Changes in arthroscopic findings in the anterior cruciate ligament deficient knee prior to reconstructive surgery

Early ACLR and Risk and Timing of Secondary Meniscal Injury Compared With Delayed ACLR or Nonoperative Treatment: A Time-to-Event Analysis Using Machine Learning

BACKGROUND

Surgical and nonoperative management of anterior cruciate ligament (ACL) injuries seek to mitigate the risk of knee instability and secondary meniscal injury. However, the associated risk and timing of secondary meniscal tears have not been completely elucidated.

PURPOSE

To compare risk and timing of secondary meniscal injury between patients receiving nonoperative management, delayed ACL reconstruction (ACLR), and early ACLR using a machine learning survival analysis.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A geographic database was used to identify and review records of patients with a diagnosis of ACL rupture between 1990 and 2016 with minimum 2-year follow-up. Patients undergoing ACLR were matched 1:1 with nonoperatively treated controls. Rate and time to secondary meniscal tear were compared using random survival forest algorithms; independent models were developed and internally validated for predicting injury-free duration in both cohorts. Performance was measured using out-of-bag c-statistic, calibration, and Brier score. Model interpretability was enhanced using global variable importance and partial dependence curves.

RESULTS

The study included 1369 patients who underwent ACLR and 294 patients who had nonoperative treatment. After matching, no significant differences in rates of secondary meniscal tear were found (P = .09); subgroup analysis revealed the shortest periods of meniscal survival in patients undergoing delayed ACLR. The random survival forest algorithm achieved excellent predictive performance for the ACLR cohort, with an out-of-bag c-statistic of 0.80 and a Brier score of 0.11. Significant variables for risk of meniscal tear for the ACLR cohort included time to return to sports or activity ≤350 days, time to surgery ≥50 days, age at injury ≤40 years, and high-impact or rotational landing sports, whereas those in the nonoperative cohort model included time to RTS ≤200 days, visual analog scale pain score >3 at consultation, hypermobility, and noncontact sports.

CONCLUSION

Delayed ACLR demonstrated the greatest long-term risk of meniscal injury compared with nonoperative treatment or early ACLR. Risk factors for decreased meniscal survival after ACLR included increased time to surgery, shorter time to return to sports or activity, older age at injury, and involvement in high-impact or rotational landing sports. Pending careful external validation, these models may be deployed in the clinical space to provide real-time insights and enhance decision making.

Is Insurance Status Associated With Likelihood of Operative ACL Injury Treatment Compared With Nonoperative Treatment?

Background:

While many factors inform the choice of operative versus nonoperative treatment of injuries to the anterior cruciate ligament (ACL) of the knee, socioeconomic status influences this decision, as has been reported with other procedures.

Purpose:

To identify any associations between insurance status and likelihood of operative treatment of ACL injuries.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

The Nationwide Inpatient Sample database was queried using International Classification of Diseases, 9th Revision codes for ACL injuries and reconstruction from 2001 to 2013. Chi-square analysis was performed to determine significant predictors of operative intervention. Binary logistic regression was used to account for demographic and significant predictor variables. Results were recorded as odds ratios (ORs) and 95% CIs. Significance was defined as P < .05.

Results:

A total of 32,541 patients with ACL injuries were included in the final analysis. Overall incidence of surgical reconstruction was 85.4% (n = 27,805). Multivariable regression revealed that nonprivate insurance types were associated with lower likelihoods of operative reconstruction compared with private insurance: the lowest likelihood of operation was seen in uninsured patients (OR, 0.31; P < .01), followed by Medicare (OR, 0.33; P < .01) and Medicaid (OR, 0.51; P < .01) patients. There was also a decreased likelihood of surgery for elderly (OR, 0.0 [for age ≥75 years]; P < .01) and Black patients (OR, 0.65; P < .01). An increased likelihood of surgery was seen with female patients (OR, 1.14; P < .01). Patients in the highest median household income quartile were more likely to undergo surgery than those in the lowest (OR, 1.36; P < .01).

Conclusion:

Compared with privately insured patients, patients with nonprivate insurance had lower likelihood of surgery. Furthermore, patients in higher income quartiles were more likely to undergo operative fixation. These findings may suggest a need for more precise treatment guidelines and studies that investigate causes of such differences.

The Natural History of Medial Meniscal Tears in the ACL Deficient and ACL Reconstructed Rat Knee

OBJECTIVE

The process of anterior cruciate ligament (ACL) injury-induced meniscal tear formation is not fully understood. Clinical studies have shown that ACL reconstruction (ACLR) reduces the development of secondary meniscal tears, but it is difficult to gain insight into the protective effects of ACLR from clinical studies alone. Using rat ACL transection (ACLT) and ACLR models, we aimed to reveal (1) the formation process of meniscal tears secondary to ACLT and (2) the protective effects of ACLR on secondary meniscal tears.

DESIGN

ACLT surgery alone or with ACLR was performed on the knees of rats. Histomorphological and histopathological changes were examined in the posteromedial region of the meniscus in intact rats and in rats that received ACLT or ACLR up to 12 weeks postsurgery. In addition, anterior-posterior joint laxity was measured using the universal testing machine to evaluate the effects of ACLT and ACLR on joint laxity.

