Arthroscopic reconstruction of the popliteus complex: accuracy and reproducibility of a new surgical technique

Arthroscopic and open reconstruction of the posterolateral corner of the knee have equally good clinical results: first results of a prospective 12-month follow-up study

PURPOSE

Arthroscopic reconstruction techniques for higher-grade posterolateral corner (PLC) injuries (Fanelli Type B, PoLIS LI-B) have not yet been validated in clinical studies. The open reconstruction technique described by Arciero is well-established and showed good restoration of joint stability in previous studies. This study aimed to compare clinical outcomes of this established open surgery technique to a newly developed arthroscopic technique in a prospective randomized clinical trial.

METHODS

Between 2019 and 2021, this study focused on chronic high-grade PLC injuries (Fanelli Type B, PoLIS LI-B). Group A consisted of patients treated with conventional open surgery following Arciero's technique, while Group B included patients treated with Arciero's arthroscopic technique. All cases underwent additional PCL reconstruction. After a minimum 12-month follow-up, clinical scores and objective stability assessments were compared between the groups.

RESULTS

In total, 26 (group A 12, group B 14) eligible patients with a mean follow-up of 14.9 ± 7.2 months were evaluated in the present study. Knee stability and patient-reported outcome scores (PROMS) were significantly improved when comparing pre- and post-operative values (p < 0.0001). No clinically relevant differences in PROMS (Lysholm: A 83.9 ± 11.4 vs. B 85.3 ± 13.8; IKDC: A 76.91 ± 12.6 vs. B 76.8 ± 15.7) were shown in both groups. Additionally, no statistically significant differences were detected between groups with respect to external rotation, range of motion and instrumental stability testing. Arthroscopic reconstruction showed significantly shorter operation time (p = 0.0109). There were no clinical failures or neurovascular complications of the surgical procedures.

CONCLUSION

Both surgical techniques for isolated chronic PLC Fanelli Type B injuries significantly improved the knee stability, were equivalent with respect to PROMs and led to good clinical results. However, arthroscopic PLC reconstruction was associated with a shorter surgery time compared to open PLC reconstruction. Therefore, arthroscopic PLC reconstruction may be a viable option in the hands of an experienced surgeon.

LEVEL OF EVIDENCE

Prospective cohort study, II.

[Posterolateral instability of the knee joint]

The posterolateral corner of the knee is composed of a multilayered complex of ligamentous, musculotendinous, and capsular structures, which interact in a synergistic stabilizing manner with the central structures, particularly the posterior cruciate ligament. Injuries of the posterolateral corner are generally accompanied by rupture of the posterior cruciate ligament. Depending on the injured structures, injuries of the posterolateral corner result in posterolateral rotational instability alone (Fanelli A) or with lateral instability (Fanelli B/C). For rotational instability alone, isolated popliteus bypass is an effective procedure; with concomitant lateral instability in flexion, additional stabilization of the lateral collateral ligament is required. Most of the various available techniques are described as open reconstruction procedures. In recent years, arthroscopic techniques for posterolateral reconstruction have also been successfully developed.

Most Publications Regarding Arthroscopic Treatment of Posterolateral Corner Injuries of the Knee Have a Low Level of Evidence and Provide Limited Information to Determine the Most Effective Treatment

Purpose

To examine the Level of Evidence and overall quality of studies addressing arthroscopic posterolateral corner reconstructions of the knee.

Methods

A search was performed using the PubMed/Medline, Web of Science, and Google Scholar databases for all studies investigating arthroscopic treatment of posterolateral corner injuries of the knee. Studies reporting outcomes or describing arthroscopic techniques for treatment of posterolateral corner injuries of the knee were the focus of this analysis. Clinical as well as biomechanical and cadaveric studies were included. Studies only investigating open techniques were excluded. Two independent reviewers determined the level of evidence for each included study using the criteria established by the Journal of Bone and Joint Surgery and scored each clinical study from 0 to 100 based on 10 criteria from the modified Coleman Methodology Score.

Results

Twenty-four studies matched the inclusion criteria. There were 6 cadaveric technique descriptions, 6 clinical technique descriptions, 3 biomechanical studies, 4 technical repair descriptions, and 5 clinical outcome studies. Thirty-eight percent of all studies were of Level V evidence. Fifty percent of studies were of Level IV evidence, and 12% of studies were of Level III evidence. The mean modified Coleman Methodology Score for the clinical studies was 43 ± 11.4, which is regarded as poor, mainly due to the limited number of patients and the retrospective nature of the studies.

