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.

Material Properties of Fiber Bundles of the Superficial Medial Collateral Ligament of the Knee Joint.

The superficial medial collateral ligament (sMCL) of the human knee joint has functionally separate anterior and posterior fiber bundles. The two bundles are alternatively loaded as the knee flexion angle changes during walking. To date, the two bundles are usually not distinguished in knee ligament simulations because there has been little information about their material properties. In this study, we conducted quasi-static tensile tests on the sMCL of matured porcine stifle joints and obtained the material properties of the anterior bundle (AB), posterior bundle (PB), and whole ligament (WL). AB and PB have similar failure stress but different threshold strain, modulus, and failure strain. As a result, we recommend assigning different material properties (i.e., modulus and failure strain) to the two fiber bundles to realize biofidelic ligament responses in human body models. However, it is often inconvenient to perform tensile tests on AB and PB. Hence, we proposed a microstructural model-based approach to predict the material properties of AB and PB from the test results of WL. Such obtained modulus values of AB and PB had an error of 2% and 0.3%, respectively, compared with those measured from the tests. This approach can reduce the experimental cost for acquiring the needed mechanical property data for simulations.

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.

Does mechanical loading restore ligament biomechanics after injury? A systematic review of studies using animal models.

BACKGROUND: Mechanical loading is purported to restore ligament biomechanics post-injury. But this is difficult to corroborate in clinical research when key ligament tissue properties (e.g. strength, stiffness), cannot be accurately measured. We reviewed experimental animal models, to evaluate if post-injury loading restores tissue biomechanics more favourably than immobilisation or unloading. Our second objective was to explore if outcomes are moderated by loading parameters (e.g. nature, magnitude, duration, frequency of loading). METHODS: Electronic and supplemental searches were performed in April 2021 and updated in May 2023. We included controlled trials using injured animal ligament models, where at least one group was subjected to a mechanical loading intervention postinjury. There were no restrictions on the dose, time of initiation, intensity, or nature of the load. Animals with concomitant fractures or tendon injuries were excluded. Prespecified primary and secondary outcomes were force/stress at ligament failure, stiffness, laxity/deformation. The Systematic Review Center for Laboratory animal Experimentation tool was used to assess the risk of bias. RESULTS: There were seven eligible studies; all had a high risk of bias. All studies used surgically induced injury to the medial collateral ligament of the rat or rabbit knee. Three studies recorded large effects in favour of ad libitum loading postinjury (vs. unloading), for force at failure and stiffness at 12-week follow up. However, loaded ligaments had greater laxity at initial recruitment (vs. unloaded) at 6 and 12 weeks postinjury. There were trends from two studies that adding structured exercise intervention (short bouts of daily swimming) to ad libitum activity further enhances ligament behaviour under high loads (force at failure, stiffness). Only one study compared different loading parameters (e.g. type, frequency); reporting that an increase in loading duration (from 5 to 15 min/day) had minimal effect on biomechanical outcomes. CONCLUSION: There is preliminary evidence that post-injury loading results in stronger, stiffer ligament tissue, but has a negative effect on low load extensibility. Findings are preliminary due to high risk of bias in animal models, and the optimal loading dose for healing ligaments remains unclear.

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.

Comparison of side-cutting maneuvers versus low impact baseball swing on knee ligament loading in adolescent populations.

BACKGROUND: High impact sports are associated with an increased incidence rate for knee ligament injuries, specifically pertaining to the anterior cruciate ligament and medial collateral ligament. What is less clear is (i) the extent to which high impact activities preferentially load the anterior cruciate ligament versus the medial collateral ligament, and (ii) whether both ligaments experience similar stretch ratios during high loading scenarios. Therefore, the goal of this project was to assess how different loading conditions experienced through more at-risk sporting maneuvers influence the relative displacements of the anterior cruciate ligament and medial collateral ligament. The focus of the study was on adolescent patients - a group that has largely been overlooked when studying knee ligament biomechanics. METHODS: Through kinetic knee data obtained through motion capture experimentation, two different loading conditions (high vs low impact) were applied to 22 specimen-specific adolescent finite element knee models to investigate the biomechanical impact various sporting maneuvers place on the knee ligaments. FINDINGS: The high impact side cutting maneuver resulted in 102% and 47% increases in ligament displacement compared to the low impact baseball swing (p < 0.05) for both the anterior cruciate ligament and medial collateral ligament. INTERPRETATION: Quantifying biomechanical risks that sporting activities place on adolescent subjects provides physicians with insight into knee ligament vulnerability. More specifically, knowing the risks that various sports place on ligaments helps guide the selection of sports for at-risk patients (especially those who have undergone knee ligament surgery).

