Popliteus bypass and popliteofibular ligament reconstructions reduce posterior tibial translations and forces in a posterior cruciate ligament graft

Single-stage arthroscopic-assisted treatment of anteromedial tibial plateau fracture with posterolateral corner injury: a retrospective study

Background

Anteromedial tibial plateau fracture with posterolateral corner (PLC) injury is a relatively rare combined injury in the clinic. In addition, there is no unified treatment scheme for this combined injury. The purpose of this study was to evaluate the clinical and imaging results of single-stage arthroscopic-assisted surgery for anteromedial tibial plateau fracture with PLC injury, and to explore the advantages of this surgical technique.

Method

In this retrospective study, a total of 9 patients (7 males and 2 females) were included, aged 24–64 years (average 40.7 years), treated in our Department of Orthopedics from January 2016 to January 2021. In the preoperative evaluations, there were 9 cases of anteromedial tibial plateau fractures with PLC injuries, 6 cases of concomitant PCL injuries, 6 cases of concomitant medial or lateral meniscus injuries, and 2 cases of concomitant fibular head avulsion fractures. All patients underwent single-stage arthroscopic-assisted surgery.

Results

All patients were followed up, and the average follow-up period was 15.2 months (range 12–18 months). The average operation time was 135.6 min (range 100–160 min), and the average surgical blood loss was 87.2 ml (range 60–110 ml). The anatomical reduction was achieved in 9 cases, and the anatomical reduction rate was 100%. The average fracture healing time was 13.1 weeks (range 12–16 weeks). At the last follow-up, the average VAS score was 1 (range 0–2); the average Lysholm function score was 90.7 (range 86–95), and the average IKDC score was 91.4 (range 88–95); the average knee extension angle of all patients was 0° and the average knee flexion angle was 128.3° (average 120–135°); The posterior drawer test, the Lachman test and the dial test were negative for all cases. None of the patients had operation-related complications.

Conclusion

Single-stage arthroscopy-assisted surgery in the treatment of anteromedial tibial plateau fracture with PLC injury can achieve good clinical outcomes, restore the stability of the knee joint, and reduce the risk of severe lower extremity dysfunction.

Classification of the popliteofibular ligament

PURPOSE

The purpose of this study was to characterize the morphological variations in the distal attachment of the popliteofibular ligament (PFL) and create an accurate classification for use in planning surgical procedures in this area and in evaluating radiological imaging.

METHODS

One hundred and thirty-seven lower limbs of body donors fixed in 10% formalin solution were examined for the presence and course of the popliteofibular ligament.

RESULTS

The PFL was present in 88.3% of cases. We propose the following three-fold classification: type I (72.3%), the most common type, characterized by the attachment onto the apex of the head of the fibula, type II (8.7%), characterized by a bifurcation, with the dominant band inserting on the anterior slope of the styloid process of the fibula and the smaller band onto the posterior surface of the styloid process of the fibula and type III (7.3%), characterized by a double PFL: the first PFL (main) originated from the popliteus tendon and inserted onto the anterior slope of the styloid process of the fibula, while the second originated from the musculotendinous junction of the popliteus muscle and inserted on the posterior surface of the styloid process of the fibula.

CONCLUSION

The PFL was characterized by high morphological variation, as reflected in our proposed classification. This variation may present clinical and biomechanical issues for both medical personnel and researchers. Our proposed classification may be valuable for clinicians who evaluate and perform surgical procedures within the knee joint area.

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.

The External Rotation Radiographic Technique for Posterolateral Injury

Posterolateral corner injuries are a severe and often unrecognized pathology. Injuries to these structures are difficult to identify using magnetic resonance images. Physical examination tests including the dial test, frog-leg test, and varus stress test can be difficult to perform. In addition it is difficult to correctly evaluate the results in a multiligament injury setting. The correct diagnosis of this pathology is essential to determine the proper treatment and improve outcomes. Furthermore, failure to recognize this pathology is associated with a high risk of failure following isolated anterior cruciate ligament reconstructions. The purpose of this Technical Note is to present an alternative method for the evaluation of posterolateral corner injuries using radiographic images.

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.

