A Systematic Review of the Outcomes of Posterolateral Corner Knee Injuries, Part 1: Surgical Treatment of Acute Injuries

Autograft Versus Allograft in Posterolateral Corner Reconstruction: A Systematic Review and Meta-analysis

Background

Several approaches to surgical techniques and graft types exist in posterolateral corner (PLC) reconstruction. The literature lacks knowledge regarding outcomes after autograft versus allograft reconstruction for PLC injuries.

Purpose

To comprehensively review the current literature on PLC reconstruction and compare outcomes between autograft and allograft tissues.

Study Design

Systematic review; Level of evidence, 4.

Methods

The PubMed and Scopus online databases were searched with the terms "PLC,""posterolateral knee,""posterolateral corner," and "reconstruction" in varying combinations. Patient characteristics, graft type, graft failure, surgical techniques, functional outcome scores, and varus laxity on stress radiographs were reviewed and compared between PLC reconstruction with autografts versus allografts.

Results

Included were 22 studies comprising 33 cohorts: 16 autografts (n = 280 knees) and 17 allografts (336 knees). There were 69 isolated PLC reconstructions (58 allografts and 11 autografts) and 493 multiligament reconstructions (269 autografts and 224 allografts). There was no difference in the mean patient age (30.5 vs 33.5 years, respectively; P = .11) or mean follow-up (39.5 vs 37.7 months, respectively; P = .68) between the autograft and allograft groups. There was no evidence to suggest a difference in graft failures between graft types (pooled mean autograft vs allograft: 0.44 vs 0.41 failures; P = .95). There was a significant difference in the mean postoperative Lysholm scores for autografts versus allografts (89.6 vs 85.5, respectively; P = .04). There was no difference between the cohorts in preoperative or postoperative International Knee Documentation Committee (IKDC) scores or postoperative varus laxity.

Conclusion

Our review and meta-analysis indicated no significant differences in graft failure rates or objective outcomes after PLC reconstruction based on graft type alone. There was a significant difference in postoperative Lysholm scores in favor of the autograft group and no significant difference in IKDC subjective scores.

Higher success rate observed in reconstruction techniques of acute posterolateral corner knee injuries as compared to repair: an updated systematic review

PURPOSE

There remains controversy regarding the optimal surgical treatment for acute complete (grade III) posterolateral corner (PLC) injuries. The purpose of this article is to systematically review the contemporary literature regarding surgical options and subsequent outcomes of acute grade III PLC injuries.

METHODS

A systematic review was performed using the following search terms: posterolateral corner knee, posterolateral knee, posterolateral instability, multi-ligament knee, and knee dislocation. Inclusion criteria consisted of studies with level I-IV evidence, reporting on human patients with acute grade III PLC injuries undergoing operative management within 4 weeks from injury, with subjective and/or objective outcomes (including varus stress examinations or varus stress radiographs) reported at a minimum 2-year follow-up. Two investigators independently performed the search by sequentially screening articles. Accepted definitions of varus stability on examination or stress radiographs and revision surgery were used to determine success and failure of treatment.

RESULTS

A total of 12 studies, consisting of 288 patients were included. Ten studies reported primary repair, while reconstruction techniques were reported in seven studies. Overall, 43% (n = 125/288) of injuries involved the PLC, ACL and PCL. Staged reconstruction was reported in 25% (n = 3/12) of studies. The Lysholm score was the most commonly reported outcome measure. An overall failure rate of 12.4% (n = 35/282) was observed. Surgical failure was significantly higher in patients undergoing repair (21.9%; n = 21/96) compared to reconstruction (7.1%; n = 6/84) (p = 0.0058). Return to sport was greater in patients undergoing reconstruction (100%; n = 22/22) compared to repair (94%; n = 48/51) (n.s). The most common post-operative complication was arthrofibrosis requiring manipulation under anesthesia (8.7%; n = 25/288). A total of 3.8% (n = 11/288) of patients underwent revision PLC reconstruction.

CONCLUSION

There remains substantial heterogeneity in the surgical techniques of acute, grade III PLC injuries with an overall failure rate of 12.4%. Failure rates were significantly lower, and return to sport rates higher in patients undergoing PLC reconstruction compared to repair. The most common postoperative complication was arthrofibrosis requiring manipulation under anesthesia.

LEVEL OF EVIDENCE

Level IV.

Tissue Augmentation Techniques in the Management of Ligamentous Knee Injuries

Despite early reports of high failure rates in knee ligament repair techniques resulting in favor of reconstruction, newer advances in surgical technology have shifted the attention back to repair with the addition of various tissue augmentation techniques. Ligament repair preserves proprioceptors in the native ligament and avoids autograft tendon harvest, minimizing the complications associated with donor site ruptures in reconstruction techniques. Tissue augmentation has been successfully used in knee ligamentous and tendon repair procedures, as well as in some upper extremity procedures. This study provides a clinical update on the surgical techniques, biomechanics, and outcomes with the application of various tissue augmentation techniques in the ligaments surrounding the knee joint.

A comparison of stiffness of six knee braces with application for posterolateral corner reconstructions

Posterolateral corner knee injuries are clinically significant, and often require surgical reconstruction. The optimal knee brace following posterolateral corner reconstructions has not yet been determined via clinical nor biomechanical study. We sought to evaluate the stiffness of six types of knee braces to determine the ideal brace type for reducing varus forces, which may have clinical utility for posterolateral corner knee reconstruction rehabilitation. Six different groups of knee braces underwent mechanical testing: cruciate braces, cruciate braces with a valgus bend, medial unloaders, articulating sleeves, hinged braces, and tri-panel immobilizers. Each brace was fitted to the same fiberglass leg model and was secured to the testing apparatus. Force was applied under four-point bending to generate a varus moment about the artificial knee. The stiffness in Newtons per millimeter (N/mm) of each brace was calculated from the slope of the force-displacement curve. The cruciate brace with a valgus bend had the highest average stiffness at 192.61 N/mm (SD 28.53). The articulating sleeve was the least stiff with an average stiffness of 49.86 N/mm (SD 8.99). Stiffness of the cruciate brace was not statistically different compared to cruciate valgus (p = 0.083) or medial unloader (p = 0.098). In this experimental design, a cruciate brace with a valgus bend was shown to have the highest overall stiffness, while an articulating sleeve had the lowest stiffness. Future work will investigate whether this translates into clinical performance.

Over One-Third of Patients With Multiligament Knee Injuries and an Intact Anterior Cruciate Ligament Demonstrate Medial Meniscal Ramp Lesions on Magnetic Resonance Imaging

PURPOSE

To determine the incidence of ramp lesions and posteromedial tibial plateau (PMTP) bone bruising on magnetic resonance imaging (MRI) in patients with multiligament knee injuries (MLKIs) and an intact anterior cruciate ligament (ACL).

METHODS

A retrospective review of consecutive patients surgically treated for MLKIs at 2 level I trauma centers between January 2001 and March 2021 was performed. Only MLKIs with an intact ACL that received MRI scans within 90 days of the injury were included. All MLKIs were diagnosed on MRI and confirmed with operative reports. Two musculoskeletal radiologists retrospectively rereviewed preoperative MRIs for evidence of medial meniscus ramp lesions (MMRLs) and PMTP bone bruises using previously established classification systems. Intraclass correlation coefficients were used to calculate the reliability between the radiologists. The incidence of MMRLs and PMTP bone bruises was quantified using descriptive statistics.

RESULTS

A total of 221 MLKIs were identified, of which 32 (14.5%) had an intact ACL (87.5% male; mean age of 29.9 ± 8.6 years) and were included. The most common MLKI pattern was combined injury to the posterior cruciate ligament and posterolateral corner (n = 27, 84.4%). PMTP bone bruises were observed in 12 of 32 (37.5%) patients. Similarly, MMRLs were diagnosed in 12 of 32 (37.5%) patients. A total of 8 of 12 (66.7%) patients with MMRLs demonstrated evidence PMTP bone bruising.

CONCLUSIONS

Over one-third of MLKI patients with an intact ACL were diagnosed with MMRLs on MRI in this series. PMTP bone bruising was observed in 66.7% of patients with MMRLs, suggesting that increased vigilance for identifying MMRLs at the time of ligament reconstruction should be practiced in patients with this bone bruising pattern.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Comparative Success of Repair Versus Reconstruction for Knee Extra-articular Ligament Injuries

Background

Surgical techniques and associated outcomes in treating acute and chronic extra-articular ligament knee injuries are in evolution, and there is question as to whether repair or reconstruction is optimal.

Purpose/Hypothesis

The purpose of this study was to compare the subsequent surgery rate between surgical repair versus reconstruction for all extra-articular ligament injuries of the knee utilizing a large database. Our hypothesis was that overall surgical repair of both lateral and medial extra-articular knee injuries would have a higher revision rate than those treated by reconstruction.

Study Design

Cohort study; Level of evidence, 3.

Methods

The PearlDiver Mariner data set (2010-2019), with 122 million patients, was utilized to generate 2 patient cohorts: those who underwent surgical repair and those who underwent surgical reconstruction of a knee extra-articular ligament injury. All patients had a minimum of 2 years follow-up. Rates of concomitant or subsequent cruciate ligament reconstruction and rates of secondary procedures were assessed and compared between the 2 cohorts.

