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A systematic review on management and outcome of irreducible knee dislocations
Abstract
Background: Irreducible knee dislocations (IKD) are rare and can often be missed or mis-daignosed. The incidence of knee dislocation is quoted between 0.01% and 0.2% of all orthopaedic injuries, with up to 4% of these dislocations sub-classified as irreducible. The primary aim of this systematic review was to analyse cases of IKD described in the literature, with a secondary aim of producing a streamlined approach for managing these patients.
Patients & Methods: A systematic review of the literature was conducted on 1st September 2021 in accordance with the PRISMA guidelines using the online databases Medline and EMBASE. The review was registered prospectively in the PROSPERO database. Case reports or clinical studies or reporting on IKD were included. The studies were appraised using the Methodological Index for Non-Randomized Studies (MINORS) tool and Newcastle-Ottawa quality assessment scale.
Results: The search strategy identified 60 studies eligible for inclusion, giving a total of 114 cases of IKD. Posterolateral dislocation was most common, seen in 85% of cases. The dimple sign was present in 70%. All cases required surgical intervention to achieve joint reduction. The most commonly involved structure blocking reduction was the medial collateral ligament (MCL) ± medial structures, seen in 52.4%. MCL reconstruction or repair was carried out in 32.3% cases. The overall incidence of neurovascular injury was 9% and the overall complication rate was 14.4%.
Conclusion: Based on the findings of this SR we conclude that: the most common type of IKDs are PL dislocations, and the MCL, medial retinaculum and capsule and vastus medialis oblique form the most common structures involved in block to reduction and often will require open reduction and repair in acute setting if arthroscopic reduction fails. The most common pattern of injury to ligament is likely to be ACL, PCL, MCL +/- other structures but the MCL will be the most commonly repaired ligament. The dimple sign is often present and is highly pathognomonic of IKD. The incidence of neuro-vascular injury is uncommon.
The most common post-operative complications likely to be encountered is medial skin necrosis and post-operative knee stiffness. Therefore, patients should be mobilised as early as possible with ROM hinge brace.
Level of evidence: IV
... The traumatic mechanism is usually a posterolateral dislocation with a valgus force applied to a flexed knee [7][8][9]. ...
... The valgus force separates the medial femoral condyle from the tibial plateau, with the medial structures, especially the medial collateral ligament (MCL) along with the capsule and the retinaculum that remain entrapped in the joint as the energy dissipates and the knee partially tries to reduce back [7][8][9]. These structures are hardly extricated with closed maneuvers, so IKDs require early surgical reduction to avoid potential skin and soft tissue necrosis [7][8][9][10]. ...
... The valgus force separates the medial femoral condyle from the tibial plateau, with the medial structures, especially the medial collateral ligament (MCL) along with the capsule and the retinaculum that remain entrapped in the joint as the energy dissipates and the knee partially tries to reduce back [7][8][9]. These structures are hardly extricated with closed maneuvers, so IKDs require early surgical reduction to avoid potential skin and soft tissue necrosis [7][8][9][10]. At inspection, the medial soft tissue entrapment presents as a "dimple sign" or "pucker sign" that, when present, is pathognomonic of IKDs [7][8][9][10]. ...
Purpose: Irreducible knee dislocations (IKDs) are a rare rotatory category of knee dislocations (KDs) characterized by medial soft tissue entrapment that requires early surgical treatment. This systematic review underlines the need for prompt surgical reduction of IKDs, either open or arthroscopically. It describes the various surgical options for ligament management following knee reduction, and it investigates their respective functional outcome scores to assist orthopedic surgeons in adequately managing this rare but harmful KD.
Methods: A comprehensive search in four databases, PubMed, Scopus, Embase, and MEDLINE, was performed, and following the PRISMA guidelines, a systematic review was conducted. Strict inclusion and exclusion criteria were applied. Studies with LoE 5 were excluded, and the risk of bias was analyzed according to the ROBINS-I tool system. This systematic review was registered on PROSPERO. Descriptive statistical analysis was performed for all data extracted.
Results: Four studies were included in the qualitative analysis for a total of 49 patients enrolled. The dimple sign was present in most cases. The surgical reduction, either open or arthroscopically performed, appeared to be the only way to disengage the entrapped medial structures. After the reduction, torn ligaments were addressed in a single acute or a double-staged procedure with improved functional outcome scores and ROM.
Conclusions: This systematic review underlines the importance of promptly reducing IKDs through a surgical procedure, either open or arthroscopically. Moreover, torn ligaments should be handled with either a single acute or a double-staged procedure, leading to improved outcomes.
Level of evidence IV.
... Knee dislocations (KD) and multi-ligament knee injuries result from high-impact trauma and require reduction to restore proper function [3]. When spontaneous or closed reductions are not feasible, the dislocation is considered irreducible, and SR is necessary. ...
Introduction
Dissociation of the knee joint, or knee dislocations (KD), can lead to severe complications, often resulting in multiligament injuries. A subset of these injuries are irreducible by closed reduction and require open reduction. Identifying KDs that necessitate surgical intervention is crucial for optimal outcomes. While previous studies have explored various risk factors, the influence of associated fractures is less understood.
Materials and Methods
We queried the Trauma Quality Improvement Program (TQIP) database from 2017 to 2021, for non-congenital closed knee dislocations requiring surgery. Demographic variables were collected, and ICD-10 codes were used to identify associated tibia, femur, acetabular, and fibula fractures. ICD-10 codes were also used to identify nerve injuries and vascular injuries. Multivariate logistic regression was used to assess factors influencing the need for surgical reduction (SR).
Results
A total of 1,467 patients with KDs were included in the study, of which 411 (28.0%) underwent open surgical reduction (SR) while 1,056 (72.0%) were treated with nonsurgical closed reduction (nSR). Factors associated with SR included concomitant tibia fracture (OR = 1.683, C.I: 1.255-2.256, p < 0.001) and fibula fracture (OR = 1.457, C.I: 1.056-2.011, p = 0.022). Vascular injury had lower odds of SR (OR = 0.455, C.I: 0.292-0.708, p < 0.001).
