Prevalence of Lateral Meniscal Extrusion for Posterior Lateral Meniscal Root Lesion With and Without Concomitant Midbody Radial Tear in Anterior Cruciate Ligament Injury.

PURPOSE: To investigate the prevalence of lateral meniscal extrusion for patients with posterior lateral meniscal root lesions (PLMRLs) and for those with concomitant midbody radial tears (MRTs) in anterior cruciate ligament (ACL) injuries. METHODS: A database of consecutive patients undergoing primary ACL reconstruction between 2011 and 2013 was retrospectively reviewed to identify patients with isolated ACL injuries and those with associated PLMRLs. Patients with (1) unavailable preoperative magnetic resonance imaging scans, (2) other concomitant ligamentous injuries, (3) severe degeneration or malalignment, (4) infection or tumor, or (5) history of surgery on the injured side were excluded. For patients with associated PLMRLs (study group), degree of concomitant MRTs and status of meniscofemoral ligaments (MFLs) were verified arthroscopically. Prevalence of lateral meniscal extrusion was compared between (1) patients in the study group and those with isolated ACL injuries and between (2) those with and without concomitant MRTs in the study group. RESULTS: Of the 1,021 consecutive patients, 412 met the inclusion and exclusion criteria. Of those, 52 (5.1%) had an associated PLMRL (study group) and another 52 were randomly chosen from the 360 isolated ACL injuries as the control group. In the study group, 33 (63.5%) were arthroscopically verified to have concomitant MRTs. Prevalence of lateral meniscal extrusion was significantly higher (P < .0001) in the study group (30.8%; 95% confidence interval [CI], 18.3 to 43.3) than in the control group (1.9%; 95% CI, -1.8 to 5.6), whereas there was no significant difference (P = .758) between patients with (33.3%; 95% CI, 17.3 to 49.3) and without (26.3%; 95% CI, 6.5 to 46.1) concomitant MRTs in the study group. However, the 7 patients who showed either complete concomitant MRTs or absence of MFLs were all diagnosed to have lateral meniscal extrusion. CONCLUSIONS: The PLMRLs, identified in 5.1% of ACL injuries, appeared to result in lateral meniscal extrusion. Although the presence of a concomitant MRT did not further increase the prevalence of lateral meniscal extrusion in the setting of a PLMRL, surgical repair might still be necessary if a complete concomitant MRT or an absence of MFL was identified to restore normal meniscal functions. LEVEL OF EVIDENCE: Level III, prognostic case-control study.

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.

[Validity of a novel arthroscopic test to diagnose posterolateral rotational instability of the knee joint: the lateral gutter drive-through test].

OBJECTIVE: To assess the validity of the lateral gutter drive-through (LGDT) test in diagnosing posterolateral rotational instability (PLRI) of the knee joint. METHODS: Between October 2009 and February 2012, 115 consecutive patients were enrolled into this prospective diagnostic study. The tibia external rotation dial test was used as the gold standard for diagnostic reference. According to the dial test, the patients were divided into a study group (35 patients) and a control group (80 patients). The LGDT test was performed on all patients during arthroscopic surgery. The sensitivity and specificity of the LGDT test were calculated. The statistical difference of sensitivities in patient subgroups defined by injury patterns was tested using χ(2) test. And the correlation between the extent of tibia external rotational instability and the sensitivity of LGDT test was analyzed using logistic regression. RESULTS: The sensitivity and specificity of the LGDT test were calculated as 91.4% and 93.8%, respectively. The sensitivity of detection for acute PLRI was 9/10 vs. 92.0% in chronic cases (χ(2) = 0.036, P = 0.849). Popliteus femoral "peel off" lesions were detected with a sensitivity of 100% vs. 87.0% in cases of non "peel off" lesions (χ(2) = 1.712, P = 0.536). The sensitivity of detecting isolated external rotational instability vs. combined instability (rotational and varus) was 90.5% and 13/14, respectively (χ(2) = 0.062, P = 0.805). The sensitivity of the LGDT test was correlated with the extent of tibial external rotational instability (r = 1.000, P = 0.011). CONCLUSIONS: The LGDT test is a reliable method to diagnose PLRI of the knee joint. The highest sensitivity is observed for patients with the femoral "peel off" injury pattern. The sensitivity of the LGDT test is correlated with the extent of tibia external rotational instability.

