Measuring Parallelism to the Ground in Bipedal Stance Phase: Mechanical Versus Kinematic Alignment in Total Knee Arthroplasty.

Introduction The goal of total knee arthroplasty is to replace diseased cartilage and bone with an artificial implant to improve the patient's quality of life. The knee has historically been reconstructed to the patient's mechanical axis (MA). However, kinematically aligned techniques have been increasingly used. Kinematic alignment requires less soft-tissue resection and aligns the knee with what is anatomically natural to the patient, while there is concern that kinematically aligned knees will lead to earlier failure due to potential unequal weight distribution on the implant. The purpose of this study is to compare the parallelism from the floor of the joint-line cuts using kinematic and mechanical alignment and understand if the MA is a proper estimation of the tibial-ankle axis (TA). Methods A retrospective study was conducted by recruiting all high tibial osteotomy and distal femoral osteotomy recipients operated on by two surgeons in two MedStar Health hospitals from 01/2013 to 07/2020 with full-length films in preparation for restorative procedures. Baseline osteoarthritis was graded using the Kellgren-Lawrence classification system with all patients presenting as Grade 0. The TA and the joint-line orientations of the MA and kinematic axis (KA) were measured on 66 legs. The average distance from parallelism to the ground was compared between the MA and the KA and between the MA and the TA using a paired t-test. Results KA joint-line orientation (1.705° deviation) was more parallel to the floor in the bipedal stance phase than the MA (2.316° deviation, p=0.0156). The MA (2.316° deviation) was not a proper estimation of the TA (4.278° deviation, p=0.0001). Conclusion By utilizing the KA technique, the restoration of the natural joint line, as well as a joint that is more parallel to the floor in the stance phase compared to the MA, is achieved. The parallelism to the ground of the KA during the bipedal stance phase suggests an even load distribution across the knee. In addition, due to its similarity to the KA and anatomical significance in weight-bearing distribution, further investigation into the hip-to-calcaneal axis as an approximation of the joint line is warranted.

Outcomes of multiligament knee injury treated with versus without internal brace suture augmentation.

PURPOSE: To compare the postoperative outcomes between Internal Brace (IB) and non-IB patients who underwent surgical management of multiple-ligament knee injuries (MLKI). METHODS: Patients who underwent surgical management of MLKI at two institutions between 2010 and 2020 were identified and offered participation in the study via the collection of postoperative functional outcomes for MLKI; Lysholm Knee score, Multiligament Quality of Life (ML-QOL), Patient-Reported Outcomes Measurement Information System (PROMIS) computer adaptive testing (CAT), Pain Interference (PI), Physical Function (PF), and Mobility instruments (MI). The postoperative outcomes and reoperation rates were compared between the IB group and non-IB group. RESULTS: One hundred and twenty-six patients were analyzed; 89 were included in the IB group (31.5% female; age 35.6 ± 1.4 years), and 37 were included in the non-IB group (25.7% female; age 38.8 ± 2.4 years). Mean follow-up time of the entire cohort was 37.9 ± 4.7 months [IB: 21.8 + 1.63; non-IB: 76.4 ± 6.2, p < 0.001). The IB group achieved similar PROMIS CAT [PROMIS Pain (51.8 + 1.1 vs. 52.1 + 1.6, p = 0.8736), Physical Function (46.6 + 1.2 vs. 46.4 + 1.8, p = 0.9168), Mobility (46.0 + 1.0 vs. 43.7 + 1.6, p = 0.2185)], ML-QOL [ML-QOL Physical Impairment (36.6 + 2.5 vs. 43.5 ± 4.2, p = 0.1485), Emotional Impairment (42.5 + 2.9 vs. 48.6 ± 4.6, p = 0.2695), Activity Limitation (34.5 + 2.8 vs. 36.2 ± 4.3, p = 0.7384), Societal Involvement (39.1 + 3.0 vs. 41.7 + 4.2, p = 0.6434)] and Lysholm knee score (64.9 + 2.5 vs. 60.4 + 4.0, p = 0.3397) postoperatively compared the non-IB group, but the differences were not significant. CONCLUSION: In this cohort of patients with MLKI treated with versus without IB, outcomes and reoperation rates trended toward favoring IB, but the study was not sufficiently powered to reach statistical significance. Internal bracing could be useful in the management of MLKI. In the future, matched patient cohorts with more patients are warranted to further evaluate the clinical impact of the internal brace in MLKI.

Postoperative Patellar Height After Undergoing Total Knee Arthroplasty: Mechanical Axis Versus Kinematic Axis.