Conclusions

Most studies addressing arthroscopic posterolateral corner reconstruction of the knee are of low level of evidence and provide limited information about the best treatment options.

Clinical Relevance

The number of publications on arthroscopic posterolateral corner reconstruction techniques continues to rise. This systematic review evaluates the level of evidence of these studies.

Adjustable-loop cortical suspension device for posterolateral corner reconstruction in the setting of fibular avulsion fracture: a case series and novel technique description

INTRODUCTION

A novel technique using an adjustable-loop cortical suspension toggle device for reduction of a fibular head avulsion fracture (arcuate fracture) in posterolateral corner (PLC) reconstruction is described. Results of clinical follow-up are presented.

MATERIALS AND METHODS

9 patients were retrospectively identified who underwent posterolateral corner reconstruction using an adjustable-loop cortical suspension toggle device. Radiographic examination was used to evaluate the successful healing of the avulsed fibular head fragments post-operatively.

RESULTS

7 patients reported satisfactory results with their clinical outcome with no feelings of knee instability or objective instability on exam at final follow-up. Post-operative radiographs obtained > 6 months following reconstruction demonstrated well reduced and healed fracture in 5 of 6 patients, with 1 patient demonstrating maintained reduction but incomplete fracture union at 6 months.

CONCLUSION

This novel surgical technique for PLC reconstruction with an avulsed fibular head fracture is a viable alternative to previously described methods. The majority of patients report subjective satisfaction with a stable knee post-operatively.

LEVEL OF EVIDENCE

IV.

Clinical results after arthroscopic reconstruction of the posterolateral corner of the knee: A prospective randomized trial comparing two different surgical techniques

INTRODUCTION

Arthroscopic reconstruction techniques of the posterolateral corner (PLC) of the knee have been developed in recent years. Reconstruction techniques for higher-grade PLC injuries have not yet been validated in clinical studies. This study aimed to compare clinical outcomes of two different techniques and to present results of the first prospective randomized clinical trial of patients to undergo these novel procedures.

MATERIALS AND METHODS

19 patients with Fanelli Type B posterolateral corner injuries and additional posterior cruciate ligament ruptures were included in this prospective study. They were randomly assigned to one of two novel arthroscopic reconstruction techniques, based on open surgeries developed by Arciero (group A) and LaPrade (group B). Follow-up was conducted at 6 and 12 months postoperatively and included clinical examinations for lateral, rotational and posterior stability, range of motion and subjective clinical outcome scores (IKDC Subjective Score, Lysholm Score, Tegner Activity Scale and Numeric Rating Scale for pain).

RESULTS

At 6 and 12 months postoperative, all patients in both groups presented stable to varus, external rotational and posterior forces, there were no significant differences between the two groups. At 12-month follow-up, group A patients showed significantly higher maximum flexion angles (134.17° ± 3.76° vs. 126.60° ± 4.22°; p = 0.021) compared to patients of group B. Duration of surgery was significantly longer in Group B patients than in group A (121.88 ± 11.63 vs. 165.00 ± 35.65 min; p = 0.003). Posterior drawer (side-to-side difference) remained more reduced in group A (2.50 ± 0.69 mm vs. 3.27 ± 0.92 mm; p = 0.184). Subjective patient outcome scores showed no significant differences between groups (Lysholm Score 83.33 ± 7.79 vs. 86.40 ± 9.21; p = 0.621).

CONCLUSIONS

This study indicates sufficient restoration of posterolateral rotational instability, varus instability and posterior drawer after arthroscopic posterolateral corner reconstruction without neurovascular complications. Increased postoperative range of motion and a shorter and less invasive surgical procedure could favor the arthroscopic reconstruction technique according to Arciero over LaPrade's technique in future treatment considerations.

Comparison of Arthroscopic versus Open Placement of the Fibular Tunnel in Posterolateral Corner Reconstruction

INTRODUCTION

 Precise fibular tunnel placement in posterolateral corner (PLC) reconstruction is crucial in restoring rotational and lateral stability. Despite the recent progress of arthroscopic PLC reconstruction techniques, landmarks for arthroscopic fibular tunnel placement and a comparison to open tunnel placement have not yet been described. This study aimed to (1) identify reasonable soft-tissue and bony landmarks, which can be identified by either arthroscopy, fluoroscopy, or open surgery in anatomic fibular tunnel placement and (2) to compare accuracy and reliability of arthroscopic fibular tunnel placement with open surgery.