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.

BACKGROUND: In posterolateral corner (PLC) injuries in which the lateral collateral ligament (LCL) is intact, there is controversy about whether reconstructing the popliteus tendon (POP), the popliteofibular ligament (PFL), or both structures (POP + PFL) is required to restore normal external tibial rotation. HYPOTHESIS: Three reconstruction techniques, POP, PFL, and POP + PFL, are able to restore external tibial rotation to normal. STUDY DESIGN: Controlled laboratory study. METHODS: Six nonpaired human knees were tested under the following states: POP and PFL intact and sectioned. The 3 different surgical techniques were used to reconstruct the sectioned structures, and the knees were retested. Each knee was subjected to a 5-N·m external rotation torque and tested at 0°, 30°, 45°, 60°, 90°, and 120° of flexion. A navigation system was used to measure motion changes of the tibia with respect to the femur. RESULTS: There were small but significant increases in external rotation after sectioning both the POP and PFL. Sectioning of either one of these structures alone produced smaller increases that were not significant. After comparing all of the tested reconstructed states to the intact state, there were significant differences at knee flexion angles from 30° to 90°. The PFL procedure restored external tibial rotation without significant differences compared with the intact knee at 30° to 90° of flexion. The POP and POP + PFL techniques significantly overconstrained external tibial rotation at all tested angles. CONCLUSION: In an LCL-intact PLC injury model, the POP and PFL function as a unit in resisting external rotation. All surgical procedures described and tested were able to reduce the increased external rotational laxity found in the sectioned state. The PFL reconstruction technique was able to restore external rotation to near normal. However, the techniques involving POP reconstruction overconstrained external rotation during laxity testing.

Surgical treatment of subacute and chronic valgus instability in multiligament-injured knees with superficial medial collateral ligament reconstruction using Achilles allografts: a quantitative analysis with a minimum 2-year follow-up.

BACKGROUND: Symptomatic medial collateral ligament (MCL) instability is rare, and it is frequently associated with multiligament injuries. Most clinical investigations have failed to clearly define the specific objective outcome measures assessing the stability of the MCL quantitatively before and after the reconstruction procedure. PURPOSE: To quantitatively evaluate the early clinical outcomes of patients with valgus instability of knee joints who had undergone superficial MCL reconstruction using Achilles tendon allografts. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: From August 2005 to December 2010, 19 consecutive patients with MCL injuries were included in this study. The inclusion criteria were (1) a subacute or chronic MCL injury, with a time from initial injury to surgery of longer than 3 weeks, and (2) valgus laxity graded C or D according to the International Knee Documentation Committee (IKDC). All patients underwent superficial MCL reconstruction using Achilles tendon allografts. To evaluate the laxity of the MCL preoperatively and postoperatively, valgus stress radiographs using a Telos device were used. Other assessments included the IKDC subjective functional evaluation and Lysholm score estimation. RESULTS: Sixteen of the 19 patients (12 men and 4 women) were available for final follow-up. The median age of the patients was 37 years (range, 19-53 years); mean body mass index (BMI) was 26.4 (range, 21.7-29.4). The mean time from injury to surgery was 15.9 months (range, 24 days to 84 months), and median follow-up period was 34 months (range, 24-67 months). The mean medial knee laxity (side-to-side difference) was 8.9 ± 3.2 mm (range, 6-15.9 mm) preoperatively and 1.1 ± 0.9 mm (range, -1.1 to 3.2 mm) postoperatively (P < .001). The preoperative mean IKDC subjective knee functional score was 49.8 ± 6.9 (range, 31-57.5), while the postoperative functional score was 84.3 ± 6.0 (range, 71.3-93.1) (P < .001). The mean Lysholm score was 69.3 ± 5.9 (range, 55-78) preoperatively and 88.6 ± 5.0 (range, 75-95) postoperatively (P < .001). There was no significant correlation between patients' BMI and the final clinical outcome scores (P = .311). CONCLUSION: In a small set of patients with multiligament-injured knees, valgus laxity can be effectively restored through surgical management with superficial MCL reconstruction, when the other associated ligament injuries are reconstructed as well. The subjective functional results were significantly improved postoperatively at short-term follow-up.

Anterior cruciate ligament reconstruction with remnant preservation: a prospective, randomized controlled study.