Results

In total, 3563 patients were identified: extra-articular ligament reconstruction was performed for 2405 (67.5%), and repair was performed for 1158 (32.5%). Cruciate ligament reconstruction was performed for 986 (27.7%), of which 888 of 986 (90.1%) were performed on the same day as their extra-articular ligament procedure. At 2-year follow-up, the reconstruction cohort had higher rates of revision surgery compared with the repair cohort (8.2% vs 2.5%; P < .001).

Conclusion

Using a large national database, knee extra-articular ligamentous reconstructions (those on both the lateral and the medial side) had a 3.3 times higher rate of revision surgery compared with repair at 2-year follow-up. Further study is needed to investigate the causes leading to revision surgery and to determine the optimal surgical treatment for both medial and lateral extra-articular knee ligament injuries.

Comparison of three surgical techniques of posterolateral knee reconstruction: A cadaver study

BACKGROUND

Injuries to the posterolateral corner (PLC) of the knee are often overlooked but, require reconstruction in order to restore stability in varus and external rotation. Among the many anatomic and non-anatomic PLC reconstruction techniques available, the modified Larson (mLR), LaPrade (LPR) and Versailles reconstruction (VR) procedures are widely used.

HYPOTHESIS

The hypothesis was that anatomic PLC reconstruction (VR and LPR procedures) provides better restoration and control of external rotation.

PATIENTS AND METHODS

Fifteen fresh-frozen cadaveric knees were tested to compare the 3 procedures. Varus laxity on stress radiographs in full knee extension and external rotatory laxity on dial test at 30° flexion were quantified at 3 phases: intact knee, PLC sectioned and PLC reconstructed.

RESULTS

Mean varus laxity did not differ significantly between techniques in intact knees (p=.14), after PLC sectioning (p=.14) or after PLC reconstruction (p=.17). After PLC reconstruction, varus laxity was restored, with no statistical difference between mLR, VR and LPR compared to intact test values (respectively, -1.0, -1.3 and -1.5; p=.98). In all 3 groups, mean external rotation laxity on dial test at 30° flexion did not significantly differ between intact knees (p=.32) and after PLC sectioning (p=.15). After PLC reconstruction, the mLR technique was significantly less effective in restoring rotational stability than the VR and LPR techniques (p=.025).

DISCUSSION

The VR technique provided similar outcomes to LPR for restoring stability in varus and external rotation. The 2 "anatomic" reconstruction procedures (VR and LPR) were significantly more effective than the modified Larson technique for external rotation control, confirming the study hypothesis. Consequently, it remains preferable to use anatomic techniques in multiligament injuries involving the PLC.

LEVEL OF EVIDENCE

IV, cadaver study.

Repair of Acute Grade 3 Combined Posterolateral Corner Avulsion Injuries Using an Enhanced Fixation Technique

Background

Previous studies have suggested that surgical repair of the posterolateral corner (PLC) may be inferior to reconstruction.

Hypothesis

We hypothesized that acute repair (<3 weeks) of avulsion-type PLC multiligament knee injuries with no midsubstance injury would lead to lower failure rates than previously reported for PLC repair.

Study Design

Case series; Level of evidence, 4.

Methods

A total of 28 patients with multiligament knee injuries who underwent acute repair between January 2007 and June 2018 of a PLC avulsion injury with no evidence of midsubstance tearing were included. All PLC avulsion injuries were treated using a transosseous Krackow suture pull-through technique without graft augmentation. Outcome metrics included lateral joint-space widening with varus stress, patient-reported clinical varus instability, patient-reported outcome measures (PROMs), and any subsequent revision or salvage procedure.

Results

The mean time from injury to repair was 8.1 ± 5 days. At a mean follow-up of 2 years (range, 3-90 months), clinical varus stress examination at 30° demonstrated a significant reduction in lateral compartment opening, from 9 ± 3 mm preoperatively to 0 ± 3 mm (P < .0001). The failure rate was calculated to be 10.7% (3/28), which was significantly lower than the failure rate from a 2016 systematic review (38%, 17/45; P = .015). Of the 28 patients, 21 (75%) had PROM scores. Patients who underwent staged bi-cruciate reconstructions (n = 5) had significantly higher subjective International Knee Documentation Committee (IKDC) (87.2 vs 65.5; P = .014) and Lysholm (90.5 vs 75.2; P = .029) scores compared to patients with untreated bi-cruciate injuries (n = 9). Patients with peroneal nerve injury (n = 4) had significantly lower IKDC (58.2 vs 80.8; P = .0045) and Tegner (3.2 vs 5.4; P = .047) scores than those without peroneal nerve injury (n = 17). The mean IKDC and Lysholm scores at final follow-up were 73.4 ± 24.0 and 80.8 ± 23.1 at 7.1 years (range, 2.3-10.6 years) of follow-up.

Conclusion

Repair of acute grade 3 combined PLC avulsion injuries using a transosseous Krackow suture pull-through technique demonstrated a failure rate of 10.7%. Patients who underwent a staged cruciate reconstruction(s) had higher subjective outcome scores than those who had cruciate injuries left untreated. Peroneal nerve injury was associated with lower outcome scores.

High Incidence of Osteoarthritis Observed in Patients at Short- to Midterm Follow-Up after Delayed Multiligament Knee Reconstruction

The aim of this study was to evaluate the incidence of knee osteoarthritis, failure rate of reconstruction, and clinical outcomes of patients with chronic multiligament knee injuries subjected to surgical treatment. Sixty-two patients with chronic knee dislocation subjected to multiligament reconstruction between April 2008 and July 2016 were evaluated, with a minimum follow-up of 24 months. Anteroposterior and lateral radiographs were performed in the pre- and last postoperative evaluation; the progression of degenerative changes according to the Kellgren-Lawrence classification (KL) was assessed. The Schenck classification, Knee Injury and Osteoarthritis Outcome Score (KOOS), time between injury and surgery, type of postoperative rehabilitation protocol (brace vs. external fixator), and physical examination for ligament instability were also evaluated. Univariate and multivariate analysis were performed, p <0.05 was considered significant. Fifty-two (83.9%) patients were men and 16.1% (n = 10) were women, with a mean age of 38.8 ± 1.3 years. The time from injury to surgery was 31.1 ± 6.1 months, and the follow-up time was 6.1 ± 0.5 years. The mean final KOOS was 79.3 ± 10.4 and the overall reconstruction failure occurred in 25.8%. Of all patients, 64.5% (n = 40) presented a KL classification of ≥2 and were defined as having radiographic osteoarthritis (OA). As 11.7% (n = 7) also presented arthritis in the contralateral knee, in 53.2% (n = 33) the progression was most likely due to the initial injury. The failure of ligament reconstruction or residual instability was present in 15 (35.7%) of patients with OA, and only one patient (4.5%) without OA. In the multivariate analysis, only reconstruction failure was an independent predictor of OA (odds ratio = 13.2 [p = 0.028]). There is a high incidence of knee OA following ligament reconstruction for chronic multiligament knee injuries. Ligament reconstruction failure was the only independent predictor for the development of OA in our study.

An Evidence-Based Approach to Multi-Ligamentous Knee Injuries

Multi ligament knee injuries (MLKIs) are highly complex injuries with associated complications and often present with difficult management strategies. MLKIs may affect the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (or posteromedial corner (PMC)), and lateral collateral ligament (or posterolateral corner (PLC)) in addition to other structures including the menisci, common peroneal nerve, and popliteal artery. MLKIs are highly associated with the male sex and are commonly seen in high-velocity motor vehicle accidents and low-velocity sports injuries. Given the multiple planes of movement in the knee and various primary and secondary stabilizers throughout those planes, there is great heterogeneity in an injury pattern and most involve the ACL and PCL. Initial evaluation of this injury includes assessment of lower extremity sensation, distal pulses, and ankle-brachial index (ABI). If vascular compromise is suspected, computed tomography angiography (CTA) or magnetic resonance angiography (MRA) are indicated to evaluate the vasculature. As opposed to CTA, MRA offers visualization of the soft-tissue structures that are commonly damaged in MLKIs. Initial management typically includes closed reduction of the knee with subsequent external fixation. Classification systems guide initial assessments; however, further management is unclear and leads the surgical team to decide the best, individualized management option for each patient. As a result, optimal surgical and postoperative treatment options remain complicated, and clinical outcomes remain difficult to predict. The purpose of this review is to consolidate the most up-to-date practices of the diagnostic workup, management, and treatment of MLKIs.

Posterolateral Corner Reconstruction of the Knee Using Gracilis Autograft and Biceps Femoris

We introduce our technique for posterolateral corner reconstruction, which is based on the principle described in Arciero's technique for anatomic reconstruction of lateral collateral ligament (LCL) and popliteofibular ligament (PFL) to gain static stability in varus strain and external rotation. This technique uses a doubled gracilis autograft to reconstruct the PFL and a split biceps tendon transfer to reconstruct the LCL. Using this technique an anatomical LCL and PFL reconstruction can be performed in combination with anterior cruciate ligament or posterior cruciate ligament reconstruction without contralateral graft harvest or allograft. The technique also enables an isolated reconstruction of LCL or PFL when required and can be performed to augment an acute repair.