MATERIALS AND METHODS

 In a retrospective study, 41 magnetic resonance images (MRIs) of the knee were analyzed with emphasis on distances of an ideal anatomic fibular tunnel to 11 soft-tissue and bony landmarks. Subsequently, in eight cadaver knees, the ideal fibular tunnel was created arthroscopically and with a standard open technique from antero-latero-inferior to postero-medio-superior with a 2-mm K-wire. Positions of both tunnels were compared on postinterventional computed tomography scans.

RESULTS

 Based on MRI measurements, the anatomic tunnel entry should be 14.50 (±2.18) mm distal to the tip of the fibular styloid and 10.76 (±1.37) mm posterior to the anterior edge of the fibula. The anatomic fibular tunnel exit was located 12.89 (±2.35) mm below the tip of the fibular head. Arthroscopic fibular tunnel placement was reliable in all cases. Instead, in five out of the eight cases with open surgery, the fibular tunnel crossed the defined safety distance to the closest cortical edge/tibiofibular joint (distance < 8 mm).

CONCLUSIONS

 Reliable soft-tissue and bony landmarks of the fibular head allow arthroscopic anatomic fibular tunnel placement in PLC surgery, which shows a lower risk of tunnel malposition compared with open surgical techniques. Future studies will have to show whether clinical results of arthroscopic PLC reconstruction are in line with this study's technical results.

LEVEL OF EVIDENCE

 Level III.

All-Arthroscopic Treatment of Combined Posterior Cruciate Ligament and Posterolateral Corner Instability

Injuries to the posterolateral corner (PLC) of the knee are uncommon, and usually associated with other ligamentous injuries. A combined posterior cruciate ligament (PCL) and PLC tear is the most frequent combination. Several studies describe anatomic reconstructive techniques using an open approach with large incisions and extensive exploration of the posterolateral structures. This Technical Note describes an all-arthroscopic technique as a safe and efficient treatment of combined PCL and PLC instability using the trans-septal approach.

The treatment of posterolateral knee instability with combined arthroscopic popliteus bypass and PCL reconstruction provides good-to-excellent clinical results in the mid-term follow-up

PURPOSE

The purpose of this study was to evaluate the clinical outcomes of patients who were treated with an arthroscopic popliteus bypass (PB) technique, in cases of a posterolateral rotational instability (PLRI) and a concomitant posterior cruciate ligament (PCL) injury of the knee.

METHODS

This was a retrospective case series in which 23 patients were clinically evaluated after a minimum of 2 years following arthroscopic PB and combined PCL reconstruction. Lysholm, Tegner and Knee Injury and Osteoarthritis Outcome scores as well as visual analog scales (VAS) for joint function and pain were evaluated. Posterior laxity was objectified with stress radiography and a Rolimeter examination. Rotational instability was graded with the dial test.

RESULTS

23 patients were available for follow-up, 46.0 ± 13.6 months after surgery. The median time interval from the initial injury to the surgery was 6.0 (3.5;10.5) months. The postoperative Lysholm Score was 95.0 (49-100); the Tegner Score changed from 6.0 (3-10) before the injury to 5.0 (0-10) at the follow-up examination (p = 0.013). The side-to-side difference on stress radiography (SSD) of posterior translation changed from 10.4 (6.6-14.8) mm before the injury to 4.0 (0.2-5.7) mm postoperatively (p < 0.01). Rotational instability was reduced to grade A (82.6%) or B (17.4%) (IKDC). The Rolimeter SSD was 2.0 (0-3) mm at the follow-up examination. VAS Function 0 (0-5), VAS pain 0 (0-6).

CONCLUSIONS

The arthroscopic PB graft technique provided good-to-excellent clinical results in the mid-term follow-up in patients with type A PLRI and concomitant PCL injury. However, an exact differentiation of lateral, rotational and dorsal instabilities of posterolateral corner (PLC) injuries is crucial, for the correct choice of therapy, as cases with lateral instabilities require more complex reconstruction techniques. Arthroscopic posterolateral corner reconstruction is a safe procedure with a high success rate in the mid-term follow-up.

LEVEL OF EVIDENCE

IV.