Conclusion
Our study demonstrated that KDs presenting with concomitant tibia and/or fibula fractures are more likely to require SR. The difficulty posed to closed reduction may be due to the influence of these fracture patterns on surrounding soft tissue as well as the lack of a stable bone structure necessary for achieving proper reduction. Physicians should be aware of the potential risk of this fracture pattern when caring for patients with KDs.
... Despite new treatment strategies and surgical techniques, the severe soft-tissue damage caused by knee dislocation results in a high rate of knee disability [30]. Only 40% of patients reported normal knee function after knee dislocation, while the majority reported abnormal and severely abnormal function [6,17,26,34]. Significant stiffness of the knee joint with limitations in ROM has been described in up to 21% of the patients in the literature, with surgical intervention required by 14% [8]. ...
Purpose
Knee dislocation is a rare but severe injury of the lower extremities. The aim of this study was to report on the epidemiology, diagnostics and treatment of such injuries and to identify negative predictors of clinical outcomes.
Methods
This retrospective analysis included all knee dislocations treated at a Level I Trauma Centre in Germany between 2009 and 2021. Medical records were categorised, collected and analysed in a standardised manner. A follow‐up visit 1 year after the injury focused on limitations in knee mobility.
Results
A total of 120 knee dislocations were included in the study. 29.3% of patients presented to the emergency department with a dislocated joint, and 17.5% ( n = 21) had a neurovascular lesion. At follow‐up 12 months after the injury, 65.8% of the patients reported limitations in the range of motion, and 11.7% ( n = 14) reported severe limitations in daily activities. Site infections due to surgery occurred in 3.3% of patients. Increased body weight ( r = 0.294; p < 0.001 and r = 0.259; p = 0.004), an increased body mass index above 25 kg/m ² (body mass index, r = 0.296; p < 0.001 and r = 0.264; p = 0.004) and deficits in peripheral perfusion as well as sensory and motor function ( r = 0.231; p = 0.040 and r = −0.192; p = 0.036) were found to be negative predictive factors for clinical outcome. For posttraumatic neurovascular injury, lack of peripheral perfusion, insufficient sensory and motor function ( r = −0.683; p < 0.0001), as well as a higher Schenck grade ( r = 0.320; p = 0.037), were identified as independent risk factors. The status of dislocation at the site of the accident and on arrival at the emergency department had no impact on the outcome or neurovascular injury.
Conclusion
Knee dislocation is a rare injury with a high rate of severe complications such as neurovascular lesions. In particular, the initial status of neurovascular structures and injury classification showed a relevant negative correlation with the posttraumatic status of nerves and vessels. In particular, patients with these characteristics need close monitoring to prevent negative long‐term consequences.
Level of Evidence
Level III.
We present an 87-year-old man who suffered a knee dislocation as a result of a low-velocity injury. Owing to an irreducible knee dislocation emergency surgery was necessary. After open reduction we carried out a ligament reconstruction and stabilized the knee with a joint-bridging external fixator.
In order to minimize subsequent damage, immediate surgical intervention should be performed. We think that older patients in particular benefit from a one-stage treatment.
Background
Most cases of bicruciate knee dislocation (KD) with associated posteromedial disruption (KD-IIIM) are reducible, but some cannot be reduced by closed reduction because of soft tissue incarceration.
Purpose
To compare the clinical characteristics and functional outcomes of KD-IIIM injuries in patients with or without incarceration of soft tissue requiring open or arthroscopic reduction.
Study Design
Cohort study; Level of evidence, 3.
Methods
This retrospective cohort study of patients with KD was conducted between January 2013 and December 2017 at a single large institution. We applied a 1:2 matching ratio between patients with irreducible KD-IIIM injuries (irreducible group; n = 14) and those with reducible KD-IIIM injuries (control group; n = 28). There were 13 patients in the irreducible group and 25 in the control group who completed follow-up (≥2 years) and were included in our analysis. The efficacy of treatment in patients with KD was evaluated based on range of motion, the Tegner score, the Lysholm score, and the International Knee Documentation Committee (IKDC) score.
Results
At the end of follow-up, the mean Tegner score was 4.5 (range, 4-6), the mean Lysholm score was 79.2 (range, 60-95), and the mean IKDC score was 78.6 (range, 60.9-95.4) in the irreducible group. The respective results in the control group were 4.6 (range, 3-8), 83.1 (range, 39-100), and 80.6 (range, 42.5-96.6). These scores did not differ significantly between the 2 groups. Similarly, mean range of motion was similar between groups (irreducible, 118.1°; control, 124.8°). In the irreducible group, the acute subgroup showed significantly higher Lysholm and IKDC scores than the chronic subgroup, while the acute and chronic subgroups in the control group showed no significant differences in these respective outcome scores.
Conclusion
In the present study, the treatment of irreducible KD led to similar functional outcomes compared with reducible KD. However, the treatment of chronic irreducible KD led to worse outcomes compared with acute irreducible KD, and therefore, urgent reduction is recommended in these patients.
Knee dislocation is one of the rare orthopedic emergencies that require special management with an annual incidence rate of less than 0.02%.Knee dislocations are classified by Kennedy, according to the direction of tibial dislocation in relation to the femur, as anteromedial, posteromedial, anterolateral, and posterolateral. Operative intervention and multi-ligament reconstruction are usually required in knee dislocation. Interposition of the vastus medialis inside the joint of a dislocated knee is an uncommon scenario where reduction becomes impossible. In this report, we present a case of irreducible knee dislocation with vastus medialis muscle interposition. Before reduction, we performed arthroscopy of the knee and removal of the interposed muscle to prevent extravasation of the fluid by sealing the torn capsular area.
Introduction:
Posterolateral rotary knee dislocation is a rare orthopedic injury that is considered to be irreducible by closed reduction because of soft tissue incarceration. Here, we present a case of posterolateral rotary knee dislocation, which was reduced by closed manipulation.
