Predictive factors for deep medial collateral ligament release in adjusted mechanical alignment total knee arthroplasty.

BACKGROUND: Total knee arthroplasty (TKA) demands precision in achieving optimal alignment and soft tissue balance, especially in cases of medial compartment osteoarthritis where the need for medial soft tissue release is critical yet challenging to ascertain. OBJECTIVE: This study aims to systematically investigate the relationship between preoperative data, initial knee conditions and the necessity for deep collateral ligament (MCL) release in adjusted mechanical alignment total knee arthroplasty. METHODS: We conducted a retrospective study involving 61 TKA patients who underwent adjusted mechanical alignment robotic-assisted procedures. Soft tissue release was carried out when clinically indicated. We collected and statistically analyzed patient demographics, initial knee conditions, and surgical details. RESULTS: Among the patients, 52% required deep MCL release. Notably, patients without soft tissue release exhibited lower initial hip-knee-ankle (HKA) angles, reduced varus-valgus stress test angles, and a greater range of flexion. We identified a predictive threshold HKA angle of 6.250 degrees, demonstrating high sensitivity and specificity for determining the need for deep MCL release. CONCLUSION: This study underscores the significance of the initial HKA angle and varus-valgus stress tests in predicting deep MCL release during TKA. The established HKA angle threshold simplifies surgical decision-making, reducing the likelihood of unnecessary soft tissue release.

Career Length After Surgically Treated ACL Plus Collateral Ligament Injury in Elite Athletes.

BACKGROUND: Limited data are available regarding career length and competition level after combined anterior cruciate ligament (ACL) and medial- or lateral-sided surgeries in elite athletes. PURPOSE: To evaluate career length after surgical treatment of combined ACL plus medial collateral ligament (MCL) and ACL plus posterolateral corner (PLC) injuries in elite athletes and, in a subgroup analysis of male professional soccer players, to compare career length and competition level after combined ACL+MCL or ACL+PLC surgeries with a cohort who underwent isolated ACL reconstruction (ACLR). STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A consecutive cohort of elite athletes undergoing combined ACL+MCL and ACL+PLC surgery was analyzed between February 2001 and October 2019. A subgroup of male elite soccer players from this population was compared with a previously identified cohort having had isolated primary ACLR without other ligament surgery. A minimum 2-year follow-up was required. Outcome measures were career length and competition level. RESULTS: A total of 98 elite athletes met the inclusion criteria, comprising 50 ACL+PLC and 48 ACL+MCL surgeries. The mean career length after surgical treatment of combined ACL+MCL and ACL+PLC injuries was 4.5 years. Return-to-play (RTP) time was significantly longer for ACL+PLC injuries (12.8 months; P = .019) than for ACL+MCL injuries (10.9 months). In the subgroup analysis of soccer players, a significantly lower number of players with combined ACL+PLC surgery were able to RTP (88%; P = .003) compared with 100% for ACL+MCL surgery and 97% for isolated ACLR, as well as requiring an almost 3 months longer RTP timeline (12.9 months; P = .002) when compared with the isolated ACL (10.2 months) and combined ACL+MCL (10.0 months) groups. However, career length and competition level were not significantly different between groups. CONCLUSION: Among elite athletes, the mean career length after surgical treatment of combined ACL+MCL and ACL+PLC injuries was 4.5 years. Professional soccer players with combined ACL+PLC surgery returned at a lower rate and required a longer RTP time when compared with the players with isolated ACL or combined ACL+MCL injuries. However, those who did RTP had the same career longevity and competition level.

Double-Bundle Medial Collateral Ligament Reconstruction Improves Anteromedial Rotatory Instability.