RESULTS

AAnterior-posterior laxity was significantly increased by ACLT compared to the intact knee. This ACLT-induced joint laxity was partially but significantly reduced by ACLR. Meniscal proliferation and hyaline cartilage-like tissue formation were detected in the medial meniscus at 4 weeks post-ACLT. At 12 weeks post-ACLT, hyaline cartilage-like tissue was replaced by ossicles and meniscal tears were observed. These ACLT-induced abnormalities were attenuated by ACLR.

CONCLUSIONS

Our results suggest that ACLT-induced joint laxity induces secondary medial meniscal tears through meniscal proliferation and ossicle formation via endochondral ossification. Joint re-stabilization by ACLR suppresses meniscal proliferation and ossicle formation and consequently prevents secondary meniscal tears.

Decision Making for Treatment After ACL Injury From an Orthopaedic Surgeon and Patient Perspective: Results From the NACOX Study

Background:

In the treatment of anterior cruciate ligament (ACL) injuries, there is little evidence of when and why a decision for ACL reconstruction (ACLR) or nonoperative treatment (non-ACLR) is made.

Purpose:

To (1) describe the key characteristics of ACL injury treatment decisions and (2) compare patient-reported knee instability, function, and preinjury activity level between patients with non-ACLR and ACLR treatment decisions.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

A total of 216 patients with acute ACL injury were evaluated during the first year after injury. The treatment decision was non-ACLR in 73 patients and ACLR in 143. Reasons guiding treatment decision were obtained from medical charts and questionnaires to patients and orthopaedic surgeons. Patient-reported instability and function were obtained via questionnaires and compared between patients with non-ACLR and ACLR treatment decisions. The ACLR treatment group was classified retrospectively by decision phase: acute phase (decision made between injury day and 31 days after injury), subacute phase (decision made between 32 days and up to 5 months after injury), and late phase (decision made 5-12 months after injury). Data were evaluated using descriptive statistics, and group comparisons were made using parametric or nonparametric tests as appropriate.

Results:

The main reasons for a non-ACLR treatment decision were no knee instability and no problems with knee function. The main reasons for an ACLR treatment decision were high activity demands and knee instability. Patients in the non-ACLR group were significantly older (P = .031) and had a lower preinjury activity level than did those in the acute-phase (P < .01) and subacute-phase (P = .006) ACLR decision groups. There were no differences in patient-reported instability and function between treatment decision groups at baseline, 4 weeks after injury, or 3 months after injury.

Conclusion:

Activity demands, not patient-reported knee instability, may be the most important factor in the decision-making process for treatment after ACL injury. We suggest a decision-making algorithm for patients with ACL injuries and no high activity demands; waiting for >3 months can help distinguish those who need surgical intervention from those who can undergo nonoperative management.

Registration:

NCT02931084 (ClinicalTrials.gov identifier).

Delayed Anterior Cruciate Ligament Reconstruction Increases the Risk of Abnormal Prereconstruction Laxity, Cartilage, and Medial Meniscus Injuries

PURPOSE

To determine the association between a delay in anterior cruciate ligament reconstruction (ACLR), age, sex, body mass index (BMI) and cartilage injuries, meniscus injuries, meniscus repair, and abnormal prereconstruction laxity.

METHODS

Patients who underwent primary ACLR at our institution from January 2005 to March 2017, with no associated ligament injuries, were identified. Logistic regression analyses were used to evaluate whether delay in ACLR, age, sex, and BMI were risk factors for cartilage and meniscus injuries, meniscus repair, and abnormal (side-to-side difference >5 mm) prereconstruction laxity.

RESULTS

A total of 3976 patients (mean age 28.6 ± 10.6 years, range 10-61 years) were included. The risk of cartilage injury increased with a delay in ACLR (12-24 months: odds ratio [OR] 1.20; 95% confidence interval [CI] 1.05-1.29; P = .005; and > 24 months: OR 1.20; 95% CI 1.11-1.30; P < .001) and age ≥30 years (OR 2.27; 95% CI 1.98-2.60; P < .001). The risk of medial meniscus (MM) injury increased with a delay in ACLR (12-24 months: OR 1.20; 95% CI 1.07-1.29; P = .001; and >24 months: OR 1.22; 95% CI 1.13-1.30; P < .001), male sex (OR 1.16; 95% CI 1.04-1.30; P = .04) and age ≥30 years (OR 1.20; 95% CI 1.04-1.33; P = .008). The risk of lateral meniscus (LM) injury decreased with a delay in ACLR of >3 months and age ≥30 years (OR 0.75; 95% CI 0.66-0.85; P < .001), whereas it increased with male sex (OR 1.32; 95% CI 1.22-1.41; P < .001). MM repairs relative to MM injury decreased with a delay in ACLR (6-12 months: OR 0.70; 95% CI 0.54-0.92; P = .01; 12-24 months: OR 0.69; 95% CI 0.57-0.85; P < .001; >24 months: OR 0.61; 95% CI 0.52-0.72; P < .001) and age ≥30 years (OR 0.60; 95% CI 0.48-0.74; P < .001). LM repairs relative to LM injury only decreased with age ≥30 years (OR 0.34; 95% CI 0.26-0.45; P < .001). The risk of having abnormal knee laxity increased with a delay in ACLR of >6 months and MM injury (OR 1.52; 95% CI 1.16-1.97; P = .002), whereas it decreased with a BMI of ≥25 (OR 0.68; 95% CI 0.52-0.89; P = .006).