Isolated Femoral LCL Avulsion Fracture in the Adult Knee: Two Patient Cases and Literature Review

Avulsion injuries of the LCL most commonly occur at the fibular insertion. Femoral LCL avulsion injuries have only been previously described in pediatric patients or as multiligament knee injury components among adults. This case series with comprehensive literature review describes for the first time 2 cases of isolated LCL femoral avulsion fractures in adults including conservative treatment outcomes. Both patients sustained a strong varus stress mechanism to their right knee, following sport injury or road traffic accident. For both patients, a complete radiographic evaluation including X-rays, MRI, and CT scan confirmed no other associated knee lesions. The femoral LCL avulsion fractures that were observed were minimally displaced and noncomminuted. Furthermore, imagery suggested preserved integrity at the superior lateral genicular artery, adjacent articular capsule, and IT band. Based on clinical and imaging evaluations, the decision was made to follow conservative treatment. By 10 weeks postinjury, both patients were asymptomatic with early radiological fracture healing evidence. Comparative varus stress radiographs at 20° knee flexion revealed no side-to-side differences and clinical exam showed no posterolateral rotatory instability. The second patient case presented with mild femoral LCL attachment calcification on follow-up CT-scan. Following a detailed analysis of anatomic injury characteristics, we suggest that patients with isolated femoral LCL avulsion fractures have low secondary displacement risk provided SLGA, articular capsule, and IT band integrity are present. In contrast to high-grade ligamentous and distal avulsion LCL injuries, we recommend conservative treatment for patients who sustain these lesions.

Elongation Patterns of Posterolateral Corner Reconstruction Techniques: Results Using 3-Dimensional Weightbearing Computed Tomography Simulation

Background:

The isometric characteristics of nonanatomic and anatomic posterolateral corner (PLC) reconstruction techniques under weightbearing conditions remain unclear.

Purpose:

To (1) simulate graft elongation patterns during knee flexion for 3 different PLC reconstruction techniques (Larson, Arciero, and LaPrade) and (2) compute the most isometric insertion points of the fibular collateral ligament (FCL) graft strands for each technique and report quantitative radiographic landmarks.

Study Design:

Descriptive laboratory study.

Methods:

The authors performed a 3-dimensional simulation of 10 healthy knees from 0° to 120° of flexion using weightbearing computed tomography (CT) scans. The simulation was used to calculate ligament length changes during knee flexion for the PLC reconstruction techniques of Larson (nonanatomic single-bundle fibular sling reconstruction), Arciero (anatomic reconstruction with additional popliteofibular ligament graft strand), and LaPrade (anatomic reconstruction with popliteofibular ligament graft strand and popliteus tendon graft strand). The most isometric femoral insertion points for the FCL graft strands were computed within a 10-mm radius around the lateral epicondyle (LE), using an automatic string generation algorithm (0 indicating perfect isometry). Radiographic landmarks for the most isometric points were reported.

Results:

Median graft lengthening during knee flexion was similar for the anterior graft strands of all 3 techniques. The posterior graft strands demonstrated significant differences, from lengthening for the Arciero (9.9 mm [range, 6.7 to 15.9 mm]) and LaPrade (10.2 mm [range, 4.1 to 19.7 mm]) techniques to shortening for the Larson technique (−17.1 mm [range, −9.3 to −22.3 mm]; P < .0010). The most isometric point for the FCL graft strands of all techniques was located at a median of 2.2 mm (range, −2.2 to 4.5 mm) posterior and 0.3 mm (range, −1.8 to 3.7 mm) distal to the LE.

Conclusion:

Overconstraint can be avoided by tensioning the posterior graft strands in the Larson technique in extension, and in the Arciero and LaPrade techniques at a minimum of 60° of knee flexion. The most isometric point was located posterodistal to the LE.

Clinical Relevance:

The described isometric behavior of nonanatomic and anatomic PLC reconstruction techniques can guide optimal surgical reconstruction and prevent graft lengthening and overconstraint of the lateral compartment in knee flexion. Repetitive graft lengthening has been found to be associated with graft failure, and overconstraint favors lateral compartment pressure and cartilage degeneration.

Anatomical reconstruction of the Posterolateral Corner of the knee preserving dynamic function of the popliteus tendon complex

Almost cases of Posterolateral Corner (PLC) injuries are combined injuries involving the anterior or posterior cruciate ligament. Although numerous techniques of PLC reconstruction have been reported, it is unknown whether these techniques reconstruct PLC sufficiently. The anatomy of PLC is complex of tendon-muscle and ligament. The major structures are the fibular collateral ligament (FCL) and the Popliteus Tendon Complex. The latter comprises the popliteus tendon-muscle and the popliteo-fibular ligament (PFL). The FCL and PFL are static stabilizers, whereas the popliteus tendon-muscle is a dynamic stabilizer. The most of current PLC reconstructions statically restore all component parts, therefore not true “anatomically”. We describe an operative technique to reconstruct PLC anatomically. Our technique preserves dynamic stability of the popliteus tendon-muscle and reconstructs the PFL and FCL selectively.Semitendinosus tendon is harvested, and almost used for the anterior or posterior cruciate ligament reconstruction. Gracilis tendon or contralateral semitendinosus tendon is used for PLC. Femoral bone tunnel for FCL is prepared at anatomical insertion. Fibular bone tunnel is prepared to connect PFL insertion with FCL insertion. One end of the graft is sutured to the popliteus tendon. The other end is passed though the fibular tunnel, and fixed at the femoral tunnel. The interference screws are used at each tunnel. One half of the graft composes PFL part, the other half composes FCL part.

Advantages of this technique are preservation of dynamic popliteus tendon-muscle function, and simplifying preparation.

Outcomes after Multiligament Knee Injury Reconstruction using Novel Graft Constructs and Techniques

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.

Development and Assessment of Novel Multiligament Knee Injury Reconstruction Graft Constructs and Techniques

Multiligament knee injury (MLKI) typically requires surgical reconstruction to achieve the optimal outcomes for patients. Revision and failure rates after surgical reconstruction for MLKI can be as high as 40%, suggesting the need for improvements in graft constructs and implantation techniques. This study assessed novel graft constructs and surgical implantation and fixation techniques for anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), posterior medial corner (PMC), and posterior lateral corner (PLC) reconstruction. Study objectives were (1) to describe each construct and technique in detail, and (2) to optimize MLKI reconstruction surgical techniques using these constructs so as to consistently implant grafts in correct anatomical locations while preserving bone stock and minimizing overlap. Cadaveric knees (n = 3) were instrumented to perform arthroscopic-assisted and open surgical creation of sockets and tunnels for all components of MLKI reconstruction using our novel techniques. Sockets and tunnels with potential for overlap were identified and assessed to measure the minimum distances between them using gross, computed tomographic, and finite element analysis-based measurements. Percentage of bone volume spared for each knee was also calculated. Femoral PLC-lateral collateral ligament and femoral PMC sockets, as well as tibial PCL and tibial PMC posterior oblique ligament sockets, were at high risk for overlap. Femoral ACL and femoral PLC lateral collateral ligament sockets and tibial popliteal tendon and tibial posterior oblique ligament sockets were at moderate risk for overlap. However, with careful planning based on awareness of at-risk MLKI graft combinations in conjunction with protection of the socket/tunnel and trajectory adjustment using fluoroscopic guidance, the novel constructs and techniques allow for consistent surgical reconstruction of all major ligaments in MLKIs such that socket and tunnel overlap can be consistently avoided. As such, the potential advantages of the constructs, including improved graft-to-bone integration, capabilities for sequential tensioning of the graft, and bone sparing effects, can be implemented.

The clinical outcome of minimally invasive popliteal tendon recess procedure is comparable to arthroscopic popliteal tendon reconstruction in patients with type A posterolateral rotational instability

PURPOSE

To compare the objective and subjective clinical outcome of minimally invasive popliteal tendon (PT) recess procedure versus arthroscopic PT reconstruction, combined with posterior cruciate ligament reconstruction in patients with Type A posterolateral rotational instability (PLRI). The hypothesis was that the two techniques had comparable clinical outcomes.

METHODS

Between 2012 and 2017, patients who were eligible for inclusion in this study if they (1) had Type A PLRI according to Fanelli's classification with posterior tibial translation > 12 mm on stress radiography and side-to-side difference of dial test external rotation > 10°, (2) PT peel-off lesion or laxity with structural integrity (3) were followed for a minimum of 2 years with examination under anesthesia (EUA) and stress radiograph results. Evaluation included subjective scoring, knee stability examinations and second-look arthroscopic lateral gutter drive-through (LGDT) test. Patients who underwent PT recess procedure were designated as Group A, while patients who underwent arthroscopic PT reconstruction were labelled as Group B. The differences between the two groups were analyzed.

RESULTS

A total of 61 eligible patients with a minimum follow-up time of 2 years were evaluated in the present study. At the final follow-up, there were no significant inter-group differences in Lysholm scores (Group A: 69.0 ± 16.5, Group B: 75.8 ± 14.6, ns), Tegner scores [Group A: 2 (1-4), Group B: 3 (1-5), ns], or IKDC subjective scores (Group A: 70.5 ± 13.5, Group B: 71.1 ± 9.1, ns). No significant difference in side-to-side difference on posterior stress radiography (Group A: 4.3 ± 3.8 mm, Group B: 4.7 ± 4.6 mm, P = 0.701), dial test result (Group A: 0.9 ± 4.4°, Group B: 1.6 ± 4.9°, ns) or LGDT test positive rate (Group A: 2/34, 5.9%, Group B: 2/27, 7.7%, ns) was observed.

