Outpatient-based diagnostic criteria for partial ACL injury: clinical outcomes of non-operative treatment and radiographic predictor

Anterior Cruciate Ligament Tear: Individualized Indications for Non-Operative Management

Anterior cruciate ligament (ACL) rupture represents a common sports injury that is mostly managed operatively. However, non-operative treatment can also play a role, despite the limited high-quality published data on ACL tear management. Both methods have shown favorable outcomes, but clear guidelines based on high-quality research are lacking. Several factors should be considered and discussed with the patient before deciding on the best treatment method. These include patient characteristics and expectations, concomitant injuries, and clinical evaluation, with laxity or/and instability being one of the most essential parameters examined. This should eventually lead to an individualized approach for each patient to ensure the best possible outcome. This review aims to delve into all parameters that are related to ACL rupture and guide physicians in choosing the most appropriate treatment method for each patient.

Comparison between a Novel Knee Arthrometer and Simultaneous Stress Radiography for the Diagnosis of Complete and Partial Acute Anterior Cruciate Ligament Tears

OBJECTIVES

The type of ligamentous tear and the degree of knee laxity have important guiding significance for the diagnosis and management of anterior cruciate ligament (ACL) tears. Instrumental measurement is necessary for ACL tears since physical examination and magnetic resonance imaging (MRI) cannot provide an objective and quantitative assessment of knee laxity. This study aimed to compare the application of a novel knee arthrometer and simultaneous stress radiography in differentiating between complete and partial acute ACL tears, and further assess the correlation between the two measurements.

METHODS

A total of 106 patients with complete acute ACL tears and 52 patients with partial acute ACL tears were included in the study. Preoperative arthrometry and simultaneous stress radiography were performed using the Ligs arthrometer at 90, 120, and 150 N to assess side-to-side difference (SSD) in anterior knee laxity. The optimal threshold was determined using the receiver operating characteristic (ROC) curve. The area under the ROC curve (AUC) was used to assess the diagnostic value of the measurement. Pearson's correlation coefficient was used to assess the correlation between the two measurements.

RESULTS

The optimal differential SSD thresholds in the Ligs arthrometer were 2.7 mm at 90 N, 3.8 mm at 120 N, and 4.6 mm at 150 N. Similarly, the optimal differential SSD thresholds in simultaneous stress radiography were 3.8 mm at 90 N, 5.1 mm at 120 N, and 5.6 mm at 150 N. The AUC analysis revealed that the Ligs arthrometer was fairly informative at 90 N (AUC = 0.851), 120 N (AUC = 0.878), and 150 N (AUC = 0.884), and simultaneous stress radiography was highly informative at 90 N (AUC = 0.910), 120 N (AUC = 0.925), and 150 N (AUC = 0.948). Moreover, the AUC of the combined measurements was 0.914 at 90 N, 0.931 at 120 N, and 0.951 at 150 N. A significantly strong correlation was found between the two measurements at 90 N (r = 0.743, p < 0.001), 120 N (r = 0.802, p < 0.001), and 150 N (r = 0.823, p < 0.001).

CONCLUSIONS

The Ligs arthrometer and simultaneous stress radiography proved to be valid diagnostic tools to differentiate between complete and partial acute ACL tears, with a strong correlation between the two measurements in SSD values. Compared with single instrumental measurement, the combination of the two measurements can further improve the diagnostic value in this regard.

Optimal measurement method for anterior instability on stress radiographs in anterior cruciate ligament tear: Considering the effect of static anterior tibial subluxation

INTRODUCTION

Accurate assessment of anterior cruciate ligament (ACL) function is vital for guiding treatment. Nevertheless, the presence of tibial subluxation in the neutral position of a patient with an ACL injury may potentially introduce a confounding factor. This study aims to investigate whether tibial subluxation in the neutral position affects the diagnosis of anterior instability in patients with ACL injuries, potentially impacting the reliability and diagnostic accuracy of stress radiography.

METHODS

This study included 88 patients: 30 with acute complete ACL tears (acute group), 28 with chronic complete ACL tears (chronic group), and 30 patients who underwent knee arthroscopic surgery other than ACL reconstruction (control group). Side-to-side differences (SSD) in stress radiography were measured using the Telos load status and the SSD of the gap between the Telos load and unload statuses. Diagnostic accuracy of the two methods was assessed using areas under the receiver operating characteristic curves (AUCs).