A Modified LaPrade Technique in Posterolateral Corner Reconstruction of the Knee

Posterolateral corner (PLC) injuries represent a complex injury pattern whose repair is essential for varus and rotational stability of the knee. Several surgical techniques have been described for PLC injuries, which can be divided into 2 main groups: anatomical and nonanatomical. Due to insufficiency of posterior stabilization of nonanatomic procedure, LaPrade represented an anatomical reconstruction. In this Technical Note, we describe and illustrate some modifications in the anatomic reconstruction of the PLC and lateral collateral ligament.

Clinical and Patient-Reported Outcomes After Hybrid Russe Procedure for Scaphoid Nonunion

Background: Hybrid Russe technique for the treatment of scaphoid nonunion with humpback deformity has been described with a reported 100% union rate. We sought to evaluate the reproducibility of this technique. Methods: We completed a retrospective chart review of patients with a scaphoid waist nonunion and humpback deformity treated with the hybrid Russe technique from 2015 to 2019 with a minimum of 3-month follow-up. Twenty patients with 21 nonunions were included (mean follow-up: 7.0 months). Scapholunate angle was the primary outcome measure. Secondary outcomes included: intrascaphoid angle, radiolunate angle, pain on the visual analog scale (VAS), and Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score. Other variables included: time to computed tomography (CT) union, range of motion, and complications. Descriptive statistics were presented. Pre- and postoperative angles, VAS, and QuickDASH scores were evaluated with Wilcoxon signed rank tests. Results: The mean scapholunate angle improved -17.6° ± 6.4°. The mean intrascaphoid angle improved 28.2° ± 6.3°. The mean radiolunate angle improved 12.8° ± 8.8°. Of the 21 scaphoids, 20 (95%) demonstrated union on a CT scan. One patient was diagnosed with a nonunion. In total, 90% of patients noted symmetric range of motion compared with the contralateral side. The mean VAS pain score improved 6 ± 3 points. The mean QuickDASH score improved 10 ± 8 points. Complications (aside from nonunion) included 1 patient with persistent wrist pain that resolved with removal of hardware. Conclusions: The hybrid Russe technique for the treatment of scaphoid nonunions with humpback deformity demonstrates a 95% union rate. This technique is effective, reproducible, and may serve as an alternative to techniques that include structural grafts from distant sites.

Arthroscopic anatomy of the posterolateral corner of the knee: anatomic relations and arthroscopic approaches

INTRODUCTION

Although open-surgical techniques for the reconstruction of the posterolateral corner (PLC) are well established, the use of arthroscopic procedures has recently increased. When compared with open surgical preparation, arthroscopic orientation in the PLC is challenging and anatomic relations may not be familiar. Nevertheless, a profound knowledge of anatomic key structures and possible structures at risk as well as technical variations of arthroscopic approaches are mandatory to allow a precise and safe surgical intervention.

MATERIALS AND METHODS

In a cadaveric video demonstration, an anterolateral (AL), anteromedial (AM), posteromedial (PM) and posterolateral (PL) portal, as well as a transseptal approach (TSA) were developed. Key structures of the PLC were defined and sequentially exposed during posterolateral arthroscopy. Finally, anatomic relations of all key structures were demonstrated.

RESULTS

All key structures of the PLC can be visualized during arthroscopy. Thereby, careful portal placement is crucial in order to allow an effective exposure. Two alternatives of the TSA were described, depending on the region of interest. The peroneal nerve can be visualized dorsal to the biceps femoris tendon (BT), lateral to the soleus muscle (SM) and about 3 cm distal to the fibular styloid (FS). The distal attachment of the fibular collateral ligament (FCL) can be exposed on the lateral side of the fibular head (FH). The fibular attachment of the popliteofibular ligament (PFL) is exposed at the tip of the FS.

CONCLUSION

Arthroscopy of the posterolateral recessus allows full visualization of all key structures of the posterolateral corner, which provides the basis for anatomic and safe drill channel placement in PLC reconstruction. A sufficient exposure of relevant anatomic landmarks and precise portal preparation reduce the risk of iatrogenic vascular and peroneal nerve injury.