Tibial inlay technique using hamstring graft for posterior cruciate ligament reconstruction and remnant revision

The posterior tibial inlay technique is currently accepted as a standard operation for the posterior cruciate ligament-deficient knee. The classical technique requires a graft construct consisting of a bony part to be fitted into the posterior tibial socket. When an autogenous source is chosen, morbidity at the donor site generated by obtaining the graft with a bony part (e.g., bone-patellar tendon-bone or quadriceps tendon-bone) can be more serious than when obtaining the soft-tissue graft (e.g., hamstring). This study describes an alternative use of soft-tissue graft anchored in a bone socket at the posterior tibial margin by a transfixing cancellous screw. The graft is secured on top by a "bone washer" harvested from this bone socket to provide biological bone-tendon-bone healing. The posterior cruciate ligament remnant with integral fibers at the femur can have its tibial part revised, tensioned, and reattached concomitantly. This additional procedure is deemed to enhance joint stability and promote graft healing.

All-arthroscopic anatomic repair of an avulsed popliteus tendon in a multiple ligament-injured knee

Multiple ligament-injured knees are a heterogeneous group of knee injuries that lack a clear consensus on optimal treatment. Current areas of controversy include optimal timing of surgery, ligamentous repair vs reconstruction, and combined vs staged procedures. In addition, multiple open, arthroscopic, and arthroscopic-assisted techniques exist for repair and reconstruction of the injured stabilizers of the knee.Many open posterolateral corner reconstruction techniques have been described, and this article represents the first description of an arthroscopic technique for repair of an avulsed popliteus tendon. This was performed with a standard anterolateral portal in addition to anterior and posterior superolateral portals. Nonabsorbable sutures were passed through the avulsed popliteus tendon in an outside-in technique using a suture shuttle. The nonabsorbable sutures were threaded though a tibial Beath pin, which was then passed through the prepared popliteus footprint and brought out medially. The final position of the popliteus was confirmed arthroscopically, and the sutures were tied medially over a screw post with a washer.Arthroscopic popliteus repair has many possible advantages. Because the popliteus tendon insertion is intracapsular, open repair necessitates a capsulotomy, with the potential for complications such as postoperative wound drainage, intra-articular sinus formation, infection, and stiffness. Arthroscopic repair may avoid these complications. The current case was performed in conjunction with an open but extracapsular posterolateral corner repair. Further experience with this technique is required to determine its safety and efficacy.

Single-bundle posterior cruciate ligament reconstruction and mini-open popliteofibular ligament reconstruction in knees with severe posterior and posterolateral rotation instability: clinical results of minimum 2-year follow-up

PURPOSE

The aim of this study was to assess the clinical outcome of arthroscopy-assisted posterior cruciate ligament (PCL) reconstruction and mini-open popliteofibular ligament (PFL) reconstruction for severe posterior and posterolateral rotation instability of the knee with lateral collateral ligament intact.

METHODS

Arthroscopic PCL reconstruction and mini-open PFL reconstruction were performed consecutively in 24 patients with chronic posterior and posterolateral rotation instability of the knee. The inclusion criteria for surgery were a side-to-side difference in posterior translation of more than 12 mm measured with stress radiography and tibial external rotation of 10 degrees more than that of the contralateral uninjured knee without varus laxity. The exclusion criterion was combined anterior cruciate ligament injury. The patients underwent single-bundle PCL reconstruction with Achilles tendon allograft. A mini-open PFL reconstruction was performed with anterior tibialis allograft. A 2-cm incision was made on the lateral epicondyle to build the femoral tunnel, and a 3-cm incision was made near the fibular head for the fibular tunnel.

RESULTS

The minimum follow up was 2 years. At final follow up, 18 patients (75% [18 of 24]) were enrolled in the study group and 6 patients were lost. Postoperatively, mean posterior tibial translation (side-to-side difference) in our patients was reduced from 17.3 +/- 4.1 mm to 4.6 +/- 3.2 mm. Tibial external rotation was decreased from a mean of 14.7 degrees +/- 4.6 degrees to -2.8 degrees +/- 3.8 degrees, as compared with the contralateral uninjured knee. These differences were statistically significant. The International Knee Documentation Committee grade preoperatively was grade D in all 18 patients, whereas postoperatively, 5 were classified as grade A, 8 as grade B, and 5 as grade C.

CONCLUSIONS

In this small clinical series, single-bundle PCL reconstruction combined with mini-open PFL reconstruction was proven to correct pathologic excessive posterior and posterolateral rotation instability.

LEVEL OF EVIDENCE

Level IV, therapeutic case series (no control or historical group).