CONCLUSIONS

A delay in ACLR of >12 months increased the risk of cartilage and MM injuries, whereas a delay of >6 months increased the risk of abnormal prereconstruction laxity and reduced the likelihood of MM repair. To reduce meniscus loss and the risk of jeopardizing knee laxity, ACLR should be performed within 6 months after the injury.

LEVEL OF EVIDENCE

Level III, retrospective therapeutic comparative study.

Anterior Cruciate Ligament Tears: The Impact of Increased Time From Injury to Surgery on Intra-articular Lesions

Background:

Previous research has shown that meniscal and articular cartilage lesions increase with time in the anterior cruciate ligament (ACL)–deficient knee.

Purpose:

To analyze the association between increased time from ACL injury to reconstruction and the presence of intra-articular lesions.

Design:

Cross-sectional study; Level of evidence, 3.

Methods:

A retrospective chart review was performed for patients who sustained an ACL injury and underwent reconstruction from January 1, 2009, to May 14, 2015. Factors analyzed included age, sex, and body mass index, as well as time from injury to surgery, the presence of meniscal tears, and the presence of cartilage lesions. The data were evaluated to quantify the association between time from ACL injury to reconstruction and presence of intra-articular lesions.

Results:

Overall, 405 patients were included in this study. Regarding time from injury, 27.3% patients were treated at <3 months, 23.6% at 3 to <6 months, 18% at 6 to <12 months, 13.6% at 12 to <24 months, 10.6% at 24 to <60 months, and 6.9% at ≥60 months. When compared with the group treated <3 months from injury, a significant increase in the rate of medial meniscal tears was seen in the groups treated at 6 to <12 months (odds ratio [OR], 2.2), 12 to <24 months (OR, 3.5), 24 to <60 months (OR, 7.0), and ≥60 months (OR, 6.3). A similar trend was seen with medial femoral condyle lesions in the groups treated at 6 to <12 months (OR, 2.5), 12 to <24 months (OR, 2.6), 24 to <60 months (OR, 2.6), and ≥60 months (OR, 6.9). The prevalence of lateral tibial plateau and lateral femoral condyle lesions also significantly increased with increased time between ACL injury and reconstruction, but this association was not seen until 24 to <60 months (ORs, 5.1 and 11.5, respectively).

Conclusion:

For patients undergoing ACL reconstruction, an interval >6 months between injury and surgery was associated with an increased prevalence of medial meniscal tears and medial compartment chondral lesions at the time of surgery. An interval >24 months between injury and surgery was associated with an increased prevalence of lateral compartment chondral lesions at the time of surgery.

Does Anterior Cruciate Ligament Reconstruction Protect the Meniscus and Its Repair? A Systematic Review

Background:

Anterior cruciate ligament (ACL) tear and meniscal injury often co-occur. The protective effect of early ACL reconstruction (ACLR) on meniscal injury and its repair is not clear. Critical literature review can support or change clinical strategies and identify gaps in the available evidence.

Purpose:

To assess the protective effect of ACLR on the meniscus and provide clinical guidelines for managing ACL tears and subsequent meniscal injury. We aimed to answer the following questions: (1) Does ACLR protect the meniscus from subsequent injury? (2) Does early ACLR reduce secondary meniscal injury compared with delayed ACLR? (3) Does ACLR protect the repaired meniscus?

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A systematic review was performed through use of MEDLINE and Embase electronic databases according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Search terms included ACL, reconstruction, and meniscus. Studies describing primary ACLR and nonoperative treatment in adult patients were included, as well as studies indicating timing of ACLR. The included articles were assessed individually for risk of bias through use of the modified Cochrane Risk of Bias and MINORS (Methodological Index for Nonrandomized Studies) tools.

Results:

One level 2 randomized controlled trial and several level 3 and 4 studies indicated a protective effect of ACLR on meniscal injury compared with nonoperative treatment. There was weak (level 3) evidence of the protective effect of early ACLR on the meniscus. Meniscal repair failure was less frequent in patients with ACL reconstruction than in patients with ACL deficiency (level 4).

Conclusion:

The evidence collected in this review suggests a protective effect of ACLR for subsequent meniscal injury (level 2 evidence). ACLR should be performed within 3 months of injury (level 3 evidence). Meniscal injury requiring surgical repair in the ACL-deficient knee should be treated with repair accompanied by ACLR (level 3 evidence). The paucity of level 2 studies prevents the formation of guidelines based on level 1 evidence. There is a strong clinical need for randomized or prospective trials to provide guidelines on timing of ACLR and meniscal repair.

Non-operative treatment of ACL injury is associated with opposing subjective and objective outcomes over 20 years of follow-up

PURPOSE

The aim of this study was the evaluation of long-term clinical and radiological outcomes of non-operative treatment of anterior cruciate ligament (ACL) deficiency. The hypothesis was that conservative treatment would be associated with a deterioration of subjective and objective measures of joint health and disability over time.

METHODS

From an initial sample of 41 patients conservatively treated for ACL rupture, 10 received secondary ACL reconstruction, 1 was excluded due to contralateral ACL injury, and 1 patient required total knee replacement and a high tibial osteotomy. Seven further patients were lost to follow-up. The remaining 21 patients (15 male, 6 female, mean age 53.1 ± 9.2 years at the last follow-up) were evaluated by the same two examiners 5-7, 10-13 and 20-22 years after the injury. The evaluation was based on objective and subjective scores, instrumented testing, radiographic examination and assessment of sports activity.