CONCLUSION

Both minimally invasive PT recess procedure and arthroscopic PT reconstruction significantly improved the knee stability and subjective outcome comparing with preoperative value. In a comparison with arthroscopic PT reconstruction, the recess procedure demonstrated comparable subjective and objective clinical outcome. When both PT reconstruction and PT recess procedure are indicated, the minimally invasive and graft-free recess procedure can be a viable option.

LEVEL OF EVIDENCE

III.

Clinical outcomes of rectangular tunnel technique in posterior cruciate ligament reconstruction were comparable to the results of conventional round tunnel technique

PURPOSE

To compare clinical outcomes between the conventional round and rectangular tunnel techniques in single-bundle posterior cruciate ligament (PCL) reconstruction.

METHODS

Twenty-seven and 108 patients who underwent PCL reconstructions using a rectangular dilator (Group 1) and rounded tunnel reamer (Group 2), respectively, were included. The exclusion criteria were having a concomitant fracture, osteotomy, subtotal or total meniscectomy, and no remnant PCL tissue. A 4:1 propensity score matching was performed. The knee laxity on stress radiography, International Knee Documentation Committee Subjective Knee Evaluation score, Tegner activity score and Orthopädische Arbeitsgruppe Knie score were evaluated.

RESULTS

No significant differences were found between the groups in terms of clinical scores. (n.s.) The mean posterior translations were also not significantly different between the Group 1 and 2 (3.6 ± 2.8 and 3.8. ± 3.1 mm, respectively; n.s.). However, 3 patients (11.1%) in Group 1 and 15 patients (13.8%) in Group 2 showed posterior translation of > 5 mm. The combined posterolateral corner sling technique was performed for 27 patients (100%) in Group 1 and for 96 patients (88.9%) in Group 2. We found no significant difference in rotational stability at the final follow-up. One patient was found to have a femoral condyle fracture during rectangular femoral tunnel establishment, which was healed after screw fixation, without laxity, during follow-up. The intra- and inter-observer reliabilities of the radiological measurements ranged from 0.81 to 0.89.

CONCLUSION

Arthroscopic anatomical remnant-preserving PCL reconstruction using a rectangular dilator showed satisfactory clinical results and stability as compared with PCL reconstruction using a conventional rounded reamer. Rectangular tunnel technique in PCL reconstruction could be a good treatment option with theoretical advantage to be anatomic.

LEVEL OF EVIDENCE

Level IV.

Knee Posterolateral Corner Reconstruction with a Single Tendon

Knee posterolateral corner (PLC) injuries are troublesome conditions and are always involved in complicated knee-ligament injuries. Various surgical techniques have been reported to address these conditions, in either an open or an arthroscopic manner. However, a simple and effective method is still being pursued. We introduce a mini-invasive PLC reconstruction technique in which a single tendon is used to reconstruct the lateral collateral ligament, the popliteofibular ligament and the popliteal tendon simultaneously. The critical points of this technique are proper location and creation of the tibial, fibular and femoral tunnels, proper passing and setting of the tendon graft, as well as protection of the peroneal nerve. Our clinical experience indicates that this technique is easy to perform and effective. We consider that the introduction of this technique will provide more reasonable options when PLC reconstruction is indicated.

Incidence of Intraoperative and Postoperative Complications After Posterolateral Corner Reconstruction or Repair: A Systematic Review of the Current Literature

BACKGROUND

Posterolateral corner (PLC) injuries of the knee are being increasingly recognized and treated in current orthopaedic practice. While there are numerous systematic reviews evaluating the management and outcomes after PLC injuries, there are limited data investigating complications after PLC reconstruction or repair.

PURPOSE

To systematically review the literature to determine the incidence of postoperative complications after the surgical treatment of PLC injury.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

The Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed (2008-2019), Embase (2008-2019), and MEDLINE (2008-2019) were queried for literature reporting on PLC reconstruction or repair, with or without concomitant ligamentous or meniscal surgery. Data including type of surgery performed, concomitant procedures, and follow-up time were extracted. Complications recorded included intra- and postoperative complications.

RESULTS

After the intra- and postoperative complication data of 60 studies (1747 cases) were combined, surgical management of PLC injuries was associated with an intraoperative complication rate of 0.34% (range, 0%-2.8%) and a postoperative complication rate of 20% (range, 0%-51.2%). The most common postoperative complication was arthrofibrosis (range, 0%-20%). The overall infection rate was 1.3% (range, 0%-10%). Four cases of postoperative common peroneal nerve palsy were reported. Failure of reconstruction or repair was reported in 164 (9.4%) of all cases examined (range, 0%-37.1%).

CONCLUSION

Although the intraoperative rate of complications during PLC reconstructions is low, postoperative complications rates of 20% can be expected, including arthrofibrosis, infection, and neurovascular injury. PLC structures repaired or reconstructed failed in 9.4% of the cases.

ANATOMICAL STUDY OF THE POSTEROLATERAL LIGAMENT COMPLEX OF THE KNEE: LCL AND POPLITEUS TENDON

Objective:

To analyse the distances between the femoral insertions of the popliteus tendon (PT) and the lateral collateral ligament (LCL) through dissections of cadaveric specimens in a mixed population.

Methods:

Fresh cadavers were dissected, and the anthropometric data of all specimens were recorded. The distances from the origin of the PT to the LCL in the femoral region and the diameter of each structure were measured using a digital calliper.

Results:

In total, 11 unpaired knees were dissected, eight men and three women, with an average age of 71.5 ± 15.2 years, weight of 57.2 ± 15.6 kg, and a mean height of 170.5 ± 8.2 cm. The distance from the center of the femoral footprint of the LCL to the PT was 10.0 ± 2.4 mm. The distances between the edges closest to each other and those more distant from each other were 3.1 ± 1.1 mm and 16.3 ± 2.4 mm, respectively.

Conclusion:

The distance between the midpoints of the PT and the LCL in our mixed population is smaller than the distances often reported in the literature. PLC reconstruction with separate tunnels for the LCL and PT may not be technically possible for individuals of any population.Level of Evidence III, Diagnostic studies.

Is There a Disadvantage to Early Physical Therapy After Multiligament Surgery for Knee Dislocation? A Pilot Randomized Clinical Trial

BACKGROUND

Multiligament knee injuries, though rare, can be profoundly disabling. Surgeons disagree about when to initiate rehabilitation after surgical reconstruction due to the conflicting priorities of postoperative stability and motion.

QUESTIONS/PURPOSES

(1) Does early or late initiation of physical therapy after multiligament knee surgery result in fewer postoperative manipulations? (2) Does early versus late physical therapy compromise stability postoperatively? (3) Does early initiation of physical therapy result in improved patient-reported outcomes, as measured by the Multi-ligament Quality of Life (ML-QOL) score?

METHODS

Between 2011 and 2016, 36 adults undergoing multiligament repair or reconstruction were prospectively enrolled in a randomized controlled trial and randomized 1:1 to either early rehabilitation or late rehabilitation after surgery. Eligibility included those with an injury to the posterior cruciate ligament (PCL) and at least one other ligament, as well as the ability to participate in early rehabilitation. Patients who were obtunded or unable to adhere to the protocols for other reasons were excluded. Early rehabilitation consisted of initiating a standardized physical therapy protocol on postoperative day 1 involving removal of the extension splint for quadriceps activation and ROM exercises. Late rehabilitation consisted of full-time immobilization in an extension splint for 3 weeks. Following this 3-week period, both groups engaged in the same standardized physical therapy protocol. All surgical reconstructions were performed at a single center by one of two fellowship-trained sports orthopaedic surgeons, and all involved allograft Achilles tendon PCL reconstruction. When possible, hamstring autograft was used for ACL and medial collateral ligament reconstructions, whereas lateral collateral ligament and posterolateral reconstruction was performed primarily with allograft. The primary outcome was the number of patients undergoing manipulation during the first 6 months. Additional outcomes added after trial registration were patient-reported quality of life scores (ML-QOL) at 1 year and an objective assessment of laxity through a physical examination and stress radiographs at 1 year. One patient from each group was not assessed for laxity or ROM at 1 year, and one patient from each group did not complete the ML-QOL questionnaires. No patient crossover was observed.

RESULTS

With the numbers available, there was no difference in the use of knee manipulation during the first 6 months between the rehabilitation groups: 1 of 18 patients in the early group and 4 of 18 patients in the late group (p = 0.34). Similarly, there were no differences in knee ROM, stability, or patient-reported quality of life (ML-QOL) between the groups at 1 year.

CONCLUSION

With the numbers available in this study, we were unable to demonstrate a difference between early and late knee rehabilitation with regard to knee stiffness, laxity, or patient-reported quality of life outcomes. The results of this small, randomized pilot study suggest a potential role for early rehabilitation after multiligament reconstruction for knee dislocation, which should be further explored in larger multi-institutional studies.

LEVEL OF EVIDENCE

Level II, therapeutic study.

Low-Energy Multiligament Knee Injuries Are Associated With Higher Postoperative Activity Scores Compared With High-Energy Multiligament Knee Injuries: A Systematic Review and Meta-analysis of the Literature

BACKGROUND

Multiligament knee injuries (MLKIs) can result from high-energy injury mechanisms such as motor vehicle accidents or low-energy injury mechanisms such as activities of daily living or sports.

PURPOSE/HYPOTHESIS

The purpose was to conduct a systematic review on postoperative patient-reported outcomes after MLKIs and to conduct a meta-analysis of comparable outcome variables based upon high- versus low-energy injury mechanisms. It was hypothesized that MLKIs with low-energy injury mechanisms would demonstrate significantly improved subjective clinical outcome scores compared with high-energy injuries.