Introduction When performing total knee arthroplasty (TKA), surgeons may use either the mechanical alignment (MA) or the kinematic alignment (KA) to guide implant placement and joint balancing. By measuring preoperative and postoperative patellar height (PH), surgeons can predict knee stability after TKA. Improper PH is associated with knee instability which may complicate the postoperative course and lead to patient dissatisfaction or need for revision. The purpose of this study is to measure patellar height using the Insall-Salvati Index (ISI), Caton-Deschamps Index (CDI), and Blackburne-Peel Index (BPI) preoperatively and postoperatively in patients who underwent TKA with either MA or KA to assess for changes in patellar height. Methods We performed a retrospective eight-year review of 256 patients who underwent TKA with either MA or KA by a single surgeon at a single hospital site. We obtained demographic data, including gender, age, and BMI, via the electronic health record. Furthermore, we calculated the ISI, CDI, and BPI using necessary parameters from preoperative and postoperative radiographs. We used these measurements to assess any statistically significant difference in postoperative PH. Results The MA cohort consisted of 104 patients with an average age of 63 years and an average BMI of 34.1 kg/m2. The KA cohort included 152 patients with an average age of 64 years and an average BMI of 34.9 kg/m2.  For the MA population, the average postoperative score with ISI was 1.10 [1.05 to 1.16] (p < 0.001), with CDI was 1.05 [0.98 to 1.11] (p < 0.001), and with BPI was was 0.94 [0.89 to 0.99] (p < 0.001). While for the KA population, the average postoperative score with ISI was 1.03 [0.99 to 1.06] (p = 0.17), with CDI was 0.87 [0.82 to 0.91] (p = 0.15), and with BPI was 0.82 [0.78 to 0.86] (p = 0.34). Conclusion TKA with a KA has a statistically significant improvement in postoperative PH and better postoperative maintenance of preoperative PH. Improved PH may lead to increased patellofemoral stability and superior postoperative outcomes in patients undergoing TKA. Future studies should focus on whether differences in preoperative and postoperative PH measurements result in changes in clinical outcomes in patients with MA versus KA TKA.

A comparison of postoperative pain between anterior cruciate ligament reconstruction and repair.

PURPOSE: To determine if patients who underwent ACL repair experienced less short-term postoperative pain versus patients who underwent ACL reconstruction. METHODS: Electronic charts were retrospectively reviewed of patients who underwent ACL surgery from November 2014 through April 2019 by a single surgeon. Patients were divided into two groups based on whether they underwent ACL repair or ACL reconstruction. A two-tailed equal variance t-test was used to evaluate visual analog scale (VAS) pain scores at the first postoperative visit. A chi-squared test of independence was used to evaluate narcotic prescription refills at the first postoperative visit. RESULTS: 36 ACL repair patients and 71 ACL reconstruction patients were included. The mean visual analog scale (VAS) pain score at the first postoperative visit (12.9 ± 3.7 days post-op) for ACL repair patients (2.81 ± 1.79) was significantly lower (p = .004) compared to ACL reconstruction patients (4.07 ± 2.26). The number of narcotic prescription refills at the first postoperative visit was significantly lower (p = .027, ARR = 21.4%, NNT = 4.67) in the ACL repair group (7 of 36, 19.4%) compared to the ACL reconstruction group (29 of 71, 40.8%). CONCLUSION: Patients who underwent ACL repair experienced less short-term postoperative pain and were prescribed fewer narcotics compared to patients who underwent ACL reconstruction.

Posterior Cruciate Ligament Repair With Suture Augmentation: A Report of Two Cases With Two-Year Follow-Up.

We present two cases of posterior cruciate ligament (PCL) repair with suture augmentation (SA) in the setting of multiligamentous knee injury (MLKI). Excellent clinical outcomes were obtained at two-year follow-up with both patients returning to sport following injury. Both patients demonstrated improvements in Knee Injury and Osteoarthritis Outcome Score (KOOS) that exceeded the minimal clinically important difference (MCID) as reported in the literature for ligamentous knee injuries. One patient developed arthrofibrosis, which was successfully treated with manipulation under anesthesia and arthroscopic lysis of adhesions two months postoperatively. Both patients had full knee range of motion (ROM) by a one-year follow-up. One patient returned to full preinjury level of sport at six months postoperatively while the other patient returned to 50% of preinjury intensity at two-year follow-up. This series of two cases of PCL repair with SA in MLKIs demonstrates that PCL repair with SA is a viable procedure that can result in excellent short-term outcomes and restore knee stability.