Reconstruction of the Posterolateral Corner of the Knee Using LaPrade and Modified Larson Technique: A Prospective Study

BACKGROUND

Posterolateral corner (PLC) injuries of the knee are often overlooked for its complex anatomy, and frequent association with cruciate ligament injuries. Overlooked injuries lead to reconstruction failure of cruciate ligaments, chronic knee pain and early arthritic changes. Many reconstruction methods are described, but the best treatment still remains elusive. In this study, we have treated grade-III PLC injuries by the 'anatomic LaPrade' technique and the 'fibula-based Modified Larson' technique, and evaluated their outcomes. Our hypothesis was that both the groups will have similar improvements after surgery.

METHODS

An open-label prospective comparative study was done with a total of 28 patients from August 2013 to July 2019. Patients were treated alternatively by LaPrade or Modified Larson technique using hamstring autografts. Follow-up visits were done at sixth week and subsequently at 3, 6, 12, 18 and 24 months postoperatively. Outcomes were measured by Dial Test, side-to-side difference in lateral opening on varus stress radiographs, Lysholm score and IKDC subjective score.

RESULTS

During analysis, we considered 25 patients only as three patients were lost to follow-up. Both the groups had comparable improvements in rotational stability, lateral opening on varus stress, Lysholm score and IKDC subjective score.

CONCLUSION

Both LaPrade and Modified Larson technique showed good clinical results in restoring varus and rotational stability of knee in grade-III posterolateral corner injury of the knee.

LEVEL OF EVIDENCE

II (prospective, comparative study).

The Posterolateral Instability Score (PoLIS) of the knee joint: a guideline for standardized documentation, classification, and surgical decision-making

PURPOSE

There has been a recent resurgence in interest in posterolateral instabilities of the knee joint. As this terminology comprises a large variety of pathologies, confusion and ambiguity in communication between surgeons and allied health professionals are generated. Consequently, accurate classification criteria are required to account for thorough preoperative diagnostics, surgical decision-making, and a standardized scientific documentation of injury severity.

METHODS

A working group of five knee surgeons, who retrospect more than 2000 reconstructions of the posterolateral corner (PLC) at the minimum, was founded. An advanced PubMed search was conducted to identify key definitions. After defining an accurate diagnostic work-up, popular consensus was reached on definitions and covariates for a novel classification, rating of injury severity, and the resulting surgical decision-making.

RESULTS

Three columns (lateral instability, cruciate ligament involvement, and relevant covariates), each ranging from A to D with increasing severity and assigning a number of points, were needed to meet the requirements. The generated terminology translated into the Posterolateral Instability Score (PoLIS) and the added number of points, ranging from 1 to 18, depicted the injury severity score.

CONCLUSION

The presented classification may enable an objective assessment and documentation of the injury severity of the inherently complex pathology of injuries to the lateral side of the knee joint.

LEVEL OF EVIDENCE

V.

The Popliteus Bypass provides superior biomechanical properties compared to the Larson technique in the reconstruction of combined posterolateral corner and posterior cruciate ligament injury

PURPOSE

This study aimed to compare the biomechanical properties of the popliteus bypass against the Larson technique for the reconstruction of a combined posterolateral corner and posterior cruciate ligament injury.

METHODS

In 18 human cadaver knees, the kinematics for 134 N posterior loads, 10 Nm varus loads, and 5 Nm external rotational loads in 0°, 20°, 30°, 60,° and 90° of knee flexion were measured using a robotic and optical tracking system. The (1) posterior cruciate ligament, (2) meniscofibular/-tibial fibers, (3) popliteofibular ligament (PFL), (4) popliteotibial fascicle, (5) popliteus tendon, and (6) lateral collateral ligament were cut, and the measurements were repeated. The knees underwent posterior cruciate ligament reconstruction, and were randomized into two groups. Group PB (Popliteus Bypass; n = 9) underwent a lateral collateral ligament and popliteus bypass reconstruction and was compared to Group FS (Fibular Sling; n = 9) which underwent the Larson technique.

RESULTS

Varus angulation, posterior translation, and external rotation increased after dissection (p < 0.01). The varus angulation was effectively reduced in both groups and did not significantly differ from the intact knee. No significant differences were found between the groups. Posterior translation was reduced by both techniques (p < 0.01), but none of the groups had restored stability to the intact state (p < 0.02), with the exception of group PB at 0°. No significant differences were found between the two groups. The two techniques revealed major differences in their abilities to reduce external rotational instability. Group PB had less external rotational instability compared to Group FS (p < 0.03). Only Group PB had restored rotational instability compared to the state of the intact knee (p < 0.04) at all degrees of flexion.

