Outcomes of Combined Unicompartmental Knee Replacement and Anterior Cruciate Ligament Reconstruction: A Systematic Review

Background The incidence of osteoarthritis of the medial compartment after ACL injury has been quoted to range from 33% to 70%. Medial osteoarthritis in ACL deficient knee is a challenge. Patients are mainly young and active. First reports highlighted a higher incidence of complications, in terms of tibial loosening and higher revision rate, when UKA were performed in ACL-deficient knees. They defined ACL deficiency is a contraindication to UKA. Objectives A systematic review and meta-analysis of literature to assess functional outcomes of combined unicompartmental knee arthroplasty with ACL reconstruction and revision rate. Data Sources The following electronic databases were searched up to 2019: PubMed, Google Scholar search engine, JBJS {Journal of bone and joint Surgery}, Cochrane database of systematic reviews, EMBASE and Science Direct. Results A total of 10 studies met the inclusion criteria encompassing 218 patients who were treated with simultaneous ACL reconstruction and unicompartmental knee arthroplasty. The mean age was 49.5 years (range from 36 to 71) with a mean follow-up of 49.3 months (range from 9 to 258). There was an improvement in mean Oxford Score from 29 to 42.5. The mean knee society score improved from 88.3 to 159. Complications reported included tibial inlay dislocation (n = 3), conversion to a total knee arthroplasty (n = 2), infection requiring two-stage revision (n = 2), stiffness requiring manipulation under anaesthesia (n = 1). Average revision rate was 1.8%. Conclusion Literature has strong evidence to support that combined UKA and ACL reconstruction show good functional outcomes and less revision rate. It is a valid treatment option for MOA more in young age group in whom MOA secondary to ACL tear and intact other knee compartments. there is no clinical trial or study suggest that UKA and ACL reconstruction is superior to UKA with tibial slope change or using fixed bearing prosthesis for MOA in ACL deficient knee with instability.

The Meniscus Deficient Knee: Options for Repair and Reconstruction

The preservation of the structure of the meniscus despite a tear has been widely discussed in the literature. However, meniscectomy continues to be the most-performed meniscus surgery. In a percentage of patients, knee pain and swelling, as well as tibial plateau bony edema, follow meniscus resection; this panoply of symptoms is known as “post-meniscectomy syndrome”. The management of this condition requires meniscus transplant in case of total meniscectomy or a meniscus scaffold in the case of a partial resection. This chapter aims to discuss the indication, surgical technique, and outcomes of collagen meniscus implants (CMI) for partial resections and meniscus transplants for full resections.

Increased Rotatory Laxity after Anterolateral Ligament Lesion in Anterior Cruciate Ligament- (ACL-) Deficient Knees: A Cadaveric Study with Noninvasive Inertial Sensors

The anterolateral ligament (ALL) has been suggested as an important secondary knee restrain on the dynamic laxity in anterior cruciate ligament- (ACL-) deficient knees. Nevertheless, its kinematical contribution to the pivot-shift (PS) phenomenon has not been clearly and objectively defined, and noninvasive sensor technology could give a crucial contribution in this direction. The aim of the present study was to quantify in vitro the PS phenomenon in order to investigate the differences between an ACL-deficient knee and an ACL+ALL-deficient knee. Ten fresh-frozen paired human cadaveric knees ( n = 20 ) were included in this controlled laboratory study. Intact, ACL-deficient, and ACL+ALL-deficient knees were subjected to a manual PS test quantified by a noninvasive triaxial accelerometer (KiRA, OrthoKey). Kinematic data (i.e., posterior acceleration of the tibial lateral compartment) were recorded and compared among the three statuses. Pairwise Student’s t -test was used to compare the single groups ( p < 0.05 ). Intact knees, ACL-deficient knees, and ACL+ALL-deficient knees showed an acceleration of 5.3 ± 2.1 m/s2, 6.3 ± 2.3 m/s2, and 7.8 ± 2.1 m/s2, respectively. Combined sectioning of ACL and ALL resulted in a statistically significant acceleration increase compared to both the intact state ( p < 0.01 ) and the ACL-deficient state ( p < 0.01 ). The acceleration increase determined by isolated ACL resection compared to the intact state was not statistically significant ( p > 0.05 ). The ALL sectioning increased the rotatory laxity during the PS after ACL sectioning as measured through a user-friendly, noninvasive triaxial accelerometer.