RESULTS

While subjective patient satisfaction improved over time, objective scores stayed constant or deteriorated (radiologic evaluation). Instrumented knee laxity testing showed an initial tendency to increasing instability, followed by a decrease in anterior tibial translation in the second half of the observation period. Physical activity levels, particularly in high-risk sports, decreased significantly (p < 0.05) compared to preinjury levels. All patients developed significant arthritic degenerative changes over time compared to the uninjured contralateral knee. No correlation to activities in high- or low-risk pivoting sports was found.

CONCLUSIONS

Patient satisfaction with conservative treatment of ACL injuries is good in spite of objective measures indicating increasing degenerative changes.

LEVEL OF EVIDENCE

IV.

The ACL-deficient knee and the prevalence of meniscus and cartilage lesions: a systematic review and meta-analysis (CRD42017076897)

INTRODUCTION

The purpose of this systematic review and meta-analysis was to analyze and compare the rate of secondary meniscus and cartilage lesions diagnosed at different time points of ACL reconstruction.

MATERIALS AND METHODS

A systematic search for articles comparing the rate of secondary meniscus and cartilage lesions diagnosed at different time points of ACL reconstruction was performed. PubMed central was the database used for the literature review.

RESULTS

Forty articles out of 1836 were included. In 35 trials (88%), there was evidence of a positive correlation between the rate of meniscus and/or cartilage lesions and the time since ACL injury. This correlation was more evident for the medial meniscus in comparison with the lateral meniscus. In particular, a delay of more than 6 months was critical for secondary medial meniscus injuries [risk ratio 0.58 (95% CI 0.44-0.79)] and a delay of more than 12 months was critical for cartilage injuries [risk ratio 0.42 (95% CI 0.29-0.59)]. Additionally, there is evidence that the chance for meniscal repair decreases as the time since ACL rupture increases.

CONCLUSION

Chronic instability in the ACL-deficient knee is associated with a significant increase of medial meniscus injuries after 6 months followed by a significant increase of cartilage lesions after 12 months.

Surgical timing of anterior cruciate ligament reconstruction to prevent associated meniscal and cartilage lesions

BACKGROUND

The purpose of this study was to analyze the association between the prevalence of meniscal and chondral lesions and the timing of surgery in patients undergoing primary anterior cruciate ligament (ACL) reconstruction to determine a safe time for surgery.

METHODS

This retrospective study involved 226 patients (91 females and 135 males; median age, 29 years) undergoing primary ACL reconstruction. Time interval from ACL injury to surgery (median, 4 months; range, 1-420 months) and concomitant meniscal and cartilage lesions in ACL reconstruction were reviewed. Receiver operating characteristic (ROC) curve analysis was used to determine the precise threshold interval to surgery to prevent meniscal or cartilage lesions. The risk of lesion occurrence after each cutoff period was determined using odds ratio (OR).

RESULTS

The incidences of medial meniscus (MM), lateral meniscus (LM), and cartilage lesions were 43.8%, 32.7%, and 27.4%, respectively. ROC analysis revealed that patients who waited for more than 6, 4, and 5 months for ACL reconstruction had a significantly greater risk of associated MM, LM, and chondral lesions, respectively. Patients who underwent ACL reconstruction ≥7 months after injury had OR of 4.1 (p < 0.001) for the presence of MM lesion as compared with those who underwent reconstruction within 6 months. Similarly, patients who underwent ACL reconstruction ≥5 months after injury had OR of 1.9 (p = 0.023) for the presence of LM lesion as compared with those who underwent reconstruction within 4 months, and patients who underwent ACL reconstruction ≥6 months after injury had OR of 2.9 (p < 0.001) for chondral lesion as compared with those who underwent reconstruction within 6 months.

CONCLUSION

ACL reconstruction should be performed within approximately 6 months after the injury to prevent associated meniscal or chondral lesions.

Timing of anterior cruciate ligament reconstruction within the first year after trauma and its influence on treatment of cartilage and meniscus pathology

PURPOSE

Anterior cruciate ligament (ACL) ruptures are often associated with primary meniscal and cartilage lesions. Late reconstruction of ACL-deficient knees may increase the risk of developing secondary meniscal and cartilage lesions; hence, the timing of ACL repair is of the utmost importance. Because meniscus outcome is also a potential predictor for osteoarthritis (OA), this study compared ACL repair within the first 6 months after injury to that of surgery conducted 7-12 months after injury with regard to the incidence of meniscal and cartilage lesions.

METHODS

This prospective cross-sectional study included all complete isolated primary ACL ruptures treated in our institution within 1 year after trauma over a 12-month period. Exclusion criteria were revision ACL, complex ligament injuries, previous knee surgery, and missing injury data. Cartilage lesions were classified according to the score established by the International Cartilage Repair Society (ICRS score) and meniscal tears according to their treatment options.

RESULTS

Two hundred and thirty-three of 730 patients (162 men, 71 women) with ACL repair met the inclusion criteria. 86.3 % of surgical interventions were conducted within 6 months and 13.7 % after 6 months of trauma. Severe cartilage lesions grade III-IV did not significantly differ between the different time points of ACL repair (<6 months 39.9 %; >6 months 31.3 %; p = n.s.). Medial meniscus lesions received significantly higher meniscal repair in early compared to delayed ACL repair. Significantly higher rate of meniscal repair of the medial meniscus was seen in cases of early ACL repair compared to delayed (<6 months 77.2 %, >6 months 46.7; p = 0.022). The rate of medial meniscal repair in early ACL repair was significantly higher for women (89.5-0 %; p = 0.002), however, not for men (73.3-53.8 %; p = n.s.). No differences were found for lateral meniscal lesions, with regard to neither the different time points (p = n.s.) nor the sex (p = n.s.).

