

An analysis of the incidence, risk factors, and timing of development of cyclops lesions after anterior cruciate ligament reconstruction

BACKGROUND

Cyclops lesions are a known complication following anterior cruciate ligament reconstruction (ACLR) with a described incidence between 1.9% to 10.9%. The objective of this study was to identify the incidence, timing, and variables that correlated with development of a cyclops lesion, and if objective functional testing differed between patients with and without cyclops lesions.

METHODS

313 consecutive patients who underwent ACLR and participated in Lower-Extremity Assessment Protocol (LEAP) testing at a single, academic institution were analyzed. Retrospective chart review was performed to identify patient demographic factors, medical comorbidities, and potential peri-operative risk factors. Postoperative functional outcome metrics and patient reported outcomes were collected per the institution's LEAP testing protocol. Binary logistic regression was utilized to identify risk factors for cyclops lesions. Objective functional outcomes and patient reported outcomes were compared between patients with and without cyclops lesions.

RESULTS

23/313 (7.35%) patients developed a cyclops lesion following ACLR, of which 17 (73.91%) were found to be symptomatic. Concomitant meniscal repair correlated with an increased likelihood of developing a cyclops lesion (p = 0.040); no other risk factors significantly differed between cohorts. There were no clinically relevant extension deficits or differences in objective functional performance measures at six months post-operatively between study cohorts.

CONCLUSIONS

Concomitant meniscal repair may be associated with the development of cyclops lesions due to restrictive postoperative range of motion protocols; however no other pre- or intra-operative factors demonstrated significant correlation. Presence of a cyclops lesion should be considered with late loss of knee extension after ACLR.

Bone-patellar tendon-bone autograft and female sex are associated with the presence of cyclops lesions and syndrome after anterior cruciate ligament reconstruction

PURPOSE

Associated risk factors for the development of cyclops lesions have been little. Investigated, because most previous studies have limited their research to cases with symptomatic cyclops lesions (cyclops syndrome). The purpose of this study was to evaluate the presence of cyclops lesions using magnetic resonance image (MRI) at 6 and 12 months after anterior cruciate ligament reconstruction (ACL-R), and to investigate the associated risk factors of cyclops lesions and syndrome.

METHODS

A retrospective analysis of patients who underwent ACL-R using bone-patellar tendon-bone (BTPB) or hamstring tendon autograft from 2008 to 2017 was conducted. Predictor variables (age, sex, body mass index [BMI], time from injury to ACL-R, preinjury Tegner activity score, graft, meniscal and cartilage injury, and notch width index on MRI for the presence of cyclops lesions and syndrome were analyzed with multivariate logistic regression.

RESULTS

Four hundred and fifty-five patients (225 males and 230 females) were enrolled. One hundred and four patients (22.9%) had cyclops lesions, and all cyclops lesions were detected on MRI at 6 months post-operatively. In addition, 20 patients (4.4%) had cyclops syndrome which means that these were symptomatic cases. The risk factors for presence of cyclops lesions were BPTB autograft (OR = 2.85; 95% CI 1.75-4.63; P < 0.001) and female sex (OR = 2.03; 95% CI 1.27-3.25; P = 0.003). The presence of cyclops syndrome increased with graft (BPTB) (OR = 18.0; 95% CI 3.67-88.3; Powered by Editorial Manager^® and ProduXion Manager^® from Aries Systems Corporation P < 0.001), female sex (OR = 3.27; 95% CI 1.07-10.0; P = 0.038), and increased BMI (OR = 1.21; 95% CI 1.05-1.39; P = 0.008).

CONCLUSIONS

All cyclops lesions were detected 6 months after ACL-R, and the majority of them were asymptomatic. BPTB autograft and female sex were the significant risk factors for the presence of cyclops lesions and syndrome. In addition, increased BMI was associated with a higher risk of developing cyclops syndrome. When BPTB autograft is used for a female patient, full active knee extension should be encouraged in the early period after ACL-R to prevent cyclops lesion formation.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Range of Motion, Strength, and Function After ACL Reconstruction Using a Contralateral Patellar Tendon Graft

BACKGROUND

Regaining preinjury levels of activity and progressing rehabilitation factors after anterior cruciate ligament (ACL) reconstruction have shown mixed results.