Case report:
The patientwas a 33-year-old man who sustained a twisting injury to his right knee that was diagnosed as posterolateral rotary knee dislocation by plain radiographs and the characteristic physical finding known as a dimple sign. Under general anesthesia, the knee dislocation was reduced by closed manipulation with internal rotation of the lower leg at knee flexion and reproduced by valgus and external rotation stress. There were was complete tear of posterior cruciate ligament, and partial tear of the anterior cruciate ligament which were not reconstructed. The medial collateral ligament that was detached from the femoral footprint was repaired. One year postoperatively, the range of motion was 0-145°. There was no knee symptom and no ligament instability.
Conclusion:
This is the first report of a successful closed reduction for posterolateral knee dislocation. The mechanism of dislocation was considered valgus and external rotation stress during knee flexion.
Knee dislocation is a rare injury. It represents less than 0.2% of orthopaedic injuries. This case reports a rare form of knee dislocation caused by the impact of a high-energy trauma. In these cases the appropriate assessment and management is needed to ensure that patient receives the proper treatment.
Posterolateral dislocations of the knee are rare injuries. Early recognition and emergent open reduction is crucial. A 48-year-old Caucasian male presented with right knee pain and limb swelling 3 d after sustaining a twisting injury in the bathroom. Examination revealed the pathognomonic anteromedial "pucker" sign. Ankle-brachial indices were greater than 1.0 and symmetrical. Radiographs showed a posterolateral dislocation of the right knee. He underwent emergency open reduction without an attempt at closed reduction. Attempts at closed reduction of posterolateral dislocations of the knee are usually impossible because of incarceration of medial soft tissue in the intercondylar notch and may only to delay surgical management and increase the risk of skin necrosis. Magnetic resonance imaging is not crucial in the preoperative period and can lead to delays of up to 24 h. Instead, open reduction should be performed once vascular compromise is excluded.
Irreducible posterolateral dislocations of the knee are rare lesions, generally caused by high-energy trauma inducing rotational stress and a posterior and lateral displacement of the tibia.
In these conditions, the interposition of abundant soft tissue inside the enlarged medial joint space prevents spontaneous reduction or non-surgical treatment by manipulation of the dislocation. Surgical treatment is therefore compulsory.
We report the clinical case of a woman who suffered a subluxation of the knee while jogging. The case we describe is of interest because it shows that even less severe knee dislocations, like this subluxation caused by a low-velocity sports trauma, may present in an irreducible form requiring open surgery. Clinical-instrumental monitoring did not reveal any signs of vascular or nerve injury. Owing to the irreducibility of the lesion we were obliged to perform open surgery in order to free the joint from the interposed muscle tissue and repair medial capsule-ligament lesions. Repair of the damaged cruciate ligaments was deferred to a second stage, but ultimately rendered necessary by the persistence of joint instability and the need to address the patient’s functional needs. In the literature, different one- and two-step surgical options, performed by arthroscopy or arthrotomy, are reported for such related problems.
The Authors discuss these various options and examine and discuss their own decision taken during the surgical work-up of this case.
Vascular injury is a devastating complication of acute knee dislocation. However, there are wide discrepancies in the reported frequency of vascular injury after knee dislocations, as well as important differences among approaches for diagnosis of this potentially limb-threatening problem.
We determined (1) the frequency of vascular and neurologic injury after knee dislocation and whether it varied by the type of knee dislocation, (2) the frequency with which surgical intervention was performed for vascular injury in this setting, and (3) the frequency with which each imaging modality was used to detect vascular injury.
We searched the MEDLINE(®) literature database for studies in English that examined the clinical sequelae and diagnostic evaluation after knee dislocation. Vascular and nerve injury incidence after knee dislocation, surgical repair rate within vascular injury, and amputation rate after vascular injury were used to perform a meta-analysis. Other measures such as diagnostic modality used and the vessel injured after knee dislocation were also evaluated.
We identified 862 patients with knee dislocations, of whom 171 sustained vascular injury, yielding a weighted frequency of 18%. The frequency of nerve injuries after knee dislocation was 25% (75 of 272). We found that 80% (134 of 160) of vascular injuries underwent repair, and 12% (22 of 134) of vascular injuries resulted in amputation. The Schenck and Kennedy knee dislocation classifications with the highest vascular injury prevalence were observed in knees that involved the ACL, PCL, and medial collateral liagment (KDIIIL) (32%) and posterior dislocation (25%), respectively. Selective angiography was the most frequently used diagnostic modality (61%, 14 of 23), followed by nonselective angiography and duplex ultrasonography (22%, five of 23), ankle-brachial index (17%, four of 23), and MR angiography (9%, two of 23).
This review enhances our understanding of the frequency of vascular injury and repair, amputation, and nerve injuries after knee dislocation. It also illustrates the lack of consensus among practitioners regarding the diagnostic and treatment algorithm for vascular injury. After pooling existing data on this topic, no outcomes-driven conclusions could be drawn regarding the ideal diagnostic modality or indications for surgical repair. In light of these findings and the morbidity associated with a missed diagnosis, clinicians should err on the side of caution in ruling out arterial injury.
Irreducibility of the knee following complete dislocation is a rare event determined by the interposition of various capsulo-ligamentous structures in the joint space. Such cases often require urgent surgical treatment. We report the case of a healthy 70-year-old man with a sprain of the left knee that occurred after a sports trauma. The patient showed knee dislocation with multiple ligamentous injuries and articular block due to interposition of a portion of the vastus medialis muscle. After arthroscopic evaluation, we performed surgical treatment to free the muscle, regularize the medial meniscus and suture the posterior and medial capsule and ligaments; the cruciate ligaments were not treated. The most interesting aspect of the articular damage in this case was a wide detachment of the vastus medialis muscle with intra-articular dislocation. The decision to treat only the posterior lesions and allow the healing of the front ones by rehabilitation treatment was supported by full functional recovery and return to sports activity.