LCL IN A SINGLE CORONAL SLICE – A NOVEL SIGN FOR IDENTIFYING ACL DEFICIENT PATIENTS AND PREDICTING RISK OF FUTURE GRAFT FAILURE

Background: The ACL deficient knee is predisposed to anterior translation and internal rotation of the tibia. Hypothesis/Purpose: To show that knee deformity in an ACL deficient knee will produce a more vertical orientation of the lateral collateral ligament (LCL), allowing for the entire length of the LCL to be visualized on a single coronal slice (coronal LCL sign) on MRI, and that this sign is indicative of a greater risk for graft failure after ACL reconstruction. Methods: Charts were retrospectively reviewed to create 3 separate cohorts: normal ACL and no pathology involving the collateral ligaments (control cohort), ACL reconstruction without evidence for graft rupture, and ACL reconstruction with graft failure. Tibial translation and femorotibial rotation were measured on MRI, and posterior tibial slope was measured on lateral knee radiographs. Imaging was reviewed for the presence of the coronal LCL sign. Results: Deficient ACL (n=153) compared with intact ACL (n=70) was associated with significantly greater displacement regarding anterior translation (5.8mm internal rotation vs 0.3mm external rotation, p<0.001, respectively) and internal rotation (5.2 degrees vs. -2.4 degrees, p<0.001, respectively). The coronal LCL sign was present in a greater percentage of ACL deficient patients than intact ACL controls (68.6% vs. 18.6%, p<0.001, respectively) and associated with greater anterior tibial translation (7.2mm vs. 0.2mm vs., p<0.001) and internal tibial rotation (7.5 degrees vs 2.4 degrees, p=0.074). Multivariate analysis revealed the coronal LCL sign was significantly associated with an ACL tear (OR 12.8, p<0.001). Of the 153 ACL deficient cohort, 114 had no graft failure patients and 39 experienced graft failure. Mean follow-up time was 3.5 years (2 – 9.4 years). Coronal LCL sign was associated with graft failure (p=0.013), with an odds ratio of 4.3 for graft failure (p=0.003). Comparison of pre- and post-ACL reconstruction MRI in the graft failure cohort demonstrated reduced internal rotation, p= 0.00, but no change in coronal LCL sign (p=0.922). Conclusion: Our study shows that the coronal LCL sign correlates with the presence of an ACL tear and functions as a surrogate for the extent of axial and sagittal deformity. Further, we show that tibia internal rotation and posterior slope are independent predictors of ACL graft failure in adolescents. Whereas, the value of internal rotation could be improved with ACL reconstruction, the presence of the coronal LCL sign persisted over time and was predictive of graft rupture (without the need to make measurements or memorize values of significant risk). [Table: see text][Figure: see text]

High Rate of Initially Overlooked Kaplan Fiber Complex Injuries in Patients With Isolated Anterior Cruciate Ligament Injury

Background: Injuries to the Kaplan fiber complex (KFC) are not routinely assessed for in the anterior cruciate ligament (ACL)-deficient knee during preoperative magnetic resonance imaging (MRI). As injuries to the KFC lead to anterolateral rotatory instability (ALRI) in the ACL-deficient knee, preoperative detection of these injuries on MRI scans may help surgeons to individualize treatment and improve outcomes, as well as to reduce failure rates. Purpose: To retrospectively determine the rate of initially overlooked KFC injuries on routine MRI in knees with isolated primary ACL deficiency. Study Design: Case series; Level of evidence, 4. Methods: Patients who underwent isolated ACL reconstruction between August 2013 and December 2019 were identified. No patient had had Kaplan fiber (KF) injury identified on the initial reading of the MRI scan or at the time of surgery. Preoperative knee MRI scans (minimum 1.5 T) were reviewed and injuries to the proximal and distal KFs were recorded by 3 independent reviewers. KF length and distance to nearby anatomic landmarks (the lateral joint line and the lateral femoral epicondyle) were measured. Additional radiological findings, including bleeding, lateral femoral notch sign, and bone marrow edema (BME), were identified to detect correlations with KFC injury. Results: The intact KFC could reliably be identified by all 3 reviewers (85.9% agreement; Kappa, 0.716). Also, 53% to 56% of the patients with initially diagnosed isolated ACL ruptures showed initially overlooked injuries to the KFC. Injuries to the distal KFs were more frequent (48.1%, 53.8%, and 43.3% by the first, second, and third reviewers, respectively) than injuries to the proximal KFs (35.6%, 47.1%, and 45.2% by the first, second, and third reviewers, respectively). Bleeding in the lateral supracondylar region was associated with KFC injuries ( P = .023). Additionally, there was a positive correlation between distal KF injuries and lateral tibial plateau BME ( P = .035), but no associations were found with the lateral femoral notch sign or other patterns of BME, including pivot-shift BME. Conclusion: KF integrity and injury can be reliably detected on routine knee MRI scans. Also, 53% to 56% of the patients presenting with initially diagnosed isolated ACL ruptures had concomitant injuries to the KFC. This is of clinical relevance, as ACL injuries diagnosed by current routine MRI examination protocols may come with a high number of occult or hidden KFC injuries. As injuries to the KFC contribute to persistent ALRI, which may influence ACL graft failure or reoperation rates, significant improvements in preoperative diagnostic imaging are required to determine the exact injury pattern and to assist in surgical decision making.