Biomechanical Properties of Knee Medial Collateral Ligament Compared to Palmaris Longus for Ulnar Collateral Ligament Reconstruction.

Ulnar collateral ligament reconstruction (UCLR) is frequently performed among injured overhead-throwing athletes. One of the most common graft choices when performing a UCLR is the ipsilateral palmaris longus tendon (PL). The purpose of this study was to investigate the material properties of aseptically processed cadaveric knee collateral ligaments (kMCL) as a potential graft source for UCLR and compare them to the gold standard PL autograft. Each PL and kMCL cadaveric sample was subjected to cyclic preconditioning, stress relaxation, and load-to-failure testing, and the mechanical properties were recorded. PL samples exhibited a greater average decrease in stress compared to the kMCL samples during the stress-relaxation test (p < 0.0001). PL samples also demonstrated a greater average Young's modulus in the linear region of the stress-strain curve compared to the kMCL samples (p < 0.01). The average yield strain and maximum strain of kMCL samples were significantly greater than the PL, p = 0.03 and 0.02, respectively. Both graft materials had comparable maximum toughness and demonstrated a similar ability to deform plastically without rupture. The clinical significance of our result is that prepared knee medial collateral ligament allografts may provide a viable graft material for use in the reconstruction of elbow ligaments.

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.

Anterolateral ligament of the knee-Cadaver study in a Caucasian population / Ligamento anterolateral de la rodilla. Estudio en cadáver en una población caucásica

Introduction: Despite the recognized importance of the anterolateral ligament (ALL) in rotational stability of the knee, some studies still deny its role and even its existence. We studied the prevalence of the ALL in a Caucasian population, as well as its characteristics and anatomical relationships. Materials and methods: The study was performed on 20 knees from 10 embalmed cadavers. A lateral approach, as described by Steven Claes, was used and the relations of the ALL with the lateral epicondyle, lateral inferior genicular artery, lateral meniscus, Gerdy's tubercle and fibular head were recorded. Its length and its width were also measured. Results: The ALL was identified in 16 knees. Its origin was at a distance inferior to 1mm posterior and proximal to the lateral femoral epicondyle and insertion within a mean distance of 2.1±0.6mm from de tibial articular surface, 20.6±1.3mm from the Gerdy's tubercle and 20.3±1.2mm from the fibular head. In all cases ALL presented mutual fibers with the lateral meniscus. The length was 35.8±4.6mm and the width was 4.2±1.3/4.9±1.0/6.5±1.5mm at its proximal, middle and distal third, respectively. No difference was found between gender and the dimensions of the ligament. Conclusions: The ALL was found in 80% of the knees. Its origin is closely related to the lateral collateral ligament and its insertion is halfway between the fibular head and the Gerdy's tubercle. In all cases, we verified the connection between ALL and the lateral meniscus.(AU)

Introducción: Aunque ha sido reconocida la importancia del ligamento anterolateral (ALL) en la estabilidad rotacional de la rodilla, algunos estudios siguen negando su existencia. Estudiamos la prevalencia del ALL en una población caucásica, así como sus características y relaciones anatómicas. Métodos: El estudio se realizó en 20 rodillas de 10 cadáveres embalsamados. Se utilizó un abordaje lateral, como lo describe Steven Claes, y se registraron las relaciones del ALL con el epicóndilo lateral, la arteria genicular inferior lateral, el menisco lateral, el tubérculo de Gerdy y la cabeza del peroné. También se midió el ancho y el largo. Resultados: El ALL fue identificado en 16 rodillas. Su origen estaba a una distancia inferior a 1mm posterior y proximal al epicóndilo femoral lateral y su inserción a una distancia media de 2,1±0,6mm de la superficie articular tibial, 20,6±1,3mm de la tuberosidad de Gerdy y 20,3±1,2mm de la cabeza del peroné. En todos los casos se presentaban fibras mutuas con el menisco lateral. El largo fue de 35,8±4,6mm y el ancho fue de 4,2±1,3/4,9±1,0/6,5±1,5mm en su tercio proximal, medio y distal. Conclusiones: El ALL se encontró en el 80% de las rodillas. Su origen está íntimamente relacionado con el ligamento colateral lateral y su inserción se encuentra a media distancia entre la cabeza del peroné y el tubérculo de Gerdy. En todos los casos comprobamos la conexión entre el ALL y el menisco lateral.(AU)

