In vitro comparison of popliteus tendon and popliteofibular ligament reconstruction in an external rotation injury model of the knee: a cadaveric study evaluated by a navigation system

Isolated femoral avulsion of the popliteus tendon: a systematic review of the literature

The popliteus tendon is an important part of the posterolateral corner of the knee. Isolated injuries to the posterolateral corner are very rare, as most injuries occur in multiligamentous knee trauma. Purely isolated popliteus tendon injuries are even more rare. There is very little evidence for treatment of isolated popliteus tendon avulsion injuries. The aim of this systematic review is to report on all publications regarding isolated popliteus tendon avulsion injuries and hopefully provide some guidance for future treatment algorithms. A systematic review of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Studies were included if they documented isolated popliteus tendon avulsion injuries. Exclusion criteria were studies with popliteus injuries in combination with other knee ligamentous injuries and popliteus tendon injuries other than femoral avulsion injuries. Twenty-eight studies were included which mentioned in total 38 patients with isolated popliteus tendon avulsion injuries. 24 patients (63%) were treated operatively. 3 (8%) patients were diagnosed arthroscopically but did not receive any surgical treatment. 9 patients (24%) were treated conservatively. In two publications, there was no mention of treatment. We found no clear recommendations in the literature for treatment of this rare injury.

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.

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.

[Anatomical posterolateral complex reconstruction in treating severe posterolateral knee instability using Y-shaped allogeneic Achilles tendon]

OBJECTIVE

To investigate the surgical technique and effectiveness of anatomical posterolateral complex (PLC) reconstruction in treating severe posterolateral knee instability using Y-shaped allogeneic Achilles tendon.

METHODS

The clinical data of 12 patients with Fanelli type C chronic PLC injury with severe posterolateral knee instability who met the selection criteria between June 2013 and August 2017 were retrospectively analyzed. There were 9 males and 3 females, with a median age of 34.5 years (range, 18-57 years). The average time from injury to surgery was 10.5 months (range, 3-24 months). All of them were multi-ligament injuries and were treated with anatomical reconstruction of Y-shaped allogeneic Achilles tendon. The posterior and varus stress X-ray films were used to measure and calculate the difference of posterior displacement of tibia and difference of lateral joint opening distance between bilateral knees to evaluate the backward stability of LCL and knee joint; the knee flexion 30° tibial external rotation test was used to calculate the difference of tibial external rotation angle between bilateral knees to evaluate the stability of knee external rotation. The knee function was evaluated by the International Knee Documentation Committee (IKDC) 2000 subjective and objective scores.

RESULTS

The operation successfully completed in 12 patients, and there was no vascular and nerve injury during operation. The operation time was 2.5-3.5 hours, with an average of 2.7 hours; the intraoperative blood loss was 20-100 mL, with an average of 55 mL. All patients were followed up 13-41 months, with an average of 28.1 months. At last follow-up, the difference of posterior displacement of tibia, the difference of lateral joint opening, the difference of tibial external rotation angle between bilateral knees, and the IKDC2000 subjective score, the objective scores of tibial external rotation and knee varus significantly improved when compared with those before operation ( P<0.05). The knee joint of 1 patient with anterior cruciate ligament, posterior cruciate ligament, and PLC reconstruction was stiff at 15 months after operation, and the range of motion of the knee joint was 10°-80°. After arthroscopic release, the range of motion of the knee joint was 5°-120°, the reconstructed ligament was stable. In the other patients, the knee flexion angle was normal in 2 cases; 9 cases had knee flexion limitation of 5°-10°, with an average of 6.4°; no knee extension was limited.

CONCLUSION

Anatomical PLC reconstruction using Y-shaped allogeneic Achilles tendon can effectively treat Fanelli type C chronic PLC injury with severe posterolateral knee instability and improve the knee joint stability.

Midterm Clinical Outcome of Combined Posterior Cruciate Ligament Reconstruction and Posterolateral Corner Surgery Using Second-Look Arthroscopic "Lateral Gutter Drive-Through" Test as an Adjunctive Evaluation

Objectives

The arthroscopic “lateral gutter drive‐through” (LGDT) sign is reported to diagnose popliteus tendon (PT) injury with high sensitivity and specificity. However, no study has provided a postoperative evaluation of combined posterior cruciate ligament (PCL) and posterolateral corner (PLC) injuries using the LGDT test.