STUDY DESIGN

Meta-analysis and systematic review.

METHODS

A systematic review was performed with the inclusion criteria of postoperative MLKI outcomes based upon high-versus low-energy mechanisms of injury with a minimum 2-year follow-up. Outcome scores included were the Lysholm knee scoring scale, Tegner activity scale, and the International Knee Documentation Committee (IKDC) score. High-energy mechanisms included motor vehicle accidents or falls from a height >5 feet; low-energy mechanisms included sports-related injuries, activities of daily living, or falls from <5 feet. A meta-analysis was performed comparing the outcome scores of high- versus low-energy mechanisms of MLKIs.

RESULTS

Overall, 1214 studies were identified, 15 of which were included in the systematic review and meta-analysis. Thirteen studies included surgical reconstructions of all injured ligaments. A total of 641 patients with 275 high-energy and 366 low-energy injuries were grouped for comparison in the meta-analysis. No significant differences in Lysholm scale (78.6 vs 78.0) or IKDC scores (69.0 vs 68.4) were found between high- and low-energy groups at a minimum of 2 years (range, 2-10 years) postoperatively (P > .05). The low-energy injury group demonstrated significantly higher Tegner activity scale scores (5.0 vs 3.9; P = .03). There was no significant difference in failure rates between groups (3.5% vs 2.0%; P = .23).

CONCLUSION

We found in this systematic review and meta-analysis that patients with low-energy mechanisms of MLKI surgery had improved postoperative Tegner activity scores compared with those patients with high-energy mechanisms after MLKI surgery. However, there were no differences in Lysholm score, IKDC score, or failure rates between high- and low-energy MLKI patients at an average of 5.3 years postoperatively.

Posterolateral Corner Repair With Internal Bracing and Peroneal Nerve Neurolysis

Posterolateral corner (PLC) reconstruction has been shown to be an effective treatment for PLC injuries. Acute anatomical repair of the PLC has the same potential to stabilize the knee; however, outcomes are less defined. Surgical repair minimizes graft harvest morbidity and allows for the maintenance of native tissue proprioception. Furthermore, augmentation with a flat-braided suture (SutureTape; Arthrex) portends additional repair strength and protection. The purpose of this Technical Note and video is to provide our preferred method of PLC repair in a patient with an acute knee dislocation and injury to the biceps femoris, lateral collateral ligament, iliotibial band, popliteofibular ligament, and the meniscocapsular attachment of the lateral meniscus.

Multiple Ligament Reconstructions of the Knee and Posterolateral Corner

Injuries to the knee involving multiple ligaments occur in a variety of circumstances and require careful assessment and planning. A wide constellation of injuries can occur with causes sufficiently traumatic to produce bicruciate ligament deficiency, and this technical report will describe diagnosis, treatment and rehabilitation for a knee dislocation with lateral injury (KD-III-L on the Schenk classification). Reconstruction in the acute setting is preferred, with anatomic-based, single-bundle anterior cruciate ligament reconstruction, double-bundle posterior cruciate ligament reconstruction, and anatomic reconstruction of the posterolateral corner using two grafts for the 3 primary posterolateral corner stabilizers. Tunnel orientation to prevent convergence and sequence of graft tensioning and fixation are discussed as well. Successful outcomes have been achieved using these anatomic-based reconstruction techniques along with appropriate rehabilitation and bracing.

The anatomical relationship of the common peroneal nerve to the proximal fibula and its clinical significance when performing fibular-based posterolateral reconstructions

PURPOSE

The common peroneal nerve (CPN) can be injured during fibular-based posterolateral reconstructions due to its close relationship to the neck of the fibula. Therefore, the purpose of this study was to observe the course of the CPN and its branches around the fibular head and neck and quantify the position in relation to relevant bony landmarks and observe the relation between tunnel drilling for posterolateral corner reconstruction and both the tunnel entry and exit at the proximal fibula and the CPN and its branches was observed.

METHODS

In 101 (mean age = 70.6 ± 16 years) embalmed cadaver knees, the relationship between bony landmarks (tibial tuberosity, styloid process of fibula (APR)) and the CPN and its branches were established and 8 (M1-M8) distances from these landmarks measured; mean, SD and 95% CI were recorded. In 21 of these knees, a fibula tunnel was drilled as in PLC reconstruction and the association of the CPN and its branches to the tunnel entry and exit were judged by two independent observers. Fisher's exact test of independence was used to determine significant differences between genders. Tunnel intersection was analysed in a binary yes/no fashion and was described in frequencies and percentages.

RESULTS

The mean distance from the APR to where the CPN reaches the fibula neck (M1) was 31.4 ± 8.9 mm (CI:29.8-33.0); from the apex of the styloid process (APR) to where the CPN passes posterior to the broadest point of the fibular head (M3) was 21.7 ± 12.6 mm (CI:19.4-24.0); from the apex of the APR to the most proximal point of the CPN/CPN first branch in the midline of the fibular head (M2) was 37.0 ± 6.7 mm (CI: 35.4-37.7). Out of the 21 randomly selected knees for drilling, the first branch of the CPN was damaged at the tunnel entry point in 7 (33%), and in 5 knees (24%), the CPN was damaged at the tunnel exit. In one knee, at both the tunnel entry and exit, the first branch of the CPN and the CPN were intersected, respectively.

CONCLUSION

The results of this study strongly suggest that the CPN is at risk when drilling the fibula tunnel performing fibula-based posterolateral corner reconstructions. The total injury rate was 57% with a 33% incidence of injury to the first branch of the nerve at the tunnel entry and 24% to the CPN at the tunnel exit.

CLINICAL RELEVANCE

Due to the high incidence of injury, percutaneous placement of guide pins and tunnel drilling is not recommended. The nerve should be visualized and protected by either a traditional open approach or minimally invasive techniques. With a minimally invasive approach, the nerve should be identified at the fibula neck and then followed ante- and retrograde.

Anatomic Posterolateral Corner Reconstruction Using Semitendinosus and Gracilis Autografts: Surgical Technique

An anatomically based posterolateral corner (PLC) reconstruction has emerged as a viable and clinically effective surgical technique for midsubstance ligamentous injuries in both the acute and chronic settings. There are several surgical techniques for PLC reconstruction; however, the classic anatomic reconstruction technique (LaPrade technique) is now considered the gold standard and was originally described using an Achilles tendon allograft. In this article, we describe a modified LaPrade autograft technique, in which the same tunnel position, graft passage, and fixation are used to reproduce the 3 primary stabilizers of the PLC. Instead of allografts, hamstring autografts are used while tunnel diameters and fixation devices are adapted to them. With the use of autograft tendons, difficulties related to graft length or asymmetry are encountered. We consider this technique a good alternative for an anatomically based PLC reconstruction, especially given the lower availability and higher cost of allograft tissues in several countries.

Clinical Outcomes of Posterolateral Complex Reconstruction Performed with a Single Femoral Tunnel

The objective of this study is to report the functional outcomes, complications, and reconstruction failure rate of patients undergoing posterolateral complex reconstruction with a single femoral tunnel technique. Patients with posterolateral complex injuries associated with injury of the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), or both undergoing surgical treatment with the single femoral tunnel technique were included in the study. The International Knee Documentation Committee (IKDC) and Lysholm's scales were evaluated, in addition to age, gender, time between trauma and surgery, trauma type, range of motion (ROM) restrictions, peroneal nerve injury, and reconstruction failure. Sixty-six patients were included. Eighteen underwent ACL and posterolateral complex (PLC) reconstruction (group 1), 24 underwent ACL, PCL, and PLC reconstruction (group 2), and 24 underwent PCL and PLC reconstruction (group 3). The mean follow-up was 63 months. The subjective IKDC was 83.7 ± 14.6 for group 1, 74.3 ± 12.6 for group 2, and 66.3 ± 16.0 for group 3 (p < 0.001). The Lysholm's score was 87.1 ± 12.8 for group 1, 79.5 ± 15.0 for group 2, and 77.7 ± 15.2 for group 3 (p = 0.042). There were six reconstruction failures among the patients (9.1%) with no differences among the groups (p = 0.368). Female gender and reconstruction failure were associated with worse outcomes. Patients undergoing reconstruction of PLC structures with the single femoral tunnel technique achieved good functional outcomes and a failure rate similar to literature. Patients undergoing only combined ACL reconstruction showed better outcomes than patients undergoing combined PCL reconstruction. Female gender was associated with a worse functional outcome irrespective of the injury type.

An isolated Posterolateral corner injury with rotational instability and hypermobile lateral meniscus: a novel entity

Purpose

Although complete tear of the knee posterolateral corner (PLC) commonly occurs in combination with other knee ligamentous injuries, the incidence of isolated PLC injury was reported only 28% and overlooked in many cases. Nevertheless, an isolated PLC injury does not only provoke posterolateral instability, but also may be associated to hypermobile lateral meniscus. This study aims at showing the characteristics of isolated PLC injuries and to alert potential overlooked cases by describing their arthroscopic findings and clinical characteristics.