RESULTS

The load SSD (5.92 ± 5.28 mm) was higher than the load-unload SSD (4.27 ± 5.99 mm) in the chronic group (P = 0.017). The load SSD demonstrated a significantly higher diagnostic value than that of the load-unload SSD in the combined group (AUC = 0.920 vs. 0.830; P = 0.012) and chronic group (AUC = 0.913 vs. 0.754; P = 0.002). After adjusting the symptoms for radiographic duration from 6 to 3 months in the chronic group, the load SSD exhibited a significantly higher diagnostic value (AUC = 0.902) than that of the load-unload SSD (AUC = 0.740; P < 0.001).

CONCLUSION

The load SSD provides superior diagnostic accuracy compared to the load-unload SSD in ACL tear cases, where static anterior tibial subluxation may result in false negatives. Although load-unload SSD may have diagnostic value within the first 3 months post-injury, the load SSD method provides a reliable assessment of ACL function for patients beyond this timeframe.

The optimal measurement method considering reliability and validity in the anterior knee laxity of anterior cruciate ligament tears

INTRODUCTION

To seek an optimal measurement method with high reliability and high validity for evaluation of the anterior knee laxity on stress radiographs and comparing the translation values to those of KT-2000 arthrometer.

METHODS

Anterior knee laxity in 77 patients was measured preoperatively using the TelosTM and the KT-2000 arthrometer. Side-to-side difference measurements were taken using three conventional measuring methods and one proposed method (Modified Lateral). The knee position on the stress radiograph was evaluated and scored based on the stress radiograph qualifying criteria depending on stress film correctiveness. Intraclass correlation coefficients were analyzed to evaluate the reliability of the measurement methods and were compared between high (Group H) and low (Group L) radiograph quality score groups for each method. Validity was assessed by comparing the KT-2000 and the TelosTM using Pearson correlation (r value).

RESULTS

The Modified Lateral method showed the best Intraclass Correlation Coefficients (ICCs), followed by Center to Center, and Medial to Medial and Lateral to Lateral methods without considering the quality of Telos. In the comparison between groups based on Telos quality for intra-rater reliability, the Medial to Medial (MM) method demonstrated the best reliability in both groups (MM: ICCs, Group H = 0.942, Group L = 0.917, P = 0.693). As for inter-rater reliability, the Modified Lateral (ML) method exhibited the best reliability in both groups (ML: ICCs, Group H = 0.923, Group L = 0.882, P = 0.547). The value measured using the ML method in Telos showed the highest correlation coefficient with the KT-2000 measured value in both groups H and L. There were no statistically significant differences among the correlation coefficient values.

CONCLUSION

The Modified Lateral method is recommended for its high reliability, taking into account the differences in bilateral knee positions and anatomical discriminability on stress radiographs when evaluating anterior knee translation with Telos. It also best reflected the KT-2000 arthrometer.

LEVEL OF EVIDENCE

Case Series, Level IV.

Spontaneous healing of acute ACL ruptures: rate, prognostic factors and short-term outcome

INTRODUCTION

Anterior cruciate ligament (ACL) reconstruction is considered the first line treatment in ACL rupture. However, some patients return to high intensity sport activities and show a normal knee function without ACL reconstruction. Therefore, aim of this study was to evaluate the rate and prognostic factors of spontaneous healing in patients with ACL rupture and the short-term functional outcome.

METHODS

The rate, prognostic factors and short-term functional results of spontaneous healing in patients with ACL rupture were evaluated in 381 patients. Morphology of ACL rupture and extent of posterior tibial slope (PTS) were classified by MR- and x-ray imaging. In patients with normal knee stability in anesthesia examination and healed ACL during the arthroscopy 6 weeks after trauma ACL reconstruction was canceled. IKDC -, Tegner Activity Score, KT 1000 testing and radiological characteristics were collected 12 months postoperatively in these patients.

RESULTS

14.17% of the patients with ACL rupture showed a spontaneous healing after 6 weeks. Femoral ACL-rupture (p < 0.02) with integrity of ligament stump > 50% (p < 0.001), without bundle separation (p < 0.001) and decreased PTS (p < 0.001) was found significantly more often in patients with a spontaneous healed ACL. The average IKDC score was high at 84,63 in patients with healed ACL at 1 year follow-up, but KT 1000 testing was inferior compared to non-injured side.

CONCLUSION

Spontaneous healing of a ruptured ACL happened in 14% of the patients. Especially in low-demand patients with femoral single bundle lesions without increased posterior tibial slope delayed ACL surgery should be considered to await the possibility for potential spontaneous ACL healing.