CONCLUSION

The popliteus bypass for posterolateral reconstruction has superior biomechanical properties related to external rotational stability compared to the Larson technique. Therefore, the popliteus bypass may have a positive influence on the clinical outcome. This needs to be proven through clinical trials.

Arthroscopic Identification of the Knee Posterolateral Corner Structures and Anatomic Arthroscopic Posterolateral Corner Reconstruction: Technical Note - Part 2

Posterolateral corner injuries are complex injuries, and their therapeutic management varies from one individual to another. Biomechanical studies demonstrate that anatomic posterolateral corner reconstruction restores knee kinematics better than nonanatomic reconstruction. The purpose of this report is to describe an all-arthroscopic procedure for anatomic posterolateral corner reconstruction.

Arthroscopic Identification of the Knee Posterolateral Corner Structures and Anatomic Arthroscopic Posterolateral Corner Reconstruction: Technical Note - Part 1

Arthroscopic assessment of posterior compartments of the knee and the posterior aspect of the proximal tibial and fibula is challenging because of the relative proximity of the neurovascular bundle. This Technical Note describes a reproducible arthroscopic surgical approach in a cadaveric model that aims to identify and expose the popliteus tendon, posterior fibular head, fibular collateral ligament popliteal fibular ligament, biceps femoris tendon, and peroneal nerve.

Posterolateral corner of the knee: a systematic literature review of current concepts of arthroscopic reconstruction

INTRODUCTION

Injuries of the posterolateral corner (PLC) of the knee lead to chronic lateral and external rotational instability and are often associated with PCL injuries. Numerous surgical techniques for repair and reconstruction of the PLC are established. Recently, several arthroscopic techniques have been published in order to address different degrees of PLC injuries through reconstruction of one or more functional structures. The purpose of this systematic review is to give an overview about arthroscopic techniques of posterolateral corner reconstructions and to evaluate their safeness.

MATERIALS AND METHODS

A systematic review of the literature on arthroscopic reconstructions of the posterolateral corner of the knee according to the PRISMA guidelines was performed using PubMed MEDLINE and Web of Science Databases on June 15th, 2020. Inclusion criteria were descriptions of surgical techniques to reconstruct different aspects of the posterolateral corner either strictly arthroscopically or minimally-invasive with an arthroscopic assistance.

RESULTS

Arthroscopic techniques differ with regard to the extent of reconstructed units (popliteus tendon, popliteofibular ligament, lateral collateral ligament), surgical approach (transseptal, lateral) and biomechanical results (anatomic vs. non-anatomic reconstruction, restoration of rotational instability and/or lateral instability).

CONCLUSION

Different approaches to arthroscopic PLC reconstruction are presented, yet clinical results are scarce. Up to now good and excellent clinical results are reported. No major complications are reported in the literature so far.

Arthroscopic-assisted anatomical reconstruction of the posterolateral corner of the knee joint

Several surgical techniques have been suggested to anatomically reconstruct the posterolateral corner of the knee joint. However, most of them are open techniques that require dissection of the skin and soft tissues without utilizing the advantages of arthroscopic-assisted techniques. Therefore, this study aimed to describe a novel arthroscopic technique that anatomically reconstructs the posterolateral corner of the knee joint. This novel arthroscopic technique can properly identify important landmarks for reconstruction and anatomically reconstruct the three key components (lateral collateral ligament, popliteus tendon, and popliteofibular ligament) of the posterolateral corner of the knee joint.

An All-Arthroscopic Technique for Complex Posterolateral Corner Reconstruction

Injuries to the posterolateral corner (PLC) often result in lateral, rotational, and dorsal instability, which need appropriate and differentiated treatment. Besides posterior cruciate ligament reconstruction for posterior instability, the technique according to LaPrade et al. efficiently stabilizes posterolateral rotational and lateral instability as described in Fanelli type B or C injuries. This technique has been exclusively used as an open procedure. In this article, we present an all-arthroscopic technique for the posterolateral stabilization procedure. To achieve this, 5 different arthroscopic portals are needed. The PLC is visualized by a trans-septal approach. Directly posterior to the popliteal tendon, arthroscopic preparation is started and the medial part of the fibular head is exposed. Two anatomic drill channels are placed in the lateral femoral condyle, with one tibial channel in the distal third of the sulcus popliteus and one channel in the fibular head. The popliteal tendon, popliteofibular ligament, and lateral collateral ligament are reconstructed with autologous hamstring tendons. The advantages of an all-arthroscopic anatomic PLC reconstruction are the protection of the soft tissues and the precise anatomic tunnel placement under direct visualization. The described procedure is a safe and anatomic method for posterolateral stabilization.