Methods

Seventy-one patients with a clinically proven isolated PLC injury who underwent knee arthroscopy were included in this study. Pre-operative symptoms and clinical signs at examination were recorded: Pain at the posterolateral aspect, feelings of instability, catching, locking; and for clinical signs: McMurray test, varus stress test in extension and at 30° of flexion, posterolateral drawer test at 30° and 80°, dial test at 30° and 80° of flexion. In terms of arthroscopic findings, systematic meniscal stability was performed to evaluate the presence of hypermobile lateral meniscus, “lateral drive through test” was also recorded in all cases.

Results

Positive Lateral Drive through test was found in 69 patients (95.8%). Hypermobile lateral meniscus was seen in all patients.

Conclusions

Hyper mobile lateral meniscus was concomitant with all isolated PLC injuries in our case series. As the typical arthroscopic characteristic, lateral drive through test positive were seen in 95.8%. In order to prevent overlooking this concomitant pathology, meticulous arthroscopic observation is crucial.

Level of evidence

Level IV.

The Pathoanatomy of Posterolateral Corner Ligamentous Disruption in Multiligament Knee Injuries Is Predictive of Peroneal Nerve Injury

BACKGROUND

A description of the precise locations of ligamentous and myotendinous injury patterns of acute posterolateral corner (PLC) injuries and their associated osseous and neurovascular injuries is lacking in the literature.

PURPOSE

To characterize the ligamentous and myotendinous injury patterns and zones of injury that occur in acute PLC injuries and determine associated rates of peroneal nerve palsies and vascular injuries, as well as fracture and dislocation.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

We retrospectively identified all patients treated for an acute multiligament knee injury (MLKI) at our level 1 trauma center from 2001 to 2018. From this cohort, all patients with PLC injuries were identified. Demographics, involved ligaments and tendons, neurovascular injury, and presence of fracture and dislocation were compared with the larger multiligament knee cohort. Incidence and location of injury of PLC structures-from proximal to midsubstance and distal injury-were recorded.

RESULTS

A total of 100 knees in 100 patients were identified as having MLKIs. A total of 74 patients (74%) had lateral-sided ligament injuries. Of these, 23 (31%) had a peroneal nerve palsy associated with their injury; 10 (14%), a vascular injury; and 23 (31%), a fracture. Patients with PLC injuries had higher rates of peroneal nerve injury as compared with those having acute MLKIs without a PLC injury (31% vs 4%; P = .005). Patients with a complete peroneal nerve palsy (n = 17) were less likely to regain function than those with a partial peroneal nerve palsy (n = 6; 12% vs 100%; P < .0001). Complete injury to the lateral collateral ligament (LCL) occurred in 71 of 74 (96%) PLC injuries, with 3 distinct patterns of injury demonstrated. Fibular avulsion of the LCL was the most common zone of injury (65%), followed by femoral avulsion (20%) and midsubstance tear (15%). Location of injury to the LCL was associated with the rate of peroneal nerve injury, with midsubstance tears and fibular avulsions associated with higher rates of peroneal nerve injury.

CONCLUSION

MLKIs with involvement of the PLC are more likely to suffer peroneal nerve injury. The LCL is nearly always involved, and its location of injury is predictive of peroneal nerve injury. Patients with a complete peroneal nerve palsy at presentation are much less likely to regain function.

Knee Dislocations in the Morbidly Obese Patient

Ultra-low-velocity knee dislocations are historically rare but increasingly common events. They occur most frequently in obese, morbidly obese, and super obese patients during everyday activities, but they can be as severe or more severe than high-velocity knee dislocations. Ultra-low-velocity knee dislocations frequently are associated with neurovascular injury and other complications. Diagnosis, early reduction, and identification and treatment of vascular injuries are critical to reducing the risk of limb ischemia and possibly amputation. Given the size of the limb, maintenance of reduction in these patients almost always requires external fixation. Although surgery on morbidly obese patients may be technically challenging, surgical reconstruction leads to improved subjective and objective results and is recommended.

Controversies in acute multiligamentary knee injuries (MLKI)

Multiligament injuries of the knee (MLKI), remain an infrequent pathology especially in developed countries compared to mono-ligament lesions. In Colombia, MLKI is frequent due to the high accident rate on motorcycles. In the city of Bogota alone, about 160 motorcycle accidents have been estimated daily, being one of the cities that proportionately use this means of transport less compared to small cities. The term MLKI, include all ruptures of two or more major ligaments and therefore it has a broad spectrum of clinical presentation which creates a great challenge for the orthopedists and the surgeons envolved in this topic. The literature is rich in studies level IV but very poor in level I and level II, which generates controversies and little consensus in the diagnosis and treatment of this pathology. However there has been a gradual and better understanding of all factors involved in the treatment of MLKI that has improved the functional results of these knees in our patients, in fact we currently are more precise to achieve accurate diagnosis, evolved from not surgical approach to operate most, applying new anatomical and biomechanical concepts, with specialized and skill surgical techniques with more stable and biocompatible fixation implants, which allow in most cases to initiate an early integral rehabilitation program. Nevertheless due to the complexity and severity of the lesions, in some patients the functional results are poor. The goal of this revision is to identify the most frequent controversies in the diagnosis and treatment of MLKI, defining which of them are agreed according to what is reported in the literature and share some concepts based from the experience of more than 25 years of the senior author (MM) in the management of these injuries. LEVEL OF EVIDENCE: V - Expert Opinion.

Long term outcome of early single stage surgery in multi-ligamentous injuries of knee

BACKGROUD

Multi-ligamentous knee injuries have been a grey area due to unavailability of large scale control trials with a long term follow up. Several studies have documented good results with different protocols of management regarding time of treatment, repair versus reconstruction, choice of graft and sequence of repair. The author wishes to put forward long-term results of early (<6 weeks) single-stage surgery in multi ligamentous injuries.

METHODS

The prospective trial included 29 patients diagnosed with three or more ligaments involved. Patients having fractures involving proximal tibia, distal femur, patella, patients with history of compound trauma to knee, osteochondral lesions, associated neuro-vascular injury & poly-trauma patients were excluded from the study. The patients also underwent AP, lateral & stress skiagrams in addition to a standard 3T MR scan for pre-operative planning and confirmation of diagnosis. The pre & post-operative outcomes were assessed using KSS & Lysholm score. The patients were followed up for two years with clinical examination and stress skiagrams.

RESULTS

The mean increase in knee scores was statistically significant at both 12 months and 24 months (p < 0.05) with mean ROM of 132.8° at final follow-up. Three patients required manipulation under anaesthesia. All patients could carry out their activities of daily living at mean period of 8.2 months. Osteoarthritis was most common complication at 2 years follow-up.

CONCLUSION

The most important aspect of a single stage reconstruction lies in earlier restoration of function with a tremendous decrease in loss of medical expenses, improvement of quality of life and early & improved function in terms of both physical and psychological factors. Better restoration of kinematics from early rehabilitation is probably the factor responsible for the results. Osteoarthritis remains an important follow-up finding.

Large variability exists in the management of posterolateral corner injuries in the global surgical community

PURPOSE

The management of posterolateral corner (PLC) injuries has significantly evolved over the past 2 decades. The purpose of this study was to determine the current worldview of key concepts on the diagnosis, treatment strategy, and rehabilitation for patients presenting with PLC injuries.

METHODS

A 12-question multiple-choice online survey was designed to address key questions in the diagnosis, treatment, and rehabilitation of PLC injuries. The survey was distributed to the most important international sports medicine societies worldwide. Clinical agreement was defined as > 80% of agreement in responses and general agreement was defined as > 60% of agreement in responses.

RESULTS

975 surgeons completed the survey with 49% from Europe, 21% from North America, 12% from Latin America, 12% from Asia, and smaller percentages from Africa and Oceania. Less than 14% of respondents manage more than ten PCL injuries yearly. Clinical agreement of > 80% was only evident in the use of MRI in the diagnosis of PLC injury. Responses for surgical treatment were split between isometric fibular-based reconstruction techniques and anatomically based fibular and tibial-based reconstructions. A general agreement of > 60% was present for the use of a post-operative brace in the early rehabilitation.

CONCLUSION

In the global surgical community, there remains a significant variability in the diagnosis, treatment, and postoperative management of PLC injuries. The number of PLC injuries treated yearly by most surgeons remains low. As global clinical consensus for PLC remains elusive, societies will need to play an important role in the dissemination of evidence-based practices for PLC injuries.

LEVEL OF EVIDENCE

IV.

Proximal Tibiofibular Dislocation in a Closing-Wedge High Tibial Osteotomy Causes Lateral Radiological Gapping of the Knee: A Prospective Randomized Study

BACKGROUND

To determine whether a proximal tibiofibular joint dislocation (TFJD) increases lateral compartment gapping more than a fibular head osteotomy (FHO) during a closing-wedge high tibial osteotomy (CWHTO). The second objective was to determine whether lateral compartment gapping affects clinical outcomes.

METHODS

A prospective randomized clinical study was carried out that included 18 patients in Group 1 (FHO) and 18 in Group 2 (TFJD). Varus-stress radiographs of all the patients with both knees at full extension and at 30 ° of flexion were studied pre-operatively and 12 months post-operatively. Lateral compartment gapping was measured in millimeters. The Knee Society Score (KSS) was used to assess clinical stability.