BACKGROUND: New techniques have been proposed to better address anteromedial rotatory instability in a medial collateral ligament (MCL)-injured knee that require an extra graft and more surgical implants, which might not be feasible in every clinical setting. PURPOSE: To investigate if improved resistance to anteromedial rotatory instability can be achieved by using a single-graft, double-bundle (DB) MCL reconstruction with a proximal fixation more anteriorly on the tibia, in comparison with the gold standard single-bundle (SB) MCL reconstruction. STUDY DESIGN: Controlled laboratory study. METHODS: Eight fresh-frozen human cadaveric knees were tested using a 6 degrees of freedom robotic simulator in intact knee, superficial MCL/deep MCL-deficient, and reconstruction states. Three different reconstructions were tested: DB MCL no proximal tibial fixation and DB and SB MCL reconstruction with proximal tibial fixation. Knee kinematics were recorded at 0°, 30°, 60°, and 90° of knee flexion for the following measurements: 8 N·m of valgus rotation (VR), 5 N·m of external tibial rotation, 5 N·m of internal tibial rotation, combined 89 N of anterior tibial translation and 5 N·m of external rotation for anteromedial rotation (AMR) and anteromedial translation (AMT). The differences between each state for every measurement were analyzed with VR and AMR/AMT as primary outcomes. RESULTS: Cutting the superficial MCL/deep MCL increased VR and AMR/AMT in all knee positions except at 90° for VR (P < .05). All reconstructions restored VR to the intact state except at 90° of knee flexion (P < .05). The DB MCL no proximal tibial fixation reconstruction could not restore intact AMR/AMT kinematics in any knee position (P < .05). Adding an anterior-based proximal tibial fixation restored intact AMR/AMT kinematics at ≥30° of knee flexion except at 90° for AMT (P < .05). The SB MCL reconstruction could not restore intact AMR/AMT kinematics at 0° and 90° of knee flexion (P < .05). CONCLUSION: In this in vitro cadaveric study, a DB MCL reconstruction with anteriorly placed proximal tibial fixation was able to control AMR and AMT better than the gold standard SB MCL reconstruction. CLINICAL RELEVANCE: In patients with anteromedial rotatory instability and valgus instability, a DB MCL reconstruction may be superior to the SB MCL reconstruction, without causing extra surgical morbidity or additional costs.

Lack of Consensus on the Management of Medial Collateral Ligament Tears in the Setting of Concomitant Anterior Cruciate Ligament Injury: A Critical Analysis.

¼ There is no clear agreement on the optimal timing or superior type of fixation for medial collateral ligament (MCL) tears in the setting of anterior cruciate ligament (ACL) injury.¼ Anatomic healing of medial knee structures is critical to maintain native knee kinematics, supported by biomechanical studies that demonstrate increased graft laxity and residual valgus rotational instability after ACL reconstruction (ACLR) alone in the setting of concomitant ACL/MCL injury.¼ Historically, most surgeons have favored treating acute combined ACL/MCL tears conservatively with MCL rehabilitation, followed by stress radiographs at 6 weeks after injury to assess for persistent valgus laxity before performing delayed ACLR to allow for full knee range of motion, and reduce the risk of postoperative stiffness and arthrofibrosis.¼ However, with the advancement of early mobilization and aggressive physical therapy protocols, acute surgical management of MCL tears in the setting of ACL injury can have benefits of avoiding residual laxity and further intra-articular damage, as well as earlier return to sport.¼ Residual valgus laxity from incomplete MCL healing at the time of ACLR should be addressed surgically, as this can lead to an increased risk of ACLR graft failure.¼ The treatment of combined ACL/MCL injuries requires an individualized approach, including athlete-specific factors such as level and position of play, timing of injury related to in-season play, contact vs. noncontact sport, and anticipated longevity, as well as consideration of the tear pattern, acuity of injury, tissue quality, and surgeon familiarity with the available techniques.

Proximal Tibia Fracture Through Suture Augmentation Sites Following ACL/MCL Repairs: A Case Report.

CASE: A 35-year-old man sustained a proximal tibia fracture from a low-energy mechanism 1 year after anterior cruciate and medial collateral ligament repairs with suture augmentation (SA). The fracture propagated through both tibial SA anchor sites. Following intramedullary tibial nailing, he returned to his prior level of function. CONCLUSION: While complications of SA for ligamentous procedures are rare, these techniques are being implemented more frequently and the full complication profile is yet to be determined. Our report documents a new complication and potential risk factors that surgeons should consider when performing SA for multiligament knee surgery in active individuals.

Anterior-Posterior Laxity in Midflexion After Posterior-Stabilized TKA Is Sensitive to MCL Tension in Passive Flexion: An in Vitro Biomechanical Study.

