At 1 year of follow-up, average extension was 0 degrees, and mean active and passive range of motion was 123 (range, 100 to 140) and 124 (range, 100 to 140) degrees, respectively. All but 1 patient achieved full extension, which developed a 5-degree flexion contracture. None of the 5 peroneal palsies recovered motor function. Two patients elected to have a tendon transfer. Anterior and posterior tibiofemoral translation of >5 mm measured with KT-1000 was present in 6/47 (13%) and 1 (2%) patient, respectively. The mean±SD IKDC scores were 53.3±26.7 (8 to 97.7). Using the IKDC scores, 16/47 (34%) knees were found to be normal, 13/47 (27.6%) near normal, 13 (27.6%) abnormal, and 5 (10.6%) severely abnormal (Table 5). The mean Lysholm knee score was 75.4±22.1 (range, 25 to 98). On the Tegner Activity Level Scale, mean±SD was 5.2±2.7 (range, 1 to 9). On the Tegner score, 17/47 (36%) patients reported their knee function to have a function between 7 and 10 (0 to 10 scale). No patients in the study had rotational instability at final follow-up with clinical assessment of posteromedial or posterolateral rotation (Dial test). Instability, swelling, and pain were equally frequent among patients with poor functional outcome. The mean Pain Visual Analog Scale (VAS) score at rest was 5.2±2.7 SD. Most patients reported some type of pain even with mild activity (Table 3).
Sixteen (34%) patients reported subjective IKDC scores of <50, whereas 21 (45%) had a score between 50 and 74 and 10 (21%) of ≥75. Of the 16 patients in the lowest scoring group, 3 had both medial and lateral meniscus tears. One patient in the mid-scoring group and 2 patients in the high-scoring group also had both medial and lateral meniscus tears. Furthermore, of the 3 open dislocations, 2 occurred in the lowest scoring group. Associated musculoskeletal and other injuries were equally found across all patients. A peroneal nerve palsy was identified in 2 patients in the lowest scoring group, in 2 patients in the mid-scoring group, and in 1 patient in the high-scoring group. Initial popliteal artery occlusion not requiring repair was found in 1 patient in the low-scoring group and 2 in the mid-scoring group.
Complications included 2 superficial infections requiring treatment with oral antibiotics alone, 1 patient with laxity and instability required revision arthroscopic reconstruction of a PCL and subsequent manipulation under anesthesia (MUA) (Table 6). Three other patients required either open lysis of adhesions or MUA. One of the patients underwent an MUA and also underwent concomitant removal of a prominent painful staple (Table 4).
We had a low complication rate in our series. We had 2 superficial infections not requiring operative debridement. One patient had laxity and instability requiring revision arthroscopic reconstruction of the PCL and MUA. Three patients required MUA or open lysis because of stiffness.
One important finding in our study was that utilizing the IKDC, overall one-third of patients had a satisfactory subjective outcome, one-third had an acceptable outcome, and one-third a poor outcome. Scores from objective assessment mirror these results. Pain, instability, and swelling seem to contribute similarly to symptoms in patients with less favorable results.
The intent of this manuscript was to present the high-grade multiligament injuries; hence, KD II’s were not included. Historically, KD II’s are not as unstable, and typically present in a manner in which delayed management is an option.
Some of these injuries represent the most severe knee dislocations in which an almost circumferential avulsion of the capsule occurs, leaving the meniscus devoid of peripheral attachments (Fig. 17). Six of 47 patients (13%) had circumferential avulsions. Similarly, one of the patients with a poor subjective outcome had a concomitant complete patellar tendon avulsion in the setting of an open dislocation. As seen in Figure 17, full thickness cartilage lesions further jeopardize long-term outcome, and may dictate final function but unlikely contributed to the outcomes in our studies, as our follow-up was 12 months. Typically, the effects of cartilage injuries are seen years later after injury.15
Our results show that with the presented protocol, good range of motion can be achieved. In our study all but 1 patient obtained full extension and an acceptable mean range of motion of 0 to 124 degrees. Only 4 patients (8.5%) required an additional procedure to address residual stiffness, and revision surgery to address instability was performed in only 1 patient (2%) at the time of final follow-up.