CONCLUSIONS

Because of the significantly higher rate of prognostically advantageous meniscal repair, the recommendation for an ACL reconstruction within 6 months after trauma was made to preserve the meniscus and reduce the risk of developing OA.

LEVEL OF EVIDENCE

Prospective cross-sectional cohort study, Level II.

The Relationship between Anterior Cruciate Ligament Injury and Osteoarthritis of the Knee

Anterior cruciate ligament (ACL) tears are a common injury, particularly in the athletic and youth populations. The known association between ACL injury and subsequent osteoarthritis (OA) of the knee merits a more in-depth understanding of the relationship between the ACL-injured knee and osteoarthritis. ACL injury, especially with concomitant meniscal or other ligamentous pathology, predisposes the knee to an increased risk of osteoarthritis. ACL insufficiency results in deterioration of the normal physiologic knee bending culminating in increased anterior tibial translation and increased internal tibial rotation. This leads to increased mean contact stresses in the posterior medial and lateral compartments under anterior and rotational loading. However, surgical reconstruction of the ACL has not been shown to reduce the risk of future OA development back to baseline and has variability based on operative factors of graft choice, timing of surgery, presence of meniscal and chondral abnormalities, and surgical technique. Known strategies to prevent OA development are applicable to patients with ACL deficiency or after ACL reconstruction and include weight management, avoidance of excessive musculoskeletal loading, and strength training. Reconstruction of the ACL does not necessarily prevent osteoarthritis in many of these patients and may depend on several external variables.

Prevalence and consequences of delayed diagnosis of anterior cruciate ligament ruptures

PURPOSE

Rupture of the anterior cruciate ligament (ACL) is a common injury, often presenting with a typical injury pattern. Historically, the literature indicates that the accuracy of diagnosis of ACL ruptures is poor at the initial medical consultation. The aims of this study were to determine: the mechanism of injury; changes in accuracy of diagnosis of ACL ruptures at initial presentation over the last decade; and the effect of subsequent delay in diagnosis and definitive treatment.

METHODS

A prospective cohort of one hundred and thirty-two consecutive patients who underwent ACL reconstruction between 2005 and 2009 were analysed. The median age of the patients was 18 years (12-57). Sixteen patients were excluded due to chronic ACL injury.

RESULTS

One hundred and sixteen patients (117 ACL ruptures) were included in the analysis. A typical injury pattern was documented in 87 (74.4 %) of cases. The most common sporting activities associated with an ACL injury were football (35.3 %), skiing (21.6 %) and rugby (10.3 %). The majority of patients (67.5 %) sought medical attention within 1 week from time of injury. The correct diagnosis of an ACL rupture was made in 33 cases (28.2 %) at the initial medical consultation. The diagnosis was made following medical consultation in 13 (11.1 %) of cases with the use of magnetic resonance imaging and 6 (5.1 %) cases at arthroscopy. The median time to diagnosis was 6 weeks (0-192), and the median time to ACL reconstruction was 24 weeks (1-240). A delay in diagnosis of >6 months was associated with a medial meniscal tear rate of 72.2 % compared to 23.1 % if the diagnosis was made within 4 months of the injury (p < 0.05).

CONCLUSIONS

Despite a 'typical' mechanism of injury leading to ACL rupture, the rate of initial diagnosis in the UK still remains poor. This often leads to an unnecessary delay in the diagnosis and subsequent treatment and increases the risk of secondary injury to the knee. A delay in diagnosis of >6 months was associated with an increased medial meniscal tear rate. Patients who present with a 'typical' injury pattern should therefore be referred for further assessment by a knee specialist within 6 weeks.

LEVEL OF EVIDENCE

IV.

Anterior cruciate ligament bracing: evidence in providing stability and preventing injury or graft re-rupture

Ligamentous knee injuries are common and costly, both in financial terms and time missed from work and recreational activities. Furthermore, ligamentous injuries appear to predispose patients to future osteoarthritis and other morbidities. Therefore, prevention strategies are important in limiting the potential impact of these injuries. Knee braces are one of the most often prescribed devices in the billion-dollar orthotic industry. Despite widespread use of prophylactic and functional knee braces, the evidence supporting their efficacy in reducing and/or preventing injury remains limited. Knee braces have been shown to be more effective in preventing medial collateral ligament injuries than anterior cruciate ligament injuries in both cadaveric and clinical studies. The use of functional braces after anterior cruciate ligament reconstruction has been supported and refuted in both postoperative and long-term studies.

Graft failure versus graft fixation in ACL reconstruction: histological and immunohistochemical studies in rabbits

The causes of graft failure after anterior cruciate ligament (ACL) reconstruction are multifactorial including the methods of graft fixation. The purpose of this study was to examine the ACL graft failure in three different methods of graft fixations including interference screw fixation, suture-post fixation and combined interference screw and suture-post fixation. We hypothesized that the fixation method after ACL reconstruction can affect the graft healing in tibial tunnel. Eighteen New Zealand white rabbits were categorized into three groups according to the method of fixation in unilateral ACL reconstruction with long digital extensor autograft. Histological examination demonstrated that the combined fixation and suture-post fixation groups showed significantly better integration between tendon and bone (P = 0.04). In immunohistochemical analysis, the combined fixation and suture-post fixation groups showed significantly higher BMP-2 and VEGF expressions than interference screw (P < 0.01). The tendon-bone healing after ACL reconstruction was affected by the method of graft fixation. Combined fixation with interference screw and suture-post reduced graft-tunnel micromotion and improved the graft healing in tibial tunnel.