BACKGROUND: Knee instability in midflexion may contribute to patient dissatisfaction following total knee arthroplasty (TKA). Midflexion instability involves abnormal motions and tissue loading in multiple planes. Therefore, we quantified and compared the tensions carried by the medial and lateral collateral ligaments (MCL and LCL) following posterior-stabilized (PS) TKA through knee flexion, and then compared these tensions with those carried by the native knee. Finally, we examined the relationships between collateral ligament tensions and anterior tibial translation (ATT). METHODS: Eight cadaveric knees (from 5 male and 3 female donors with a mean age of 62.6 years and standard deviation of 10.9 years) underwent PS TKA. Each specimen was mounted to a robotic manipulator and flexed to 90°. ATT was quantified by applying 30 N of anterior force to the tibia. Tensions carried by the collateral ligaments were determined via serial sectioning. Robotic testing was also conducted on a cohort of 15 healthy native cadaveric knees (from 9 male and 6 female donors with a mean age of 36 years and standard deviation of 11 years). Relationships between collateral ligament tensions during passive flexion and ATT were assessed via linear and nonlinear regressions. RESULTS: MCL tensions were greater following PS TKA than in the native knee at 15° and 30° of passive flexion, by a median of ≥27 N (p = 0.002), while the LCL tensions did not differ. Median tensions following PS TKA were greater in the MCL than in the LCL at 15°, 30°, and 90° of flexion, by ≥4 N (p ≤ 0.02). Median tensions in the MCL of the native knee were small (≤11 N) and did not exceed those in the LCL (p ≥ 0.25). A logarithmic relationship was identified between MCL tension and ATT following TKA. CONCLUSIONS: MCL tensions were greater following PS TKA with this typical nonconforming PS implant than in the native knee. Anterior laxity at 30° of flexion was highly sensitive to MCL tension during passive flexion following PS TKA but not in the native knee. CLINICAL RELEVANCE: Surgeons face competing objectives when performing PS TKA: they can either impart supraphysiological MCL tension to reduce anterior-posterior laxity or maintain native MCL tensions that lead to heightened anterior-posterior laxity, as shown in this study.

The pie-crusting release of the medial collateral ligament in arthroscopic partial meniscectomy is associated with improved clinical outcomes without altering radiological measurements.

PURPOSE: The aim of this study was to evaluate how the pie-crusting technique affects clinical and radiological outcomes in patients undergoing arthroscopic partial meniscectomy. METHODS: A total of 68 patients with Kellgren-Lawrence (K-L) grade 2 who underwent arthroscopic partial meniscectomy between 2015 and 2021 were evaluated and divided into two groups as arthroscopic partial meniscectomy (36 patients) and arthroscopic partial meniscectomy with pie-crusting (32 patients) according to whether the pie-crusting technique was applied or not. All patients were evaluated at a minimum 2-year follow-up in terms of Lysholm score, Tegner activity score, International Knee Documentation Committee (IKDC) score and Visual Analogue Scale (VAS) score. To assess the impact of the pie-crusting technique, radiological measurements were conducted using radiographs taken before and after pie-crusting, as well as postoperative radiographs. RESULTS: Lysholm, Tegner, IKDC and VAS scores exhibited statistically significant differences after surgery compared to preoperative evaluations in both groups (p < 0.05). Furthermore, these scores were significantly superior in the arthroscopic partial meniscectomy with pie-crusting group compared to the arthroscopic partial meniscectomy group at 24 months postoperatively (p < 0.05). While the radiological measurements in the arthroscopic partial meniscectomy with pie-crusting group showed statistically significant differences before and after pie-crusting (p < 0.05), no significant difference was observed between before pie-crusting and 12 and 24 months postoperatively (n.s.). CONCLUSION: The current study is the first to demonstrate the true effectiveness of the pie-crusting technique. The application of the pie-crusting technique when necessary results in a statistically significant improvement in clinical scores without affecting radiological measurements for patients undergoing arthroscopic partial meniscectomy compared to not utilising it. LEVEL OF EVIDENCE: Level III.

Risk factors and prevalence of ramp lesions in ACL ruptures: An analysis from the registry of the Francophone Arthroscopic Society.

PURPOSE: The study aimed to estimate the prevalence of ramp lesions among patients undergoing anterior cruciate ligament (ACL) reconstruction and identify risk factors associated with these lesions. METHODS: A retrospective, multicentre cohort study was conducted using data from the Francophone Arthroscopic Society's registry, including 5359 patients who underwent ACL reconstruction (ACLR) from June 2020 to June 2023. Potential risk factors for ramp lesion such as patient demographics, revision surgery, pivot shift, side-to-side anteroposterior laxity, medial collateral ligament (MCL) injury, lateral meniscal tear and the volume of ligament remnant were evaluated using multivariate regression analyses. BMI and delay to surgery were also assessed. RESULTS: Ramp lesions were identified in 822 patients (15.3%). Univariate analysis identified male sex, younger age, revision surgery, lateral meniscal injury, percentage of ACL remnant (all p < 0.0001) and pivot shift (p = 0.0103) as significant risk factors. MCL injury was associated with a lower risk (p < 0.0001). In multivariate analysis, male sex, younger age, revision surgery, lateral meniscal injury and percentage of ACL remnants remained significant risk factors, while MCL injury remained a protective factor. The anteroposterior laxity wasn't a significant predictor in either analysis. In subgroup analysis, there were no differences concerning body mass index (n.s) and the delay to surgery (n.s). CONCLUSION: The study identified male sex, younger age, revision surgery, lateral meniscal injury and pourcentage of ACL remnant as significant risk factors for ramp lesions, with MCL injury acting as a protective factor. This will help regarding the suspicion and identification of ramp lesions. LEVEL OF EVIDENCE: Level III.