PURPOSE

To evaluate the timing and rate of return for knee range of motion (ROM), stability, strength, and subjective scores after ACL reconstruction with contralateral patellar tendon graft (PTG).

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Included were 2148 patients (1238 male patients, 910 female patients) who underwent primary ACL reconstruction with a contralateral PTG between 1995 and 2017 and had complete objective data through 3 months of follow-up. All patients participated in a rehabilitation program specific to goals for each knee. Patients were evaluated objectively with goniometric measurement of ROM, isokinetic quadriceps strength testing, and laxity with a KT-2000 arthrometer. Subjective data were collected at 2 and 5 years.

RESULTS

Normal extension on the reconstructed knee was attained for 95% of patients at 1 week postoperatively; normal flexion on the reconstructed knee was reached by 77% of patients by 3 months. At 3 months postoperatively, mean limb symmetry index strength was 104%, and the strength on the ACL-reconstructed and graft-donor knees was 87% and 86% of their respective preoperative strength. Mean manual maximum side-to-side difference in laxity was 2.0 mm at 1 month. Most patients (90%) returned to level 8 sports or higher and did so at an average of 5.7 months. Mean International Knee Documentation Committee scores for the ACL-reconstructed and graft-donor knees were 89 and 91 at 2 years (n = 1015 patients) and 84 and 90 at 5 years (n = 1275 patients), respectively. Mean Cincinnati Knee Rating Scale scores for the ACL-reconstructed and graft-donor knees were 92 and 96 at 2 years (n = 1184) and 88 and 94 at 5 years (n = 1236), respectively.

CONCLUSION

For patients who underwent ACL reconstruction with a contralateral PTG, postoperative ROM and strength were restored quickly by splitting the rehabilitation into different goals between the two knees. Using a contralateral PTG, this structured rehabilitation plan can lead to a relatively quick return to sport and good subjective long-term outcomes.

Quadriceps Tendon Anterior Cruciate Ligament Reconstruction: A Systematic Review of Postoperative Rehabilitation and Complication Profiles

PURPOSE

The purposes of this study are to explore current elements for postoperative rehabilitation protocol after quadriceps tendon-anterior cruciate ligament reconstruction (QT-ACLR), outline general timelines for progression of those elements, and explore their associated complication rates and profiles.

METHODS

In accordance with PRISMA guidelines, 5 online databases (EMBASE, MEDLINE, CINAHL, Cochrane, and PubMed) were searched and screened in duplicate using predetermined criteria for studies on the aforementioned patient population. Descriptive statistics are presented.

RESULTS

A total of 56 studies were included, with 31 studies using quadriceps tendon with bone block (B-QT) and 26 studies using all-soft tissue quadriceps tendon (S-QT). The majority of studies permitted full weightbearing and range of motion (ROM) within the first 12 postoperative weeks, and motion-controlled braces within 6 weeks. Isometric exercises were initiated within 1 week after surgery, closed-chain exercises within 12 weeks, and open-chain and sports-specific exercises within 36 weeks. Complication profiles were similar between graft types and included graft failure (1.2%-1.6%), cyclops syndrome (0.4%-0.7%), and persistent stiffness (0.9%).

CONCLUSIONS

Current postoperative rehabilitation strategies in ACLR with QT offer a complication profile comparable to those reported with other graft types. Based on the included rehabilitation regimen, these protocols should focus on early ROM, specifically on achieving full extension, alongside isometric quadriceps strengthening. Progression to closed- and open-chain exercises should follow in a progressive manner, similar to existing protocols in ACLR. Adjuncts such as motion-controlled bracing and continuous passive motion machines may be used if graft protection is prioritized. This review highlights the need for comparison of defined protocols against one another in the setting of QT-ACLR.

LEVEL OF EVIDENCE

IV, systematic review of Level I-IV studies.