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.

Minimally Invasive, Arthroscopic-Assisted, Anatomic Posterolateral Corner Reconstruction

As the anatomy and biomechanics of the posterolateral corner (PLC) of the knee have become better understood, the importance of the PLC's proper function has become a more frequently raised subject. Misdiagnosed chronic posterolateral instability may lead to serious consequences, including cruciate ligament reconstruction graft failure. It has been proved that high-grade PLC injuries need to be treated operatively. Surgical approaches vary, and techniques are still developing. Considering avoidance of an extended surgical approach and minimizing the risk of common peroneal nerve or popliteal artery injuries, we developed the minimally invasive, arthroscopic-assisted, anatomic PLC reconstruction.

Anatomic Reconstruction of the Posterolateral Corner: An All-Arthroscopic Technique

Injuries of the posterolateral corner (PLC) of the knee lead to chronic lateral and external rotational instability. Successful treatment of PLC injuries requires an understanding of the complex anatomy and biomechanics of the PLC. Several open PLC reconstruction techniques have been published. It is understood that anatomic reconstruction is superior to extra-anatomic techniques, leading to better clinical results. An open, anatomic, fibula-based technique for reconstruction to address lateral and rotational instability has been described. However, when an open technique is used, surgeon and patient are faced with disadvantages, such as soft tissue damage or exposure of vulnerable structures. Few arthroscopic techniques for tibia- or fibula-based reconstruction of rotational posterolateral instability have been described. A complete arthroscopic stabilization of the combined lateral and posterolateral rotational instability of the knee has not yet been described. We therefore present the first all-arthroscopic technique for complete PLC reconstruction, based on an open technique described previously. All relevant landmarks of the PLC can be arthroscopically visualized in detail, allowing safe and effective treatment of PLC injuries.

The Use of Fluoroscopy Leads to Improved Identification of the Femoral Lateral Collateral Ligament Origin Site When Compared With Traditional Tactile Techniques

PURPOSE

To determine whether a fluoroscopic technique can be used to improve the accuracy of the determination of the femoral origin of the lateral collateral ligament (LCL).

METHODS

A 1-cm incision was made over the lateral epicondyle in 13 fresh-frozen cadaveric knee specimens, and the LCL origin was determined first by palpation and then with a previously described fluoroscopic method. Both points for the LCL origin were marked with 2-mm Kirschner wires. The distances between the center of the anatomic LCL origin and the LCL origin points determined by palpation and fluoroscopic imaging were calculated. An independent t-test was used to compare the distances between the anatomic LCL origin center and the determined LCL origin points.

RESULTS

The LCL origin points determined by fluoroscopic imaging were significantly (P = .005) closer to the anatomic center of the LCL origin point than the ones determined by palpation (3.2 mm ± 1.6 mm vs 5.0 mm ± 1.6 mm, respectively). A total of 92.7% fluoroscopically determined LCL origin points were within a 5 mm radius surrounding the anatomic LCL origin point. In contrast, only 53.8% LCL origin points determined by palpation were within a 5 mm radius surrounding the anatomic LCL origin point.

CONCLUSIONS

The use of palpation to identify the LCL origin may not be an accurate method for performing an isometric and anatomic LCL reconstruction. The use of fluoroscopic imaging appears to be a feasible method for identifying the LCL origin in clinical practice and may increase the accuracy of LCL origin identification. Fluoroscopic guidance improves accuracy in determining the anatomic LCL origin, which may help avoiding tunnel malplacement during LCL reconstruction. CLINICAL RELEVANCE: The use of a previously described radiographic method for identifying the LCL origin may be used to achieve a more anatomic LCL reconstruction.