Clinical outcomes after reconstruction for multiligamentous knee injury (MLKI) can be consistently favorable. However, recent implants and technique advances may allow for improvement in outcomes. Our institution has developed novel graft constructs and techniques for reconstructions with preclinical data supporting clinical use. Our study purpose was to assess clinical outcomes after reconstruction for MKLI using our constructs and techniques. Overall success rate, failure/revision rates, return to work (RTW)/return to sports (RTS) rates, and complications were evaluated testing the hypothesis that novel methods would be associated with clinical benefits with respect to applications and outcomes compared with historical results. We reviewed a single-surgeon, longitudinal database of 42 patients who underwent multiligament reconstruction at our institution using these techniques for at least two-ligament injuries. Visual analogue scale (VAS) pain score and PROMIS (patient-reported outcomes measurement information system) were collected preoperatively and postoperatively at a minimum 1-year follow-up. Among these patients, 33 patients (mean age of 28.9 years, mean body mass index (BMI) of 33.2 kg/m2, mean follow-up of 14.2 months) were included for outcomes analyses. With the definition of success as having a VAS score of less than or equal to 2 without revision/salvage surgery due to recurrent/residual instability or arthritis, overall success rate was 88% (29/33). The mean VAS scores improved from 5 ± 2 to 2 ± 2. The mean preoperative PROMIS mental health score was 36.2 ± 7, general health was 33.5 ± 6, pain was 62.7 ± 8, and physical function score was 29.4 ± 3. At the final follow-up, PROMIS MH was 50.2 ± 10, GH was 44.4 ± 9, pain was 54.3 ± 9, and PF was 42.6 ± 8.4. Return to work rate was 94% (31/33), and 52% (17/33) of patients were able to RTS at any level. Our results demonstrated excellent clinical outcomes associated with a primary success rate of 88% and RTW rate of 94%. Intraoperative complications occurred in 9.5% of cases and revision and failure rates were 9% and 3%, respectively. Our initial results suggest that multiligament reconstructions using novel graft constructs and techniques are safe and effective and can be considered an appropriate option for reconstruction of the full clinical spectrum of MLKIs.
Case:
A 43-year-old man suffered an irreducible posterolateral knee dislocation while snowboarding with associated tears of the anterior cruciate, posterior cruciate, medial collateral, and posterolateral corner ligaments. Two closed reduction attempts failed, and magnetic resonance imaging revealed incarcerated soft tissue from a tertiary gastrocnemius muscle head. The patient underwent open reduction and repair/reconstruction of his multiligamentous knee injury. At the 6-year follow-up, the patient did not have pain or instability and returned to recreational activities.
Conclusions:
This case demonstrates that a tertiary gastrocnemius muscle head, the most common anatomical variation, may complicate the closed reduction of an irreducible posterolateral knee dislocation.
Irreducible knee dislocations are a small subset of acute knee dislocations and are extremely rare. The most common type of irreducible knee dislocation is posterolateral, which can be challenging to diagnose both clinically and on plain radiographs. Vascular injury is uncommon and closed reduction is seldom possible due to medial femoral condyle buttonholing through soft tissues requiring open or arthroscopic reduction. Ligament injuries mostly include medial collateral ligament, anterior cruciate ligament, and posterior cruciate ligament. Literature has numerous case reports with a couple of small series giving short- to mid-term outcomes of posterolateral knee dislocations. There is, however, no consensus on management of ligament injuries with case reports showing good outcomes in early or delayed ligament reconstruction. This article sheds light on previous case reports and describes how to identify irreducible knee dislocations and provides an algorithm on how to manage ligament injuries in posterolateral dislocations.
Background
Surgical treatment of multiligament knee injuries (MLKIs) leads to better outcomes but there are controversies about optimal surgical strategies. Debates remain about timing of surgery: acute, staged or delayed and about graft choice: autograft, allograft or a combination of both. Therefore, we performed a retrospective study aiming to evaluate postoperative laxity using stress radiographs and clinical outcomes after one-stage reconstructions of injured ligaments using non-irradiated, fresh-frozen allografts.
Hypothesis
MLKIs treated by one-stage reconstructions using non-irradiated, fresh-frozen allograft may lead to satisfactorily postoperative laxity and clinical outcomes.
Methods
Between November 2013 and July 2015, 23 patients with MLKIs underwent one-stage reconstruction using allograft. Knee injuries were defined according Schenk classification of Knee Dislocation (KD). Patients were evaluated using the Knee injury and Osteoarthritis Outcome Score (KOOS), the Lysholm Knee Scoring Scale, and the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form at a minimum follow-up of 24 months. Postoperative anterior, posterior, varus, and valgus laxities were assessed using stress radiographs and expressed as side-to-side differences (SSD) in millimeters.
Results
Three of 23 patients were lost to follow-up. There were 6 KD-I, 12 KD-III, and 2 KD-IV lesions, 12 lateral-side and 10 medial-side lesions, and 13 acute and 7 chronic cases. Three patients had associated neurovascular injuries. Mean follow-up was at 29.4 ± 6.1 months. Mean valgus SSD was 0.2 mm ± 1.4 mm (range, −2.1–2.2 mm), mean varus SSD was 1.4 mm ± 2.5 mm (range, −1.7 – 6.0 mm), mean posterior SSD was 7.2 mm ± 3.9 mm (range, 1.2 – 16.0 mm), mean anterior SSD was 3.6 mm ± 5.1 mm (range, − 4.8 – 16.8 mm). Overall IKDC ratings were: 4 grade A, 3B, 7C, and 6D. Three patients complained of postoperative instability, with an IKDC rating of D. The mean subjective IKDC score was 67.2 ± 19.6, the mean Lysholm Knee Scoring Scale was 77.3 ± 16.5, and the mean KOOS results were 78.5 ± 16.6 for pain, 67.7 ± 17.4 for symptoms, 86.5 ± 14.2 for daily activities, 56 ± 25.4 for sports, and 47.2 ± 28.6 for quality of life. Nineteen of 20 patients returned to sport—6 to the same level. One patient underwent an arthroscopic arthrolysis due to postoperative arthrofibrosis.
Conclusions
Using non-irradiated allografts for one-stage reconstructions of all the injured ligaments in MLKIs is effective and safe. Anteroposterior stability was difficult to restore, but patients returned to their daily activities and sometimes to their sports activity at the same preinjury level.
Level of evidence
Level IV, case series.