Early Return to Play After Anterior Cruciate Ligament Reconstruction: Is It Worth the Risk?

Objective

To compare the outcomes of a 6-month-long accelerated rehabilitation with a 12-month-long rehabilitation. There is no consensus on the optimal duration of rehabilitation after anterior cruciate ligament reconstruction (ACLR). Trends in the past decades have shifted towards accelerated programs, often resulting in a return to play (RTP) at 4–6 months, postoperatively. However, longer rehabilitation cycles have recently experienced renaissance due to a greater understanding of graft remodeling.

Methods

Adult athletes who underwent ACLR between 2015 and 2018 by the same surgeon were included and followed-up prospectively for 24 months. Participants were allocated into two groups based on their RTP (6 months vs. 12 months) and compared with graft elongation, reoperation rate, and sports career (quit or continue) outcomes.

Results

Fifty-four patients underwent accelerated rehabilitation and 92 completed conventional rehabilitation. The accelerated rehabilitation was significantly associated with graft elongation—the accelerated rehabilitation group (n=9) and the conventional rehabilitation group (n=0), p<0.001—and need for reoperation—the accelerated rehabilitation group (n=5) and the conventional rehabilitation group (n=1), p=0.026. Although the relationship between rehabilitation time and quitting competitive sports did not reach significance at 0.05 level (p=0.063), it was significant when p<0.1, thereby showing a clear trend.

Conclusion

Accelerated rehabilitation increased graft elongation risk. Knee laxity ≥3 mm measured at 6 months after ACLR should be accompanied by RTP time frame re-evaluation. Arthrometry checkups or routine magnetic resonance imaging shortly after RTP may be considered in cases of accelerated rehabilitation.

Femoral intercondylar notch: Accuracy of a novel MRI measurement protocol

OBJECTIVE

The most common mechanical complication following an anterior cruciate ligament (ACL) reconstruction is joint stiffness, due in part to cyclops syndrome. A narrow intercondylar notch is an anatomical risk factor. A reliable preoperative notch measurement would help anticipate proper graft size, or plan a notchplasty during the ligament reconstruction, if necessary. No study has yet assessed the accuracy of the methods used to measure notch size.

HYPOTHESIS

The novel measurement protocol proposed in this study would be more reproducible than the reference technique.

METHODS

A total of 20 preoperative knee MRIs performed during the assessment of an ACL rupture were randomly selected. The notch size was measured using 2 methods: traditional (ratio of the notch and metaphyseal widths measured on a line drawn through the popliteal groove) and novel. The latter was measured using the same ratio but took into account the notch width in its proximal third, according to a coronal slice that passes through the ACL tibial attachment. Three orthopedic surgeons with different levels of experience (senior surgeon, junior surgeon and surgical resident) performed these measurement protocols twice on anonymized MRI scans, 10days apart. Spearman's rank correlation coefficient was used to assess the intraobserver correlations and a concordance index was used to assess the interobserver correlations. The influence of the second MRI reading was analyzed with a bootstrap test.

RESULTS

The mean intraobserver reliability was 0.73 for the reference method and 0.83 for the proposed method. The values of the bootstrap tests were higher for the proposed method (0.45 vs. 0.45 and 0.70; p<05 for interobserver; 0.49 vs. 0.69 and 0.62; p<05 for intraobserver).

CONCLUSION

The proposed measurement protocol showed a higher reproducibility in assessing notch size than the traditional method. This technique therefore provides a reliable assessment of the intercondylar notch width.

LEVEL OF EVIDENCE

IV; retrospective study.

Significant risk of arthrolysis after simultaneous anterior cruciate ligament reconstruction and treatment of dislocated bucket-handle meniscal tear

INTRODUCTION

Postoperative stiffness is a feared complication after anterior cruciate ligament (ACL) reconstruction. In case of associated dislocated bucket-handle meniscal tear (BHMT), reduction is urgent, with ligament reconstruction in the same surgical step.

HYPOTHESIS

Treatment of associated dislocated BHMT in ACL reconstruction incurs increased risk of arthrolysis for stiffness in flexion and/or extension.