[Artículo traducido] Ligamento anterolateral de la rodilla. Estudio en cadáver en una población caucásica / Anterolateral ligament of the knee-Cadaver study in a Caucasian population

Introduction: Despite the recognized importance of the anterolateral ligament (ALL) in rotational stability of the knee, some studies still deny its role and even its existence. We studied the prevalence of the ALL in a Caucasian population, as well as its characteristics and anatomical relationships. Materials and methods: The study was performed on 20 knees from 10 embalmed cadavers. A lateral approach, as described by Steven Claes, was used and the relations of the ALL with the lateral epicondyle, lateral inferior genicular artery, lateral meniscus, Gerdy's tubercle and fibular head were recorded. Its length and its width were also measured. Results: The ALL was identified in 16 knees. Its origin was at a distance inferior to 1mm posterior and proximal to the lateral femoral epicondyle and insertion within a mean distance of 2.1±0.6mm from de tibial articular surface, 20.6±1.3mm from the Gerdy's tubercle and 20.3±1.2mm from the fibular head. In all cases ALL presented mutual fibers with the lateral meniscus. The length was 35.8±4.6mm and the width was 4.2±1.3/4.9±1.0/6.5±1.5mm at its proximal, middle and distal third, respectively. No difference was found between gender and the dimensions of the ligament. Conclusions: The ALL was found in 80% of the knees. Its origin is closely related to the lateral collateral ligament and its insertion is halfway between the fibular head and the Gerdy's tubercle. In all cases, we verified the connection between ALL and the lateral meniscus.(AU)

Introducción: Aunque ha sido reconocida la importancia del ligamento anterolateral (ALL) en la estabilidad rotacional de la rodilla, algunos estudios siguen negando su existencia. Estudiamos la prevalencia del ALL en una población caucásica, así como sus características y relaciones anatómicas. Métodos: El estudio se realizó en 20 rodillas de 10 cadáveres embalsamados. Se utilizó un abordaje lateral, como lo describe Steven Claes, y se registraron las relaciones del ALL con el epicóndilo lateral, la arteria genicular inferior lateral, el menisco lateral, el tubérculo de Gerdy y la cabeza del peroné. También se midió el ancho y el largo. Resultados: El ALL fue identificado en 16 rodillas. Su origen estaba a una distancia inferior a 1mm posterior y proximal al epicóndilo femoral lateral y su inserción a una distancia media de 2,1±0,6mm de la superficie articular tibial, 20,6±1,3mm de la tuberosidad de Gerdy y 20,3±1,2mm de la cabeza del peroné. En todos los casos se presentaban fibras mutuas con el menisco lateral. El largo fue de 35,8±4,6mm y el ancho fue de 4,2±1,3/4,9±1,0/6,5±1,5mm en su tercio proximal, medio y distal. Conclusiones: El ALL se encontró en el 80% de las rodillas. Su origen está íntimamente relacionado con el ligamento colateral lateral y su inserción se encuentra a media distancia entre la cabeza del peroné y el tubérculo de Gerdy. En todos los casos comprobamos la conexión entre el ALL y el menisco lateral.(AU)

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.

Treating Combined Anterior Cruciate Ligament and Medial Collateral Ligament Injuries Operatively in the Acute Setting Is Potentially Advantageous.

Combined injury of the anterior cruciate ligament (ACL) and medial collateral ligament (MCL) remains among the most common knee injury patterns in orthopaedics. Optimal treatment of grade III MCL injuries is still debated, especially when combined with ACL injury. Most patients with these severe injuries are treated conservatively for at least 6 weeks to allow for MCL healing, followed by delayed ACL reconstruction. Although acute treatment of the MCL was common in the 1970s, postoperative stiffness was frequently reported. Moreover, studies of such treatment failed to show clinical benefits of surgical over conservative treatment, and the MCL exhibited intrinsic healing capacity, leading to the consensus that all MCL injuries are treated conservatively. The current delayed treatment algorithm for ACL-MCL injuries has several disadvantages. First, MCL healing may be incomplete, resulting in residual valgus laxity that places the ACL graft at greater risk of failure. Second, delayed treatment lengthens the overall rehabilitation period, thereby prolonging the presence of atrophy and delaying return to preinjury activity levels. Third, the initial healing period leaves the knee unstable for longer and risks further intra-articular damage. Acute simultaneous surgical treatment of both ligaments has the potential to avoid these shortcomings. This article will review the evolution of treatment of ACL-MCL injuries and explain how it shifted toward the current treatment algorithm. We will (1) discuss why the consensus shifted, (2) discuss the shortcomings of the current treatment plan, (3) discuss the potential advantages of acute simultaneous treatment, and (4) present an overview of the available literature.