BACKGROUND: Efforts still need to be made to improve the technique for surgical anterior cruciate ligament reconstruction (ACLR). Several reports have claimed that ACLR with the remnant preservation technique can obtain satisfactory clinical results. PURPOSE: To compare the short-term clinical outcome of remnant-preserving ACLR with standard ACLR. STUDY DESIGN: Randomized controlled trial; Level of evidence, 2. METHODS: A prospective, randomized controlled study was performed in 90 consecutive patients who underwent ACLR with the remnant preservation technique (study group, n = 45) or the standard technique (control group, n = 45) with the use of a 4-strand allograft. The Lysholm score, International Knee Documentation Committee (IKDC) grade, stability assessments (Lachman test, pivot-shift test, and KT-1000 arthrometer side-to-side differences), synovial coverage of the graft, and proprioception measurements were evaluated preoperatively and at the last follow-up. RESULTS: All consecutive patients who were screened for eligibility between August 2008 and April 2010 were enrolled and followed clinically. There were 39 patients in the study group and 41 in the control group who were followed for at least 2 years (mean follow-up, 25.7 months). At the last follow-up, the median Lysholm score was 99 in the study group and 95 in the control group (P = .07). The IKDC grade was A or B in 38 patients in the study group and 40 patients in the control group (P = .548). Lachman test results were negative in 38 patients in the study group and 40 patients in the control group (P = .862), and the pivot-shift test result was negative in 37 patients in the study group and 36 patients in the control group (P = .523). The mean KT-1000 arthrometer side-to-side difference averaged 1.6 ± 1.7 mm in the study group and 1.8 ± 1.8 mm in the control group (P = .694). Second-look arthroscopy was performed to evaluate synovial coverage of the graft. Normal or nearly normal synovial coverage, graded as A or B, was 71.4% (20/28) in the study group and 70.4% (19/27) in the control group (P = .966). The passive angle reproduction test result at 15° was 3.6° ± 1.8° in the study group and 3.9° ± 2.2° in the control group (P = .739). CONCLUSION: This short-term study showed that, in terms of stability, synovial coverage, and proprioception recovery, remnant preservation ACLR using an allograft had no evident advantages in clinical outcome over the standard technique.

Arthroscopic Bankart repair combined with remplissage technique for the treatment of anterior shoulder instability with engaging Hill-Sachs lesion: a report of 49 cases with a minimum 2-year follow-up.

BACKGROUND: Engaging Hill-Sachs lesions are known to be a risk factor for recurrence dislocation after arthroscopic repair in patients with anterior shoulder instability. For a large engaging Hill-Sachs lesion, arthroscopic remplissage is a solution. HYPOTHESIS: Arthroscopic Bankart repair combined with the Hill-Sachs remplissage technique can achieve good results without significant impairment of shoulder function. STUDY DESIGN: Case Series; Level of evidence, 4. METHODS: Forty-nine consecutive patients who underwent arthroscopic Bankart repair and Hill-Sachs remplissage for anterior shoulder instability were followed up for a mean duration of 29.0 months (range, 24-35 months). There were 42 males and 7 females with a mean age of 28.4 years (range, 16.7-54.7 years). All patients had diagnosed traumatic unidirectional anterior shoulder instability with a bony lesion of glenoid and an engaging Hill-Sachs lesion. Physical examination, radiographs, and magnetic resonance imaging were performed during postoperative follow-up. The American Shoulder and Elbow Surgeons (ASES) score, Constant score, and Rowe score were used to evaluate shoulder function. RESULTS: The active forward elevation increased a mean of 8.0° (range, -10° to 80°) postoperatively. However, the patients lost 1.9° (range, -40° to 30°) of external rotation to the side. Significant improvement was detected with regard to the ASES score (84.7 vs 96.0, P < .001), Constant score (93.3 vs 97.8, P = .005), and Rowe score (36.8 vs 89.8, P < .001).There were 1 redislocation, 2 subluxations, and 1 patient with a positive apprehension test; the overall failure rate was 8.2% (4 of 49). Successful healing of the infraspinatus tendon within the Hill-Sachs lesion was shown by magnetic resonance imaging. CONCLUSION: Arthroscopic Bankart repair combined with Hill-Sachs remplissage can restore shoulder stability without significant impairment of shoulder function in patients with engaging Hill-Sachs lesions.