MATERIAL AND METHODS

A retrospective exposure/non-exposure study included 208 patients undergoing ACL reconstruction between January 2009 and December 2018. Those showing dislocated medial or lateral BHMT at surgery (group A) were compared versus those free of meniscal lesions (group B). The main objective was to assess the risk of surgical revision for arthrolysis within 12 months. Group A included 69 patients: 40 male (58%), 29 female (42%); mean age, 29.0±11.2 years. Group B included 139 patients: 68 male (49%), 71 female (51%); mean age, 30.0±10.4 years. Patients were classified according to age of ACL tear, as acute (<6 weeks), subacute (6 weeks to 6 months), or chronic (>6 months).

RESULTS

Risk of revision surgery for arthrolysis was greater in Group A than in Group B, with 7 (10.1%) and 4 (2.9%) cases respectively (p=0.044), with 12-month arthrolysis-free survival of 89.7% (95% CI, 82.7-97.2) and 97.1% (95% CI, 94.3-99.9) respectively (p=0.023). Stiffness in flexion and extension was more frequent in Group A at 6 weeks and at 6 months (p>0.05). Risk of arthrolysis did not significantly differ according to accident-to-surgery time in the overall series (p=0.421) or specifically in Group A (p=0.887). The BHMT was sutured in 39 cases (56.5%), including 3 failures (7.7%) at 12 months' follow-up. Arthrolysis was required in 6 patients treated by meniscal suture (15.4%) and just 1 patient treated by meniscectomy (3.3%) (p=0.128).

CONCLUSION

The present study confirmed increased risk of surgical revision for arthrolysis after ACL reconstruction in case of dislocated BHMT treated in the same surgical step. Age of ACL tear and type of BHMT treatment (suture or meniscectomy) showed no impact on postoperative stiffness.

LEVEL OF EVIDENCE

IV, retrospective exposure/non-exposure cohort study.

The importance of continuous remnant preservation in anterior cruciate ligament reconstruction

PURPOSE

Selective anteromedial or posterolateral bundle reconstruction is recognized as a treatment modality in partial anterior cruciate ligament (ACL) reconstruction (ACLR) with a biomechanically sufficient ACL remnant. However, there is paucity in literature investigating clinical outcomes of standard ACLR with preservation of residual continuous but biomechanically insufficient ACL tissue. The aim of this study was to investigate the influence of preservation of residual continuous but biomechanical insufficient ACL tissue in standard ACLR on complication and repeat surgery rate, and patient reported and clinical outcome.

METHODS

The retrospective cohort comprised 134 patients (age 23 ± 7 years; Tegner 6 ± 3) with an isolated acute ACL tear. In 67 patients, residual continuous but biomechanically insufficient ACL tissue was present and preserved based on visual inspection, probing of the ACL tissue and Lachman test under arthroscopic view (standard reconstruction with tissue preservation; SRTP). These patients were matched to 67 patients that underwent ACLR where no residual ACL tissue could be preserved (standard reconstruction; SR) based on gender, age and chondral and/or meniscal status. Clinical failure (recurrent instability, pathological ACL graft laxity and/or ACL graft discontinuity), other complication and repeat-surgery rate within index surgery and 1-year and within index surgery and 2-year follow-up, and patient reported and clinical outcomes at 1-year and at 2-year follow-up were compared.

RESULTS

A statistically significant lower clinical failure rate within index surgery and 1-year (SRTP, 3%; SR, 13%; P = 0.028) and within index surgery and 2-year follow-up (SRTP, 3%; SR, 23%; P = 0.001), and revision ACL surgery rate within index surgery and 1-year (SRTP, 2%; ST, 10%; P = 0.029) and within index surgery and 2-year follow-up (SRTP, 2%; SR, 18%; P = 0.001) was found in the SRTP group. No statistically significant differences were found for other investigated outcomes in patients that were without clinical failure.