Methods

From January 2012 to January 2015, a total of 80 consecutive patients who underwent combined PCL reconstruction and PLC surgeries were identified. Fifty eligible patients were included in this study for evaluation with subjective scoring systems, physical examinations, posterior and varus stress radiographs, and second‐look arthroscopic surgeries during hardware removal operation.

Results

Forty‐nine patients were available for a mean of 31.5 ± 9.3 months follow‐up (range, 24.0–81.0 months). In terms of PLC injury pattern, there were 27 type A, 10 type B, and 12 type C patients, with 21 acute cases and 28 chronic cases. At the final follow‐up, subjective scores were all significantly improved. The side‐to‐side difference (SSD) of posterior tibial translation (PTT) improved from 18.4 ± 9.2 mm (range, 12.9–25.6 mm) to 5.2 ± 5.0 mm (range, −5.0−18.5 mm, P < 0.001), and the SSD of tibial external rotation by dial test (ER) decreased from 18.0° ± 14.4° (range, 13.0°–22.0°) to 1.2° ± 7.5° (range, −9.0°–22.0°, P < 0.001). In patients with type C injury, the SSD of the lateral opening decreased from 14.2 ± 6.6 mm (range, 22–10.2 mm) to 0.9 ± 3.1 mm (range, −4.4‐6 mm, P < 0.001). In a comparison between patients with positive and negative LGDT signs, the LGDT‐negative patients had significant superiority in subjective scores, SSD of PTT, and SSD of ER. The sensitivity and specificity of the LGDT test in detecting postoperative posterolateral rotational instability (PLRI) were calculated as 100% and 88.4%, respectively.

Conclusions

In the series of surgically treated patients with PCL and PLC injury: (i) patients had improved subjective and objective clinical outcome after combined PCL reconstruction and PLC surgery at a minimum of 24‐months follow‐up; and (ii) second arthroscopic LGDT sign testing had high sensitivity and specificity in detecting postoperative PLRI, and a positive LGDT sign was related with inferior subjective and objective results.

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.

Anatomical popliteofibular ligament reconstruction of the knee joints: 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. The present paper describes an all-arthroscopic technique that anatomically reconstructs the popliteofibular ligament (PFL) using either a semitendinosus autograft or an anterior tibialis allograft. During the surgery, the fibular insertion site as well as the distal portion of PFL is feasible to be identified under arthroscopy without any additional skin incision. Level of evidence V.

Posterolateral knee reconstruction

Injury to the cruciate ligaments of the knee commonly occurs in association with posterolateral instability, which can cause severe functional disability including varus, posterior translation, and external rotational instability. Failure to diagnose and treat an injury of the posterolateral corner in a patient who has a tear of the cruciate ligament can also result in the failure of the reconstructed cruciate ligament. There seems to be a consensus of opinion that injury to the posterolateral corner, whether isolated or combined, is best treated by reconstructing the posterolateral corner along with the coexisting cruciate ligament injury, if combined. Commonly proposed methods of reconstructing the posterolateral corner have focused on the reconstruction of the popliteus, the popliteofibular ligament, and the lateral collateral ligament. The aim of this conference is to describe the posterolateral corner reconstruction technique and to provide an algorithm of treatment.

Evaluation of the Length and Isometric Pattern of the Anterolateral Ligament With Serial Computer Tomography

BACKGROUND

Recent anatomical studies have identified the anterolateral ligament (ALL). Injury to this structure may lead to the presence of residual pivot shift in some reconstructions of the anterior cruciate ligament. The behavior of the length of this structure and its tension during range of motion has not been established and is essential when planning reconstruction.

PURPOSE

To establish differences in the ALL length during range of knee motion.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Ten unpaired cadavers were dissected. The attachments of the ALL were isolated. Its origin and insertion were marked with a 2 mm-diameter metallic sphere. Computed tomography scans were performed on the dissected parts under extension and 30°, 60°, and 90° of flexion; measurements of the distance between the 2 markers were taken at all mentioned degrees of flexion. The distances between the points were compared.