RESULTS

The difference between the pre- and post-operative measurements relative to gapping in the lateral knee compartment at 0 ° of knee flexion was 1.3 mm (SD 1.8) in Group 1 and 4.5 mm (SD 2.4) in Group 2 (p = 0.006). At 30 ° of knee flexion, this difference was 1.9 mm (SD 1.2) in Group 1 and 5.2 mm (SD 3.1) in Group 2 (p = 0.01). No differences were observed in the pre- and post-operative period relative to gapping in healthy knees. Pre-operatively, both groups presented similar KSS knee values: Group 1 with 54.7 (SD 11.7), Group 2 with 54.8 (SD 11.1) (n.s.). Post-operatively, these values were also similar: Group 1 with 93.2 (SD 7.4), Group 2 with 93.5 (SD 5.5) (n.s.).

CONCLUSIONS

In patients who have undergone a CWHTO, TFJ dislocation increases knee lateral compartment gapping when compared to an FHO at 0 ° and 30 ° of knee flexion. However, this fact seems to have no repercussion on the functional status of the knees as measured with the KSS at the one-year follow-up.

Editorial Commentary: Those Who Don't Know History Are Condemned to Repeat It-What Are the Next Steps to Improve Posterolateral Knee Outcomes?

Two decades ago, it was not uncommon to call the posterolateral corner of the knee the "dark side of the knee." This was because there were few quantitative anatomic data, no anatomic-based reconstructions, and a high rate of clinical outcome failures. Most nonanatomic posterolateral reconstruction procedures at the time commonly resulted in significant recurrent increases in varus gapping and significant overconstraint in external rotation. Postoperative protocols for treating these injuries were designed to often either cast or immobilize the operative knee for 2 to 6 weeks, which resulted in a higher incidence of arthrofibrosis. In addition, missed or neglected posterolateral corner injuries were frequently the cause of failed anterior and posterior cruciate ligament reconstruction graft failures. Anatomic-based posterolateral corner reconstructions have now been validated clinically to significantly improve patient outcomes. The next steps in improving patient outcomes would be to further refine these anatomic-based techniques, improve postoperative rehabilitation protocols, and ensure that future outcome studies have both patient-reported outcomes and objective data with stress radiographs to confirm that we are building a better mousetrap to treat this pathology.

Biomechanics Following Isolated Posterolateral Corner Reconstruction Comparing a Fibular-Based Docking Technique With a Tibia and Fibular-Based Anatomic Technique Show Either Technique is Acceptable

PURPOSE

To analyze the biomechanical integrity of 2 posterolateral corner (PLC) reconstruction techniques using a sophisticated robotic biomechanical system that enables analysis of joint kinematics under dynamic external loads.

METHODS

Eight cadaveric human knee specimens were tested. Five N·m external torque followed by 5 N·m varus torque was dynamically applied to each specimen. The 6 degrees of freedom kinematics of the joint were measured in 4 states (intact, PLC-deficient, fibular-based docking, and anatomic PLC reconstructed) at 30°, 60°, and 90° of flexion. Tibial external rotation (ER) and varus rotation (VR) were compared.

RESULTS

Under external torque, ER significantly increased from the intact state to the PLC-deficient state across all flexion angles. At 30° of flexion, ER was not significantly different between the intact state (19.9°) and fibular-based (18.7°, P = .336) and anatomic reconstructions (14.9°, P = .0977). At 60°, ER was not significantly different between the intact state and fibular-based reconstruction (22.4°, compared with 19.8° in intact; P = .152) but showed overconstraint after anatomic reconstruction (15.7°; P = .0315). At 90°, ER was not significantly different between the intact state and anatomic reconstruction (15.4°, compared with 19.7° in intact; P = .386) but was with the fibular-based technique (23.5°; P = .0125).

CONCLUSION

Both a fibular-based docking technique and an anatomic technique for isolated PLC reconstruction provided appropriate constraint through most tested knee range of motion, yet the fibular-based docking technique underconstrained the knee at 90°, and the anatomic reconstruction overconstrained the knee at 60°. Biomechanically, either technique may be considered for surgical treatment of high-grade isolated PLC injuries.

CLINICAL RELEVANCE

This biomechanical study utilizing clinically-relevant dynamic forces on the knee shows that either a simplified fibular-based docking technique or a more complex anatomic technique may be considered for surgical treatment of high-grade isolated PLC injuries.

Management of multiligament knee injuries

Up to 18% of multiligament knee injuries (MLKI) have an associated vascular injury.All MLKI should be assessed using the ankle brachial pressure index (ABPI) with selective arteriography if ABPI is < 0.9.An ischaemic limb following knee dislocation must be taken to the operating theatre immediately for stabilization and re-vascularization.Partial common peroneal nerve (CPN) injury following MLKI has better recovery than complete palsy.Posterior tibial tendon transfer is offered to patients with complete CPN palsy if there is no recovery at six months.Operative treatment with acute or staged reconstructions provides the best outcome in MLKI.Effective repair can only be performed within three weeks of injury.There is no difference between repair and reconstruction of medial collateral ligament and posteromedial corner.Posterolateral corner reconstruction has a lower failure rate than repair.Early mobilization following MLKI surgery results in fewer range-of-motion deficits. Cite this article: EFORT Open Rev 2020;5:145-155. DOI: 10.1302/2058-5241.5.190012.

Comparison of concomitant injuries and patient-reported outcome in patients that have undergone both primary and revision ACL reconstruction-a national registry study

BACKGROUND

Anterior cruciate ligament (ACL) revision surgery has been associated with inferior outcome compared with primary ACL reconstruction. However, this has rarely been investigated in a consecutive cohort limited to patients that have undergone both primary and revision ACL reconstruction. This study aimed to assess differences in outcome and concomitant injuries between primary and revision ACL reconstruction in such a cohort, and to identify predictors of the patient-reported outcome after ACL revision.

METHODS

Patients who had undergone both primary and revision ACL reconstruction were identified in the Swedish National Knee Ligament Registry. Patients aged 13-49 years with hamstring tendon primary ACL reconstruction and data on the Knee Injury and Osteoarthritis Outcome Score (KOOS) on at least one occasion (preoperative or one year postoperatively) at both surgeries were eligible. Concomitant injuries and the KOOS were compared between each patient's primary and revision ACL reconstruction. Linear regression analyses were performed to determine predictors of the one-year KOOS after ACL revision.

RESULTS

A total of 1014 patients were included. Cartilage injuries increased at ACL revision (p < 0.001), as 23.0% had a cartilage injury at ACL revision that was not present at primary ACL reconstruction. The 1-year KOOS was lower after ACL revision compared with primary ACL reconstruction, with the largest difference in the KOOS sports and recreation (5.2 points, SD 32.2, p = 0.002). A posterolateral corner (PLC) injury at ACL revision was a negative predictor of KOOS, with the largest effect on the sports and recreation subscale (β = - 29.20 [95% CI - 50.71; - 6.69], p = 0.011). The use of allograft for ACL revision was an independent predictor of a poorer KOOS QoL (β = - 12.69 [95% CI - 21.84; - 3.55], p = 0.0066) and KOOS₄ (β = - 11.40 [95% CI - 19.24; - 3.57], p = 0.0044).

CONCLUSION

Patients undergoing ACL revision reported a 1-year outcome that was slightly inferior to the 1-year outcome after their primary ACL reconstruction. An ACL revision was associated with an increase in cartilage injuries. A PLC injury at ACL revision and the use of allograft for ACL revision predicted a clinically relevant poorer KOOS one year after ACL revision.

Single-Stage Multiple-Ligament Knee Reconstructions for Sports-Related Injuries: Outcomes in 194 Patients

BACKGROUND

Outcomes after sports-related multiple-ligament knee reconstructions are limited.

PURPOSE

To evaluate outcomes after single-stage surgical treatment of sports-related multiple-ligament knee injuries and to compare outcomes after anterior cruciate ligament (ACL)-based and posterior cruciate ligament (PCL)-based multiple-ligament knee reconstructions.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Skeletally mature patients with at least 2 major knee ligaments torn during a sporting activity that required surgery with a minimum of 2 years' follow-up were included. The Lysholm score, Tegner activity scale, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and 12-Item Short Form Health Survey Physical Component Summary were collected preoperatively and at a minimum of 2 years' follow-up. Clinical data, including range of motion and knee stability, were also recorded at final follow-up.

RESULTS

A total of 276 patients with multiple-ligament knee injuries incurred during sport participation from 2010 to 2016 were identified. Of the 276 patients, 194 (70.5%) had complete follow-up at a mean 3.5 years (range, 2-8 years). There was a significant improvement in all outcome scores as compared with the preoperative scores (P < .001 for all scores). The median (first and third quartiles) Tegner activity score improved from 1 (0, 2) preoperatively to 6 (4, 7) postoperatively. Significant improvements were from 41 (22, 57) to 90 (78, 95) and 44 (24, 60) to 3 (1, 8) for median Lysholm and WOMAC scores, respectively. There was no significant difference in postoperative outcome scores between patients treated in the acute and chronic phases. Furthermore, there was no significant difference between PCL- and ACL-based multiple-ligament knee injuries. Eighteen (9.3%) patients developed arthrofibrosis requiring reintervention surgery.

CONCLUSION

These results demonstrated that single-stage anatomic-based knee ligament reconstructions with immediate postoperative rehabilitation in the setting of sports-related multiligament injuries yielded significantly improved outcomes irrespective of the ligament injury pattern. In addition, there was no difference in outcomes between ACL- and PCL-based injuries in the setting of sports-related multiligament injuries.

Posterolateral corner of the knee: an expert consensus statement on diagnosis, classification, treatment, and rehabilitation

PURPOSE

To develop a statement on the diagnosis, classification, treatment, and rehabilitation concepts of posterolateral corner (PLC) injuries of the knee using a modified Delphi technique.