Evaluating the optimal management strategy for intraoperative iatrogenic injury to the medial collateral ligament during primary total knee arthroplasty: A systematic review.

INTRODUCTION: Intraoperative iatrogenic MCL injuries during primary TKA are rare complications that lack a gold standard management protocol. This review aims to provide insight into various treatment modalities and evidence-based guidance for improved patient outcomes. METHODS: A comprehensive search across five databases identified relevant randomized control trials and retrospective cohort studies with reported outcomes. A total of 17 studies were included, and variables such as patient demographics, injury type, management, and Knee Society Scores (KSS) were assessed. The quality of included studies was evaluated using the Critical Appraisal Skills Programme tool. RESULTS: Mean age of included patients ranged from 60.0 to 71.4 years. The mean Body Mass Index ranged from 26.75 to 34.40 kg/m2. Among the included knees, 298 were categorized as MCL avulsion, and 167 as midsubstance/transection injuries. Primary repair with sutures or bone staples emerged as the most common management. Intraoperative MCL injury was correlated with reduced preoperative range of motion (ROM) and postoperative KSS clinical, functional, and pain scores compared to control groups. Postoperative ROM was comparable between MCL injury and control groups, ranging from 100.0° to 130.0° and 107.0° to 130.0°, respectively. CONCLUSION: Current evidence supports primary repair as the preferred management for this complication. Factors such as extent of the tear, type of injury, and the surgeon's experience also help to guide treatment. While treatment modalities like allograft or autograft reconstruction show promise, further research with larger sample sizes is needed to enhance future outcomes.

Alignment is only part of the equation: High variability in soft tissue distractibility in the varus knee undergoing primary TKA.

PURPOSE: The purpose of this study is to evaluate the in vivo medial and lateral joint laxities across various total knee arthroplasty (TKA) alignment categories correlated to (1) hip-knee-ankle angle, (2) proximal tibial angle and (3) distal femoral angle in a consecutive group of patients undergoing robotic-assisted TKA. METHODS: Using ligament tensions acquired during 805 robotic-assisted TKA with a dynamic ligament tensor under a load of 70-90 N, the relationship between medial and lateral collateral ligament laxity and overall limb alignment was established. Only knees with neutral or mechanical varus alignment were included and divided into five groups: neutral (0°-3°), varus 3°-5°, varus 6°-9°, varus 10°-13° and varus ≥14°. Groups were further subdivided by the intraoperative medial proximal tibial angle (MPTA) and lateral distal femoral angle (LDFA). The distraction of the medial and lateral sides was compared across the various alignments using an analysis of variance. RESULTS: The ability to distract the medial collateral ligament in extension and flexion was proportional to the degree of varus deformity, increasing from 4.0 ± 2.3 mm in the neutral group to 8.7 ± 3.2 mm in the varus ≥14° group (p < 0.0001). On the lateral side, the distraction of the lateral collateral ligament decreased in both extension (2.2 ± 2.4 vs. 1.2 ± 2.7, p < 0.0001) and flexion (2.8 ± 2.8 to 1.7 ± 3.0, p < 0.0001) with increasing native varus deformity. MPTA and LDFA had similar effects, where increasing MPTA varus and LDFA valgus increased medial distractibility in extension and flexion. There was significant variability of the stretch of the ligaments within and across all alignment categories, in which the standard deviation of the groups ranged from 2.0 to 3.0 mm. CONCLUSION: This study demonstrates increased medial ligament distractibility with increasing varus deformity. However, there was significant variability in ligamentous laxity within various limb alignment categories suggesting the anatomy and soft tissue identity of the knee is complex and highly variable. TKAs seeking to be more anatomic will not only need to restore alignment but also native soft tissue tensions. LEVEL OF EVIDENCE: Level III, prognostic.