The incidence of secondary pathology after anterior cruciate ligament rupture in 5086 patients requiring ligament reconstruction

We reviewed 5086 patients with a mean age of 30 years (9 to 69) undergoing primary reconstruction of the anterior cruciate ligament (ACL) in order to determine the incidence of secondary pathology with respect to the time between injury and reconstruction. There was an increasing incidence of medial meniscal tears and chondral damage, but not lateral meniscal tears, with increasing intervals before surgery. The chances of requiring medial meniscal surgery was increased by a factor of two if ACL reconstruction was delayed more than five months, and increased by a factor of six if surgery was delayed by > 12 months. The effect of delaying surgery on medial meniscal injury was also pronounced in the patients aged < 17 years, where a delay of five to 12 months doubled the odds of medial meniscal surgery (odds ratio (OR) 2.0, p = 0.001) and a delay of > 12 months quadrupled the odds (OR 4.3, p = 0.001). Increasing age was associated with a greater odds of chondral damage (OR 4.6, p = 0.001) and medial meniscal injury (OR 2.9, p = 0.001), but not lateral meniscal injury. The gender split (3251 men, 1835 women) revealed that males had a greater incidence of both lateral (34% (n = 1114) vs 20% (n = 364), p = 0.001) and medial meniscal tears (28% (n = 924) vs 25% (n = 457), p = 0.006), but not chondral damage (35% (n = 1152) vs 36% (n = 665), p = 0.565). We conclude that ideally, and particularly in younger patients, ACL reconstruction should not be delayed more than five months from injury.

Relationship of native tibial plateau anatomy with stability testing in the anterior cruciate ligament-deficient knee

PURPOSE

Recent attention has been drawn to tibial plateau slope and depth with relation to both risk of anterior cruciate ligament (ACL) tear and kinematics in the cruciate-deficient knee. The purpose was to evaluate the relationship between native proximal tibial anatomy and knee kinematics in the anterior cruciate-deficient knee.

METHODS

Twenty-two cadaveric knees underwent CT scanning to measure proximal tibia anatomy. Translation was measured during Lachman and mechanized pivot-shift tests on the intact knee and then after resection of the ACL. Pearson's correlation was calculated to assess the relationship between tibial translation of the ACL-deficient knee and tibial plateau anatomic parameters.

RESULTS

No significant correlation was found between ACL-deficient kinematic testing and tibial slope or depth (n.s.). Lateral compartment translation on Lachman and pivot-shift testing correlated with lateral compartment AP length (P = 0.007 and P = 0.033, respectively). The ratio of lateral AP length to medial AP length correlated with lateral compartment translation during the pivot shift (P = 0.002).

CONCLUSION

There was a poor correlation between native tibial slope and kinematic testing. There were, however, increases in translation during pivot-shift and Lachman testing with increased AP length of the lateral compartment. In addition, the finding of increased pivot-shift magnitude when the lateral compartment was relatively wide in the AP plane compared to the medial compartment suggests that patients with a "dominant" lateral compartment may be prone to a greater magnitude of instability after ACL injury.

Meniscal and chondral injuries associated with pediatric anterior cruciate ligament tears: relationship of treatment time and patient-specific factors

BACKGROUND

Anterior cruciate ligament (ACL) tears are commonly associated with meniscal and chondral injuries. Although lateral meniscal tears are commonly associated with acute ACL injuries, the chronically ACL-deficient knee is associated with an increased rate of medial meniscal injury. These associations have been described in the adult knee literature.

PURPOSE

To evaluate the relationship of elapsed time from injury with the incidence of meniscal and chondral injuries noted at the time of surgical treatment for ACL tears in pediatric patients. The effect of age, gender, weight, and mechanism of injury was also evaluated.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A retrospective chart review of pediatric patients undergoing primary arthroscopic ACL reconstruction between January 2005 and January 2011 was performed. The presence of meniscal tear, chondral injury, number of days from injury to treatment, age, weight, gender, and mechanism of injury were recorded. The data were analyzed for associations between elapsed time before surgery as well as patient-specific factors with rates of meniscal and chondral injuries.

RESULTS

Three hundred seventy pediatric patients who underwent primary ACL reconstruction were included. Two hundred forty-one were treated ≤150 days (early) from injury, and 129 were treated >150 days (delayed) from injury. Ninety-one (37.8%) patients in the early treatment group and 69 (53.5%) patients in the delayed treatment group had medial meniscal tears (MMTs) (P = .014; odds ratio [OR], 1.8; 95% confidence interval [CI], 1.12-2.83). Lateral meniscal tear (LMT) rates were similar (56.0% and 57.4%) in each group. Age >15 years also influenced the presence of MMTs (P = .033; OR, 1.6; CI, 1.04-2.54). Increased patient weight was associated with an increased rate of MMTs and LMTs. Fifty-four of 170 (31.8%) patients weighing ≤65 kg and 106 of 200 (53%) weighing >65 kg had MMTs (P < .001; OR, 2.2; CI, 1.36-3.42). Eighty-two of 170 (48.2%) patients weighing ≤65 kg and 127 of 200 (63.5%) weighing >65 kg had LMTs (P < .018; OR, 1.7; CI, 1.10-2.68). The presence of chondral injury was significantly associated with the presence of meniscal tear in the same compartment of the knee.

