The necessity of clinical application of tibial reduction for detection of underestimated posterolateral rotatory instability in combined posterior cruciate ligament and posterolateral corner deficient knee

Non-anatomical reconstruction of chronic posterolateral corner knee injuries show failure rates from 0% to 36% versus 4.3% to 24.2% for anatomic reconstruction techniques: An updated systematic review reflecting the 2019 expert consensus statement

OBJECTIVE

To review and update the literature regarding outcomes following surgical management of chronic, grade III posterolateral corner (PLC) injuries, with an emphasis on estimating failure rates based upon objective parameters in light of the 2019 expert consensus, while secondarily comparing the failure rates of anatomic versus non-anatomic reconstruction techniques.

METHODS

A literature search was performed using the PubMed, Embase, MEDLINE, and Cochrane Library databases. Inclusion criteria consisted of level I-IV human clinical studies reporting subjective and objective outcomes in patients following surgical management for chronic (>6 weeks from injury) grade III PLC injuries, with a minimum two-year follow-up. The criterion for objective surgical failure was based on post-operative varus stress radiographs and defined as a side-to-side difference of 3 ​mm or more of lateral gapping.

RESULTS

A total of six studies, consisting of 10 separate cohorts encompassing a total of 230 patients, were identified. PLC reconstruction was performed in all cohorts, with 80 ​% (n ​= ​8/10) of these cohorts utilising an anatomic reconstruction technique. A failure rate ranging from 4.3 ​% to 36 ​% was found. Subgroup analysis revealed a failure rate of 4.3 ​%-24.2 ​% for anatomic reconstruction techniques, whereas a 0 ​%-36 ​% failure rate was found for non-anatomic reconstruction. Arthrofibrosis was the most common complication (range, 0 ​%-12.1 ​%) following surgery. 0 ​%-8 ​% of patients required revision PLC surgery.

CONCLUSION

PLC reconstruction yields a wide variability in failure rates according to the side-to-side difference of 3 ​mm or more of lateral gapping on post-operative varus stress radiographs, with low revision rates following anatomic and non-anatomic reconstruction techniques.

LEVEL OF EVIDENCE

IV; Systematic Review of Level III and IV studies.

Combined PCL and PLC Reconstruction Improves Residual Laxity in PCL Injury Patients with Posterolateral Knee Laxity Less Than Grade III

PURPOSE

To compare the short-term clinical and radiologic outcomes of combined posterior cruciate ligament (PCL) and posterolateral complex (PLC) reconstruction to those of isolated PCL reconstruction (PCLR) for patients with posterolateral knee laxity less than grade III.

MATERIALS AND METHODS

We retrospectively reviewed 49 patients (51 knees) who underwent PCLR between January 2008 and December 2015. Patients with a minimum follow-up of 24 months were included and divided into two groups (group A, isolated PCLR; group B, combined PCL and PLC reconstruction). Clinical outcomes were evaluated as the International Knee Documentation Committee (IKDC) subjective, Lysholm, and Tegner activity scale scores. Radiologic outcomes were also assessed using the side-to-side differences in posterior tibial translation via stress radiographs.

RESULTS

A total of 30 cases were analyzed. There were no significant differences in the Lysholm and Tegner activity scale scores between the two groups preoperatively and at the final follow-up. However, group B showed a higher IKDC subjective score compared to group A at the final follow-up (group A, 72.8±8.9; group B, 77.7±10.1; p<0.05). Regarding the radiologic outcomes, group B also showed a significantly less side-to-side difference in posterior tibial translation compared to group A at the final follow-up (group A, 4.8±2.3 mm; group B, 3.8±2.1 mm; p<0.05).

CONCLUSION

Combined PCL and PLC reconstruction resulted in improved clinical and radiologic outcomes than isolated PCLR in patients who have less than grade III posterolateral laxity of the knee. In cases of PCL rupture with ambiguous PLC injury, combined PCL and PLC reconstruction may help to improve posterior residual laxity of the knee.

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.

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.

Rater agreement reliability of the dial test in the ACL-deficient knee

Background

Posterolateral rotatory instability (PLRI) of the knee can easily be missed, because attention is paid to injury of the cruciate ligaments. If left untreated this clinical instability may persist after reconstruction of the cruciate ligaments and may put the graft at risk of failure. Even though the dial test is widely used to diagnose PLRI, no validity and reliability studies of the manual dial test are yet performed in patients. This study focuses on the reliability of the manual dial test by determining the rater agreement.

Methods

Two independent examiners performed the dial test in knees of 52 patients after knee distorsion with a suspicion on ACL rupture. The dial test was performed in prone position in 30°, 60° and 90° of flexion of the knees. ≥10° side-to-side difference was considered a positive dial test. For quantification of the amount of rotation in degrees, a measuring device was used with a standardized 6 Nm force, using a digital torque adapter on a booth. The intra-rater, inter-rater and rater-device agreement were determined by calculating kappa (κ) for the dial test.