A Comparative Biomechanical Study of Alternative Medial Collateral Ligament Reconstruction Techniques.

BACKGROUND: There is little evidence of the biomechanical performance of medial collateral ligament (MCL) reconstructions for restoring stability to the MCL-deficient knee regarding valgus, external rotation (ER), and anteromedial rotatory instability (AMRI). HYPOTHESIS: A short isometric reconstruction will better restore stability than a longer superficial MCL (sMCL) reconstruction, and an additional deep MCL (dMCL) graft will better control ER and AMRI than single-strand reconstructions. STUDY DESIGN: Controlled laboratory study. METHODS: Nine cadaveric human knees were tested in a kinematics rig that allowed tibial loading while the knee was flexed-extended 0° to 100°. Optical markers were placed on the femur and tibia and displacements were measured using a stereo camera system. The knee was tested intact, and then after MCL (sMCL + dMCL) transection, and loaded in anterior tibial translation (ATT), ER, varus-valgus, and combined ATT + ER (AMRI loading). Five different isometric MCL reconstructions were tested: isolated long sMCL, a short construct, each with and without dMCL addition, and isolated dMCL reconstruction, using an 8 mm-wide synthetic graft. RESULTS: MCL deficiency caused an increase in ER of 4° at 0° of flexion (P = .271) up to 14° at 100° of flexion (P = .002), and valgus laxity increased by 5° to 8° between 0° and 100° of flexion (P < .024 at 0°-90°). ATT did not increase significantly in isolated MCL deficiency (P > .999). All 5 reconstructions restored native stability across the arc of flexion apart from the isolated long sMCL, which demonstrated residual ER instability (P≤ .047 vs other reconstructions). CONCLUSION: All tested techniques apart from the isolated long sMCL graft are satisfactory in the context of restoring the valgus, ER, and AMRI stability to the MCL-deficient knee in a cadaveric model. CLINICAL RELEVANCE: Contemporary MCL reconstruction techniques fail to control ER and therefore AMRI as they use a long sMCL graft and do not address the dMCL. This study compares 5 MCL reconstruction techniques. Both long and short isometric constructs other than the long sMCL achieved native stability in valgus and ER/AMRI. Double-strand reconstructions (sMCL + dMCL) tended to provide more stability. This study shows which reconstructions demonstrate the best biomechanical performance, informs surgical reconstruction techniques for AMRI, and questions the efficacy of current popular techniques.

Ultrasound-guided treatment of medial collateral ligament calcification of the knee with TenJet™: a case report.

Calcification of the medial collateral ligament is a rare cause of medial knee pain along with functional impairment. Most cases are asymptomatic but those that are symptomatic typically respond to conservative management. However, in those instances with persistent symptoms that desire further intervention but want to minimize the risks associated with surgery, we present a novel approach for calcium removal with an ultrasound-guided percutaneous needle tenotomy with TenJet™ as a reasonable treatment modality.

Nonoperative Management, Repair, or Reconstruction of the Medial Collateral Ligament in Combined Anterior Cruciate and Medial Collateral Ligament Injuries-Which Is Best? A Systematic Review and Meta-analysis.

BACKGROUND: Combined injury of the anterior cruciate ligament (ACL) and the medial collateral ligament (MCL) is a common injury pattern and accounts for 20% of all ligamentous knee injuries. Despite advancements in surgical technique, there is no up-to-date consensus regarding the superiority of nonoperative versus operative management in higher-grade MCL tears of combined ACL-MCL injuries. PURPOSE: To interpret recent literature on treatment options and to provide an updated evidence-based approach for management of combined ACL-MCL knee injuries. STUDY DESIGN: Systematic review and meta-analysis; Level of evidence, 4. METHODS: We performed a systematic review on outcomes following treatment of concomitant ACL and MCL injuries. A computerized search was conducted in PubMed, Embase.com, and Scopus.com. Authors independently assessed eligible studies and screened titles and abstracts. Articles reporting on patients with concomitant ACL and MCL injuries with or without concomitant procedures were included. Data regarding study design, sample size, patient age and sex, length of follow-up, timing of surgery, indications, surgical methods, concomitant procedures, outcomes, and complications were recorded. Patient-reported outcomes (PROs) and functional outcomes, including Knee injury and Osteoarthritis Outcome Score, International Knee Documentation Committee scores, Lysholm and Tegner scores, and range of motion, were estimated via meta-analysis and compared statistically by surgical approach. RESULTS: In total, 18 studies were included in the systematic review with level 1 to level 4 evidence, with a total of 1,534 cases, were included in the systematic review. Of these, 16 studies with sufficient statistical reporting including 997 cases with sufficient follow-up were included in meta-analysis. Three different approaches to combined ACL-MCL injuries were identified: ACL reconstruction with (1) nonoperative MCL, (2) MCL repair, and (3) MCL reconstruction. There was no statistical difference between nonoperative versus surgically managed MCL injuries for PROs, range of motion at final follow up, or quadriceps strength. CONCLUSION: Reconstruction of combined injury in a delayed fashion facilitates return of range of motion and may allow time for low-grade MCL tears to heal. If residual valgus or anteromedial rotatory laxity remains after a period of rehabilitation, then concomitant surgical management of ACL and MCL injuries is warranted. Avulsion MCL injuries and Stener-type lesions may benefit from early repair techniques.

