Summary

Atypical multi-ligamentous knee injuries (MLKI) involve binary injury: avulsion of one cruciate and tear of the other, or both cruciates avulsion with or without collateral ligament injury. This is the world largest case series from high velocity trauma. The incidence of atypical MLKI in multi-ligamentous injury was 9.53% (66/692). Atypical MLKI can be treated with ARIF and Ligament reconstruction

Abstract

Background

Multi-ligamentous knee injuries(MLKI) fall within a narrow spectrum, accounting for around 11% of all knee injuries. Atypical multi-ligamentous knee injuries (MLKI) involve binary injury: avulsion of one cruciate and tear of the other, or both cruciates avulsion with or without collateral ligament injury.

Purpose

–Of this study is to analyse the clinical and radiological outcomes of patients diagnosed with atypical MLKI, and to assess the differences in outcomes between patients with collateral injury and those without.

Methods

–A retrospective cohort, from total of 692 patients with MLKI who underwent surgery during time period 2010 to 2022, and out of those, 66 patients with atypical MLKI established that they met our selection criteria. 32 of these patients did not have collateral injuries, while the remaining 34 patients did have collateral injuries. Reconstruction for the cruciate tears and open or arthroscopic reduction and Fixation (ORIF/ARIF) of the cruciate avulsion were performed. PCL avulsions were fixed using the double draping approach or single draping technique. Conservative or surgical management of the collateral ligaments was determined based on intraoperative laxity, tissue quality, injury site, and chronicity. Group 1 were atypical MLKI patients who did not have collateral ligament injuries, the and Group 2 were atypical-MLKI patients who had collateral ligament injuries. subgroups of Group 1:Group 1A consists of an ACL tear with PCL-avulsion; Group 1B consists of ACL avulsion with PCL tear; Group 1C- bi-cruciate avulsion; and subgroups of Group 2 consist of components of Group 1 with collateral ligament injury. Comparative statistical analysis was conducted on IKDC score, Lysholm score, knee flexion range of motion (ROM), and laxity on stress radiographs. Friedman test, standard t test, Mann Whitney test for comparing the groups. Multiple linear regression was carried out for method of fixation (suture pull out/staples/CC screws)

Results

– Male : female ratio- 54:12 patients. Average follow up-26.48 months(23-30months). Average age of patients is 37.66(20 – 50years). All patients had significant improvement from pre-op scores to final follow up scores(p<0.001). There was no significant difference between the Atypical MLKI with collateral and Atypical MLKI without collateral injury in terms of the postoperativeIKDC score (P= 0.154),Lysholm score(P =0.387), knee flexion ROM(P= 0.314), laxity on radiographs with anterior stress(P =0.108) and posterior stress(P=0.272). The intergroup analysis was not statistically significant. There was no significant difference in patients' functional outcomes at final follow-up based on fixation modality. Patients recovered to their pre-injury activity levels without knee joint giving way on daily activities. 2in our series had infections. Double draping patients with a PCL avulsion have an average tourniquet time of102.74 +/- 0.64, while single draping patients have an average tourniquet time of103.93 +/- 0.67.

Conclusion

– Incidence of atypical MLKI in multi-ligamentous injury was9.53% (66/692). Atypical MLKI with cruciate avulsion can be treated with ARIF and cruciate tears with reconstruction in single stage – single draping method with good clinical and radiographic results. Atypical MLKI with or without collateral ligament injury had similar outcomes when appropriate techniques are instituted to address collateral ligaments.

Keywords – atypical MLKI, multi-ligamentous knee injury(MLKI), cruciate avulsion, cruciate tear, collateral ligament tear, ORIF, ARIF, staples, suture pull-out.