The "lateral gutter drive-through" sign: an arthroscopic indicator of acute femoral avulsion of the popliteus tendon in knee joints

Acute avulsions of the popliteus tendon and the lateral collateral ligament of the femur (peel-off lesion) are common and can both be missed during preoperative assessment and later overlooked during surgery if not specifically sought out. Arthroscopic observation of the direct avulsion sign of the torn end of the popliteus tendon occurs less frequently in patients with acute and subacute injuries. This study describes an arthroscopic sign that detects these tears when they either involve only the popliteal tendon or include the lateral collateral ligament assessed from the lateral gutter of the joint. The "lateral gutter drive-through," visualized during diagnostic arthroscopy, is described as entering of the arthroscope into the posterolateral compartment through the interval between the popliteal tendon and the lateral femoral condyle. A positive sign indicates (1) the presence of femoral avulsion tears of the popliteal tendon or concomitant lateral collateral ligament, (2) the presence of repairable posterolateral corner tears, and (3) the enablement of mini-open surgery for the repair of these avulsion tears with a recess or reattachment procedure. In addition, arthroscopic evaluation of the lateral compartment and preoperative magnetic resonance imaging assessment are used to eliminate the multiple-level injuries of the popliteus tendon and lateral collateral ligament.

Popliteofibular ligament reconstruction for posterolateral external rotation instability of the knee

The aim of this study was to assess the clinical outcome of popliteofibular ligament (PFL) reconstruction for posterolateral external rotation instability of the knee. PFL reconstruction was performed consecutively in 22 patients with chronic external rotation instability of the knee. The inclusion criterion for surgery was tibial external rotation of 10 degrees more than the contralateral uninjured knee without varus laxity. A double bone tunnel was created at the PFL insertion of the fibular head through the lateral incision of the knee joint and a single bone tunnel at the popliteus tendon insertion on the femoral side. A semitendinosus autograft tendon or tibialis anterior allograft tendon was introduced through the fibular tunnel as a loop, then both free ends of the graft were introduced through the femoral tunnel and a bioabsorbable interference screw was used to fix the graft. The minimum follow-up was 2 years. Clinical review included the International Knee Documentation Committee (IKDC) scale and tibial external rotation assessment. All patients' preoperational tibial external rotation averaged 15 degrees more than the contralateral uninjured knee. operatively the tibial external rotation was decreased, average -3 degrees compared with the contralateral side. This difference was statistically significant. The final IKDC grades were: 22 cases with grade D preoperatively, and 6 were grade A, 8 were grade B, 7 were grade C and 1 was grade D postoperatively. In this small clinical series, PFL reconstruction technique was shown to correct pathological excessive tibial external rotation.

Posterolateral sling reconstruction of the popliteus tendon: an all-arthroscopic technique

Injuries to the posterolateral corner of the knee present with variable injury patterns that have produced a number of reconstructive procedures in the literature. We present an all-arthroscopic technique that reconstructs the popliteus tendon using either a semitendinosus autograft or an anterior tibialis allograft. After exposure of the posterior tibia by use of the posteromedial and trans-septal portals for visualization and posterolateral portal as a working portal, the popliteus musculotendinous junction is identified. In preparation for tibial tunnel drilling, a Kirschner wire is passed from the Gerdy tubercle to the popliteus musculotendinous junction on the posterior tibia, which is localized by use of an anterior cruciate ligament tibial tunnel guide brought in through the posterolateral portal. The 6-mm tibial tunnel is then created. The femoral insertion site is identified by use of the anterolateral portals for visualization and by use of the accessory superolateral portal for debriding the synovial fold at the insertion of the popliteus tendon. A K-wire is inserted, and a socket is established. The selected graft is then implanted by passing the graft through the tibial tunnel from anterior to posterior with a passing suture and pulling it up anteriorly and superiorly to the femoral socket. The graft is tensioned with the knee in 90 degrees of flexion and in neutral rotation before fixation of both ends of the graft with bio-interference screws.

Collateral ligament augmentation versus reconstruction using allograft tissue

Injuries to the collateral ligaments of the knee are very common. Recognition of collateral ligament laxity is extremely important, especially when associated with a cruciate ligament injury. Reconstruction of the collaterals are necessary when addressing these combined instabilities.

Posterolateral corner anatomy and its anatomical reconstruction with single fibula and double femoral sling method: anatomical study and surgical technique

This paper reports a novel method for reconstructing the posterolateral structures [lateral collateral ligament (LCL), popliteus tendon, popliteofibular ligament] based on an anatomical study of a cadaveric dissection. The popliteus tendon was found to always be attached to the anterior-inferior portion of the femoral attachment site of the LCL, and the average distance from the origin of the popliteal tendon in the femoral side to that of the LCL was 18.5 mm (17-20). The insertion site of the LCL in the fibular side was located anterior-inferior-superficially and the popliteofibular ligament was inserted into the posterior-superior-deep portion around the styloid process. Two femoral tunnels and one fibular head tunnel were made at the proximal and distal portion of the anatomical insertion sites.