The purpose of this study was to evaluate the clinical outcomes after arthroscopic management of irreducible posterolateral knee dislocation. Twenty-one patients with irreducible posterolateral knee dislocation were treated in our institution from January 2009 to May 2014. Inclusion criteria were as follows: (1) patients who underwent one-stage arthroscopic reduction combined with multiligament reconstruction or repair and (2) patients with a minimum 2-year follow-up. Knee stability was assessed using physical examination and side-to-side differences (SSD) determined with a KT-1000 arthrometer and Telos stress device. Other assessments included the International Knee Documentation Committee (IKDC) subjective score, Lysholm score, Tegner score, and patient satisfaction rate. Thirteen of the 21 patients (8 males and 5 females) met our inclusion criteria and were included in this analysis. The mean age was 37.8 years (range, 27–56 years). The mean time from injury to surgery was 1.84 days (range, 1–3 days). The mean follow-up period was 32.6 months (range, 24–46 months). At the final follow-up, with the exception of one patient who had an abnormal valgus stress test, all patients achieved normal or nearly normal Lachman test, pivot shift test, posterior drawer test, and varus and valgus stress tests. The mean SSD of total anterior–posterior translation and isolated anterior translation determined with a KT-1000 arthrometer were 2.15 ± 1.57 mm (range, 0–6 mm) and 1.61 ± 0.86 mm (range, 1–4 mm), respectively. The mean SSD of anterior translation, posterior translation, and medial and lateral joint gapping determined with a Telos stress device were 2.23 ± 0.92 mm (range, 1–4 mm), 3.23 ± 1.16 mm (range, 2–5 mm), 1.77 ± 1.87 mm (range, 0–7 mm), and 0.46 ± 0.52 mm (range, 0–2 mm), respectively. The IKDC subjective score, Lysholm score, and Tegner score improved significantly postoperatively (p = 0.001) with a satisfaction rate of 84.6%. One-stage arthroscopic reduction combined with multiligament reconstruction or repair was an effective, reliable treatment for irreducible posterolateral knee dislocation. This is a case series with level of evidence as IV.
Irreducible knee dislocation is a rare but devastating orthopedic emergency. Limited discussion about its characteristics has been undertaken due to its low incidence. The purpose of this study was to present a series of irreducible dislocated knees and cumulatively reviewed all existing publications in this filed. A retrospective case series study was undertaken in patients with irreducible knee dislocation. Patients' data were carefully collected and presented. Historical cases of irreducible knee dislocation in published papers were reviewed, and their diagnosis, treatment, and prognosis were summarized. Six patients with six irreducible knee dislocations were enrolled with an average age of 51.2 ± 9.7 years. Patterns of injuries were classified into KD-III M (three cases), KD-IV (two cases), and KD-V (one case). Dimple sign was presented in all cases on both physical examination and MRI. All patients received single-stage arthrotomy together with cruciate ligament reconstruction acutely. In cumulative literature review, 34 papers with 45 irreducible knee dislocations were included. KD-III M was the most familiar type of ligamentous injury (75.0%). Dimple sign was recorded in 83.7% occasions and the most frequent two trapped structures were medial retinaculum (31.8%) and MCL (43.1%). Open reduction was conducted in all cases to reduce the knee, and the prognosis of 88.0% cases was considered to be acceptable after different staged surgery. The "dimple" sign is pathognomonic but not necessary for diagnosis of irreducible knee dislocations. The general consensus for treatment is immediate neurovascular status assessment and acute open reduction.
Knee dislocation is a rare injury. It represents less than 0.2% of orthopaedic injuries. This case reports a rare form of knee dislocation caused by the impact of a high-energy trauma. In these cases the appropriate assessment and management is needed to ensure that patient receives the proper treatment.
Irreducible knee dislocation is a rare orthopedic emergency, which account for approximately 4% of all knee dislocations and the classical “dimple sign” or “pucker sign” on physical examination is been presented as a specific feature that injured medial structure is invaginated into joint space, together with the prominence of the medial femoral condyle. Here we reported a 38-year-old male with irreducible posterolateral knee dislocation and neural compromise. Close reduction was failed in local hospital. Physical examination and radiograph assessment indicated the entrapment of torn medial capsuloligamentous structure, which was later confirmed by arthroscopy. Urgent open reduction and reconstruction was performed in single stage.
Background:
Neglected knee dislocations are extremely uncommon and their management cannot be evidence-based since only a few case reports have been published describing different treatment methods. We present the case of a young man with a neglected posterolateral knee dislocation and a concomitant sciatic nerve injury.
Methods:
A two-stage treatment strategy with gradual reduction using the Ilizarov technique and subsequent arthroscopic anterior and posterior cruciate ligament reconstruction was followed.
Results:
The two-stage treatment approach led to a satisfactory clinical outcome. At the latest follow-up evaluation the patient was fully ambulatory and the knee was painless with no anteroposterior instability.
Conclusions:
In neglected knee dislocations treatment optios are guided by the severity of the concomitant injuries and the status of articulating surfaces. Gradual reduction with the Ilizarov technique and subsequent arthroscopic ligamentous reconstruction is a reliable alternative to open surgical procedures.
A paucity of data exists on the effects of articular cartilage and meniscal injury in the setting of knee dislocations. The purpose of this study is to determine whether concomitant intra-articular injuries at the time of multiligament reconstruction for knee dislocation are associated with inferior outcomes.
The records of patients who underwent surgical treatment for multiligament knee injury between 1992 and 2012 were retrospectively reviewed. Patients included had a PCL-based multiligament knee injury or a minimum of three disrupted ligaments, both indicative of knee dislocation. A logistic regression model was used to determine whether articular cartilage injuries (grade 2 involving ≥50 % of the condylar width or greater, or any grade III/IV lesions) and meniscus tears are predictors of IKDC outcome scores collected at a minimum of 2 years postoperatively.
Of the 121 patients who met inclusion criteria, 2-year minimum follow-up was available on 95 patients (79 %). The cohort was 77 % male and had a median age of 32 years (16-62) at the time of surgery and was followed for an average of 6 years. Articular cartilage injury was present in 40 % of knees: medial femoral condyle (20 %); medial tibial plateau (9 %); lateral femoral condyle (5 %); lateral tibial plateau (4 %); patella (18 %); trochlear (5 %). Meniscal injury was present in 56 % of patients (isolated medial, 22 %; isolated lateral, 22 %; combined, 12 %). IKDC scores were significantly lower for patients with any cartilage damage (p = 0.03), combined medial and lateral meniscus tears (p = 0.02), medial-sided articular cartilage damage (p = 0.03), medial femoral condyle (p = 0.04) and trochlear (p = 0.03) lesions.