The soft tissue disruption present in these injuries does not permit safe arthroscopic management in the acute phase, because of the almost invariable presence of capsular disruption and resultant increased risk of compartment syndrome from fluid extravasation into the muscle compartments.16,17 The current literature on knee dislocations favors operative treatment compared with nonoperative management.3,4 In the meta-analysis by Dedmond and Almekinders,3 higher range of motion and Lysholm scores were found in the operative group compared with nonoperative management. The literature also favors early treatment (within 6 wk) over delayed reconstruction, with early treatment showing higher subjective knee scores and activity ratings.5–8 Several studies further support staged surgical treatment consisting of either acute collateral ligament repair or reconstruction and delayed ACL, and/or PCL reconstruction18 or early PCL reconstruction with delayed ACL and collateral ligament reconstruction,13–19 while other studies have shown that delayed reconstruction can also have good results.5,20–22
Open ligamentous repair or arthroscopic repair remains controversial. One concern of open repair is postoperative arthrofibrosis.23 However, a series with open repair and early aggressive modern rehabilitation demonstrated acceptable outcomes. In 2007 Owens et al7 reported a series of patients primarily repaired within 14 days of injury, who had a resultant mean arc of motion of 119.3 degrees and no incidence of late loosening requiring reconstruction. At 2-year follow-up, the mean Lysholm was 89 and Tegner score was 4.4 with arthrofibrosis requiring arthroscopic lysis of adhesions in 5 patients (19%).7 Our patients had an average range of motion arc of 124 degrees, which is comparable to the findings reported by Owen et al7 and other arthroscopic treatment protocols with only 4 additional operations because of stiffness and 3 of these were for a closed manipulation.1,18,21–24
Early stabilization of the PLC historically has been recommended by Shelbourne and Klootwyk.25 Because of risk of late loosening with staged procedures of repair of lateral or medial collaterals and delayed arthroscopic cruciate reconstruction, reconstruction has been recommended in 2 studies and in a JAAOS review article.26–28 One study showing higher failure rates in primary repair of the PLC was published by Stannard et al29 in 2005. This prospective cohort study included 57 PLC injuries in 56 patients of which 44 (77%) were MLIs. Patients were not randomized but were treated with either primary repair of the PLC (n=35) or reconstruction using allograft (n=22), and we found higher failure rates in the primary repair group (37% vs. 9%). Lysholm scores were similar in the repair and reconstruction cohorts of the patients who did not fail (88.2 vs. 89.6).
Levy et al26 also reported similar results in a recent study comparing primary repair versus reconstruction of the posterolateral corner. Both of these studies staged the collateral repair, and the arthroscopic cruciate reconstruction was delayed by an average of 115 days.
Stannard et al30 recently published a randomized control trial of delayed reconstruction of all ligaments with or without the use of a hinged fixator. The patients without the fixator had a significantly increased number of ligament failures (21% vs. 7%, P<0.001), but no difference in the overall percentage of patients who had ligament failure (29% vs. 15%, P=0.15). No differences between groups were seen in Lysholm, IKDC, Pain VAS, or ROM. The IKDC scores for patients in the Stannard study were nearly the same as this study (Ex fix, 56.8; No ex fix, 49.5; Acute repair, 50).
Engebretsen and colleagues have published the largest series (n=85 patients) of early treatment of patients with knee dislocations (KD III-KD V) within 2 weeks of injury with at least 2 years of follow-up. The ACL and PCL were reconstructed arthroscopically and collaterals were repaired if able. This group, which is similar to our cohort, had similar outcome scores as well.24
The efficiency of early surgical treatment and rehabilitation protocol allows 1 hospitalization and operation for the vast majority of patients. Less than 25% of our patients had a secondary surgery. A staged protocol requires additional hospitalizations and a potentially significant cost and morbidity of an external fixator. A staged protocol also makes it difficult to address many associated injuries, such as displaced menisci, patellar tendon tears, periarticular fractures, or quadriceps ruptures.
An important point of this series of patients is that a variety of injuries occur with this injury that can be treated simultaneously early in the postinjury period. Open injuries usually have an initial debridement and closure of the wound and then primary repair or reconstruction of all damaged structures. The patients who had a patellar fracture had the fracture and all ligaments repaired at the time of surgery, and range of motion was initiated at 4 weeks.
Our study has several limitations. We did not identify whether associated fractures and meniscal tears as prognostic indicators of outcome could be a focus of a future study. Because of the small size of our sample, it was not possible to perform a statistical analysis to determine whether predictive factors pertaining to patient demographics or injury pattern exist. Our sample size is relatively limited but larger than most all similar studies except the Engebretson and colleagues cohort. The lack of a control group does not allow for a comparative analysis with, for example, all arthroscopic or staged treatment. Our study included only high-grade multiligamentous injuries (KD III-KD V) that had at least 3 disrupted ligaments. Although there is some heterogeneity in the included group, it does offer a more homogeneous analysis than that offered by most studies, in which all types of knee dislocations are analyzed as a group. Our low follow-up of 64% could have skewed the data. Varus and valgus laxity was not formally recorded by stress radiographs in this study. It is important to note that even this was not formally recorded, and only 1 patient in this study needed revision because of laxity or instability. The KT-1000 was used to identify posterior laxity but has been shown to be only moderately reliable in identifying posterior laxity because of posterior sag.31 Furthermore, we performed a prospective follow-up of our patients using a standardized protocol and widely used and validated outcomes scores.
Open operative treatment within 3 weeks of injury with primary repair or reconstruction yields good outcomes in two-thirds of patients, as assessed by standardized knee outcome scores. Neither stiffness nor late laxity is a significant problem, and patients receive only one operation. On the basis of our study and other studies that promote a reconstruction, patients should be counselled that a significant loss of function should be expected.
The authors acknowledge William Neterville, Scott Zuckerman MD for assistance with data collection and Basem Attum for manuscript preparation.
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Keywords:Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved
knee dislocation; anterior cruciate ligament; posterior cruciate ligament; meniscus; patellar tendon; allograft; lateral collateral ligament; medial collateral ligament; posterolateral corner