Medial Collateral Ligament Pie-Crusting for Isolated Medial Meniscal Root Repair Is Associated With Improved Clinical Outcomes with Minimum 2-Year Follow-Up.

PURPOSE: To determine clinical and radiographic outcomes of medial collateral ligament (MCL) pie-crusting during isolated medial meniscal root repair. METHODS: A retrospective review was conducted between August 2013 and December 2019 in patients undergoing isolated medial meniscal root repair. Outcomes, including International Knee Documentation Committee (IKDC) score, Lysholm score, re-tears, MCL laxity, and conversion to total knee arthroplasty (TKA), were compared between pie crust (PC) and non-pie crust (NPC) cohorts. Other assessments included subjective instability or stiffness, infection, and intra-operative chondromalacia. Additionally, radiographic outcomes were compared to determine progression of medial compartment arthrosis. RESULTS: Final analysis included 97 knees, 45 in the PC, and 52 in the NPC group. IKDC and Lysholm scores were similar between both groups preoperatively and 3 months postoperatively. However, at the 6,12, and 24-month follow up, the PC group had a significantly higher measured IKDC and Lysholm scores than the NPC group. PASS percentages for the IKDC score were significantly higher in the PC group at 6 months, 1 year, and 2 years (96.2%; P = .02) follow-up compared to the NPC group. MCID percentages for the IKDC score were also significantly higher at the 1- and 2-year (100%; P = .05) follow-up in the PC group compared to the NPC group. There was also a significantly higher rate of recurrent medial meniscal root tears in the NPC group (4 [8.9%]) compared to the PC group (0 [P = .03]). No MCL laxity was observed at 6 months follow-up. CONCLUSIONS: MCL pie-crusting during isolated medial meniscal root repair can be used as an alternative surgical technique, as it leads to improved clinical and patient outcomes compared to patients who do not undergo MCL pie-crusting in the short term. Additionally, those that underwent MCL pie-crusting had a lower incidence of recurrent tears, and no patients experienced MCL laxity at 6 months. LEVEL OF EVIDENCE: Level III, retrospective cohort/comparative study.

Atelocollagen Injections Improve Outcomes in the Nonsurgical Treatment of Grade III Medial Collateral Ligament Injuries.

Background: The purpose of this study was to evaluate the clinical outcomes of atelocollagen injections in isolated grade III medial collateral ligament (MCL) injuries of the knee joint. Methods: A total of 50 participants were included in this retrospective study. Twenty-six patients underwent conservative treatment with a single atelocollagen injection, while the remaining patients underwent only typical conservative treatment. All participants underwent magnetic resonance imaging to identify and grade MCL injury. Valgus stress radiography was performed on both knees at 6 and 12 months after the injury. The visual analog scale (VAS) score was collected at the first visit and at 2 weeks, 6 weeks, 6 months, and 12 months after injury. The International Knee Documentation Committee (IKDC) formula activity level and Lysholm score were evaluated for patient-reported outcomes at the first visit and at 6 and 12 months after injury. The participant's return to the pre-injury activity level ratio was measured by comparing the IKDC formula activity level at 12 months after the injury with that before the injury. Results: The VAS and Lysholm scores improved over time in both groups. The VAS and Lysholm scores were significantly better in the collagen injection group than in the control group. Regarding the activity level, the collagen injection group showed significantly better results at the 6-month follow-up, but there was no significant difference at the 12-month follow-up. The medial gap in the injured knee and the side-to-side difference (SSD) in both groups gradually decreased over time. The SSD in the collagen injection group was significantly smaller than that in the control group. Conclusions: Atelocollagen injections resulted in better clinical and radiologic outcomes along with a higher rate of return to the pre-injury activity level, thereby exhibiting a positive effect in the nonsurgical treatment of grade III MCL injuries.

