Schenck’s knee dislocation (KD) I injury: An uncommon pattern

Abstract

Schenck's knee dislocation (KD) I is a very uncommon pattern of KD, where the knee presents with clinical or radiographic evidence of a KD with one of the ligaments of the central pivot preserved. The correlation between imaging and physical examination is of the highest importance to correctly classify this injury. Recently, there have been reports in the literature with large numbers of Schenk's KD I, however this is due to classifying multiligament knee injuries as if they all were KDs rather to an increase of the pattern. In this report the case of an 18-year old patient that sustained a KD with a preserved posterior cruciate ligament is presented.

Examining the Schenck KD I Classification in Patients With Documented Tibiofemoral Knee Dislocations: A Multicenter Retrospective Case Series

“…To our knowledge, there are only 14 cases of radiologically confirmed tibiofemoral Schenck KD I that have been well described in the current orthopaedic literature ( Table 2 ). 4 , 6 , 9 , 10 , 33 , 35 Cooper et al 6 first described 4 cases of anterior KDs with either an isolated ACL disruption or an ACL disruption with an additional PLC injury. Bratt and Newman 4 presented a separate series that included KD cases with injury to either the ACL or PCL and a concomitant complete tear of the MCL.…”

“…Additional examples of Schenck KD I with similar injury patterns were presented in 2 separate case series by Shelbourne 33 and Toritsuka. 35 Most recently, Figueroa et al 9 acknowledged the rarity of these Schenck KD I injuries and presented a case of a posterior KD with an ACL avulsion, intact PCL, and PMC involvement. Collectively, these documented cases provide evidence of there being several unique injury patterns of KDs that involve a single cruciate, yet they all currently fall under the same anatomic classification of a Schenck KD I.…”

“…The protocol for this multicenter study received institutional review board approval. A retrospective chart review was conducted at 2 separate institutions (Yale School of Medicine and NYU Langone Orthopaedic Center) to 33 3 1 isolated ACL, 2 ACL/MCL Bratt (1993) 4 4 2 ACL/LCL, 1 ACL/MCL, 1 PCL/LCL Toritsuka (1999) 35 1 1 isolated ACL Flowers (2003) 10 1 1 ACL/MCL Figueroa (2021) 9 1 identify the patients treated for an MLKI between January 2001 and June 2022. Specific Current Procedural Terminology (CPT) and International Classification of Disease (ICD) codes were used to determine if patients were treated for an MLKI or KD.…”

“…23 Complete tearing of only a single cruciate ligament and clinical and/or radiological evidence of tibiofemoral dislocation (Schenck KD I) is a particularly rare anatomic injury pattern, with only 14 well-characterized instances and only 1 instance involving the posterior cruciate ligament (PCL) (Table 2). 4,6,9,10,33,35 Additional studies have reported cases of Schenck KD I that may have a clinically and/or radiologically confirmed tibiofemoral dislocation. 16,34,36 In the recent literature, there has been a noticeable rise in the reported incidence of multiligament knee injuries (MLKIs) that are classified as Schenck KD I because of the lack of a designated MLKI classification system for non-dislocated MLKIs.…”

“… 23 Complete tearing of only a single cruciate ligament and clinical and/or radiological evidence of tibiofemoral dislocation (Schenck KD I) is a particularly rare anatomic injury pattern, with only 14 well-characterized instances and only 1 instance involving the posterior cruciate ligament (PCL) ( Table 2 ). 4 , 6 , 9 , 10 , 33 , 35 Additional studies have reported cases of Schenck KD I that may have a clinically and/or radiologically confirmed tibiofemoral dislocation. 16 , 34 , 36 …”