Articular cartilage damage and meniscus tears are frequently associated with a knee dislocation. This study showed IKDC scores were significantly lower for patients with cartilage damage or combined medial and lateral meniscus tears at mid-term follow-up of 6 years.
IV.
Closed reduction attempts may be unsuccessful after traumatic knee dislocations on rare occasions. The interposition of the soft tissues on the medial aspect of the joint into the femoral condyle and tibial plateau is shown to be the cause of an unsuccessful reduction. In such cases, open reduction is the recommended method of treatment. In our study, we presented a 16-year-old male with an open knee dislocation after a motorcycle accident. As our closed reduction attempt failed, open joint reduction and repair of the medial collateral ligament and retinaculum was performed in the first stage of treatment. In the second stage, arthroscopic anterior cruciate ligament and posterior cruciate ligament reconstructions were carried out.
Knee dislocation is a serious and relatively uncommon traumatism that every emergency room is supposed to diagnose and treat rapidly. Most of the time these dislocations reduce spontaneously or with closed reduction. If a subluxation persists, an incarceration of soft tissue in the joint must be suspected. Irreducible knee subluxations after dislocation are rare entities better described in the orthopaedic than in the radiological literature. However, the initial radiological assessment is an important tool to obtain the correct diagnosis, to detect neurovascular complications, and to plan the most suitable treatment. In cases of delayed diagnosis, the functional prognosis of the joint and even the limb may be seriously compromised primarily because of vascular lesions. Thereby, vascular imaging is essential in cases of dislocation of the knee, and we will discuss the role of angiography and the more recent use of computed tomography angiography or magnetic resonance angiography. Our patient presented with an irreducible knee subluxation due to interposition of the vastus medialis, and we will review the classical clinical presentation and ‘do not miss’ imaging findings on conventional radiography, computed tomography angiography, and magnetic resonance imaging. Finally, we will also report the classical imaging pathway indicated in knee dislocation, with a special emphasis on the irreducible form.
Knee dislocations are defined as ligament injuries involving at least two of the four most important knee ligaments. Results from recent studies have shown a tendency towards improvement of the functional outcomes with use of an articulated external fixator during the postoperative period following multiligament reconstruction. Our hypothesis was that good knee stability and early gain of range of motion could be achieved with the use of the external fixator after ligament reconstructions.
Fourteen patients with knee dislocations were evaluated after multiligament reconstruction in association with use of a lateral monoplanar external fixator for six weeks. Reconstructions were performed using grafts from a tissue bank. Range of motion was measured after one, two, three, six, twelve months and at the final evaluation at a mean time of 49 months. The assessments were made using objective and subjective IKDC, Lysholm and Tegner scales.
The mean scores were 71.7 for the subjective IKDC score, 81.5 for the Lysholm score. No patient was able to return to previous Tegner score. Out of the 45 ligament reconstructions performed, only four failed during the follow-up time. The mean range of motion of the knee presented a progressive increase from the first to the twelfth month, from 67.8° to 115.7°. Two cases of superficial infection on the site of the external fixator pins were observed.
The use of an external fixator enabled early rehabilitation with range of motion gains starting from the first postoperative month, a low rate of reconstruction failure and minimal complications. Nevertheless, none of the patients returned to the level of activity prevailing prior to the injury.
Level IV, retrospective therapeutic case series.
Copyright © 2014 Elsevier Masson SAS. All rights reserved.
Unlabelled:
We report here a unique case of a 3 year neglected rotatory tibiofemoral dislocation associated with a lateral patellar dislocation. The rotational deformity was gradually corrected using a Taylor spatial frame and the patella was realigned by tibial tubercle osteotomy and transfer. The patient also underwent multiple soft tissue releases and quadricepsplasty to improve knee flexion. At nine year follow-up, the patient has good knee range of motion, a congruent knee joint and a good functional result.
Clinical relevance:
Taylor spatial frame combined with other orthopedic approaches can be a useful tool while dealing with neglected knee dislocations.
Posterolateral knee dislocations are very rare and generally irreducible by closed reduction. It is due to interposition of various portions of medial capsule-ligamentous structure in the knee joint space. In such cases, open reduction is recommended. Only a few cases have been reported in the literature. This article presents an unusual case of irreducible knee dislocation, in which the medial femoral condyle buttonholed through the medial retinaculum and capsular structure. Closed reduction attempt was unsuccessful. Open joint reduction was performed. Direct repair of the medial collateral ligament and retinaculum, and arthroscopic assisted posterior cruciate ligament reconstruction were also performed. Arthroscopic-assisted anterior cruciate ligament reconstruction was carried out in staged operation.
Traumatic knee dislocations are relatively rare and almost always respond to closed reduction; however, a small percentage of knee dislocations are irreducible and in these cases open reduction is frequently required. A 65-year-old man with an unreduced posterolateral knee dislocation with laterally dislocated patella was seen 3 weeks after a motor vehicle accident. Medial femoral condyle was found buttonholed through the medial capsule together with the medial collateral ligament and lying in the medial joint space that allowed posterior rotary dislocation of the joint. Both cruciate ligaments and medial meniscus were torn. There was no evidence of any vascular or nerve injury. Reduction was accomplished by removal of the capsuloligamentous structures which were incarcerated in the trochlea and intercondylar notch and by excision of meniscal tear. Following posterior cruciate ligament reconstruction with patellar tendon autograft, lateral patellar release, vastus medialis advancement, and gracilis transfer were done.
Irreducible posterolateral knee dislocations are rare and complex injuries that are often difficult to treat. Prompt recognition and appropriate early management are vital to the successful long-term outcome for the patient. In this case report, we highlight a single patient presenting with an irreducible posterolateral knee dislocation following a high-energy trauma. Evaluation and management included careful history and physical examination, appropriate imaging studies, and formulation of an early operative plan, leading to a safe and successful knee reduction for this patient. We review the best available evidence to guide orthopedic surgeons in their evaluation and management of the irreducible knee dislocation.