Results

A positive dial test was found in 21.2% and 18.0% of the patients as assessed by a blinded examiner and orthopaedic surgeon respectively. Fair inter-rater agreement was found in 30° of flexion, κ_F = 0.29 (95% CI: 0.01 to 0.56), p = 0.044 and 90° of flexion, κ_F = 0.38 (95% CI: 0.10 to 0.66), p = 0.007. Almost perfect rater-device agreement was found in 30° of flexion, κ_C = 0.84 (95% CI: 0.52 to 1.15), p < 0.001. Moderate rater-device agreement was found in 30° and 90° combined, κ_C = 0.50 (95% CI: 0.13 to 0.86), p = 0.008. No significant intra-rater agreement was found.

Conclusions

Rater agreement reliability of the manual dial test is questionable. It has a fair inter-rater agreement in 30° and 90° of flexion.

Dial Test: Unrecognized Predictor of Anterior Cruciate Ligament Deficiency

PURPOSE

To evaluate the effect of isolated anterior cruciate ligament (ACL) injury on tibial external rotation as measured by the dial test.

METHODS

Twenty-seven consecutive patients scheduled to undergo a primary ACL reconstruction were prospectively evaluated. Physical examination and magnetic resonance imaging findings were analyzed to exclude multiligamentous injury. The dial test was performed with the patient under anesthesia with a goniometer on both the affected and unaffected knees at 30° and 90°. Intraoperatively, the arthroscopic posterolateral corner gaps before reconstruction and after reconstruction were documented. Postoperatively, the dial test was again performed on both knees at 30° and 90°.

RESULTS

At 30°, there was a significantly larger dial test result in the affected knee before ACL reconstruction compared with after ACL reconstruction (27.6° vs 21.0°, P < .0001) and compared with the unaffected knee (27.6° vs 20.5°, P < .0001), but this difference was eliminated after reconstruction (21.0° vs 20.5°, P = .5089). At 90°, there was a significantly larger dial test result in the affected knee before ACL reconstruction compared with after ACL reconstruction (27.6° vs 21.1°, P < .0001) and compared with the unaffected knee (27.6° vs 20.9°, P < .0001), with this difference was eliminated after reconstruction (21.1° vs 20.9°, P = .7831).

CONCLUSIONS

Incompetence of the ACL accounts for nearly 7° of tibial external rotation found by the dial test. During examination of an injured knee, if the dial test is positive, an isolated ACL injury should not be excluded. Findings of the dial test should thus be interpreted with caution in the setting of ACL injury.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Magnetic resonance imaging findings of the lateral collateral ligament and popliteus tendon in symptomatic knees without instability

PURPOSE

To describe normative values of the thicknesses of the lateral collateral ligament (LCL) and popliteus tendon in patients who underwent knee surgery but had no evidence of knee instability and identify factors associated with the variations, and to estimate the prevalence and associated factors of abnormal magnetic resonance imaging (MRI) findings of the LCL and popliteus tendon.

METHODS

MRI scans in 120 patients without knee instability were evaluated to measure the thicknesses of the LCL and popliteus tendon and estimate the prevalence of signal alteration and abnormal thickening and thinning. We then investigated the factors associated with the thicknesses and abnormal MRI findings.

RESULTS

The mean thicknesses of the LCL and popliteus tendon were 5.3 ± 1.0 mm and 3.8 ± 0.6 mm, respectively. Elderly, heavier patients and patients with more varus alignment had thicker LCLs, whereas taller, heavier, and male patients had thicker popliteus tendons. Signal alterations of the LCL and popliteus tendon were found in 33% and 23%, respectively, of the knees; abnormal thickening was found in 33% and 8%, respectively. Regression analyses found the mechanical tibiofemoral angle (more varus angle) to be the only predictor for abnormal MRI findings of the LCL (odds ratio of 0.81 [95% confidence interval, 0.66 to 0.98] for signal alteration and odds ratio of 0.73 [95% confidence interval, 0.59 to 0.90] for abnormal thickening); however, no predictors were found for abnormal MRI findings of the popliteus tendon.

CONCLUSIONS

Even in patients without varus and posterolateral rotary instability, signal alteration and thickening of the LCL and/or popliteus tendon can be frequently found with MRI. In particular, abnormal MRI findings of the LCL were likely to be more frequent in the patients with more varus knee alignment. These findings may be considered when interpreting MRI evaluation to diagnose patients with chronic posterolateral corner injury.

LEVEL OF EVIDENCE

Level III, diagnostic study of nonconsecutive patients.

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.