Arthroscopic Posterolateral Corner Stabilization With Popliteus Tenodesis

The injuries of the posterolateral corner (PLC) of the knee often remain misdiagnosed. Because most structures in this anatomical region have low potential to heal, the posterolateral rotational instability results in a deterioration in patient quality of life, impaired biomechanics of the knee, and increased tension on other ligaments and the meniscus. Many open and a few arthroscopic techniques have been developed to repair or reconstruct the damaged structures of the PLC. Creating an additional midlateral arthroscopic portal on the lateral side of the knee was the key to developing the technique to recreate a static stabilizer against external rotational instability of the PLC by fixing the popliteus tendon as a native, vascularized material to the tibia.

Kinematics of Different Components of the Posterolateral Corner of the Knee in the Lateral Collateral Ligament-intact State: A Human Cadaveric Study

PURPOSE

To determine the static stabilizing effects of different anatomical structures of the posterolateral corner (PLC) of the knee in the lateral collateral ligament (LCL)-intact state.

METHODS

Thirteen fresh-frozen human cadaveric knees were dissected and tested using an industrial robot with an optical tracking system. Kinematics were determined for 134 N anterior/posterior loads, 10 N m valgus/varus loads, and 5 N m internal/external rotatory loads in 0°, 20°, 30°, 60°, and 90° of knee flexion. The PLC structures were dissected and consecutively released: (I) intact knee joint, (II) with released posterior cruciate ligament (PCL), (III) popliteomeniscal fibers, (IV) popliteofibular ligament, (V) arcuat and popliteotibial fibers, (VI) popliteus tendon (PLT), and (VII) LCL. Repeated-measures analysis of variance was performed with significance set at P < .05.

RESULTS

After releasing the PCL, posterior tibial translation increased by 5.2 mm at 20° to 9.4 mm at 90° of joint flexion (P < .0001). A mild 1.8° varus instability was measured in 0° of flexion (P = .0017). After releasing the PLC structures, posterior tibial translation further increased by 2.9 mm at 20° to 5.9 mm at 90° of flexion (P < .05) and external rotation angle increased by 2.6° at 0° to 7.9° at 90° of flexion (P < .05, vs II). Varus stability did not decrease. Mild differences between states V and VI were found in 60° and 90° external rotation tests (2.1° and 3.1°; P < .05).

CONCLUSIONS

The connecting ligaments/fibers to the PLT act as a primary static stabilizer against external rotatory loads and a secondary stabilizer against posterior tibial loads (when PCL is injured). After releasing these structures, most static stabilizing function of the intact PLT is lost. The PLC has no varus-stabilizing function in the LCL-intact knee.

CLINICAL RELEVANCE

Anatomy and function of these structures for primary and secondary joint stability should be considered for clinical diagnostics and when performing surgery in the PLC.

Arthroscopic popliteus bypass graft for posterolateral instabilities of the knee : A new surgical technique

Objective

An arthroscopic technique for the reconstruction of the posterolateral corner combined with posterior cruciate ligament (PCL) reconstruction was developed.

Indications

Posterolateral rotational instabilities of the knee. Combined lesions of the PCL, the popliteus complex (PLT) and the posterolateral corner. Isolated PLT lesions lacking static stabilizing function.

Contraindications

Neuromuscular disorders; knee deformities or fractures; severe posterolateral soft tissue damage.

Surgical technique

Six arthroscopic portals are necessary. Using the posteromedial portal, resect dorsal septum with a shaver. Visualize the PCL, the lateral femoral condyle and the posterolateral recessus with the PLT. Dissect the popliteomeniscal fibers; retract PLT until sulcus popliteus is visualized. Drill a 6-mm tunnel anteriorly into the distal third of the sulcus popliteus. Visualize femoral footprint of the PLT and place an anatomical drill tunnel. Pull the popliteus bypass graft into the knee and fix with bioscrews. Fix the reconstructed PCL. In cases of additional LCL injury, reconstruct LCL with autologous graft.

Postoperative management

Partial weight-bearing for 6 weeks, range of motion exercises, quadriceps-strengthening exercises on postoperative day 1. Full extension allowed immediately with flexion limited to 20° for 2 weeks, to 45° for up to week 4, and to 60° up to week 6. Use a PCL brace for 3 months, running and squatting exercises allowed after 3 months.

Results

In the 35 patients treated, no technique-related complications. After 1 year, 12 patients had a mean Lysholm Score of 88.6 (± 8.7) points and a side-to-side difference in the posterior drawer test of 2.9 (± 2.2) mm (preoperative 13.3 [± 1.9] mm).

Conclusion

Low complication risk and good and excellent clinical results after arthroscopic posterolateral corner reconstruction.