CONCLUSION

Pediatric patients treated >150 days after injury for ACL tears have a higher rate of MMT than those treated ≤150 days after injury. Increased age and weight are independently associated with a higher rate of MMT. Patients with ACL tears and an MMT or LMT are more likely to have a chondral injury in that particular compartment than those without meniscal tears.

Guideline on anterior cruciate ligament injury

The Dutch Orthopaedic Association has a long tradition of development of practical clinical guidelines. Here we present the recommendations from the multidisciplinary clinical guideline working group for anterior cruciate ligament injury. The following 8 clinical questions were formulated by a steering group of the Dutch Orthopaedic Association. What is the role of physical examination and additional diagnostic tools? Which patient-related outcome measures should be used? What are the relevant parameters that influence the indication for an ACL reconstruction? Which findings or complaints are predictive of a bad result of an ACL injury treatment? What is the optimal timing for surgery for an ACL injury? What is the outcome of different conservative treatment modalities? Which kind of graft gives the best result in an ACL reconstruction? What is the optimal postoperative treatment concerning rehabilitation, resumption of sports, and physiotherapy? These 8 questions were answered and recommendations were made, using the "Appraisal of Guidelines for Research and Evaluation" instrument. This instrument seeks to improve the quality and effectiveness of clinical practical guidelines by establishing a shared framework to develop, report, and assess. The steering group has also developed 7 internal indicators to aid in measuring and enhancing the quality of the treatment of patients with an ACL injury, for use in a hospital or practice.

Are meniscus and cartilage injuries related to time to anterior cruciate ligament reconstruction?

BACKGROUND

Functional instability after anterior cruciate ligament injury can be successfully treated with ligament reconstruction. However, the associated meniscus and cartilage lesions often cannot be repaired and may have long-term detrimental effects on knee function.

PURPOSE

The authors used the large database within the Kaiser Permanente Anterior Cruciate Ligament Reconstruction Registry to evaluate time to surgery, age, and gender as risk factors for meniscus and cartilage injury and associations with meniscus repair rates in patients.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A retrospective review of the Kaiser Permanente Anterior Cruciate Ligament Reconstruction Registry was performed. The associations between time to surgery, age, and gender with meniscus and cartilage lesions and meniscus repair were analyzed using binary logistic regression modeling to calculate odds ratios (ORs) while adjusting for potential confounding variables.

RESULTS

A total of 1252 patients met the inclusion criteria. The risk of medial meniscus injury increased only with time to surgery (6-12 months: OR = 1.81, 95% confidence internal [CI] 1.29-2.54, P = .001; and >12 months: OR = 2.19, 95% CI 1.58-3.02, P < .001). The risk of lateral meniscus injury decreased only with female gender (OR = 0.65, 95% CI 0.51-0.83, P = .001). The risk of cartilage injury increased with age (OR = 1.05 per year, 95% CI 1.04-1.07, P < .001) and time to surgery >12 months (OR = 1.57, 95% CI 1.12-2.20, P = .009), but decreased with female gender (OR = 0.71, 95% CI 0.54-0.92, P = .009). Medial meniscus repairs relative to medial meniscus injury decreased with increasing time to surgery (3-6 months: OR = 0.61, 95% CI 0.37-1.00, P = .050; and >12 months: OR = 0.41, 95% CI 0.25-0.67, P < .001) and increasing age (OR = 0.96 per year, 95% CI 0.94-0.98, P < .001).

CONCLUSION

Increased risk of medial meniscus injury and decreased repair rate were strongly associated with increasing time to surgery. Increased risk of cartilage injury was associated with increasing age, increasing time to surgery, and male gender.

Posterior horn instability of the medial meniscus a sign of posterior meniscotibial ligament insufficiency

PURPOSE

In longstanding chronic anterior cruciate ligament (ACL) insufficiency, we identified an abnormal movement of the posterior medial meniscal horn, likely due to insufficiency of the posteromedial meniscotibial ligament. Passing from extension to flexion or vice versa, the medial posterior horn slides below the posterior rim of the tibia exposing the tibial plateau. Fixation with suture anchors of the meniscotibial ligament through a posteromedial portal restored normal meniscotibial tension and reduced instability of the meniscal posterior horn. The purpose of the present study was to present the arthroscopic features of posterior medial meniscus instability and to report results following arthroscopic repair.

METHODS

During the two-year study period, from 2007 through 2008, this arthroscopic feature was detected in 12 patients, 5 patients had failure of a previous ACL reconstruction and 7 patients had delay in ligamentous reconstruction for various reasons. All patients were affected by severe anterior-posterior translation with 11.3 ± 4.3 mm of side-to-side difference at KT-2000 and by associated rotatory laxity with grade 3 of pivot shift.

RESULTS

At follow-up of 1 year, the combined ACL reconstruction and fixation of the posteromedial horn showed a reduction in the rotatory and anteroposterior laxity.

CONCLUSIONS

This study suggests the importance of a proper arthroscopic evaluation of the posterior medial capsule in patients with chronic ACL insufficiency and highlights the potential presence of an unstable posterior horn of the medial meniscus as an indirect arthroscopic sign of peripheral laxity.