METHODS

A working group of three individuals generated a list of statements relating to the diagnosis, classification, treatment, and rehabilitation of PLC injuries to form the basis of an initial survey for rating by an international group of experts. The PLC expert group (composed of 27 experts throughout the world) was surveyed on three occasions to establish consensus on the inclusion/exclusion of each item. In addition to rating agreement, experts were invited to propose further items for inclusion or to suggest modifications of existing items at each round. Pre-defined criteria were used to refine item lists after each survey. Statements reaching consensus in round three were included within the final consensus document.

RESULTS

Twenty-seven experts (100% response rate) completed three rounds of surveys. After three rounds, 29 items achieved consensus with over 75% agreement and less than 5% disagreement. Consensus was reached in 92% of the statements relating to diagnosis of PLC injuries, 100% relating to classification, 70% relating to treatment and in 88% of items relating to rehabilitation statements, with an overall consensus of 81%.

CONCLUSIONS

This study has established a consensus statement relating to the diagnosis, classification, treatment, and rehabilitation of PLC injuries. Further research is needed to develop updated classification systems, and better understand the role of non-invasive and minimally invasive approaches along with standardized rehabilitation protocols.

LEVEL OF EVIDENCE

Consensus of expert opinion, Level V.

The Clinical Outcome of Arthroscopic Versus Open Popliteal Tendon Reconstruction Combined With Posterior Cruciate Ligament Reconstruction in Patients With Type A Posterolateral Rotational Instability

PURPOSE

To compare the objective and subjective clinical outcomes of arthroscopic versus open popliteal tendon (PT) reconstruction combined with posterior cruciate ligament reconstruction in patients with type A posterolateral corner injury.

METHODS

From January 2012 to March 2016, patients were eligible for inclusion in this study if they (1) had type A posterolateral rotational instability according to Fanelli's classification, (2) underwent arthroscopic (group A) or open PT (group B) reconstruction, and (3) were followed for a minimum of 2 years with second-look arthroscopic findings. For evaluation, this study used subjective scoring systems (Lysholm, Tegner, and International Knee Documentation Committee subjective scores), knee stability examinations (side-to-side differences of tibial external rotation angle by dial test and posterior and varus stress radiographs), and second-look arthroscopic lateral gutter drive-through tests during hardware removal operations.

RESULTS

A total of 38 patients were included in the study. The mean follow-up period was 31.0 ± 5.8 months in group A (n = 21) and 34.8 ± 12.7 months in group B (n = 17). At the final follow-up, all subjective and objective evaluation results were significantly improved compared with the preoperative condition. There were no significant intergroup differences in Lysholm score (group A, 72.7 ± 17.2; group B, 67.2 ± 14.2; P = .818), Tegner score (group A, 2; group B, 2; P = .710), or International Knee Documentation Committee subjective score (group A, 73.0 ± 13.8; group B, 69.7 ± 20.7; P = .561) at the final follow-up. In terms of objective evaluations, there was no difference in side-to-side difference of posterior stress radiography (group A, 4.0 ± 3.2 mm; group B, 5.0 ± 2.9 mm; P = .336) or lateral gutter drive-through test positive rate (group A, 1/21, 4.8%; group B, 2/17, 11.8%; P = .426).

CONCLUSION

Both arthroscopic and open PT reconstruction significantly improved the knee stability and subjective outcome of patients with type A posterolateral rotational instability. In comparison with the open procedure, the arthroscopic PT reconstruction showed similar subjective and objective clinical outcomes.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

A Hamstring-Based Anatomic Posterolateral Knee Reconstruction With Autografts Improves Both Radiographic Instability and Functional Outcomes

PURPOSE

To report the subjective outcomes and objective stability in a series of chronically grade III posterolateral injured knees treated with a hamstring-based anatomic posterolateral corner (PLC) reconstruction technique using autografts.

METHODS

An outcome study of patients with a chronic complete tear of all ligamentous structures of the PLC (>5 mm of varus gapping at 30^o, ≥10° of external tibial rotation during the dial test, ≥4 mm of increased lateral compartment opening during varus stress radiographs) was performed. The patients were evaluated subjectively with Lysholm, International Knee Documentation Committee (IKDC), and Tegner scores and objectively with varus stress radiographs at 20° of knee flexion, IKDC objective scores, and recurvatum evaluation. Institutional review board approval: CEP/UNIFESP n: 1251/2016.

RESULTS

Twenty-nine of 33 patients were available for follow up at an average of 31.9 ± 12.3 months (range, 24-59 months) postoperatively. Twenty-five patients underwent multiple-ligament reconstruction without prior osteotomy. No patient had an isolated PLC knee reconstruction. The average comparative preoperative and postoperative outcomes were, respectively: Lysholm: 49.7 ± 10.3, 81.2 ± 12.8, P < .001, 89.7% met minimal detectable change; IKDC: 36.7 ± 8.3, 70.4 ± 19.8, P < .001, 82.8% met minimal clinically important difference; Tegner, 6.6 ± 1.3, 5.5 ± 1.6, P < .001; and varus stress radiograph: 7.1 ± 3.1 mm, 1.8 ± 1.8 mm, P < .001. A significant improvement, P < .001, was found between preoperative and postoperative IKDC objective scores for varus opening at 0° and 30° and external rotation measured by the dial test at 30°. Recurvatum was also improved: preoperatively, 52% had a low-grade and 48% had a high-grade recurvatum, whereas postoperatively, 100% were classified as low grade, P < .001.

CONCLUSIONS

The presented anatomic PLC reconstruction, concomitant to other surgical procedures and ligament reconstructions, is a valid technique in a multiligamentous knee injury involving the PLC, improving subjective outcomes and objective stability in patients with a chronic PLC knee injury, similar to historical controls.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

The use of allograft tissue in posterior cruciate, collateral and multi-ligament knee reconstruction

PURPOSE

Currently both autograft and allograft tissues are available for reconstruction of posterior cruciate, collateral and multi-ligament knee injuries. Decision-making is based on a complex interplay between anatomical structures, functional bundles and varying biomechanical requirements. Despite theoretically better biological healing and reduced risk of disease transmission autografts are associated with donor site morbidity as well as being limited by size and quantity. The use of allografts eliminates donor-site morbidity but raises cost and issues of clinical effectiveness. The purpose of this paper is to review current concepts and evidence for the use of allografts in primary posterior cruciate, collateral and multi-ligament reconstructions.

METHODS

A narrative review of the relevant literature was conducted for PCL, collateral ligament and multi-ligament knee reconstruction. Studies were identified using a targeted and systematic search with focus on recent comparative studies and all clinical systematic reviews and meta-analyses. The rationale and principles of management underpinning the role of allograft tissue were identified and the clinical and functional outcomes were analysed. Finally, the position of postoperative physiotherapy and rehabilitation was identified.

RESULTS

The review demonstrated paucity in high quality and up-to-date results addressing the issue especially on collaterals and multi-ligament reconstructions. There was no significant evidence of superiority of a graft type over another for PCL reconstruction. Contemporary principles in the management of posterolateral corner, MCL and multi-ligament injuries support the use of allograft tissue.

CONCLUSION

The present review demonstrates equivalent clinical results with the use of autografts or allografts. It remains, however, difficult to generate a conclusive evidence-based approach due to the paucity of high-level research. When confronted by the need for combined reconstructions with multiple grafts, preservation of synergistic muscles, and adapted postoperative rehabilitation; the current evidence does offer support for the use of allograft tissue.

LEVEL OF EVIDENCE

IV.

Preoperative MRI for the Multiligament Knee Injury: What the Surgeon Needs to Know

The multiligament knee injury is devastating and potentially limb threatening. Preoperative magnetic resonance imaging for the evaluation of the multiligament knee injury is an invaluable clinical tool, and when the radiologist is familiar with how certain injury patterns influence management, optimal outcomes can be achieved. We provide a detailed description of the relationship between salient imaging features of the multiligament knee injury, focusing on the preoperative magnetic resonance imaging, and their influence on clinical decision-making.

Repair and Augmentation with Internal Brace in the Multiligament Injured Knee

The internal brace is a ligament repair bridging concept using braided ultra-high-molecular-weight polyethylene suture tape and knotless bone anchors to reinforce ligament strength to allow early mobilization during early-phase healing. This concept can be used in the management of anterior cruciate ligament, posterior cruciate ligament, anterolateral ligament, medial collateral ligament, posteromedial corner, and posterolateral corner injuries. Ligament reinforcement is a concept in which a graft is reinforced and can be used in all aspects of knee ligament reconstruction. There has been a recent resurgence in ligament repair and recent evidence suggests equivalent outcome results.

Fibular Collateral Ligament/ Posterolateral Corner Injury: When to Repair, Reconstruct, or Both

The posterolateral corner (PLC) of the knee was regarded as the "dark side" of the knee because of limited understanding of its anatomy and biomechanics and because of poor outcomes after injuries to PLC structures. These injuries rarely occur in isolation, with 28% reported as isolated PLC injuries. Nonoperative treatment of these injuries has led to persistent instability, development of early osteoarthritis, and poor outcomes. Several techniques for reconstruction of the PLC have been described, and all are reported to improve outcomes. Biomechanically validated anatomic reconstructions are preferred because they restore native knee kinematics and improve clinical outcomes without over-constraining the knee.