RESULTS

The mean ALL length increased with knee flexion. Its mean length at full extension and at 30°, 60°, and 90° of flexion was 37.9 ± 5.3, 39.3 ± 5.4, 40.9 ± 5.4, and 44.1 ± 6.4 mm, respectively. The mean increase in length from 0° to 30° was 3.99% ± 4.7%, from 30° to 60° was 4.20% ± 3.2%, and from 60° to 90° was 7.45% ± 4.8%. From full extension to 90° of flexion, the ligament length increased on average 16.7% ± 12.1%. From 60° to 90° of flexion, there was a significantly higher increase in the mean distance between the points compared with the flexion from 0° to 30° and from 30° to 60°.

CONCLUSION

The ALL shows no isometric behavior during the range of motion of the knee. The ALL increases in length from full extension to 90° of flexion by 16.7%, on average. The increase in length was greater from 60° to 90° than from 0° to 30° and from 30° to 60°. The increase in length at higher degrees of flexion suggests greater tension with increasing flexion.

CLINICAL RELEVANCE

Knowledge of ALL behavior during the range of motion of the knee will allow for fixation (during its reconstruction) to be performed with a higher or lower tension, depending on the chosen degree of flexion.

The "lateral gutter drive-through" sign revisited: a cadaveric study exploring its real mechanism based on the individual posterolateral structure of knee joints

BACKGROUND

Although the validity of the "lateral gutter drive-through" (LGDT) test has been proved to offer high sensitivity and specificity in diagnosing the posterolateral rotational instability of knee joints, the real mechanism on how the injury pattern of individual posterolateral knee structure triggers the positive LGDT sign still remains unknown.

HYPOTHESIS

A certain amount of popliteus tendon (POP-T) laxity resulted from specific injury patterns of individual posterolateral knee structure or some degree of medial structural injury will lead to positive LGDT sign.

STUDY DESIGN

Controlled laboratory study.

METHODS

Seven non-paired intact cadaveric knees were divided into four groups and tested under unique sequential sectioning sequences including: (1) distal POP-T and popliteofibular ligament (PFL) (n = 2); (2) PFL and distal POP-T (n = 3); (3) lateral collateral ligament (LCL), distal POP-T and PFL (n = 1); (4) superficial medial collateral ligament (sMCL), deep MCL, posterior oblique ligament (POL), anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) (n = 1). The LGDT tests and the measurements of external tibial rotational angle (ETRA) were first performed on all the intact knees and then at each time point when an additional structure was sectioned. Results of each LGDT test and the absolute value of increased ETRA compared with the intact knee were recorded. Each knee was tested at 30° of flexion. A navigation system was used to measure motion changes of the tibia with respect to the femur.

RESULTS

Initially, the LGDT tests all showed negative on each of the intact knee. Isolated sectioning of the distal POP-T, PFL or the LCL produced increased but insignificant ETRA with the LGDT tests still negative. However, simultaneous sectioning of the distal POP-T and PFL produced significantly increased ETRA with the LGDT tests changed to positive. In addition, for the knee with medial structural injuries, the LGDT test could also be positive only when the posteromedial structures (sMCL, deep MCL, POL) and the cruciate ligaments (ACL and PCL) were all sectioned.

CONCLUSION

In this cadaveric sequential sectioning study, the LGDT test showed positive merely at the following two situations: (1) the distal POP-T and PFL were both sectioned; (2) the posteromedial structures (sMCL, deep MCL and POL) and the cruciate ligaments (ACL and PCL) were all sectioned.

CLINICAL RELEVANCE

Accuracy of the LGDT test in diagnosing acute or chronic posterolateral corner (PLC) injuries will improve with the information in this study. It was the combined POP-T and PFL injuries that finally led to a positive LGDT sign. However, one should be cautious to use the LGDT test in diagnosing the PLC injuries when posteromedial structures and cruciate ligaments were all involved.