CONCLUSION

This study shows that in ACLR surgery, preservation of residual continuous but biomechanical insufficient ACL tissue might lead to lower clinical failure rate and ACL revision surgery rate within index surgery and 1-year, and within index surgery and 2-year follow-up compared to standard ACLR where no residual continuous ACL tissue could be preserved.

LEVEL OF EVIDENCE

III.

Both arthroscopic and open posterior knee capsulotomy are effective in terms of extension recovery and functional improvement-systematic review

PURPOSE

To assess the recovery of extension and improvement in functional scores after an arthroscopic or open posterior knee capsulotomy in the setting of an extension deficit.

METHODS

A systematic search of articles published between 1980 and 2020 was performed in the MEDLINE/PubMed database, EMBASE/Ovid database and Web of Science database. The inclusion criteria consisted of patients with primary extension deficits > 5° who underwent an arthroscopic or open posterior knee capsulotomy. The assessed outcomes were preoperative and postoperative range of motion and functional outcome scores. Randomized controlled trials, cohort studies and case series with a follow-up longer than 6 months were included. The risk of bias was assessed using the Joanna Briggs Institute critical appraisal tool for case series. The certainty of evidence was assessed using the GRADE approach.

RESULTS

Of 226 records identified through database searching, 7 studies were included in the final analysis. The outcomes of 107 patients with a mean age of 34.1 (range 15-63) years were available. In all the included studies, a posterior capsulotomy resulted in the restoration of knee extension to normal or nearly normal values (mean postoperative extension deficit: 0.4-4.2 degrees) with a significant increase in functional outcome scores. No neurovascular complications were reported within the studies. Due to the diverse methodology of studies, the direct comparison of arthroscopic versus open approaches was not possible. Concerning the risk of bias assessment, the greatest concerns raised the selection of participants among the included studies and the methods of outcome measurement. The certainty of evidence was very low according to the GRADE.

CONCLUSIONS

Both arthroscopic and open posterior capsulotomy of the knee results in restoration of normal or nearly normal knee extension and significant improvement in functional outcomes.

LEVEL OF EVIDENCE

IV.

Excision of a Knee Cyclops Lesion Using a Needle Arthroscope

After anterior cruciate ligament (ACL) reconstruction surgery, achieving full range of motion and strength of the postoperative knee is critical for optimal surgical outcomes. Abnormal tissue growth and scar formation in the postoperative knee can create a block to terminal extension of the knee. Cyclops lesions are areas of granulation tissue with neovascularization and fibrous tissue formation peripherally, most commonly at the anterolateral aspect of the tibial graft site after ACL reconstruction. When these lesions block terminal extension and cause mechanical symptoms, cyclops syndrome is diagnosed, and secondary knee arthroscopy is often performed to remove this tissue to allow for full range of motion. This Technical Note describes a minimally invasive approach with the NanoScope. The NanoScope allows for decreased postoperative pain and swelling with a likely quicker recovery back to normal postoperative therapy.

Early postoperative practices following anterior cruciate ligament reconstruction in France

INTRODUCTION

The early postoperative period after anterior cruciate ligament reconstruction (ACL) is critical for optimal functional recovery. Despite an abundance of literature, there is no consensus regarding good practices. This period is often under-considered by orthopedic surgeons. The aim of this study was to identify early postoperative practices after ACL reconstruction in France.

HYPOTHESIS

The hypothesis was that there was a discrepancy between validated data in the literature and the current practices of orthopedic surgeons in France.

MATERIAL AND METHODS

In 2019, a questionnaire was sent to all the members of the French Arthroscopy Society to investigate their postoperative practices after ACL reconstruction. Two hundred sixty-nine members responded. Surgeons were divided into two groups of experienced (n=137) and less experienced (n=132) surgeons, according to the number of ACL reconstructions performed per year (<or≥50/year). Outpatient management, effusion prevention measures, and rehabilitation instructions and goals were collected. Overall responses were analyzed after multiple linear logistic regression and the responses of the two groups were compared.