MCL internal brace does not fully recapitulate normal MCL function in valgus stress.

PURPOSE: The null hypothesis is that there would be no difference in medial gapping under valgus load between the intact MCL and the ruptured MCL with an internal brace in place. METHODS: Eight pairs of cadaver knees were used (16 knees). Alternating sides, one knee from each pair was used for one of two "internal brace" constructs. The constructs involved different methods of fixation for securing FiberTape (Arthrex, Naples, FL) to both the femur and tibia in an effort to brace the MCL. The knees were then subjected to valgus stress by applying 10 N m of torque with the knee at 20 degrees of flexion. The amount of medial joint space opening was measured on radiographs. The stress testing was conducted with three MCL states: intact, grade 2 tear, and grade 3 tear. RESULTS: In the Construct I specimens, gapping increased from 0.7 mm with the MCL intact to 1.1 mm with grade 2 tearing (p < 0.01), and to 1.3 mm with grade 3 tearing (p < 0.01). In the Construct II specimens, gapping increased from 0.7 mm with the MCL intact to 1.0 mm with grade 2 tearing (p < 0.01), and to 1.1 mm with grade 3 tearing (n.s.). Construct I specimens failed primarily at the femoral attachment. All Construct II specimens survived the valgus stress testing. CONCLUSION: Construct I did not maintain tension. Construct II did maintain tension during application of valgus load, but did not restore valgus opening to the intact state. It is important for clinicians who are considering using this commercially available technique to be aware of how the construct performs under valgus stress testing compared to the intact MCL.

Medial Varus Proximal Tibial Resection is Superior to Pie-Crusting of the Medial Collateral Ligament During Primary Total Knee Arthroplasty.

BACKGROUND: Medial varus proximal tibial (MPT) resection or soft tissue releases (STRs) of the medial collateral ligament (MCL) in the form of pie-crusting can be performed to achieve a balanced knee in a varus deformity. Studies comparing the 2 modalities have not been addressed within the literature. Therefore, the aims of this study were to assess the following: (1) compartmental changes between the 2 methods and (2) changes in patient-reported outcome measurements. METHODS: Using our institution's total joint arthroplasty registry, patients who underwent primary total knee arthroplasty from January 1, 2017, to December 31, 2019, were identified. The MPT resection and STR patients were 1:1 matched with baseline parameters yielding 196 patients. Outcomes of interest included: changes in compartmental pressures at 10, 45, and 90° degrees and change to the Short-Form 12, Western Ontario and McMaster Universities Osteoarthritis Index, and Forgotten Joint Scores (FJSs) at the 2-year follow-up period. A P value less than .05 was used as our threshold for statistical difference. RESULTS: The MPT resection led to significant reductions in compartmental pressures at 10° [43 versus 19 pounds (lbs.), P < .0001], 45° (43 versus 27 lbs., P < .0001), and 90° degrees (27 versus 16 lbs., P < .0001) compared to STR. MPT resection also had significantly improved Short-Form 12 (47 versus 38, P < .0001), Western Ontario and McMaster Universities Osteoarthritis Index (9 versus 21, P < .0001), and Forgotten Joint Score (79 versus 68, P = .005). CONCLUSION: Bone modification was superior to pie-crusting of the MCL in achieving consistent pressure balancing and improved outcomes. The investigation can guide surgeons on the preferred method to achieve a well-balanced knee.

Medial Collateral Ligament Reconstruction and Repair Show Similar Improvement in Outcome Scores, But Repair Shows Higher Rates of Knee Stiffness and Failure: A Systematic Review.