Calcificación del ligamento colateral medial de la rodilla: manejo rehabilitador con ondas de choque más iontoforesis de una entidad poco frecuente. Caso clínico y revisión / Calcification of the medial collateral ligament of the knee: Rehabilitative management with radial electro shock wave therapy plus iontophoresis of a rare entity. Clinical case and review

El ligamento colateral medial (LCM) de la rodilla es una estructura ligamentosa muy frecuentemente lesionada. La calcificación del LCM es muy infrecuente, benigna, relacionada con desórdenes metabólicos y es consecuencia del depósito de hidroxiapatita de calcio en la región periarticular. El cuadro clínico, histológico y radiológico de la tendinitis calcificante está definido y la etiología es multifactorial. El tratamiento es inicialmente conservador, y si fracasara, intervencionista, siendo la cirugía el último escalón terapéutico. Existen muy pocos reportes en la literatura, estando publicados apenas 10 casos/series de casos. Es importante diferenciarlo del signo y/o síndrome de Pellegrini-Stieda, donde el antecedente traumático es fundamental para diagnosticarlo.El caso clínico es el de una mujer de 64 años en quien presentamos el tratamiento de la calcificación del LCM mediante ondas de choque más iontoforesis, reportamos la efectividad del tratamiento en el manejo del dolor y la calcificación y realizamos una somera revisión sobre el tema.(AU)

The medial collateral ligament (MCL) of the knee is a commonly injured ligament structure. Calcification of the MCL is very infrequent, benign, related to metabolic disorders and is a consequence of the deposition of calcium hydroxyapatite in the periarticular region. The clinical, histological and radiological picture of calcific tendonitis is defined and the etiology is multifactorial. Treatment is initially conservative and if it fails, interventionist; surgery being the last therapeutic step. There are very few reports in the literature, with only 10 cases/case series published. It is important to differentiate it from the Pellegrini–Stieda sign and/or syndrome, where the traumatic history is essential to diagnose it.The clinical case is that of a 64-year-old woman in whom we present the treatment of calcification of the MCL using radial electro shock wave therapy plus iontophoresis, we report the effectiveness of the treatment in the management of pain and calcification, and we carry out a brief review on the subject.(AU)

Comparative study of superficial medial collateral ligament reconstruction combined with posterior oblique ligament reconstruction or posteromedial capsule advance in grade III injuries of the medial compartment in a complex knee injury scenario.

BACKGROUND: The purpose of this study was to compare the combined reconstruction of the superficial medial collateral ligament (sMCL) and the posterior oblique ligament (POL) with the reconstruction of the sMCL associated with the advancement of the posteromedial capsule in a complex knee injury scenario. We hypothesized that both techniques would present similar knee stability and failure rates. METHODS: This is a retrospective case-control study designed to compare the results of the two reported techniques for grade III MCL instability. Patients undergoing MCL reconstruction associated with anterior cruciate ligament, posterior cruciate ligament, or both, from 2010 to 2019, were included. The following parameters were evaluated: demographic data, type of graft, time from injury to surgery, associated meniscus injuries, follow up time, mechanism of trauma, postoperative objective IKDC, subjective IKDC and Lysholm scales, range of motion, reconstruction failure and complications. RESULTS: Seventy-eight patients were evaluated, 37 of whom underwent reconstruction of the sMCL and POL, and 41 of whom underwent reconstruction of the sMCL with advancement of posteromedial structures. There was no difference in any preoperative variable. Patients undergoing reconstruction of the sMCL + advancement had greater loss of flexion (Group 1 3.4 ± 4.6 vs Group 2 8.4 ± 7.9; P = 0.002) and more individuals with flexion loss greater than 10° (Group 1, seven patients (18.9%) vs Group 2, 17 patients (41.5%); P = 0.031). Postoperative knee stability, failures and complications were similar between groups. CONCLUSION: Both techniques presented good functional results and low rates of complications. However, the advancement technique showed greater flexion loss, which should be considered when choosing the best surgical option.