RESULTS

ACL reconstruction was performed as an outpatient procedure in 72.9% of cases. This rate increased with surgical experience (p=0.009×10^-3). Among measures to prevent effusion, cryotherapy was recommended in 97.8% of cases. The experienced group more often used compressive cryotherapy devices (p=0.004). Rehabilitation was started immediately in 75.5% of cases, with as main objective recovery of full extension (89.6%). Weight-bearing was allowed in 98.5% of cases and a brace was prescribed in 69.9% of cases. In the experienced group, braces were less frequent (p=0.02) and self-rehabilitation was preferred (p=0.0006).

CONCLUSION

Early postoperative practices after ACL reconstruction in France are related to surgical experience. The greater the surgical experience, the greater the role of joint effusion prevention and self-rehabilitation. Despite recommendations in the literature, a quarter of the French orthopedic surgeons who responded to this survey did not perform this procedure on an outpatient basis and more than two-thirds prescribed braces.

LEVEL OF EVIDENCE

IV.

Current and future of anterior cruciate ligament reconstruction techniques

In recent years, anterior cruciate ligament (ACL) reconstruction has generally yielded favorable outcomes. However, ACL reconstruction has not provided satisfactory results in terms of the rate of returning to sports and prevention of osteoarthritis (OA) progression. In this paper, we outline current techniques for ACL reconstruction such as graft materials, double-bundle or single-bundle reconstruction, femoral tunnel drilling, all-inside technique, graft fixation, preservation of remnant, anterolateral ligament reconstruction, ACL repair, revision surgery, treatment for ACL injury with OA and problems, and discuss expected future trends. To enable many more orthopedic surgeons to achieve excellent ACL reconstruction outcomes with less invasive surgery, further studies aimed at improving surgical techniques are warranted. Further development of biological augmentation and robotic surgery technologies for ACL reconstruction is also required.

Analysis of intercondylar notch size and shape in patients with cyclops syndrome after anterior cruciate ligament reconstruction

Background

Cyclops lesion is the second most common cause of extension loss after anterior cruciate ligament reconstruction. This study focused on the correlation between the anatomy of the intercondylar notch and the incidence of cyclops lesion. To determine whether the size and shape of the intercondylar notch are related to cyclops lesion formation following anterior cruciate ligament reconstruction according to magnetic resonance imaging (MRI) findings.

Methods

One hundred twenty-five (125) patients were retrospectively evaluated. The notch width index (NWI) and notch shape index (NSI) were measured based on coronal and axial MRI sections in patients diagnosed with cyclops syndrome (n = 25), diagnosed with complete anterior cruciate ligament (ACL) tears (n = 50), and without cyclops lesions or ACL ruptures (n = 50).

Results

Imaging analysis results showed that the cyclops and ACL groups had lower mean NWI and NSI values than the control group. Significant between-group differences were found in NSI (p = 0.0140) based on coronal cross-sections and in NWI (p = 0.0026) and NSI (p < 0.0001) based on axial sections.

Conclusions

The geometry of the intercondylar notch was found to be associated with the risk of cyclops lesion formation and ACL rupture.

Increased Posterior Tibial Slope Is Associated With Greater Risk of Graft Roof Impingement After Anatomic Anterior Cruciate Ligament Reconstruction

BACKGROUND

Increased posterior tibial slope (PTS) has been reported to be associated with irreducible anterior tibial subluxation in extension after anatomic anterior cruciate ligament (ACL) reconstruction (ACLR), which raises concerns about the greater risk of graft roof impingement (GRI) although the tibial tunnel is positioned anatomically.

HYPOTHESIS

Increased PTS would be associated with greater risk of GRI after anatomic ACLR.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Between January 2016 and December 2017, a total of 418 consecutive patients were diagnosed as having noncontact ACL injuries and underwent primary anatomic ACLR. Among them, 26 patients had ≥1 of the following features during the second-look arthroscopy: fractured/guillotined bundles at the tibial insertion or cyclops lesion. These patients were confirmed to have GRI and were allocated to the study group. They were also matched 1:2 to 52 control participants without GRI. PTS was measured on true lateral whole-leg radiographs. Intra-articular ACL graft signal intensity was evaluated on postoperative magnetic resonance imaging scans (mean, 32.8 months; range, 26-38 months) and divided into 3 grades (I, good; II, moderate; III, poor) based on degree of GRI. Moreover, anterior subluxation of the lateral compartment (ASLC) and medial compartment (ASMC) in extension relative to the femoral condyles were measured on postoperative magnetic resonance imaging scans and compared between the groups. In addition, predictors of GRI were evaluated using multivariate logistic regression analysis and included body mass index, PTS, pivot-shift test, KT-1000 side-to-side difference, and concomitant meniscal tears.