Traumatic knee joint dislocations are relatively rare. Most of knee dislocations are reduced by closed manipulation. However occasionally, especially in the case of soft tissue incarceration, closed reduction may not be possible and open reduction is mandatory. This report introduces a case of irreducible posterolateral rotary knee dislocation with interposition of vastus medialis treated through two-staged operations. In this report, we included preoperative magnetic resonance images (MRI), detailed intraoperative descriptions with photographs and video illustration that show the status of an injured knee joint and the effectiveness of the treatment.
The occurrence rate of common peroneal nerve (CPN) palsy associated with knee dislocation or bicruciate ligament injury ranges from 10 to 40%. The present study sought first to describe the anatomic lesions encountered and their associated prognoses and second to recommend adequate treatment strategy based on a prospective multicenter observational series of knee ligament trauma cases.
Twelve out of 67 knees treated for dislocation or bicruciate lesion presented associated CPN palsy: two females, 10 males; mean age, 32 years. Four sports injuries,three traffic accidents and five other etiologies led to seven complete dislocations and five bicruciate ruptures. Four cases involved associated popliteal artery laceration ischemia; one of the dislocations was open. Paralysis was total in eight cases and partial in four. There were two complete ruptures, three contusions with CPN in continuity stretch lesions and three macroscopically normal aspects.
At a minimum 1 year's follow-up, regardless of the initial surgical technique performed,recovery was complete in six cases, partial (in terms of motor function) in one and absent in five. Without specific CPN surgery, spontaneous recovery was partial in one case, complete in two and absent in none. Following simple emergency or secondary neurolysis, remission was total in four cases and absent in one. Three nerve grafts were all associated with non-recovery.
The present results agree with literature findings. Palsy rates varied with trauma circumstances and departmental recruitment. Neurologic impairment was commensurate to ligamentary damages. The anatomic status of the CPN, subjected to violent traction by dislocation,was the most significant prognostic factor for neurologic recovery. In about 25% of dislocations, contusion-elongation over several centimeters was associated with as poor a prognosis as total rupture. CPN neurolysis is recommended when early clinical and EMG recovery fails to progress and/or in case of lateral ligamentary reconstruction. Possible peripheral nerve impairment needs to be included in the overall functional assessment of treatment for severe ligaments injuries and knee dislocation.
Level IV, prospective study.
Posterolateral knee dislocations are generally irreducible due to the interposition of the medial capsule and retinaculum. These injuries have a 'dimple sign' which shows the invagination of the tissues in the medial joint line. We present an unusual case of an open posterolateral traumatic knee dislocation (KD-4 [ACL/PCL/MCL/LCL-PLC torn] open knee dislocation) without a 'dimple sign'. Closed reduction attempts were unsuccessful. In surgery, it was found that the medial meniscus was detached from the meniscocapsular junction and entrapped in the joint. The medial meniscus was extracted from the joint, and the joint was reduced. The medial meniscus was sutured to the meniscocapsular junction with anchors. This is the first study reporting medial meniscus interposition in an open posterolateral knee dislocation. Moreover, the presented case is peculiar because although it was a posterolateral knee dislocation, the posterolateral ligament complex was also torn.
An 8-year-old man presented after sustaining an injury during a fall. A closed reduction attempt failed, and after several tests, an open reduction was performed. With posterolateral dislocation of the knee, there can be anterior cruciate ligament, posterior cruciate ligament, and medial collateral ligament disruption. At the 6-month (final) follow-up, the patient had no subjective pain or instability. With this type of injury, the approach can be conservative monitoring or repair of all of the ligaments. Because of the age and activity level of our patient, we opted for repair of the medial collateral ligament initially with the possibility of late anterior cruciate ligament and/or posterior cruciate ligament reconstruction.
Knee dislocations are rare injuries. Posterolateral knee dislocations are only a small subset of them. There is a paucity of literature regarding the management of such neglected cases. We report here, a case of neglected irreducible posterolateral knee dislocation treated with open reduction and isolated posterior cruciate ligament reconstruction followed by gradual rehabilitation with good outcome at 3 years followup.
Knowledge of the mechanisms of bicruciate lesions and dislocation of the knee enables analysis and classification in terms of injuries’ location and type, guiding surgery and facilitating assessment. Careful history taking and clinical examination shed light on the mechanism involved, but exact identification of the lesion further requires examination under anesthesia and static and dynamic X-rays and MRI, which together enable precise determination of lesion type and location. There are two types of mechanism: gaping, causing ligament tear; and translation, causing detachment. When a single mechanism is involved, the lesion is said to be “simple”. Simple gaping causes bicruciate lesions without medial, lateral or posterior dislocation. Simple translation causes pure anterior or posterior dislocation. Gaping and translation may also occur in combination, causing dislocation with peripheral tearing. There are two types of classification: descriptive, based on X-ray findings – i.e., static classification; and physiopathological, based on clinical and dynamic X-ray findings. MRI further explores ligament detachment and bone lesions that are inaccessible to clinical and conventional X-ray examination. Physiopathological assessment-based techniques enable surgical procedure to be refined, defining the surgical approach according to lesion location and differentiating between lesions requiring repair (tears) and those with a good likelihood of spontaneous healing (capsuloperiosteal detachment). The classification advocated here is largely inspired by that of Neyret and Rongieras, extended to include dislocation with single bicruciate ligament lesion. It covers peripheral lesions completely, specifying type (tear or detachment) and including all bicruciate lesions as well as dislocations.
Introduction:
The incidence of associated vascular lesions in biligamentous cruciate injuries of the knee ranges from 16 to 64%, with a mean rate of 30%. Treatment of ischemic vascular lesions associated with ligaments injury is well established, comprising emergency arterial vascular repair, most of the times combined to external fixation. In the absence of clinical symptoms of vascular lesion, some authors recommend systematically performing arteriography, while others advocate selectively prescribing this examination in doubtful clinical situations. The present study analyzed data extracted from the prospective series of the 2008 SOFCOT Symposium (dedicated to management of bicruciate knee lesions) and from an analysis of the literature, with emphasis on developing a diagnostic strategy for vascular lesions associated with bicruciate lesions.