The impact of an Acute Knee Clinic

INTRODUCTION

The aim of this audit was to analyse the impact of an open access clinic for the treatment of soft tissue knee injuries with regard to delay to treatment.

PATIENTS AND METHODS

Data from 100 consecutive patients seen in our sports clinic in 2000 were collected. Following this audit, an Acute Knee Clinic was introduced and took place once per week. In 2006, the audit loop was closed and data from 100 consecutive patients seen in the Acute Knee Clinic were collected.

RESULTS

The time from injury to the first review by a specialist is referred to as the time to diagnosis. The introduction of the Acute Knee Clinic led to an 89% reduction in the time to diagnosis for accident and emergency referrals and a 32% reduction for general practitioner referrals. The average number of visits of any sort made by the patient prior to review by a specialist in 2000 was five as opposed to one in 2006.

CONCLUSIONS

An Acute Knee Clinic with open access is a simple method of dramatically reducing the delay to diagnosis. This decreases the total delay to treatment which is of particular importance in patients requiring anterior cruciate ligament (ACL) reconstruction due to the risk of secondary meniscal and chondral injuries. Decreasing the delay to diagnosis and appropriate treatment reduces the recovery time. This not only reduces the socio-economic cost of soft tissue knee injuries but may also decrease the psychosocial consequences for the patient. By reducing the number of times a patient is seen by medical practitioners prior to review by a specialist has the potential to decrease the total cost of treatment. The socio-economic impact and potential actual cost savings of treatment are particularly important with the current economic climate.

Osteoarthritis in patients with anterior cruciate ligament rupture: a review of risk factors

The risk factors for the development of osteoarthritis (OA) in patients who have had an anterior cruciate ligament (ACL) rupture are reviewed. Although the principle arthrogenic factor is the increased anterior tibial displacement that is associated with the rupture, other direct and indirect factors contribute. Meniscal and chondral injuries can be present before, during, and develop after the index injury, making assessment of the relative importance of each difficult. Most studies concentrate on the radiological changes following ACL rupture and reconstruction. However the rate of significant symptomatic OA needing major surgical intervention is lower. This needs to be considered when advising patients on the management of their ruptured ACL. The long-term outcome in patients who are symptomatically stable following an ACL rupture is uncertain, although in a small cohort of elite athletes all had degenerative changes by 35 years and eight out of 19 (42%) had undergone total knee replacement. At 20 years follow-up the reported risk of developing osteoarthritis is lower after ACL reconstruction (14%-26% with a normal medial meniscus, 37% with meniscectomy) to untreated ruptures (60%-100%).

A correlation of time with meniscal tears in anterior cruciate ligament deficiency: stratifying the risk of surgical delay

Two hundred and five patients with ACL rupture, who had been diagnosed pre-operatively by either MRI scan or knee arthroscopy, had reconstructions between 2003 and 2007. The diagnostic meniscal findings were compared with those at reconstruction, and any further damage along with time from diagnosis to reconstruction was recorded. Those patients with no meniscal damage at the time of diagnosis, and who had no further damage at surgery had a median time of 6 months. This time was significantly different from those with no meniscal damage at diagnosis, but who were found subsequently to have sustained damage to one meniscus, when the median time was 11 months (P = 0.0017) or both menisci, when the median time was 32 months (P = 0.0184). For patients with solitary ACL rupture undergoing a trial of conservative management, an early and thorough assessment of functional stability is essential. If the instability is unacceptable, the patient should be informed of the time dependent risk to the menisci with further delay to surgical reconstruction.

Surgical treatment of an unstable varus knee: one-stage or two-stage?

We present a case of a young female athlete with chronic knee instability and constitutional varus limb, in which the failure of an initial stabilising operation required multiple operations to correct the unstable varus knee: in particular valgus osteotomy and ligament reconstruction using contralateral patellar tendon were performed in two staged operations in order to minimise surgical aggression, optimise rehabilitation and prevent postop complications. The final result is evaluated according to the IKDC chart as normal category A.

Managing anterior cruciate ligament deficiency in the skeletally immature individual: a systematic review of the literature

OBJECTIVE

To perform a systematic review of the literature to answer whether early ACL reconstruction for a skeletally immature individuals result in improved outcome compared with nonsurgical treatment or delaying the reconstruction until skeletal maturity in the pediatric athlete.

DATA SOURCES

Articles were restricted to the English language, and 6 databases were searched (MEDLINE, CINAHL, EMBASE, ACP Journal Club, Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews). The following keywords were used: anterior cruciate ligament, ACL, child, immature, pediatric, pediatric, and young.

SELECTION CRITERIA

All studies examining the ACL reconstruction in skeletally immature individuals, including citations describing complications. Excluded were articles looking at ACL repairs and ACL avulsion injuries. All types of study design, including review articles, were included. Comparative studies were reviewed in detail and analyzed qualitatively.

DATA EXTRACTION AND SYNTHESIS

A total of 615 articles were identified. Sixty-six articles met the inclusion and exclusion criteria. There were no articles with levels of evidence better than level III. The majority of the articles represented case series and reviews with expert opinion.

RESULTS

There were 7 articles that provided comparisons between surgical and nonsurgical treatment in order to answer the question.

CONCLUSIONS

The study designs are inadequate to answer the question of whether early or delayed ACL reconstruction results in the best possible outcome in skeletally immature individuals. Future prospective studies are required to answer the question adequately. A proposed algorithm was described to deal with the question.