RESULTS

PTS in the study group was significantly higher than that in control group (mean ± SD, 13.8°± 1.5° vs 9.5°± 1.8°; P < .05). In the study group (n = 26), patients with grade III (poor) graft signal intensity (n = 9) showed significantly higher PTS than those with grade II (moderate; n = 17) (16.4°± 1.7° vs 12.4°± 1.3°; P < .05). Moreover, the mean postoperative ASLC and ASMC in extension were significantly larger in the study group than the control group (ASLC, 4.1 ± 1.3 vs 0.8 ± 0.4 mm; ASMC, 4.3 ± 1.5 vs 0.9 ± 0.3 mm; P < .05). Furthermore, the abnormal degree of PTS (≥12°) was determined to be an independent risk factor associated with GRI after anatomic ACLR (odds ratio, 9.0 [95% CI, 3.7-30.2]; P < .001), whereas body mass index, grade of pivot-shift test, KT-1000 side-to-side difference, and concomitant meniscal tears were not.

CONCLUSION

Increased PTS (≥12°) was associated with greater risk of GRI after anatomic ACLR. This may provide additional information for counseling patients with greater risk of GRI.

Risk of arthrofibrosis in anatomical anterior cruciate ligament reconstruction: the role of timing and meniscus suture

BACKGROUND

The optimal timing of anterior cruciate ligament (ACL) reconstruction remains controversial. Several studies have shown that early surgery leads to an increased rate of arthrofibrosis and poorer postoperative function. Other studies found no correlation between time of surgery and arthrofibrosis. The influence of simultaneous meniscus treatment is also discussed. Aim of this study was to ascertain whether the timing of surgery and treatment of meniscus influences the occurrence rate of arthrofibrosis.

METHODS

Two hundred and six patients could be included. These were split into two groups. Group 1: surgery within 6 weeks after ACL rupture (n = 68), group 2: surgery after more than 6 weeks (n = 68). In addition, 2 matched groups were created (n = 138 ). Follow-up was 12 months after surgery. The primary endpoint was the rate of subsequent arthrofibrosis procedures (arthroscopic arthrolysis). Secondary endpoints were knee function (knee osteoarthritis outcome score: KOOS), knee pain (numeric rating scale: NRS) and patient satisfaction measured on a 5 point Likert scale.

RESULTS

In 6 of the 68 patients in group 1 (8.8%) and 3 of the 138 patients in group 2 (2.2%) a subsequent arthroscopic arthrolysis was performed (OR 4.4). A simultaneous meniscal suture was performed in 58 patients (30 of them in group 1). Five of the six patients with subsequent arthrolysis in group 1 received meniscal repair (OR for arthrolysis 3.4). There was no difference between the groups in terms of knee function (KOOS), pain (NRS) and patient satisfaction.

CONCLUSION

The rate of subsequent arthroscopic arthrolysis was higher in the acute surgery group. However, most of these subsequent procedures were associated with meniscal repair at index surgery with a more restrictive rehabilitation protocol than after ACL reconstruction without meniscus repair. This allows the assessment that the meniscal suturing poses an increased risk. Therefore, this allows the conclusion that if using an anatomical surgical technique and considering the signs of inflammation with effusion, pain and movement deficit less than 90° there is no increased risk of arthrofibrosis.

Revision ACL Reconstruction: Principles and Practice

INTRODUCTION

The incidence of anterior cruciate ligament reconstruction (ACLR) surgeries is increasing and so is the number of revision surgeries for a failed ACLR. The spectrum of ACL failure includes symptoms of recurrent instability, pain, and/or stiffness.