PURPOSE: To compare patient-reported outcomes and complications in patients with medial collateral ligament (MCL) injuries undergoing repair versus reconstruction with a minimum 2-year follow-up. METHODS: A literature search was conducted using the PubMed, Scopus, and Embase-computerized databases from database inception to November 2022, according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies evaluating clinical outcomes and complications at a minimum of 2 years following MCL repair versus reconstruction were included. Study quality was assessed using the MINORS criteria. RESULTS: A total of 18 studies published from 1997 to 2022, consisting of 503 patients were identified. Twelve studies (n = 308 patients; mean age: 32.6 years) reported outcomes following MCL reconstruction, and 8 studies (n = 195 patients; mean age: 28.5 years) reported results following MCL repair. Postoperative International Knee Documentation Committee, Lysholm, and Tegner scores ranged from 67.6 to 91, 75.8 to 94.8, and 4.4 to 8, respectively, in the MCL reconstruction group, compared to 73 to 91, 75.1 to 98.5, and 5.2 to 10, respectively, in the MCL repair group. Knee stiffness was the most commonly reported complication following MCL repair (range: 0% - 50%) and reconstruction (range: 0% - 26.7%). Failures occurred in 0% to 14.6% of patients following reconstruction versus 0% to 35.1% of patients undergoing MCL repair. Manipulation under anesthesia (MUA) for postoperative arthrofibrosis (range: 0% - 12.2%) and surgical debridement for arthrofibrosis (range: 0% - 20%) were the most commonly reported reoperations in the MCL reconstruction and repair groups, respectively. CONCLUSIONS: MCL reconstruction versus repair both demonstrate improved International Knee Documentation Committee, Lysholm, and Tegner scores. MCL repair demonstrates higher rates of postoperative knee stiffness and failure at a minimum 2-year follow-up. LEVEL OF EVIDENCE: Level IV, systematic review of Level III and IV studies.

Bicruciate-retaining total knee arthroplasty procedure reduced tensile force in the middle and posterior components of lateral collateral ligament during deep knee flexion activities with no effect on tensile force of the medial collateral ligament.

PURPOSE: To analyse the effects of bicruciate-retaining total knee arthroplasty (BCR-TKA) on the tensile force of the collateral ligaments during two deep knee flexion activities, cross-leg sitting and squatting. METHODS: Thirteen patients (15 knees) treated using bicruciate-retaining total knee arthroplasty (BCR-TKA) for knee joint osteoarthritis were analysed. Knee joint kinematics during cross-leg sitting (open-chain flexion) and squatting (closed-chain flexion) were evaluated through fluoroscopy. The tensile force was calculated in vivo based on the change in the distance between the femoral and tibial attachment areas for the anterior, middle, and posterior components of the superficial (sMCL) and deep (dMCL) medial collateral ligament and the lateral collateral ligament (LCL). Differences in the calculated tensile forces of the collateral ligaments were evaluated using repeated measures of analysis of variance, with post hoc pairwise comparison (Bonferroni test). Statistical significance was set at P ≤ 0.05. RESULTS: The correction of the coronal alignment was related to the surgical technique, not to the implant design. No significant change in the tensile force in all three components of the sMCL from pre- to post-TKA (n.s.) was observed. For dMCL, a pre- to post-TKA change in the tensile force was observed only for the anterior dMCL component (p = 0.03). No change was observed in the tensile force of the anterior LCL with increasing flexion, with no difference in pre- to post-TKA and between activities (n.s.). In contrast, tensile force in the middle LCL slightly decreased with increasing flexion during squatting, pre- and post-TKA. After surgery, lower forces were generated at 40° of flexion (p = 0.04). Tensile force in the posterior LCL was higher in extension than flexion, which remained high in the extension post-TKA. However, after surgery, lower tensile forces were generated at 10° (p = 0.04) and 40° (p = 0.04) of flexion. CONCLUSIONS: The in vivo change in tensile forces of the collateral ligaments of the knee before and after BCR-TKA can inform the development of appropriate ligament balancing strategies to facilitate recovery of deep knee flexion activities after TKA, as well as for continued improvement of BCR-TKA designs. LEVEL OF EVIDENCE: III.

[Diagnosis and treatment progress in the femoral insertion injury of medial collateral ligament of knee].

Objective: To summarize the diagnosis and treatment progress in the femoral insertion injury of the medial collateral ligament (MCL) of knee, and to provide a clinical reference for diagnosis and treatment. Methods: The literature on the femoral insertion injury of the MCL of knee was widely reviewed. The incidence, mechanisms of injury and anatomy, the diagnosis and classification, and status of treatment were summarized. Results: The mechanism of the femoral insertion injury of the MCL of knee is related to its anatomical and histological characteristics, as well as the abnormal valgus of the knee joint, excessive external rotation of the tibial platform and it is classified according to the injury characteristics to guide the refined and individualized clinical treatment. Conclusion: Due to different understanding of femoral insertion injury of MCL of knee, the treatment methods are different, and thus is the healing effect. Additional studies are still needed to promote the healing of insertion injuries.