Material and methods:
This multicenter prospective study included all patients treated in the reference centers for dislocation or bicruciate lesion of the knee between January 2007 and January 2008. All patients underwent early objective vascular imaging.
Results:
Sixty-seven patients were included. Mean dislocation reduction time was 2 hrs 45 min (max, 21 hrs). There were nine vascular lesions (12%). Absence of vascular lesion could be confirmed in 58 of the 59 patients exhibiting presence of peripheral pulses at initial examination. In one case, a vascular lesion was found on early imaging, but with no clinical consequence. In all eight cases with associated clinical pulse abnormality, complementary vascular check-up confirmed the presence of a vascular lesion. Angioscan induced no error of vascular assessment in this series, with no false positives or false negatives. One patient underwent amputation for critical ischemia. Three patients had vascular surgical treatment, two not undergoing secondary ligament surgery. Four of the five patients whose vascular lesion was conservatively managed by simple observation were able to undergo the scheduled treatment for their ligament lesions.
Discussion:
At initial examination, it is essential to look for the peripheral pulse. In case of ischemic syndrome, the priority is a revascularization procedure associated to intraoperative arteriography. In case of abnormal pulse without obvious ischemia, emergency imaging (usually arteriogram or angioscan) is essential. Where there is no initial clinical vascular abnormality, good practice is less clearly cut. Initially, present pulses are found in a mean 30% (17-55%) of cases of popliteal artery lesion, according to the series. Different authors draw diverging conclusions from this fact. For some, the absence of frank abnormality on clinical examination is sufficient to exclude not any possible anatomic vascular lesion but any vascular lesion requiring surgery. However, even without pulse abnormality, we consider systematic imaging to be justified, partly by the difficulty of ensuring strict monitoring, and partly by the decompensation risk of clinically asymptomatic intimal lesions during the ligament surgery under consideration in most cases. Although many authors cling to the dogma of late emergency arteriography, recent reports argue against this attitude. Angio-MRI has good diagnostic value, but in practice is difficult to obtain in emergency. We would rather advocate angioscanning, which is easily available in emergency and does not incur the risk of local complication associated with arteriography.
This case report describes an irreducible posterolateral knee dislocation with a bone avulsion of the medial epicondyle attached to the medial collateral ligament and adductor magnus tendon entrapped within the joint space.
Knee dislocations are uncommon as isolated orthopaedic injuries, but their prevalence is increased in the setting of high-energy multiple trauma. In these circumstances, it is important for the orthopaedic clinician to recognize and appropriately treat the knee dislocation in parallel with other significant injuries. We report the case of an 18-year-old woman who was involved in a motor vehicle collision and sustained multiple injuries in addition to a posterolateral knee dislocation. An attempt at reduction was made in the initial trauma setting, and the patient was medically stabilized. She was discharged from the hospital in a splint with orthopaedic follow-up and presented 3 months after injury with an unreduced posterolateral dislocation. A single-stage operation was performed with reduction and stabilization of the knee. Postoperatively, the patient has done well and regained significant range of motion.
While posterolateral knee dislocation is a rare entity, its identification has important implications. The invagination of skin seen in posterolateral knee dislocations is referred to as the "dimple sign" on physical exam. We report a case where the "dimple sign" was also demonstrated on magnetic resonance imaging. Failure to recognize this finding on imaging will render the knee irreducible, as a result of interposed tissues, until discovered by the orthopedic surgeon intraoperatively. The incarcerated medial capsule and medial collateral ligament could also be misinterpreted as torn meniscus, as occurred in our case.
Recently published studies have raised the question of whether arteriography is warranted in the evaluation of multiligamentous injuries of the knee.
The objective is to report the frequency of associated vascular injuries in the multiligament-injured knee and examine the role arteriography plays in the treatment protocol.
Case series; Level of evidence, 4.
A retrospective analysis was performed on 71 patients over a 12-year period who had a diagnosis of multiligamentous injury of the knee with a tibial-femoral dislocation documented based on physical examination and magnetic resonance imaging findings.
Of 72 knee injuries involving multiple ligaments, 12 vascular injuries were identified. Four knees were found to have a vascular injury at initial presentation based on abnormal physical examination and confirmed with arteriography. Eight patients with a vascular injury had normal pulses. Routine arteriography discovered an intimal injury of the popliteal artery in 5 of these patients. Arteriography in the remaining 3 patients was interpreted as normal.
These findings suggest that physical examination alone is not sufficient in detecting the majority of vascular injuries after a suspected knee dislocation.
Knee dislocations normally respond to closed reduction; however, a small percentage must be reduced by open operations. A 24-year-old man exhibited typical medial joint-line puckering during repeated reduction attempts and a mild lateral displacement on roentgenograms. A 31-year-old woman had a complete dislocation of her knee, with the femur "buttonholed" through medial soft tissue and entrapped by the joint capsule. Longitudinal incision of the medial joint capsule was the method of reduction. The lateral collateral ligament and both lateral and medial menisci were intact in both cases. However, the medial collateral ligament and the anterior and posterior cruciate ligaments were avulsed from the femur and required fixation.
Irreducible knee dislocation is a rare effection of the knee joint; only 23 cases have been reported in the literature. This is a case report of a 35-year-old man who injured his left knee in a motorcycle accident. Dislocation was documented on radiograph. His neurovascular status was intact. Attempts under sedation and anesthesia and even arthroscopy failed to reduce the dislocation. Eventually, the patient had open reduction of the dislocation. An arthroscopy view of the dislocation showed that the medial femoral condyle was buttonholed through the anteromedial capsule and retinaculum. Arthroscopy was an excellent tool for partial lateral meniscectomy and planning the open surgical procedure.
A unique case of an irreducible fracture dislocation of the knee is reported. A review of the literature revealed no previously reported cases of fracture dislocation of the distal femur not amenable to closed reduction.