DISCUSSION

Factors contributing to ACL failure may be classified as patient-related, surgeon-related, and biological factors. Of these, tunnel malposition and recurrent trauma are the most common causes. Detailed patient assessment, imaging, and studying details of the index surgery are critical prior to planning revision surgery. Infection has to be ruled out prior to planning any reconstructive surgical procedure. Osseous malalignment in the coronal or sagittal planes would also need correction along with or prior to revision ACL surgery. Revision ACL reconstruction maybe performed as a one-stage or two-stage procedure. Severe tunnel dilatation, infection, or arthrofibrosis necessitates a two-stage approach. Autografts are preferred for revision ACL due their lesser re-tear rates and better outcomes. Associated meniscus tears and cartilage injuries are more common in revision than in primary surgery and need to be managed appropriately. Extra-articular reconstruction for controlling anterolateral instability is frequently required as well.

CONCLUSION

Revision ACL reconstruction is a complex undertaking due to limited graft options, compromised anatomy and high frequency of associated injuries. Patient expectations must be tempered because functional outcomes and return to pre-injury sports are inferior to a primary surgery.

Cyclops Lesions of the Knee: A Narrative Review of the Literature

Cyclops lesion is a known complication of anterior cruciate ligament reconstruction (ACLR). Although the incidence of cyclops lesion appears to be decreasing, it remains an important cause of restriction of extension after ACLR. We reviewed the available literature regarding the cyclops lesion and syndrome and cyclops-like lesions to analyze available evidence on cyclops lesions and variants of cyclops lesions. A keyword search in PubMed, Scopus, Web of Science, and EMBASE, Ovid Medline, and Ovid journals provided 47 relevant articles in the English literature, which were used to create this review. We classified cyclops lesions based on clinical presentation, pathology, and location. Risk factors, management options, tips to reduce the condition, and controversies related to the condition have been discussed. Female sex, greater graft volume, bony avulsion injuries, excessively anterior tibial tunnel, double-bundle ACLR, and bicruciate-retaining arthroplasty appear to predispose patients to cyclops lesions. Cyclops syndrome is a cyclops lesion that causes a loss of terminal extension. Arthroscopic debridement is an effective treatment for cyclops syndrome, whereas cyclops lesions are usually managed conservatively. It is important to distinguish between cyclops lesion and cyclops syndrome, as management differs based on symptoms. Cyclops lesion is diagnosed using magnetic resonance imaging. The management of choice for symptomatic lesions is surgical excision. Outcomes after excision are very good, and recurrence is rare.

Incidence and risk factors of joint stiffness after Anterior Cruciate Ligament reconstruction

Background

Joint stiffness is a common complication after anterior cruciate ligament (ACL) reconstruction, which seriously affects the efficacy of the operation and patient satisfaction. After ACL reconstruction, the identification of joint stiffness’ risk factors can help its prevention. This meta-analysis was conducted to evaluate joint stiffness’ risk factors and incidence after ACL reconstruction and provide guidance on its prevention.

Methods

PubMed, Embase, and Cochrane Library were searched to obtain relevant studies. The odds ratios (ORs) with 95% confidence intervals (CIs) for all potential risk factors were analyzed using fixed or random-effects meta-analysis in RevMan 5.2.

Results

In total, there were 37 studies and 113,740 patients that were included in this study. After ACL reconstruction, joint stiffness’ incidence negatively correlated with the studies publication time (R = −0.62, P = 0.0094). After ACL reconstruction, the joint stiffness overall pooled incidence was 3% (95% CI, 3-4%). Gender (OR, 0.51; 95% CI, 0.38-0.68; P < 0.00001) was identified as a risk factor. Potential risk factors, such as trauma to surgery time interval, graft type, and concomitant surgery with meniscus injury, have no significant correlation with joint stiffness after ACL reconstruction.

Conclusion

This study indicated that joint stiffness’ incidence after ACL reconstruction is 3% and that gender is a risk factor for joint stiffness after ACL reconstruction.